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alistair23-linux/arch/x86/net/bpf_jit_comp.c

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net: filter: Just In Time compiler for x86-64 In order to speedup packet filtering, here is an implementation of a JIT compiler for x86_64 It is disabled by default, and must be enabled by the admin. echo 1 >/proc/sys/net/core/bpf_jit_enable It uses module_alloc() and module_free() to get memory in the 2GB text kernel range since we call helpers functions from the generated code. EAX : BPF A accumulator EBX : BPF X accumulator RDI : pointer to skb (first argument given to JIT function) RBP : frame pointer (even if CONFIG_FRAME_POINTER=n) r9d : skb->len - skb->data_len (headlen) r8 : skb->data To get a trace of generated code, use : echo 2 >/proc/sys/net/core/bpf_jit_enable Example of generated code : # tcpdump -p -n -s 0 -i eth1 host 192.168.20.0/24 flen=18 proglen=147 pass=3 image=ffffffffa00b5000 JIT code: ffffffffa00b5000: 55 48 89 e5 48 83 ec 60 48 89 5d f8 44 8b 4f 60 JIT code: ffffffffa00b5010: 44 2b 4f 64 4c 8b 87 b8 00 00 00 be 0c 00 00 00 JIT code: ffffffffa00b5020: e8 24 7b f7 e0 3d 00 08 00 00 75 28 be 1a 00 00 JIT code: ffffffffa00b5030: 00 e8 fe 7a f7 e0 24 00 3d 00 14 a8 c0 74 49 be JIT code: ffffffffa00b5040: 1e 00 00 00 e8 eb 7a f7 e0 24 00 3d 00 14 a8 c0 JIT code: ffffffffa00b5050: 74 36 eb 3b 3d 06 08 00 00 74 07 3d 35 80 00 00 JIT code: ffffffffa00b5060: 75 2d be 1c 00 00 00 e8 c8 7a f7 e0 24 00 3d 00 JIT code: ffffffffa00b5070: 14 a8 c0 74 13 be 26 00 00 00 e8 b5 7a f7 e0 24 JIT code: ffffffffa00b5080: 00 3d 00 14 a8 c0 75 07 b8 ff ff 00 00 eb 02 31 JIT code: ffffffffa00b5090: c0 c9 c3 BPF program is 144 bytes long, so native program is almost same size ;) (000) ldh [12] (001) jeq #0x800 jt 2 jf 8 (002) ld [26] (003) and #0xffffff00 (004) jeq #0xc0a81400 jt 16 jf 5 (005) ld [30] (006) and #0xffffff00 (007) jeq #0xc0a81400 jt 16 jf 17 (008) jeq #0x806 jt 10 jf 9 (009) jeq #0x8035 jt 10 jf 17 (010) ld [28] (011) and #0xffffff00 (012) jeq #0xc0a81400 jt 16 jf 13 (013) ld [38] (014) and #0xffffff00 (015) jeq #0xc0a81400 jt 16 jf 17 (016) ret #65535 (017) ret #0 Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Cc: Arnaldo Carvalho de Melo <acme@infradead.org> Cc: Ben Hutchings <bhutchings@solarflare.com> Cc: Hagen Paul Pfeifer <hagen@jauu.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-04-20 03:27:32 -06:00
/* bpf_jit_comp.c : BPF JIT compiler
*
x86: bpf_jit_comp: add pkt_type support Supporting access to skb->pkt_type is a bit tricky if we want to have a generic code, allowing pkt_type to be moved in struct sk_buff pkt_type is a bit field, so compiler cannot really help us to find its offset. Let's use a helper for this : It will throw a one time message if pkt_type no longer starts at a byte boundary or is no longer a 3bit field. Reported-by: Willem de Bruijn <willemb@google.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Maciej Żenczykowski <maze@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-01-30 18:51:44 -07:00
* Copyright (C) 2011-2013 Eric Dumazet (eric.dumazet@gmail.com)
net: filter: x86: internal BPF JIT Maps all internal BPF instructions into x86_64 instructions. This patch replaces original BPF x64 JIT with internal BPF x64 JIT. sysctl net.core.bpf_jit_enable is reused as on/off switch. Performance: 1. old BPF JIT and internal BPF JIT generate equivalent x86_64 code. No performance difference is observed for filters that were JIT-able before Example assembler code for BPF filter "tcpdump port 22" original BPF -> old JIT: original BPF -> internal BPF -> new JIT: 0: push %rbp 0: push %rbp 1: mov %rsp,%rbp 1: mov %rsp,%rbp 4: sub $0x60,%rsp 4: sub $0x228,%rsp 8: mov %rbx,-0x8(%rbp) b: mov %rbx,-0x228(%rbp) // prologue 12: mov %r13,-0x220(%rbp) 19: mov %r14,-0x218(%rbp) 20: mov %r15,-0x210(%rbp) 27: xor %eax,%eax // clear A c: xor %ebx,%ebx 29: xor %r13,%r13 // clear X e: mov 0x68(%rdi),%r9d 2c: mov 0x68(%rdi),%r9d 12: sub 0x6c(%rdi),%r9d 30: sub 0x6c(%rdi),%r9d 16: mov 0xd8(%rdi),%r8 34: mov 0xd8(%rdi),%r10 3b: mov %rdi,%rbx 1d: mov $0xc,%esi 3e: mov $0xc,%esi 22: callq 0xffffffffe1021e15 43: callq 0xffffffffe102bd75 27: cmp $0x86dd,%eax 48: cmp $0x86dd,%rax 2c: jne 0x0000000000000069 4f: jne 0x000000000000009a 2e: mov $0x14,%esi 51: mov $0x14,%esi 33: callq 0xffffffffe1021e31 56: callq 0xffffffffe102bd91 38: cmp $0x84,%eax 5b: cmp $0x84,%rax 3d: je 0x0000000000000049 62: je 0x0000000000000074 3f: cmp $0x6,%eax 64: cmp $0x6,%rax 42: je 0x0000000000000049 68: je 0x0000000000000074 44: cmp $0x11,%eax 6a: cmp $0x11,%rax 47: jne 0x00000000000000c6 6e: jne 0x0000000000000117 49: mov $0x36,%esi 74: mov $0x36,%esi 4e: callq 0xffffffffe1021e15 79: callq 0xffffffffe102bd75 53: cmp $0x16,%eax 7e: cmp $0x16,%rax 56: je 0x00000000000000bf 82: je 0x0000000000000110 58: mov $0x38,%esi 88: mov $0x38,%esi 5d: callq 0xffffffffe1021e15 8d: callq 0xffffffffe102bd75 62: cmp $0x16,%eax 92: cmp $0x16,%rax 65: je 0x00000000000000bf 96: je 0x0000000000000110 67: jmp 0x00000000000000c6 98: jmp 0x0000000000000117 69: cmp $0x800,%eax 9a: cmp $0x800,%rax 6e: jne 0x00000000000000c6 a1: jne 0x0000000000000117 70: mov $0x17,%esi a3: mov $0x17,%esi 75: callq 0xffffffffe1021e31 a8: callq 0xffffffffe102bd91 7a: cmp $0x84,%eax ad: cmp $0x84,%rax 7f: je 0x000000000000008b b4: je 0x00000000000000c2 81: cmp $0x6,%eax b6: cmp $0x6,%rax 84: je 0x000000000000008b ba: je 0x00000000000000c2 86: cmp $0x11,%eax bc: cmp $0x11,%rax 89: jne 0x00000000000000c6 c0: jne 0x0000000000000117 8b: mov $0x14,%esi c2: mov $0x14,%esi 90: callq 0xffffffffe1021e15 c7: callq 0xffffffffe102bd75 95: test $0x1fff,%ax cc: test $0x1fff,%rax 99: jne 0x00000000000000c6 d3: jne 0x0000000000000117 d5: mov %rax,%r14 9b: mov $0xe,%esi d8: mov $0xe,%esi a0: callq 0xffffffffe1021e44 dd: callq 0xffffffffe102bd91 // MSH e2: and $0xf,%eax e5: shl $0x2,%eax e8: mov %rax,%r13 eb: mov %r14,%rax ee: mov %r13,%rsi a5: lea 0xe(%rbx),%esi f1: add $0xe,%esi a8: callq 0xffffffffe1021e0d f4: callq 0xffffffffe102bd6d ad: cmp $0x16,%eax f9: cmp $0x16,%rax b0: je 0x00000000000000bf fd: je 0x0000000000000110 ff: mov %r13,%rsi b2: lea 0x10(%rbx),%esi 102: add $0x10,%esi b5: callq 0xffffffffe1021e0d 105: callq 0xffffffffe102bd6d ba: cmp $0x16,%eax 10a: cmp $0x16,%rax bd: jne 0x00000000000000c6 10e: jne 0x0000000000000117 bf: mov $0xffff,%eax 110: mov $0xffff,%eax c4: jmp 0x00000000000000c8 115: jmp 0x000000000000011c c6: xor %eax,%eax 117: mov $0x0,%eax c8: mov -0x8(%rbp),%rbx 11c: mov -0x228(%rbp),%rbx // epilogue cc: leaveq 123: mov -0x220(%rbp),%r13 cd: retq 12a: mov -0x218(%rbp),%r14 131: mov -0x210(%rbp),%r15 138: leaveq 139: retq On fully cached SKBs both JITed functions take 12 nsec to execute. BPF interpreter executes the program in 30 nsec. The difference in generated assembler is due to the following: Old BPF imlements LDX_MSH instruction via sk_load_byte_msh() helper function inside bpf_jit.S. New JIT removes the helper and does it explicitly, so ldx_msh cost is the same for both JITs, but generated code looks longer. New JIT has 4 registers to save, so prologue/epilogue are larger, but the cost is within noise on x64. Old JIT checks whether first insn clears A and if not emits 'xor %eax,%eax'. New JIT clears %rax unconditionally. 2. old BPF JIT doesn't support ANC_NLATTR, ANC_PAY_OFFSET, ANC_RANDOM extensions. New JIT supports all BPF extensions. Performance of such filters improves 2-4 times depending on a filter. The longer the filter the higher performance gain. Synthetic benchmarks with many ancillary loads see 20x speedup which seems to be the maximum gain from JIT Notes: . net.core.bpf_jit_enable=2 + tools/net/bpf_jit_disasm is still functional and can be used to see generated assembler . there are two jit_compile() functions and code flow for classic filters is: sk_attach_filter() - load classic BPF bpf_jit_compile() - try to JIT from classic BPF sk_convert_filter() - convert classic to internal bpf_int_jit_compile() - JIT from internal BPF seccomp and tracing filters will just call bpf_int_jit_compile() Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 20:50:46 -06:00
* Internal BPF Copyright (c) 2011-2014 PLUMgrid, http://plumgrid.com
net: filter: Just In Time compiler for x86-64 In order to speedup packet filtering, here is an implementation of a JIT compiler for x86_64 It is disabled by default, and must be enabled by the admin. echo 1 >/proc/sys/net/core/bpf_jit_enable It uses module_alloc() and module_free() to get memory in the 2GB text kernel range since we call helpers functions from the generated code. EAX : BPF A accumulator EBX : BPF X accumulator RDI : pointer to skb (first argument given to JIT function) RBP : frame pointer (even if CONFIG_FRAME_POINTER=n) r9d : skb->len - skb->data_len (headlen) r8 : skb->data To get a trace of generated code, use : echo 2 >/proc/sys/net/core/bpf_jit_enable Example of generated code : # tcpdump -p -n -s 0 -i eth1 host 192.168.20.0/24 flen=18 proglen=147 pass=3 image=ffffffffa00b5000 JIT code: ffffffffa00b5000: 55 48 89 e5 48 83 ec 60 48 89 5d f8 44 8b 4f 60 JIT code: ffffffffa00b5010: 44 2b 4f 64 4c 8b 87 b8 00 00 00 be 0c 00 00 00 JIT code: ffffffffa00b5020: e8 24 7b f7 e0 3d 00 08 00 00 75 28 be 1a 00 00 JIT code: ffffffffa00b5030: 00 e8 fe 7a f7 e0 24 00 3d 00 14 a8 c0 74 49 be JIT code: ffffffffa00b5040: 1e 00 00 00 e8 eb 7a f7 e0 24 00 3d 00 14 a8 c0 JIT code: ffffffffa00b5050: 74 36 eb 3b 3d 06 08 00 00 74 07 3d 35 80 00 00 JIT code: ffffffffa00b5060: 75 2d be 1c 00 00 00 e8 c8 7a f7 e0 24 00 3d 00 JIT code: ffffffffa00b5070: 14 a8 c0 74 13 be 26 00 00 00 e8 b5 7a f7 e0 24 JIT code: ffffffffa00b5080: 00 3d 00 14 a8 c0 75 07 b8 ff ff 00 00 eb 02 31 JIT code: ffffffffa00b5090: c0 c9 c3 BPF program is 144 bytes long, so native program is almost same size ;) (000) ldh [12] (001) jeq #0x800 jt 2 jf 8 (002) ld [26] (003) and #0xffffff00 (004) jeq #0xc0a81400 jt 16 jf 5 (005) ld [30] (006) and #0xffffff00 (007) jeq #0xc0a81400 jt 16 jf 17 (008) jeq #0x806 jt 10 jf 9 (009) jeq #0x8035 jt 10 jf 17 (010) ld [28] (011) and #0xffffff00 (012) jeq #0xc0a81400 jt 16 jf 13 (013) ld [38] (014) and #0xffffff00 (015) jeq #0xc0a81400 jt 16 jf 17 (016) ret #65535 (017) ret #0 Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Cc: Arnaldo Carvalho de Melo <acme@infradead.org> Cc: Ben Hutchings <bhutchings@solarflare.com> Cc: Hagen Paul Pfeifer <hagen@jauu.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-04-20 03:27:32 -06:00
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; version 2
* of the License.
*/
#include <linux/netdevice.h>
#include <linux/filter.h>
x86: bpf_jit_comp: add vlan tag support This patch is a follow-up for patch "net: filter: add vlan tag access" to support the new VLAN_TAG/VLAN_TAG_PRESENT accessors in BPF JIT. Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Ani Sinha <ani@aristanetworks.com> Cc: Daniel Borkmann <danborkmann@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-10-26 20:26:22 -06:00
#include <linux/if_vlan.h>
net: bpf: consolidate JIT binary allocator Introduced in commit 314beb9bcabf ("x86: bpf_jit_comp: secure bpf jit against spraying attacks") and later on replicated in aa2d2c73c21f ("s390/bpf,jit: address randomize and write protect jit code") for s390 architecture, write protection for BPF JIT images got added and a random start address of the JIT code, so that it's not on a page boundary anymore. Since both use a very similar allocator for the BPF binary header, we can consolidate this code into the BPF core as it's mostly JIT independant anyway. This will also allow for future archs that support DEBUG_SET_MODULE_RONX to just reuse instead of reimplementing it. JIT tested on x86_64 and s390x with BPF test suite. Signed-off-by: Daniel Borkmann <dborkman@redhat.com> Acked-by: Alexei Starovoitov <ast@plumgrid.com> Cc: Eric Dumazet <edumazet@google.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-08 00:04:47 -06:00
#include <asm/cacheflush.h>
x86: bpf_jit: implement bpf_tail_call() helper bpf_tail_call() arguments: ctx - context pointer jmp_table - one of BPF_MAP_TYPE_PROG_ARRAY maps used as the jump table index - index in the jump table In this implementation x64 JIT bypasses stack unwind and jumps into the callee program after prologue, so the callee program reuses the same stack. The logic can be roughly expressed in C like: u32 tail_call_cnt; void *jumptable[2] = { &&label1, &&label2 }; int bpf_prog1(void *ctx) { label1: ... } int bpf_prog2(void *ctx) { label2: ... } int bpf_prog1(void *ctx) { ... if (tail_call_cnt++ < MAX_TAIL_CALL_CNT) goto *jumptable[index]; ... and pass my 'ctx' to callee ... ... fall through if no entry in jumptable ... } Note that 'skip current program epilogue and next program prologue' is an optimization. Other JITs don't have to do it the same way. >From safety point of view it's valid as well, since programs always initialize the stack before use, so any residue in the stack left by the current program is not going be read. The same verifier checks are done for the calls from the kernel into all bpf programs. Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-19 17:59:04 -06:00
#include <linux/bpf.h>
net: filter: Just In Time compiler for x86-64 In order to speedup packet filtering, here is an implementation of a JIT compiler for x86_64 It is disabled by default, and must be enabled by the admin. echo 1 >/proc/sys/net/core/bpf_jit_enable It uses module_alloc() and module_free() to get memory in the 2GB text kernel range since we call helpers functions from the generated code. EAX : BPF A accumulator EBX : BPF X accumulator RDI : pointer to skb (first argument given to JIT function) RBP : frame pointer (even if CONFIG_FRAME_POINTER=n) r9d : skb->len - skb->data_len (headlen) r8 : skb->data To get a trace of generated code, use : echo 2 >/proc/sys/net/core/bpf_jit_enable Example of generated code : # tcpdump -p -n -s 0 -i eth1 host 192.168.20.0/24 flen=18 proglen=147 pass=3 image=ffffffffa00b5000 JIT code: ffffffffa00b5000: 55 48 89 e5 48 83 ec 60 48 89 5d f8 44 8b 4f 60 JIT code: ffffffffa00b5010: 44 2b 4f 64 4c 8b 87 b8 00 00 00 be 0c 00 00 00 JIT code: ffffffffa00b5020: e8 24 7b f7 e0 3d 00 08 00 00 75 28 be 1a 00 00 JIT code: ffffffffa00b5030: 00 e8 fe 7a f7 e0 24 00 3d 00 14 a8 c0 74 49 be JIT code: ffffffffa00b5040: 1e 00 00 00 e8 eb 7a f7 e0 24 00 3d 00 14 a8 c0 JIT code: ffffffffa00b5050: 74 36 eb 3b 3d 06 08 00 00 74 07 3d 35 80 00 00 JIT code: ffffffffa00b5060: 75 2d be 1c 00 00 00 e8 c8 7a f7 e0 24 00 3d 00 JIT code: ffffffffa00b5070: 14 a8 c0 74 13 be 26 00 00 00 e8 b5 7a f7 e0 24 JIT code: ffffffffa00b5080: 00 3d 00 14 a8 c0 75 07 b8 ff ff 00 00 eb 02 31 JIT code: ffffffffa00b5090: c0 c9 c3 BPF program is 144 bytes long, so native program is almost same size ;) (000) ldh [12] (001) jeq #0x800 jt 2 jf 8 (002) ld [26] (003) and #0xffffff00 (004) jeq #0xc0a81400 jt 16 jf 5 (005) ld [30] (006) and #0xffffff00 (007) jeq #0xc0a81400 jt 16 jf 17 (008) jeq #0x806 jt 10 jf 9 (009) jeq #0x8035 jt 10 jf 17 (010) ld [28] (011) and #0xffffff00 (012) jeq #0xc0a81400 jt 16 jf 13 (013) ld [38] (014) and #0xffffff00 (015) jeq #0xc0a81400 jt 16 jf 17 (016) ret #65535 (017) ret #0 Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Cc: Arnaldo Carvalho de Melo <acme@infradead.org> Cc: Ben Hutchings <bhutchings@solarflare.com> Cc: Hagen Paul Pfeifer <hagen@jauu.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-04-20 03:27:32 -06:00
int bpf_jit_enable __read_mostly;
/*
* assembly code in arch/x86/net/bpf_jit.S
*/
net: filter: x86: internal BPF JIT Maps all internal BPF instructions into x86_64 instructions. This patch replaces original BPF x64 JIT with internal BPF x64 JIT. sysctl net.core.bpf_jit_enable is reused as on/off switch. Performance: 1. old BPF JIT and internal BPF JIT generate equivalent x86_64 code. No performance difference is observed for filters that were JIT-able before Example assembler code for BPF filter "tcpdump port 22" original BPF -> old JIT: original BPF -> internal BPF -> new JIT: 0: push %rbp 0: push %rbp 1: mov %rsp,%rbp 1: mov %rsp,%rbp 4: sub $0x60,%rsp 4: sub $0x228,%rsp 8: mov %rbx,-0x8(%rbp) b: mov %rbx,-0x228(%rbp) // prologue 12: mov %r13,-0x220(%rbp) 19: mov %r14,-0x218(%rbp) 20: mov %r15,-0x210(%rbp) 27: xor %eax,%eax // clear A c: xor %ebx,%ebx 29: xor %r13,%r13 // clear X e: mov 0x68(%rdi),%r9d 2c: mov 0x68(%rdi),%r9d 12: sub 0x6c(%rdi),%r9d 30: sub 0x6c(%rdi),%r9d 16: mov 0xd8(%rdi),%r8 34: mov 0xd8(%rdi),%r10 3b: mov %rdi,%rbx 1d: mov $0xc,%esi 3e: mov $0xc,%esi 22: callq 0xffffffffe1021e15 43: callq 0xffffffffe102bd75 27: cmp $0x86dd,%eax 48: cmp $0x86dd,%rax 2c: jne 0x0000000000000069 4f: jne 0x000000000000009a 2e: mov $0x14,%esi 51: mov $0x14,%esi 33: callq 0xffffffffe1021e31 56: callq 0xffffffffe102bd91 38: cmp $0x84,%eax 5b: cmp $0x84,%rax 3d: je 0x0000000000000049 62: je 0x0000000000000074 3f: cmp $0x6,%eax 64: cmp $0x6,%rax 42: je 0x0000000000000049 68: je 0x0000000000000074 44: cmp $0x11,%eax 6a: cmp $0x11,%rax 47: jne 0x00000000000000c6 6e: jne 0x0000000000000117 49: mov $0x36,%esi 74: mov $0x36,%esi 4e: callq 0xffffffffe1021e15 79: callq 0xffffffffe102bd75 53: cmp $0x16,%eax 7e: cmp $0x16,%rax 56: je 0x00000000000000bf 82: je 0x0000000000000110 58: mov $0x38,%esi 88: mov $0x38,%esi 5d: callq 0xffffffffe1021e15 8d: callq 0xffffffffe102bd75 62: cmp $0x16,%eax 92: cmp $0x16,%rax 65: je 0x00000000000000bf 96: je 0x0000000000000110 67: jmp 0x00000000000000c6 98: jmp 0x0000000000000117 69: cmp $0x800,%eax 9a: cmp $0x800,%rax 6e: jne 0x00000000000000c6 a1: jne 0x0000000000000117 70: mov $0x17,%esi a3: mov $0x17,%esi 75: callq 0xffffffffe1021e31 a8: callq 0xffffffffe102bd91 7a: cmp $0x84,%eax ad: cmp $0x84,%rax 7f: je 0x000000000000008b b4: je 0x00000000000000c2 81: cmp $0x6,%eax b6: cmp $0x6,%rax 84: je 0x000000000000008b ba: je 0x00000000000000c2 86: cmp $0x11,%eax bc: cmp $0x11,%rax 89: jne 0x00000000000000c6 c0: jne 0x0000000000000117 8b: mov $0x14,%esi c2: mov $0x14,%esi 90: callq 0xffffffffe1021e15 c7: callq 0xffffffffe102bd75 95: test $0x1fff,%ax cc: test $0x1fff,%rax 99: jne 0x00000000000000c6 d3: jne 0x0000000000000117 d5: mov %rax,%r14 9b: mov $0xe,%esi d8: mov $0xe,%esi a0: callq 0xffffffffe1021e44 dd: callq 0xffffffffe102bd91 // MSH e2: and $0xf,%eax e5: shl $0x2,%eax e8: mov %rax,%r13 eb: mov %r14,%rax ee: mov %r13,%rsi a5: lea 0xe(%rbx),%esi f1: add $0xe,%esi a8: callq 0xffffffffe1021e0d f4: callq 0xffffffffe102bd6d ad: cmp $0x16,%eax f9: cmp $0x16,%rax b0: je 0x00000000000000bf fd: je 0x0000000000000110 ff: mov %r13,%rsi b2: lea 0x10(%rbx),%esi 102: add $0x10,%esi b5: callq 0xffffffffe1021e0d 105: callq 0xffffffffe102bd6d ba: cmp $0x16,%eax 10a: cmp $0x16,%rax bd: jne 0x00000000000000c6 10e: jne 0x0000000000000117 bf: mov $0xffff,%eax 110: mov $0xffff,%eax c4: jmp 0x00000000000000c8 115: jmp 0x000000000000011c c6: xor %eax,%eax 117: mov $0x0,%eax c8: mov -0x8(%rbp),%rbx 11c: mov -0x228(%rbp),%rbx // epilogue cc: leaveq 123: mov -0x220(%rbp),%r13 cd: retq 12a: mov -0x218(%rbp),%r14 131: mov -0x210(%rbp),%r15 138: leaveq 139: retq On fully cached SKBs both JITed functions take 12 nsec to execute. BPF interpreter executes the program in 30 nsec. The difference in generated assembler is due to the following: Old BPF imlements LDX_MSH instruction via sk_load_byte_msh() helper function inside bpf_jit.S. New JIT removes the helper and does it explicitly, so ldx_msh cost is the same for both JITs, but generated code looks longer. New JIT has 4 registers to save, so prologue/epilogue are larger, but the cost is within noise on x64. Old JIT checks whether first insn clears A and if not emits 'xor %eax,%eax'. New JIT clears %rax unconditionally. 2. old BPF JIT doesn't support ANC_NLATTR, ANC_PAY_OFFSET, ANC_RANDOM extensions. New JIT supports all BPF extensions. Performance of such filters improves 2-4 times depending on a filter. The longer the filter the higher performance gain. Synthetic benchmarks with many ancillary loads see 20x speedup which seems to be the maximum gain from JIT Notes: . net.core.bpf_jit_enable=2 + tools/net/bpf_jit_disasm is still functional and can be used to see generated assembler . there are two jit_compile() functions and code flow for classic filters is: sk_attach_filter() - load classic BPF bpf_jit_compile() - try to JIT from classic BPF sk_convert_filter() - convert classic to internal bpf_int_jit_compile() - JIT from internal BPF seccomp and tracing filters will just call bpf_int_jit_compile() Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 20:50:46 -06:00
extern u8 sk_load_word[], sk_load_half[], sk_load_byte[];
bpf jit: Let the x86 jit handle negative offsets Now the helper function from filter.c for negative offsets is exported, it can be used it in the jit to handle negative offsets. First modify the asm load helper functions to handle: - know positive offsets - know negative offsets - any offset then the compiler can be modified to explicitly use these helper when appropriate. This fixes the case of a negative X register and allows to lift the restriction that bpf programs with negative offsets can't be jited. Signed-of-by: Jan Seiffert <kaffeemonster@googlemail.com> Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-03-29 23:24:05 -06:00
extern u8 sk_load_word_positive_offset[], sk_load_half_positive_offset[];
net: filter: x86: internal BPF JIT Maps all internal BPF instructions into x86_64 instructions. This patch replaces original BPF x64 JIT with internal BPF x64 JIT. sysctl net.core.bpf_jit_enable is reused as on/off switch. Performance: 1. old BPF JIT and internal BPF JIT generate equivalent x86_64 code. No performance difference is observed for filters that were JIT-able before Example assembler code for BPF filter "tcpdump port 22" original BPF -> old JIT: original BPF -> internal BPF -> new JIT: 0: push %rbp 0: push %rbp 1: mov %rsp,%rbp 1: mov %rsp,%rbp 4: sub $0x60,%rsp 4: sub $0x228,%rsp 8: mov %rbx,-0x8(%rbp) b: mov %rbx,-0x228(%rbp) // prologue 12: mov %r13,-0x220(%rbp) 19: mov %r14,-0x218(%rbp) 20: mov %r15,-0x210(%rbp) 27: xor %eax,%eax // clear A c: xor %ebx,%ebx 29: xor %r13,%r13 // clear X e: mov 0x68(%rdi),%r9d 2c: mov 0x68(%rdi),%r9d 12: sub 0x6c(%rdi),%r9d 30: sub 0x6c(%rdi),%r9d 16: mov 0xd8(%rdi),%r8 34: mov 0xd8(%rdi),%r10 3b: mov %rdi,%rbx 1d: mov $0xc,%esi 3e: mov $0xc,%esi 22: callq 0xffffffffe1021e15 43: callq 0xffffffffe102bd75 27: cmp $0x86dd,%eax 48: cmp $0x86dd,%rax 2c: jne 0x0000000000000069 4f: jne 0x000000000000009a 2e: mov $0x14,%esi 51: mov $0x14,%esi 33: callq 0xffffffffe1021e31 56: callq 0xffffffffe102bd91 38: cmp $0x84,%eax 5b: cmp $0x84,%rax 3d: je 0x0000000000000049 62: je 0x0000000000000074 3f: cmp $0x6,%eax 64: cmp $0x6,%rax 42: je 0x0000000000000049 68: je 0x0000000000000074 44: cmp $0x11,%eax 6a: cmp $0x11,%rax 47: jne 0x00000000000000c6 6e: jne 0x0000000000000117 49: mov $0x36,%esi 74: mov $0x36,%esi 4e: callq 0xffffffffe1021e15 79: callq 0xffffffffe102bd75 53: cmp $0x16,%eax 7e: cmp $0x16,%rax 56: je 0x00000000000000bf 82: je 0x0000000000000110 58: mov $0x38,%esi 88: mov $0x38,%esi 5d: callq 0xffffffffe1021e15 8d: callq 0xffffffffe102bd75 62: cmp $0x16,%eax 92: cmp $0x16,%rax 65: je 0x00000000000000bf 96: je 0x0000000000000110 67: jmp 0x00000000000000c6 98: jmp 0x0000000000000117 69: cmp $0x800,%eax 9a: cmp $0x800,%rax 6e: jne 0x00000000000000c6 a1: jne 0x0000000000000117 70: mov $0x17,%esi a3: mov $0x17,%esi 75: callq 0xffffffffe1021e31 a8: callq 0xffffffffe102bd91 7a: cmp $0x84,%eax ad: cmp $0x84,%rax 7f: je 0x000000000000008b b4: je 0x00000000000000c2 81: cmp $0x6,%eax b6: cmp $0x6,%rax 84: je 0x000000000000008b ba: je 0x00000000000000c2 86: cmp $0x11,%eax bc: cmp $0x11,%rax 89: jne 0x00000000000000c6 c0: jne 0x0000000000000117 8b: mov $0x14,%esi c2: mov $0x14,%esi 90: callq 0xffffffffe1021e15 c7: callq 0xffffffffe102bd75 95: test $0x1fff,%ax cc: test $0x1fff,%rax 99: jne 0x00000000000000c6 d3: jne 0x0000000000000117 d5: mov %rax,%r14 9b: mov $0xe,%esi d8: mov $0xe,%esi a0: callq 0xffffffffe1021e44 dd: callq 0xffffffffe102bd91 // MSH e2: and $0xf,%eax e5: shl $0x2,%eax e8: mov %rax,%r13 eb: mov %r14,%rax ee: mov %r13,%rsi a5: lea 0xe(%rbx),%esi f1: add $0xe,%esi a8: callq 0xffffffffe1021e0d f4: callq 0xffffffffe102bd6d ad: cmp $0x16,%eax f9: cmp $0x16,%rax b0: je 0x00000000000000bf fd: je 0x0000000000000110 ff: mov %r13,%rsi b2: lea 0x10(%rbx),%esi 102: add $0x10,%esi b5: callq 0xffffffffe1021e0d 105: callq 0xffffffffe102bd6d ba: cmp $0x16,%eax 10a: cmp $0x16,%rax bd: jne 0x00000000000000c6 10e: jne 0x0000000000000117 bf: mov $0xffff,%eax 110: mov $0xffff,%eax c4: jmp 0x00000000000000c8 115: jmp 0x000000000000011c c6: xor %eax,%eax 117: mov $0x0,%eax c8: mov -0x8(%rbp),%rbx 11c: mov -0x228(%rbp),%rbx // epilogue cc: leaveq 123: mov -0x220(%rbp),%r13 cd: retq 12a: mov -0x218(%rbp),%r14 131: mov -0x210(%rbp),%r15 138: leaveq 139: retq On fully cached SKBs both JITed functions take 12 nsec to execute. BPF interpreter executes the program in 30 nsec. The difference in generated assembler is due to the following: Old BPF imlements LDX_MSH instruction via sk_load_byte_msh() helper function inside bpf_jit.S. New JIT removes the helper and does it explicitly, so ldx_msh cost is the same for both JITs, but generated code looks longer. New JIT has 4 registers to save, so prologue/epilogue are larger, but the cost is within noise on x64. Old JIT checks whether first insn clears A and if not emits 'xor %eax,%eax'. New JIT clears %rax unconditionally. 2. old BPF JIT doesn't support ANC_NLATTR, ANC_PAY_OFFSET, ANC_RANDOM extensions. New JIT supports all BPF extensions. Performance of such filters improves 2-4 times depending on a filter. The longer the filter the higher performance gain. Synthetic benchmarks with many ancillary loads see 20x speedup which seems to be the maximum gain from JIT Notes: . net.core.bpf_jit_enable=2 + tools/net/bpf_jit_disasm is still functional and can be used to see generated assembler . there are two jit_compile() functions and code flow for classic filters is: sk_attach_filter() - load classic BPF bpf_jit_compile() - try to JIT from classic BPF sk_convert_filter() - convert classic to internal bpf_int_jit_compile() - JIT from internal BPF seccomp and tracing filters will just call bpf_int_jit_compile() Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 20:50:46 -06:00
extern u8 sk_load_byte_positive_offset[];
bpf jit: Let the x86 jit handle negative offsets Now the helper function from filter.c for negative offsets is exported, it can be used it in the jit to handle negative offsets. First modify the asm load helper functions to handle: - know positive offsets - know negative offsets - any offset then the compiler can be modified to explicitly use these helper when appropriate. This fixes the case of a negative X register and allows to lift the restriction that bpf programs with negative offsets can't be jited. Signed-of-by: Jan Seiffert <kaffeemonster@googlemail.com> Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-03-29 23:24:05 -06:00
extern u8 sk_load_word_negative_offset[], sk_load_half_negative_offset[];
net: filter: x86: internal BPF JIT Maps all internal BPF instructions into x86_64 instructions. This patch replaces original BPF x64 JIT with internal BPF x64 JIT. sysctl net.core.bpf_jit_enable is reused as on/off switch. Performance: 1. old BPF JIT and internal BPF JIT generate equivalent x86_64 code. No performance difference is observed for filters that were JIT-able before Example assembler code for BPF filter "tcpdump port 22" original BPF -> old JIT: original BPF -> internal BPF -> new JIT: 0: push %rbp 0: push %rbp 1: mov %rsp,%rbp 1: mov %rsp,%rbp 4: sub $0x60,%rsp 4: sub $0x228,%rsp 8: mov %rbx,-0x8(%rbp) b: mov %rbx,-0x228(%rbp) // prologue 12: mov %r13,-0x220(%rbp) 19: mov %r14,-0x218(%rbp) 20: mov %r15,-0x210(%rbp) 27: xor %eax,%eax // clear A c: xor %ebx,%ebx 29: xor %r13,%r13 // clear X e: mov 0x68(%rdi),%r9d 2c: mov 0x68(%rdi),%r9d 12: sub 0x6c(%rdi),%r9d 30: sub 0x6c(%rdi),%r9d 16: mov 0xd8(%rdi),%r8 34: mov 0xd8(%rdi),%r10 3b: mov %rdi,%rbx 1d: mov $0xc,%esi 3e: mov $0xc,%esi 22: callq 0xffffffffe1021e15 43: callq 0xffffffffe102bd75 27: cmp $0x86dd,%eax 48: cmp $0x86dd,%rax 2c: jne 0x0000000000000069 4f: jne 0x000000000000009a 2e: mov $0x14,%esi 51: mov $0x14,%esi 33: callq 0xffffffffe1021e31 56: callq 0xffffffffe102bd91 38: cmp $0x84,%eax 5b: cmp $0x84,%rax 3d: je 0x0000000000000049 62: je 0x0000000000000074 3f: cmp $0x6,%eax 64: cmp $0x6,%rax 42: je 0x0000000000000049 68: je 0x0000000000000074 44: cmp $0x11,%eax 6a: cmp $0x11,%rax 47: jne 0x00000000000000c6 6e: jne 0x0000000000000117 49: mov $0x36,%esi 74: mov $0x36,%esi 4e: callq 0xffffffffe1021e15 79: callq 0xffffffffe102bd75 53: cmp $0x16,%eax 7e: cmp $0x16,%rax 56: je 0x00000000000000bf 82: je 0x0000000000000110 58: mov $0x38,%esi 88: mov $0x38,%esi 5d: callq 0xffffffffe1021e15 8d: callq 0xffffffffe102bd75 62: cmp $0x16,%eax 92: cmp $0x16,%rax 65: je 0x00000000000000bf 96: je 0x0000000000000110 67: jmp 0x00000000000000c6 98: jmp 0x0000000000000117 69: cmp $0x800,%eax 9a: cmp $0x800,%rax 6e: jne 0x00000000000000c6 a1: jne 0x0000000000000117 70: mov $0x17,%esi a3: mov $0x17,%esi 75: callq 0xffffffffe1021e31 a8: callq 0xffffffffe102bd91 7a: cmp $0x84,%eax ad: cmp $0x84,%rax 7f: je 0x000000000000008b b4: je 0x00000000000000c2 81: cmp $0x6,%eax b6: cmp $0x6,%rax 84: je 0x000000000000008b ba: je 0x00000000000000c2 86: cmp $0x11,%eax bc: cmp $0x11,%rax 89: jne 0x00000000000000c6 c0: jne 0x0000000000000117 8b: mov $0x14,%esi c2: mov $0x14,%esi 90: callq 0xffffffffe1021e15 c7: callq 0xffffffffe102bd75 95: test $0x1fff,%ax cc: test $0x1fff,%rax 99: jne 0x00000000000000c6 d3: jne 0x0000000000000117 d5: mov %rax,%r14 9b: mov $0xe,%esi d8: mov $0xe,%esi a0: callq 0xffffffffe1021e44 dd: callq 0xffffffffe102bd91 // MSH e2: and $0xf,%eax e5: shl $0x2,%eax e8: mov %rax,%r13 eb: mov %r14,%rax ee: mov %r13,%rsi a5: lea 0xe(%rbx),%esi f1: add $0xe,%esi a8: callq 0xffffffffe1021e0d f4: callq 0xffffffffe102bd6d ad: cmp $0x16,%eax f9: cmp $0x16,%rax b0: je 0x00000000000000bf fd: je 0x0000000000000110 ff: mov %r13,%rsi b2: lea 0x10(%rbx),%esi 102: add $0x10,%esi b5: callq 0xffffffffe1021e0d 105: callq 0xffffffffe102bd6d ba: cmp $0x16,%eax 10a: cmp $0x16,%rax bd: jne 0x00000000000000c6 10e: jne 0x0000000000000117 bf: mov $0xffff,%eax 110: mov $0xffff,%eax c4: jmp 0x00000000000000c8 115: jmp 0x000000000000011c c6: xor %eax,%eax 117: mov $0x0,%eax c8: mov -0x8(%rbp),%rbx 11c: mov -0x228(%rbp),%rbx // epilogue cc: leaveq 123: mov -0x220(%rbp),%r13 cd: retq 12a: mov -0x218(%rbp),%r14 131: mov -0x210(%rbp),%r15 138: leaveq 139: retq On fully cached SKBs both JITed functions take 12 nsec to execute. BPF interpreter executes the program in 30 nsec. The difference in generated assembler is due to the following: Old BPF imlements LDX_MSH instruction via sk_load_byte_msh() helper function inside bpf_jit.S. New JIT removes the helper and does it explicitly, so ldx_msh cost is the same for both JITs, but generated code looks longer. New JIT has 4 registers to save, so prologue/epilogue are larger, but the cost is within noise on x64. Old JIT checks whether first insn clears A and if not emits 'xor %eax,%eax'. New JIT clears %rax unconditionally. 2. old BPF JIT doesn't support ANC_NLATTR, ANC_PAY_OFFSET, ANC_RANDOM extensions. New JIT supports all BPF extensions. Performance of such filters improves 2-4 times depending on a filter. The longer the filter the higher performance gain. Synthetic benchmarks with many ancillary loads see 20x speedup which seems to be the maximum gain from JIT Notes: . net.core.bpf_jit_enable=2 + tools/net/bpf_jit_disasm is still functional and can be used to see generated assembler . there are two jit_compile() functions and code flow for classic filters is: sk_attach_filter() - load classic BPF bpf_jit_compile() - try to JIT from classic BPF sk_convert_filter() - convert classic to internal bpf_int_jit_compile() - JIT from internal BPF seccomp and tracing filters will just call bpf_int_jit_compile() Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 20:50:46 -06:00
extern u8 sk_load_byte_negative_offset[];
net: filter: Just In Time compiler for x86-64 In order to speedup packet filtering, here is an implementation of a JIT compiler for x86_64 It is disabled by default, and must be enabled by the admin. echo 1 >/proc/sys/net/core/bpf_jit_enable It uses module_alloc() and module_free() to get memory in the 2GB text kernel range since we call helpers functions from the generated code. EAX : BPF A accumulator EBX : BPF X accumulator RDI : pointer to skb (first argument given to JIT function) RBP : frame pointer (even if CONFIG_FRAME_POINTER=n) r9d : skb->len - skb->data_len (headlen) r8 : skb->data To get a trace of generated code, use : echo 2 >/proc/sys/net/core/bpf_jit_enable Example of generated code : # tcpdump -p -n -s 0 -i eth1 host 192.168.20.0/24 flen=18 proglen=147 pass=3 image=ffffffffa00b5000 JIT code: ffffffffa00b5000: 55 48 89 e5 48 83 ec 60 48 89 5d f8 44 8b 4f 60 JIT code: ffffffffa00b5010: 44 2b 4f 64 4c 8b 87 b8 00 00 00 be 0c 00 00 00 JIT code: ffffffffa00b5020: e8 24 7b f7 e0 3d 00 08 00 00 75 28 be 1a 00 00 JIT code: ffffffffa00b5030: 00 e8 fe 7a f7 e0 24 00 3d 00 14 a8 c0 74 49 be JIT code: ffffffffa00b5040: 1e 00 00 00 e8 eb 7a f7 e0 24 00 3d 00 14 a8 c0 JIT code: ffffffffa00b5050: 74 36 eb 3b 3d 06 08 00 00 74 07 3d 35 80 00 00 JIT code: ffffffffa00b5060: 75 2d be 1c 00 00 00 e8 c8 7a f7 e0 24 00 3d 00 JIT code: ffffffffa00b5070: 14 a8 c0 74 13 be 26 00 00 00 e8 b5 7a f7 e0 24 JIT code: ffffffffa00b5080: 00 3d 00 14 a8 c0 75 07 b8 ff ff 00 00 eb 02 31 JIT code: ffffffffa00b5090: c0 c9 c3 BPF program is 144 bytes long, so native program is almost same size ;) (000) ldh [12] (001) jeq #0x800 jt 2 jf 8 (002) ld [26] (003) and #0xffffff00 (004) jeq #0xc0a81400 jt 16 jf 5 (005) ld [30] (006) and #0xffffff00 (007) jeq #0xc0a81400 jt 16 jf 17 (008) jeq #0x806 jt 10 jf 9 (009) jeq #0x8035 jt 10 jf 17 (010) ld [28] (011) and #0xffffff00 (012) jeq #0xc0a81400 jt 16 jf 13 (013) ld [38] (014) and #0xffffff00 (015) jeq #0xc0a81400 jt 16 jf 17 (016) ret #65535 (017) ret #0 Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Cc: Arnaldo Carvalho de Melo <acme@infradead.org> Cc: Ben Hutchings <bhutchings@solarflare.com> Cc: Hagen Paul Pfeifer <hagen@jauu.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-04-20 03:27:32 -06:00
x86: bpf_jit_comp: Remove inline from static function definitions Let the compiler decide instead. No change in object size x86-64 -O2 no profiling Signed-off-by: Joe Perches <joe@perches.com> Suggested-by: Eric Dumazet <eric.dumazet@gmail.com> Acked-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-12-04 18:01:24 -07:00
static u8 *emit_code(u8 *ptr, u32 bytes, unsigned int len)
net: filter: Just In Time compiler for x86-64 In order to speedup packet filtering, here is an implementation of a JIT compiler for x86_64 It is disabled by default, and must be enabled by the admin. echo 1 >/proc/sys/net/core/bpf_jit_enable It uses module_alloc() and module_free() to get memory in the 2GB text kernel range since we call helpers functions from the generated code. EAX : BPF A accumulator EBX : BPF X accumulator RDI : pointer to skb (first argument given to JIT function) RBP : frame pointer (even if CONFIG_FRAME_POINTER=n) r9d : skb->len - skb->data_len (headlen) r8 : skb->data To get a trace of generated code, use : echo 2 >/proc/sys/net/core/bpf_jit_enable Example of generated code : # tcpdump -p -n -s 0 -i eth1 host 192.168.20.0/24 flen=18 proglen=147 pass=3 image=ffffffffa00b5000 JIT code: ffffffffa00b5000: 55 48 89 e5 48 83 ec 60 48 89 5d f8 44 8b 4f 60 JIT code: ffffffffa00b5010: 44 2b 4f 64 4c 8b 87 b8 00 00 00 be 0c 00 00 00 JIT code: ffffffffa00b5020: e8 24 7b f7 e0 3d 00 08 00 00 75 28 be 1a 00 00 JIT code: ffffffffa00b5030: 00 e8 fe 7a f7 e0 24 00 3d 00 14 a8 c0 74 49 be JIT code: ffffffffa00b5040: 1e 00 00 00 e8 eb 7a f7 e0 24 00 3d 00 14 a8 c0 JIT code: ffffffffa00b5050: 74 36 eb 3b 3d 06 08 00 00 74 07 3d 35 80 00 00 JIT code: ffffffffa00b5060: 75 2d be 1c 00 00 00 e8 c8 7a f7 e0 24 00 3d 00 JIT code: ffffffffa00b5070: 14 a8 c0 74 13 be 26 00 00 00 e8 b5 7a f7 e0 24 JIT code: ffffffffa00b5080: 00 3d 00 14 a8 c0 75 07 b8 ff ff 00 00 eb 02 31 JIT code: ffffffffa00b5090: c0 c9 c3 BPF program is 144 bytes long, so native program is almost same size ;) (000) ldh [12] (001) jeq #0x800 jt 2 jf 8 (002) ld [26] (003) and #0xffffff00 (004) jeq #0xc0a81400 jt 16 jf 5 (005) ld [30] (006) and #0xffffff00 (007) jeq #0xc0a81400 jt 16 jf 17 (008) jeq #0x806 jt 10 jf 9 (009) jeq #0x8035 jt 10 jf 17 (010) ld [28] (011) and #0xffffff00 (012) jeq #0xc0a81400 jt 16 jf 13 (013) ld [38] (014) and #0xffffff00 (015) jeq #0xc0a81400 jt 16 jf 17 (016) ret #65535 (017) ret #0 Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Cc: Arnaldo Carvalho de Melo <acme@infradead.org> Cc: Ben Hutchings <bhutchings@solarflare.com> Cc: Hagen Paul Pfeifer <hagen@jauu.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-04-20 03:27:32 -06:00
{
if (len == 1)
*ptr = bytes;
else if (len == 2)
*(u16 *)ptr = bytes;
else {
*(u32 *)ptr = bytes;
barrier();
}
return ptr + len;
}
x86: bpf_jit: implement bpf_tail_call() helper bpf_tail_call() arguments: ctx - context pointer jmp_table - one of BPF_MAP_TYPE_PROG_ARRAY maps used as the jump table index - index in the jump table In this implementation x64 JIT bypasses stack unwind and jumps into the callee program after prologue, so the callee program reuses the same stack. The logic can be roughly expressed in C like: u32 tail_call_cnt; void *jumptable[2] = { &&label1, &&label2 }; int bpf_prog1(void *ctx) { label1: ... } int bpf_prog2(void *ctx) { label2: ... } int bpf_prog1(void *ctx) { ... if (tail_call_cnt++ < MAX_TAIL_CALL_CNT) goto *jumptable[index]; ... and pass my 'ctx' to callee ... ... fall through if no entry in jumptable ... } Note that 'skip current program epilogue and next program prologue' is an optimization. Other JITs don't have to do it the same way. >From safety point of view it's valid as well, since programs always initialize the stack before use, so any residue in the stack left by the current program is not going be read. The same verifier checks are done for the calls from the kernel into all bpf programs. Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-19 17:59:04 -06:00
#define EMIT(bytes, len) \
do { prog = emit_code(prog, bytes, len); cnt += len; } while (0)
net: filter: Just In Time compiler for x86-64 In order to speedup packet filtering, here is an implementation of a JIT compiler for x86_64 It is disabled by default, and must be enabled by the admin. echo 1 >/proc/sys/net/core/bpf_jit_enable It uses module_alloc() and module_free() to get memory in the 2GB text kernel range since we call helpers functions from the generated code. EAX : BPF A accumulator EBX : BPF X accumulator RDI : pointer to skb (first argument given to JIT function) RBP : frame pointer (even if CONFIG_FRAME_POINTER=n) r9d : skb->len - skb->data_len (headlen) r8 : skb->data To get a trace of generated code, use : echo 2 >/proc/sys/net/core/bpf_jit_enable Example of generated code : # tcpdump -p -n -s 0 -i eth1 host 192.168.20.0/24 flen=18 proglen=147 pass=3 image=ffffffffa00b5000 JIT code: ffffffffa00b5000: 55 48 89 e5 48 83 ec 60 48 89 5d f8 44 8b 4f 60 JIT code: ffffffffa00b5010: 44 2b 4f 64 4c 8b 87 b8 00 00 00 be 0c 00 00 00 JIT code: ffffffffa00b5020: e8 24 7b f7 e0 3d 00 08 00 00 75 28 be 1a 00 00 JIT code: ffffffffa00b5030: 00 e8 fe 7a f7 e0 24 00 3d 00 14 a8 c0 74 49 be JIT code: ffffffffa00b5040: 1e 00 00 00 e8 eb 7a f7 e0 24 00 3d 00 14 a8 c0 JIT code: ffffffffa00b5050: 74 36 eb 3b 3d 06 08 00 00 74 07 3d 35 80 00 00 JIT code: ffffffffa00b5060: 75 2d be 1c 00 00 00 e8 c8 7a f7 e0 24 00 3d 00 JIT code: ffffffffa00b5070: 14 a8 c0 74 13 be 26 00 00 00 e8 b5 7a f7 e0 24 JIT code: ffffffffa00b5080: 00 3d 00 14 a8 c0 75 07 b8 ff ff 00 00 eb 02 31 JIT code: ffffffffa00b5090: c0 c9 c3 BPF program is 144 bytes long, so native program is almost same size ;) (000) ldh [12] (001) jeq #0x800 jt 2 jf 8 (002) ld [26] (003) and #0xffffff00 (004) jeq #0xc0a81400 jt 16 jf 5 (005) ld [30] (006) and #0xffffff00 (007) jeq #0xc0a81400 jt 16 jf 17 (008) jeq #0x806 jt 10 jf 9 (009) jeq #0x8035 jt 10 jf 17 (010) ld [28] (011) and #0xffffff00 (012) jeq #0xc0a81400 jt 16 jf 13 (013) ld [38] (014) and #0xffffff00 (015) jeq #0xc0a81400 jt 16 jf 17 (016) ret #65535 (017) ret #0 Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Cc: Arnaldo Carvalho de Melo <acme@infradead.org> Cc: Ben Hutchings <bhutchings@solarflare.com> Cc: Hagen Paul Pfeifer <hagen@jauu.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-04-20 03:27:32 -06:00
#define EMIT1(b1) EMIT(b1, 1)
#define EMIT2(b1, b2) EMIT((b1) + ((b2) << 8), 2)
#define EMIT3(b1, b2, b3) EMIT((b1) + ((b2) << 8) + ((b3) << 16), 3)
#define EMIT4(b1, b2, b3, b4) EMIT((b1) + ((b2) << 8) + ((b3) << 16) + ((b4) << 24), 4)
net: filter: x86: internal BPF JIT Maps all internal BPF instructions into x86_64 instructions. This patch replaces original BPF x64 JIT with internal BPF x64 JIT. sysctl net.core.bpf_jit_enable is reused as on/off switch. Performance: 1. old BPF JIT and internal BPF JIT generate equivalent x86_64 code. No performance difference is observed for filters that were JIT-able before Example assembler code for BPF filter "tcpdump port 22" original BPF -> old JIT: original BPF -> internal BPF -> new JIT: 0: push %rbp 0: push %rbp 1: mov %rsp,%rbp 1: mov %rsp,%rbp 4: sub $0x60,%rsp 4: sub $0x228,%rsp 8: mov %rbx,-0x8(%rbp) b: mov %rbx,-0x228(%rbp) // prologue 12: mov %r13,-0x220(%rbp) 19: mov %r14,-0x218(%rbp) 20: mov %r15,-0x210(%rbp) 27: xor %eax,%eax // clear A c: xor %ebx,%ebx 29: xor %r13,%r13 // clear X e: mov 0x68(%rdi),%r9d 2c: mov 0x68(%rdi),%r9d 12: sub 0x6c(%rdi),%r9d 30: sub 0x6c(%rdi),%r9d 16: mov 0xd8(%rdi),%r8 34: mov 0xd8(%rdi),%r10 3b: mov %rdi,%rbx 1d: mov $0xc,%esi 3e: mov $0xc,%esi 22: callq 0xffffffffe1021e15 43: callq 0xffffffffe102bd75 27: cmp $0x86dd,%eax 48: cmp $0x86dd,%rax 2c: jne 0x0000000000000069 4f: jne 0x000000000000009a 2e: mov $0x14,%esi 51: mov $0x14,%esi 33: callq 0xffffffffe1021e31 56: callq 0xffffffffe102bd91 38: cmp $0x84,%eax 5b: cmp $0x84,%rax 3d: je 0x0000000000000049 62: je 0x0000000000000074 3f: cmp $0x6,%eax 64: cmp $0x6,%rax 42: je 0x0000000000000049 68: je 0x0000000000000074 44: cmp $0x11,%eax 6a: cmp $0x11,%rax 47: jne 0x00000000000000c6 6e: jne 0x0000000000000117 49: mov $0x36,%esi 74: mov $0x36,%esi 4e: callq 0xffffffffe1021e15 79: callq 0xffffffffe102bd75 53: cmp $0x16,%eax 7e: cmp $0x16,%rax 56: je 0x00000000000000bf 82: je 0x0000000000000110 58: mov $0x38,%esi 88: mov $0x38,%esi 5d: callq 0xffffffffe1021e15 8d: callq 0xffffffffe102bd75 62: cmp $0x16,%eax 92: cmp $0x16,%rax 65: je 0x00000000000000bf 96: je 0x0000000000000110 67: jmp 0x00000000000000c6 98: jmp 0x0000000000000117 69: cmp $0x800,%eax 9a: cmp $0x800,%rax 6e: jne 0x00000000000000c6 a1: jne 0x0000000000000117 70: mov $0x17,%esi a3: mov $0x17,%esi 75: callq 0xffffffffe1021e31 a8: callq 0xffffffffe102bd91 7a: cmp $0x84,%eax ad: cmp $0x84,%rax 7f: je 0x000000000000008b b4: je 0x00000000000000c2 81: cmp $0x6,%eax b6: cmp $0x6,%rax 84: je 0x000000000000008b ba: je 0x00000000000000c2 86: cmp $0x11,%eax bc: cmp $0x11,%rax 89: jne 0x00000000000000c6 c0: jne 0x0000000000000117 8b: mov $0x14,%esi c2: mov $0x14,%esi 90: callq 0xffffffffe1021e15 c7: callq 0xffffffffe102bd75 95: test $0x1fff,%ax cc: test $0x1fff,%rax 99: jne 0x00000000000000c6 d3: jne 0x0000000000000117 d5: mov %rax,%r14 9b: mov $0xe,%esi d8: mov $0xe,%esi a0: callq 0xffffffffe1021e44 dd: callq 0xffffffffe102bd91 // MSH e2: and $0xf,%eax e5: shl $0x2,%eax e8: mov %rax,%r13 eb: mov %r14,%rax ee: mov %r13,%rsi a5: lea 0xe(%rbx),%esi f1: add $0xe,%esi a8: callq 0xffffffffe1021e0d f4: callq 0xffffffffe102bd6d ad: cmp $0x16,%eax f9: cmp $0x16,%rax b0: je 0x00000000000000bf fd: je 0x0000000000000110 ff: mov %r13,%rsi b2: lea 0x10(%rbx),%esi 102: add $0x10,%esi b5: callq 0xffffffffe1021e0d 105: callq 0xffffffffe102bd6d ba: cmp $0x16,%eax 10a: cmp $0x16,%rax bd: jne 0x00000000000000c6 10e: jne 0x0000000000000117 bf: mov $0xffff,%eax 110: mov $0xffff,%eax c4: jmp 0x00000000000000c8 115: jmp 0x000000000000011c c6: xor %eax,%eax 117: mov $0x0,%eax c8: mov -0x8(%rbp),%rbx 11c: mov -0x228(%rbp),%rbx // epilogue cc: leaveq 123: mov -0x220(%rbp),%r13 cd: retq 12a: mov -0x218(%rbp),%r14 131: mov -0x210(%rbp),%r15 138: leaveq 139: retq On fully cached SKBs both JITed functions take 12 nsec to execute. BPF interpreter executes the program in 30 nsec. The difference in generated assembler is due to the following: Old BPF imlements LDX_MSH instruction via sk_load_byte_msh() helper function inside bpf_jit.S. New JIT removes the helper and does it explicitly, so ldx_msh cost is the same for both JITs, but generated code looks longer. New JIT has 4 registers to save, so prologue/epilogue are larger, but the cost is within noise on x64. Old JIT checks whether first insn clears A and if not emits 'xor %eax,%eax'. New JIT clears %rax unconditionally. 2. old BPF JIT doesn't support ANC_NLATTR, ANC_PAY_OFFSET, ANC_RANDOM extensions. New JIT supports all BPF extensions. Performance of such filters improves 2-4 times depending on a filter. The longer the filter the higher performance gain. Synthetic benchmarks with many ancillary loads see 20x speedup which seems to be the maximum gain from JIT Notes: . net.core.bpf_jit_enable=2 + tools/net/bpf_jit_disasm is still functional and can be used to see generated assembler . there are two jit_compile() functions and code flow for classic filters is: sk_attach_filter() - load classic BPF bpf_jit_compile() - try to JIT from classic BPF sk_convert_filter() - convert classic to internal bpf_int_jit_compile() - JIT from internal BPF seccomp and tracing filters will just call bpf_int_jit_compile() Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 20:50:46 -06:00
#define EMIT1_off32(b1, off) \
do {EMIT1(b1); EMIT(off, 4); } while (0)
#define EMIT2_off32(b1, b2, off) \
do {EMIT2(b1, b2); EMIT(off, 4); } while (0)
#define EMIT3_off32(b1, b2, b3, off) \
do {EMIT3(b1, b2, b3); EMIT(off, 4); } while (0)
#define EMIT4_off32(b1, b2, b3, b4, off) \
do {EMIT4(b1, b2, b3, b4); EMIT(off, 4); } while (0)
net: filter: Just In Time compiler for x86-64 In order to speedup packet filtering, here is an implementation of a JIT compiler for x86_64 It is disabled by default, and must be enabled by the admin. echo 1 >/proc/sys/net/core/bpf_jit_enable It uses module_alloc() and module_free() to get memory in the 2GB text kernel range since we call helpers functions from the generated code. EAX : BPF A accumulator EBX : BPF X accumulator RDI : pointer to skb (first argument given to JIT function) RBP : frame pointer (even if CONFIG_FRAME_POINTER=n) r9d : skb->len - skb->data_len (headlen) r8 : skb->data To get a trace of generated code, use : echo 2 >/proc/sys/net/core/bpf_jit_enable Example of generated code : # tcpdump -p -n -s 0 -i eth1 host 192.168.20.0/24 flen=18 proglen=147 pass=3 image=ffffffffa00b5000 JIT code: ffffffffa00b5000: 55 48 89 e5 48 83 ec 60 48 89 5d f8 44 8b 4f 60 JIT code: ffffffffa00b5010: 44 2b 4f 64 4c 8b 87 b8 00 00 00 be 0c 00 00 00 JIT code: ffffffffa00b5020: e8 24 7b f7 e0 3d 00 08 00 00 75 28 be 1a 00 00 JIT code: ffffffffa00b5030: 00 e8 fe 7a f7 e0 24 00 3d 00 14 a8 c0 74 49 be JIT code: ffffffffa00b5040: 1e 00 00 00 e8 eb 7a f7 e0 24 00 3d 00 14 a8 c0 JIT code: ffffffffa00b5050: 74 36 eb 3b 3d 06 08 00 00 74 07 3d 35 80 00 00 JIT code: ffffffffa00b5060: 75 2d be 1c 00 00 00 e8 c8 7a f7 e0 24 00 3d 00 JIT code: ffffffffa00b5070: 14 a8 c0 74 13 be 26 00 00 00 e8 b5 7a f7 e0 24 JIT code: ffffffffa00b5080: 00 3d 00 14 a8 c0 75 07 b8 ff ff 00 00 eb 02 31 JIT code: ffffffffa00b5090: c0 c9 c3 BPF program is 144 bytes long, so native program is almost same size ;) (000) ldh [12] (001) jeq #0x800 jt 2 jf 8 (002) ld [26] (003) and #0xffffff00 (004) jeq #0xc0a81400 jt 16 jf 5 (005) ld [30] (006) and #0xffffff00 (007) jeq #0xc0a81400 jt 16 jf 17 (008) jeq #0x806 jt 10 jf 9 (009) jeq #0x8035 jt 10 jf 17 (010) ld [28] (011) and #0xffffff00 (012) jeq #0xc0a81400 jt 16 jf 13 (013) ld [38] (014) and #0xffffff00 (015) jeq #0xc0a81400 jt 16 jf 17 (016) ret #65535 (017) ret #0 Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Cc: Arnaldo Carvalho de Melo <acme@infradead.org> Cc: Ben Hutchings <bhutchings@solarflare.com> Cc: Hagen Paul Pfeifer <hagen@jauu.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-04-20 03:27:32 -06:00
x86: bpf_jit_comp: Remove inline from static function definitions Let the compiler decide instead. No change in object size x86-64 -O2 no profiling Signed-off-by: Joe Perches <joe@perches.com> Suggested-by: Eric Dumazet <eric.dumazet@gmail.com> Acked-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-12-04 18:01:24 -07:00
static bool is_imm8(int value)
net: filter: Just In Time compiler for x86-64 In order to speedup packet filtering, here is an implementation of a JIT compiler for x86_64 It is disabled by default, and must be enabled by the admin. echo 1 >/proc/sys/net/core/bpf_jit_enable It uses module_alloc() and module_free() to get memory in the 2GB text kernel range since we call helpers functions from the generated code. EAX : BPF A accumulator EBX : BPF X accumulator RDI : pointer to skb (first argument given to JIT function) RBP : frame pointer (even if CONFIG_FRAME_POINTER=n) r9d : skb->len - skb->data_len (headlen) r8 : skb->data To get a trace of generated code, use : echo 2 >/proc/sys/net/core/bpf_jit_enable Example of generated code : # tcpdump -p -n -s 0 -i eth1 host 192.168.20.0/24 flen=18 proglen=147 pass=3 image=ffffffffa00b5000 JIT code: ffffffffa00b5000: 55 48 89 e5 48 83 ec 60 48 89 5d f8 44 8b 4f 60 JIT code: ffffffffa00b5010: 44 2b 4f 64 4c 8b 87 b8 00 00 00 be 0c 00 00 00 JIT code: ffffffffa00b5020: e8 24 7b f7 e0 3d 00 08 00 00 75 28 be 1a 00 00 JIT code: ffffffffa00b5030: 00 e8 fe 7a f7 e0 24 00 3d 00 14 a8 c0 74 49 be JIT code: ffffffffa00b5040: 1e 00 00 00 e8 eb 7a f7 e0 24 00 3d 00 14 a8 c0 JIT code: ffffffffa00b5050: 74 36 eb 3b 3d 06 08 00 00 74 07 3d 35 80 00 00 JIT code: ffffffffa00b5060: 75 2d be 1c 00 00 00 e8 c8 7a f7 e0 24 00 3d 00 JIT code: ffffffffa00b5070: 14 a8 c0 74 13 be 26 00 00 00 e8 b5 7a f7 e0 24 JIT code: ffffffffa00b5080: 00 3d 00 14 a8 c0 75 07 b8 ff ff 00 00 eb 02 31 JIT code: ffffffffa00b5090: c0 c9 c3 BPF program is 144 bytes long, so native program is almost same size ;) (000) ldh [12] (001) jeq #0x800 jt 2 jf 8 (002) ld [26] (003) and #0xffffff00 (004) jeq #0xc0a81400 jt 16 jf 5 (005) ld [30] (006) and #0xffffff00 (007) jeq #0xc0a81400 jt 16 jf 17 (008) jeq #0x806 jt 10 jf 9 (009) jeq #0x8035 jt 10 jf 17 (010) ld [28] (011) and #0xffffff00 (012) jeq #0xc0a81400 jt 16 jf 13 (013) ld [38] (014) and #0xffffff00 (015) jeq #0xc0a81400 jt 16 jf 17 (016) ret #65535 (017) ret #0 Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Cc: Arnaldo Carvalho de Melo <acme@infradead.org> Cc: Ben Hutchings <bhutchings@solarflare.com> Cc: Hagen Paul Pfeifer <hagen@jauu.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-04-20 03:27:32 -06:00
{
return value <= 127 && value >= -128;
}
x86: bpf_jit_comp: Remove inline from static function definitions Let the compiler decide instead. No change in object size x86-64 -O2 no profiling Signed-off-by: Joe Perches <joe@perches.com> Suggested-by: Eric Dumazet <eric.dumazet@gmail.com> Acked-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-12-04 18:01:24 -07:00
static bool is_simm32(s64 value)
net: filter: Just In Time compiler for x86-64 In order to speedup packet filtering, here is an implementation of a JIT compiler for x86_64 It is disabled by default, and must be enabled by the admin. echo 1 >/proc/sys/net/core/bpf_jit_enable It uses module_alloc() and module_free() to get memory in the 2GB text kernel range since we call helpers functions from the generated code. EAX : BPF A accumulator EBX : BPF X accumulator RDI : pointer to skb (first argument given to JIT function) RBP : frame pointer (even if CONFIG_FRAME_POINTER=n) r9d : skb->len - skb->data_len (headlen) r8 : skb->data To get a trace of generated code, use : echo 2 >/proc/sys/net/core/bpf_jit_enable Example of generated code : # tcpdump -p -n -s 0 -i eth1 host 192.168.20.0/24 flen=18 proglen=147 pass=3 image=ffffffffa00b5000 JIT code: ffffffffa00b5000: 55 48 89 e5 48 83 ec 60 48 89 5d f8 44 8b 4f 60 JIT code: ffffffffa00b5010: 44 2b 4f 64 4c 8b 87 b8 00 00 00 be 0c 00 00 00 JIT code: ffffffffa00b5020: e8 24 7b f7 e0 3d 00 08 00 00 75 28 be 1a 00 00 JIT code: ffffffffa00b5030: 00 e8 fe 7a f7 e0 24 00 3d 00 14 a8 c0 74 49 be JIT code: ffffffffa00b5040: 1e 00 00 00 e8 eb 7a f7 e0 24 00 3d 00 14 a8 c0 JIT code: ffffffffa00b5050: 74 36 eb 3b 3d 06 08 00 00 74 07 3d 35 80 00 00 JIT code: ffffffffa00b5060: 75 2d be 1c 00 00 00 e8 c8 7a f7 e0 24 00 3d 00 JIT code: ffffffffa00b5070: 14 a8 c0 74 13 be 26 00 00 00 e8 b5 7a f7 e0 24 JIT code: ffffffffa00b5080: 00 3d 00 14 a8 c0 75 07 b8 ff ff 00 00 eb 02 31 JIT code: ffffffffa00b5090: c0 c9 c3 BPF program is 144 bytes long, so native program is almost same size ;) (000) ldh [12] (001) jeq #0x800 jt 2 jf 8 (002) ld [26] (003) and #0xffffff00 (004) jeq #0xc0a81400 jt 16 jf 5 (005) ld [30] (006) and #0xffffff00 (007) jeq #0xc0a81400 jt 16 jf 17 (008) jeq #0x806 jt 10 jf 9 (009) jeq #0x8035 jt 10 jf 17 (010) ld [28] (011) and #0xffffff00 (012) jeq #0xc0a81400 jt 16 jf 13 (013) ld [38] (014) and #0xffffff00 (015) jeq #0xc0a81400 jt 16 jf 17 (016) ret #65535 (017) ret #0 Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Cc: Arnaldo Carvalho de Melo <acme@infradead.org> Cc: Ben Hutchings <bhutchings@solarflare.com> Cc: Hagen Paul Pfeifer <hagen@jauu.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-04-20 03:27:32 -06:00
{
net: filter: x86: internal BPF JIT Maps all internal BPF instructions into x86_64 instructions. This patch replaces original BPF x64 JIT with internal BPF x64 JIT. sysctl net.core.bpf_jit_enable is reused as on/off switch. Performance: 1. old BPF JIT and internal BPF JIT generate equivalent x86_64 code. No performance difference is observed for filters that were JIT-able before Example assembler code for BPF filter "tcpdump port 22" original BPF -> old JIT: original BPF -> internal BPF -> new JIT: 0: push %rbp 0: push %rbp 1: mov %rsp,%rbp 1: mov %rsp,%rbp 4: sub $0x60,%rsp 4: sub $0x228,%rsp 8: mov %rbx,-0x8(%rbp) b: mov %rbx,-0x228(%rbp) // prologue 12: mov %r13,-0x220(%rbp) 19: mov %r14,-0x218(%rbp) 20: mov %r15,-0x210(%rbp) 27: xor %eax,%eax // clear A c: xor %ebx,%ebx 29: xor %r13,%r13 // clear X e: mov 0x68(%rdi),%r9d 2c: mov 0x68(%rdi),%r9d 12: sub 0x6c(%rdi),%r9d 30: sub 0x6c(%rdi),%r9d 16: mov 0xd8(%rdi),%r8 34: mov 0xd8(%rdi),%r10 3b: mov %rdi,%rbx 1d: mov $0xc,%esi 3e: mov $0xc,%esi 22: callq 0xffffffffe1021e15 43: callq 0xffffffffe102bd75 27: cmp $0x86dd,%eax 48: cmp $0x86dd,%rax 2c: jne 0x0000000000000069 4f: jne 0x000000000000009a 2e: mov $0x14,%esi 51: mov $0x14,%esi 33: callq 0xffffffffe1021e31 56: callq 0xffffffffe102bd91 38: cmp $0x84,%eax 5b: cmp $0x84,%rax 3d: je 0x0000000000000049 62: je 0x0000000000000074 3f: cmp $0x6,%eax 64: cmp $0x6,%rax 42: je 0x0000000000000049 68: je 0x0000000000000074 44: cmp $0x11,%eax 6a: cmp $0x11,%rax 47: jne 0x00000000000000c6 6e: jne 0x0000000000000117 49: mov $0x36,%esi 74: mov $0x36,%esi 4e: callq 0xffffffffe1021e15 79: callq 0xffffffffe102bd75 53: cmp $0x16,%eax 7e: cmp $0x16,%rax 56: je 0x00000000000000bf 82: je 0x0000000000000110 58: mov $0x38,%esi 88: mov $0x38,%esi 5d: callq 0xffffffffe1021e15 8d: callq 0xffffffffe102bd75 62: cmp $0x16,%eax 92: cmp $0x16,%rax 65: je 0x00000000000000bf 96: je 0x0000000000000110 67: jmp 0x00000000000000c6 98: jmp 0x0000000000000117 69: cmp $0x800,%eax 9a: cmp $0x800,%rax 6e: jne 0x00000000000000c6 a1: jne 0x0000000000000117 70: mov $0x17,%esi a3: mov $0x17,%esi 75: callq 0xffffffffe1021e31 a8: callq 0xffffffffe102bd91 7a: cmp $0x84,%eax ad: cmp $0x84,%rax 7f: je 0x000000000000008b b4: je 0x00000000000000c2 81: cmp $0x6,%eax b6: cmp $0x6,%rax 84: je 0x000000000000008b ba: je 0x00000000000000c2 86: cmp $0x11,%eax bc: cmp $0x11,%rax 89: jne 0x00000000000000c6 c0: jne 0x0000000000000117 8b: mov $0x14,%esi c2: mov $0x14,%esi 90: callq 0xffffffffe1021e15 c7: callq 0xffffffffe102bd75 95: test $0x1fff,%ax cc: test $0x1fff,%rax 99: jne 0x00000000000000c6 d3: jne 0x0000000000000117 d5: mov %rax,%r14 9b: mov $0xe,%esi d8: mov $0xe,%esi a0: callq 0xffffffffe1021e44 dd: callq 0xffffffffe102bd91 // MSH e2: and $0xf,%eax e5: shl $0x2,%eax e8: mov %rax,%r13 eb: mov %r14,%rax ee: mov %r13,%rsi a5: lea 0xe(%rbx),%esi f1: add $0xe,%esi a8: callq 0xffffffffe1021e0d f4: callq 0xffffffffe102bd6d ad: cmp $0x16,%eax f9: cmp $0x16,%rax b0: je 0x00000000000000bf fd: je 0x0000000000000110 ff: mov %r13,%rsi b2: lea 0x10(%rbx),%esi 102: add $0x10,%esi b5: callq 0xffffffffe1021e0d 105: callq 0xffffffffe102bd6d ba: cmp $0x16,%eax 10a: cmp $0x16,%rax bd: jne 0x00000000000000c6 10e: jne 0x0000000000000117 bf: mov $0xffff,%eax 110: mov $0xffff,%eax c4: jmp 0x00000000000000c8 115: jmp 0x000000000000011c c6: xor %eax,%eax 117: mov $0x0,%eax c8: mov -0x8(%rbp),%rbx 11c: mov -0x228(%rbp),%rbx // epilogue cc: leaveq 123: mov -0x220(%rbp),%r13 cd: retq 12a: mov -0x218(%rbp),%r14 131: mov -0x210(%rbp),%r15 138: leaveq 139: retq On fully cached SKBs both JITed functions take 12 nsec to execute. BPF interpreter executes the program in 30 nsec. The difference in generated assembler is due to the following: Old BPF imlements LDX_MSH instruction via sk_load_byte_msh() helper function inside bpf_jit.S. New JIT removes the helper and does it explicitly, so ldx_msh cost is the same for both JITs, but generated code looks longer. New JIT has 4 registers to save, so prologue/epilogue are larger, but the cost is within noise on x64. Old JIT checks whether first insn clears A and if not emits 'xor %eax,%eax'. New JIT clears %rax unconditionally. 2. old BPF JIT doesn't support ANC_NLATTR, ANC_PAY_OFFSET, ANC_RANDOM extensions. New JIT supports all BPF extensions. Performance of such filters improves 2-4 times depending on a filter. The longer the filter the higher performance gain. Synthetic benchmarks with many ancillary loads see 20x speedup which seems to be the maximum gain from JIT Notes: . net.core.bpf_jit_enable=2 + tools/net/bpf_jit_disasm is still functional and can be used to see generated assembler . there are two jit_compile() functions and code flow for classic filters is: sk_attach_filter() - load classic BPF bpf_jit_compile() - try to JIT from classic BPF sk_convert_filter() - convert classic to internal bpf_int_jit_compile() - JIT from internal BPF seccomp and tracing filters will just call bpf_int_jit_compile() Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 20:50:46 -06:00
return value == (s64) (s32) value;
net: filter: Just In Time compiler for x86-64 In order to speedup packet filtering, here is an implementation of a JIT compiler for x86_64 It is disabled by default, and must be enabled by the admin. echo 1 >/proc/sys/net/core/bpf_jit_enable It uses module_alloc() and module_free() to get memory in the 2GB text kernel range since we call helpers functions from the generated code. EAX : BPF A accumulator EBX : BPF X accumulator RDI : pointer to skb (first argument given to JIT function) RBP : frame pointer (even if CONFIG_FRAME_POINTER=n) r9d : skb->len - skb->data_len (headlen) r8 : skb->data To get a trace of generated code, use : echo 2 >/proc/sys/net/core/bpf_jit_enable Example of generated code : # tcpdump -p -n -s 0 -i eth1 host 192.168.20.0/24 flen=18 proglen=147 pass=3 image=ffffffffa00b5000 JIT code: ffffffffa00b5000: 55 48 89 e5 48 83 ec 60 48 89 5d f8 44 8b 4f 60 JIT code: ffffffffa00b5010: 44 2b 4f 64 4c 8b 87 b8 00 00 00 be 0c 00 00 00 JIT code: ffffffffa00b5020: e8 24 7b f7 e0 3d 00 08 00 00 75 28 be 1a 00 00 JIT code: ffffffffa00b5030: 00 e8 fe 7a f7 e0 24 00 3d 00 14 a8 c0 74 49 be JIT code: ffffffffa00b5040: 1e 00 00 00 e8 eb 7a f7 e0 24 00 3d 00 14 a8 c0 JIT code: ffffffffa00b5050: 74 36 eb 3b 3d 06 08 00 00 74 07 3d 35 80 00 00 JIT code: ffffffffa00b5060: 75 2d be 1c 00 00 00 e8 c8 7a f7 e0 24 00 3d 00 JIT code: ffffffffa00b5070: 14 a8 c0 74 13 be 26 00 00 00 e8 b5 7a f7 e0 24 JIT code: ffffffffa00b5080: 00 3d 00 14 a8 c0 75 07 b8 ff ff 00 00 eb 02 31 JIT code: ffffffffa00b5090: c0 c9 c3 BPF program is 144 bytes long, so native program is almost same size ;) (000) ldh [12] (001) jeq #0x800 jt 2 jf 8 (002) ld [26] (003) and #0xffffff00 (004) jeq #0xc0a81400 jt 16 jf 5 (005) ld [30] (006) and #0xffffff00 (007) jeq #0xc0a81400 jt 16 jf 17 (008) jeq #0x806 jt 10 jf 9 (009) jeq #0x8035 jt 10 jf 17 (010) ld [28] (011) and #0xffffff00 (012) jeq #0xc0a81400 jt 16 jf 13 (013) ld [38] (014) and #0xffffff00 (015) jeq #0xc0a81400 jt 16 jf 17 (016) ret #65535 (017) ret #0 Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Cc: Arnaldo Carvalho de Melo <acme@infradead.org> Cc: Ben Hutchings <bhutchings@solarflare.com> Cc: Hagen Paul Pfeifer <hagen@jauu.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-04-20 03:27:32 -06:00
}
net: filter: cleanup A/X name usage The macro 'A' used in internal BPF interpreter: #define A regs[insn->a_reg] was easily confused with the name of classic BPF register 'A', since 'A' would mean two different things depending on context. This patch is trying to clean up the naming and clarify its usage in the following way: - A and X are names of two classic BPF registers - BPF_REG_A denotes internal BPF register R0 used to map classic register A in internal BPF programs generated from classic - BPF_REG_X denotes internal BPF register R7 used to map classic register X in internal BPF programs generated from classic - internal BPF instruction format: struct sock_filter_int { __u8 code; /* opcode */ __u8 dst_reg:4; /* dest register */ __u8 src_reg:4; /* source register */ __s16 off; /* signed offset */ __s32 imm; /* signed immediate constant */ }; - BPF_X/BPF_K is 1 bit used to encode source operand of instruction In classic: BPF_X - means use register X as source operand BPF_K - means use 32-bit immediate as source operand In internal: BPF_X - means use 'src_reg' register as source operand BPF_K - means use 32-bit immediate as source operand Suggested-by: Chema Gonzalez <chema@google.com> Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Acked-by: Daniel Borkmann <dborkman@redhat.com> Acked-by: Chema Gonzalez <chema@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-06-06 15:46:06 -06:00
/* mov dst, src */
#define EMIT_mov(DST, SRC) \
do {if (DST != SRC) \
EMIT3(add_2mod(0x48, DST, SRC), 0x89, add_2reg(0xC0, DST, SRC)); \
net: filter: x86: internal BPF JIT Maps all internal BPF instructions into x86_64 instructions. This patch replaces original BPF x64 JIT with internal BPF x64 JIT. sysctl net.core.bpf_jit_enable is reused as on/off switch. Performance: 1. old BPF JIT and internal BPF JIT generate equivalent x86_64 code. No performance difference is observed for filters that were JIT-able before Example assembler code for BPF filter "tcpdump port 22" original BPF -> old JIT: original BPF -> internal BPF -> new JIT: 0: push %rbp 0: push %rbp 1: mov %rsp,%rbp 1: mov %rsp,%rbp 4: sub $0x60,%rsp 4: sub $0x228,%rsp 8: mov %rbx,-0x8(%rbp) b: mov %rbx,-0x228(%rbp) // prologue 12: mov %r13,-0x220(%rbp) 19: mov %r14,-0x218(%rbp) 20: mov %r15,-0x210(%rbp) 27: xor %eax,%eax // clear A c: xor %ebx,%ebx 29: xor %r13,%r13 // clear X e: mov 0x68(%rdi),%r9d 2c: mov 0x68(%rdi),%r9d 12: sub 0x6c(%rdi),%r9d 30: sub 0x6c(%rdi),%r9d 16: mov 0xd8(%rdi),%r8 34: mov 0xd8(%rdi),%r10 3b: mov %rdi,%rbx 1d: mov $0xc,%esi 3e: mov $0xc,%esi 22: callq 0xffffffffe1021e15 43: callq 0xffffffffe102bd75 27: cmp $0x86dd,%eax 48: cmp $0x86dd,%rax 2c: jne 0x0000000000000069 4f: jne 0x000000000000009a 2e: mov $0x14,%esi 51: mov $0x14,%esi 33: callq 0xffffffffe1021e31 56: callq 0xffffffffe102bd91 38: cmp $0x84,%eax 5b: cmp $0x84,%rax 3d: je 0x0000000000000049 62: je 0x0000000000000074 3f: cmp $0x6,%eax 64: cmp $0x6,%rax 42: je 0x0000000000000049 68: je 0x0000000000000074 44: cmp $0x11,%eax 6a: cmp $0x11,%rax 47: jne 0x00000000000000c6 6e: jne 0x0000000000000117 49: mov $0x36,%esi 74: mov $0x36,%esi 4e: callq 0xffffffffe1021e15 79: callq 0xffffffffe102bd75 53: cmp $0x16,%eax 7e: cmp $0x16,%rax 56: je 0x00000000000000bf 82: je 0x0000000000000110 58: mov $0x38,%esi 88: mov $0x38,%esi 5d: callq 0xffffffffe1021e15 8d: callq 0xffffffffe102bd75 62: cmp $0x16,%eax 92: cmp $0x16,%rax 65: je 0x00000000000000bf 96: je 0x0000000000000110 67: jmp 0x00000000000000c6 98: jmp 0x0000000000000117 69: cmp $0x800,%eax 9a: cmp $0x800,%rax 6e: jne 0x00000000000000c6 a1: jne 0x0000000000000117 70: mov $0x17,%esi a3: mov $0x17,%esi 75: callq 0xffffffffe1021e31 a8: callq 0xffffffffe102bd91 7a: cmp $0x84,%eax ad: cmp $0x84,%rax 7f: je 0x000000000000008b b4: je 0x00000000000000c2 81: cmp $0x6,%eax b6: cmp $0x6,%rax 84: je 0x000000000000008b ba: je 0x00000000000000c2 86: cmp $0x11,%eax bc: cmp $0x11,%rax 89: jne 0x00000000000000c6 c0: jne 0x0000000000000117 8b: mov $0x14,%esi c2: mov $0x14,%esi 90: callq 0xffffffffe1021e15 c7: callq 0xffffffffe102bd75 95: test $0x1fff,%ax cc: test $0x1fff,%rax 99: jne 0x00000000000000c6 d3: jne 0x0000000000000117 d5: mov %rax,%r14 9b: mov $0xe,%esi d8: mov $0xe,%esi a0: callq 0xffffffffe1021e44 dd: callq 0xffffffffe102bd91 // MSH e2: and $0xf,%eax e5: shl $0x2,%eax e8: mov %rax,%r13 eb: mov %r14,%rax ee: mov %r13,%rsi a5: lea 0xe(%rbx),%esi f1: add $0xe,%esi a8: callq 0xffffffffe1021e0d f4: callq 0xffffffffe102bd6d ad: cmp $0x16,%eax f9: cmp $0x16,%rax b0: je 0x00000000000000bf fd: je 0x0000000000000110 ff: mov %r13,%rsi b2: lea 0x10(%rbx),%esi 102: add $0x10,%esi b5: callq 0xffffffffe1021e0d 105: callq 0xffffffffe102bd6d ba: cmp $0x16,%eax 10a: cmp $0x16,%rax bd: jne 0x00000000000000c6 10e: jne 0x0000000000000117 bf: mov $0xffff,%eax 110: mov $0xffff,%eax c4: jmp 0x00000000000000c8 115: jmp 0x000000000000011c c6: xor %eax,%eax 117: mov $0x0,%eax c8: mov -0x8(%rbp),%rbx 11c: mov -0x228(%rbp),%rbx // epilogue cc: leaveq 123: mov -0x220(%rbp),%r13 cd: retq 12a: mov -0x218(%rbp),%r14 131: mov -0x210(%rbp),%r15 138: leaveq 139: retq On fully cached SKBs both JITed functions take 12 nsec to execute. BPF interpreter executes the program in 30 nsec. The difference in generated assembler is due to the following: Old BPF imlements LDX_MSH instruction via sk_load_byte_msh() helper function inside bpf_jit.S. New JIT removes the helper and does it explicitly, so ldx_msh cost is the same for both JITs, but generated code looks longer. New JIT has 4 registers to save, so prologue/epilogue are larger, but the cost is within noise on x64. Old JIT checks whether first insn clears A and if not emits 'xor %eax,%eax'. New JIT clears %rax unconditionally. 2. old BPF JIT doesn't support ANC_NLATTR, ANC_PAY_OFFSET, ANC_RANDOM extensions. New JIT supports all BPF extensions. Performance of such filters improves 2-4 times depending on a filter. The longer the filter the higher performance gain. Synthetic benchmarks with many ancillary loads see 20x speedup which seems to be the maximum gain from JIT Notes: . net.core.bpf_jit_enable=2 + tools/net/bpf_jit_disasm is still functional and can be used to see generated assembler . there are two jit_compile() functions and code flow for classic filters is: sk_attach_filter() - load classic BPF bpf_jit_compile() - try to JIT from classic BPF sk_convert_filter() - convert classic to internal bpf_int_jit_compile() - JIT from internal BPF seccomp and tracing filters will just call bpf_int_jit_compile() Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 20:50:46 -06:00
} while (0)
static int bpf_size_to_x86_bytes(int bpf_size)
{
if (bpf_size == BPF_W)
return 4;
else if (bpf_size == BPF_H)
return 2;
else if (bpf_size == BPF_B)
return 1;
else if (bpf_size == BPF_DW)
return 4; /* imm32 */
else
return 0;
}
net: filter: Just In Time compiler for x86-64 In order to speedup packet filtering, here is an implementation of a JIT compiler for x86_64 It is disabled by default, and must be enabled by the admin. echo 1 >/proc/sys/net/core/bpf_jit_enable It uses module_alloc() and module_free() to get memory in the 2GB text kernel range since we call helpers functions from the generated code. EAX : BPF A accumulator EBX : BPF X accumulator RDI : pointer to skb (first argument given to JIT function) RBP : frame pointer (even if CONFIG_FRAME_POINTER=n) r9d : skb->len - skb->data_len (headlen) r8 : skb->data To get a trace of generated code, use : echo 2 >/proc/sys/net/core/bpf_jit_enable Example of generated code : # tcpdump -p -n -s 0 -i eth1 host 192.168.20.0/24 flen=18 proglen=147 pass=3 image=ffffffffa00b5000 JIT code: ffffffffa00b5000: 55 48 89 e5 48 83 ec 60 48 89 5d f8 44 8b 4f 60 JIT code: ffffffffa00b5010: 44 2b 4f 64 4c 8b 87 b8 00 00 00 be 0c 00 00 00 JIT code: ffffffffa00b5020: e8 24 7b f7 e0 3d 00 08 00 00 75 28 be 1a 00 00 JIT code: ffffffffa00b5030: 00 e8 fe 7a f7 e0 24 00 3d 00 14 a8 c0 74 49 be JIT code: ffffffffa00b5040: 1e 00 00 00 e8 eb 7a f7 e0 24 00 3d 00 14 a8 c0 JIT code: ffffffffa00b5050: 74 36 eb 3b 3d 06 08 00 00 74 07 3d 35 80 00 00 JIT code: ffffffffa00b5060: 75 2d be 1c 00 00 00 e8 c8 7a f7 e0 24 00 3d 00 JIT code: ffffffffa00b5070: 14 a8 c0 74 13 be 26 00 00 00 e8 b5 7a f7 e0 24 JIT code: ffffffffa00b5080: 00 3d 00 14 a8 c0 75 07 b8 ff ff 00 00 eb 02 31 JIT code: ffffffffa00b5090: c0 c9 c3 BPF program is 144 bytes long, so native program is almost same size ;) (000) ldh [12] (001) jeq #0x800 jt 2 jf 8 (002) ld [26] (003) and #0xffffff00 (004) jeq #0xc0a81400 jt 16 jf 5 (005) ld [30] (006) and #0xffffff00 (007) jeq #0xc0a81400 jt 16 jf 17 (008) jeq #0x806 jt 10 jf 9 (009) jeq #0x8035 jt 10 jf 17 (010) ld [28] (011) and #0xffffff00 (012) jeq #0xc0a81400 jt 16 jf 13 (013) ld [38] (014) and #0xffffff00 (015) jeq #0xc0a81400 jt 16 jf 17 (016) ret #65535 (017) ret #0 Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Cc: Arnaldo Carvalho de Melo <acme@infradead.org> Cc: Ben Hutchings <bhutchings@solarflare.com> Cc: Hagen Paul Pfeifer <hagen@jauu.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-04-20 03:27:32 -06:00
/* list of x86 cond jumps opcodes (. + s8)
* Add 0x10 (and an extra 0x0f) to generate far jumps (. + s32)
*/
#define X86_JB 0x72
#define X86_JAE 0x73
#define X86_JE 0x74
#define X86_JNE 0x75
#define X86_JBE 0x76
#define X86_JA 0x77
net: filter: x86: internal BPF JIT Maps all internal BPF instructions into x86_64 instructions. This patch replaces original BPF x64 JIT with internal BPF x64 JIT. sysctl net.core.bpf_jit_enable is reused as on/off switch. Performance: 1. old BPF JIT and internal BPF JIT generate equivalent x86_64 code. No performance difference is observed for filters that were JIT-able before Example assembler code for BPF filter "tcpdump port 22" original BPF -> old JIT: original BPF -> internal BPF -> new JIT: 0: push %rbp 0: push %rbp 1: mov %rsp,%rbp 1: mov %rsp,%rbp 4: sub $0x60,%rsp 4: sub $0x228,%rsp 8: mov %rbx,-0x8(%rbp) b: mov %rbx,-0x228(%rbp) // prologue 12: mov %r13,-0x220(%rbp) 19: mov %r14,-0x218(%rbp) 20: mov %r15,-0x210(%rbp) 27: xor %eax,%eax // clear A c: xor %ebx,%ebx 29: xor %r13,%r13 // clear X e: mov 0x68(%rdi),%r9d 2c: mov 0x68(%rdi),%r9d 12: sub 0x6c(%rdi),%r9d 30: sub 0x6c(%rdi),%r9d 16: mov 0xd8(%rdi),%r8 34: mov 0xd8(%rdi),%r10 3b: mov %rdi,%rbx 1d: mov $0xc,%esi 3e: mov $0xc,%esi 22: callq 0xffffffffe1021e15 43: callq 0xffffffffe102bd75 27: cmp $0x86dd,%eax 48: cmp $0x86dd,%rax 2c: jne 0x0000000000000069 4f: jne 0x000000000000009a 2e: mov $0x14,%esi 51: mov $0x14,%esi 33: callq 0xffffffffe1021e31 56: callq 0xffffffffe102bd91 38: cmp $0x84,%eax 5b: cmp $0x84,%rax 3d: je 0x0000000000000049 62: je 0x0000000000000074 3f: cmp $0x6,%eax 64: cmp $0x6,%rax 42: je 0x0000000000000049 68: je 0x0000000000000074 44: cmp $0x11,%eax 6a: cmp $0x11,%rax 47: jne 0x00000000000000c6 6e: jne 0x0000000000000117 49: mov $0x36,%esi 74: mov $0x36,%esi 4e: callq 0xffffffffe1021e15 79: callq 0xffffffffe102bd75 53: cmp $0x16,%eax 7e: cmp $0x16,%rax 56: je 0x00000000000000bf 82: je 0x0000000000000110 58: mov $0x38,%esi 88: mov $0x38,%esi 5d: callq 0xffffffffe1021e15 8d: callq 0xffffffffe102bd75 62: cmp $0x16,%eax 92: cmp $0x16,%rax 65: je 0x00000000000000bf 96: je 0x0000000000000110 67: jmp 0x00000000000000c6 98: jmp 0x0000000000000117 69: cmp $0x800,%eax 9a: cmp $0x800,%rax 6e: jne 0x00000000000000c6 a1: jne 0x0000000000000117 70: mov $0x17,%esi a3: mov $0x17,%esi 75: callq 0xffffffffe1021e31 a8: callq 0xffffffffe102bd91 7a: cmp $0x84,%eax ad: cmp $0x84,%rax 7f: je 0x000000000000008b b4: je 0x00000000000000c2 81: cmp $0x6,%eax b6: cmp $0x6,%rax 84: je 0x000000000000008b ba: je 0x00000000000000c2 86: cmp $0x11,%eax bc: cmp $0x11,%rax 89: jne 0x00000000000000c6 c0: jne 0x0000000000000117 8b: mov $0x14,%esi c2: mov $0x14,%esi 90: callq 0xffffffffe1021e15 c7: callq 0xffffffffe102bd75 95: test $0x1fff,%ax cc: test $0x1fff,%rax 99: jne 0x00000000000000c6 d3: jne 0x0000000000000117 d5: mov %rax,%r14 9b: mov $0xe,%esi d8: mov $0xe,%esi a0: callq 0xffffffffe1021e44 dd: callq 0xffffffffe102bd91 // MSH e2: and $0xf,%eax e5: shl $0x2,%eax e8: mov %rax,%r13 eb: mov %r14,%rax ee: mov %r13,%rsi a5: lea 0xe(%rbx),%esi f1: add $0xe,%esi a8: callq 0xffffffffe1021e0d f4: callq 0xffffffffe102bd6d ad: cmp $0x16,%eax f9: cmp $0x16,%rax b0: je 0x00000000000000bf fd: je 0x0000000000000110 ff: mov %r13,%rsi b2: lea 0x10(%rbx),%esi 102: add $0x10,%esi b5: callq 0xffffffffe1021e0d 105: callq 0xffffffffe102bd6d ba: cmp $0x16,%eax 10a: cmp $0x16,%rax bd: jne 0x00000000000000c6 10e: jne 0x0000000000000117 bf: mov $0xffff,%eax 110: mov $0xffff,%eax c4: jmp 0x00000000000000c8 115: jmp 0x000000000000011c c6: xor %eax,%eax 117: mov $0x0,%eax c8: mov -0x8(%rbp),%rbx 11c: mov -0x228(%rbp),%rbx // epilogue cc: leaveq 123: mov -0x220(%rbp),%r13 cd: retq 12a: mov -0x218(%rbp),%r14 131: mov -0x210(%rbp),%r15 138: leaveq 139: retq On fully cached SKBs both JITed functions take 12 nsec to execute. BPF interpreter executes the program in 30 nsec. The difference in generated assembler is due to the following: Old BPF imlements LDX_MSH instruction via sk_load_byte_msh() helper function inside bpf_jit.S. New JIT removes the helper and does it explicitly, so ldx_msh cost is the same for both JITs, but generated code looks longer. New JIT has 4 registers to save, so prologue/epilogue are larger, but the cost is within noise on x64. Old JIT checks whether first insn clears A and if not emits 'xor %eax,%eax'. New JIT clears %rax unconditionally. 2. old BPF JIT doesn't support ANC_NLATTR, ANC_PAY_OFFSET, ANC_RANDOM extensions. New JIT supports all BPF extensions. Performance of such filters improves 2-4 times depending on a filter. The longer the filter the higher performance gain. Synthetic benchmarks with many ancillary loads see 20x speedup which seems to be the maximum gain from JIT Notes: . net.core.bpf_jit_enable=2 + tools/net/bpf_jit_disasm is still functional and can be used to see generated assembler . there are two jit_compile() functions and code flow for classic filters is: sk_attach_filter() - load classic BPF bpf_jit_compile() - try to JIT from classic BPF sk_convert_filter() - convert classic to internal bpf_int_jit_compile() - JIT from internal BPF seccomp and tracing filters will just call bpf_int_jit_compile() Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 20:50:46 -06:00
#define X86_JGE 0x7D
#define X86_JG 0x7F
net: filter: Just In Time compiler for x86-64 In order to speedup packet filtering, here is an implementation of a JIT compiler for x86_64 It is disabled by default, and must be enabled by the admin. echo 1 >/proc/sys/net/core/bpf_jit_enable It uses module_alloc() and module_free() to get memory in the 2GB text kernel range since we call helpers functions from the generated code. EAX : BPF A accumulator EBX : BPF X accumulator RDI : pointer to skb (first argument given to JIT function) RBP : frame pointer (even if CONFIG_FRAME_POINTER=n) r9d : skb->len - skb->data_len (headlen) r8 : skb->data To get a trace of generated code, use : echo 2 >/proc/sys/net/core/bpf_jit_enable Example of generated code : # tcpdump -p -n -s 0 -i eth1 host 192.168.20.0/24 flen=18 proglen=147 pass=3 image=ffffffffa00b5000 JIT code: ffffffffa00b5000: 55 48 89 e5 48 83 ec 60 48 89 5d f8 44 8b 4f 60 JIT code: ffffffffa00b5010: 44 2b 4f 64 4c 8b 87 b8 00 00 00 be 0c 00 00 00 JIT code: ffffffffa00b5020: e8 24 7b f7 e0 3d 00 08 00 00 75 28 be 1a 00 00 JIT code: ffffffffa00b5030: 00 e8 fe 7a f7 e0 24 00 3d 00 14 a8 c0 74 49 be JIT code: ffffffffa00b5040: 1e 00 00 00 e8 eb 7a f7 e0 24 00 3d 00 14 a8 c0 JIT code: ffffffffa00b5050: 74 36 eb 3b 3d 06 08 00 00 74 07 3d 35 80 00 00 JIT code: ffffffffa00b5060: 75 2d be 1c 00 00 00 e8 c8 7a f7 e0 24 00 3d 00 JIT code: ffffffffa00b5070: 14 a8 c0 74 13 be 26 00 00 00 e8 b5 7a f7 e0 24 JIT code: ffffffffa00b5080: 00 3d 00 14 a8 c0 75 07 b8 ff ff 00 00 eb 02 31 JIT code: ffffffffa00b5090: c0 c9 c3 BPF program is 144 bytes long, so native program is almost same size ;) (000) ldh [12] (001) jeq #0x800 jt 2 jf 8 (002) ld [26] (003) and #0xffffff00 (004) jeq #0xc0a81400 jt 16 jf 5 (005) ld [30] (006) and #0xffffff00 (007) jeq #0xc0a81400 jt 16 jf 17 (008) jeq #0x806 jt 10 jf 9 (009) jeq #0x8035 jt 10 jf 17 (010) ld [28] (011) and #0xffffff00 (012) jeq #0xc0a81400 jt 16 jf 13 (013) ld [38] (014) and #0xffffff00 (015) jeq #0xc0a81400 jt 16 jf 17 (016) ret #65535 (017) ret #0 Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Cc: Arnaldo Carvalho de Melo <acme@infradead.org> Cc: Ben Hutchings <bhutchings@solarflare.com> Cc: Hagen Paul Pfeifer <hagen@jauu.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-04-20 03:27:32 -06:00
x86: bpf_jit_comp: Remove inline from static function definitions Let the compiler decide instead. No change in object size x86-64 -O2 no profiling Signed-off-by: Joe Perches <joe@perches.com> Suggested-by: Eric Dumazet <eric.dumazet@gmail.com> Acked-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-12-04 18:01:24 -07:00
static void bpf_flush_icache(void *start, void *end)
net: filter: Just In Time compiler for x86-64 In order to speedup packet filtering, here is an implementation of a JIT compiler for x86_64 It is disabled by default, and must be enabled by the admin. echo 1 >/proc/sys/net/core/bpf_jit_enable It uses module_alloc() and module_free() to get memory in the 2GB text kernel range since we call helpers functions from the generated code. EAX : BPF A accumulator EBX : BPF X accumulator RDI : pointer to skb (first argument given to JIT function) RBP : frame pointer (even if CONFIG_FRAME_POINTER=n) r9d : skb->len - skb->data_len (headlen) r8 : skb->data To get a trace of generated code, use : echo 2 >/proc/sys/net/core/bpf_jit_enable Example of generated code : # tcpdump -p -n -s 0 -i eth1 host 192.168.20.0/24 flen=18 proglen=147 pass=3 image=ffffffffa00b5000 JIT code: ffffffffa00b5000: 55 48 89 e5 48 83 ec 60 48 89 5d f8 44 8b 4f 60 JIT code: ffffffffa00b5010: 44 2b 4f 64 4c 8b 87 b8 00 00 00 be 0c 00 00 00 JIT code: ffffffffa00b5020: e8 24 7b f7 e0 3d 00 08 00 00 75 28 be 1a 00 00 JIT code: ffffffffa00b5030: 00 e8 fe 7a f7 e0 24 00 3d 00 14 a8 c0 74 49 be JIT code: ffffffffa00b5040: 1e 00 00 00 e8 eb 7a f7 e0 24 00 3d 00 14 a8 c0 JIT code: ffffffffa00b5050: 74 36 eb 3b 3d 06 08 00 00 74 07 3d 35 80 00 00 JIT code: ffffffffa00b5060: 75 2d be 1c 00 00 00 e8 c8 7a f7 e0 24 00 3d 00 JIT code: ffffffffa00b5070: 14 a8 c0 74 13 be 26 00 00 00 e8 b5 7a f7 e0 24 JIT code: ffffffffa00b5080: 00 3d 00 14 a8 c0 75 07 b8 ff ff 00 00 eb 02 31 JIT code: ffffffffa00b5090: c0 c9 c3 BPF program is 144 bytes long, so native program is almost same size ;) (000) ldh [12] (001) jeq #0x800 jt 2 jf 8 (002) ld [26] (003) and #0xffffff00 (004) jeq #0xc0a81400 jt 16 jf 5 (005) ld [30] (006) and #0xffffff00 (007) jeq #0xc0a81400 jt 16 jf 17 (008) jeq #0x806 jt 10 jf 9 (009) jeq #0x8035 jt 10 jf 17 (010) ld [28] (011) and #0xffffff00 (012) jeq #0xc0a81400 jt 16 jf 13 (013) ld [38] (014) and #0xffffff00 (015) jeq #0xc0a81400 jt 16 jf 17 (016) ret #65535 (017) ret #0 Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Cc: Arnaldo Carvalho de Melo <acme@infradead.org> Cc: Ben Hutchings <bhutchings@solarflare.com> Cc: Hagen Paul Pfeifer <hagen@jauu.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-04-20 03:27:32 -06:00
{
mm_segment_t old_fs = get_fs();
set_fs(KERNEL_DS);
smp_wmb();
flush_icache_range((unsigned long)start, (unsigned long)end);
set_fs(old_fs);
}
bpf jit: Let the x86 jit handle negative offsets Now the helper function from filter.c for negative offsets is exported, it can be used it in the jit to handle negative offsets. First modify the asm load helper functions to handle: - know positive offsets - know negative offsets - any offset then the compiler can be modified to explicitly use these helper when appropriate. This fixes the case of a negative X register and allows to lift the restriction that bpf programs with negative offsets can't be jited. Signed-of-by: Jan Seiffert <kaffeemonster@googlemail.com> Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-03-29 23:24:05 -06:00
#define CHOOSE_LOAD_FUNC(K, func) \
((int)K < 0 ? ((int)K >= SKF_LL_OFF ? func##_negative_offset : func) : func##_positive_offset)
net: filter: Just In Time compiler for x86-64 In order to speedup packet filtering, here is an implementation of a JIT compiler for x86_64 It is disabled by default, and must be enabled by the admin. echo 1 >/proc/sys/net/core/bpf_jit_enable It uses module_alloc() and module_free() to get memory in the 2GB text kernel range since we call helpers functions from the generated code. EAX : BPF A accumulator EBX : BPF X accumulator RDI : pointer to skb (first argument given to JIT function) RBP : frame pointer (even if CONFIG_FRAME_POINTER=n) r9d : skb->len - skb->data_len (headlen) r8 : skb->data To get a trace of generated code, use : echo 2 >/proc/sys/net/core/bpf_jit_enable Example of generated code : # tcpdump -p -n -s 0 -i eth1 host 192.168.20.0/24 flen=18 proglen=147 pass=3 image=ffffffffa00b5000 JIT code: ffffffffa00b5000: 55 48 89 e5 48 83 ec 60 48 89 5d f8 44 8b 4f 60 JIT code: ffffffffa00b5010: 44 2b 4f 64 4c 8b 87 b8 00 00 00 be 0c 00 00 00 JIT code: ffffffffa00b5020: e8 24 7b f7 e0 3d 00 08 00 00 75 28 be 1a 00 00 JIT code: ffffffffa00b5030: 00 e8 fe 7a f7 e0 24 00 3d 00 14 a8 c0 74 49 be JIT code: ffffffffa00b5040: 1e 00 00 00 e8 eb 7a f7 e0 24 00 3d 00 14 a8 c0 JIT code: ffffffffa00b5050: 74 36 eb 3b 3d 06 08 00 00 74 07 3d 35 80 00 00 JIT code: ffffffffa00b5060: 75 2d be 1c 00 00 00 e8 c8 7a f7 e0 24 00 3d 00 JIT code: ffffffffa00b5070: 14 a8 c0 74 13 be 26 00 00 00 e8 b5 7a f7 e0 24 JIT code: ffffffffa00b5080: 00 3d 00 14 a8 c0 75 07 b8 ff ff 00 00 eb 02 31 JIT code: ffffffffa00b5090: c0 c9 c3 BPF program is 144 bytes long, so native program is almost same size ;) (000) ldh [12] (001) jeq #0x800 jt 2 jf 8 (002) ld [26] (003) and #0xffffff00 (004) jeq #0xc0a81400 jt 16 jf 5 (005) ld [30] (006) and #0xffffff00 (007) jeq #0xc0a81400 jt 16 jf 17 (008) jeq #0x806 jt 10 jf 9 (009) jeq #0x8035 jt 10 jf 17 (010) ld [28] (011) and #0xffffff00 (012) jeq #0xc0a81400 jt 16 jf 13 (013) ld [38] (014) and #0xffffff00 (015) jeq #0xc0a81400 jt 16 jf 17 (016) ret #65535 (017) ret #0 Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Cc: Arnaldo Carvalho de Melo <acme@infradead.org> Cc: Ben Hutchings <bhutchings@solarflare.com> Cc: Hagen Paul Pfeifer <hagen@jauu.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-04-20 03:27:32 -06:00
net: filter: x86: internal BPF JIT Maps all internal BPF instructions into x86_64 instructions. This patch replaces original BPF x64 JIT with internal BPF x64 JIT. sysctl net.core.bpf_jit_enable is reused as on/off switch. Performance: 1. old BPF JIT and internal BPF JIT generate equivalent x86_64 code. No performance difference is observed for filters that were JIT-able before Example assembler code for BPF filter "tcpdump port 22" original BPF -> old JIT: original BPF -> internal BPF -> new JIT: 0: push %rbp 0: push %rbp 1: mov %rsp,%rbp 1: mov %rsp,%rbp 4: sub $0x60,%rsp 4: sub $0x228,%rsp 8: mov %rbx,-0x8(%rbp) b: mov %rbx,-0x228(%rbp) // prologue 12: mov %r13,-0x220(%rbp) 19: mov %r14,-0x218(%rbp) 20: mov %r15,-0x210(%rbp) 27: xor %eax,%eax // clear A c: xor %ebx,%ebx 29: xor %r13,%r13 // clear X e: mov 0x68(%rdi),%r9d 2c: mov 0x68(%rdi),%r9d 12: sub 0x6c(%rdi),%r9d 30: sub 0x6c(%rdi),%r9d 16: mov 0xd8(%rdi),%r8 34: mov 0xd8(%rdi),%r10 3b: mov %rdi,%rbx 1d: mov $0xc,%esi 3e: mov $0xc,%esi 22: callq 0xffffffffe1021e15 43: callq 0xffffffffe102bd75 27: cmp $0x86dd,%eax 48: cmp $0x86dd,%rax 2c: jne 0x0000000000000069 4f: jne 0x000000000000009a 2e: mov $0x14,%esi 51: mov $0x14,%esi 33: callq 0xffffffffe1021e31 56: callq 0xffffffffe102bd91 38: cmp $0x84,%eax 5b: cmp $0x84,%rax 3d: je 0x0000000000000049 62: je 0x0000000000000074 3f: cmp $0x6,%eax 64: cmp $0x6,%rax 42: je 0x0000000000000049 68: je 0x0000000000000074 44: cmp $0x11,%eax 6a: cmp $0x11,%rax 47: jne 0x00000000000000c6 6e: jne 0x0000000000000117 49: mov $0x36,%esi 74: mov $0x36,%esi 4e: callq 0xffffffffe1021e15 79: callq 0xffffffffe102bd75 53: cmp $0x16,%eax 7e: cmp $0x16,%rax 56: je 0x00000000000000bf 82: je 0x0000000000000110 58: mov $0x38,%esi 88: mov $0x38,%esi 5d: callq 0xffffffffe1021e15 8d: callq 0xffffffffe102bd75 62: cmp $0x16,%eax 92: cmp $0x16,%rax 65: je 0x00000000000000bf 96: je 0x0000000000000110 67: jmp 0x00000000000000c6 98: jmp 0x0000000000000117 69: cmp $0x800,%eax 9a: cmp $0x800,%rax 6e: jne 0x00000000000000c6 a1: jne 0x0000000000000117 70: mov $0x17,%esi a3: mov $0x17,%esi 75: callq 0xffffffffe1021e31 a8: callq 0xffffffffe102bd91 7a: cmp $0x84,%eax ad: cmp $0x84,%rax 7f: je 0x000000000000008b b4: je 0x00000000000000c2 81: cmp $0x6,%eax b6: cmp $0x6,%rax 84: je 0x000000000000008b ba: je 0x00000000000000c2 86: cmp $0x11,%eax bc: cmp $0x11,%rax 89: jne 0x00000000000000c6 c0: jne 0x0000000000000117 8b: mov $0x14,%esi c2: mov $0x14,%esi 90: callq 0xffffffffe1021e15 c7: callq 0xffffffffe102bd75 95: test $0x1fff,%ax cc: test $0x1fff,%rax 99: jne 0x00000000000000c6 d3: jne 0x0000000000000117 d5: mov %rax,%r14 9b: mov $0xe,%esi d8: mov $0xe,%esi a0: callq 0xffffffffe1021e44 dd: callq 0xffffffffe102bd91 // MSH e2: and $0xf,%eax e5: shl $0x2,%eax e8: mov %rax,%r13 eb: mov %r14,%rax ee: mov %r13,%rsi a5: lea 0xe(%rbx),%esi f1: add $0xe,%esi a8: callq 0xffffffffe1021e0d f4: callq 0xffffffffe102bd6d ad: cmp $0x16,%eax f9: cmp $0x16,%rax b0: je 0x00000000000000bf fd: je 0x0000000000000110 ff: mov %r13,%rsi b2: lea 0x10(%rbx),%esi 102: add $0x10,%esi b5: callq 0xffffffffe1021e0d 105: callq 0xffffffffe102bd6d ba: cmp $0x16,%eax 10a: cmp $0x16,%rax bd: jne 0x00000000000000c6 10e: jne 0x0000000000000117 bf: mov $0xffff,%eax 110: mov $0xffff,%eax c4: jmp 0x00000000000000c8 115: jmp 0x000000000000011c c6: xor %eax,%eax 117: mov $0x0,%eax c8: mov -0x8(%rbp),%rbx 11c: mov -0x228(%rbp),%rbx // epilogue cc: leaveq 123: mov -0x220(%rbp),%r13 cd: retq 12a: mov -0x218(%rbp),%r14 131: mov -0x210(%rbp),%r15 138: leaveq 139: retq On fully cached SKBs both JITed functions take 12 nsec to execute. BPF interpreter executes the program in 30 nsec. The difference in generated assembler is due to the following: Old BPF imlements LDX_MSH instruction via sk_load_byte_msh() helper function inside bpf_jit.S. New JIT removes the helper and does it explicitly, so ldx_msh cost is the same for both JITs, but generated code looks longer. New JIT has 4 registers to save, so prologue/epilogue are larger, but the cost is within noise on x64. Old JIT checks whether first insn clears A and if not emits 'xor %eax,%eax'. New JIT clears %rax unconditionally. 2. old BPF JIT doesn't support ANC_NLATTR, ANC_PAY_OFFSET, ANC_RANDOM extensions. New JIT supports all BPF extensions. Performance of such filters improves 2-4 times depending on a filter. The longer the filter the higher performance gain. Synthetic benchmarks with many ancillary loads see 20x speedup which seems to be the maximum gain from JIT Notes: . net.core.bpf_jit_enable=2 + tools/net/bpf_jit_disasm is still functional and can be used to see generated assembler . there are two jit_compile() functions and code flow for classic filters is: sk_attach_filter() - load classic BPF bpf_jit_compile() - try to JIT from classic BPF sk_convert_filter() - convert classic to internal bpf_int_jit_compile() - JIT from internal BPF seccomp and tracing filters will just call bpf_int_jit_compile() Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 20:50:46 -06:00
/* pick a register outside of BPF range for JIT internal work */
bpf, x86: add support for constant blinding This patch adds recently added constant blinding helpers into the x86 eBPF JIT. In the bpf_int_jit_compile() path, requirements are to utilize bpf_jit_blind_constants()/bpf_jit_prog_release_other() pair for rewriting the program into a blinded one, and to map the BPF_REG_AX register to a CPU register. The mapping of BPF_REG_AX is at non-callee saved register r10, and thus shared with cached skb->data used for ld_abs/ind and not in every program type needed. When blinding is not used, there's zero additional overhead in the generated image. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-05-13 11:08:33 -06:00
#define AUX_REG (MAX_BPF_JIT_REG + 1)
net: filter: x86: internal BPF JIT Maps all internal BPF instructions into x86_64 instructions. This patch replaces original BPF x64 JIT with internal BPF x64 JIT. sysctl net.core.bpf_jit_enable is reused as on/off switch. Performance: 1. old BPF JIT and internal BPF JIT generate equivalent x86_64 code. No performance difference is observed for filters that were JIT-able before Example assembler code for BPF filter "tcpdump port 22" original BPF -> old JIT: original BPF -> internal BPF -> new JIT: 0: push %rbp 0: push %rbp 1: mov %rsp,%rbp 1: mov %rsp,%rbp 4: sub $0x60,%rsp 4: sub $0x228,%rsp 8: mov %rbx,-0x8(%rbp) b: mov %rbx,-0x228(%rbp) // prologue 12: mov %r13,-0x220(%rbp) 19: mov %r14,-0x218(%rbp) 20: mov %r15,-0x210(%rbp) 27: xor %eax,%eax // clear A c: xor %ebx,%ebx 29: xor %r13,%r13 // clear X e: mov 0x68(%rdi),%r9d 2c: mov 0x68(%rdi),%r9d 12: sub 0x6c(%rdi),%r9d 30: sub 0x6c(%rdi),%r9d 16: mov 0xd8(%rdi),%r8 34: mov 0xd8(%rdi),%r10 3b: mov %rdi,%rbx 1d: mov $0xc,%esi 3e: mov $0xc,%esi 22: callq 0xffffffffe1021e15 43: callq 0xffffffffe102bd75 27: cmp $0x86dd,%eax 48: cmp $0x86dd,%rax 2c: jne 0x0000000000000069 4f: jne 0x000000000000009a 2e: mov $0x14,%esi 51: mov $0x14,%esi 33: callq 0xffffffffe1021e31 56: callq 0xffffffffe102bd91 38: cmp $0x84,%eax 5b: cmp $0x84,%rax 3d: je 0x0000000000000049 62: je 0x0000000000000074 3f: cmp $0x6,%eax 64: cmp $0x6,%rax 42: je 0x0000000000000049 68: je 0x0000000000000074 44: cmp $0x11,%eax 6a: cmp $0x11,%rax 47: jne 0x00000000000000c6 6e: jne 0x0000000000000117 49: mov $0x36,%esi 74: mov $0x36,%esi 4e: callq 0xffffffffe1021e15 79: callq 0xffffffffe102bd75 53: cmp $0x16,%eax 7e: cmp $0x16,%rax 56: je 0x00000000000000bf 82: je 0x0000000000000110 58: mov $0x38,%esi 88: mov $0x38,%esi 5d: callq 0xffffffffe1021e15 8d: callq 0xffffffffe102bd75 62: cmp $0x16,%eax 92: cmp $0x16,%rax 65: je 0x00000000000000bf 96: je 0x0000000000000110 67: jmp 0x00000000000000c6 98: jmp 0x0000000000000117 69: cmp $0x800,%eax 9a: cmp $0x800,%rax 6e: jne 0x00000000000000c6 a1: jne 0x0000000000000117 70: mov $0x17,%esi a3: mov $0x17,%esi 75: callq 0xffffffffe1021e31 a8: callq 0xffffffffe102bd91 7a: cmp $0x84,%eax ad: cmp $0x84,%rax 7f: je 0x000000000000008b b4: je 0x00000000000000c2 81: cmp $0x6,%eax b6: cmp $0x6,%rax 84: je 0x000000000000008b ba: je 0x00000000000000c2 86: cmp $0x11,%eax bc: cmp $0x11,%rax 89: jne 0x00000000000000c6 c0: jne 0x0000000000000117 8b: mov $0x14,%esi c2: mov $0x14,%esi 90: callq 0xffffffffe1021e15 c7: callq 0xffffffffe102bd75 95: test $0x1fff,%ax cc: test $0x1fff,%rax 99: jne 0x00000000000000c6 d3: jne 0x0000000000000117 d5: mov %rax,%r14 9b: mov $0xe,%esi d8: mov $0xe,%esi a0: callq 0xffffffffe1021e44 dd: callq 0xffffffffe102bd91 // MSH e2: and $0xf,%eax e5: shl $0x2,%eax e8: mov %rax,%r13 eb: mov %r14,%rax ee: mov %r13,%rsi a5: lea 0xe(%rbx),%esi f1: add $0xe,%esi a8: callq 0xffffffffe1021e0d f4: callq 0xffffffffe102bd6d ad: cmp $0x16,%eax f9: cmp $0x16,%rax b0: je 0x00000000000000bf fd: je 0x0000000000000110 ff: mov %r13,%rsi b2: lea 0x10(%rbx),%esi 102: add $0x10,%esi b5: callq 0xffffffffe1021e0d 105: callq 0xffffffffe102bd6d ba: cmp $0x16,%eax 10a: cmp $0x16,%rax bd: jne 0x00000000000000c6 10e: jne 0x0000000000000117 bf: mov $0xffff,%eax 110: mov $0xffff,%eax c4: jmp 0x00000000000000c8 115: jmp 0x000000000000011c c6: xor %eax,%eax 117: mov $0x0,%eax c8: mov -0x8(%rbp),%rbx 11c: mov -0x228(%rbp),%rbx // epilogue cc: leaveq 123: mov -0x220(%rbp),%r13 cd: retq 12a: mov -0x218(%rbp),%r14 131: mov -0x210(%rbp),%r15 138: leaveq 139: retq On fully cached SKBs both JITed functions take 12 nsec to execute. BPF interpreter executes the program in 30 nsec. The difference in generated assembler is due to the following: Old BPF imlements LDX_MSH instruction via sk_load_byte_msh() helper function inside bpf_jit.S. New JIT removes the helper and does it explicitly, so ldx_msh cost is the same for both JITs, but generated code looks longer. New JIT has 4 registers to save, so prologue/epilogue are larger, but the cost is within noise on x64. Old JIT checks whether first insn clears A and if not emits 'xor %eax,%eax'. New JIT clears %rax unconditionally. 2. old BPF JIT doesn't support ANC_NLATTR, ANC_PAY_OFFSET, ANC_RANDOM extensions. New JIT supports all BPF extensions. Performance of such filters improves 2-4 times depending on a filter. The longer the filter the higher performance gain. Synthetic benchmarks with many ancillary loads see 20x speedup which seems to be the maximum gain from JIT Notes: . net.core.bpf_jit_enable=2 + tools/net/bpf_jit_disasm is still functional and can be used to see generated assembler . there are two jit_compile() functions and code flow for classic filters is: sk_attach_filter() - load classic BPF bpf_jit_compile() - try to JIT from classic BPF sk_convert_filter() - convert classic to internal bpf_int_jit_compile() - JIT from internal BPF seccomp and tracing filters will just call bpf_int_jit_compile() Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 20:50:46 -06:00
bpf, x86: add support for constant blinding This patch adds recently added constant blinding helpers into the x86 eBPF JIT. In the bpf_int_jit_compile() path, requirements are to utilize bpf_jit_blind_constants()/bpf_jit_prog_release_other() pair for rewriting the program into a blinded one, and to map the BPF_REG_AX register to a CPU register. The mapping of BPF_REG_AX is at non-callee saved register r10, and thus shared with cached skb->data used for ld_abs/ind and not in every program type needed. When blinding is not used, there's zero additional overhead in the generated image. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-05-13 11:08:33 -06:00
/* The following table maps BPF registers to x64 registers.
*
* x64 register r12 is unused, since if used as base address
* register in load/store instructions, it always needs an
* extra byte of encoding and is callee saved.
*
* r9 caches skb->len - skb->data_len
* r10 caches skb->data, and used for blinding (if enabled)
net: filter: x86: internal BPF JIT Maps all internal BPF instructions into x86_64 instructions. This patch replaces original BPF x64 JIT with internal BPF x64 JIT. sysctl net.core.bpf_jit_enable is reused as on/off switch. Performance: 1. old BPF JIT and internal BPF JIT generate equivalent x86_64 code. No performance difference is observed for filters that were JIT-able before Example assembler code for BPF filter "tcpdump port 22" original BPF -> old JIT: original BPF -> internal BPF -> new JIT: 0: push %rbp 0: push %rbp 1: mov %rsp,%rbp 1: mov %rsp,%rbp 4: sub $0x60,%rsp 4: sub $0x228,%rsp 8: mov %rbx,-0x8(%rbp) b: mov %rbx,-0x228(%rbp) // prologue 12: mov %r13,-0x220(%rbp) 19: mov %r14,-0x218(%rbp) 20: mov %r15,-0x210(%rbp) 27: xor %eax,%eax // clear A c: xor %ebx,%ebx 29: xor %r13,%r13 // clear X e: mov 0x68(%rdi),%r9d 2c: mov 0x68(%rdi),%r9d 12: sub 0x6c(%rdi),%r9d 30: sub 0x6c(%rdi),%r9d 16: mov 0xd8(%rdi),%r8 34: mov 0xd8(%rdi),%r10 3b: mov %rdi,%rbx 1d: mov $0xc,%esi 3e: mov $0xc,%esi 22: callq 0xffffffffe1021e15 43: callq 0xffffffffe102bd75 27: cmp $0x86dd,%eax 48: cmp $0x86dd,%rax 2c: jne 0x0000000000000069 4f: jne 0x000000000000009a 2e: mov $0x14,%esi 51: mov $0x14,%esi 33: callq 0xffffffffe1021e31 56: callq 0xffffffffe102bd91 38: cmp $0x84,%eax 5b: cmp $0x84,%rax 3d: je 0x0000000000000049 62: je 0x0000000000000074 3f: cmp $0x6,%eax 64: cmp $0x6,%rax 42: je 0x0000000000000049 68: je 0x0000000000000074 44: cmp $0x11,%eax 6a: cmp $0x11,%rax 47: jne 0x00000000000000c6 6e: jne 0x0000000000000117 49: mov $0x36,%esi 74: mov $0x36,%esi 4e: callq 0xffffffffe1021e15 79: callq 0xffffffffe102bd75 53: cmp $0x16,%eax 7e: cmp $0x16,%rax 56: je 0x00000000000000bf 82: je 0x0000000000000110 58: mov $0x38,%esi 88: mov $0x38,%esi 5d: callq 0xffffffffe1021e15 8d: callq 0xffffffffe102bd75 62: cmp $0x16,%eax 92: cmp $0x16,%rax 65: je 0x00000000000000bf 96: je 0x0000000000000110 67: jmp 0x00000000000000c6 98: jmp 0x0000000000000117 69: cmp $0x800,%eax 9a: cmp $0x800,%rax 6e: jne 0x00000000000000c6 a1: jne 0x0000000000000117 70: mov $0x17,%esi a3: mov $0x17,%esi 75: callq 0xffffffffe1021e31 a8: callq 0xffffffffe102bd91 7a: cmp $0x84,%eax ad: cmp $0x84,%rax 7f: je 0x000000000000008b b4: je 0x00000000000000c2 81: cmp $0x6,%eax b6: cmp $0x6,%rax 84: je 0x000000000000008b ba: je 0x00000000000000c2 86: cmp $0x11,%eax bc: cmp $0x11,%rax 89: jne 0x00000000000000c6 c0: jne 0x0000000000000117 8b: mov $0x14,%esi c2: mov $0x14,%esi 90: callq 0xffffffffe1021e15 c7: callq 0xffffffffe102bd75 95: test $0x1fff,%ax cc: test $0x1fff,%rax 99: jne 0x00000000000000c6 d3: jne 0x0000000000000117 d5: mov %rax,%r14 9b: mov $0xe,%esi d8: mov $0xe,%esi a0: callq 0xffffffffe1021e44 dd: callq 0xffffffffe102bd91 // MSH e2: and $0xf,%eax e5: shl $0x2,%eax e8: mov %rax,%r13 eb: mov %r14,%rax ee: mov %r13,%rsi a5: lea 0xe(%rbx),%esi f1: add $0xe,%esi a8: callq 0xffffffffe1021e0d f4: callq 0xffffffffe102bd6d ad: cmp $0x16,%eax f9: cmp $0x16,%rax b0: je 0x00000000000000bf fd: je 0x0000000000000110 ff: mov %r13,%rsi b2: lea 0x10(%rbx),%esi 102: add $0x10,%esi b5: callq 0xffffffffe1021e0d 105: callq 0xffffffffe102bd6d ba: cmp $0x16,%eax 10a: cmp $0x16,%rax bd: jne 0x00000000000000c6 10e: jne 0x0000000000000117 bf: mov $0xffff,%eax 110: mov $0xffff,%eax c4: jmp 0x00000000000000c8 115: jmp 0x000000000000011c c6: xor %eax,%eax 117: mov $0x0,%eax c8: mov -0x8(%rbp),%rbx 11c: mov -0x228(%rbp),%rbx // epilogue cc: leaveq 123: mov -0x220(%rbp),%r13 cd: retq 12a: mov -0x218(%rbp),%r14 131: mov -0x210(%rbp),%r15 138: leaveq 139: retq On fully cached SKBs both JITed functions take 12 nsec to execute. BPF interpreter executes the program in 30 nsec. The difference in generated assembler is due to the following: Old BPF imlements LDX_MSH instruction via sk_load_byte_msh() helper function inside bpf_jit.S. New JIT removes the helper and does it explicitly, so ldx_msh cost is the same for both JITs, but generated code looks longer. New JIT has 4 registers to save, so prologue/epilogue are larger, but the cost is within noise on x64. Old JIT checks whether first insn clears A and if not emits 'xor %eax,%eax'. New JIT clears %rax unconditionally. 2. old BPF JIT doesn't support ANC_NLATTR, ANC_PAY_OFFSET, ANC_RANDOM extensions. New JIT supports all BPF extensions. Performance of such filters improves 2-4 times depending on a filter. The longer the filter the higher performance gain. Synthetic benchmarks with many ancillary loads see 20x speedup which seems to be the maximum gain from JIT Notes: . net.core.bpf_jit_enable=2 + tools/net/bpf_jit_disasm is still functional and can be used to see generated assembler . there are two jit_compile() functions and code flow for classic filters is: sk_attach_filter() - load classic BPF bpf_jit_compile() - try to JIT from classic BPF sk_convert_filter() - convert classic to internal bpf_int_jit_compile() - JIT from internal BPF seccomp and tracing filters will just call bpf_int_jit_compile() Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 20:50:46 -06:00
*/
static const int reg2hex[] = {
[BPF_REG_0] = 0, /* rax */
[BPF_REG_1] = 7, /* rdi */
[BPF_REG_2] = 6, /* rsi */
[BPF_REG_3] = 2, /* rdx */
[BPF_REG_4] = 1, /* rcx */
[BPF_REG_5] = 0, /* r8 */
[BPF_REG_6] = 3, /* rbx callee saved */
[BPF_REG_7] = 5, /* r13 callee saved */
[BPF_REG_8] = 6, /* r14 callee saved */
[BPF_REG_9] = 7, /* r15 callee saved */
[BPF_REG_FP] = 5, /* rbp readonly */
bpf, x86: add support for constant blinding This patch adds recently added constant blinding helpers into the x86 eBPF JIT. In the bpf_int_jit_compile() path, requirements are to utilize bpf_jit_blind_constants()/bpf_jit_prog_release_other() pair for rewriting the program into a blinded one, and to map the BPF_REG_AX register to a CPU register. The mapping of BPF_REG_AX is at non-callee saved register r10, and thus shared with cached skb->data used for ld_abs/ind and not in every program type needed. When blinding is not used, there's zero additional overhead in the generated image. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-05-13 11:08:33 -06:00
[BPF_REG_AX] = 2, /* r10 temp register */
net: filter: x86: internal BPF JIT Maps all internal BPF instructions into x86_64 instructions. This patch replaces original BPF x64 JIT with internal BPF x64 JIT. sysctl net.core.bpf_jit_enable is reused as on/off switch. Performance: 1. old BPF JIT and internal BPF JIT generate equivalent x86_64 code. No performance difference is observed for filters that were JIT-able before Example assembler code for BPF filter "tcpdump port 22" original BPF -> old JIT: original BPF -> internal BPF -> new JIT: 0: push %rbp 0: push %rbp 1: mov %rsp,%rbp 1: mov %rsp,%rbp 4: sub $0x60,%rsp 4: sub $0x228,%rsp 8: mov %rbx,-0x8(%rbp) b: mov %rbx,-0x228(%rbp) // prologue 12: mov %r13,-0x220(%rbp) 19: mov %r14,-0x218(%rbp) 20: mov %r15,-0x210(%rbp) 27: xor %eax,%eax // clear A c: xor %ebx,%ebx 29: xor %r13,%r13 // clear X e: mov 0x68(%rdi),%r9d 2c: mov 0x68(%rdi),%r9d 12: sub 0x6c(%rdi),%r9d 30: sub 0x6c(%rdi),%r9d 16: mov 0xd8(%rdi),%r8 34: mov 0xd8(%rdi),%r10 3b: mov %rdi,%rbx 1d: mov $0xc,%esi 3e: mov $0xc,%esi 22: callq 0xffffffffe1021e15 43: callq 0xffffffffe102bd75 27: cmp $0x86dd,%eax 48: cmp $0x86dd,%rax 2c: jne 0x0000000000000069 4f: jne 0x000000000000009a 2e: mov $0x14,%esi 51: mov $0x14,%esi 33: callq 0xffffffffe1021e31 56: callq 0xffffffffe102bd91 38: cmp $0x84,%eax 5b: cmp $0x84,%rax 3d: je 0x0000000000000049 62: je 0x0000000000000074 3f: cmp $0x6,%eax 64: cmp $0x6,%rax 42: je 0x0000000000000049 68: je 0x0000000000000074 44: cmp $0x11,%eax 6a: cmp $0x11,%rax 47: jne 0x00000000000000c6 6e: jne 0x0000000000000117 49: mov $0x36,%esi 74: mov $0x36,%esi 4e: callq 0xffffffffe1021e15 79: callq 0xffffffffe102bd75 53: cmp $0x16,%eax 7e: cmp $0x16,%rax 56: je 0x00000000000000bf 82: je 0x0000000000000110 58: mov $0x38,%esi 88: mov $0x38,%esi 5d: callq 0xffffffffe1021e15 8d: callq 0xffffffffe102bd75 62: cmp $0x16,%eax 92: cmp $0x16,%rax 65: je 0x00000000000000bf 96: je 0x0000000000000110 67: jmp 0x00000000000000c6 98: jmp 0x0000000000000117 69: cmp $0x800,%eax 9a: cmp $0x800,%rax 6e: jne 0x00000000000000c6 a1: jne 0x0000000000000117 70: mov $0x17,%esi a3: mov $0x17,%esi 75: callq 0xffffffffe1021e31 a8: callq 0xffffffffe102bd91 7a: cmp $0x84,%eax ad: cmp $0x84,%rax 7f: je 0x000000000000008b b4: je 0x00000000000000c2 81: cmp $0x6,%eax b6: cmp $0x6,%rax 84: je 0x000000000000008b ba: je 0x00000000000000c2 86: cmp $0x11,%eax bc: cmp $0x11,%rax 89: jne 0x00000000000000c6 c0: jne 0x0000000000000117 8b: mov $0x14,%esi c2: mov $0x14,%esi 90: callq 0xffffffffe1021e15 c7: callq 0xffffffffe102bd75 95: test $0x1fff,%ax cc: test $0x1fff,%rax 99: jne 0x00000000000000c6 d3: jne 0x0000000000000117 d5: mov %rax,%r14 9b: mov $0xe,%esi d8: mov $0xe,%esi a0: callq 0xffffffffe1021e44 dd: callq 0xffffffffe102bd91 // MSH e2: and $0xf,%eax e5: shl $0x2,%eax e8: mov %rax,%r13 eb: mov %r14,%rax ee: mov %r13,%rsi a5: lea 0xe(%rbx),%esi f1: add $0xe,%esi a8: callq 0xffffffffe1021e0d f4: callq 0xffffffffe102bd6d ad: cmp $0x16,%eax f9: cmp $0x16,%rax b0: je 0x00000000000000bf fd: je 0x0000000000000110 ff: mov %r13,%rsi b2: lea 0x10(%rbx),%esi 102: add $0x10,%esi b5: callq 0xffffffffe1021e0d 105: callq 0xffffffffe102bd6d ba: cmp $0x16,%eax 10a: cmp $0x16,%rax bd: jne 0x00000000000000c6 10e: jne 0x0000000000000117 bf: mov $0xffff,%eax 110: mov $0xffff,%eax c4: jmp 0x00000000000000c8 115: jmp 0x000000000000011c c6: xor %eax,%eax 117: mov $0x0,%eax c8: mov -0x8(%rbp),%rbx 11c: mov -0x228(%rbp),%rbx // epilogue cc: leaveq 123: mov -0x220(%rbp),%r13 cd: retq 12a: mov -0x218(%rbp),%r14 131: mov -0x210(%rbp),%r15 138: leaveq 139: retq On fully cached SKBs both JITed functions take 12 nsec to execute. BPF interpreter executes the program in 30 nsec. The difference in generated assembler is due to the following: Old BPF imlements LDX_MSH instruction via sk_load_byte_msh() helper function inside bpf_jit.S. New JIT removes the helper and does it explicitly, so ldx_msh cost is the same for both JITs, but generated code looks longer. New JIT has 4 registers to save, so prologue/epilogue are larger, but the cost is within noise on x64. Old JIT checks whether first insn clears A and if not emits 'xor %eax,%eax'. New JIT clears %rax unconditionally. 2. old BPF JIT doesn't support ANC_NLATTR, ANC_PAY_OFFSET, ANC_RANDOM extensions. New JIT supports all BPF extensions. Performance of such filters improves 2-4 times depending on a filter. The longer the filter the higher performance gain. Synthetic benchmarks with many ancillary loads see 20x speedup which seems to be the maximum gain from JIT Notes: . net.core.bpf_jit_enable=2 + tools/net/bpf_jit_disasm is still functional and can be used to see generated assembler . there are two jit_compile() functions and code flow for classic filters is: sk_attach_filter() - load classic BPF bpf_jit_compile() - try to JIT from classic BPF sk_convert_filter() - convert classic to internal bpf_int_jit_compile() - JIT from internal BPF seccomp and tracing filters will just call bpf_int_jit_compile() Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 20:50:46 -06:00
[AUX_REG] = 3, /* r11 temp register */
};
/* is_ereg() == true if BPF register 'reg' maps to x64 r8..r15
* which need extra byte of encoding.
* rax,rcx,...,rbp have simpler encoding
*/
x86: bpf_jit_comp: Remove inline from static function definitions Let the compiler decide instead. No change in object size x86-64 -O2 no profiling Signed-off-by: Joe Perches <joe@perches.com> Suggested-by: Eric Dumazet <eric.dumazet@gmail.com> Acked-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-12-04 18:01:24 -07:00
static bool is_ereg(u32 reg)
net: filter: x86: internal BPF JIT Maps all internal BPF instructions into x86_64 instructions. This patch replaces original BPF x64 JIT with internal BPF x64 JIT. sysctl net.core.bpf_jit_enable is reused as on/off switch. Performance: 1. old BPF JIT and internal BPF JIT generate equivalent x86_64 code. No performance difference is observed for filters that were JIT-able before Example assembler code for BPF filter "tcpdump port 22" original BPF -> old JIT: original BPF -> internal BPF -> new JIT: 0: push %rbp 0: push %rbp 1: mov %rsp,%rbp 1: mov %rsp,%rbp 4: sub $0x60,%rsp 4: sub $0x228,%rsp 8: mov %rbx,-0x8(%rbp) b: mov %rbx,-0x228(%rbp) // prologue 12: mov %r13,-0x220(%rbp) 19: mov %r14,-0x218(%rbp) 20: mov %r15,-0x210(%rbp) 27: xor %eax,%eax // clear A c: xor %ebx,%ebx 29: xor %r13,%r13 // clear X e: mov 0x68(%rdi),%r9d 2c: mov 0x68(%rdi),%r9d 12: sub 0x6c(%rdi),%r9d 30: sub 0x6c(%rdi),%r9d 16: mov 0xd8(%rdi),%r8 34: mov 0xd8(%rdi),%r10 3b: mov %rdi,%rbx 1d: mov $0xc,%esi 3e: mov $0xc,%esi 22: callq 0xffffffffe1021e15 43: callq 0xffffffffe102bd75 27: cmp $0x86dd,%eax 48: cmp $0x86dd,%rax 2c: jne 0x0000000000000069 4f: jne 0x000000000000009a 2e: mov $0x14,%esi 51: mov $0x14,%esi 33: callq 0xffffffffe1021e31 56: callq 0xffffffffe102bd91 38: cmp $0x84,%eax 5b: cmp $0x84,%rax 3d: je 0x0000000000000049 62: je 0x0000000000000074 3f: cmp $0x6,%eax 64: cmp $0x6,%rax 42: je 0x0000000000000049 68: je 0x0000000000000074 44: cmp $0x11,%eax 6a: cmp $0x11,%rax 47: jne 0x00000000000000c6 6e: jne 0x0000000000000117 49: mov $0x36,%esi 74: mov $0x36,%esi 4e: callq 0xffffffffe1021e15 79: callq 0xffffffffe102bd75 53: cmp $0x16,%eax 7e: cmp $0x16,%rax 56: je 0x00000000000000bf 82: je 0x0000000000000110 58: mov $0x38,%esi 88: mov $0x38,%esi 5d: callq 0xffffffffe1021e15 8d: callq 0xffffffffe102bd75 62: cmp $0x16,%eax 92: cmp $0x16,%rax 65: je 0x00000000000000bf 96: je 0x0000000000000110 67: jmp 0x00000000000000c6 98: jmp 0x0000000000000117 69: cmp $0x800,%eax 9a: cmp $0x800,%rax 6e: jne 0x00000000000000c6 a1: jne 0x0000000000000117 70: mov $0x17,%esi a3: mov $0x17,%esi 75: callq 0xffffffffe1021e31 a8: callq 0xffffffffe102bd91 7a: cmp $0x84,%eax ad: cmp $0x84,%rax 7f: je 0x000000000000008b b4: je 0x00000000000000c2 81: cmp $0x6,%eax b6: cmp $0x6,%rax 84: je 0x000000000000008b ba: je 0x00000000000000c2 86: cmp $0x11,%eax bc: cmp $0x11,%rax 89: jne 0x00000000000000c6 c0: jne 0x0000000000000117 8b: mov $0x14,%esi c2: mov $0x14,%esi 90: callq 0xffffffffe1021e15 c7: callq 0xffffffffe102bd75 95: test $0x1fff,%ax cc: test $0x1fff,%rax 99: jne 0x00000000000000c6 d3: jne 0x0000000000000117 d5: mov %rax,%r14 9b: mov $0xe,%esi d8: mov $0xe,%esi a0: callq 0xffffffffe1021e44 dd: callq 0xffffffffe102bd91 // MSH e2: and $0xf,%eax e5: shl $0x2,%eax e8: mov %rax,%r13 eb: mov %r14,%rax ee: mov %r13,%rsi a5: lea 0xe(%rbx),%esi f1: add $0xe,%esi a8: callq 0xffffffffe1021e0d f4: callq 0xffffffffe102bd6d ad: cmp $0x16,%eax f9: cmp $0x16,%rax b0: je 0x00000000000000bf fd: je 0x0000000000000110 ff: mov %r13,%rsi b2: lea 0x10(%rbx),%esi 102: add $0x10,%esi b5: callq 0xffffffffe1021e0d 105: callq 0xffffffffe102bd6d ba: cmp $0x16,%eax 10a: cmp $0x16,%rax bd: jne 0x00000000000000c6 10e: jne 0x0000000000000117 bf: mov $0xffff,%eax 110: mov $0xffff,%eax c4: jmp 0x00000000000000c8 115: jmp 0x000000000000011c c6: xor %eax,%eax 117: mov $0x0,%eax c8: mov -0x8(%rbp),%rbx 11c: mov -0x228(%rbp),%rbx // epilogue cc: leaveq 123: mov -0x220(%rbp),%r13 cd: retq 12a: mov -0x218(%rbp),%r14 131: mov -0x210(%rbp),%r15 138: leaveq 139: retq On fully cached SKBs both JITed functions take 12 nsec to execute. BPF interpreter executes the program in 30 nsec. The difference in generated assembler is due to the following: Old BPF imlements LDX_MSH instruction via sk_load_byte_msh() helper function inside bpf_jit.S. New JIT removes the helper and does it explicitly, so ldx_msh cost is the same for both JITs, but generated code looks longer. New JIT has 4 registers to save, so prologue/epilogue are larger, but the cost is within noise on x64. Old JIT checks whether first insn clears A and if not emits 'xor %eax,%eax'. New JIT clears %rax unconditionally. 2. old BPF JIT doesn't support ANC_NLATTR, ANC_PAY_OFFSET, ANC_RANDOM extensions. New JIT supports all BPF extensions. Performance of such filters improves 2-4 times depending on a filter. The longer the filter the higher performance gain. Synthetic benchmarks with many ancillary loads see 20x speedup which seems to be the maximum gain from JIT Notes: . net.core.bpf_jit_enable=2 + tools/net/bpf_jit_disasm is still functional and can be used to see generated assembler . there are two jit_compile() functions and code flow for classic filters is: sk_attach_filter() - load classic BPF bpf_jit_compile() - try to JIT from classic BPF sk_convert_filter() - convert classic to internal bpf_int_jit_compile() - JIT from internal BPF seccomp and tracing filters will just call bpf_int_jit_compile() Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 20:50:46 -06:00
{
x86: bpf_jit_comp: Reduce is_ereg() code size Use the (1 << reg) & mask trick to reduce code size. x86-64 size difference -O2 without profiling for various gcc versions: $ size arch/x86/net/bpf_jit_comp.o* text data bss dec hex filename 9266 4 0 9270 2436 arch/x86/net/bpf_jit_comp.o.4.4.new 10042 4 0 10046 273e arch/x86/net/bpf_jit_comp.o.4.4.old 9109 4 0 9113 2399 arch/x86/net/bpf_jit_comp.o.4.6.new 9717 4 0 9721 25f9 arch/x86/net/bpf_jit_comp.o.4.6.old 8789 4 0 8793 2259 arch/x86/net/bpf_jit_comp.o.4.7.new 10245 4 0 10249 2809 arch/x86/net/bpf_jit_comp.o.4.7.old 9671 4 0 9675 25cb arch/x86/net/bpf_jit_comp.o.4.9.new 10679 4 0 10683 29bb arch/x86/net/bpf_jit_comp.o.4.9.old Signed-off-by: Joe Perches <joe@perches.com> Tested-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-12-04 16:00:48 -07:00
return (1 << reg) & (BIT(BPF_REG_5) |
BIT(AUX_REG) |
BIT(BPF_REG_7) |
BIT(BPF_REG_8) |
bpf, x86: add support for constant blinding This patch adds recently added constant blinding helpers into the x86 eBPF JIT. In the bpf_int_jit_compile() path, requirements are to utilize bpf_jit_blind_constants()/bpf_jit_prog_release_other() pair for rewriting the program into a blinded one, and to map the BPF_REG_AX register to a CPU register. The mapping of BPF_REG_AX is at non-callee saved register r10, and thus shared with cached skb->data used for ld_abs/ind and not in every program type needed. When blinding is not used, there's zero additional overhead in the generated image. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-05-13 11:08:33 -06:00
BIT(BPF_REG_9) |
BIT(BPF_REG_AX));
net: filter: x86: internal BPF JIT Maps all internal BPF instructions into x86_64 instructions. This patch replaces original BPF x64 JIT with internal BPF x64 JIT. sysctl net.core.bpf_jit_enable is reused as on/off switch. Performance: 1. old BPF JIT and internal BPF JIT generate equivalent x86_64 code. No performance difference is observed for filters that were JIT-able before Example assembler code for BPF filter "tcpdump port 22" original BPF -> old JIT: original BPF -> internal BPF -> new JIT: 0: push %rbp 0: push %rbp 1: mov %rsp,%rbp 1: mov %rsp,%rbp 4: sub $0x60,%rsp 4: sub $0x228,%rsp 8: mov %rbx,-0x8(%rbp) b: mov %rbx,-0x228(%rbp) // prologue 12: mov %r13,-0x220(%rbp) 19: mov %r14,-0x218(%rbp) 20: mov %r15,-0x210(%rbp) 27: xor %eax,%eax // clear A c: xor %ebx,%ebx 29: xor %r13,%r13 // clear X e: mov 0x68(%rdi),%r9d 2c: mov 0x68(%rdi),%r9d 12: sub 0x6c(%rdi),%r9d 30: sub 0x6c(%rdi),%r9d 16: mov 0xd8(%rdi),%r8 34: mov 0xd8(%rdi),%r10 3b: mov %rdi,%rbx 1d: mov $0xc,%esi 3e: mov $0xc,%esi 22: callq 0xffffffffe1021e15 43: callq 0xffffffffe102bd75 27: cmp $0x86dd,%eax 48: cmp $0x86dd,%rax 2c: jne 0x0000000000000069 4f: jne 0x000000000000009a 2e: mov $0x14,%esi 51: mov $0x14,%esi 33: callq 0xffffffffe1021e31 56: callq 0xffffffffe102bd91 38: cmp $0x84,%eax 5b: cmp $0x84,%rax 3d: je 0x0000000000000049 62: je 0x0000000000000074 3f: cmp $0x6,%eax 64: cmp $0x6,%rax 42: je 0x0000000000000049 68: je 0x0000000000000074 44: cmp $0x11,%eax 6a: cmp $0x11,%rax 47: jne 0x00000000000000c6 6e: jne 0x0000000000000117 49: mov $0x36,%esi 74: mov $0x36,%esi 4e: callq 0xffffffffe1021e15 79: callq 0xffffffffe102bd75 53: cmp $0x16,%eax 7e: cmp $0x16,%rax 56: je 0x00000000000000bf 82: je 0x0000000000000110 58: mov $0x38,%esi 88: mov $0x38,%esi 5d: callq 0xffffffffe1021e15 8d: callq 0xffffffffe102bd75 62: cmp $0x16,%eax 92: cmp $0x16,%rax 65: je 0x00000000000000bf 96: je 0x0000000000000110 67: jmp 0x00000000000000c6 98: jmp 0x0000000000000117 69: cmp $0x800,%eax 9a: cmp $0x800,%rax 6e: jne 0x00000000000000c6 a1: jne 0x0000000000000117 70: mov $0x17,%esi a3: mov $0x17,%esi 75: callq 0xffffffffe1021e31 a8: callq 0xffffffffe102bd91 7a: cmp $0x84,%eax ad: cmp $0x84,%rax 7f: je 0x000000000000008b b4: je 0x00000000000000c2 81: cmp $0x6,%eax b6: cmp $0x6,%rax 84: je 0x000000000000008b ba: je 0x00000000000000c2 86: cmp $0x11,%eax bc: cmp $0x11,%rax 89: jne 0x00000000000000c6 c0: jne 0x0000000000000117 8b: mov $0x14,%esi c2: mov $0x14,%esi 90: callq 0xffffffffe1021e15 c7: callq 0xffffffffe102bd75 95: test $0x1fff,%ax cc: test $0x1fff,%rax 99: jne 0x00000000000000c6 d3: jne 0x0000000000000117 d5: mov %rax,%r14 9b: mov $0xe,%esi d8: mov $0xe,%esi a0: callq 0xffffffffe1021e44 dd: callq 0xffffffffe102bd91 // MSH e2: and $0xf,%eax e5: shl $0x2,%eax e8: mov %rax,%r13 eb: mov %r14,%rax ee: mov %r13,%rsi a5: lea 0xe(%rbx),%esi f1: add $0xe,%esi a8: callq 0xffffffffe1021e0d f4: callq 0xffffffffe102bd6d ad: cmp $0x16,%eax f9: cmp $0x16,%rax b0: je 0x00000000000000bf fd: je 0x0000000000000110 ff: mov %r13,%rsi b2: lea 0x10(%rbx),%esi 102: add $0x10,%esi b5: callq 0xffffffffe1021e0d 105: callq 0xffffffffe102bd6d ba: cmp $0x16,%eax 10a: cmp $0x16,%rax bd: jne 0x00000000000000c6 10e: jne 0x0000000000000117 bf: mov $0xffff,%eax 110: mov $0xffff,%eax c4: jmp 0x00000000000000c8 115: jmp 0x000000000000011c c6: xor %eax,%eax 117: mov $0x0,%eax c8: mov -0x8(%rbp),%rbx 11c: mov -0x228(%rbp),%rbx // epilogue cc: leaveq 123: mov -0x220(%rbp),%r13 cd: retq 12a: mov -0x218(%rbp),%r14 131: mov -0x210(%rbp),%r15 138: leaveq 139: retq On fully cached SKBs both JITed functions take 12 nsec to execute. BPF interpreter executes the program in 30 nsec. The difference in generated assembler is due to the following: Old BPF imlements LDX_MSH instruction via sk_load_byte_msh() helper function inside bpf_jit.S. New JIT removes the helper and does it explicitly, so ldx_msh cost is the same for both JITs, but generated code looks longer. New JIT has 4 registers to save, so prologue/epilogue are larger, but the cost is within noise on x64. Old JIT checks whether first insn clears A and if not emits 'xor %eax,%eax'. New JIT clears %rax unconditionally. 2. old BPF JIT doesn't support ANC_NLATTR, ANC_PAY_OFFSET, ANC_RANDOM extensions. New JIT supports all BPF extensions. Performance of such filters improves 2-4 times depending on a filter. The longer the filter the higher performance gain. Synthetic benchmarks with many ancillary loads see 20x speedup which seems to be the maximum gain from JIT Notes: . net.core.bpf_jit_enable=2 + tools/net/bpf_jit_disasm is still functional and can be used to see generated assembler . there are two jit_compile() functions and code flow for classic filters is: sk_attach_filter() - load classic BPF bpf_jit_compile() - try to JIT from classic BPF sk_convert_filter() - convert classic to internal bpf_int_jit_compile() - JIT from internal BPF seccomp and tracing filters will just call bpf_int_jit_compile() Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 20:50:46 -06:00
}
/* add modifiers if 'reg' maps to x64 registers r8..r15 */
x86: bpf_jit_comp: Remove inline from static function definitions Let the compiler decide instead. No change in object size x86-64 -O2 no profiling Signed-off-by: Joe Perches <joe@perches.com> Suggested-by: Eric Dumazet <eric.dumazet@gmail.com> Acked-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-12-04 18:01:24 -07:00
static u8 add_1mod(u8 byte, u32 reg)
net: filter: x86: internal BPF JIT Maps all internal BPF instructions into x86_64 instructions. This patch replaces original BPF x64 JIT with internal BPF x64 JIT. sysctl net.core.bpf_jit_enable is reused as on/off switch. Performance: 1. old BPF JIT and internal BPF JIT generate equivalent x86_64 code. No performance difference is observed for filters that were JIT-able before Example assembler code for BPF filter "tcpdump port 22" original BPF -> old JIT: original BPF -> internal BPF -> new JIT: 0: push %rbp 0: push %rbp 1: mov %rsp,%rbp 1: mov %rsp,%rbp 4: sub $0x60,%rsp 4: sub $0x228,%rsp 8: mov %rbx,-0x8(%rbp) b: mov %rbx,-0x228(%rbp) // prologue 12: mov %r13,-0x220(%rbp) 19: mov %r14,-0x218(%rbp) 20: mov %r15,-0x210(%rbp) 27: xor %eax,%eax // clear A c: xor %ebx,%ebx 29: xor %r13,%r13 // clear X e: mov 0x68(%rdi),%r9d 2c: mov 0x68(%rdi),%r9d 12: sub 0x6c(%rdi),%r9d 30: sub 0x6c(%rdi),%r9d 16: mov 0xd8(%rdi),%r8 34: mov 0xd8(%rdi),%r10 3b: mov %rdi,%rbx 1d: mov $0xc,%esi 3e: mov $0xc,%esi 22: callq 0xffffffffe1021e15 43: callq 0xffffffffe102bd75 27: cmp $0x86dd,%eax 48: cmp $0x86dd,%rax 2c: jne 0x0000000000000069 4f: jne 0x000000000000009a 2e: mov $0x14,%esi 51: mov $0x14,%esi 33: callq 0xffffffffe1021e31 56: callq 0xffffffffe102bd91 38: cmp $0x84,%eax 5b: cmp $0x84,%rax 3d: je 0x0000000000000049 62: je 0x0000000000000074 3f: cmp $0x6,%eax 64: cmp $0x6,%rax 42: je 0x0000000000000049 68: je 0x0000000000000074 44: cmp $0x11,%eax 6a: cmp $0x11,%rax 47: jne 0x00000000000000c6 6e: jne 0x0000000000000117 49: mov $0x36,%esi 74: mov $0x36,%esi 4e: callq 0xffffffffe1021e15 79: callq 0xffffffffe102bd75 53: cmp $0x16,%eax 7e: cmp $0x16,%rax 56: je 0x00000000000000bf 82: je 0x0000000000000110 58: mov $0x38,%esi 88: mov $0x38,%esi 5d: callq 0xffffffffe1021e15 8d: callq 0xffffffffe102bd75 62: cmp $0x16,%eax 92: cmp $0x16,%rax 65: je 0x00000000000000bf 96: je 0x0000000000000110 67: jmp 0x00000000000000c6 98: jmp 0x0000000000000117 69: cmp $0x800,%eax 9a: cmp $0x800,%rax 6e: jne 0x00000000000000c6 a1: jne 0x0000000000000117 70: mov $0x17,%esi a3: mov $0x17,%esi 75: callq 0xffffffffe1021e31 a8: callq 0xffffffffe102bd91 7a: cmp $0x84,%eax ad: cmp $0x84,%rax 7f: je 0x000000000000008b b4: je 0x00000000000000c2 81: cmp $0x6,%eax b6: cmp $0x6,%rax 84: je 0x000000000000008b ba: je 0x00000000000000c2 86: cmp $0x11,%eax bc: cmp $0x11,%rax 89: jne 0x00000000000000c6 c0: jne 0x0000000000000117 8b: mov $0x14,%esi c2: mov $0x14,%esi 90: callq 0xffffffffe1021e15 c7: callq 0xffffffffe102bd75 95: test $0x1fff,%ax cc: test $0x1fff,%rax 99: jne 0x00000000000000c6 d3: jne 0x0000000000000117 d5: mov %rax,%r14 9b: mov $0xe,%esi d8: mov $0xe,%esi a0: callq 0xffffffffe1021e44 dd: callq 0xffffffffe102bd91 // MSH e2: and $0xf,%eax e5: shl $0x2,%eax e8: mov %rax,%r13 eb: mov %r14,%rax ee: mov %r13,%rsi a5: lea 0xe(%rbx),%esi f1: add $0xe,%esi a8: callq 0xffffffffe1021e0d f4: callq 0xffffffffe102bd6d ad: cmp $0x16,%eax f9: cmp $0x16,%rax b0: je 0x00000000000000bf fd: je 0x0000000000000110 ff: mov %r13,%rsi b2: lea 0x10(%rbx),%esi 102: add $0x10,%esi b5: callq 0xffffffffe1021e0d 105: callq 0xffffffffe102bd6d ba: cmp $0x16,%eax 10a: cmp $0x16,%rax bd: jne 0x00000000000000c6 10e: jne 0x0000000000000117 bf: mov $0xffff,%eax 110: mov $0xffff,%eax c4: jmp 0x00000000000000c8 115: jmp 0x000000000000011c c6: xor %eax,%eax 117: mov $0x0,%eax c8: mov -0x8(%rbp),%rbx 11c: mov -0x228(%rbp),%rbx // epilogue cc: leaveq 123: mov -0x220(%rbp),%r13 cd: retq 12a: mov -0x218(%rbp),%r14 131: mov -0x210(%rbp),%r15 138: leaveq 139: retq On fully cached SKBs both JITed functions take 12 nsec to execute. BPF interpreter executes the program in 30 nsec. The difference in generated assembler is due to the following: Old BPF imlements LDX_MSH instruction via sk_load_byte_msh() helper function inside bpf_jit.S. New JIT removes the helper and does it explicitly, so ldx_msh cost is the same for both JITs, but generated code looks longer. New JIT has 4 registers to save, so prologue/epilogue are larger, but the cost is within noise on x64. Old JIT checks whether first insn clears A and if not emits 'xor %eax,%eax'. New JIT clears %rax unconditionally. 2. old BPF JIT doesn't support ANC_NLATTR, ANC_PAY_OFFSET, ANC_RANDOM extensions. New JIT supports all BPF extensions. Performance of such filters improves 2-4 times depending on a filter. The longer the filter the higher performance gain. Synthetic benchmarks with many ancillary loads see 20x speedup which seems to be the maximum gain from JIT Notes: . net.core.bpf_jit_enable=2 + tools/net/bpf_jit_disasm is still functional and can be used to see generated assembler . there are two jit_compile() functions and code flow for classic filters is: sk_attach_filter() - load classic BPF bpf_jit_compile() - try to JIT from classic BPF sk_convert_filter() - convert classic to internal bpf_int_jit_compile() - JIT from internal BPF seccomp and tracing filters will just call bpf_int_jit_compile() Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 20:50:46 -06:00
{
if (is_ereg(reg))
byte |= 1;
return byte;
}
x86: bpf_jit_comp: Remove inline from static function definitions Let the compiler decide instead. No change in object size x86-64 -O2 no profiling Signed-off-by: Joe Perches <joe@perches.com> Suggested-by: Eric Dumazet <eric.dumazet@gmail.com> Acked-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-12-04 18:01:24 -07:00
static u8 add_2mod(u8 byte, u32 r1, u32 r2)
net: filter: x86: internal BPF JIT Maps all internal BPF instructions into x86_64 instructions. This patch replaces original BPF x64 JIT with internal BPF x64 JIT. sysctl net.core.bpf_jit_enable is reused as on/off switch. Performance: 1. old BPF JIT and internal BPF JIT generate equivalent x86_64 code. No performance difference is observed for filters that were JIT-able before Example assembler code for BPF filter "tcpdump port 22" original BPF -> old JIT: original BPF -> internal BPF -> new JIT: 0: push %rbp 0: push %rbp 1: mov %rsp,%rbp 1: mov %rsp,%rbp 4: sub $0x60,%rsp 4: sub $0x228,%rsp 8: mov %rbx,-0x8(%rbp) b: mov %rbx,-0x228(%rbp) // prologue 12: mov %r13,-0x220(%rbp) 19: mov %r14,-0x218(%rbp) 20: mov %r15,-0x210(%rbp) 27: xor %eax,%eax // clear A c: xor %ebx,%ebx 29: xor %r13,%r13 // clear X e: mov 0x68(%rdi),%r9d 2c: mov 0x68(%rdi),%r9d 12: sub 0x6c(%rdi),%r9d 30: sub 0x6c(%rdi),%r9d 16: mov 0xd8(%rdi),%r8 34: mov 0xd8(%rdi),%r10 3b: mov %rdi,%rbx 1d: mov $0xc,%esi 3e: mov $0xc,%esi 22: callq 0xffffffffe1021e15 43: callq 0xffffffffe102bd75 27: cmp $0x86dd,%eax 48: cmp $0x86dd,%rax 2c: jne 0x0000000000000069 4f: jne 0x000000000000009a 2e: mov $0x14,%esi 51: mov $0x14,%esi 33: callq 0xffffffffe1021e31 56: callq 0xffffffffe102bd91 38: cmp $0x84,%eax 5b: cmp $0x84,%rax 3d: je 0x0000000000000049 62: je 0x0000000000000074 3f: cmp $0x6,%eax 64: cmp $0x6,%rax 42: je 0x0000000000000049 68: je 0x0000000000000074 44: cmp $0x11,%eax 6a: cmp $0x11,%rax 47: jne 0x00000000000000c6 6e: jne 0x0000000000000117 49: mov $0x36,%esi 74: mov $0x36,%esi 4e: callq 0xffffffffe1021e15 79: callq 0xffffffffe102bd75 53: cmp $0x16,%eax 7e: cmp $0x16,%rax 56: je 0x00000000000000bf 82: je 0x0000000000000110 58: mov $0x38,%esi 88: mov $0x38,%esi 5d: callq 0xffffffffe1021e15 8d: callq 0xffffffffe102bd75 62: cmp $0x16,%eax 92: cmp $0x16,%rax 65: je 0x00000000000000bf 96: je 0x0000000000000110 67: jmp 0x00000000000000c6 98: jmp 0x0000000000000117 69: cmp $0x800,%eax 9a: cmp $0x800,%rax 6e: jne 0x00000000000000c6 a1: jne 0x0000000000000117 70: mov $0x17,%esi a3: mov $0x17,%esi 75: callq 0xffffffffe1021e31 a8: callq 0xffffffffe102bd91 7a: cmp $0x84,%eax ad: cmp $0x84,%rax 7f: je 0x000000000000008b b4: je 0x00000000000000c2 81: cmp $0x6,%eax b6: cmp $0x6,%rax 84: je 0x000000000000008b ba: je 0x00000000000000c2 86: cmp $0x11,%eax bc: cmp $0x11,%rax 89: jne 0x00000000000000c6 c0: jne 0x0000000000000117 8b: mov $0x14,%esi c2: mov $0x14,%esi 90: callq 0xffffffffe1021e15 c7: callq 0xffffffffe102bd75 95: test $0x1fff,%ax cc: test $0x1fff,%rax 99: jne 0x00000000000000c6 d3: jne 0x0000000000000117 d5: mov %rax,%r14 9b: mov $0xe,%esi d8: mov $0xe,%esi a0: callq 0xffffffffe1021e44 dd: callq 0xffffffffe102bd91 // MSH e2: and $0xf,%eax e5: shl $0x2,%eax e8: mov %rax,%r13 eb: mov %r14,%rax ee: mov %r13,%rsi a5: lea 0xe(%rbx),%esi f1: add $0xe,%esi a8: callq 0xffffffffe1021e0d f4: callq 0xffffffffe102bd6d ad: cmp $0x16,%eax f9: cmp $0x16,%rax b0: je 0x00000000000000bf fd: je 0x0000000000000110 ff: mov %r13,%rsi b2: lea 0x10(%rbx),%esi 102: add $0x10,%esi b5: callq 0xffffffffe1021e0d 105: callq 0xffffffffe102bd6d ba: cmp $0x16,%eax 10a: cmp $0x16,%rax bd: jne 0x00000000000000c6 10e: jne 0x0000000000000117 bf: mov $0xffff,%eax 110: mov $0xffff,%eax c4: jmp 0x00000000000000c8 115: jmp 0x000000000000011c c6: xor %eax,%eax 117: mov $0x0,%eax c8: mov -0x8(%rbp),%rbx 11c: mov -0x228(%rbp),%rbx // epilogue cc: leaveq 123: mov -0x220(%rbp),%r13 cd: retq 12a: mov -0x218(%rbp),%r14 131: mov -0x210(%rbp),%r15 138: leaveq 139: retq On fully cached SKBs both JITed functions take 12 nsec to execute. BPF interpreter executes the program in 30 nsec. The difference in generated assembler is due to the following: Old BPF imlements LDX_MSH instruction via sk_load_byte_msh() helper function inside bpf_jit.S. New JIT removes the helper and does it explicitly, so ldx_msh cost is the same for both JITs, but generated code looks longer. New JIT has 4 registers to save, so prologue/epilogue are larger, but the cost is within noise on x64. Old JIT checks whether first insn clears A and if not emits 'xor %eax,%eax'. New JIT clears %rax unconditionally. 2. old BPF JIT doesn't support ANC_NLATTR, ANC_PAY_OFFSET, ANC_RANDOM extensions. New JIT supports all BPF extensions. Performance of such filters improves 2-4 times depending on a filter. The longer the filter the higher performance gain. Synthetic benchmarks with many ancillary loads see 20x speedup which seems to be the maximum gain from JIT Notes: . net.core.bpf_jit_enable=2 + tools/net/bpf_jit_disasm is still functional and can be used to see generated assembler . there are two jit_compile() functions and code flow for classic filters is: sk_attach_filter() - load classic BPF bpf_jit_compile() - try to JIT from classic BPF sk_convert_filter() - convert classic to internal bpf_int_jit_compile() - JIT from internal BPF seccomp and tracing filters will just call bpf_int_jit_compile() Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 20:50:46 -06:00
{
if (is_ereg(r1))
byte |= 1;
if (is_ereg(r2))
byte |= 4;
return byte;
}
net: filter: cleanup A/X name usage The macro 'A' used in internal BPF interpreter: #define A regs[insn->a_reg] was easily confused with the name of classic BPF register 'A', since 'A' would mean two different things depending on context. This patch is trying to clean up the naming and clarify its usage in the following way: - A and X are names of two classic BPF registers - BPF_REG_A denotes internal BPF register R0 used to map classic register A in internal BPF programs generated from classic - BPF_REG_X denotes internal BPF register R7 used to map classic register X in internal BPF programs generated from classic - internal BPF instruction format: struct sock_filter_int { __u8 code; /* opcode */ __u8 dst_reg:4; /* dest register */ __u8 src_reg:4; /* source register */ __s16 off; /* signed offset */ __s32 imm; /* signed immediate constant */ }; - BPF_X/BPF_K is 1 bit used to encode source operand of instruction In classic: BPF_X - means use register X as source operand BPF_K - means use 32-bit immediate as source operand In internal: BPF_X - means use 'src_reg' register as source operand BPF_K - means use 32-bit immediate as source operand Suggested-by: Chema Gonzalez <chema@google.com> Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Acked-by: Daniel Borkmann <dborkman@redhat.com> Acked-by: Chema Gonzalez <chema@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-06-06 15:46:06 -06:00
/* encode 'dst_reg' register into x64 opcode 'byte' */
x86: bpf_jit_comp: Remove inline from static function definitions Let the compiler decide instead. No change in object size x86-64 -O2 no profiling Signed-off-by: Joe Perches <joe@perches.com> Suggested-by: Eric Dumazet <eric.dumazet@gmail.com> Acked-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-12-04 18:01:24 -07:00
static u8 add_1reg(u8 byte, u32 dst_reg)
net: filter: x86: internal BPF JIT Maps all internal BPF instructions into x86_64 instructions. This patch replaces original BPF x64 JIT with internal BPF x64 JIT. sysctl net.core.bpf_jit_enable is reused as on/off switch. Performance: 1. old BPF JIT and internal BPF JIT generate equivalent x86_64 code. No performance difference is observed for filters that were JIT-able before Example assembler code for BPF filter "tcpdump port 22" original BPF -> old JIT: original BPF -> internal BPF -> new JIT: 0: push %rbp 0: push %rbp 1: mov %rsp,%rbp 1: mov %rsp,%rbp 4: sub $0x60,%rsp 4: sub $0x228,%rsp 8: mov %rbx,-0x8(%rbp) b: mov %rbx,-0x228(%rbp) // prologue 12: mov %r13,-0x220(%rbp) 19: mov %r14,-0x218(%rbp) 20: mov %r15,-0x210(%rbp) 27: xor %eax,%eax // clear A c: xor %ebx,%ebx 29: xor %r13,%r13 // clear X e: mov 0x68(%rdi),%r9d 2c: mov 0x68(%rdi),%r9d 12: sub 0x6c(%rdi),%r9d 30: sub 0x6c(%rdi),%r9d 16: mov 0xd8(%rdi),%r8 34: mov 0xd8(%rdi),%r10 3b: mov %rdi,%rbx 1d: mov $0xc,%esi 3e: mov $0xc,%esi 22: callq 0xffffffffe1021e15 43: callq 0xffffffffe102bd75 27: cmp $0x86dd,%eax 48: cmp $0x86dd,%rax 2c: jne 0x0000000000000069 4f: jne 0x000000000000009a 2e: mov $0x14,%esi 51: mov $0x14,%esi 33: callq 0xffffffffe1021e31 56: callq 0xffffffffe102bd91 38: cmp $0x84,%eax 5b: cmp $0x84,%rax 3d: je 0x0000000000000049 62: je 0x0000000000000074 3f: cmp $0x6,%eax 64: cmp $0x6,%rax 42: je 0x0000000000000049 68: je 0x0000000000000074 44: cmp $0x11,%eax 6a: cmp $0x11,%rax 47: jne 0x00000000000000c6 6e: jne 0x0000000000000117 49: mov $0x36,%esi 74: mov $0x36,%esi 4e: callq 0xffffffffe1021e15 79: callq 0xffffffffe102bd75 53: cmp $0x16,%eax 7e: cmp $0x16,%rax 56: je 0x00000000000000bf 82: je 0x0000000000000110 58: mov $0x38,%esi 88: mov $0x38,%esi 5d: callq 0xffffffffe1021e15 8d: callq 0xffffffffe102bd75 62: cmp $0x16,%eax 92: cmp $0x16,%rax 65: je 0x00000000000000bf 96: je 0x0000000000000110 67: jmp 0x00000000000000c6 98: jmp 0x0000000000000117 69: cmp $0x800,%eax 9a: cmp $0x800,%rax 6e: jne 0x00000000000000c6 a1: jne 0x0000000000000117 70: mov $0x17,%esi a3: mov $0x17,%esi 75: callq 0xffffffffe1021e31 a8: callq 0xffffffffe102bd91 7a: cmp $0x84,%eax ad: cmp $0x84,%rax 7f: je 0x000000000000008b b4: je 0x00000000000000c2 81: cmp $0x6,%eax b6: cmp $0x6,%rax 84: je 0x000000000000008b ba: je 0x00000000000000c2 86: cmp $0x11,%eax bc: cmp $0x11,%rax 89: jne 0x00000000000000c6 c0: jne 0x0000000000000117 8b: mov $0x14,%esi c2: mov $0x14,%esi 90: callq 0xffffffffe1021e15 c7: callq 0xffffffffe102bd75 95: test $0x1fff,%ax cc: test $0x1fff,%rax 99: jne 0x00000000000000c6 d3: jne 0x0000000000000117 d5: mov %rax,%r14 9b: mov $0xe,%esi d8: mov $0xe,%esi a0: callq 0xffffffffe1021e44 dd: callq 0xffffffffe102bd91 // MSH e2: and $0xf,%eax e5: shl $0x2,%eax e8: mov %rax,%r13 eb: mov %r14,%rax ee: mov %r13,%rsi a5: lea 0xe(%rbx),%esi f1: add $0xe,%esi a8: callq 0xffffffffe1021e0d f4: callq 0xffffffffe102bd6d ad: cmp $0x16,%eax f9: cmp $0x16,%rax b0: je 0x00000000000000bf fd: je 0x0000000000000110 ff: mov %r13,%rsi b2: lea 0x10(%rbx),%esi 102: add $0x10,%esi b5: callq 0xffffffffe1021e0d 105: callq 0xffffffffe102bd6d ba: cmp $0x16,%eax 10a: cmp $0x16,%rax bd: jne 0x00000000000000c6 10e: jne 0x0000000000000117 bf: mov $0xffff,%eax 110: mov $0xffff,%eax c4: jmp 0x00000000000000c8 115: jmp 0x000000000000011c c6: xor %eax,%eax 117: mov $0x0,%eax c8: mov -0x8(%rbp),%rbx 11c: mov -0x228(%rbp),%rbx // epilogue cc: leaveq 123: mov -0x220(%rbp),%r13 cd: retq 12a: mov -0x218(%rbp),%r14 131: mov -0x210(%rbp),%r15 138: leaveq 139: retq On fully cached SKBs both JITed functions take 12 nsec to execute. BPF interpreter executes the program in 30 nsec. The difference in generated assembler is due to the following: Old BPF imlements LDX_MSH instruction via sk_load_byte_msh() helper function inside bpf_jit.S. New JIT removes the helper and does it explicitly, so ldx_msh cost is the same for both JITs, but generated code looks longer. New JIT has 4 registers to save, so prologue/epilogue are larger, but the cost is within noise on x64. Old JIT checks whether first insn clears A and if not emits 'xor %eax,%eax'. New JIT clears %rax unconditionally. 2. old BPF JIT doesn't support ANC_NLATTR, ANC_PAY_OFFSET, ANC_RANDOM extensions. New JIT supports all BPF extensions. Performance of such filters improves 2-4 times depending on a filter. The longer the filter the higher performance gain. Synthetic benchmarks with many ancillary loads see 20x speedup which seems to be the maximum gain from JIT Notes: . net.core.bpf_jit_enable=2 + tools/net/bpf_jit_disasm is still functional and can be used to see generated assembler . there are two jit_compile() functions and code flow for classic filters is: sk_attach_filter() - load classic BPF bpf_jit_compile() - try to JIT from classic BPF sk_convert_filter() - convert classic to internal bpf_int_jit_compile() - JIT from internal BPF seccomp and tracing filters will just call bpf_int_jit_compile() Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 20:50:46 -06:00
{
net: filter: cleanup A/X name usage The macro 'A' used in internal BPF interpreter: #define A regs[insn->a_reg] was easily confused with the name of classic BPF register 'A', since 'A' would mean two different things depending on context. This patch is trying to clean up the naming and clarify its usage in the following way: - A and X are names of two classic BPF registers - BPF_REG_A denotes internal BPF register R0 used to map classic register A in internal BPF programs generated from classic - BPF_REG_X denotes internal BPF register R7 used to map classic register X in internal BPF programs generated from classic - internal BPF instruction format: struct sock_filter_int { __u8 code; /* opcode */ __u8 dst_reg:4; /* dest register */ __u8 src_reg:4; /* source register */ __s16 off; /* signed offset */ __s32 imm; /* signed immediate constant */ }; - BPF_X/BPF_K is 1 bit used to encode source operand of instruction In classic: BPF_X - means use register X as source operand BPF_K - means use 32-bit immediate as source operand In internal: BPF_X - means use 'src_reg' register as source operand BPF_K - means use 32-bit immediate as source operand Suggested-by: Chema Gonzalez <chema@google.com> Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Acked-by: Daniel Borkmann <dborkman@redhat.com> Acked-by: Chema Gonzalez <chema@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-06-06 15:46:06 -06:00
return byte + reg2hex[dst_reg];
net: filter: x86: internal BPF JIT Maps all internal BPF instructions into x86_64 instructions. This patch replaces original BPF x64 JIT with internal BPF x64 JIT. sysctl net.core.bpf_jit_enable is reused as on/off switch. Performance: 1. old BPF JIT and internal BPF JIT generate equivalent x86_64 code. No performance difference is observed for filters that were JIT-able before Example assembler code for BPF filter "tcpdump port 22" original BPF -> old JIT: original BPF -> internal BPF -> new JIT: 0: push %rbp 0: push %rbp 1: mov %rsp,%rbp 1: mov %rsp,%rbp 4: sub $0x60,%rsp 4: sub $0x228,%rsp 8: mov %rbx,-0x8(%rbp) b: mov %rbx,-0x228(%rbp) // prologue 12: mov %r13,-0x220(%rbp) 19: mov %r14,-0x218(%rbp) 20: mov %r15,-0x210(%rbp) 27: xor %eax,%eax // clear A c: xor %ebx,%ebx 29: xor %r13,%r13 // clear X e: mov 0x68(%rdi),%r9d 2c: mov 0x68(%rdi),%r9d 12: sub 0x6c(%rdi),%r9d 30: sub 0x6c(%rdi),%r9d 16: mov 0xd8(%rdi),%r8 34: mov 0xd8(%rdi),%r10 3b: mov %rdi,%rbx 1d: mov $0xc,%esi 3e: mov $0xc,%esi 22: callq 0xffffffffe1021e15 43: callq 0xffffffffe102bd75 27: cmp $0x86dd,%eax 48: cmp $0x86dd,%rax 2c: jne 0x0000000000000069 4f: jne 0x000000000000009a 2e: mov $0x14,%esi 51: mov $0x14,%esi 33: callq 0xffffffffe1021e31 56: callq 0xffffffffe102bd91 38: cmp $0x84,%eax 5b: cmp $0x84,%rax 3d: je 0x0000000000000049 62: je 0x0000000000000074 3f: cmp $0x6,%eax 64: cmp $0x6,%rax 42: je 0x0000000000000049 68: je 0x0000000000000074 44: cmp $0x11,%eax 6a: cmp $0x11,%rax 47: jne 0x00000000000000c6 6e: jne 0x0000000000000117 49: mov $0x36,%esi 74: mov $0x36,%esi 4e: callq 0xffffffffe1021e15 79: callq 0xffffffffe102bd75 53: cmp $0x16,%eax 7e: cmp $0x16,%rax 56: je 0x00000000000000bf 82: je 0x0000000000000110 58: mov $0x38,%esi 88: mov $0x38,%esi 5d: callq 0xffffffffe1021e15 8d: callq 0xffffffffe102bd75 62: cmp $0x16,%eax 92: cmp $0x16,%rax 65: je 0x00000000000000bf 96: je 0x0000000000000110 67: jmp 0x00000000000000c6 98: jmp 0x0000000000000117 69: cmp $0x800,%eax 9a: cmp $0x800,%rax 6e: jne 0x00000000000000c6 a1: jne 0x0000000000000117 70: mov $0x17,%esi a3: mov $0x17,%esi 75: callq 0xffffffffe1021e31 a8: callq 0xffffffffe102bd91 7a: cmp $0x84,%eax ad: cmp $0x84,%rax 7f: je 0x000000000000008b b4: je 0x00000000000000c2 81: cmp $0x6,%eax b6: cmp $0x6,%rax 84: je 0x000000000000008b ba: je 0x00000000000000c2 86: cmp $0x11,%eax bc: cmp $0x11,%rax 89: jne 0x00000000000000c6 c0: jne 0x0000000000000117 8b: mov $0x14,%esi c2: mov $0x14,%esi 90: callq 0xffffffffe1021e15 c7: callq 0xffffffffe102bd75 95: test $0x1fff,%ax cc: test $0x1fff,%rax 99: jne 0x00000000000000c6 d3: jne 0x0000000000000117 d5: mov %rax,%r14 9b: mov $0xe,%esi d8: mov $0xe,%esi a0: callq 0xffffffffe1021e44 dd: callq 0xffffffffe102bd91 // MSH e2: and $0xf,%eax e5: shl $0x2,%eax e8: mov %rax,%r13 eb: mov %r14,%rax ee: mov %r13,%rsi a5: lea 0xe(%rbx),%esi f1: add $0xe,%esi a8: callq 0xffffffffe1021e0d f4: callq 0xffffffffe102bd6d ad: cmp $0x16,%eax f9: cmp $0x16,%rax b0: je 0x00000000000000bf fd: je 0x0000000000000110 ff: mov %r13,%rsi b2: lea 0x10(%rbx),%esi 102: add $0x10,%esi b5: callq 0xffffffffe1021e0d 105: callq 0xffffffffe102bd6d ba: cmp $0x16,%eax 10a: cmp $0x16,%rax bd: jne 0x00000000000000c6 10e: jne 0x0000000000000117 bf: mov $0xffff,%eax 110: mov $0xffff,%eax c4: jmp 0x00000000000000c8 115: jmp 0x000000000000011c c6: xor %eax,%eax 117: mov $0x0,%eax c8: mov -0x8(%rbp),%rbx 11c: mov -0x228(%rbp),%rbx // epilogue cc: leaveq 123: mov -0x220(%rbp),%r13 cd: retq 12a: mov -0x218(%rbp),%r14 131: mov -0x210(%rbp),%r15 138: leaveq 139: retq On fully cached SKBs both JITed functions take 12 nsec to execute. BPF interpreter executes the program in 30 nsec. The difference in generated assembler is due to the following: Old BPF imlements LDX_MSH instruction via sk_load_byte_msh() helper function inside bpf_jit.S. New JIT removes the helper and does it explicitly, so ldx_msh cost is the same for both JITs, but generated code looks longer. New JIT has 4 registers to save, so prologue/epilogue are larger, but the cost is within noise on x64. Old JIT checks whether first insn clears A and if not emits 'xor %eax,%eax'. New JIT clears %rax unconditionally. 2. old BPF JIT doesn't support ANC_NLATTR, ANC_PAY_OFFSET, ANC_RANDOM extensions. New JIT supports all BPF extensions. Performance of such filters improves 2-4 times depending on a filter. The longer the filter the higher performance gain. Synthetic benchmarks with many ancillary loads see 20x speedup which seems to be the maximum gain from JIT Notes: . net.core.bpf_jit_enable=2 + tools/net/bpf_jit_disasm is still functional and can be used to see generated assembler . there are two jit_compile() functions and code flow for classic filters is: sk_attach_filter() - load classic BPF bpf_jit_compile() - try to JIT from classic BPF sk_convert_filter() - convert classic to internal bpf_int_jit_compile() - JIT from internal BPF seccomp and tracing filters will just call bpf_int_jit_compile() Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 20:50:46 -06:00
}
net: filter: cleanup A/X name usage The macro 'A' used in internal BPF interpreter: #define A regs[insn->a_reg] was easily confused with the name of classic BPF register 'A', since 'A' would mean two different things depending on context. This patch is trying to clean up the naming and clarify its usage in the following way: - A and X are names of two classic BPF registers - BPF_REG_A denotes internal BPF register R0 used to map classic register A in internal BPF programs generated from classic - BPF_REG_X denotes internal BPF register R7 used to map classic register X in internal BPF programs generated from classic - internal BPF instruction format: struct sock_filter_int { __u8 code; /* opcode */ __u8 dst_reg:4; /* dest register */ __u8 src_reg:4; /* source register */ __s16 off; /* signed offset */ __s32 imm; /* signed immediate constant */ }; - BPF_X/BPF_K is 1 bit used to encode source operand of instruction In classic: BPF_X - means use register X as source operand BPF_K - means use 32-bit immediate as source operand In internal: BPF_X - means use 'src_reg' register as source operand BPF_K - means use 32-bit immediate as source operand Suggested-by: Chema Gonzalez <chema@google.com> Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Acked-by: Daniel Borkmann <dborkman@redhat.com> Acked-by: Chema Gonzalez <chema@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-06-06 15:46:06 -06:00
/* encode 'dst_reg' and 'src_reg' registers into x64 opcode 'byte' */
x86: bpf_jit_comp: Remove inline from static function definitions Let the compiler decide instead. No change in object size x86-64 -O2 no profiling Signed-off-by: Joe Perches <joe@perches.com> Suggested-by: Eric Dumazet <eric.dumazet@gmail.com> Acked-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-12-04 18:01:24 -07:00
static u8 add_2reg(u8 byte, u32 dst_reg, u32 src_reg)
net: filter: x86: internal BPF JIT Maps all internal BPF instructions into x86_64 instructions. This patch replaces original BPF x64 JIT with internal BPF x64 JIT. sysctl net.core.bpf_jit_enable is reused as on/off switch. Performance: 1. old BPF JIT and internal BPF JIT generate equivalent x86_64 code. No performance difference is observed for filters that were JIT-able before Example assembler code for BPF filter "tcpdump port 22" original BPF -> old JIT: original BPF -> internal BPF -> new JIT: 0: push %rbp 0: push %rbp 1: mov %rsp,%rbp 1: mov %rsp,%rbp 4: sub $0x60,%rsp 4: sub $0x228,%rsp 8: mov %rbx,-0x8(%rbp) b: mov %rbx,-0x228(%rbp) // prologue 12: mov %r13,-0x220(%rbp) 19: mov %r14,-0x218(%rbp) 20: mov %r15,-0x210(%rbp) 27: xor %eax,%eax // clear A c: xor %ebx,%ebx 29: xor %r13,%r13 // clear X e: mov 0x68(%rdi),%r9d 2c: mov 0x68(%rdi),%r9d 12: sub 0x6c(%rdi),%r9d 30: sub 0x6c(%rdi),%r9d 16: mov 0xd8(%rdi),%r8 34: mov 0xd8(%rdi),%r10 3b: mov %rdi,%rbx 1d: mov $0xc,%esi 3e: mov $0xc,%esi 22: callq 0xffffffffe1021e15 43: callq 0xffffffffe102bd75 27: cmp $0x86dd,%eax 48: cmp $0x86dd,%rax 2c: jne 0x0000000000000069 4f: jne 0x000000000000009a 2e: mov $0x14,%esi 51: mov $0x14,%esi 33: callq 0xffffffffe1021e31 56: callq 0xffffffffe102bd91 38: cmp $0x84,%eax 5b: cmp $0x84,%rax 3d: je 0x0000000000000049 62: je 0x0000000000000074 3f: cmp $0x6,%eax 64: cmp $0x6,%rax 42: je 0x0000000000000049 68: je 0x0000000000000074 44: cmp $0x11,%eax 6a: cmp $0x11,%rax 47: jne 0x00000000000000c6 6e: jne 0x0000000000000117 49: mov $0x36,%esi 74: mov $0x36,%esi 4e: callq 0xffffffffe1021e15 79: callq 0xffffffffe102bd75 53: cmp $0x16,%eax 7e: cmp $0x16,%rax 56: je 0x00000000000000bf 82: je 0x0000000000000110 58: mov $0x38,%esi 88: mov $0x38,%esi 5d: callq 0xffffffffe1021e15 8d: callq 0xffffffffe102bd75 62: cmp $0x16,%eax 92: cmp $0x16,%rax 65: je 0x00000000000000bf 96: je 0x0000000000000110 67: jmp 0x00000000000000c6 98: jmp 0x0000000000000117 69: cmp $0x800,%eax 9a: cmp $0x800,%rax 6e: jne 0x00000000000000c6 a1: jne 0x0000000000000117 70: mov $0x17,%esi a3: mov $0x17,%esi 75: callq 0xffffffffe1021e31 a8: callq 0xffffffffe102bd91 7a: cmp $0x84,%eax ad: cmp $0x84,%rax 7f: je 0x000000000000008b b4: je 0x00000000000000c2 81: cmp $0x6,%eax b6: cmp $0x6,%rax 84: je 0x000000000000008b ba: je 0x00000000000000c2 86: cmp $0x11,%eax bc: cmp $0x11,%rax 89: jne 0x00000000000000c6 c0: jne 0x0000000000000117 8b: mov $0x14,%esi c2: mov $0x14,%esi 90: callq 0xffffffffe1021e15 c7: callq 0xffffffffe102bd75 95: test $0x1fff,%ax cc: test $0x1fff,%rax 99: jne 0x00000000000000c6 d3: jne 0x0000000000000117 d5: mov %rax,%r14 9b: mov $0xe,%esi d8: mov $0xe,%esi a0: callq 0xffffffffe1021e44 dd: callq 0xffffffffe102bd91 // MSH e2: and $0xf,%eax e5: shl $0x2,%eax e8: mov %rax,%r13 eb: mov %r14,%rax ee: mov %r13,%rsi a5: lea 0xe(%rbx),%esi f1: add $0xe,%esi a8: callq 0xffffffffe1021e0d f4: callq 0xffffffffe102bd6d ad: cmp $0x16,%eax f9: cmp $0x16,%rax b0: je 0x00000000000000bf fd: je 0x0000000000000110 ff: mov %r13,%rsi b2: lea 0x10(%rbx),%esi 102: add $0x10,%esi b5: callq 0xffffffffe1021e0d 105: callq 0xffffffffe102bd6d ba: cmp $0x16,%eax 10a: cmp $0x16,%rax bd: jne 0x00000000000000c6 10e: jne 0x0000000000000117 bf: mov $0xffff,%eax 110: mov $0xffff,%eax c4: jmp 0x00000000000000c8 115: jmp 0x000000000000011c c6: xor %eax,%eax 117: mov $0x0,%eax c8: mov -0x8(%rbp),%rbx 11c: mov -0x228(%rbp),%rbx // epilogue cc: leaveq 123: mov -0x220(%rbp),%r13 cd: retq 12a: mov -0x218(%rbp),%r14 131: mov -0x210(%rbp),%r15 138: leaveq 139: retq On fully cached SKBs both JITed functions take 12 nsec to execute. BPF interpreter executes the program in 30 nsec. The difference in generated assembler is due to the following: Old BPF imlements LDX_MSH instruction via sk_load_byte_msh() helper function inside bpf_jit.S. New JIT removes the helper and does it explicitly, so ldx_msh cost is the same for both JITs, but generated code looks longer. New JIT has 4 registers to save, so prologue/epilogue are larger, but the cost is within noise on x64. Old JIT checks whether first insn clears A and if not emits 'xor %eax,%eax'. New JIT clears %rax unconditionally. 2. old BPF JIT doesn't support ANC_NLATTR, ANC_PAY_OFFSET, ANC_RANDOM extensions. New JIT supports all BPF extensions. Performance of such filters improves 2-4 times depending on a filter. The longer the filter the higher performance gain. Synthetic benchmarks with many ancillary loads see 20x speedup which seems to be the maximum gain from JIT Notes: . net.core.bpf_jit_enable=2 + tools/net/bpf_jit_disasm is still functional and can be used to see generated assembler . there are two jit_compile() functions and code flow for classic filters is: sk_attach_filter() - load classic BPF bpf_jit_compile() - try to JIT from classic BPF sk_convert_filter() - convert classic to internal bpf_int_jit_compile() - JIT from internal BPF seccomp and tracing filters will just call bpf_int_jit_compile() Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 20:50:46 -06:00
{
net: filter: cleanup A/X name usage The macro 'A' used in internal BPF interpreter: #define A regs[insn->a_reg] was easily confused with the name of classic BPF register 'A', since 'A' would mean two different things depending on context. This patch is trying to clean up the naming and clarify its usage in the following way: - A and X are names of two classic BPF registers - BPF_REG_A denotes internal BPF register R0 used to map classic register A in internal BPF programs generated from classic - BPF_REG_X denotes internal BPF register R7 used to map classic register X in internal BPF programs generated from classic - internal BPF instruction format: struct sock_filter_int { __u8 code; /* opcode */ __u8 dst_reg:4; /* dest register */ __u8 src_reg:4; /* source register */ __s16 off; /* signed offset */ __s32 imm; /* signed immediate constant */ }; - BPF_X/BPF_K is 1 bit used to encode source operand of instruction In classic: BPF_X - means use register X as source operand BPF_K - means use 32-bit immediate as source operand In internal: BPF_X - means use 'src_reg' register as source operand BPF_K - means use 32-bit immediate as source operand Suggested-by: Chema Gonzalez <chema@google.com> Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Acked-by: Daniel Borkmann <dborkman@redhat.com> Acked-by: Chema Gonzalez <chema@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-06-06 15:46:06 -06:00
return byte + reg2hex[dst_reg] + (reg2hex[src_reg] << 3);
net: filter: x86: internal BPF JIT Maps all internal BPF instructions into x86_64 instructions. This patch replaces original BPF x64 JIT with internal BPF x64 JIT. sysctl net.core.bpf_jit_enable is reused as on/off switch. Performance: 1. old BPF JIT and internal BPF JIT generate equivalent x86_64 code. No performance difference is observed for filters that were JIT-able before Example assembler code for BPF filter "tcpdump port 22" original BPF -> old JIT: original BPF -> internal BPF -> new JIT: 0: push %rbp 0: push %rbp 1: mov %rsp,%rbp 1: mov %rsp,%rbp 4: sub $0x60,%rsp 4: sub $0x228,%rsp 8: mov %rbx,-0x8(%rbp) b: mov %rbx,-0x228(%rbp) // prologue 12: mov %r13,-0x220(%rbp) 19: mov %r14,-0x218(%rbp) 20: mov %r15,-0x210(%rbp) 27: xor %eax,%eax // clear A c: xor %ebx,%ebx 29: xor %r13,%r13 // clear X e: mov 0x68(%rdi),%r9d 2c: mov 0x68(%rdi),%r9d 12: sub 0x6c(%rdi),%r9d 30: sub 0x6c(%rdi),%r9d 16: mov 0xd8(%rdi),%r8 34: mov 0xd8(%rdi),%r10 3b: mov %rdi,%rbx 1d: mov $0xc,%esi 3e: mov $0xc,%esi 22: callq 0xffffffffe1021e15 43: callq 0xffffffffe102bd75 27: cmp $0x86dd,%eax 48: cmp $0x86dd,%rax 2c: jne 0x0000000000000069 4f: jne 0x000000000000009a 2e: mov $0x14,%esi 51: mov $0x14,%esi 33: callq 0xffffffffe1021e31 56: callq 0xffffffffe102bd91 38: cmp $0x84,%eax 5b: cmp $0x84,%rax 3d: je 0x0000000000000049 62: je 0x0000000000000074 3f: cmp $0x6,%eax 64: cmp $0x6,%rax 42: je 0x0000000000000049 68: je 0x0000000000000074 44: cmp $0x11,%eax 6a: cmp $0x11,%rax 47: jne 0x00000000000000c6 6e: jne 0x0000000000000117 49: mov $0x36,%esi 74: mov $0x36,%esi 4e: callq 0xffffffffe1021e15 79: callq 0xffffffffe102bd75 53: cmp $0x16,%eax 7e: cmp $0x16,%rax 56: je 0x00000000000000bf 82: je 0x0000000000000110 58: mov $0x38,%esi 88: mov $0x38,%esi 5d: callq 0xffffffffe1021e15 8d: callq 0xffffffffe102bd75 62: cmp $0x16,%eax 92: cmp $0x16,%rax 65: je 0x00000000000000bf 96: je 0x0000000000000110 67: jmp 0x00000000000000c6 98: jmp 0x0000000000000117 69: cmp $0x800,%eax 9a: cmp $0x800,%rax 6e: jne 0x00000000000000c6 a1: jne 0x0000000000000117 70: mov $0x17,%esi a3: mov $0x17,%esi 75: callq 0xffffffffe1021e31 a8: callq 0xffffffffe102bd91 7a: cmp $0x84,%eax ad: cmp $0x84,%rax 7f: je 0x000000000000008b b4: je 0x00000000000000c2 81: cmp $0x6,%eax b6: cmp $0x6,%rax 84: je 0x000000000000008b ba: je 0x00000000000000c2 86: cmp $0x11,%eax bc: cmp $0x11,%rax 89: jne 0x00000000000000c6 c0: jne 0x0000000000000117 8b: mov $0x14,%esi c2: mov $0x14,%esi 90: callq 0xffffffffe1021e15 c7: callq 0xffffffffe102bd75 95: test $0x1fff,%ax cc: test $0x1fff,%rax 99: jne 0x00000000000000c6 d3: jne 0x0000000000000117 d5: mov %rax,%r14 9b: mov $0xe,%esi d8: mov $0xe,%esi a0: callq 0xffffffffe1021e44 dd: callq 0xffffffffe102bd91 // MSH e2: and $0xf,%eax e5: shl $0x2,%eax e8: mov %rax,%r13 eb: mov %r14,%rax ee: mov %r13,%rsi a5: lea 0xe(%rbx),%esi f1: add $0xe,%esi a8: callq 0xffffffffe1021e0d f4: callq 0xffffffffe102bd6d ad: cmp $0x16,%eax f9: cmp $0x16,%rax b0: je 0x00000000000000bf fd: je 0x0000000000000110 ff: mov %r13,%rsi b2: lea 0x10(%rbx),%esi 102: add $0x10,%esi b5: callq 0xffffffffe1021e0d 105: callq 0xffffffffe102bd6d ba: cmp $0x16,%eax 10a: cmp $0x16,%rax bd: jne 0x00000000000000c6 10e: jne 0x0000000000000117 bf: mov $0xffff,%eax 110: mov $0xffff,%eax c4: jmp 0x00000000000000c8 115: jmp 0x000000000000011c c6: xor %eax,%eax 117: mov $0x0,%eax c8: mov -0x8(%rbp),%rbx 11c: mov -0x228(%rbp),%rbx // epilogue cc: leaveq 123: mov -0x220(%rbp),%r13 cd: retq 12a: mov -0x218(%rbp),%r14 131: mov -0x210(%rbp),%r15 138: leaveq 139: retq On fully cached SKBs both JITed functions take 12 nsec to execute. BPF interpreter executes the program in 30 nsec. The difference in generated assembler is due to the following: Old BPF imlements LDX_MSH instruction via sk_load_byte_msh() helper function inside bpf_jit.S. New JIT removes the helper and does it explicitly, so ldx_msh cost is the same for both JITs, but generated code looks longer. New JIT has 4 registers to save, so prologue/epilogue are larger, but the cost is within noise on x64. Old JIT checks whether first insn clears A and if not emits 'xor %eax,%eax'. New JIT clears %rax unconditionally. 2. old BPF JIT doesn't support ANC_NLATTR, ANC_PAY_OFFSET, ANC_RANDOM extensions. New JIT supports all BPF extensions. Performance of such filters improves 2-4 times depending on a filter. The longer the filter the higher performance gain. Synthetic benchmarks with many ancillary loads see 20x speedup which seems to be the maximum gain from JIT Notes: . net.core.bpf_jit_enable=2 + tools/net/bpf_jit_disasm is still functional and can be used to see generated assembler . there are two jit_compile() functions and code flow for classic filters is: sk_attach_filter() - load classic BPF bpf_jit_compile() - try to JIT from classic BPF sk_convert_filter() - convert classic to internal bpf_int_jit_compile() - JIT from internal BPF seccomp and tracing filters will just call bpf_int_jit_compile() Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 20:50:46 -06:00
}
net: bpf: consolidate JIT binary allocator Introduced in commit 314beb9bcabf ("x86: bpf_jit_comp: secure bpf jit against spraying attacks") and later on replicated in aa2d2c73c21f ("s390/bpf,jit: address randomize and write protect jit code") for s390 architecture, write protection for BPF JIT images got added and a random start address of the JIT code, so that it's not on a page boundary anymore. Since both use a very similar allocator for the BPF binary header, we can consolidate this code into the BPF core as it's mostly JIT independant anyway. This will also allow for future archs that support DEBUG_SET_MODULE_RONX to just reuse instead of reimplementing it. JIT tested on x86_64 and s390x with BPF test suite. Signed-off-by: Daniel Borkmann <dborkman@redhat.com> Acked-by: Alexei Starovoitov <ast@plumgrid.com> Cc: Eric Dumazet <edumazet@google.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-08 00:04:47 -06:00
static void jit_fill_hole(void *area, unsigned int size)
{
/* fill whole space with int3 instructions */
memset(area, 0xcc, size);
}
net: filter: x86: split bpf_jit_compile() Split bpf_jit_compile() into two functions to improve readability of for(pass++) loop. The change follows similar style of JIT compilers for arm, powerpc, s390 The body of new do_jit() was not reformatted to reduce noise in this patch, since the following patch replaces most of it. Tested with BPF testsuite. Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 20:50:45 -06:00
struct jit_context {
bpf: x86: fix epilogue generation for eBPF programs classic BPF has a restriction that last insn is always BPF_RET. eBPF doesn't have BPF_RET instruction and this restriction. It has BPF_EXIT insn which can appear anywhere in the program one or more times and it doesn't have to be last insn. Fix eBPF JIT to emit epilogue when first BPF_EXIT is seen and all other BPF_EXIT instructions will be emitted as jump. Since jump offset to epilogue is computed as: jmp_offset = ctx->cleanup_addr - addrs[i] we need to change type of cleanup_addr to signed to compute the offset as: (long long) ((int)20 - (int)30) instead of: (long long) ((unsigned int)20 - (int)30) Fixes: 622582786c9e ("net: filter: x86: internal BPF JIT") Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-11-29 15:46:13 -07:00
int cleanup_addr; /* epilogue code offset */
net: filter: x86: internal BPF JIT Maps all internal BPF instructions into x86_64 instructions. This patch replaces original BPF x64 JIT with internal BPF x64 JIT. sysctl net.core.bpf_jit_enable is reused as on/off switch. Performance: 1. old BPF JIT and internal BPF JIT generate equivalent x86_64 code. No performance difference is observed for filters that were JIT-able before Example assembler code for BPF filter "tcpdump port 22" original BPF -> old JIT: original BPF -> internal BPF -> new JIT: 0: push %rbp 0: push %rbp 1: mov %rsp,%rbp 1: mov %rsp,%rbp 4: sub $0x60,%rsp 4: sub $0x228,%rsp 8: mov %rbx,-0x8(%rbp) b: mov %rbx,-0x228(%rbp) // prologue 12: mov %r13,-0x220(%rbp) 19: mov %r14,-0x218(%rbp) 20: mov %r15,-0x210(%rbp) 27: xor %eax,%eax // clear A c: xor %ebx,%ebx 29: xor %r13,%r13 // clear X e: mov 0x68(%rdi),%r9d 2c: mov 0x68(%rdi),%r9d 12: sub 0x6c(%rdi),%r9d 30: sub 0x6c(%rdi),%r9d 16: mov 0xd8(%rdi),%r8 34: mov 0xd8(%rdi),%r10 3b: mov %rdi,%rbx 1d: mov $0xc,%esi 3e: mov $0xc,%esi 22: callq 0xffffffffe1021e15 43: callq 0xffffffffe102bd75 27: cmp $0x86dd,%eax 48: cmp $0x86dd,%rax 2c: jne 0x0000000000000069 4f: jne 0x000000000000009a 2e: mov $0x14,%esi 51: mov $0x14,%esi 33: callq 0xffffffffe1021e31 56: callq 0xffffffffe102bd91 38: cmp $0x84,%eax 5b: cmp $0x84,%rax 3d: je 0x0000000000000049 62: je 0x0000000000000074 3f: cmp $0x6,%eax 64: cmp $0x6,%rax 42: je 0x0000000000000049 68: je 0x0000000000000074 44: cmp $0x11,%eax 6a: cmp $0x11,%rax 47: jne 0x00000000000000c6 6e: jne 0x0000000000000117 49: mov $0x36,%esi 74: mov $0x36,%esi 4e: callq 0xffffffffe1021e15 79: callq 0xffffffffe102bd75 53: cmp $0x16,%eax 7e: cmp $0x16,%rax 56: je 0x00000000000000bf 82: je 0x0000000000000110 58: mov $0x38,%esi 88: mov $0x38,%esi 5d: callq 0xffffffffe1021e15 8d: callq 0xffffffffe102bd75 62: cmp $0x16,%eax 92: cmp $0x16,%rax 65: je 0x00000000000000bf 96: je 0x0000000000000110 67: jmp 0x00000000000000c6 98: jmp 0x0000000000000117 69: cmp $0x800,%eax 9a: cmp $0x800,%rax 6e: jne 0x00000000000000c6 a1: jne 0x0000000000000117 70: mov $0x17,%esi a3: mov $0x17,%esi 75: callq 0xffffffffe1021e31 a8: callq 0xffffffffe102bd91 7a: cmp $0x84,%eax ad: cmp $0x84,%rax 7f: je 0x000000000000008b b4: je 0x00000000000000c2 81: cmp $0x6,%eax b6: cmp $0x6,%rax 84: je 0x000000000000008b ba: je 0x00000000000000c2 86: cmp $0x11,%eax bc: cmp $0x11,%rax 89: jne 0x00000000000000c6 c0: jne 0x0000000000000117 8b: mov $0x14,%esi c2: mov $0x14,%esi 90: callq 0xffffffffe1021e15 c7: callq 0xffffffffe102bd75 95: test $0x1fff,%ax cc: test $0x1fff,%rax 99: jne 0x00000000000000c6 d3: jne 0x0000000000000117 d5: mov %rax,%r14 9b: mov $0xe,%esi d8: mov $0xe,%esi a0: callq 0xffffffffe1021e44 dd: callq 0xffffffffe102bd91 // MSH e2: and $0xf,%eax e5: shl $0x2,%eax e8: mov %rax,%r13 eb: mov %r14,%rax ee: mov %r13,%rsi a5: lea 0xe(%rbx),%esi f1: add $0xe,%esi a8: callq 0xffffffffe1021e0d f4: callq 0xffffffffe102bd6d ad: cmp $0x16,%eax f9: cmp $0x16,%rax b0: je 0x00000000000000bf fd: je 0x0000000000000110 ff: mov %r13,%rsi b2: lea 0x10(%rbx),%esi 102: add $0x10,%esi b5: callq 0xffffffffe1021e0d 105: callq 0xffffffffe102bd6d ba: cmp $0x16,%eax 10a: cmp $0x16,%rax bd: jne 0x00000000000000c6 10e: jne 0x0000000000000117 bf: mov $0xffff,%eax 110: mov $0xffff,%eax c4: jmp 0x00000000000000c8 115: jmp 0x000000000000011c c6: xor %eax,%eax 117: mov $0x0,%eax c8: mov -0x8(%rbp),%rbx 11c: mov -0x228(%rbp),%rbx // epilogue cc: leaveq 123: mov -0x220(%rbp),%r13 cd: retq 12a: mov -0x218(%rbp),%r14 131: mov -0x210(%rbp),%r15 138: leaveq 139: retq On fully cached SKBs both JITed functions take 12 nsec to execute. BPF interpreter executes the program in 30 nsec. The difference in generated assembler is due to the following: Old BPF imlements LDX_MSH instruction via sk_load_byte_msh() helper function inside bpf_jit.S. New JIT removes the helper and does it explicitly, so ldx_msh cost is the same for both JITs, but generated code looks longer. New JIT has 4 registers to save, so prologue/epilogue are larger, but the cost is within noise on x64. Old JIT checks whether first insn clears A and if not emits 'xor %eax,%eax'. New JIT clears %rax unconditionally. 2. old BPF JIT doesn't support ANC_NLATTR, ANC_PAY_OFFSET, ANC_RANDOM extensions. New JIT supports all BPF extensions. Performance of such filters improves 2-4 times depending on a filter. The longer the filter the higher performance gain. Synthetic benchmarks with many ancillary loads see 20x speedup which seems to be the maximum gain from JIT Notes: . net.core.bpf_jit_enable=2 + tools/net/bpf_jit_disasm is still functional and can be used to see generated assembler . there are two jit_compile() functions and code flow for classic filters is: sk_attach_filter() - load classic BPF bpf_jit_compile() - try to JIT from classic BPF sk_convert_filter() - convert classic to internal bpf_int_jit_compile() - JIT from internal BPF seccomp and tracing filters will just call bpf_int_jit_compile() Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 20:50:46 -06:00
bool seen_ld_abs;
bpf, x86: add support for constant blinding This patch adds recently added constant blinding helpers into the x86 eBPF JIT. In the bpf_int_jit_compile() path, requirements are to utilize bpf_jit_blind_constants()/bpf_jit_prog_release_other() pair for rewriting the program into a blinded one, and to map the BPF_REG_AX register to a CPU register. The mapping of BPF_REG_AX is at non-callee saved register r10, and thus shared with cached skb->data used for ld_abs/ind and not in every program type needed. When blinding is not used, there's zero additional overhead in the generated image. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-05-13 11:08:33 -06:00
bool seen_ax_reg;
net: filter: x86: split bpf_jit_compile() Split bpf_jit_compile() into two functions to improve readability of for(pass++) loop. The change follows similar style of JIT compilers for arm, powerpc, s390 The body of new do_jit() was not reformatted to reduce noise in this patch, since the following patch replaces most of it. Tested with BPF testsuite. Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 20:50:45 -06:00
};
x86: bpf_jit: fix two bugs in eBPF JIT compiler 1. JIT compiler using multi-pass approach to converge to final image size, since x86 instructions are variable length. It starts with large gaps between instructions (so some jumps may use imm32 instead of imm8) and iterates until total program size is the same as in previous pass. This algorithm works only if program size is strictly decreasing. Programs that use LD_ABS insn need additional code in prologue, but it was not emitted during 1st pass, so there was a chance that 2nd pass would adjust imm32->imm8 jump offsets to the same number of bytes as increase in prologue, which may cause algorithm to erroneously decide that size converged. Fix it by always emitting largest prologue in the first pass which is detected by oldproglen==0 check. Also change error check condition 'proglen != oldproglen' to fail gracefully. 2. while staring at the code realized that 64-byte buffer may not be enough when 1st insn is large, so increase it to 128 to avoid buffer overflow (theoretical maximum size of prologue+div is 109) and add runtime check. Fixes: 622582786c9e ("net: filter: x86: internal BPF JIT") Reported-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Tested-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-10-10 21:30:23 -06:00
/* maximum number of bytes emitted while JITing one eBPF insn */
#define BPF_MAX_INSN_SIZE 128
#define BPF_INSN_SAFETY 64
x86: bpf_jit: implement bpf_tail_call() helper bpf_tail_call() arguments: ctx - context pointer jmp_table - one of BPF_MAP_TYPE_PROG_ARRAY maps used as the jump table index - index in the jump table In this implementation x64 JIT bypasses stack unwind and jumps into the callee program after prologue, so the callee program reuses the same stack. The logic can be roughly expressed in C like: u32 tail_call_cnt; void *jumptable[2] = { &&label1, &&label2 }; int bpf_prog1(void *ctx) { label1: ... } int bpf_prog2(void *ctx) { label2: ... } int bpf_prog1(void *ctx) { ... if (tail_call_cnt++ < MAX_TAIL_CALL_CNT) goto *jumptable[index]; ... and pass my 'ctx' to callee ... ... fall through if no entry in jumptable ... } Note that 'skip current program epilogue and next program prologue' is an optimization. Other JITs don't have to do it the same way. >From safety point of view it's valid as well, since programs always initialize the stack before use, so any residue in the stack left by the current program is not going be read. The same verifier checks are done for the calls from the kernel into all bpf programs. Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-19 17:59:04 -06:00
#define STACKSIZE \
(MAX_BPF_STACK + \
32 /* space for rbx, r13, r14, r15 */ + \
8 /* space for skb_copy_bits() buffer */)
bpf: move clearing of A/X into classic to eBPF migration prologue Back in the days where eBPF (or back then "internal BPF" ;->) was not exposed to user space, and only the classic BPF programs internally translated into eBPF programs, we missed the fact that for classic BPF A and X needed to be cleared. It was fixed back then via 83d5b7ef99c9 ("net: filter: initialize A and X registers"), and thus classic BPF specifics were added to the eBPF interpreter core to work around it. This added some confusion for JIT developers later on that take the eBPF interpreter code as an example for deriving their JIT. F.e. in f75298f5c3fe ("s390/bpf: clear correct BPF accumulator register"), at least X could leak stack memory. Furthermore, since this is only needed for classic BPF translations and not for eBPF (verifier takes care that read access to regs cannot be done uninitialized), more complexity is added to JITs as they need to determine whether they deal with migrations or native eBPF where they can just omit clearing A/X in their prologue and thus reduce image size a bit, see f.e. cde66c2d88da ("s390/bpf: Only clear A and X for converted BPF programs"). In other cases (x86, arm64), A and X is being cleared in the prologue also for eBPF case, which is unnecessary. Lets move this into the BPF migration in bpf_convert_filter() where it actually belongs as long as the number of eBPF JITs are still few. It can thus be done generically; allowing us to remove the quirk from __bpf_prog_run() and to slightly reduce JIT image size in case of eBPF, while reducing code duplication on this matter in current(/future) eBPF JITs. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Reviewed-by: Michael Holzheu <holzheu@linux.vnet.ibm.com> Tested-by: Michael Holzheu <holzheu@linux.vnet.ibm.com> Cc: Zi Shen Lim <zlim.lnx@gmail.com> Cc: Yang Shi <yang.shi@linaro.org> Acked-by: Yang Shi <yang.shi@linaro.org> Acked-by: Zi Shen Lim <zlim.lnx@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-12-17 15:51:54 -07:00
#define PROLOGUE_SIZE 48
x86: bpf_jit: implement bpf_tail_call() helper bpf_tail_call() arguments: ctx - context pointer jmp_table - one of BPF_MAP_TYPE_PROG_ARRAY maps used as the jump table index - index in the jump table In this implementation x64 JIT bypasses stack unwind and jumps into the callee program after prologue, so the callee program reuses the same stack. The logic can be roughly expressed in C like: u32 tail_call_cnt; void *jumptable[2] = { &&label1, &&label2 }; int bpf_prog1(void *ctx) { label1: ... } int bpf_prog2(void *ctx) { label2: ... } int bpf_prog1(void *ctx) { ... if (tail_call_cnt++ < MAX_TAIL_CALL_CNT) goto *jumptable[index]; ... and pass my 'ctx' to callee ... ... fall through if no entry in jumptable ... } Note that 'skip current program epilogue and next program prologue' is an optimization. Other JITs don't have to do it the same way. >From safety point of view it's valid as well, since programs always initialize the stack before use, so any residue in the stack left by the current program is not going be read. The same verifier checks are done for the calls from the kernel into all bpf programs. Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-19 17:59:04 -06:00
/* emit x64 prologue code for BPF program and check it's size.
* bpf_tail_call helper will skip it while jumping into another program
*/
static void emit_prologue(u8 **pprog)
net: filter: Just In Time compiler for x86-64 In order to speedup packet filtering, here is an implementation of a JIT compiler for x86_64 It is disabled by default, and must be enabled by the admin. echo 1 >/proc/sys/net/core/bpf_jit_enable It uses module_alloc() and module_free() to get memory in the 2GB text kernel range since we call helpers functions from the generated code. EAX : BPF A accumulator EBX : BPF X accumulator RDI : pointer to skb (first argument given to JIT function) RBP : frame pointer (even if CONFIG_FRAME_POINTER=n) r9d : skb->len - skb->data_len (headlen) r8 : skb->data To get a trace of generated code, use : echo 2 >/proc/sys/net/core/bpf_jit_enable Example of generated code : # tcpdump -p -n -s 0 -i eth1 host 192.168.20.0/24 flen=18 proglen=147 pass=3 image=ffffffffa00b5000 JIT code: ffffffffa00b5000: 55 48 89 e5 48 83 ec 60 48 89 5d f8 44 8b 4f 60 JIT code: ffffffffa00b5010: 44 2b 4f 64 4c 8b 87 b8 00 00 00 be 0c 00 00 00 JIT code: ffffffffa00b5020: e8 24 7b f7 e0 3d 00 08 00 00 75 28 be 1a 00 00 JIT code: ffffffffa00b5030: 00 e8 fe 7a f7 e0 24 00 3d 00 14 a8 c0 74 49 be JIT code: ffffffffa00b5040: 1e 00 00 00 e8 eb 7a f7 e0 24 00 3d 00 14 a8 c0 JIT code: ffffffffa00b5050: 74 36 eb 3b 3d 06 08 00 00 74 07 3d 35 80 00 00 JIT code: ffffffffa00b5060: 75 2d be 1c 00 00 00 e8 c8 7a f7 e0 24 00 3d 00 JIT code: ffffffffa00b5070: 14 a8 c0 74 13 be 26 00 00 00 e8 b5 7a f7 e0 24 JIT code: ffffffffa00b5080: 00 3d 00 14 a8 c0 75 07 b8 ff ff 00 00 eb 02 31 JIT code: ffffffffa00b5090: c0 c9 c3 BPF program is 144 bytes long, so native program is almost same size ;) (000) ldh [12] (001) jeq #0x800 jt 2 jf 8 (002) ld [26] (003) and #0xffffff00 (004) jeq #0xc0a81400 jt 16 jf 5 (005) ld [30] (006) and #0xffffff00 (007) jeq #0xc0a81400 jt 16 jf 17 (008) jeq #0x806 jt 10 jf 9 (009) jeq #0x8035 jt 10 jf 17 (010) ld [28] (011) and #0xffffff00 (012) jeq #0xc0a81400 jt 16 jf 13 (013) ld [38] (014) and #0xffffff00 (015) jeq #0xc0a81400 jt 16 jf 17 (016) ret #65535 (017) ret #0 Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Cc: Arnaldo Carvalho de Melo <acme@infradead.org> Cc: Ben Hutchings <bhutchings@solarflare.com> Cc: Hagen Paul Pfeifer <hagen@jauu.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-04-20 03:27:32 -06:00
{
x86: bpf_jit: implement bpf_tail_call() helper bpf_tail_call() arguments: ctx - context pointer jmp_table - one of BPF_MAP_TYPE_PROG_ARRAY maps used as the jump table index - index in the jump table In this implementation x64 JIT bypasses stack unwind and jumps into the callee program after prologue, so the callee program reuses the same stack. The logic can be roughly expressed in C like: u32 tail_call_cnt; void *jumptable[2] = { &&label1, &&label2 }; int bpf_prog1(void *ctx) { label1: ... } int bpf_prog2(void *ctx) { label2: ... } int bpf_prog1(void *ctx) { ... if (tail_call_cnt++ < MAX_TAIL_CALL_CNT) goto *jumptable[index]; ... and pass my 'ctx' to callee ... ... fall through if no entry in jumptable ... } Note that 'skip current program epilogue and next program prologue' is an optimization. Other JITs don't have to do it the same way. >From safety point of view it's valid as well, since programs always initialize the stack before use, so any residue in the stack left by the current program is not going be read. The same verifier checks are done for the calls from the kernel into all bpf programs. Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-19 17:59:04 -06:00
u8 *prog = *pprog;
int cnt = 0;
net: filter: Just In Time compiler for x86-64 In order to speedup packet filtering, here is an implementation of a JIT compiler for x86_64 It is disabled by default, and must be enabled by the admin. echo 1 >/proc/sys/net/core/bpf_jit_enable It uses module_alloc() and module_free() to get memory in the 2GB text kernel range since we call helpers functions from the generated code. EAX : BPF A accumulator EBX : BPF X accumulator RDI : pointer to skb (first argument given to JIT function) RBP : frame pointer (even if CONFIG_FRAME_POINTER=n) r9d : skb->len - skb->data_len (headlen) r8 : skb->data To get a trace of generated code, use : echo 2 >/proc/sys/net/core/bpf_jit_enable Example of generated code : # tcpdump -p -n -s 0 -i eth1 host 192.168.20.0/24 flen=18 proglen=147 pass=3 image=ffffffffa00b5000 JIT code: ffffffffa00b5000: 55 48 89 e5 48 83 ec 60 48 89 5d f8 44 8b 4f 60 JIT code: ffffffffa00b5010: 44 2b 4f 64 4c 8b 87 b8 00 00 00 be 0c 00 00 00 JIT code: ffffffffa00b5020: e8 24 7b f7 e0 3d 00 08 00 00 75 28 be 1a 00 00 JIT code: ffffffffa00b5030: 00 e8 fe 7a f7 e0 24 00 3d 00 14 a8 c0 74 49 be JIT code: ffffffffa00b5040: 1e 00 00 00 e8 eb 7a f7 e0 24 00 3d 00 14 a8 c0 JIT code: ffffffffa00b5050: 74 36 eb 3b 3d 06 08 00 00 74 07 3d 35 80 00 00 JIT code: ffffffffa00b5060: 75 2d be 1c 00 00 00 e8 c8 7a f7 e0 24 00 3d 00 JIT code: ffffffffa00b5070: 14 a8 c0 74 13 be 26 00 00 00 e8 b5 7a f7 e0 24 JIT code: ffffffffa00b5080: 00 3d 00 14 a8 c0 75 07 b8 ff ff 00 00 eb 02 31 JIT code: ffffffffa00b5090: c0 c9 c3 BPF program is 144 bytes long, so native program is almost same size ;) (000) ldh [12] (001) jeq #0x800 jt 2 jf 8 (002) ld [26] (003) and #0xffffff00 (004) jeq #0xc0a81400 jt 16 jf 5 (005) ld [30] (006) and #0xffffff00 (007) jeq #0xc0a81400 jt 16 jf 17 (008) jeq #0x806 jt 10 jf 9 (009) jeq #0x8035 jt 10 jf 17 (010) ld [28] (011) and #0xffffff00 (012) jeq #0xc0a81400 jt 16 jf 13 (013) ld [38] (014) and #0xffffff00 (015) jeq #0xc0a81400 jt 16 jf 17 (016) ret #65535 (017) ret #0 Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Cc: Arnaldo Carvalho de Melo <acme@infradead.org> Cc: Ben Hutchings <bhutchings@solarflare.com> Cc: Hagen Paul Pfeifer <hagen@jauu.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-04-20 03:27:32 -06:00
net: filter: x86: internal BPF JIT Maps all internal BPF instructions into x86_64 instructions. This patch replaces original BPF x64 JIT with internal BPF x64 JIT. sysctl net.core.bpf_jit_enable is reused as on/off switch. Performance: 1. old BPF JIT and internal BPF JIT generate equivalent x86_64 code. No performance difference is observed for filters that were JIT-able before Example assembler code for BPF filter "tcpdump port 22" original BPF -> old JIT: original BPF -> internal BPF -> new JIT: 0: push %rbp 0: push %rbp 1: mov %rsp,%rbp 1: mov %rsp,%rbp 4: sub $0x60,%rsp 4: sub $0x228,%rsp 8: mov %rbx,-0x8(%rbp) b: mov %rbx,-0x228(%rbp) // prologue 12: mov %r13,-0x220(%rbp) 19: mov %r14,-0x218(%rbp) 20: mov %r15,-0x210(%rbp) 27: xor %eax,%eax // clear A c: xor %ebx,%ebx 29: xor %r13,%r13 // clear X e: mov 0x68(%rdi),%r9d 2c: mov 0x68(%rdi),%r9d 12: sub 0x6c(%rdi),%r9d 30: sub 0x6c(%rdi),%r9d 16: mov 0xd8(%rdi),%r8 34: mov 0xd8(%rdi),%r10 3b: mov %rdi,%rbx 1d: mov $0xc,%esi 3e: mov $0xc,%esi 22: callq 0xffffffffe1021e15 43: callq 0xffffffffe102bd75 27: cmp $0x86dd,%eax 48: cmp $0x86dd,%rax 2c: jne 0x0000000000000069 4f: jne 0x000000000000009a 2e: mov $0x14,%esi 51: mov $0x14,%esi 33: callq 0xffffffffe1021e31 56: callq 0xffffffffe102bd91 38: cmp $0x84,%eax 5b: cmp $0x84,%rax 3d: je 0x0000000000000049 62: je 0x0000000000000074 3f: cmp $0x6,%eax 64: cmp $0x6,%rax 42: je 0x0000000000000049 68: je 0x0000000000000074 44: cmp $0x11,%eax 6a: cmp $0x11,%rax 47: jne 0x00000000000000c6 6e: jne 0x0000000000000117 49: mov $0x36,%esi 74: mov $0x36,%esi 4e: callq 0xffffffffe1021e15 79: callq 0xffffffffe102bd75 53: cmp $0x16,%eax 7e: cmp $0x16,%rax 56: je 0x00000000000000bf 82: je 0x0000000000000110 58: mov $0x38,%esi 88: mov $0x38,%esi 5d: callq 0xffffffffe1021e15 8d: callq 0xffffffffe102bd75 62: cmp $0x16,%eax 92: cmp $0x16,%rax 65: je 0x00000000000000bf 96: je 0x0000000000000110 67: jmp 0x00000000000000c6 98: jmp 0x0000000000000117 69: cmp $0x800,%eax 9a: cmp $0x800,%rax 6e: jne 0x00000000000000c6 a1: jne 0x0000000000000117 70: mov $0x17,%esi a3: mov $0x17,%esi 75: callq 0xffffffffe1021e31 a8: callq 0xffffffffe102bd91 7a: cmp $0x84,%eax ad: cmp $0x84,%rax 7f: je 0x000000000000008b b4: je 0x00000000000000c2 81: cmp $0x6,%eax b6: cmp $0x6,%rax 84: je 0x000000000000008b ba: je 0x00000000000000c2 86: cmp $0x11,%eax bc: cmp $0x11,%rax 89: jne 0x00000000000000c6 c0: jne 0x0000000000000117 8b: mov $0x14,%esi c2: mov $0x14,%esi 90: callq 0xffffffffe1021e15 c7: callq 0xffffffffe102bd75 95: test $0x1fff,%ax cc: test $0x1fff,%rax 99: jne 0x00000000000000c6 d3: jne 0x0000000000000117 d5: mov %rax,%r14 9b: mov $0xe,%esi d8: mov $0xe,%esi a0: callq 0xffffffffe1021e44 dd: callq 0xffffffffe102bd91 // MSH e2: and $0xf,%eax e5: shl $0x2,%eax e8: mov %rax,%r13 eb: mov %r14,%rax ee: mov %r13,%rsi a5: lea 0xe(%rbx),%esi f1: add $0xe,%esi a8: callq 0xffffffffe1021e0d f4: callq 0xffffffffe102bd6d ad: cmp $0x16,%eax f9: cmp $0x16,%rax b0: je 0x00000000000000bf fd: je 0x0000000000000110 ff: mov %r13,%rsi b2: lea 0x10(%rbx),%esi 102: add $0x10,%esi b5: callq 0xffffffffe1021e0d 105: callq 0xffffffffe102bd6d ba: cmp $0x16,%eax 10a: cmp $0x16,%rax bd: jne 0x00000000000000c6 10e: jne 0x0000000000000117 bf: mov $0xffff,%eax 110: mov $0xffff,%eax c4: jmp 0x00000000000000c8 115: jmp 0x000000000000011c c6: xor %eax,%eax 117: mov $0x0,%eax c8: mov -0x8(%rbp),%rbx 11c: mov -0x228(%rbp),%rbx // epilogue cc: leaveq 123: mov -0x220(%rbp),%r13 cd: retq 12a: mov -0x218(%rbp),%r14 131: mov -0x210(%rbp),%r15 138: leaveq 139: retq On fully cached SKBs both JITed functions take 12 nsec to execute. BPF interpreter executes the program in 30 nsec. The difference in generated assembler is due to the following: Old BPF imlements LDX_MSH instruction via sk_load_byte_msh() helper function inside bpf_jit.S. New JIT removes the helper and does it explicitly, so ldx_msh cost is the same for both JITs, but generated code looks longer. New JIT has 4 registers to save, so prologue/epilogue are larger, but the cost is within noise on x64. Old JIT checks whether first insn clears A and if not emits 'xor %eax,%eax'. New JIT clears %rax unconditionally. 2. old BPF JIT doesn't support ANC_NLATTR, ANC_PAY_OFFSET, ANC_RANDOM extensions. New JIT supports all BPF extensions. Performance of such filters improves 2-4 times depending on a filter. The longer the filter the higher performance gain. Synthetic benchmarks with many ancillary loads see 20x speedup which seems to be the maximum gain from JIT Notes: . net.core.bpf_jit_enable=2 + tools/net/bpf_jit_disasm is still functional and can be used to see generated assembler . there are two jit_compile() functions and code flow for classic filters is: sk_attach_filter() - load classic BPF bpf_jit_compile() - try to JIT from classic BPF sk_convert_filter() - convert classic to internal bpf_int_jit_compile() - JIT from internal BPF seccomp and tracing filters will just call bpf_int_jit_compile() Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 20:50:46 -06:00
EMIT1(0x55); /* push rbp */
EMIT3(0x48, 0x89, 0xE5); /* mov rbp,rsp */
net: filter: Just In Time compiler for x86-64 In order to speedup packet filtering, here is an implementation of a JIT compiler for x86_64 It is disabled by default, and must be enabled by the admin. echo 1 >/proc/sys/net/core/bpf_jit_enable It uses module_alloc() and module_free() to get memory in the 2GB text kernel range since we call helpers functions from the generated code. EAX : BPF A accumulator EBX : BPF X accumulator RDI : pointer to skb (first argument given to JIT function) RBP : frame pointer (even if CONFIG_FRAME_POINTER=n) r9d : skb->len - skb->data_len (headlen) r8 : skb->data To get a trace of generated code, use : echo 2 >/proc/sys/net/core/bpf_jit_enable Example of generated code : # tcpdump -p -n -s 0 -i eth1 host 192.168.20.0/24 flen=18 proglen=147 pass=3 image=ffffffffa00b5000 JIT code: ffffffffa00b5000: 55 48 89 e5 48 83 ec 60 48 89 5d f8 44 8b 4f 60 JIT code: ffffffffa00b5010: 44 2b 4f 64 4c 8b 87 b8 00 00 00 be 0c 00 00 00 JIT code: ffffffffa00b5020: e8 24 7b f7 e0 3d 00 08 00 00 75 28 be 1a 00 00 JIT code: ffffffffa00b5030: 00 e8 fe 7a f7 e0 24 00 3d 00 14 a8 c0 74 49 be JIT code: ffffffffa00b5040: 1e 00 00 00 e8 eb 7a f7 e0 24 00 3d 00 14 a8 c0 JIT code: ffffffffa00b5050: 74 36 eb 3b 3d 06 08 00 00 74 07 3d 35 80 00 00 JIT code: ffffffffa00b5060: 75 2d be 1c 00 00 00 e8 c8 7a f7 e0 24 00 3d 00 JIT code: ffffffffa00b5070: 14 a8 c0 74 13 be 26 00 00 00 e8 b5 7a f7 e0 24 JIT code: ffffffffa00b5080: 00 3d 00 14 a8 c0 75 07 b8 ff ff 00 00 eb 02 31 JIT code: ffffffffa00b5090: c0 c9 c3 BPF program is 144 bytes long, so native program is almost same size ;) (000) ldh [12] (001) jeq #0x800 jt 2 jf 8 (002) ld [26] (003) and #0xffffff00 (004) jeq #0xc0a81400 jt 16 jf 5 (005) ld [30] (006) and #0xffffff00 (007) jeq #0xc0a81400 jt 16 jf 17 (008) jeq #0x806 jt 10 jf 9 (009) jeq #0x8035 jt 10 jf 17 (010) ld [28] (011) and #0xffffff00 (012) jeq #0xc0a81400 jt 16 jf 13 (013) ld [38] (014) and #0xffffff00 (015) jeq #0xc0a81400 jt 16 jf 17 (016) ret #65535 (017) ret #0 Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Cc: Arnaldo Carvalho de Melo <acme@infradead.org> Cc: Ben Hutchings <bhutchings@solarflare.com> Cc: Hagen Paul Pfeifer <hagen@jauu.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-04-20 03:27:32 -06:00
x86: bpf_jit: implement bpf_tail_call() helper bpf_tail_call() arguments: ctx - context pointer jmp_table - one of BPF_MAP_TYPE_PROG_ARRAY maps used as the jump table index - index in the jump table In this implementation x64 JIT bypasses stack unwind and jumps into the callee program after prologue, so the callee program reuses the same stack. The logic can be roughly expressed in C like: u32 tail_call_cnt; void *jumptable[2] = { &&label1, &&label2 }; int bpf_prog1(void *ctx) { label1: ... } int bpf_prog2(void *ctx) { label2: ... } int bpf_prog1(void *ctx) { ... if (tail_call_cnt++ < MAX_TAIL_CALL_CNT) goto *jumptable[index]; ... and pass my 'ctx' to callee ... ... fall through if no entry in jumptable ... } Note that 'skip current program epilogue and next program prologue' is an optimization. Other JITs don't have to do it the same way. >From safety point of view it's valid as well, since programs always initialize the stack before use, so any residue in the stack left by the current program is not going be read. The same verifier checks are done for the calls from the kernel into all bpf programs. Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-19 17:59:04 -06:00
/* sub rsp, STACKSIZE */
EMIT3_off32(0x48, 0x81, 0xEC, STACKSIZE);
net: filter: x86: internal BPF JIT Maps all internal BPF instructions into x86_64 instructions. This patch replaces original BPF x64 JIT with internal BPF x64 JIT. sysctl net.core.bpf_jit_enable is reused as on/off switch. Performance: 1. old BPF JIT and internal BPF JIT generate equivalent x86_64 code. No performance difference is observed for filters that were JIT-able before Example assembler code for BPF filter "tcpdump port 22" original BPF -> old JIT: original BPF -> internal BPF -> new JIT: 0: push %rbp 0: push %rbp 1: mov %rsp,%rbp 1: mov %rsp,%rbp 4: sub $0x60,%rsp 4: sub $0x228,%rsp 8: mov %rbx,-0x8(%rbp) b: mov %rbx,-0x228(%rbp) // prologue 12: mov %r13,-0x220(%rbp) 19: mov %r14,-0x218(%rbp) 20: mov %r15,-0x210(%rbp) 27: xor %eax,%eax // clear A c: xor %ebx,%ebx 29: xor %r13,%r13 // clear X e: mov 0x68(%rdi),%r9d 2c: mov 0x68(%rdi),%r9d 12: sub 0x6c(%rdi),%r9d 30: sub 0x6c(%rdi),%r9d 16: mov 0xd8(%rdi),%r8 34: mov 0xd8(%rdi),%r10 3b: mov %rdi,%rbx 1d: mov $0xc,%esi 3e: mov $0xc,%esi 22: callq 0xffffffffe1021e15 43: callq 0xffffffffe102bd75 27: cmp $0x86dd,%eax 48: cmp $0x86dd,%rax 2c: jne 0x0000000000000069 4f: jne 0x000000000000009a 2e: mov $0x14,%esi 51: mov $0x14,%esi 33: callq 0xffffffffe1021e31 56: callq 0xffffffffe102bd91 38: cmp $0x84,%eax 5b: cmp $0x84,%rax 3d: je 0x0000000000000049 62: je 0x0000000000000074 3f: cmp $0x6,%eax 64: cmp $0x6,%rax 42: je 0x0000000000000049 68: je 0x0000000000000074 44: cmp $0x11,%eax 6a: cmp $0x11,%rax 47: jne 0x00000000000000c6 6e: jne 0x0000000000000117 49: mov $0x36,%esi 74: mov $0x36,%esi 4e: callq 0xffffffffe1021e15 79: callq 0xffffffffe102bd75 53: cmp $0x16,%eax 7e: cmp $0x16,%rax 56: je 0x00000000000000bf 82: je 0x0000000000000110 58: mov $0x38,%esi 88: mov $0x38,%esi 5d: callq 0xffffffffe1021e15 8d: callq 0xffffffffe102bd75 62: cmp $0x16,%eax 92: cmp $0x16,%rax 65: je 0x00000000000000bf 96: je 0x0000000000000110 67: jmp 0x00000000000000c6 98: jmp 0x0000000000000117 69: cmp $0x800,%eax 9a: cmp $0x800,%rax 6e: jne 0x00000000000000c6 a1: jne 0x0000000000000117 70: mov $0x17,%esi a3: mov $0x17,%esi 75: callq 0xffffffffe1021e31 a8: callq 0xffffffffe102bd91 7a: cmp $0x84,%eax ad: cmp $0x84,%rax 7f: je 0x000000000000008b b4: je 0x00000000000000c2 81: cmp $0x6,%eax b6: cmp $0x6,%rax 84: je 0x000000000000008b ba: je 0x00000000000000c2 86: cmp $0x11,%eax bc: cmp $0x11,%rax 89: jne 0x00000000000000c6 c0: jne 0x0000000000000117 8b: mov $0x14,%esi c2: mov $0x14,%esi 90: callq 0xffffffffe1021e15 c7: callq 0xffffffffe102bd75 95: test $0x1fff,%ax cc: test $0x1fff,%rax 99: jne 0x00000000000000c6 d3: jne 0x0000000000000117 d5: mov %rax,%r14 9b: mov $0xe,%esi d8: mov $0xe,%esi a0: callq 0xffffffffe1021e44 dd: callq 0xffffffffe102bd91 // MSH e2: and $0xf,%eax e5: shl $0x2,%eax e8: mov %rax,%r13 eb: mov %r14,%rax ee: mov %r13,%rsi a5: lea 0xe(%rbx),%esi f1: add $0xe,%esi a8: callq 0xffffffffe1021e0d f4: callq 0xffffffffe102bd6d ad: cmp $0x16,%eax f9: cmp $0x16,%rax b0: je 0x00000000000000bf fd: je 0x0000000000000110 ff: mov %r13,%rsi b2: lea 0x10(%rbx),%esi 102: add $0x10,%esi b5: callq 0xffffffffe1021e0d 105: callq 0xffffffffe102bd6d ba: cmp $0x16,%eax 10a: cmp $0x16,%rax bd: jne 0x00000000000000c6 10e: jne 0x0000000000000117 bf: mov $0xffff,%eax 110: mov $0xffff,%eax c4: jmp 0x00000000000000c8 115: jmp 0x000000000000011c c6: xor %eax,%eax 117: mov $0x0,%eax c8: mov -0x8(%rbp),%rbx 11c: mov -0x228(%rbp),%rbx // epilogue cc: leaveq 123: mov -0x220(%rbp),%r13 cd: retq 12a: mov -0x218(%rbp),%r14 131: mov -0x210(%rbp),%r15 138: leaveq 139: retq On fully cached SKBs both JITed functions take 12 nsec to execute. BPF interpreter executes the program in 30 nsec. The difference in generated assembler is due to the following: Old BPF imlements LDX_MSH instruction via sk_load_byte_msh() helper function inside bpf_jit.S. New JIT removes the helper and does it explicitly, so ldx_msh cost is the same for both JITs, but generated code looks longer. New JIT has 4 registers to save, so prologue/epilogue are larger, but the cost is within noise on x64. Old JIT checks whether first insn clears A and if not emits 'xor %eax,%eax'. New JIT clears %rax unconditionally. 2. old BPF JIT doesn't support ANC_NLATTR, ANC_PAY_OFFSET, ANC_RANDOM extensions. New JIT supports all BPF extensions. Performance of such filters improves 2-4 times depending on a filter. The longer the filter the higher performance gain. Synthetic benchmarks with many ancillary loads see 20x speedup which seems to be the maximum gain from JIT Notes: . net.core.bpf_jit_enable=2 + tools/net/bpf_jit_disasm is still functional and can be used to see generated assembler . there are two jit_compile() functions and code flow for classic filters is: sk_attach_filter() - load classic BPF bpf_jit_compile() - try to JIT from classic BPF sk_convert_filter() - convert classic to internal bpf_int_jit_compile() - JIT from internal BPF seccomp and tracing filters will just call bpf_int_jit_compile() Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 20:50:46 -06:00
/* all classic BPF filters use R6(rbx) save it */
/* mov qword ptr [rbp-X],rbx */
x86: bpf_jit: implement bpf_tail_call() helper bpf_tail_call() arguments: ctx - context pointer jmp_table - one of BPF_MAP_TYPE_PROG_ARRAY maps used as the jump table index - index in the jump table In this implementation x64 JIT bypasses stack unwind and jumps into the callee program after prologue, so the callee program reuses the same stack. The logic can be roughly expressed in C like: u32 tail_call_cnt; void *jumptable[2] = { &&label1, &&label2 }; int bpf_prog1(void *ctx) { label1: ... } int bpf_prog2(void *ctx) { label2: ... } int bpf_prog1(void *ctx) { ... if (tail_call_cnt++ < MAX_TAIL_CALL_CNT) goto *jumptable[index]; ... and pass my 'ctx' to callee ... ... fall through if no entry in jumptable ... } Note that 'skip current program epilogue and next program prologue' is an optimization. Other JITs don't have to do it the same way. >From safety point of view it's valid as well, since programs always initialize the stack before use, so any residue in the stack left by the current program is not going be read. The same verifier checks are done for the calls from the kernel into all bpf programs. Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-19 17:59:04 -06:00
EMIT3_off32(0x48, 0x89, 0x9D, -STACKSIZE);
net: filter: x86: internal BPF JIT Maps all internal BPF instructions into x86_64 instructions. This patch replaces original BPF x64 JIT with internal BPF x64 JIT. sysctl net.core.bpf_jit_enable is reused as on/off switch. Performance: 1. old BPF JIT and internal BPF JIT generate equivalent x86_64 code. No performance difference is observed for filters that were JIT-able before Example assembler code for BPF filter "tcpdump port 22" original BPF -> old JIT: original BPF -> internal BPF -> new JIT: 0: push %rbp 0: push %rbp 1: mov %rsp,%rbp 1: mov %rsp,%rbp 4: sub $0x60,%rsp 4: sub $0x228,%rsp 8: mov %rbx,-0x8(%rbp) b: mov %rbx,-0x228(%rbp) // prologue 12: mov %r13,-0x220(%rbp) 19: mov %r14,-0x218(%rbp) 20: mov %r15,-0x210(%rbp) 27: xor %eax,%eax // clear A c: xor %ebx,%ebx 29: xor %r13,%r13 // clear X e: mov 0x68(%rdi),%r9d 2c: mov 0x68(%rdi),%r9d 12: sub 0x6c(%rdi),%r9d 30: sub 0x6c(%rdi),%r9d 16: mov 0xd8(%rdi),%r8 34: mov 0xd8(%rdi),%r10 3b: mov %rdi,%rbx 1d: mov $0xc,%esi 3e: mov $0xc,%esi 22: callq 0xffffffffe1021e15 43: callq 0xffffffffe102bd75 27: cmp $0x86dd,%eax 48: cmp $0x86dd,%rax 2c: jne 0x0000000000000069 4f: jne 0x000000000000009a 2e: mov $0x14,%esi 51: mov $0x14,%esi 33: callq 0xffffffffe1021e31 56: callq 0xffffffffe102bd91 38: cmp $0x84,%eax 5b: cmp $0x84,%rax 3d: je 0x0000000000000049 62: je 0x0000000000000074 3f: cmp $0x6,%eax 64: cmp $0x6,%rax 42: je 0x0000000000000049 68: je 0x0000000000000074 44: cmp $0x11,%eax 6a: cmp $0x11,%rax 47: jne 0x00000000000000c6 6e: jne 0x0000000000000117 49: mov $0x36,%esi 74: mov $0x36,%esi 4e: callq 0xffffffffe1021e15 79: callq 0xffffffffe102bd75 53: cmp $0x16,%eax 7e: cmp $0x16,%rax 56: je 0x00000000000000bf 82: je 0x0000000000000110 58: mov $0x38,%esi 88: mov $0x38,%esi 5d: callq 0xffffffffe1021e15 8d: callq 0xffffffffe102bd75 62: cmp $0x16,%eax 92: cmp $0x16,%rax 65: je 0x00000000000000bf 96: je 0x0000000000000110 67: jmp 0x00000000000000c6 98: jmp 0x0000000000000117 69: cmp $0x800,%eax 9a: cmp $0x800,%rax 6e: jne 0x00000000000000c6 a1: jne 0x0000000000000117 70: mov $0x17,%esi a3: mov $0x17,%esi 75: callq 0xffffffffe1021e31 a8: callq 0xffffffffe102bd91 7a: cmp $0x84,%eax ad: cmp $0x84,%rax 7f: je 0x000000000000008b b4: je 0x00000000000000c2 81: cmp $0x6,%eax b6: cmp $0x6,%rax 84: je 0x000000000000008b ba: je 0x00000000000000c2 86: cmp $0x11,%eax bc: cmp $0x11,%rax 89: jne 0x00000000000000c6 c0: jne 0x0000000000000117 8b: mov $0x14,%esi c2: mov $0x14,%esi 90: callq 0xffffffffe1021e15 c7: callq 0xffffffffe102bd75 95: test $0x1fff,%ax cc: test $0x1fff,%rax 99: jne 0x00000000000000c6 d3: jne 0x0000000000000117 d5: mov %rax,%r14 9b: mov $0xe,%esi d8: mov $0xe,%esi a0: callq 0xffffffffe1021e44 dd: callq 0xffffffffe102bd91 // MSH e2: and $0xf,%eax e5: shl $0x2,%eax e8: mov %rax,%r13 eb: mov %r14,%rax ee: mov %r13,%rsi a5: lea 0xe(%rbx),%esi f1: add $0xe,%esi a8: callq 0xffffffffe1021e0d f4: callq 0xffffffffe102bd6d ad: cmp $0x16,%eax f9: cmp $0x16,%rax b0: je 0x00000000000000bf fd: je 0x0000000000000110 ff: mov %r13,%rsi b2: lea 0x10(%rbx),%esi 102: add $0x10,%esi b5: callq 0xffffffffe1021e0d 105: callq 0xffffffffe102bd6d ba: cmp $0x16,%eax 10a: cmp $0x16,%rax bd: jne 0x00000000000000c6 10e: jne 0x0000000000000117 bf: mov $0xffff,%eax 110: mov $0xffff,%eax c4: jmp 0x00000000000000c8 115: jmp 0x000000000000011c c6: xor %eax,%eax 117: mov $0x0,%eax c8: mov -0x8(%rbp),%rbx 11c: mov -0x228(%rbp),%rbx // epilogue cc: leaveq 123: mov -0x220(%rbp),%r13 cd: retq 12a: mov -0x218(%rbp),%r14 131: mov -0x210(%rbp),%r15 138: leaveq 139: retq On fully cached SKBs both JITed functions take 12 nsec to execute. BPF interpreter executes the program in 30 nsec. The difference in generated assembler is due to the following: Old BPF imlements LDX_MSH instruction via sk_load_byte_msh() helper function inside bpf_jit.S. New JIT removes the helper and does it explicitly, so ldx_msh cost is the same for both JITs, but generated code looks longer. New JIT has 4 registers to save, so prologue/epilogue are larger, but the cost is within noise on x64. Old JIT checks whether first insn clears A and if not emits 'xor %eax,%eax'. New JIT clears %rax unconditionally. 2. old BPF JIT doesn't support ANC_NLATTR, ANC_PAY_OFFSET, ANC_RANDOM extensions. New JIT supports all BPF extensions. Performance of such filters improves 2-4 times depending on a filter. The longer the filter the higher performance gain. Synthetic benchmarks with many ancillary loads see 20x speedup which seems to be the maximum gain from JIT Notes: . net.core.bpf_jit_enable=2 + tools/net/bpf_jit_disasm is still functional and can be used to see generated assembler . there are two jit_compile() functions and code flow for classic filters is: sk_attach_filter() - load classic BPF bpf_jit_compile() - try to JIT from classic BPF sk_convert_filter() - convert classic to internal bpf_int_jit_compile() - JIT from internal BPF seccomp and tracing filters will just call bpf_int_jit_compile() Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 20:50:46 -06:00
net: filter: rename sk_convert_filter() -> bpf_convert_filter() to indicate that this function is converting classic BPF into eBPF and not related to sockets Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-07-30 21:34:15 -06:00
/* bpf_convert_filter() maps classic BPF register X to R7 and uses R8
net: filter: x86: internal BPF JIT Maps all internal BPF instructions into x86_64 instructions. This patch replaces original BPF x64 JIT with internal BPF x64 JIT. sysctl net.core.bpf_jit_enable is reused as on/off switch. Performance: 1. old BPF JIT and internal BPF JIT generate equivalent x86_64 code. No performance difference is observed for filters that were JIT-able before Example assembler code for BPF filter "tcpdump port 22" original BPF -> old JIT: original BPF -> internal BPF -> new JIT: 0: push %rbp 0: push %rbp 1: mov %rsp,%rbp 1: mov %rsp,%rbp 4: sub $0x60,%rsp 4: sub $0x228,%rsp 8: mov %rbx,-0x8(%rbp) b: mov %rbx,-0x228(%rbp) // prologue 12: mov %r13,-0x220(%rbp) 19: mov %r14,-0x218(%rbp) 20: mov %r15,-0x210(%rbp) 27: xor %eax,%eax // clear A c: xor %ebx,%ebx 29: xor %r13,%r13 // clear X e: mov 0x68(%rdi),%r9d 2c: mov 0x68(%rdi),%r9d 12: sub 0x6c(%rdi),%r9d 30: sub 0x6c(%rdi),%r9d 16: mov 0xd8(%rdi),%r8 34: mov 0xd8(%rdi),%r10 3b: mov %rdi,%rbx 1d: mov $0xc,%esi 3e: mov $0xc,%esi 22: callq 0xffffffffe1021e15 43: callq 0xffffffffe102bd75 27: cmp $0x86dd,%eax 48: cmp $0x86dd,%rax 2c: jne 0x0000000000000069 4f: jne 0x000000000000009a 2e: mov $0x14,%esi 51: mov $0x14,%esi 33: callq 0xffffffffe1021e31 56: callq 0xffffffffe102bd91 38: cmp $0x84,%eax 5b: cmp $0x84,%rax 3d: je 0x0000000000000049 62: je 0x0000000000000074 3f: cmp $0x6,%eax 64: cmp $0x6,%rax 42: je 0x0000000000000049 68: je 0x0000000000000074 44: cmp $0x11,%eax 6a: cmp $0x11,%rax 47: jne 0x00000000000000c6 6e: jne 0x0000000000000117 49: mov $0x36,%esi 74: mov $0x36,%esi 4e: callq 0xffffffffe1021e15 79: callq 0xffffffffe102bd75 53: cmp $0x16,%eax 7e: cmp $0x16,%rax 56: je 0x00000000000000bf 82: je 0x0000000000000110 58: mov $0x38,%esi 88: mov $0x38,%esi 5d: callq 0xffffffffe1021e15 8d: callq 0xffffffffe102bd75 62: cmp $0x16,%eax 92: cmp $0x16,%rax 65: je 0x00000000000000bf 96: je 0x0000000000000110 67: jmp 0x00000000000000c6 98: jmp 0x0000000000000117 69: cmp $0x800,%eax 9a: cmp $0x800,%rax 6e: jne 0x00000000000000c6 a1: jne 0x0000000000000117 70: mov $0x17,%esi a3: mov $0x17,%esi 75: callq 0xffffffffe1021e31 a8: callq 0xffffffffe102bd91 7a: cmp $0x84,%eax ad: cmp $0x84,%rax 7f: je 0x000000000000008b b4: je 0x00000000000000c2 81: cmp $0x6,%eax b6: cmp $0x6,%rax 84: je 0x000000000000008b ba: je 0x00000000000000c2 86: cmp $0x11,%eax bc: cmp $0x11,%rax 89: jne 0x00000000000000c6 c0: jne 0x0000000000000117 8b: mov $0x14,%esi c2: mov $0x14,%esi 90: callq 0xffffffffe1021e15 c7: callq 0xffffffffe102bd75 95: test $0x1fff,%ax cc: test $0x1fff,%rax 99: jne 0x00000000000000c6 d3: jne 0x0000000000000117 d5: mov %rax,%r14 9b: mov $0xe,%esi d8: mov $0xe,%esi a0: callq 0xffffffffe1021e44 dd: callq 0xffffffffe102bd91 // MSH e2: and $0xf,%eax e5: shl $0x2,%eax e8: mov %rax,%r13 eb: mov %r14,%rax ee: mov %r13,%rsi a5: lea 0xe(%rbx),%esi f1: add $0xe,%esi a8: callq 0xffffffffe1021e0d f4: callq 0xffffffffe102bd6d ad: cmp $0x16,%eax f9: cmp $0x16,%rax b0: je 0x00000000000000bf fd: je 0x0000000000000110 ff: mov %r13,%rsi b2: lea 0x10(%rbx),%esi 102: add $0x10,%esi b5: callq 0xffffffffe1021e0d 105: callq 0xffffffffe102bd6d ba: cmp $0x16,%eax 10a: cmp $0x16,%rax bd: jne 0x00000000000000c6 10e: jne 0x0000000000000117 bf: mov $0xffff,%eax 110: mov $0xffff,%eax c4: jmp 0x00000000000000c8 115: jmp 0x000000000000011c c6: xor %eax,%eax 117: mov $0x0,%eax c8: mov -0x8(%rbp),%rbx 11c: mov -0x228(%rbp),%rbx // epilogue cc: leaveq 123: mov -0x220(%rbp),%r13 cd: retq 12a: mov -0x218(%rbp),%r14 131: mov -0x210(%rbp),%r15 138: leaveq 139: retq On fully cached SKBs both JITed functions take 12 nsec to execute. BPF interpreter executes the program in 30 nsec. The difference in generated assembler is due to the following: Old BPF imlements LDX_MSH instruction via sk_load_byte_msh() helper function inside bpf_jit.S. New JIT removes the helper and does it explicitly, so ldx_msh cost is the same for both JITs, but generated code looks longer. New JIT has 4 registers to save, so prologue/epilogue are larger, but the cost is within noise on x64. Old JIT checks whether first insn clears A and if not emits 'xor %eax,%eax'. New JIT clears %rax unconditionally. 2. old BPF JIT doesn't support ANC_NLATTR, ANC_PAY_OFFSET, ANC_RANDOM extensions. New JIT supports all BPF extensions. Performance of such filters improves 2-4 times depending on a filter. The longer the filter the higher performance gain. Synthetic benchmarks with many ancillary loads see 20x speedup which seems to be the maximum gain from JIT Notes: . net.core.bpf_jit_enable=2 + tools/net/bpf_jit_disasm is still functional and can be used to see generated assembler . there are two jit_compile() functions and code flow for classic filters is: sk_attach_filter() - load classic BPF bpf_jit_compile() - try to JIT from classic BPF sk_convert_filter() - convert classic to internal bpf_int_jit_compile() - JIT from internal BPF seccomp and tracing filters will just call bpf_int_jit_compile() Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 20:50:46 -06:00
* as temporary, so all tcpdump filters need to spill/fill R7(r13) and
* R8(r14). R9(r15) spill could be made conditional, but there is only
* one 'bpf_error' return path out of helper functions inside bpf_jit.S
* The overhead of extra spill is negligible for any filter other
* than synthetic ones. Therefore not worth adding complexity.
*/
/* mov qword ptr [rbp-X],r13 */
x86: bpf_jit: implement bpf_tail_call() helper bpf_tail_call() arguments: ctx - context pointer jmp_table - one of BPF_MAP_TYPE_PROG_ARRAY maps used as the jump table index - index in the jump table In this implementation x64 JIT bypasses stack unwind and jumps into the callee program after prologue, so the callee program reuses the same stack. The logic can be roughly expressed in C like: u32 tail_call_cnt; void *jumptable[2] = { &&label1, &&label2 }; int bpf_prog1(void *ctx) { label1: ... } int bpf_prog2(void *ctx) { label2: ... } int bpf_prog1(void *ctx) { ... if (tail_call_cnt++ < MAX_TAIL_CALL_CNT) goto *jumptable[index]; ... and pass my 'ctx' to callee ... ... fall through if no entry in jumptable ... } Note that 'skip current program epilogue and next program prologue' is an optimization. Other JITs don't have to do it the same way. >From safety point of view it's valid as well, since programs always initialize the stack before use, so any residue in the stack left by the current program is not going be read. The same verifier checks are done for the calls from the kernel into all bpf programs. Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-19 17:59:04 -06:00
EMIT3_off32(0x4C, 0x89, 0xAD, -STACKSIZE + 8);
net: filter: x86: internal BPF JIT Maps all internal BPF instructions into x86_64 instructions. This patch replaces original BPF x64 JIT with internal BPF x64 JIT. sysctl net.core.bpf_jit_enable is reused as on/off switch. Performance: 1. old BPF JIT and internal BPF JIT generate equivalent x86_64 code. No performance difference is observed for filters that were JIT-able before Example assembler code for BPF filter "tcpdump port 22" original BPF -> old JIT: original BPF -> internal BPF -> new JIT: 0: push %rbp 0: push %rbp 1: mov %rsp,%rbp 1: mov %rsp,%rbp 4: sub $0x60,%rsp 4: sub $0x228,%rsp 8: mov %rbx,-0x8(%rbp) b: mov %rbx,-0x228(%rbp) // prologue 12: mov %r13,-0x220(%rbp) 19: mov %r14,-0x218(%rbp) 20: mov %r15,-0x210(%rbp) 27: xor %eax,%eax // clear A c: xor %ebx,%ebx 29: xor %r13,%r13 // clear X e: mov 0x68(%rdi),%r9d 2c: mov 0x68(%rdi),%r9d 12: sub 0x6c(%rdi),%r9d 30: sub 0x6c(%rdi),%r9d 16: mov 0xd8(%rdi),%r8 34: mov 0xd8(%rdi),%r10 3b: mov %rdi,%rbx 1d: mov $0xc,%esi 3e: mov $0xc,%esi 22: callq 0xffffffffe1021e15 43: callq 0xffffffffe102bd75 27: cmp $0x86dd,%eax 48: cmp $0x86dd,%rax 2c: jne 0x0000000000000069 4f: jne 0x000000000000009a 2e: mov $0x14,%esi 51: mov $0x14,%esi 33: callq 0xffffffffe1021e31 56: callq 0xffffffffe102bd91 38: cmp $0x84,%eax 5b: cmp $0x84,%rax 3d: je 0x0000000000000049 62: je 0x0000000000000074 3f: cmp $0x6,%eax 64: cmp $0x6,%rax 42: je 0x0000000000000049 68: je 0x0000000000000074 44: cmp $0x11,%eax 6a: cmp $0x11,%rax 47: jne 0x00000000000000c6 6e: jne 0x0000000000000117 49: mov $0x36,%esi 74: mov $0x36,%esi 4e: callq 0xffffffffe1021e15 79: callq 0xffffffffe102bd75 53: cmp $0x16,%eax 7e: cmp $0x16,%rax 56: je 0x00000000000000bf 82: je 0x0000000000000110 58: mov $0x38,%esi 88: mov $0x38,%esi 5d: callq 0xffffffffe1021e15 8d: callq 0xffffffffe102bd75 62: cmp $0x16,%eax 92: cmp $0x16,%rax 65: je 0x00000000000000bf 96: je 0x0000000000000110 67: jmp 0x00000000000000c6 98: jmp 0x0000000000000117 69: cmp $0x800,%eax 9a: cmp $0x800,%rax 6e: jne 0x00000000000000c6 a1: jne 0x0000000000000117 70: mov $0x17,%esi a3: mov $0x17,%esi 75: callq 0xffffffffe1021e31 a8: callq 0xffffffffe102bd91 7a: cmp $0x84,%eax ad: cmp $0x84,%rax 7f: je 0x000000000000008b b4: je 0x00000000000000c2 81: cmp $0x6,%eax b6: cmp $0x6,%rax 84: je 0x000000000000008b ba: je 0x00000000000000c2 86: cmp $0x11,%eax bc: cmp $0x11,%rax 89: jne 0x00000000000000c6 c0: jne 0x0000000000000117 8b: mov $0x14,%esi c2: mov $0x14,%esi 90: callq 0xffffffffe1021e15 c7: callq 0xffffffffe102bd75 95: test $0x1fff,%ax cc: test $0x1fff,%rax 99: jne 0x00000000000000c6 d3: jne 0x0000000000000117 d5: mov %rax,%r14 9b: mov $0xe,%esi d8: mov $0xe,%esi a0: callq 0xffffffffe1021e44 dd: callq 0xffffffffe102bd91 // MSH e2: and $0xf,%eax e5: shl $0x2,%eax e8: mov %rax,%r13 eb: mov %r14,%rax ee: mov %r13,%rsi a5: lea 0xe(%rbx),%esi f1: add $0xe,%esi a8: callq 0xffffffffe1021e0d f4: callq 0xffffffffe102bd6d ad: cmp $0x16,%eax f9: cmp $0x16,%rax b0: je 0x00000000000000bf fd: je 0x0000000000000110 ff: mov %r13,%rsi b2: lea 0x10(%rbx),%esi 102: add $0x10,%esi b5: callq 0xffffffffe1021e0d 105: callq 0xffffffffe102bd6d ba: cmp $0x16,%eax 10a: cmp $0x16,%rax bd: jne 0x00000000000000c6 10e: jne 0x0000000000000117 bf: mov $0xffff,%eax 110: mov $0xffff,%eax c4: jmp 0x00000000000000c8 115: jmp 0x000000000000011c c6: xor %eax,%eax 117: mov $0x0,%eax c8: mov -0x8(%rbp),%rbx 11c: mov -0x228(%rbp),%rbx // epilogue cc: leaveq 123: mov -0x220(%rbp),%r13 cd: retq 12a: mov -0x218(%rbp),%r14 131: mov -0x210(%rbp),%r15 138: leaveq 139: retq On fully cached SKBs both JITed functions take 12 nsec to execute. BPF interpreter executes the program in 30 nsec. The difference in generated assembler is due to the following: Old BPF imlements LDX_MSH instruction via sk_load_byte_msh() helper function inside bpf_jit.S. New JIT removes the helper and does it explicitly, so ldx_msh cost is the same for both JITs, but generated code looks longer. New JIT has 4 registers to save, so prologue/epilogue are larger, but the cost is within noise on x64. Old JIT checks whether first insn clears A and if not emits 'xor %eax,%eax'. New JIT clears %rax unconditionally. 2. old BPF JIT doesn't support ANC_NLATTR, ANC_PAY_OFFSET, ANC_RANDOM extensions. New JIT supports all BPF extensions. Performance of such filters improves 2-4 times depending on a filter. The longer the filter the higher performance gain. Synthetic benchmarks with many ancillary loads see 20x speedup which seems to be the maximum gain from JIT Notes: . net.core.bpf_jit_enable=2 + tools/net/bpf_jit_disasm is still functional and can be used to see generated assembler . there are two jit_compile() functions and code flow for classic filters is: sk_attach_filter() - load classic BPF bpf_jit_compile() - try to JIT from classic BPF sk_convert_filter() - convert classic to internal bpf_int_jit_compile() - JIT from internal BPF seccomp and tracing filters will just call bpf_int_jit_compile() Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 20:50:46 -06:00
/* mov qword ptr [rbp-X],r14 */
x86: bpf_jit: implement bpf_tail_call() helper bpf_tail_call() arguments: ctx - context pointer jmp_table - one of BPF_MAP_TYPE_PROG_ARRAY maps used as the jump table index - index in the jump table In this implementation x64 JIT bypasses stack unwind and jumps into the callee program after prologue, so the callee program reuses the same stack. The logic can be roughly expressed in C like: u32 tail_call_cnt; void *jumptable[2] = { &&label1, &&label2 }; int bpf_prog1(void *ctx) { label1: ... } int bpf_prog2(void *ctx) { label2: ... } int bpf_prog1(void *ctx) { ... if (tail_call_cnt++ < MAX_TAIL_CALL_CNT) goto *jumptable[index]; ... and pass my 'ctx' to callee ... ... fall through if no entry in jumptable ... } Note that 'skip current program epilogue and next program prologue' is an optimization. Other JITs don't have to do it the same way. >From safety point of view it's valid as well, since programs always initialize the stack before use, so any residue in the stack left by the current program is not going be read. The same verifier checks are done for the calls from the kernel into all bpf programs. Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-19 17:59:04 -06:00
EMIT3_off32(0x4C, 0x89, 0xB5, -STACKSIZE + 16);
net: filter: x86: internal BPF JIT Maps all internal BPF instructions into x86_64 instructions. This patch replaces original BPF x64 JIT with internal BPF x64 JIT. sysctl net.core.bpf_jit_enable is reused as on/off switch. Performance: 1. old BPF JIT and internal BPF JIT generate equivalent x86_64 code. No performance difference is observed for filters that were JIT-able before Example assembler code for BPF filter "tcpdump port 22" original BPF -> old JIT: original BPF -> internal BPF -> new JIT: 0: push %rbp 0: push %rbp 1: mov %rsp,%rbp 1: mov %rsp,%rbp 4: sub $0x60,%rsp 4: sub $0x228,%rsp 8: mov %rbx,-0x8(%rbp) b: mov %rbx,-0x228(%rbp) // prologue 12: mov %r13,-0x220(%rbp) 19: mov %r14,-0x218(%rbp) 20: mov %r15,-0x210(%rbp) 27: xor %eax,%eax // clear A c: xor %ebx,%ebx 29: xor %r13,%r13 // clear X e: mov 0x68(%rdi),%r9d 2c: mov 0x68(%rdi),%r9d 12: sub 0x6c(%rdi),%r9d 30: sub 0x6c(%rdi),%r9d 16: mov 0xd8(%rdi),%r8 34: mov 0xd8(%rdi),%r10 3b: mov %rdi,%rbx 1d: mov $0xc,%esi 3e: mov $0xc,%esi 22: callq 0xffffffffe1021e15 43: callq 0xffffffffe102bd75 27: cmp $0x86dd,%eax 48: cmp $0x86dd,%rax 2c: jne 0x0000000000000069 4f: jne 0x000000000000009a 2e: mov $0x14,%esi 51: mov $0x14,%esi 33: callq 0xffffffffe1021e31 56: callq 0xffffffffe102bd91 38: cmp $0x84,%eax 5b: cmp $0x84,%rax 3d: je 0x0000000000000049 62: je 0x0000000000000074 3f: cmp $0x6,%eax 64: cmp $0x6,%rax 42: je 0x0000000000000049 68: je 0x0000000000000074 44: cmp $0x11,%eax 6a: cmp $0x11,%rax 47: jne 0x00000000000000c6 6e: jne 0x0000000000000117 49: mov $0x36,%esi 74: mov $0x36,%esi 4e: callq 0xffffffffe1021e15 79: callq 0xffffffffe102bd75 53: cmp $0x16,%eax 7e: cmp $0x16,%rax 56: je 0x00000000000000bf 82: je 0x0000000000000110 58: mov $0x38,%esi 88: mov $0x38,%esi 5d: callq 0xffffffffe1021e15 8d: callq 0xffffffffe102bd75 62: cmp $0x16,%eax 92: cmp $0x16,%rax 65: je 0x00000000000000bf 96: je 0x0000000000000110 67: jmp 0x00000000000000c6 98: jmp 0x0000000000000117 69: cmp $0x800,%eax 9a: cmp $0x800,%rax 6e: jne 0x00000000000000c6 a1: jne 0x0000000000000117 70: mov $0x17,%esi a3: mov $0x17,%esi 75: callq 0xffffffffe1021e31 a8: callq 0xffffffffe102bd91 7a: cmp $0x84,%eax ad: cmp $0x84,%rax 7f: je 0x000000000000008b b4: je 0x00000000000000c2 81: cmp $0x6,%eax b6: cmp $0x6,%rax 84: je 0x000000000000008b ba: je 0x00000000000000c2 86: cmp $0x11,%eax bc: cmp $0x11,%rax 89: jne 0x00000000000000c6 c0: jne 0x0000000000000117 8b: mov $0x14,%esi c2: mov $0x14,%esi 90: callq 0xffffffffe1021e15 c7: callq 0xffffffffe102bd75 95: test $0x1fff,%ax cc: test $0x1fff,%rax 99: jne 0x00000000000000c6 d3: jne 0x0000000000000117 d5: mov %rax,%r14 9b: mov $0xe,%esi d8: mov $0xe,%esi a0: callq 0xffffffffe1021e44 dd: callq 0xffffffffe102bd91 // MSH e2: and $0xf,%eax e5: shl $0x2,%eax e8: mov %rax,%r13 eb: mov %r14,%rax ee: mov %r13,%rsi a5: lea 0xe(%rbx),%esi f1: add $0xe,%esi a8: callq 0xffffffffe1021e0d f4: callq 0xffffffffe102bd6d ad: cmp $0x16,%eax f9: cmp $0x16,%rax b0: je 0x00000000000000bf fd: je 0x0000000000000110 ff: mov %r13,%rsi b2: lea 0x10(%rbx),%esi 102: add $0x10,%esi b5: callq 0xffffffffe1021e0d 105: callq 0xffffffffe102bd6d ba: cmp $0x16,%eax 10a: cmp $0x16,%rax bd: jne 0x00000000000000c6 10e: jne 0x0000000000000117 bf: mov $0xffff,%eax 110: mov $0xffff,%eax c4: jmp 0x00000000000000c8 115: jmp 0x000000000000011c c6: xor %eax,%eax 117: mov $0x0,%eax c8: mov -0x8(%rbp),%rbx 11c: mov -0x228(%rbp),%rbx // epilogue cc: leaveq 123: mov -0x220(%rbp),%r13 cd: retq 12a: mov -0x218(%rbp),%r14 131: mov -0x210(%rbp),%r15 138: leaveq 139: retq On fully cached SKBs both JITed functions take 12 nsec to execute. BPF interpreter executes the program in 30 nsec. The difference in generated assembler is due to the following: Old BPF imlements LDX_MSH instruction via sk_load_byte_msh() helper function inside bpf_jit.S. New JIT removes the helper and does it explicitly, so ldx_msh cost is the same for both JITs, but generated code looks longer. New JIT has 4 registers to save, so prologue/epilogue are larger, but the cost is within noise on x64. Old JIT checks whether first insn clears A and if not emits 'xor %eax,%eax'. New JIT clears %rax unconditionally. 2. old BPF JIT doesn't support ANC_NLATTR, ANC_PAY_OFFSET, ANC_RANDOM extensions. New JIT supports all BPF extensions. Performance of such filters improves 2-4 times depending on a filter. The longer the filter the higher performance gain. Synthetic benchmarks with many ancillary loads see 20x speedup which seems to be the maximum gain from JIT Notes: . net.core.bpf_jit_enable=2 + tools/net/bpf_jit_disasm is still functional and can be used to see generated assembler . there are two jit_compile() functions and code flow for classic filters is: sk_attach_filter() - load classic BPF bpf_jit_compile() - try to JIT from classic BPF sk_convert_filter() - convert classic to internal bpf_int_jit_compile() - JIT from internal BPF seccomp and tracing filters will just call bpf_int_jit_compile() Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 20:50:46 -06:00
/* mov qword ptr [rbp-X],r15 */
x86: bpf_jit: implement bpf_tail_call() helper bpf_tail_call() arguments: ctx - context pointer jmp_table - one of BPF_MAP_TYPE_PROG_ARRAY maps used as the jump table index - index in the jump table In this implementation x64 JIT bypasses stack unwind and jumps into the callee program after prologue, so the callee program reuses the same stack. The logic can be roughly expressed in C like: u32 tail_call_cnt; void *jumptable[2] = { &&label1, &&label2 }; int bpf_prog1(void *ctx) { label1: ... } int bpf_prog2(void *ctx) { label2: ... } int bpf_prog1(void *ctx) { ... if (tail_call_cnt++ < MAX_TAIL_CALL_CNT) goto *jumptable[index]; ... and pass my 'ctx' to callee ... ... fall through if no entry in jumptable ... } Note that 'skip current program epilogue and next program prologue' is an optimization. Other JITs don't have to do it the same way. >From safety point of view it's valid as well, since programs always initialize the stack before use, so any residue in the stack left by the current program is not going be read. The same verifier checks are done for the calls from the kernel into all bpf programs. Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-19 17:59:04 -06:00
EMIT3_off32(0x4C, 0x89, 0xBD, -STACKSIZE + 24);
net: filter: x86: internal BPF JIT Maps all internal BPF instructions into x86_64 instructions. This patch replaces original BPF x64 JIT with internal BPF x64 JIT. sysctl net.core.bpf_jit_enable is reused as on/off switch. Performance: 1. old BPF JIT and internal BPF JIT generate equivalent x86_64 code. No performance difference is observed for filters that were JIT-able before Example assembler code for BPF filter "tcpdump port 22" original BPF -> old JIT: original BPF -> internal BPF -> new JIT: 0: push %rbp 0: push %rbp 1: mov %rsp,%rbp 1: mov %rsp,%rbp 4: sub $0x60,%rsp 4: sub $0x228,%rsp 8: mov %rbx,-0x8(%rbp) b: mov %rbx,-0x228(%rbp) // prologue 12: mov %r13,-0x220(%rbp) 19: mov %r14,-0x218(%rbp) 20: mov %r15,-0x210(%rbp) 27: xor %eax,%eax // clear A c: xor %ebx,%ebx 29: xor %r13,%r13 // clear X e: mov 0x68(%rdi),%r9d 2c: mov 0x68(%rdi),%r9d 12: sub 0x6c(%rdi),%r9d 30: sub 0x6c(%rdi),%r9d 16: mov 0xd8(%rdi),%r8 34: mov 0xd8(%rdi),%r10 3b: mov %rdi,%rbx 1d: mov $0xc,%esi 3e: mov $0xc,%esi 22: callq 0xffffffffe1021e15 43: callq 0xffffffffe102bd75 27: cmp $0x86dd,%eax 48: cmp $0x86dd,%rax 2c: jne 0x0000000000000069 4f: jne 0x000000000000009a 2e: mov $0x14,%esi 51: mov $0x14,%esi 33: callq 0xffffffffe1021e31 56: callq 0xffffffffe102bd91 38: cmp $0x84,%eax 5b: cmp $0x84,%rax 3d: je 0x0000000000000049 62: je 0x0000000000000074 3f: cmp $0x6,%eax 64: cmp $0x6,%rax 42: je 0x0000000000000049 68: je 0x0000000000000074 44: cmp $0x11,%eax 6a: cmp $0x11,%rax 47: jne 0x00000000000000c6 6e: jne 0x0000000000000117 49: mov $0x36,%esi 74: mov $0x36,%esi 4e: callq 0xffffffffe1021e15 79: callq 0xffffffffe102bd75 53: cmp $0x16,%eax 7e: cmp $0x16,%rax 56: je 0x00000000000000bf 82: je 0x0000000000000110 58: mov $0x38,%esi 88: mov $0x38,%esi 5d: callq 0xffffffffe1021e15 8d: callq 0xffffffffe102bd75 62: cmp $0x16,%eax 92: cmp $0x16,%rax 65: je 0x00000000000000bf 96: je 0x0000000000000110 67: jmp 0x00000000000000c6 98: jmp 0x0000000000000117 69: cmp $0x800,%eax 9a: cmp $0x800,%rax 6e: jne 0x00000000000000c6 a1: jne 0x0000000000000117 70: mov $0x17,%esi a3: mov $0x17,%esi 75: callq 0xffffffffe1021e31 a8: callq 0xffffffffe102bd91 7a: cmp $0x84,%eax ad: cmp $0x84,%rax 7f: je 0x000000000000008b b4: je 0x00000000000000c2 81: cmp $0x6,%eax b6: cmp $0x6,%rax 84: je 0x000000000000008b ba: je 0x00000000000000c2 86: cmp $0x11,%eax bc: cmp $0x11,%rax 89: jne 0x00000000000000c6 c0: jne 0x0000000000000117 8b: mov $0x14,%esi c2: mov $0x14,%esi 90: callq 0xffffffffe1021e15 c7: callq 0xffffffffe102bd75 95: test $0x1fff,%ax cc: test $0x1fff,%rax 99: jne 0x00000000000000c6 d3: jne 0x0000000000000117 d5: mov %rax,%r14 9b: mov $0xe,%esi d8: mov $0xe,%esi a0: callq 0xffffffffe1021e44 dd: callq 0xffffffffe102bd91 // MSH e2: and $0xf,%eax e5: shl $0x2,%eax e8: mov %rax,%r13 eb: mov %r14,%rax ee: mov %r13,%rsi a5: lea 0xe(%rbx),%esi f1: add $0xe,%esi a8: callq 0xffffffffe1021e0d f4: callq 0xffffffffe102bd6d ad: cmp $0x16,%eax f9: cmp $0x16,%rax b0: je 0x00000000000000bf fd: je 0x0000000000000110 ff: mov %r13,%rsi b2: lea 0x10(%rbx),%esi 102: add $0x10,%esi b5: callq 0xffffffffe1021e0d 105: callq 0xffffffffe102bd6d ba: cmp $0x16,%eax 10a: cmp $0x16,%rax bd: jne 0x00000000000000c6 10e: jne 0x0000000000000117 bf: mov $0xffff,%eax 110: mov $0xffff,%eax c4: jmp 0x00000000000000c8 115: jmp 0x000000000000011c c6: xor %eax,%eax 117: mov $0x0,%eax c8: mov -0x8(%rbp),%rbx 11c: mov -0x228(%rbp),%rbx // epilogue cc: leaveq 123: mov -0x220(%rbp),%r13 cd: retq 12a: mov -0x218(%rbp),%r14 131: mov -0x210(%rbp),%r15 138: leaveq 139: retq On fully cached SKBs both JITed functions take 12 nsec to execute. BPF interpreter executes the program in 30 nsec. The difference in generated assembler is due to the following: Old BPF imlements LDX_MSH instruction via sk_load_byte_msh() helper function inside bpf_jit.S. New JIT removes the helper and does it explicitly, so ldx_msh cost is the same for both JITs, but generated code looks longer. New JIT has 4 registers to save, so prologue/epilogue are larger, but the cost is within noise on x64. Old JIT checks whether first insn clears A and if not emits 'xor %eax,%eax'. New JIT clears %rax unconditionally. 2. old BPF JIT doesn't support ANC_NLATTR, ANC_PAY_OFFSET, ANC_RANDOM extensions. New JIT supports all BPF extensions. Performance of such filters improves 2-4 times depending on a filter. The longer the filter the higher performance gain. Synthetic benchmarks with many ancillary loads see 20x speedup which seems to be the maximum gain from JIT Notes: . net.core.bpf_jit_enable=2 + tools/net/bpf_jit_disasm is still functional and can be used to see generated assembler . there are two jit_compile() functions and code flow for classic filters is: sk_attach_filter() - load classic BPF bpf_jit_compile() - try to JIT from classic BPF sk_convert_filter() - convert classic to internal bpf_int_jit_compile() - JIT from internal BPF seccomp and tracing filters will just call bpf_int_jit_compile() Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 20:50:46 -06:00
bpf: move clearing of A/X into classic to eBPF migration prologue Back in the days where eBPF (or back then "internal BPF" ;->) was not exposed to user space, and only the classic BPF programs internally translated into eBPF programs, we missed the fact that for classic BPF A and X needed to be cleared. It was fixed back then via 83d5b7ef99c9 ("net: filter: initialize A and X registers"), and thus classic BPF specifics were added to the eBPF interpreter core to work around it. This added some confusion for JIT developers later on that take the eBPF interpreter code as an example for deriving their JIT. F.e. in f75298f5c3fe ("s390/bpf: clear correct BPF accumulator register"), at least X could leak stack memory. Furthermore, since this is only needed for classic BPF translations and not for eBPF (verifier takes care that read access to regs cannot be done uninitialized), more complexity is added to JITs as they need to determine whether they deal with migrations or native eBPF where they can just omit clearing A/X in their prologue and thus reduce image size a bit, see f.e. cde66c2d88da ("s390/bpf: Only clear A and X for converted BPF programs"). In other cases (x86, arm64), A and X is being cleared in the prologue also for eBPF case, which is unnecessary. Lets move this into the BPF migration in bpf_convert_filter() where it actually belongs as long as the number of eBPF JITs are still few. It can thus be done generically; allowing us to remove the quirk from __bpf_prog_run() and to slightly reduce JIT image size in case of eBPF, while reducing code duplication on this matter in current(/future) eBPF JITs. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Reviewed-by: Michael Holzheu <holzheu@linux.vnet.ibm.com> Tested-by: Michael Holzheu <holzheu@linux.vnet.ibm.com> Cc: Zi Shen Lim <zlim.lnx@gmail.com> Cc: Yang Shi <yang.shi@linaro.org> Acked-by: Yang Shi <yang.shi@linaro.org> Acked-by: Zi Shen Lim <zlim.lnx@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-12-17 15:51:54 -07:00
/* Clear the tail call counter (tail_call_cnt): for eBPF tail calls
* we need to reset the counter to 0. It's done in two instructions,
* resetting rax register to 0 (xor on eax gets 0 extended), and
* moving it to the counter location.
*/
net: filter: x86: internal BPF JIT Maps all internal BPF instructions into x86_64 instructions. This patch replaces original BPF x64 JIT with internal BPF x64 JIT. sysctl net.core.bpf_jit_enable is reused as on/off switch. Performance: 1. old BPF JIT and internal BPF JIT generate equivalent x86_64 code. No performance difference is observed for filters that were JIT-able before Example assembler code for BPF filter "tcpdump port 22" original BPF -> old JIT: original BPF -> internal BPF -> new JIT: 0: push %rbp 0: push %rbp 1: mov %rsp,%rbp 1: mov %rsp,%rbp 4: sub $0x60,%rsp 4: sub $0x228,%rsp 8: mov %rbx,-0x8(%rbp) b: mov %rbx,-0x228(%rbp) // prologue 12: mov %r13,-0x220(%rbp) 19: mov %r14,-0x218(%rbp) 20: mov %r15,-0x210(%rbp) 27: xor %eax,%eax // clear A c: xor %ebx,%ebx 29: xor %r13,%r13 // clear X e: mov 0x68(%rdi),%r9d 2c: mov 0x68(%rdi),%r9d 12: sub 0x6c(%rdi),%r9d 30: sub 0x6c(%rdi),%r9d 16: mov 0xd8(%rdi),%r8 34: mov 0xd8(%rdi),%r10 3b: mov %rdi,%rbx 1d: mov $0xc,%esi 3e: mov $0xc,%esi 22: callq 0xffffffffe1021e15 43: callq 0xffffffffe102bd75 27: cmp $0x86dd,%eax 48: cmp $0x86dd,%rax 2c: jne 0x0000000000000069 4f: jne 0x000000000000009a 2e: mov $0x14,%esi 51: mov $0x14,%esi 33: callq 0xffffffffe1021e31 56: callq 0xffffffffe102bd91 38: cmp $0x84,%eax 5b: cmp $0x84,%rax 3d: je 0x0000000000000049 62: je 0x0000000000000074 3f: cmp $0x6,%eax 64: cmp $0x6,%rax 42: je 0x0000000000000049 68: je 0x0000000000000074 44: cmp $0x11,%eax 6a: cmp $0x11,%rax 47: jne 0x00000000000000c6 6e: jne 0x0000000000000117 49: mov $0x36,%esi 74: mov $0x36,%esi 4e: callq 0xffffffffe1021e15 79: callq 0xffffffffe102bd75 53: cmp $0x16,%eax 7e: cmp $0x16,%rax 56: je 0x00000000000000bf 82: je 0x0000000000000110 58: mov $0x38,%esi 88: mov $0x38,%esi 5d: callq 0xffffffffe1021e15 8d: callq 0xffffffffe102bd75 62: cmp $0x16,%eax 92: cmp $0x16,%rax 65: je 0x00000000000000bf 96: je 0x0000000000000110 67: jmp 0x00000000000000c6 98: jmp 0x0000000000000117 69: cmp $0x800,%eax 9a: cmp $0x800,%rax 6e: jne 0x00000000000000c6 a1: jne 0x0000000000000117 70: mov $0x17,%esi a3: mov $0x17,%esi 75: callq 0xffffffffe1021e31 a8: callq 0xffffffffe102bd91 7a: cmp $0x84,%eax ad: cmp $0x84,%rax 7f: je 0x000000000000008b b4: je 0x00000000000000c2 81: cmp $0x6,%eax b6: cmp $0x6,%rax 84: je 0x000000000000008b ba: je 0x00000000000000c2 86: cmp $0x11,%eax bc: cmp $0x11,%rax 89: jne 0x00000000000000c6 c0: jne 0x0000000000000117 8b: mov $0x14,%esi c2: mov $0x14,%esi 90: callq 0xffffffffe1021e15 c7: callq 0xffffffffe102bd75 95: test $0x1fff,%ax cc: test $0x1fff,%rax 99: jne 0x00000000000000c6 d3: jne 0x0000000000000117 d5: mov %rax,%r14 9b: mov $0xe,%esi d8: mov $0xe,%esi a0: callq 0xffffffffe1021e44 dd: callq 0xffffffffe102bd91 // MSH e2: and $0xf,%eax e5: shl $0x2,%eax e8: mov %rax,%r13 eb: mov %r14,%rax ee: mov %r13,%rsi a5: lea 0xe(%rbx),%esi f1: add $0xe,%esi a8: callq 0xffffffffe1021e0d f4: callq 0xffffffffe102bd6d ad: cmp $0x16,%eax f9: cmp $0x16,%rax b0: je 0x00000000000000bf fd: je 0x0000000000000110 ff: mov %r13,%rsi b2: lea 0x10(%rbx),%esi 102: add $0x10,%esi b5: callq 0xffffffffe1021e0d 105: callq 0xffffffffe102bd6d ba: cmp $0x16,%eax 10a: cmp $0x16,%rax bd: jne 0x00000000000000c6 10e: jne 0x0000000000000117 bf: mov $0xffff,%eax 110: mov $0xffff,%eax c4: jmp 0x00000000000000c8 115: jmp 0x000000000000011c c6: xor %eax,%eax 117: mov $0x0,%eax c8: mov -0x8(%rbp),%rbx 11c: mov -0x228(%rbp),%rbx // epilogue cc: leaveq 123: mov -0x220(%rbp),%r13 cd: retq 12a: mov -0x218(%rbp),%r14 131: mov -0x210(%rbp),%r15 138: leaveq 139: retq On fully cached SKBs both JITed functions take 12 nsec to execute. BPF interpreter executes the program in 30 nsec. The difference in generated assembler is due to the following: Old BPF imlements LDX_MSH instruction via sk_load_byte_msh() helper function inside bpf_jit.S. New JIT removes the helper and does it explicitly, so ldx_msh cost is the same for both JITs, but generated code looks longer. New JIT has 4 registers to save, so prologue/epilogue are larger, but the cost is within noise on x64. Old JIT checks whether first insn clears A and if not emits 'xor %eax,%eax'. New JIT clears %rax unconditionally. 2. old BPF JIT doesn't support ANC_NLATTR, ANC_PAY_OFFSET, ANC_RANDOM extensions. New JIT supports all BPF extensions. Performance of such filters improves 2-4 times depending on a filter. The longer the filter the higher performance gain. Synthetic benchmarks with many ancillary loads see 20x speedup which seems to be the maximum gain from JIT Notes: . net.core.bpf_jit_enable=2 + tools/net/bpf_jit_disasm is still functional and can be used to see generated assembler . there are two jit_compile() functions and code flow for classic filters is: sk_attach_filter() - load classic BPF bpf_jit_compile() - try to JIT from classic BPF sk_convert_filter() - convert classic to internal bpf_int_jit_compile() - JIT from internal BPF seccomp and tracing filters will just call bpf_int_jit_compile() Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 20:50:46 -06:00
bpf: move clearing of A/X into classic to eBPF migration prologue Back in the days where eBPF (or back then "internal BPF" ;->) was not exposed to user space, and only the classic BPF programs internally translated into eBPF programs, we missed the fact that for classic BPF A and X needed to be cleared. It was fixed back then via 83d5b7ef99c9 ("net: filter: initialize A and X registers"), and thus classic BPF specifics were added to the eBPF interpreter core to work around it. This added some confusion for JIT developers later on that take the eBPF interpreter code as an example for deriving their JIT. F.e. in f75298f5c3fe ("s390/bpf: clear correct BPF accumulator register"), at least X could leak stack memory. Furthermore, since this is only needed for classic BPF translations and not for eBPF (verifier takes care that read access to regs cannot be done uninitialized), more complexity is added to JITs as they need to determine whether they deal with migrations or native eBPF where they can just omit clearing A/X in their prologue and thus reduce image size a bit, see f.e. cde66c2d88da ("s390/bpf: Only clear A and X for converted BPF programs"). In other cases (x86, arm64), A and X is being cleared in the prologue also for eBPF case, which is unnecessary. Lets move this into the BPF migration in bpf_convert_filter() where it actually belongs as long as the number of eBPF JITs are still few. It can thus be done generically; allowing us to remove the quirk from __bpf_prog_run() and to slightly reduce JIT image size in case of eBPF, while reducing code duplication on this matter in current(/future) eBPF JITs. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Reviewed-by: Michael Holzheu <holzheu@linux.vnet.ibm.com> Tested-by: Michael Holzheu <holzheu@linux.vnet.ibm.com> Cc: Zi Shen Lim <zlim.lnx@gmail.com> Cc: Yang Shi <yang.shi@linaro.org> Acked-by: Yang Shi <yang.shi@linaro.org> Acked-by: Zi Shen Lim <zlim.lnx@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-12-17 15:51:54 -07:00
/* xor eax, eax */
EMIT2(0x31, 0xc0);
/* mov qword ptr [rbp-X], rax */
x86: bpf_jit: implement bpf_tail_call() helper bpf_tail_call() arguments: ctx - context pointer jmp_table - one of BPF_MAP_TYPE_PROG_ARRAY maps used as the jump table index - index in the jump table In this implementation x64 JIT bypasses stack unwind and jumps into the callee program after prologue, so the callee program reuses the same stack. The logic can be roughly expressed in C like: u32 tail_call_cnt; void *jumptable[2] = { &&label1, &&label2 }; int bpf_prog1(void *ctx) { label1: ... } int bpf_prog2(void *ctx) { label2: ... } int bpf_prog1(void *ctx) { ... if (tail_call_cnt++ < MAX_TAIL_CALL_CNT) goto *jumptable[index]; ... and pass my 'ctx' to callee ... ... fall through if no entry in jumptable ... } Note that 'skip current program epilogue and next program prologue' is an optimization. Other JITs don't have to do it the same way. >From safety point of view it's valid as well, since programs always initialize the stack before use, so any residue in the stack left by the current program is not going be read. The same verifier checks are done for the calls from the kernel into all bpf programs. Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-19 17:59:04 -06:00
EMIT3_off32(0x48, 0x89, 0x85, -STACKSIZE + 32);
BUILD_BUG_ON(cnt != PROLOGUE_SIZE);
*pprog = prog;
}
/* generate the following code:
* ... bpf_tail_call(void *ctx, struct bpf_array *array, u64 index) ...
* if (index >= array->map.max_entries)
* goto out;
* if (++tail_call_cnt > MAX_TAIL_CALL_CNT)
* goto out;
bpf: Make the bpf_prog_array_map more generic All the map backends are of generic nature. In order to avoid adding much special code into the eBPF core, rewrite part of the bpf_prog_array map code and make it more generic. So the new perf_event_array map type can reuse most of code with bpf_prog_array map and add fewer lines of special code. Signed-off-by: Wang Nan <wangnan0@huawei.com> Signed-off-by: Kaixu Xia <xiakaixu@huawei.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-08-06 01:02:33 -06:00
* prog = array->ptrs[index];
x86: bpf_jit: implement bpf_tail_call() helper bpf_tail_call() arguments: ctx - context pointer jmp_table - one of BPF_MAP_TYPE_PROG_ARRAY maps used as the jump table index - index in the jump table In this implementation x64 JIT bypasses stack unwind and jumps into the callee program after prologue, so the callee program reuses the same stack. The logic can be roughly expressed in C like: u32 tail_call_cnt; void *jumptable[2] = { &&label1, &&label2 }; int bpf_prog1(void *ctx) { label1: ... } int bpf_prog2(void *ctx) { label2: ... } int bpf_prog1(void *ctx) { ... if (tail_call_cnt++ < MAX_TAIL_CALL_CNT) goto *jumptable[index]; ... and pass my 'ctx' to callee ... ... fall through if no entry in jumptable ... } Note that 'skip current program epilogue and next program prologue' is an optimization. Other JITs don't have to do it the same way. >From safety point of view it's valid as well, since programs always initialize the stack before use, so any residue in the stack left by the current program is not going be read. The same verifier checks are done for the calls from the kernel into all bpf programs. Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-19 17:59:04 -06:00
* if (prog == NULL)
* goto out;
* goto *(prog->bpf_func + prologue_size);
* out:
*/
static void emit_bpf_tail_call(u8 **pprog)
{
u8 *prog = *pprog;
int label1, label2, label3;
int cnt = 0;
/* rdi - pointer to ctx
* rsi - pointer to bpf_array
* rdx - index in bpf_array
*/
/* if (index >= array->map.max_entries)
* goto out;
*/
EMIT4(0x48, 0x8B, 0x46, /* mov rax, qword ptr [rsi + 16] */
offsetof(struct bpf_array, map.max_entries));
EMIT3(0x48, 0x39, 0xD0); /* cmp rax, rdx */
ebpf, x86: fix general protection fault when tail call is invoked With eBPF JIT compiler enabled on x86_64, I was able to reliably trigger the following general protection fault out of an eBPF program with a simple tail call, f.e. tracex5 (or a stripped down version of it): [ 927.097918] general protection fault: 0000 [#1] SMP DEBUG_PAGEALLOC [...] [ 927.100870] task: ffff8801f228b780 ti: ffff880016a64000 task.ti: ffff880016a64000 [ 927.102096] RIP: 0010:[<ffffffffa002440d>] [<ffffffffa002440d>] 0xffffffffa002440d [ 927.103390] RSP: 0018:ffff880016a67a68 EFLAGS: 00010006 [ 927.104683] RAX: 5a5a5a5a5a5a5a5a RBX: 0000000000000000 RCX: 0000000000000001 [ 927.105921] RDX: 0000000000000000 RSI: ffff88014e438000 RDI: ffff880016a67e00 [ 927.107137] RBP: ffff880016a67c90 R08: 0000000000000000 R09: 0000000000000001 [ 927.108351] R10: 0000000000000000 R11: 0000000000000000 R12: ffff880016a67e00 [ 927.109567] R13: 0000000000000000 R14: ffff88026500e460 R15: ffff880220a81520 [ 927.110787] FS: 00007fe7d5c1f740(0000) GS:ffff880265000000(0000) knlGS:0000000000000000 [ 927.112021] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 927.113255] CR2: 0000003e7bbb91a0 CR3: 000000006e04b000 CR4: 00000000001407e0 [ 927.114500] Stack: [ 927.115737] ffffc90008cdb000 ffff880016a67e00 ffff88026500e460 ffff880220a81520 [ 927.117005] 0000000100000000 000000000000001b ffff880016a67aa8 ffffffff8106c548 [ 927.118276] 00007ffcdaf22e58 0000000000000000 0000000000000000 ffff880016a67ff0 [ 927.119543] Call Trace: [ 927.120797] [<ffffffff8106c548>] ? lookup_address+0x28/0x30 [ 927.122058] [<ffffffff8113d176>] ? __module_text_address+0x16/0x70 [ 927.123314] [<ffffffff8117bf0e>] ? is_ftrace_trampoline+0x3e/0x70 [ 927.124562] [<ffffffff810c1a0f>] ? __kernel_text_address+0x5f/0x80 [ 927.125806] [<ffffffff8102086f>] ? print_context_stack+0x7f/0xf0 [ 927.127033] [<ffffffff810f7852>] ? __lock_acquire+0x572/0x2050 [ 927.128254] [<ffffffff810f7852>] ? __lock_acquire+0x572/0x2050 [ 927.129461] [<ffffffff8119edfa>] ? trace_call_bpf+0x3a/0x140 [ 927.130654] [<ffffffff8119ee4a>] trace_call_bpf+0x8a/0x140 [ 927.131837] [<ffffffff8119edfa>] ? trace_call_bpf+0x3a/0x140 [ 927.133015] [<ffffffff8119f008>] kprobe_perf_func+0x28/0x220 [ 927.134195] [<ffffffff811a1668>] kprobe_dispatcher+0x38/0x60 [ 927.135367] [<ffffffff81174b91>] ? seccomp_phase1+0x1/0x230 [ 927.136523] [<ffffffff81061400>] kprobe_ftrace_handler+0xf0/0x150 [ 927.137666] [<ffffffff81174b95>] ? seccomp_phase1+0x5/0x230 [ 927.138802] [<ffffffff8117950c>] ftrace_ops_recurs_func+0x5c/0xb0 [ 927.139934] [<ffffffffa022b0d5>] 0xffffffffa022b0d5 [ 927.141066] [<ffffffff81174b91>] ? seccomp_phase1+0x1/0x230 [ 927.142199] [<ffffffff81174b95>] seccomp_phase1+0x5/0x230 [ 927.143323] [<ffffffff8102c0a4>] syscall_trace_enter_phase1+0xc4/0x150 [ 927.144450] [<ffffffff81174b95>] ? seccomp_phase1+0x5/0x230 [ 927.145572] [<ffffffff8102c0a4>] ? syscall_trace_enter_phase1+0xc4/0x150 [ 927.146666] [<ffffffff817f9a9f>] tracesys+0xd/0x44 [ 927.147723] Code: 48 8b 46 10 48 39 d0 76 2c 8b 85 fc fd ff ff 83 f8 20 77 21 83 c0 01 89 85 fc fd ff ff 48 8d 44 d6 80 48 8b 00 48 83 f8 00 74 0a <48> 8b 40 20 48 83 c0 33 ff e0 48 89 d8 48 8b 9d d8 fd ff ff 4c [ 927.150046] RIP [<ffffffffa002440d>] 0xffffffffa002440d The code section with the instructions that traps points into the eBPF JIT image of the root program (the one invoking the tail call instruction). Using bpf_jit_disasm -o on the eBPF root program image: [...] 4e: mov -0x204(%rbp),%eax 8b 85 fc fd ff ff 54: cmp $0x20,%eax <--- if (tail_call_cnt > MAX_TAIL_CALL_CNT) 83 f8 20 57: ja 0x000000000000007a 77 21 59: add $0x1,%eax <--- tail_call_cnt++ 83 c0 01 5c: mov %eax,-0x204(%rbp) 89 85 fc fd ff ff 62: lea -0x80(%rsi,%rdx,8),%rax <--- prog = array->prog[index] 48 8d 44 d6 80 67: mov (%rax),%rax 48 8b 00 6a: cmp $0x0,%rax <--- check for NULL 48 83 f8 00 6e: je 0x000000000000007a 74 0a 70: mov 0x20(%rax),%rax <--- GPF triggered here! fetch of bpf_func 48 8b 40 20 [ matches <48> 8b 40 20 ... from above ] 74: add $0x33,%rax <--- prologue skip of new prog 48 83 c0 33 78: jmpq *%rax <--- jump to new prog insns ff e0 [...] The problem is that rax has 5a5a5a5a5a5a5a5a, which suggests a tail call jump to map slot 0 is pointing to a poisoned page. The issue is the following: lea instruction has a wrong offset, i.e. it should be ... lea 0x80(%rsi,%rdx,8),%rax ... but it actually seems to be ... lea -0x80(%rsi,%rdx,8),%rax ... where 0x80 is offsetof(struct bpf_array, prog), thus the offset needs to be positive instead of negative. Disassembling the interpreter, we btw similarly do: [...] c88: lea 0x80(%rax,%rdx,8),%rax <--- prog = array->prog[index] 48 8d 84 d0 80 00 00 00 c90: add $0x1,%r13d 41 83 c5 01 c94: mov (%rax),%rax 48 8b 00 [...] Now the other interesting fact is that this panic triggers only when things like CONFIG_LOCKDEP are being used. In that case offsetof(struct bpf_array, prog) starts at offset 0x80 and in non-CONFIG_LOCKDEP case at offset 0x50. Reason is that the work_struct inside struct bpf_map grows by 48 bytes in my case due to the lockdep_map member (which also has CONFIG_LOCK_STAT enabled members). Changing the emitter to always use the 4 byte displacement in the lea instruction fixes the panic on my side. It increases the tail call instruction emission by 3 more byte, but it should cover us from various combinations (and perhaps other future increases on related structures). After patch, disassembly: [...] 9e: lea 0x80(%rsi,%rdx,8),%rax <--- CONFIG_LOCKDEP/CONFIG_LOCK_STAT 48 8d 84 d6 80 00 00 00 a6: mov (%rax),%rax 48 8b 00 [...] [...] 9e: lea 0x50(%rsi,%rdx,8),%rax <--- No CONFIG_LOCKDEP 48 8d 84 d6 50 00 00 00 a6: mov (%rax),%rax 48 8b 00 [...] Fixes: b52f00e6a715 ("x86: bpf_jit: implement bpf_tail_call() helper") Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-28 07:26:36 -06:00
#define OFFSET1 47 /* number of bytes to jump */
x86: bpf_jit: implement bpf_tail_call() helper bpf_tail_call() arguments: ctx - context pointer jmp_table - one of BPF_MAP_TYPE_PROG_ARRAY maps used as the jump table index - index in the jump table In this implementation x64 JIT bypasses stack unwind and jumps into the callee program after prologue, so the callee program reuses the same stack. The logic can be roughly expressed in C like: u32 tail_call_cnt; void *jumptable[2] = { &&label1, &&label2 }; int bpf_prog1(void *ctx) { label1: ... } int bpf_prog2(void *ctx) { label2: ... } int bpf_prog1(void *ctx) { ... if (tail_call_cnt++ < MAX_TAIL_CALL_CNT) goto *jumptable[index]; ... and pass my 'ctx' to callee ... ... fall through if no entry in jumptable ... } Note that 'skip current program epilogue and next program prologue' is an optimization. Other JITs don't have to do it the same way. >From safety point of view it's valid as well, since programs always initialize the stack before use, so any residue in the stack left by the current program is not going be read. The same verifier checks are done for the calls from the kernel into all bpf programs. Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-19 17:59:04 -06:00
EMIT2(X86_JBE, OFFSET1); /* jbe out */
label1 = cnt;
/* if (tail_call_cnt > MAX_TAIL_CALL_CNT)
* goto out;
*/
EMIT2_off32(0x8B, 0x85, -STACKSIZE + 36); /* mov eax, dword ptr [rbp - 516] */
EMIT3(0x83, 0xF8, MAX_TAIL_CALL_CNT); /* cmp eax, MAX_TAIL_CALL_CNT */
ebpf, x86: fix general protection fault when tail call is invoked With eBPF JIT compiler enabled on x86_64, I was able to reliably trigger the following general protection fault out of an eBPF program with a simple tail call, f.e. tracex5 (or a stripped down version of it): [ 927.097918] general protection fault: 0000 [#1] SMP DEBUG_PAGEALLOC [...] [ 927.100870] task: ffff8801f228b780 ti: ffff880016a64000 task.ti: ffff880016a64000 [ 927.102096] RIP: 0010:[<ffffffffa002440d>] [<ffffffffa002440d>] 0xffffffffa002440d [ 927.103390] RSP: 0018:ffff880016a67a68 EFLAGS: 00010006 [ 927.104683] RAX: 5a5a5a5a5a5a5a5a RBX: 0000000000000000 RCX: 0000000000000001 [ 927.105921] RDX: 0000000000000000 RSI: ffff88014e438000 RDI: ffff880016a67e00 [ 927.107137] RBP: ffff880016a67c90 R08: 0000000000000000 R09: 0000000000000001 [ 927.108351] R10: 0000000000000000 R11: 0000000000000000 R12: ffff880016a67e00 [ 927.109567] R13: 0000000000000000 R14: ffff88026500e460 R15: ffff880220a81520 [ 927.110787] FS: 00007fe7d5c1f740(0000) GS:ffff880265000000(0000) knlGS:0000000000000000 [ 927.112021] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 927.113255] CR2: 0000003e7bbb91a0 CR3: 000000006e04b000 CR4: 00000000001407e0 [ 927.114500] Stack: [ 927.115737] ffffc90008cdb000 ffff880016a67e00 ffff88026500e460 ffff880220a81520 [ 927.117005] 0000000100000000 000000000000001b ffff880016a67aa8 ffffffff8106c548 [ 927.118276] 00007ffcdaf22e58 0000000000000000 0000000000000000 ffff880016a67ff0 [ 927.119543] Call Trace: [ 927.120797] [<ffffffff8106c548>] ? lookup_address+0x28/0x30 [ 927.122058] [<ffffffff8113d176>] ? __module_text_address+0x16/0x70 [ 927.123314] [<ffffffff8117bf0e>] ? is_ftrace_trampoline+0x3e/0x70 [ 927.124562] [<ffffffff810c1a0f>] ? __kernel_text_address+0x5f/0x80 [ 927.125806] [<ffffffff8102086f>] ? print_context_stack+0x7f/0xf0 [ 927.127033] [<ffffffff810f7852>] ? __lock_acquire+0x572/0x2050 [ 927.128254] [<ffffffff810f7852>] ? __lock_acquire+0x572/0x2050 [ 927.129461] [<ffffffff8119edfa>] ? trace_call_bpf+0x3a/0x140 [ 927.130654] [<ffffffff8119ee4a>] trace_call_bpf+0x8a/0x140 [ 927.131837] [<ffffffff8119edfa>] ? trace_call_bpf+0x3a/0x140 [ 927.133015] [<ffffffff8119f008>] kprobe_perf_func+0x28/0x220 [ 927.134195] [<ffffffff811a1668>] kprobe_dispatcher+0x38/0x60 [ 927.135367] [<ffffffff81174b91>] ? seccomp_phase1+0x1/0x230 [ 927.136523] [<ffffffff81061400>] kprobe_ftrace_handler+0xf0/0x150 [ 927.137666] [<ffffffff81174b95>] ? seccomp_phase1+0x5/0x230 [ 927.138802] [<ffffffff8117950c>] ftrace_ops_recurs_func+0x5c/0xb0 [ 927.139934] [<ffffffffa022b0d5>] 0xffffffffa022b0d5 [ 927.141066] [<ffffffff81174b91>] ? seccomp_phase1+0x1/0x230 [ 927.142199] [<ffffffff81174b95>] seccomp_phase1+0x5/0x230 [ 927.143323] [<ffffffff8102c0a4>] syscall_trace_enter_phase1+0xc4/0x150 [ 927.144450] [<ffffffff81174b95>] ? seccomp_phase1+0x5/0x230 [ 927.145572] [<ffffffff8102c0a4>] ? syscall_trace_enter_phase1+0xc4/0x150 [ 927.146666] [<ffffffff817f9a9f>] tracesys+0xd/0x44 [ 927.147723] Code: 48 8b 46 10 48 39 d0 76 2c 8b 85 fc fd ff ff 83 f8 20 77 21 83 c0 01 89 85 fc fd ff ff 48 8d 44 d6 80 48 8b 00 48 83 f8 00 74 0a <48> 8b 40 20 48 83 c0 33 ff e0 48 89 d8 48 8b 9d d8 fd ff ff 4c [ 927.150046] RIP [<ffffffffa002440d>] 0xffffffffa002440d The code section with the instructions that traps points into the eBPF JIT image of the root program (the one invoking the tail call instruction). Using bpf_jit_disasm -o on the eBPF root program image: [...] 4e: mov -0x204(%rbp),%eax 8b 85 fc fd ff ff 54: cmp $0x20,%eax <--- if (tail_call_cnt > MAX_TAIL_CALL_CNT) 83 f8 20 57: ja 0x000000000000007a 77 21 59: add $0x1,%eax <--- tail_call_cnt++ 83 c0 01 5c: mov %eax,-0x204(%rbp) 89 85 fc fd ff ff 62: lea -0x80(%rsi,%rdx,8),%rax <--- prog = array->prog[index] 48 8d 44 d6 80 67: mov (%rax),%rax 48 8b 00 6a: cmp $0x0,%rax <--- check for NULL 48 83 f8 00 6e: je 0x000000000000007a 74 0a 70: mov 0x20(%rax),%rax <--- GPF triggered here! fetch of bpf_func 48 8b 40 20 [ matches <48> 8b 40 20 ... from above ] 74: add $0x33,%rax <--- prologue skip of new prog 48 83 c0 33 78: jmpq *%rax <--- jump to new prog insns ff e0 [...] The problem is that rax has 5a5a5a5a5a5a5a5a, which suggests a tail call jump to map slot 0 is pointing to a poisoned page. The issue is the following: lea instruction has a wrong offset, i.e. it should be ... lea 0x80(%rsi,%rdx,8),%rax ... but it actually seems to be ... lea -0x80(%rsi,%rdx,8),%rax ... where 0x80 is offsetof(struct bpf_array, prog), thus the offset needs to be positive instead of negative. Disassembling the interpreter, we btw similarly do: [...] c88: lea 0x80(%rax,%rdx,8),%rax <--- prog = array->prog[index] 48 8d 84 d0 80 00 00 00 c90: add $0x1,%r13d 41 83 c5 01 c94: mov (%rax),%rax 48 8b 00 [...] Now the other interesting fact is that this panic triggers only when things like CONFIG_LOCKDEP are being used. In that case offsetof(struct bpf_array, prog) starts at offset 0x80 and in non-CONFIG_LOCKDEP case at offset 0x50. Reason is that the work_struct inside struct bpf_map grows by 48 bytes in my case due to the lockdep_map member (which also has CONFIG_LOCK_STAT enabled members). Changing the emitter to always use the 4 byte displacement in the lea instruction fixes the panic on my side. It increases the tail call instruction emission by 3 more byte, but it should cover us from various combinations (and perhaps other future increases on related structures). After patch, disassembly: [...] 9e: lea 0x80(%rsi,%rdx,8),%rax <--- CONFIG_LOCKDEP/CONFIG_LOCK_STAT 48 8d 84 d6 80 00 00 00 a6: mov (%rax),%rax 48 8b 00 [...] [...] 9e: lea 0x50(%rsi,%rdx,8),%rax <--- No CONFIG_LOCKDEP 48 8d 84 d6 50 00 00 00 a6: mov (%rax),%rax 48 8b 00 [...] Fixes: b52f00e6a715 ("x86: bpf_jit: implement bpf_tail_call() helper") Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-28 07:26:36 -06:00
#define OFFSET2 36
x86: bpf_jit: implement bpf_tail_call() helper bpf_tail_call() arguments: ctx - context pointer jmp_table - one of BPF_MAP_TYPE_PROG_ARRAY maps used as the jump table index - index in the jump table In this implementation x64 JIT bypasses stack unwind and jumps into the callee program after prologue, so the callee program reuses the same stack. The logic can be roughly expressed in C like: u32 tail_call_cnt; void *jumptable[2] = { &&label1, &&label2 }; int bpf_prog1(void *ctx) { label1: ... } int bpf_prog2(void *ctx) { label2: ... } int bpf_prog1(void *ctx) { ... if (tail_call_cnt++ < MAX_TAIL_CALL_CNT) goto *jumptable[index]; ... and pass my 'ctx' to callee ... ... fall through if no entry in jumptable ... } Note that 'skip current program epilogue and next program prologue' is an optimization. Other JITs don't have to do it the same way. >From safety point of view it's valid as well, since programs always initialize the stack before use, so any residue in the stack left by the current program is not going be read. The same verifier checks are done for the calls from the kernel into all bpf programs. Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-19 17:59:04 -06:00
EMIT2(X86_JA, OFFSET2); /* ja out */
label2 = cnt;
EMIT3(0x83, 0xC0, 0x01); /* add eax, 1 */
EMIT2_off32(0x89, 0x85, -STACKSIZE + 36); /* mov dword ptr [rbp - 516], eax */
bpf: Make the bpf_prog_array_map more generic All the map backends are of generic nature. In order to avoid adding much special code into the eBPF core, rewrite part of the bpf_prog_array map code and make it more generic. So the new perf_event_array map type can reuse most of code with bpf_prog_array map and add fewer lines of special code. Signed-off-by: Wang Nan <wangnan0@huawei.com> Signed-off-by: Kaixu Xia <xiakaixu@huawei.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-08-06 01:02:33 -06:00
/* prog = array->ptrs[index]; */
ebpf, x86: fix general protection fault when tail call is invoked With eBPF JIT compiler enabled on x86_64, I was able to reliably trigger the following general protection fault out of an eBPF program with a simple tail call, f.e. tracex5 (or a stripped down version of it): [ 927.097918] general protection fault: 0000 [#1] SMP DEBUG_PAGEALLOC [...] [ 927.100870] task: ffff8801f228b780 ti: ffff880016a64000 task.ti: ffff880016a64000 [ 927.102096] RIP: 0010:[<ffffffffa002440d>] [<ffffffffa002440d>] 0xffffffffa002440d [ 927.103390] RSP: 0018:ffff880016a67a68 EFLAGS: 00010006 [ 927.104683] RAX: 5a5a5a5a5a5a5a5a RBX: 0000000000000000 RCX: 0000000000000001 [ 927.105921] RDX: 0000000000000000 RSI: ffff88014e438000 RDI: ffff880016a67e00 [ 927.107137] RBP: ffff880016a67c90 R08: 0000000000000000 R09: 0000000000000001 [ 927.108351] R10: 0000000000000000 R11: 0000000000000000 R12: ffff880016a67e00 [ 927.109567] R13: 0000000000000000 R14: ffff88026500e460 R15: ffff880220a81520 [ 927.110787] FS: 00007fe7d5c1f740(0000) GS:ffff880265000000(0000) knlGS:0000000000000000 [ 927.112021] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 927.113255] CR2: 0000003e7bbb91a0 CR3: 000000006e04b000 CR4: 00000000001407e0 [ 927.114500] Stack: [ 927.115737] ffffc90008cdb000 ffff880016a67e00 ffff88026500e460 ffff880220a81520 [ 927.117005] 0000000100000000 000000000000001b ffff880016a67aa8 ffffffff8106c548 [ 927.118276] 00007ffcdaf22e58 0000000000000000 0000000000000000 ffff880016a67ff0 [ 927.119543] Call Trace: [ 927.120797] [<ffffffff8106c548>] ? lookup_address+0x28/0x30 [ 927.122058] [<ffffffff8113d176>] ? __module_text_address+0x16/0x70 [ 927.123314] [<ffffffff8117bf0e>] ? is_ftrace_trampoline+0x3e/0x70 [ 927.124562] [<ffffffff810c1a0f>] ? __kernel_text_address+0x5f/0x80 [ 927.125806] [<ffffffff8102086f>] ? print_context_stack+0x7f/0xf0 [ 927.127033] [<ffffffff810f7852>] ? __lock_acquire+0x572/0x2050 [ 927.128254] [<ffffffff810f7852>] ? __lock_acquire+0x572/0x2050 [ 927.129461] [<ffffffff8119edfa>] ? trace_call_bpf+0x3a/0x140 [ 927.130654] [<ffffffff8119ee4a>] trace_call_bpf+0x8a/0x140 [ 927.131837] [<ffffffff8119edfa>] ? trace_call_bpf+0x3a/0x140 [ 927.133015] [<ffffffff8119f008>] kprobe_perf_func+0x28/0x220 [ 927.134195] [<ffffffff811a1668>] kprobe_dispatcher+0x38/0x60 [ 927.135367] [<ffffffff81174b91>] ? seccomp_phase1+0x1/0x230 [ 927.136523] [<ffffffff81061400>] kprobe_ftrace_handler+0xf0/0x150 [ 927.137666] [<ffffffff81174b95>] ? seccomp_phase1+0x5/0x230 [ 927.138802] [<ffffffff8117950c>] ftrace_ops_recurs_func+0x5c/0xb0 [ 927.139934] [<ffffffffa022b0d5>] 0xffffffffa022b0d5 [ 927.141066] [<ffffffff81174b91>] ? seccomp_phase1+0x1/0x230 [ 927.142199] [<ffffffff81174b95>] seccomp_phase1+0x5/0x230 [ 927.143323] [<ffffffff8102c0a4>] syscall_trace_enter_phase1+0xc4/0x150 [ 927.144450] [<ffffffff81174b95>] ? seccomp_phase1+0x5/0x230 [ 927.145572] [<ffffffff8102c0a4>] ? syscall_trace_enter_phase1+0xc4/0x150 [ 927.146666] [<ffffffff817f9a9f>] tracesys+0xd/0x44 [ 927.147723] Code: 48 8b 46 10 48 39 d0 76 2c 8b 85 fc fd ff ff 83 f8 20 77 21 83 c0 01 89 85 fc fd ff ff 48 8d 44 d6 80 48 8b 00 48 83 f8 00 74 0a <48> 8b 40 20 48 83 c0 33 ff e0 48 89 d8 48 8b 9d d8 fd ff ff 4c [ 927.150046] RIP [<ffffffffa002440d>] 0xffffffffa002440d The code section with the instructions that traps points into the eBPF JIT image of the root program (the one invoking the tail call instruction). Using bpf_jit_disasm -o on the eBPF root program image: [...] 4e: mov -0x204(%rbp),%eax 8b 85 fc fd ff ff 54: cmp $0x20,%eax <--- if (tail_call_cnt > MAX_TAIL_CALL_CNT) 83 f8 20 57: ja 0x000000000000007a 77 21 59: add $0x1,%eax <--- tail_call_cnt++ 83 c0 01 5c: mov %eax,-0x204(%rbp) 89 85 fc fd ff ff 62: lea -0x80(%rsi,%rdx,8),%rax <--- prog = array->prog[index] 48 8d 44 d6 80 67: mov (%rax),%rax 48 8b 00 6a: cmp $0x0,%rax <--- check for NULL 48 83 f8 00 6e: je 0x000000000000007a 74 0a 70: mov 0x20(%rax),%rax <--- GPF triggered here! fetch of bpf_func 48 8b 40 20 [ matches <48> 8b 40 20 ... from above ] 74: add $0x33,%rax <--- prologue skip of new prog 48 83 c0 33 78: jmpq *%rax <--- jump to new prog insns ff e0 [...] The problem is that rax has 5a5a5a5a5a5a5a5a, which suggests a tail call jump to map slot 0 is pointing to a poisoned page. The issue is the following: lea instruction has a wrong offset, i.e. it should be ... lea 0x80(%rsi,%rdx,8),%rax ... but it actually seems to be ... lea -0x80(%rsi,%rdx,8),%rax ... where 0x80 is offsetof(struct bpf_array, prog), thus the offset needs to be positive instead of negative. Disassembling the interpreter, we btw similarly do: [...] c88: lea 0x80(%rax,%rdx,8),%rax <--- prog = array->prog[index] 48 8d 84 d0 80 00 00 00 c90: add $0x1,%r13d 41 83 c5 01 c94: mov (%rax),%rax 48 8b 00 [...] Now the other interesting fact is that this panic triggers only when things like CONFIG_LOCKDEP are being used. In that case offsetof(struct bpf_array, prog) starts at offset 0x80 and in non-CONFIG_LOCKDEP case at offset 0x50. Reason is that the work_struct inside struct bpf_map grows by 48 bytes in my case due to the lockdep_map member (which also has CONFIG_LOCK_STAT enabled members). Changing the emitter to always use the 4 byte displacement in the lea instruction fixes the panic on my side. It increases the tail call instruction emission by 3 more byte, but it should cover us from various combinations (and perhaps other future increases on related structures). After patch, disassembly: [...] 9e: lea 0x80(%rsi,%rdx,8),%rax <--- CONFIG_LOCKDEP/CONFIG_LOCK_STAT 48 8d 84 d6 80 00 00 00 a6: mov (%rax),%rax 48 8b 00 [...] [...] 9e: lea 0x50(%rsi,%rdx,8),%rax <--- No CONFIG_LOCKDEP 48 8d 84 d6 50 00 00 00 a6: mov (%rax),%rax 48 8b 00 [...] Fixes: b52f00e6a715 ("x86: bpf_jit: implement bpf_tail_call() helper") Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-28 07:26:36 -06:00
EMIT4_off32(0x48, 0x8D, 0x84, 0xD6, /* lea rax, [rsi + rdx * 8 + offsetof(...)] */
bpf: Make the bpf_prog_array_map more generic All the map backends are of generic nature. In order to avoid adding much special code into the eBPF core, rewrite part of the bpf_prog_array map code and make it more generic. So the new perf_event_array map type can reuse most of code with bpf_prog_array map and add fewer lines of special code. Signed-off-by: Wang Nan <wangnan0@huawei.com> Signed-off-by: Kaixu Xia <xiakaixu@huawei.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-08-06 01:02:33 -06:00
offsetof(struct bpf_array, ptrs));
x86: bpf_jit: implement bpf_tail_call() helper bpf_tail_call() arguments: ctx - context pointer jmp_table - one of BPF_MAP_TYPE_PROG_ARRAY maps used as the jump table index - index in the jump table In this implementation x64 JIT bypasses stack unwind and jumps into the callee program after prologue, so the callee program reuses the same stack. The logic can be roughly expressed in C like: u32 tail_call_cnt; void *jumptable[2] = { &&label1, &&label2 }; int bpf_prog1(void *ctx) { label1: ... } int bpf_prog2(void *ctx) { label2: ... } int bpf_prog1(void *ctx) { ... if (tail_call_cnt++ < MAX_TAIL_CALL_CNT) goto *jumptable[index]; ... and pass my 'ctx' to callee ... ... fall through if no entry in jumptable ... } Note that 'skip current program epilogue and next program prologue' is an optimization. Other JITs don't have to do it the same way. >From safety point of view it's valid as well, since programs always initialize the stack before use, so any residue in the stack left by the current program is not going be read. The same verifier checks are done for the calls from the kernel into all bpf programs. Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-19 17:59:04 -06:00
EMIT3(0x48, 0x8B, 0x00); /* mov rax, qword ptr [rax] */
/* if (prog == NULL)
* goto out;
*/
EMIT4(0x48, 0x83, 0xF8, 0x00); /* cmp rax, 0 */
#define OFFSET3 10
EMIT2(X86_JE, OFFSET3); /* je out */
label3 = cnt;
/* goto *(prog->bpf_func + prologue_size); */
EMIT4(0x48, 0x8B, 0x40, /* mov rax, qword ptr [rax + 32] */
offsetof(struct bpf_prog, bpf_func));
EMIT4(0x48, 0x83, 0xC0, PROLOGUE_SIZE); /* add rax, prologue_size */
/* now we're ready to jump into next BPF program
* rdi == ctx (1st arg)
* rax == prog->bpf_func + prologue_size
*/
EMIT2(0xFF, 0xE0); /* jmp rax */
/* out: */
BUILD_BUG_ON(cnt - label1 != OFFSET1);
BUILD_BUG_ON(cnt - label2 != OFFSET2);
BUILD_BUG_ON(cnt - label3 != OFFSET3);
*pprog = prog;
}
bpf: introduce bpf_skb_vlan_push/pop() helpers Allow eBPF programs attached to TC qdiscs call skb_vlan_push/pop via helper functions. These functions may change skb->data/hlen which are cached by some JITs to improve performance of ld_abs/ld_ind instructions. Therefore JITs need to recognize bpf_skb_vlan_push/pop() calls, re-compute header len and re-cache skb->data/hlen back into cpu registers. Note, skb->data/hlen are not directly accessible from the programs, so any changes to skb->data done either by these helpers or by other TC actions are safe. eBPF JIT supported by three architectures: - arm64 JIT is using bpf_load_pointer() without caching, so it's ok as-is. - x64 JIT re-caches skb->data/hlen unconditionally after vlan_push/pop calls (experiments showed that conditional re-caching is slower). - s390 JIT falls back to interpreter for now when bpf_skb_vlan_push() is present in the program (re-caching is tbd). These helpers allow more scalable handling of vlan from the programs. Instead of creating thousands of vlan netdevs on top of eth0 and attaching TC+ingress+bpf to all of them, the program can be attached to eth0 directly and manipulate vlans as necessary. Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-20 21:34:18 -06:00
static void emit_load_skb_data_hlen(u8 **pprog)
{
u8 *prog = *pprog;
int cnt = 0;
/* r9d = skb->len - skb->data_len (headlen)
* r10 = skb->data
*/
/* mov %r9d, off32(%rdi) */
EMIT3_off32(0x44, 0x8b, 0x8f, offsetof(struct sk_buff, len));
/* sub %r9d, off32(%rdi) */
EMIT3_off32(0x44, 0x2b, 0x8f, offsetof(struct sk_buff, data_len));
/* mov %r10, off32(%rdi) */
EMIT3_off32(0x4c, 0x8b, 0x97, offsetof(struct sk_buff, data));
*pprog = prog;
}
x86: bpf_jit: implement bpf_tail_call() helper bpf_tail_call() arguments: ctx - context pointer jmp_table - one of BPF_MAP_TYPE_PROG_ARRAY maps used as the jump table index - index in the jump table In this implementation x64 JIT bypasses stack unwind and jumps into the callee program after prologue, so the callee program reuses the same stack. The logic can be roughly expressed in C like: u32 tail_call_cnt; void *jumptable[2] = { &&label1, &&label2 }; int bpf_prog1(void *ctx) { label1: ... } int bpf_prog2(void *ctx) { label2: ... } int bpf_prog1(void *ctx) { ... if (tail_call_cnt++ < MAX_TAIL_CALL_CNT) goto *jumptable[index]; ... and pass my 'ctx' to callee ... ... fall through if no entry in jumptable ... } Note that 'skip current program epilogue and next program prologue' is an optimization. Other JITs don't have to do it the same way. >From safety point of view it's valid as well, since programs always initialize the stack before use, so any residue in the stack left by the current program is not going be read. The same verifier checks are done for the calls from the kernel into all bpf programs. Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-19 17:59:04 -06:00
static int do_jit(struct bpf_prog *bpf_prog, int *addrs, u8 *image,
int oldproglen, struct jit_context *ctx)
{
struct bpf_insn *insn = bpf_prog->insnsi;
int insn_cnt = bpf_prog->len;
bool seen_ld_abs = ctx->seen_ld_abs | (oldproglen == 0);
bpf, x86: add support for constant blinding This patch adds recently added constant blinding helpers into the x86 eBPF JIT. In the bpf_int_jit_compile() path, requirements are to utilize bpf_jit_blind_constants()/bpf_jit_prog_release_other() pair for rewriting the program into a blinded one, and to map the BPF_REG_AX register to a CPU register. The mapping of BPF_REG_AX is at non-callee saved register r10, and thus shared with cached skb->data used for ld_abs/ind and not in every program type needed. When blinding is not used, there's zero additional overhead in the generated image. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-05-13 11:08:33 -06:00
bool seen_ax_reg = ctx->seen_ax_reg | (oldproglen == 0);
x86: bpf_jit: implement bpf_tail_call() helper bpf_tail_call() arguments: ctx - context pointer jmp_table - one of BPF_MAP_TYPE_PROG_ARRAY maps used as the jump table index - index in the jump table In this implementation x64 JIT bypasses stack unwind and jumps into the callee program after prologue, so the callee program reuses the same stack. The logic can be roughly expressed in C like: u32 tail_call_cnt; void *jumptable[2] = { &&label1, &&label2 }; int bpf_prog1(void *ctx) { label1: ... } int bpf_prog2(void *ctx) { label2: ... } int bpf_prog1(void *ctx) { ... if (tail_call_cnt++ < MAX_TAIL_CALL_CNT) goto *jumptable[index]; ... and pass my 'ctx' to callee ... ... fall through if no entry in jumptable ... } Note that 'skip current program epilogue and next program prologue' is an optimization. Other JITs don't have to do it the same way. >From safety point of view it's valid as well, since programs always initialize the stack before use, so any residue in the stack left by the current program is not going be read. The same verifier checks are done for the calls from the kernel into all bpf programs. Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-19 17:59:04 -06:00
bool seen_exit = false;
u8 temp[BPF_MAX_INSN_SIZE + BPF_INSN_SAFETY];
int i, cnt = 0;
int proglen = 0;
u8 *prog = temp;
emit_prologue(&prog);
bpf: introduce bpf_skb_vlan_push/pop() helpers Allow eBPF programs attached to TC qdiscs call skb_vlan_push/pop via helper functions. These functions may change skb->data/hlen which are cached by some JITs to improve performance of ld_abs/ld_ind instructions. Therefore JITs need to recognize bpf_skb_vlan_push/pop() calls, re-compute header len and re-cache skb->data/hlen back into cpu registers. Note, skb->data/hlen are not directly accessible from the programs, so any changes to skb->data done either by these helpers or by other TC actions are safe. eBPF JIT supported by three architectures: - arm64 JIT is using bpf_load_pointer() without caching, so it's ok as-is. - x64 JIT re-caches skb->data/hlen unconditionally after vlan_push/pop calls (experiments showed that conditional re-caching is slower). - s390 JIT falls back to interpreter for now when bpf_skb_vlan_push() is present in the program (re-caching is tbd). These helpers allow more scalable handling of vlan from the programs. Instead of creating thousands of vlan netdevs on top of eth0 and attaching TC+ingress+bpf to all of them, the program can be attached to eth0 directly and manipulate vlans as necessary. Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-20 21:34:18 -06:00
if (seen_ld_abs)
emit_load_skb_data_hlen(&prog);
net: filter: x86: internal BPF JIT Maps all internal BPF instructions into x86_64 instructions. This patch replaces original BPF x64 JIT with internal BPF x64 JIT. sysctl net.core.bpf_jit_enable is reused as on/off switch. Performance: 1. old BPF JIT and internal BPF JIT generate equivalent x86_64 code. No performance difference is observed for filters that were JIT-able before Example assembler code for BPF filter "tcpdump port 22" original BPF -> old JIT: original BPF -> internal BPF -> new JIT: 0: push %rbp 0: push %rbp 1: mov %rsp,%rbp 1: mov %rsp,%rbp 4: sub $0x60,%rsp 4: sub $0x228,%rsp 8: mov %rbx,-0x8(%rbp) b: mov %rbx,-0x228(%rbp) // prologue 12: mov %r13,-0x220(%rbp) 19: mov %r14,-0x218(%rbp) 20: mov %r15,-0x210(%rbp) 27: xor %eax,%eax // clear A c: xor %ebx,%ebx 29: xor %r13,%r13 // clear X e: mov 0x68(%rdi),%r9d 2c: mov 0x68(%rdi),%r9d 12: sub 0x6c(%rdi),%r9d 30: sub 0x6c(%rdi),%r9d 16: mov 0xd8(%rdi),%r8 34: mov 0xd8(%rdi),%r10 3b: mov %rdi,%rbx 1d: mov $0xc,%esi 3e: mov $0xc,%esi 22: callq 0xffffffffe1021e15 43: callq 0xffffffffe102bd75 27: cmp $0x86dd,%eax 48: cmp $0x86dd,%rax 2c: jne 0x0000000000000069 4f: jne 0x000000000000009a 2e: mov $0x14,%esi 51: mov $0x14,%esi 33: callq 0xffffffffe1021e31 56: callq 0xffffffffe102bd91 38: cmp $0x84,%eax 5b: cmp $0x84,%rax 3d: je 0x0000000000000049 62: je 0x0000000000000074 3f: cmp $0x6,%eax 64: cmp $0x6,%rax 42: je 0x0000000000000049 68: je 0x0000000000000074 44: cmp $0x11,%eax 6a: cmp $0x11,%rax 47: jne 0x00000000000000c6 6e: jne 0x0000000000000117 49: mov $0x36,%esi 74: mov $0x36,%esi 4e: callq 0xffffffffe1021e15 79: callq 0xffffffffe102bd75 53: cmp $0x16,%eax 7e: cmp $0x16,%rax 56: je 0x00000000000000bf 82: je 0x0000000000000110 58: mov $0x38,%esi 88: mov $0x38,%esi 5d: callq 0xffffffffe1021e15 8d: callq 0xffffffffe102bd75 62: cmp $0x16,%eax 92: cmp $0x16,%rax 65: je 0x00000000000000bf 96: je 0x0000000000000110 67: jmp 0x00000000000000c6 98: jmp 0x0000000000000117 69: cmp $0x800,%eax 9a: cmp $0x800,%rax 6e: jne 0x00000000000000c6 a1: jne 0x0000000000000117 70: mov $0x17,%esi a3: mov $0x17,%esi 75: callq 0xffffffffe1021e31 a8: callq 0xffffffffe102bd91 7a: cmp $0x84,%eax ad: cmp $0x84,%rax 7f: je 0x000000000000008b b4: je 0x00000000000000c2 81: cmp $0x6,%eax b6: cmp $0x6,%rax 84: je 0x000000000000008b ba: je 0x00000000000000c2 86: cmp $0x11,%eax bc: cmp $0x11,%rax 89: jne 0x00000000000000c6 c0: jne 0x0000000000000117 8b: mov $0x14,%esi c2: mov $0x14,%esi 90: callq 0xffffffffe1021e15 c7: callq 0xffffffffe102bd75 95: test $0x1fff,%ax cc: test $0x1fff,%rax 99: jne 0x00000000000000c6 d3: jne 0x0000000000000117 d5: mov %rax,%r14 9b: mov $0xe,%esi d8: mov $0xe,%esi a0: callq 0xffffffffe1021e44 dd: callq 0xffffffffe102bd91 // MSH e2: and $0xf,%eax e5: shl $0x2,%eax e8: mov %rax,%r13 eb: mov %r14,%rax ee: mov %r13,%rsi a5: lea 0xe(%rbx),%esi f1: add $0xe,%esi a8: callq 0xffffffffe1021e0d f4: callq 0xffffffffe102bd6d ad: cmp $0x16,%eax f9: cmp $0x16,%rax b0: je 0x00000000000000bf fd: je 0x0000000000000110 ff: mov %r13,%rsi b2: lea 0x10(%rbx),%esi 102: add $0x10,%esi b5: callq 0xffffffffe1021e0d 105: callq 0xffffffffe102bd6d ba: cmp $0x16,%eax 10a: cmp $0x16,%rax bd: jne 0x00000000000000c6 10e: jne 0x0000000000000117 bf: mov $0xffff,%eax 110: mov $0xffff,%eax c4: jmp 0x00000000000000c8 115: jmp 0x000000000000011c c6: xor %eax,%eax 117: mov $0x0,%eax c8: mov -0x8(%rbp),%rbx 11c: mov -0x228(%rbp),%rbx // epilogue cc: leaveq 123: mov -0x220(%rbp),%r13 cd: retq 12a: mov -0x218(%rbp),%r14 131: mov -0x210(%rbp),%r15 138: leaveq 139: retq On fully cached SKBs both JITed functions take 12 nsec to execute. BPF interpreter executes the program in 30 nsec. The difference in generated assembler is due to the following: Old BPF imlements LDX_MSH instruction via sk_load_byte_msh() helper function inside bpf_jit.S. New JIT removes the helper and does it explicitly, so ldx_msh cost is the same for both JITs, but generated code looks longer. New JIT has 4 registers to save, so prologue/epilogue are larger, but the cost is within noise on x64. Old JIT checks whether first insn clears A and if not emits 'xor %eax,%eax'. New JIT clears %rax unconditionally. 2. old BPF JIT doesn't support ANC_NLATTR, ANC_PAY_OFFSET, ANC_RANDOM extensions. New JIT supports all BPF extensions. Performance of such filters improves 2-4 times depending on a filter. The longer the filter the higher performance gain. Synthetic benchmarks with many ancillary loads see 20x speedup which seems to be the maximum gain from JIT Notes: . net.core.bpf_jit_enable=2 + tools/net/bpf_jit_disasm is still functional and can be used to see generated assembler . there are two jit_compile() functions and code flow for classic filters is: sk_attach_filter() - load classic BPF bpf_jit_compile() - try to JIT from classic BPF sk_convert_filter() - convert classic to internal bpf_int_jit_compile() - JIT from internal BPF seccomp and tracing filters will just call bpf_int_jit_compile() Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 20:50:46 -06:00
for (i = 0; i < insn_cnt; i++, insn++) {
net: filter: cleanup A/X name usage The macro 'A' used in internal BPF interpreter: #define A regs[insn->a_reg] was easily confused with the name of classic BPF register 'A', since 'A' would mean two different things depending on context. This patch is trying to clean up the naming and clarify its usage in the following way: - A and X are names of two classic BPF registers - BPF_REG_A denotes internal BPF register R0 used to map classic register A in internal BPF programs generated from classic - BPF_REG_X denotes internal BPF register R7 used to map classic register X in internal BPF programs generated from classic - internal BPF instruction format: struct sock_filter_int { __u8 code; /* opcode */ __u8 dst_reg:4; /* dest register */ __u8 src_reg:4; /* source register */ __s16 off; /* signed offset */ __s32 imm; /* signed immediate constant */ }; - BPF_X/BPF_K is 1 bit used to encode source operand of instruction In classic: BPF_X - means use register X as source operand BPF_K - means use 32-bit immediate as source operand In internal: BPF_X - means use 'src_reg' register as source operand BPF_K - means use 32-bit immediate as source operand Suggested-by: Chema Gonzalez <chema@google.com> Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Acked-by: Daniel Borkmann <dborkman@redhat.com> Acked-by: Chema Gonzalez <chema@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-06-06 15:46:06 -06:00
const s32 imm32 = insn->imm;
u32 dst_reg = insn->dst_reg;
u32 src_reg = insn->src_reg;
net: filter: x86: internal BPF JIT Maps all internal BPF instructions into x86_64 instructions. This patch replaces original BPF x64 JIT with internal BPF x64 JIT. sysctl net.core.bpf_jit_enable is reused as on/off switch. Performance: 1. old BPF JIT and internal BPF JIT generate equivalent x86_64 code. No performance difference is observed for filters that were JIT-able before Example assembler code for BPF filter "tcpdump port 22" original BPF -> old JIT: original BPF -> internal BPF -> new JIT: 0: push %rbp 0: push %rbp 1: mov %rsp,%rbp 1: mov %rsp,%rbp 4: sub $0x60,%rsp 4: sub $0x228,%rsp 8: mov %rbx,-0x8(%rbp) b: mov %rbx,-0x228(%rbp) // prologue 12: mov %r13,-0x220(%rbp) 19: mov %r14,-0x218(%rbp) 20: mov %r15,-0x210(%rbp) 27: xor %eax,%eax // clear A c: xor %ebx,%ebx 29: xor %r13,%r13 // clear X e: mov 0x68(%rdi),%r9d 2c: mov 0x68(%rdi),%r9d 12: sub 0x6c(%rdi),%r9d 30: sub 0x6c(%rdi),%r9d 16: mov 0xd8(%rdi),%r8 34: mov 0xd8(%rdi),%r10 3b: mov %rdi,%rbx 1d: mov $0xc,%esi 3e: mov $0xc,%esi 22: callq 0xffffffffe1021e15 43: callq 0xffffffffe102bd75 27: cmp $0x86dd,%eax 48: cmp $0x86dd,%rax 2c: jne 0x0000000000000069 4f: jne 0x000000000000009a 2e: mov $0x14,%esi 51: mov $0x14,%esi 33: callq 0xffffffffe1021e31 56: callq 0xffffffffe102bd91 38: cmp $0x84,%eax 5b: cmp $0x84,%rax 3d: je 0x0000000000000049 62: je 0x0000000000000074 3f: cmp $0x6,%eax 64: cmp $0x6,%rax 42: je 0x0000000000000049 68: je 0x0000000000000074 44: cmp $0x11,%eax 6a: cmp $0x11,%rax 47: jne 0x00000000000000c6 6e: jne 0x0000000000000117 49: mov $0x36,%esi 74: mov $0x36,%esi 4e: callq 0xffffffffe1021e15 79: callq 0xffffffffe102bd75 53: cmp $0x16,%eax 7e: cmp $0x16,%rax 56: je 0x00000000000000bf 82: je 0x0000000000000110 58: mov $0x38,%esi 88: mov $0x38,%esi 5d: callq 0xffffffffe1021e15 8d: callq 0xffffffffe102bd75 62: cmp $0x16,%eax 92: cmp $0x16,%rax 65: je 0x00000000000000bf 96: je 0x0000000000000110 67: jmp 0x00000000000000c6 98: jmp 0x0000000000000117 69: cmp $0x800,%eax 9a: cmp $0x800,%rax 6e: jne 0x00000000000000c6 a1: jne 0x0000000000000117 70: mov $0x17,%esi a3: mov $0x17,%esi 75: callq 0xffffffffe1021e31 a8: callq 0xffffffffe102bd91 7a: cmp $0x84,%eax ad: cmp $0x84,%rax 7f: je 0x000000000000008b b4: je 0x00000000000000c2 81: cmp $0x6,%eax b6: cmp $0x6,%rax 84: je 0x000000000000008b ba: je 0x00000000000000c2 86: cmp $0x11,%eax bc: cmp $0x11,%rax 89: jne 0x00000000000000c6 c0: jne 0x0000000000000117 8b: mov $0x14,%esi c2: mov $0x14,%esi 90: callq 0xffffffffe1021e15 c7: callq 0xffffffffe102bd75 95: test $0x1fff,%ax cc: test $0x1fff,%rax 99: jne 0x00000000000000c6 d3: jne 0x0000000000000117 d5: mov %rax,%r14 9b: mov $0xe,%esi d8: mov $0xe,%esi a0: callq 0xffffffffe1021e44 dd: callq 0xffffffffe102bd91 // MSH e2: and $0xf,%eax e5: shl $0x2,%eax e8: mov %rax,%r13 eb: mov %r14,%rax ee: mov %r13,%rsi a5: lea 0xe(%rbx),%esi f1: add $0xe,%esi a8: callq 0xffffffffe1021e0d f4: callq 0xffffffffe102bd6d ad: cmp $0x16,%eax f9: cmp $0x16,%rax b0: je 0x00000000000000bf fd: je 0x0000000000000110 ff: mov %r13,%rsi b2: lea 0x10(%rbx),%esi 102: add $0x10,%esi b5: callq 0xffffffffe1021e0d 105: callq 0xffffffffe102bd6d ba: cmp $0x16,%eax 10a: cmp $0x16,%rax bd: jne 0x00000000000000c6 10e: jne 0x0000000000000117 bf: mov $0xffff,%eax 110: mov $0xffff,%eax c4: jmp 0x00000000000000c8 115: jmp 0x000000000000011c c6: xor %eax,%eax 117: mov $0x0,%eax c8: mov -0x8(%rbp),%rbx 11c: mov -0x228(%rbp),%rbx // epilogue cc: leaveq 123: mov -0x220(%rbp),%r13 cd: retq 12a: mov -0x218(%rbp),%r14 131: mov -0x210(%rbp),%r15 138: leaveq 139: retq On fully cached SKBs both JITed functions take 12 nsec to execute. BPF interpreter executes the program in 30 nsec. The difference in generated assembler is due to the following: Old BPF imlements LDX_MSH instruction via sk_load_byte_msh() helper function inside bpf_jit.S. New JIT removes the helper and does it explicitly, so ldx_msh cost is the same for both JITs, but generated code looks longer. New JIT has 4 registers to save, so prologue/epilogue are larger, but the cost is within noise on x64. Old JIT checks whether first insn clears A and if not emits 'xor %eax,%eax'. New JIT clears %rax unconditionally. 2. old BPF JIT doesn't support ANC_NLATTR, ANC_PAY_OFFSET, ANC_RANDOM extensions. New JIT supports all BPF extensions. Performance of such filters improves 2-4 times depending on a filter. The longer the filter the higher performance gain. Synthetic benchmarks with many ancillary loads see 20x speedup which seems to be the maximum gain from JIT Notes: . net.core.bpf_jit_enable=2 + tools/net/bpf_jit_disasm is still functional and can be used to see generated assembler . there are two jit_compile() functions and code flow for classic filters is: sk_attach_filter() - load classic BPF bpf_jit_compile() - try to JIT from classic BPF sk_convert_filter() - convert classic to internal bpf_int_jit_compile() - JIT from internal BPF seccomp and tracing filters will just call bpf_int_jit_compile() Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 20:50:46 -06:00
u8 b1 = 0, b2 = 0, b3 = 0;
s64 jmp_offset;
u8 jmp_cond;
bpf: introduce bpf_skb_vlan_push/pop() helpers Allow eBPF programs attached to TC qdiscs call skb_vlan_push/pop via helper functions. These functions may change skb->data/hlen which are cached by some JITs to improve performance of ld_abs/ld_ind instructions. Therefore JITs need to recognize bpf_skb_vlan_push/pop() calls, re-compute header len and re-cache skb->data/hlen back into cpu registers. Note, skb->data/hlen are not directly accessible from the programs, so any changes to skb->data done either by these helpers or by other TC actions are safe. eBPF JIT supported by three architectures: - arm64 JIT is using bpf_load_pointer() without caching, so it's ok as-is. - x64 JIT re-caches skb->data/hlen unconditionally after vlan_push/pop calls (experiments showed that conditional re-caching is slower). - s390 JIT falls back to interpreter for now when bpf_skb_vlan_push() is present in the program (re-caching is tbd). These helpers allow more scalable handling of vlan from the programs. Instead of creating thousands of vlan netdevs on top of eth0 and attaching TC+ingress+bpf to all of them, the program can be attached to eth0 directly and manipulate vlans as necessary. Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-20 21:34:18 -06:00
bool reload_skb_data;
net: filter: x86: internal BPF JIT Maps all internal BPF instructions into x86_64 instructions. This patch replaces original BPF x64 JIT with internal BPF x64 JIT. sysctl net.core.bpf_jit_enable is reused as on/off switch. Performance: 1. old BPF JIT and internal BPF JIT generate equivalent x86_64 code. No performance difference is observed for filters that were JIT-able before Example assembler code for BPF filter "tcpdump port 22" original BPF -> old JIT: original BPF -> internal BPF -> new JIT: 0: push %rbp 0: push %rbp 1: mov %rsp,%rbp 1: mov %rsp,%rbp 4: sub $0x60,%rsp 4: sub $0x228,%rsp 8: mov %rbx,-0x8(%rbp) b: mov %rbx,-0x228(%rbp) // prologue 12: mov %r13,-0x220(%rbp) 19: mov %r14,-0x218(%rbp) 20: mov %r15,-0x210(%rbp) 27: xor %eax,%eax // clear A c: xor %ebx,%ebx 29: xor %r13,%r13 // clear X e: mov 0x68(%rdi),%r9d 2c: mov 0x68(%rdi),%r9d 12: sub 0x6c(%rdi),%r9d 30: sub 0x6c(%rdi),%r9d 16: mov 0xd8(%rdi),%r8 34: mov 0xd8(%rdi),%r10 3b: mov %rdi,%rbx 1d: mov $0xc,%esi 3e: mov $0xc,%esi 22: callq 0xffffffffe1021e15 43: callq 0xffffffffe102bd75 27: cmp $0x86dd,%eax 48: cmp $0x86dd,%rax 2c: jne 0x0000000000000069 4f: jne 0x000000000000009a 2e: mov $0x14,%esi 51: mov $0x14,%esi 33: callq 0xffffffffe1021e31 56: callq 0xffffffffe102bd91 38: cmp $0x84,%eax 5b: cmp $0x84,%rax 3d: je 0x0000000000000049 62: je 0x0000000000000074 3f: cmp $0x6,%eax 64: cmp $0x6,%rax 42: je 0x0000000000000049 68: je 0x0000000000000074 44: cmp $0x11,%eax 6a: cmp $0x11,%rax 47: jne 0x00000000000000c6 6e: jne 0x0000000000000117 49: mov $0x36,%esi 74: mov $0x36,%esi 4e: callq 0xffffffffe1021e15 79: callq 0xffffffffe102bd75 53: cmp $0x16,%eax 7e: cmp $0x16,%rax 56: je 0x00000000000000bf 82: je 0x0000000000000110 58: mov $0x38,%esi 88: mov $0x38,%esi 5d: callq 0xffffffffe1021e15 8d: callq 0xffffffffe102bd75 62: cmp $0x16,%eax 92: cmp $0x16,%rax 65: je 0x00000000000000bf 96: je 0x0000000000000110 67: jmp 0x00000000000000c6 98: jmp 0x0000000000000117 69: cmp $0x800,%eax 9a: cmp $0x800,%rax 6e: jne 0x00000000000000c6 a1: jne 0x0000000000000117 70: mov $0x17,%esi a3: mov $0x17,%esi 75: callq 0xffffffffe1021e31 a8: callq 0xffffffffe102bd91 7a: cmp $0x84,%eax ad: cmp $0x84,%rax 7f: je 0x000000000000008b b4: je 0x00000000000000c2 81: cmp $0x6,%eax b6: cmp $0x6,%rax 84: je 0x000000000000008b ba: je 0x00000000000000c2 86: cmp $0x11,%eax bc: cmp $0x11,%rax 89: jne 0x00000000000000c6 c0: jne 0x0000000000000117 8b: mov $0x14,%esi c2: mov $0x14,%esi 90: callq 0xffffffffe1021e15 c7: callq 0xffffffffe102bd75 95: test $0x1fff,%ax cc: test $0x1fff,%rax 99: jne 0x00000000000000c6 d3: jne 0x0000000000000117 d5: mov %rax,%r14 9b: mov $0xe,%esi d8: mov $0xe,%esi a0: callq 0xffffffffe1021e44 dd: callq 0xffffffffe102bd91 // MSH e2: and $0xf,%eax e5: shl $0x2,%eax e8: mov %rax,%r13 eb: mov %r14,%rax ee: mov %r13,%rsi a5: lea 0xe(%rbx),%esi f1: add $0xe,%esi a8: callq 0xffffffffe1021e0d f4: callq 0xffffffffe102bd6d ad: cmp $0x16,%eax f9: cmp $0x16,%rax b0: je 0x00000000000000bf fd: je 0x0000000000000110 ff: mov %r13,%rsi b2: lea 0x10(%rbx),%esi 102: add $0x10,%esi b5: callq 0xffffffffe1021e0d 105: callq 0xffffffffe102bd6d ba: cmp $0x16,%eax 10a: cmp $0x16,%rax bd: jne 0x00000000000000c6 10e: jne 0x0000000000000117 bf: mov $0xffff,%eax 110: mov $0xffff,%eax c4: jmp 0x00000000000000c8 115: jmp 0x000000000000011c c6: xor %eax,%eax 117: mov $0x0,%eax c8: mov -0x8(%rbp),%rbx 11c: mov -0x228(%rbp),%rbx // epilogue cc: leaveq 123: mov -0x220(%rbp),%r13 cd: retq 12a: mov -0x218(%rbp),%r14 131: mov -0x210(%rbp),%r15 138: leaveq 139: retq On fully cached SKBs both JITed functions take 12 nsec to execute. BPF interpreter executes the program in 30 nsec. The difference in generated assembler is due to the following: Old BPF imlements LDX_MSH instruction via sk_load_byte_msh() helper function inside bpf_jit.S. New JIT removes the helper and does it explicitly, so ldx_msh cost is the same for both JITs, but generated code looks longer. New JIT has 4 registers to save, so prologue/epilogue are larger, but the cost is within noise on x64. Old JIT checks whether first insn clears A and if not emits 'xor %eax,%eax'. New JIT clears %rax unconditionally. 2. old BPF JIT doesn't support ANC_NLATTR, ANC_PAY_OFFSET, ANC_RANDOM extensions. New JIT supports all BPF extensions. Performance of such filters improves 2-4 times depending on a filter. The longer the filter the higher performance gain. Synthetic benchmarks with many ancillary loads see 20x speedup which seems to be the maximum gain from JIT Notes: . net.core.bpf_jit_enable=2 + tools/net/bpf_jit_disasm is still functional and can be used to see generated assembler . there are two jit_compile() functions and code flow for classic filters is: sk_attach_filter() - load classic BPF bpf_jit_compile() - try to JIT from classic BPF sk_convert_filter() - convert classic to internal bpf_int_jit_compile() - JIT from internal BPF seccomp and tracing filters will just call bpf_int_jit_compile() Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 20:50:46 -06:00
int ilen;
u8 *func;
bpf, x86: add support for constant blinding This patch adds recently added constant blinding helpers into the x86 eBPF JIT. In the bpf_int_jit_compile() path, requirements are to utilize bpf_jit_blind_constants()/bpf_jit_prog_release_other() pair for rewriting the program into a blinded one, and to map the BPF_REG_AX register to a CPU register. The mapping of BPF_REG_AX is at non-callee saved register r10, and thus shared with cached skb->data used for ld_abs/ind and not in every program type needed. When blinding is not used, there's zero additional overhead in the generated image. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-05-13 11:08:33 -06:00
if (dst_reg == BPF_REG_AX || src_reg == BPF_REG_AX)
ctx->seen_ax_reg = seen_ax_reg = true;
net: filter: x86: internal BPF JIT Maps all internal BPF instructions into x86_64 instructions. This patch replaces original BPF x64 JIT with internal BPF x64 JIT. sysctl net.core.bpf_jit_enable is reused as on/off switch. Performance: 1. old BPF JIT and internal BPF JIT generate equivalent x86_64 code. No performance difference is observed for filters that were JIT-able before Example assembler code for BPF filter "tcpdump port 22" original BPF -> old JIT: original BPF -> internal BPF -> new JIT: 0: push %rbp 0: push %rbp 1: mov %rsp,%rbp 1: mov %rsp,%rbp 4: sub $0x60,%rsp 4: sub $0x228,%rsp 8: mov %rbx,-0x8(%rbp) b: mov %rbx,-0x228(%rbp) // prologue 12: mov %r13,-0x220(%rbp) 19: mov %r14,-0x218(%rbp) 20: mov %r15,-0x210(%rbp) 27: xor %eax,%eax // clear A c: xor %ebx,%ebx 29: xor %r13,%r13 // clear X e: mov 0x68(%rdi),%r9d 2c: mov 0x68(%rdi),%r9d 12: sub 0x6c(%rdi),%r9d 30: sub 0x6c(%rdi),%r9d 16: mov 0xd8(%rdi),%r8 34: mov 0xd8(%rdi),%r10 3b: mov %rdi,%rbx 1d: mov $0xc,%esi 3e: mov $0xc,%esi 22: callq 0xffffffffe1021e15 43: callq 0xffffffffe102bd75 27: cmp $0x86dd,%eax 48: cmp $0x86dd,%rax 2c: jne 0x0000000000000069 4f: jne 0x000000000000009a 2e: mov $0x14,%esi 51: mov $0x14,%esi 33: callq 0xffffffffe1021e31 56: callq 0xffffffffe102bd91 38: cmp $0x84,%eax 5b: cmp $0x84,%rax 3d: je 0x0000000000000049 62: je 0x0000000000000074 3f: cmp $0x6,%eax 64: cmp $0x6,%rax 42: je 0x0000000000000049 68: je 0x0000000000000074 44: cmp $0x11,%eax 6a: cmp $0x11,%rax 47: jne 0x00000000000000c6 6e: jne 0x0000000000000117 49: mov $0x36,%esi 74: mov $0x36,%esi 4e: callq 0xffffffffe1021e15 79: callq 0xffffffffe102bd75 53: cmp $0x16,%eax 7e: cmp $0x16,%rax 56: je 0x00000000000000bf 82: je 0x0000000000000110 58: mov $0x38,%esi 88: mov $0x38,%esi 5d: callq 0xffffffffe1021e15 8d: callq 0xffffffffe102bd75 62: cmp $0x16,%eax 92: cmp $0x16,%rax 65: je 0x00000000000000bf 96: je 0x0000000000000110 67: jmp 0x00000000000000c6 98: jmp 0x0000000000000117 69: cmp $0x800,%eax 9a: cmp $0x800,%rax 6e: jne 0x00000000000000c6 a1: jne 0x0000000000000117 70: mov $0x17,%esi a3: mov $0x17,%esi 75: callq 0xffffffffe1021e31 a8: callq 0xffffffffe102bd91 7a: cmp $0x84,%eax ad: cmp $0x84,%rax 7f: je 0x000000000000008b b4: je 0x00000000000000c2 81: cmp $0x6,%eax b6: cmp $0x6,%rax 84: je 0x000000000000008b ba: je 0x00000000000000c2 86: cmp $0x11,%eax bc: cmp $0x11,%rax 89: jne 0x00000000000000c6 c0: jne 0x0000000000000117 8b: mov $0x14,%esi c2: mov $0x14,%esi 90: callq 0xffffffffe1021e15 c7: callq 0xffffffffe102bd75 95: test $0x1fff,%ax cc: test $0x1fff,%rax 99: jne 0x00000000000000c6 d3: jne 0x0000000000000117 d5: mov %rax,%r14 9b: mov $0xe,%esi d8: mov $0xe,%esi a0: callq 0xffffffffe1021e44 dd: callq 0xffffffffe102bd91 // MSH e2: and $0xf,%eax e5: shl $0x2,%eax e8: mov %rax,%r13 eb: mov %r14,%rax ee: mov %r13,%rsi a5: lea 0xe(%rbx),%esi f1: add $0xe,%esi a8: callq 0xffffffffe1021e0d f4: callq 0xffffffffe102bd6d ad: cmp $0x16,%eax f9: cmp $0x16,%rax b0: je 0x00000000000000bf fd: je 0x0000000000000110 ff: mov %r13,%rsi b2: lea 0x10(%rbx),%esi 102: add $0x10,%esi b5: callq 0xffffffffe1021e0d 105: callq 0xffffffffe102bd6d ba: cmp $0x16,%eax 10a: cmp $0x16,%rax bd: jne 0x00000000000000c6 10e: jne 0x0000000000000117 bf: mov $0xffff,%eax 110: mov $0xffff,%eax c4: jmp 0x00000000000000c8 115: jmp 0x000000000000011c c6: xor %eax,%eax 117: mov $0x0,%eax c8: mov -0x8(%rbp),%rbx 11c: mov -0x228(%rbp),%rbx // epilogue cc: leaveq 123: mov -0x220(%rbp),%r13 cd: retq 12a: mov -0x218(%rbp),%r14 131: mov -0x210(%rbp),%r15 138: leaveq 139: retq On fully cached SKBs both JITed functions take 12 nsec to execute. BPF interpreter executes the program in 30 nsec. The difference in generated assembler is due to the following: Old BPF imlements LDX_MSH instruction via sk_load_byte_msh() helper function inside bpf_jit.S. New JIT removes the helper and does it explicitly, so ldx_msh cost is the same for both JITs, but generated code looks longer. New JIT has 4 registers to save, so prologue/epilogue are larger, but the cost is within noise on x64. Old JIT checks whether first insn clears A and if not emits 'xor %eax,%eax'. New JIT clears %rax unconditionally. 2. old BPF JIT doesn't support ANC_NLATTR, ANC_PAY_OFFSET, ANC_RANDOM extensions. New JIT supports all BPF extensions. Performance of such filters improves 2-4 times depending on a filter. The longer the filter the higher performance gain. Synthetic benchmarks with many ancillary loads see 20x speedup which seems to be the maximum gain from JIT Notes: . net.core.bpf_jit_enable=2 + tools/net/bpf_jit_disasm is still functional and can be used to see generated assembler . there are two jit_compile() functions and code flow for classic filters is: sk_attach_filter() - load classic BPF bpf_jit_compile() - try to JIT from classic BPF sk_convert_filter() - convert classic to internal bpf_int_jit_compile() - JIT from internal BPF seccomp and tracing filters will just call bpf_int_jit_compile() Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 20:50:46 -06:00
switch (insn->code) {
/* ALU */
case BPF_ALU | BPF_ADD | BPF_X:
case BPF_ALU | BPF_SUB | BPF_X:
case BPF_ALU | BPF_AND | BPF_X:
case BPF_ALU | BPF_OR | BPF_X:
case BPF_ALU | BPF_XOR | BPF_X:
case BPF_ALU64 | BPF_ADD | BPF_X:
case BPF_ALU64 | BPF_SUB | BPF_X:
case BPF_ALU64 | BPF_AND | BPF_X:
case BPF_ALU64 | BPF_OR | BPF_X:
case BPF_ALU64 | BPF_XOR | BPF_X:
switch (BPF_OP(insn->code)) {
case BPF_ADD: b2 = 0x01; break;
case BPF_SUB: b2 = 0x29; break;
case BPF_AND: b2 = 0x21; break;
case BPF_OR: b2 = 0x09; break;
case BPF_XOR: b2 = 0x31; break;
net: filter: Just In Time compiler for x86-64 In order to speedup packet filtering, here is an implementation of a JIT compiler for x86_64 It is disabled by default, and must be enabled by the admin. echo 1 >/proc/sys/net/core/bpf_jit_enable It uses module_alloc() and module_free() to get memory in the 2GB text kernel range since we call helpers functions from the generated code. EAX : BPF A accumulator EBX : BPF X accumulator RDI : pointer to skb (first argument given to JIT function) RBP : frame pointer (even if CONFIG_FRAME_POINTER=n) r9d : skb->len - skb->data_len (headlen) r8 : skb->data To get a trace of generated code, use : echo 2 >/proc/sys/net/core/bpf_jit_enable Example of generated code : # tcpdump -p -n -s 0 -i eth1 host 192.168.20.0/24 flen=18 proglen=147 pass=3 image=ffffffffa00b5000 JIT code: ffffffffa00b5000: 55 48 89 e5 48 83 ec 60 48 89 5d f8 44 8b 4f 60 JIT code: ffffffffa00b5010: 44 2b 4f 64 4c 8b 87 b8 00 00 00 be 0c 00 00 00 JIT code: ffffffffa00b5020: e8 24 7b f7 e0 3d 00 08 00 00 75 28 be 1a 00 00 JIT code: ffffffffa00b5030: 00 e8 fe 7a f7 e0 24 00 3d 00 14 a8 c0 74 49 be JIT code: ffffffffa00b5040: 1e 00 00 00 e8 eb 7a f7 e0 24 00 3d 00 14 a8 c0 JIT code: ffffffffa00b5050: 74 36 eb 3b 3d 06 08 00 00 74 07 3d 35 80 00 00 JIT code: ffffffffa00b5060: 75 2d be 1c 00 00 00 e8 c8 7a f7 e0 24 00 3d 00 JIT code: ffffffffa00b5070: 14 a8 c0 74 13 be 26 00 00 00 e8 b5 7a f7 e0 24 JIT code: ffffffffa00b5080: 00 3d 00 14 a8 c0 75 07 b8 ff ff 00 00 eb 02 31 JIT code: ffffffffa00b5090: c0 c9 c3 BPF program is 144 bytes long, so native program is almost same size ;) (000) ldh [12] (001) jeq #0x800 jt 2 jf 8 (002) ld [26] (003) and #0xffffff00 (004) jeq #0xc0a81400 jt 16 jf 5 (005) ld [30] (006) and #0xffffff00 (007) jeq #0xc0a81400 jt 16 jf 17 (008) jeq #0x806 jt 10 jf 9 (009) jeq #0x8035 jt 10 jf 17 (010) ld [28] (011) and #0xffffff00 (012) jeq #0xc0a81400 jt 16 jf 13 (013) ld [38] (014) and #0xffffff00 (015) jeq #0xc0a81400 jt 16 jf 17 (016) ret #65535 (017) ret #0 Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Cc: Arnaldo Carvalho de Melo <acme@infradead.org> Cc: Ben Hutchings <bhutchings@solarflare.com> Cc: Hagen Paul Pfeifer <hagen@jauu.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-04-20 03:27:32 -06:00
}
net: filter: x86: internal BPF JIT Maps all internal BPF instructions into x86_64 instructions. This patch replaces original BPF x64 JIT with internal BPF x64 JIT. sysctl net.core.bpf_jit_enable is reused as on/off switch. Performance: 1. old BPF JIT and internal BPF JIT generate equivalent x86_64 code. No performance difference is observed for filters that were JIT-able before Example assembler code for BPF filter "tcpdump port 22" original BPF -> old JIT: original BPF -> internal BPF -> new JIT: 0: push %rbp 0: push %rbp 1: mov %rsp,%rbp 1: mov %rsp,%rbp 4: sub $0x60,%rsp 4: sub $0x228,%rsp 8: mov %rbx,-0x8(%rbp) b: mov %rbx,-0x228(%rbp) // prologue 12: mov %r13,-0x220(%rbp) 19: mov %r14,-0x218(%rbp) 20: mov %r15,-0x210(%rbp) 27: xor %eax,%eax // clear A c: xor %ebx,%ebx 29: xor %r13,%r13 // clear X e: mov 0x68(%rdi),%r9d 2c: mov 0x68(%rdi),%r9d 12: sub 0x6c(%rdi),%r9d 30: sub 0x6c(%rdi),%r9d 16: mov 0xd8(%rdi),%r8 34: mov 0xd8(%rdi),%r10 3b: mov %rdi,%rbx 1d: mov $0xc,%esi 3e: mov $0xc,%esi 22: callq 0xffffffffe1021e15 43: callq 0xffffffffe102bd75 27: cmp $0x86dd,%eax 48: cmp $0x86dd,%rax 2c: jne 0x0000000000000069 4f: jne 0x000000000000009a 2e: mov $0x14,%esi 51: mov $0x14,%esi 33: callq 0xffffffffe1021e31 56: callq 0xffffffffe102bd91 38: cmp $0x84,%eax 5b: cmp $0x84,%rax 3d: je 0x0000000000000049 62: je 0x0000000000000074 3f: cmp $0x6,%eax 64: cmp $0x6,%rax 42: je 0x0000000000000049 68: je 0x0000000000000074 44: cmp $0x11,%eax 6a: cmp $0x11,%rax 47: jne 0x00000000000000c6 6e: jne 0x0000000000000117 49: mov $0x36,%esi 74: mov $0x36,%esi 4e: callq 0xffffffffe1021e15 79: callq 0xffffffffe102bd75 53: cmp $0x16,%eax 7e: cmp $0x16,%rax 56: je 0x00000000000000bf 82: je 0x0000000000000110 58: mov $0x38,%esi 88: mov $0x38,%esi 5d: callq 0xffffffffe1021e15 8d: callq 0xffffffffe102bd75 62: cmp $0x16,%eax 92: cmp $0x16,%rax 65: je 0x00000000000000bf 96: je 0x0000000000000110 67: jmp 0x00000000000000c6 98: jmp 0x0000000000000117 69: cmp $0x800,%eax 9a: cmp $0x800,%rax 6e: jne 0x00000000000000c6 a1: jne 0x0000000000000117 70: mov $0x17,%esi a3: mov $0x17,%esi 75: callq 0xffffffffe1021e31 a8: callq 0xffffffffe102bd91 7a: cmp $0x84,%eax ad: cmp $0x84,%rax 7f: je 0x000000000000008b b4: je 0x00000000000000c2 81: cmp $0x6,%eax b6: cmp $0x6,%rax 84: je 0x000000000000008b ba: je 0x00000000000000c2 86: cmp $0x11,%eax bc: cmp $0x11,%rax 89: jne 0x00000000000000c6 c0: jne 0x0000000000000117 8b: mov $0x14,%esi c2: mov $0x14,%esi 90: callq 0xffffffffe1021e15 c7: callq 0xffffffffe102bd75 95: test $0x1fff,%ax cc: test $0x1fff,%rax 99: jne 0x00000000000000c6 d3: jne 0x0000000000000117 d5: mov %rax,%r14 9b: mov $0xe,%esi d8: mov $0xe,%esi a0: callq 0xffffffffe1021e44 dd: callq 0xffffffffe102bd91 // MSH e2: and $0xf,%eax e5: shl $0x2,%eax e8: mov %rax,%r13 eb: mov %r14,%rax ee: mov %r13,%rsi a5: lea 0xe(%rbx),%esi f1: add $0xe,%esi a8: callq 0xffffffffe1021e0d f4: callq 0xffffffffe102bd6d ad: cmp $0x16,%eax f9: cmp $0x16,%rax b0: je 0x00000000000000bf fd: je 0x0000000000000110 ff: mov %r13,%rsi b2: lea 0x10(%rbx),%esi 102: add $0x10,%esi b5: callq 0xffffffffe1021e0d 105: callq 0xffffffffe102bd6d ba: cmp $0x16,%eax 10a: cmp $0x16,%rax bd: jne 0x00000000000000c6 10e: jne 0x0000000000000117 bf: mov $0xffff,%eax 110: mov $0xffff,%eax c4: jmp 0x00000000000000c8 115: jmp 0x000000000000011c c6: xor %eax,%eax 117: mov $0x0,%eax c8: mov -0x8(%rbp),%rbx 11c: mov -0x228(%rbp),%rbx // epilogue cc: leaveq 123: mov -0x220(%rbp),%r13 cd: retq 12a: mov -0x218(%rbp),%r14 131: mov -0x210(%rbp),%r15 138: leaveq 139: retq On fully cached SKBs both JITed functions take 12 nsec to execute. BPF interpreter executes the program in 30 nsec. The difference in generated assembler is due to the following: Old BPF imlements LDX_MSH instruction via sk_load_byte_msh() helper function inside bpf_jit.S. New JIT removes the helper and does it explicitly, so ldx_msh cost is the same for both JITs, but generated code looks longer. New JIT has 4 registers to save, so prologue/epilogue are larger, but the cost is within noise on x64. Old JIT checks whether first insn clears A and if not emits 'xor %eax,%eax'. New JIT clears %rax unconditionally. 2. old BPF JIT doesn't support ANC_NLATTR, ANC_PAY_OFFSET, ANC_RANDOM extensions. New JIT supports all BPF extensions. Performance of such filters improves 2-4 times depending on a filter. The longer the filter the higher performance gain. Synthetic benchmarks with many ancillary loads see 20x speedup which seems to be the maximum gain from JIT Notes: . net.core.bpf_jit_enable=2 + tools/net/bpf_jit_disasm is still functional and can be used to see generated assembler . there are two jit_compile() functions and code flow for classic filters is: sk_attach_filter() - load classic BPF bpf_jit_compile() - try to JIT from classic BPF sk_convert_filter() - convert classic to internal bpf_int_jit_compile() - JIT from internal BPF seccomp and tracing filters will just call bpf_int_jit_compile() Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 20:50:46 -06:00
if (BPF_CLASS(insn->code) == BPF_ALU64)
net: filter: cleanup A/X name usage The macro 'A' used in internal BPF interpreter: #define A regs[insn->a_reg] was easily confused with the name of classic BPF register 'A', since 'A' would mean two different things depending on context. This patch is trying to clean up the naming and clarify its usage in the following way: - A and X are names of two classic BPF registers - BPF_REG_A denotes internal BPF register R0 used to map classic register A in internal BPF programs generated from classic - BPF_REG_X denotes internal BPF register R7 used to map classic register X in internal BPF programs generated from classic - internal BPF instruction format: struct sock_filter_int { __u8 code; /* opcode */ __u8 dst_reg:4; /* dest register */ __u8 src_reg:4; /* source register */ __s16 off; /* signed offset */ __s32 imm; /* signed immediate constant */ }; - BPF_X/BPF_K is 1 bit used to encode source operand of instruction In classic: BPF_X - means use register X as source operand BPF_K - means use 32-bit immediate as source operand In internal: BPF_X - means use 'src_reg' register as source operand BPF_K - means use 32-bit immediate as source operand Suggested-by: Chema Gonzalez <chema@google.com> Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Acked-by: Daniel Borkmann <dborkman@redhat.com> Acked-by: Chema Gonzalez <chema@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-06-06 15:46:06 -06:00
EMIT1(add_2mod(0x48, dst_reg, src_reg));
else if (is_ereg(dst_reg) || is_ereg(src_reg))
EMIT1(add_2mod(0x40, dst_reg, src_reg));
EMIT2(b2, add_2reg(0xC0, dst_reg, src_reg));
net: filter: x86: internal BPF JIT Maps all internal BPF instructions into x86_64 instructions. This patch replaces original BPF x64 JIT with internal BPF x64 JIT. sysctl net.core.bpf_jit_enable is reused as on/off switch. Performance: 1. old BPF JIT and internal BPF JIT generate equivalent x86_64 code. No performance difference is observed for filters that were JIT-able before Example assembler code for BPF filter "tcpdump port 22" original BPF -> old JIT: original BPF -> internal BPF -> new JIT: 0: push %rbp 0: push %rbp 1: mov %rsp,%rbp 1: mov %rsp,%rbp 4: sub $0x60,%rsp 4: sub $0x228,%rsp 8: mov %rbx,-0x8(%rbp) b: mov %rbx,-0x228(%rbp) // prologue 12: mov %r13,-0x220(%rbp) 19: mov %r14,-0x218(%rbp) 20: mov %r15,-0x210(%rbp) 27: xor %eax,%eax // clear A c: xor %ebx,%ebx 29: xor %r13,%r13 // clear X e: mov 0x68(%rdi),%r9d 2c: mov 0x68(%rdi),%r9d 12: sub 0x6c(%rdi),%r9d 30: sub 0x6c(%rdi),%r9d 16: mov 0xd8(%rdi),%r8 34: mov 0xd8(%rdi),%r10 3b: mov %rdi,%rbx 1d: mov $0xc,%esi 3e: mov $0xc,%esi 22: callq 0xffffffffe1021e15 43: callq 0xffffffffe102bd75 27: cmp $0x86dd,%eax 48: cmp $0x86dd,%rax 2c: jne 0x0000000000000069 4f: jne 0x000000000000009a 2e: mov $0x14,%esi 51: mov $0x14,%esi 33: callq 0xffffffffe1021e31 56: callq 0xffffffffe102bd91 38: cmp $0x84,%eax 5b: cmp $0x84,%rax 3d: je 0x0000000000000049 62: je 0x0000000000000074 3f: cmp $0x6,%eax 64: cmp $0x6,%rax 42: je 0x0000000000000049 68: je 0x0000000000000074 44: cmp $0x11,%eax 6a: cmp $0x11,%rax 47: jne 0x00000000000000c6 6e: jne 0x0000000000000117 49: mov $0x36,%esi 74: mov $0x36,%esi 4e: callq 0xffffffffe1021e15 79: callq 0xffffffffe102bd75 53: cmp $0x16,%eax 7e: cmp $0x16,%rax 56: je 0x00000000000000bf 82: je 0x0000000000000110 58: mov $0x38,%esi 88: mov $0x38,%esi 5d: callq 0xffffffffe1021e15 8d: callq 0xffffffffe102bd75 62: cmp $0x16,%eax 92: cmp $0x16,%rax 65: je 0x00000000000000bf 96: je 0x0000000000000110 67: jmp 0x00000000000000c6 98: jmp 0x0000000000000117 69: cmp $0x800,%eax 9a: cmp $0x800,%rax 6e: jne 0x00000000000000c6 a1: jne 0x0000000000000117 70: mov $0x17,%esi a3: mov $0x17,%esi 75: callq 0xffffffffe1021e31 a8: callq 0xffffffffe102bd91 7a: cmp $0x84,%eax ad: cmp $0x84,%rax 7f: je 0x000000000000008b b4: je 0x00000000000000c2 81: cmp $0x6,%eax b6: cmp $0x6,%rax 84: je 0x000000000000008b ba: je 0x00000000000000c2 86: cmp $0x11,%eax bc: cmp $0x11,%rax 89: jne 0x00000000000000c6 c0: jne 0x0000000000000117 8b: mov $0x14,%esi c2: mov $0x14,%esi 90: callq 0xffffffffe1021e15 c7: callq 0xffffffffe102bd75 95: test $0x1fff,%ax cc: test $0x1fff,%rax 99: jne 0x00000000000000c6 d3: jne 0x0000000000000117 d5: mov %rax,%r14 9b: mov $0xe,%esi d8: mov $0xe,%esi a0: callq 0xffffffffe1021e44 dd: callq 0xffffffffe102bd91 // MSH e2: and $0xf,%eax e5: shl $0x2,%eax e8: mov %rax,%r13 eb: mov %r14,%rax ee: mov %r13,%rsi a5: lea 0xe(%rbx),%esi f1: add $0xe,%esi a8: callq 0xffffffffe1021e0d f4: callq 0xffffffffe102bd6d ad: cmp $0x16,%eax f9: cmp $0x16,%rax b0: je 0x00000000000000bf fd: je 0x0000000000000110 ff: mov %r13,%rsi b2: lea 0x10(%rbx),%esi 102: add $0x10,%esi b5: callq 0xffffffffe1021e0d 105: callq 0xffffffffe102bd6d ba: cmp $0x16,%eax 10a: cmp $0x16,%rax bd: jne 0x00000000000000c6 10e: jne 0x0000000000000117 bf: mov $0xffff,%eax 110: mov $0xffff,%eax c4: jmp 0x00000000000000c8 115: jmp 0x000000000000011c c6: xor %eax,%eax 117: mov $0x0,%eax c8: mov -0x8(%rbp),%rbx 11c: mov -0x228(%rbp),%rbx // epilogue cc: leaveq 123: mov -0x220(%rbp),%r13 cd: retq 12a: mov -0x218(%rbp),%r14 131: mov -0x210(%rbp),%r15 138: leaveq 139: retq On fully cached SKBs both JITed functions take 12 nsec to execute. BPF interpreter executes the program in 30 nsec. The difference in generated assembler is due to the following: Old BPF imlements LDX_MSH instruction via sk_load_byte_msh() helper function inside bpf_jit.S. New JIT removes the helper and does it explicitly, so ldx_msh cost is the same for both JITs, but generated code looks longer. New JIT has 4 registers to save, so prologue/epilogue are larger, but the cost is within noise on x64. Old JIT checks whether first insn clears A and if not emits 'xor %eax,%eax'. New JIT clears %rax unconditionally. 2. old BPF JIT doesn't support ANC_NLATTR, ANC_PAY_OFFSET, ANC_RANDOM extensions. New JIT supports all BPF extensions. Performance of such filters improves 2-4 times depending on a filter. The longer the filter the higher performance gain. Synthetic benchmarks with many ancillary loads see 20x speedup which seems to be the maximum gain from JIT Notes: . net.core.bpf_jit_enable=2 + tools/net/bpf_jit_disasm is still functional and can be used to see generated assembler . there are two jit_compile() functions and code flow for classic filters is: sk_attach_filter() - load classic BPF bpf_jit_compile() - try to JIT from classic BPF sk_convert_filter() - convert classic to internal bpf_int_jit_compile() - JIT from internal BPF seccomp and tracing filters will just call bpf_int_jit_compile() Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 20:50:46 -06:00
break;
net: filter: Just In Time compiler for x86-64 In order to speedup packet filtering, here is an implementation of a JIT compiler for x86_64 It is disabled by default, and must be enabled by the admin. echo 1 >/proc/sys/net/core/bpf_jit_enable It uses module_alloc() and module_free() to get memory in the 2GB text kernel range since we call helpers functions from the generated code. EAX : BPF A accumulator EBX : BPF X accumulator RDI : pointer to skb (first argument given to JIT function) RBP : frame pointer (even if CONFIG_FRAME_POINTER=n) r9d : skb->len - skb->data_len (headlen) r8 : skb->data To get a trace of generated code, use : echo 2 >/proc/sys/net/core/bpf_jit_enable Example of generated code : # tcpdump -p -n -s 0 -i eth1 host 192.168.20.0/24 flen=18 proglen=147 pass=3 image=ffffffffa00b5000 JIT code: ffffffffa00b5000: 55 48 89 e5 48 83 ec 60 48 89 5d f8 44 8b 4f 60 JIT code: ffffffffa00b5010: 44 2b 4f 64 4c 8b 87 b8 00 00 00 be 0c 00 00 00 JIT code: ffffffffa00b5020: e8 24 7b f7 e0 3d 00 08 00 00 75 28 be 1a 00 00 JIT code: ffffffffa00b5030: 00 e8 fe 7a f7 e0 24 00 3d 00 14 a8 c0 74 49 be JIT code: ffffffffa00b5040: 1e 00 00 00 e8 eb 7a f7 e0 24 00 3d 00 14 a8 c0 JIT code: ffffffffa00b5050: 74 36 eb 3b 3d 06 08 00 00 74 07 3d 35 80 00 00 JIT code: ffffffffa00b5060: 75 2d be 1c 00 00 00 e8 c8 7a f7 e0 24 00 3d 00 JIT code: ffffffffa00b5070: 14 a8 c0 74 13 be 26 00 00 00 e8 b5 7a f7 e0 24 JIT code: ffffffffa00b5080: 00 3d 00 14 a8 c0 75 07 b8 ff ff 00 00 eb 02 31 JIT code: ffffffffa00b5090: c0 c9 c3 BPF program is 144 bytes long, so native program is almost same size ;) (000) ldh [12] (001) jeq #0x800 jt 2 jf 8 (002) ld [26] (003) and #0xffffff00 (004) jeq #0xc0a81400 jt 16 jf 5 (005) ld [30] (006) and #0xffffff00 (007) jeq #0xc0a81400 jt 16 jf 17 (008) jeq #0x806 jt 10 jf 9 (009) jeq #0x8035 jt 10 jf 17 (010) ld [28] (011) and #0xffffff00 (012) jeq #0xc0a81400 jt 16 jf 13 (013) ld [38] (014) and #0xffffff00 (015) jeq #0xc0a81400 jt 16 jf 17 (016) ret #65535 (017) ret #0 Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Cc: Arnaldo Carvalho de Melo <acme@infradead.org> Cc: Ben Hutchings <bhutchings@solarflare.com> Cc: Hagen Paul Pfeifer <hagen@jauu.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-04-20 03:27:32 -06:00
net: filter: cleanup A/X name usage The macro 'A' used in internal BPF interpreter: #define A regs[insn->a_reg] was easily confused with the name of classic BPF register 'A', since 'A' would mean two different things depending on context. This patch is trying to clean up the naming and clarify its usage in the following way: - A and X are names of two classic BPF registers - BPF_REG_A denotes internal BPF register R0 used to map classic register A in internal BPF programs generated from classic - BPF_REG_X denotes internal BPF register R7 used to map classic register X in internal BPF programs generated from classic - internal BPF instruction format: struct sock_filter_int { __u8 code; /* opcode */ __u8 dst_reg:4; /* dest register */ __u8 src_reg:4; /* source register */ __s16 off; /* signed offset */ __s32 imm; /* signed immediate constant */ }; - BPF_X/BPF_K is 1 bit used to encode source operand of instruction In classic: BPF_X - means use register X as source operand BPF_K - means use 32-bit immediate as source operand In internal: BPF_X - means use 'src_reg' register as source operand BPF_K - means use 32-bit immediate as source operand Suggested-by: Chema Gonzalez <chema@google.com> Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Acked-by: Daniel Borkmann <dborkman@redhat.com> Acked-by: Chema Gonzalez <chema@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-06-06 15:46:06 -06:00
/* mov dst, src */
net: filter: x86: internal BPF JIT Maps all internal BPF instructions into x86_64 instructions. This patch replaces original BPF x64 JIT with internal BPF x64 JIT. sysctl net.core.bpf_jit_enable is reused as on/off switch. Performance: 1. old BPF JIT and internal BPF JIT generate equivalent x86_64 code. No performance difference is observed for filters that were JIT-able before Example assembler code for BPF filter "tcpdump port 22" original BPF -> old JIT: original BPF -> internal BPF -> new JIT: 0: push %rbp 0: push %rbp 1: mov %rsp,%rbp 1: mov %rsp,%rbp 4: sub $0x60,%rsp 4: sub $0x228,%rsp 8: mov %rbx,-0x8(%rbp) b: mov %rbx,-0x228(%rbp) // prologue 12: mov %r13,-0x220(%rbp) 19: mov %r14,-0x218(%rbp) 20: mov %r15,-0x210(%rbp) 27: xor %eax,%eax // clear A c: xor %ebx,%ebx 29: xor %r13,%r13 // clear X e: mov 0x68(%rdi),%r9d 2c: mov 0x68(%rdi),%r9d 12: sub 0x6c(%rdi),%r9d 30: sub 0x6c(%rdi),%r9d 16: mov 0xd8(%rdi),%r8 34: mov 0xd8(%rdi),%r10 3b: mov %rdi,%rbx 1d: mov $0xc,%esi 3e: mov $0xc,%esi 22: callq 0xffffffffe1021e15 43: callq 0xffffffffe102bd75 27: cmp $0x86dd,%eax 48: cmp $0x86dd,%rax 2c: jne 0x0000000000000069 4f: jne 0x000000000000009a 2e: mov $0x14,%esi 51: mov $0x14,%esi 33: callq 0xffffffffe1021e31 56: callq 0xffffffffe102bd91 38: cmp $0x84,%eax 5b: cmp $0x84,%rax 3d: je 0x0000000000000049 62: je 0x0000000000000074 3f: cmp $0x6,%eax 64: cmp $0x6,%rax 42: je 0x0000000000000049 68: je 0x0000000000000074 44: cmp $0x11,%eax 6a: cmp $0x11,%rax 47: jne 0x00000000000000c6 6e: jne 0x0000000000000117 49: mov $0x36,%esi 74: mov $0x36,%esi 4e: callq 0xffffffffe1021e15 79: callq 0xffffffffe102bd75 53: cmp $0x16,%eax 7e: cmp $0x16,%rax 56: je 0x00000000000000bf 82: je 0x0000000000000110 58: mov $0x38,%esi 88: mov $0x38,%esi 5d: callq 0xffffffffe1021e15 8d: callq 0xffffffffe102bd75 62: cmp $0x16,%eax 92: cmp $0x16,%rax 65: je 0x00000000000000bf 96: je 0x0000000000000110 67: jmp 0x00000000000000c6 98: jmp 0x0000000000000117 69: cmp $0x800,%eax 9a: cmp $0x800,%rax 6e: jne 0x00000000000000c6 a1: jne 0x0000000000000117 70: mov $0x17,%esi a3: mov $0x17,%esi 75: callq 0xffffffffe1021e31 a8: callq 0xffffffffe102bd91 7a: cmp $0x84,%eax ad: cmp $0x84,%rax 7f: je 0x000000000000008b b4: je 0x00000000000000c2 81: cmp $0x6,%eax b6: cmp $0x6,%rax 84: je 0x000000000000008b ba: je 0x00000000000000c2 86: cmp $0x11,%eax bc: cmp $0x11,%rax 89: jne 0x00000000000000c6 c0: jne 0x0000000000000117 8b: mov $0x14,%esi c2: mov $0x14,%esi 90: callq 0xffffffffe1021e15 c7: callq 0xffffffffe102bd75 95: test $0x1fff,%ax cc: test $0x1fff,%rax 99: jne 0x00000000000000c6 d3: jne 0x0000000000000117 d5: mov %rax,%r14 9b: mov $0xe,%esi d8: mov $0xe,%esi a0: callq 0xffffffffe1021e44 dd: callq 0xffffffffe102bd91 // MSH e2: and $0xf,%eax e5: shl $0x2,%eax e8: mov %rax,%r13 eb: mov %r14,%rax ee: mov %r13,%rsi a5: lea 0xe(%rbx),%esi f1: add $0xe,%esi a8: callq 0xffffffffe1021e0d f4: callq 0xffffffffe102bd6d ad: cmp $0x16,%eax f9: cmp $0x16,%rax b0: je 0x00000000000000bf fd: je 0x0000000000000110 ff: mov %r13,%rsi b2: lea 0x10(%rbx),%esi 102: add $0x10,%esi b5: callq 0xffffffffe1021e0d 105: callq 0xffffffffe102bd6d ba: cmp $0x16,%eax 10a: cmp $0x16,%rax bd: jne 0x00000000000000c6 10e: jne 0x0000000000000117 bf: mov $0xffff,%eax 110: mov $0xffff,%eax c4: jmp 0x00000000000000c8 115: jmp 0x000000000000011c c6: xor %eax,%eax 117: mov $0x0,%eax c8: mov -0x8(%rbp),%rbx 11c: mov -0x228(%rbp),%rbx // epilogue cc: leaveq 123: mov -0x220(%rbp),%r13 cd: retq 12a: mov -0x218(%rbp),%r14 131: mov -0x210(%rbp),%r15 138: leaveq 139: retq On fully cached SKBs both JITed functions take 12 nsec to execute. BPF interpreter executes the program in 30 nsec. The difference in generated assembler is due to the following: Old BPF imlements LDX_MSH instruction via sk_load_byte_msh() helper function inside bpf_jit.S. New JIT removes the helper and does it explicitly, so ldx_msh cost is the same for both JITs, but generated code looks longer. New JIT has 4 registers to save, so prologue/epilogue are larger, but the cost is within noise on x64. Old JIT checks whether first insn clears A and if not emits 'xor %eax,%eax'. New JIT clears %rax unconditionally. 2. old BPF JIT doesn't support ANC_NLATTR, ANC_PAY_OFFSET, ANC_RANDOM extensions. New JIT supports all BPF extensions. Performance of such filters improves 2-4 times depending on a filter. The longer the filter the higher performance gain. Synthetic benchmarks with many ancillary loads see 20x speedup which seems to be the maximum gain from JIT Notes: . net.core.bpf_jit_enable=2 + tools/net/bpf_jit_disasm is still functional and can be used to see generated assembler . there are two jit_compile() functions and code flow for classic filters is: sk_attach_filter() - load classic BPF bpf_jit_compile() - try to JIT from classic BPF sk_convert_filter() - convert classic to internal bpf_int_jit_compile() - JIT from internal BPF seccomp and tracing filters will just call bpf_int_jit_compile() Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 20:50:46 -06:00
case BPF_ALU64 | BPF_MOV | BPF_X:
net: filter: cleanup A/X name usage The macro 'A' used in internal BPF interpreter: #define A regs[insn->a_reg] was easily confused with the name of classic BPF register 'A', since 'A' would mean two different things depending on context. This patch is trying to clean up the naming and clarify its usage in the following way: - A and X are names of two classic BPF registers - BPF_REG_A denotes internal BPF register R0 used to map classic register A in internal BPF programs generated from classic - BPF_REG_X denotes internal BPF register R7 used to map classic register X in internal BPF programs generated from classic - internal BPF instruction format: struct sock_filter_int { __u8 code; /* opcode */ __u8 dst_reg:4; /* dest register */ __u8 src_reg:4; /* source register */ __s16 off; /* signed offset */ __s32 imm; /* signed immediate constant */ }; - BPF_X/BPF_K is 1 bit used to encode source operand of instruction In classic: BPF_X - means use register X as source operand BPF_K - means use 32-bit immediate as source operand In internal: BPF_X - means use 'src_reg' register as source operand BPF_K - means use 32-bit immediate as source operand Suggested-by: Chema Gonzalez <chema@google.com> Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Acked-by: Daniel Borkmann <dborkman@redhat.com> Acked-by: Chema Gonzalez <chema@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-06-06 15:46:06 -06:00
EMIT_mov(dst_reg, src_reg);
net: filter: Just In Time compiler for x86-64 In order to speedup packet filtering, here is an implementation of a JIT compiler for x86_64 It is disabled by default, and must be enabled by the admin. echo 1 >/proc/sys/net/core/bpf_jit_enable It uses module_alloc() and module_free() to get memory in the 2GB text kernel range since we call helpers functions from the generated code. EAX : BPF A accumulator EBX : BPF X accumulator RDI : pointer to skb (first argument given to JIT function) RBP : frame pointer (even if CONFIG_FRAME_POINTER=n) r9d : skb->len - skb->data_len (headlen) r8 : skb->data To get a trace of generated code, use : echo 2 >/proc/sys/net/core/bpf_jit_enable Example of generated code : # tcpdump -p -n -s 0 -i eth1 host 192.168.20.0/24 flen=18 proglen=147 pass=3 image=ffffffffa00b5000 JIT code: ffffffffa00b5000: 55 48 89 e5 48 83 ec 60 48 89 5d f8 44 8b 4f 60 JIT code: ffffffffa00b5010: 44 2b 4f 64 4c 8b 87 b8 00 00 00 be 0c 00 00 00 JIT code: ffffffffa00b5020: e8 24 7b f7 e0 3d 00 08 00 00 75 28 be 1a 00 00 JIT code: ffffffffa00b5030: 00 e8 fe 7a f7 e0 24 00 3d 00 14 a8 c0 74 49 be JIT code: ffffffffa00b5040: 1e 00 00 00 e8 eb 7a f7 e0 24 00 3d 00 14 a8 c0 JIT code: ffffffffa00b5050: 74 36 eb 3b 3d 06 08 00 00 74 07 3d 35 80 00 00 JIT code: ffffffffa00b5060: 75 2d be 1c 00 00 00 e8 c8 7a f7 e0 24 00 3d 00 JIT code: ffffffffa00b5070: 14 a8 c0 74 13 be 26 00 00 00 e8 b5 7a f7 e0 24 JIT code: ffffffffa00b5080: 00 3d 00 14 a8 c0 75 07 b8 ff ff 00 00 eb 02 31 JIT code: ffffffffa00b5090: c0 c9 c3 BPF program is 144 bytes long, so native program is almost same size ;) (000) ldh [12] (001) jeq #0x800 jt 2 jf 8 (002) ld [26] (003) and #0xffffff00 (004) jeq #0xc0a81400 jt 16 jf 5 (005) ld [30] (006) and #0xffffff00 (007) jeq #0xc0a81400 jt 16 jf 17 (008) jeq #0x806 jt 10 jf 9 (009) jeq #0x8035 jt 10 jf 17 (010) ld [28] (011) and #0xffffff00 (012) jeq #0xc0a81400 jt 16 jf 13 (013) ld [38] (014) and #0xffffff00 (015) jeq #0xc0a81400 jt 16 jf 17 (016) ret #65535 (017) ret #0 Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Cc: Arnaldo Carvalho de Melo <acme@infradead.org> Cc: Ben Hutchings <bhutchings@solarflare.com> Cc: Hagen Paul Pfeifer <hagen@jauu.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-04-20 03:27:32 -06:00
break;
net: filter: cleanup A/X name usage The macro 'A' used in internal BPF interpreter: #define A regs[insn->a_reg] was easily confused with the name of classic BPF register 'A', since 'A' would mean two different things depending on context. This patch is trying to clean up the naming and clarify its usage in the following way: - A and X are names of two classic BPF registers - BPF_REG_A denotes internal BPF register R0 used to map classic register A in internal BPF programs generated from classic - BPF_REG_X denotes internal BPF register R7 used to map classic register X in internal BPF programs generated from classic - internal BPF instruction format: struct sock_filter_int { __u8 code; /* opcode */ __u8 dst_reg:4; /* dest register */ __u8 src_reg:4; /* source register */ __s16 off; /* signed offset */ __s32 imm; /* signed immediate constant */ }; - BPF_X/BPF_K is 1 bit used to encode source operand of instruction In classic: BPF_X - means use register X as source operand BPF_K - means use 32-bit immediate as source operand In internal: BPF_X - means use 'src_reg' register as source operand BPF_K - means use 32-bit immediate as source operand Suggested-by: Chema Gonzalez <chema@google.com> Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Acked-by: Daniel Borkmann <dborkman@redhat.com> Acked-by: Chema Gonzalez <chema@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-06-06 15:46:06 -06:00
/* mov32 dst, src */
net: filter: x86: internal BPF JIT Maps all internal BPF instructions into x86_64 instructions. This patch replaces original BPF x64 JIT with internal BPF x64 JIT. sysctl net.core.bpf_jit_enable is reused as on/off switch. Performance: 1. old BPF JIT and internal BPF JIT generate equivalent x86_64 code. No performance difference is observed for filters that were JIT-able before Example assembler code for BPF filter "tcpdump port 22" original BPF -> old JIT: original BPF -> internal BPF -> new JIT: 0: push %rbp 0: push %rbp 1: mov %rsp,%rbp 1: mov %rsp,%rbp 4: sub $0x60,%rsp 4: sub $0x228,%rsp 8: mov %rbx,-0x8(%rbp) b: mov %rbx,-0x228(%rbp) // prologue 12: mov %r13,-0x220(%rbp) 19: mov %r14,-0x218(%rbp) 20: mov %r15,-0x210(%rbp) 27: xor %eax,%eax // clear A c: xor %ebx,%ebx 29: xor %r13,%r13 // clear X e: mov 0x68(%rdi),%r9d 2c: mov 0x68(%rdi),%r9d 12: sub 0x6c(%rdi),%r9d 30: sub 0x6c(%rdi),%r9d 16: mov 0xd8(%rdi),%r8 34: mov 0xd8(%rdi),%r10 3b: mov %rdi,%rbx 1d: mov $0xc,%esi 3e: mov $0xc,%esi 22: callq 0xffffffffe1021e15 43: callq 0xffffffffe102bd75 27: cmp $0x86dd,%eax 48: cmp $0x86dd,%rax 2c: jne 0x0000000000000069 4f: jne 0x000000000000009a 2e: mov $0x14,%esi 51: mov $0x14,%esi 33: callq 0xffffffffe1021e31 56: callq 0xffffffffe102bd91 38: cmp $0x84,%eax 5b: cmp $0x84,%rax 3d: je 0x0000000000000049 62: je 0x0000000000000074 3f: cmp $0x6,%eax 64: cmp $0x6,%rax 42: je 0x0000000000000049 68: je 0x0000000000000074 44: cmp $0x11,%eax 6a: cmp $0x11,%rax 47: jne 0x00000000000000c6 6e: jne 0x0000000000000117 49: mov $0x36,%esi 74: mov $0x36,%esi 4e: callq 0xffffffffe1021e15 79: callq 0xffffffffe102bd75 53: cmp $0x16,%eax 7e: cmp $0x16,%rax 56: je 0x00000000000000bf 82: je 0x0000000000000110 58: mov $0x38,%esi 88: mov $0x38,%esi 5d: callq 0xffffffffe1021e15 8d: callq 0xffffffffe102bd75 62: cmp $0x16,%eax 92: cmp $0x16,%rax 65: je 0x00000000000000bf 96: je 0x0000000000000110 67: jmp 0x00000000000000c6 98: jmp 0x0000000000000117 69: cmp $0x800,%eax 9a: cmp $0x800,%rax 6e: jne 0x00000000000000c6 a1: jne 0x0000000000000117 70: mov $0x17,%esi a3: mov $0x17,%esi 75: callq 0xffffffffe1021e31 a8: callq 0xffffffffe102bd91 7a: cmp $0x84,%eax ad: cmp $0x84,%rax 7f: je 0x000000000000008b b4: je 0x00000000000000c2 81: cmp $0x6,%eax b6: cmp $0x6,%rax 84: je 0x000000000000008b ba: je 0x00000000000000c2 86: cmp $0x11,%eax bc: cmp $0x11,%rax 89: jne 0x00000000000000c6 c0: jne 0x0000000000000117 8b: mov $0x14,%esi c2: mov $0x14,%esi 90: callq 0xffffffffe1021e15 c7: callq 0xffffffffe102bd75 95: test $0x1fff,%ax cc: test $0x1fff,%rax 99: jne 0x00000000000000c6 d3: jne 0x0000000000000117 d5: mov %rax,%r14 9b: mov $0xe,%esi d8: mov $0xe,%esi a0: callq 0xffffffffe1021e44 dd: callq 0xffffffffe102bd91 // MSH e2: and $0xf,%eax e5: shl $0x2,%eax e8: mov %rax,%r13 eb: mov %r14,%rax ee: mov %r13,%rsi a5: lea 0xe(%rbx),%esi f1: add $0xe,%esi a8: callq 0xffffffffe1021e0d f4: callq 0xffffffffe102bd6d ad: cmp $0x16,%eax f9: cmp $0x16,%rax b0: je 0x00000000000000bf fd: je 0x0000000000000110 ff: mov %r13,%rsi b2: lea 0x10(%rbx),%esi 102: add $0x10,%esi b5: callq 0xffffffffe1021e0d 105: callq 0xffffffffe102bd6d ba: cmp $0x16,%eax 10a: cmp $0x16,%rax bd: jne 0x00000000000000c6 10e: jne 0x0000000000000117 bf: mov $0xffff,%eax 110: mov $0xffff,%eax c4: jmp 0x00000000000000c8 115: jmp 0x000000000000011c c6: xor %eax,%eax 117: mov $0x0,%eax c8: mov -0x8(%rbp),%rbx 11c: mov -0x228(%rbp),%rbx // epilogue cc: leaveq 123: mov -0x220(%rbp),%r13 cd: retq 12a: mov -0x218(%rbp),%r14 131: mov -0x210(%rbp),%r15 138: leaveq 139: retq On fully cached SKBs both JITed functions take 12 nsec to execute. BPF interpreter executes the program in 30 nsec. The difference in generated assembler is due to the following: Old BPF imlements LDX_MSH instruction via sk_load_byte_msh() helper function inside bpf_jit.S. New JIT removes the helper and does it explicitly, so ldx_msh cost is the same for both JITs, but generated code looks longer. New JIT has 4 registers to save, so prologue/epilogue are larger, but the cost is within noise on x64. Old JIT checks whether first insn clears A and if not emits 'xor %eax,%eax'. New JIT clears %rax unconditionally. 2. old BPF JIT doesn't support ANC_NLATTR, ANC_PAY_OFFSET, ANC_RANDOM extensions. New JIT supports all BPF extensions. Performance of such filters improves 2-4 times depending on a filter. The longer the filter the higher performance gain. Synthetic benchmarks with many ancillary loads see 20x speedup which seems to be the maximum gain from JIT Notes: . net.core.bpf_jit_enable=2 + tools/net/bpf_jit_disasm is still functional and can be used to see generated assembler . there are two jit_compile() functions and code flow for classic filters is: sk_attach_filter() - load classic BPF bpf_jit_compile() - try to JIT from classic BPF sk_convert_filter() - convert classic to internal bpf_int_jit_compile() - JIT from internal BPF seccomp and tracing filters will just call bpf_int_jit_compile() Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 20:50:46 -06:00
case BPF_ALU | BPF_MOV | BPF_X:
net: filter: cleanup A/X name usage The macro 'A' used in internal BPF interpreter: #define A regs[insn->a_reg] was easily confused with the name of classic BPF register 'A', since 'A' would mean two different things depending on context. This patch is trying to clean up the naming and clarify its usage in the following way: - A and X are names of two classic BPF registers - BPF_REG_A denotes internal BPF register R0 used to map classic register A in internal BPF programs generated from classic - BPF_REG_X denotes internal BPF register R7 used to map classic register X in internal BPF programs generated from classic - internal BPF instruction format: struct sock_filter_int { __u8 code; /* opcode */ __u8 dst_reg:4; /* dest register */ __u8 src_reg:4; /* source register */ __s16 off; /* signed offset */ __s32 imm; /* signed immediate constant */ }; - BPF_X/BPF_K is 1 bit used to encode source operand of instruction In classic: BPF_X - means use register X as source operand BPF_K - means use 32-bit immediate as source operand In internal: BPF_X - means use 'src_reg' register as source operand BPF_K - means use 32-bit immediate as source operand Suggested-by: Chema Gonzalez <chema@google.com> Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Acked-by: Daniel Borkmann <dborkman@redhat.com> Acked-by: Chema Gonzalez <chema@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-06-06 15:46:06 -06:00
if (is_ereg(dst_reg) || is_ereg(src_reg))
EMIT1(add_2mod(0x40, dst_reg, src_reg));
EMIT2(0x89, add_2reg(0xC0, dst_reg, src_reg));
net: filter: x86: internal BPF JIT Maps all internal BPF instructions into x86_64 instructions. This patch replaces original BPF x64 JIT with internal BPF x64 JIT. sysctl net.core.bpf_jit_enable is reused as on/off switch. Performance: 1. old BPF JIT and internal BPF JIT generate equivalent x86_64 code. No performance difference is observed for filters that were JIT-able before Example assembler code for BPF filter "tcpdump port 22" original BPF -> old JIT: original BPF -> internal BPF -> new JIT: 0: push %rbp 0: push %rbp 1: mov %rsp,%rbp 1: mov %rsp,%rbp 4: sub $0x60,%rsp 4: sub $0x228,%rsp 8: mov %rbx,-0x8(%rbp) b: mov %rbx,-0x228(%rbp) // prologue 12: mov %r13,-0x220(%rbp) 19: mov %r14,-0x218(%rbp) 20: mov %r15,-0x210(%rbp) 27: xor %eax,%eax // clear A c: xor %ebx,%ebx 29: xor %r13,%r13 // clear X e: mov 0x68(%rdi),%r9d 2c: mov 0x68(%rdi),%r9d 12: sub 0x6c(%rdi),%r9d 30: sub 0x6c(%rdi),%r9d 16: mov 0xd8(%rdi),%r8 34: mov 0xd8(%rdi),%r10 3b: mov %rdi,%rbx 1d: mov $0xc,%esi 3e: mov $0xc,%esi 22: callq 0xffffffffe1021e15 43: callq 0xffffffffe102bd75 27: cmp $0x86dd,%eax 48: cmp $0x86dd,%rax 2c: jne 0x0000000000000069 4f: jne 0x000000000000009a 2e: mov $0x14,%esi 51: mov $0x14,%esi 33: callq 0xffffffffe1021e31 56: callq 0xffffffffe102bd91 38: cmp $0x84,%eax 5b: cmp $0x84,%rax 3d: je 0x0000000000000049 62: je 0x0000000000000074 3f: cmp $0x6,%eax 64: cmp $0x6,%rax 42: je 0x0000000000000049 68: je 0x0000000000000074 44: cmp $0x11,%eax 6a: cmp $0x11,%rax 47: jne 0x00000000000000c6 6e: jne 0x0000000000000117 49: mov $0x36,%esi 74: mov $0x36,%esi 4e: callq 0xffffffffe1021e15 79: callq 0xffffffffe102bd75 53: cmp $0x16,%eax 7e: cmp $0x16,%rax 56: je 0x00000000000000bf 82: je 0x0000000000000110 58: mov $0x38,%esi 88: mov $0x38,%esi 5d: callq 0xffffffffe1021e15 8d: callq 0xffffffffe102bd75 62: cmp $0x16,%eax 92: cmp $0x16,%rax 65: je 0x00000000000000bf 96: je 0x0000000000000110 67: jmp 0x00000000000000c6 98: jmp 0x0000000000000117 69: cmp $0x800,%eax 9a: cmp $0x800,%rax 6e: jne 0x00000000000000c6 a1: jne 0x0000000000000117 70: mov $0x17,%esi a3: mov $0x17,%esi 75: callq 0xffffffffe1021e31 a8: callq 0xffffffffe102bd91 7a: cmp $0x84,%eax ad: cmp $0x84,%rax 7f: je 0x000000000000008b b4: je 0x00000000000000c2 81: cmp $0x6,%eax b6: cmp $0x6,%rax 84: je 0x000000000000008b ba: je 0x00000000000000c2 86: cmp $0x11,%eax bc: cmp $0x11,%rax 89: jne 0x00000000000000c6 c0: jne 0x0000000000000117 8b: mov $0x14,%esi c2: mov $0x14,%esi 90: callq 0xffffffffe1021e15 c7: callq 0xffffffffe102bd75 95: test $0x1fff,%ax cc: test $0x1fff,%rax 99: jne 0x00000000000000c6 d3: jne 0x0000000000000117 d5: mov %rax,%r14 9b: mov $0xe,%esi d8: mov $0xe,%esi a0: callq 0xffffffffe1021e44 dd: callq 0xffffffffe102bd91 // MSH e2: and $0xf,%eax e5: shl $0x2,%eax e8: mov %rax,%r13 eb: mov %r14,%rax ee: mov %r13,%rsi a5: lea 0xe(%rbx),%esi f1: add $0xe,%esi a8: callq 0xffffffffe1021e0d f4: callq 0xffffffffe102bd6d ad: cmp $0x16,%eax f9: cmp $0x16,%rax b0: je 0x00000000000000bf fd: je 0x0000000000000110 ff: mov %r13,%rsi b2: lea 0x10(%rbx),%esi 102: add $0x10,%esi b5: callq 0xffffffffe1021e0d 105: callq 0xffffffffe102bd6d ba: cmp $0x16,%eax 10a: cmp $0x16,%rax bd: jne 0x00000000000000c6 10e: jne 0x0000000000000117 bf: mov $0xffff,%eax 110: mov $0xffff,%eax c4: jmp 0x00000000000000c8 115: jmp 0x000000000000011c c6: xor %eax,%eax 117: mov $0x0,%eax c8: mov -0x8(%rbp),%rbx 11c: mov -0x228(%rbp),%rbx // epilogue cc: leaveq 123: mov -0x220(%rbp),%r13 cd: retq 12a: mov -0x218(%rbp),%r14 131: mov -0x210(%rbp),%r15 138: leaveq 139: retq On fully cached SKBs both JITed functions take 12 nsec to execute. BPF interpreter executes the program in 30 nsec. The difference in generated assembler is due to the following: Old BPF imlements LDX_MSH instruction via sk_load_byte_msh() helper function inside bpf_jit.S. New JIT removes the helper and does it explicitly, so ldx_msh cost is the same for both JITs, but generated code looks longer. New JIT has 4 registers to save, so prologue/epilogue are larger, but the cost is within noise on x64. Old JIT checks whether first insn clears A and if not emits 'xor %eax,%eax'. New JIT clears %rax unconditionally. 2. old BPF JIT doesn't support ANC_NLATTR, ANC_PAY_OFFSET, ANC_RANDOM extensions. New JIT supports all BPF extensions. Performance of such filters improves 2-4 times depending on a filter. The longer the filter the higher performance gain. Synthetic benchmarks with many ancillary loads see 20x speedup which seems to be the maximum gain from JIT Notes: . net.core.bpf_jit_enable=2 + tools/net/bpf_jit_disasm is still functional and can be used to see generated assembler . there are two jit_compile() functions and code flow for classic filters is: sk_attach_filter() - load classic BPF bpf_jit_compile() - try to JIT from classic BPF sk_convert_filter() - convert classic to internal bpf_int_jit_compile() - JIT from internal BPF seccomp and tracing filters will just call bpf_int_jit_compile() Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 20:50:46 -06:00
break;
net: filter: Just In Time compiler for x86-64 In order to speedup packet filtering, here is an implementation of a JIT compiler for x86_64 It is disabled by default, and must be enabled by the admin. echo 1 >/proc/sys/net/core/bpf_jit_enable It uses module_alloc() and module_free() to get memory in the 2GB text kernel range since we call helpers functions from the generated code. EAX : BPF A accumulator EBX : BPF X accumulator RDI : pointer to skb (first argument given to JIT function) RBP : frame pointer (even if CONFIG_FRAME_POINTER=n) r9d : skb->len - skb->data_len (headlen) r8 : skb->data To get a trace of generated code, use : echo 2 >/proc/sys/net/core/bpf_jit_enable Example of generated code : # tcpdump -p -n -s 0 -i eth1 host 192.168.20.0/24 flen=18 proglen=147 pass=3 image=ffffffffa00b5000 JIT code: ffffffffa00b5000: 55 48 89 e5 48 83 ec 60 48 89 5d f8 44 8b 4f 60 JIT code: ffffffffa00b5010: 44 2b 4f 64 4c 8b 87 b8 00 00 00 be 0c 00 00 00 JIT code: ffffffffa00b5020: e8 24 7b f7 e0 3d 00 08 00 00 75 28 be 1a 00 00 JIT code: ffffffffa00b5030: 00 e8 fe 7a f7 e0 24 00 3d 00 14 a8 c0 74 49 be JIT code: ffffffffa00b5040: 1e 00 00 00 e8 eb 7a f7 e0 24 00 3d 00 14 a8 c0 JIT code: ffffffffa00b5050: 74 36 eb 3b 3d 06 08 00 00 74 07 3d 35 80 00 00 JIT code: ffffffffa00b5060: 75 2d be 1c 00 00 00 e8 c8 7a f7 e0 24 00 3d 00 JIT code: ffffffffa00b5070: 14 a8 c0 74 13 be 26 00 00 00 e8 b5 7a f7 e0 24 JIT code: ffffffffa00b5080: 00 3d 00 14 a8 c0 75 07 b8 ff ff 00 00 eb 02 31 JIT code: ffffffffa00b5090: c0 c9 c3 BPF program is 144 bytes long, so native program is almost same size ;) (000) ldh [12] (001) jeq #0x800 jt 2 jf 8 (002) ld [26] (003) and #0xffffff00 (004) jeq #0xc0a81400 jt 16 jf 5 (005) ld [30] (006) and #0xffffff00 (007) jeq #0xc0a81400 jt 16 jf 17 (008) jeq #0x806 jt 10 jf 9 (009) jeq #0x8035 jt 10 jf 17 (010) ld [28] (011) and #0xffffff00 (012) jeq #0xc0a81400 jt 16 jf 13 (013) ld [38] (014) and #0xffffff00 (015) jeq #0xc0a81400 jt 16 jf 17 (016) ret #65535 (017) ret #0 Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Cc: Arnaldo Carvalho de Melo <acme@infradead.org> Cc: Ben Hutchings <bhutchings@solarflare.com> Cc: Hagen Paul Pfeifer <hagen@jauu.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-04-20 03:27:32 -06:00
net: filter: cleanup A/X name usage The macro 'A' used in internal BPF interpreter: #define A regs[insn->a_reg] was easily confused with the name of classic BPF register 'A', since 'A' would mean two different things depending on context. This patch is trying to clean up the naming and clarify its usage in the following way: - A and X are names of two classic BPF registers - BPF_REG_A denotes internal BPF register R0 used to map classic register A in internal BPF programs generated from classic - BPF_REG_X denotes internal BPF register R7 used to map classic register X in internal BPF programs generated from classic - internal BPF instruction format: struct sock_filter_int { __u8 code; /* opcode */ __u8 dst_reg:4; /* dest register */ __u8 src_reg:4; /* source register */ __s16 off; /* signed offset */ __s32 imm; /* signed immediate constant */ }; - BPF_X/BPF_K is 1 bit used to encode source operand of instruction In classic: BPF_X - means use register X as source operand BPF_K - means use 32-bit immediate as source operand In internal: BPF_X - means use 'src_reg' register as source operand BPF_K - means use 32-bit immediate as source operand Suggested-by: Chema Gonzalez <chema@google.com> Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Acked-by: Daniel Borkmann <dborkman@redhat.com> Acked-by: Chema Gonzalez <chema@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-06-06 15:46:06 -06:00
/* neg dst */
net: filter: x86: internal BPF JIT Maps all internal BPF instructions into x86_64 instructions. This patch replaces original BPF x64 JIT with internal BPF x64 JIT. sysctl net.core.bpf_jit_enable is reused as on/off switch. Performance: 1. old BPF JIT and internal BPF JIT generate equivalent x86_64 code. No performance difference is observed for filters that were JIT-able before Example assembler code for BPF filter "tcpdump port 22" original BPF -> old JIT: original BPF -> internal BPF -> new JIT: 0: push %rbp 0: push %rbp 1: mov %rsp,%rbp 1: mov %rsp,%rbp 4: sub $0x60,%rsp 4: sub $0x228,%rsp 8: mov %rbx,-0x8(%rbp) b: mov %rbx,-0x228(%rbp) // prologue 12: mov %r13,-0x220(%rbp) 19: mov %r14,-0x218(%rbp) 20: mov %r15,-0x210(%rbp) 27: xor %eax,%eax // clear A c: xor %ebx,%ebx 29: xor %r13,%r13 // clear X e: mov 0x68(%rdi),%r9d 2c: mov 0x68(%rdi),%r9d 12: sub 0x6c(%rdi),%r9d 30: sub 0x6c(%rdi),%r9d 16: mov 0xd8(%rdi),%r8 34: mov 0xd8(%rdi),%r10 3b: mov %rdi,%rbx 1d: mov $0xc,%esi 3e: mov $0xc,%esi 22: callq 0xffffffffe1021e15 43: callq 0xffffffffe102bd75 27: cmp $0x86dd,%eax 48: cmp $0x86dd,%rax 2c: jne 0x0000000000000069 4f: jne 0x000000000000009a 2e: mov $0x14,%esi 51: mov $0x14,%esi 33: callq 0xffffffffe1021e31 56: callq 0xffffffffe102bd91 38: cmp $0x84,%eax 5b: cmp $0x84,%rax 3d: je 0x0000000000000049 62: je 0x0000000000000074 3f: cmp $0x6,%eax 64: cmp $0x6,%rax 42: je 0x0000000000000049 68: je 0x0000000000000074 44: cmp $0x11,%eax 6a: cmp $0x11,%rax 47: jne 0x00000000000000c6 6e: jne 0x0000000000000117 49: mov $0x36,%esi 74: mov $0x36,%esi 4e: callq 0xffffffffe1021e15 79: callq 0xffffffffe102bd75 53: cmp $0x16,%eax 7e: cmp $0x16,%rax 56: je 0x00000000000000bf 82: je 0x0000000000000110 58: mov $0x38,%esi 88: mov $0x38,%esi 5d: callq 0xffffffffe1021e15 8d: callq 0xffffffffe102bd75 62: cmp $0x16,%eax 92: cmp $0x16,%rax 65: je 0x00000000000000bf 96: je 0x0000000000000110 67: jmp 0x00000000000000c6 98: jmp 0x0000000000000117 69: cmp $0x800,%eax 9a: cmp $0x800,%rax 6e: jne 0x00000000000000c6 a1: jne 0x0000000000000117 70: mov $0x17,%esi a3: mov $0x17,%esi 75: callq 0xffffffffe1021e31 a8: callq 0xffffffffe102bd91 7a: cmp $0x84,%eax ad: cmp $0x84,%rax 7f: je 0x000000000000008b b4: je 0x00000000000000c2 81: cmp $0x6,%eax b6: cmp $0x6,%rax 84: je 0x000000000000008b ba: je 0x00000000000000c2 86: cmp $0x11,%eax bc: cmp $0x11,%rax 89: jne 0x00000000000000c6 c0: jne 0x0000000000000117 8b: mov $0x14,%esi c2: mov $0x14,%esi 90: callq 0xffffffffe1021e15 c7: callq 0xffffffffe102bd75 95: test $0x1fff,%ax cc: test $0x1fff,%rax 99: jne 0x00000000000000c6 d3: jne 0x0000000000000117 d5: mov %rax,%r14 9b: mov $0xe,%esi d8: mov $0xe,%esi a0: callq 0xffffffffe1021e44 dd: callq 0xffffffffe102bd91 // MSH e2: and $0xf,%eax e5: shl $0x2,%eax e8: mov %rax,%r13 eb: mov %r14,%rax ee: mov %r13,%rsi a5: lea 0xe(%rbx),%esi f1: add $0xe,%esi a8: callq 0xffffffffe1021e0d f4: callq 0xffffffffe102bd6d ad: cmp $0x16,%eax f9: cmp $0x16,%rax b0: je 0x00000000000000bf fd: je 0x0000000000000110 ff: mov %r13,%rsi b2: lea 0x10(%rbx),%esi 102: add $0x10,%esi b5: callq 0xffffffffe1021e0d 105: callq 0xffffffffe102bd6d ba: cmp $0x16,%eax 10a: cmp $0x16,%rax bd: jne 0x00000000000000c6 10e: jne 0x0000000000000117 bf: mov $0xffff,%eax 110: mov $0xffff,%eax c4: jmp 0x00000000000000c8 115: jmp 0x000000000000011c c6: xor %eax,%eax 117: mov $0x0,%eax c8: mov -0x8(%rbp),%rbx 11c: mov -0x228(%rbp),%rbx // epilogue cc: leaveq 123: mov -0x220(%rbp),%r13 cd: retq 12a: mov -0x218(%rbp),%r14 131: mov -0x210(%rbp),%r15 138: leaveq 139: retq On fully cached SKBs both JITed functions take 12 nsec to execute. BPF interpreter executes the program in 30 nsec. The difference in generated assembler is due to the following: Old BPF imlements LDX_MSH instruction via sk_load_byte_msh() helper function inside bpf_jit.S. New JIT removes the helper and does it explicitly, so ldx_msh cost is the same for both JITs, but generated code looks longer. New JIT has 4 registers to save, so prologue/epilogue are larger, but the cost is within noise on x64. Old JIT checks whether first insn clears A and if not emits 'xor %eax,%eax'. New JIT clears %rax unconditionally. 2. old BPF JIT doesn't support ANC_NLATTR, ANC_PAY_OFFSET, ANC_RANDOM extensions. New JIT supports all BPF extensions. Performance of such filters improves 2-4 times depending on a filter. The longer the filter the higher performance gain. Synthetic benchmarks with many ancillary loads see 20x speedup which seems to be the maximum gain from JIT Notes: . net.core.bpf_jit_enable=2 + tools/net/bpf_jit_disasm is still functional and can be used to see generated assembler . there are two jit_compile() functions and code flow for classic filters is: sk_attach_filter() - load classic BPF bpf_jit_compile() - try to JIT from classic BPF sk_convert_filter() - convert classic to internal bpf_int_jit_compile() - JIT from internal BPF seccomp and tracing filters will just call bpf_int_jit_compile() Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 20:50:46 -06:00
case BPF_ALU | BPF_NEG:
case BPF_ALU64 | BPF_NEG:
if (BPF_CLASS(insn->code) == BPF_ALU64)
net: filter: cleanup A/X name usage The macro 'A' used in internal BPF interpreter: #define A regs[insn->a_reg] was easily confused with the name of classic BPF register 'A', since 'A' would mean two different things depending on context. This patch is trying to clean up the naming and clarify its usage in the following way: - A and X are names of two classic BPF registers - BPF_REG_A denotes internal BPF register R0 used to map classic register A in internal BPF programs generated from classic - BPF_REG_X denotes internal BPF register R7 used to map classic register X in internal BPF programs generated from classic - internal BPF instruction format: struct sock_filter_int { __u8 code; /* opcode */ __u8 dst_reg:4; /* dest register */ __u8 src_reg:4; /* source register */ __s16 off; /* signed offset */ __s32 imm; /* signed immediate constant */ }; - BPF_X/BPF_K is 1 bit used to encode source operand of instruction In classic: BPF_X - means use register X as source operand BPF_K - means use 32-bit immediate as source operand In internal: BPF_X - means use 'src_reg' register as source operand BPF_K - means use 32-bit immediate as source operand Suggested-by: Chema Gonzalez <chema@google.com> Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Acked-by: Daniel Borkmann <dborkman@redhat.com> Acked-by: Chema Gonzalez <chema@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-06-06 15:46:06 -06:00
EMIT1(add_1mod(0x48, dst_reg));
else if (is_ereg(dst_reg))
EMIT1(add_1mod(0x40, dst_reg));
EMIT2(0xF7, add_1reg(0xD8, dst_reg));
net: filter: x86: internal BPF JIT Maps all internal BPF instructions into x86_64 instructions. This patch replaces original BPF x64 JIT with internal BPF x64 JIT. sysctl net.core.bpf_jit_enable is reused as on/off switch. Performance: 1. old BPF JIT and internal BPF JIT generate equivalent x86_64 code. No performance difference is observed for filters that were JIT-able before Example assembler code for BPF filter "tcpdump port 22" original BPF -> old JIT: original BPF -> internal BPF -> new JIT: 0: push %rbp 0: push %rbp 1: mov %rsp,%rbp 1: mov %rsp,%rbp 4: sub $0x60,%rsp 4: sub $0x228,%rsp 8: mov %rbx,-0x8(%rbp) b: mov %rbx,-0x228(%rbp) // prologue 12: mov %r13,-0x220(%rbp) 19: mov %r14,-0x218(%rbp) 20: mov %r15,-0x210(%rbp) 27: xor %eax,%eax // clear A c: xor %ebx,%ebx 29: xor %r13,%r13 // clear X e: mov 0x68(%rdi),%r9d 2c: mov 0x68(%rdi),%r9d 12: sub 0x6c(%rdi),%r9d 30: sub 0x6c(%rdi),%r9d 16: mov 0xd8(%rdi),%r8 34: mov 0xd8(%rdi),%r10 3b: mov %rdi,%rbx 1d: mov $0xc,%esi 3e: mov $0xc,%esi 22: callq 0xffffffffe1021e15 43: callq 0xffffffffe102bd75 27: cmp $0x86dd,%eax 48: cmp $0x86dd,%rax 2c: jne 0x0000000000000069 4f: jne 0x000000000000009a 2e: mov $0x14,%esi 51: mov $0x14,%esi 33: callq 0xffffffffe1021e31 56: callq 0xffffffffe102bd91 38: cmp $0x84,%eax 5b: cmp $0x84,%rax 3d: je 0x0000000000000049 62: je 0x0000000000000074 3f: cmp $0x6,%eax 64: cmp $0x6,%rax 42: je 0x0000000000000049 68: je 0x0000000000000074 44: cmp $0x11,%eax 6a: cmp $0x11,%rax 47: jne 0x00000000000000c6 6e: jne 0x0000000000000117 49: mov $0x36,%esi 74: mov $0x36,%esi 4e: callq 0xffffffffe1021e15 79: callq 0xffffffffe102bd75 53: cmp $0x16,%eax 7e: cmp $0x16,%rax 56: je 0x00000000000000bf 82: je 0x0000000000000110 58: mov $0x38,%esi 88: mov $0x38,%esi 5d: callq 0xffffffffe1021e15 8d: callq 0xffffffffe102bd75 62: cmp $0x16,%eax 92: cmp $0x16,%rax 65: je 0x00000000000000bf 96: je 0x0000000000000110 67: jmp 0x00000000000000c6 98: jmp 0x0000000000000117 69: cmp $0x800,%eax 9a: cmp $0x800,%rax 6e: jne 0x00000000000000c6 a1: jne 0x0000000000000117 70: mov $0x17,%esi a3: mov $0x17,%esi 75: callq 0xffffffffe1021e31 a8: callq 0xffffffffe102bd91 7a: cmp $0x84,%eax ad: cmp $0x84,%rax 7f: je 0x000000000000008b b4: je 0x00000000000000c2 81: cmp $0x6,%eax b6: cmp $0x6,%rax 84: je 0x000000000000008b ba: je 0x00000000000000c2 86: cmp $0x11,%eax bc: cmp $0x11,%rax 89: jne 0x00000000000000c6 c0: jne 0x0000000000000117 8b: mov $0x14,%esi c2: mov $0x14,%esi 90: callq 0xffffffffe1021e15 c7: callq 0xffffffffe102bd75 95: test $0x1fff,%ax cc: test $0x1fff,%rax 99: jne 0x00000000000000c6 d3: jne 0x0000000000000117 d5: mov %rax,%r14 9b: mov $0xe,%esi d8: mov $0xe,%esi a0: callq 0xffffffffe1021e44 dd: callq 0xffffffffe102bd91 // MSH e2: and $0xf,%eax e5: shl $0x2,%eax e8: mov %rax,%r13 eb: mov %r14,%rax ee: mov %r13,%rsi a5: lea 0xe(%rbx),%esi f1: add $0xe,%esi a8: callq 0xffffffffe1021e0d f4: callq 0xffffffffe102bd6d ad: cmp $0x16,%eax f9: cmp $0x16,%rax b0: je 0x00000000000000bf fd: je 0x0000000000000110 ff: mov %r13,%rsi b2: lea 0x10(%rbx),%esi 102: add $0x10,%esi b5: callq 0xffffffffe1021e0d 105: callq 0xffffffffe102bd6d ba: cmp $0x16,%eax 10a: cmp $0x16,%rax bd: jne 0x00000000000000c6 10e: jne 0x0000000000000117 bf: mov $0xffff,%eax 110: mov $0xffff,%eax c4: jmp 0x00000000000000c8 115: jmp 0x000000000000011c c6: xor %eax,%eax 117: mov $0x0,%eax c8: mov -0x8(%rbp),%rbx 11c: mov -0x228(%rbp),%rbx // epilogue cc: leaveq 123: mov -0x220(%rbp),%r13 cd: retq 12a: mov -0x218(%rbp),%r14 131: mov -0x210(%rbp),%r15 138: leaveq 139: retq On fully cached SKBs both JITed functions take 12 nsec to execute. BPF interpreter executes the program in 30 nsec. The difference in generated assembler is due to the following: Old BPF imlements LDX_MSH instruction via sk_load_byte_msh() helper function inside bpf_jit.S. New JIT removes the helper and does it explicitly, so ldx_msh cost is the same for both JITs, but generated code looks longer. New JIT has 4 registers to save, so prologue/epilogue are larger, but the cost is within noise on x64. Old JIT checks whether first insn clears A and if not emits 'xor %eax,%eax'. New JIT clears %rax unconditionally. 2. old BPF JIT doesn't support ANC_NLATTR, ANC_PAY_OFFSET, ANC_RANDOM extensions. New JIT supports all BPF extensions. Performance of such filters improves 2-4 times depending on a filter. The longer the filter the higher performance gain. Synthetic benchmarks with many ancillary loads see 20x speedup which seems to be the maximum gain from JIT Notes: . net.core.bpf_jit_enable=2 + tools/net/bpf_jit_disasm is still functional and can be used to see generated assembler . there are two jit_compile() functions and code flow for classic filters is: sk_attach_filter() - load classic BPF bpf_jit_compile() - try to JIT from classic BPF sk_convert_filter() - convert classic to internal bpf_int_jit_compile() - JIT from internal BPF seccomp and tracing filters will just call bpf_int_jit_compile() Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 20:50:46 -06:00
break;
case BPF_ALU | BPF_ADD | BPF_K:
case BPF_ALU | BPF_SUB | BPF_K:
case BPF_ALU | BPF_AND | BPF_K:
case BPF_ALU | BPF_OR | BPF_K:
case BPF_ALU | BPF_XOR | BPF_K:
case BPF_ALU64 | BPF_ADD | BPF_K:
case BPF_ALU64 | BPF_SUB | BPF_K:
case BPF_ALU64 | BPF_AND | BPF_K:
case BPF_ALU64 | BPF_OR | BPF_K:
case BPF_ALU64 | BPF_XOR | BPF_K:
if (BPF_CLASS(insn->code) == BPF_ALU64)
net: filter: cleanup A/X name usage The macro 'A' used in internal BPF interpreter: #define A regs[insn->a_reg] was easily confused with the name of classic BPF register 'A', since 'A' would mean two different things depending on context. This patch is trying to clean up the naming and clarify its usage in the following way: - A and X are names of two classic BPF registers - BPF_REG_A denotes internal BPF register R0 used to map classic register A in internal BPF programs generated from classic - BPF_REG_X denotes internal BPF register R7 used to map classic register X in internal BPF programs generated from classic - internal BPF instruction format: struct sock_filter_int { __u8 code; /* opcode */ __u8 dst_reg:4; /* dest register */ __u8 src_reg:4; /* source register */ __s16 off; /* signed offset */ __s32 imm; /* signed immediate constant */ }; - BPF_X/BPF_K is 1 bit used to encode source operand of instruction In classic: BPF_X - means use register X as source operand BPF_K - means use 32-bit immediate as source operand In internal: BPF_X - means use 'src_reg' register as source operand BPF_K - means use 32-bit immediate as source operand Suggested-by: Chema Gonzalez <chema@google.com> Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Acked-by: Daniel Borkmann <dborkman@redhat.com> Acked-by: Chema Gonzalez <chema@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-06-06 15:46:06 -06:00
EMIT1(add_1mod(0x48, dst_reg));
else if (is_ereg(dst_reg))
EMIT1(add_1mod(0x40, dst_reg));
net: filter: x86: internal BPF JIT Maps all internal BPF instructions into x86_64 instructions. This patch replaces original BPF x64 JIT with internal BPF x64 JIT. sysctl net.core.bpf_jit_enable is reused as on/off switch. Performance: 1. old BPF JIT and internal BPF JIT generate equivalent x86_64 code. No performance difference is observed for filters that were JIT-able before Example assembler code for BPF filter "tcpdump port 22" original BPF -> old JIT: original BPF -> internal BPF -> new JIT: 0: push %rbp 0: push %rbp 1: mov %rsp,%rbp 1: mov %rsp,%rbp 4: sub $0x60,%rsp 4: sub $0x228,%rsp 8: mov %rbx,-0x8(%rbp) b: mov %rbx,-0x228(%rbp) // prologue 12: mov %r13,-0x220(%rbp) 19: mov %r14,-0x218(%rbp) 20: mov %r15,-0x210(%rbp) 27: xor %eax,%eax // clear A c: xor %ebx,%ebx 29: xor %r13,%r13 // clear X e: mov 0x68(%rdi),%r9d 2c: mov 0x68(%rdi),%r9d 12: sub 0x6c(%rdi),%r9d 30: sub 0x6c(%rdi),%r9d 16: mov 0xd8(%rdi),%r8 34: mov 0xd8(%rdi),%r10 3b: mov %rdi,%rbx 1d: mov $0xc,%esi 3e: mov $0xc,%esi 22: callq 0xffffffffe1021e15 43: callq 0xffffffffe102bd75 27: cmp $0x86dd,%eax 48: cmp $0x86dd,%rax 2c: jne 0x0000000000000069 4f: jne 0x000000000000009a 2e: mov $0x14,%esi 51: mov $0x14,%esi 33: callq 0xffffffffe1021e31 56: callq 0xffffffffe102bd91 38: cmp $0x84,%eax 5b: cmp $0x84,%rax 3d: je 0x0000000000000049 62: je 0x0000000000000074 3f: cmp $0x6,%eax 64: cmp $0x6,%rax 42: je 0x0000000000000049 68: je 0x0000000000000074 44: cmp $0x11,%eax 6a: cmp $0x11,%rax 47: jne 0x00000000000000c6 6e: jne 0x0000000000000117 49: mov $0x36,%esi 74: mov $0x36,%esi 4e: callq 0xffffffffe1021e15 79: callq 0xffffffffe102bd75 53: cmp $0x16,%eax 7e: cmp $0x16,%rax 56: je 0x00000000000000bf 82: je 0x0000000000000110 58: mov $0x38,%esi 88: mov $0x38,%esi 5d: callq 0xffffffffe1021e15 8d: callq 0xffffffffe102bd75 62: cmp $0x16,%eax 92: cmp $0x16,%rax 65: je 0x00000000000000bf 96: je 0x0000000000000110 67: jmp 0x00000000000000c6 98: jmp 0x0000000000000117 69: cmp $0x800,%eax 9a: cmp $0x800,%rax 6e: jne 0x00000000000000c6 a1: jne 0x0000000000000117 70: mov $0x17,%esi a3: mov $0x17,%esi 75: callq 0xffffffffe1021e31 a8: callq 0xffffffffe102bd91 7a: cmp $0x84,%eax ad: cmp $0x84,%rax 7f: je 0x000000000000008b b4: je 0x00000000000000c2 81: cmp $0x6,%eax b6: cmp $0x6,%rax 84: je 0x000000000000008b ba: je 0x00000000000000c2 86: cmp $0x11,%eax bc: cmp $0x11,%rax 89: jne 0x00000000000000c6 c0: jne 0x0000000000000117 8b: mov $0x14,%esi c2: mov $0x14,%esi 90: callq 0xffffffffe1021e15 c7: callq 0xffffffffe102bd75 95: test $0x1fff,%ax cc: test $0x1fff,%rax 99: jne 0x00000000000000c6 d3: jne 0x0000000000000117 d5: mov %rax,%r14 9b: mov $0xe,%esi d8: mov $0xe,%esi a0: callq 0xffffffffe1021e44 dd: callq 0xffffffffe102bd91 // MSH e2: and $0xf,%eax e5: shl $0x2,%eax e8: mov %rax,%r13 eb: mov %r14,%rax ee: mov %r13,%rsi a5: lea 0xe(%rbx),%esi f1: add $0xe,%esi a8: callq 0xffffffffe1021e0d f4: callq 0xffffffffe102bd6d ad: cmp $0x16,%eax f9: cmp $0x16,%rax b0: je 0x00000000000000bf fd: je 0x0000000000000110 ff: mov %r13,%rsi b2: lea 0x10(%rbx),%esi 102: add $0x10,%esi b5: callq 0xffffffffe1021e0d 105: callq 0xffffffffe102bd6d ba: cmp $0x16,%eax 10a: cmp $0x16,%rax bd: jne 0x00000000000000c6 10e: jne 0x0000000000000117 bf: mov $0xffff,%eax 110: mov $0xffff,%eax c4: jmp 0x00000000000000c8 115: jmp 0x000000000000011c c6: xor %eax,%eax 117: mov $0x0,%eax c8: mov -0x8(%rbp),%rbx 11c: mov -0x228(%rbp),%rbx // epilogue cc: leaveq 123: mov -0x220(%rbp),%r13 cd: retq 12a: mov -0x218(%rbp),%r14 131: mov -0x210(%rbp),%r15 138: leaveq 139: retq On fully cached SKBs both JITed functions take 12 nsec to execute. BPF interpreter executes the program in 30 nsec. The difference in generated assembler is due to the following: Old BPF imlements LDX_MSH instruction via sk_load_byte_msh() helper function inside bpf_jit.S. New JIT removes the helper and does it explicitly, so ldx_msh cost is the same for both JITs, but generated code looks longer. New JIT has 4 registers to save, so prologue/epilogue are larger, but the cost is within noise on x64. Old JIT checks whether first insn clears A and if not emits 'xor %eax,%eax'. New JIT clears %rax unconditionally. 2. old BPF JIT doesn't support ANC_NLATTR, ANC_PAY_OFFSET, ANC_RANDOM extensions. New JIT supports all BPF extensions. Performance of such filters improves 2-4 times depending on a filter. The longer the filter the higher performance gain. Synthetic benchmarks with many ancillary loads see 20x speedup which seems to be the maximum gain from JIT Notes: . net.core.bpf_jit_enable=2 + tools/net/bpf_jit_disasm is still functional and can be used to see generated assembler . there are two jit_compile() functions and code flow for classic filters is: sk_attach_filter() - load classic BPF bpf_jit_compile() - try to JIT from classic BPF sk_convert_filter() - convert classic to internal bpf_int_jit_compile() - JIT from internal BPF seccomp and tracing filters will just call bpf_int_jit_compile() Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 20:50:46 -06:00
switch (BPF_OP(insn->code)) {
case BPF_ADD: b3 = 0xC0; break;
case BPF_SUB: b3 = 0xE8; break;
case BPF_AND: b3 = 0xE0; break;
case BPF_OR: b3 = 0xC8; break;
case BPF_XOR: b3 = 0xF0; break;
}
net: filter: cleanup A/X name usage The macro 'A' used in internal BPF interpreter: #define A regs[insn->a_reg] was easily confused with the name of classic BPF register 'A', since 'A' would mean two different things depending on context. This patch is trying to clean up the naming and clarify its usage in the following way: - A and X are names of two classic BPF registers - BPF_REG_A denotes internal BPF register R0 used to map classic register A in internal BPF programs generated from classic - BPF_REG_X denotes internal BPF register R7 used to map classic register X in internal BPF programs generated from classic - internal BPF instruction format: struct sock_filter_int { __u8 code; /* opcode */ __u8 dst_reg:4; /* dest register */ __u8 src_reg:4; /* source register */ __s16 off; /* signed offset */ __s32 imm; /* signed immediate constant */ }; - BPF_X/BPF_K is 1 bit used to encode source operand of instruction In classic: BPF_X - means use register X as source operand BPF_K - means use 32-bit immediate as source operand In internal: BPF_X - means use 'src_reg' register as source operand BPF_K - means use 32-bit immediate as source operand Suggested-by: Chema Gonzalez <chema@google.com> Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Acked-by: Daniel Borkmann <dborkman@redhat.com> Acked-by: Chema Gonzalez <chema@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-06-06 15:46:06 -06:00
if (is_imm8(imm32))
EMIT3(0x83, add_1reg(b3, dst_reg), imm32);
net: filter: x86: internal BPF JIT Maps all internal BPF instructions into x86_64 instructions. This patch replaces original BPF x64 JIT with internal BPF x64 JIT. sysctl net.core.bpf_jit_enable is reused as on/off switch. Performance: 1. old BPF JIT and internal BPF JIT generate equivalent x86_64 code. No performance difference is observed for filters that were JIT-able before Example assembler code for BPF filter "tcpdump port 22" original BPF -> old JIT: original BPF -> internal BPF -> new JIT: 0: push %rbp 0: push %rbp 1: mov %rsp,%rbp 1: mov %rsp,%rbp 4: sub $0x60,%rsp 4: sub $0x228,%rsp 8: mov %rbx,-0x8(%rbp) b: mov %rbx,-0x228(%rbp) // prologue 12: mov %r13,-0x220(%rbp) 19: mov %r14,-0x218(%rbp) 20: mov %r15,-0x210(%rbp) 27: xor %eax,%eax // clear A c: xor %ebx,%ebx 29: xor %r13,%r13 // clear X e: mov 0x68(%rdi),%r9d 2c: mov 0x68(%rdi),%r9d 12: sub 0x6c(%rdi),%r9d 30: sub 0x6c(%rdi),%r9d 16: mov 0xd8(%rdi),%r8 34: mov 0xd8(%rdi),%r10 3b: mov %rdi,%rbx 1d: mov $0xc,%esi 3e: mov $0xc,%esi 22: callq 0xffffffffe1021e15 43: callq 0xffffffffe102bd75 27: cmp $0x86dd,%eax 48: cmp $0x86dd,%rax 2c: jne 0x0000000000000069 4f: jne 0x000000000000009a 2e: mov $0x14,%esi 51: mov $0x14,%esi 33: callq 0xffffffffe1021e31 56: callq 0xffffffffe102bd91 38: cmp $0x84,%eax 5b: cmp $0x84,%rax 3d: je 0x0000000000000049 62: je 0x0000000000000074 3f: cmp $0x6,%eax 64: cmp $0x6,%rax 42: je 0x0000000000000049 68: je 0x0000000000000074 44: cmp $0x11,%eax 6a: cmp $0x11,%rax 47: jne 0x00000000000000c6 6e: jne 0x0000000000000117 49: mov $0x36,%esi 74: mov $0x36,%esi 4e: callq 0xffffffffe1021e15 79: callq 0xffffffffe102bd75 53: cmp $0x16,%eax 7e: cmp $0x16,%rax 56: je 0x00000000000000bf 82: je 0x0000000000000110 58: mov $0x38,%esi 88: mov $0x38,%esi 5d: callq 0xffffffffe1021e15 8d: callq 0xffffffffe102bd75 62: cmp $0x16,%eax 92: cmp $0x16,%rax 65: je 0x00000000000000bf 96: je 0x0000000000000110 67: jmp 0x00000000000000c6 98: jmp 0x0000000000000117 69: cmp $0x800,%eax 9a: cmp $0x800,%rax 6e: jne 0x00000000000000c6 a1: jne 0x0000000000000117 70: mov $0x17,%esi a3: mov $0x17,%esi 75: callq 0xffffffffe1021e31 a8: callq 0xffffffffe102bd91 7a: cmp $0x84,%eax ad: cmp $0x84,%rax 7f: je 0x000000000000008b b4: je 0x00000000000000c2 81: cmp $0x6,%eax b6: cmp $0x6,%rax 84: je 0x000000000000008b ba: je 0x00000000000000c2 86: cmp $0x11,%eax bc: cmp $0x11,%rax 89: jne 0x00000000000000c6 c0: jne 0x0000000000000117 8b: mov $0x14,%esi c2: mov $0x14,%esi 90: callq 0xffffffffe1021e15 c7: callq 0xffffffffe102bd75 95: test $0x1fff,%ax cc: test $0x1fff,%rax 99: jne 0x00000000000000c6 d3: jne 0x0000000000000117 d5: mov %rax,%r14 9b: mov $0xe,%esi d8: mov $0xe,%esi a0: callq 0xffffffffe1021e44 dd: callq 0xffffffffe102bd91 // MSH e2: and $0xf,%eax e5: shl $0x2,%eax e8: mov %rax,%r13 eb: mov %r14,%rax ee: mov %r13,%rsi a5: lea 0xe(%rbx),%esi f1: add $0xe,%esi a8: callq 0xffffffffe1021e0d f4: callq 0xffffffffe102bd6d ad: cmp $0x16,%eax f9: cmp $0x16,%rax b0: je 0x00000000000000bf fd: je 0x0000000000000110 ff: mov %r13,%rsi b2: lea 0x10(%rbx),%esi 102: add $0x10,%esi b5: callq 0xffffffffe1021e0d 105: callq 0xffffffffe102bd6d ba: cmp $0x16,%eax 10a: cmp $0x16,%rax bd: jne 0x00000000000000c6 10e: jne 0x0000000000000117 bf: mov $0xffff,%eax 110: mov $0xffff,%eax c4: jmp 0x00000000000000c8 115: jmp 0x000000000000011c c6: xor %eax,%eax 117: mov $0x0,%eax c8: mov -0x8(%rbp),%rbx 11c: mov -0x228(%rbp),%rbx // epilogue cc: leaveq 123: mov -0x220(%rbp),%r13 cd: retq 12a: mov -0x218(%rbp),%r14 131: mov -0x210(%rbp),%r15 138: leaveq 139: retq On fully cached SKBs both JITed functions take 12 nsec to execute. BPF interpreter executes the program in 30 nsec. The difference in generated assembler is due to the following: Old BPF imlements LDX_MSH instruction via sk_load_byte_msh() helper function inside bpf_jit.S. New JIT removes the helper and does it explicitly, so ldx_msh cost is the same for both JITs, but generated code looks longer. New JIT has 4 registers to save, so prologue/epilogue are larger, but the cost is within noise on x64. Old JIT checks whether first insn clears A and if not emits 'xor %eax,%eax'. New JIT clears %rax unconditionally. 2. old BPF JIT doesn't support ANC_NLATTR, ANC_PAY_OFFSET, ANC_RANDOM extensions. New JIT supports all BPF extensions. Performance of such filters improves 2-4 times depending on a filter. The longer the filter the higher performance gain. Synthetic benchmarks with many ancillary loads see 20x speedup which seems to be the maximum gain from JIT Notes: . net.core.bpf_jit_enable=2 + tools/net/bpf_jit_disasm is still functional and can be used to see generated assembler . there are two jit_compile() functions and code flow for classic filters is: sk_attach_filter() - load classic BPF bpf_jit_compile() - try to JIT from classic BPF sk_convert_filter() - convert classic to internal bpf_int_jit_compile() - JIT from internal BPF seccomp and tracing filters will just call bpf_int_jit_compile() Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 20:50:46 -06:00
else
net: filter: cleanup A/X name usage The macro 'A' used in internal BPF interpreter: #define A regs[insn->a_reg] was easily confused with the name of classic BPF register 'A', since 'A' would mean two different things depending on context. This patch is trying to clean up the naming and clarify its usage in the following way: - A and X are names of two classic BPF registers - BPF_REG_A denotes internal BPF register R0 used to map classic register A in internal BPF programs generated from classic - BPF_REG_X denotes internal BPF register R7 used to map classic register X in internal BPF programs generated from classic - internal BPF instruction format: struct sock_filter_int { __u8 code; /* opcode */ __u8 dst_reg:4; /* dest register */ __u8 src_reg:4; /* source register */ __s16 off; /* signed offset */ __s32 imm; /* signed immediate constant */ }; - BPF_X/BPF_K is 1 bit used to encode source operand of instruction In classic: BPF_X - means use register X as source operand BPF_K - means use 32-bit immediate as source operand In internal: BPF_X - means use 'src_reg' register as source operand BPF_K - means use 32-bit immediate as source operand Suggested-by: Chema Gonzalez <chema@google.com> Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Acked-by: Daniel Borkmann <dborkman@redhat.com> Acked-by: Chema Gonzalez <chema@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-06-06 15:46:06 -06:00
EMIT2_off32(0x81, add_1reg(b3, dst_reg), imm32);
net: filter: x86: internal BPF JIT Maps all internal BPF instructions into x86_64 instructions. This patch replaces original BPF x64 JIT with internal BPF x64 JIT. sysctl net.core.bpf_jit_enable is reused as on/off switch. Performance: 1. old BPF JIT and internal BPF JIT generate equivalent x86_64 code. No performance difference is observed for filters that were JIT-able before Example assembler code for BPF filter "tcpdump port 22" original BPF -> old JIT: original BPF -> internal BPF -> new JIT: 0: push %rbp 0: push %rbp 1: mov %rsp,%rbp 1: mov %rsp,%rbp 4: sub $0x60,%rsp 4: sub $0x228,%rsp 8: mov %rbx,-0x8(%rbp) b: mov %rbx,-0x228(%rbp) // prologue 12: mov %r13,-0x220(%rbp) 19: mov %r14,-0x218(%rbp) 20: mov %r15,-0x210(%rbp) 27: xor %eax,%eax // clear A c: xor %ebx,%ebx 29: xor %r13,%r13 // clear X e: mov 0x68(%rdi),%r9d 2c: mov 0x68(%rdi),%r9d 12: sub 0x6c(%rdi),%r9d 30: sub 0x6c(%rdi),%r9d 16: mov 0xd8(%rdi),%r8 34: mov 0xd8(%rdi),%r10 3b: mov %rdi,%rbx 1d: mov $0xc,%esi 3e: mov $0xc,%esi 22: callq 0xffffffffe1021e15 43: callq 0xffffffffe102bd75 27: cmp $0x86dd,%eax 48: cmp $0x86dd,%rax 2c: jne 0x0000000000000069 4f: jne 0x000000000000009a 2e: mov $0x14,%esi 51: mov $0x14,%esi 33: callq 0xffffffffe1021e31 56: callq 0xffffffffe102bd91 38: cmp $0x84,%eax 5b: cmp $0x84,%rax 3d: je 0x0000000000000049 62: je 0x0000000000000074 3f: cmp $0x6,%eax 64: cmp $0x6,%rax 42: je 0x0000000000000049 68: je 0x0000000000000074 44: cmp $0x11,%eax 6a: cmp $0x11,%rax 47: jne 0x00000000000000c6 6e: jne 0x0000000000000117 49: mov $0x36,%esi 74: mov $0x36,%esi 4e: callq 0xffffffffe1021e15 79: callq 0xffffffffe102bd75 53: cmp $0x16,%eax 7e: cmp $0x16,%rax 56: je 0x00000000000000bf 82: je 0x0000000000000110 58: mov $0x38,%esi 88: mov $0x38,%esi 5d: callq 0xffffffffe1021e15 8d: callq 0xffffffffe102bd75 62: cmp $0x16,%eax 92: cmp $0x16,%rax 65: je 0x00000000000000bf 96: je 0x0000000000000110 67: jmp 0x00000000000000c6 98: jmp 0x0000000000000117 69: cmp $0x800,%eax 9a: cmp $0x800,%rax 6e: jne 0x00000000000000c6 a1: jne 0x0000000000000117 70: mov $0x17,%esi a3: mov $0x17,%esi 75: callq 0xffffffffe1021e31 a8: callq 0xffffffffe102bd91 7a: cmp $0x84,%eax ad: cmp $0x84,%rax 7f: je 0x000000000000008b b4: je 0x00000000000000c2 81: cmp $0x6,%eax b6: cmp $0x6,%rax 84: je 0x000000000000008b ba: je 0x00000000000000c2 86: cmp $0x11,%eax bc: cmp $0x11,%rax 89: jne 0x00000000000000c6 c0: jne 0x0000000000000117 8b: mov $0x14,%esi c2: mov $0x14,%esi 90: callq 0xffffffffe1021e15 c7: callq 0xffffffffe102bd75 95: test $0x1fff,%ax cc: test $0x1fff,%rax 99: jne 0x00000000000000c6 d3: jne 0x0000000000000117 d5: mov %rax,%r14 9b: mov $0xe,%esi d8: mov $0xe,%esi a0: callq 0xffffffffe1021e44 dd: callq 0xffffffffe102bd91 // MSH e2: and $0xf,%eax e5: shl $0x2,%eax e8: mov %rax,%r13 eb: mov %r14,%rax ee: mov %r13,%rsi a5: lea 0xe(%rbx),%esi f1: add $0xe,%esi a8: callq 0xffffffffe1021e0d f4: callq 0xffffffffe102bd6d ad: cmp $0x16,%eax f9: cmp $0x16,%rax b0: je 0x00000000000000bf fd: je 0x0000000000000110 ff: mov %r13,%rsi b2: lea 0x10(%rbx),%esi 102: add $0x10,%esi b5: callq 0xffffffffe1021e0d 105: callq 0xffffffffe102bd6d ba: cmp $0x16,%eax 10a: cmp $0x16,%rax bd: jne 0x00000000000000c6 10e: jne 0x0000000000000117 bf: mov $0xffff,%eax 110: mov $0xffff,%eax c4: jmp 0x00000000000000c8 115: jmp 0x000000000000011c c6: xor %eax,%eax 117: mov $0x0,%eax c8: mov -0x8(%rbp),%rbx 11c: mov -0x228(%rbp),%rbx // epilogue cc: leaveq 123: mov -0x220(%rbp),%r13 cd: retq 12a: mov -0x218(%rbp),%r14 131: mov -0x210(%rbp),%r15 138: leaveq 139: retq On fully cached SKBs both JITed functions take 12 nsec to execute. BPF interpreter executes the program in 30 nsec. The difference in generated assembler is due to the following: Old BPF imlements LDX_MSH instruction via sk_load_byte_msh() helper function inside bpf_jit.S. New JIT removes the helper and does it explicitly, so ldx_msh cost is the same for both JITs, but generated code looks longer. New JIT has 4 registers to save, so prologue/epilogue are larger, but the cost is within noise on x64. Old JIT checks whether first insn clears A and if not emits 'xor %eax,%eax'. New JIT clears %rax unconditionally. 2. old BPF JIT doesn't support ANC_NLATTR, ANC_PAY_OFFSET, ANC_RANDOM extensions. New JIT supports all BPF extensions. Performance of such filters improves 2-4 times depending on a filter. The longer the filter the higher performance gain. Synthetic benchmarks with many ancillary loads see 20x speedup which seems to be the maximum gain from JIT Notes: . net.core.bpf_jit_enable=2 + tools/net/bpf_jit_disasm is still functional and can be used to see generated assembler . there are two jit_compile() functions and code flow for classic filters is: sk_attach_filter() - load classic BPF bpf_jit_compile() - try to JIT from classic BPF sk_convert_filter() - convert classic to internal bpf_int_jit_compile() - JIT from internal BPF seccomp and tracing filters will just call bpf_int_jit_compile() Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 20:50:46 -06:00
break;
case BPF_ALU64 | BPF_MOV | BPF_K:
/* optimization: if imm32 is positive,
* use 'mov eax, imm32' (which zero-extends imm32)
* to save 2 bytes
*/
net: filter: cleanup A/X name usage The macro 'A' used in internal BPF interpreter: #define A regs[insn->a_reg] was easily confused with the name of classic BPF register 'A', since 'A' would mean two different things depending on context. This patch is trying to clean up the naming and clarify its usage in the following way: - A and X are names of two classic BPF registers - BPF_REG_A denotes internal BPF register R0 used to map classic register A in internal BPF programs generated from classic - BPF_REG_X denotes internal BPF register R7 used to map classic register X in internal BPF programs generated from classic - internal BPF instruction format: struct sock_filter_int { __u8 code; /* opcode */ __u8 dst_reg:4; /* dest register */ __u8 src_reg:4; /* source register */ __s16 off; /* signed offset */ __s32 imm; /* signed immediate constant */ }; - BPF_X/BPF_K is 1 bit used to encode source operand of instruction In classic: BPF_X - means use register X as source operand BPF_K - means use 32-bit immediate as source operand In internal: BPF_X - means use 'src_reg' register as source operand BPF_K - means use 32-bit immediate as source operand Suggested-by: Chema Gonzalez <chema@google.com> Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Acked-by: Daniel Borkmann <dborkman@redhat.com> Acked-by: Chema Gonzalez <chema@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-06-06 15:46:06 -06:00
if (imm32 < 0) {
net: filter: x86: internal BPF JIT Maps all internal BPF instructions into x86_64 instructions. This patch replaces original BPF x64 JIT with internal BPF x64 JIT. sysctl net.core.bpf_jit_enable is reused as on/off switch. Performance: 1. old BPF JIT and internal BPF JIT generate equivalent x86_64 code. No performance difference is observed for filters that were JIT-able before Example assembler code for BPF filter "tcpdump port 22" original BPF -> old JIT: original BPF -> internal BPF -> new JIT: 0: push %rbp 0: push %rbp 1: mov %rsp,%rbp 1: mov %rsp,%rbp 4: sub $0x60,%rsp 4: sub $0x228,%rsp 8: mov %rbx,-0x8(%rbp) b: mov %rbx,-0x228(%rbp) // prologue 12: mov %r13,-0x220(%rbp) 19: mov %r14,-0x218(%rbp) 20: mov %r15,-0x210(%rbp) 27: xor %eax,%eax // clear A c: xor %ebx,%ebx 29: xor %r13,%r13 // clear X e: mov 0x68(%rdi),%r9d 2c: mov 0x68(%rdi),%r9d 12: sub 0x6c(%rdi),%r9d 30: sub 0x6c(%rdi),%r9d 16: mov 0xd8(%rdi),%r8 34: mov 0xd8(%rdi),%r10 3b: mov %rdi,%rbx 1d: mov $0xc,%esi 3e: mov $0xc,%esi 22: callq 0xffffffffe1021e15 43: callq 0xffffffffe102bd75 27: cmp $0x86dd,%eax 48: cmp $0x86dd,%rax 2c: jne 0x0000000000000069 4f: jne 0x000000000000009a 2e: mov $0x14,%esi 51: mov $0x14,%esi 33: callq 0xffffffffe1021e31 56: callq 0xffffffffe102bd91 38: cmp $0x84,%eax 5b: cmp $0x84,%rax 3d: je 0x0000000000000049 62: je 0x0000000000000074 3f: cmp $0x6,%eax 64: cmp $0x6,%rax 42: je 0x0000000000000049 68: je 0x0000000000000074 44: cmp $0x11,%eax 6a: cmp $0x11,%rax 47: jne 0x00000000000000c6 6e: jne 0x0000000000000117 49: mov $0x36,%esi 74: mov $0x36,%esi 4e: callq 0xffffffffe1021e15 79: callq 0xffffffffe102bd75 53: cmp $0x16,%eax 7e: cmp $0x16,%rax 56: je 0x00000000000000bf 82: je 0x0000000000000110 58: mov $0x38,%esi 88: mov $0x38,%esi 5d: callq 0xffffffffe1021e15 8d: callq 0xffffffffe102bd75 62: cmp $0x16,%eax 92: cmp $0x16,%rax 65: je 0x00000000000000bf 96: je 0x0000000000000110 67: jmp 0x00000000000000c6 98: jmp 0x0000000000000117 69: cmp $0x800,%eax 9a: cmp $0x800,%rax 6e: jne 0x00000000000000c6 a1: jne 0x0000000000000117 70: mov $0x17,%esi a3: mov $0x17,%esi 75: callq 0xffffffffe1021e31 a8: callq 0xffffffffe102bd91 7a: cmp $0x84,%eax ad: cmp $0x84,%rax 7f: je 0x000000000000008b b4: je 0x00000000000000c2 81: cmp $0x6,%eax b6: cmp $0x6,%rax 84: je 0x000000000000008b ba: je 0x00000000000000c2 86: cmp $0x11,%eax bc: cmp $0x11,%rax 89: jne 0x00000000000000c6 c0: jne 0x0000000000000117 8b: mov $0x14,%esi c2: mov $0x14,%esi 90: callq 0xffffffffe1021e15 c7: callq 0xffffffffe102bd75 95: test $0x1fff,%ax cc: test $0x1fff,%rax 99: jne 0x00000000000000c6 d3: jne 0x0000000000000117 d5: mov %rax,%r14 9b: mov $0xe,%esi d8: mov $0xe,%esi a0: callq 0xffffffffe1021e44 dd: callq 0xffffffffe102bd91 // MSH e2: and $0xf,%eax e5: shl $0x2,%eax e8: mov %rax,%r13 eb: mov %r14,%rax ee: mov %r13,%rsi a5: lea 0xe(%rbx),%esi f1: add $0xe,%esi a8: callq 0xffffffffe1021e0d f4: callq 0xffffffffe102bd6d ad: cmp $0x16,%eax f9: cmp $0x16,%rax b0: je 0x00000000000000bf fd: je 0x0000000000000110 ff: mov %r13,%rsi b2: lea 0x10(%rbx),%esi 102: add $0x10,%esi b5: callq 0xffffffffe1021e0d 105: callq 0xffffffffe102bd6d ba: cmp $0x16,%eax 10a: cmp $0x16,%rax bd: jne 0x00000000000000c6 10e: jne 0x0000000000000117 bf: mov $0xffff,%eax 110: mov $0xffff,%eax c4: jmp 0x00000000000000c8 115: jmp 0x000000000000011c c6: xor %eax,%eax 117: mov $0x0,%eax c8: mov -0x8(%rbp),%rbx 11c: mov -0x228(%rbp),%rbx // epilogue cc: leaveq 123: mov -0x220(%rbp),%r13 cd: retq 12a: mov -0x218(%rbp),%r14 131: mov -0x210(%rbp),%r15 138: leaveq 139: retq On fully cached SKBs both JITed functions take 12 nsec to execute. BPF interpreter executes the program in 30 nsec. The difference in generated assembler is due to the following: Old BPF imlements LDX_MSH instruction via sk_load_byte_msh() helper function inside bpf_jit.S. New JIT removes the helper and does it explicitly, so ldx_msh cost is the same for both JITs, but generated code looks longer. New JIT has 4 registers to save, so prologue/epilogue are larger, but the cost is within noise on x64. Old JIT checks whether first insn clears A and if not emits 'xor %eax,%eax'. New JIT clears %rax unconditionally. 2. old BPF JIT doesn't support ANC_NLATTR, ANC_PAY_OFFSET, ANC_RANDOM extensions. New JIT supports all BPF extensions. Performance of such filters improves 2-4 times depending on a filter. The longer the filter the higher performance gain. Synthetic benchmarks with many ancillary loads see 20x speedup which seems to be the maximum gain from JIT Notes: . net.core.bpf_jit_enable=2 + tools/net/bpf_jit_disasm is still functional and can be used to see generated assembler . there are two jit_compile() functions and code flow for classic filters is: sk_attach_filter() - load classic BPF bpf_jit_compile() - try to JIT from classic BPF sk_convert_filter() - convert classic to internal bpf_int_jit_compile() - JIT from internal BPF seccomp and tracing filters will just call bpf_int_jit_compile() Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 20:50:46 -06:00
/* 'mov rax, imm32' sign extends imm32 */
net: filter: cleanup A/X name usage The macro 'A' used in internal BPF interpreter: #define A regs[insn->a_reg] was easily confused with the name of classic BPF register 'A', since 'A' would mean two different things depending on context. This patch is trying to clean up the naming and clarify its usage in the following way: - A and X are names of two classic BPF registers - BPF_REG_A denotes internal BPF register R0 used to map classic register A in internal BPF programs generated from classic - BPF_REG_X denotes internal BPF register R7 used to map classic register X in internal BPF programs generated from classic - internal BPF instruction format: struct sock_filter_int { __u8 code; /* opcode */ __u8 dst_reg:4; /* dest register */ __u8 src_reg:4; /* source register */ __s16 off; /* signed offset */ __s32 imm; /* signed immediate constant */ }; - BPF_X/BPF_K is 1 bit used to encode source operand of instruction In classic: BPF_X - means use register X as source operand BPF_K - means use 32-bit immediate as source operand In internal: BPF_X - means use 'src_reg' register as source operand BPF_K - means use 32-bit immediate as source operand Suggested-by: Chema Gonzalez <chema@google.com> Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Acked-by: Daniel Borkmann <dborkman@redhat.com> Acked-by: Chema Gonzalez <chema@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-06-06 15:46:06 -06:00
b1 = add_1mod(0x48, dst_reg);
net: filter: x86: internal BPF JIT Maps all internal BPF instructions into x86_64 instructions. This patch replaces original BPF x64 JIT with internal BPF x64 JIT. sysctl net.core.bpf_jit_enable is reused as on/off switch. Performance: 1. old BPF JIT and internal BPF JIT generate equivalent x86_64 code. No performance difference is observed for filters that were JIT-able before Example assembler code for BPF filter "tcpdump port 22" original BPF -> old JIT: original BPF -> internal BPF -> new JIT: 0: push %rbp 0: push %rbp 1: mov %rsp,%rbp 1: mov %rsp,%rbp 4: sub $0x60,%rsp 4: sub $0x228,%rsp 8: mov %rbx,-0x8(%rbp) b: mov %rbx,-0x228(%rbp) // prologue 12: mov %r13,-0x220(%rbp) 19: mov %r14,-0x218(%rbp) 20: mov %r15,-0x210(%rbp) 27: xor %eax,%eax // clear A c: xor %ebx,%ebx 29: xor %r13,%r13 // clear X e: mov 0x68(%rdi),%r9d 2c: mov 0x68(%rdi),%r9d 12: sub 0x6c(%rdi),%r9d 30: sub 0x6c(%rdi),%r9d 16: mov 0xd8(%rdi),%r8 34: mov 0xd8(%rdi),%r10 3b: mov %rdi,%rbx 1d: mov $0xc,%esi 3e: mov $0xc,%esi 22: callq 0xffffffffe1021e15 43: callq 0xffffffffe102bd75 27: cmp $0x86dd,%eax 48: cmp $0x86dd,%rax 2c: jne 0x0000000000000069 4f: jne 0x000000000000009a 2e: mov $0x14,%esi 51: mov $0x14,%esi 33: callq 0xffffffffe1021e31 56: callq 0xffffffffe102bd91 38: cmp $0x84,%eax 5b: cmp $0x84,%rax 3d: je 0x0000000000000049 62: je 0x0000000000000074 3f: cmp $0x6,%eax 64: cmp $0x6,%rax 42: je 0x0000000000000049 68: je 0x0000000000000074 44: cmp $0x11,%eax 6a: cmp $0x11,%rax 47: jne 0x00000000000000c6 6e: jne 0x0000000000000117 49: mov $0x36,%esi 74: mov $0x36,%esi 4e: callq 0xffffffffe1021e15 79: callq 0xffffffffe102bd75 53: cmp $0x16,%eax 7e: cmp $0x16,%rax 56: je 0x00000000000000bf 82: je 0x0000000000000110 58: mov $0x38,%esi 88: mov $0x38,%esi 5d: callq 0xffffffffe1021e15 8d: callq 0xffffffffe102bd75 62: cmp $0x16,%eax 92: cmp $0x16,%rax 65: je 0x00000000000000bf 96: je 0x0000000000000110 67: jmp 0x00000000000000c6 98: jmp 0x0000000000000117 69: cmp $0x800,%eax 9a: cmp $0x800,%rax 6e: jne 0x00000000000000c6 a1: jne 0x0000000000000117 70: mov $0x17,%esi a3: mov $0x17,%esi 75: callq 0xffffffffe1021e31 a8: callq 0xffffffffe102bd91 7a: cmp $0x84,%eax ad: cmp $0x84,%rax 7f: je 0x000000000000008b b4: je 0x00000000000000c2 81: cmp $0x6,%eax b6: cmp $0x6,%rax 84: je 0x000000000000008b ba: je 0x00000000000000c2 86: cmp $0x11,%eax bc: cmp $0x11,%rax 89: jne 0x00000000000000c6 c0: jne 0x0000000000000117 8b: mov $0x14,%esi c2: mov $0x14,%esi 90: callq 0xffffffffe1021e15 c7: callq 0xffffffffe102bd75 95: test $0x1fff,%ax cc: test $0x1fff,%rax 99: jne 0x00000000000000c6 d3: jne 0x0000000000000117 d5: mov %rax,%r14 9b: mov $0xe,%esi d8: mov $0xe,%esi a0: callq 0xffffffffe1021e44 dd: callq 0xffffffffe102bd91 // MSH e2: and $0xf,%eax e5: shl $0x2,%eax e8: mov %rax,%r13 eb: mov %r14,%rax ee: mov %r13,%rsi a5: lea 0xe(%rbx),%esi f1: add $0xe,%esi a8: callq 0xffffffffe1021e0d f4: callq 0xffffffffe102bd6d ad: cmp $0x16,%eax f9: cmp $0x16,%rax b0: je 0x00000000000000bf fd: je 0x0000000000000110 ff: mov %r13,%rsi b2: lea 0x10(%rbx),%esi 102: add $0x10,%esi b5: callq 0xffffffffe1021e0d 105: callq 0xffffffffe102bd6d ba: cmp $0x16,%eax 10a: cmp $0x16,%rax bd: jne 0x00000000000000c6 10e: jne 0x0000000000000117 bf: mov $0xffff,%eax 110: mov $0xffff,%eax c4: jmp 0x00000000000000c8 115: jmp 0x000000000000011c c6: xor %eax,%eax 117: mov $0x0,%eax c8: mov -0x8(%rbp),%rbx 11c: mov -0x228(%rbp),%rbx // epilogue cc: leaveq 123: mov -0x220(%rbp),%r13 cd: retq 12a: mov -0x218(%rbp),%r14 131: mov -0x210(%rbp),%r15 138: leaveq 139: retq On fully cached SKBs both JITed functions take 12 nsec to execute. BPF interpreter executes the program in 30 nsec. The difference in generated assembler is due to the following: Old BPF imlements LDX_MSH instruction via sk_load_byte_msh() helper function inside bpf_jit.S. New JIT removes the helper and does it explicitly, so ldx_msh cost is the same for both JITs, but generated code looks longer. New JIT has 4 registers to save, so prologue/epilogue are larger, but the cost is within noise on x64. Old JIT checks whether first insn clears A and if not emits 'xor %eax,%eax'. New JIT clears %rax unconditionally. 2. old BPF JIT doesn't support ANC_NLATTR, ANC_PAY_OFFSET, ANC_RANDOM extensions. New JIT supports all BPF extensions. Performance of such filters improves 2-4 times depending on a filter. The longer the filter the higher performance gain. Synthetic benchmarks with many ancillary loads see 20x speedup which seems to be the maximum gain from JIT Notes: . net.core.bpf_jit_enable=2 + tools/net/bpf_jit_disasm is still functional and can be used to see generated assembler . there are two jit_compile() functions and code flow for classic filters is: sk_attach_filter() - load classic BPF bpf_jit_compile() - try to JIT from classic BPF sk_convert_filter() - convert classic to internal bpf_int_jit_compile() - JIT from internal BPF seccomp and tracing filters will just call bpf_int_jit_compile() Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 20:50:46 -06:00
b2 = 0xC7;
b3 = 0xC0;
net: filter: cleanup A/X name usage The macro 'A' used in internal BPF interpreter: #define A regs[insn->a_reg] was easily confused with the name of classic BPF register 'A', since 'A' would mean two different things depending on context. This patch is trying to clean up the naming and clarify its usage in the following way: - A and X are names of two classic BPF registers - BPF_REG_A denotes internal BPF register R0 used to map classic register A in internal BPF programs generated from classic - BPF_REG_X denotes internal BPF register R7 used to map classic register X in internal BPF programs generated from classic - internal BPF instruction format: struct sock_filter_int { __u8 code; /* opcode */ __u8 dst_reg:4; /* dest register */ __u8 src_reg:4; /* source register */ __s16 off; /* signed offset */ __s32 imm; /* signed immediate constant */ }; - BPF_X/BPF_K is 1 bit used to encode source operand of instruction In classic: BPF_X - means use register X as source operand BPF_K - means use 32-bit immediate as source operand In internal: BPF_X - means use 'src_reg' register as source operand BPF_K - means use 32-bit immediate as source operand Suggested-by: Chema Gonzalez <chema@google.com> Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Acked-by: Daniel Borkmann <dborkman@redhat.com> Acked-by: Chema Gonzalez <chema@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-06-06 15:46:06 -06:00
EMIT3_off32(b1, b2, add_1reg(b3, dst_reg), imm32);
net: filter: Just In Time compiler for x86-64 In order to speedup packet filtering, here is an implementation of a JIT compiler for x86_64 It is disabled by default, and must be enabled by the admin. echo 1 >/proc/sys/net/core/bpf_jit_enable It uses module_alloc() and module_free() to get memory in the 2GB text kernel range since we call helpers functions from the generated code. EAX : BPF A accumulator EBX : BPF X accumulator RDI : pointer to skb (first argument given to JIT function) RBP : frame pointer (even if CONFIG_FRAME_POINTER=n) r9d : skb->len - skb->data_len (headlen) r8 : skb->data To get a trace of generated code, use : echo 2 >/proc/sys/net/core/bpf_jit_enable Example of generated code : # tcpdump -p -n -s 0 -i eth1 host 192.168.20.0/24 flen=18 proglen=147 pass=3 image=ffffffffa00b5000 JIT code: ffffffffa00b5000: 55 48 89 e5 48 83 ec 60 48 89 5d f8 44 8b 4f 60 JIT code: ffffffffa00b5010: 44 2b 4f 64 4c 8b 87 b8 00 00 00 be 0c 00 00 00 JIT code: ffffffffa00b5020: e8 24 7b f7 e0 3d 00 08 00 00 75 28 be 1a 00 00 JIT code: ffffffffa00b5030: 00 e8 fe 7a f7 e0 24 00 3d 00 14 a8 c0 74 49 be JIT code: ffffffffa00b5040: 1e 00 00 00 e8 eb 7a f7 e0 24 00 3d 00 14 a8 c0 JIT code: ffffffffa00b5050: 74 36 eb 3b 3d 06 08 00 00 74 07 3d 35 80 00 00 JIT code: ffffffffa00b5060: 75 2d be 1c 00 00 00 e8 c8 7a f7 e0 24 00 3d 00 JIT code: ffffffffa00b5070: 14 a8 c0 74 13 be 26 00 00 00 e8 b5 7a f7 e0 24 JIT code: ffffffffa00b5080: 00 3d 00 14 a8 c0 75 07 b8 ff ff 00 00 eb 02 31 JIT code: ffffffffa00b5090: c0 c9 c3 BPF program is 144 bytes long, so native program is almost same size ;) (000) ldh [12] (001) jeq #0x800 jt 2 jf 8 (002) ld [26] (003) and #0xffffff00 (004) jeq #0xc0a81400 jt 16 jf 5 (005) ld [30] (006) and #0xffffff00 (007) jeq #0xc0a81400 jt 16 jf 17 (008) jeq #0x806 jt 10 jf 9 (009) jeq #0x8035 jt 10 jf 17 (010) ld [28] (011) and #0xffffff00 (012) jeq #0xc0a81400 jt 16 jf 13 (013) ld [38] (014) and #0xffffff00 (015) jeq #0xc0a81400 jt 16 jf 17 (016) ret #65535 (017) ret #0 Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Cc: Arnaldo Carvalho de Melo <acme@infradead.org> Cc: Ben Hutchings <bhutchings@solarflare.com> Cc: Hagen Paul Pfeifer <hagen@jauu.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-04-20 03:27:32 -06:00
break;
net: filter: x86: internal BPF JIT Maps all internal BPF instructions into x86_64 instructions. This patch replaces original BPF x64 JIT with internal BPF x64 JIT. sysctl net.core.bpf_jit_enable is reused as on/off switch. Performance: 1. old BPF JIT and internal BPF JIT generate equivalent x86_64 code. No performance difference is observed for filters that were JIT-able before Example assembler code for BPF filter "tcpdump port 22" original BPF -> old JIT: original BPF -> internal BPF -> new JIT: 0: push %rbp 0: push %rbp 1: mov %rsp,%rbp 1: mov %rsp,%rbp 4: sub $0x60,%rsp 4: sub $0x228,%rsp 8: mov %rbx,-0x8(%rbp) b: mov %rbx,-0x228(%rbp) // prologue 12: mov %r13,-0x220(%rbp) 19: mov %r14,-0x218(%rbp) 20: mov %r15,-0x210(%rbp) 27: xor %eax,%eax // clear A c: xor %ebx,%ebx 29: xor %r13,%r13 // clear X e: mov 0x68(%rdi),%r9d 2c: mov 0x68(%rdi),%r9d 12: sub 0x6c(%rdi),%r9d 30: sub 0x6c(%rdi),%r9d 16: mov 0xd8(%rdi),%r8 34: mov 0xd8(%rdi),%r10 3b: mov %rdi,%rbx 1d: mov $0xc,%esi 3e: mov $0xc,%esi 22: callq 0xffffffffe1021e15 43: callq 0xffffffffe102bd75 27: cmp $0x86dd,%eax 48: cmp $0x86dd,%rax 2c: jne 0x0000000000000069 4f: jne 0x000000000000009a 2e: mov $0x14,%esi 51: mov $0x14,%esi 33: callq 0xffffffffe1021e31 56: callq 0xffffffffe102bd91 38: cmp $0x84,%eax 5b: cmp $0x84,%rax 3d: je 0x0000000000000049 62: je 0x0000000000000074 3f: cmp $0x6,%eax 64: cmp $0x6,%rax 42: je 0x0000000000000049 68: je 0x0000000000000074 44: cmp $0x11,%eax 6a: cmp $0x11,%rax 47: jne 0x00000000000000c6 6e: jne 0x0000000000000117 49: mov $0x36,%esi 74: mov $0x36,%esi 4e: callq 0xffffffffe1021e15 79: callq 0xffffffffe102bd75 53: cmp $0x16,%eax 7e: cmp $0x16,%rax 56: je 0x00000000000000bf 82: je 0x0000000000000110 58: mov $0x38,%esi 88: mov $0x38,%esi 5d: callq 0xffffffffe1021e15 8d: callq 0xffffffffe102bd75 62: cmp $0x16,%eax 92: cmp $0x16,%rax 65: je 0x00000000000000bf 96: je 0x0000000000000110 67: jmp 0x00000000000000c6 98: jmp 0x0000000000000117 69: cmp $0x800,%eax 9a: cmp $0x800,%rax 6e: jne 0x00000000000000c6 a1: jne 0x0000000000000117 70: mov $0x17,%esi a3: mov $0x17,%esi 75: callq 0xffffffffe1021e31 a8: callq 0xffffffffe102bd91 7a: cmp $0x84,%eax ad: cmp $0x84,%rax 7f: je 0x000000000000008b b4: je 0x00000000000000c2 81: cmp $0x6,%eax b6: cmp $0x6,%rax 84: je 0x000000000000008b ba: je 0x00000000000000c2 86: cmp $0x11,%eax bc: cmp $0x11,%rax 89: jne 0x00000000000000c6 c0: jne 0x0000000000000117 8b: mov $0x14,%esi c2: mov $0x14,%esi 90: callq 0xffffffffe1021e15 c7: callq 0xffffffffe102bd75 95: test $0x1fff,%ax cc: test $0x1fff,%rax 99: jne 0x00000000000000c6 d3: jne 0x0000000000000117 d5: mov %rax,%r14 9b: mov $0xe,%esi d8: mov $0xe,%esi a0: callq 0xffffffffe1021e44 dd: callq 0xffffffffe102bd91 // MSH e2: and $0xf,%eax e5: shl $0x2,%eax e8: mov %rax,%r13 eb: mov %r14,%rax ee: mov %r13,%rsi a5: lea 0xe(%rbx),%esi f1: add $0xe,%esi a8: callq 0xffffffffe1021e0d f4: callq 0xffffffffe102bd6d ad: cmp $0x16,%eax f9: cmp $0x16,%rax b0: je 0x00000000000000bf fd: je 0x0000000000000110 ff: mov %r13,%rsi b2: lea 0x10(%rbx),%esi 102: add $0x10,%esi b5: callq 0xffffffffe1021e0d 105: callq 0xffffffffe102bd6d ba: cmp $0x16,%eax 10a: cmp $0x16,%rax bd: jne 0x00000000000000c6 10e: jne 0x0000000000000117 bf: mov $0xffff,%eax 110: mov $0xffff,%eax c4: jmp 0x00000000000000c8 115: jmp 0x000000000000011c c6: xor %eax,%eax 117: mov $0x0,%eax c8: mov -0x8(%rbp),%rbx 11c: mov -0x228(%rbp),%rbx // epilogue cc: leaveq 123: mov -0x220(%rbp),%r13 cd: retq 12a: mov -0x218(%rbp),%r14 131: mov -0x210(%rbp),%r15 138: leaveq 139: retq On fully cached SKBs both JITed functions take 12 nsec to execute. BPF interpreter executes the program in 30 nsec. The difference in generated assembler is due to the following: Old BPF imlements LDX_MSH instruction via sk_load_byte_msh() helper function inside bpf_jit.S. New JIT removes the helper and does it explicitly, so ldx_msh cost is the same for both JITs, but generated code looks longer. New JIT has 4 registers to save, so prologue/epilogue are larger, but the cost is within noise on x64. Old JIT checks whether first insn clears A and if not emits 'xor %eax,%eax'. New JIT clears %rax unconditionally. 2. old BPF JIT doesn't support ANC_NLATTR, ANC_PAY_OFFSET, ANC_RANDOM extensions. New JIT supports all BPF extensions. Performance of such filters improves 2-4 times depending on a filter. The longer the filter the higher performance gain. Synthetic benchmarks with many ancillary loads see 20x speedup which seems to be the maximum gain from JIT Notes: . net.core.bpf_jit_enable=2 + tools/net/bpf_jit_disasm is still functional and can be used to see generated assembler . there are two jit_compile() functions and code flow for classic filters is: sk_attach_filter() - load classic BPF bpf_jit_compile() - try to JIT from classic BPF sk_convert_filter() - convert classic to internal bpf_int_jit_compile() - JIT from internal BPF seccomp and tracing filters will just call bpf_int_jit_compile() Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 20:50:46 -06:00
}
case BPF_ALU | BPF_MOV | BPF_K:
bpf, x86: detect/optimize loading 0 immediates When sometimes structs or variables need to be initialized/'memset' to 0 in an eBPF C program, the x86 BPF JIT converts this to use immediates. We can however save a couple of bytes (f.e. even up to 7 bytes on a single emmission of BPF_LD | BPF_IMM | BPF_DW) in the image by detecting such case and use xor on the dst register instead. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-12-17 15:51:56 -07:00
/* optimization: if imm32 is zero, use 'xor <dst>,<dst>'
* to save 3 bytes.
*/
if (imm32 == 0) {
if (is_ereg(dst_reg))
EMIT1(add_2mod(0x40, dst_reg, dst_reg));
b2 = 0x31; /* xor */
b3 = 0xC0;
EMIT2(b2, add_2reg(b3, dst_reg, dst_reg));
break;
}
net: filter: x86: internal BPF JIT Maps all internal BPF instructions into x86_64 instructions. This patch replaces original BPF x64 JIT with internal BPF x64 JIT. sysctl net.core.bpf_jit_enable is reused as on/off switch. Performance: 1. old BPF JIT and internal BPF JIT generate equivalent x86_64 code. No performance difference is observed for filters that were JIT-able before Example assembler code for BPF filter "tcpdump port 22" original BPF -> old JIT: original BPF -> internal BPF -> new JIT: 0: push %rbp 0: push %rbp 1: mov %rsp,%rbp 1: mov %rsp,%rbp 4: sub $0x60,%rsp 4: sub $0x228,%rsp 8: mov %rbx,-0x8(%rbp) b: mov %rbx,-0x228(%rbp) // prologue 12: mov %r13,-0x220(%rbp) 19: mov %r14,-0x218(%rbp) 20: mov %r15,-0x210(%rbp) 27: xor %eax,%eax // clear A c: xor %ebx,%ebx 29: xor %r13,%r13 // clear X e: mov 0x68(%rdi),%r9d 2c: mov 0x68(%rdi),%r9d 12: sub 0x6c(%rdi),%r9d 30: sub 0x6c(%rdi),%r9d 16: mov 0xd8(%rdi),%r8 34: mov 0xd8(%rdi),%r10 3b: mov %rdi,%rbx 1d: mov $0xc,%esi 3e: mov $0xc,%esi 22: callq 0xffffffffe1021e15 43: callq 0xffffffffe102bd75 27: cmp $0x86dd,%eax 48: cmp $0x86dd,%rax 2c: jne 0x0000000000000069 4f: jne 0x000000000000009a 2e: mov $0x14,%esi 51: mov $0x14,%esi 33: callq 0xffffffffe1021e31 56: callq 0xffffffffe102bd91 38: cmp $0x84,%eax 5b: cmp $0x84,%rax 3d: je 0x0000000000000049 62: je 0x0000000000000074 3f: cmp $0x6,%eax 64: cmp $0x6,%rax 42: je 0x0000000000000049 68: je 0x0000000000000074 44: cmp $0x11,%eax 6a: cmp $0x11,%rax 47: jne 0x00000000000000c6 6e: jne 0x0000000000000117 49: mov $0x36,%esi 74: mov $0x36,%esi 4e: callq 0xffffffffe1021e15 79: callq 0xffffffffe102bd75 53: cmp $0x16,%eax 7e: cmp $0x16,%rax 56: je 0x00000000000000bf 82: je 0x0000000000000110 58: mov $0x38,%esi 88: mov $0x38,%esi 5d: callq 0xffffffffe1021e15 8d: callq 0xffffffffe102bd75 62: cmp $0x16,%eax 92: cmp $0x16,%rax 65: je 0x00000000000000bf 96: je 0x0000000000000110 67: jmp 0x00000000000000c6 98: jmp 0x0000000000000117 69: cmp $0x800,%eax 9a: cmp $0x800,%rax 6e: jne 0x00000000000000c6 a1: jne 0x0000000000000117 70: mov $0x17,%esi a3: mov $0x17,%esi 75: callq 0xffffffffe1021e31 a8: callq 0xffffffffe102bd91 7a: cmp $0x84,%eax ad: cmp $0x84,%rax 7f: je 0x000000000000008b b4: je 0x00000000000000c2 81: cmp $0x6,%eax b6: cmp $0x6,%rax 84: je 0x000000000000008b ba: je 0x00000000000000c2 86: cmp $0x11,%eax bc: cmp $0x11,%rax 89: jne 0x00000000000000c6 c0: jne 0x0000000000000117 8b: mov $0x14,%esi c2: mov $0x14,%esi 90: callq 0xffffffffe1021e15 c7: callq 0xffffffffe102bd75 95: test $0x1fff,%ax cc: test $0x1fff,%rax 99: jne 0x00000000000000c6 d3: jne 0x0000000000000117 d5: mov %rax,%r14 9b: mov $0xe,%esi d8: mov $0xe,%esi a0: callq 0xffffffffe1021e44 dd: callq 0xffffffffe102bd91 // MSH e2: and $0xf,%eax e5: shl $0x2,%eax e8: mov %rax,%r13 eb: mov %r14,%rax ee: mov %r13,%rsi a5: lea 0xe(%rbx),%esi f1: add $0xe,%esi a8: callq 0xffffffffe1021e0d f4: callq 0xffffffffe102bd6d ad: cmp $0x16,%eax f9: cmp $0x16,%rax b0: je 0x00000000000000bf fd: je 0x0000000000000110 ff: mov %r13,%rsi b2: lea 0x10(%rbx),%esi 102: add $0x10,%esi b5: callq 0xffffffffe1021e0d 105: callq 0xffffffffe102bd6d ba: cmp $0x16,%eax 10a: cmp $0x16,%rax bd: jne 0x00000000000000c6 10e: jne 0x0000000000000117 bf: mov $0xffff,%eax 110: mov $0xffff,%eax c4: jmp 0x00000000000000c8 115: jmp 0x000000000000011c c6: xor %eax,%eax 117: mov $0x0,%eax c8: mov -0x8(%rbp),%rbx 11c: mov -0x228(%rbp),%rbx // epilogue cc: leaveq 123: mov -0x220(%rbp),%r13 cd: retq 12a: mov -0x218(%rbp),%r14 131: mov -0x210(%rbp),%r15 138: leaveq 139: retq On fully cached SKBs both JITed functions take 12 nsec to execute. BPF interpreter executes the program in 30 nsec. The difference in generated assembler is due to the following: Old BPF imlements LDX_MSH instruction via sk_load_byte_msh() helper function inside bpf_jit.S. New JIT removes the helper and does it explicitly, so ldx_msh cost is the same for both JITs, but generated code looks longer. New JIT has 4 registers to save, so prologue/epilogue are larger, but the cost is within noise on x64. Old JIT checks whether first insn clears A and if not emits 'xor %eax,%eax'. New JIT clears %rax unconditionally. 2. old BPF JIT doesn't support ANC_NLATTR, ANC_PAY_OFFSET, ANC_RANDOM extensions. New JIT supports all BPF extensions. Performance of such filters improves 2-4 times depending on a filter. The longer the filter the higher performance gain. Synthetic benchmarks with many ancillary loads see 20x speedup which seems to be the maximum gain from JIT Notes: . net.core.bpf_jit_enable=2 + tools/net/bpf_jit_disasm is still functional and can be used to see generated assembler . there are two jit_compile() functions and code flow for classic filters is: sk_attach_filter() - load classic BPF bpf_jit_compile() - try to JIT from classic BPF sk_convert_filter() - convert classic to internal bpf_int_jit_compile() - JIT from internal BPF seccomp and tracing filters will just call bpf_int_jit_compile() Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 20:50:46 -06:00
/* mov %eax, imm32 */
net: filter: cleanup A/X name usage The macro 'A' used in internal BPF interpreter: #define A regs[insn->a_reg] was easily confused with the name of classic BPF register 'A', since 'A' would mean two different things depending on context. This patch is trying to clean up the naming and clarify its usage in the following way: - A and X are names of two classic BPF registers - BPF_REG_A denotes internal BPF register R0 used to map classic register A in internal BPF programs generated from classic - BPF_REG_X denotes internal BPF register R7 used to map classic register X in internal BPF programs generated from classic - internal BPF instruction format: struct sock_filter_int { __u8 code; /* opcode */ __u8 dst_reg:4; /* dest register */ __u8 src_reg:4; /* source register */ __s16 off; /* signed offset */ __s32 imm; /* signed immediate constant */ }; - BPF_X/BPF_K is 1 bit used to encode source operand of instruction In classic: BPF_X - means use register X as source operand BPF_K - means use 32-bit immediate as source operand In internal: BPF_X - means use 'src_reg' register as source operand BPF_K - means use 32-bit immediate as source operand Suggested-by: Chema Gonzalez <chema@google.com> Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Acked-by: Daniel Borkmann <dborkman@redhat.com> Acked-by: Chema Gonzalez <chema@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-06-06 15:46:06 -06:00
if (is_ereg(dst_reg))
EMIT1(add_1mod(0x40, dst_reg));
EMIT1_off32(add_1reg(0xB8, dst_reg), imm32);
net: filter: x86: internal BPF JIT Maps all internal BPF instructions into x86_64 instructions. This patch replaces original BPF x64 JIT with internal BPF x64 JIT. sysctl net.core.bpf_jit_enable is reused as on/off switch. Performance: 1. old BPF JIT and internal BPF JIT generate equivalent x86_64 code. No performance difference is observed for filters that were JIT-able before Example assembler code for BPF filter "tcpdump port 22" original BPF -> old JIT: original BPF -> internal BPF -> new JIT: 0: push %rbp 0: push %rbp 1: mov %rsp,%rbp 1: mov %rsp,%rbp 4: sub $0x60,%rsp 4: sub $0x228,%rsp 8: mov %rbx,-0x8(%rbp) b: mov %rbx,-0x228(%rbp) // prologue 12: mov %r13,-0x220(%rbp) 19: mov %r14,-0x218(%rbp) 20: mov %r15,-0x210(%rbp) 27: xor %eax,%eax // clear A c: xor %ebx,%ebx 29: xor %r13,%r13 // clear X e: mov 0x68(%rdi),%r9d 2c: mov 0x68(%rdi),%r9d 12: sub 0x6c(%rdi),%r9d 30: sub 0x6c(%rdi),%r9d 16: mov 0xd8(%rdi),%r8 34: mov 0xd8(%rdi),%r10 3b: mov %rdi,%rbx 1d: mov $0xc,%esi 3e: mov $0xc,%esi 22: callq 0xffffffffe1021e15 43: callq 0xffffffffe102bd75 27: cmp $0x86dd,%eax 48: cmp $0x86dd,%rax 2c: jne 0x0000000000000069 4f: jne 0x000000000000009a 2e: mov $0x14,%esi 51: mov $0x14,%esi 33: callq 0xffffffffe1021e31 56: callq 0xffffffffe102bd91 38: cmp $0x84,%eax 5b: cmp $0x84,%rax 3d: je 0x0000000000000049 62: je 0x0000000000000074 3f: cmp $0x6,%eax 64: cmp $0x6,%rax 42: je 0x0000000000000049 68: je 0x0000000000000074 44: cmp $0x11,%eax 6a: cmp $0x11,%rax 47: jne 0x00000000000000c6 6e: jne 0x0000000000000117 49: mov $0x36,%esi 74: mov $0x36,%esi 4e: callq 0xffffffffe1021e15 79: callq 0xffffffffe102bd75 53: cmp $0x16,%eax 7e: cmp $0x16,%rax 56: je 0x00000000000000bf 82: je 0x0000000000000110 58: mov $0x38,%esi 88: mov $0x38,%esi 5d: callq 0xffffffffe1021e15 8d: callq 0xffffffffe102bd75 62: cmp $0x16,%eax 92: cmp $0x16,%rax 65: je 0x00000000000000bf 96: je 0x0000000000000110 67: jmp 0x00000000000000c6 98: jmp 0x0000000000000117 69: cmp $0x800,%eax 9a: cmp $0x800,%rax 6e: jne 0x00000000000000c6 a1: jne 0x0000000000000117 70: mov $0x17,%esi a3: mov $0x17,%esi 75: callq 0xffffffffe1021e31 a8: callq 0xffffffffe102bd91 7a: cmp $0x84,%eax ad: cmp $0x84,%rax 7f: je 0x000000000000008b b4: je 0x00000000000000c2 81: cmp $0x6,%eax b6: cmp $0x6,%rax 84: je 0x000000000000008b ba: je 0x00000000000000c2 86: cmp $0x11,%eax bc: cmp $0x11,%rax 89: jne 0x00000000000000c6 c0: jne 0x0000000000000117 8b: mov $0x14,%esi c2: mov $0x14,%esi 90: callq 0xffffffffe1021e15 c7: callq 0xffffffffe102bd75 95: test $0x1fff,%ax cc: test $0x1fff,%rax 99: jne 0x00000000000000c6 d3: jne 0x0000000000000117 d5: mov %rax,%r14 9b: mov $0xe,%esi d8: mov $0xe,%esi a0: callq 0xffffffffe1021e44 dd: callq 0xffffffffe102bd91 // MSH e2: and $0xf,%eax e5: shl $0x2,%eax e8: mov %rax,%r13 eb: mov %r14,%rax ee: mov %r13,%rsi a5: lea 0xe(%rbx),%esi f1: add $0xe,%esi a8: callq 0xffffffffe1021e0d f4: callq 0xffffffffe102bd6d ad: cmp $0x16,%eax f9: cmp $0x16,%rax b0: je 0x00000000000000bf fd: je 0x0000000000000110 ff: mov %r13,%rsi b2: lea 0x10(%rbx),%esi 102: add $0x10,%esi b5: callq 0xffffffffe1021e0d 105: callq 0xffffffffe102bd6d ba: cmp $0x16,%eax 10a: cmp $0x16,%rax bd: jne 0x00000000000000c6 10e: jne 0x0000000000000117 bf: mov $0xffff,%eax 110: mov $0xffff,%eax c4: jmp 0x00000000000000c8 115: jmp 0x000000000000011c c6: xor %eax,%eax 117: mov $0x0,%eax c8: mov -0x8(%rbp),%rbx 11c: mov -0x228(%rbp),%rbx // epilogue cc: leaveq 123: mov -0x220(%rbp),%r13 cd: retq 12a: mov -0x218(%rbp),%r14 131: mov -0x210(%rbp),%r15 138: leaveq 139: retq On fully cached SKBs both JITed functions take 12 nsec to execute. BPF interpreter executes the program in 30 nsec. The difference in generated assembler is due to the following: Old BPF imlements LDX_MSH instruction via sk_load_byte_msh() helper function inside bpf_jit.S. New JIT removes the helper and does it explicitly, so ldx_msh cost is the same for both JITs, but generated code looks longer. New JIT has 4 registers to save, so prologue/epilogue are larger, but the cost is within noise on x64. Old JIT checks whether first insn clears A and if not emits 'xor %eax,%eax'. New JIT clears %rax unconditionally. 2. old BPF JIT doesn't support ANC_NLATTR, ANC_PAY_OFFSET, ANC_RANDOM extensions. New JIT supports all BPF extensions. Performance of such filters improves 2-4 times depending on a filter. The longer the filter the higher performance gain. Synthetic benchmarks with many ancillary loads see 20x speedup which seems to be the maximum gain from JIT Notes: . net.core.bpf_jit_enable=2 + tools/net/bpf_jit_disasm is still functional and can be used to see generated assembler . there are two jit_compile() functions and code flow for classic filters is: sk_attach_filter() - load classic BPF bpf_jit_compile() - try to JIT from classic BPF sk_convert_filter() - convert classic to internal bpf_int_jit_compile() - JIT from internal BPF seccomp and tracing filters will just call bpf_int_jit_compile() Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 20:50:46 -06:00
break;
net: filter: add "load 64-bit immediate" eBPF instruction add BPF_LD_IMM64 instruction to load 64-bit immediate value into a register. All previous instructions were 8-byte. This is first 16-byte instruction. Two consecutive 'struct bpf_insn' blocks are interpreted as single instruction: insn[0].code = BPF_LD | BPF_DW | BPF_IMM insn[0].dst_reg = destination register insn[0].imm = lower 32-bit insn[1].code = 0 insn[1].imm = upper 32-bit All unused fields must be zero. Classic BPF has similar instruction: BPF_LD | BPF_W | BPF_IMM which loads 32-bit immediate value into a register. x64 JITs it as single 'movabsq %rax, imm64' arm64 may JIT as sequence of four 'movk x0, #imm16, lsl #shift' insn Note that old eBPF programs are binary compatible with new interpreter. It helps eBPF programs load 64-bit constant into a register with one instruction instead of using two registers and 4 instructions: BPF_MOV32_IMM(R1, imm32) BPF_ALU64_IMM(BPF_LSH, R1, 32) BPF_MOV32_IMM(R2, imm32) BPF_ALU64_REG(BPF_OR, R1, R2) User space generated programs will use this instruction to load constants only. To tell kernel that user space needs a pointer the _pseudo_ variant of this instruction may be added later, which will use extra bits of encoding to indicate what type of pointer user space is asking kernel to provide. For example 'off' or 'src_reg' fields can be used for such purpose. src_reg = 1 could mean that user space is asking kernel to validate and load in-kernel map pointer. src_reg = 2 could mean that user space needs readonly data section pointer src_reg = 3 could mean that user space needs a pointer to per-cpu local data All such future pseudo instructions will not be carrying the actual pointer as part of the instruction, but rather will be treated as a request to kernel to provide one. The kernel will verify the request_for_a_pointer, then will drop _pseudo_ marking and will store actual internal pointer inside the instruction, so the end result is the interpreter and JITs never see pseudo BPF_LD_IMM64 insns and only operate on generic BPF_LD_IMM64 that loads 64-bit immediate into a register. User space never operates on direct pointers and verifier can easily recognize request_for_pointer vs other instructions. Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-04 23:17:17 -06:00
case BPF_LD | BPF_IMM | BPF_DW:
bpf, x86: detect/optimize loading 0 immediates When sometimes structs or variables need to be initialized/'memset' to 0 in an eBPF C program, the x86 BPF JIT converts this to use immediates. We can however save a couple of bytes (f.e. even up to 7 bytes on a single emmission of BPF_LD | BPF_IMM | BPF_DW) in the image by detecting such case and use xor on the dst register instead. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-12-17 15:51:56 -07:00
/* optimization: if imm64 is zero, use 'xor <dst>,<dst>'
* to save 7 bytes.
*/
if (insn[0].imm == 0 && insn[1].imm == 0) {
b1 = add_2mod(0x48, dst_reg, dst_reg);
b2 = 0x31; /* xor */
b3 = 0xC0;
EMIT3(b1, b2, add_2reg(b3, dst_reg, dst_reg));
insn++;
i++;
break;
}
net: filter: add "load 64-bit immediate" eBPF instruction add BPF_LD_IMM64 instruction to load 64-bit immediate value into a register. All previous instructions were 8-byte. This is first 16-byte instruction. Two consecutive 'struct bpf_insn' blocks are interpreted as single instruction: insn[0].code = BPF_LD | BPF_DW | BPF_IMM insn[0].dst_reg = destination register insn[0].imm = lower 32-bit insn[1].code = 0 insn[1].imm = upper 32-bit All unused fields must be zero. Classic BPF has similar instruction: BPF_LD | BPF_W | BPF_IMM which loads 32-bit immediate value into a register. x64 JITs it as single 'movabsq %rax, imm64' arm64 may JIT as sequence of four 'movk x0, #imm16, lsl #shift' insn Note that old eBPF programs are binary compatible with new interpreter. It helps eBPF programs load 64-bit constant into a register with one instruction instead of using two registers and 4 instructions: BPF_MOV32_IMM(R1, imm32) BPF_ALU64_IMM(BPF_LSH, R1, 32) BPF_MOV32_IMM(R2, imm32) BPF_ALU64_REG(BPF_OR, R1, R2) User space generated programs will use this instruction to load constants only. To tell kernel that user space needs a pointer the _pseudo_ variant of this instruction may be added later, which will use extra bits of encoding to indicate what type of pointer user space is asking kernel to provide. For example 'off' or 'src_reg' fields can be used for such purpose. src_reg = 1 could mean that user space is asking kernel to validate and load in-kernel map pointer. src_reg = 2 could mean that user space needs readonly data section pointer src_reg = 3 could mean that user space needs a pointer to per-cpu local data All such future pseudo instructions will not be carrying the actual pointer as part of the instruction, but rather will be treated as a request to kernel to provide one. The kernel will verify the request_for_a_pointer, then will drop _pseudo_ marking and will store actual internal pointer inside the instruction, so the end result is the interpreter and JITs never see pseudo BPF_LD_IMM64 insns and only operate on generic BPF_LD_IMM64 that loads 64-bit immediate into a register. User space never operates on direct pointers and verifier can easily recognize request_for_pointer vs other instructions. Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-04 23:17:17 -06:00
/* movabsq %rax, imm64 */
EMIT2(add_1mod(0x48, dst_reg), add_1reg(0xB8, dst_reg));
EMIT(insn[0].imm, 4);
EMIT(insn[1].imm, 4);
insn++;
i++;
break;
net: filter: cleanup A/X name usage The macro 'A' used in internal BPF interpreter: #define A regs[insn->a_reg] was easily confused with the name of classic BPF register 'A', since 'A' would mean two different things depending on context. This patch is trying to clean up the naming and clarify its usage in the following way: - A and X are names of two classic BPF registers - BPF_REG_A denotes internal BPF register R0 used to map classic register A in internal BPF programs generated from classic - BPF_REG_X denotes internal BPF register R7 used to map classic register X in internal BPF programs generated from classic - internal BPF instruction format: struct sock_filter_int { __u8 code; /* opcode */ __u8 dst_reg:4; /* dest register */ __u8 src_reg:4; /* source register */ __s16 off; /* signed offset */ __s32 imm; /* signed immediate constant */ }; - BPF_X/BPF_K is 1 bit used to encode source operand of instruction In classic: BPF_X - means use register X as source operand BPF_K - means use 32-bit immediate as source operand In internal: BPF_X - means use 'src_reg' register as source operand BPF_K - means use 32-bit immediate as source operand Suggested-by: Chema Gonzalez <chema@google.com> Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Acked-by: Daniel Borkmann <dborkman@redhat.com> Acked-by: Chema Gonzalez <chema@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-06-06 15:46:06 -06:00
/* dst %= src, dst /= src, dst %= imm32, dst /= imm32 */
net: filter: x86: internal BPF JIT Maps all internal BPF instructions into x86_64 instructions. This patch replaces original BPF x64 JIT with internal BPF x64 JIT. sysctl net.core.bpf_jit_enable is reused as on/off switch. Performance: 1. old BPF JIT and internal BPF JIT generate equivalent x86_64 code. No performance difference is observed for filters that were JIT-able before Example assembler code for BPF filter "tcpdump port 22" original BPF -> old JIT: original BPF -> internal BPF -> new JIT: 0: push %rbp 0: push %rbp 1: mov %rsp,%rbp 1: mov %rsp,%rbp 4: sub $0x60,%rsp 4: sub $0x228,%rsp 8: mov %rbx,-0x8(%rbp) b: mov %rbx,-0x228(%rbp) // prologue 12: mov %r13,-0x220(%rbp) 19: mov %r14,-0x218(%rbp) 20: mov %r15,-0x210(%rbp) 27: xor %eax,%eax // clear A c: xor %ebx,%ebx 29: xor %r13,%r13 // clear X e: mov 0x68(%rdi),%r9d 2c: mov 0x68(%rdi),%r9d 12: sub 0x6c(%rdi),%r9d 30: sub 0x6c(%rdi),%r9d 16: mov 0xd8(%rdi),%r8 34: mov 0xd8(%rdi),%r10 3b: mov %rdi,%rbx 1d: mov $0xc,%esi 3e: mov $0xc,%esi 22: callq 0xffffffffe1021e15 43: callq 0xffffffffe102bd75 27: cmp $0x86dd,%eax 48: cmp $0x86dd,%rax 2c: jne 0x0000000000000069 4f: jne 0x000000000000009a 2e: mov $0x14,%esi 51: mov $0x14,%esi 33: callq 0xffffffffe1021e31 56: callq 0xffffffffe102bd91 38: cmp $0x84,%eax 5b: cmp $0x84,%rax 3d: je 0x0000000000000049 62: je 0x0000000000000074 3f: cmp $0x6,%eax 64: cmp $0x6,%rax 42: je 0x0000000000000049 68: je 0x0000000000000074 44: cmp $0x11,%eax 6a: cmp $0x11,%rax 47: jne 0x00000000000000c6 6e: jne 0x0000000000000117 49: mov $0x36,%esi 74: mov $0x36,%esi 4e: callq 0xffffffffe1021e15 79: callq 0xffffffffe102bd75 53: cmp $0x16,%eax 7e: cmp $0x16,%rax 56: je 0x00000000000000bf 82: je 0x0000000000000110 58: mov $0x38,%esi 88: mov $0x38,%esi 5d: callq 0xffffffffe1021e15 8d: callq 0xffffffffe102bd75 62: cmp $0x16,%eax 92: cmp $0x16,%rax 65: je 0x00000000000000bf 96: je 0x0000000000000110 67: jmp 0x00000000000000c6 98: jmp 0x0000000000000117 69: cmp $0x800,%eax 9a: cmp $0x800,%rax 6e: jne 0x00000000000000c6 a1: jne 0x0000000000000117 70: mov $0x17,%esi a3: mov $0x17,%esi 75: callq 0xffffffffe1021e31 a8: callq 0xffffffffe102bd91 7a: cmp $0x84,%eax ad: cmp $0x84,%rax 7f: je 0x000000000000008b b4: je 0x00000000000000c2 81: cmp $0x6,%eax b6: cmp $0x6,%rax 84: je 0x000000000000008b ba: je 0x00000000000000c2 86: cmp $0x11,%eax bc: cmp $0x11,%rax 89: jne 0x00000000000000c6 c0: jne 0x0000000000000117 8b: mov $0x14,%esi c2: mov $0x14,%esi 90: callq 0xffffffffe1021e15 c7: callq 0xffffffffe102bd75 95: test $0x1fff,%ax cc: test $0x1fff,%rax 99: jne 0x00000000000000c6 d3: jne 0x0000000000000117 d5: mov %rax,%r14 9b: mov $0xe,%esi d8: mov $0xe,%esi a0: callq 0xffffffffe1021e44 dd: callq 0xffffffffe102bd91 // MSH e2: and $0xf,%eax e5: shl $0x2,%eax e8: mov %rax,%r13 eb: mov %r14,%rax ee: mov %r13,%rsi a5: lea 0xe(%rbx),%esi f1: add $0xe,%esi a8: callq 0xffffffffe1021e0d f4: callq 0xffffffffe102bd6d ad: cmp $0x16,%eax f9: cmp $0x16,%rax b0: je 0x00000000000000bf fd: je 0x0000000000000110 ff: mov %r13,%rsi b2: lea 0x10(%rbx),%esi 102: add $0x10,%esi b5: callq 0xffffffffe1021e0d 105: callq 0xffffffffe102bd6d ba: cmp $0x16,%eax 10a: cmp $0x16,%rax bd: jne 0x00000000000000c6 10e: jne 0x0000000000000117 bf: mov $0xffff,%eax 110: mov $0xffff,%eax c4: jmp 0x00000000000000c8 115: jmp 0x000000000000011c c6: xor %eax,%eax 117: mov $0x0,%eax c8: mov -0x8(%rbp),%rbx 11c: mov -0x228(%rbp),%rbx // epilogue cc: leaveq 123: mov -0x220(%rbp),%r13 cd: retq 12a: mov -0x218(%rbp),%r14 131: mov -0x210(%rbp),%r15 138: leaveq 139: retq On fully cached SKBs both JITed functions take 12 nsec to execute. BPF interpreter executes the program in 30 nsec. The difference in generated assembler is due to the following: Old BPF imlements LDX_MSH instruction via sk_load_byte_msh() helper function inside bpf_jit.S. New JIT removes the helper and does it explicitly, so ldx_msh cost is the same for both JITs, but generated code looks longer. New JIT has 4 registers to save, so prologue/epilogue are larger, but the cost is within noise on x64. Old JIT checks whether first insn clears A and if not emits 'xor %eax,%eax'. New JIT clears %rax unconditionally. 2. old BPF JIT doesn't support ANC_NLATTR, ANC_PAY_OFFSET, ANC_RANDOM extensions. New JIT supports all BPF extensions. Performance of such filters improves 2-4 times depending on a filter. The longer the filter the higher performance gain. Synthetic benchmarks with many ancillary loads see 20x speedup which seems to be the maximum gain from JIT Notes: . net.core.bpf_jit_enable=2 + tools/net/bpf_jit_disasm is still functional and can be used to see generated assembler . there are two jit_compile() functions and code flow for classic filters is: sk_attach_filter() - load classic BPF bpf_jit_compile() - try to JIT from classic BPF sk_convert_filter() - convert classic to internal bpf_int_jit_compile() - JIT from internal BPF seccomp and tracing filters will just call bpf_int_jit_compile() Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 20:50:46 -06:00
case BPF_ALU | BPF_MOD | BPF_X:
case BPF_ALU | BPF_DIV | BPF_X:
case BPF_ALU | BPF_MOD | BPF_K:
case BPF_ALU | BPF_DIV | BPF_K:
case BPF_ALU64 | BPF_MOD | BPF_X:
case BPF_ALU64 | BPF_DIV | BPF_X:
case BPF_ALU64 | BPF_MOD | BPF_K:
case BPF_ALU64 | BPF_DIV | BPF_K:
EMIT1(0x50); /* push rax */
EMIT1(0x52); /* push rdx */
if (BPF_SRC(insn->code) == BPF_X)
net: filter: cleanup A/X name usage The macro 'A' used in internal BPF interpreter: #define A regs[insn->a_reg] was easily confused with the name of classic BPF register 'A', since 'A' would mean two different things depending on context. This patch is trying to clean up the naming and clarify its usage in the following way: - A and X are names of two classic BPF registers - BPF_REG_A denotes internal BPF register R0 used to map classic register A in internal BPF programs generated from classic - BPF_REG_X denotes internal BPF register R7 used to map classic register X in internal BPF programs generated from classic - internal BPF instruction format: struct sock_filter_int { __u8 code; /* opcode */ __u8 dst_reg:4; /* dest register */ __u8 src_reg:4; /* source register */ __s16 off; /* signed offset */ __s32 imm; /* signed immediate constant */ }; - BPF_X/BPF_K is 1 bit used to encode source operand of instruction In classic: BPF_X - means use register X as source operand BPF_K - means use 32-bit immediate as source operand In internal: BPF_X - means use 'src_reg' register as source operand BPF_K - means use 32-bit immediate as source operand Suggested-by: Chema Gonzalez <chema@google.com> Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Acked-by: Daniel Borkmann <dborkman@redhat.com> Acked-by: Chema Gonzalez <chema@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-06-06 15:46:06 -06:00
/* mov r11, src_reg */
EMIT_mov(AUX_REG, src_reg);
net: filter: x86: internal BPF JIT Maps all internal BPF instructions into x86_64 instructions. This patch replaces original BPF x64 JIT with internal BPF x64 JIT. sysctl net.core.bpf_jit_enable is reused as on/off switch. Performance: 1. old BPF JIT and internal BPF JIT generate equivalent x86_64 code. No performance difference is observed for filters that were JIT-able before Example assembler code for BPF filter "tcpdump port 22" original BPF -> old JIT: original BPF -> internal BPF -> new JIT: 0: push %rbp 0: push %rbp 1: mov %rsp,%rbp 1: mov %rsp,%rbp 4: sub $0x60,%rsp 4: sub $0x228,%rsp 8: mov %rbx,-0x8(%rbp) b: mov %rbx,-0x228(%rbp) // prologue 12: mov %r13,-0x220(%rbp) 19: mov %r14,-0x218(%rbp) 20: mov %r15,-0x210(%rbp) 27: xor %eax,%eax // clear A c: xor %ebx,%ebx 29: xor %r13,%r13 // clear X e: mov 0x68(%rdi),%r9d 2c: mov 0x68(%rdi),%r9d 12: sub 0x6c(%rdi),%r9d 30: sub 0x6c(%rdi),%r9d 16: mov 0xd8(%rdi),%r8 34: mov 0xd8(%rdi),%r10 3b: mov %rdi,%rbx 1d: mov $0xc,%esi 3e: mov $0xc,%esi 22: callq 0xffffffffe1021e15 43: callq 0xffffffffe102bd75 27: cmp $0x86dd,%eax 48: cmp $0x86dd,%rax 2c: jne 0x0000000000000069 4f: jne 0x000000000000009a 2e: mov $0x14,%esi 51: mov $0x14,%esi 33: callq 0xffffffffe1021e31 56: callq 0xffffffffe102bd91 38: cmp $0x84,%eax 5b: cmp $0x84,%rax 3d: je 0x0000000000000049 62: je 0x0000000000000074 3f: cmp $0x6,%eax 64: cmp $0x6,%rax 42: je 0x0000000000000049 68: je 0x0000000000000074 44: cmp $0x11,%eax 6a: cmp $0x11,%rax 47: jne 0x00000000000000c6 6e: jne 0x0000000000000117 49: mov $0x36,%esi 74: mov $0x36,%esi 4e: callq 0xffffffffe1021e15 79: callq 0xffffffffe102bd75 53: cmp $0x16,%eax 7e: cmp $0x16,%rax 56: je 0x00000000000000bf 82: je 0x0000000000000110 58: mov $0x38,%esi 88: mov $0x38,%esi 5d: callq 0xffffffffe1021e15 8d: callq 0xffffffffe102bd75 62: cmp $0x16,%eax 92: cmp $0x16,%rax 65: je 0x00000000000000bf 96: je 0x0000000000000110 67: jmp 0x00000000000000c6 98: jmp 0x0000000000000117 69: cmp $0x800,%eax 9a: cmp $0x800,%rax 6e: jne 0x00000000000000c6 a1: jne 0x0000000000000117 70: mov $0x17,%esi a3: mov $0x17,%esi 75: callq 0xffffffffe1021e31 a8: callq 0xffffffffe102bd91 7a: cmp $0x84,%eax ad: cmp $0x84,%rax 7f: je 0x000000000000008b b4: je 0x00000000000000c2 81: cmp $0x6,%eax b6: cmp $0x6,%rax 84: je 0x000000000000008b ba: je 0x00000000000000c2 86: cmp $0x11,%eax bc: cmp $0x11,%rax 89: jne 0x00000000000000c6 c0: jne 0x0000000000000117 8b: mov $0x14,%esi c2: mov $0x14,%esi 90: callq 0xffffffffe1021e15 c7: callq 0xffffffffe102bd75 95: test $0x1fff,%ax cc: test $0x1fff,%rax 99: jne 0x00000000000000c6 d3: jne 0x0000000000000117 d5: mov %rax,%r14 9b: mov $0xe,%esi d8: mov $0xe,%esi a0: callq 0xffffffffe1021e44 dd: callq 0xffffffffe102bd91 // MSH e2: and $0xf,%eax e5: shl $0x2,%eax e8: mov %rax,%r13 eb: mov %r14,%rax ee: mov %r13,%rsi a5: lea 0xe(%rbx),%esi f1: add $0xe,%esi a8: callq 0xffffffffe1021e0d f4: callq 0xffffffffe102bd6d ad: cmp $0x16,%eax f9: cmp $0x16,%rax b0: je 0x00000000000000bf fd: je 0x0000000000000110 ff: mov %r13,%rsi b2: lea 0x10(%rbx),%esi 102: add $0x10,%esi b5: callq 0xffffffffe1021e0d 105: callq 0xffffffffe102bd6d ba: cmp $0x16,%eax 10a: cmp $0x16,%rax bd: jne 0x00000000000000c6 10e: jne 0x0000000000000117 bf: mov $0xffff,%eax 110: mov $0xffff,%eax c4: jmp 0x00000000000000c8 115: jmp 0x000000000000011c c6: xor %eax,%eax 117: mov $0x0,%eax c8: mov -0x8(%rbp),%rbx 11c: mov -0x228(%rbp),%rbx // epilogue cc: leaveq 123: mov -0x220(%rbp),%r13 cd: retq 12a: mov -0x218(%rbp),%r14 131: mov -0x210(%rbp),%r15 138: leaveq 139: retq On fully cached SKBs both JITed functions take 12 nsec to execute. BPF interpreter executes the program in 30 nsec. The difference in generated assembler is due to the following: Old BPF imlements LDX_MSH instruction via sk_load_byte_msh() helper function inside bpf_jit.S. New JIT removes the helper and does it explicitly, so ldx_msh cost is the same for both JITs, but generated code looks longer. New JIT has 4 registers to save, so prologue/epilogue are larger, but the cost is within noise on x64. Old JIT checks whether first insn clears A and if not emits 'xor %eax,%eax'. New JIT clears %rax unconditionally. 2. old BPF JIT doesn't support ANC_NLATTR, ANC_PAY_OFFSET, ANC_RANDOM extensions. New JIT supports all BPF extensions. Performance of such filters improves 2-4 times depending on a filter. The longer the filter the higher performance gain. Synthetic benchmarks with many ancillary loads see 20x speedup which seems to be the maximum gain from JIT Notes: . net.core.bpf_jit_enable=2 + tools/net/bpf_jit_disasm is still functional and can be used to see generated assembler . there are two jit_compile() functions and code flow for classic filters is: sk_attach_filter() - load classic BPF bpf_jit_compile() - try to JIT from classic BPF sk_convert_filter() - convert classic to internal bpf_int_jit_compile() - JIT from internal BPF seccomp and tracing filters will just call bpf_int_jit_compile() Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 20:50:46 -06:00
else
net: filter: cleanup A/X name usage The macro 'A' used in internal BPF interpreter: #define A regs[insn->a_reg] was easily confused with the name of classic BPF register 'A', since 'A' would mean two different things depending on context. This patch is trying to clean up the naming and clarify its usage in the following way: - A and X are names of two classic BPF registers - BPF_REG_A denotes internal BPF register R0 used to map classic register A in internal BPF programs generated from classic - BPF_REG_X denotes internal BPF register R7 used to map classic register X in internal BPF programs generated from classic - internal BPF instruction format: struct sock_filter_int { __u8 code; /* opcode */ __u8 dst_reg:4; /* dest register */ __u8 src_reg:4; /* source register */ __s16 off; /* signed offset */ __s32 imm; /* signed immediate constant */ }; - BPF_X/BPF_K is 1 bit used to encode source operand of instruction In classic: BPF_X - means use register X as source operand BPF_K - means use 32-bit immediate as source operand In internal: BPF_X - means use 'src_reg' register as source operand BPF_K - means use 32-bit immediate as source operand Suggested-by: Chema Gonzalez <chema@google.com> Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Acked-by: Daniel Borkmann <dborkman@redhat.com> Acked-by: Chema Gonzalez <chema@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-06-06 15:46:06 -06:00
/* mov r11, imm32 */
EMIT3_off32(0x49, 0xC7, 0xC3, imm32);
net: filter: x86: internal BPF JIT Maps all internal BPF instructions into x86_64 instructions. This patch replaces original BPF x64 JIT with internal BPF x64 JIT. sysctl net.core.bpf_jit_enable is reused as on/off switch. Performance: 1. old BPF JIT and internal BPF JIT generate equivalent x86_64 code. No performance difference is observed for filters that were JIT-able before Example assembler code for BPF filter "tcpdump port 22" original BPF -> old JIT: original BPF -> internal BPF -> new JIT: 0: push %rbp 0: push %rbp 1: mov %rsp,%rbp 1: mov %rsp,%rbp 4: sub $0x60,%rsp 4: sub $0x228,%rsp 8: mov %rbx,-0x8(%rbp) b: mov %rbx,-0x228(%rbp) // prologue 12: mov %r13,-0x220(%rbp) 19: mov %r14,-0x218(%rbp) 20: mov %r15,-0x210(%rbp) 27: xor %eax,%eax // clear A c: xor %ebx,%ebx 29: xor %r13,%r13 // clear X e: mov 0x68(%rdi),%r9d 2c: mov 0x68(%rdi),%r9d 12: sub 0x6c(%rdi),%r9d 30: sub 0x6c(%rdi),%r9d 16: mov 0xd8(%rdi),%r8 34: mov 0xd8(%rdi),%r10 3b: mov %rdi,%rbx 1d: mov $0xc,%esi 3e: mov $0xc,%esi 22: callq 0xffffffffe1021e15 43: callq 0xffffffffe102bd75 27: cmp $0x86dd,%eax 48: cmp $0x86dd,%rax 2c: jne 0x0000000000000069 4f: jne 0x000000000000009a 2e: mov $0x14,%esi 51: mov $0x14,%esi 33: callq 0xffffffffe1021e31 56: callq 0xffffffffe102bd91 38: cmp $0x84,%eax 5b: cmp $0x84,%rax 3d: je 0x0000000000000049 62: je 0x0000000000000074 3f: cmp $0x6,%eax 64: cmp $0x6,%rax 42: je 0x0000000000000049 68: je 0x0000000000000074 44: cmp $0x11,%eax 6a: cmp $0x11,%rax 47: jne 0x00000000000000c6 6e: jne 0x0000000000000117 49: mov $0x36,%esi 74: mov $0x36,%esi 4e: callq 0xffffffffe1021e15 79: callq 0xffffffffe102bd75 53: cmp $0x16,%eax 7e: cmp $0x16,%rax 56: je 0x00000000000000bf 82: je 0x0000000000000110 58: mov $0x38,%esi 88: mov $0x38,%esi 5d: callq 0xffffffffe1021e15 8d: callq 0xffffffffe102bd75 62: cmp $0x16,%eax 92: cmp $0x16,%rax 65: je 0x00000000000000bf 96: je 0x0000000000000110 67: jmp 0x00000000000000c6 98: jmp 0x0000000000000117 69: cmp $0x800,%eax 9a: cmp $0x800,%rax 6e: jne 0x00000000000000c6 a1: jne 0x0000000000000117 70: mov $0x17,%esi a3: mov $0x17,%esi 75: callq 0xffffffffe1021e31 a8: callq 0xffffffffe102bd91 7a: cmp $0x84,%eax ad: cmp $0x84,%rax 7f: je 0x000000000000008b b4: je 0x00000000000000c2 81: cmp $0x6,%eax b6: cmp $0x6,%rax 84: je 0x000000000000008b ba: je 0x00000000000000c2 86: cmp $0x11,%eax bc: cmp $0x11,%rax 89: jne 0x00000000000000c6 c0: jne 0x0000000000000117 8b: mov $0x14,%esi c2: mov $0x14,%esi 90: callq 0xffffffffe1021e15 c7: callq 0xffffffffe102bd75 95: test $0x1fff,%ax cc: test $0x1fff,%rax 99: jne 0x00000000000000c6 d3: jne 0x0000000000000117 d5: mov %rax,%r14 9b: mov $0xe,%esi d8: mov $0xe,%esi a0: callq 0xffffffffe1021e44 dd: callq 0xffffffffe102bd91 // MSH e2: and $0xf,%eax e5: shl $0x2,%eax e8: mov %rax,%r13 eb: mov %r14,%rax ee: mov %r13,%rsi a5: lea 0xe(%rbx),%esi f1: add $0xe,%esi a8: callq 0xffffffffe1021e0d f4: callq 0xffffffffe102bd6d ad: cmp $0x16,%eax f9: cmp $0x16,%rax b0: je 0x00000000000000bf fd: je 0x0000000000000110 ff: mov %r13,%rsi b2: lea 0x10(%rbx),%esi 102: add $0x10,%esi b5: callq 0xffffffffe1021e0d 105: callq 0xffffffffe102bd6d ba: cmp $0x16,%eax 10a: cmp $0x16,%rax bd: jne 0x00000000000000c6 10e: jne 0x0000000000000117 bf: mov $0xffff,%eax 110: mov $0xffff,%eax c4: jmp 0x00000000000000c8 115: jmp 0x000000000000011c c6: xor %eax,%eax 117: mov $0x0,%eax c8: mov -0x8(%rbp),%rbx 11c: mov -0x228(%rbp),%rbx // epilogue cc: leaveq 123: mov -0x220(%rbp),%r13 cd: retq 12a: mov -0x218(%rbp),%r14 131: mov -0x210(%rbp),%r15 138: leaveq 139: retq On fully cached SKBs both JITed functions take 12 nsec to execute. BPF interpreter executes the program in 30 nsec. The difference in generated assembler is due to the following: Old BPF imlements LDX_MSH instruction via sk_load_byte_msh() helper function inside bpf_jit.S. New JIT removes the helper and does it explicitly, so ldx_msh cost is the same for both JITs, but generated code looks longer. New JIT has 4 registers to save, so prologue/epilogue are larger, but the cost is within noise on x64. Old JIT checks whether first insn clears A and if not emits 'xor %eax,%eax'. New JIT clears %rax unconditionally. 2. old BPF JIT doesn't support ANC_NLATTR, ANC_PAY_OFFSET, ANC_RANDOM extensions. New JIT supports all BPF extensions. Performance of such filters improves 2-4 times depending on a filter. The longer the filter the higher performance gain. Synthetic benchmarks with many ancillary loads see 20x speedup which seems to be the maximum gain from JIT Notes: . net.core.bpf_jit_enable=2 + tools/net/bpf_jit_disasm is still functional and can be used to see generated assembler . there are two jit_compile() functions and code flow for classic filters is: sk_attach_filter() - load classic BPF bpf_jit_compile() - try to JIT from classic BPF sk_convert_filter() - convert classic to internal bpf_int_jit_compile() - JIT from internal BPF seccomp and tracing filters will just call bpf_int_jit_compile() Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 20:50:46 -06:00
net: filter: cleanup A/X name usage The macro 'A' used in internal BPF interpreter: #define A regs[insn->a_reg] was easily confused with the name of classic BPF register 'A', since 'A' would mean two different things depending on context. This patch is trying to clean up the naming and clarify its usage in the following way: - A and X are names of two classic BPF registers - BPF_REG_A denotes internal BPF register R0 used to map classic register A in internal BPF programs generated from classic - BPF_REG_X denotes internal BPF register R7 used to map classic register X in internal BPF programs generated from classic - internal BPF instruction format: struct sock_filter_int { __u8 code; /* opcode */ __u8 dst_reg:4; /* dest register */ __u8 src_reg:4; /* source register */ __s16 off; /* signed offset */ __s32 imm; /* signed immediate constant */ }; - BPF_X/BPF_K is 1 bit used to encode source operand of instruction In classic: BPF_X - means use register X as source operand BPF_K - means use 32-bit immediate as source operand In internal: BPF_X - means use 'src_reg' register as source operand BPF_K - means use 32-bit immediate as source operand Suggested-by: Chema Gonzalez <chema@google.com> Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Acked-by: Daniel Borkmann <dborkman@redhat.com> Acked-by: Chema Gonzalez <chema@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-06-06 15:46:06 -06:00
/* mov rax, dst_reg */
EMIT_mov(BPF_REG_0, dst_reg);
net: filter: x86: internal BPF JIT Maps all internal BPF instructions into x86_64 instructions. This patch replaces original BPF x64 JIT with internal BPF x64 JIT. sysctl net.core.bpf_jit_enable is reused as on/off switch. Performance: 1. old BPF JIT and internal BPF JIT generate equivalent x86_64 code. No performance difference is observed for filters that were JIT-able before Example assembler code for BPF filter "tcpdump port 22" original BPF -> old JIT: original BPF -> internal BPF -> new JIT: 0: push %rbp 0: push %rbp 1: mov %rsp,%rbp 1: mov %rsp,%rbp 4: sub $0x60,%rsp 4: sub $0x228,%rsp 8: mov %rbx,-0x8(%rbp) b: mov %rbx,-0x228(%rbp) // prologue 12: mov %r13,-0x220(%rbp) 19: mov %r14,-0x218(%rbp) 20: mov %r15,-0x210(%rbp) 27: xor %eax,%eax // clear A c: xor %ebx,%ebx 29: xor %r13,%r13 // clear X e: mov 0x68(%rdi),%r9d 2c: mov 0x68(%rdi),%r9d 12: sub 0x6c(%rdi),%r9d 30: sub 0x6c(%rdi),%r9d 16: mov 0xd8(%rdi),%r8 34: mov 0xd8(%rdi),%r10 3b: mov %rdi,%rbx 1d: mov $0xc,%esi 3e: mov $0xc,%esi 22: callq 0xffffffffe1021e15 43: callq 0xffffffffe102bd75 27: cmp $0x86dd,%eax 48: cmp $0x86dd,%rax 2c: jne 0x0000000000000069 4f: jne 0x000000000000009a 2e: mov $0x14,%esi 51: mov $0x14,%esi 33: callq 0xffffffffe1021e31 56: callq 0xffffffffe102bd91 38: cmp $0x84,%eax 5b: cmp $0x84,%rax 3d: je 0x0000000000000049 62: je 0x0000000000000074 3f: cmp $0x6,%eax 64: cmp $0x6,%rax 42: je 0x0000000000000049 68: je 0x0000000000000074 44: cmp $0x11,%eax 6a: cmp $0x11,%rax 47: jne 0x00000000000000c6 6e: jne 0x0000000000000117 49: mov $0x36,%esi 74: mov $0x36,%esi 4e: callq 0xffffffffe1021e15 79: callq 0xffffffffe102bd75 53: cmp $0x16,%eax 7e: cmp $0x16,%rax 56: je 0x00000000000000bf 82: je 0x0000000000000110 58: mov $0x38,%esi 88: mov $0x38,%esi 5d: callq 0xffffffffe1021e15 8d: callq 0xffffffffe102bd75 62: cmp $0x16,%eax 92: cmp $0x16,%rax 65: je 0x00000000000000bf 96: je 0x0000000000000110 67: jmp 0x00000000000000c6 98: jmp 0x0000000000000117 69: cmp $0x800,%eax 9a: cmp $0x800,%rax 6e: jne 0x00000000000000c6 a1: jne 0x0000000000000117 70: mov $0x17,%esi a3: mov $0x17,%esi 75: callq 0xffffffffe1021e31 a8: callq 0xffffffffe102bd91 7a: cmp $0x84,%eax ad: cmp $0x84,%rax 7f: je 0x000000000000008b b4: je 0x00000000000000c2 81: cmp $0x6,%eax b6: cmp $0x6,%rax 84: je 0x000000000000008b ba: je 0x00000000000000c2 86: cmp $0x11,%eax bc: cmp $0x11,%rax 89: jne 0x00000000000000c6 c0: jne 0x0000000000000117 8b: mov $0x14,%esi c2: mov $0x14,%esi 90: callq 0xffffffffe1021e15 c7: callq 0xffffffffe102bd75 95: test $0x1fff,%ax cc: test $0x1fff,%rax 99: jne 0x00000000000000c6 d3: jne 0x0000000000000117 d5: mov %rax,%r14 9b: mov $0xe,%esi d8: mov $0xe,%esi a0: callq 0xffffffffe1021e44 dd: callq 0xffffffffe102bd91 // MSH e2: and $0xf,%eax e5: shl $0x2,%eax e8: mov %rax,%r13 eb: mov %r14,%rax ee: mov %r13,%rsi a5: lea 0xe(%rbx),%esi f1: add $0xe,%esi a8: callq 0xffffffffe1021e0d f4: callq 0xffffffffe102bd6d ad: cmp $0x16,%eax f9: cmp $0x16,%rax b0: je 0x00000000000000bf fd: je 0x0000000000000110 ff: mov %r13,%rsi b2: lea 0x10(%rbx),%esi 102: add $0x10,%esi b5: callq 0xffffffffe1021e0d 105: callq 0xffffffffe102bd6d ba: cmp $0x16,%eax 10a: cmp $0x16,%rax bd: jne 0x00000000000000c6 10e: jne 0x0000000000000117 bf: mov $0xffff,%eax 110: mov $0xffff,%eax c4: jmp 0x00000000000000c8 115: jmp 0x000000000000011c c6: xor %eax,%eax 117: mov $0x0,%eax c8: mov -0x8(%rbp),%rbx 11c: mov -0x228(%rbp),%rbx // epilogue cc: leaveq 123: mov -0x220(%rbp),%r13 cd: retq 12a: mov -0x218(%rbp),%r14 131: mov -0x210(%rbp),%r15 138: leaveq 139: retq On fully cached SKBs both JITed functions take 12 nsec to execute. BPF interpreter executes the program in 30 nsec. The difference in generated assembler is due to the following: Old BPF imlements LDX_MSH instruction via sk_load_byte_msh() helper function inside bpf_jit.S. New JIT removes the helper and does it explicitly, so ldx_msh cost is the same for both JITs, but generated code looks longer. New JIT has 4 registers to save, so prologue/epilogue are larger, but the cost is within noise on x64. Old JIT checks whether first insn clears A and if not emits 'xor %eax,%eax'. New JIT clears %rax unconditionally. 2. old BPF JIT doesn't support ANC_NLATTR, ANC_PAY_OFFSET, ANC_RANDOM extensions. New JIT supports all BPF extensions. Performance of such filters improves 2-4 times depending on a filter. The longer the filter the higher performance gain. Synthetic benchmarks with many ancillary loads see 20x speedup which seems to be the maximum gain from JIT Notes: . net.core.bpf_jit_enable=2 + tools/net/bpf_jit_disasm is still functional and can be used to see generated assembler . there are two jit_compile() functions and code flow for classic filters is: sk_attach_filter() - load classic BPF bpf_jit_compile() - try to JIT from classic BPF sk_convert_filter() - convert classic to internal bpf_int_jit_compile() - JIT from internal BPF seccomp and tracing filters will just call bpf_int_jit_compile() Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 20:50:46 -06:00
/* xor edx, edx
* equivalent to 'xor rdx, rdx', but one byte less
*/
EMIT2(0x31, 0xd2);
if (BPF_SRC(insn->code) == BPF_X) {
net: filter: cleanup A/X name usage The macro 'A' used in internal BPF interpreter: #define A regs[insn->a_reg] was easily confused with the name of classic BPF register 'A', since 'A' would mean two different things depending on context. This patch is trying to clean up the naming and clarify its usage in the following way: - A and X are names of two classic BPF registers - BPF_REG_A denotes internal BPF register R0 used to map classic register A in internal BPF programs generated from classic - BPF_REG_X denotes internal BPF register R7 used to map classic register X in internal BPF programs generated from classic - internal BPF instruction format: struct sock_filter_int { __u8 code; /* opcode */ __u8 dst_reg:4; /* dest register */ __u8 src_reg:4; /* source register */ __s16 off; /* signed offset */ __s32 imm; /* signed immediate constant */ }; - BPF_X/BPF_K is 1 bit used to encode source operand of instruction In classic: BPF_X - means use register X as source operand BPF_K - means use 32-bit immediate as source operand In internal: BPF_X - means use 'src_reg' register as source operand BPF_K - means use 32-bit immediate as source operand Suggested-by: Chema Gonzalez <chema@google.com> Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Acked-by: Daniel Borkmann <dborkman@redhat.com> Acked-by: Chema Gonzalez <chema@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-06-06 15:46:06 -06:00
/* if (src_reg == 0) return 0 */
net: filter: x86: internal BPF JIT Maps all internal BPF instructions into x86_64 instructions. This patch replaces original BPF x64 JIT with internal BPF x64 JIT. sysctl net.core.bpf_jit_enable is reused as on/off switch. Performance: 1. old BPF JIT and internal BPF JIT generate equivalent x86_64 code. No performance difference is observed for filters that were JIT-able before Example assembler code for BPF filter "tcpdump port 22" original BPF -> old JIT: original BPF -> internal BPF -> new JIT: 0: push %rbp 0: push %rbp 1: mov %rsp,%rbp 1: mov %rsp,%rbp 4: sub $0x60,%rsp 4: sub $0x228,%rsp 8: mov %rbx,-0x8(%rbp) b: mov %rbx,-0x228(%rbp) // prologue 12: mov %r13,-0x220(%rbp) 19: mov %r14,-0x218(%rbp) 20: mov %r15,-0x210(%rbp) 27: xor %eax,%eax // clear A c: xor %ebx,%ebx 29: xor %r13,%r13 // clear X e: mov 0x68(%rdi),%r9d 2c: mov 0x68(%rdi),%r9d 12: sub 0x6c(%rdi),%r9d 30: sub 0x6c(%rdi),%r9d 16: mov 0xd8(%rdi),%r8 34: mov 0xd8(%rdi),%r10 3b: mov %rdi,%rbx 1d: mov $0xc,%esi 3e: mov $0xc,%esi 22: callq 0xffffffffe1021e15 43: callq 0xffffffffe102bd75 27: cmp $0x86dd,%eax 48: cmp $0x86dd,%rax 2c: jne 0x0000000000000069 4f: jne 0x000000000000009a 2e: mov $0x14,%esi 51: mov $0x14,%esi 33: callq 0xffffffffe1021e31 56: callq 0xffffffffe102bd91 38: cmp $0x84,%eax 5b: cmp $0x84,%rax 3d: je 0x0000000000000049 62: je 0x0000000000000074 3f: cmp $0x6,%eax 64: cmp $0x6,%rax 42: je 0x0000000000000049 68: je 0x0000000000000074 44: cmp $0x11,%eax 6a: cmp $0x11,%rax 47: jne 0x00000000000000c6 6e: jne 0x0000000000000117 49: mov $0x36,%esi 74: mov $0x36,%esi 4e: callq 0xffffffffe1021e15 79: callq 0xffffffffe102bd75 53: cmp $0x16,%eax 7e: cmp $0x16,%rax 56: je 0x00000000000000bf 82: je 0x0000000000000110 58: mov $0x38,%esi 88: mov $0x38,%esi 5d: callq 0xffffffffe1021e15 8d: callq 0xffffffffe102bd75 62: cmp $0x16,%eax 92: cmp $0x16,%rax 65: je 0x00000000000000bf 96: je 0x0000000000000110 67: jmp 0x00000000000000c6 98: jmp 0x0000000000000117 69: cmp $0x800,%eax 9a: cmp $0x800,%rax 6e: jne 0x00000000000000c6 a1: jne 0x0000000000000117 70: mov $0x17,%esi a3: mov $0x17,%esi 75: callq 0xffffffffe1021e31 a8: callq 0xffffffffe102bd91 7a: cmp $0x84,%eax ad: cmp $0x84,%rax 7f: je 0x000000000000008b b4: je 0x00000000000000c2 81: cmp $0x6,%eax b6: cmp $0x6,%rax 84: je 0x000000000000008b ba: je 0x00000000000000c2 86: cmp $0x11,%eax bc: cmp $0x11,%rax 89: jne 0x00000000000000c6 c0: jne 0x0000000000000117 8b: mov $0x14,%esi c2: mov $0x14,%esi 90: callq 0xffffffffe1021e15 c7: callq 0xffffffffe102bd75 95: test $0x1fff,%ax cc: test $0x1fff,%rax 99: jne 0x00000000000000c6 d3: jne 0x0000000000000117 d5: mov %rax,%r14 9b: mov $0xe,%esi d8: mov $0xe,%esi a0: callq 0xffffffffe1021e44 dd: callq 0xffffffffe102bd91 // MSH e2: and $0xf,%eax e5: shl $0x2,%eax e8: mov %rax,%r13 eb: mov %r14,%rax ee: mov %r13,%rsi a5: lea 0xe(%rbx),%esi f1: add $0xe,%esi a8: callq 0xffffffffe1021e0d f4: callq 0xffffffffe102bd6d ad: cmp $0x16,%eax f9: cmp $0x16,%rax b0: je 0x00000000000000bf fd: je 0x0000000000000110 ff: mov %r13,%rsi b2: lea 0x10(%rbx),%esi 102: add $0x10,%esi b5: callq 0xffffffffe1021e0d 105: callq 0xffffffffe102bd6d ba: cmp $0x16,%eax 10a: cmp $0x16,%rax bd: jne 0x00000000000000c6 10e: jne 0x0000000000000117 bf: mov $0xffff,%eax 110: mov $0xffff,%eax c4: jmp 0x00000000000000c8 115: jmp 0x000000000000011c c6: xor %eax,%eax 117: mov $0x0,%eax c8: mov -0x8(%rbp),%rbx 11c: mov -0x228(%rbp),%rbx // epilogue cc: leaveq 123: mov -0x220(%rbp),%r13 cd: retq 12a: mov -0x218(%rbp),%r14 131: mov -0x210(%rbp),%r15 138: leaveq 139: retq On fully cached SKBs both JITed functions take 12 nsec to execute. BPF interpreter executes the program in 30 nsec. The difference in generated assembler is due to the following: Old BPF imlements LDX_MSH instruction via sk_load_byte_msh() helper function inside bpf_jit.S. New JIT removes the helper and does it explicitly, so ldx_msh cost is the same for both JITs, but generated code looks longer. New JIT has 4 registers to save, so prologue/epilogue are larger, but the cost is within noise on x64. Old JIT checks whether first insn clears A and if not emits 'xor %eax,%eax'. New JIT clears %rax unconditionally. 2. old BPF JIT doesn't support ANC_NLATTR, ANC_PAY_OFFSET, ANC_RANDOM extensions. New JIT supports all BPF extensions. Performance of such filters improves 2-4 times depending on a filter. The longer the filter the higher performance gain. Synthetic benchmarks with many ancillary loads see 20x speedup which seems to be the maximum gain from JIT Notes: . net.core.bpf_jit_enable=2 + tools/net/bpf_jit_disasm is still functional and can be used to see generated assembler . there are two jit_compile() functions and code flow for classic filters is: sk_attach_filter() - load classic BPF bpf_jit_compile() - try to JIT from classic BPF sk_convert_filter() - convert classic to internal bpf_int_jit_compile() - JIT from internal BPF seccomp and tracing filters will just call bpf_int_jit_compile() Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 20:50:46 -06:00
/* cmp r11, 0 */
EMIT4(0x49, 0x83, 0xFB, 0x00);
/* jne .+9 (skip over pop, pop, xor and jmp) */
EMIT2(X86_JNE, 1 + 1 + 2 + 5);
EMIT1(0x5A); /* pop rdx */
EMIT1(0x58); /* pop rax */
EMIT2(0x31, 0xc0); /* xor eax, eax */
/* jmp cleanup_addr
* addrs[i] - 11, because there are 11 bytes
* after this insn: div, mov, pop, pop, mov
*/
jmp_offset = ctx->cleanup_addr - (addrs[i] - 11);
EMIT1_off32(0xE9, jmp_offset);
}
if (BPF_CLASS(insn->code) == BPF_ALU64)
/* div r11 */
EMIT3(0x49, 0xF7, 0xF3);
else
/* div r11d */
EMIT3(0x41, 0xF7, 0xF3);
if (BPF_OP(insn->code) == BPF_MOD)
/* mov r11, rdx */
EMIT3(0x49, 0x89, 0xD3);
else
/* mov r11, rax */
EMIT3(0x49, 0x89, 0xC3);
EMIT1(0x5A); /* pop rdx */
EMIT1(0x58); /* pop rax */
net: filter: cleanup A/X name usage The macro 'A' used in internal BPF interpreter: #define A regs[insn->a_reg] was easily confused with the name of classic BPF register 'A', since 'A' would mean two different things depending on context. This patch is trying to clean up the naming and clarify its usage in the following way: - A and X are names of two classic BPF registers - BPF_REG_A denotes internal BPF register R0 used to map classic register A in internal BPF programs generated from classic - BPF_REG_X denotes internal BPF register R7 used to map classic register X in internal BPF programs generated from classic - internal BPF instruction format: struct sock_filter_int { __u8 code; /* opcode */ __u8 dst_reg:4; /* dest register */ __u8 src_reg:4; /* source register */ __s16 off; /* signed offset */ __s32 imm; /* signed immediate constant */ }; - BPF_X/BPF_K is 1 bit used to encode source operand of instruction In classic: BPF_X - means use register X as source operand BPF_K - means use 32-bit immediate as source operand In internal: BPF_X - means use 'src_reg' register as source operand BPF_K - means use 32-bit immediate as source operand Suggested-by: Chema Gonzalez <chema@google.com> Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Acked-by: Daniel Borkmann <dborkman@redhat.com> Acked-by: Chema Gonzalez <chema@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-06-06 15:46:06 -06:00
/* mov dst_reg, r11 */
EMIT_mov(dst_reg, AUX_REG);
net: filter: x86: internal BPF JIT Maps all internal BPF instructions into x86_64 instructions. This patch replaces original BPF x64 JIT with internal BPF x64 JIT. sysctl net.core.bpf_jit_enable is reused as on/off switch. Performance: 1. old BPF JIT and internal BPF JIT generate equivalent x86_64 code. No performance difference is observed for filters that were JIT-able before Example assembler code for BPF filter "tcpdump port 22" original BPF -> old JIT: original BPF -> internal BPF -> new JIT: 0: push %rbp 0: push %rbp 1: mov %rsp,%rbp 1: mov %rsp,%rbp 4: sub $0x60,%rsp 4: sub $0x228,%rsp 8: mov %rbx,-0x8(%rbp) b: mov %rbx,-0x228(%rbp) // prologue 12: mov %r13,-0x220(%rbp) 19: mov %r14,-0x218(%rbp) 20: mov %r15,-0x210(%rbp) 27: xor %eax,%eax // clear A c: xor %ebx,%ebx 29: xor %r13,%r13 // clear X e: mov 0x68(%rdi),%r9d 2c: mov 0x68(%rdi),%r9d 12: sub 0x6c(%rdi),%r9d 30: sub 0x6c(%rdi),%r9d 16: mov 0xd8(%rdi),%r8 34: mov 0xd8(%rdi),%r10 3b: mov %rdi,%rbx 1d: mov $0xc,%esi 3e: mov $0xc,%esi 22: callq 0xffffffffe1021e15 43: callq 0xffffffffe102bd75 27: cmp $0x86dd,%eax 48: cmp $0x86dd,%rax 2c: jne 0x0000000000000069 4f: jne 0x000000000000009a 2e: mov $0x14,%esi 51: mov $0x14,%esi 33: callq 0xffffffffe1021e31 56: callq 0xffffffffe102bd91 38: cmp $0x84,%eax 5b: cmp $0x84,%rax 3d: je 0x0000000000000049 62: je 0x0000000000000074 3f: cmp $0x6,%eax 64: cmp $0x6,%rax 42: je 0x0000000000000049 68: je 0x0000000000000074 44: cmp $0x11,%eax 6a: cmp $0x11,%rax 47: jne 0x00000000000000c6 6e: jne 0x0000000000000117 49: mov $0x36,%esi 74: mov $0x36,%esi 4e: callq 0xffffffffe1021e15 79: callq 0xffffffffe102bd75 53: cmp $0x16,%eax 7e: cmp $0x16,%rax 56: je 0x00000000000000bf 82: je 0x0000000000000110 58: mov $0x38,%esi 88: mov $0x38,%esi 5d: callq 0xffffffffe1021e15 8d: callq 0xffffffffe102bd75 62: cmp $0x16,%eax 92: cmp $0x16,%rax 65: je 0x00000000000000bf 96: je 0x0000000000000110 67: jmp 0x00000000000000c6 98: jmp 0x0000000000000117 69: cmp $0x800,%eax 9a: cmp $0x800,%rax 6e: jne 0x00000000000000c6 a1: jne 0x0000000000000117 70: mov $0x17,%esi a3: mov $0x17,%esi 75: callq 0xffffffffe1021e31 a8: callq 0xffffffffe102bd91 7a: cmp $0x84,%eax ad: cmp $0x84,%rax 7f: je 0x000000000000008b b4: je 0x00000000000000c2 81: cmp $0x6,%eax b6: cmp $0x6,%rax 84: je 0x000000000000008b ba: je 0x00000000000000c2 86: cmp $0x11,%eax bc: cmp $0x11,%rax 89: jne 0x00000000000000c6 c0: jne 0x0000000000000117 8b: mov $0x14,%esi c2: mov $0x14,%esi 90: callq 0xffffffffe1021e15 c7: callq 0xffffffffe102bd75 95: test $0x1fff,%ax cc: test $0x1fff,%rax 99: jne 0x00000000000000c6 d3: jne 0x0000000000000117 d5: mov %rax,%r14 9b: mov $0xe,%esi d8: mov $0xe,%esi a0: callq 0xffffffffe1021e44 dd: callq 0xffffffffe102bd91 // MSH e2: and $0xf,%eax e5: shl $0x2,%eax e8: mov %rax,%r13 eb: mov %r14,%rax ee: mov %r13,%rsi a5: lea 0xe(%rbx),%esi f1: add $0xe,%esi a8: callq 0xffffffffe1021e0d f4: callq 0xffffffffe102bd6d ad: cmp $0x16,%eax f9: cmp $0x16,%rax b0: je 0x00000000000000bf fd: je 0x0000000000000110 ff: mov %r13,%rsi b2: lea 0x10(%rbx),%esi 102: add $0x10,%esi b5: callq 0xffffffffe1021e0d 105: callq 0xffffffffe102bd6d ba: cmp $0x16,%eax 10a: cmp $0x16,%rax bd: jne 0x00000000000000c6 10e: jne 0x0000000000000117 bf: mov $0xffff,%eax 110: mov $0xffff,%eax c4: jmp 0x00000000000000c8 115: jmp 0x000000000000011c c6: xor %eax,%eax 117: mov $0x0,%eax c8: mov -0x8(%rbp),%rbx 11c: mov -0x228(%rbp),%rbx // epilogue cc: leaveq 123: mov -0x220(%rbp),%r13 cd: retq 12a: mov -0x218(%rbp),%r14 131: mov -0x210(%rbp),%r15 138: leaveq 139: retq On fully cached SKBs both JITed functions take 12 nsec to execute. BPF interpreter executes the program in 30 nsec. The difference in generated assembler is due to the following: Old BPF imlements LDX_MSH instruction via sk_load_byte_msh() helper function inside bpf_jit.S. New JIT removes the helper and does it explicitly, so ldx_msh cost is the same for both JITs, but generated code looks longer. New JIT has 4 registers to save, so prologue/epilogue are larger, but the cost is within noise on x64. Old JIT checks whether first insn clears A and if not emits 'xor %eax,%eax'. New JIT clears %rax unconditionally. 2. old BPF JIT doesn't support ANC_NLATTR, ANC_PAY_OFFSET, ANC_RANDOM extensions. New JIT supports all BPF extensions. Performance of such filters improves 2-4 times depending on a filter. The longer the filter the higher performance gain. Synthetic benchmarks with many ancillary loads see 20x speedup which seems to be the maximum gain from JIT Notes: . net.core.bpf_jit_enable=2 + tools/net/bpf_jit_disasm is still functional and can be used to see generated assembler . there are two jit_compile() functions and code flow for classic filters is: sk_attach_filter() - load classic BPF bpf_jit_compile() - try to JIT from classic BPF sk_convert_filter() - convert classic to internal bpf_int_jit_compile() - JIT from internal BPF seccomp and tracing filters will just call bpf_int_jit_compile() Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 20:50:46 -06:00
break;
case BPF_ALU | BPF_MUL | BPF_K:
case BPF_ALU | BPF_MUL | BPF_X:
case BPF_ALU64 | BPF_MUL | BPF_K:
case BPF_ALU64 | BPF_MUL | BPF_X:
EMIT1(0x50); /* push rax */
EMIT1(0x52); /* push rdx */
net: filter: cleanup A/X name usage The macro 'A' used in internal BPF interpreter: #define A regs[insn->a_reg] was easily confused with the name of classic BPF register 'A', since 'A' would mean two different things depending on context. This patch is trying to clean up the naming and clarify its usage in the following way: - A and X are names of two classic BPF registers - BPF_REG_A denotes internal BPF register R0 used to map classic register A in internal BPF programs generated from classic - BPF_REG_X denotes internal BPF register R7 used to map classic register X in internal BPF programs generated from classic - internal BPF instruction format: struct sock_filter_int { __u8 code; /* opcode */ __u8 dst_reg:4; /* dest register */ __u8 src_reg:4; /* source register */ __s16 off; /* signed offset */ __s32 imm; /* signed immediate constant */ }; - BPF_X/BPF_K is 1 bit used to encode source operand of instruction In classic: BPF_X - means use register X as source operand BPF_K - means use 32-bit immediate as source operand In internal: BPF_X - means use 'src_reg' register as source operand BPF_K - means use 32-bit immediate as source operand Suggested-by: Chema Gonzalez <chema@google.com> Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Acked-by: Daniel Borkmann <dborkman@redhat.com> Acked-by: Chema Gonzalez <chema@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-06-06 15:46:06 -06:00
/* mov r11, dst_reg */
EMIT_mov(AUX_REG, dst_reg);
net: filter: x86: internal BPF JIT Maps all internal BPF instructions into x86_64 instructions. This patch replaces original BPF x64 JIT with internal BPF x64 JIT. sysctl net.core.bpf_jit_enable is reused as on/off switch. Performance: 1. old BPF JIT and internal BPF JIT generate equivalent x86_64 code. No performance difference is observed for filters that were JIT-able before Example assembler code for BPF filter "tcpdump port 22" original BPF -> old JIT: original BPF -> internal BPF -> new JIT: 0: push %rbp 0: push %rbp 1: mov %rsp,%rbp 1: mov %rsp,%rbp 4: sub $0x60,%rsp 4: sub $0x228,%rsp 8: mov %rbx,-0x8(%rbp) b: mov %rbx,-0x228(%rbp) // prologue 12: mov %r13,-0x220(%rbp) 19: mov %r14,-0x218(%rbp) 20: mov %r15,-0x210(%rbp) 27: xor %eax,%eax // clear A c: xor %ebx,%ebx 29: xor %r13,%r13 // clear X e: mov 0x68(%rdi),%r9d 2c: mov 0x68(%rdi),%r9d 12: sub 0x6c(%rdi),%r9d 30: sub 0x6c(%rdi),%r9d 16: mov 0xd8(%rdi),%r8 34: mov 0xd8(%rdi),%r10 3b: mov %rdi,%rbx 1d: mov $0xc,%esi 3e: mov $0xc,%esi 22: callq 0xffffffffe1021e15 43: callq 0xffffffffe102bd75 27: cmp $0x86dd,%eax 48: cmp $0x86dd,%rax 2c: jne 0x0000000000000069 4f: jne 0x000000000000009a 2e: mov $0x14,%esi 51: mov $0x14,%esi 33: callq 0xffffffffe1021e31 56: callq 0xffffffffe102bd91 38: cmp $0x84,%eax 5b: cmp $0x84,%rax 3d: je 0x0000000000000049 62: je 0x0000000000000074 3f: cmp $0x6,%eax 64: cmp $0x6,%rax 42: je 0x0000000000000049 68: je 0x0000000000000074 44: cmp $0x11,%eax 6a: cmp $0x11,%rax 47: jne 0x00000000000000c6 6e: jne 0x0000000000000117 49: mov $0x36,%esi 74: mov $0x36,%esi 4e: callq 0xffffffffe1021e15 79: callq 0xffffffffe102bd75 53: cmp $0x16,%eax 7e: cmp $0x16,%rax 56: je 0x00000000000000bf 82: je 0x0000000000000110 58: mov $0x38,%esi 88: mov $0x38,%esi 5d: callq 0xffffffffe1021e15 8d: callq 0xffffffffe102bd75 62: cmp $0x16,%eax 92: cmp $0x16,%rax 65: je 0x00000000000000bf 96: je 0x0000000000000110 67: jmp 0x00000000000000c6 98: jmp 0x0000000000000117 69: cmp $0x800,%eax 9a: cmp $0x800,%rax 6e: jne 0x00000000000000c6 a1: jne 0x0000000000000117 70: mov $0x17,%esi a3: mov $0x17,%esi 75: callq 0xffffffffe1021e31 a8: callq 0xffffffffe102bd91 7a: cmp $0x84,%eax ad: cmp $0x84,%rax 7f: je 0x000000000000008b b4: je 0x00000000000000c2 81: cmp $0x6,%eax b6: cmp $0x6,%rax 84: je 0x000000000000008b ba: je 0x00000000000000c2 86: cmp $0x11,%eax bc: cmp $0x11,%rax 89: jne 0x00000000000000c6 c0: jne 0x0000000000000117 8b: mov $0x14,%esi c2: mov $0x14,%esi 90: callq 0xffffffffe1021e15 c7: callq 0xffffffffe102bd75 95: test $0x1fff,%ax cc: test $0x1fff,%rax 99: jne 0x00000000000000c6 d3: jne 0x0000000000000117 d5: mov %rax,%r14 9b: mov $0xe,%esi d8: mov $0xe,%esi a0: callq 0xffffffffe1021e44 dd: callq 0xffffffffe102bd91 // MSH e2: and $0xf,%eax e5: shl $0x2,%eax e8: mov %rax,%r13 eb: mov %r14,%rax ee: mov %r13,%rsi a5: lea 0xe(%rbx),%esi f1: add $0xe,%esi a8: callq 0xffffffffe1021e0d f4: callq 0xffffffffe102bd6d ad: cmp $0x16,%eax f9: cmp $0x16,%rax b0: je 0x00000000000000bf fd: je 0x0000000000000110 ff: mov %r13,%rsi b2: lea 0x10(%rbx),%esi 102: add $0x10,%esi b5: callq 0xffffffffe1021e0d 105: callq 0xffffffffe102bd6d ba: cmp $0x16,%eax 10a: cmp $0x16,%rax bd: jne 0x00000000000000c6 10e: jne 0x0000000000000117 bf: mov $0xffff,%eax 110: mov $0xffff,%eax c4: jmp 0x00000000000000c8 115: jmp 0x000000000000011c c6: xor %eax,%eax 117: mov $0x0,%eax c8: mov -0x8(%rbp),%rbx 11c: mov -0x228(%rbp),%rbx // epilogue cc: leaveq 123: mov -0x220(%rbp),%r13 cd: retq 12a: mov -0x218(%rbp),%r14 131: mov -0x210(%rbp),%r15 138: leaveq 139: retq On fully cached SKBs both JITed functions take 12 nsec to execute. BPF interpreter executes the program in 30 nsec. The difference in generated assembler is due to the following: Old BPF imlements LDX_MSH instruction via sk_load_byte_msh() helper function inside bpf_jit.S. New JIT removes the helper and does it explicitly, so ldx_msh cost is the same for both JITs, but generated code looks longer. New JIT has 4 registers to save, so prologue/epilogue are larger, but the cost is within noise on x64. Old JIT checks whether first insn clears A and if not emits 'xor %eax,%eax'. New JIT clears %rax unconditionally. 2. old BPF JIT doesn't support ANC_NLATTR, ANC_PAY_OFFSET, ANC_RANDOM extensions. New JIT supports all BPF extensions. Performance of such filters improves 2-4 times depending on a filter. The longer the filter the higher performance gain. Synthetic benchmarks with many ancillary loads see 20x speedup which seems to be the maximum gain from JIT Notes: . net.core.bpf_jit_enable=2 + tools/net/bpf_jit_disasm is still functional and can be used to see generated assembler . there are two jit_compile() functions and code flow for classic filters is: sk_attach_filter() - load classic BPF bpf_jit_compile() - try to JIT from classic BPF sk_convert_filter() - convert classic to internal bpf_int_jit_compile() - JIT from internal BPF seccomp and tracing filters will just call bpf_int_jit_compile() Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 20:50:46 -06:00
if (BPF_SRC(insn->code) == BPF_X)
net: filter: cleanup A/X name usage The macro 'A' used in internal BPF interpreter: #define A regs[insn->a_reg] was easily confused with the name of classic BPF register 'A', since 'A' would mean two different things depending on context. This patch is trying to clean up the naming and clarify its usage in the following way: - A and X are names of two classic BPF registers - BPF_REG_A denotes internal BPF register R0 used to map classic register A in internal BPF programs generated from classic - BPF_REG_X denotes internal BPF register R7 used to map classic register X in internal BPF programs generated from classic - internal BPF instruction format: struct sock_filter_int { __u8 code; /* opcode */ __u8 dst_reg:4; /* dest register */ __u8 src_reg:4; /* source register */ __s16 off; /* signed offset */ __s32 imm; /* signed immediate constant */ }; - BPF_X/BPF_K is 1 bit used to encode source operand of instruction In classic: BPF_X - means use register X as source operand BPF_K - means use 32-bit immediate as source operand In internal: BPF_X - means use 'src_reg' register as source operand BPF_K - means use 32-bit immediate as source operand Suggested-by: Chema Gonzalez <chema@google.com> Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Acked-by: Daniel Borkmann <dborkman@redhat.com> Acked-by: Chema Gonzalez <chema@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-06-06 15:46:06 -06:00
/* mov rax, src_reg */
EMIT_mov(BPF_REG_0, src_reg);
net: filter: x86: internal BPF JIT Maps all internal BPF instructions into x86_64 instructions. This patch replaces original BPF x64 JIT with internal BPF x64 JIT. sysctl net.core.bpf_jit_enable is reused as on/off switch. Performance: 1. old BPF JIT and internal BPF JIT generate equivalent x86_64 code. No performance difference is observed for filters that were JIT-able before Example assembler code for BPF filter "tcpdump port 22" original BPF -> old JIT: original BPF -> internal BPF -> new JIT: 0: push %rbp 0: push %rbp 1: mov %rsp,%rbp 1: mov %rsp,%rbp 4: sub $0x60,%rsp 4: sub $0x228,%rsp 8: mov %rbx,-0x8(%rbp) b: mov %rbx,-0x228(%rbp) // prologue 12: mov %r13,-0x220(%rbp) 19: mov %r14,-0x218(%rbp) 20: mov %r15,-0x210(%rbp) 27: xor %eax,%eax // clear A c: xor %ebx,%ebx 29: xor %r13,%r13 // clear X e: mov 0x68(%rdi),%r9d 2c: mov 0x68(%rdi),%r9d 12: sub 0x6c(%rdi),%r9d 30: sub 0x6c(%rdi),%r9d 16: mov 0xd8(%rdi),%r8 34: mov 0xd8(%rdi),%r10 3b: mov %rdi,%rbx 1d: mov $0xc,%esi 3e: mov $0xc,%esi 22: callq 0xffffffffe1021e15 43: callq 0xffffffffe102bd75 27: cmp $0x86dd,%eax 48: cmp $0x86dd,%rax 2c: jne 0x0000000000000069 4f: jne 0x000000000000009a 2e: mov $0x14,%esi 51: mov $0x14,%esi 33: callq 0xffffffffe1021e31 56: callq 0xffffffffe102bd91 38: cmp $0x84,%eax 5b: cmp $0x84,%rax 3d: je 0x0000000000000049 62: je 0x0000000000000074 3f: cmp $0x6,%eax 64: cmp $0x6,%rax 42: je 0x0000000000000049 68: je 0x0000000000000074 44: cmp $0x11,%eax 6a: cmp $0x11,%rax 47: jne 0x00000000000000c6 6e: jne 0x0000000000000117 49: mov $0x36,%esi 74: mov $0x36,%esi 4e: callq 0xffffffffe1021e15 79: callq 0xffffffffe102bd75 53: cmp $0x16,%eax 7e: cmp $0x16,%rax 56: je 0x00000000000000bf 82: je 0x0000000000000110 58: mov $0x38,%esi 88: mov $0x38,%esi 5d: callq 0xffffffffe1021e15 8d: callq 0xffffffffe102bd75 62: cmp $0x16,%eax 92: cmp $0x16,%rax 65: je 0x00000000000000bf 96: je 0x0000000000000110 67: jmp 0x00000000000000c6 98: jmp 0x0000000000000117 69: cmp $0x800,%eax 9a: cmp $0x800,%rax 6e: jne 0x00000000000000c6 a1: jne 0x0000000000000117 70: mov $0x17,%esi a3: mov $0x17,%esi 75: callq 0xffffffffe1021e31 a8: callq 0xffffffffe102bd91 7a: cmp $0x84,%eax ad: cmp $0x84,%rax 7f: je 0x000000000000008b b4: je 0x00000000000000c2 81: cmp $0x6,%eax b6: cmp $0x6,%rax 84: je 0x000000000000008b ba: je 0x00000000000000c2 86: cmp $0x11,%eax bc: cmp $0x11,%rax 89: jne 0x00000000000000c6 c0: jne 0x0000000000000117 8b: mov $0x14,%esi c2: mov $0x14,%esi 90: callq 0xffffffffe1021e15 c7: callq 0xffffffffe102bd75 95: test $0x1fff,%ax cc: test $0x1fff,%rax 99: jne 0x00000000000000c6 d3: jne 0x0000000000000117 d5: mov %rax,%r14 9b: mov $0xe,%esi d8: mov $0xe,%esi a0: callq 0xffffffffe1021e44 dd: callq 0xffffffffe102bd91 // MSH e2: and $0xf,%eax e5: shl $0x2,%eax e8: mov %rax,%r13 eb: mov %r14,%rax ee: mov %r13,%rsi a5: lea 0xe(%rbx),%esi f1: add $0xe,%esi a8: callq 0xffffffffe1021e0d f4: callq 0xffffffffe102bd6d ad: cmp $0x16,%eax f9: cmp $0x16,%rax b0: je 0x00000000000000bf fd: je 0x0000000000000110 ff: mov %r13,%rsi b2: lea 0x10(%rbx),%esi 102: add $0x10,%esi b5: callq 0xffffffffe1021e0d 105: callq 0xffffffffe102bd6d ba: cmp $0x16,%eax 10a: cmp $0x16,%rax bd: jne 0x00000000000000c6 10e: jne 0x0000000000000117 bf: mov $0xffff,%eax 110: mov $0xffff,%eax c4: jmp 0x00000000000000c8 115: jmp 0x000000000000011c c6: xor %eax,%eax 117: mov $0x0,%eax c8: mov -0x8(%rbp),%rbx 11c: mov -0x228(%rbp),%rbx // epilogue cc: leaveq 123: mov -0x220(%rbp),%r13 cd: retq 12a: mov -0x218(%rbp),%r14 131: mov -0x210(%rbp),%r15 138: leaveq 139: retq On fully cached SKBs both JITed functions take 12 nsec to execute. BPF interpreter executes the program in 30 nsec. The difference in generated assembler is due to the following: Old BPF imlements LDX_MSH instruction via sk_load_byte_msh() helper function inside bpf_jit.S. New JIT removes the helper and does it explicitly, so ldx_msh cost is the same for both JITs, but generated code looks longer. New JIT has 4 registers to save, so prologue/epilogue are larger, but the cost is within noise on x64. Old JIT checks whether first insn clears A and if not emits 'xor %eax,%eax'. New JIT clears %rax unconditionally. 2. old BPF JIT doesn't support ANC_NLATTR, ANC_PAY_OFFSET, ANC_RANDOM extensions. New JIT supports all BPF extensions. Performance of such filters improves 2-4 times depending on a filter. The longer the filter the higher performance gain. Synthetic benchmarks with many ancillary loads see 20x speedup which seems to be the maximum gain from JIT Notes: . net.core.bpf_jit_enable=2 + tools/net/bpf_jit_disasm is still functional and can be used to see generated assembler . there are two jit_compile() functions and code flow for classic filters is: sk_attach_filter() - load classic BPF bpf_jit_compile() - try to JIT from classic BPF sk_convert_filter() - convert classic to internal bpf_int_jit_compile() - JIT from internal BPF seccomp and tracing filters will just call bpf_int_jit_compile() Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 20:50:46 -06:00
else
net: filter: cleanup A/X name usage The macro 'A' used in internal BPF interpreter: #define A regs[insn->a_reg] was easily confused with the name of classic BPF register 'A', since 'A' would mean two different things depending on context. This patch is trying to clean up the naming and clarify its usage in the following way: - A and X are names of two classic BPF registers - BPF_REG_A denotes internal BPF register R0 used to map classic register A in internal BPF programs generated from classic - BPF_REG_X denotes internal BPF register R7 used to map classic register X in internal BPF programs generated from classic - internal BPF instruction format: struct sock_filter_int { __u8 code; /* opcode */ __u8 dst_reg:4; /* dest register */ __u8 src_reg:4; /* source register */ __s16 off; /* signed offset */ __s32 imm; /* signed immediate constant */ }; - BPF_X/BPF_K is 1 bit used to encode source operand of instruction In classic: BPF_X - means use register X as source operand BPF_K - means use 32-bit immediate as source operand In internal: BPF_X - means use 'src_reg' register as source operand BPF_K - means use 32-bit immediate as source operand Suggested-by: Chema Gonzalez <chema@google.com> Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Acked-by: Daniel Borkmann <dborkman@redhat.com> Acked-by: Chema Gonzalez <chema@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-06-06 15:46:06 -06:00
/* mov rax, imm32 */
EMIT3_off32(0x48, 0xC7, 0xC0, imm32);
net: filter: x86: internal BPF JIT Maps all internal BPF instructions into x86_64 instructions. This patch replaces original BPF x64 JIT with internal BPF x64 JIT. sysctl net.core.bpf_jit_enable is reused as on/off switch. Performance: 1. old BPF JIT and internal BPF JIT generate equivalent x86_64 code. No performance difference is observed for filters that were JIT-able before Example assembler code for BPF filter "tcpdump port 22" original BPF -> old JIT: original BPF -> internal BPF -> new JIT: 0: push %rbp 0: push %rbp 1: mov %rsp,%rbp 1: mov %rsp,%rbp 4: sub $0x60,%rsp 4: sub $0x228,%rsp 8: mov %rbx,-0x8(%rbp) b: mov %rbx,-0x228(%rbp) // prologue 12: mov %r13,-0x220(%rbp) 19: mov %r14,-0x218(%rbp) 20: mov %r15,-0x210(%rbp) 27: xor %eax,%eax // clear A c: xor %ebx,%ebx 29: xor %r13,%r13 // clear X e: mov 0x68(%rdi),%r9d 2c: mov 0x68(%rdi),%r9d 12: sub 0x6c(%rdi),%r9d 30: sub 0x6c(%rdi),%r9d 16: mov 0xd8(%rdi),%r8 34: mov 0xd8(%rdi),%r10 3b: mov %rdi,%rbx 1d: mov $0xc,%esi 3e: mov $0xc,%esi 22: callq 0xffffffffe1021e15 43: callq 0xffffffffe102bd75 27: cmp $0x86dd,%eax 48: cmp $0x86dd,%rax 2c: jne 0x0000000000000069 4f: jne 0x000000000000009a 2e: mov $0x14,%esi 51: mov $0x14,%esi 33: callq 0xffffffffe1021e31 56: callq 0xffffffffe102bd91 38: cmp $0x84,%eax 5b: cmp $0x84,%rax 3d: je 0x0000000000000049 62: je 0x0000000000000074 3f: cmp $0x6,%eax 64: cmp $0x6,%rax 42: je 0x0000000000000049 68: je 0x0000000000000074 44: cmp $0x11,%eax 6a: cmp $0x11,%rax 47: jne 0x00000000000000c6 6e: jne 0x0000000000000117 49: mov $0x36,%esi 74: mov $0x36,%esi 4e: callq 0xffffffffe1021e15 79: callq 0xffffffffe102bd75 53: cmp $0x16,%eax 7e: cmp $0x16,%rax 56: je 0x00000000000000bf 82: je 0x0000000000000110 58: mov $0x38,%esi 88: mov $0x38,%esi 5d: callq 0xffffffffe1021e15 8d: callq 0xffffffffe102bd75 62: cmp $0x16,%eax 92: cmp $0x16,%rax 65: je 0x00000000000000bf 96: je 0x0000000000000110 67: jmp 0x00000000000000c6 98: jmp 0x0000000000000117 69: cmp $0x800,%eax 9a: cmp $0x800,%rax 6e: jne 0x00000000000000c6 a1: jne 0x0000000000000117 70: mov $0x17,%esi a3: mov $0x17,%esi 75: callq 0xffffffffe1021e31 a8: callq 0xffffffffe102bd91 7a: cmp $0x84,%eax ad: cmp $0x84,%rax 7f: je 0x000000000000008b b4: je 0x00000000000000c2 81: cmp $0x6,%eax b6: cmp $0x6,%rax 84: je 0x000000000000008b ba: je 0x00000000000000c2 86: cmp $0x11,%eax bc: cmp $0x11,%rax 89: jne 0x00000000000000c6 c0: jne 0x0000000000000117 8b: mov $0x14,%esi c2: mov $0x14,%esi 90: callq 0xffffffffe1021e15 c7: callq 0xffffffffe102bd75 95: test $0x1fff,%ax cc: test $0x1fff,%rax 99: jne 0x00000000000000c6 d3: jne 0x0000000000000117 d5: mov %rax,%r14 9b: mov $0xe,%esi d8: mov $0xe,%esi a0: callq 0xffffffffe1021e44 dd: callq 0xffffffffe102bd91 // MSH e2: and $0xf,%eax e5: shl $0x2,%eax e8: mov %rax,%r13 eb: mov %r14,%rax ee: mov %r13,%rsi a5: lea 0xe(%rbx),%esi f1: add $0xe,%esi a8: callq 0xffffffffe1021e0d f4: callq 0xffffffffe102bd6d ad: cmp $0x16,%eax f9: cmp $0x16,%rax b0: je 0x00000000000000bf fd: je 0x0000000000000110 ff: mov %r13,%rsi b2: lea 0x10(%rbx),%esi 102: add $0x10,%esi b5: callq 0xffffffffe1021e0d 105: callq 0xffffffffe102bd6d ba: cmp $0x16,%eax 10a: cmp $0x16,%rax bd: jne 0x00000000000000c6 10e: jne 0x0000000000000117 bf: mov $0xffff,%eax 110: mov $0xffff,%eax c4: jmp 0x00000000000000c8 115: jmp 0x000000000000011c c6: xor %eax,%eax 117: mov $0x0,%eax c8: mov -0x8(%rbp),%rbx 11c: mov -0x228(%rbp),%rbx // epilogue cc: leaveq 123: mov -0x220(%rbp),%r13 cd: retq 12a: mov -0x218(%rbp),%r14 131: mov -0x210(%rbp),%r15 138: leaveq 139: retq On fully cached SKBs both JITed functions take 12 nsec to execute. BPF interpreter executes the program in 30 nsec. The difference in generated assembler is due to the following: Old BPF imlements LDX_MSH instruction via sk_load_byte_msh() helper function inside bpf_jit.S. New JIT removes the helper and does it explicitly, so ldx_msh cost is the same for both JITs, but generated code looks longer. New JIT has 4 registers to save, so prologue/epilogue are larger, but the cost is within noise on x64. Old JIT checks whether first insn clears A and if not emits 'xor %eax,%eax'. New JIT clears %rax unconditionally. 2. old BPF JIT doesn't support ANC_NLATTR, ANC_PAY_OFFSET, ANC_RANDOM extensions. New JIT supports all BPF extensions. Performance of such filters improves 2-4 times depending on a filter. The longer the filter the higher performance gain. Synthetic benchmarks with many ancillary loads see 20x speedup which seems to be the maximum gain from JIT Notes: . net.core.bpf_jit_enable=2 + tools/net/bpf_jit_disasm is still functional and can be used to see generated assembler . there are two jit_compile() functions and code flow for classic filters is: sk_attach_filter() - load classic BPF bpf_jit_compile() - try to JIT from classic BPF sk_convert_filter() - convert classic to internal bpf_int_jit_compile() - JIT from internal BPF seccomp and tracing filters will just call bpf_int_jit_compile() Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 20:50:46 -06:00
if (BPF_CLASS(insn->code) == BPF_ALU64)
EMIT1(add_1mod(0x48, AUX_REG));
else if (is_ereg(AUX_REG))
EMIT1(add_1mod(0x40, AUX_REG));
/* mul(q) r11 */
EMIT2(0xF7, add_1reg(0xE0, AUX_REG));
/* mov r11, rax */
EMIT_mov(AUX_REG, BPF_REG_0);
EMIT1(0x5A); /* pop rdx */
EMIT1(0x58); /* pop rax */
net: filter: cleanup A/X name usage The macro 'A' used in internal BPF interpreter: #define A regs[insn->a_reg] was easily confused with the name of classic BPF register 'A', since 'A' would mean two different things depending on context. This patch is trying to clean up the naming and clarify its usage in the following way: - A and X are names of two classic BPF registers - BPF_REG_A denotes internal BPF register R0 used to map classic register A in internal BPF programs generated from classic - BPF_REG_X denotes internal BPF register R7 used to map classic register X in internal BPF programs generated from classic - internal BPF instruction format: struct sock_filter_int { __u8 code; /* opcode */ __u8 dst_reg:4; /* dest register */ __u8 src_reg:4; /* source register */ __s16 off; /* signed offset */ __s32 imm; /* signed immediate constant */ }; - BPF_X/BPF_K is 1 bit used to encode source operand of instruction In classic: BPF_X - means use register X as source operand BPF_K - means use 32-bit immediate as source operand In internal: BPF_X - means use 'src_reg' register as source operand BPF_K - means use 32-bit immediate as source operand Suggested-by: Chema Gonzalez <chema@google.com> Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Acked-by: Daniel Borkmann <dborkman@redhat.com> Acked-by: Chema Gonzalez <chema@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-06-06 15:46:06 -06:00
/* mov dst_reg, r11 */
EMIT_mov(dst_reg, AUX_REG);
net: filter: x86: internal BPF JIT Maps all internal BPF instructions into x86_64 instructions. This patch replaces original BPF x64 JIT with internal BPF x64 JIT. sysctl net.core.bpf_jit_enable is reused as on/off switch. Performance: 1. old BPF JIT and internal BPF JIT generate equivalent x86_64 code. No performance difference is observed for filters that were JIT-able before Example assembler code for BPF filter "tcpdump port 22" original BPF -> old JIT: original BPF -> internal BPF -> new JIT: 0: push %rbp 0: push %rbp 1: mov %rsp,%rbp 1: mov %rsp,%rbp 4: sub $0x60,%rsp 4: sub $0x228,%rsp 8: mov %rbx,-0x8(%rbp) b: mov %rbx,-0x228(%rbp) // prologue 12: mov %r13,-0x220(%rbp) 19: mov %r14,-0x218(%rbp) 20: mov %r15,-0x210(%rbp) 27: xor %eax,%eax // clear A c: xor %ebx,%ebx 29: xor %r13,%r13 // clear X e: mov 0x68(%rdi),%r9d 2c: mov 0x68(%rdi),%r9d 12: sub 0x6c(%rdi),%r9d 30: sub 0x6c(%rdi),%r9d 16: mov 0xd8(%rdi),%r8 34: mov 0xd8(%rdi),%r10 3b: mov %rdi,%rbx 1d: mov $0xc,%esi 3e: mov $0xc,%esi 22: callq 0xffffffffe1021e15 43: callq 0xffffffffe102bd75 27: cmp $0x86dd,%eax 48: cmp $0x86dd,%rax 2c: jne 0x0000000000000069 4f: jne 0x000000000000009a 2e: mov $0x14,%esi 51: mov $0x14,%esi 33: callq 0xffffffffe1021e31 56: callq 0xffffffffe102bd91 38: cmp $0x84,%eax 5b: cmp $0x84,%rax 3d: je 0x0000000000000049 62: je 0x0000000000000074 3f: cmp $0x6,%eax 64: cmp $0x6,%rax 42: je 0x0000000000000049 68: je 0x0000000000000074 44: cmp $0x11,%eax 6a: cmp $0x11,%rax 47: jne 0x00000000000000c6 6e: jne 0x0000000000000117 49: mov $0x36,%esi 74: mov $0x36,%esi 4e: callq 0xffffffffe1021e15 79: callq 0xffffffffe102bd75 53: cmp $0x16,%eax 7e: cmp $0x16,%rax 56: je 0x00000000000000bf 82: je 0x0000000000000110 58: mov $0x38,%esi 88: mov $0x38,%esi 5d: callq 0xffffffffe1021e15 8d: callq 0xffffffffe102bd75 62: cmp $0x16,%eax 92: cmp $0x16,%rax 65: je 0x00000000000000bf 96: je 0x0000000000000110 67: jmp 0x00000000000000c6 98: jmp 0x0000000000000117 69: cmp $0x800,%eax 9a: cmp $0x800,%rax 6e: jne 0x00000000000000c6 a1: jne 0x0000000000000117 70: mov $0x17,%esi a3: mov $0x17,%esi 75: callq 0xffffffffe1021e31 a8: callq 0xffffffffe102bd91 7a: cmp $0x84,%eax ad: cmp $0x84,%rax 7f: je 0x000000000000008b b4: je 0x00000000000000c2 81: cmp $0x6,%eax b6: cmp $0x6,%rax 84: je 0x000000000000008b ba: je 0x00000000000000c2 86: cmp $0x11,%eax bc: cmp $0x11,%rax 89: jne 0x00000000000000c6 c0: jne 0x0000000000000117 8b: mov $0x14,%esi c2: mov $0x14,%esi 90: callq 0xffffffffe1021e15 c7: callq 0xffffffffe102bd75 95: test $0x1fff,%ax cc: test $0x1fff,%rax 99: jne 0x00000000000000c6 d3: jne 0x0000000000000117 d5: mov %rax,%r14 9b: mov $0xe,%esi d8: mov $0xe,%esi a0: callq 0xffffffffe1021e44 dd: callq 0xffffffffe102bd91 // MSH e2: and $0xf,%eax e5: shl $0x2,%eax e8: mov %rax,%r13 eb: mov %r14,%rax ee: mov %r13,%rsi a5: lea 0xe(%rbx),%esi f1: add $0xe,%esi a8: callq 0xffffffffe1021e0d f4: callq 0xffffffffe102bd6d ad: cmp $0x16,%eax f9: cmp $0x16,%rax b0: je 0x00000000000000bf fd: je 0x0000000000000110 ff: mov %r13,%rsi b2: lea 0x10(%rbx),%esi 102: add $0x10,%esi b5: callq 0xffffffffe1021e0d 105: callq 0xffffffffe102bd6d ba: cmp $0x16,%eax 10a: cmp $0x16,%rax bd: jne 0x00000000000000c6 10e: jne 0x0000000000000117 bf: mov $0xffff,%eax 110: mov $0xffff,%eax c4: jmp 0x00000000000000c8 115: jmp 0x000000000000011c c6: xor %eax,%eax 117: mov $0x0,%eax c8: mov -0x8(%rbp),%rbx 11c: mov -0x228(%rbp),%rbx // epilogue cc: leaveq 123: mov -0x220(%rbp),%r13 cd: retq 12a: mov -0x218(%rbp),%r14 131: mov -0x210(%rbp),%r15 138: leaveq 139: retq On fully cached SKBs both JITed functions take 12 nsec to execute. BPF interpreter executes the program in 30 nsec. The difference in generated assembler is due to the following: Old BPF imlements LDX_MSH instruction via sk_load_byte_msh() helper function inside bpf_jit.S. New JIT removes the helper and does it explicitly, so ldx_msh cost is the same for both JITs, but generated code looks longer. New JIT has 4 registers to save, so prologue/epilogue are larger, but the cost is within noise on x64. Old JIT checks whether first insn clears A and if not emits 'xor %eax,%eax'. New JIT clears %rax unconditionally. 2. old BPF JIT doesn't support ANC_NLATTR, ANC_PAY_OFFSET, ANC_RANDOM extensions. New JIT supports all BPF extensions. Performance of such filters improves 2-4 times depending on a filter. The longer the filter the higher performance gain. Synthetic benchmarks with many ancillary loads see 20x speedup which seems to be the maximum gain from JIT Notes: . net.core.bpf_jit_enable=2 + tools/net/bpf_jit_disasm is still functional and can be used to see generated assembler . there are two jit_compile() functions and code flow for classic filters is: sk_attach_filter() - load classic BPF bpf_jit_compile() - try to JIT from classic BPF sk_convert_filter() - convert classic to internal bpf_int_jit_compile() - JIT from internal BPF seccomp and tracing filters will just call bpf_int_jit_compile() Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 20:50:46 -06:00
break;
/* shifts */
case BPF_ALU | BPF_LSH | BPF_K:
case BPF_ALU | BPF_RSH | BPF_K:
case BPF_ALU | BPF_ARSH | BPF_K:
case BPF_ALU64 | BPF_LSH | BPF_K:
case BPF_ALU64 | BPF_RSH | BPF_K:
case BPF_ALU64 | BPF_ARSH | BPF_K:
if (BPF_CLASS(insn->code) == BPF_ALU64)
net: filter: cleanup A/X name usage The macro 'A' used in internal BPF interpreter: #define A regs[insn->a_reg] was easily confused with the name of classic BPF register 'A', since 'A' would mean two different things depending on context. This patch is trying to clean up the naming and clarify its usage in the following way: - A and X are names of two classic BPF registers - BPF_REG_A denotes internal BPF register R0 used to map classic register A in internal BPF programs generated from classic - BPF_REG_X denotes internal BPF register R7 used to map classic register X in internal BPF programs generated from classic - internal BPF instruction format: struct sock_filter_int { __u8 code; /* opcode */ __u8 dst_reg:4; /* dest register */ __u8 src_reg:4; /* source register */ __s16 off; /* signed offset */ __s32 imm; /* signed immediate constant */ }; - BPF_X/BPF_K is 1 bit used to encode source operand of instruction In classic: BPF_X - means use register X as source operand BPF_K - means use 32-bit immediate as source operand In internal: BPF_X - means use 'src_reg' register as source operand BPF_K - means use 32-bit immediate as source operand Suggested-by: Chema Gonzalez <chema@google.com> Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Acked-by: Daniel Borkmann <dborkman@redhat.com> Acked-by: Chema Gonzalez <chema@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-06-06 15:46:06 -06:00
EMIT1(add_1mod(0x48, dst_reg));
else if (is_ereg(dst_reg))
EMIT1(add_1mod(0x40, dst_reg));
net: filter: x86: internal BPF JIT Maps all internal BPF instructions into x86_64 instructions. This patch replaces original BPF x64 JIT with internal BPF x64 JIT. sysctl net.core.bpf_jit_enable is reused as on/off switch. Performance: 1. old BPF JIT and internal BPF JIT generate equivalent x86_64 code. No performance difference is observed for filters that were JIT-able before Example assembler code for BPF filter "tcpdump port 22" original BPF -> old JIT: original BPF -> internal BPF -> new JIT: 0: push %rbp 0: push %rbp 1: mov %rsp,%rbp 1: mov %rsp,%rbp 4: sub $0x60,%rsp 4: sub $0x228,%rsp 8: mov %rbx,-0x8(%rbp) b: mov %rbx,-0x228(%rbp) // prologue 12: mov %r13,-0x220(%rbp) 19: mov %r14,-0x218(%rbp) 20: mov %r15,-0x210(%rbp) 27: xor %eax,%eax // clear A c: xor %ebx,%ebx 29: xor %r13,%r13 // clear X e: mov 0x68(%rdi),%r9d 2c: mov 0x68(%rdi),%r9d 12: sub 0x6c(%rdi),%r9d 30: sub 0x6c(%rdi),%r9d 16: mov 0xd8(%rdi),%r8 34: mov 0xd8(%rdi),%r10 3b: mov %rdi,%rbx 1d: mov $0xc,%esi 3e: mov $0xc,%esi 22: callq 0xffffffffe1021e15 43: callq 0xffffffffe102bd75 27: cmp $0x86dd,%eax 48: cmp $0x86dd,%rax 2c: jne 0x0000000000000069 4f: jne 0x000000000000009a 2e: mov $0x14,%esi 51: mov $0x14,%esi 33: callq 0xffffffffe1021e31 56: callq 0xffffffffe102bd91 38: cmp $0x84,%eax 5b: cmp $0x84,%rax 3d: je 0x0000000000000049 62: je 0x0000000000000074 3f: cmp $0x6,%eax 64: cmp $0x6,%rax 42: je 0x0000000000000049 68: je 0x0000000000000074 44: cmp $0x11,%eax 6a: cmp $0x11,%rax 47: jne 0x00000000000000c6 6e: jne 0x0000000000000117 49: mov $0x36,%esi 74: mov $0x36,%esi 4e: callq 0xffffffffe1021e15 79: callq 0xffffffffe102bd75 53: cmp $0x16,%eax 7e: cmp $0x16,%rax 56: je 0x00000000000000bf 82: je 0x0000000000000110 58: mov $0x38,%esi 88: mov $0x38,%esi 5d: callq 0xffffffffe1021e15 8d: callq 0xffffffffe102bd75 62: cmp $0x16,%eax 92: cmp $0x16,%rax 65: je 0x00000000000000bf 96: je 0x0000000000000110 67: jmp 0x00000000000000c6 98: jmp 0x0000000000000117 69: cmp $0x800,%eax 9a: cmp $0x800,%rax 6e: jne 0x00000000000000c6 a1: jne 0x0000000000000117 70: mov $0x17,%esi a3: mov $0x17,%esi 75: callq 0xffffffffe1021e31 a8: callq 0xffffffffe102bd91 7a: cmp $0x84,%eax ad: cmp $0x84,%rax 7f: je 0x000000000000008b b4: je 0x00000000000000c2 81: cmp $0x6,%eax b6: cmp $0x6,%rax 84: je 0x000000000000008b ba: je 0x00000000000000c2 86: cmp $0x11,%eax bc: cmp $0x11,%rax 89: jne 0x00000000000000c6 c0: jne 0x0000000000000117 8b: mov $0x14,%esi c2: mov $0x14,%esi 90: callq 0xffffffffe1021e15 c7: callq 0xffffffffe102bd75 95: test $0x1fff,%ax cc: test $0x1fff,%rax 99: jne 0x00000000000000c6 d3: jne 0x0000000000000117 d5: mov %rax,%r14 9b: mov $0xe,%esi d8: mov $0xe,%esi a0: callq 0xffffffffe1021e44 dd: callq 0xffffffffe102bd91 // MSH e2: and $0xf,%eax e5: shl $0x2,%eax e8: mov %rax,%r13 eb: mov %r14,%rax ee: mov %r13,%rsi a5: lea 0xe(%rbx),%esi f1: add $0xe,%esi a8: callq 0xffffffffe1021e0d f4: callq 0xffffffffe102bd6d ad: cmp $0x16,%eax f9: cmp $0x16,%rax b0: je 0x00000000000000bf fd: je 0x0000000000000110 ff: mov %r13,%rsi b2: lea 0x10(%rbx),%esi 102: add $0x10,%esi b5: callq 0xffffffffe1021e0d 105: callq 0xffffffffe102bd6d ba: cmp $0x16,%eax 10a: cmp $0x16,%rax bd: jne 0x00000000000000c6 10e: jne 0x0000000000000117 bf: mov $0xffff,%eax 110: mov $0xffff,%eax c4: jmp 0x00000000000000c8 115: jmp 0x000000000000011c c6: xor %eax,%eax 117: mov $0x0,%eax c8: mov -0x8(%rbp),%rbx 11c: mov -0x228(%rbp),%rbx // epilogue cc: leaveq 123: mov -0x220(%rbp),%r13 cd: retq 12a: mov -0x218(%rbp),%r14 131: mov -0x210(%rbp),%r15 138: leaveq 139: retq On fully cached SKBs both JITed functions take 12 nsec to execute. BPF interpreter executes the program in 30 nsec. The difference in generated assembler is due to the following: Old BPF imlements LDX_MSH instruction via sk_load_byte_msh() helper function inside bpf_jit.S. New JIT removes the helper and does it explicitly, so ldx_msh cost is the same for both JITs, but generated code looks longer. New JIT has 4 registers to save, so prologue/epilogue are larger, but the cost is within noise on x64. Old JIT checks whether first insn clears A and if not emits 'xor %eax,%eax'. New JIT clears %rax unconditionally. 2. old BPF JIT doesn't support ANC_NLATTR, ANC_PAY_OFFSET, ANC_RANDOM extensions. New JIT supports all BPF extensions. Performance of such filters improves 2-4 times depending on a filter. The longer the filter the higher performance gain. Synthetic benchmarks with many ancillary loads see 20x speedup which seems to be the maximum gain from JIT Notes: . net.core.bpf_jit_enable=2 + tools/net/bpf_jit_disasm is still functional and can be used to see generated assembler . there are two jit_compile() functions and code flow for classic filters is: sk_attach_filter() - load classic BPF bpf_jit_compile() - try to JIT from classic BPF sk_convert_filter() - convert classic to internal bpf_int_jit_compile() - JIT from internal BPF seccomp and tracing filters will just call bpf_int_jit_compile() Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 20:50:46 -06:00
switch (BPF_OP(insn->code)) {
case BPF_LSH: b3 = 0xE0; break;
case BPF_RSH: b3 = 0xE8; break;
case BPF_ARSH: b3 = 0xF8; break;
}
net: filter: cleanup A/X name usage The macro 'A' used in internal BPF interpreter: #define A regs[insn->a_reg] was easily confused with the name of classic BPF register 'A', since 'A' would mean two different things depending on context. This patch is trying to clean up the naming and clarify its usage in the following way: - A and X are names of two classic BPF registers - BPF_REG_A denotes internal BPF register R0 used to map classic register A in internal BPF programs generated from classic - BPF_REG_X denotes internal BPF register R7 used to map classic register X in internal BPF programs generated from classic - internal BPF instruction format: struct sock_filter_int { __u8 code; /* opcode */ __u8 dst_reg:4; /* dest register */ __u8 src_reg:4; /* source register */ __s16 off; /* signed offset */ __s32 imm; /* signed immediate constant */ }; - BPF_X/BPF_K is 1 bit used to encode source operand of instruction In classic: BPF_X - means use register X as source operand BPF_K - means use 32-bit immediate as source operand In internal: BPF_X - means use 'src_reg' register as source operand BPF_K - means use 32-bit immediate as source operand Suggested-by: Chema Gonzalez <chema@google.com> Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Acked-by: Daniel Borkmann <dborkman@redhat.com> Acked-by: Chema Gonzalez <chema@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-06-06 15:46:06 -06:00
EMIT3(0xC1, add_1reg(b3, dst_reg), imm32);
net: filter: x86: internal BPF JIT Maps all internal BPF instructions into x86_64 instructions. This patch replaces original BPF x64 JIT with internal BPF x64 JIT. sysctl net.core.bpf_jit_enable is reused as on/off switch. Performance: 1. old BPF JIT and internal BPF JIT generate equivalent x86_64 code. No performance difference is observed for filters that were JIT-able before Example assembler code for BPF filter "tcpdump port 22" original BPF -> old JIT: original BPF -> internal BPF -> new JIT: 0: push %rbp 0: push %rbp 1: mov %rsp,%rbp 1: mov %rsp,%rbp 4: sub $0x60,%rsp 4: sub $0x228,%rsp 8: mov %rbx,-0x8(%rbp) b: mov %rbx,-0x228(%rbp) // prologue 12: mov %r13,-0x220(%rbp) 19: mov %r14,-0x218(%rbp) 20: mov %r15,-0x210(%rbp) 27: xor %eax,%eax // clear A c: xor %ebx,%ebx 29: xor %r13,%r13 // clear X e: mov 0x68(%rdi),%r9d 2c: mov 0x68(%rdi),%r9d 12: sub 0x6c(%rdi),%r9d 30: sub 0x6c(%rdi),%r9d 16: mov 0xd8(%rdi),%r8 34: mov 0xd8(%rdi),%r10 3b: mov %rdi,%rbx 1d: mov $0xc,%esi 3e: mov $0xc,%esi 22: callq 0xffffffffe1021e15 43: callq 0xffffffffe102bd75 27: cmp $0x86dd,%eax 48: cmp $0x86dd,%rax 2c: jne 0x0000000000000069 4f: jne 0x000000000000009a 2e: mov $0x14,%esi 51: mov $0x14,%esi 33: callq 0xffffffffe1021e31 56: callq 0xffffffffe102bd91 38: cmp $0x84,%eax 5b: cmp $0x84,%rax 3d: je 0x0000000000000049 62: je 0x0000000000000074 3f: cmp $0x6,%eax 64: cmp $0x6,%rax 42: je 0x0000000000000049 68: je 0x0000000000000074 44: cmp $0x11,%eax 6a: cmp $0x11,%rax 47: jne 0x00000000000000c6 6e: jne 0x0000000000000117 49: mov $0x36,%esi 74: mov $0x36,%esi 4e: callq 0xffffffffe1021e15 79: callq 0xffffffffe102bd75 53: cmp $0x16,%eax 7e: cmp $0x16,%rax 56: je 0x00000000000000bf 82: je 0x0000000000000110 58: mov $0x38,%esi 88: mov $0x38,%esi 5d: callq 0xffffffffe1021e15 8d: callq 0xffffffffe102bd75 62: cmp $0x16,%eax 92: cmp $0x16,%rax 65: je 0x00000000000000bf 96: je 0x0000000000000110 67: jmp 0x00000000000000c6 98: jmp 0x0000000000000117 69: cmp $0x800,%eax 9a: cmp $0x800,%rax 6e: jne 0x00000000000000c6 a1: jne 0x0000000000000117 70: mov $0x17,%esi a3: mov $0x17,%esi 75: callq 0xffffffffe1021e31 a8: callq 0xffffffffe102bd91 7a: cmp $0x84,%eax ad: cmp $0x84,%rax 7f: je 0x000000000000008b b4: je 0x00000000000000c2 81: cmp $0x6,%eax b6: cmp $0x6,%rax 84: je 0x000000000000008b ba: je 0x00000000000000c2 86: cmp $0x11,%eax bc: cmp $0x11,%rax 89: jne 0x00000000000000c6 c0: jne 0x0000000000000117 8b: mov $0x14,%esi c2: mov $0x14,%esi 90: callq 0xffffffffe1021e15 c7: callq 0xffffffffe102bd75 95: test $0x1fff,%ax cc: test $0x1fff,%rax 99: jne 0x00000000000000c6 d3: jne 0x0000000000000117 d5: mov %rax,%r14 9b: mov $0xe,%esi d8: mov $0xe,%esi a0: callq 0xffffffffe1021e44 dd: callq 0xffffffffe102bd91 // MSH e2: and $0xf,%eax e5: shl $0x2,%eax e8: mov %rax,%r13 eb: mov %r14,%rax ee: mov %r13,%rsi a5: lea 0xe(%rbx),%esi f1: add $0xe,%esi a8: callq 0xffffffffe1021e0d f4: callq 0xffffffffe102bd6d ad: cmp $0x16,%eax f9: cmp $0x16,%rax b0: je 0x00000000000000bf fd: je 0x0000000000000110 ff: mov %r13,%rsi b2: lea 0x10(%rbx),%esi 102: add $0x10,%esi b5: callq 0xffffffffe1021e0d 105: callq 0xffffffffe102bd6d ba: cmp $0x16,%eax 10a: cmp $0x16,%rax bd: jne 0x00000000000000c6 10e: jne 0x0000000000000117 bf: mov $0xffff,%eax 110: mov $0xffff,%eax c4: jmp 0x00000000000000c8 115: jmp 0x000000000000011c c6: xor %eax,%eax 117: mov $0x0,%eax c8: mov -0x8(%rbp),%rbx 11c: mov -0x228(%rbp),%rbx // epilogue cc: leaveq 123: mov -0x220(%rbp),%r13 cd: retq 12a: mov -0x218(%rbp),%r14 131: mov -0x210(%rbp),%r15 138: leaveq 139: retq On fully cached SKBs both JITed functions take 12 nsec to execute. BPF interpreter executes the program in 30 nsec. The difference in generated assembler is due to the following: Old BPF imlements LDX_MSH instruction via sk_load_byte_msh() helper function inside bpf_jit.S. New JIT removes the helper and does it explicitly, so ldx_msh cost is the same for both JITs, but generated code looks longer. New JIT has 4 registers to save, so prologue/epilogue are larger, but the cost is within noise on x64. Old JIT checks whether first insn clears A and if not emits 'xor %eax,%eax'. New JIT clears %rax unconditionally. 2. old BPF JIT doesn't support ANC_NLATTR, ANC_PAY_OFFSET, ANC_RANDOM extensions. New JIT supports all BPF extensions. Performance of such filters improves 2-4 times depending on a filter. The longer the filter the higher performance gain. Synthetic benchmarks with many ancillary loads see 20x speedup which seems to be the maximum gain from JIT Notes: . net.core.bpf_jit_enable=2 + tools/net/bpf_jit_disasm is still functional and can be used to see generated assembler . there are two jit_compile() functions and code flow for classic filters is: sk_attach_filter() - load classic BPF bpf_jit_compile() - try to JIT from classic BPF sk_convert_filter() - convert classic to internal bpf_int_jit_compile() - JIT from internal BPF seccomp and tracing filters will just call bpf_int_jit_compile() Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 20:50:46 -06:00
break;
bpf: x86: add missing 'shift by register' instructions to x64 eBPF JIT 'shift by register' operations are supported by eBPF interpreter, but were accidently left out of x64 JIT compiler. Fix it and add a testcase. Reported-by: Brendan Gregg <brendan.d.gregg@gmail.com> Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Fixes: 622582786c9e ("net: filter: x86: internal BPF JIT") Signed-off-by: David S. Miller <davem@davemloft.net>
2014-08-25 13:27:02 -06:00
case BPF_ALU | BPF_LSH | BPF_X:
case BPF_ALU | BPF_RSH | BPF_X:
case BPF_ALU | BPF_ARSH | BPF_X:
case BPF_ALU64 | BPF_LSH | BPF_X:
case BPF_ALU64 | BPF_RSH | BPF_X:
case BPF_ALU64 | BPF_ARSH | BPF_X:
/* check for bad case when dst_reg == rcx */
if (dst_reg == BPF_REG_4) {
/* mov r11, dst_reg */
EMIT_mov(AUX_REG, dst_reg);
dst_reg = AUX_REG;
}
if (src_reg != BPF_REG_4) { /* common case */
EMIT1(0x51); /* push rcx */
/* mov rcx, src_reg */
EMIT_mov(BPF_REG_4, src_reg);
}
/* shl %rax, %cl | shr %rax, %cl | sar %rax, %cl */
if (BPF_CLASS(insn->code) == BPF_ALU64)
EMIT1(add_1mod(0x48, dst_reg));
else if (is_ereg(dst_reg))
EMIT1(add_1mod(0x40, dst_reg));
switch (BPF_OP(insn->code)) {
case BPF_LSH: b3 = 0xE0; break;
case BPF_RSH: b3 = 0xE8; break;
case BPF_ARSH: b3 = 0xF8; break;
}
EMIT2(0xD3, add_1reg(b3, dst_reg));
if (src_reg != BPF_REG_4)
EMIT1(0x59); /* pop rcx */
if (insn->dst_reg == BPF_REG_4)
/* mov dst_reg, r11 */
EMIT_mov(insn->dst_reg, AUX_REG);
break;
net: filter: x86: internal BPF JIT Maps all internal BPF instructions into x86_64 instructions. This patch replaces original BPF x64 JIT with internal BPF x64 JIT. sysctl net.core.bpf_jit_enable is reused as on/off switch. Performance: 1. old BPF JIT and internal BPF JIT generate equivalent x86_64 code. No performance difference is observed for filters that were JIT-able before Example assembler code for BPF filter "tcpdump port 22" original BPF -> old JIT: original BPF -> internal BPF -> new JIT: 0: push %rbp 0: push %rbp 1: mov %rsp,%rbp 1: mov %rsp,%rbp 4: sub $0x60,%rsp 4: sub $0x228,%rsp 8: mov %rbx,-0x8(%rbp) b: mov %rbx,-0x228(%rbp) // prologue 12: mov %r13,-0x220(%rbp) 19: mov %r14,-0x218(%rbp) 20: mov %r15,-0x210(%rbp) 27: xor %eax,%eax // clear A c: xor %ebx,%ebx 29: xor %r13,%r13 // clear X e: mov 0x68(%rdi),%r9d 2c: mov 0x68(%rdi),%r9d 12: sub 0x6c(%rdi),%r9d 30: sub 0x6c(%rdi),%r9d 16: mov 0xd8(%rdi),%r8 34: mov 0xd8(%rdi),%r10 3b: mov %rdi,%rbx 1d: mov $0xc,%esi 3e: mov $0xc,%esi 22: callq 0xffffffffe1021e15 43: callq 0xffffffffe102bd75 27: cmp $0x86dd,%eax 48: cmp $0x86dd,%rax 2c: jne 0x0000000000000069 4f: jne 0x000000000000009a 2e: mov $0x14,%esi 51: mov $0x14,%esi 33: callq 0xffffffffe1021e31 56: callq 0xffffffffe102bd91 38: cmp $0x84,%eax 5b: cmp $0x84,%rax 3d: je 0x0000000000000049 62: je 0x0000000000000074 3f: cmp $0x6,%eax 64: cmp $0x6,%rax 42: je 0x0000000000000049 68: je 0x0000000000000074 44: cmp $0x11,%eax 6a: cmp $0x11,%rax 47: jne 0x00000000000000c6 6e: jne 0x0000000000000117 49: mov $0x36,%esi 74: mov $0x36,%esi 4e: callq 0xffffffffe1021e15 79: callq 0xffffffffe102bd75 53: cmp $0x16,%eax 7e: cmp $0x16,%rax 56: je 0x00000000000000bf 82: je 0x0000000000000110 58: mov $0x38,%esi 88: mov $0x38,%esi 5d: callq 0xffffffffe1021e15 8d: callq 0xffffffffe102bd75 62: cmp $0x16,%eax 92: cmp $0x16,%rax 65: je 0x00000000000000bf 96: je 0x0000000000000110 67: jmp 0x00000000000000c6 98: jmp 0x0000000000000117 69: cmp $0x800,%eax 9a: cmp $0x800,%rax 6e: jne 0x00000000000000c6 a1: jne 0x0000000000000117 70: mov $0x17,%esi a3: mov $0x17,%esi 75: callq 0xffffffffe1021e31 a8: callq 0xffffffffe102bd91 7a: cmp $0x84,%eax ad: cmp $0x84,%rax 7f: je 0x000000000000008b b4: je 0x00000000000000c2 81: cmp $0x6,%eax b6: cmp $0x6,%rax 84: je 0x000000000000008b ba: je 0x00000000000000c2 86: cmp $0x11,%eax bc: cmp $0x11,%rax 89: jne 0x00000000000000c6 c0: jne 0x0000000000000117 8b: mov $0x14,%esi c2: mov $0x14,%esi 90: callq 0xffffffffe1021e15 c7: callq 0xffffffffe102bd75 95: test $0x1fff,%ax cc: test $0x1fff,%rax 99: jne 0x00000000000000c6 d3: jne 0x0000000000000117 d5: mov %rax,%r14 9b: mov $0xe,%esi d8: mov $0xe,%esi a0: callq 0xffffffffe1021e44 dd: callq 0xffffffffe102bd91 // MSH e2: and $0xf,%eax e5: shl $0x2,%eax e8: mov %rax,%r13 eb: mov %r14,%rax ee: mov %r13,%rsi a5: lea 0xe(%rbx),%esi f1: add $0xe,%esi a8: callq 0xffffffffe1021e0d f4: callq 0xffffffffe102bd6d ad: cmp $0x16,%eax f9: cmp $0x16,%rax b0: je 0x00000000000000bf fd: je 0x0000000000000110 ff: mov %r13,%rsi b2: lea 0x10(%rbx),%esi 102: add $0x10,%esi b5: callq 0xffffffffe1021e0d 105: callq 0xffffffffe102bd6d ba: cmp $0x16,%eax 10a: cmp $0x16,%rax bd: jne 0x00000000000000c6 10e: jne 0x0000000000000117 bf: mov $0xffff,%eax 110: mov $0xffff,%eax c4: jmp 0x00000000000000c8 115: jmp 0x000000000000011c c6: xor %eax,%eax 117: mov $0x0,%eax c8: mov -0x8(%rbp),%rbx 11c: mov -0x228(%rbp),%rbx // epilogue cc: leaveq 123: mov -0x220(%rbp),%r13 cd: retq 12a: mov -0x218(%rbp),%r14 131: mov -0x210(%rbp),%r15 138: leaveq 139: retq On fully cached SKBs both JITed functions take 12 nsec to execute. BPF interpreter executes the program in 30 nsec. The difference in generated assembler is due to the following: Old BPF imlements LDX_MSH instruction via sk_load_byte_msh() helper function inside bpf_jit.S. New JIT removes the helper and does it explicitly, so ldx_msh cost is the same for both JITs, but generated code looks longer. New JIT has 4 registers to save, so prologue/epilogue are larger, but the cost is within noise on x64. Old JIT checks whether first insn clears A and if not emits 'xor %eax,%eax'. New JIT clears %rax unconditionally. 2. old BPF JIT doesn't support ANC_NLATTR, ANC_PAY_OFFSET, ANC_RANDOM extensions. New JIT supports all BPF extensions. Performance of such filters improves 2-4 times depending on a filter. The longer the filter the higher performance gain. Synthetic benchmarks with many ancillary loads see 20x speedup which seems to be the maximum gain from JIT Notes: . net.core.bpf_jit_enable=2 + tools/net/bpf_jit_disasm is still functional and can be used to see generated assembler . there are two jit_compile() functions and code flow for classic filters is: sk_attach_filter() - load classic BPF bpf_jit_compile() - try to JIT from classic BPF sk_convert_filter() - convert classic to internal bpf_int_jit_compile() - JIT from internal BPF seccomp and tracing filters will just call bpf_int_jit_compile() Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 20:50:46 -06:00
case BPF_ALU | BPF_END | BPF_FROM_BE:
net: filter: cleanup A/X name usage The macro 'A' used in internal BPF interpreter: #define A regs[insn->a_reg] was easily confused with the name of classic BPF register 'A', since 'A' would mean two different things depending on context. This patch is trying to clean up the naming and clarify its usage in the following way: - A and X are names of two classic BPF registers - BPF_REG_A denotes internal BPF register R0 used to map classic register A in internal BPF programs generated from classic - BPF_REG_X denotes internal BPF register R7 used to map classic register X in internal BPF programs generated from classic - internal BPF instruction format: struct sock_filter_int { __u8 code; /* opcode */ __u8 dst_reg:4; /* dest register */ __u8 src_reg:4; /* source register */ __s16 off; /* signed offset */ __s32 imm; /* signed immediate constant */ }; - BPF_X/BPF_K is 1 bit used to encode source operand of instruction In classic: BPF_X - means use register X as source operand BPF_K - means use 32-bit immediate as source operand In internal: BPF_X - means use 'src_reg' register as source operand BPF_K - means use 32-bit immediate as source operand Suggested-by: Chema Gonzalez <chema@google.com> Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Acked-by: Daniel Borkmann <dborkman@redhat.com> Acked-by: Chema Gonzalez <chema@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-06-06 15:46:06 -06:00
switch (imm32) {
net: filter: x86: internal BPF JIT Maps all internal BPF instructions into x86_64 instructions. This patch replaces original BPF x64 JIT with internal BPF x64 JIT. sysctl net.core.bpf_jit_enable is reused as on/off switch. Performance: 1. old BPF JIT and internal BPF JIT generate equivalent x86_64 code. No performance difference is observed for filters that were JIT-able before Example assembler code for BPF filter "tcpdump port 22" original BPF -> old JIT: original BPF -> internal BPF -> new JIT: 0: push %rbp 0: push %rbp 1: mov %rsp,%rbp 1: mov %rsp,%rbp 4: sub $0x60,%rsp 4: sub $0x228,%rsp 8: mov %rbx,-0x8(%rbp) b: mov %rbx,-0x228(%rbp) // prologue 12: mov %r13,-0x220(%rbp) 19: mov %r14,-0x218(%rbp) 20: mov %r15,-0x210(%rbp) 27: xor %eax,%eax // clear A c: xor %ebx,%ebx 29: xor %r13,%r13 // clear X e: mov 0x68(%rdi),%r9d 2c: mov 0x68(%rdi),%r9d 12: sub 0x6c(%rdi),%r9d 30: sub 0x6c(%rdi),%r9d 16: mov 0xd8(%rdi),%r8 34: mov 0xd8(%rdi),%r10 3b: mov %rdi,%rbx 1d: mov $0xc,%esi 3e: mov $0xc,%esi 22: callq 0xffffffffe1021e15 43: callq 0xffffffffe102bd75 27: cmp $0x86dd,%eax 48: cmp $0x86dd,%rax 2c: jne 0x0000000000000069 4f: jne 0x000000000000009a 2e: mov $0x14,%esi 51: mov $0x14,%esi 33: callq 0xffffffffe1021e31 56: callq 0xffffffffe102bd91 38: cmp $0x84,%eax 5b: cmp $0x84,%rax 3d: je 0x0000000000000049 62: je 0x0000000000000074 3f: cmp $0x6,%eax 64: cmp $0x6,%rax 42: je 0x0000000000000049 68: je 0x0000000000000074 44: cmp $0x11,%eax 6a: cmp $0x11,%rax 47: jne 0x00000000000000c6 6e: jne 0x0000000000000117 49: mov $0x36,%esi 74: mov $0x36,%esi 4e: callq 0xffffffffe1021e15 79: callq 0xffffffffe102bd75 53: cmp $0x16,%eax 7e: cmp $0x16,%rax 56: je 0x00000000000000bf 82: je 0x0000000000000110 58: mov $0x38,%esi 88: mov $0x38,%esi 5d: callq 0xffffffffe1021e15 8d: callq 0xffffffffe102bd75 62: cmp $0x16,%eax 92: cmp $0x16,%rax 65: je 0x00000000000000bf 96: je 0x0000000000000110 67: jmp 0x00000000000000c6 98: jmp 0x0000000000000117 69: cmp $0x800,%eax 9a: cmp $0x800,%rax 6e: jne 0x00000000000000c6 a1: jne 0x0000000000000117 70: mov $0x17,%esi a3: mov $0x17,%esi 75: callq 0xffffffffe1021e31 a8: callq 0xffffffffe102bd91 7a: cmp $0x84,%eax ad: cmp $0x84,%rax 7f: je 0x000000000000008b b4: je 0x00000000000000c2 81: cmp $0x6,%eax b6: cmp $0x6,%rax 84: je 0x000000000000008b ba: je 0x00000000000000c2 86: cmp $0x11,%eax bc: cmp $0x11,%rax 89: jne 0x00000000000000c6 c0: jne 0x0000000000000117 8b: mov $0x14,%esi c2: mov $0x14,%esi 90: callq 0xffffffffe1021e15 c7: callq 0xffffffffe102bd75 95: test $0x1fff,%ax cc: test $0x1fff,%rax 99: jne 0x00000000000000c6 d3: jne 0x0000000000000117 d5: mov %rax,%r14 9b: mov $0xe,%esi d8: mov $0xe,%esi a0: callq 0xffffffffe1021e44 dd: callq 0xffffffffe102bd91 // MSH e2: and $0xf,%eax e5: shl $0x2,%eax e8: mov %rax,%r13 eb: mov %r14,%rax ee: mov %r13,%rsi a5: lea 0xe(%rbx),%esi f1: add $0xe,%esi a8: callq 0xffffffffe1021e0d f4: callq 0xffffffffe102bd6d ad: cmp $0x16,%eax f9: cmp $0x16,%rax b0: je 0x00000000000000bf fd: je 0x0000000000000110 ff: mov %r13,%rsi b2: lea 0x10(%rbx),%esi 102: add $0x10,%esi b5: callq 0xffffffffe1021e0d 105: callq 0xffffffffe102bd6d ba: cmp $0x16,%eax 10a: cmp $0x16,%rax bd: jne 0x00000000000000c6 10e: jne 0x0000000000000117 bf: mov $0xffff,%eax 110: mov $0xffff,%eax c4: jmp 0x00000000000000c8 115: jmp 0x000000000000011c c6: xor %eax,%eax 117: mov $0x0,%eax c8: mov -0x8(%rbp),%rbx 11c: mov -0x228(%rbp),%rbx // epilogue cc: leaveq 123: mov -0x220(%rbp),%r13 cd: retq 12a: mov -0x218(%rbp),%r14 131: mov -0x210(%rbp),%r15 138: leaveq 139: retq On fully cached SKBs both JITed functions take 12 nsec to execute. BPF interpreter executes the program in 30 nsec. The difference in generated assembler is due to the following: Old BPF imlements LDX_MSH instruction via sk_load_byte_msh() helper function inside bpf_jit.S. New JIT removes the helper and does it explicitly, so ldx_msh cost is the same for both JITs, but generated code looks longer. New JIT has 4 registers to save, so prologue/epilogue are larger, but the cost is within noise on x64. Old JIT checks whether first insn clears A and if not emits 'xor %eax,%eax'. New JIT clears %rax unconditionally. 2. old BPF JIT doesn't support ANC_NLATTR, ANC_PAY_OFFSET, ANC_RANDOM extensions. New JIT supports all BPF extensions. Performance of such filters improves 2-4 times depending on a filter. The longer the filter the higher performance gain. Synthetic benchmarks with many ancillary loads see 20x speedup which seems to be the maximum gain from JIT Notes: . net.core.bpf_jit_enable=2 + tools/net/bpf_jit_disasm is still functional and can be used to see generated assembler . there are two jit_compile() functions and code flow for classic filters is: sk_attach_filter() - load classic BPF bpf_jit_compile() - try to JIT from classic BPF sk_convert_filter() - convert classic to internal bpf_int_jit_compile() - JIT from internal BPF seccomp and tracing filters will just call bpf_int_jit_compile() Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 20:50:46 -06:00
case 16:
/* emit 'ror %ax, 8' to swap lower 2 bytes */
EMIT1(0x66);
net: filter: cleanup A/X name usage The macro 'A' used in internal BPF interpreter: #define A regs[insn->a_reg] was easily confused with the name of classic BPF register 'A', since 'A' would mean two different things depending on context. This patch is trying to clean up the naming and clarify its usage in the following way: - A and X are names of two classic BPF registers - BPF_REG_A denotes internal BPF register R0 used to map classic register A in internal BPF programs generated from classic - BPF_REG_X denotes internal BPF register R7 used to map classic register X in internal BPF programs generated from classic - internal BPF instruction format: struct sock_filter_int { __u8 code; /* opcode */ __u8 dst_reg:4; /* dest register */ __u8 src_reg:4; /* source register */ __s16 off; /* signed offset */ __s32 imm; /* signed immediate constant */ }; - BPF_X/BPF_K is 1 bit used to encode source operand of instruction In classic: BPF_X - means use register X as source operand BPF_K - means use 32-bit immediate as source operand In internal: BPF_X - means use 'src_reg' register as source operand BPF_K - means use 32-bit immediate as source operand Suggested-by: Chema Gonzalez <chema@google.com> Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Acked-by: Daniel Borkmann <dborkman@redhat.com> Acked-by: Chema Gonzalez <chema@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-06-06 15:46:06 -06:00
if (is_ereg(dst_reg))
net: filter: x86: internal BPF JIT Maps all internal BPF instructions into x86_64 instructions. This patch replaces original BPF x64 JIT with internal BPF x64 JIT. sysctl net.core.bpf_jit_enable is reused as on/off switch. Performance: 1. old BPF JIT and internal BPF JIT generate equivalent x86_64 code. No performance difference is observed for filters that were JIT-able before Example assembler code for BPF filter "tcpdump port 22" original BPF -> old JIT: original BPF -> internal BPF -> new JIT: 0: push %rbp 0: push %rbp 1: mov %rsp,%rbp 1: mov %rsp,%rbp 4: sub $0x60,%rsp 4: sub $0x228,%rsp 8: mov %rbx,-0x8(%rbp) b: mov %rbx,-0x228(%rbp) // prologue 12: mov %r13,-0x220(%rbp) 19: mov %r14,-0x218(%rbp) 20: mov %r15,-0x210(%rbp) 27: xor %eax,%eax // clear A c: xor %ebx,%ebx 29: xor %r13,%r13 // clear X e: mov 0x68(%rdi),%r9d 2c: mov 0x68(%rdi),%r9d 12: sub 0x6c(%rdi),%r9d 30: sub 0x6c(%rdi),%r9d 16: mov 0xd8(%rdi),%r8 34: mov 0xd8(%rdi),%r10 3b: mov %rdi,%rbx 1d: mov $0xc,%esi 3e: mov $0xc,%esi 22: callq 0xffffffffe1021e15 43: callq 0xffffffffe102bd75 27: cmp $0x86dd,%eax 48: cmp $0x86dd,%rax 2c: jne 0x0000000000000069 4f: jne 0x000000000000009a 2e: mov $0x14,%esi 51: mov $0x14,%esi 33: callq 0xffffffffe1021e31 56: callq 0xffffffffe102bd91 38: cmp $0x84,%eax 5b: cmp $0x84,%rax 3d: je 0x0000000000000049 62: je 0x0000000000000074 3f: cmp $0x6,%eax 64: cmp $0x6,%rax 42: je 0x0000000000000049 68: je 0x0000000000000074 44: cmp $0x11,%eax 6a: cmp $0x11,%rax 47: jne 0x00000000000000c6 6e: jne 0x0000000000000117 49: mov $0x36,%esi 74: mov $0x36,%esi 4e: callq 0xffffffffe1021e15 79: callq 0xffffffffe102bd75 53: cmp $0x16,%eax 7e: cmp $0x16,%rax 56: je 0x00000000000000bf 82: je 0x0000000000000110 58: mov $0x38,%esi 88: mov $0x38,%esi 5d: callq 0xffffffffe1021e15 8d: callq 0xffffffffe102bd75 62: cmp $0x16,%eax 92: cmp $0x16,%rax 65: je 0x00000000000000bf 96: je 0x0000000000000110 67: jmp 0x00000000000000c6 98: jmp 0x0000000000000117 69: cmp $0x800,%eax 9a: cmp $0x800,%rax 6e: jne 0x00000000000000c6 a1: jne 0x0000000000000117 70: mov $0x17,%esi a3: mov $0x17,%esi 75: callq 0xffffffffe1021e31 a8: callq 0xffffffffe102bd91 7a: cmp $0x84,%eax ad: cmp $0x84,%rax 7f: je 0x000000000000008b b4: je 0x00000000000000c2 81: cmp $0x6,%eax b6: cmp $0x6,%rax 84: je 0x000000000000008b ba: je 0x00000000000000c2 86: cmp $0x11,%eax bc: cmp $0x11,%rax 89: jne 0x00000000000000c6 c0: jne 0x0000000000000117 8b: mov $0x14,%esi c2: mov $0x14,%esi 90: callq 0xffffffffe1021e15 c7: callq 0xffffffffe102bd75 95: test $0x1fff,%ax cc: test $0x1fff,%rax 99: jne 0x00000000000000c6 d3: jne 0x0000000000000117 d5: mov %rax,%r14 9b: mov $0xe,%esi d8: mov $0xe,%esi a0: callq 0xffffffffe1021e44 dd: callq 0xffffffffe102bd91 // MSH e2: and $0xf,%eax e5: shl $0x2,%eax e8: mov %rax,%r13 eb: mov %r14,%rax ee: mov %r13,%rsi a5: lea 0xe(%rbx),%esi f1: add $0xe,%esi a8: callq 0xffffffffe1021e0d f4: callq 0xffffffffe102bd6d ad: cmp $0x16,%eax f9: cmp $0x16,%rax b0: je 0x00000000000000bf fd: je 0x0000000000000110 ff: mov %r13,%rsi b2: lea 0x10(%rbx),%esi 102: add $0x10,%esi b5: callq 0xffffffffe1021e0d 105: callq 0xffffffffe102bd6d ba: cmp $0x16,%eax 10a: cmp $0x16,%rax bd: jne 0x00000000000000c6 10e: jne 0x0000000000000117 bf: mov $0xffff,%eax 110: mov $0xffff,%eax c4: jmp 0x00000000000000c8 115: jmp 0x000000000000011c c6: xor %eax,%eax 117: mov $0x0,%eax c8: mov -0x8(%rbp),%rbx 11c: mov -0x228(%rbp),%rbx // epilogue cc: leaveq 123: mov -0x220(%rbp),%r13 cd: retq 12a: mov -0x218(%rbp),%r14 131: mov -0x210(%rbp),%r15 138: leaveq 139: retq On fully cached SKBs both JITed functions take 12 nsec to execute. BPF interpreter executes the program in 30 nsec. The difference in generated assembler is due to the following: Old BPF imlements LDX_MSH instruction via sk_load_byte_msh() helper function inside bpf_jit.S. New JIT removes the helper and does it explicitly, so ldx_msh cost is the same for both JITs, but generated code looks longer. New JIT has 4 registers to save, so prologue/epilogue are larger, but the cost is within noise on x64. Old JIT checks whether first insn clears A and if not emits 'xor %eax,%eax'. New JIT clears %rax unconditionally. 2. old BPF JIT doesn't support ANC_NLATTR, ANC_PAY_OFFSET, ANC_RANDOM extensions. New JIT supports all BPF extensions. Performance of such filters improves 2-4 times depending on a filter. The longer the filter the higher performance gain. Synthetic benchmarks with many ancillary loads see 20x speedup which seems to be the maximum gain from JIT Notes: . net.core.bpf_jit_enable=2 + tools/net/bpf_jit_disasm is still functional and can be used to see generated assembler . there are two jit_compile() functions and code flow for classic filters is: sk_attach_filter() - load classic BPF bpf_jit_compile() - try to JIT from classic BPF sk_convert_filter() - convert classic to internal bpf_int_jit_compile() - JIT from internal BPF seccomp and tracing filters will just call bpf_int_jit_compile() Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 20:50:46 -06:00
EMIT1(0x41);
net: filter: cleanup A/X name usage The macro 'A' used in internal BPF interpreter: #define A regs[insn->a_reg] was easily confused with the name of classic BPF register 'A', since 'A' would mean two different things depending on context. This patch is trying to clean up the naming and clarify its usage in the following way: - A and X are names of two classic BPF registers - BPF_REG_A denotes internal BPF register R0 used to map classic register A in internal BPF programs generated from classic - BPF_REG_X denotes internal BPF register R7 used to map classic register X in internal BPF programs generated from classic - internal BPF instruction format: struct sock_filter_int { __u8 code; /* opcode */ __u8 dst_reg:4; /* dest register */ __u8 src_reg:4; /* source register */ __s16 off; /* signed offset */ __s32 imm; /* signed immediate constant */ }; - BPF_X/BPF_K is 1 bit used to encode source operand of instruction In classic: BPF_X - means use register X as source operand BPF_K - means use 32-bit immediate as source operand In internal: BPF_X - means use 'src_reg' register as source operand BPF_K - means use 32-bit immediate as source operand Suggested-by: Chema Gonzalez <chema@google.com> Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Acked-by: Daniel Borkmann <dborkman@redhat.com> Acked-by: Chema Gonzalez <chema@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-06-06 15:46:06 -06:00
EMIT3(0xC1, add_1reg(0xC8, dst_reg), 8);
x86: bpf_jit: fix FROM_BE16 and FROM_LE16/32 instructions FROM_BE16: 'ror %reg, 8' doesn't clear upper bits of the register, so use additional 'movzwl' insn to zero extend 16 bits into 64 FROM_LE16: should zero extend lower 16 bits into 64 bit FROM_LE32: should zero extend lower 32 bits into 64 bit Fixes: 89aa075832b0 ("net: sock: allow eBPF programs to be attached to sockets") Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-12 00:25:16 -06:00
/* emit 'movzwl eax, ax' */
if (is_ereg(dst_reg))
EMIT3(0x45, 0x0F, 0xB7);
else
EMIT2(0x0F, 0xB7);
EMIT1(add_2reg(0xC0, dst_reg, dst_reg));
net: filter: x86: internal BPF JIT Maps all internal BPF instructions into x86_64 instructions. This patch replaces original BPF x64 JIT with internal BPF x64 JIT. sysctl net.core.bpf_jit_enable is reused as on/off switch. Performance: 1. old BPF JIT and internal BPF JIT generate equivalent x86_64 code. No performance difference is observed for filters that were JIT-able before Example assembler code for BPF filter "tcpdump port 22" original BPF -> old JIT: original BPF -> internal BPF -> new JIT: 0: push %rbp 0: push %rbp 1: mov %rsp,%rbp 1: mov %rsp,%rbp 4: sub $0x60,%rsp 4: sub $0x228,%rsp 8: mov %rbx,-0x8(%rbp) b: mov %rbx,-0x228(%rbp) // prologue 12: mov %r13,-0x220(%rbp) 19: mov %r14,-0x218(%rbp) 20: mov %r15,-0x210(%rbp) 27: xor %eax,%eax // clear A c: xor %ebx,%ebx 29: xor %r13,%r13 // clear X e: mov 0x68(%rdi),%r9d 2c: mov 0x68(%rdi),%r9d 12: sub 0x6c(%rdi),%r9d 30: sub 0x6c(%rdi),%r9d 16: mov 0xd8(%rdi),%r8 34: mov 0xd8(%rdi),%r10 3b: mov %rdi,%rbx 1d: mov $0xc,%esi 3e: mov $0xc,%esi 22: callq 0xffffffffe1021e15 43: callq 0xffffffffe102bd75 27: cmp $0x86dd,%eax 48: cmp $0x86dd,%rax 2c: jne 0x0000000000000069 4f: jne 0x000000000000009a 2e: mov $0x14,%esi 51: mov $0x14,%esi 33: callq 0xffffffffe1021e31 56: callq 0xffffffffe102bd91 38: cmp $0x84,%eax 5b: cmp $0x84,%rax 3d: je 0x0000000000000049 62: je 0x0000000000000074 3f: cmp $0x6,%eax 64: cmp $0x6,%rax 42: je 0x0000000000000049 68: je 0x0000000000000074 44: cmp $0x11,%eax 6a: cmp $0x11,%rax 47: jne 0x00000000000000c6 6e: jne 0x0000000000000117 49: mov $0x36,%esi 74: mov $0x36,%esi 4e: callq 0xffffffffe1021e15 79: callq 0xffffffffe102bd75 53: cmp $0x16,%eax 7e: cmp $0x16,%rax 56: je 0x00000000000000bf 82: je 0x0000000000000110 58: mov $0x38,%esi 88: mov $0x38,%esi 5d: callq 0xffffffffe1021e15 8d: callq 0xffffffffe102bd75 62: cmp $0x16,%eax 92: cmp $0x16,%rax 65: je 0x00000000000000bf 96: je 0x0000000000000110 67: jmp 0x00000000000000c6 98: jmp 0x0000000000000117 69: cmp $0x800,%eax 9a: cmp $0x800,%rax 6e: jne 0x00000000000000c6 a1: jne 0x0000000000000117 70: mov $0x17,%esi a3: mov $0x17,%esi 75: callq 0xffffffffe1021e31 a8: callq 0xffffffffe102bd91 7a: cmp $0x84,%eax ad: cmp $0x84,%rax 7f: je 0x000000000000008b b4: je 0x00000000000000c2 81: cmp $0x6,%eax b6: cmp $0x6,%rax 84: je 0x000000000000008b ba: je 0x00000000000000c2 86: cmp $0x11,%eax bc: cmp $0x11,%rax 89: jne 0x00000000000000c6 c0: jne 0x0000000000000117 8b: mov $0x14,%esi c2: mov $0x14,%esi 90: callq 0xffffffffe1021e15 c7: callq 0xffffffffe102bd75 95: test $0x1fff,%ax cc: test $0x1fff,%rax 99: jne 0x00000000000000c6 d3: jne 0x0000000000000117 d5: mov %rax,%r14 9b: mov $0xe,%esi d8: mov $0xe,%esi a0: callq 0xffffffffe1021e44 dd: callq 0xffffffffe102bd91 // MSH e2: and $0xf,%eax e5: shl $0x2,%eax e8: mov %rax,%r13 eb: mov %r14,%rax ee: mov %r13,%rsi a5: lea 0xe(%rbx),%esi f1: add $0xe,%esi a8: callq 0xffffffffe1021e0d f4: callq 0xffffffffe102bd6d ad: cmp $0x16,%eax f9: cmp $0x16,%rax b0: je 0x00000000000000bf fd: je 0x0000000000000110 ff: mov %r13,%rsi b2: lea 0x10(%rbx),%esi 102: add $0x10,%esi b5: callq 0xffffffffe1021e0d 105: callq 0xffffffffe102bd6d ba: cmp $0x16,%eax 10a: cmp $0x16,%rax bd: jne 0x00000000000000c6 10e: jne 0x0000000000000117 bf: mov $0xffff,%eax 110: mov $0xffff,%eax c4: jmp 0x00000000000000c8 115: jmp 0x000000000000011c c6: xor %eax,%eax 117: mov $0x0,%eax c8: mov -0x8(%rbp),%rbx 11c: mov -0x228(%rbp),%rbx // epilogue cc: leaveq 123: mov -0x220(%rbp),%r13 cd: retq 12a: mov -0x218(%rbp),%r14 131: mov -0x210(%rbp),%r15 138: leaveq 139: retq On fully cached SKBs both JITed functions take 12 nsec to execute. BPF interpreter executes the program in 30 nsec. The difference in generated assembler is due to the following: Old BPF imlements LDX_MSH instruction via sk_load_byte_msh() helper function inside bpf_jit.S. New JIT removes the helper and does it explicitly, so ldx_msh cost is the same for both JITs, but generated code looks longer. New JIT has 4 registers to save, so prologue/epilogue are larger, but the cost is within noise on x64. Old JIT checks whether first insn clears A and if not emits 'xor %eax,%eax'. New JIT clears %rax unconditionally. 2. old BPF JIT doesn't support ANC_NLATTR, ANC_PAY_OFFSET, ANC_RANDOM extensions. New JIT supports all BPF extensions. Performance of such filters improves 2-4 times depending on a filter. The longer the filter the higher performance gain. Synthetic benchmarks with many ancillary loads see 20x speedup which seems to be the maximum gain from JIT Notes: . net.core.bpf_jit_enable=2 + tools/net/bpf_jit_disasm is still functional and can be used to see generated assembler . there are two jit_compile() functions and code flow for classic filters is: sk_attach_filter() - load classic BPF bpf_jit_compile() - try to JIT from classic BPF sk_convert_filter() - convert classic to internal bpf_int_jit_compile() - JIT from internal BPF seccomp and tracing filters will just call bpf_int_jit_compile() Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 20:50:46 -06:00
break;
case 32:
/* emit 'bswap eax' to swap lower 4 bytes */
net: filter: cleanup A/X name usage The macro 'A' used in internal BPF interpreter: #define A regs[insn->a_reg] was easily confused with the name of classic BPF register 'A', since 'A' would mean two different things depending on context. This patch is trying to clean up the naming and clarify its usage in the following way: - A and X are names of two classic BPF registers - BPF_REG_A denotes internal BPF register R0 used to map classic register A in internal BPF programs generated from classic - BPF_REG_X denotes internal BPF register R7 used to map classic register X in internal BPF programs generated from classic - internal BPF instruction format: struct sock_filter_int { __u8 code; /* opcode */ __u8 dst_reg:4; /* dest register */ __u8 src_reg:4; /* source register */ __s16 off; /* signed offset */ __s32 imm; /* signed immediate constant */ }; - BPF_X/BPF_K is 1 bit used to encode source operand of instruction In classic: BPF_X - means use register X as source operand BPF_K - means use 32-bit immediate as source operand In internal: BPF_X - means use 'src_reg' register as source operand BPF_K - means use 32-bit immediate as source operand Suggested-by: Chema Gonzalez <chema@google.com> Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Acked-by: Daniel Borkmann <dborkman@redhat.com> Acked-by: Chema Gonzalez <chema@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-06-06 15:46:06 -06:00
if (is_ereg(dst_reg))
net: filter: x86: internal BPF JIT Maps all internal BPF instructions into x86_64 instructions. This patch replaces original BPF x64 JIT with internal BPF x64 JIT. sysctl net.core.bpf_jit_enable is reused as on/off switch. Performance: 1. old BPF JIT and internal BPF JIT generate equivalent x86_64 code. No performance difference is observed for filters that were JIT-able before Example assembler code for BPF filter "tcpdump port 22" original BPF -> old JIT: original BPF -> internal BPF -> new JIT: 0: push %rbp 0: push %rbp 1: mov %rsp,%rbp 1: mov %rsp,%rbp 4: sub $0x60,%rsp 4: sub $0x228,%rsp 8: mov %rbx,-0x8(%rbp) b: mov %rbx,-0x228(%rbp) // prologue 12: mov %r13,-0x220(%rbp) 19: mov %r14,-0x218(%rbp) 20: mov %r15,-0x210(%rbp) 27: xor %eax,%eax // clear A c: xor %ebx,%ebx 29: xor %r13,%r13 // clear X e: mov 0x68(%rdi),%r9d 2c: mov 0x68(%rdi),%r9d 12: sub 0x6c(%rdi),%r9d 30: sub 0x6c(%rdi),%r9d 16: mov 0xd8(%rdi),%r8 34: mov 0xd8(%rdi),%r10 3b: mov %rdi,%rbx 1d: mov $0xc,%esi 3e: mov $0xc,%esi 22: callq 0xffffffffe1021e15 43: callq 0xffffffffe102bd75 27: cmp $0x86dd,%eax 48: cmp $0x86dd,%rax 2c: jne 0x0000000000000069 4f: jne 0x000000000000009a 2e: mov $0x14,%esi 51: mov $0x14,%esi 33: callq 0xffffffffe1021e31 56: callq 0xffffffffe102bd91 38: cmp $0x84,%eax 5b: cmp $0x84,%rax 3d: je 0x0000000000000049 62: je 0x0000000000000074 3f: cmp $0x6,%eax 64: cmp $0x6,%rax 42: je 0x0000000000000049 68: je 0x0000000000000074 44: cmp $0x11,%eax 6a: cmp $0x11,%rax 47: jne 0x00000000000000c6 6e: jne 0x0000000000000117 49: mov $0x36,%esi 74: mov $0x36,%esi 4e: callq 0xffffffffe1021e15 79: callq 0xffffffffe102bd75 53: cmp $0x16,%eax 7e: cmp $0x16,%rax 56: je 0x00000000000000bf 82: je 0x0000000000000110 58: mov $0x38,%esi 88: mov $0x38,%esi 5d: callq 0xffffffffe1021e15 8d: callq 0xffffffffe102bd75 62: cmp $0x16,%eax 92: cmp $0x16,%rax 65: je 0x00000000000000bf 96: je 0x0000000000000110 67: jmp 0x00000000000000c6 98: jmp 0x0000000000000117 69: cmp $0x800,%eax 9a: cmp $0x800,%rax 6e: jne 0x00000000000000c6 a1: jne 0x0000000000000117 70: mov $0x17,%esi a3: mov $0x17,%esi 75: callq 0xffffffffe1021e31 a8: callq 0xffffffffe102bd91 7a: cmp $0x84,%eax ad: cmp $0x84,%rax 7f: je 0x000000000000008b b4: je 0x00000000000000c2 81: cmp $0x6,%eax b6: cmp $0x6,%rax 84: je 0x000000000000008b ba: je 0x00000000000000c2 86: cmp $0x11,%eax bc: cmp $0x11,%rax 89: jne 0x00000000000000c6 c0: jne 0x0000000000000117 8b: mov $0x14,%esi c2: mov $0x14,%esi 90: callq 0xffffffffe1021e15 c7: callq 0xffffffffe102bd75 95: test $0x1fff,%ax cc: test $0x1fff,%rax 99: jne 0x00000000000000c6 d3: jne 0x0000000000000117 d5: mov %rax,%r14 9b: mov $0xe,%esi d8: mov $0xe,%esi a0: callq 0xffffffffe1021e44 dd: callq 0xffffffffe102bd91 // MSH e2: and $0xf,%eax e5: shl $0x2,%eax e8: mov %rax,%r13 eb: mov %r14,%rax ee: mov %r13,%rsi a5: lea 0xe(%rbx),%esi f1: add $0xe,%esi a8: callq 0xffffffffe1021e0d f4: callq 0xffffffffe102bd6d ad: cmp $0x16,%eax f9: cmp $0x16,%rax b0: je 0x00000000000000bf fd: je 0x0000000000000110 ff: mov %r13,%rsi b2: lea 0x10(%rbx),%esi 102: add $0x10,%esi b5: callq 0xffffffffe1021e0d 105: callq 0xffffffffe102bd6d ba: cmp $0x16,%eax 10a: cmp $0x16,%rax bd: jne 0x00000000000000c6 10e: jne 0x0000000000000117 bf: mov $0xffff,%eax 110: mov $0xffff,%eax c4: jmp 0x00000000000000c8 115: jmp 0x000000000000011c c6: xor %eax,%eax 117: mov $0x0,%eax c8: mov -0x8(%rbp),%rbx 11c: mov -0x228(%rbp),%rbx // epilogue cc: leaveq 123: mov -0x220(%rbp),%r13 cd: retq 12a: mov -0x218(%rbp),%r14 131: mov -0x210(%rbp),%r15 138: leaveq 139: retq On fully cached SKBs both JITed functions take 12 nsec to execute. BPF interpreter executes the program in 30 nsec. The difference in generated assembler is due to the following: Old BPF imlements LDX_MSH instruction via sk_load_byte_msh() helper function inside bpf_jit.S. New JIT removes the helper and does it explicitly, so ldx_msh cost is the same for both JITs, but generated code looks longer. New JIT has 4 registers to save, so prologue/epilogue are larger, but the cost is within noise on x64. Old JIT checks whether first insn clears A and if not emits 'xor %eax,%eax'. New JIT clears %rax unconditionally. 2. old BPF JIT doesn't support ANC_NLATTR, ANC_PAY_OFFSET, ANC_RANDOM extensions. New JIT supports all BPF extensions. Performance of such filters improves 2-4 times depending on a filter. The longer the filter the higher performance gain. Synthetic benchmarks with many ancillary loads see 20x speedup which seems to be the maximum gain from JIT Notes: . net.core.bpf_jit_enable=2 + tools/net/bpf_jit_disasm is still functional and can be used to see generated assembler . there are two jit_compile() functions and code flow for classic filters is: sk_attach_filter() - load classic BPF bpf_jit_compile() - try to JIT from classic BPF sk_convert_filter() - convert classic to internal bpf_int_jit_compile() - JIT from internal BPF seccomp and tracing filters will just call bpf_int_jit_compile() Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 20:50:46 -06:00
EMIT2(0x41, 0x0F);
net: filter: Just In Time compiler for x86-64 In order to speedup packet filtering, here is an implementation of a JIT compiler for x86_64 It is disabled by default, and must be enabled by the admin. echo 1 >/proc/sys/net/core/bpf_jit_enable It uses module_alloc() and module_free() to get memory in the 2GB text kernel range since we call helpers functions from the generated code. EAX : BPF A accumulator EBX : BPF X accumulator RDI : pointer to skb (first argument given to JIT function) RBP : frame pointer (even if CONFIG_FRAME_POINTER=n) r9d : skb->len - skb->data_len (headlen) r8 : skb->data To get a trace of generated code, use : echo 2 >/proc/sys/net/core/bpf_jit_enable Example of generated code : # tcpdump -p -n -s 0 -i eth1 host 192.168.20.0/24 flen=18 proglen=147 pass=3 image=ffffffffa00b5000 JIT code: ffffffffa00b5000: 55 48 89 e5 48 83 ec 60 48 89 5d f8 44 8b 4f 60 JIT code: ffffffffa00b5010: 44 2b 4f 64 4c 8b 87 b8 00 00 00 be 0c 00 00 00 JIT code: ffffffffa00b5020: e8 24 7b f7 e0 3d 00 08 00 00 75 28 be 1a 00 00 JIT code: ffffffffa00b5030: 00 e8 fe 7a f7 e0 24 00 3d 00 14 a8 c0 74 49 be JIT code: ffffffffa00b5040: 1e 00 00 00 e8 eb 7a f7 e0 24 00 3d 00 14 a8 c0 JIT code: ffffffffa00b5050: 74 36 eb 3b 3d 06 08 00 00 74 07 3d 35 80 00 00 JIT code: ffffffffa00b5060: 75 2d be 1c 00 00 00 e8 c8 7a f7 e0 24 00 3d 00 JIT code: ffffffffa00b5070: 14 a8 c0 74 13 be 26 00 00 00 e8 b5 7a f7 e0 24 JIT code: ffffffffa00b5080: 00 3d 00 14 a8 c0 75 07 b8 ff ff 00 00 eb 02 31 JIT code: ffffffffa00b5090: c0 c9 c3 BPF program is 144 bytes long, so native program is almost same size ;) (000) ldh [12] (001) jeq #0x800 jt 2 jf 8 (002) ld [26] (003) and #0xffffff00 (004) jeq #0xc0a81400 jt 16 jf 5 (005) ld [30] (006) and #0xffffff00 (007) jeq #0xc0a81400 jt 16 jf 17 (008) jeq #0x806 jt 10 jf 9 (009) jeq #0x8035 jt 10 jf 17 (010) ld [28] (011) and #0xffffff00 (012) jeq #0xc0a81400 jt 16 jf 13 (013) ld [38] (014) and #0xffffff00 (015) jeq #0xc0a81400 jt 16 jf 17 (016) ret #65535 (017) ret #0 Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Cc: Arnaldo Carvalho de Melo <acme@infradead.org> Cc: Ben Hutchings <bhutchings@solarflare.com> Cc: Hagen Paul Pfeifer <hagen@jauu.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-04-20 03:27:32 -06:00
else
net: filter: x86: internal BPF JIT Maps all internal BPF instructions into x86_64 instructions. This patch replaces original BPF x64 JIT with internal BPF x64 JIT. sysctl net.core.bpf_jit_enable is reused as on/off switch. Performance: 1. old BPF JIT and internal BPF JIT generate equivalent x86_64 code. No performance difference is observed for filters that were JIT-able before Example assembler code for BPF filter "tcpdump port 22" original BPF -> old JIT: original BPF -> internal BPF -> new JIT: 0: push %rbp 0: push %rbp 1: mov %rsp,%rbp 1: mov %rsp,%rbp 4: sub $0x60,%rsp 4: sub $0x228,%rsp 8: mov %rbx,-0x8(%rbp) b: mov %rbx,-0x228(%rbp) // prologue 12: mov %r13,-0x220(%rbp) 19: mov %r14,-0x218(%rbp) 20: mov %r15,-0x210(%rbp) 27: xor %eax,%eax // clear A c: xor %ebx,%ebx 29: xor %r13,%r13 // clear X e: mov 0x68(%rdi),%r9d 2c: mov 0x68(%rdi),%r9d 12: sub 0x6c(%rdi),%r9d 30: sub 0x6c(%rdi),%r9d 16: mov 0xd8(%rdi),%r8 34: mov 0xd8(%rdi),%r10 3b: mov %rdi,%rbx 1d: mov $0xc,%esi 3e: mov $0xc,%esi 22: callq 0xffffffffe1021e15 43: callq 0xffffffffe102bd75 27: cmp $0x86dd,%eax 48: cmp $0x86dd,%rax 2c: jne 0x0000000000000069 4f: jne 0x000000000000009a 2e: mov $0x14,%esi 51: mov $0x14,%esi 33: callq 0xffffffffe1021e31 56: callq 0xffffffffe102bd91 38: cmp $0x84,%eax 5b: cmp $0x84,%rax 3d: je 0x0000000000000049 62: je 0x0000000000000074 3f: cmp $0x6,%eax 64: cmp $0x6,%rax 42: je 0x0000000000000049 68: je 0x0000000000000074 44: cmp $0x11,%eax 6a: cmp $0x11,%rax 47: jne 0x00000000000000c6 6e: jne 0x0000000000000117 49: mov $0x36,%esi 74: mov $0x36,%esi 4e: callq 0xffffffffe1021e15 79: callq 0xffffffffe102bd75 53: cmp $0x16,%eax 7e: cmp $0x16,%rax 56: je 0x00000000000000bf 82: je 0x0000000000000110 58: mov $0x38,%esi 88: mov $0x38,%esi 5d: callq 0xffffffffe1021e15 8d: callq 0xffffffffe102bd75 62: cmp $0x16,%eax 92: cmp $0x16,%rax 65: je 0x00000000000000bf 96: je 0x0000000000000110 67: jmp 0x00000000000000c6 98: jmp 0x0000000000000117 69: cmp $0x800,%eax 9a: cmp $0x800,%rax 6e: jne 0x00000000000000c6 a1: jne 0x0000000000000117 70: mov $0x17,%esi a3: mov $0x17,%esi 75: callq 0xffffffffe1021e31 a8: callq 0xffffffffe102bd91 7a: cmp $0x84,%eax ad: cmp $0x84,%rax 7f: je 0x000000000000008b b4: je 0x00000000000000c2 81: cmp $0x6,%eax b6: cmp $0x6,%rax 84: je 0x000000000000008b ba: je 0x00000000000000c2 86: cmp $0x11,%eax bc: cmp $0x11,%rax 89: jne 0x00000000000000c6 c0: jne 0x0000000000000117 8b: mov $0x14,%esi c2: mov $0x14,%esi 90: callq 0xffffffffe1021e15 c7: callq 0xffffffffe102bd75 95: test $0x1fff,%ax cc: test $0x1fff,%rax 99: jne 0x00000000000000c6 d3: jne 0x0000000000000117 d5: mov %rax,%r14 9b: mov $0xe,%esi d8: mov $0xe,%esi a0: callq 0xffffffffe1021e44 dd: callq 0xffffffffe102bd91 // MSH e2: and $0xf,%eax e5: shl $0x2,%eax e8: mov %rax,%r13 eb: mov %r14,%rax ee: mov %r13,%rsi a5: lea 0xe(%rbx),%esi f1: add $0xe,%esi a8: callq 0xffffffffe1021e0d f4: callq 0xffffffffe102bd6d ad: cmp $0x16,%eax f9: cmp $0x16,%rax b0: je 0x00000000000000bf fd: je 0x0000000000000110 ff: mov %r13,%rsi b2: lea 0x10(%rbx),%esi 102: add $0x10,%esi b5: callq 0xffffffffe1021e0d 105: callq 0xffffffffe102bd6d ba: cmp $0x16,%eax 10a: cmp $0x16,%rax bd: jne 0x00000000000000c6 10e: jne 0x0000000000000117 bf: mov $0xffff,%eax 110: mov $0xffff,%eax c4: jmp 0x00000000000000c8 115: jmp 0x000000000000011c c6: xor %eax,%eax 117: mov $0x0,%eax c8: mov -0x8(%rbp),%rbx 11c: mov -0x228(%rbp),%rbx // epilogue cc: leaveq 123: mov -0x220(%rbp),%r13 cd: retq 12a: mov -0x218(%rbp),%r14 131: mov -0x210(%rbp),%r15 138: leaveq 139: retq On fully cached SKBs both JITed functions take 12 nsec to execute. BPF interpreter executes the program in 30 nsec. The difference in generated assembler is due to the following: Old BPF imlements LDX_MSH instruction via sk_load_byte_msh() helper function inside bpf_jit.S. New JIT removes the helper and does it explicitly, so ldx_msh cost is the same for both JITs, but generated code looks longer. New JIT has 4 registers to save, so prologue/epilogue are larger, but the cost is within noise on x64. Old JIT checks whether first insn clears A and if not emits 'xor %eax,%eax'. New JIT clears %rax unconditionally. 2. old BPF JIT doesn't support ANC_NLATTR, ANC_PAY_OFFSET, ANC_RANDOM extensions. New JIT supports all BPF extensions. Performance of such filters improves 2-4 times depending on a filter. The longer the filter the higher performance gain. Synthetic benchmarks with many ancillary loads see 20x speedup which seems to be the maximum gain from JIT Notes: . net.core.bpf_jit_enable=2 + tools/net/bpf_jit_disasm is still functional and can be used to see generated assembler . there are two jit_compile() functions and code flow for classic filters is: sk_attach_filter() - load classic BPF bpf_jit_compile() - try to JIT from classic BPF sk_convert_filter() - convert classic to internal bpf_int_jit_compile() - JIT from internal BPF seccomp and tracing filters will just call bpf_int_jit_compile() Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 20:50:46 -06:00
EMIT1(0x0F);
net: filter: cleanup A/X name usage The macro 'A' used in internal BPF interpreter: #define A regs[insn->a_reg] was easily confused with the name of classic BPF register 'A', since 'A' would mean two different things depending on context. This patch is trying to clean up the naming and clarify its usage in the following way: - A and X are names of two classic BPF registers - BPF_REG_A denotes internal BPF register R0 used to map classic register A in internal BPF programs generated from classic - BPF_REG_X denotes internal BPF register R7 used to map classic register X in internal BPF programs generated from classic - internal BPF instruction format: struct sock_filter_int { __u8 code; /* opcode */ __u8 dst_reg:4; /* dest register */ __u8 src_reg:4; /* source register */ __s16 off; /* signed offset */ __s32 imm; /* signed immediate constant */ }; - BPF_X/BPF_K is 1 bit used to encode source operand of instruction In classic: BPF_X - means use register X as source operand BPF_K - means use 32-bit immediate as source operand In internal: BPF_X - means use 'src_reg' register as source operand BPF_K - means use 32-bit immediate as source operand Suggested-by: Chema Gonzalez <chema@google.com> Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Acked-by: Daniel Borkmann <dborkman@redhat.com> Acked-by: Chema Gonzalez <chema@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-06-06 15:46:06 -06:00
EMIT1(add_1reg(0xC8, dst_reg));
net: filter: Just In Time compiler for x86-64 In order to speedup packet filtering, here is an implementation of a JIT compiler for x86_64 It is disabled by default, and must be enabled by the admin. echo 1 >/proc/sys/net/core/bpf_jit_enable It uses module_alloc() and module_free() to get memory in the 2GB text kernel range since we call helpers functions from the generated code. EAX : BPF A accumulator EBX : BPF X accumulator RDI : pointer to skb (first argument given to JIT function) RBP : frame pointer (even if CONFIG_FRAME_POINTER=n) r9d : skb->len - skb->data_len (headlen) r8 : skb->data To get a trace of generated code, use : echo 2 >/proc/sys/net/core/bpf_jit_enable Example of generated code : # tcpdump -p -n -s 0 -i eth1 host 192.168.20.0/24 flen=18 proglen=147 pass=3 image=ffffffffa00b5000 JIT code: ffffffffa00b5000: 55 48 89 e5 48 83 ec 60 48 89 5d f8 44 8b 4f 60 JIT code: ffffffffa00b5010: 44 2b 4f 64 4c 8b 87 b8 00 00 00 be 0c 00 00 00 JIT code: ffffffffa00b5020: e8 24 7b f7 e0 3d 00 08 00 00 75 28 be 1a 00 00 JIT code: ffffffffa00b5030: 00 e8 fe 7a f7 e0 24 00 3d 00 14 a8 c0 74 49 be JIT code: ffffffffa00b5040: 1e 00 00 00 e8 eb 7a f7 e0 24 00 3d 00 14 a8 c0 JIT code: ffffffffa00b5050: 74 36 eb 3b 3d 06 08 00 00 74 07 3d 35 80 00 00 JIT code: ffffffffa00b5060: 75 2d be 1c 00 00 00 e8 c8 7a f7 e0 24 00 3d 00 JIT code: ffffffffa00b5070: 14 a8 c0 74 13 be 26 00 00 00 e8 b5 7a f7 e0 24 JIT code: ffffffffa00b5080: 00 3d 00 14 a8 c0 75 07 b8 ff ff 00 00 eb 02 31 JIT code: ffffffffa00b5090: c0 c9 c3 BPF program is 144 bytes long, so native program is almost same size ;) (000) ldh [12] (001) jeq #0x800 jt 2 jf 8 (002) ld [26] (003) and #0xffffff00 (004) jeq #0xc0a81400 jt 16 jf 5 (005) ld [30] (006) and #0xffffff00 (007) jeq #0xc0a81400 jt 16 jf 17 (008) jeq #0x806 jt 10 jf 9 (009) jeq #0x8035 jt 10 jf 17 (010) ld [28] (011) and #0xffffff00 (012) jeq #0xc0a81400 jt 16 jf 13 (013) ld [38] (014) and #0xffffff00 (015) jeq #0xc0a81400 jt 16 jf 17 (016) ret #65535 (017) ret #0 Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Cc: Arnaldo Carvalho de Melo <acme@infradead.org> Cc: Ben Hutchings <bhutchings@solarflare.com> Cc: Hagen Paul Pfeifer <hagen@jauu.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-04-20 03:27:32 -06:00
break;
net: filter: x86: internal BPF JIT Maps all internal BPF instructions into x86_64 instructions. This patch replaces original BPF x64 JIT with internal BPF x64 JIT. sysctl net.core.bpf_jit_enable is reused as on/off switch. Performance: 1. old BPF JIT and internal BPF JIT generate equivalent x86_64 code. No performance difference is observed for filters that were JIT-able before Example assembler code for BPF filter "tcpdump port 22" original BPF -> old JIT: original BPF -> internal BPF -> new JIT: 0: push %rbp 0: push %rbp 1: mov %rsp,%rbp 1: mov %rsp,%rbp 4: sub $0x60,%rsp 4: sub $0x228,%rsp 8: mov %rbx,-0x8(%rbp) b: mov %rbx,-0x228(%rbp) // prologue 12: mov %r13,-0x220(%rbp) 19: mov %r14,-0x218(%rbp) 20: mov %r15,-0x210(%rbp) 27: xor %eax,%eax // clear A c: xor %ebx,%ebx 29: xor %r13,%r13 // clear X e: mov 0x68(%rdi),%r9d 2c: mov 0x68(%rdi),%r9d 12: sub 0x6c(%rdi),%r9d 30: sub 0x6c(%rdi),%r9d 16: mov 0xd8(%rdi),%r8 34: mov 0xd8(%rdi),%r10 3b: mov %rdi,%rbx 1d: mov $0xc,%esi 3e: mov $0xc,%esi 22: callq 0xffffffffe1021e15 43: callq 0xffffffffe102bd75 27: cmp $0x86dd,%eax 48: cmp $0x86dd,%rax 2c: jne 0x0000000000000069 4f: jne 0x000000000000009a 2e: mov $0x14,%esi 51: mov $0x14,%esi 33: callq 0xffffffffe1021e31 56: callq 0xffffffffe102bd91 38: cmp $0x84,%eax 5b: cmp $0x84,%rax 3d: je 0x0000000000000049 62: je 0x0000000000000074 3f: cmp $0x6,%eax 64: cmp $0x6,%rax 42: je 0x0000000000000049 68: je 0x0000000000000074 44: cmp $0x11,%eax 6a: cmp $0x11,%rax 47: jne 0x00000000000000c6 6e: jne 0x0000000000000117 49: mov $0x36,%esi 74: mov $0x36,%esi 4e: callq 0xffffffffe1021e15 79: callq 0xffffffffe102bd75 53: cmp $0x16,%eax 7e: cmp $0x16,%rax 56: je 0x00000000000000bf 82: je 0x0000000000000110 58: mov $0x38,%esi 88: mov $0x38,%esi 5d: callq 0xffffffffe1021e15 8d: callq 0xffffffffe102bd75 62: cmp $0x16,%eax 92: cmp $0x16,%rax 65: je 0x00000000000000bf 96: je 0x0000000000000110 67: jmp 0x00000000000000c6 98: jmp 0x0000000000000117 69: cmp $0x800,%eax 9a: cmp $0x800,%rax 6e: jne 0x00000000000000c6 a1: jne 0x0000000000000117 70: mov $0x17,%esi a3: mov $0x17,%esi 75: callq 0xffffffffe1021e31 a8: callq 0xffffffffe102bd91 7a: cmp $0x84,%eax ad: cmp $0x84,%rax 7f: je 0x000000000000008b b4: je 0x00000000000000c2 81: cmp $0x6,%eax b6: cmp $0x6,%rax 84: je 0x000000000000008b ba: je 0x00000000000000c2 86: cmp $0x11,%eax bc: cmp $0x11,%rax 89: jne 0x00000000000000c6 c0: jne 0x0000000000000117 8b: mov $0x14,%esi c2: mov $0x14,%esi 90: callq 0xffffffffe1021e15 c7: callq 0xffffffffe102bd75 95: test $0x1fff,%ax cc: test $0x1fff,%rax 99: jne 0x00000000000000c6 d3: jne 0x0000000000000117 d5: mov %rax,%r14 9b: mov $0xe,%esi d8: mov $0xe,%esi a0: callq 0xffffffffe1021e44 dd: callq 0xffffffffe102bd91 // MSH e2: and $0xf,%eax e5: shl $0x2,%eax e8: mov %rax,%r13 eb: mov %r14,%rax ee: mov %r13,%rsi a5: lea 0xe(%rbx),%esi f1: add $0xe,%esi a8: callq 0xffffffffe1021e0d f4: callq 0xffffffffe102bd6d ad: cmp $0x16,%eax f9: cmp $0x16,%rax b0: je 0x00000000000000bf fd: je 0x0000000000000110 ff: mov %r13,%rsi b2: lea 0x10(%rbx),%esi 102: add $0x10,%esi b5: callq 0xffffffffe1021e0d 105: callq 0xffffffffe102bd6d ba: cmp $0x16,%eax 10a: cmp $0x16,%rax bd: jne 0x00000000000000c6 10e: jne 0x0000000000000117 bf: mov $0xffff,%eax 110: mov $0xffff,%eax c4: jmp 0x00000000000000c8 115: jmp 0x000000000000011c c6: xor %eax,%eax 117: mov $0x0,%eax c8: mov -0x8(%rbp),%rbx 11c: mov -0x228(%rbp),%rbx // epilogue cc: leaveq 123: mov -0x220(%rbp),%r13 cd: retq 12a: mov -0x218(%rbp),%r14 131: mov -0x210(%rbp),%r15 138: leaveq 139: retq On fully cached SKBs both JITed functions take 12 nsec to execute. BPF interpreter executes the program in 30 nsec. The difference in generated assembler is due to the following: Old BPF imlements LDX_MSH instruction via sk_load_byte_msh() helper function inside bpf_jit.S. New JIT removes the helper and does it explicitly, so ldx_msh cost is the same for both JITs, but generated code looks longer. New JIT has 4 registers to save, so prologue/epilogue are larger, but the cost is within noise on x64. Old JIT checks whether first insn clears A and if not emits 'xor %eax,%eax'. New JIT clears %rax unconditionally. 2. old BPF JIT doesn't support ANC_NLATTR, ANC_PAY_OFFSET, ANC_RANDOM extensions. New JIT supports all BPF extensions. Performance of such filters improves 2-4 times depending on a filter. The longer the filter the higher performance gain. Synthetic benchmarks with many ancillary loads see 20x speedup which seems to be the maximum gain from JIT Notes: . net.core.bpf_jit_enable=2 + tools/net/bpf_jit_disasm is still functional and can be used to see generated assembler . there are two jit_compile() functions and code flow for classic filters is: sk_attach_filter() - load classic BPF bpf_jit_compile() - try to JIT from classic BPF sk_convert_filter() - convert classic to internal bpf_int_jit_compile() - JIT from internal BPF seccomp and tracing filters will just call bpf_int_jit_compile() Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 20:50:46 -06:00
case 64:
/* emit 'bswap rax' to swap 8 bytes */
net: filter: cleanup A/X name usage The macro 'A' used in internal BPF interpreter: #define A regs[insn->a_reg] was easily confused with the name of classic BPF register 'A', since 'A' would mean two different things depending on context. This patch is trying to clean up the naming and clarify its usage in the following way: - A and X are names of two classic BPF registers - BPF_REG_A denotes internal BPF register R0 used to map classic register A in internal BPF programs generated from classic - BPF_REG_X denotes internal BPF register R7 used to map classic register X in internal BPF programs generated from classic - internal BPF instruction format: struct sock_filter_int { __u8 code; /* opcode */ __u8 dst_reg:4; /* dest register */ __u8 src_reg:4; /* source register */ __s16 off; /* signed offset */ __s32 imm; /* signed immediate constant */ }; - BPF_X/BPF_K is 1 bit used to encode source operand of instruction In classic: BPF_X - means use register X as source operand BPF_K - means use 32-bit immediate as source operand In internal: BPF_X - means use 'src_reg' register as source operand BPF_K - means use 32-bit immediate as source operand Suggested-by: Chema Gonzalez <chema@google.com> Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Acked-by: Daniel Borkmann <dborkman@redhat.com> Acked-by: Chema Gonzalez <chema@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-06-06 15:46:06 -06:00
EMIT3(add_1mod(0x48, dst_reg), 0x0F,
add_1reg(0xC8, dst_reg));
x86: bpf_jit_comp: add pkt_type support Supporting access to skb->pkt_type is a bit tricky if we want to have a generic code, allowing pkt_type to be moved in struct sk_buff pkt_type is a bit field, so compiler cannot really help us to find its offset. Let's use a helper for this : It will throw a one time message if pkt_type no longer starts at a byte boundary or is no longer a 3bit field. Reported-by: Willem de Bruijn <willemb@google.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Maciej Żenczykowski <maze@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-01-30 18:51:44 -07:00
break;
}
net: filter: x86: internal BPF JIT Maps all internal BPF instructions into x86_64 instructions. This patch replaces original BPF x64 JIT with internal BPF x64 JIT. sysctl net.core.bpf_jit_enable is reused as on/off switch. Performance: 1. old BPF JIT and internal BPF JIT generate equivalent x86_64 code. No performance difference is observed for filters that were JIT-able before Example assembler code for BPF filter "tcpdump port 22" original BPF -> old JIT: original BPF -> internal BPF -> new JIT: 0: push %rbp 0: push %rbp 1: mov %rsp,%rbp 1: mov %rsp,%rbp 4: sub $0x60,%rsp 4: sub $0x228,%rsp 8: mov %rbx,-0x8(%rbp) b: mov %rbx,-0x228(%rbp) // prologue 12: mov %r13,-0x220(%rbp) 19: mov %r14,-0x218(%rbp) 20: mov %r15,-0x210(%rbp) 27: xor %eax,%eax // clear A c: xor %ebx,%ebx 29: xor %r13,%r13 // clear X e: mov 0x68(%rdi),%r9d 2c: mov 0x68(%rdi),%r9d 12: sub 0x6c(%rdi),%r9d 30: sub 0x6c(%rdi),%r9d 16: mov 0xd8(%rdi),%r8 34: mov 0xd8(%rdi),%r10 3b: mov %rdi,%rbx 1d: mov $0xc,%esi 3e: mov $0xc,%esi 22: callq 0xffffffffe1021e15 43: callq 0xffffffffe102bd75 27: cmp $0x86dd,%eax 48: cmp $0x86dd,%rax 2c: jne 0x0000000000000069 4f: jne 0x000000000000009a 2e: mov $0x14,%esi 51: mov $0x14,%esi 33: callq 0xffffffffe1021e31 56: callq 0xffffffffe102bd91 38: cmp $0x84,%eax 5b: cmp $0x84,%rax 3d: je 0x0000000000000049 62: je 0x0000000000000074 3f: cmp $0x6,%eax 64: cmp $0x6,%rax 42: je 0x0000000000000049 68: je 0x0000000000000074 44: cmp $0x11,%eax 6a: cmp $0x11,%rax 47: jne 0x00000000000000c6 6e: jne 0x0000000000000117 49: mov $0x36,%esi 74: mov $0x36,%esi 4e: callq 0xffffffffe1021e15 79: callq 0xffffffffe102bd75 53: cmp $0x16,%eax 7e: cmp $0x16,%rax 56: je 0x00000000000000bf 82: je 0x0000000000000110 58: mov $0x38,%esi 88: mov $0x38,%esi 5d: callq 0xffffffffe1021e15 8d: callq 0xffffffffe102bd75 62: cmp $0x16,%eax 92: cmp $0x16,%rax 65: je 0x00000000000000bf 96: je 0x0000000000000110 67: jmp 0x00000000000000c6 98: jmp 0x0000000000000117 69: cmp $0x800,%eax 9a: cmp $0x800,%rax 6e: jne 0x00000000000000c6 a1: jne 0x0000000000000117 70: mov $0x17,%esi a3: mov $0x17,%esi 75: callq 0xffffffffe1021e31 a8: callq 0xffffffffe102bd91 7a: cmp $0x84,%eax ad: cmp $0x84,%rax 7f: je 0x000000000000008b b4: je 0x00000000000000c2 81: cmp $0x6,%eax b6: cmp $0x6,%rax 84: je 0x000000000000008b ba: je 0x00000000000000c2 86: cmp $0x11,%eax bc: cmp $0x11,%rax 89: jne 0x00000000000000c6 c0: jne 0x0000000000000117 8b: mov $0x14,%esi c2: mov $0x14,%esi 90: callq 0xffffffffe1021e15 c7: callq 0xffffffffe102bd75 95: test $0x1fff,%ax cc: test $0x1fff,%rax 99: jne 0x00000000000000c6 d3: jne 0x0000000000000117 d5: mov %rax,%r14 9b: mov $0xe,%esi d8: mov $0xe,%esi a0: callq 0xffffffffe1021e44 dd: callq 0xffffffffe102bd91 // MSH e2: and $0xf,%eax e5: shl $0x2,%eax e8: mov %rax,%r13 eb: mov %r14,%rax ee: mov %r13,%rsi a5: lea 0xe(%rbx),%esi f1: add $0xe,%esi a8: callq 0xffffffffe1021e0d f4: callq 0xffffffffe102bd6d ad: cmp $0x16,%eax f9: cmp $0x16,%rax b0: je 0x00000000000000bf fd: je 0x0000000000000110 ff: mov %r13,%rsi b2: lea 0x10(%rbx),%esi 102: add $0x10,%esi b5: callq 0xffffffffe1021e0d 105: callq 0xffffffffe102bd6d ba: cmp $0x16,%eax 10a: cmp $0x16,%rax bd: jne 0x00000000000000c6 10e: jne 0x0000000000000117 bf: mov $0xffff,%eax 110: mov $0xffff,%eax c4: jmp 0x00000000000000c8 115: jmp 0x000000000000011c c6: xor %eax,%eax 117: mov $0x0,%eax c8: mov -0x8(%rbp),%rbx 11c: mov -0x228(%rbp),%rbx // epilogue cc: leaveq 123: mov -0x220(%rbp),%r13 cd: retq 12a: mov -0x218(%rbp),%r14 131: mov -0x210(%rbp),%r15 138: leaveq 139: retq On fully cached SKBs both JITed functions take 12 nsec to execute. BPF interpreter executes the program in 30 nsec. The difference in generated assembler is due to the following: Old BPF imlements LDX_MSH instruction via sk_load_byte_msh() helper function inside bpf_jit.S. New JIT removes the helper and does it explicitly, so ldx_msh cost is the same for both JITs, but generated code looks longer. New JIT has 4 registers to save, so prologue/epilogue are larger, but the cost is within noise on x64. Old JIT checks whether first insn clears A and if not emits 'xor %eax,%eax'. New JIT clears %rax unconditionally. 2. old BPF JIT doesn't support ANC_NLATTR, ANC_PAY_OFFSET, ANC_RANDOM extensions. New JIT supports all BPF extensions. Performance of such filters improves 2-4 times depending on a filter. The longer the filter the higher performance gain. Synthetic benchmarks with many ancillary loads see 20x speedup which seems to be the maximum gain from JIT Notes: . net.core.bpf_jit_enable=2 + tools/net/bpf_jit_disasm is still functional and can be used to see generated assembler . there are two jit_compile() functions and code flow for classic filters is: sk_attach_filter() - load classic BPF bpf_jit_compile() - try to JIT from classic BPF sk_convert_filter() - convert classic to internal bpf_int_jit_compile() - JIT from internal BPF seccomp and tracing filters will just call bpf_int_jit_compile() Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 20:50:46 -06:00
break;
case BPF_ALU | BPF_END | BPF_FROM_LE:
x86: bpf_jit: fix FROM_BE16 and FROM_LE16/32 instructions FROM_BE16: 'ror %reg, 8' doesn't clear upper bits of the register, so use additional 'movzwl' insn to zero extend 16 bits into 64 FROM_LE16: should zero extend lower 16 bits into 64 bit FROM_LE32: should zero extend lower 32 bits into 64 bit Fixes: 89aa075832b0 ("net: sock: allow eBPF programs to be attached to sockets") Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-12 00:25:16 -06:00
switch (imm32) {
case 16:
/* emit 'movzwl eax, ax' to zero extend 16-bit
* into 64 bit
*/
if (is_ereg(dst_reg))
EMIT3(0x45, 0x0F, 0xB7);
else
EMIT2(0x0F, 0xB7);
EMIT1(add_2reg(0xC0, dst_reg, dst_reg));
break;
case 32:
/* emit 'mov eax, eax' to clear upper 32-bits */
if (is_ereg(dst_reg))
EMIT1(0x45);
EMIT2(0x89, add_2reg(0xC0, dst_reg, dst_reg));
break;
case 64:
/* nop */
break;
}
net: filter: x86: internal BPF JIT Maps all internal BPF instructions into x86_64 instructions. This patch replaces original BPF x64 JIT with internal BPF x64 JIT. sysctl net.core.bpf_jit_enable is reused as on/off switch. Performance: 1. old BPF JIT and internal BPF JIT generate equivalent x86_64 code. No performance difference is observed for filters that were JIT-able before Example assembler code for BPF filter "tcpdump port 22" original BPF -> old JIT: original BPF -> internal BPF -> new JIT: 0: push %rbp 0: push %rbp 1: mov %rsp,%rbp 1: mov %rsp,%rbp 4: sub $0x60,%rsp 4: sub $0x228,%rsp 8: mov %rbx,-0x8(%rbp) b: mov %rbx,-0x228(%rbp) // prologue 12: mov %r13,-0x220(%rbp) 19: mov %r14,-0x218(%rbp) 20: mov %r15,-0x210(%rbp) 27: xor %eax,%eax // clear A c: xor %ebx,%ebx 29: xor %r13,%r13 // clear X e: mov 0x68(%rdi),%r9d 2c: mov 0x68(%rdi),%r9d 12: sub 0x6c(%rdi),%r9d 30: sub 0x6c(%rdi),%r9d 16: mov 0xd8(%rdi),%r8 34: mov 0xd8(%rdi),%r10 3b: mov %rdi,%rbx 1d: mov $0xc,%esi 3e: mov $0xc,%esi 22: callq 0xffffffffe1021e15 43: callq 0xffffffffe102bd75 27: cmp $0x86dd,%eax 48: cmp $0x86dd,%rax 2c: jne 0x0000000000000069 4f: jne 0x000000000000009a 2e: mov $0x14,%esi 51: mov $0x14,%esi 33: callq 0xffffffffe1021e31 56: callq 0xffffffffe102bd91 38: cmp $0x84,%eax 5b: cmp $0x84,%rax 3d: je 0x0000000000000049 62: je 0x0000000000000074 3f: cmp $0x6,%eax 64: cmp $0x6,%rax 42: je 0x0000000000000049 68: je 0x0000000000000074 44: cmp $0x11,%eax 6a: cmp $0x11,%rax 47: jne 0x00000000000000c6 6e: jne 0x0000000000000117 49: mov $0x36,%esi 74: mov $0x36,%esi 4e: callq 0xffffffffe1021e15 79: callq 0xffffffffe102bd75 53: cmp $0x16,%eax 7e: cmp $0x16,%rax 56: je 0x00000000000000bf 82: je 0x0000000000000110 58: mov $0x38,%esi 88: mov $0x38,%esi 5d: callq 0xffffffffe1021e15 8d: callq 0xffffffffe102bd75 62: cmp $0x16,%eax 92: cmp $0x16,%rax 65: je 0x00000000000000bf 96: je 0x0000000000000110 67: jmp 0x00000000000000c6 98: jmp 0x0000000000000117 69: cmp $0x800,%eax 9a: cmp $0x800,%rax 6e: jne 0x00000000000000c6 a1: jne 0x0000000000000117 70: mov $0x17,%esi a3: mov $0x17,%esi 75: callq 0xffffffffe1021e31 a8: callq 0xffffffffe102bd91 7a: cmp $0x84,%eax ad: cmp $0x84,%rax 7f: je 0x000000000000008b b4: je 0x00000000000000c2 81: cmp $0x6,%eax b6: cmp $0x6,%rax 84: je 0x000000000000008b ba: je 0x00000000000000c2 86: cmp $0x11,%eax bc: cmp $0x11,%rax 89: jne 0x00000000000000c6 c0: jne 0x0000000000000117 8b: mov $0x14,%esi c2: mov $0x14,%esi 90: callq 0xffffffffe1021e15 c7: callq 0xffffffffe102bd75 95: test $0x1fff,%ax cc: test $0x1fff,%rax 99: jne 0x00000000000000c6 d3: jne 0x0000000000000117 d5: mov %rax,%r14 9b: mov $0xe,%esi d8: mov $0xe,%esi a0: callq 0xffffffffe1021e44 dd: callq 0xffffffffe102bd91 // MSH e2: and $0xf,%eax e5: shl $0x2,%eax e8: mov %rax,%r13 eb: mov %r14,%rax ee: mov %r13,%rsi a5: lea 0xe(%rbx),%esi f1: add $0xe,%esi a8: callq 0xffffffffe1021e0d f4: callq 0xffffffffe102bd6d ad: cmp $0x16,%eax f9: cmp $0x16,%rax b0: je 0x00000000000000bf fd: je 0x0000000000000110 ff: mov %r13,%rsi b2: lea 0x10(%rbx),%esi 102: add $0x10,%esi b5: callq 0xffffffffe1021e0d 105: callq 0xffffffffe102bd6d ba: cmp $0x16,%eax 10a: cmp $0x16,%rax bd: jne 0x00000000000000c6 10e: jne 0x0000000000000117 bf: mov $0xffff,%eax 110: mov $0xffff,%eax c4: jmp 0x00000000000000c8 115: jmp 0x000000000000011c c6: xor %eax,%eax 117: mov $0x0,%eax c8: mov -0x8(%rbp),%rbx 11c: mov -0x228(%rbp),%rbx // epilogue cc: leaveq 123: mov -0x220(%rbp),%r13 cd: retq 12a: mov -0x218(%rbp),%r14 131: mov -0x210(%rbp),%r15 138: leaveq 139: retq On fully cached SKBs both JITed functions take 12 nsec to execute. BPF interpreter executes the program in 30 nsec. The difference in generated assembler is due to the following: Old BPF imlements LDX_MSH instruction via sk_load_byte_msh() helper function inside bpf_jit.S. New JIT removes the helper and does it explicitly, so ldx_msh cost is the same for both JITs, but generated code looks longer. New JIT has 4 registers to save, so prologue/epilogue are larger, but the cost is within noise on x64. Old JIT checks whether first insn clears A and if not emits 'xor %eax,%eax'. New JIT clears %rax unconditionally. 2. old BPF JIT doesn't support ANC_NLATTR, ANC_PAY_OFFSET, ANC_RANDOM extensions. New JIT supports all BPF extensions. Performance of such filters improves 2-4 times depending on a filter. The longer the filter the higher performance gain. Synthetic benchmarks with many ancillary loads see 20x speedup which seems to be the maximum gain from JIT Notes: . net.core.bpf_jit_enable=2 + tools/net/bpf_jit_disasm is still functional and can be used to see generated assembler . there are two jit_compile() functions and code flow for classic filters is: sk_attach_filter() - load classic BPF bpf_jit_compile() - try to JIT from classic BPF sk_convert_filter() - convert classic to internal bpf_int_jit_compile() - JIT from internal BPF seccomp and tracing filters will just call bpf_int_jit_compile() Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 20:50:46 -06:00
break;
net: filter: cleanup A/X name usage The macro 'A' used in internal BPF interpreter: #define A regs[insn->a_reg] was easily confused with the name of classic BPF register 'A', since 'A' would mean two different things depending on context. This patch is trying to clean up the naming and clarify its usage in the following way: - A and X are names of two classic BPF registers - BPF_REG_A denotes internal BPF register R0 used to map classic register A in internal BPF programs generated from classic - BPF_REG_X denotes internal BPF register R7 used to map classic register X in internal BPF programs generated from classic - internal BPF instruction format: struct sock_filter_int { __u8 code; /* opcode */ __u8 dst_reg:4; /* dest register */ __u8 src_reg:4; /* source register */ __s16 off; /* signed offset */ __s32 imm; /* signed immediate constant */ }; - BPF_X/BPF_K is 1 bit used to encode source operand of instruction In classic: BPF_X - means use register X as source operand BPF_K - means use 32-bit immediate as source operand In internal: BPF_X - means use 'src_reg' register as source operand BPF_K - means use 32-bit immediate as source operand Suggested-by: Chema Gonzalez <chema@google.com> Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Acked-by: Daniel Borkmann <dborkman@redhat.com> Acked-by: Chema Gonzalez <chema@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-06-06 15:46:06 -06:00
/* ST: *(u8*)(dst_reg + off) = imm */
net: filter: x86: internal BPF JIT Maps all internal BPF instructions into x86_64 instructions. This patch replaces original BPF x64 JIT with internal BPF x64 JIT. sysctl net.core.bpf_jit_enable is reused as on/off switch. Performance: 1. old BPF JIT and internal BPF JIT generate equivalent x86_64 code. No performance difference is observed for filters that were JIT-able before Example assembler code for BPF filter "tcpdump port 22" original BPF -> old JIT: original BPF -> internal BPF -> new JIT: 0: push %rbp 0: push %rbp 1: mov %rsp,%rbp 1: mov %rsp,%rbp 4: sub $0x60,%rsp 4: sub $0x228,%rsp 8: mov %rbx,-0x8(%rbp) b: mov %rbx,-0x228(%rbp) // prologue 12: mov %r13,-0x220(%rbp) 19: mov %r14,-0x218(%rbp) 20: mov %r15,-0x210(%rbp) 27: xor %eax,%eax // clear A c: xor %ebx,%ebx 29: xor %r13,%r13 // clear X e: mov 0x68(%rdi),%r9d 2c: mov 0x68(%rdi),%r9d 12: sub 0x6c(%rdi),%r9d 30: sub 0x6c(%rdi),%r9d 16: mov 0xd8(%rdi),%r8 34: mov 0xd8(%rdi),%r10 3b: mov %rdi,%rbx 1d: mov $0xc,%esi 3e: mov $0xc,%esi 22: callq 0xffffffffe1021e15 43: callq 0xffffffffe102bd75 27: cmp $0x86dd,%eax 48: cmp $0x86dd,%rax 2c: jne 0x0000000000000069 4f: jne 0x000000000000009a 2e: mov $0x14,%esi 51: mov $0x14,%esi 33: callq 0xffffffffe1021e31 56: callq 0xffffffffe102bd91 38: cmp $0x84,%eax 5b: cmp $0x84,%rax 3d: je 0x0000000000000049 62: je 0x0000000000000074 3f: cmp $0x6,%eax 64: cmp $0x6,%rax 42: je 0x0000000000000049 68: je 0x0000000000000074 44: cmp $0x11,%eax 6a: cmp $0x11,%rax 47: jne 0x00000000000000c6 6e: jne 0x0000000000000117 49: mov $0x36,%esi 74: mov $0x36,%esi 4e: callq 0xffffffffe1021e15 79: callq 0xffffffffe102bd75 53: cmp $0x16,%eax 7e: cmp $0x16,%rax 56: je 0x00000000000000bf 82: je 0x0000000000000110 58: mov $0x38,%esi 88: mov $0x38,%esi 5d: callq 0xffffffffe1021e15 8d: callq 0xffffffffe102bd75 62: cmp $0x16,%eax 92: cmp $0x16,%rax 65: je 0x00000000000000bf 96: je 0x0000000000000110 67: jmp 0x00000000000000c6 98: jmp 0x0000000000000117 69: cmp $0x800,%eax 9a: cmp $0x800,%rax 6e: jne 0x00000000000000c6 a1: jne 0x0000000000000117 70: mov $0x17,%esi a3: mov $0x17,%esi 75: callq 0xffffffffe1021e31 a8: callq 0xffffffffe102bd91 7a: cmp $0x84,%eax ad: cmp $0x84,%rax 7f: je 0x000000000000008b b4: je 0x00000000000000c2 81: cmp $0x6,%eax b6: cmp $0x6,%rax 84: je 0x000000000000008b ba: je 0x00000000000000c2 86: cmp $0x11,%eax bc: cmp $0x11,%rax 89: jne 0x00000000000000c6 c0: jne 0x0000000000000117 8b: mov $0x14,%esi c2: mov $0x14,%esi 90: callq 0xffffffffe1021e15 c7: callq 0xffffffffe102bd75 95: test $0x1fff,%ax cc: test $0x1fff,%rax 99: jne 0x00000000000000c6 d3: jne 0x0000000000000117 d5: mov %rax,%r14 9b: mov $0xe,%esi d8: mov $0xe,%esi a0: callq 0xffffffffe1021e44 dd: callq 0xffffffffe102bd91 // MSH e2: and $0xf,%eax e5: shl $0x2,%eax e8: mov %rax,%r13 eb: mov %r14,%rax ee: mov %r13,%rsi a5: lea 0xe(%rbx),%esi f1: add $0xe,%esi a8: callq 0xffffffffe1021e0d f4: callq 0xffffffffe102bd6d ad: cmp $0x16,%eax f9: cmp $0x16,%rax b0: je 0x00000000000000bf fd: je 0x0000000000000110 ff: mov %r13,%rsi b2: lea 0x10(%rbx),%esi 102: add $0x10,%esi b5: callq 0xffffffffe1021e0d 105: callq 0xffffffffe102bd6d ba: cmp $0x16,%eax 10a: cmp $0x16,%rax bd: jne 0x00000000000000c6 10e: jne 0x0000000000000117 bf: mov $0xffff,%eax 110: mov $0xffff,%eax c4: jmp 0x00000000000000c8 115: jmp 0x000000000000011c c6: xor %eax,%eax 117: mov $0x0,%eax c8: mov -0x8(%rbp),%rbx 11c: mov -0x228(%rbp),%rbx // epilogue cc: leaveq 123: mov -0x220(%rbp),%r13 cd: retq 12a: mov -0x218(%rbp),%r14 131: mov -0x210(%rbp),%r15 138: leaveq 139: retq On fully cached SKBs both JITed functions take 12 nsec to execute. BPF interpreter executes the program in 30 nsec. The difference in generated assembler is due to the following: Old BPF imlements LDX_MSH instruction via sk_load_byte_msh() helper function inside bpf_jit.S. New JIT removes the helper and does it explicitly, so ldx_msh cost is the same for both JITs, but generated code looks longer. New JIT has 4 registers to save, so prologue/epilogue are larger, but the cost is within noise on x64. Old JIT checks whether first insn clears A and if not emits 'xor %eax,%eax'. New JIT clears %rax unconditionally. 2. old BPF JIT doesn't support ANC_NLATTR, ANC_PAY_OFFSET, ANC_RANDOM extensions. New JIT supports all BPF extensions. Performance of such filters improves 2-4 times depending on a filter. The longer the filter the higher performance gain. Synthetic benchmarks with many ancillary loads see 20x speedup which seems to be the maximum gain from JIT Notes: . net.core.bpf_jit_enable=2 + tools/net/bpf_jit_disasm is still functional and can be used to see generated assembler . there are two jit_compile() functions and code flow for classic filters is: sk_attach_filter() - load classic BPF bpf_jit_compile() - try to JIT from classic BPF sk_convert_filter() - convert classic to internal bpf_int_jit_compile() - JIT from internal BPF seccomp and tracing filters will just call bpf_int_jit_compile() Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 20:50:46 -06:00
case BPF_ST | BPF_MEM | BPF_B:
net: filter: cleanup A/X name usage The macro 'A' used in internal BPF interpreter: #define A regs[insn->a_reg] was easily confused with the name of classic BPF register 'A', since 'A' would mean two different things depending on context. This patch is trying to clean up the naming and clarify its usage in the following way: - A and X are names of two classic BPF registers - BPF_REG_A denotes internal BPF register R0 used to map classic register A in internal BPF programs generated from classic - BPF_REG_X denotes internal BPF register R7 used to map classic register X in internal BPF programs generated from classic - internal BPF instruction format: struct sock_filter_int { __u8 code; /* opcode */ __u8 dst_reg:4; /* dest register */ __u8 src_reg:4; /* source register */ __s16 off; /* signed offset */ __s32 imm; /* signed immediate constant */ }; - BPF_X/BPF_K is 1 bit used to encode source operand of instruction In classic: BPF_X - means use register X as source operand BPF_K - means use 32-bit immediate as source operand In internal: BPF_X - means use 'src_reg' register as source operand BPF_K - means use 32-bit immediate as source operand Suggested-by: Chema Gonzalez <chema@google.com> Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Acked-by: Daniel Borkmann <dborkman@redhat.com> Acked-by: Chema Gonzalez <chema@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-06-06 15:46:06 -06:00
if (is_ereg(dst_reg))
net: filter: x86: internal BPF JIT Maps all internal BPF instructions into x86_64 instructions. This patch replaces original BPF x64 JIT with internal BPF x64 JIT. sysctl net.core.bpf_jit_enable is reused as on/off switch. Performance: 1. old BPF JIT and internal BPF JIT generate equivalent x86_64 code. No performance difference is observed for filters that were JIT-able before Example assembler code for BPF filter "tcpdump port 22" original BPF -> old JIT: original BPF -> internal BPF -> new JIT: 0: push %rbp 0: push %rbp 1: mov %rsp,%rbp 1: mov %rsp,%rbp 4: sub $0x60,%rsp 4: sub $0x228,%rsp 8: mov %rbx,-0x8(%rbp) b: mov %rbx,-0x228(%rbp) // prologue 12: mov %r13,-0x220(%rbp) 19: mov %r14,-0x218(%rbp) 20: mov %r15,-0x210(%rbp) 27: xor %eax,%eax // clear A c: xor %ebx,%ebx 29: xor %r13,%r13 // clear X e: mov 0x68(%rdi),%r9d 2c: mov 0x68(%rdi),%r9d 12: sub 0x6c(%rdi),%r9d 30: sub 0x6c(%rdi),%r9d 16: mov 0xd8(%rdi),%r8 34: mov 0xd8(%rdi),%r10 3b: mov %rdi,%rbx 1d: mov $0xc,%esi 3e: mov $0xc,%esi 22: callq 0xffffffffe1021e15 43: callq 0xffffffffe102bd75 27: cmp $0x86dd,%eax 48: cmp $0x86dd,%rax 2c: jne 0x0000000000000069 4f: jne 0x000000000000009a 2e: mov $0x14,%esi 51: mov $0x14,%esi 33: callq 0xffffffffe1021e31 56: callq 0xffffffffe102bd91 38: cmp $0x84,%eax 5b: cmp $0x84,%rax 3d: je 0x0000000000000049 62: je 0x0000000000000074 3f: cmp $0x6,%eax 64: cmp $0x6,%rax 42: je 0x0000000000000049 68: je 0x0000000000000074 44: cmp $0x11,%eax 6a: cmp $0x11,%rax 47: jne 0x00000000000000c6 6e: jne 0x0000000000000117 49: mov $0x36,%esi 74: mov $0x36,%esi 4e: callq 0xffffffffe1021e15 79: callq 0xffffffffe102bd75 53: cmp $0x16,%eax 7e: cmp $0x16,%rax 56: je 0x00000000000000bf 82: je 0x0000000000000110 58: mov $0x38,%esi 88: mov $0x38,%esi 5d: callq 0xffffffffe1021e15 8d: callq 0xffffffffe102bd75 62: cmp $0x16,%eax 92: cmp $0x16,%rax 65: je 0x00000000000000bf 96: je 0x0000000000000110 67: jmp 0x00000000000000c6 98: jmp 0x0000000000000117 69: cmp $0x800,%eax 9a: cmp $0x800,%rax 6e: jne 0x00000000000000c6 a1: jne 0x0000000000000117 70: mov $0x17,%esi a3: mov $0x17,%esi 75: callq 0xffffffffe1021e31 a8: callq 0xffffffffe102bd91 7a: cmp $0x84,%eax ad: cmp $0x84,%rax 7f: je 0x000000000000008b b4: je 0x00000000000000c2 81: cmp $0x6,%eax b6: cmp $0x6,%rax 84: je 0x000000000000008b ba: je 0x00000000000000c2 86: cmp $0x11,%eax bc: cmp $0x11,%rax 89: jne 0x00000000000000c6 c0: jne 0x0000000000000117 8b: mov $0x14,%esi c2: mov $0x14,%esi 90: callq 0xffffffffe1021e15 c7: callq 0xffffffffe102bd75 95: test $0x1fff,%ax cc: test $0x1fff,%rax 99: jne 0x00000000000000c6 d3: jne 0x0000000000000117 d5: mov %rax,%r14 9b: mov $0xe,%esi d8: mov $0xe,%esi a0: callq 0xffffffffe1021e44 dd: callq 0xffffffffe102bd91 // MSH e2: and $0xf,%eax e5: shl $0x2,%eax e8: mov %rax,%r13 eb: mov %r14,%rax ee: mov %r13,%rsi a5: lea 0xe(%rbx),%esi f1: add $0xe,%esi a8: callq 0xffffffffe1021e0d f4: callq 0xffffffffe102bd6d ad: cmp $0x16,%eax f9: cmp $0x16,%rax b0: je 0x00000000000000bf fd: je 0x0000000000000110 ff: mov %r13,%rsi b2: lea 0x10(%rbx),%esi 102: add $0x10,%esi b5: callq 0xffffffffe1021e0d 105: callq 0xffffffffe102bd6d ba: cmp $0x16,%eax 10a: cmp $0x16,%rax bd: jne 0x00000000000000c6 10e: jne 0x0000000000000117 bf: mov $0xffff,%eax 110: mov $0xffff,%eax c4: jmp 0x00000000000000c8 115: jmp 0x000000000000011c c6: xor %eax,%eax 117: mov $0x0,%eax c8: mov -0x8(%rbp),%rbx 11c: mov -0x228(%rbp),%rbx // epilogue cc: leaveq 123: mov -0x220(%rbp),%r13 cd: retq 12a: mov -0x218(%rbp),%r14 131: mov -0x210(%rbp),%r15 138: leaveq 139: retq On fully cached SKBs both JITed functions take 12 nsec to execute. BPF interpreter executes the program in 30 nsec. The difference in generated assembler is due to the following: Old BPF imlements LDX_MSH instruction via sk_load_byte_msh() helper function inside bpf_jit.S. New JIT removes the helper and does it explicitly, so ldx_msh cost is the same for both JITs, but generated code looks longer. New JIT has 4 registers to save, so prologue/epilogue are larger, but the cost is within noise on x64. Old JIT checks whether first insn clears A and if not emits 'xor %eax,%eax'. New JIT clears %rax unconditionally. 2. old BPF JIT doesn't support ANC_NLATTR, ANC_PAY_OFFSET, ANC_RANDOM extensions. New JIT supports all BPF extensions. Performance of such filters improves 2-4 times depending on a filter. The longer the filter the higher performance gain. Synthetic benchmarks with many ancillary loads see 20x speedup which seems to be the maximum gain from JIT Notes: . net.core.bpf_jit_enable=2 + tools/net/bpf_jit_disasm is still functional and can be used to see generated assembler . there are two jit_compile() functions and code flow for classic filters is: sk_attach_filter() - load classic BPF bpf_jit_compile() - try to JIT from classic BPF sk_convert_filter() - convert classic to internal bpf_int_jit_compile() - JIT from internal BPF seccomp and tracing filters will just call bpf_int_jit_compile() Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 20:50:46 -06:00
EMIT2(0x41, 0xC6);
else
EMIT1(0xC6);
goto st;
case BPF_ST | BPF_MEM | BPF_H:
net: filter: cleanup A/X name usage The macro 'A' used in internal BPF interpreter: #define A regs[insn->a_reg] was easily confused with the name of classic BPF register 'A', since 'A' would mean two different things depending on context. This patch is trying to clean up the naming and clarify its usage in the following way: - A and X are names of two classic BPF registers - BPF_REG_A denotes internal BPF register R0 used to map classic register A in internal BPF programs generated from classic - BPF_REG_X denotes internal BPF register R7 used to map classic register X in internal BPF programs generated from classic - internal BPF instruction format: struct sock_filter_int { __u8 code; /* opcode */ __u8 dst_reg:4; /* dest register */ __u8 src_reg:4; /* source register */ __s16 off; /* signed offset */ __s32 imm; /* signed immediate constant */ }; - BPF_X/BPF_K is 1 bit used to encode source operand of instruction In classic: BPF_X - means use register X as source operand BPF_K - means use 32-bit immediate as source operand In internal: BPF_X - means use 'src_reg' register as source operand BPF_K - means use 32-bit immediate as source operand Suggested-by: Chema Gonzalez <chema@google.com> Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Acked-by: Daniel Borkmann <dborkman@redhat.com> Acked-by: Chema Gonzalez <chema@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-06-06 15:46:06 -06:00
if (is_ereg(dst_reg))
net: filter: x86: internal BPF JIT Maps all internal BPF instructions into x86_64 instructions. This patch replaces original BPF x64 JIT with internal BPF x64 JIT. sysctl net.core.bpf_jit_enable is reused as on/off switch. Performance: 1. old BPF JIT and internal BPF JIT generate equivalent x86_64 code. No performance difference is observed for filters that were JIT-able before Example assembler code for BPF filter "tcpdump port 22" original BPF -> old JIT: original BPF -> internal BPF -> new JIT: 0: push %rbp 0: push %rbp 1: mov %rsp,%rbp 1: mov %rsp,%rbp 4: sub $0x60,%rsp 4: sub $0x228,%rsp 8: mov %rbx,-0x8(%rbp) b: mov %rbx,-0x228(%rbp) // prologue 12: mov %r13,-0x220(%rbp) 19: mov %r14,-0x218(%rbp) 20: mov %r15,-0x210(%rbp) 27: xor %eax,%eax // clear A c: xor %ebx,%ebx 29: xor %r13,%r13 // clear X e: mov 0x68(%rdi),%r9d 2c: mov 0x68(%rdi),%r9d 12: sub 0x6c(%rdi),%r9d 30: sub 0x6c(%rdi),%r9d 16: mov 0xd8(%rdi),%r8 34: mov 0xd8(%rdi),%r10 3b: mov %rdi,%rbx 1d: mov $0xc,%esi 3e: mov $0xc,%esi 22: callq 0xffffffffe1021e15 43: callq 0xffffffffe102bd75 27: cmp $0x86dd,%eax 48: cmp $0x86dd,%rax 2c: jne 0x0000000000000069 4f: jne 0x000000000000009a 2e: mov $0x14,%esi 51: mov $0x14,%esi 33: callq 0xffffffffe1021e31 56: callq 0xffffffffe102bd91 38: cmp $0x84,%eax 5b: cmp $0x84,%rax 3d: je 0x0000000000000049 62: je 0x0000000000000074 3f: cmp $0x6,%eax 64: cmp $0x6,%rax 42: je 0x0000000000000049 68: je 0x0000000000000074 44: cmp $0x11,%eax 6a: cmp $0x11,%rax 47: jne 0x00000000000000c6 6e: jne 0x0000000000000117 49: mov $0x36,%esi 74: mov $0x36,%esi 4e: callq 0xffffffffe1021e15 79: callq 0xffffffffe102bd75 53: cmp $0x16,%eax 7e: cmp $0x16,%rax 56: je 0x00000000000000bf 82: je 0x0000000000000110 58: mov $0x38,%esi 88: mov $0x38,%esi 5d: callq 0xffffffffe1021e15 8d: callq 0xffffffffe102bd75 62: cmp $0x16,%eax 92: cmp $0x16,%rax 65: je 0x00000000000000bf 96: je 0x0000000000000110 67: jmp 0x00000000000000c6 98: jmp 0x0000000000000117 69: cmp $0x800,%eax 9a: cmp $0x800,%rax 6e: jne 0x00000000000000c6 a1: jne 0x0000000000000117 70: mov $0x17,%esi a3: mov $0x17,%esi 75: callq 0xffffffffe1021e31 a8: callq 0xffffffffe102bd91 7a: cmp $0x84,%eax ad: cmp $0x84,%rax 7f: je 0x000000000000008b b4: je 0x00000000000000c2 81: cmp $0x6,%eax b6: cmp $0x6,%rax 84: je 0x000000000000008b ba: je 0x00000000000000c2 86: cmp $0x11,%eax bc: cmp $0x11,%rax 89: jne 0x00000000000000c6 c0: jne 0x0000000000000117 8b: mov $0x14,%esi c2: mov $0x14,%esi 90: callq 0xffffffffe1021e15 c7: callq 0xffffffffe102bd75 95: test $0x1fff,%ax cc: test $0x1fff,%rax 99: jne 0x00000000000000c6 d3: jne 0x0000000000000117 d5: mov %rax,%r14 9b: mov $0xe,%esi d8: mov $0xe,%esi a0: callq 0xffffffffe1021e44 dd: callq 0xffffffffe102bd91 // MSH e2: and $0xf,%eax e5: shl $0x2,%eax e8: mov %rax,%r13 eb: mov %r14,%rax ee: mov %r13,%rsi a5: lea 0xe(%rbx),%esi f1: add $0xe,%esi a8: callq 0xffffffffe1021e0d f4: callq 0xffffffffe102bd6d ad: cmp $0x16,%eax f9: cmp $0x16,%rax b0: je 0x00000000000000bf fd: je 0x0000000000000110 ff: mov %r13,%rsi b2: lea 0x10(%rbx),%esi 102: add $0x10,%esi b5: callq 0xffffffffe1021e0d 105: callq 0xffffffffe102bd6d ba: cmp $0x16,%eax 10a: cmp $0x16,%rax bd: jne 0x00000000000000c6 10e: jne 0x0000000000000117 bf: mov $0xffff,%eax 110: mov $0xffff,%eax c4: jmp 0x00000000000000c8 115: jmp 0x000000000000011c c6: xor %eax,%eax 117: mov $0x0,%eax c8: mov -0x8(%rbp),%rbx 11c: mov -0x228(%rbp),%rbx // epilogue cc: leaveq 123: mov -0x220(%rbp),%r13 cd: retq 12a: mov -0x218(%rbp),%r14 131: mov -0x210(%rbp),%r15 138: leaveq 139: retq On fully cached SKBs both JITed functions take 12 nsec to execute. BPF interpreter executes the program in 30 nsec. The difference in generated assembler is due to the following: Old BPF imlements LDX_MSH instruction via sk_load_byte_msh() helper function inside bpf_jit.S. New JIT removes the helper and does it explicitly, so ldx_msh cost is the same for both JITs, but generated code looks longer. New JIT has 4 registers to save, so prologue/epilogue are larger, but the cost is within noise on x64. Old JIT checks whether first insn clears A and if not emits 'xor %eax,%eax'. New JIT clears %rax unconditionally. 2. old BPF JIT doesn't support ANC_NLATTR, ANC_PAY_OFFSET, ANC_RANDOM extensions. New JIT supports all BPF extensions. Performance of such filters improves 2-4 times depending on a filter. The longer the filter the higher performance gain. Synthetic benchmarks with many ancillary loads see 20x speedup which seems to be the maximum gain from JIT Notes: . net.core.bpf_jit_enable=2 + tools/net/bpf_jit_disasm is still functional and can be used to see generated assembler . there are two jit_compile() functions and code flow for classic filters is: sk_attach_filter() - load classic BPF bpf_jit_compile() - try to JIT from classic BPF sk_convert_filter() - convert classic to internal bpf_int_jit_compile() - JIT from internal BPF seccomp and tracing filters will just call bpf_int_jit_compile() Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 20:50:46 -06:00
EMIT3(0x66, 0x41, 0xC7);
else
EMIT2(0x66, 0xC7);
goto st;
case BPF_ST | BPF_MEM | BPF_W:
net: filter: cleanup A/X name usage The macro 'A' used in internal BPF interpreter: #define A regs[insn->a_reg] was easily confused with the name of classic BPF register 'A', since 'A' would mean two different things depending on context. This patch is trying to clean up the naming and clarify its usage in the following way: - A and X are names of two classic BPF registers - BPF_REG_A denotes internal BPF register R0 used to map classic register A in internal BPF programs generated from classic - BPF_REG_X denotes internal BPF register R7 used to map classic register X in internal BPF programs generated from classic - internal BPF instruction format: struct sock_filter_int { __u8 code; /* opcode */ __u8 dst_reg:4; /* dest register */ __u8 src_reg:4; /* source register */ __s16 off; /* signed offset */ __s32 imm; /* signed immediate constant */ }; - BPF_X/BPF_K is 1 bit used to encode source operand of instruction In classic: BPF_X - means use register X as source operand BPF_K - means use 32-bit immediate as source operand In internal: BPF_X - means use 'src_reg' register as source operand BPF_K - means use 32-bit immediate as source operand Suggested-by: Chema Gonzalez <chema@google.com> Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Acked-by: Daniel Borkmann <dborkman@redhat.com> Acked-by: Chema Gonzalez <chema@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-06-06 15:46:06 -06:00
if (is_ereg(dst_reg))
net: filter: x86: internal BPF JIT Maps all internal BPF instructions into x86_64 instructions. This patch replaces original BPF x64 JIT with internal BPF x64 JIT. sysctl net.core.bpf_jit_enable is reused as on/off switch. Performance: 1. old BPF JIT and internal BPF JIT generate equivalent x86_64 code. No performance difference is observed for filters that were JIT-able before Example assembler code for BPF filter "tcpdump port 22" original BPF -> old JIT: original BPF -> internal BPF -> new JIT: 0: push %rbp 0: push %rbp 1: mov %rsp,%rbp 1: mov %rsp,%rbp 4: sub $0x60,%rsp 4: sub $0x228,%rsp 8: mov %rbx,-0x8(%rbp) b: mov %rbx,-0x228(%rbp) // prologue 12: mov %r13,-0x220(%rbp) 19: mov %r14,-0x218(%rbp) 20: mov %r15,-0x210(%rbp) 27: xor %eax,%eax // clear A c: xor %ebx,%ebx 29: xor %r13,%r13 // clear X e: mov 0x68(%rdi),%r9d 2c: mov 0x68(%rdi),%r9d 12: sub 0x6c(%rdi),%r9d 30: sub 0x6c(%rdi),%r9d 16: mov 0xd8(%rdi),%r8 34: mov 0xd8(%rdi),%r10 3b: mov %rdi,%rbx 1d: mov $0xc,%esi 3e: mov $0xc,%esi 22: callq 0xffffffffe1021e15 43: callq 0xffffffffe102bd75 27: cmp $0x86dd,%eax 48: cmp $0x86dd,%rax 2c: jne 0x0000000000000069 4f: jne 0x000000000000009a 2e: mov $0x14,%esi 51: mov $0x14,%esi 33: callq 0xffffffffe1021e31 56: callq 0xffffffffe102bd91 38: cmp $0x84,%eax 5b: cmp $0x84,%rax 3d: je 0x0000000000000049 62: je 0x0000000000000074 3f: cmp $0x6,%eax 64: cmp $0x6,%rax 42: je 0x0000000000000049 68: je 0x0000000000000074 44: cmp $0x11,%eax 6a: cmp $0x11,%rax 47: jne 0x00000000000000c6 6e: jne 0x0000000000000117 49: mov $0x36,%esi 74: mov $0x36,%esi 4e: callq 0xffffffffe1021e15 79: callq 0xffffffffe102bd75 53: cmp $0x16,%eax 7e: cmp $0x16,%rax 56: je 0x00000000000000bf 82: je 0x0000000000000110 58: mov $0x38,%esi 88: mov $0x38,%esi 5d: callq 0xffffffffe1021e15 8d: callq 0xffffffffe102bd75 62: cmp $0x16,%eax 92: cmp $0x16,%rax 65: je 0x00000000000000bf 96: je 0x0000000000000110 67: jmp 0x00000000000000c6 98: jmp 0x0000000000000117 69: cmp $0x800,%eax 9a: cmp $0x800,%rax 6e: jne 0x00000000000000c6 a1: jne 0x0000000000000117 70: mov $0x17,%esi a3: mov $0x17,%esi 75: callq 0xffffffffe1021e31 a8: callq 0xffffffffe102bd91 7a: cmp $0x84,%eax ad: cmp $0x84,%rax 7f: je 0x000000000000008b b4: je 0x00000000000000c2 81: cmp $0x6,%eax b6: cmp $0x6,%rax 84: je 0x000000000000008b ba: je 0x00000000000000c2 86: cmp $0x11,%eax bc: cmp $0x11,%rax 89: jne 0x00000000000000c6 c0: jne 0x0000000000000117 8b: mov $0x14,%esi c2: mov $0x14,%esi 90: callq 0xffffffffe1021e15 c7: callq 0xffffffffe102bd75 95: test $0x1fff,%ax cc: test $0x1fff,%rax 99: jne 0x00000000000000c6 d3: jne 0x0000000000000117 d5: mov %rax,%r14 9b: mov $0xe,%esi d8: mov $0xe,%esi a0: callq 0xffffffffe1021e44 dd: callq 0xffffffffe102bd91 // MSH e2: and $0xf,%eax e5: shl $0x2,%eax e8: mov %rax,%r13 eb: mov %r14,%rax ee: mov %r13,%rsi a5: lea 0xe(%rbx),%esi f1: add $0xe,%esi a8: callq 0xffffffffe1021e0d f4: callq 0xffffffffe102bd6d ad: cmp $0x16,%eax f9: cmp $0x16,%rax b0: je 0x00000000000000bf fd: je 0x0000000000000110 ff: mov %r13,%rsi b2: lea 0x10(%rbx),%esi 102: add $0x10,%esi b5: callq 0xffffffffe1021e0d 105: callq 0xffffffffe102bd6d ba: cmp $0x16,%eax 10a: cmp $0x16,%rax bd: jne 0x00000000000000c6 10e: jne 0x0000000000000117 bf: mov $0xffff,%eax 110: mov $0xffff,%eax c4: jmp 0x00000000000000c8 115: jmp 0x000000000000011c c6: xor %eax,%eax 117: mov $0x0,%eax c8: mov -0x8(%rbp),%rbx 11c: mov -0x228(%rbp),%rbx // epilogue cc: leaveq 123: mov -0x220(%rbp),%r13 cd: retq 12a: mov -0x218(%rbp),%r14 131: mov -0x210(%rbp),%r15 138: leaveq 139: retq On fully cached SKBs both JITed functions take 12 nsec to execute. BPF interpreter executes the program in 30 nsec. The difference in generated assembler is due to the following: Old BPF imlements LDX_MSH instruction via sk_load_byte_msh() helper function inside bpf_jit.S. New JIT removes the helper and does it explicitly, so ldx_msh cost is the same for both JITs, but generated code looks longer. New JIT has 4 registers to save, so prologue/epilogue are larger, but the cost is within noise on x64. Old JIT checks whether first insn clears A and if not emits 'xor %eax,%eax'. New JIT clears %rax unconditionally. 2. old BPF JIT doesn't support ANC_NLATTR, ANC_PAY_OFFSET, ANC_RANDOM extensions. New JIT supports all BPF extensions. Performance of such filters improves 2-4 times depending on a filter. The longer the filter the higher performance gain. Synthetic benchmarks with many ancillary loads see 20x speedup which seems to be the maximum gain from JIT Notes: . net.core.bpf_jit_enable=2 + tools/net/bpf_jit_disasm is still functional and can be used to see generated assembler . there are two jit_compile() functions and code flow for classic filters is: sk_attach_filter() - load classic BPF bpf_jit_compile() - try to JIT from classic BPF sk_convert_filter() - convert classic to internal bpf_int_jit_compile() - JIT from internal BPF seccomp and tracing filters will just call bpf_int_jit_compile() Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 20:50:46 -06:00
EMIT2(0x41, 0xC7);
else
EMIT1(0xC7);
goto st;
case BPF_ST | BPF_MEM | BPF_DW:
net: filter: cleanup A/X name usage The macro 'A' used in internal BPF interpreter: #define A regs[insn->a_reg] was easily confused with the name of classic BPF register 'A', since 'A' would mean two different things depending on context. This patch is trying to clean up the naming and clarify its usage in the following way: - A and X are names of two classic BPF registers - BPF_REG_A denotes internal BPF register R0 used to map classic register A in internal BPF programs generated from classic - BPF_REG_X denotes internal BPF register R7 used to map classic register X in internal BPF programs generated from classic - internal BPF instruction format: struct sock_filter_int { __u8 code; /* opcode */ __u8 dst_reg:4; /* dest register */ __u8 src_reg:4; /* source register */ __s16 off; /* signed offset */ __s32 imm; /* signed immediate constant */ }; - BPF_X/BPF_K is 1 bit used to encode source operand of instruction In classic: BPF_X - means use register X as source operand BPF_K - means use 32-bit immediate as source operand In internal: BPF_X - means use 'src_reg' register as source operand BPF_K - means use 32-bit immediate as source operand Suggested-by: Chema Gonzalez <chema@google.com> Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Acked-by: Daniel Borkmann <dborkman@redhat.com> Acked-by: Chema Gonzalez <chema@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-06-06 15:46:06 -06:00
EMIT2(add_1mod(0x48, dst_reg), 0xC7);
net: filter: x86: internal BPF JIT Maps all internal BPF instructions into x86_64 instructions. This patch replaces original BPF x64 JIT with internal BPF x64 JIT. sysctl net.core.bpf_jit_enable is reused as on/off switch. Performance: 1. old BPF JIT and internal BPF JIT generate equivalent x86_64 code. No performance difference is observed for filters that were JIT-able before Example assembler code for BPF filter "tcpdump port 22" original BPF -> old JIT: original BPF -> internal BPF -> new JIT: 0: push %rbp 0: push %rbp 1: mov %rsp,%rbp 1: mov %rsp,%rbp 4: sub $0x60,%rsp 4: sub $0x228,%rsp 8: mov %rbx,-0x8(%rbp) b: mov %rbx,-0x228(%rbp) // prologue 12: mov %r13,-0x220(%rbp) 19: mov %r14,-0x218(%rbp) 20: mov %r15,-0x210(%rbp) 27: xor %eax,%eax // clear A c: xor %ebx,%ebx 29: xor %r13,%r13 // clear X e: mov 0x68(%rdi),%r9d 2c: mov 0x68(%rdi),%r9d 12: sub 0x6c(%rdi),%r9d 30: sub 0x6c(%rdi),%r9d 16: mov 0xd8(%rdi),%r8 34: mov 0xd8(%rdi),%r10 3b: mov %rdi,%rbx 1d: mov $0xc,%esi 3e: mov $0xc,%esi 22: callq 0xffffffffe1021e15 43: callq 0xffffffffe102bd75 27: cmp $0x86dd,%eax 48: cmp $0x86dd,%rax 2c: jne 0x0000000000000069 4f: jne 0x000000000000009a 2e: mov $0x14,%esi 51: mov $0x14,%esi 33: callq 0xffffffffe1021e31 56: callq 0xffffffffe102bd91 38: cmp $0x84,%eax 5b: cmp $0x84,%rax 3d: je 0x0000000000000049 62: je 0x0000000000000074 3f: cmp $0x6,%eax 64: cmp $0x6,%rax 42: je 0x0000000000000049 68: je 0x0000000000000074 44: cmp $0x11,%eax 6a: cmp $0x11,%rax 47: jne 0x00000000000000c6 6e: jne 0x0000000000000117 49: mov $0x36,%esi 74: mov $0x36,%esi 4e: callq 0xffffffffe1021e15 79: callq 0xffffffffe102bd75 53: cmp $0x16,%eax 7e: cmp $0x16,%rax 56: je 0x00000000000000bf 82: je 0x0000000000000110 58: mov $0x38,%esi 88: mov $0x38,%esi 5d: callq 0xffffffffe1021e15 8d: callq 0xffffffffe102bd75 62: cmp $0x16,%eax 92: cmp $0x16,%rax 65: je 0x00000000000000bf 96: je 0x0000000000000110 67: jmp 0x00000000000000c6 98: jmp 0x0000000000000117 69: cmp $0x800,%eax 9a: cmp $0x800,%rax 6e: jne 0x00000000000000c6 a1: jne 0x0000000000000117 70: mov $0x17,%esi a3: mov $0x17,%esi 75: callq 0xffffffffe1021e31 a8: callq 0xffffffffe102bd91 7a: cmp $0x84,%eax ad: cmp $0x84,%rax 7f: je 0x000000000000008b b4: je 0x00000000000000c2 81: cmp $0x6,%eax b6: cmp $0x6,%rax 84: je 0x000000000000008b ba: je 0x00000000000000c2 86: cmp $0x11,%eax bc: cmp $0x11,%rax 89: jne 0x00000000000000c6 c0: jne 0x0000000000000117 8b: mov $0x14,%esi c2: mov $0x14,%esi 90: callq 0xffffffffe1021e15 c7: callq 0xffffffffe102bd75 95: test $0x1fff,%ax cc: test $0x1fff,%rax 99: jne 0x00000000000000c6 d3: jne 0x0000000000000117 d5: mov %rax,%r14 9b: mov $0xe,%esi d8: mov $0xe,%esi a0: callq 0xffffffffe1021e44 dd: callq 0xffffffffe102bd91 // MSH e2: and $0xf,%eax e5: shl $0x2,%eax e8: mov %rax,%r13 eb: mov %r14,%rax ee: mov %r13,%rsi a5: lea 0xe(%rbx),%esi f1: add $0xe,%esi a8: callq 0xffffffffe1021e0d f4: callq 0xffffffffe102bd6d ad: cmp $0x16,%eax f9: cmp $0x16,%rax b0: je 0x00000000000000bf fd: je 0x0000000000000110 ff: mov %r13,%rsi b2: lea 0x10(%rbx),%esi 102: add $0x10,%esi b5: callq 0xffffffffe1021e0d 105: callq 0xffffffffe102bd6d ba: cmp $0x16,%eax 10a: cmp $0x16,%rax bd: jne 0x00000000000000c6 10e: jne 0x0000000000000117 bf: mov $0xffff,%eax 110: mov $0xffff,%eax c4: jmp 0x00000000000000c8 115: jmp 0x000000000000011c c6: xor %eax,%eax 117: mov $0x0,%eax c8: mov -0x8(%rbp),%rbx 11c: mov -0x228(%rbp),%rbx // epilogue cc: leaveq 123: mov -0x220(%rbp),%r13 cd: retq 12a: mov -0x218(%rbp),%r14 131: mov -0x210(%rbp),%r15 138: leaveq 139: retq On fully cached SKBs both JITed functions take 12 nsec to execute. BPF interpreter executes the program in 30 nsec. The difference in generated assembler is due to the following: Old BPF imlements LDX_MSH instruction via sk_load_byte_msh() helper function inside bpf_jit.S. New JIT removes the helper and does it explicitly, so ldx_msh cost is the same for both JITs, but generated code looks longer. New JIT has 4 registers to save, so prologue/epilogue are larger, but the cost is within noise on x64. Old JIT checks whether first insn clears A and if not emits 'xor %eax,%eax'. New JIT clears %rax unconditionally. 2. old BPF JIT doesn't support ANC_NLATTR, ANC_PAY_OFFSET, ANC_RANDOM extensions. New JIT supports all BPF extensions. Performance of such filters improves 2-4 times depending on a filter. The longer the filter the higher performance gain. Synthetic benchmarks with many ancillary loads see 20x speedup which seems to be the maximum gain from JIT Notes: . net.core.bpf_jit_enable=2 + tools/net/bpf_jit_disasm is still functional and can be used to see generated assembler . there are two jit_compile() functions and code flow for classic filters is: sk_attach_filter() - load classic BPF bpf_jit_compile() - try to JIT from classic BPF sk_convert_filter() - convert classic to internal bpf_int_jit_compile() - JIT from internal BPF seccomp and tracing filters will just call bpf_int_jit_compile() Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 20:50:46 -06:00
st: if (is_imm8(insn->off))
net: filter: cleanup A/X name usage The macro 'A' used in internal BPF interpreter: #define A regs[insn->a_reg] was easily confused with the name of classic BPF register 'A', since 'A' would mean two different things depending on context. This patch is trying to clean up the naming and clarify its usage in the following way: - A and X are names of two classic BPF registers - BPF_REG_A denotes internal BPF register R0 used to map classic register A in internal BPF programs generated from classic - BPF_REG_X denotes internal BPF register R7 used to map classic register X in internal BPF programs generated from classic - internal BPF instruction format: struct sock_filter_int { __u8 code; /* opcode */ __u8 dst_reg:4; /* dest register */ __u8 src_reg:4; /* source register */ __s16 off; /* signed offset */ __s32 imm; /* signed immediate constant */ }; - BPF_X/BPF_K is 1 bit used to encode source operand of instruction In classic: BPF_X - means use register X as source operand BPF_K - means use 32-bit immediate as source operand In internal: BPF_X - means use 'src_reg' register as source operand BPF_K - means use 32-bit immediate as source operand Suggested-by: Chema Gonzalez <chema@google.com> Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Acked-by: Daniel Borkmann <dborkman@redhat.com> Acked-by: Chema Gonzalez <chema@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-06-06 15:46:06 -06:00
EMIT2(add_1reg(0x40, dst_reg), insn->off);
net: filter: x86: internal BPF JIT Maps all internal BPF instructions into x86_64 instructions. This patch replaces original BPF x64 JIT with internal BPF x64 JIT. sysctl net.core.bpf_jit_enable is reused as on/off switch. Performance: 1. old BPF JIT and internal BPF JIT generate equivalent x86_64 code. No performance difference is observed for filters that were JIT-able before Example assembler code for BPF filter "tcpdump port 22" original BPF -> old JIT: original BPF -> internal BPF -> new JIT: 0: push %rbp 0: push %rbp 1: mov %rsp,%rbp 1: mov %rsp,%rbp 4: sub $0x60,%rsp 4: sub $0x228,%rsp 8: mov %rbx,-0x8(%rbp) b: mov %rbx,-0x228(%rbp) // prologue 12: mov %r13,-0x220(%rbp) 19: mov %r14,-0x218(%rbp) 20: mov %r15,-0x210(%rbp) 27: xor %eax,%eax // clear A c: xor %ebx,%ebx 29: xor %r13,%r13 // clear X e: mov 0x68(%rdi),%r9d 2c: mov 0x68(%rdi),%r9d 12: sub 0x6c(%rdi),%r9d 30: sub 0x6c(%rdi),%r9d 16: mov 0xd8(%rdi),%r8 34: mov 0xd8(%rdi),%r10 3b: mov %rdi,%rbx 1d: mov $0xc,%esi 3e: mov $0xc,%esi 22: callq 0xffffffffe1021e15 43: callq 0xffffffffe102bd75 27: cmp $0x86dd,%eax 48: cmp $0x86dd,%rax 2c: jne 0x0000000000000069 4f: jne 0x000000000000009a 2e: mov $0x14,%esi 51: mov $0x14,%esi 33: callq 0xffffffffe1021e31 56: callq 0xffffffffe102bd91 38: cmp $0x84,%eax 5b: cmp $0x84,%rax 3d: je 0x0000000000000049 62: je 0x0000000000000074 3f: cmp $0x6,%eax 64: cmp $0x6,%rax 42: je 0x0000000000000049 68: je 0x0000000000000074 44: cmp $0x11,%eax 6a: cmp $0x11,%rax 47: jne 0x00000000000000c6 6e: jne 0x0000000000000117 49: mov $0x36,%esi 74: mov $0x36,%esi 4e: callq 0xffffffffe1021e15 79: callq 0xffffffffe102bd75 53: cmp $0x16,%eax 7e: cmp $0x16,%rax 56: je 0x00000000000000bf 82: je 0x0000000000000110 58: mov $0x38,%esi 88: mov $0x38,%esi 5d: callq 0xffffffffe1021e15 8d: callq 0xffffffffe102bd75 62: cmp $0x16,%eax 92: cmp $0x16,%rax 65: je 0x00000000000000bf 96: je 0x0000000000000110 67: jmp 0x00000000000000c6 98: jmp 0x0000000000000117 69: cmp $0x800,%eax 9a: cmp $0x800,%rax 6e: jne 0x00000000000000c6 a1: jne 0x0000000000000117 70: mov $0x17,%esi a3: mov $0x17,%esi 75: callq 0xffffffffe1021e31 a8: callq 0xffffffffe102bd91 7a: cmp $0x84,%eax ad: cmp $0x84,%rax 7f: je 0x000000000000008b b4: je 0x00000000000000c2 81: cmp $0x6,%eax b6: cmp $0x6,%rax 84: je 0x000000000000008b ba: je 0x00000000000000c2 86: cmp $0x11,%eax bc: cmp $0x11,%rax 89: jne 0x00000000000000c6 c0: jne 0x0000000000000117 8b: mov $0x14,%esi c2: mov $0x14,%esi 90: callq 0xffffffffe1021e15 c7: callq 0xffffffffe102bd75 95: test $0x1fff,%ax cc: test $0x1fff,%rax 99: jne 0x00000000000000c6 d3: jne 0x0000000000000117 d5: mov %rax,%r14 9b: mov $0xe,%esi d8: mov $0xe,%esi a0: callq 0xffffffffe1021e44 dd: callq 0xffffffffe102bd91 // MSH e2: and $0xf,%eax e5: shl $0x2,%eax e8: mov %rax,%r13 eb: mov %r14,%rax ee: mov %r13,%rsi a5: lea 0xe(%rbx),%esi f1: add $0xe,%esi a8: callq 0xffffffffe1021e0d f4: callq 0xffffffffe102bd6d ad: cmp $0x16,%eax f9: cmp $0x16,%rax b0: je 0x00000000000000bf fd: je 0x0000000000000110 ff: mov %r13,%rsi b2: lea 0x10(%rbx),%esi 102: add $0x10,%esi b5: callq 0xffffffffe1021e0d 105: callq 0xffffffffe102bd6d ba: cmp $0x16,%eax 10a: cmp $0x16,%rax bd: jne 0x00000000000000c6 10e: jne 0x0000000000000117 bf: mov $0xffff,%eax 110: mov $0xffff,%eax c4: jmp 0x00000000000000c8 115: jmp 0x000000000000011c c6: xor %eax,%eax 117: mov $0x0,%eax c8: mov -0x8(%rbp),%rbx 11c: mov -0x228(%rbp),%rbx // epilogue cc: leaveq 123: mov -0x220(%rbp),%r13 cd: retq 12a: mov -0x218(%rbp),%r14 131: mov -0x210(%rbp),%r15 138: leaveq 139: retq On fully cached SKBs both JITed functions take 12 nsec to execute. BPF interpreter executes the program in 30 nsec. The difference in generated assembler is due to the following: Old BPF imlements LDX_MSH instruction via sk_load_byte_msh() helper function inside bpf_jit.S. New JIT removes the helper and does it explicitly, so ldx_msh cost is the same for both JITs, but generated code looks longer. New JIT has 4 registers to save, so prologue/epilogue are larger, but the cost is within noise on x64. Old JIT checks whether first insn clears A and if not emits 'xor %eax,%eax'. New JIT clears %rax unconditionally. 2. old BPF JIT doesn't support ANC_NLATTR, ANC_PAY_OFFSET, ANC_RANDOM extensions. New JIT supports all BPF extensions. Performance of such filters improves 2-4 times depending on a filter. The longer the filter the higher performance gain. Synthetic benchmarks with many ancillary loads see 20x speedup which seems to be the maximum gain from JIT Notes: . net.core.bpf_jit_enable=2 + tools/net/bpf_jit_disasm is still functional and can be used to see generated assembler . there are two jit_compile() functions and code flow for classic filters is: sk_attach_filter() - load classic BPF bpf_jit_compile() - try to JIT from classic BPF sk_convert_filter() - convert classic to internal bpf_int_jit_compile() - JIT from internal BPF seccomp and tracing filters will just call bpf_int_jit_compile() Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 20:50:46 -06:00
else
net: filter: cleanup A/X name usage The macro 'A' used in internal BPF interpreter: #define A regs[insn->a_reg] was easily confused with the name of classic BPF register 'A', since 'A' would mean two different things depending on context. This patch is trying to clean up the naming and clarify its usage in the following way: - A and X are names of two classic BPF registers - BPF_REG_A denotes internal BPF register R0 used to map classic register A in internal BPF programs generated from classic - BPF_REG_X denotes internal BPF register R7 used to map classic register X in internal BPF programs generated from classic - internal BPF instruction format: struct sock_filter_int { __u8 code; /* opcode */ __u8 dst_reg:4; /* dest register */ __u8 src_reg:4; /* source register */ __s16 off; /* signed offset */ __s32 imm; /* signed immediate constant */ }; - BPF_X/BPF_K is 1 bit used to encode source operand of instruction In classic: BPF_X - means use register X as source operand BPF_K - means use 32-bit immediate as source operand In internal: BPF_X - means use 'src_reg' register as source operand BPF_K - means use 32-bit immediate as source operand Suggested-by: Chema Gonzalez <chema@google.com> Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Acked-by: Daniel Borkmann <dborkman@redhat.com> Acked-by: Chema Gonzalez <chema@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-06-06 15:46:06 -06:00
EMIT1_off32(add_1reg(0x80, dst_reg), insn->off);
net: filter: x86: internal BPF JIT Maps all internal BPF instructions into x86_64 instructions. This patch replaces original BPF x64 JIT with internal BPF x64 JIT. sysctl net.core.bpf_jit_enable is reused as on/off switch. Performance: 1. old BPF JIT and internal BPF JIT generate equivalent x86_64 code. No performance difference is observed for filters that were JIT-able before Example assembler code for BPF filter "tcpdump port 22" original BPF -> old JIT: original BPF -> internal BPF -> new JIT: 0: push %rbp 0: push %rbp 1: mov %rsp,%rbp 1: mov %rsp,%rbp 4: sub $0x60,%rsp 4: sub $0x228,%rsp 8: mov %rbx,-0x8(%rbp) b: mov %rbx,-0x228(%rbp) // prologue 12: mov %r13,-0x220(%rbp) 19: mov %r14,-0x218(%rbp) 20: mov %r15,-0x210(%rbp) 27: xor %eax,%eax // clear A c: xor %ebx,%ebx 29: xor %r13,%r13 // clear X e: mov 0x68(%rdi),%r9d 2c: mov 0x68(%rdi),%r9d 12: sub 0x6c(%rdi),%r9d 30: sub 0x6c(%rdi),%r9d 16: mov 0xd8(%rdi),%r8 34: mov 0xd8(%rdi),%r10 3b: mov %rdi,%rbx 1d: mov $0xc,%esi 3e: mov $0xc,%esi 22: callq 0xffffffffe1021e15 43: callq 0xffffffffe102bd75 27: cmp $0x86dd,%eax 48: cmp $0x86dd,%rax 2c: jne 0x0000000000000069 4f: jne 0x000000000000009a 2e: mov $0x14,%esi 51: mov $0x14,%esi 33: callq 0xffffffffe1021e31 56: callq 0xffffffffe102bd91 38: cmp $0x84,%eax 5b: cmp $0x84,%rax 3d: je 0x0000000000000049 62: je 0x0000000000000074 3f: cmp $0x6,%eax 64: cmp $0x6,%rax 42: je 0x0000000000000049 68: je 0x0000000000000074 44: cmp $0x11,%eax 6a: cmp $0x11,%rax 47: jne 0x00000000000000c6 6e: jne 0x0000000000000117 49: mov $0x36,%esi 74: mov $0x36,%esi 4e: callq 0xffffffffe1021e15 79: callq 0xffffffffe102bd75 53: cmp $0x16,%eax 7e: cmp $0x16,%rax 56: je 0x00000000000000bf 82: je 0x0000000000000110 58: mov $0x38,%esi 88: mov $0x38,%esi 5d: callq 0xffffffffe1021e15 8d: callq 0xffffffffe102bd75 62: cmp $0x16,%eax 92: cmp $0x16,%rax 65: je 0x00000000000000bf 96: je 0x0000000000000110 67: jmp 0x00000000000000c6 98: jmp 0x0000000000000117 69: cmp $0x800,%eax 9a: cmp $0x800,%rax 6e: jne 0x00000000000000c6 a1: jne 0x0000000000000117 70: mov $0x17,%esi a3: mov $0x17,%esi 75: callq 0xffffffffe1021e31 a8: callq 0xffffffffe102bd91 7a: cmp $0x84,%eax ad: cmp $0x84,%rax 7f: je 0x000000000000008b b4: je 0x00000000000000c2 81: cmp $0x6,%eax b6: cmp $0x6,%rax 84: je 0x000000000000008b ba: je 0x00000000000000c2 86: cmp $0x11,%eax bc: cmp $0x11,%rax 89: jne 0x00000000000000c6 c0: jne 0x0000000000000117 8b: mov $0x14,%esi c2: mov $0x14,%esi 90: callq 0xffffffffe1021e15 c7: callq 0xffffffffe102bd75 95: test $0x1fff,%ax cc: test $0x1fff,%rax 99: jne 0x00000000000000c6 d3: jne 0x0000000000000117 d5: mov %rax,%r14 9b: mov $0xe,%esi d8: mov $0xe,%esi a0: callq 0xffffffffe1021e44 dd: callq 0xffffffffe102bd91 // MSH e2: and $0xf,%eax e5: shl $0x2,%eax e8: mov %rax,%r13 eb: mov %r14,%rax ee: mov %r13,%rsi a5: lea 0xe(%rbx),%esi f1: add $0xe,%esi a8: callq 0xffffffffe1021e0d f4: callq 0xffffffffe102bd6d ad: cmp $0x16,%eax f9: cmp $0x16,%rax b0: je 0x00000000000000bf fd: je 0x0000000000000110 ff: mov %r13,%rsi b2: lea 0x10(%rbx),%esi 102: add $0x10,%esi b5: callq 0xffffffffe1021e0d 105: callq 0xffffffffe102bd6d ba: cmp $0x16,%eax 10a: cmp $0x16,%rax bd: jne 0x00000000000000c6 10e: jne 0x0000000000000117 bf: mov $0xffff,%eax 110: mov $0xffff,%eax c4: jmp 0x00000000000000c8 115: jmp 0x000000000000011c c6: xor %eax,%eax 117: mov $0x0,%eax c8: mov -0x8(%rbp),%rbx 11c: mov -0x228(%rbp),%rbx // epilogue cc: leaveq 123: mov -0x220(%rbp),%r13 cd: retq 12a: mov -0x218(%rbp),%r14 131: mov -0x210(%rbp),%r15 138: leaveq 139: retq On fully cached SKBs both JITed functions take 12 nsec to execute. BPF interpreter executes the program in 30 nsec. The difference in generated assembler is due to the following: Old BPF imlements LDX_MSH instruction via sk_load_byte_msh() helper function inside bpf_jit.S. New JIT removes the helper and does it explicitly, so ldx_msh cost is the same for both JITs, but generated code looks longer. New JIT has 4 registers to save, so prologue/epilogue are larger, but the cost is within noise on x64. Old JIT checks whether first insn clears A and if not emits 'xor %eax,%eax'. New JIT clears %rax unconditionally. 2. old BPF JIT doesn't support ANC_NLATTR, ANC_PAY_OFFSET, ANC_RANDOM extensions. New JIT supports all BPF extensions. Performance of such filters improves 2-4 times depending on a filter. The longer the filter the higher performance gain. Synthetic benchmarks with many ancillary loads see 20x speedup which seems to be the maximum gain from JIT Notes: . net.core.bpf_jit_enable=2 + tools/net/bpf_jit_disasm is still functional and can be used to see generated assembler . there are two jit_compile() functions and code flow for classic filters is: sk_attach_filter() - load classic BPF bpf_jit_compile() - try to JIT from classic BPF sk_convert_filter() - convert classic to internal bpf_int_jit_compile() - JIT from internal BPF seccomp and tracing filters will just call bpf_int_jit_compile() Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 20:50:46 -06:00
net: filter: cleanup A/X name usage The macro 'A' used in internal BPF interpreter: #define A regs[insn->a_reg] was easily confused with the name of classic BPF register 'A', since 'A' would mean two different things depending on context. This patch is trying to clean up the naming and clarify its usage in the following way: - A and X are names of two classic BPF registers - BPF_REG_A denotes internal BPF register R0 used to map classic register A in internal BPF programs generated from classic - BPF_REG_X denotes internal BPF register R7 used to map classic register X in internal BPF programs generated from classic - internal BPF instruction format: struct sock_filter_int { __u8 code; /* opcode */ __u8 dst_reg:4; /* dest register */ __u8 src_reg:4; /* source register */ __s16 off; /* signed offset */ __s32 imm; /* signed immediate constant */ }; - BPF_X/BPF_K is 1 bit used to encode source operand of instruction In classic: BPF_X - means use register X as source operand BPF_K - means use 32-bit immediate as source operand In internal: BPF_X - means use 'src_reg' register as source operand BPF_K - means use 32-bit immediate as source operand Suggested-by: Chema Gonzalez <chema@google.com> Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Acked-by: Daniel Borkmann <dborkman@redhat.com> Acked-by: Chema Gonzalez <chema@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-06-06 15:46:06 -06:00
EMIT(imm32, bpf_size_to_x86_bytes(BPF_SIZE(insn->code)));
net: filter: x86: internal BPF JIT Maps all internal BPF instructions into x86_64 instructions. This patch replaces original BPF x64 JIT with internal BPF x64 JIT. sysctl net.core.bpf_jit_enable is reused as on/off switch. Performance: 1. old BPF JIT and internal BPF JIT generate equivalent x86_64 code. No performance difference is observed for filters that were JIT-able before Example assembler code for BPF filter "tcpdump port 22" original BPF -> old JIT: original BPF -> internal BPF -> new JIT: 0: push %rbp 0: push %rbp 1: mov %rsp,%rbp 1: mov %rsp,%rbp 4: sub $0x60,%rsp 4: sub $0x228,%rsp 8: mov %rbx,-0x8(%rbp) b: mov %rbx,-0x228(%rbp) // prologue 12: mov %r13,-0x220(%rbp) 19: mov %r14,-0x218(%rbp) 20: mov %r15,-0x210(%rbp) 27: xor %eax,%eax // clear A c: xor %ebx,%ebx 29: xor %r13,%r13 // clear X e: mov 0x68(%rdi),%r9d 2c: mov 0x68(%rdi),%r9d 12: sub 0x6c(%rdi),%r9d 30: sub 0x6c(%rdi),%r9d 16: mov 0xd8(%rdi),%r8 34: mov 0xd8(%rdi),%r10 3b: mov %rdi,%rbx 1d: mov $0xc,%esi 3e: mov $0xc,%esi 22: callq 0xffffffffe1021e15 43: callq 0xffffffffe102bd75 27: cmp $0x86dd,%eax 48: cmp $0x86dd,%rax 2c: jne 0x0000000000000069 4f: jne 0x000000000000009a 2e: mov $0x14,%esi 51: mov $0x14,%esi 33: callq 0xffffffffe1021e31 56: callq 0xffffffffe102bd91 38: cmp $0x84,%eax 5b: cmp $0x84,%rax 3d: je 0x0000000000000049 62: je 0x0000000000000074 3f: cmp $0x6,%eax 64: cmp $0x6,%rax 42: je 0x0000000000000049 68: je 0x0000000000000074 44: cmp $0x11,%eax 6a: cmp $0x11,%rax 47: jne 0x00000000000000c6 6e: jne 0x0000000000000117 49: mov $0x36,%esi 74: mov $0x36,%esi 4e: callq 0xffffffffe1021e15 79: callq 0xffffffffe102bd75 53: cmp $0x16,%eax 7e: cmp $0x16,%rax 56: je 0x00000000000000bf 82: je 0x0000000000000110 58: mov $0x38,%esi 88: mov $0x38,%esi 5d: callq 0xffffffffe1021e15 8d: callq 0xffffffffe102bd75 62: cmp $0x16,%eax 92: cmp $0x16,%rax 65: je 0x00000000000000bf 96: je 0x0000000000000110 67: jmp 0x00000000000000c6 98: jmp 0x0000000000000117 69: cmp $0x800,%eax 9a: cmp $0x800,%rax 6e: jne 0x00000000000000c6 a1: jne 0x0000000000000117 70: mov $0x17,%esi a3: mov $0x17,%esi 75: callq 0xffffffffe1021e31 a8: callq 0xffffffffe102bd91 7a: cmp $0x84,%eax ad: cmp $0x84,%rax 7f: je 0x000000000000008b b4: je 0x00000000000000c2 81: cmp $0x6,%eax b6: cmp $0x6,%rax 84: je 0x000000000000008b ba: je 0x00000000000000c2 86: cmp $0x11,%eax bc: cmp $0x11,%rax 89: jne 0x00000000000000c6 c0: jne 0x0000000000000117 8b: mov $0x14,%esi c2: mov $0x14,%esi 90: callq 0xffffffffe1021e15 c7: callq 0xffffffffe102bd75 95: test $0x1fff,%ax cc: test $0x1fff,%rax 99: jne 0x00000000000000c6 d3: jne 0x0000000000000117 d5: mov %rax,%r14 9b: mov $0xe,%esi d8: mov $0xe,%esi a0: callq 0xffffffffe1021e44 dd: callq 0xffffffffe102bd91 // MSH e2: and $0xf,%eax e5: shl $0x2,%eax e8: mov %rax,%r13 eb: mov %r14,%rax ee: mov %r13,%rsi a5: lea 0xe(%rbx),%esi f1: add $0xe,%esi a8: callq 0xffffffffe1021e0d f4: callq 0xffffffffe102bd6d ad: cmp $0x16,%eax f9: cmp $0x16,%rax b0: je 0x00000000000000bf fd: je 0x0000000000000110 ff: mov %r13,%rsi b2: lea 0x10(%rbx),%esi 102: add $0x10,%esi b5: callq 0xffffffffe1021e0d 105: callq 0xffffffffe102bd6d ba: cmp $0x16,%eax 10a: cmp $0x16,%rax bd: jne 0x00000000000000c6 10e: jne 0x0000000000000117 bf: mov $0xffff,%eax 110: mov $0xffff,%eax c4: jmp 0x00000000000000c8 115: jmp 0x000000000000011c c6: xor %eax,%eax 117: mov $0x0,%eax c8: mov -0x8(%rbp),%rbx 11c: mov -0x228(%rbp),%rbx // epilogue cc: leaveq 123: mov -0x220(%rbp),%r13 cd: retq 12a: mov -0x218(%rbp),%r14 131: mov -0x210(%rbp),%r15 138: leaveq 139: retq On fully cached SKBs both JITed functions take 12 nsec to execute. BPF interpreter executes the program in 30 nsec. The difference in generated assembler is due to the following: Old BPF imlements LDX_MSH instruction via sk_load_byte_msh() helper function inside bpf_jit.S. New JIT removes the helper and does it explicitly, so ldx_msh cost is the same for both JITs, but generated code looks longer. New JIT has 4 registers to save, so prologue/epilogue are larger, but the cost is within noise on x64. Old JIT checks whether first insn clears A and if not emits 'xor %eax,%eax'. New JIT clears %rax unconditionally. 2. old BPF JIT doesn't support ANC_NLATTR, ANC_PAY_OFFSET, ANC_RANDOM extensions. New JIT supports all BPF extensions. Performance of such filters improves 2-4 times depending on a filter. The longer the filter the higher performance gain. Synthetic benchmarks with many ancillary loads see 20x speedup which seems to be the maximum gain from JIT Notes: . net.core.bpf_jit_enable=2 + tools/net/bpf_jit_disasm is still functional and can be used to see generated assembler . there are two jit_compile() functions and code flow for classic filters is: sk_attach_filter() - load classic BPF bpf_jit_compile() - try to JIT from classic BPF sk_convert_filter() - convert classic to internal bpf_int_jit_compile() - JIT from internal BPF seccomp and tracing filters will just call bpf_int_jit_compile() Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 20:50:46 -06:00
break;
net: filter: cleanup A/X name usage The macro 'A' used in internal BPF interpreter: #define A regs[insn->a_reg] was easily confused with the name of classic BPF register 'A', since 'A' would mean two different things depending on context. This patch is trying to clean up the naming and clarify its usage in the following way: - A and X are names of two classic BPF registers - BPF_REG_A denotes internal BPF register R0 used to map classic register A in internal BPF programs generated from classic - BPF_REG_X denotes internal BPF register R7 used to map classic register X in internal BPF programs generated from classic - internal BPF instruction format: struct sock_filter_int { __u8 code; /* opcode */ __u8 dst_reg:4; /* dest register */ __u8 src_reg:4; /* source register */ __s16 off; /* signed offset */ __s32 imm; /* signed immediate constant */ }; - BPF_X/BPF_K is 1 bit used to encode source operand of instruction In classic: BPF_X - means use register X as source operand BPF_K - means use 32-bit immediate as source operand In internal: BPF_X - means use 'src_reg' register as source operand BPF_K - means use 32-bit immediate as source operand Suggested-by: Chema Gonzalez <chema@google.com> Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Acked-by: Daniel Borkmann <dborkman@redhat.com> Acked-by: Chema Gonzalez <chema@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-06-06 15:46:06 -06:00
/* STX: *(u8*)(dst_reg + off) = src_reg */
net: filter: x86: internal BPF JIT Maps all internal BPF instructions into x86_64 instructions. This patch replaces original BPF x64 JIT with internal BPF x64 JIT. sysctl net.core.bpf_jit_enable is reused as on/off switch. Performance: 1. old BPF JIT and internal BPF JIT generate equivalent x86_64 code. No performance difference is observed for filters that were JIT-able before Example assembler code for BPF filter "tcpdump port 22" original BPF -> old JIT: original BPF -> internal BPF -> new JIT: 0: push %rbp 0: push %rbp 1: mov %rsp,%rbp 1: mov %rsp,%rbp 4: sub $0x60,%rsp 4: sub $0x228,%rsp 8: mov %rbx,-0x8(%rbp) b: mov %rbx,-0x228(%rbp) // prologue 12: mov %r13,-0x220(%rbp) 19: mov %r14,-0x218(%rbp) 20: mov %r15,-0x210(%rbp) 27: xor %eax,%eax // clear A c: xor %ebx,%ebx 29: xor %r13,%r13 // clear X e: mov 0x68(%rdi),%r9d 2c: mov 0x68(%rdi),%r9d 12: sub 0x6c(%rdi),%r9d 30: sub 0x6c(%rdi),%r9d 16: mov 0xd8(%rdi),%r8 34: mov 0xd8(%rdi),%r10 3b: mov %rdi,%rbx 1d: mov $0xc,%esi 3e: mov $0xc,%esi 22: callq 0xffffffffe1021e15 43: callq 0xffffffffe102bd75 27: cmp $0x86dd,%eax 48: cmp $0x86dd,%rax 2c: jne 0x0000000000000069 4f: jne 0x000000000000009a 2e: mov $0x14,%esi 51: mov $0x14,%esi 33: callq 0xffffffffe1021e31 56: callq 0xffffffffe102bd91 38: cmp $0x84,%eax 5b: cmp $0x84,%rax 3d: je 0x0000000000000049 62: je 0x0000000000000074 3f: cmp $0x6,%eax 64: cmp $0x6,%rax 42: je 0x0000000000000049 68: je 0x0000000000000074 44: cmp $0x11,%eax 6a: cmp $0x11,%rax 47: jne 0x00000000000000c6 6e: jne 0x0000000000000117 49: mov $0x36,%esi 74: mov $0x36,%esi 4e: callq 0xffffffffe1021e15 79: callq 0xffffffffe102bd75 53: cmp $0x16,%eax 7e: cmp $0x16,%rax 56: je 0x00000000000000bf 82: je 0x0000000000000110 58: mov $0x38,%esi 88: mov $0x38,%esi 5d: callq 0xffffffffe1021e15 8d: callq 0xffffffffe102bd75 62: cmp $0x16,%eax 92: cmp $0x16,%rax 65: je 0x00000000000000bf 96: je 0x0000000000000110 67: jmp 0x00000000000000c6 98: jmp 0x0000000000000117 69: cmp $0x800,%eax 9a: cmp $0x800,%rax 6e: jne 0x00000000000000c6 a1: jne 0x0000000000000117 70: mov $0x17,%esi a3: mov $0x17,%esi 75: callq 0xffffffffe1021e31 a8: callq 0xffffffffe102bd91 7a: cmp $0x84,%eax ad: cmp $0x84,%rax 7f: je 0x000000000000008b b4: je 0x00000000000000c2 81: cmp $0x6,%eax b6: cmp $0x6,%rax 84: je 0x000000000000008b ba: je 0x00000000000000c2 86: cmp $0x11,%eax bc: cmp $0x11,%rax 89: jne 0x00000000000000c6 c0: jne 0x0000000000000117 8b: mov $0x14,%esi c2: mov $0x14,%esi 90: callq 0xffffffffe1021e15 c7: callq 0xffffffffe102bd75 95: test $0x1fff,%ax cc: test $0x1fff,%rax 99: jne 0x00000000000000c6 d3: jne 0x0000000000000117 d5: mov %rax,%r14 9b: mov $0xe,%esi d8: mov $0xe,%esi a0: callq 0xffffffffe1021e44 dd: callq 0xffffffffe102bd91 // MSH e2: and $0xf,%eax e5: shl $0x2,%eax e8: mov %rax,%r13 eb: mov %r14,%rax ee: mov %r13,%rsi a5: lea 0xe(%rbx),%esi f1: add $0xe,%esi a8: callq 0xffffffffe1021e0d f4: callq 0xffffffffe102bd6d ad: cmp $0x16,%eax f9: cmp $0x16,%rax b0: je 0x00000000000000bf fd: je 0x0000000000000110 ff: mov %r13,%rsi b2: lea 0x10(%rbx),%esi 102: add $0x10,%esi b5: callq 0xffffffffe1021e0d 105: callq 0xffffffffe102bd6d ba: cmp $0x16,%eax 10a: cmp $0x16,%rax bd: jne 0x00000000000000c6 10e: jne 0x0000000000000117 bf: mov $0xffff,%eax 110: mov $0xffff,%eax c4: jmp 0x00000000000000c8 115: jmp 0x000000000000011c c6: xor %eax,%eax 117: mov $0x0,%eax c8: mov -0x8(%rbp),%rbx 11c: mov -0x228(%rbp),%rbx // epilogue cc: leaveq 123: mov -0x220(%rbp),%r13 cd: retq 12a: mov -0x218(%rbp),%r14 131: mov -0x210(%rbp),%r15 138: leaveq 139: retq On fully cached SKBs both JITed functions take 12 nsec to execute. BPF interpreter executes the program in 30 nsec. The difference in generated assembler is due to the following: Old BPF imlements LDX_MSH instruction via sk_load_byte_msh() helper function inside bpf_jit.S. New JIT removes the helper and does it explicitly, so ldx_msh cost is the same for both JITs, but generated code looks longer. New JIT has 4 registers to save, so prologue/epilogue are larger, but the cost is within noise on x64. Old JIT checks whether first insn clears A and if not emits 'xor %eax,%eax'. New JIT clears %rax unconditionally. 2. old BPF JIT doesn't support ANC_NLATTR, ANC_PAY_OFFSET, ANC_RANDOM extensions. New JIT supports all BPF extensions. Performance of such filters improves 2-4 times depending on a filter. The longer the filter the higher performance gain. Synthetic benchmarks with many ancillary loads see 20x speedup which seems to be the maximum gain from JIT Notes: . net.core.bpf_jit_enable=2 + tools/net/bpf_jit_disasm is still functional and can be used to see generated assembler . there are two jit_compile() functions and code flow for classic filters is: sk_attach_filter() - load classic BPF bpf_jit_compile() - try to JIT from classic BPF sk_convert_filter() - convert classic to internal bpf_int_jit_compile() - JIT from internal BPF seccomp and tracing filters will just call bpf_int_jit_compile() Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 20:50:46 -06:00
case BPF_STX | BPF_MEM | BPF_B:
/* emit 'mov byte ptr [rax + off], al' */
net: filter: cleanup A/X name usage The macro 'A' used in internal BPF interpreter: #define A regs[insn->a_reg] was easily confused with the name of classic BPF register 'A', since 'A' would mean two different things depending on context. This patch is trying to clean up the naming and clarify its usage in the following way: - A and X are names of two classic BPF registers - BPF_REG_A denotes internal BPF register R0 used to map classic register A in internal BPF programs generated from classic - BPF_REG_X denotes internal BPF register R7 used to map classic register X in internal BPF programs generated from classic - internal BPF instruction format: struct sock_filter_int { __u8 code; /* opcode */ __u8 dst_reg:4; /* dest register */ __u8 src_reg:4; /* source register */ __s16 off; /* signed offset */ __s32 imm; /* signed immediate constant */ }; - BPF_X/BPF_K is 1 bit used to encode source operand of instruction In classic: BPF_X - means use register X as source operand BPF_K - means use 32-bit immediate as source operand In internal: BPF_X - means use 'src_reg' register as source operand BPF_K - means use 32-bit immediate as source operand Suggested-by: Chema Gonzalez <chema@google.com> Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Acked-by: Daniel Borkmann <dborkman@redhat.com> Acked-by: Chema Gonzalez <chema@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-06-06 15:46:06 -06:00
if (is_ereg(dst_reg) || is_ereg(src_reg) ||
net: filter: x86: internal BPF JIT Maps all internal BPF instructions into x86_64 instructions. This patch replaces original BPF x64 JIT with internal BPF x64 JIT. sysctl net.core.bpf_jit_enable is reused as on/off switch. Performance: 1. old BPF JIT and internal BPF JIT generate equivalent x86_64 code. No performance difference is observed for filters that were JIT-able before Example assembler code for BPF filter "tcpdump port 22" original BPF -> old JIT: original BPF -> internal BPF -> new JIT: 0: push %rbp 0: push %rbp 1: mov %rsp,%rbp 1: mov %rsp,%rbp 4: sub $0x60,%rsp 4: sub $0x228,%rsp 8: mov %rbx,-0x8(%rbp) b: mov %rbx,-0x228(%rbp) // prologue 12: mov %r13,-0x220(%rbp) 19: mov %r14,-0x218(%rbp) 20: mov %r15,-0x210(%rbp) 27: xor %eax,%eax // clear A c: xor %ebx,%ebx 29: xor %r13,%r13 // clear X e: mov 0x68(%rdi),%r9d 2c: mov 0x68(%rdi),%r9d 12: sub 0x6c(%rdi),%r9d 30: sub 0x6c(%rdi),%r9d 16: mov 0xd8(%rdi),%r8 34: mov 0xd8(%rdi),%r10 3b: mov %rdi,%rbx 1d: mov $0xc,%esi 3e: mov $0xc,%esi 22: callq 0xffffffffe1021e15 43: callq 0xffffffffe102bd75 27: cmp $0x86dd,%eax 48: cmp $0x86dd,%rax 2c: jne 0x0000000000000069 4f: jne 0x000000000000009a 2e: mov $0x14,%esi 51: mov $0x14,%esi 33: callq 0xffffffffe1021e31 56: callq 0xffffffffe102bd91 38: cmp $0x84,%eax 5b: cmp $0x84,%rax 3d: je 0x0000000000000049 62: je 0x0000000000000074 3f: cmp $0x6,%eax 64: cmp $0x6,%rax 42: je 0x0000000000000049 68: je 0x0000000000000074 44: cmp $0x11,%eax 6a: cmp $0x11,%rax 47: jne 0x00000000000000c6 6e: jne 0x0000000000000117 49: mov $0x36,%esi 74: mov $0x36,%esi 4e: callq 0xffffffffe1021e15 79: callq 0xffffffffe102bd75 53: cmp $0x16,%eax 7e: cmp $0x16,%rax 56: je 0x00000000000000bf 82: je 0x0000000000000110 58: mov $0x38,%esi 88: mov $0x38,%esi 5d: callq 0xffffffffe1021e15 8d: callq 0xffffffffe102bd75 62: cmp $0x16,%eax 92: cmp $0x16,%rax 65: je 0x00000000000000bf 96: je 0x0000000000000110 67: jmp 0x00000000000000c6 98: jmp 0x0000000000000117 69: cmp $0x800,%eax 9a: cmp $0x800,%rax 6e: jne 0x00000000000000c6 a1: jne 0x0000000000000117 70: mov $0x17,%esi a3: mov $0x17,%esi 75: callq 0xffffffffe1021e31 a8: callq 0xffffffffe102bd91 7a: cmp $0x84,%eax ad: cmp $0x84,%rax 7f: je 0x000000000000008b b4: je 0x00000000000000c2 81: cmp $0x6,%eax b6: cmp $0x6,%rax 84: je 0x000000000000008b ba: je 0x00000000000000c2 86: cmp $0x11,%eax bc: cmp $0x11,%rax 89: jne 0x00000000000000c6 c0: jne 0x0000000000000117 8b: mov $0x14,%esi c2: mov $0x14,%esi 90: callq 0xffffffffe1021e15 c7: callq 0xffffffffe102bd75 95: test $0x1fff,%ax cc: test $0x1fff,%rax 99: jne 0x00000000000000c6 d3: jne 0x0000000000000117 d5: mov %rax,%r14 9b: mov $0xe,%esi d8: mov $0xe,%esi a0: callq 0xffffffffe1021e44 dd: callq 0xffffffffe102bd91 // MSH e2: and $0xf,%eax e5: shl $0x2,%eax e8: mov %rax,%r13 eb: mov %r14,%rax ee: mov %r13,%rsi a5: lea 0xe(%rbx),%esi f1: add $0xe,%esi a8: callq 0xffffffffe1021e0d f4: callq 0xffffffffe102bd6d ad: cmp $0x16,%eax f9: cmp $0x16,%rax b0: je 0x00000000000000bf fd: je 0x0000000000000110 ff: mov %r13,%rsi b2: lea 0x10(%rbx),%esi 102: add $0x10,%esi b5: callq 0xffffffffe1021e0d 105: callq 0xffffffffe102bd6d ba: cmp $0x16,%eax 10a: cmp $0x16,%rax bd: jne 0x00000000000000c6 10e: jne 0x0000000000000117 bf: mov $0xffff,%eax 110: mov $0xffff,%eax c4: jmp 0x00000000000000c8 115: jmp 0x000000000000011c c6: xor %eax,%eax 117: mov $0x0,%eax c8: mov -0x8(%rbp),%rbx 11c: mov -0x228(%rbp),%rbx // epilogue cc: leaveq 123: mov -0x220(%rbp),%r13 cd: retq 12a: mov -0x218(%rbp),%r14 131: mov -0x210(%rbp),%r15 138: leaveq 139: retq On fully cached SKBs both JITed functions take 12 nsec to execute. BPF interpreter executes the program in 30 nsec. The difference in generated assembler is due to the following: Old BPF imlements LDX_MSH instruction via sk_load_byte_msh() helper function inside bpf_jit.S. New JIT removes the helper and does it explicitly, so ldx_msh cost is the same for both JITs, but generated code looks longer. New JIT has 4 registers to save, so prologue/epilogue are larger, but the cost is within noise on x64. Old JIT checks whether first insn clears A and if not emits 'xor %eax,%eax'. New JIT clears %rax unconditionally. 2. old BPF JIT doesn't support ANC_NLATTR, ANC_PAY_OFFSET, ANC_RANDOM extensions. New JIT supports all BPF extensions. Performance of such filters improves 2-4 times depending on a filter. The longer the filter the higher performance gain. Synthetic benchmarks with many ancillary loads see 20x speedup which seems to be the maximum gain from JIT Notes: . net.core.bpf_jit_enable=2 + tools/net/bpf_jit_disasm is still functional and can be used to see generated assembler . there are two jit_compile() functions and code flow for classic filters is: sk_attach_filter() - load classic BPF bpf_jit_compile() - try to JIT from classic BPF sk_convert_filter() - convert classic to internal bpf_int_jit_compile() - JIT from internal BPF seccomp and tracing filters will just call bpf_int_jit_compile() Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 20:50:46 -06:00
/* have to add extra byte for x86 SIL, DIL regs */
net: filter: cleanup A/X name usage The macro 'A' used in internal BPF interpreter: #define A regs[insn->a_reg] was easily confused with the name of classic BPF register 'A', since 'A' would mean two different things depending on context. This patch is trying to clean up the naming and clarify its usage in the following way: - A and X are names of two classic BPF registers - BPF_REG_A denotes internal BPF register R0 used to map classic register A in internal BPF programs generated from classic - BPF_REG_X denotes internal BPF register R7 used to map classic register X in internal BPF programs generated from classic - internal BPF instruction format: struct sock_filter_int { __u8 code; /* opcode */ __u8 dst_reg:4; /* dest register */ __u8 src_reg:4; /* source register */ __s16 off; /* signed offset */ __s32 imm; /* signed immediate constant */ }; - BPF_X/BPF_K is 1 bit used to encode source operand of instruction In classic: BPF_X - means use register X as source operand BPF_K - means use 32-bit immediate as source operand In internal: BPF_X - means use 'src_reg' register as source operand BPF_K - means use 32-bit immediate as source operand Suggested-by: Chema Gonzalez <chema@google.com> Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Acked-by: Daniel Borkmann <dborkman@redhat.com> Acked-by: Chema Gonzalez <chema@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-06-06 15:46:06 -06:00
src_reg == BPF_REG_1 || src_reg == BPF_REG_2)
EMIT2(add_2mod(0x40, dst_reg, src_reg), 0x88);
net: filter: x86: internal BPF JIT Maps all internal BPF instructions into x86_64 instructions. This patch replaces original BPF x64 JIT with internal BPF x64 JIT. sysctl net.core.bpf_jit_enable is reused as on/off switch. Performance: 1. old BPF JIT and internal BPF JIT generate equivalent x86_64 code. No performance difference is observed for filters that were JIT-able before Example assembler code for BPF filter "tcpdump port 22" original BPF -> old JIT: original BPF -> internal BPF -> new JIT: 0: push %rbp 0: push %rbp 1: mov %rsp,%rbp 1: mov %rsp,%rbp 4: sub $0x60,%rsp 4: sub $0x228,%rsp 8: mov %rbx,-0x8(%rbp) b: mov %rbx,-0x228(%rbp) // prologue 12: mov %r13,-0x220(%rbp) 19: mov %r14,-0x218(%rbp) 20: mov %r15,-0x210(%rbp) 27: xor %eax,%eax // clear A c: xor %ebx,%ebx 29: xor %r13,%r13 // clear X e: mov 0x68(%rdi),%r9d 2c: mov 0x68(%rdi),%r9d 12: sub 0x6c(%rdi),%r9d 30: sub 0x6c(%rdi),%r9d 16: mov 0xd8(%rdi),%r8 34: mov 0xd8(%rdi),%r10 3b: mov %rdi,%rbx 1d: mov $0xc,%esi 3e: mov $0xc,%esi 22: callq 0xffffffffe1021e15 43: callq 0xffffffffe102bd75 27: cmp $0x86dd,%eax 48: cmp $0x86dd,%rax 2c: jne 0x0000000000000069 4f: jne 0x000000000000009a 2e: mov $0x14,%esi 51: mov $0x14,%esi 33: callq 0xffffffffe1021e31 56: callq 0xffffffffe102bd91 38: cmp $0x84,%eax 5b: cmp $0x84,%rax 3d: je 0x0000000000000049 62: je 0x0000000000000074 3f: cmp $0x6,%eax 64: cmp $0x6,%rax 42: je 0x0000000000000049 68: je 0x0000000000000074 44: cmp $0x11,%eax 6a: cmp $0x11,%rax 47: jne 0x00000000000000c6 6e: jne 0x0000000000000117 49: mov $0x36,%esi 74: mov $0x36,%esi 4e: callq 0xffffffffe1021e15 79: callq 0xffffffffe102bd75 53: cmp $0x16,%eax 7e: cmp $0x16,%rax 56: je 0x00000000000000bf 82: je 0x0000000000000110 58: mov $0x38,%esi 88: mov $0x38,%esi 5d: callq 0xffffffffe1021e15 8d: callq 0xffffffffe102bd75 62: cmp $0x16,%eax 92: cmp $0x16,%rax 65: je 0x00000000000000bf 96: je 0x0000000000000110 67: jmp 0x00000000000000c6 98: jmp 0x0000000000000117 69: cmp $0x800,%eax 9a: cmp $0x800,%rax 6e: jne 0x00000000000000c6 a1: jne 0x0000000000000117 70: mov $0x17,%esi a3: mov $0x17,%esi 75: callq 0xffffffffe1021e31 a8: callq 0xffffffffe102bd91 7a: cmp $0x84,%eax ad: cmp $0x84,%rax 7f: je 0x000000000000008b b4: je 0x00000000000000c2 81: cmp $0x6,%eax b6: cmp $0x6,%rax 84: je 0x000000000000008b ba: je 0x00000000000000c2 86: cmp $0x11,%eax bc: cmp $0x11,%rax 89: jne 0x00000000000000c6 c0: jne 0x0000000000000117 8b: mov $0x14,%esi c2: mov $0x14,%esi 90: callq 0xffffffffe1021e15 c7: callq 0xffffffffe102bd75 95: test $0x1fff,%ax cc: test $0x1fff,%rax 99: jne 0x00000000000000c6 d3: jne 0x0000000000000117 d5: mov %rax,%r14 9b: mov $0xe,%esi d8: mov $0xe,%esi a0: callq 0xffffffffe1021e44 dd: callq 0xffffffffe102bd91 // MSH e2: and $0xf,%eax e5: shl $0x2,%eax e8: mov %rax,%r13 eb: mov %r14,%rax ee: mov %r13,%rsi a5: lea 0xe(%rbx),%esi f1: add $0xe,%esi a8: callq 0xffffffffe1021e0d f4: callq 0xffffffffe102bd6d ad: cmp $0x16,%eax f9: cmp $0x16,%rax b0: je 0x00000000000000bf fd: je 0x0000000000000110 ff: mov %r13,%rsi b2: lea 0x10(%rbx),%esi 102: add $0x10,%esi b5: callq 0xffffffffe1021e0d 105: callq 0xffffffffe102bd6d ba: cmp $0x16,%eax 10a: cmp $0x16,%rax bd: jne 0x00000000000000c6 10e: jne 0x0000000000000117 bf: mov $0xffff,%eax 110: mov $0xffff,%eax c4: jmp 0x00000000000000c8 115: jmp 0x000000000000011c c6: xor %eax,%eax 117: mov $0x0,%eax c8: mov -0x8(%rbp),%rbx 11c: mov -0x228(%rbp),%rbx // epilogue cc: leaveq 123: mov -0x220(%rbp),%r13 cd: retq 12a: mov -0x218(%rbp),%r14 131: mov -0x210(%rbp),%r15 138: leaveq 139: retq On fully cached SKBs both JITed functions take 12 nsec to execute. BPF interpreter executes the program in 30 nsec. The difference in generated assembler is due to the following: Old BPF imlements LDX_MSH instruction via sk_load_byte_msh() helper function inside bpf_jit.S. New JIT removes the helper and does it explicitly, so ldx_msh cost is the same for both JITs, but generated code looks longer. New JIT has 4 registers to save, so prologue/epilogue are larger, but the cost is within noise on x64. Old JIT checks whether first insn clears A and if not emits 'xor %eax,%eax'. New JIT clears %rax unconditionally. 2. old BPF JIT doesn't support ANC_NLATTR, ANC_PAY_OFFSET, ANC_RANDOM extensions. New JIT supports all BPF extensions. Performance of such filters improves 2-4 times depending on a filter. The longer the filter the higher performance gain. Synthetic benchmarks with many ancillary loads see 20x speedup which seems to be the maximum gain from JIT Notes: . net.core.bpf_jit_enable=2 + tools/net/bpf_jit_disasm is still functional and can be used to see generated assembler . there are two jit_compile() functions and code flow for classic filters is: sk_attach_filter() - load classic BPF bpf_jit_compile() - try to JIT from classic BPF sk_convert_filter() - convert classic to internal bpf_int_jit_compile() - JIT from internal BPF seccomp and tracing filters will just call bpf_int_jit_compile() Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 20:50:46 -06:00
else
EMIT1(0x88);
goto stx;
case BPF_STX | BPF_MEM | BPF_H:
net: filter: cleanup A/X name usage The macro 'A' used in internal BPF interpreter: #define A regs[insn->a_reg] was easily confused with the name of classic BPF register 'A', since 'A' would mean two different things depending on context. This patch is trying to clean up the naming and clarify its usage in the following way: - A and X are names of two classic BPF registers - BPF_REG_A denotes internal BPF register R0 used to map classic register A in internal BPF programs generated from classic - BPF_REG_X denotes internal BPF register R7 used to map classic register X in internal BPF programs generated from classic - internal BPF instruction format: struct sock_filter_int { __u8 code; /* opcode */ __u8 dst_reg:4; /* dest register */ __u8 src_reg:4; /* source register */ __s16 off; /* signed offset */ __s32 imm; /* signed immediate constant */ }; - BPF_X/BPF_K is 1 bit used to encode source operand of instruction In classic: BPF_X - means use register X as source operand BPF_K - means use 32-bit immediate as source operand In internal: BPF_X - means use 'src_reg' register as source operand BPF_K - means use 32-bit immediate as source operand Suggested-by: Chema Gonzalez <chema@google.com> Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Acked-by: Daniel Borkmann <dborkman@redhat.com> Acked-by: Chema Gonzalez <chema@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-06-06 15:46:06 -06:00
if (is_ereg(dst_reg) || is_ereg(src_reg))
EMIT3(0x66, add_2mod(0x40, dst_reg, src_reg), 0x89);
net: filter: x86: internal BPF JIT Maps all internal BPF instructions into x86_64 instructions. This patch replaces original BPF x64 JIT with internal BPF x64 JIT. sysctl net.core.bpf_jit_enable is reused as on/off switch. Performance: 1. old BPF JIT and internal BPF JIT generate equivalent x86_64 code. No performance difference is observed for filters that were JIT-able before Example assembler code for BPF filter "tcpdump port 22" original BPF -> old JIT: original BPF -> internal BPF -> new JIT: 0: push %rbp 0: push %rbp 1: mov %rsp,%rbp 1: mov %rsp,%rbp 4: sub $0x60,%rsp 4: sub $0x228,%rsp 8: mov %rbx,-0x8(%rbp) b: mov %rbx,-0x228(%rbp) // prologue 12: mov %r13,-0x220(%rbp) 19: mov %r14,-0x218(%rbp) 20: mov %r15,-0x210(%rbp) 27: xor %eax,%eax // clear A c: xor %ebx,%ebx 29: xor %r13,%r13 // clear X e: mov 0x68(%rdi),%r9d 2c: mov 0x68(%rdi),%r9d 12: sub 0x6c(%rdi),%r9d 30: sub 0x6c(%rdi),%r9d 16: mov 0xd8(%rdi),%r8 34: mov 0xd8(%rdi),%r10 3b: mov %rdi,%rbx 1d: mov $0xc,%esi 3e: mov $0xc,%esi 22: callq 0xffffffffe1021e15 43: callq 0xffffffffe102bd75 27: cmp $0x86dd,%eax 48: cmp $0x86dd,%rax 2c: jne 0x0000000000000069 4f: jne 0x000000000000009a 2e: mov $0x14,%esi 51: mov $0x14,%esi 33: callq 0xffffffffe1021e31 56: callq 0xffffffffe102bd91 38: cmp $0x84,%eax 5b: cmp $0x84,%rax 3d: je 0x0000000000000049 62: je 0x0000000000000074 3f: cmp $0x6,%eax 64: cmp $0x6,%rax 42: je 0x0000000000000049 68: je 0x0000000000000074 44: cmp $0x11,%eax 6a: cmp $0x11,%rax 47: jne 0x00000000000000c6 6e: jne 0x0000000000000117 49: mov $0x36,%esi 74: mov $0x36,%esi 4e: callq 0xffffffffe1021e15 79: callq 0xffffffffe102bd75 53: cmp $0x16,%eax 7e: cmp $0x16,%rax 56: je 0x00000000000000bf 82: je 0x0000000000000110 58: mov $0x38,%esi 88: mov $0x38,%esi 5d: callq 0xffffffffe1021e15 8d: callq 0xffffffffe102bd75 62: cmp $0x16,%eax 92: cmp $0x16,%rax 65: je 0x00000000000000bf 96: je 0x0000000000000110 67: jmp 0x00000000000000c6 98: jmp 0x0000000000000117 69: cmp $0x800,%eax 9a: cmp $0x800,%rax 6e: jne 0x00000000000000c6 a1: jne 0x0000000000000117 70: mov $0x17,%esi a3: mov $0x17,%esi 75: callq 0xffffffffe1021e31 a8: callq 0xffffffffe102bd91 7a: cmp $0x84,%eax ad: cmp $0x84,%rax 7f: je 0x000000000000008b b4: je 0x00000000000000c2 81: cmp $0x6,%eax b6: cmp $0x6,%rax 84: je 0x000000000000008b ba: je 0x00000000000000c2 86: cmp $0x11,%eax bc: cmp $0x11,%rax 89: jne 0x00000000000000c6 c0: jne 0x0000000000000117 8b: mov $0x14,%esi c2: mov $0x14,%esi 90: callq 0xffffffffe1021e15 c7: callq 0xffffffffe102bd75 95: test $0x1fff,%ax cc: test $0x1fff,%rax 99: jne 0x00000000000000c6 d3: jne 0x0000000000000117 d5: mov %rax,%r14 9b: mov $0xe,%esi d8: mov $0xe,%esi a0: callq 0xffffffffe1021e44 dd: callq 0xffffffffe102bd91 // MSH e2: and $0xf,%eax e5: shl $0x2,%eax e8: mov %rax,%r13 eb: mov %r14,%rax ee: mov %r13,%rsi a5: lea 0xe(%rbx),%esi f1: add $0xe,%esi a8: callq 0xffffffffe1021e0d f4: callq 0xffffffffe102bd6d ad: cmp $0x16,%eax f9: cmp $0x16,%rax b0: je 0x00000000000000bf fd: je 0x0000000000000110 ff: mov %r13,%rsi b2: lea 0x10(%rbx),%esi 102: add $0x10,%esi b5: callq 0xffffffffe1021e0d 105: callq 0xffffffffe102bd6d ba: cmp $0x16,%eax 10a: cmp $0x16,%rax bd: jne 0x00000000000000c6 10e: jne 0x0000000000000117 bf: mov $0xffff,%eax 110: mov $0xffff,%eax c4: jmp 0x00000000000000c8 115: jmp 0x000000000000011c c6: xor %eax,%eax 117: mov $0x0,%eax c8: mov -0x8(%rbp),%rbx 11c: mov -0x228(%rbp),%rbx // epilogue cc: leaveq 123: mov -0x220(%rbp),%r13 cd: retq 12a: mov -0x218(%rbp),%r14 131: mov -0x210(%rbp),%r15 138: leaveq 139: retq On fully cached SKBs both JITed functions take 12 nsec to execute. BPF interpreter executes the program in 30 nsec. The difference in generated assembler is due to the following: Old BPF imlements LDX_MSH instruction via sk_load_byte_msh() helper function inside bpf_jit.S. New JIT removes the helper and does it explicitly, so ldx_msh cost is the same for both JITs, but generated code looks longer. New JIT has 4 registers to save, so prologue/epilogue are larger, but the cost is within noise on x64. Old JIT checks whether first insn clears A and if not emits 'xor %eax,%eax'. New JIT clears %rax unconditionally. 2. old BPF JIT doesn't support ANC_NLATTR, ANC_PAY_OFFSET, ANC_RANDOM extensions. New JIT supports all BPF extensions. Performance of such filters improves 2-4 times depending on a filter. The longer the filter the higher performance gain. Synthetic benchmarks with many ancillary loads see 20x speedup which seems to be the maximum gain from JIT Notes: . net.core.bpf_jit_enable=2 + tools/net/bpf_jit_disasm is still functional and can be used to see generated assembler . there are two jit_compile() functions and code flow for classic filters is: sk_attach_filter() - load classic BPF bpf_jit_compile() - try to JIT from classic BPF sk_convert_filter() - convert classic to internal bpf_int_jit_compile() - JIT from internal BPF seccomp and tracing filters will just call bpf_int_jit_compile() Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 20:50:46 -06:00
else
EMIT2(0x66, 0x89);
goto stx;
case BPF_STX | BPF_MEM | BPF_W:
net: filter: cleanup A/X name usage The macro 'A' used in internal BPF interpreter: #define A regs[insn->a_reg] was easily confused with the name of classic BPF register 'A', since 'A' would mean two different things depending on context. This patch is trying to clean up the naming and clarify its usage in the following way: - A and X are names of two classic BPF registers - BPF_REG_A denotes internal BPF register R0 used to map classic register A in internal BPF programs generated from classic - BPF_REG_X denotes internal BPF register R7 used to map classic register X in internal BPF programs generated from classic - internal BPF instruction format: struct sock_filter_int { __u8 code; /* opcode */ __u8 dst_reg:4; /* dest register */ __u8 src_reg:4; /* source register */ __s16 off; /* signed offset */ __s32 imm; /* signed immediate constant */ }; - BPF_X/BPF_K is 1 bit used to encode source operand of instruction In classic: BPF_X - means use register X as source operand BPF_K - means use 32-bit immediate as source operand In internal: BPF_X - means use 'src_reg' register as source operand BPF_K - means use 32-bit immediate as source operand Suggested-by: Chema Gonzalez <chema@google.com> Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Acked-by: Daniel Borkmann <dborkman@redhat.com> Acked-by: Chema Gonzalez <chema@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-06-06 15:46:06 -06:00
if (is_ereg(dst_reg) || is_ereg(src_reg))
EMIT2(add_2mod(0x40, dst_reg, src_reg), 0x89);
net: filter: x86: internal BPF JIT Maps all internal BPF instructions into x86_64 instructions. This patch replaces original BPF x64 JIT with internal BPF x64 JIT. sysctl net.core.bpf_jit_enable is reused as on/off switch. Performance: 1. old BPF JIT and internal BPF JIT generate equivalent x86_64 code. No performance difference is observed for filters that were JIT-able before Example assembler code for BPF filter "tcpdump port 22" original BPF -> old JIT: original BPF -> internal BPF -> new JIT: 0: push %rbp 0: push %rbp 1: mov %rsp,%rbp 1: mov %rsp,%rbp 4: sub $0x60,%rsp 4: sub $0x228,%rsp 8: mov %rbx,-0x8(%rbp) b: mov %rbx,-0x228(%rbp) // prologue 12: mov %r13,-0x220(%rbp) 19: mov %r14,-0x218(%rbp) 20: mov %r15,-0x210(%rbp) 27: xor %eax,%eax // clear A c: xor %ebx,%ebx 29: xor %r13,%r13 // clear X e: mov 0x68(%rdi),%r9d 2c: mov 0x68(%rdi),%r9d 12: sub 0x6c(%rdi),%r9d 30: sub 0x6c(%rdi),%r9d 16: mov 0xd8(%rdi),%r8 34: mov 0xd8(%rdi),%r10 3b: mov %rdi,%rbx 1d: mov $0xc,%esi 3e: mov $0xc,%esi 22: callq 0xffffffffe1021e15 43: callq 0xffffffffe102bd75 27: cmp $0x86dd,%eax 48: cmp $0x86dd,%rax 2c: jne 0x0000000000000069 4f: jne 0x000000000000009a 2e: mov $0x14,%esi 51: mov $0x14,%esi 33: callq 0xffffffffe1021e31 56: callq 0xffffffffe102bd91 38: cmp $0x84,%eax 5b: cmp $0x84,%rax 3d: je 0x0000000000000049 62: je 0x0000000000000074 3f: cmp $0x6,%eax 64: cmp $0x6,%rax 42: je 0x0000000000000049 68: je 0x0000000000000074 44: cmp $0x11,%eax 6a: cmp $0x11,%rax 47: jne 0x00000000000000c6 6e: jne 0x0000000000000117 49: mov $0x36,%esi 74: mov $0x36,%esi 4e: callq 0xffffffffe1021e15 79: callq 0xffffffffe102bd75 53: cmp $0x16,%eax 7e: cmp $0x16,%rax 56: je 0x00000000000000bf 82: je 0x0000000000000110 58: mov $0x38,%esi 88: mov $0x38,%esi 5d: callq 0xffffffffe1021e15 8d: callq 0xffffffffe102bd75 62: cmp $0x16,%eax 92: cmp $0x16,%rax 65: je 0x00000000000000bf 96: je 0x0000000000000110 67: jmp 0x00000000000000c6 98: jmp 0x0000000000000117 69: cmp $0x800,%eax 9a: cmp $0x800,%rax 6e: jne 0x00000000000000c6 a1: jne 0x0000000000000117 70: mov $0x17,%esi a3: mov $0x17,%esi 75: callq 0xffffffffe1021e31 a8: callq 0xffffffffe102bd91 7a: cmp $0x84,%eax ad: cmp $0x84,%rax 7f: je 0x000000000000008b b4: je 0x00000000000000c2 81: cmp $0x6,%eax b6: cmp $0x6,%rax 84: je 0x000000000000008b ba: je 0x00000000000000c2 86: cmp $0x11,%eax bc: cmp $0x11,%rax 89: jne 0x00000000000000c6 c0: jne 0x0000000000000117 8b: mov $0x14,%esi c2: mov $0x14,%esi 90: callq 0xffffffffe1021e15 c7: callq 0xffffffffe102bd75 95: test $0x1fff,%ax cc: test $0x1fff,%rax 99: jne 0x00000000000000c6 d3: jne 0x0000000000000117 d5: mov %rax,%r14 9b: mov $0xe,%esi d8: mov $0xe,%esi a0: callq 0xffffffffe1021e44 dd: callq 0xffffffffe102bd91 // MSH e2: and $0xf,%eax e5: shl $0x2,%eax e8: mov %rax,%r13 eb: mov %r14,%rax ee: mov %r13,%rsi a5: lea 0xe(%rbx),%esi f1: add $0xe,%esi a8: callq 0xffffffffe1021e0d f4: callq 0xffffffffe102bd6d ad: cmp $0x16,%eax f9: cmp $0x16,%rax b0: je 0x00000000000000bf fd: je 0x0000000000000110 ff: mov %r13,%rsi b2: lea 0x10(%rbx),%esi 102: add $0x10,%esi b5: callq 0xffffffffe1021e0d 105: callq 0xffffffffe102bd6d ba: cmp $0x16,%eax 10a: cmp $0x16,%rax bd: jne 0x00000000000000c6 10e: jne 0x0000000000000117 bf: mov $0xffff,%eax 110: mov $0xffff,%eax c4: jmp 0x00000000000000c8 115: jmp 0x000000000000011c c6: xor %eax,%eax 117: mov $0x0,%eax c8: mov -0x8(%rbp),%rbx 11c: mov -0x228(%rbp),%rbx // epilogue cc: leaveq 123: mov -0x220(%rbp),%r13 cd: retq 12a: mov -0x218(%rbp),%r14 131: mov -0x210(%rbp),%r15 138: leaveq 139: retq On fully cached SKBs both JITed functions take 12 nsec to execute. BPF interpreter executes the program in 30 nsec. The difference in generated assembler is due to the following: Old BPF imlements LDX_MSH instruction via sk_load_byte_msh() helper function inside bpf_jit.S. New JIT removes the helper and does it explicitly, so ldx_msh cost is the same for both JITs, but generated code looks longer. New JIT has 4 registers to save, so prologue/epilogue are larger, but the cost is within noise on x64. Old JIT checks whether first insn clears A and if not emits 'xor %eax,%eax'. New JIT clears %rax unconditionally. 2. old BPF JIT doesn't support ANC_NLATTR, ANC_PAY_OFFSET, ANC_RANDOM extensions. New JIT supports all BPF extensions. Performance of such filters improves 2-4 times depending on a filter. The longer the filter the higher performance gain. Synthetic benchmarks with many ancillary loads see 20x speedup which seems to be the maximum gain from JIT Notes: . net.core.bpf_jit_enable=2 + tools/net/bpf_jit_disasm is still functional and can be used to see generated assembler . there are two jit_compile() functions and code flow for classic filters is: sk_attach_filter() - load classic BPF bpf_jit_compile() - try to JIT from classic BPF sk_convert_filter() - convert classic to internal bpf_int_jit_compile() - JIT from internal BPF seccomp and tracing filters will just call bpf_int_jit_compile() Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 20:50:46 -06:00
else
EMIT1(0x89);
goto stx;
case BPF_STX | BPF_MEM | BPF_DW:
net: filter: cleanup A/X name usage The macro 'A' used in internal BPF interpreter: #define A regs[insn->a_reg] was easily confused with the name of classic BPF register 'A', since 'A' would mean two different things depending on context. This patch is trying to clean up the naming and clarify its usage in the following way: - A and X are names of two classic BPF registers - BPF_REG_A denotes internal BPF register R0 used to map classic register A in internal BPF programs generated from classic - BPF_REG_X denotes internal BPF register R7 used to map classic register X in internal BPF programs generated from classic - internal BPF instruction format: struct sock_filter_int { __u8 code; /* opcode */ __u8 dst_reg:4; /* dest register */ __u8 src_reg:4; /* source register */ __s16 off; /* signed offset */ __s32 imm; /* signed immediate constant */ }; - BPF_X/BPF_K is 1 bit used to encode source operand of instruction In classic: BPF_X - means use register X as source operand BPF_K - means use 32-bit immediate as source operand In internal: BPF_X - means use 'src_reg' register as source operand BPF_K - means use 32-bit immediate as source operand Suggested-by: Chema Gonzalez <chema@google.com> Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Acked-by: Daniel Borkmann <dborkman@redhat.com> Acked-by: Chema Gonzalez <chema@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-06-06 15:46:06 -06:00
EMIT2(add_2mod(0x48, dst_reg, src_reg), 0x89);
net: filter: x86: internal BPF JIT Maps all internal BPF instructions into x86_64 instructions. This patch replaces original BPF x64 JIT with internal BPF x64 JIT. sysctl net.core.bpf_jit_enable is reused as on/off switch. Performance: 1. old BPF JIT and internal BPF JIT generate equivalent x86_64 code. No performance difference is observed for filters that were JIT-able before Example assembler code for BPF filter "tcpdump port 22" original BPF -> old JIT: original BPF -> internal BPF -> new JIT: 0: push %rbp 0: push %rbp 1: mov %rsp,%rbp 1: mov %rsp,%rbp 4: sub $0x60,%rsp 4: sub $0x228,%rsp 8: mov %rbx,-0x8(%rbp) b: mov %rbx,-0x228(%rbp) // prologue 12: mov %r13,-0x220(%rbp) 19: mov %r14,-0x218(%rbp) 20: mov %r15,-0x210(%rbp) 27: xor %eax,%eax // clear A c: xor %ebx,%ebx 29: xor %r13,%r13 // clear X e: mov 0x68(%rdi),%r9d 2c: mov 0x68(%rdi),%r9d 12: sub 0x6c(%rdi),%r9d 30: sub 0x6c(%rdi),%r9d 16: mov 0xd8(%rdi),%r8 34: mov 0xd8(%rdi),%r10 3b: mov %rdi,%rbx 1d: mov $0xc,%esi 3e: mov $0xc,%esi 22: callq 0xffffffffe1021e15 43: callq 0xffffffffe102bd75 27: cmp $0x86dd,%eax 48: cmp $0x86dd,%rax 2c: jne 0x0000000000000069 4f: jne 0x000000000000009a 2e: mov $0x14,%esi 51: mov $0x14,%esi 33: callq 0xffffffffe1021e31 56: callq 0xffffffffe102bd91 38: cmp $0x84,%eax 5b: cmp $0x84,%rax 3d: je 0x0000000000000049 62: je 0x0000000000000074 3f: cmp $0x6,%eax 64: cmp $0x6,%rax 42: je 0x0000000000000049 68: je 0x0000000000000074 44: cmp $0x11,%eax 6a: cmp $0x11,%rax 47: jne 0x00000000000000c6 6e: jne 0x0000000000000117 49: mov $0x36,%esi 74: mov $0x36,%esi 4e: callq 0xffffffffe1021e15 79: callq 0xffffffffe102bd75 53: cmp $0x16,%eax 7e: cmp $0x16,%rax 56: je 0x00000000000000bf 82: je 0x0000000000000110 58: mov $0x38,%esi 88: mov $0x38,%esi 5d: callq 0xffffffffe1021e15 8d: callq 0xffffffffe102bd75 62: cmp $0x16,%eax 92: cmp $0x16,%rax 65: je 0x00000000000000bf 96: je 0x0000000000000110 67: jmp 0x00000000000000c6 98: jmp 0x0000000000000117 69: cmp $0x800,%eax 9a: cmp $0x800,%rax 6e: jne 0x00000000000000c6 a1: jne 0x0000000000000117 70: mov $0x17,%esi a3: mov $0x17,%esi 75: callq 0xffffffffe1021e31 a8: callq 0xffffffffe102bd91 7a: cmp $0x84,%eax ad: cmp $0x84,%rax 7f: je 0x000000000000008b b4: je 0x00000000000000c2 81: cmp $0x6,%eax b6: cmp $0x6,%rax 84: je 0x000000000000008b ba: je 0x00000000000000c2 86: cmp $0x11,%eax bc: cmp $0x11,%rax 89: jne 0x00000000000000c6 c0: jne 0x0000000000000117 8b: mov $0x14,%esi c2: mov $0x14,%esi 90: callq 0xffffffffe1021e15 c7: callq 0xffffffffe102bd75 95: test $0x1fff,%ax cc: test $0x1fff,%rax 99: jne 0x00000000000000c6 d3: jne 0x0000000000000117 d5: mov %rax,%r14 9b: mov $0xe,%esi d8: mov $0xe,%esi a0: callq 0xffffffffe1021e44 dd: callq 0xffffffffe102bd91 // MSH e2: and $0xf,%eax e5: shl $0x2,%eax e8: mov %rax,%r13 eb: mov %r14,%rax ee: mov %r13,%rsi a5: lea 0xe(%rbx),%esi f1: add $0xe,%esi a8: callq 0xffffffffe1021e0d f4: callq 0xffffffffe102bd6d ad: cmp $0x16,%eax f9: cmp $0x16,%rax b0: je 0x00000000000000bf fd: je 0x0000000000000110 ff: mov %r13,%rsi b2: lea 0x10(%rbx),%esi 102: add $0x10,%esi b5: callq 0xffffffffe1021e0d 105: callq 0xffffffffe102bd6d ba: cmp $0x16,%eax 10a: cmp $0x16,%rax bd: jne 0x00000000000000c6 10e: jne 0x0000000000000117 bf: mov $0xffff,%eax 110: mov $0xffff,%eax c4: jmp 0x00000000000000c8 115: jmp 0x000000000000011c c6: xor %eax,%eax 117: mov $0x0,%eax c8: mov -0x8(%rbp),%rbx 11c: mov -0x228(%rbp),%rbx // epilogue cc: leaveq 123: mov -0x220(%rbp),%r13 cd: retq 12a: mov -0x218(%rbp),%r14 131: mov -0x210(%rbp),%r15 138: leaveq 139: retq On fully cached SKBs both JITed functions take 12 nsec to execute. BPF interpreter executes the program in 30 nsec. The difference in generated assembler is due to the following: Old BPF imlements LDX_MSH instruction via sk_load_byte_msh() helper function inside bpf_jit.S. New JIT removes the helper and does it explicitly, so ldx_msh cost is the same for both JITs, but generated code looks longer. New JIT has 4 registers to save, so prologue/epilogue are larger, but the cost is within noise on x64. Old JIT checks whether first insn clears A and if not emits 'xor %eax,%eax'. New JIT clears %rax unconditionally. 2. old BPF JIT doesn't support ANC_NLATTR, ANC_PAY_OFFSET, ANC_RANDOM extensions. New JIT supports all BPF extensions. Performance of such filters improves 2-4 times depending on a filter. The longer the filter the higher performance gain. Synthetic benchmarks with many ancillary loads see 20x speedup which seems to be the maximum gain from JIT Notes: . net.core.bpf_jit_enable=2 + tools/net/bpf_jit_disasm is still functional and can be used to see generated assembler . there are two jit_compile() functions and code flow for classic filters is: sk_attach_filter() - load classic BPF bpf_jit_compile() - try to JIT from classic BPF sk_convert_filter() - convert classic to internal bpf_int_jit_compile() - JIT from internal BPF seccomp and tracing filters will just call bpf_int_jit_compile() Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 20:50:46 -06:00
stx: if (is_imm8(insn->off))
net: filter: cleanup A/X name usage The macro 'A' used in internal BPF interpreter: #define A regs[insn->a_reg] was easily confused with the name of classic BPF register 'A', since 'A' would mean two different things depending on context. This patch is trying to clean up the naming and clarify its usage in the following way: - A and X are names of two classic BPF registers - BPF_REG_A denotes internal BPF register R0 used to map classic register A in internal BPF programs generated from classic - BPF_REG_X denotes internal BPF register R7 used to map classic register X in internal BPF programs generated from classic - internal BPF instruction format: struct sock_filter_int { __u8 code; /* opcode */ __u8 dst_reg:4; /* dest register */ __u8 src_reg:4; /* source register */ __s16 off; /* signed offset */ __s32 imm; /* signed immediate constant */ }; - BPF_X/BPF_K is 1 bit used to encode source operand of instruction In classic: BPF_X - means use register X as source operand BPF_K - means use 32-bit immediate as source operand In internal: BPF_X - means use 'src_reg' register as source operand BPF_K - means use 32-bit immediate as source operand Suggested-by: Chema Gonzalez <chema@google.com> Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Acked-by: Daniel Borkmann <dborkman@redhat.com> Acked-by: Chema Gonzalez <chema@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-06-06 15:46:06 -06:00
EMIT2(add_2reg(0x40, dst_reg, src_reg), insn->off);
net: filter: x86: internal BPF JIT Maps all internal BPF instructions into x86_64 instructions. This patch replaces original BPF x64 JIT with internal BPF x64 JIT. sysctl net.core.bpf_jit_enable is reused as on/off switch. Performance: 1. old BPF JIT and internal BPF JIT generate equivalent x86_64 code. No performance difference is observed for filters that were JIT-able before Example assembler code for BPF filter "tcpdump port 22" original BPF -> old JIT: original BPF -> internal BPF -> new JIT: 0: push %rbp 0: push %rbp 1: mov %rsp,%rbp 1: mov %rsp,%rbp 4: sub $0x60,%rsp 4: sub $0x228,%rsp 8: mov %rbx,-0x8(%rbp) b: mov %rbx,-0x228(%rbp) // prologue 12: mov %r13,-0x220(%rbp) 19: mov %r14,-0x218(%rbp) 20: mov %r15,-0x210(%rbp) 27: xor %eax,%eax // clear A c: xor %ebx,%ebx 29: xor %r13,%r13 // clear X e: mov 0x68(%rdi),%r9d 2c: mov 0x68(%rdi),%r9d 12: sub 0x6c(%rdi),%r9d 30: sub 0x6c(%rdi),%r9d 16: mov 0xd8(%rdi),%r8 34: mov 0xd8(%rdi),%r10 3b: mov %rdi,%rbx 1d: mov $0xc,%esi 3e: mov $0xc,%esi 22: callq 0xffffffffe1021e15 43: callq 0xffffffffe102bd75 27: cmp $0x86dd,%eax 48: cmp $0x86dd,%rax 2c: jne 0x0000000000000069 4f: jne 0x000000000000009a 2e: mov $0x14,%esi 51: mov $0x14,%esi 33: callq 0xffffffffe1021e31 56: callq 0xffffffffe102bd91 38: cmp $0x84,%eax 5b: cmp $0x84,%rax 3d: je 0x0000000000000049 62: je 0x0000000000000074 3f: cmp $0x6,%eax 64: cmp $0x6,%rax 42: je 0x0000000000000049 68: je 0x0000000000000074 44: cmp $0x11,%eax 6a: cmp $0x11,%rax 47: jne 0x00000000000000c6 6e: jne 0x0000000000000117 49: mov $0x36,%esi 74: mov $0x36,%esi 4e: callq 0xffffffffe1021e15 79: callq 0xffffffffe102bd75 53: cmp $0x16,%eax 7e: cmp $0x16,%rax 56: je 0x00000000000000bf 82: je 0x0000000000000110 58: mov $0x38,%esi 88: mov $0x38,%esi 5d: callq 0xffffffffe1021e15 8d: callq 0xffffffffe102bd75 62: cmp $0x16,%eax 92: cmp $0x16,%rax 65: je 0x00000000000000bf 96: je 0x0000000000000110 67: jmp 0x00000000000000c6 98: jmp 0x0000000000000117 69: cmp $0x800,%eax 9a: cmp $0x800,%rax 6e: jne 0x00000000000000c6 a1: jne 0x0000000000000117 70: mov $0x17,%esi a3: mov $0x17,%esi 75: callq 0xffffffffe1021e31 a8: callq 0xffffffffe102bd91 7a: cmp $0x84,%eax ad: cmp $0x84,%rax 7f: je 0x000000000000008b b4: je 0x00000000000000c2 81: cmp $0x6,%eax b6: cmp $0x6,%rax 84: je 0x000000000000008b ba: je 0x00000000000000c2 86: cmp $0x11,%eax bc: cmp $0x11,%rax 89: jne 0x00000000000000c6 c0: jne 0x0000000000000117 8b: mov $0x14,%esi c2: mov $0x14,%esi 90: callq 0xffffffffe1021e15 c7: callq 0xffffffffe102bd75 95: test $0x1fff,%ax cc: test $0x1fff,%rax 99: jne 0x00000000000000c6 d3: jne 0x0000000000000117 d5: mov %rax,%r14 9b: mov $0xe,%esi d8: mov $0xe,%esi a0: callq 0xffffffffe1021e44 dd: callq 0xffffffffe102bd91 // MSH e2: and $0xf,%eax e5: shl $0x2,%eax e8: mov %rax,%r13 eb: mov %r14,%rax ee: mov %r13,%rsi a5: lea 0xe(%rbx),%esi f1: add $0xe,%esi a8: callq 0xffffffffe1021e0d f4: callq 0xffffffffe102bd6d ad: cmp $0x16,%eax f9: cmp $0x16,%rax b0: je 0x00000000000000bf fd: je 0x0000000000000110 ff: mov %r13,%rsi b2: lea 0x10(%rbx),%esi 102: add $0x10,%esi b5: callq 0xffffffffe1021e0d 105: callq 0xffffffffe102bd6d ba: cmp $0x16,%eax 10a: cmp $0x16,%rax bd: jne 0x00000000000000c6 10e: jne 0x0000000000000117 bf: mov $0xffff,%eax 110: mov $0xffff,%eax c4: jmp 0x00000000000000c8 115: jmp 0x000000000000011c c6: xor %eax,%eax 117: mov $0x0,%eax c8: mov -0x8(%rbp),%rbx 11c: mov -0x228(%rbp),%rbx // epilogue cc: leaveq 123: mov -0x220(%rbp),%r13 cd: retq 12a: mov -0x218(%rbp),%r14 131: mov -0x210(%rbp),%r15 138: leaveq 139: retq On fully cached SKBs both JITed functions take 12 nsec to execute. BPF interpreter executes the program in 30 nsec. The difference in generated assembler is due to the following: Old BPF imlements LDX_MSH instruction via sk_load_byte_msh() helper function inside bpf_jit.S. New JIT removes the helper and does it explicitly, so ldx_msh cost is the same for both JITs, but generated code looks longer. New JIT has 4 registers to save, so prologue/epilogue are larger, but the cost is within noise on x64. Old JIT checks whether first insn clears A and if not emits 'xor %eax,%eax'. New JIT clears %rax unconditionally. 2. old BPF JIT doesn't support ANC_NLATTR, ANC_PAY_OFFSET, ANC_RANDOM extensions. New JIT supports all BPF extensions. Performance of such filters improves 2-4 times depending on a filter. The longer the filter the higher performance gain. Synthetic benchmarks with many ancillary loads see 20x speedup which seems to be the maximum gain from JIT Notes: . net.core.bpf_jit_enable=2 + tools/net/bpf_jit_disasm is still functional and can be used to see generated assembler . there are two jit_compile() functions and code flow for classic filters is: sk_attach_filter() - load classic BPF bpf_jit_compile() - try to JIT from classic BPF sk_convert_filter() - convert classic to internal bpf_int_jit_compile() - JIT from internal BPF seccomp and tracing filters will just call bpf_int_jit_compile() Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 20:50:46 -06:00
else
net: filter: cleanup A/X name usage The macro 'A' used in internal BPF interpreter: #define A regs[insn->a_reg] was easily confused with the name of classic BPF register 'A', since 'A' would mean two different things depending on context. This patch is trying to clean up the naming and clarify its usage in the following way: - A and X are names of two classic BPF registers - BPF_REG_A denotes internal BPF register R0 used to map classic register A in internal BPF programs generated from classic - BPF_REG_X denotes internal BPF register R7 used to map classic register X in internal BPF programs generated from classic - internal BPF instruction format: struct sock_filter_int { __u8 code; /* opcode */ __u8 dst_reg:4; /* dest register */ __u8 src_reg:4; /* source register */ __s16 off; /* signed offset */ __s32 imm; /* signed immediate constant */ }; - BPF_X/BPF_K is 1 bit used to encode source operand of instruction In classic: BPF_X - means use register X as source operand BPF_K - means use 32-bit immediate as source operand In internal: BPF_X - means use 'src_reg' register as source operand BPF_K - means use 32-bit immediate as source operand Suggested-by: Chema Gonzalez <chema@google.com> Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Acked-by: Daniel Borkmann <dborkman@redhat.com> Acked-by: Chema Gonzalez <chema@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-06-06 15:46:06 -06:00
EMIT1_off32(add_2reg(0x80, dst_reg, src_reg),
net: filter: x86: internal BPF JIT Maps all internal BPF instructions into x86_64 instructions. This patch replaces original BPF x64 JIT with internal BPF x64 JIT. sysctl net.core.bpf_jit_enable is reused as on/off switch. Performance: 1. old BPF JIT and internal BPF JIT generate equivalent x86_64 code. No performance difference is observed for filters that were JIT-able before Example assembler code for BPF filter "tcpdump port 22" original BPF -> old JIT: original BPF -> internal BPF -> new JIT: 0: push %rbp 0: push %rbp 1: mov %rsp,%rbp 1: mov %rsp,%rbp 4: sub $0x60,%rsp 4: sub $0x228,%rsp 8: mov %rbx,-0x8(%rbp) b: mov %rbx,-0x228(%rbp) // prologue 12: mov %r13,-0x220(%rbp) 19: mov %r14,-0x218(%rbp) 20: mov %r15,-0x210(%rbp) 27: xor %eax,%eax // clear A c: xor %ebx,%ebx 29: xor %r13,%r13 // clear X e: mov 0x68(%rdi),%r9d 2c: mov 0x68(%rdi),%r9d 12: sub 0x6c(%rdi),%r9d 30: sub 0x6c(%rdi),%r9d 16: mov 0xd8(%rdi),%r8 34: mov 0xd8(%rdi),%r10 3b: mov %rdi,%rbx 1d: mov $0xc,%esi 3e: mov $0xc,%esi 22: callq 0xffffffffe1021e15 43: callq 0xffffffffe102bd75 27: cmp $0x86dd,%eax 48: cmp $0x86dd,%rax 2c: jne 0x0000000000000069 4f: jne 0x000000000000009a 2e: mov $0x14,%esi 51: mov $0x14,%esi 33: callq 0xffffffffe1021e31 56: callq 0xffffffffe102bd91 38: cmp $0x84,%eax 5b: cmp $0x84,%rax 3d: je 0x0000000000000049 62: je 0x0000000000000074 3f: cmp $0x6,%eax 64: cmp $0x6,%rax 42: je 0x0000000000000049 68: je 0x0000000000000074 44: cmp $0x11,%eax 6a: cmp $0x11,%rax 47: jne 0x00000000000000c6 6e: jne 0x0000000000000117 49: mov $0x36,%esi 74: mov $0x36,%esi 4e: callq 0xffffffffe1021e15 79: callq 0xffffffffe102bd75 53: cmp $0x16,%eax 7e: cmp $0x16,%rax 56: je 0x00000000000000bf 82: je 0x0000000000000110 58: mov $0x38,%esi 88: mov $0x38,%esi 5d: callq 0xffffffffe1021e15 8d: callq 0xffffffffe102bd75 62: cmp $0x16,%eax 92: cmp $0x16,%rax 65: je 0x00000000000000bf 96: je 0x0000000000000110 67: jmp 0x00000000000000c6 98: jmp 0x0000000000000117 69: cmp $0x800,%eax 9a: cmp $0x800,%rax 6e: jne 0x00000000000000c6 a1: jne 0x0000000000000117 70: mov $0x17,%esi a3: mov $0x17,%esi 75: callq 0xffffffffe1021e31 a8: callq 0xffffffffe102bd91 7a: cmp $0x84,%eax ad: cmp $0x84,%rax 7f: je 0x000000000000008b b4: je 0x00000000000000c2 81: cmp $0x6,%eax b6: cmp $0x6,%rax 84: je 0x000000000000008b ba: je 0x00000000000000c2 86: cmp $0x11,%eax bc: cmp $0x11,%rax 89: jne 0x00000000000000c6 c0: jne 0x0000000000000117 8b: mov $0x14,%esi c2: mov $0x14,%esi 90: callq 0xffffffffe1021e15 c7: callq 0xffffffffe102bd75 95: test $0x1fff,%ax cc: test $0x1fff,%rax 99: jne 0x00000000000000c6 d3: jne 0x0000000000000117 d5: mov %rax,%r14 9b: mov $0xe,%esi d8: mov $0xe,%esi a0: callq 0xffffffffe1021e44 dd: callq 0xffffffffe102bd91 // MSH e2: and $0xf,%eax e5: shl $0x2,%eax e8: mov %rax,%r13 eb: mov %r14,%rax ee: mov %r13,%rsi a5: lea 0xe(%rbx),%esi f1: add $0xe,%esi a8: callq 0xffffffffe1021e0d f4: callq 0xffffffffe102bd6d ad: cmp $0x16,%eax f9: cmp $0x16,%rax b0: je 0x00000000000000bf fd: je 0x0000000000000110 ff: mov %r13,%rsi b2: lea 0x10(%rbx),%esi 102: add $0x10,%esi b5: callq 0xffffffffe1021e0d 105: callq 0xffffffffe102bd6d ba: cmp $0x16,%eax 10a: cmp $0x16,%rax bd: jne 0x00000000000000c6 10e: jne 0x0000000000000117 bf: mov $0xffff,%eax 110: mov $0xffff,%eax c4: jmp 0x00000000000000c8 115: jmp 0x000000000000011c c6: xor %eax,%eax 117: mov $0x0,%eax c8: mov -0x8(%rbp),%rbx 11c: mov -0x228(%rbp),%rbx // epilogue cc: leaveq 123: mov -0x220(%rbp),%r13 cd: retq 12a: mov -0x218(%rbp),%r14 131: mov -0x210(%rbp),%r15 138: leaveq 139: retq On fully cached SKBs both JITed functions take 12 nsec to execute. BPF interpreter executes the program in 30 nsec. The difference in generated assembler is due to the following: Old BPF imlements LDX_MSH instruction via sk_load_byte_msh() helper function inside bpf_jit.S. New JIT removes the helper and does it explicitly, so ldx_msh cost is the same for both JITs, but generated code looks longer. New JIT has 4 registers to save, so prologue/epilogue are larger, but the cost is within noise on x64. Old JIT checks whether first insn clears A and if not emits 'xor %eax,%eax'. New JIT clears %rax unconditionally. 2. old BPF JIT doesn't support ANC_NLATTR, ANC_PAY_OFFSET, ANC_RANDOM extensions. New JIT supports all BPF extensions. Performance of such filters improves 2-4 times depending on a filter. The longer the filter the higher performance gain. Synthetic benchmarks with many ancillary loads see 20x speedup which seems to be the maximum gain from JIT Notes: . net.core.bpf_jit_enable=2 + tools/net/bpf_jit_disasm is still functional and can be used to see generated assembler . there are two jit_compile() functions and code flow for classic filters is: sk_attach_filter() - load classic BPF bpf_jit_compile() - try to JIT from classic BPF sk_convert_filter() - convert classic to internal bpf_int_jit_compile() - JIT from internal BPF seccomp and tracing filters will just call bpf_int_jit_compile() Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 20:50:46 -06:00
insn->off);
break;
net: filter: cleanup A/X name usage The macro 'A' used in internal BPF interpreter: #define A regs[insn->a_reg] was easily confused with the name of classic BPF register 'A', since 'A' would mean two different things depending on context. This patch is trying to clean up the naming and clarify its usage in the following way: - A and X are names of two classic BPF registers - BPF_REG_A denotes internal BPF register R0 used to map classic register A in internal BPF programs generated from classic - BPF_REG_X denotes internal BPF register R7 used to map classic register X in internal BPF programs generated from classic - internal BPF instruction format: struct sock_filter_int { __u8 code; /* opcode */ __u8 dst_reg:4; /* dest register */ __u8 src_reg:4; /* source register */ __s16 off; /* signed offset */ __s32 imm; /* signed immediate constant */ }; - BPF_X/BPF_K is 1 bit used to encode source operand of instruction In classic: BPF_X - means use register X as source operand BPF_K - means use 32-bit immediate as source operand In internal: BPF_X - means use 'src_reg' register as source operand BPF_K - means use 32-bit immediate as source operand Suggested-by: Chema Gonzalez <chema@google.com> Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Acked-by: Daniel Borkmann <dborkman@redhat.com> Acked-by: Chema Gonzalez <chema@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-06-06 15:46:06 -06:00
/* LDX: dst_reg = *(u8*)(src_reg + off) */
net: filter: x86: internal BPF JIT Maps all internal BPF instructions into x86_64 instructions. This patch replaces original BPF x64 JIT with internal BPF x64 JIT. sysctl net.core.bpf_jit_enable is reused as on/off switch. Performance: 1. old BPF JIT and internal BPF JIT generate equivalent x86_64 code. No performance difference is observed for filters that were JIT-able before Example assembler code for BPF filter "tcpdump port 22" original BPF -> old JIT: original BPF -> internal BPF -> new JIT: 0: push %rbp 0: push %rbp 1: mov %rsp,%rbp 1: mov %rsp,%rbp 4: sub $0x60,%rsp 4: sub $0x228,%rsp 8: mov %rbx,-0x8(%rbp) b: mov %rbx,-0x228(%rbp) // prologue 12: mov %r13,-0x220(%rbp) 19: mov %r14,-0x218(%rbp) 20: mov %r15,-0x210(%rbp) 27: xor %eax,%eax // clear A c: xor %ebx,%ebx 29: xor %r13,%r13 // clear X e: mov 0x68(%rdi),%r9d 2c: mov 0x68(%rdi),%r9d 12: sub 0x6c(%rdi),%r9d 30: sub 0x6c(%rdi),%r9d 16: mov 0xd8(%rdi),%r8 34: mov 0xd8(%rdi),%r10 3b: mov %rdi,%rbx 1d: mov $0xc,%esi 3e: mov $0xc,%esi 22: callq 0xffffffffe1021e15 43: callq 0xffffffffe102bd75 27: cmp $0x86dd,%eax 48: cmp $0x86dd,%rax 2c: jne 0x0000000000000069 4f: jne 0x000000000000009a 2e: mov $0x14,%esi 51: mov $0x14,%esi 33: callq 0xffffffffe1021e31 56: callq 0xffffffffe102bd91 38: cmp $0x84,%eax 5b: cmp $0x84,%rax 3d: je 0x0000000000000049 62: je 0x0000000000000074 3f: cmp $0x6,%eax 64: cmp $0x6,%rax 42: je 0x0000000000000049 68: je 0x0000000000000074 44: cmp $0x11,%eax 6a: cmp $0x11,%rax 47: jne 0x00000000000000c6 6e: jne 0x0000000000000117 49: mov $0x36,%esi 74: mov $0x36,%esi 4e: callq 0xffffffffe1021e15 79: callq 0xffffffffe102bd75 53: cmp $0x16,%eax 7e: cmp $0x16,%rax 56: je 0x00000000000000bf 82: je 0x0000000000000110 58: mov $0x38,%esi 88: mov $0x38,%esi 5d: callq 0xffffffffe1021e15 8d: callq 0xffffffffe102bd75 62: cmp $0x16,%eax 92: cmp $0x16,%rax 65: je 0x00000000000000bf 96: je 0x0000000000000110 67: jmp 0x00000000000000c6 98: jmp 0x0000000000000117 69: cmp $0x800,%eax 9a: cmp $0x800,%rax 6e: jne 0x00000000000000c6 a1: jne 0x0000000000000117 70: mov $0x17,%esi a3: mov $0x17,%esi 75: callq 0xffffffffe1021e31 a8: callq 0xffffffffe102bd91 7a: cmp $0x84,%eax ad: cmp $0x84,%rax 7f: je 0x000000000000008b b4: je 0x00000000000000c2 81: cmp $0x6,%eax b6: cmp $0x6,%rax 84: je 0x000000000000008b ba: je 0x00000000000000c2 86: cmp $0x11,%eax bc: cmp $0x11,%rax 89: jne 0x00000000000000c6 c0: jne 0x0000000000000117 8b: mov $0x14,%esi c2: mov $0x14,%esi 90: callq 0xffffffffe1021e15 c7: callq 0xffffffffe102bd75 95: test $0x1fff,%ax cc: test $0x1fff,%rax 99: jne 0x00000000000000c6 d3: jne 0x0000000000000117 d5: mov %rax,%r14 9b: mov $0xe,%esi d8: mov $0xe,%esi a0: callq 0xffffffffe1021e44 dd: callq 0xffffffffe102bd91 // MSH e2: and $0xf,%eax e5: shl $0x2,%eax e8: mov %rax,%r13 eb: mov %r14,%rax ee: mov %r13,%rsi a5: lea 0xe(%rbx),%esi f1: add $0xe,%esi a8: callq 0xffffffffe1021e0d f4: callq 0xffffffffe102bd6d ad: cmp $0x16,%eax f9: cmp $0x16,%rax b0: je 0x00000000000000bf fd: je 0x0000000000000110 ff: mov %r13,%rsi b2: lea 0x10(%rbx),%esi 102: add $0x10,%esi b5: callq 0xffffffffe1021e0d 105: callq 0xffffffffe102bd6d ba: cmp $0x16,%eax 10a: cmp $0x16,%rax bd: jne 0x00000000000000c6 10e: jne 0x0000000000000117 bf: mov $0xffff,%eax 110: mov $0xffff,%eax c4: jmp 0x00000000000000c8 115: jmp 0x000000000000011c c6: xor %eax,%eax 117: mov $0x0,%eax c8: mov -0x8(%rbp),%rbx 11c: mov -0x228(%rbp),%rbx // epilogue cc: leaveq 123: mov -0x220(%rbp),%r13 cd: retq 12a: mov -0x218(%rbp),%r14 131: mov -0x210(%rbp),%r15 138: leaveq 139: retq On fully cached SKBs both JITed functions take 12 nsec to execute. BPF interpreter executes the program in 30 nsec. The difference in generated assembler is due to the following: Old BPF imlements LDX_MSH instruction via sk_load_byte_msh() helper function inside bpf_jit.S. New JIT removes the helper and does it explicitly, so ldx_msh cost is the same for both JITs, but generated code looks longer. New JIT has 4 registers to save, so prologue/epilogue are larger, but the cost is within noise on x64. Old JIT checks whether first insn clears A and if not emits 'xor %eax,%eax'. New JIT clears %rax unconditionally. 2. old BPF JIT doesn't support ANC_NLATTR, ANC_PAY_OFFSET, ANC_RANDOM extensions. New JIT supports all BPF extensions. Performance of such filters improves 2-4 times depending on a filter. The longer the filter the higher performance gain. Synthetic benchmarks with many ancillary loads see 20x speedup which seems to be the maximum gain from JIT Notes: . net.core.bpf_jit_enable=2 + tools/net/bpf_jit_disasm is still functional and can be used to see generated assembler . there are two jit_compile() functions and code flow for classic filters is: sk_attach_filter() - load classic BPF bpf_jit_compile() - try to JIT from classic BPF sk_convert_filter() - convert classic to internal bpf_int_jit_compile() - JIT from internal BPF seccomp and tracing filters will just call bpf_int_jit_compile() Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 20:50:46 -06:00
case BPF_LDX | BPF_MEM | BPF_B:
/* emit 'movzx rax, byte ptr [rax + off]' */
net: filter: cleanup A/X name usage The macro 'A' used in internal BPF interpreter: #define A regs[insn->a_reg] was easily confused with the name of classic BPF register 'A', since 'A' would mean two different things depending on context. This patch is trying to clean up the naming and clarify its usage in the following way: - A and X are names of two classic BPF registers - BPF_REG_A denotes internal BPF register R0 used to map classic register A in internal BPF programs generated from classic - BPF_REG_X denotes internal BPF register R7 used to map classic register X in internal BPF programs generated from classic - internal BPF instruction format: struct sock_filter_int { __u8 code; /* opcode */ __u8 dst_reg:4; /* dest register */ __u8 src_reg:4; /* source register */ __s16 off; /* signed offset */ __s32 imm; /* signed immediate constant */ }; - BPF_X/BPF_K is 1 bit used to encode source operand of instruction In classic: BPF_X - means use register X as source operand BPF_K - means use 32-bit immediate as source operand In internal: BPF_X - means use 'src_reg' register as source operand BPF_K - means use 32-bit immediate as source operand Suggested-by: Chema Gonzalez <chema@google.com> Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Acked-by: Daniel Borkmann <dborkman@redhat.com> Acked-by: Chema Gonzalez <chema@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-06-06 15:46:06 -06:00
EMIT3(add_2mod(0x48, src_reg, dst_reg), 0x0F, 0xB6);
net: filter: x86: internal BPF JIT Maps all internal BPF instructions into x86_64 instructions. This patch replaces original BPF x64 JIT with internal BPF x64 JIT. sysctl net.core.bpf_jit_enable is reused as on/off switch. Performance: 1. old BPF JIT and internal BPF JIT generate equivalent x86_64 code. No performance difference is observed for filters that were JIT-able before Example assembler code for BPF filter "tcpdump port 22" original BPF -> old JIT: original BPF -> internal BPF -> new JIT: 0: push %rbp 0: push %rbp 1: mov %rsp,%rbp 1: mov %rsp,%rbp 4: sub $0x60,%rsp 4: sub $0x228,%rsp 8: mov %rbx,-0x8(%rbp) b: mov %rbx,-0x228(%rbp) // prologue 12: mov %r13,-0x220(%rbp) 19: mov %r14,-0x218(%rbp) 20: mov %r15,-0x210(%rbp) 27: xor %eax,%eax // clear A c: xor %ebx,%ebx 29: xor %r13,%r13 // clear X e: mov 0x68(%rdi),%r9d 2c: mov 0x68(%rdi),%r9d 12: sub 0x6c(%rdi),%r9d 30: sub 0x6c(%rdi),%r9d 16: mov 0xd8(%rdi),%r8 34: mov 0xd8(%rdi),%r10 3b: mov %rdi,%rbx 1d: mov $0xc,%esi 3e: mov $0xc,%esi 22: callq 0xffffffffe1021e15 43: callq 0xffffffffe102bd75 27: cmp $0x86dd,%eax 48: cmp $0x86dd,%rax 2c: jne 0x0000000000000069 4f: jne 0x000000000000009a 2e: mov $0x14,%esi 51: mov $0x14,%esi 33: callq 0xffffffffe1021e31 56: callq 0xffffffffe102bd91 38: cmp $0x84,%eax 5b: cmp $0x84,%rax 3d: je 0x0000000000000049 62: je 0x0000000000000074 3f: cmp $0x6,%eax 64: cmp $0x6,%rax 42: je 0x0000000000000049 68: je 0x0000000000000074 44: cmp $0x11,%eax 6a: cmp $0x11,%rax 47: jne 0x00000000000000c6 6e: jne 0x0000000000000117 49: mov $0x36,%esi 74: mov $0x36,%esi 4e: callq 0xffffffffe1021e15 79: callq 0xffffffffe102bd75 53: cmp $0x16,%eax 7e: cmp $0x16,%rax 56: je 0x00000000000000bf 82: je 0x0000000000000110 58: mov $0x38,%esi 88: mov $0x38,%esi 5d: callq 0xffffffffe1021e15 8d: callq 0xffffffffe102bd75 62: cmp $0x16,%eax 92: cmp $0x16,%rax 65: je 0x00000000000000bf 96: je 0x0000000000000110 67: jmp 0x00000000000000c6 98: jmp 0x0000000000000117 69: cmp $0x800,%eax 9a: cmp $0x800,%rax 6e: jne 0x00000000000000c6 a1: jne 0x0000000000000117 70: mov $0x17,%esi a3: mov $0x17,%esi 75: callq 0xffffffffe1021e31 a8: callq 0xffffffffe102bd91 7a: cmp $0x84,%eax ad: cmp $0x84,%rax 7f: je 0x000000000000008b b4: je 0x00000000000000c2 81: cmp $0x6,%eax b6: cmp $0x6,%rax 84: je 0x000000000000008b ba: je 0x00000000000000c2 86: cmp $0x11,%eax bc: cmp $0x11,%rax 89: jne 0x00000000000000c6 c0: jne 0x0000000000000117 8b: mov $0x14,%esi c2: mov $0x14,%esi 90: callq 0xffffffffe1021e15 c7: callq 0xffffffffe102bd75 95: test $0x1fff,%ax cc: test $0x1fff,%rax 99: jne 0x00000000000000c6 d3: jne 0x0000000000000117 d5: mov %rax,%r14 9b: mov $0xe,%esi d8: mov $0xe,%esi a0: callq 0xffffffffe1021e44 dd: callq 0xffffffffe102bd91 // MSH e2: and $0xf,%eax e5: shl $0x2,%eax e8: mov %rax,%r13 eb: mov %r14,%rax ee: mov %r13,%rsi a5: lea 0xe(%rbx),%esi f1: add $0xe,%esi a8: callq 0xffffffffe1021e0d f4: callq 0xffffffffe102bd6d ad: cmp $0x16,%eax f9: cmp $0x16,%rax b0: je 0x00000000000000bf fd: je 0x0000000000000110 ff: mov %r13,%rsi b2: lea 0x10(%rbx),%esi 102: add $0x10,%esi b5: callq 0xffffffffe1021e0d 105: callq 0xffffffffe102bd6d ba: cmp $0x16,%eax 10a: cmp $0x16,%rax bd: jne 0x00000000000000c6 10e: jne 0x0000000000000117 bf: mov $0xffff,%eax 110: mov $0xffff,%eax c4: jmp 0x00000000000000c8 115: jmp 0x000000000000011c c6: xor %eax,%eax 117: mov $0x0,%eax c8: mov -0x8(%rbp),%rbx 11c: mov -0x228(%rbp),%rbx // epilogue cc: leaveq 123: mov -0x220(%rbp),%r13 cd: retq 12a: mov -0x218(%rbp),%r14 131: mov -0x210(%rbp),%r15 138: leaveq 139: retq On fully cached SKBs both JITed functions take 12 nsec to execute. BPF interpreter executes the program in 30 nsec. The difference in generated assembler is due to the following: Old BPF imlements LDX_MSH instruction via sk_load_byte_msh() helper function inside bpf_jit.S. New JIT removes the helper and does it explicitly, so ldx_msh cost is the same for both JITs, but generated code looks longer. New JIT has 4 registers to save, so prologue/epilogue are larger, but the cost is within noise on x64. Old JIT checks whether first insn clears A and if not emits 'xor %eax,%eax'. New JIT clears %rax unconditionally. 2. old BPF JIT doesn't support ANC_NLATTR, ANC_PAY_OFFSET, ANC_RANDOM extensions. New JIT supports all BPF extensions. Performance of such filters improves 2-4 times depending on a filter. The longer the filter the higher performance gain. Synthetic benchmarks with many ancillary loads see 20x speedup which seems to be the maximum gain from JIT Notes: . net.core.bpf_jit_enable=2 + tools/net/bpf_jit_disasm is still functional and can be used to see generated assembler . there are two jit_compile() functions and code flow for classic filters is: sk_attach_filter() - load classic BPF bpf_jit_compile() - try to JIT from classic BPF sk_convert_filter() - convert classic to internal bpf_int_jit_compile() - JIT from internal BPF seccomp and tracing filters will just call bpf_int_jit_compile() Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 20:50:46 -06:00
goto ldx;
case BPF_LDX | BPF_MEM | BPF_H:
/* emit 'movzx rax, word ptr [rax + off]' */
net: filter: cleanup A/X name usage The macro 'A' used in internal BPF interpreter: #define A regs[insn->a_reg] was easily confused with the name of classic BPF register 'A', since 'A' would mean two different things depending on context. This patch is trying to clean up the naming and clarify its usage in the following way: - A and X are names of two classic BPF registers - BPF_REG_A denotes internal BPF register R0 used to map classic register A in internal BPF programs generated from classic - BPF_REG_X denotes internal BPF register R7 used to map classic register X in internal BPF programs generated from classic - internal BPF instruction format: struct sock_filter_int { __u8 code; /* opcode */ __u8 dst_reg:4; /* dest register */ __u8 src_reg:4; /* source register */ __s16 off; /* signed offset */ __s32 imm; /* signed immediate constant */ }; - BPF_X/BPF_K is 1 bit used to encode source operand of instruction In classic: BPF_X - means use register X as source operand BPF_K - means use 32-bit immediate as source operand In internal: BPF_X - means use 'src_reg' register as source operand BPF_K - means use 32-bit immediate as source operand Suggested-by: Chema Gonzalez <chema@google.com> Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Acked-by: Daniel Borkmann <dborkman@redhat.com> Acked-by: Chema Gonzalez <chema@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-06-06 15:46:06 -06:00
EMIT3(add_2mod(0x48, src_reg, dst_reg), 0x0F, 0xB7);
net: filter: x86: internal BPF JIT Maps all internal BPF instructions into x86_64 instructions. This patch replaces original BPF x64 JIT with internal BPF x64 JIT. sysctl net.core.bpf_jit_enable is reused as on/off switch. Performance: 1. old BPF JIT and internal BPF JIT generate equivalent x86_64 code. No performance difference is observed for filters that were JIT-able before Example assembler code for BPF filter "tcpdump port 22" original BPF -> old JIT: original BPF -> internal BPF -> new JIT: 0: push %rbp 0: push %rbp 1: mov %rsp,%rbp 1: mov %rsp,%rbp 4: sub $0x60,%rsp 4: sub $0x228,%rsp 8: mov %rbx,-0x8(%rbp) b: mov %rbx,-0x228(%rbp) // prologue 12: mov %r13,-0x220(%rbp) 19: mov %r14,-0x218(%rbp) 20: mov %r15,-0x210(%rbp) 27: xor %eax,%eax // clear A c: xor %ebx,%ebx 29: xor %r13,%r13 // clear X e: mov 0x68(%rdi),%r9d 2c: mov 0x68(%rdi),%r9d 12: sub 0x6c(%rdi),%r9d 30: sub 0x6c(%rdi),%r9d 16: mov 0xd8(%rdi),%r8 34: mov 0xd8(%rdi),%r10 3b: mov %rdi,%rbx 1d: mov $0xc,%esi 3e: mov $0xc,%esi 22: callq 0xffffffffe1021e15 43: callq 0xffffffffe102bd75 27: cmp $0x86dd,%eax 48: cmp $0x86dd,%rax 2c: jne 0x0000000000000069 4f: jne 0x000000000000009a 2e: mov $0x14,%esi 51: mov $0x14,%esi 33: callq 0xffffffffe1021e31 56: callq 0xffffffffe102bd91 38: cmp $0x84,%eax 5b: cmp $0x84,%rax 3d: je 0x0000000000000049 62: je 0x0000000000000074 3f: cmp $0x6,%eax 64: cmp $0x6,%rax 42: je 0x0000000000000049 68: je 0x0000000000000074 44: cmp $0x11,%eax 6a: cmp $0x11,%rax 47: jne 0x00000000000000c6 6e: jne 0x0000000000000117 49: mov $0x36,%esi 74: mov $0x36,%esi 4e: callq 0xffffffffe1021e15 79: callq 0xffffffffe102bd75 53: cmp $0x16,%eax 7e: cmp $0x16,%rax 56: je 0x00000000000000bf 82: je 0x0000000000000110 58: mov $0x38,%esi 88: mov $0x38,%esi 5d: callq 0xffffffffe1021e15 8d: callq 0xffffffffe102bd75 62: cmp $0x16,%eax 92: cmp $0x16,%rax 65: je 0x00000000000000bf 96: je 0x0000000000000110 67: jmp 0x00000000000000c6 98: jmp 0x0000000000000117 69: cmp $0x800,%eax 9a: cmp $0x800,%rax 6e: jne 0x00000000000000c6 a1: jne 0x0000000000000117 70: mov $0x17,%esi a3: mov $0x17,%esi 75: callq 0xffffffffe1021e31 a8: callq 0xffffffffe102bd91 7a: cmp $0x84,%eax ad: cmp $0x84,%rax 7f: je 0x000000000000008b b4: je 0x00000000000000c2 81: cmp $0x6,%eax b6: cmp $0x6,%rax 84: je 0x000000000000008b ba: je 0x00000000000000c2 86: cmp $0x11,%eax bc: cmp $0x11,%rax 89: jne 0x00000000000000c6 c0: jne 0x0000000000000117 8b: mov $0x14,%esi c2: mov $0x14,%esi 90: callq 0xffffffffe1021e15 c7: callq 0xffffffffe102bd75 95: test $0x1fff,%ax cc: test $0x1fff,%rax 99: jne 0x00000000000000c6 d3: jne 0x0000000000000117 d5: mov %rax,%r14 9b: mov $0xe,%esi d8: mov $0xe,%esi a0: callq 0xffffffffe1021e44 dd: callq 0xffffffffe102bd91 // MSH e2: and $0xf,%eax e5: shl $0x2,%eax e8: mov %rax,%r13 eb: mov %r14,%rax ee: mov %r13,%rsi a5: lea 0xe(%rbx),%esi f1: add $0xe,%esi a8: callq 0xffffffffe1021e0d f4: callq 0xffffffffe102bd6d ad: cmp $0x16,%eax f9: cmp $0x16,%rax b0: je 0x00000000000000bf fd: je 0x0000000000000110 ff: mov %r13,%rsi b2: lea 0x10(%rbx),%esi 102: add $0x10,%esi b5: callq 0xffffffffe1021e0d 105: callq 0xffffffffe102bd6d ba: cmp $0x16,%eax 10a: cmp $0x16,%rax bd: jne 0x00000000000000c6 10e: jne 0x0000000000000117 bf: mov $0xffff,%eax 110: mov $0xffff,%eax c4: jmp 0x00000000000000c8 115: jmp 0x000000000000011c c6: xor %eax,%eax 117: mov $0x0,%eax c8: mov -0x8(%rbp),%rbx 11c: mov -0x228(%rbp),%rbx // epilogue cc: leaveq 123: mov -0x220(%rbp),%r13 cd: retq 12a: mov -0x218(%rbp),%r14 131: mov -0x210(%rbp),%r15 138: leaveq 139: retq On fully cached SKBs both JITed functions take 12 nsec to execute. BPF interpreter executes the program in 30 nsec. The difference in generated assembler is due to the following: Old BPF imlements LDX_MSH instruction via sk_load_byte_msh() helper function inside bpf_jit.S. New JIT removes the helper and does it explicitly, so ldx_msh cost is the same for both JITs, but generated code looks longer. New JIT has 4 registers to save, so prologue/epilogue are larger, but the cost is within noise on x64. Old JIT checks whether first insn clears A and if not emits 'xor %eax,%eax'. New JIT clears %rax unconditionally. 2. old BPF JIT doesn't support ANC_NLATTR, ANC_PAY_OFFSET, ANC_RANDOM extensions. New JIT supports all BPF extensions. Performance of such filters improves 2-4 times depending on a filter. The longer the filter the higher performance gain. Synthetic benchmarks with many ancillary loads see 20x speedup which seems to be the maximum gain from JIT Notes: . net.core.bpf_jit_enable=2 + tools/net/bpf_jit_disasm is still functional and can be used to see generated assembler . there are two jit_compile() functions and code flow for classic filters is: sk_attach_filter() - load classic BPF bpf_jit_compile() - try to JIT from classic BPF sk_convert_filter() - convert classic to internal bpf_int_jit_compile() - JIT from internal BPF seccomp and tracing filters will just call bpf_int_jit_compile() Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 20:50:46 -06:00
goto ldx;
case BPF_LDX | BPF_MEM | BPF_W:
/* emit 'mov eax, dword ptr [rax+0x14]' */
net: filter: cleanup A/X name usage The macro 'A' used in internal BPF interpreter: #define A regs[insn->a_reg] was easily confused with the name of classic BPF register 'A', since 'A' would mean two different things depending on context. This patch is trying to clean up the naming and clarify its usage in the following way: - A and X are names of two classic BPF registers - BPF_REG_A denotes internal BPF register R0 used to map classic register A in internal BPF programs generated from classic - BPF_REG_X denotes internal BPF register R7 used to map classic register X in internal BPF programs generated from classic - internal BPF instruction format: struct sock_filter_int { __u8 code; /* opcode */ __u8 dst_reg:4; /* dest register */ __u8 src_reg:4; /* source register */ __s16 off; /* signed offset */ __s32 imm; /* signed immediate constant */ }; - BPF_X/BPF_K is 1 bit used to encode source operand of instruction In classic: BPF_X - means use register X as source operand BPF_K - means use 32-bit immediate as source operand In internal: BPF_X - means use 'src_reg' register as source operand BPF_K - means use 32-bit immediate as source operand Suggested-by: Chema Gonzalez <chema@google.com> Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Acked-by: Daniel Borkmann <dborkman@redhat.com> Acked-by: Chema Gonzalez <chema@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-06-06 15:46:06 -06:00
if (is_ereg(dst_reg) || is_ereg(src_reg))
EMIT2(add_2mod(0x40, src_reg, dst_reg), 0x8B);
net: filter: x86: internal BPF JIT Maps all internal BPF instructions into x86_64 instructions. This patch replaces original BPF x64 JIT with internal BPF x64 JIT. sysctl net.core.bpf_jit_enable is reused as on/off switch. Performance: 1. old BPF JIT and internal BPF JIT generate equivalent x86_64 code. No performance difference is observed for filters that were JIT-able before Example assembler code for BPF filter "tcpdump port 22" original BPF -> old JIT: original BPF -> internal BPF -> new JIT: 0: push %rbp 0: push %rbp 1: mov %rsp,%rbp 1: mov %rsp,%rbp 4: sub $0x60,%rsp 4: sub $0x228,%rsp 8: mov %rbx,-0x8(%rbp) b: mov %rbx,-0x228(%rbp) // prologue 12: mov %r13,-0x220(%rbp) 19: mov %r14,-0x218(%rbp) 20: mov %r15,-0x210(%rbp) 27: xor %eax,%eax // clear A c: xor %ebx,%ebx 29: xor %r13,%r13 // clear X e: mov 0x68(%rdi),%r9d 2c: mov 0x68(%rdi),%r9d 12: sub 0x6c(%rdi),%r9d 30: sub 0x6c(%rdi),%r9d 16: mov 0xd8(%rdi),%r8 34: mov 0xd8(%rdi),%r10 3b: mov %rdi,%rbx 1d: mov $0xc,%esi 3e: mov $0xc,%esi 22: callq 0xffffffffe1021e15 43: callq 0xffffffffe102bd75 27: cmp $0x86dd,%eax 48: cmp $0x86dd,%rax 2c: jne 0x0000000000000069 4f: jne 0x000000000000009a 2e: mov $0x14,%esi 51: mov $0x14,%esi 33: callq 0xffffffffe1021e31 56: callq 0xffffffffe102bd91 38: cmp $0x84,%eax 5b: cmp $0x84,%rax 3d: je 0x0000000000000049 62: je 0x0000000000000074 3f: cmp $0x6,%eax 64: cmp $0x6,%rax 42: je 0x0000000000000049 68: je 0x0000000000000074 44: cmp $0x11,%eax 6a: cmp $0x11,%rax 47: jne 0x00000000000000c6 6e: jne 0x0000000000000117 49: mov $0x36,%esi 74: mov $0x36,%esi 4e: callq 0xffffffffe1021e15 79: callq 0xffffffffe102bd75 53: cmp $0x16,%eax 7e: cmp $0x16,%rax 56: je 0x00000000000000bf 82: je 0x0000000000000110 58: mov $0x38,%esi 88: mov $0x38,%esi 5d: callq 0xffffffffe1021e15 8d: callq 0xffffffffe102bd75 62: cmp $0x16,%eax 92: cmp $0x16,%rax 65: je 0x00000000000000bf 96: je 0x0000000000000110 67: jmp 0x00000000000000c6 98: jmp 0x0000000000000117 69: cmp $0x800,%eax 9a: cmp $0x800,%rax 6e: jne 0x00000000000000c6 a1: jne 0x0000000000000117 70: mov $0x17,%esi a3: mov $0x17,%esi 75: callq 0xffffffffe1021e31 a8: callq 0xffffffffe102bd91 7a: cmp $0x84,%eax ad: cmp $0x84,%rax 7f: je 0x000000000000008b b4: je 0x00000000000000c2 81: cmp $0x6,%eax b6: cmp $0x6,%rax 84: je 0x000000000000008b ba: je 0x00000000000000c2 86: cmp $0x11,%eax bc: cmp $0x11,%rax 89: jne 0x00000000000000c6 c0: jne 0x0000000000000117 8b: mov $0x14,%esi c2: mov $0x14,%esi 90: callq 0xffffffffe1021e15 c7: callq 0xffffffffe102bd75 95: test $0x1fff,%ax cc: test $0x1fff,%rax 99: jne 0x00000000000000c6 d3: jne 0x0000000000000117 d5: mov %rax,%r14 9b: mov $0xe,%esi d8: mov $0xe,%esi a0: callq 0xffffffffe1021e44 dd: callq 0xffffffffe102bd91 // MSH e2: and $0xf,%eax e5: shl $0x2,%eax e8: mov %rax,%r13 eb: mov %r14,%rax ee: mov %r13,%rsi a5: lea 0xe(%rbx),%esi f1: add $0xe,%esi a8: callq 0xffffffffe1021e0d f4: callq 0xffffffffe102bd6d ad: cmp $0x16,%eax f9: cmp $0x16,%rax b0: je 0x00000000000000bf fd: je 0x0000000000000110 ff: mov %r13,%rsi b2: lea 0x10(%rbx),%esi 102: add $0x10,%esi b5: callq 0xffffffffe1021e0d 105: callq 0xffffffffe102bd6d ba: cmp $0x16,%eax 10a: cmp $0x16,%rax bd: jne 0x00000000000000c6 10e: jne 0x0000000000000117 bf: mov $0xffff,%eax 110: mov $0xffff,%eax c4: jmp 0x00000000000000c8 115: jmp 0x000000000000011c c6: xor %eax,%eax 117: mov $0x0,%eax c8: mov -0x8(%rbp),%rbx 11c: mov -0x228(%rbp),%rbx // epilogue cc: leaveq 123: mov -0x220(%rbp),%r13 cd: retq 12a: mov -0x218(%rbp),%r14 131: mov -0x210(%rbp),%r15 138: leaveq 139: retq On fully cached SKBs both JITed functions take 12 nsec to execute. BPF interpreter executes the program in 30 nsec. The difference in generated assembler is due to the following: Old BPF imlements LDX_MSH instruction via sk_load_byte_msh() helper function inside bpf_jit.S. New JIT removes the helper and does it explicitly, so ldx_msh cost is the same for both JITs, but generated code looks longer. New JIT has 4 registers to save, so prologue/epilogue are larger, but the cost is within noise on x64. Old JIT checks whether first insn clears A and if not emits 'xor %eax,%eax'. New JIT clears %rax unconditionally. 2. old BPF JIT doesn't support ANC_NLATTR, ANC_PAY_OFFSET, ANC_RANDOM extensions. New JIT supports all BPF extensions. Performance of such filters improves 2-4 times depending on a filter. The longer the filter the higher performance gain. Synthetic benchmarks with many ancillary loads see 20x speedup which seems to be the maximum gain from JIT Notes: . net.core.bpf_jit_enable=2 + tools/net/bpf_jit_disasm is still functional and can be used to see generated assembler . there are two jit_compile() functions and code flow for classic filters is: sk_attach_filter() - load classic BPF bpf_jit_compile() - try to JIT from classic BPF sk_convert_filter() - convert classic to internal bpf_int_jit_compile() - JIT from internal BPF seccomp and tracing filters will just call bpf_int_jit_compile() Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 20:50:46 -06:00
else
EMIT1(0x8B);
goto ldx;
case BPF_LDX | BPF_MEM | BPF_DW:
/* emit 'mov rax, qword ptr [rax+0x14]' */
net: filter: cleanup A/X name usage The macro 'A' used in internal BPF interpreter: #define A regs[insn->a_reg] was easily confused with the name of classic BPF register 'A', since 'A' would mean two different things depending on context. This patch is trying to clean up the naming and clarify its usage in the following way: - A and X are names of two classic BPF registers - BPF_REG_A denotes internal BPF register R0 used to map classic register A in internal BPF programs generated from classic - BPF_REG_X denotes internal BPF register R7 used to map classic register X in internal BPF programs generated from classic - internal BPF instruction format: struct sock_filter_int { __u8 code; /* opcode */ __u8 dst_reg:4; /* dest register */ __u8 src_reg:4; /* source register */ __s16 off; /* signed offset */ __s32 imm; /* signed immediate constant */ }; - BPF_X/BPF_K is 1 bit used to encode source operand of instruction In classic: BPF_X - means use register X as source operand BPF_K - means use 32-bit immediate as source operand In internal: BPF_X - means use 'src_reg' register as source operand BPF_K - means use 32-bit immediate as source operand Suggested-by: Chema Gonzalez <chema@google.com> Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Acked-by: Daniel Borkmann <dborkman@redhat.com> Acked-by: Chema Gonzalez <chema@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-06-06 15:46:06 -06:00
EMIT2(add_2mod(0x48, src_reg, dst_reg), 0x8B);
net: filter: x86: internal BPF JIT Maps all internal BPF instructions into x86_64 instructions. This patch replaces original BPF x64 JIT with internal BPF x64 JIT. sysctl net.core.bpf_jit_enable is reused as on/off switch. Performance: 1. old BPF JIT and internal BPF JIT generate equivalent x86_64 code. No performance difference is observed for filters that were JIT-able before Example assembler code for BPF filter "tcpdump port 22" original BPF -> old JIT: original BPF -> internal BPF -> new JIT: 0: push %rbp 0: push %rbp 1: mov %rsp,%rbp 1: mov %rsp,%rbp 4: sub $0x60,%rsp 4: sub $0x228,%rsp 8: mov %rbx,-0x8(%rbp) b: mov %rbx,-0x228(%rbp) // prologue 12: mov %r13,-0x220(%rbp) 19: mov %r14,-0x218(%rbp) 20: mov %r15,-0x210(%rbp) 27: xor %eax,%eax // clear A c: xor %ebx,%ebx 29: xor %r13,%r13 // clear X e: mov 0x68(%rdi),%r9d 2c: mov 0x68(%rdi),%r9d 12: sub 0x6c(%rdi),%r9d 30: sub 0x6c(%rdi),%r9d 16: mov 0xd8(%rdi),%r8 34: mov 0xd8(%rdi),%r10 3b: mov %rdi,%rbx 1d: mov $0xc,%esi 3e: mov $0xc,%esi 22: callq 0xffffffffe1021e15 43: callq 0xffffffffe102bd75 27: cmp $0x86dd,%eax 48: cmp $0x86dd,%rax 2c: jne 0x0000000000000069 4f: jne 0x000000000000009a 2e: mov $0x14,%esi 51: mov $0x14,%esi 33: callq 0xffffffffe1021e31 56: callq 0xffffffffe102bd91 38: cmp $0x84,%eax 5b: cmp $0x84,%rax 3d: je 0x0000000000000049 62: je 0x0000000000000074 3f: cmp $0x6,%eax 64: cmp $0x6,%rax 42: je 0x0000000000000049 68: je 0x0000000000000074 44: cmp $0x11,%eax 6a: cmp $0x11,%rax 47: jne 0x00000000000000c6 6e: jne 0x0000000000000117 49: mov $0x36,%esi 74: mov $0x36,%esi 4e: callq 0xffffffffe1021e15 79: callq 0xffffffffe102bd75 53: cmp $0x16,%eax 7e: cmp $0x16,%rax 56: je 0x00000000000000bf 82: je 0x0000000000000110 58: mov $0x38,%esi 88: mov $0x38,%esi 5d: callq 0xffffffffe1021e15 8d: callq 0xffffffffe102bd75 62: cmp $0x16,%eax 92: cmp $0x16,%rax 65: je 0x00000000000000bf 96: je 0x0000000000000110 67: jmp 0x00000000000000c6 98: jmp 0x0000000000000117 69: cmp $0x800,%eax 9a: cmp $0x800,%rax 6e: jne 0x00000000000000c6 a1: jne 0x0000000000000117 70: mov $0x17,%esi a3: mov $0x17,%esi 75: callq 0xffffffffe1021e31 a8: callq 0xffffffffe102bd91 7a: cmp $0x84,%eax ad: cmp $0x84,%rax 7f: je 0x000000000000008b b4: je 0x00000000000000c2 81: cmp $0x6,%eax b6: cmp $0x6,%rax 84: je 0x000000000000008b ba: je 0x00000000000000c2 86: cmp $0x11,%eax bc: cmp $0x11,%rax 89: jne 0x00000000000000c6 c0: jne 0x0000000000000117 8b: mov $0x14,%esi c2: mov $0x14,%esi 90: callq 0xffffffffe1021e15 c7: callq 0xffffffffe102bd75 95: test $0x1fff,%ax cc: test $0x1fff,%rax 99: jne 0x00000000000000c6 d3: jne 0x0000000000000117 d5: mov %rax,%r14 9b: mov $0xe,%esi d8: mov $0xe,%esi a0: callq 0xffffffffe1021e44 dd: callq 0xffffffffe102bd91 // MSH e2: and $0xf,%eax e5: shl $0x2,%eax e8: mov %rax,%r13 eb: mov %r14,%rax ee: mov %r13,%rsi a5: lea 0xe(%rbx),%esi f1: add $0xe,%esi a8: callq 0xffffffffe1021e0d f4: callq 0xffffffffe102bd6d ad: cmp $0x16,%eax f9: cmp $0x16,%rax b0: je 0x00000000000000bf fd: je 0x0000000000000110 ff: mov %r13,%rsi b2: lea 0x10(%rbx),%esi 102: add $0x10,%esi b5: callq 0xffffffffe1021e0d 105: callq 0xffffffffe102bd6d ba: cmp $0x16,%eax 10a: cmp $0x16,%rax bd: jne 0x00000000000000c6 10e: jne 0x0000000000000117 bf: mov $0xffff,%eax 110: mov $0xffff,%eax c4: jmp 0x00000000000000c8 115: jmp 0x000000000000011c c6: xor %eax,%eax 117: mov $0x0,%eax c8: mov -0x8(%rbp),%rbx 11c: mov -0x228(%rbp),%rbx // epilogue cc: leaveq 123: mov -0x220(%rbp),%r13 cd: retq 12a: mov -0x218(%rbp),%r14 131: mov -0x210(%rbp),%r15 138: leaveq 139: retq On fully cached SKBs both JITed functions take 12 nsec to execute. BPF interpreter executes the program in 30 nsec. The difference in generated assembler is due to the following: Old BPF imlements LDX_MSH instruction via sk_load_byte_msh() helper function inside bpf_jit.S. New JIT removes the helper and does it explicitly, so ldx_msh cost is the same for both JITs, but generated code looks longer. New JIT has 4 registers to save, so prologue/epilogue are larger, but the cost is within noise on x64. Old JIT checks whether first insn clears A and if not emits 'xor %eax,%eax'. New JIT clears %rax unconditionally. 2. old BPF JIT doesn't support ANC_NLATTR, ANC_PAY_OFFSET, ANC_RANDOM extensions. New JIT supports all BPF extensions. Performance of such filters improves 2-4 times depending on a filter. The longer the filter the higher performance gain. Synthetic benchmarks with many ancillary loads see 20x speedup which seems to be the maximum gain from JIT Notes: . net.core.bpf_jit_enable=2 + tools/net/bpf_jit_disasm is still functional and can be used to see generated assembler . there are two jit_compile() functions and code flow for classic filters is: sk_attach_filter() - load classic BPF bpf_jit_compile() - try to JIT from classic BPF sk_convert_filter() - convert classic to internal bpf_int_jit_compile() - JIT from internal BPF seccomp and tracing filters will just call bpf_int_jit_compile() Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 20:50:46 -06:00
ldx: /* if insn->off == 0 we can save one extra byte, but
* special case of x86 r13 which always needs an offset
* is not worth the hassle
*/
if (is_imm8(insn->off))
net: filter: cleanup A/X name usage The macro 'A' used in internal BPF interpreter: #define A regs[insn->a_reg] was easily confused with the name of classic BPF register 'A', since 'A' would mean two different things depending on context. This patch is trying to clean up the naming and clarify its usage in the following way: - A and X are names of two classic BPF registers - BPF_REG_A denotes internal BPF register R0 used to map classic register A in internal BPF programs generated from classic - BPF_REG_X denotes internal BPF register R7 used to map classic register X in internal BPF programs generated from classic - internal BPF instruction format: struct sock_filter_int { __u8 code; /* opcode */ __u8 dst_reg:4; /* dest register */ __u8 src_reg:4; /* source register */ __s16 off; /* signed offset */ __s32 imm; /* signed immediate constant */ }; - BPF_X/BPF_K is 1 bit used to encode source operand of instruction In classic: BPF_X - means use register X as source operand BPF_K - means use 32-bit immediate as source operand In internal: BPF_X - means use 'src_reg' register as source operand BPF_K - means use 32-bit immediate as source operand Suggested-by: Chema Gonzalez <chema@google.com> Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Acked-by: Daniel Borkmann <dborkman@redhat.com> Acked-by: Chema Gonzalez <chema@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-06-06 15:46:06 -06:00
EMIT2(add_2reg(0x40, src_reg, dst_reg), insn->off);
net: filter: x86: internal BPF JIT Maps all internal BPF instructions into x86_64 instructions. This patch replaces original BPF x64 JIT with internal BPF x64 JIT. sysctl net.core.bpf_jit_enable is reused as on/off switch. Performance: 1. old BPF JIT and internal BPF JIT generate equivalent x86_64 code. No performance difference is observed for filters that were JIT-able before Example assembler code for BPF filter "tcpdump port 22" original BPF -> old JIT: original BPF -> internal BPF -> new JIT: 0: push %rbp 0: push %rbp 1: mov %rsp,%rbp 1: mov %rsp,%rbp 4: sub $0x60,%rsp 4: sub $0x228,%rsp 8: mov %rbx,-0x8(%rbp) b: mov %rbx,-0x228(%rbp) // prologue 12: mov %r13,-0x220(%rbp) 19: mov %r14,-0x218(%rbp) 20: mov %r15,-0x210(%rbp) 27: xor %eax,%eax // clear A c: xor %ebx,%ebx 29: xor %r13,%r13 // clear X e: mov 0x68(%rdi),%r9d 2c: mov 0x68(%rdi),%r9d 12: sub 0x6c(%rdi),%r9d 30: sub 0x6c(%rdi),%r9d 16: mov 0xd8(%rdi),%r8 34: mov 0xd8(%rdi),%r10 3b: mov %rdi,%rbx 1d: mov $0xc,%esi 3e: mov $0xc,%esi 22: callq 0xffffffffe1021e15 43: callq 0xffffffffe102bd75 27: cmp $0x86dd,%eax 48: cmp $0x86dd,%rax 2c: jne 0x0000000000000069 4f: jne 0x000000000000009a 2e: mov $0x14,%esi 51: mov $0x14,%esi 33: callq 0xffffffffe1021e31 56: callq 0xffffffffe102bd91 38: cmp $0x84,%eax 5b: cmp $0x84,%rax 3d: je 0x0000000000000049 62: je 0x0000000000000074 3f: cmp $0x6,%eax 64: cmp $0x6,%rax 42: je 0x0000000000000049 68: je 0x0000000000000074 44: cmp $0x11,%eax 6a: cmp $0x11,%rax 47: jne 0x00000000000000c6 6e: jne 0x0000000000000117 49: mov $0x36,%esi 74: mov $0x36,%esi 4e: callq 0xffffffffe1021e15 79: callq 0xffffffffe102bd75 53: cmp $0x16,%eax 7e: cmp $0x16,%rax 56: je 0x00000000000000bf 82: je 0x0000000000000110 58: mov $0x38,%esi 88: mov $0x38,%esi 5d: callq 0xffffffffe1021e15 8d: callq 0xffffffffe102bd75 62: cmp $0x16,%eax 92: cmp $0x16,%rax 65: je 0x00000000000000bf 96: je 0x0000000000000110 67: jmp 0x00000000000000c6 98: jmp 0x0000000000000117 69: cmp $0x800,%eax 9a: cmp $0x800,%rax 6e: jne 0x00000000000000c6 a1: jne 0x0000000000000117 70: mov $0x17,%esi a3: mov $0x17,%esi 75: callq 0xffffffffe1021e31 a8: callq 0xffffffffe102bd91 7a: cmp $0x84,%eax ad: cmp $0x84,%rax 7f: je 0x000000000000008b b4: je 0x00000000000000c2 81: cmp $0x6,%eax b6: cmp $0x6,%rax 84: je 0x000000000000008b ba: je 0x00000000000000c2 86: cmp $0x11,%eax bc: cmp $0x11,%rax 89: jne 0x00000000000000c6 c0: jne 0x0000000000000117 8b: mov $0x14,%esi c2: mov $0x14,%esi 90: callq 0xffffffffe1021e15 c7: callq 0xffffffffe102bd75 95: test $0x1fff,%ax cc: test $0x1fff,%rax 99: jne 0x00000000000000c6 d3: jne 0x0000000000000117 d5: mov %rax,%r14 9b: mov $0xe,%esi d8: mov $0xe,%esi a0: callq 0xffffffffe1021e44 dd: callq 0xffffffffe102bd91 // MSH e2: and $0xf,%eax e5: shl $0x2,%eax e8: mov %rax,%r13 eb: mov %r14,%rax ee: mov %r13,%rsi a5: lea 0xe(%rbx),%esi f1: add $0xe,%esi a8: callq 0xffffffffe1021e0d f4: callq 0xffffffffe102bd6d ad: cmp $0x16,%eax f9: cmp $0x16,%rax b0: je 0x00000000000000bf fd: je 0x0000000000000110 ff: mov %r13,%rsi b2: lea 0x10(%rbx),%esi 102: add $0x10,%esi b5: callq 0xffffffffe1021e0d 105: callq 0xffffffffe102bd6d ba: cmp $0x16,%eax 10a: cmp $0x16,%rax bd: jne 0x00000000000000c6 10e: jne 0x0000000000000117 bf: mov $0xffff,%eax 110: mov $0xffff,%eax c4: jmp 0x00000000000000c8 115: jmp 0x000000000000011c c6: xor %eax,%eax 117: mov $0x0,%eax c8: mov -0x8(%rbp),%rbx 11c: mov -0x228(%rbp),%rbx // epilogue cc: leaveq 123: mov -0x220(%rbp),%r13 cd: retq 12a: mov -0x218(%rbp),%r14 131: mov -0x210(%rbp),%r15 138: leaveq 139: retq On fully cached SKBs both JITed functions take 12 nsec to execute. BPF interpreter executes the program in 30 nsec. The difference in generated assembler is due to the following: Old BPF imlements LDX_MSH instruction via sk_load_byte_msh() helper function inside bpf_jit.S. New JIT removes the helper and does it explicitly, so ldx_msh cost is the same for both JITs, but generated code looks longer. New JIT has 4 registers to save, so prologue/epilogue are larger, but the cost is within noise on x64. Old JIT checks whether first insn clears A and if not emits 'xor %eax,%eax'. New JIT clears %rax unconditionally. 2. old BPF JIT doesn't support ANC_NLATTR, ANC_PAY_OFFSET, ANC_RANDOM extensions. New JIT supports all BPF extensions. Performance of such filters improves 2-4 times depending on a filter. The longer the filter the higher performance gain. Synthetic benchmarks with many ancillary loads see 20x speedup which seems to be the maximum gain from JIT Notes: . net.core.bpf_jit_enable=2 + tools/net/bpf_jit_disasm is still functional and can be used to see generated assembler . there are two jit_compile() functions and code flow for classic filters is: sk_attach_filter() - load classic BPF bpf_jit_compile() - try to JIT from classic BPF sk_convert_filter() - convert classic to internal bpf_int_jit_compile() - JIT from internal BPF seccomp and tracing filters will just call bpf_int_jit_compile() Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 20:50:46 -06:00
else
net: filter: cleanup A/X name usage The macro 'A' used in internal BPF interpreter: #define A regs[insn->a_reg] was easily confused with the name of classic BPF register 'A', since 'A' would mean two different things depending on context. This patch is trying to clean up the naming and clarify its usage in the following way: - A and X are names of two classic BPF registers - BPF_REG_A denotes internal BPF register R0 used to map classic register A in internal BPF programs generated from classic - BPF_REG_X denotes internal BPF register R7 used to map classic register X in internal BPF programs generated from classic - internal BPF instruction format: struct sock_filter_int { __u8 code; /* opcode */ __u8 dst_reg:4; /* dest register */ __u8 src_reg:4; /* source register */ __s16 off; /* signed offset */ __s32 imm; /* signed immediate constant */ }; - BPF_X/BPF_K is 1 bit used to encode source operand of instruction In classic: BPF_X - means use register X as source operand BPF_K - means use 32-bit immediate as source operand In internal: BPF_X - means use 'src_reg' register as source operand BPF_K - means use 32-bit immediate as source operand Suggested-by: Chema Gonzalez <chema@google.com> Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Acked-by: Daniel Borkmann <dborkman@redhat.com> Acked-by: Chema Gonzalez <chema@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-06-06 15:46:06 -06:00
EMIT1_off32(add_2reg(0x80, src_reg, dst_reg),
net: filter: x86: internal BPF JIT Maps all internal BPF instructions into x86_64 instructions. This patch replaces original BPF x64 JIT with internal BPF x64 JIT. sysctl net.core.bpf_jit_enable is reused as on/off switch. Performance: 1. old BPF JIT and internal BPF JIT generate equivalent x86_64 code. No performance difference is observed for filters that were JIT-able before Example assembler code for BPF filter "tcpdump port 22" original BPF -> old JIT: original BPF -> internal BPF -> new JIT: 0: push %rbp 0: push %rbp 1: mov %rsp,%rbp 1: mov %rsp,%rbp 4: sub $0x60,%rsp 4: sub $0x228,%rsp 8: mov %rbx,-0x8(%rbp) b: mov %rbx,-0x228(%rbp) // prologue 12: mov %r13,-0x220(%rbp) 19: mov %r14,-0x218(%rbp) 20: mov %r15,-0x210(%rbp) 27: xor %eax,%eax // clear A c: xor %ebx,%ebx 29: xor %r13,%r13 // clear X e: mov 0x68(%rdi),%r9d 2c: mov 0x68(%rdi),%r9d 12: sub 0x6c(%rdi),%r9d 30: sub 0x6c(%rdi),%r9d 16: mov 0xd8(%rdi),%r8 34: mov 0xd8(%rdi),%r10 3b: mov %rdi,%rbx 1d: mov $0xc,%esi 3e: mov $0xc,%esi 22: callq 0xffffffffe1021e15 43: callq 0xffffffffe102bd75 27: cmp $0x86dd,%eax 48: cmp $0x86dd,%rax 2c: jne 0x0000000000000069 4f: jne 0x000000000000009a 2e: mov $0x14,%esi 51: mov $0x14,%esi 33: callq 0xffffffffe1021e31 56: callq 0xffffffffe102bd91 38: cmp $0x84,%eax 5b: cmp $0x84,%rax 3d: je 0x0000000000000049 62: je 0x0000000000000074 3f: cmp $0x6,%eax 64: cmp $0x6,%rax 42: je 0x0000000000000049 68: je 0x0000000000000074 44: cmp $0x11,%eax 6a: cmp $0x11,%rax 47: jne 0x00000000000000c6 6e: jne 0x0000000000000117 49: mov $0x36,%esi 74: mov $0x36,%esi 4e: callq 0xffffffffe1021e15 79: callq 0xffffffffe102bd75 53: cmp $0x16,%eax 7e: cmp $0x16,%rax 56: je 0x00000000000000bf 82: je 0x0000000000000110 58: mov $0x38,%esi 88: mov $0x38,%esi 5d: callq 0xffffffffe1021e15 8d: callq 0xffffffffe102bd75 62: cmp $0x16,%eax 92: cmp $0x16,%rax 65: je 0x00000000000000bf 96: je 0x0000000000000110 67: jmp 0x00000000000000c6 98: jmp 0x0000000000000117 69: cmp $0x800,%eax 9a: cmp $0x800,%rax 6e: jne 0x00000000000000c6 a1: jne 0x0000000000000117 70: mov $0x17,%esi a3: mov $0x17,%esi 75: callq 0xffffffffe1021e31 a8: callq 0xffffffffe102bd91 7a: cmp $0x84,%eax ad: cmp $0x84,%rax 7f: je 0x000000000000008b b4: je 0x00000000000000c2 81: cmp $0x6,%eax b6: cmp $0x6,%rax 84: je 0x000000000000008b ba: je 0x00000000000000c2 86: cmp $0x11,%eax bc: cmp $0x11,%rax 89: jne 0x00000000000000c6 c0: jne 0x0000000000000117 8b: mov $0x14,%esi c2: mov $0x14,%esi 90: callq 0xffffffffe1021e15 c7: callq 0xffffffffe102bd75 95: test $0x1fff,%ax cc: test $0x1fff,%rax 99: jne 0x00000000000000c6 d3: jne 0x0000000000000117 d5: mov %rax,%r14 9b: mov $0xe,%esi d8: mov $0xe,%esi a0: callq 0xffffffffe1021e44 dd: callq 0xffffffffe102bd91 // MSH e2: and $0xf,%eax e5: shl $0x2,%eax e8: mov %rax,%r13 eb: mov %r14,%rax ee: mov %r13,%rsi a5: lea 0xe(%rbx),%esi f1: add $0xe,%esi a8: callq 0xffffffffe1021e0d f4: callq 0xffffffffe102bd6d ad: cmp $0x16,%eax f9: cmp $0x16,%rax b0: je 0x00000000000000bf fd: je 0x0000000000000110 ff: mov %r13,%rsi b2: lea 0x10(%rbx),%esi 102: add $0x10,%esi b5: callq 0xffffffffe1021e0d 105: callq 0xffffffffe102bd6d ba: cmp $0x16,%eax 10a: cmp $0x16,%rax bd: jne 0x00000000000000c6 10e: jne 0x0000000000000117 bf: mov $0xffff,%eax 110: mov $0xffff,%eax c4: jmp 0x00000000000000c8 115: jmp 0x000000000000011c c6: xor %eax,%eax 117: mov $0x0,%eax c8: mov -0x8(%rbp),%rbx 11c: mov -0x228(%rbp),%rbx // epilogue cc: leaveq 123: mov -0x220(%rbp),%r13 cd: retq 12a: mov -0x218(%rbp),%r14 131: mov -0x210(%rbp),%r15 138: leaveq 139: retq On fully cached SKBs both JITed functions take 12 nsec to execute. BPF interpreter executes the program in 30 nsec. The difference in generated assembler is due to the following: Old BPF imlements LDX_MSH instruction via sk_load_byte_msh() helper function inside bpf_jit.S. New JIT removes the helper and does it explicitly, so ldx_msh cost is the same for both JITs, but generated code looks longer. New JIT has 4 registers to save, so prologue/epilogue are larger, but the cost is within noise on x64. Old JIT checks whether first insn clears A and if not emits 'xor %eax,%eax'. New JIT clears %rax unconditionally. 2. old BPF JIT doesn't support ANC_NLATTR, ANC_PAY_OFFSET, ANC_RANDOM extensions. New JIT supports all BPF extensions. Performance of such filters improves 2-4 times depending on a filter. The longer the filter the higher performance gain. Synthetic benchmarks with many ancillary loads see 20x speedup which seems to be the maximum gain from JIT Notes: . net.core.bpf_jit_enable=2 + tools/net/bpf_jit_disasm is still functional and can be used to see generated assembler . there are two jit_compile() functions and code flow for classic filters is: sk_attach_filter() - load classic BPF bpf_jit_compile() - try to JIT from classic BPF sk_convert_filter() - convert classic to internal bpf_int_jit_compile() - JIT from internal BPF seccomp and tracing filters will just call bpf_int_jit_compile() Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 20:50:46 -06:00
insn->off);
break;
net: filter: cleanup A/X name usage The macro 'A' used in internal BPF interpreter: #define A regs[insn->a_reg] was easily confused with the name of classic BPF register 'A', since 'A' would mean two different things depending on context. This patch is trying to clean up the naming and clarify its usage in the following way: - A and X are names of two classic BPF registers - BPF_REG_A denotes internal BPF register R0 used to map classic register A in internal BPF programs generated from classic - BPF_REG_X denotes internal BPF register R7 used to map classic register X in internal BPF programs generated from classic - internal BPF instruction format: struct sock_filter_int { __u8 code; /* opcode */ __u8 dst_reg:4; /* dest register */ __u8 src_reg:4; /* source register */ __s16 off; /* signed offset */ __s32 imm; /* signed immediate constant */ }; - BPF_X/BPF_K is 1 bit used to encode source operand of instruction In classic: BPF_X - means use register X as source operand BPF_K - means use 32-bit immediate as source operand In internal: BPF_X - means use 'src_reg' register as source operand BPF_K - means use 32-bit immediate as source operand Suggested-by: Chema Gonzalez <chema@google.com> Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Acked-by: Daniel Borkmann <dborkman@redhat.com> Acked-by: Chema Gonzalez <chema@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-06-06 15:46:06 -06:00
/* STX XADD: lock *(u32*)(dst_reg + off) += src_reg */
net: filter: x86: internal BPF JIT Maps all internal BPF instructions into x86_64 instructions. This patch replaces original BPF x64 JIT with internal BPF x64 JIT. sysctl net.core.bpf_jit_enable is reused as on/off switch. Performance: 1. old BPF JIT and internal BPF JIT generate equivalent x86_64 code. No performance difference is observed for filters that were JIT-able before Example assembler code for BPF filter "tcpdump port 22" original BPF -> old JIT: original BPF -> internal BPF -> new JIT: 0: push %rbp 0: push %rbp 1: mov %rsp,%rbp 1: mov %rsp,%rbp 4: sub $0x60,%rsp 4: sub $0x228,%rsp 8: mov %rbx,-0x8(%rbp) b: mov %rbx,-0x228(%rbp) // prologue 12: mov %r13,-0x220(%rbp) 19: mov %r14,-0x218(%rbp) 20: mov %r15,-0x210(%rbp) 27: xor %eax,%eax // clear A c: xor %ebx,%ebx 29: xor %r13,%r13 // clear X e: mov 0x68(%rdi),%r9d 2c: mov 0x68(%rdi),%r9d 12: sub 0x6c(%rdi),%r9d 30: sub 0x6c(%rdi),%r9d 16: mov 0xd8(%rdi),%r8 34: mov 0xd8(%rdi),%r10 3b: mov %rdi,%rbx 1d: mov $0xc,%esi 3e: mov $0xc,%esi 22: callq 0xffffffffe1021e15 43: callq 0xffffffffe102bd75 27: cmp $0x86dd,%eax 48: cmp $0x86dd,%rax 2c: jne 0x0000000000000069 4f: jne 0x000000000000009a 2e: mov $0x14,%esi 51: mov $0x14,%esi 33: callq 0xffffffffe1021e31 56: callq 0xffffffffe102bd91 38: cmp $0x84,%eax 5b: cmp $0x84,%rax 3d: je 0x0000000000000049 62: je 0x0000000000000074 3f: cmp $0x6,%eax 64: cmp $0x6,%rax 42: je 0x0000000000000049 68: je 0x0000000000000074 44: cmp $0x11,%eax 6a: cmp $0x11,%rax 47: jne 0x00000000000000c6 6e: jne 0x0000000000000117 49: mov $0x36,%esi 74: mov $0x36,%esi 4e: callq 0xffffffffe1021e15 79: callq 0xffffffffe102bd75 53: cmp $0x16,%eax 7e: cmp $0x16,%rax 56: je 0x00000000000000bf 82: je 0x0000000000000110 58: mov $0x38,%esi 88: mov $0x38,%esi 5d: callq 0xffffffffe1021e15 8d: callq 0xffffffffe102bd75 62: cmp $0x16,%eax 92: cmp $0x16,%rax 65: je 0x00000000000000bf 96: je 0x0000000000000110 67: jmp 0x00000000000000c6 98: jmp 0x0000000000000117 69: cmp $0x800,%eax 9a: cmp $0x800,%rax 6e: jne 0x00000000000000c6 a1: jne 0x0000000000000117 70: mov $0x17,%esi a3: mov $0x17,%esi 75: callq 0xffffffffe1021e31 a8: callq 0xffffffffe102bd91 7a: cmp $0x84,%eax ad: cmp $0x84,%rax 7f: je 0x000000000000008b b4: je 0x00000000000000c2 81: cmp $0x6,%eax b6: cmp $0x6,%rax 84: je 0x000000000000008b ba: je 0x00000000000000c2 86: cmp $0x11,%eax bc: cmp $0x11,%rax 89: jne 0x00000000000000c6 c0: jne 0x0000000000000117 8b: mov $0x14,%esi c2: mov $0x14,%esi 90: callq 0xffffffffe1021e15 c7: callq 0xffffffffe102bd75 95: test $0x1fff,%ax cc: test $0x1fff,%rax 99: jne 0x00000000000000c6 d3: jne 0x0000000000000117 d5: mov %rax,%r14 9b: mov $0xe,%esi d8: mov $0xe,%esi a0: callq 0xffffffffe1021e44 dd: callq 0xffffffffe102bd91 // MSH e2: and $0xf,%eax e5: shl $0x2,%eax e8: mov %rax,%r13 eb: mov %r14,%rax ee: mov %r13,%rsi a5: lea 0xe(%rbx),%esi f1: add $0xe,%esi a8: callq 0xffffffffe1021e0d f4: callq 0xffffffffe102bd6d ad: cmp $0x16,%eax f9: cmp $0x16,%rax b0: je 0x00000000000000bf fd: je 0x0000000000000110 ff: mov %r13,%rsi b2: lea 0x10(%rbx),%esi 102: add $0x10,%esi b5: callq 0xffffffffe1021e0d 105: callq 0xffffffffe102bd6d ba: cmp $0x16,%eax 10a: cmp $0x16,%rax bd: jne 0x00000000000000c6 10e: jne 0x0000000000000117 bf: mov $0xffff,%eax 110: mov $0xffff,%eax c4: jmp 0x00000000000000c8 115: jmp 0x000000000000011c c6: xor %eax,%eax 117: mov $0x0,%eax c8: mov -0x8(%rbp),%rbx 11c: mov -0x228(%rbp),%rbx // epilogue cc: leaveq 123: mov -0x220(%rbp),%r13 cd: retq 12a: mov -0x218(%rbp),%r14 131: mov -0x210(%rbp),%r15 138: leaveq 139: retq On fully cached SKBs both JITed functions take 12 nsec to execute. BPF interpreter executes the program in 30 nsec. The difference in generated assembler is due to the following: Old BPF imlements LDX_MSH instruction via sk_load_byte_msh() helper function inside bpf_jit.S. New JIT removes the helper and does it explicitly, so ldx_msh cost is the same for both JITs, but generated code looks longer. New JIT has 4 registers to save, so prologue/epilogue are larger, but the cost is within noise on x64. Old JIT checks whether first insn clears A and if not emits 'xor %eax,%eax'. New JIT clears %rax unconditionally. 2. old BPF JIT doesn't support ANC_NLATTR, ANC_PAY_OFFSET, ANC_RANDOM extensions. New JIT supports all BPF extensions. Performance of such filters improves 2-4 times depending on a filter. The longer the filter the higher performance gain. Synthetic benchmarks with many ancillary loads see 20x speedup which seems to be the maximum gain from JIT Notes: . net.core.bpf_jit_enable=2 + tools/net/bpf_jit_disasm is still functional and can be used to see generated assembler . there are two jit_compile() functions and code flow for classic filters is: sk_attach_filter() - load classic BPF bpf_jit_compile() - try to JIT from classic BPF sk_convert_filter() - convert classic to internal bpf_int_jit_compile() - JIT from internal BPF seccomp and tracing filters will just call bpf_int_jit_compile() Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 20:50:46 -06:00
case BPF_STX | BPF_XADD | BPF_W:
/* emit 'lock add dword ptr [rax + off], eax' */
net: filter: cleanup A/X name usage The macro 'A' used in internal BPF interpreter: #define A regs[insn->a_reg] was easily confused with the name of classic BPF register 'A', since 'A' would mean two different things depending on context. This patch is trying to clean up the naming and clarify its usage in the following way: - A and X are names of two classic BPF registers - BPF_REG_A denotes internal BPF register R0 used to map classic register A in internal BPF programs generated from classic - BPF_REG_X denotes internal BPF register R7 used to map classic register X in internal BPF programs generated from classic - internal BPF instruction format: struct sock_filter_int { __u8 code; /* opcode */ __u8 dst_reg:4; /* dest register */ __u8 src_reg:4; /* source register */ __s16 off; /* signed offset */ __s32 imm; /* signed immediate constant */ }; - BPF_X/BPF_K is 1 bit used to encode source operand of instruction In classic: BPF_X - means use register X as source operand BPF_K - means use 32-bit immediate as source operand In internal: BPF_X - means use 'src_reg' register as source operand BPF_K - means use 32-bit immediate as source operand Suggested-by: Chema Gonzalez <chema@google.com> Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Acked-by: Daniel Borkmann <dborkman@redhat.com> Acked-by: Chema Gonzalez <chema@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-06-06 15:46:06 -06:00
if (is_ereg(dst_reg) || is_ereg(src_reg))
EMIT3(0xF0, add_2mod(0x40, dst_reg, src_reg), 0x01);
net: filter: x86: internal BPF JIT Maps all internal BPF instructions into x86_64 instructions. This patch replaces original BPF x64 JIT with internal BPF x64 JIT. sysctl net.core.bpf_jit_enable is reused as on/off switch. Performance: 1. old BPF JIT and internal BPF JIT generate equivalent x86_64 code. No performance difference is observed for filters that were JIT-able before Example assembler code for BPF filter "tcpdump port 22" original BPF -> old JIT: original BPF -> internal BPF -> new JIT: 0: push %rbp 0: push %rbp 1: mov %rsp,%rbp 1: mov %rsp,%rbp 4: sub $0x60,%rsp 4: sub $0x228,%rsp 8: mov %rbx,-0x8(%rbp) b: mov %rbx,-0x228(%rbp) // prologue 12: mov %r13,-0x220(%rbp) 19: mov %r14,-0x218(%rbp) 20: mov %r15,-0x210(%rbp) 27: xor %eax,%eax // clear A c: xor %ebx,%ebx 29: xor %r13,%r13 // clear X e: mov 0x68(%rdi),%r9d 2c: mov 0x68(%rdi),%r9d 12: sub 0x6c(%rdi),%r9d 30: sub 0x6c(%rdi),%r9d 16: mov 0xd8(%rdi),%r8 34: mov 0xd8(%rdi),%r10 3b: mov %rdi,%rbx 1d: mov $0xc,%esi 3e: mov $0xc,%esi 22: callq 0xffffffffe1021e15 43: callq 0xffffffffe102bd75 27: cmp $0x86dd,%eax 48: cmp $0x86dd,%rax 2c: jne 0x0000000000000069 4f: jne 0x000000000000009a 2e: mov $0x14,%esi 51: mov $0x14,%esi 33: callq 0xffffffffe1021e31 56: callq 0xffffffffe102bd91 38: cmp $0x84,%eax 5b: cmp $0x84,%rax 3d: je 0x0000000000000049 62: je 0x0000000000000074 3f: cmp $0x6,%eax 64: cmp $0x6,%rax 42: je 0x0000000000000049 68: je 0x0000000000000074 44: cmp $0x11,%eax 6a: cmp $0x11,%rax 47: jne 0x00000000000000c6 6e: jne 0x0000000000000117 49: mov $0x36,%esi 74: mov $0x36,%esi 4e: callq 0xffffffffe1021e15 79: callq 0xffffffffe102bd75 53: cmp $0x16,%eax 7e: cmp $0x16,%rax 56: je 0x00000000000000bf 82: je 0x0000000000000110 58: mov $0x38,%esi 88: mov $0x38,%esi 5d: callq 0xffffffffe1021e15 8d: callq 0xffffffffe102bd75 62: cmp $0x16,%eax 92: cmp $0x16,%rax 65: je 0x00000000000000bf 96: je 0x0000000000000110 67: jmp 0x00000000000000c6 98: jmp 0x0000000000000117 69: cmp $0x800,%eax 9a: cmp $0x800,%rax 6e: jne 0x00000000000000c6 a1: jne 0x0000000000000117 70: mov $0x17,%esi a3: mov $0x17,%esi 75: callq 0xffffffffe1021e31 a8: callq 0xffffffffe102bd91 7a: cmp $0x84,%eax ad: cmp $0x84,%rax 7f: je 0x000000000000008b b4: je 0x00000000000000c2 81: cmp $0x6,%eax b6: cmp $0x6,%rax 84: je 0x000000000000008b ba: je 0x00000000000000c2 86: cmp $0x11,%eax bc: cmp $0x11,%rax 89: jne 0x00000000000000c6 c0: jne 0x0000000000000117 8b: mov $0x14,%esi c2: mov $0x14,%esi 90: callq 0xffffffffe1021e15 c7: callq 0xffffffffe102bd75 95: test $0x1fff,%ax cc: test $0x1fff,%rax 99: jne 0x00000000000000c6 d3: jne 0x0000000000000117 d5: mov %rax,%r14 9b: mov $0xe,%esi d8: mov $0xe,%esi a0: callq 0xffffffffe1021e44 dd: callq 0xffffffffe102bd91 // MSH e2: and $0xf,%eax e5: shl $0x2,%eax e8: mov %rax,%r13 eb: mov %r14,%rax ee: mov %r13,%rsi a5: lea 0xe(%rbx),%esi f1: add $0xe,%esi a8: callq 0xffffffffe1021e0d f4: callq 0xffffffffe102bd6d ad: cmp $0x16,%eax f9: cmp $0x16,%rax b0: je 0x00000000000000bf fd: je 0x0000000000000110 ff: mov %r13,%rsi b2: lea 0x10(%rbx),%esi 102: add $0x10,%esi b5: callq 0xffffffffe1021e0d 105: callq 0xffffffffe102bd6d ba: cmp $0x16,%eax 10a: cmp $0x16,%rax bd: jne 0x00000000000000c6 10e: jne 0x0000000000000117 bf: mov $0xffff,%eax 110: mov $0xffff,%eax c4: jmp 0x00000000000000c8 115: jmp 0x000000000000011c c6: xor %eax,%eax 117: mov $0x0,%eax c8: mov -0x8(%rbp),%rbx 11c: mov -0x228(%rbp),%rbx // epilogue cc: leaveq 123: mov -0x220(%rbp),%r13 cd: retq 12a: mov -0x218(%rbp),%r14 131: mov -0x210(%rbp),%r15 138: leaveq 139: retq On fully cached SKBs both JITed functions take 12 nsec to execute. BPF interpreter executes the program in 30 nsec. The difference in generated assembler is due to the following: Old BPF imlements LDX_MSH instruction via sk_load_byte_msh() helper function inside bpf_jit.S. New JIT removes the helper and does it explicitly, so ldx_msh cost is the same for both JITs, but generated code looks longer. New JIT has 4 registers to save, so prologue/epilogue are larger, but the cost is within noise on x64. Old JIT checks whether first insn clears A and if not emits 'xor %eax,%eax'. New JIT clears %rax unconditionally. 2. old BPF JIT doesn't support ANC_NLATTR, ANC_PAY_OFFSET, ANC_RANDOM extensions. New JIT supports all BPF extensions. Performance of such filters improves 2-4 times depending on a filter. The longer the filter the higher performance gain. Synthetic benchmarks with many ancillary loads see 20x speedup which seems to be the maximum gain from JIT Notes: . net.core.bpf_jit_enable=2 + tools/net/bpf_jit_disasm is still functional and can be used to see generated assembler . there are two jit_compile() functions and code flow for classic filters is: sk_attach_filter() - load classic BPF bpf_jit_compile() - try to JIT from classic BPF sk_convert_filter() - convert classic to internal bpf_int_jit_compile() - JIT from internal BPF seccomp and tracing filters will just call bpf_int_jit_compile() Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 20:50:46 -06:00
else
EMIT2(0xF0, 0x01);
goto xadd;
case BPF_STX | BPF_XADD | BPF_DW:
net: filter: cleanup A/X name usage The macro 'A' used in internal BPF interpreter: #define A regs[insn->a_reg] was easily confused with the name of classic BPF register 'A', since 'A' would mean two different things depending on context. This patch is trying to clean up the naming and clarify its usage in the following way: - A and X are names of two classic BPF registers - BPF_REG_A denotes internal BPF register R0 used to map classic register A in internal BPF programs generated from classic - BPF_REG_X denotes internal BPF register R7 used to map classic register X in internal BPF programs generated from classic - internal BPF instruction format: struct sock_filter_int { __u8 code; /* opcode */ __u8 dst_reg:4; /* dest register */ __u8 src_reg:4; /* source register */ __s16 off; /* signed offset */ __s32 imm; /* signed immediate constant */ }; - BPF_X/BPF_K is 1 bit used to encode source operand of instruction In classic: BPF_X - means use register X as source operand BPF_K - means use 32-bit immediate as source operand In internal: BPF_X - means use 'src_reg' register as source operand BPF_K - means use 32-bit immediate as source operand Suggested-by: Chema Gonzalez <chema@google.com> Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Acked-by: Daniel Borkmann <dborkman@redhat.com> Acked-by: Chema Gonzalez <chema@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-06-06 15:46:06 -06:00
EMIT3(0xF0, add_2mod(0x48, dst_reg, src_reg), 0x01);
net: filter: x86: internal BPF JIT Maps all internal BPF instructions into x86_64 instructions. This patch replaces original BPF x64 JIT with internal BPF x64 JIT. sysctl net.core.bpf_jit_enable is reused as on/off switch. Performance: 1. old BPF JIT and internal BPF JIT generate equivalent x86_64 code. No performance difference is observed for filters that were JIT-able before Example assembler code for BPF filter "tcpdump port 22" original BPF -> old JIT: original BPF -> internal BPF -> new JIT: 0: push %rbp 0: push %rbp 1: mov %rsp,%rbp 1: mov %rsp,%rbp 4: sub $0x60,%rsp 4: sub $0x228,%rsp 8: mov %rbx,-0x8(%rbp) b: mov %rbx,-0x228(%rbp) // prologue 12: mov %r13,-0x220(%rbp) 19: mov %r14,-0x218(%rbp) 20: mov %r15,-0x210(%rbp) 27: xor %eax,%eax // clear A c: xor %ebx,%ebx 29: xor %r13,%r13 // clear X e: mov 0x68(%rdi),%r9d 2c: mov 0x68(%rdi),%r9d 12: sub 0x6c(%rdi),%r9d 30: sub 0x6c(%rdi),%r9d 16: mov 0xd8(%rdi),%r8 34: mov 0xd8(%rdi),%r10 3b: mov %rdi,%rbx 1d: mov $0xc,%esi 3e: mov $0xc,%esi 22: callq 0xffffffffe1021e15 43: callq 0xffffffffe102bd75 27: cmp $0x86dd,%eax 48: cmp $0x86dd,%rax 2c: jne 0x0000000000000069 4f: jne 0x000000000000009a 2e: mov $0x14,%esi 51: mov $0x14,%esi 33: callq 0xffffffffe1021e31 56: callq 0xffffffffe102bd91 38: cmp $0x84,%eax 5b: cmp $0x84,%rax 3d: je 0x0000000000000049 62: je 0x0000000000000074 3f: cmp $0x6,%eax 64: cmp $0x6,%rax 42: je 0x0000000000000049 68: je 0x0000000000000074 44: cmp $0x11,%eax 6a: cmp $0x11,%rax 47: jne 0x00000000000000c6 6e: jne 0x0000000000000117 49: mov $0x36,%esi 74: mov $0x36,%esi 4e: callq 0xffffffffe1021e15 79: callq 0xffffffffe102bd75 53: cmp $0x16,%eax 7e: cmp $0x16,%rax 56: je 0x00000000000000bf 82: je 0x0000000000000110 58: mov $0x38,%esi 88: mov $0x38,%esi 5d: callq 0xffffffffe1021e15 8d: callq 0xffffffffe102bd75 62: cmp $0x16,%eax 92: cmp $0x16,%rax 65: je 0x00000000000000bf 96: je 0x0000000000000110 67: jmp 0x00000000000000c6 98: jmp 0x0000000000000117 69: cmp $0x800,%eax 9a: cmp $0x800,%rax 6e: jne 0x00000000000000c6 a1: jne 0x0000000000000117 70: mov $0x17,%esi a3: mov $0x17,%esi 75: callq 0xffffffffe1021e31 a8: callq 0xffffffffe102bd91 7a: cmp $0x84,%eax ad: cmp $0x84,%rax 7f: je 0x000000000000008b b4: je 0x00000000000000c2 81: cmp $0x6,%eax b6: cmp $0x6,%rax 84: je 0x000000000000008b ba: je 0x00000000000000c2 86: cmp $0x11,%eax bc: cmp $0x11,%rax 89: jne 0x00000000000000c6 c0: jne 0x0000000000000117 8b: mov $0x14,%esi c2: mov $0x14,%esi 90: callq 0xffffffffe1021e15 c7: callq 0xffffffffe102bd75 95: test $0x1fff,%ax cc: test $0x1fff,%rax 99: jne 0x00000000000000c6 d3: jne 0x0000000000000117 d5: mov %rax,%r14 9b: mov $0xe,%esi d8: mov $0xe,%esi a0: callq 0xffffffffe1021e44 dd: callq 0xffffffffe102bd91 // MSH e2: and $0xf,%eax e5: shl $0x2,%eax e8: mov %rax,%r13 eb: mov %r14,%rax ee: mov %r13,%rsi a5: lea 0xe(%rbx),%esi f1: add $0xe,%esi a8: callq 0xffffffffe1021e0d f4: callq 0xffffffffe102bd6d ad: cmp $0x16,%eax f9: cmp $0x16,%rax b0: je 0x00000000000000bf fd: je 0x0000000000000110 ff: mov %r13,%rsi b2: lea 0x10(%rbx),%esi 102: add $0x10,%esi b5: callq 0xffffffffe1021e0d 105: callq 0xffffffffe102bd6d ba: cmp $0x16,%eax 10a: cmp $0x16,%rax bd: jne 0x00000000000000c6 10e: jne 0x0000000000000117 bf: mov $0xffff,%eax 110: mov $0xffff,%eax c4: jmp 0x00000000000000c8 115: jmp 0x000000000000011c c6: xor %eax,%eax 117: mov $0x0,%eax c8: mov -0x8(%rbp),%rbx 11c: mov -0x228(%rbp),%rbx // epilogue cc: leaveq 123: mov -0x220(%rbp),%r13 cd: retq 12a: mov -0x218(%rbp),%r14 131: mov -0x210(%rbp),%r15 138: leaveq 139: retq On fully cached SKBs both JITed functions take 12 nsec to execute. BPF interpreter executes the program in 30 nsec. The difference in generated assembler is due to the following: Old BPF imlements LDX_MSH instruction via sk_load_byte_msh() helper function inside bpf_jit.S. New JIT removes the helper and does it explicitly, so ldx_msh cost is the same for both JITs, but generated code looks longer. New JIT has 4 registers to save, so prologue/epilogue are larger, but the cost is within noise on x64. Old JIT checks whether first insn clears A and if not emits 'xor %eax,%eax'. New JIT clears %rax unconditionally. 2. old BPF JIT doesn't support ANC_NLATTR, ANC_PAY_OFFSET, ANC_RANDOM extensions. New JIT supports all BPF extensions. Performance of such filters improves 2-4 times depending on a filter. The longer the filter the higher performance gain. Synthetic benchmarks with many ancillary loads see 20x speedup which seems to be the maximum gain from JIT Notes: . net.core.bpf_jit_enable=2 + tools/net/bpf_jit_disasm is still functional and can be used to see generated assembler . there are two jit_compile() functions and code flow for classic filters is: sk_attach_filter() - load classic BPF bpf_jit_compile() - try to JIT from classic BPF sk_convert_filter() - convert classic to internal bpf_int_jit_compile() - JIT from internal BPF seccomp and tracing filters will just call bpf_int_jit_compile() Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 20:50:46 -06:00
xadd: if (is_imm8(insn->off))
net: filter: cleanup A/X name usage The macro 'A' used in internal BPF interpreter: #define A regs[insn->a_reg] was easily confused with the name of classic BPF register 'A', since 'A' would mean two different things depending on context. This patch is trying to clean up the naming and clarify its usage in the following way: - A and X are names of two classic BPF registers - BPF_REG_A denotes internal BPF register R0 used to map classic register A in internal BPF programs generated from classic - BPF_REG_X denotes internal BPF register R7 used to map classic register X in internal BPF programs generated from classic - internal BPF instruction format: struct sock_filter_int { __u8 code; /* opcode */ __u8 dst_reg:4; /* dest register */ __u8 src_reg:4; /* source register */ __s16 off; /* signed offset */ __s32 imm; /* signed immediate constant */ }; - BPF_X/BPF_K is 1 bit used to encode source operand of instruction In classic: BPF_X - means use register X as source operand BPF_K - means use 32-bit immediate as source operand In internal: BPF_X - means use 'src_reg' register as source operand BPF_K - means use 32-bit immediate as source operand Suggested-by: Chema Gonzalez <chema@google.com> Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Acked-by: Daniel Borkmann <dborkman@redhat.com> Acked-by: Chema Gonzalez <chema@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-06-06 15:46:06 -06:00
EMIT2(add_2reg(0x40, dst_reg, src_reg), insn->off);
net: filter: x86: internal BPF JIT Maps all internal BPF instructions into x86_64 instructions. This patch replaces original BPF x64 JIT with internal BPF x64 JIT. sysctl net.core.bpf_jit_enable is reused as on/off switch. Performance: 1. old BPF JIT and internal BPF JIT generate equivalent x86_64 code. No performance difference is observed for filters that were JIT-able before Example assembler code for BPF filter "tcpdump port 22" original BPF -> old JIT: original BPF -> internal BPF -> new JIT: 0: push %rbp 0: push %rbp 1: mov %rsp,%rbp 1: mov %rsp,%rbp 4: sub $0x60,%rsp 4: sub $0x228,%rsp 8: mov %rbx,-0x8(%rbp) b: mov %rbx,-0x228(%rbp) // prologue 12: mov %r13,-0x220(%rbp) 19: mov %r14,-0x218(%rbp) 20: mov %r15,-0x210(%rbp) 27: xor %eax,%eax // clear A c: xor %ebx,%ebx 29: xor %r13,%r13 // clear X e: mov 0x68(%rdi),%r9d 2c: mov 0x68(%rdi),%r9d 12: sub 0x6c(%rdi),%r9d 30: sub 0x6c(%rdi),%r9d 16: mov 0xd8(%rdi),%r8 34: mov 0xd8(%rdi),%r10 3b: mov %rdi,%rbx 1d: mov $0xc,%esi 3e: mov $0xc,%esi 22: callq 0xffffffffe1021e15 43: callq 0xffffffffe102bd75 27: cmp $0x86dd,%eax 48: cmp $0x86dd,%rax 2c: jne 0x0000000000000069 4f: jne 0x000000000000009a 2e: mov $0x14,%esi 51: mov $0x14,%esi 33: callq 0xffffffffe1021e31 56: callq 0xffffffffe102bd91 38: cmp $0x84,%eax 5b: cmp $0x84,%rax 3d: je 0x0000000000000049 62: je 0x0000000000000074 3f: cmp $0x6,%eax 64: cmp $0x6,%rax 42: je 0x0000000000000049 68: je 0x0000000000000074 44: cmp $0x11,%eax 6a: cmp $0x11,%rax 47: jne 0x00000000000000c6 6e: jne 0x0000000000000117 49: mov $0x36,%esi 74: mov $0x36,%esi 4e: callq 0xffffffffe1021e15 79: callq 0xffffffffe102bd75 53: cmp $0x16,%eax 7e: cmp $0x16,%rax 56: je 0x00000000000000bf 82: je 0x0000000000000110 58: mov $0x38,%esi 88: mov $0x38,%esi 5d: callq 0xffffffffe1021e15 8d: callq 0xffffffffe102bd75 62: cmp $0x16,%eax 92: cmp $0x16,%rax 65: je 0x00000000000000bf 96: je 0x0000000000000110 67: jmp 0x00000000000000c6 98: jmp 0x0000000000000117 69: cmp $0x800,%eax 9a: cmp $0x800,%rax 6e: jne 0x00000000000000c6 a1: jne 0x0000000000000117 70: mov $0x17,%esi a3: mov $0x17,%esi 75: callq 0xffffffffe1021e31 a8: callq 0xffffffffe102bd91 7a: cmp $0x84,%eax ad: cmp $0x84,%rax 7f: je 0x000000000000008b b4: je 0x00000000000000c2 81: cmp $0x6,%eax b6: cmp $0x6,%rax 84: je 0x000000000000008b ba: je 0x00000000000000c2 86: cmp $0x11,%eax bc: cmp $0x11,%rax 89: jne 0x00000000000000c6 c0: jne 0x0000000000000117 8b: mov $0x14,%esi c2: mov $0x14,%esi 90: callq 0xffffffffe1021e15 c7: callq 0xffffffffe102bd75 95: test $0x1fff,%ax cc: test $0x1fff,%rax 99: jne 0x00000000000000c6 d3: jne 0x0000000000000117 d5: mov %rax,%r14 9b: mov $0xe,%esi d8: mov $0xe,%esi a0: callq 0xffffffffe1021e44 dd: callq 0xffffffffe102bd91 // MSH e2: and $0xf,%eax e5: shl $0x2,%eax e8: mov %rax,%r13 eb: mov %r14,%rax ee: mov %r13,%rsi a5: lea 0xe(%rbx),%esi f1: add $0xe,%esi a8: callq 0xffffffffe1021e0d f4: callq 0xffffffffe102bd6d ad: cmp $0x16,%eax f9: cmp $0x16,%rax b0: je 0x00000000000000bf fd: je 0x0000000000000110 ff: mov %r13,%rsi b2: lea 0x10(%rbx),%esi 102: add $0x10,%esi b5: callq 0xffffffffe1021e0d 105: callq 0xffffffffe102bd6d ba: cmp $0x16,%eax 10a: cmp $0x16,%rax bd: jne 0x00000000000000c6 10e: jne 0x0000000000000117 bf: mov $0xffff,%eax 110: mov $0xffff,%eax c4: jmp 0x00000000000000c8 115: jmp 0x000000000000011c c6: xor %eax,%eax 117: mov $0x0,%eax c8: mov -0x8(%rbp),%rbx 11c: mov -0x228(%rbp),%rbx // epilogue cc: leaveq 123: mov -0x220(%rbp),%r13 cd: retq 12a: mov -0x218(%rbp),%r14 131: mov -0x210(%rbp),%r15 138: leaveq 139: retq On fully cached SKBs both JITed functions take 12 nsec to execute. BPF interpreter executes the program in 30 nsec. The difference in generated assembler is due to the following: Old BPF imlements LDX_MSH instruction via sk_load_byte_msh() helper function inside bpf_jit.S. New JIT removes the helper and does it explicitly, so ldx_msh cost is the same for both JITs, but generated code looks longer. New JIT has 4 registers to save, so prologue/epilogue are larger, but the cost is within noise on x64. Old JIT checks whether first insn clears A and if not emits 'xor %eax,%eax'. New JIT clears %rax unconditionally. 2. old BPF JIT doesn't support ANC_NLATTR, ANC_PAY_OFFSET, ANC_RANDOM extensions. New JIT supports all BPF extensions. Performance of such filters improves 2-4 times depending on a filter. The longer the filter the higher performance gain. Synthetic benchmarks with many ancillary loads see 20x speedup which seems to be the maximum gain from JIT Notes: . net.core.bpf_jit_enable=2 + tools/net/bpf_jit_disasm is still functional and can be used to see generated assembler . there are two jit_compile() functions and code flow for classic filters is: sk_attach_filter() - load classic BPF bpf_jit_compile() - try to JIT from classic BPF sk_convert_filter() - convert classic to internal bpf_int_jit_compile() - JIT from internal BPF seccomp and tracing filters will just call bpf_int_jit_compile() Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 20:50:46 -06:00
else
net: filter: cleanup A/X name usage The macro 'A' used in internal BPF interpreter: #define A regs[insn->a_reg] was easily confused with the name of classic BPF register 'A', since 'A' would mean two different things depending on context. This patch is trying to clean up the naming and clarify its usage in the following way: - A and X are names of two classic BPF registers - BPF_REG_A denotes internal BPF register R0 used to map classic register A in internal BPF programs generated from classic - BPF_REG_X denotes internal BPF register R7 used to map classic register X in internal BPF programs generated from classic - internal BPF instruction format: struct sock_filter_int { __u8 code; /* opcode */ __u8 dst_reg:4; /* dest register */ __u8 src_reg:4; /* source register */ __s16 off; /* signed offset */ __s32 imm; /* signed immediate constant */ }; - BPF_X/BPF_K is 1 bit used to encode source operand of instruction In classic: BPF_X - means use register X as source operand BPF_K - means use 32-bit immediate as source operand In internal: BPF_X - means use 'src_reg' register as source operand BPF_K - means use 32-bit immediate as source operand Suggested-by: Chema Gonzalez <chema@google.com> Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Acked-by: Daniel Borkmann <dborkman@redhat.com> Acked-by: Chema Gonzalez <chema@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-06-06 15:46:06 -06:00
EMIT1_off32(add_2reg(0x80, dst_reg, src_reg),
net: filter: x86: internal BPF JIT Maps all internal BPF instructions into x86_64 instructions. This patch replaces original BPF x64 JIT with internal BPF x64 JIT. sysctl net.core.bpf_jit_enable is reused as on/off switch. Performance: 1. old BPF JIT and internal BPF JIT generate equivalent x86_64 code. No performance difference is observed for filters that were JIT-able before Example assembler code for BPF filter "tcpdump port 22" original BPF -> old JIT: original BPF -> internal BPF -> new JIT: 0: push %rbp 0: push %rbp 1: mov %rsp,%rbp 1: mov %rsp,%rbp 4: sub $0x60,%rsp 4: sub $0x228,%rsp 8: mov %rbx,-0x8(%rbp) b: mov %rbx,-0x228(%rbp) // prologue 12: mov %r13,-0x220(%rbp) 19: mov %r14,-0x218(%rbp) 20: mov %r15,-0x210(%rbp) 27: xor %eax,%eax // clear A c: xor %ebx,%ebx 29: xor %r13,%r13 // clear X e: mov 0x68(%rdi),%r9d 2c: mov 0x68(%rdi),%r9d 12: sub 0x6c(%rdi),%r9d 30: sub 0x6c(%rdi),%r9d 16: mov 0xd8(%rdi),%r8 34: mov 0xd8(%rdi),%r10 3b: mov %rdi,%rbx 1d: mov $0xc,%esi 3e: mov $0xc,%esi 22: callq 0xffffffffe1021e15 43: callq 0xffffffffe102bd75 27: cmp $0x86dd,%eax 48: cmp $0x86dd,%rax 2c: jne 0x0000000000000069 4f: jne 0x000000000000009a 2e: mov $0x14,%esi 51: mov $0x14,%esi 33: callq 0xffffffffe1021e31 56: callq 0xffffffffe102bd91 38: cmp $0x84,%eax 5b: cmp $0x84,%rax 3d: je 0x0000000000000049 62: je 0x0000000000000074 3f: cmp $0x6,%eax 64: cmp $0x6,%rax 42: je 0x0000000000000049 68: je 0x0000000000000074 44: cmp $0x11,%eax 6a: cmp $0x11,%rax 47: jne 0x00000000000000c6 6e: jne 0x0000000000000117 49: mov $0x36,%esi 74: mov $0x36,%esi 4e: callq 0xffffffffe1021e15 79: callq 0xffffffffe102bd75 53: cmp $0x16,%eax 7e: cmp $0x16,%rax 56: je 0x00000000000000bf 82: je 0x0000000000000110 58: mov $0x38,%esi 88: mov $0x38,%esi 5d: callq 0xffffffffe1021e15 8d: callq 0xffffffffe102bd75 62: cmp $0x16,%eax 92: cmp $0x16,%rax 65: je 0x00000000000000bf 96: je 0x0000000000000110 67: jmp 0x00000000000000c6 98: jmp 0x0000000000000117 69: cmp $0x800,%eax 9a: cmp $0x800,%rax 6e: jne 0x00000000000000c6 a1: jne 0x0000000000000117 70: mov $0x17,%esi a3: mov $0x17,%esi 75: callq 0xffffffffe1021e31 a8: callq 0xffffffffe102bd91 7a: cmp $0x84,%eax ad: cmp $0x84,%rax 7f: je 0x000000000000008b b4: je 0x00000000000000c2 81: cmp $0x6,%eax b6: cmp $0x6,%rax 84: je 0x000000000000008b ba: je 0x00000000000000c2 86: cmp $0x11,%eax bc: cmp $0x11,%rax 89: jne 0x00000000000000c6 c0: jne 0x0000000000000117 8b: mov $0x14,%esi c2: mov $0x14,%esi 90: callq 0xffffffffe1021e15 c7: callq 0xffffffffe102bd75 95: test $0x1fff,%ax cc: test $0x1fff,%rax 99: jne 0x00000000000000c6 d3: jne 0x0000000000000117 d5: mov %rax,%r14 9b: mov $0xe,%esi d8: mov $0xe,%esi a0: callq 0xffffffffe1021e44 dd: callq 0xffffffffe102bd91 // MSH e2: and $0xf,%eax e5: shl $0x2,%eax e8: mov %rax,%r13 eb: mov %r14,%rax ee: mov %r13,%rsi a5: lea 0xe(%rbx),%esi f1: add $0xe,%esi a8: callq 0xffffffffe1021e0d f4: callq 0xffffffffe102bd6d ad: cmp $0x16,%eax f9: cmp $0x16,%rax b0: je 0x00000000000000bf fd: je 0x0000000000000110 ff: mov %r13,%rsi b2: lea 0x10(%rbx),%esi 102: add $0x10,%esi b5: callq 0xffffffffe1021e0d 105: callq 0xffffffffe102bd6d ba: cmp $0x16,%eax 10a: cmp $0x16,%rax bd: jne 0x00000000000000c6 10e: jne 0x0000000000000117 bf: mov $0xffff,%eax 110: mov $0xffff,%eax c4: jmp 0x00000000000000c8 115: jmp 0x000000000000011c c6: xor %eax,%eax 117: mov $0x0,%eax c8: mov -0x8(%rbp),%rbx 11c: mov -0x228(%rbp),%rbx // epilogue cc: leaveq 123: mov -0x220(%rbp),%r13 cd: retq 12a: mov -0x218(%rbp),%r14 131: mov -0x210(%rbp),%r15 138: leaveq 139: retq On fully cached SKBs both JITed functions take 12 nsec to execute. BPF interpreter executes the program in 30 nsec. The difference in generated assembler is due to the following: Old BPF imlements LDX_MSH instruction via sk_load_byte_msh() helper function inside bpf_jit.S. New JIT removes the helper and does it explicitly, so ldx_msh cost is the same for both JITs, but generated code looks longer. New JIT has 4 registers to save, so prologue/epilogue are larger, but the cost is within noise on x64. Old JIT checks whether first insn clears A and if not emits 'xor %eax,%eax'. New JIT clears %rax unconditionally. 2. old BPF JIT doesn't support ANC_NLATTR, ANC_PAY_OFFSET, ANC_RANDOM extensions. New JIT supports all BPF extensions. Performance of such filters improves 2-4 times depending on a filter. The longer the filter the higher performance gain. Synthetic benchmarks with many ancillary loads see 20x speedup which seems to be the maximum gain from JIT Notes: . net.core.bpf_jit_enable=2 + tools/net/bpf_jit_disasm is still functional and can be used to see generated assembler . there are two jit_compile() functions and code flow for classic filters is: sk_attach_filter() - load classic BPF bpf_jit_compile() - try to JIT from classic BPF sk_convert_filter() - convert classic to internal bpf_int_jit_compile() - JIT from internal BPF seccomp and tracing filters will just call bpf_int_jit_compile() Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 20:50:46 -06:00
insn->off);
break;
/* call */
case BPF_JMP | BPF_CALL:
net: filter: cleanup A/X name usage The macro 'A' used in internal BPF interpreter: #define A regs[insn->a_reg] was easily confused with the name of classic BPF register 'A', since 'A' would mean two different things depending on context. This patch is trying to clean up the naming and clarify its usage in the following way: - A and X are names of two classic BPF registers - BPF_REG_A denotes internal BPF register R0 used to map classic register A in internal BPF programs generated from classic - BPF_REG_X denotes internal BPF register R7 used to map classic register X in internal BPF programs generated from classic - internal BPF instruction format: struct sock_filter_int { __u8 code; /* opcode */ __u8 dst_reg:4; /* dest register */ __u8 src_reg:4; /* source register */ __s16 off; /* signed offset */ __s32 imm; /* signed immediate constant */ }; - BPF_X/BPF_K is 1 bit used to encode source operand of instruction In classic: BPF_X - means use register X as source operand BPF_K - means use 32-bit immediate as source operand In internal: BPF_X - means use 'src_reg' register as source operand BPF_K - means use 32-bit immediate as source operand Suggested-by: Chema Gonzalez <chema@google.com> Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Acked-by: Daniel Borkmann <dborkman@redhat.com> Acked-by: Chema Gonzalez <chema@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-06-06 15:46:06 -06:00
func = (u8 *) __bpf_call_base + imm32;
net: filter: x86: internal BPF JIT Maps all internal BPF instructions into x86_64 instructions. This patch replaces original BPF x64 JIT with internal BPF x64 JIT. sysctl net.core.bpf_jit_enable is reused as on/off switch. Performance: 1. old BPF JIT and internal BPF JIT generate equivalent x86_64 code. No performance difference is observed for filters that were JIT-able before Example assembler code for BPF filter "tcpdump port 22" original BPF -> old JIT: original BPF -> internal BPF -> new JIT: 0: push %rbp 0: push %rbp 1: mov %rsp,%rbp 1: mov %rsp,%rbp 4: sub $0x60,%rsp 4: sub $0x228,%rsp 8: mov %rbx,-0x8(%rbp) b: mov %rbx,-0x228(%rbp) // prologue 12: mov %r13,-0x220(%rbp) 19: mov %r14,-0x218(%rbp) 20: mov %r15,-0x210(%rbp) 27: xor %eax,%eax // clear A c: xor %ebx,%ebx 29: xor %r13,%r13 // clear X e: mov 0x68(%rdi),%r9d 2c: mov 0x68(%rdi),%r9d 12: sub 0x6c(%rdi),%r9d 30: sub 0x6c(%rdi),%r9d 16: mov 0xd8(%rdi),%r8 34: mov 0xd8(%rdi),%r10 3b: mov %rdi,%rbx 1d: mov $0xc,%esi 3e: mov $0xc,%esi 22: callq 0xffffffffe1021e15 43: callq 0xffffffffe102bd75 27: cmp $0x86dd,%eax 48: cmp $0x86dd,%rax 2c: jne 0x0000000000000069 4f: jne 0x000000000000009a 2e: mov $0x14,%esi 51: mov $0x14,%esi 33: callq 0xffffffffe1021e31 56: callq 0xffffffffe102bd91 38: cmp $0x84,%eax 5b: cmp $0x84,%rax 3d: je 0x0000000000000049 62: je 0x0000000000000074 3f: cmp $0x6,%eax 64: cmp $0x6,%rax 42: je 0x0000000000000049 68: je 0x0000000000000074 44: cmp $0x11,%eax 6a: cmp $0x11,%rax 47: jne 0x00000000000000c6 6e: jne 0x0000000000000117 49: mov $0x36,%esi 74: mov $0x36,%esi 4e: callq 0xffffffffe1021e15 79: callq 0xffffffffe102bd75 53: cmp $0x16,%eax 7e: cmp $0x16,%rax 56: je 0x00000000000000bf 82: je 0x0000000000000110 58: mov $0x38,%esi 88: mov $0x38,%esi 5d: callq 0xffffffffe1021e15 8d: callq 0xffffffffe102bd75 62: cmp $0x16,%eax 92: cmp $0x16,%rax 65: je 0x00000000000000bf 96: je 0x0000000000000110 67: jmp 0x00000000000000c6 98: jmp 0x0000000000000117 69: cmp $0x800,%eax 9a: cmp $0x800,%rax 6e: jne 0x00000000000000c6 a1: jne 0x0000000000000117 70: mov $0x17,%esi a3: mov $0x17,%esi 75: callq 0xffffffffe1021e31 a8: callq 0xffffffffe102bd91 7a: cmp $0x84,%eax ad: cmp $0x84,%rax 7f: je 0x000000000000008b b4: je 0x00000000000000c2 81: cmp $0x6,%eax b6: cmp $0x6,%rax 84: je 0x000000000000008b ba: je 0x00000000000000c2 86: cmp $0x11,%eax bc: cmp $0x11,%rax 89: jne 0x00000000000000c6 c0: jne 0x0000000000000117 8b: mov $0x14,%esi c2: mov $0x14,%esi 90: callq 0xffffffffe1021e15 c7: callq 0xffffffffe102bd75 95: test $0x1fff,%ax cc: test $0x1fff,%rax 99: jne 0x00000000000000c6 d3: jne 0x0000000000000117 d5: mov %rax,%r14 9b: mov $0xe,%esi d8: mov $0xe,%esi a0: callq 0xffffffffe1021e44 dd: callq 0xffffffffe102bd91 // MSH e2: and $0xf,%eax e5: shl $0x2,%eax e8: mov %rax,%r13 eb: mov %r14,%rax ee: mov %r13,%rsi a5: lea 0xe(%rbx),%esi f1: add $0xe,%esi a8: callq 0xffffffffe1021e0d f4: callq 0xffffffffe102bd6d ad: cmp $0x16,%eax f9: cmp $0x16,%rax b0: je 0x00000000000000bf fd: je 0x0000000000000110 ff: mov %r13,%rsi b2: lea 0x10(%rbx),%esi 102: add $0x10,%esi b5: callq 0xffffffffe1021e0d 105: callq 0xffffffffe102bd6d ba: cmp $0x16,%eax 10a: cmp $0x16,%rax bd: jne 0x00000000000000c6 10e: jne 0x0000000000000117 bf: mov $0xffff,%eax 110: mov $0xffff,%eax c4: jmp 0x00000000000000c8 115: jmp 0x000000000000011c c6: xor %eax,%eax 117: mov $0x0,%eax c8: mov -0x8(%rbp),%rbx 11c: mov -0x228(%rbp),%rbx // epilogue cc: leaveq 123: mov -0x220(%rbp),%r13 cd: retq 12a: mov -0x218(%rbp),%r14 131: mov -0x210(%rbp),%r15 138: leaveq 139: retq On fully cached SKBs both JITed functions take 12 nsec to execute. BPF interpreter executes the program in 30 nsec. The difference in generated assembler is due to the following: Old BPF imlements LDX_MSH instruction via sk_load_byte_msh() helper function inside bpf_jit.S. New JIT removes the helper and does it explicitly, so ldx_msh cost is the same for both JITs, but generated code looks longer. New JIT has 4 registers to save, so prologue/epilogue are larger, but the cost is within noise on x64. Old JIT checks whether first insn clears A and if not emits 'xor %eax,%eax'. New JIT clears %rax unconditionally. 2. old BPF JIT doesn't support ANC_NLATTR, ANC_PAY_OFFSET, ANC_RANDOM extensions. New JIT supports all BPF extensions. Performance of such filters improves 2-4 times depending on a filter. The longer the filter the higher performance gain. Synthetic benchmarks with many ancillary loads see 20x speedup which seems to be the maximum gain from JIT Notes: . net.core.bpf_jit_enable=2 + tools/net/bpf_jit_disasm is still functional and can be used to see generated assembler . there are two jit_compile() functions and code flow for classic filters is: sk_attach_filter() - load classic BPF bpf_jit_compile() - try to JIT from classic BPF sk_convert_filter() - convert classic to internal bpf_int_jit_compile() - JIT from internal BPF seccomp and tracing filters will just call bpf_int_jit_compile() Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 20:50:46 -06:00
jmp_offset = func - (image + addrs[i]);
x86: bpf_jit: fix two bugs in eBPF JIT compiler 1. JIT compiler using multi-pass approach to converge to final image size, since x86 instructions are variable length. It starts with large gaps between instructions (so some jumps may use imm32 instead of imm8) and iterates until total program size is the same as in previous pass. This algorithm works only if program size is strictly decreasing. Programs that use LD_ABS insn need additional code in prologue, but it was not emitted during 1st pass, so there was a chance that 2nd pass would adjust imm32->imm8 jump offsets to the same number of bytes as increase in prologue, which may cause algorithm to erroneously decide that size converged. Fix it by always emitting largest prologue in the first pass which is detected by oldproglen==0 check. Also change error check condition 'proglen != oldproglen' to fail gracefully. 2. while staring at the code realized that 64-byte buffer may not be enough when 1st insn is large, so increase it to 128 to avoid buffer overflow (theoretical maximum size of prologue+div is 109) and add runtime check. Fixes: 622582786c9e ("net: filter: x86: internal BPF JIT") Reported-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Tested-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-10-10 21:30:23 -06:00
if (seen_ld_abs) {
bpf: xdp: Allow head adjustment in XDP prog This patch allows XDP prog to extend/remove the packet data at the head (like adding or removing header). It is done by adding a new XDP helper bpf_xdp_adjust_head(). It also renames bpf_helper_changes_skb_data() to bpf_helper_changes_pkt_data() to better reflect that XDP prog does not work on skb. This patch adds one "xdp_adjust_head" bit to bpf_prog for the XDP-capable driver to check if the XDP prog requires bpf_xdp_adjust_head() support. The driver can then decide to error out during XDP_SETUP_PROG. Signed-off-by: Martin KaFai Lau <kafai@fb.com> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Acked-by: John Fastabend <john.r.fastabend@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-12-07 16:53:11 -07:00
reload_skb_data = bpf_helper_changes_pkt_data(func);
bpf: introduce bpf_skb_vlan_push/pop() helpers Allow eBPF programs attached to TC qdiscs call skb_vlan_push/pop via helper functions. These functions may change skb->data/hlen which are cached by some JITs to improve performance of ld_abs/ld_ind instructions. Therefore JITs need to recognize bpf_skb_vlan_push/pop() calls, re-compute header len and re-cache skb->data/hlen back into cpu registers. Note, skb->data/hlen are not directly accessible from the programs, so any changes to skb->data done either by these helpers or by other TC actions are safe. eBPF JIT supported by three architectures: - arm64 JIT is using bpf_load_pointer() without caching, so it's ok as-is. - x64 JIT re-caches skb->data/hlen unconditionally after vlan_push/pop calls (experiments showed that conditional re-caching is slower). - s390 JIT falls back to interpreter for now when bpf_skb_vlan_push() is present in the program (re-caching is tbd). These helpers allow more scalable handling of vlan from the programs. Instead of creating thousands of vlan netdevs on top of eth0 and attaching TC+ingress+bpf to all of them, the program can be attached to eth0 directly and manipulate vlans as necessary. Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-20 21:34:18 -06:00
if (reload_skb_data) {
EMIT1(0x57); /* push %rdi */
jmp_offset += 22; /* pop, mov, sub, mov */
} else {
EMIT2(0x41, 0x52); /* push %r10 */
EMIT2(0x41, 0x51); /* push %r9 */
/* need to adjust jmp offset, since
* pop %r9, pop %r10 take 4 bytes after call insn
*/
jmp_offset += 4;
}
net: filter: x86: internal BPF JIT Maps all internal BPF instructions into x86_64 instructions. This patch replaces original BPF x64 JIT with internal BPF x64 JIT. sysctl net.core.bpf_jit_enable is reused as on/off switch. Performance: 1. old BPF JIT and internal BPF JIT generate equivalent x86_64 code. No performance difference is observed for filters that were JIT-able before Example assembler code for BPF filter "tcpdump port 22" original BPF -> old JIT: original BPF -> internal BPF -> new JIT: 0: push %rbp 0: push %rbp 1: mov %rsp,%rbp 1: mov %rsp,%rbp 4: sub $0x60,%rsp 4: sub $0x228,%rsp 8: mov %rbx,-0x8(%rbp) b: mov %rbx,-0x228(%rbp) // prologue 12: mov %r13,-0x220(%rbp) 19: mov %r14,-0x218(%rbp) 20: mov %r15,-0x210(%rbp) 27: xor %eax,%eax // clear A c: xor %ebx,%ebx 29: xor %r13,%r13 // clear X e: mov 0x68(%rdi),%r9d 2c: mov 0x68(%rdi),%r9d 12: sub 0x6c(%rdi),%r9d 30: sub 0x6c(%rdi),%r9d 16: mov 0xd8(%rdi),%r8 34: mov 0xd8(%rdi),%r10 3b: mov %rdi,%rbx 1d: mov $0xc,%esi 3e: mov $0xc,%esi 22: callq 0xffffffffe1021e15 43: callq 0xffffffffe102bd75 27: cmp $0x86dd,%eax 48: cmp $0x86dd,%rax 2c: jne 0x0000000000000069 4f: jne 0x000000000000009a 2e: mov $0x14,%esi 51: mov $0x14,%esi 33: callq 0xffffffffe1021e31 56: callq 0xffffffffe102bd91 38: cmp $0x84,%eax 5b: cmp $0x84,%rax 3d: je 0x0000000000000049 62: je 0x0000000000000074 3f: cmp $0x6,%eax 64: cmp $0x6,%rax 42: je 0x0000000000000049 68: je 0x0000000000000074 44: cmp $0x11,%eax 6a: cmp $0x11,%rax 47: jne 0x00000000000000c6 6e: jne 0x0000000000000117 49: mov $0x36,%esi 74: mov $0x36,%esi 4e: callq 0xffffffffe1021e15 79: callq 0xffffffffe102bd75 53: cmp $0x16,%eax 7e: cmp $0x16,%rax 56: je 0x00000000000000bf 82: je 0x0000000000000110 58: mov $0x38,%esi 88: mov $0x38,%esi 5d: callq 0xffffffffe1021e15 8d: callq 0xffffffffe102bd75 62: cmp $0x16,%eax 92: cmp $0x16,%rax 65: je 0x00000000000000bf 96: je 0x0000000000000110 67: jmp 0x00000000000000c6 98: jmp 0x0000000000000117 69: cmp $0x800,%eax 9a: cmp $0x800,%rax 6e: jne 0x00000000000000c6 a1: jne 0x0000000000000117 70: mov $0x17,%esi a3: mov $0x17,%esi 75: callq 0xffffffffe1021e31 a8: callq 0xffffffffe102bd91 7a: cmp $0x84,%eax ad: cmp $0x84,%rax 7f: je 0x000000000000008b b4: je 0x00000000000000c2 81: cmp $0x6,%eax b6: cmp $0x6,%rax 84: je 0x000000000000008b ba: je 0x00000000000000c2 86: cmp $0x11,%eax bc: cmp $0x11,%rax 89: jne 0x00000000000000c6 c0: jne 0x0000000000000117 8b: mov $0x14,%esi c2: mov $0x14,%esi 90: callq 0xffffffffe1021e15 c7: callq 0xffffffffe102bd75 95: test $0x1fff,%ax cc: test $0x1fff,%rax 99: jne 0x00000000000000c6 d3: jne 0x0000000000000117 d5: mov %rax,%r14 9b: mov $0xe,%esi d8: mov $0xe,%esi a0: callq 0xffffffffe1021e44 dd: callq 0xffffffffe102bd91 // MSH e2: and $0xf,%eax e5: shl $0x2,%eax e8: mov %rax,%r13 eb: mov %r14,%rax ee: mov %r13,%rsi a5: lea 0xe(%rbx),%esi f1: add $0xe,%esi a8: callq 0xffffffffe1021e0d f4: callq 0xffffffffe102bd6d ad: cmp $0x16,%eax f9: cmp $0x16,%rax b0: je 0x00000000000000bf fd: je 0x0000000000000110 ff: mov %r13,%rsi b2: lea 0x10(%rbx),%esi 102: add $0x10,%esi b5: callq 0xffffffffe1021e0d 105: callq 0xffffffffe102bd6d ba: cmp $0x16,%eax 10a: cmp $0x16,%rax bd: jne 0x00000000000000c6 10e: jne 0x0000000000000117 bf: mov $0xffff,%eax 110: mov $0xffff,%eax c4: jmp 0x00000000000000c8 115: jmp 0x000000000000011c c6: xor %eax,%eax 117: mov $0x0,%eax c8: mov -0x8(%rbp),%rbx 11c: mov -0x228(%rbp),%rbx // epilogue cc: leaveq 123: mov -0x220(%rbp),%r13 cd: retq 12a: mov -0x218(%rbp),%r14 131: mov -0x210(%rbp),%r15 138: leaveq 139: retq On fully cached SKBs both JITed functions take 12 nsec to execute. BPF interpreter executes the program in 30 nsec. The difference in generated assembler is due to the following: Old BPF imlements LDX_MSH instruction via sk_load_byte_msh() helper function inside bpf_jit.S. New JIT removes the helper and does it explicitly, so ldx_msh cost is the same for both JITs, but generated code looks longer. New JIT has 4 registers to save, so prologue/epilogue are larger, but the cost is within noise on x64. Old JIT checks whether first insn clears A and if not emits 'xor %eax,%eax'. New JIT clears %rax unconditionally. 2. old BPF JIT doesn't support ANC_NLATTR, ANC_PAY_OFFSET, ANC_RANDOM extensions. New JIT supports all BPF extensions. Performance of such filters improves 2-4 times depending on a filter. The longer the filter the higher performance gain. Synthetic benchmarks with many ancillary loads see 20x speedup which seems to be the maximum gain from JIT Notes: . net.core.bpf_jit_enable=2 + tools/net/bpf_jit_disasm is still functional and can be used to see generated assembler . there are two jit_compile() functions and code flow for classic filters is: sk_attach_filter() - load classic BPF bpf_jit_compile() - try to JIT from classic BPF sk_convert_filter() - convert classic to internal bpf_int_jit_compile() - JIT from internal BPF seccomp and tracing filters will just call bpf_int_jit_compile() Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 20:50:46 -06:00
}
net: filter: cleanup A/X name usage The macro 'A' used in internal BPF interpreter: #define A regs[insn->a_reg] was easily confused with the name of classic BPF register 'A', since 'A' would mean two different things depending on context. This patch is trying to clean up the naming and clarify its usage in the following way: - A and X are names of two classic BPF registers - BPF_REG_A denotes internal BPF register R0 used to map classic register A in internal BPF programs generated from classic - BPF_REG_X denotes internal BPF register R7 used to map classic register X in internal BPF programs generated from classic - internal BPF instruction format: struct sock_filter_int { __u8 code; /* opcode */ __u8 dst_reg:4; /* dest register */ __u8 src_reg:4; /* source register */ __s16 off; /* signed offset */ __s32 imm; /* signed immediate constant */ }; - BPF_X/BPF_K is 1 bit used to encode source operand of instruction In classic: BPF_X - means use register X as source operand BPF_K - means use 32-bit immediate as source operand In internal: BPF_X - means use 'src_reg' register as source operand BPF_K - means use 32-bit immediate as source operand Suggested-by: Chema Gonzalez <chema@google.com> Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Acked-by: Daniel Borkmann <dborkman@redhat.com> Acked-by: Chema Gonzalez <chema@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-06-06 15:46:06 -06:00
if (!imm32 || !is_simm32(jmp_offset)) {
net: filter: x86: internal BPF JIT Maps all internal BPF instructions into x86_64 instructions. This patch replaces original BPF x64 JIT with internal BPF x64 JIT. sysctl net.core.bpf_jit_enable is reused as on/off switch. Performance: 1. old BPF JIT and internal BPF JIT generate equivalent x86_64 code. No performance difference is observed for filters that were JIT-able before Example assembler code for BPF filter "tcpdump port 22" original BPF -> old JIT: original BPF -> internal BPF -> new JIT: 0: push %rbp 0: push %rbp 1: mov %rsp,%rbp 1: mov %rsp,%rbp 4: sub $0x60,%rsp 4: sub $0x228,%rsp 8: mov %rbx,-0x8(%rbp) b: mov %rbx,-0x228(%rbp) // prologue 12: mov %r13,-0x220(%rbp) 19: mov %r14,-0x218(%rbp) 20: mov %r15,-0x210(%rbp) 27: xor %eax,%eax // clear A c: xor %ebx,%ebx 29: xor %r13,%r13 // clear X e: mov 0x68(%rdi),%r9d 2c: mov 0x68(%rdi),%r9d 12: sub 0x6c(%rdi),%r9d 30: sub 0x6c(%rdi),%r9d 16: mov 0xd8(%rdi),%r8 34: mov 0xd8(%rdi),%r10 3b: mov %rdi,%rbx 1d: mov $0xc,%esi 3e: mov $0xc,%esi 22: callq 0xffffffffe1021e15 43: callq 0xffffffffe102bd75 27: cmp $0x86dd,%eax 48: cmp $0x86dd,%rax 2c: jne 0x0000000000000069 4f: jne 0x000000000000009a 2e: mov $0x14,%esi 51: mov $0x14,%esi 33: callq 0xffffffffe1021e31 56: callq 0xffffffffe102bd91 38: cmp $0x84,%eax 5b: cmp $0x84,%rax 3d: je 0x0000000000000049 62: je 0x0000000000000074 3f: cmp $0x6,%eax 64: cmp $0x6,%rax 42: je 0x0000000000000049 68: je 0x0000000000000074 44: cmp $0x11,%eax 6a: cmp $0x11,%rax 47: jne 0x00000000000000c6 6e: jne 0x0000000000000117 49: mov $0x36,%esi 74: mov $0x36,%esi 4e: callq 0xffffffffe1021e15 79: callq 0xffffffffe102bd75 53: cmp $0x16,%eax 7e: cmp $0x16,%rax 56: je 0x00000000000000bf 82: je 0x0000000000000110 58: mov $0x38,%esi 88: mov $0x38,%esi 5d: callq 0xffffffffe1021e15 8d: callq 0xffffffffe102bd75 62: cmp $0x16,%eax 92: cmp $0x16,%rax 65: je 0x00000000000000bf 96: je 0x0000000000000110 67: jmp 0x00000000000000c6 98: jmp 0x0000000000000117 69: cmp $0x800,%eax 9a: cmp $0x800,%rax 6e: jne 0x00000000000000c6 a1: jne 0x0000000000000117 70: mov $0x17,%esi a3: mov $0x17,%esi 75: callq 0xffffffffe1021e31 a8: callq 0xffffffffe102bd91 7a: cmp $0x84,%eax ad: cmp $0x84,%rax 7f: je 0x000000000000008b b4: je 0x00000000000000c2 81: cmp $0x6,%eax b6: cmp $0x6,%rax 84: je 0x000000000000008b ba: je 0x00000000000000c2 86: cmp $0x11,%eax bc: cmp $0x11,%rax 89: jne 0x00000000000000c6 c0: jne 0x0000000000000117 8b: mov $0x14,%esi c2: mov $0x14,%esi 90: callq 0xffffffffe1021e15 c7: callq 0xffffffffe102bd75 95: test $0x1fff,%ax cc: test $0x1fff,%rax 99: jne 0x00000000000000c6 d3: jne 0x0000000000000117 d5: mov %rax,%r14 9b: mov $0xe,%esi d8: mov $0xe,%esi a0: callq 0xffffffffe1021e44 dd: callq 0xffffffffe102bd91 // MSH e2: and $0xf,%eax e5: shl $0x2,%eax e8: mov %rax,%r13 eb: mov %r14,%rax ee: mov %r13,%rsi a5: lea 0xe(%rbx),%esi f1: add $0xe,%esi a8: callq 0xffffffffe1021e0d f4: callq 0xffffffffe102bd6d ad: cmp $0x16,%eax f9: cmp $0x16,%rax b0: je 0x00000000000000bf fd: je 0x0000000000000110 ff: mov %r13,%rsi b2: lea 0x10(%rbx),%esi 102: add $0x10,%esi b5: callq 0xffffffffe1021e0d 105: callq 0xffffffffe102bd6d ba: cmp $0x16,%eax 10a: cmp $0x16,%rax bd: jne 0x00000000000000c6 10e: jne 0x0000000000000117 bf: mov $0xffff,%eax 110: mov $0xffff,%eax c4: jmp 0x00000000000000c8 115: jmp 0x000000000000011c c6: xor %eax,%eax 117: mov $0x0,%eax c8: mov -0x8(%rbp),%rbx 11c: mov -0x228(%rbp),%rbx // epilogue cc: leaveq 123: mov -0x220(%rbp),%r13 cd: retq 12a: mov -0x218(%rbp),%r14 131: mov -0x210(%rbp),%r15 138: leaveq 139: retq On fully cached SKBs both JITed functions take 12 nsec to execute. BPF interpreter executes the program in 30 nsec. The difference in generated assembler is due to the following: Old BPF imlements LDX_MSH instruction via sk_load_byte_msh() helper function inside bpf_jit.S. New JIT removes the helper and does it explicitly, so ldx_msh cost is the same for both JITs, but generated code looks longer. New JIT has 4 registers to save, so prologue/epilogue are larger, but the cost is within noise on x64. Old JIT checks whether first insn clears A and if not emits 'xor %eax,%eax'. New JIT clears %rax unconditionally. 2. old BPF JIT doesn't support ANC_NLATTR, ANC_PAY_OFFSET, ANC_RANDOM extensions. New JIT supports all BPF extensions. Performance of such filters improves 2-4 times depending on a filter. The longer the filter the higher performance gain. Synthetic benchmarks with many ancillary loads see 20x speedup which seems to be the maximum gain from JIT Notes: . net.core.bpf_jit_enable=2 + tools/net/bpf_jit_disasm is still functional and can be used to see generated assembler . there are two jit_compile() functions and code flow for classic filters is: sk_attach_filter() - load classic BPF bpf_jit_compile() - try to JIT from classic BPF sk_convert_filter() - convert classic to internal bpf_int_jit_compile() - JIT from internal BPF seccomp and tracing filters will just call bpf_int_jit_compile() Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 20:50:46 -06:00
pr_err("unsupported bpf func %d addr %p image %p\n",
net: filter: cleanup A/X name usage The macro 'A' used in internal BPF interpreter: #define A regs[insn->a_reg] was easily confused with the name of classic BPF register 'A', since 'A' would mean two different things depending on context. This patch is trying to clean up the naming and clarify its usage in the following way: - A and X are names of two classic BPF registers - BPF_REG_A denotes internal BPF register R0 used to map classic register A in internal BPF programs generated from classic - BPF_REG_X denotes internal BPF register R7 used to map classic register X in internal BPF programs generated from classic - internal BPF instruction format: struct sock_filter_int { __u8 code; /* opcode */ __u8 dst_reg:4; /* dest register */ __u8 src_reg:4; /* source register */ __s16 off; /* signed offset */ __s32 imm; /* signed immediate constant */ }; - BPF_X/BPF_K is 1 bit used to encode source operand of instruction In classic: BPF_X - means use register X as source operand BPF_K - means use 32-bit immediate as source operand In internal: BPF_X - means use 'src_reg' register as source operand BPF_K - means use 32-bit immediate as source operand Suggested-by: Chema Gonzalez <chema@google.com> Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Acked-by: Daniel Borkmann <dborkman@redhat.com> Acked-by: Chema Gonzalez <chema@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-06-06 15:46:06 -06:00
imm32, func, image);
net: filter: x86: internal BPF JIT Maps all internal BPF instructions into x86_64 instructions. This patch replaces original BPF x64 JIT with internal BPF x64 JIT. sysctl net.core.bpf_jit_enable is reused as on/off switch. Performance: 1. old BPF JIT and internal BPF JIT generate equivalent x86_64 code. No performance difference is observed for filters that were JIT-able before Example assembler code for BPF filter "tcpdump port 22" original BPF -> old JIT: original BPF -> internal BPF -> new JIT: 0: push %rbp 0: push %rbp 1: mov %rsp,%rbp 1: mov %rsp,%rbp 4: sub $0x60,%rsp 4: sub $0x228,%rsp 8: mov %rbx,-0x8(%rbp) b: mov %rbx,-0x228(%rbp) // prologue 12: mov %r13,-0x220(%rbp) 19: mov %r14,-0x218(%rbp) 20: mov %r15,-0x210(%rbp) 27: xor %eax,%eax // clear A c: xor %ebx,%ebx 29: xor %r13,%r13 // clear X e: mov 0x68(%rdi),%r9d 2c: mov 0x68(%rdi),%r9d 12: sub 0x6c(%rdi),%r9d 30: sub 0x6c(%rdi),%r9d 16: mov 0xd8(%rdi),%r8 34: mov 0xd8(%rdi),%r10 3b: mov %rdi,%rbx 1d: mov $0xc,%esi 3e: mov $0xc,%esi 22: callq 0xffffffffe1021e15 43: callq 0xffffffffe102bd75 27: cmp $0x86dd,%eax 48: cmp $0x86dd,%rax 2c: jne 0x0000000000000069 4f: jne 0x000000000000009a 2e: mov $0x14,%esi 51: mov $0x14,%esi 33: callq 0xffffffffe1021e31 56: callq 0xffffffffe102bd91 38: cmp $0x84,%eax 5b: cmp $0x84,%rax 3d: je 0x0000000000000049 62: je 0x0000000000000074 3f: cmp $0x6,%eax 64: cmp $0x6,%rax 42: je 0x0000000000000049 68: je 0x0000000000000074 44: cmp $0x11,%eax 6a: cmp $0x11,%rax 47: jne 0x00000000000000c6 6e: jne 0x0000000000000117 49: mov $0x36,%esi 74: mov $0x36,%esi 4e: callq 0xffffffffe1021e15 79: callq 0xffffffffe102bd75 53: cmp $0x16,%eax 7e: cmp $0x16,%rax 56: je 0x00000000000000bf 82: je 0x0000000000000110 58: mov $0x38,%esi 88: mov $0x38,%esi 5d: callq 0xffffffffe1021e15 8d: callq 0xffffffffe102bd75 62: cmp $0x16,%eax 92: cmp $0x16,%rax 65: je 0x00000000000000bf 96: je 0x0000000000000110 67: jmp 0x00000000000000c6 98: jmp 0x0000000000000117 69: cmp $0x800,%eax 9a: cmp $0x800,%rax 6e: jne 0x00000000000000c6 a1: jne 0x0000000000000117 70: mov $0x17,%esi a3: mov $0x17,%esi 75: callq 0xffffffffe1021e31 a8: callq 0xffffffffe102bd91 7a: cmp $0x84,%eax ad: cmp $0x84,%rax 7f: je 0x000000000000008b b4: je 0x00000000000000c2 81: cmp $0x6,%eax b6: cmp $0x6,%rax 84: je 0x000000000000008b ba: je 0x00000000000000c2 86: cmp $0x11,%eax bc: cmp $0x11,%rax 89: jne 0x00000000000000c6 c0: jne 0x0000000000000117 8b: mov $0x14,%esi c2: mov $0x14,%esi 90: callq 0xffffffffe1021e15 c7: callq 0xffffffffe102bd75 95: test $0x1fff,%ax cc: test $0x1fff,%rax 99: jne 0x00000000000000c6 d3: jne 0x0000000000000117 d5: mov %rax,%r14 9b: mov $0xe,%esi d8: mov $0xe,%esi a0: callq 0xffffffffe1021e44 dd: callq 0xffffffffe102bd91 // MSH e2: and $0xf,%eax e5: shl $0x2,%eax e8: mov %rax,%r13 eb: mov %r14,%rax ee: mov %r13,%rsi a5: lea 0xe(%rbx),%esi f1: add $0xe,%esi a8: callq 0xffffffffe1021e0d f4: callq 0xffffffffe102bd6d ad: cmp $0x16,%eax f9: cmp $0x16,%rax b0: je 0x00000000000000bf fd: je 0x0000000000000110 ff: mov %r13,%rsi b2: lea 0x10(%rbx),%esi 102: add $0x10,%esi b5: callq 0xffffffffe1021e0d 105: callq 0xffffffffe102bd6d ba: cmp $0x16,%eax 10a: cmp $0x16,%rax bd: jne 0x00000000000000c6 10e: jne 0x0000000000000117 bf: mov $0xffff,%eax 110: mov $0xffff,%eax c4: jmp 0x00000000000000c8 115: jmp 0x000000000000011c c6: xor %eax,%eax 117: mov $0x0,%eax c8: mov -0x8(%rbp),%rbx 11c: mov -0x228(%rbp),%rbx // epilogue cc: leaveq 123: mov -0x220(%rbp),%r13 cd: retq 12a: mov -0x218(%rbp),%r14 131: mov -0x210(%rbp),%r15 138: leaveq 139: retq On fully cached SKBs both JITed functions take 12 nsec to execute. BPF interpreter executes the program in 30 nsec. The difference in generated assembler is due to the following: Old BPF imlements LDX_MSH instruction via sk_load_byte_msh() helper function inside bpf_jit.S. New JIT removes the helper and does it explicitly, so ldx_msh cost is the same for both JITs, but generated code looks longer. New JIT has 4 registers to save, so prologue/epilogue are larger, but the cost is within noise on x64. Old JIT checks whether first insn clears A and if not emits 'xor %eax,%eax'. New JIT clears %rax unconditionally. 2. old BPF JIT doesn't support ANC_NLATTR, ANC_PAY_OFFSET, ANC_RANDOM extensions. New JIT supports all BPF extensions. Performance of such filters improves 2-4 times depending on a filter. The longer the filter the higher performance gain. Synthetic benchmarks with many ancillary loads see 20x speedup which seems to be the maximum gain from JIT Notes: . net.core.bpf_jit_enable=2 + tools/net/bpf_jit_disasm is still functional and can be used to see generated assembler . there are two jit_compile() functions and code flow for classic filters is: sk_attach_filter() - load classic BPF bpf_jit_compile() - try to JIT from classic BPF sk_convert_filter() - convert classic to internal bpf_int_jit_compile() - JIT from internal BPF seccomp and tracing filters will just call bpf_int_jit_compile() Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 20:50:46 -06:00
return -EINVAL;
}
EMIT1_off32(0xE8, jmp_offset);
x86: bpf_jit: fix two bugs in eBPF JIT compiler 1. JIT compiler using multi-pass approach to converge to final image size, since x86 instructions are variable length. It starts with large gaps between instructions (so some jumps may use imm32 instead of imm8) and iterates until total program size is the same as in previous pass. This algorithm works only if program size is strictly decreasing. Programs that use LD_ABS insn need additional code in prologue, but it was not emitted during 1st pass, so there was a chance that 2nd pass would adjust imm32->imm8 jump offsets to the same number of bytes as increase in prologue, which may cause algorithm to erroneously decide that size converged. Fix it by always emitting largest prologue in the first pass which is detected by oldproglen==0 check. Also change error check condition 'proglen != oldproglen' to fail gracefully. 2. while staring at the code realized that 64-byte buffer may not be enough when 1st insn is large, so increase it to 128 to avoid buffer overflow (theoretical maximum size of prologue+div is 109) and add runtime check. Fixes: 622582786c9e ("net: filter: x86: internal BPF JIT") Reported-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Tested-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-10-10 21:30:23 -06:00
if (seen_ld_abs) {
bpf: introduce bpf_skb_vlan_push/pop() helpers Allow eBPF programs attached to TC qdiscs call skb_vlan_push/pop via helper functions. These functions may change skb->data/hlen which are cached by some JITs to improve performance of ld_abs/ld_ind instructions. Therefore JITs need to recognize bpf_skb_vlan_push/pop() calls, re-compute header len and re-cache skb->data/hlen back into cpu registers. Note, skb->data/hlen are not directly accessible from the programs, so any changes to skb->data done either by these helpers or by other TC actions are safe. eBPF JIT supported by three architectures: - arm64 JIT is using bpf_load_pointer() without caching, so it's ok as-is. - x64 JIT re-caches skb->data/hlen unconditionally after vlan_push/pop calls (experiments showed that conditional re-caching is slower). - s390 JIT falls back to interpreter for now when bpf_skb_vlan_push() is present in the program (re-caching is tbd). These helpers allow more scalable handling of vlan from the programs. Instead of creating thousands of vlan netdevs on top of eth0 and attaching TC+ingress+bpf to all of them, the program can be attached to eth0 directly and manipulate vlans as necessary. Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-20 21:34:18 -06:00
if (reload_skb_data) {
EMIT1(0x5F); /* pop %rdi */
emit_load_skb_data_hlen(&prog);
} else {
EMIT2(0x41, 0x59); /* pop %r9 */
EMIT2(0x41, 0x5A); /* pop %r10 */
}
net: filter: x86: internal BPF JIT Maps all internal BPF instructions into x86_64 instructions. This patch replaces original BPF x64 JIT with internal BPF x64 JIT. sysctl net.core.bpf_jit_enable is reused as on/off switch. Performance: 1. old BPF JIT and internal BPF JIT generate equivalent x86_64 code. No performance difference is observed for filters that were JIT-able before Example assembler code for BPF filter "tcpdump port 22" original BPF -> old JIT: original BPF -> internal BPF -> new JIT: 0: push %rbp 0: push %rbp 1: mov %rsp,%rbp 1: mov %rsp,%rbp 4: sub $0x60,%rsp 4: sub $0x228,%rsp 8: mov %rbx,-0x8(%rbp) b: mov %rbx,-0x228(%rbp) // prologue 12: mov %r13,-0x220(%rbp) 19: mov %r14,-0x218(%rbp) 20: mov %r15,-0x210(%rbp) 27: xor %eax,%eax // clear A c: xor %ebx,%ebx 29: xor %r13,%r13 // clear X e: mov 0x68(%rdi),%r9d 2c: mov 0x68(%rdi),%r9d 12: sub 0x6c(%rdi),%r9d 30: sub 0x6c(%rdi),%r9d 16: mov 0xd8(%rdi),%r8 34: mov 0xd8(%rdi),%r10 3b: mov %rdi,%rbx 1d: mov $0xc,%esi 3e: mov $0xc,%esi 22: callq 0xffffffffe1021e15 43: callq 0xffffffffe102bd75 27: cmp $0x86dd,%eax 48: cmp $0x86dd,%rax 2c: jne 0x0000000000000069 4f: jne 0x000000000000009a 2e: mov $0x14,%esi 51: mov $0x14,%esi 33: callq 0xffffffffe1021e31 56: callq 0xffffffffe102bd91 38: cmp $0x84,%eax 5b: cmp $0x84,%rax 3d: je 0x0000000000000049 62: je 0x0000000000000074 3f: cmp $0x6,%eax 64: cmp $0x6,%rax 42: je 0x0000000000000049 68: je 0x0000000000000074 44: cmp $0x11,%eax 6a: cmp $0x11,%rax 47: jne 0x00000000000000c6 6e: jne 0x0000000000000117 49: mov $0x36,%esi 74: mov $0x36,%esi 4e: callq 0xffffffffe1021e15 79: callq 0xffffffffe102bd75 53: cmp $0x16,%eax 7e: cmp $0x16,%rax 56: je 0x00000000000000bf 82: je 0x0000000000000110 58: mov $0x38,%esi 88: mov $0x38,%esi 5d: callq 0xffffffffe1021e15 8d: callq 0xffffffffe102bd75 62: cmp $0x16,%eax 92: cmp $0x16,%rax 65: je 0x00000000000000bf 96: je 0x0000000000000110 67: jmp 0x00000000000000c6 98: jmp 0x0000000000000117 69: cmp $0x800,%eax 9a: cmp $0x800,%rax 6e: jne 0x00000000000000c6 a1: jne 0x0000000000000117 70: mov $0x17,%esi a3: mov $0x17,%esi 75: callq 0xffffffffe1021e31 a8: callq 0xffffffffe102bd91 7a: cmp $0x84,%eax ad: cmp $0x84,%rax 7f: je 0x000000000000008b b4: je 0x00000000000000c2 81: cmp $0x6,%eax b6: cmp $0x6,%rax 84: je 0x000000000000008b ba: je 0x00000000000000c2 86: cmp $0x11,%eax bc: cmp $0x11,%rax 89: jne 0x00000000000000c6 c0: jne 0x0000000000000117 8b: mov $0x14,%esi c2: mov $0x14,%esi 90: callq 0xffffffffe1021e15 c7: callq 0xffffffffe102bd75 95: test $0x1fff,%ax cc: test $0x1fff,%rax 99: jne 0x00000000000000c6 d3: jne 0x0000000000000117 d5: mov %rax,%r14 9b: mov $0xe,%esi d8: mov $0xe,%esi a0: callq 0xffffffffe1021e44 dd: callq 0xffffffffe102bd91 // MSH e2: and $0xf,%eax e5: shl $0x2,%eax e8: mov %rax,%r13 eb: mov %r14,%rax ee: mov %r13,%rsi a5: lea 0xe(%rbx),%esi f1: add $0xe,%esi a8: callq 0xffffffffe1021e0d f4: callq 0xffffffffe102bd6d ad: cmp $0x16,%eax f9: cmp $0x16,%rax b0: je 0x00000000000000bf fd: je 0x0000000000000110 ff: mov %r13,%rsi b2: lea 0x10(%rbx),%esi 102: add $0x10,%esi b5: callq 0xffffffffe1021e0d 105: callq 0xffffffffe102bd6d ba: cmp $0x16,%eax 10a: cmp $0x16,%rax bd: jne 0x00000000000000c6 10e: jne 0x0000000000000117 bf: mov $0xffff,%eax 110: mov $0xffff,%eax c4: jmp 0x00000000000000c8 115: jmp 0x000000000000011c c6: xor %eax,%eax 117: mov $0x0,%eax c8: mov -0x8(%rbp),%rbx 11c: mov -0x228(%rbp),%rbx // epilogue cc: leaveq 123: mov -0x220(%rbp),%r13 cd: retq 12a: mov -0x218(%rbp),%r14 131: mov -0x210(%rbp),%r15 138: leaveq 139: retq On fully cached SKBs both JITed functions take 12 nsec to execute. BPF interpreter executes the program in 30 nsec. The difference in generated assembler is due to the following: Old BPF imlements LDX_MSH instruction via sk_load_byte_msh() helper function inside bpf_jit.S. New JIT removes the helper and does it explicitly, so ldx_msh cost is the same for both JITs, but generated code looks longer. New JIT has 4 registers to save, so prologue/epilogue are larger, but the cost is within noise on x64. Old JIT checks whether first insn clears A and if not emits 'xor %eax,%eax'. New JIT clears %rax unconditionally. 2. old BPF JIT doesn't support ANC_NLATTR, ANC_PAY_OFFSET, ANC_RANDOM extensions. New JIT supports all BPF extensions. Performance of such filters improves 2-4 times depending on a filter. The longer the filter the higher performance gain. Synthetic benchmarks with many ancillary loads see 20x speedup which seems to be the maximum gain from JIT Notes: . net.core.bpf_jit_enable=2 + tools/net/bpf_jit_disasm is still functional and can be used to see generated assembler . there are two jit_compile() functions and code flow for classic filters is: sk_attach_filter() - load classic BPF bpf_jit_compile() - try to JIT from classic BPF sk_convert_filter() - convert classic to internal bpf_int_jit_compile() - JIT from internal BPF seccomp and tracing filters will just call bpf_int_jit_compile() Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 20:50:46 -06:00
}
break;
x86: bpf_jit: implement bpf_tail_call() helper bpf_tail_call() arguments: ctx - context pointer jmp_table - one of BPF_MAP_TYPE_PROG_ARRAY maps used as the jump table index - index in the jump table In this implementation x64 JIT bypasses stack unwind and jumps into the callee program after prologue, so the callee program reuses the same stack. The logic can be roughly expressed in C like: u32 tail_call_cnt; void *jumptable[2] = { &&label1, &&label2 }; int bpf_prog1(void *ctx) { label1: ... } int bpf_prog2(void *ctx) { label2: ... } int bpf_prog1(void *ctx) { ... if (tail_call_cnt++ < MAX_TAIL_CALL_CNT) goto *jumptable[index]; ... and pass my 'ctx' to callee ... ... fall through if no entry in jumptable ... } Note that 'skip current program epilogue and next program prologue' is an optimization. Other JITs don't have to do it the same way. >From safety point of view it's valid as well, since programs always initialize the stack before use, so any residue in the stack left by the current program is not going be read. The same verifier checks are done for the calls from the kernel into all bpf programs. Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-19 17:59:04 -06:00
case BPF_JMP | BPF_CALL | BPF_X:
emit_bpf_tail_call(&prog);
break;
net: filter: x86: internal BPF JIT Maps all internal BPF instructions into x86_64 instructions. This patch replaces original BPF x64 JIT with internal BPF x64 JIT. sysctl net.core.bpf_jit_enable is reused as on/off switch. Performance: 1. old BPF JIT and internal BPF JIT generate equivalent x86_64 code. No performance difference is observed for filters that were JIT-able before Example assembler code for BPF filter "tcpdump port 22" original BPF -> old JIT: original BPF -> internal BPF -> new JIT: 0: push %rbp 0: push %rbp 1: mov %rsp,%rbp 1: mov %rsp,%rbp 4: sub $0x60,%rsp 4: sub $0x228,%rsp 8: mov %rbx,-0x8(%rbp) b: mov %rbx,-0x228(%rbp) // prologue 12: mov %r13,-0x220(%rbp) 19: mov %r14,-0x218(%rbp) 20: mov %r15,-0x210(%rbp) 27: xor %eax,%eax // clear A c: xor %ebx,%ebx 29: xor %r13,%r13 // clear X e: mov 0x68(%rdi),%r9d 2c: mov 0x68(%rdi),%r9d 12: sub 0x6c(%rdi),%r9d 30: sub 0x6c(%rdi),%r9d 16: mov 0xd8(%rdi),%r8 34: mov 0xd8(%rdi),%r10 3b: mov %rdi,%rbx 1d: mov $0xc,%esi 3e: mov $0xc,%esi 22: callq 0xffffffffe1021e15 43: callq 0xffffffffe102bd75 27: cmp $0x86dd,%eax 48: cmp $0x86dd,%rax 2c: jne 0x0000000000000069 4f: jne 0x000000000000009a 2e: mov $0x14,%esi 51: mov $0x14,%esi 33: callq 0xffffffffe1021e31 56: callq 0xffffffffe102bd91 38: cmp $0x84,%eax 5b: cmp $0x84,%rax 3d: je 0x0000000000000049 62: je 0x0000000000000074 3f: cmp $0x6,%eax 64: cmp $0x6,%rax 42: je 0x0000000000000049 68: je 0x0000000000000074 44: cmp $0x11,%eax 6a: cmp $0x11,%rax 47: jne 0x00000000000000c6 6e: jne 0x0000000000000117 49: mov $0x36,%esi 74: mov $0x36,%esi 4e: callq 0xffffffffe1021e15 79: callq 0xffffffffe102bd75 53: cmp $0x16,%eax 7e: cmp $0x16,%rax 56: je 0x00000000000000bf 82: je 0x0000000000000110 58: mov $0x38,%esi 88: mov $0x38,%esi 5d: callq 0xffffffffe1021e15 8d: callq 0xffffffffe102bd75 62: cmp $0x16,%eax 92: cmp $0x16,%rax 65: je 0x00000000000000bf 96: je 0x0000000000000110 67: jmp 0x00000000000000c6 98: jmp 0x0000000000000117 69: cmp $0x800,%eax 9a: cmp $0x800,%rax 6e: jne 0x00000000000000c6 a1: jne 0x0000000000000117 70: mov $0x17,%esi a3: mov $0x17,%esi 75: callq 0xffffffffe1021e31 a8: callq 0xffffffffe102bd91 7a: cmp $0x84,%eax ad: cmp $0x84,%rax 7f: je 0x000000000000008b b4: je 0x00000000000000c2 81: cmp $0x6,%eax b6: cmp $0x6,%rax 84: je 0x000000000000008b ba: je 0x00000000000000c2 86: cmp $0x11,%eax bc: cmp $0x11,%rax 89: jne 0x00000000000000c6 c0: jne 0x0000000000000117 8b: mov $0x14,%esi c2: mov $0x14,%esi 90: callq 0xffffffffe1021e15 c7: callq 0xffffffffe102bd75 95: test $0x1fff,%ax cc: test $0x1fff,%rax 99: jne 0x00000000000000c6 d3: jne 0x0000000000000117 d5: mov %rax,%r14 9b: mov $0xe,%esi d8: mov $0xe,%esi a0: callq 0xffffffffe1021e44 dd: callq 0xffffffffe102bd91 // MSH e2: and $0xf,%eax e5: shl $0x2,%eax e8: mov %rax,%r13 eb: mov %r14,%rax ee: mov %r13,%rsi a5: lea 0xe(%rbx),%esi f1: add $0xe,%esi a8: callq 0xffffffffe1021e0d f4: callq 0xffffffffe102bd6d ad: cmp $0x16,%eax f9: cmp $0x16,%rax b0: je 0x00000000000000bf fd: je 0x0000000000000110 ff: mov %r13,%rsi b2: lea 0x10(%rbx),%esi 102: add $0x10,%esi b5: callq 0xffffffffe1021e0d 105: callq 0xffffffffe102bd6d ba: cmp $0x16,%eax 10a: cmp $0x16,%rax bd: jne 0x00000000000000c6 10e: jne 0x0000000000000117 bf: mov $0xffff,%eax 110: mov $0xffff,%eax c4: jmp 0x00000000000000c8 115: jmp 0x000000000000011c c6: xor %eax,%eax 117: mov $0x0,%eax c8: mov -0x8(%rbp),%rbx 11c: mov -0x228(%rbp),%rbx // epilogue cc: leaveq 123: mov -0x220(%rbp),%r13 cd: retq 12a: mov -0x218(%rbp),%r14 131: mov -0x210(%rbp),%r15 138: leaveq 139: retq On fully cached SKBs both JITed functions take 12 nsec to execute. BPF interpreter executes the program in 30 nsec. The difference in generated assembler is due to the following: Old BPF imlements LDX_MSH instruction via sk_load_byte_msh() helper function inside bpf_jit.S. New JIT removes the helper and does it explicitly, so ldx_msh cost is the same for both JITs, but generated code looks longer. New JIT has 4 registers to save, so prologue/epilogue are larger, but the cost is within noise on x64. Old JIT checks whether first insn clears A and if not emits 'xor %eax,%eax'. New JIT clears %rax unconditionally. 2. old BPF JIT doesn't support ANC_NLATTR, ANC_PAY_OFFSET, ANC_RANDOM extensions. New JIT supports all BPF extensions. Performance of such filters improves 2-4 times depending on a filter. The longer the filter the higher performance gain. Synthetic benchmarks with many ancillary loads see 20x speedup which seems to be the maximum gain from JIT Notes: . net.core.bpf_jit_enable=2 + tools/net/bpf_jit_disasm is still functional and can be used to see generated assembler . there are two jit_compile() functions and code flow for classic filters is: sk_attach_filter() - load classic BPF bpf_jit_compile() - try to JIT from classic BPF sk_convert_filter() - convert classic to internal bpf_int_jit_compile() - JIT from internal BPF seccomp and tracing filters will just call bpf_int_jit_compile() Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 20:50:46 -06:00
/* cond jump */
case BPF_JMP | BPF_JEQ | BPF_X:
case BPF_JMP | BPF_JNE | BPF_X:
case BPF_JMP | BPF_JGT | BPF_X:
case BPF_JMP | BPF_JGE | BPF_X:
case BPF_JMP | BPF_JSGT | BPF_X:
case BPF_JMP | BPF_JSGE | BPF_X:
net: filter: cleanup A/X name usage The macro 'A' used in internal BPF interpreter: #define A regs[insn->a_reg] was easily confused with the name of classic BPF register 'A', since 'A' would mean two different things depending on context. This patch is trying to clean up the naming and clarify its usage in the following way: - A and X are names of two classic BPF registers - BPF_REG_A denotes internal BPF register R0 used to map classic register A in internal BPF programs generated from classic - BPF_REG_X denotes internal BPF register R7 used to map classic register X in internal BPF programs generated from classic - internal BPF instruction format: struct sock_filter_int { __u8 code; /* opcode */ __u8 dst_reg:4; /* dest register */ __u8 src_reg:4; /* source register */ __s16 off; /* signed offset */ __s32 imm; /* signed immediate constant */ }; - BPF_X/BPF_K is 1 bit used to encode source operand of instruction In classic: BPF_X - means use register X as source operand BPF_K - means use 32-bit immediate as source operand In internal: BPF_X - means use 'src_reg' register as source operand BPF_K - means use 32-bit immediate as source operand Suggested-by: Chema Gonzalez <chema@google.com> Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Acked-by: Daniel Borkmann <dborkman@redhat.com> Acked-by: Chema Gonzalez <chema@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-06-06 15:46:06 -06:00
/* cmp dst_reg, src_reg */
EMIT3(add_2mod(0x48, dst_reg, src_reg), 0x39,
add_2reg(0xC0, dst_reg, src_reg));
net: filter: x86: internal BPF JIT Maps all internal BPF instructions into x86_64 instructions. This patch replaces original BPF x64 JIT with internal BPF x64 JIT. sysctl net.core.bpf_jit_enable is reused as on/off switch. Performance: 1. old BPF JIT and internal BPF JIT generate equivalent x86_64 code. No performance difference is observed for filters that were JIT-able before Example assembler code for BPF filter "tcpdump port 22" original BPF -> old JIT: original BPF -> internal BPF -> new JIT: 0: push %rbp 0: push %rbp 1: mov %rsp,%rbp 1: mov %rsp,%rbp 4: sub $0x60,%rsp 4: sub $0x228,%rsp 8: mov %rbx,-0x8(%rbp) b: mov %rbx,-0x228(%rbp) // prologue 12: mov %r13,-0x220(%rbp) 19: mov %r14,-0x218(%rbp) 20: mov %r15,-0x210(%rbp) 27: xor %eax,%eax // clear A c: xor %ebx,%ebx 29: xor %r13,%r13 // clear X e: mov 0x68(%rdi),%r9d 2c: mov 0x68(%rdi),%r9d 12: sub 0x6c(%rdi),%r9d 30: sub 0x6c(%rdi),%r9d 16: mov 0xd8(%rdi),%r8 34: mov 0xd8(%rdi),%r10 3b: mov %rdi,%rbx 1d: mov $0xc,%esi 3e: mov $0xc,%esi 22: callq 0xffffffffe1021e15 43: callq 0xffffffffe102bd75 27: cmp $0x86dd,%eax 48: cmp $0x86dd,%rax 2c: jne 0x0000000000000069 4f: jne 0x000000000000009a 2e: mov $0x14,%esi 51: mov $0x14,%esi 33: callq 0xffffffffe1021e31 56: callq 0xffffffffe102bd91 38: cmp $0x84,%eax 5b: cmp $0x84,%rax 3d: je 0x0000000000000049 62: je 0x0000000000000074 3f: cmp $0x6,%eax 64: cmp $0x6,%rax 42: je 0x0000000000000049 68: je 0x0000000000000074 44: cmp $0x11,%eax 6a: cmp $0x11,%rax 47: jne 0x00000000000000c6 6e: jne 0x0000000000000117 49: mov $0x36,%esi 74: mov $0x36,%esi 4e: callq 0xffffffffe1021e15 79: callq 0xffffffffe102bd75 53: cmp $0x16,%eax 7e: cmp $0x16,%rax 56: je 0x00000000000000bf 82: je 0x0000000000000110 58: mov $0x38,%esi 88: mov $0x38,%esi 5d: callq 0xffffffffe1021e15 8d: callq 0xffffffffe102bd75 62: cmp $0x16,%eax 92: cmp $0x16,%rax 65: je 0x00000000000000bf 96: je 0x0000000000000110 67: jmp 0x00000000000000c6 98: jmp 0x0000000000000117 69: cmp $0x800,%eax 9a: cmp $0x800,%rax 6e: jne 0x00000000000000c6 a1: jne 0x0000000000000117 70: mov $0x17,%esi a3: mov $0x17,%esi 75: callq 0xffffffffe1021e31 a8: callq 0xffffffffe102bd91 7a: cmp $0x84,%eax ad: cmp $0x84,%rax 7f: je 0x000000000000008b b4: je 0x00000000000000c2 81: cmp $0x6,%eax b6: cmp $0x6,%rax 84: je 0x000000000000008b ba: je 0x00000000000000c2 86: cmp $0x11,%eax bc: cmp $0x11,%rax 89: jne 0x00000000000000c6 c0: jne 0x0000000000000117 8b: mov $0x14,%esi c2: mov $0x14,%esi 90: callq 0xffffffffe1021e15 c7: callq 0xffffffffe102bd75 95: test $0x1fff,%ax cc: test $0x1fff,%rax 99: jne 0x00000000000000c6 d3: jne 0x0000000000000117 d5: mov %rax,%r14 9b: mov $0xe,%esi d8: mov $0xe,%esi a0: callq 0xffffffffe1021e44 dd: callq 0xffffffffe102bd91 // MSH e2: and $0xf,%eax e5: shl $0x2,%eax e8: mov %rax,%r13 eb: mov %r14,%rax ee: mov %r13,%rsi a5: lea 0xe(%rbx),%esi f1: add $0xe,%esi a8: callq 0xffffffffe1021e0d f4: callq 0xffffffffe102bd6d ad: cmp $0x16,%eax f9: cmp $0x16,%rax b0: je 0x00000000000000bf fd: je 0x0000000000000110 ff: mov %r13,%rsi b2: lea 0x10(%rbx),%esi 102: add $0x10,%esi b5: callq 0xffffffffe1021e0d 105: callq 0xffffffffe102bd6d ba: cmp $0x16,%eax 10a: cmp $0x16,%rax bd: jne 0x00000000000000c6 10e: jne 0x0000000000000117 bf: mov $0xffff,%eax 110: mov $0xffff,%eax c4: jmp 0x00000000000000c8 115: jmp 0x000000000000011c c6: xor %eax,%eax 117: mov $0x0,%eax c8: mov -0x8(%rbp),%rbx 11c: mov -0x228(%rbp),%rbx // epilogue cc: leaveq 123: mov -0x220(%rbp),%r13 cd: retq 12a: mov -0x218(%rbp),%r14 131: mov -0x210(%rbp),%r15 138: leaveq 139: retq On fully cached SKBs both JITed functions take 12 nsec to execute. BPF interpreter executes the program in 30 nsec. The difference in generated assembler is due to the following: Old BPF imlements LDX_MSH instruction via sk_load_byte_msh() helper function inside bpf_jit.S. New JIT removes the helper and does it explicitly, so ldx_msh cost is the same for both JITs, but generated code looks longer. New JIT has 4 registers to save, so prologue/epilogue are larger, but the cost is within noise on x64. Old JIT checks whether first insn clears A and if not emits 'xor %eax,%eax'. New JIT clears %rax unconditionally. 2. old BPF JIT doesn't support ANC_NLATTR, ANC_PAY_OFFSET, ANC_RANDOM extensions. New JIT supports all BPF extensions. Performance of such filters improves 2-4 times depending on a filter. The longer the filter the higher performance gain. Synthetic benchmarks with many ancillary loads see 20x speedup which seems to be the maximum gain from JIT Notes: . net.core.bpf_jit_enable=2 + tools/net/bpf_jit_disasm is still functional and can be used to see generated assembler . there are two jit_compile() functions and code flow for classic filters is: sk_attach_filter() - load classic BPF bpf_jit_compile() - try to JIT from classic BPF sk_convert_filter() - convert classic to internal bpf_int_jit_compile() - JIT from internal BPF seccomp and tracing filters will just call bpf_int_jit_compile() Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 20:50:46 -06:00
goto emit_cond_jmp;
case BPF_JMP | BPF_JSET | BPF_X:
net: filter: cleanup A/X name usage The macro 'A' used in internal BPF interpreter: #define A regs[insn->a_reg] was easily confused with the name of classic BPF register 'A', since 'A' would mean two different things depending on context. This patch is trying to clean up the naming and clarify its usage in the following way: - A and X are names of two classic BPF registers - BPF_REG_A denotes internal BPF register R0 used to map classic register A in internal BPF programs generated from classic - BPF_REG_X denotes internal BPF register R7 used to map classic register X in internal BPF programs generated from classic - internal BPF instruction format: struct sock_filter_int { __u8 code; /* opcode */ __u8 dst_reg:4; /* dest register */ __u8 src_reg:4; /* source register */ __s16 off; /* signed offset */ __s32 imm; /* signed immediate constant */ }; - BPF_X/BPF_K is 1 bit used to encode source operand of instruction In classic: BPF_X - means use register X as source operand BPF_K - means use 32-bit immediate as source operand In internal: BPF_X - means use 'src_reg' register as source operand BPF_K - means use 32-bit immediate as source operand Suggested-by: Chema Gonzalez <chema@google.com> Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Acked-by: Daniel Borkmann <dborkman@redhat.com> Acked-by: Chema Gonzalez <chema@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-06-06 15:46:06 -06:00
/* test dst_reg, src_reg */
EMIT3(add_2mod(0x48, dst_reg, src_reg), 0x85,
add_2reg(0xC0, dst_reg, src_reg));
net: filter: x86: internal BPF JIT Maps all internal BPF instructions into x86_64 instructions. This patch replaces original BPF x64 JIT with internal BPF x64 JIT. sysctl net.core.bpf_jit_enable is reused as on/off switch. Performance: 1. old BPF JIT and internal BPF JIT generate equivalent x86_64 code. No performance difference is observed for filters that were JIT-able before Example assembler code for BPF filter "tcpdump port 22" original BPF -> old JIT: original BPF -> internal BPF -> new JIT: 0: push %rbp 0: push %rbp 1: mov %rsp,%rbp 1: mov %rsp,%rbp 4: sub $0x60,%rsp 4: sub $0x228,%rsp 8: mov %rbx,-0x8(%rbp) b: mov %rbx,-0x228(%rbp) // prologue 12: mov %r13,-0x220(%rbp) 19: mov %r14,-0x218(%rbp) 20: mov %r15,-0x210(%rbp) 27: xor %eax,%eax // clear A c: xor %ebx,%ebx 29: xor %r13,%r13 // clear X e: mov 0x68(%rdi),%r9d 2c: mov 0x68(%rdi),%r9d 12: sub 0x6c(%rdi),%r9d 30: sub 0x6c(%rdi),%r9d 16: mov 0xd8(%rdi),%r8 34: mov 0xd8(%rdi),%r10 3b: mov %rdi,%rbx 1d: mov $0xc,%esi 3e: mov $0xc,%esi 22: callq 0xffffffffe1021e15 43: callq 0xffffffffe102bd75 27: cmp $0x86dd,%eax 48: cmp $0x86dd,%rax 2c: jne 0x0000000000000069 4f: jne 0x000000000000009a 2e: mov $0x14,%esi 51: mov $0x14,%esi 33: callq 0xffffffffe1021e31 56: callq 0xffffffffe102bd91 38: cmp $0x84,%eax 5b: cmp $0x84,%rax 3d: je 0x0000000000000049 62: je 0x0000000000000074 3f: cmp $0x6,%eax 64: cmp $0x6,%rax 42: je 0x0000000000000049 68: je 0x0000000000000074 44: cmp $0x11,%eax 6a: cmp $0x11,%rax 47: jne 0x00000000000000c6 6e: jne 0x0000000000000117 49: mov $0x36,%esi 74: mov $0x36,%esi 4e: callq 0xffffffffe1021e15 79: callq 0xffffffffe102bd75 53: cmp $0x16,%eax 7e: cmp $0x16,%rax 56: je 0x00000000000000bf 82: je 0x0000000000000110 58: mov $0x38,%esi 88: mov $0x38,%esi 5d: callq 0xffffffffe1021e15 8d: callq 0xffffffffe102bd75 62: cmp $0x16,%eax 92: cmp $0x16,%rax 65: je 0x00000000000000bf 96: je 0x0000000000000110 67: jmp 0x00000000000000c6 98: jmp 0x0000000000000117 69: cmp $0x800,%eax 9a: cmp $0x800,%rax 6e: jne 0x00000000000000c6 a1: jne 0x0000000000000117 70: mov $0x17,%esi a3: mov $0x17,%esi 75: callq 0xffffffffe1021e31 a8: callq 0xffffffffe102bd91 7a: cmp $0x84,%eax ad: cmp $0x84,%rax 7f: je 0x000000000000008b b4: je 0x00000000000000c2 81: cmp $0x6,%eax b6: cmp $0x6,%rax 84: je 0x000000000000008b ba: je 0x00000000000000c2 86: cmp $0x11,%eax bc: cmp $0x11,%rax 89: jne 0x00000000000000c6 c0: jne 0x0000000000000117 8b: mov $0x14,%esi c2: mov $0x14,%esi 90: callq 0xffffffffe1021e15 c7: callq 0xffffffffe102bd75 95: test $0x1fff,%ax cc: test $0x1fff,%rax 99: jne 0x00000000000000c6 d3: jne 0x0000000000000117 d5: mov %rax,%r14 9b: mov $0xe,%esi d8: mov $0xe,%esi a0: callq 0xffffffffe1021e44 dd: callq 0xffffffffe102bd91 // MSH e2: and $0xf,%eax e5: shl $0x2,%eax e8: mov %rax,%r13 eb: mov %r14,%rax ee: mov %r13,%rsi a5: lea 0xe(%rbx),%esi f1: add $0xe,%esi a8: callq 0xffffffffe1021e0d f4: callq 0xffffffffe102bd6d ad: cmp $0x16,%eax f9: cmp $0x16,%rax b0: je 0x00000000000000bf fd: je 0x0000000000000110 ff: mov %r13,%rsi b2: lea 0x10(%rbx),%esi 102: add $0x10,%esi b5: callq 0xffffffffe1021e0d 105: callq 0xffffffffe102bd6d ba: cmp $0x16,%eax 10a: cmp $0x16,%rax bd: jne 0x00000000000000c6 10e: jne 0x0000000000000117 bf: mov $0xffff,%eax 110: mov $0xffff,%eax c4: jmp 0x00000000000000c8 115: jmp 0x000000000000011c c6: xor %eax,%eax 117: mov $0x0,%eax c8: mov -0x8(%rbp),%rbx 11c: mov -0x228(%rbp),%rbx // epilogue cc: leaveq 123: mov -0x220(%rbp),%r13 cd: retq 12a: mov -0x218(%rbp),%r14 131: mov -0x210(%rbp),%r15 138: leaveq 139: retq On fully cached SKBs both JITed functions take 12 nsec to execute. BPF interpreter executes the program in 30 nsec. The difference in generated assembler is due to the following: Old BPF imlements LDX_MSH instruction via sk_load_byte_msh() helper function inside bpf_jit.S. New JIT removes the helper and does it explicitly, so ldx_msh cost is the same for both JITs, but generated code looks longer. New JIT has 4 registers to save, so prologue/epilogue are larger, but the cost is within noise on x64. Old JIT checks whether first insn clears A and if not emits 'xor %eax,%eax'. New JIT clears %rax unconditionally. 2. old BPF JIT doesn't support ANC_NLATTR, ANC_PAY_OFFSET, ANC_RANDOM extensions. New JIT supports all BPF extensions. Performance of such filters improves 2-4 times depending on a filter. The longer the filter the higher performance gain. Synthetic benchmarks with many ancillary loads see 20x speedup which seems to be the maximum gain from JIT Notes: . net.core.bpf_jit_enable=2 + tools/net/bpf_jit_disasm is still functional and can be used to see generated assembler . there are two jit_compile() functions and code flow for classic filters is: sk_attach_filter() - load classic BPF bpf_jit_compile() - try to JIT from classic BPF sk_convert_filter() - convert classic to internal bpf_int_jit_compile() - JIT from internal BPF seccomp and tracing filters will just call bpf_int_jit_compile() Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 20:50:46 -06:00
goto emit_cond_jmp;
case BPF_JMP | BPF_JSET | BPF_K:
net: filter: cleanup A/X name usage The macro 'A' used in internal BPF interpreter: #define A regs[insn->a_reg] was easily confused with the name of classic BPF register 'A', since 'A' would mean two different things depending on context. This patch is trying to clean up the naming and clarify its usage in the following way: - A and X are names of two classic BPF registers - BPF_REG_A denotes internal BPF register R0 used to map classic register A in internal BPF programs generated from classic - BPF_REG_X denotes internal BPF register R7 used to map classic register X in internal BPF programs generated from classic - internal BPF instruction format: struct sock_filter_int { __u8 code; /* opcode */ __u8 dst_reg:4; /* dest register */ __u8 src_reg:4; /* source register */ __s16 off; /* signed offset */ __s32 imm; /* signed immediate constant */ }; - BPF_X/BPF_K is 1 bit used to encode source operand of instruction In classic: BPF_X - means use register X as source operand BPF_K - means use 32-bit immediate as source operand In internal: BPF_X - means use 'src_reg' register as source operand BPF_K - means use 32-bit immediate as source operand Suggested-by: Chema Gonzalez <chema@google.com> Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Acked-by: Daniel Borkmann <dborkman@redhat.com> Acked-by: Chema Gonzalez <chema@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-06-06 15:46:06 -06:00
/* test dst_reg, imm32 */
EMIT1(add_1mod(0x48, dst_reg));
EMIT2_off32(0xF7, add_1reg(0xC0, dst_reg), imm32);
net: filter: x86: internal BPF JIT Maps all internal BPF instructions into x86_64 instructions. This patch replaces original BPF x64 JIT with internal BPF x64 JIT. sysctl net.core.bpf_jit_enable is reused as on/off switch. Performance: 1. old BPF JIT and internal BPF JIT generate equivalent x86_64 code. No performance difference is observed for filters that were JIT-able before Example assembler code for BPF filter "tcpdump port 22" original BPF -> old JIT: original BPF -> internal BPF -> new JIT: 0: push %rbp 0: push %rbp 1: mov %rsp,%rbp 1: mov %rsp,%rbp 4: sub $0x60,%rsp 4: sub $0x228,%rsp 8: mov %rbx,-0x8(%rbp) b: mov %rbx,-0x228(%rbp) // prologue 12: mov %r13,-0x220(%rbp) 19: mov %r14,-0x218(%rbp) 20: mov %r15,-0x210(%rbp) 27: xor %eax,%eax // clear A c: xor %ebx,%ebx 29: xor %r13,%r13 // clear X e: mov 0x68(%rdi),%r9d 2c: mov 0x68(%rdi),%r9d 12: sub 0x6c(%rdi),%r9d 30: sub 0x6c(%rdi),%r9d 16: mov 0xd8(%rdi),%r8 34: mov 0xd8(%rdi),%r10 3b: mov %rdi,%rbx 1d: mov $0xc,%esi 3e: mov $0xc,%esi 22: callq 0xffffffffe1021e15 43: callq 0xffffffffe102bd75 27: cmp $0x86dd,%eax 48: cmp $0x86dd,%rax 2c: jne 0x0000000000000069 4f: jne 0x000000000000009a 2e: mov $0x14,%esi 51: mov $0x14,%esi 33: callq 0xffffffffe1021e31 56: callq 0xffffffffe102bd91 38: cmp $0x84,%eax 5b: cmp $0x84,%rax 3d: je 0x0000000000000049 62: je 0x0000000000000074 3f: cmp $0x6,%eax 64: cmp $0x6,%rax 42: je 0x0000000000000049 68: je 0x0000000000000074 44: cmp $0x11,%eax 6a: cmp $0x11,%rax 47: jne 0x00000000000000c6 6e: jne 0x0000000000000117 49: mov $0x36,%esi 74: mov $0x36,%esi 4e: callq 0xffffffffe1021e15 79: callq 0xffffffffe102bd75 53: cmp $0x16,%eax 7e: cmp $0x16,%rax 56: je 0x00000000000000bf 82: je 0x0000000000000110 58: mov $0x38,%esi 88: mov $0x38,%esi 5d: callq 0xffffffffe1021e15 8d: callq 0xffffffffe102bd75 62: cmp $0x16,%eax 92: cmp $0x16,%rax 65: je 0x00000000000000bf 96: je 0x0000000000000110 67: jmp 0x00000000000000c6 98: jmp 0x0000000000000117 69: cmp $0x800,%eax 9a: cmp $0x800,%rax 6e: jne 0x00000000000000c6 a1: jne 0x0000000000000117 70: mov $0x17,%esi a3: mov $0x17,%esi 75: callq 0xffffffffe1021e31 a8: callq 0xffffffffe102bd91 7a: cmp $0x84,%eax ad: cmp $0x84,%rax 7f: je 0x000000000000008b b4: je 0x00000000000000c2 81: cmp $0x6,%eax b6: cmp $0x6,%rax 84: je 0x000000000000008b ba: je 0x00000000000000c2 86: cmp $0x11,%eax bc: cmp $0x11,%rax 89: jne 0x00000000000000c6 c0: jne 0x0000000000000117 8b: mov $0x14,%esi c2: mov $0x14,%esi 90: callq 0xffffffffe1021e15 c7: callq 0xffffffffe102bd75 95: test $0x1fff,%ax cc: test $0x1fff,%rax 99: jne 0x00000000000000c6 d3: jne 0x0000000000000117 d5: mov %rax,%r14 9b: mov $0xe,%esi d8: mov $0xe,%esi a0: callq 0xffffffffe1021e44 dd: callq 0xffffffffe102bd91 // MSH e2: and $0xf,%eax e5: shl $0x2,%eax e8: mov %rax,%r13 eb: mov %r14,%rax ee: mov %r13,%rsi a5: lea 0xe(%rbx),%esi f1: add $0xe,%esi a8: callq 0xffffffffe1021e0d f4: callq 0xffffffffe102bd6d ad: cmp $0x16,%eax f9: cmp $0x16,%rax b0: je 0x00000000000000bf fd: je 0x0000000000000110 ff: mov %r13,%rsi b2: lea 0x10(%rbx),%esi 102: add $0x10,%esi b5: callq 0xffffffffe1021e0d 105: callq 0xffffffffe102bd6d ba: cmp $0x16,%eax 10a: cmp $0x16,%rax bd: jne 0x00000000000000c6 10e: jne 0x0000000000000117 bf: mov $0xffff,%eax 110: mov $0xffff,%eax c4: jmp 0x00000000000000c8 115: jmp 0x000000000000011c c6: xor %eax,%eax 117: mov $0x0,%eax c8: mov -0x8(%rbp),%rbx 11c: mov -0x228(%rbp),%rbx // epilogue cc: leaveq 123: mov -0x220(%rbp),%r13 cd: retq 12a: mov -0x218(%rbp),%r14 131: mov -0x210(%rbp),%r15 138: leaveq 139: retq On fully cached SKBs both JITed functions take 12 nsec to execute. BPF interpreter executes the program in 30 nsec. The difference in generated assembler is due to the following: Old BPF imlements LDX_MSH instruction via sk_load_byte_msh() helper function inside bpf_jit.S. New JIT removes the helper and does it explicitly, so ldx_msh cost is the same for both JITs, but generated code looks longer. New JIT has 4 registers to save, so prologue/epilogue are larger, but the cost is within noise on x64. Old JIT checks whether first insn clears A and if not emits 'xor %eax,%eax'. New JIT clears %rax unconditionally. 2. old BPF JIT doesn't support ANC_NLATTR, ANC_PAY_OFFSET, ANC_RANDOM extensions. New JIT supports all BPF extensions. Performance of such filters improves 2-4 times depending on a filter. The longer the filter the higher performance gain. Synthetic benchmarks with many ancillary loads see 20x speedup which seems to be the maximum gain from JIT Notes: . net.core.bpf_jit_enable=2 + tools/net/bpf_jit_disasm is still functional and can be used to see generated assembler . there are two jit_compile() functions and code flow for classic filters is: sk_attach_filter() - load classic BPF bpf_jit_compile() - try to JIT from classic BPF sk_convert_filter() - convert classic to internal bpf_int_jit_compile() - JIT from internal BPF seccomp and tracing filters will just call bpf_int_jit_compile() Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 20:50:46 -06:00
goto emit_cond_jmp;
case BPF_JMP | BPF_JEQ | BPF_K:
case BPF_JMP | BPF_JNE | BPF_K:
case BPF_JMP | BPF_JGT | BPF_K:
case BPF_JMP | BPF_JGE | BPF_K:
case BPF_JMP | BPF_JSGT | BPF_K:
case BPF_JMP | BPF_JSGE | BPF_K:
net: filter: cleanup A/X name usage The macro 'A' used in internal BPF interpreter: #define A regs[insn->a_reg] was easily confused with the name of classic BPF register 'A', since 'A' would mean two different things depending on context. This patch is trying to clean up the naming and clarify its usage in the following way: - A and X are names of two classic BPF registers - BPF_REG_A denotes internal BPF register R0 used to map classic register A in internal BPF programs generated from classic - BPF_REG_X denotes internal BPF register R7 used to map classic register X in internal BPF programs generated from classic - internal BPF instruction format: struct sock_filter_int { __u8 code; /* opcode */ __u8 dst_reg:4; /* dest register */ __u8 src_reg:4; /* source register */ __s16 off; /* signed offset */ __s32 imm; /* signed immediate constant */ }; - BPF_X/BPF_K is 1 bit used to encode source operand of instruction In classic: BPF_X - means use register X as source operand BPF_K - means use 32-bit immediate as source operand In internal: BPF_X - means use 'src_reg' register as source operand BPF_K - means use 32-bit immediate as source operand Suggested-by: Chema Gonzalez <chema@google.com> Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Acked-by: Daniel Borkmann <dborkman@redhat.com> Acked-by: Chema Gonzalez <chema@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-06-06 15:46:06 -06:00
/* cmp dst_reg, imm8/32 */
EMIT1(add_1mod(0x48, dst_reg));
net: filter: x86: internal BPF JIT Maps all internal BPF instructions into x86_64 instructions. This patch replaces original BPF x64 JIT with internal BPF x64 JIT. sysctl net.core.bpf_jit_enable is reused as on/off switch. Performance: 1. old BPF JIT and internal BPF JIT generate equivalent x86_64 code. No performance difference is observed for filters that were JIT-able before Example assembler code for BPF filter "tcpdump port 22" original BPF -> old JIT: original BPF -> internal BPF -> new JIT: 0: push %rbp 0: push %rbp 1: mov %rsp,%rbp 1: mov %rsp,%rbp 4: sub $0x60,%rsp 4: sub $0x228,%rsp 8: mov %rbx,-0x8(%rbp) b: mov %rbx,-0x228(%rbp) // prologue 12: mov %r13,-0x220(%rbp) 19: mov %r14,-0x218(%rbp) 20: mov %r15,-0x210(%rbp) 27: xor %eax,%eax // clear A c: xor %ebx,%ebx 29: xor %r13,%r13 // clear X e: mov 0x68(%rdi),%r9d 2c: mov 0x68(%rdi),%r9d 12: sub 0x6c(%rdi),%r9d 30: sub 0x6c(%rdi),%r9d 16: mov 0xd8(%rdi),%r8 34: mov 0xd8(%rdi),%r10 3b: mov %rdi,%rbx 1d: mov $0xc,%esi 3e: mov $0xc,%esi 22: callq 0xffffffffe1021e15 43: callq 0xffffffffe102bd75 27: cmp $0x86dd,%eax 48: cmp $0x86dd,%rax 2c: jne 0x0000000000000069 4f: jne 0x000000000000009a 2e: mov $0x14,%esi 51: mov $0x14,%esi 33: callq 0xffffffffe1021e31 56: callq 0xffffffffe102bd91 38: cmp $0x84,%eax 5b: cmp $0x84,%rax 3d: je 0x0000000000000049 62: je 0x0000000000000074 3f: cmp $0x6,%eax 64: cmp $0x6,%rax 42: je 0x0000000000000049 68: je 0x0000000000000074 44: cmp $0x11,%eax 6a: cmp $0x11,%rax 47: jne 0x00000000000000c6 6e: jne 0x0000000000000117 49: mov $0x36,%esi 74: mov $0x36,%esi 4e: callq 0xffffffffe1021e15 79: callq 0xffffffffe102bd75 53: cmp $0x16,%eax 7e: cmp $0x16,%rax 56: je 0x00000000000000bf 82: je 0x0000000000000110 58: mov $0x38,%esi 88: mov $0x38,%esi 5d: callq 0xffffffffe1021e15 8d: callq 0xffffffffe102bd75 62: cmp $0x16,%eax 92: cmp $0x16,%rax 65: je 0x00000000000000bf 96: je 0x0000000000000110 67: jmp 0x00000000000000c6 98: jmp 0x0000000000000117 69: cmp $0x800,%eax 9a: cmp $0x800,%rax 6e: jne 0x00000000000000c6 a1: jne 0x0000000000000117 70: mov $0x17,%esi a3: mov $0x17,%esi 75: callq 0xffffffffe1021e31 a8: callq 0xffffffffe102bd91 7a: cmp $0x84,%eax ad: cmp $0x84,%rax 7f: je 0x000000000000008b b4: je 0x00000000000000c2 81: cmp $0x6,%eax b6: cmp $0x6,%rax 84: je 0x000000000000008b ba: je 0x00000000000000c2 86: cmp $0x11,%eax bc: cmp $0x11,%rax 89: jne 0x00000000000000c6 c0: jne 0x0000000000000117 8b: mov $0x14,%esi c2: mov $0x14,%esi 90: callq 0xffffffffe1021e15 c7: callq 0xffffffffe102bd75 95: test $0x1fff,%ax cc: test $0x1fff,%rax 99: jne 0x00000000000000c6 d3: jne 0x0000000000000117 d5: mov %rax,%r14 9b: mov $0xe,%esi d8: mov $0xe,%esi a0: callq 0xffffffffe1021e44 dd: callq 0xffffffffe102bd91 // MSH e2: and $0xf,%eax e5: shl $0x2,%eax e8: mov %rax,%r13 eb: mov %r14,%rax ee: mov %r13,%rsi a5: lea 0xe(%rbx),%esi f1: add $0xe,%esi a8: callq 0xffffffffe1021e0d f4: callq 0xffffffffe102bd6d ad: cmp $0x16,%eax f9: cmp $0x16,%rax b0: je 0x00000000000000bf fd: je 0x0000000000000110 ff: mov %r13,%rsi b2: lea 0x10(%rbx),%esi 102: add $0x10,%esi b5: callq 0xffffffffe1021e0d 105: callq 0xffffffffe102bd6d ba: cmp $0x16,%eax 10a: cmp $0x16,%rax bd: jne 0x00000000000000c6 10e: jne 0x0000000000000117 bf: mov $0xffff,%eax 110: mov $0xffff,%eax c4: jmp 0x00000000000000c8 115: jmp 0x000000000000011c c6: xor %eax,%eax 117: mov $0x0,%eax c8: mov -0x8(%rbp),%rbx 11c: mov -0x228(%rbp),%rbx // epilogue cc: leaveq 123: mov -0x220(%rbp),%r13 cd: retq 12a: mov -0x218(%rbp),%r14 131: mov -0x210(%rbp),%r15 138: leaveq 139: retq On fully cached SKBs both JITed functions take 12 nsec to execute. BPF interpreter executes the program in 30 nsec. The difference in generated assembler is due to the following: Old BPF imlements LDX_MSH instruction via sk_load_byte_msh() helper function inside bpf_jit.S. New JIT removes the helper and does it explicitly, so ldx_msh cost is the same for both JITs, but generated code looks longer. New JIT has 4 registers to save, so prologue/epilogue are larger, but the cost is within noise on x64. Old JIT checks whether first insn clears A and if not emits 'xor %eax,%eax'. New JIT clears %rax unconditionally. 2. old BPF JIT doesn't support ANC_NLATTR, ANC_PAY_OFFSET, ANC_RANDOM extensions. New JIT supports all BPF extensions. Performance of such filters improves 2-4 times depending on a filter. The longer the filter the higher performance gain. Synthetic benchmarks with many ancillary loads see 20x speedup which seems to be the maximum gain from JIT Notes: . net.core.bpf_jit_enable=2 + tools/net/bpf_jit_disasm is still functional and can be used to see generated assembler . there are two jit_compile() functions and code flow for classic filters is: sk_attach_filter() - load classic BPF bpf_jit_compile() - try to JIT from classic BPF sk_convert_filter() - convert classic to internal bpf_int_jit_compile() - JIT from internal BPF seccomp and tracing filters will just call bpf_int_jit_compile() Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 20:50:46 -06:00
net: filter: cleanup A/X name usage The macro 'A' used in internal BPF interpreter: #define A regs[insn->a_reg] was easily confused with the name of classic BPF register 'A', since 'A' would mean two different things depending on context. This patch is trying to clean up the naming and clarify its usage in the following way: - A and X are names of two classic BPF registers - BPF_REG_A denotes internal BPF register R0 used to map classic register A in internal BPF programs generated from classic - BPF_REG_X denotes internal BPF register R7 used to map classic register X in internal BPF programs generated from classic - internal BPF instruction format: struct sock_filter_int { __u8 code; /* opcode */ __u8 dst_reg:4; /* dest register */ __u8 src_reg:4; /* source register */ __s16 off; /* signed offset */ __s32 imm; /* signed immediate constant */ }; - BPF_X/BPF_K is 1 bit used to encode source operand of instruction In classic: BPF_X - means use register X as source operand BPF_K - means use 32-bit immediate as source operand In internal: BPF_X - means use 'src_reg' register as source operand BPF_K - means use 32-bit immediate as source operand Suggested-by: Chema Gonzalez <chema@google.com> Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Acked-by: Daniel Borkmann <dborkman@redhat.com> Acked-by: Chema Gonzalez <chema@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-06-06 15:46:06 -06:00
if (is_imm8(imm32))
EMIT3(0x83, add_1reg(0xF8, dst_reg), imm32);
net: filter: x86: internal BPF JIT Maps all internal BPF instructions into x86_64 instructions. This patch replaces original BPF x64 JIT with internal BPF x64 JIT. sysctl net.core.bpf_jit_enable is reused as on/off switch. Performance: 1. old BPF JIT and internal BPF JIT generate equivalent x86_64 code. No performance difference is observed for filters that were JIT-able before Example assembler code for BPF filter "tcpdump port 22" original BPF -> old JIT: original BPF -> internal BPF -> new JIT: 0: push %rbp 0: push %rbp 1: mov %rsp,%rbp 1: mov %rsp,%rbp 4: sub $0x60,%rsp 4: sub $0x228,%rsp 8: mov %rbx,-0x8(%rbp) b: mov %rbx,-0x228(%rbp) // prologue 12: mov %r13,-0x220(%rbp) 19: mov %r14,-0x218(%rbp) 20: mov %r15,-0x210(%rbp) 27: xor %eax,%eax // clear A c: xor %ebx,%ebx 29: xor %r13,%r13 // clear X e: mov 0x68(%rdi),%r9d 2c: mov 0x68(%rdi),%r9d 12: sub 0x6c(%rdi),%r9d 30: sub 0x6c(%rdi),%r9d 16: mov 0xd8(%rdi),%r8 34: mov 0xd8(%rdi),%r10 3b: mov %rdi,%rbx 1d: mov $0xc,%esi 3e: mov $0xc,%esi 22: callq 0xffffffffe1021e15 43: callq 0xffffffffe102bd75 27: cmp $0x86dd,%eax 48: cmp $0x86dd,%rax 2c: jne 0x0000000000000069 4f: jne 0x000000000000009a 2e: mov $0x14,%esi 51: mov $0x14,%esi 33: callq 0xffffffffe1021e31 56: callq 0xffffffffe102bd91 38: cmp $0x84,%eax 5b: cmp $0x84,%rax 3d: je 0x0000000000000049 62: je 0x0000000000000074 3f: cmp $0x6,%eax 64: cmp $0x6,%rax 42: je 0x0000000000000049 68: je 0x0000000000000074 44: cmp $0x11,%eax 6a: cmp $0x11,%rax 47: jne 0x00000000000000c6 6e: jne 0x0000000000000117 49: mov $0x36,%esi 74: mov $0x36,%esi 4e: callq 0xffffffffe1021e15 79: callq 0xffffffffe102bd75 53: cmp $0x16,%eax 7e: cmp $0x16,%rax 56: je 0x00000000000000bf 82: je 0x0000000000000110 58: mov $0x38,%esi 88: mov $0x38,%esi 5d: callq 0xffffffffe1021e15 8d: callq 0xffffffffe102bd75 62: cmp $0x16,%eax 92: cmp $0x16,%rax 65: je 0x00000000000000bf 96: je 0x0000000000000110 67: jmp 0x00000000000000c6 98: jmp 0x0000000000000117 69: cmp $0x800,%eax 9a: cmp $0x800,%rax 6e: jne 0x00000000000000c6 a1: jne 0x0000000000000117 70: mov $0x17,%esi a3: mov $0x17,%esi 75: callq 0xffffffffe1021e31 a8: callq 0xffffffffe102bd91 7a: cmp $0x84,%eax ad: cmp $0x84,%rax 7f: je 0x000000000000008b b4: je 0x00000000000000c2 81: cmp $0x6,%eax b6: cmp $0x6,%rax 84: je 0x000000000000008b ba: je 0x00000000000000c2 86: cmp $0x11,%eax bc: cmp $0x11,%rax 89: jne 0x00000000000000c6 c0: jne 0x0000000000000117 8b: mov $0x14,%esi c2: mov $0x14,%esi 90: callq 0xffffffffe1021e15 c7: callq 0xffffffffe102bd75 95: test $0x1fff,%ax cc: test $0x1fff,%rax 99: jne 0x00000000000000c6 d3: jne 0x0000000000000117 d5: mov %rax,%r14 9b: mov $0xe,%esi d8: mov $0xe,%esi a0: callq 0xffffffffe1021e44 dd: callq 0xffffffffe102bd91 // MSH e2: and $0xf,%eax e5: shl $0x2,%eax e8: mov %rax,%r13 eb: mov %r14,%rax ee: mov %r13,%rsi a5: lea 0xe(%rbx),%esi f1: add $0xe,%esi a8: callq 0xffffffffe1021e0d f4: callq 0xffffffffe102bd6d ad: cmp $0x16,%eax f9: cmp $0x16,%rax b0: je 0x00000000000000bf fd: je 0x0000000000000110 ff: mov %r13,%rsi b2: lea 0x10(%rbx),%esi 102: add $0x10,%esi b5: callq 0xffffffffe1021e0d 105: callq 0xffffffffe102bd6d ba: cmp $0x16,%eax 10a: cmp $0x16,%rax bd: jne 0x00000000000000c6 10e: jne 0x0000000000000117 bf: mov $0xffff,%eax 110: mov $0xffff,%eax c4: jmp 0x00000000000000c8 115: jmp 0x000000000000011c c6: xor %eax,%eax 117: mov $0x0,%eax c8: mov -0x8(%rbp),%rbx 11c: mov -0x228(%rbp),%rbx // epilogue cc: leaveq 123: mov -0x220(%rbp),%r13 cd: retq 12a: mov -0x218(%rbp),%r14 131: mov -0x210(%rbp),%r15 138: leaveq 139: retq On fully cached SKBs both JITed functions take 12 nsec to execute. BPF interpreter executes the program in 30 nsec. The difference in generated assembler is due to the following: Old BPF imlements LDX_MSH instruction via sk_load_byte_msh() helper function inside bpf_jit.S. New JIT removes the helper and does it explicitly, so ldx_msh cost is the same for both JITs, but generated code looks longer. New JIT has 4 registers to save, so prologue/epilogue are larger, but the cost is within noise on x64. Old JIT checks whether first insn clears A and if not emits 'xor %eax,%eax'. New JIT clears %rax unconditionally. 2. old BPF JIT doesn't support ANC_NLATTR, ANC_PAY_OFFSET, ANC_RANDOM extensions. New JIT supports all BPF extensions. Performance of such filters improves 2-4 times depending on a filter. The longer the filter the higher performance gain. Synthetic benchmarks with many ancillary loads see 20x speedup which seems to be the maximum gain from JIT Notes: . net.core.bpf_jit_enable=2 + tools/net/bpf_jit_disasm is still functional and can be used to see generated assembler . there are two jit_compile() functions and code flow for classic filters is: sk_attach_filter() - load classic BPF bpf_jit_compile() - try to JIT from classic BPF sk_convert_filter() - convert classic to internal bpf_int_jit_compile() - JIT from internal BPF seccomp and tracing filters will just call bpf_int_jit_compile() Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 20:50:46 -06:00
else
net: filter: cleanup A/X name usage The macro 'A' used in internal BPF interpreter: #define A regs[insn->a_reg] was easily confused with the name of classic BPF register 'A', since 'A' would mean two different things depending on context. This patch is trying to clean up the naming and clarify its usage in the following way: - A and X are names of two classic BPF registers - BPF_REG_A denotes internal BPF register R0 used to map classic register A in internal BPF programs generated from classic - BPF_REG_X denotes internal BPF register R7 used to map classic register X in internal BPF programs generated from classic - internal BPF instruction format: struct sock_filter_int { __u8 code; /* opcode */ __u8 dst_reg:4; /* dest register */ __u8 src_reg:4; /* source register */ __s16 off; /* signed offset */ __s32 imm; /* signed immediate constant */ }; - BPF_X/BPF_K is 1 bit used to encode source operand of instruction In classic: BPF_X - means use register X as source operand BPF_K - means use 32-bit immediate as source operand In internal: BPF_X - means use 'src_reg' register as source operand BPF_K - means use 32-bit immediate as source operand Suggested-by: Chema Gonzalez <chema@google.com> Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Acked-by: Daniel Borkmann <dborkman@redhat.com> Acked-by: Chema Gonzalez <chema@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-06-06 15:46:06 -06:00
EMIT2_off32(0x81, add_1reg(0xF8, dst_reg), imm32);
net: filter: x86: internal BPF JIT Maps all internal BPF instructions into x86_64 instructions. This patch replaces original BPF x64 JIT with internal BPF x64 JIT. sysctl net.core.bpf_jit_enable is reused as on/off switch. Performance: 1. old BPF JIT and internal BPF JIT generate equivalent x86_64 code. No performance difference is observed for filters that were JIT-able before Example assembler code for BPF filter "tcpdump port 22" original BPF -> old JIT: original BPF -> internal BPF -> new JIT: 0: push %rbp 0: push %rbp 1: mov %rsp,%rbp 1: mov %rsp,%rbp 4: sub $0x60,%rsp 4: sub $0x228,%rsp 8: mov %rbx,-0x8(%rbp) b: mov %rbx,-0x228(%rbp) // prologue 12: mov %r13,-0x220(%rbp) 19: mov %r14,-0x218(%rbp) 20: mov %r15,-0x210(%rbp) 27: xor %eax,%eax // clear A c: xor %ebx,%ebx 29: xor %r13,%r13 // clear X e: mov 0x68(%rdi),%r9d 2c: mov 0x68(%rdi),%r9d 12: sub 0x6c(%rdi),%r9d 30: sub 0x6c(%rdi),%r9d 16: mov 0xd8(%rdi),%r8 34: mov 0xd8(%rdi),%r10 3b: mov %rdi,%rbx 1d: mov $0xc,%esi 3e: mov $0xc,%esi 22: callq 0xffffffffe1021e15 43: callq 0xffffffffe102bd75 27: cmp $0x86dd,%eax 48: cmp $0x86dd,%rax 2c: jne 0x0000000000000069 4f: jne 0x000000000000009a 2e: mov $0x14,%esi 51: mov $0x14,%esi 33: callq 0xffffffffe1021e31 56: callq 0xffffffffe102bd91 38: cmp $0x84,%eax 5b: cmp $0x84,%rax 3d: je 0x0000000000000049 62: je 0x0000000000000074 3f: cmp $0x6,%eax 64: cmp $0x6,%rax 42: je 0x0000000000000049 68: je 0x0000000000000074 44: cmp $0x11,%eax 6a: cmp $0x11,%rax 47: jne 0x00000000000000c6 6e: jne 0x0000000000000117 49: mov $0x36,%esi 74: mov $0x36,%esi 4e: callq 0xffffffffe1021e15 79: callq 0xffffffffe102bd75 53: cmp $0x16,%eax 7e: cmp $0x16,%rax 56: je 0x00000000000000bf 82: je 0x0000000000000110 58: mov $0x38,%esi 88: mov $0x38,%esi 5d: callq 0xffffffffe1021e15 8d: callq 0xffffffffe102bd75 62: cmp $0x16,%eax 92: cmp $0x16,%rax 65: je 0x00000000000000bf 96: je 0x0000000000000110 67: jmp 0x00000000000000c6 98: jmp 0x0000000000000117 69: cmp $0x800,%eax 9a: cmp $0x800,%rax 6e: jne 0x00000000000000c6 a1: jne 0x0000000000000117 70: mov $0x17,%esi a3: mov $0x17,%esi 75: callq 0xffffffffe1021e31 a8: callq 0xffffffffe102bd91 7a: cmp $0x84,%eax ad: cmp $0x84,%rax 7f: je 0x000000000000008b b4: je 0x00000000000000c2 81: cmp $0x6,%eax b6: cmp $0x6,%rax 84: je 0x000000000000008b ba: je 0x00000000000000c2 86: cmp $0x11,%eax bc: cmp $0x11,%rax 89: jne 0x00000000000000c6 c0: jne 0x0000000000000117 8b: mov $0x14,%esi c2: mov $0x14,%esi 90: callq 0xffffffffe1021e15 c7: callq 0xffffffffe102bd75 95: test $0x1fff,%ax cc: test $0x1fff,%rax 99: jne 0x00000000000000c6 d3: jne 0x0000000000000117 d5: mov %rax,%r14 9b: mov $0xe,%esi d8: mov $0xe,%esi a0: callq 0xffffffffe1021e44 dd: callq 0xffffffffe102bd91 // MSH e2: and $0xf,%eax e5: shl $0x2,%eax e8: mov %rax,%r13 eb: mov %r14,%rax ee: mov %r13,%rsi a5: lea 0xe(%rbx),%esi f1: add $0xe,%esi a8: callq 0xffffffffe1021e0d f4: callq 0xffffffffe102bd6d ad: cmp $0x16,%eax f9: cmp $0x16,%rax b0: je 0x00000000000000bf fd: je 0x0000000000000110 ff: mov %r13,%rsi b2: lea 0x10(%rbx),%esi 102: add $0x10,%esi b5: callq 0xffffffffe1021e0d 105: callq 0xffffffffe102bd6d ba: cmp $0x16,%eax 10a: cmp $0x16,%rax bd: jne 0x00000000000000c6 10e: jne 0x0000000000000117 bf: mov $0xffff,%eax 110: mov $0xffff,%eax c4: jmp 0x00000000000000c8 115: jmp 0x000000000000011c c6: xor %eax,%eax 117: mov $0x0,%eax c8: mov -0x8(%rbp),%rbx 11c: mov -0x228(%rbp),%rbx // epilogue cc: leaveq 123: mov -0x220(%rbp),%r13 cd: retq 12a: mov -0x218(%rbp),%r14 131: mov -0x210(%rbp),%r15 138: leaveq 139: retq On fully cached SKBs both JITed functions take 12 nsec to execute. BPF interpreter executes the program in 30 nsec. The difference in generated assembler is due to the following: Old BPF imlements LDX_MSH instruction via sk_load_byte_msh() helper function inside bpf_jit.S. New JIT removes the helper and does it explicitly, so ldx_msh cost is the same for both JITs, but generated code looks longer. New JIT has 4 registers to save, so prologue/epilogue are larger, but the cost is within noise on x64. Old JIT checks whether first insn clears A and if not emits 'xor %eax,%eax'. New JIT clears %rax unconditionally. 2. old BPF JIT doesn't support ANC_NLATTR, ANC_PAY_OFFSET, ANC_RANDOM extensions. New JIT supports all BPF extensions. Performance of such filters improves 2-4 times depending on a filter. The longer the filter the higher performance gain. Synthetic benchmarks with many ancillary loads see 20x speedup which seems to be the maximum gain from JIT Notes: . net.core.bpf_jit_enable=2 + tools/net/bpf_jit_disasm is still functional and can be used to see generated assembler . there are two jit_compile() functions and code flow for classic filters is: sk_attach_filter() - load classic BPF bpf_jit_compile() - try to JIT from classic BPF sk_convert_filter() - convert classic to internal bpf_int_jit_compile() - JIT from internal BPF seccomp and tracing filters will just call bpf_int_jit_compile() Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 20:50:46 -06:00
emit_cond_jmp: /* convert BPF opcode to x86 */
switch (BPF_OP(insn->code)) {
case BPF_JEQ:
jmp_cond = X86_JE;
break;
case BPF_JSET:
case BPF_JNE:
jmp_cond = X86_JNE;
break;
case BPF_JGT:
/* GT is unsigned '>', JA in x86 */
jmp_cond = X86_JA;
break;
case BPF_JGE:
/* GE is unsigned '>=', JAE in x86 */
jmp_cond = X86_JAE;
break;
case BPF_JSGT:
/* signed '>', GT in x86 */
jmp_cond = X86_JG;
break;
case BPF_JSGE:
/* signed '>=', GE in x86 */
jmp_cond = X86_JGE;
break;
default: /* to silence gcc warning */
return -EFAULT;
}
jmp_offset = addrs[i + insn->off] - addrs[i];
if (is_imm8(jmp_offset)) {
EMIT2(jmp_cond, jmp_offset);
} else if (is_simm32(jmp_offset)) {
EMIT2_off32(0x0F, jmp_cond + 0x10, jmp_offset);
} else {
pr_err("cond_jmp gen bug %llx\n", jmp_offset);
return -EFAULT;
}
break;
net: filter: Just In Time compiler for x86-64 In order to speedup packet filtering, here is an implementation of a JIT compiler for x86_64 It is disabled by default, and must be enabled by the admin. echo 1 >/proc/sys/net/core/bpf_jit_enable It uses module_alloc() and module_free() to get memory in the 2GB text kernel range since we call helpers functions from the generated code. EAX : BPF A accumulator EBX : BPF X accumulator RDI : pointer to skb (first argument given to JIT function) RBP : frame pointer (even if CONFIG_FRAME_POINTER=n) r9d : skb->len - skb->data_len (headlen) r8 : skb->data To get a trace of generated code, use : echo 2 >/proc/sys/net/core/bpf_jit_enable Example of generated code : # tcpdump -p -n -s 0 -i eth1 host 192.168.20.0/24 flen=18 proglen=147 pass=3 image=ffffffffa00b5000 JIT code: ffffffffa00b5000: 55 48 89 e5 48 83 ec 60 48 89 5d f8 44 8b 4f 60 JIT code: ffffffffa00b5010: 44 2b 4f 64 4c 8b 87 b8 00 00 00 be 0c 00 00 00 JIT code: ffffffffa00b5020: e8 24 7b f7 e0 3d 00 08 00 00 75 28 be 1a 00 00 JIT code: ffffffffa00b5030: 00 e8 fe 7a f7 e0 24 00 3d 00 14 a8 c0 74 49 be JIT code: ffffffffa00b5040: 1e 00 00 00 e8 eb 7a f7 e0 24 00 3d 00 14 a8 c0 JIT code: ffffffffa00b5050: 74 36 eb 3b 3d 06 08 00 00 74 07 3d 35 80 00 00 JIT code: ffffffffa00b5060: 75 2d be 1c 00 00 00 e8 c8 7a f7 e0 24 00 3d 00 JIT code: ffffffffa00b5070: 14 a8 c0 74 13 be 26 00 00 00 e8 b5 7a f7 e0 24 JIT code: ffffffffa00b5080: 00 3d 00 14 a8 c0 75 07 b8 ff ff 00 00 eb 02 31 JIT code: ffffffffa00b5090: c0 c9 c3 BPF program is 144 bytes long, so native program is almost same size ;) (000) ldh [12] (001) jeq #0x800 jt 2 jf 8 (002) ld [26] (003) and #0xffffff00 (004) jeq #0xc0a81400 jt 16 jf 5 (005) ld [30] (006) and #0xffffff00 (007) jeq #0xc0a81400 jt 16 jf 17 (008) jeq #0x806 jt 10 jf 9 (009) jeq #0x8035 jt 10 jf 17 (010) ld [28] (011) and #0xffffff00 (012) jeq #0xc0a81400 jt 16 jf 13 (013) ld [38] (014) and #0xffffff00 (015) jeq #0xc0a81400 jt 16 jf 17 (016) ret #65535 (017) ret #0 Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Cc: Arnaldo Carvalho de Melo <acme@infradead.org> Cc: Ben Hutchings <bhutchings@solarflare.com> Cc: Hagen Paul Pfeifer <hagen@jauu.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-04-20 03:27:32 -06:00
net: filter: x86: internal BPF JIT Maps all internal BPF instructions into x86_64 instructions. This patch replaces original BPF x64 JIT with internal BPF x64 JIT. sysctl net.core.bpf_jit_enable is reused as on/off switch. Performance: 1. old BPF JIT and internal BPF JIT generate equivalent x86_64 code. No performance difference is observed for filters that were JIT-able before Example assembler code for BPF filter "tcpdump port 22" original BPF -> old JIT: original BPF -> internal BPF -> new JIT: 0: push %rbp 0: push %rbp 1: mov %rsp,%rbp 1: mov %rsp,%rbp 4: sub $0x60,%rsp 4: sub $0x228,%rsp 8: mov %rbx,-0x8(%rbp) b: mov %rbx,-0x228(%rbp) // prologue 12: mov %r13,-0x220(%rbp) 19: mov %r14,-0x218(%rbp) 20: mov %r15,-0x210(%rbp) 27: xor %eax,%eax // clear A c: xor %ebx,%ebx 29: xor %r13,%r13 // clear X e: mov 0x68(%rdi),%r9d 2c: mov 0x68(%rdi),%r9d 12: sub 0x6c(%rdi),%r9d 30: sub 0x6c(%rdi),%r9d 16: mov 0xd8(%rdi),%r8 34: mov 0xd8(%rdi),%r10 3b: mov %rdi,%rbx 1d: mov $0xc,%esi 3e: mov $0xc,%esi 22: callq 0xffffffffe1021e15 43: callq 0xffffffffe102bd75 27: cmp $0x86dd,%eax 48: cmp $0x86dd,%rax 2c: jne 0x0000000000000069 4f: jne 0x000000000000009a 2e: mov $0x14,%esi 51: mov $0x14,%esi 33: callq 0xffffffffe1021e31 56: callq 0xffffffffe102bd91 38: cmp $0x84,%eax 5b: cmp $0x84,%rax 3d: je 0x0000000000000049 62: je 0x0000000000000074 3f: cmp $0x6,%eax 64: cmp $0x6,%rax 42: je 0x0000000000000049 68: je 0x0000000000000074 44: cmp $0x11,%eax 6a: cmp $0x11,%rax 47: jne 0x00000000000000c6 6e: jne 0x0000000000000117 49: mov $0x36,%esi 74: mov $0x36,%esi 4e: callq 0xffffffffe1021e15 79: callq 0xffffffffe102bd75 53: cmp $0x16,%eax 7e: cmp $0x16,%rax 56: je 0x00000000000000bf 82: je 0x0000000000000110 58: mov $0x38,%esi 88: mov $0x38,%esi 5d: callq 0xffffffffe1021e15 8d: callq 0xffffffffe102bd75 62: cmp $0x16,%eax 92: cmp $0x16,%rax 65: je 0x00000000000000bf 96: je 0x0000000000000110 67: jmp 0x00000000000000c6 98: jmp 0x0000000000000117 69: cmp $0x800,%eax 9a: cmp $0x800,%rax 6e: jne 0x00000000000000c6 a1: jne 0x0000000000000117 70: mov $0x17,%esi a3: mov $0x17,%esi 75: callq 0xffffffffe1021e31 a8: callq 0xffffffffe102bd91 7a: cmp $0x84,%eax ad: cmp $0x84,%rax 7f: je 0x000000000000008b b4: je 0x00000000000000c2 81: cmp $0x6,%eax b6: cmp $0x6,%rax 84: je 0x000000000000008b ba: je 0x00000000000000c2 86: cmp $0x11,%eax bc: cmp $0x11,%rax 89: jne 0x00000000000000c6 c0: jne 0x0000000000000117 8b: mov $0x14,%esi c2: mov $0x14,%esi 90: callq 0xffffffffe1021e15 c7: callq 0xffffffffe102bd75 95: test $0x1fff,%ax cc: test $0x1fff,%rax 99: jne 0x00000000000000c6 d3: jne 0x0000000000000117 d5: mov %rax,%r14 9b: mov $0xe,%esi d8: mov $0xe,%esi a0: callq 0xffffffffe1021e44 dd: callq 0xffffffffe102bd91 // MSH e2: and $0xf,%eax e5: shl $0x2,%eax e8: mov %rax,%r13 eb: mov %r14,%rax ee: mov %r13,%rsi a5: lea 0xe(%rbx),%esi f1: add $0xe,%esi a8: callq 0xffffffffe1021e0d f4: callq 0xffffffffe102bd6d ad: cmp $0x16,%eax f9: cmp $0x16,%rax b0: je 0x00000000000000bf fd: je 0x0000000000000110 ff: mov %r13,%rsi b2: lea 0x10(%rbx),%esi 102: add $0x10,%esi b5: callq 0xffffffffe1021e0d 105: callq 0xffffffffe102bd6d ba: cmp $0x16,%eax 10a: cmp $0x16,%rax bd: jne 0x00000000000000c6 10e: jne 0x0000000000000117 bf: mov $0xffff,%eax 110: mov $0xffff,%eax c4: jmp 0x00000000000000c8 115: jmp 0x000000000000011c c6: xor %eax,%eax 117: mov $0x0,%eax c8: mov -0x8(%rbp),%rbx 11c: mov -0x228(%rbp),%rbx // epilogue cc: leaveq 123: mov -0x220(%rbp),%r13 cd: retq 12a: mov -0x218(%rbp),%r14 131: mov -0x210(%rbp),%r15 138: leaveq 139: retq On fully cached SKBs both JITed functions take 12 nsec to execute. BPF interpreter executes the program in 30 nsec. The difference in generated assembler is due to the following: Old BPF imlements LDX_MSH instruction via sk_load_byte_msh() helper function inside bpf_jit.S. New JIT removes the helper and does it explicitly, so ldx_msh cost is the same for both JITs, but generated code looks longer. New JIT has 4 registers to save, so prologue/epilogue are larger, but the cost is within noise on x64. Old JIT checks whether first insn clears A and if not emits 'xor %eax,%eax'. New JIT clears %rax unconditionally. 2. old BPF JIT doesn't support ANC_NLATTR, ANC_PAY_OFFSET, ANC_RANDOM extensions. New JIT supports all BPF extensions. Performance of such filters improves 2-4 times depending on a filter. The longer the filter the higher performance gain. Synthetic benchmarks with many ancillary loads see 20x speedup which seems to be the maximum gain from JIT Notes: . net.core.bpf_jit_enable=2 + tools/net/bpf_jit_disasm is still functional and can be used to see generated assembler . there are two jit_compile() functions and code flow for classic filters is: sk_attach_filter() - load classic BPF bpf_jit_compile() - try to JIT from classic BPF sk_convert_filter() - convert classic to internal bpf_int_jit_compile() - JIT from internal BPF seccomp and tracing filters will just call bpf_int_jit_compile() Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 20:50:46 -06:00
case BPF_JMP | BPF_JA:
jmp_offset = addrs[i + insn->off] - addrs[i];
if (!jmp_offset)
/* optimize out nop jumps */
break;
emit_jmp:
if (is_imm8(jmp_offset)) {
EMIT2(0xEB, jmp_offset);
} else if (is_simm32(jmp_offset)) {
EMIT1_off32(0xE9, jmp_offset);
} else {
pr_err("jmp gen bug %llx\n", jmp_offset);
return -EFAULT;
}
break;
case BPF_LD | BPF_IND | BPF_W:
func = sk_load_word;
goto common_load;
case BPF_LD | BPF_ABS | BPF_W:
net: filter: cleanup A/X name usage The macro 'A' used in internal BPF interpreter: #define A regs[insn->a_reg] was easily confused with the name of classic BPF register 'A', since 'A' would mean two different things depending on context. This patch is trying to clean up the naming and clarify its usage in the following way: - A and X are names of two classic BPF registers - BPF_REG_A denotes internal BPF register R0 used to map classic register A in internal BPF programs generated from classic - BPF_REG_X denotes internal BPF register R7 used to map classic register X in internal BPF programs generated from classic - internal BPF instruction format: struct sock_filter_int { __u8 code; /* opcode */ __u8 dst_reg:4; /* dest register */ __u8 src_reg:4; /* source register */ __s16 off; /* signed offset */ __s32 imm; /* signed immediate constant */ }; - BPF_X/BPF_K is 1 bit used to encode source operand of instruction In classic: BPF_X - means use register X as source operand BPF_K - means use 32-bit immediate as source operand In internal: BPF_X - means use 'src_reg' register as source operand BPF_K - means use 32-bit immediate as source operand Suggested-by: Chema Gonzalez <chema@google.com> Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Acked-by: Daniel Borkmann <dborkman@redhat.com> Acked-by: Chema Gonzalez <chema@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-06-06 15:46:06 -06:00
func = CHOOSE_LOAD_FUNC(imm32, sk_load_word);
x86: bpf_jit: fix two bugs in eBPF JIT compiler 1. JIT compiler using multi-pass approach to converge to final image size, since x86 instructions are variable length. It starts with large gaps between instructions (so some jumps may use imm32 instead of imm8) and iterates until total program size is the same as in previous pass. This algorithm works only if program size is strictly decreasing. Programs that use LD_ABS insn need additional code in prologue, but it was not emitted during 1st pass, so there was a chance that 2nd pass would adjust imm32->imm8 jump offsets to the same number of bytes as increase in prologue, which may cause algorithm to erroneously decide that size converged. Fix it by always emitting largest prologue in the first pass which is detected by oldproglen==0 check. Also change error check condition 'proglen != oldproglen' to fail gracefully. 2. while staring at the code realized that 64-byte buffer may not be enough when 1st insn is large, so increase it to 128 to avoid buffer overflow (theoretical maximum size of prologue+div is 109) and add runtime check. Fixes: 622582786c9e ("net: filter: x86: internal BPF JIT") Reported-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Tested-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-10-10 21:30:23 -06:00
common_load:
ctx->seen_ld_abs = seen_ld_abs = true;
net: filter: x86: internal BPF JIT Maps all internal BPF instructions into x86_64 instructions. This patch replaces original BPF x64 JIT with internal BPF x64 JIT. sysctl net.core.bpf_jit_enable is reused as on/off switch. Performance: 1. old BPF JIT and internal BPF JIT generate equivalent x86_64 code. No performance difference is observed for filters that were JIT-able before Example assembler code for BPF filter "tcpdump port 22" original BPF -> old JIT: original BPF -> internal BPF -> new JIT: 0: push %rbp 0: push %rbp 1: mov %rsp,%rbp 1: mov %rsp,%rbp 4: sub $0x60,%rsp 4: sub $0x228,%rsp 8: mov %rbx,-0x8(%rbp) b: mov %rbx,-0x228(%rbp) // prologue 12: mov %r13,-0x220(%rbp) 19: mov %r14,-0x218(%rbp) 20: mov %r15,-0x210(%rbp) 27: xor %eax,%eax // clear A c: xor %ebx,%ebx 29: xor %r13,%r13 // clear X e: mov 0x68(%rdi),%r9d 2c: mov 0x68(%rdi),%r9d 12: sub 0x6c(%rdi),%r9d 30: sub 0x6c(%rdi),%r9d 16: mov 0xd8(%rdi),%r8 34: mov 0xd8(%rdi),%r10 3b: mov %rdi,%rbx 1d: mov $0xc,%esi 3e: mov $0xc,%esi 22: callq 0xffffffffe1021e15 43: callq 0xffffffffe102bd75 27: cmp $0x86dd,%eax 48: cmp $0x86dd,%rax 2c: jne 0x0000000000000069 4f: jne 0x000000000000009a 2e: mov $0x14,%esi 51: mov $0x14,%esi 33: callq 0xffffffffe1021e31 56: callq 0xffffffffe102bd91 38: cmp $0x84,%eax 5b: cmp $0x84,%rax 3d: je 0x0000000000000049 62: je 0x0000000000000074 3f: cmp $0x6,%eax 64: cmp $0x6,%rax 42: je 0x0000000000000049 68: je 0x0000000000000074 44: cmp $0x11,%eax 6a: cmp $0x11,%rax 47: jne 0x00000000000000c6 6e: jne 0x0000000000000117 49: mov $0x36,%esi 74: mov $0x36,%esi 4e: callq 0xffffffffe1021e15 79: callq 0xffffffffe102bd75 53: cmp $0x16,%eax 7e: cmp $0x16,%rax 56: je 0x00000000000000bf 82: je 0x0000000000000110 58: mov $0x38,%esi 88: mov $0x38,%esi 5d: callq 0xffffffffe1021e15 8d: callq 0xffffffffe102bd75 62: cmp $0x16,%eax 92: cmp $0x16,%rax 65: je 0x00000000000000bf 96: je 0x0000000000000110 67: jmp 0x00000000000000c6 98: jmp 0x0000000000000117 69: cmp $0x800,%eax 9a: cmp $0x800,%rax 6e: jne 0x00000000000000c6 a1: jne 0x0000000000000117 70: mov $0x17,%esi a3: mov $0x17,%esi 75: callq 0xffffffffe1021e31 a8: callq 0xffffffffe102bd91 7a: cmp $0x84,%eax ad: cmp $0x84,%rax 7f: je 0x000000000000008b b4: je 0x00000000000000c2 81: cmp $0x6,%eax b6: cmp $0x6,%rax 84: je 0x000000000000008b ba: je 0x00000000000000c2 86: cmp $0x11,%eax bc: cmp $0x11,%rax 89: jne 0x00000000000000c6 c0: jne 0x0000000000000117 8b: mov $0x14,%esi c2: mov $0x14,%esi 90: callq 0xffffffffe1021e15 c7: callq 0xffffffffe102bd75 95: test $0x1fff,%ax cc: test $0x1fff,%rax 99: jne 0x00000000000000c6 d3: jne 0x0000000000000117 d5: mov %rax,%r14 9b: mov $0xe,%esi d8: mov $0xe,%esi a0: callq 0xffffffffe1021e44 dd: callq 0xffffffffe102bd91 // MSH e2: and $0xf,%eax e5: shl $0x2,%eax e8: mov %rax,%r13 eb: mov %r14,%rax ee: mov %r13,%rsi a5: lea 0xe(%rbx),%esi f1: add $0xe,%esi a8: callq 0xffffffffe1021e0d f4: callq 0xffffffffe102bd6d ad: cmp $0x16,%eax f9: cmp $0x16,%rax b0: je 0x00000000000000bf fd: je 0x0000000000000110 ff: mov %r13,%rsi b2: lea 0x10(%rbx),%esi 102: add $0x10,%esi b5: callq 0xffffffffe1021e0d 105: callq 0xffffffffe102bd6d ba: cmp $0x16,%eax 10a: cmp $0x16,%rax bd: jne 0x00000000000000c6 10e: jne 0x0000000000000117 bf: mov $0xffff,%eax 110: mov $0xffff,%eax c4: jmp 0x00000000000000c8 115: jmp 0x000000000000011c c6: xor %eax,%eax 117: mov $0x0,%eax c8: mov -0x8(%rbp),%rbx 11c: mov -0x228(%rbp),%rbx // epilogue cc: leaveq 123: mov -0x220(%rbp),%r13 cd: retq 12a: mov -0x218(%rbp),%r14 131: mov -0x210(%rbp),%r15 138: leaveq 139: retq On fully cached SKBs both JITed functions take 12 nsec to execute. BPF interpreter executes the program in 30 nsec. The difference in generated assembler is due to the following: Old BPF imlements LDX_MSH instruction via sk_load_byte_msh() helper function inside bpf_jit.S. New JIT removes the helper and does it explicitly, so ldx_msh cost is the same for both JITs, but generated code looks longer. New JIT has 4 registers to save, so prologue/epilogue are larger, but the cost is within noise on x64. Old JIT checks whether first insn clears A and if not emits 'xor %eax,%eax'. New JIT clears %rax unconditionally. 2. old BPF JIT doesn't support ANC_NLATTR, ANC_PAY_OFFSET, ANC_RANDOM extensions. New JIT supports all BPF extensions. Performance of such filters improves 2-4 times depending on a filter. The longer the filter the higher performance gain. Synthetic benchmarks with many ancillary loads see 20x speedup which seems to be the maximum gain from JIT Notes: . net.core.bpf_jit_enable=2 + tools/net/bpf_jit_disasm is still functional and can be used to see generated assembler . there are two jit_compile() functions and code flow for classic filters is: sk_attach_filter() - load classic BPF bpf_jit_compile() - try to JIT from classic BPF sk_convert_filter() - convert classic to internal bpf_int_jit_compile() - JIT from internal BPF seccomp and tracing filters will just call bpf_int_jit_compile() Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 20:50:46 -06:00
jmp_offset = func - (image + addrs[i]);
if (!func || !is_simm32(jmp_offset)) {
pr_err("unsupported bpf func %d addr %p image %p\n",
net: filter: cleanup A/X name usage The macro 'A' used in internal BPF interpreter: #define A regs[insn->a_reg] was easily confused with the name of classic BPF register 'A', since 'A' would mean two different things depending on context. This patch is trying to clean up the naming and clarify its usage in the following way: - A and X are names of two classic BPF registers - BPF_REG_A denotes internal BPF register R0 used to map classic register A in internal BPF programs generated from classic - BPF_REG_X denotes internal BPF register R7 used to map classic register X in internal BPF programs generated from classic - internal BPF instruction format: struct sock_filter_int { __u8 code; /* opcode */ __u8 dst_reg:4; /* dest register */ __u8 src_reg:4; /* source register */ __s16 off; /* signed offset */ __s32 imm; /* signed immediate constant */ }; - BPF_X/BPF_K is 1 bit used to encode source operand of instruction In classic: BPF_X - means use register X as source operand BPF_K - means use 32-bit immediate as source operand In internal: BPF_X - means use 'src_reg' register as source operand BPF_K - means use 32-bit immediate as source operand Suggested-by: Chema Gonzalez <chema@google.com> Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Acked-by: Daniel Borkmann <dborkman@redhat.com> Acked-by: Chema Gonzalez <chema@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-06-06 15:46:06 -06:00
imm32, func, image);
net: filter: x86: internal BPF JIT Maps all internal BPF instructions into x86_64 instructions. This patch replaces original BPF x64 JIT with internal BPF x64 JIT. sysctl net.core.bpf_jit_enable is reused as on/off switch. Performance: 1. old BPF JIT and internal BPF JIT generate equivalent x86_64 code. No performance difference is observed for filters that were JIT-able before Example assembler code for BPF filter "tcpdump port 22" original BPF -> old JIT: original BPF -> internal BPF -> new JIT: 0: push %rbp 0: push %rbp 1: mov %rsp,%rbp 1: mov %rsp,%rbp 4: sub $0x60,%rsp 4: sub $0x228,%rsp 8: mov %rbx,-0x8(%rbp) b: mov %rbx,-0x228(%rbp) // prologue 12: mov %r13,-0x220(%rbp) 19: mov %r14,-0x218(%rbp) 20: mov %r15,-0x210(%rbp) 27: xor %eax,%eax // clear A c: xor %ebx,%ebx 29: xor %r13,%r13 // clear X e: mov 0x68(%rdi),%r9d 2c: mov 0x68(%rdi),%r9d 12: sub 0x6c(%rdi),%r9d 30: sub 0x6c(%rdi),%r9d 16: mov 0xd8(%rdi),%r8 34: mov 0xd8(%rdi),%r10 3b: mov %rdi,%rbx 1d: mov $0xc,%esi 3e: mov $0xc,%esi 22: callq 0xffffffffe1021e15 43: callq 0xffffffffe102bd75 27: cmp $0x86dd,%eax 48: cmp $0x86dd,%rax 2c: jne 0x0000000000000069 4f: jne 0x000000000000009a 2e: mov $0x14,%esi 51: mov $0x14,%esi 33: callq 0xffffffffe1021e31 56: callq 0xffffffffe102bd91 38: cmp $0x84,%eax 5b: cmp $0x84,%rax 3d: je 0x0000000000000049 62: je 0x0000000000000074 3f: cmp $0x6,%eax 64: cmp $0x6,%rax 42: je 0x0000000000000049 68: je 0x0000000000000074 44: cmp $0x11,%eax 6a: cmp $0x11,%rax 47: jne 0x00000000000000c6 6e: jne 0x0000000000000117 49: mov $0x36,%esi 74: mov $0x36,%esi 4e: callq 0xffffffffe1021e15 79: callq 0xffffffffe102bd75 53: cmp $0x16,%eax 7e: cmp $0x16,%rax 56: je 0x00000000000000bf 82: je 0x0000000000000110 58: mov $0x38,%esi 88: mov $0x38,%esi 5d: callq 0xffffffffe1021e15 8d: callq 0xffffffffe102bd75 62: cmp $0x16,%eax 92: cmp $0x16,%rax 65: je 0x00000000000000bf 96: je 0x0000000000000110 67: jmp 0x00000000000000c6 98: jmp 0x0000000000000117 69: cmp $0x800,%eax 9a: cmp $0x800,%rax 6e: jne 0x00000000000000c6 a1: jne 0x0000000000000117 70: mov $0x17,%esi a3: mov $0x17,%esi 75: callq 0xffffffffe1021e31 a8: callq 0xffffffffe102bd91 7a: cmp $0x84,%eax ad: cmp $0x84,%rax 7f: je 0x000000000000008b b4: je 0x00000000000000c2 81: cmp $0x6,%eax b6: cmp $0x6,%rax 84: je 0x000000000000008b ba: je 0x00000000000000c2 86: cmp $0x11,%eax bc: cmp $0x11,%rax 89: jne 0x00000000000000c6 c0: jne 0x0000000000000117 8b: mov $0x14,%esi c2: mov $0x14,%esi 90: callq 0xffffffffe1021e15 c7: callq 0xffffffffe102bd75 95: test $0x1fff,%ax cc: test $0x1fff,%rax 99: jne 0x00000000000000c6 d3: jne 0x0000000000000117 d5: mov %rax,%r14 9b: mov $0xe,%esi d8: mov $0xe,%esi a0: callq 0xffffffffe1021e44 dd: callq 0xffffffffe102bd91 // MSH e2: and $0xf,%eax e5: shl $0x2,%eax e8: mov %rax,%r13 eb: mov %r14,%rax ee: mov %r13,%rsi a5: lea 0xe(%rbx),%esi f1: add $0xe,%esi a8: callq 0xffffffffe1021e0d f4: callq 0xffffffffe102bd6d ad: cmp $0x16,%eax f9: cmp $0x16,%rax b0: je 0x00000000000000bf fd: je 0x0000000000000110 ff: mov %r13,%rsi b2: lea 0x10(%rbx),%esi 102: add $0x10,%esi b5: callq 0xffffffffe1021e0d 105: callq 0xffffffffe102bd6d ba: cmp $0x16,%eax 10a: cmp $0x16,%rax bd: jne 0x00000000000000c6 10e: jne 0x0000000000000117 bf: mov $0xffff,%eax 110: mov $0xffff,%eax c4: jmp 0x00000000000000c8 115: jmp 0x000000000000011c c6: xor %eax,%eax 117: mov $0x0,%eax c8: mov -0x8(%rbp),%rbx 11c: mov -0x228(%rbp),%rbx // epilogue cc: leaveq 123: mov -0x220(%rbp),%r13 cd: retq 12a: mov -0x218(%rbp),%r14 131: mov -0x210(%rbp),%r15 138: leaveq 139: retq On fully cached SKBs both JITed functions take 12 nsec to execute. BPF interpreter executes the program in 30 nsec. The difference in generated assembler is due to the following: Old BPF imlements LDX_MSH instruction via sk_load_byte_msh() helper function inside bpf_jit.S. New JIT removes the helper and does it explicitly, so ldx_msh cost is the same for both JITs, but generated code looks longer. New JIT has 4 registers to save, so prologue/epilogue are larger, but the cost is within noise on x64. Old JIT checks whether first insn clears A and if not emits 'xor %eax,%eax'. New JIT clears %rax unconditionally. 2. old BPF JIT doesn't support ANC_NLATTR, ANC_PAY_OFFSET, ANC_RANDOM extensions. New JIT supports all BPF extensions. Performance of such filters improves 2-4 times depending on a filter. The longer the filter the higher performance gain. Synthetic benchmarks with many ancillary loads see 20x speedup which seems to be the maximum gain from JIT Notes: . net.core.bpf_jit_enable=2 + tools/net/bpf_jit_disasm is still functional and can be used to see generated assembler . there are two jit_compile() functions and code flow for classic filters is: sk_attach_filter() - load classic BPF bpf_jit_compile() - try to JIT from classic BPF sk_convert_filter() - convert classic to internal bpf_int_jit_compile() - JIT from internal BPF seccomp and tracing filters will just call bpf_int_jit_compile() Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 20:50:46 -06:00
return -EINVAL;
}
if (BPF_MODE(insn->code) == BPF_ABS) {
/* mov %esi, imm32 */
net: filter: cleanup A/X name usage The macro 'A' used in internal BPF interpreter: #define A regs[insn->a_reg] was easily confused with the name of classic BPF register 'A', since 'A' would mean two different things depending on context. This patch is trying to clean up the naming and clarify its usage in the following way: - A and X are names of two classic BPF registers - BPF_REG_A denotes internal BPF register R0 used to map classic register A in internal BPF programs generated from classic - BPF_REG_X denotes internal BPF register R7 used to map classic register X in internal BPF programs generated from classic - internal BPF instruction format: struct sock_filter_int { __u8 code; /* opcode */ __u8 dst_reg:4; /* dest register */ __u8 src_reg:4; /* source register */ __s16 off; /* signed offset */ __s32 imm; /* signed immediate constant */ }; - BPF_X/BPF_K is 1 bit used to encode source operand of instruction In classic: BPF_X - means use register X as source operand BPF_K - means use 32-bit immediate as source operand In internal: BPF_X - means use 'src_reg' register as source operand BPF_K - means use 32-bit immediate as source operand Suggested-by: Chema Gonzalez <chema@google.com> Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Acked-by: Daniel Borkmann <dborkman@redhat.com> Acked-by: Chema Gonzalez <chema@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-06-06 15:46:06 -06:00
EMIT1_off32(0xBE, imm32);
net: filter: x86: internal BPF JIT Maps all internal BPF instructions into x86_64 instructions. This patch replaces original BPF x64 JIT with internal BPF x64 JIT. sysctl net.core.bpf_jit_enable is reused as on/off switch. Performance: 1. old BPF JIT and internal BPF JIT generate equivalent x86_64 code. No performance difference is observed for filters that were JIT-able before Example assembler code for BPF filter "tcpdump port 22" original BPF -> old JIT: original BPF -> internal BPF -> new JIT: 0: push %rbp 0: push %rbp 1: mov %rsp,%rbp 1: mov %rsp,%rbp 4: sub $0x60,%rsp 4: sub $0x228,%rsp 8: mov %rbx,-0x8(%rbp) b: mov %rbx,-0x228(%rbp) // prologue 12: mov %r13,-0x220(%rbp) 19: mov %r14,-0x218(%rbp) 20: mov %r15,-0x210(%rbp) 27: xor %eax,%eax // clear A c: xor %ebx,%ebx 29: xor %r13,%r13 // clear X e: mov 0x68(%rdi),%r9d 2c: mov 0x68(%rdi),%r9d 12: sub 0x6c(%rdi),%r9d 30: sub 0x6c(%rdi),%r9d 16: mov 0xd8(%rdi),%r8 34: mov 0xd8(%rdi),%r10 3b: mov %rdi,%rbx 1d: mov $0xc,%esi 3e: mov $0xc,%esi 22: callq 0xffffffffe1021e15 43: callq 0xffffffffe102bd75 27: cmp $0x86dd,%eax 48: cmp $0x86dd,%rax 2c: jne 0x0000000000000069 4f: jne 0x000000000000009a 2e: mov $0x14,%esi 51: mov $0x14,%esi 33: callq 0xffffffffe1021e31 56: callq 0xffffffffe102bd91 38: cmp $0x84,%eax 5b: cmp $0x84,%rax 3d: je 0x0000000000000049 62: je 0x0000000000000074 3f: cmp $0x6,%eax 64: cmp $0x6,%rax 42: je 0x0000000000000049 68: je 0x0000000000000074 44: cmp $0x11,%eax 6a: cmp $0x11,%rax 47: jne 0x00000000000000c6 6e: jne 0x0000000000000117 49: mov $0x36,%esi 74: mov $0x36,%esi 4e: callq 0xffffffffe1021e15 79: callq 0xffffffffe102bd75 53: cmp $0x16,%eax 7e: cmp $0x16,%rax 56: je 0x00000000000000bf 82: je 0x0000000000000110 58: mov $0x38,%esi 88: mov $0x38,%esi 5d: callq 0xffffffffe1021e15 8d: callq 0xffffffffe102bd75 62: cmp $0x16,%eax 92: cmp $0x16,%rax 65: je 0x00000000000000bf 96: je 0x0000000000000110 67: jmp 0x00000000000000c6 98: jmp 0x0000000000000117 69: cmp $0x800,%eax 9a: cmp $0x800,%rax 6e: jne 0x00000000000000c6 a1: jne 0x0000000000000117 70: mov $0x17,%esi a3: mov $0x17,%esi 75: callq 0xffffffffe1021e31 a8: callq 0xffffffffe102bd91 7a: cmp $0x84,%eax ad: cmp $0x84,%rax 7f: je 0x000000000000008b b4: je 0x00000000000000c2 81: cmp $0x6,%eax b6: cmp $0x6,%rax 84: je 0x000000000000008b ba: je 0x00000000000000c2 86: cmp $0x11,%eax bc: cmp $0x11,%rax 89: jne 0x00000000000000c6 c0: jne 0x0000000000000117 8b: mov $0x14,%esi c2: mov $0x14,%esi 90: callq 0xffffffffe1021e15 c7: callq 0xffffffffe102bd75 95: test $0x1fff,%ax cc: test $0x1fff,%rax 99: jne 0x00000000000000c6 d3: jne 0x0000000000000117 d5: mov %rax,%r14 9b: mov $0xe,%esi d8: mov $0xe,%esi a0: callq 0xffffffffe1021e44 dd: callq 0xffffffffe102bd91 // MSH e2: and $0xf,%eax e5: shl $0x2,%eax e8: mov %rax,%r13 eb: mov %r14,%rax ee: mov %r13,%rsi a5: lea 0xe(%rbx),%esi f1: add $0xe,%esi a8: callq 0xffffffffe1021e0d f4: callq 0xffffffffe102bd6d ad: cmp $0x16,%eax f9: cmp $0x16,%rax b0: je 0x00000000000000bf fd: je 0x0000000000000110 ff: mov %r13,%rsi b2: lea 0x10(%rbx),%esi 102: add $0x10,%esi b5: callq 0xffffffffe1021e0d 105: callq 0xffffffffe102bd6d ba: cmp $0x16,%eax 10a: cmp $0x16,%rax bd: jne 0x00000000000000c6 10e: jne 0x0000000000000117 bf: mov $0xffff,%eax 110: mov $0xffff,%eax c4: jmp 0x00000000000000c8 115: jmp 0x000000000000011c c6: xor %eax,%eax 117: mov $0x0,%eax c8: mov -0x8(%rbp),%rbx 11c: mov -0x228(%rbp),%rbx // epilogue cc: leaveq 123: mov -0x220(%rbp),%r13 cd: retq 12a: mov -0x218(%rbp),%r14 131: mov -0x210(%rbp),%r15 138: leaveq 139: retq On fully cached SKBs both JITed functions take 12 nsec to execute. BPF interpreter executes the program in 30 nsec. The difference in generated assembler is due to the following: Old BPF imlements LDX_MSH instruction via sk_load_byte_msh() helper function inside bpf_jit.S. New JIT removes the helper and does it explicitly, so ldx_msh cost is the same for both JITs, but generated code looks longer. New JIT has 4 registers to save, so prologue/epilogue are larger, but the cost is within noise on x64. Old JIT checks whether first insn clears A and if not emits 'xor %eax,%eax'. New JIT clears %rax unconditionally. 2. old BPF JIT doesn't support ANC_NLATTR, ANC_PAY_OFFSET, ANC_RANDOM extensions. New JIT supports all BPF extensions. Performance of such filters improves 2-4 times depending on a filter. The longer the filter the higher performance gain. Synthetic benchmarks with many ancillary loads see 20x speedup which seems to be the maximum gain from JIT Notes: . net.core.bpf_jit_enable=2 + tools/net/bpf_jit_disasm is still functional and can be used to see generated assembler . there are two jit_compile() functions and code flow for classic filters is: sk_attach_filter() - load classic BPF bpf_jit_compile() - try to JIT from classic BPF sk_convert_filter() - convert classic to internal bpf_int_jit_compile() - JIT from internal BPF seccomp and tracing filters will just call bpf_int_jit_compile() Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 20:50:46 -06:00
} else {
net: filter: cleanup A/X name usage The macro 'A' used in internal BPF interpreter: #define A regs[insn->a_reg] was easily confused with the name of classic BPF register 'A', since 'A' would mean two different things depending on context. This patch is trying to clean up the naming and clarify its usage in the following way: - A and X are names of two classic BPF registers - BPF_REG_A denotes internal BPF register R0 used to map classic register A in internal BPF programs generated from classic - BPF_REG_X denotes internal BPF register R7 used to map classic register X in internal BPF programs generated from classic - internal BPF instruction format: struct sock_filter_int { __u8 code; /* opcode */ __u8 dst_reg:4; /* dest register */ __u8 src_reg:4; /* source register */ __s16 off; /* signed offset */ __s32 imm; /* signed immediate constant */ }; - BPF_X/BPF_K is 1 bit used to encode source operand of instruction In classic: BPF_X - means use register X as source operand BPF_K - means use 32-bit immediate as source operand In internal: BPF_X - means use 'src_reg' register as source operand BPF_K - means use 32-bit immediate as source operand Suggested-by: Chema Gonzalez <chema@google.com> Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Acked-by: Daniel Borkmann <dborkman@redhat.com> Acked-by: Chema Gonzalez <chema@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-06-06 15:46:06 -06:00
/* mov %rsi, src_reg */
EMIT_mov(BPF_REG_2, src_reg);
if (imm32) {
if (is_imm8(imm32))
net: filter: x86: internal BPF JIT Maps all internal BPF instructions into x86_64 instructions. This patch replaces original BPF x64 JIT with internal BPF x64 JIT. sysctl net.core.bpf_jit_enable is reused as on/off switch. Performance: 1. old BPF JIT and internal BPF JIT generate equivalent x86_64 code. No performance difference is observed for filters that were JIT-able before Example assembler code for BPF filter "tcpdump port 22" original BPF -> old JIT: original BPF -> internal BPF -> new JIT: 0: push %rbp 0: push %rbp 1: mov %rsp,%rbp 1: mov %rsp,%rbp 4: sub $0x60,%rsp 4: sub $0x228,%rsp 8: mov %rbx,-0x8(%rbp) b: mov %rbx,-0x228(%rbp) // prologue 12: mov %r13,-0x220(%rbp) 19: mov %r14,-0x218(%rbp) 20: mov %r15,-0x210(%rbp) 27: xor %eax,%eax // clear A c: xor %ebx,%ebx 29: xor %r13,%r13 // clear X e: mov 0x68(%rdi),%r9d 2c: mov 0x68(%rdi),%r9d 12: sub 0x6c(%rdi),%r9d 30: sub 0x6c(%rdi),%r9d 16: mov 0xd8(%rdi),%r8 34: mov 0xd8(%rdi),%r10 3b: mov %rdi,%rbx 1d: mov $0xc,%esi 3e: mov $0xc,%esi 22: callq 0xffffffffe1021e15 43: callq 0xffffffffe102bd75 27: cmp $0x86dd,%eax 48: cmp $0x86dd,%rax 2c: jne 0x0000000000000069 4f: jne 0x000000000000009a 2e: mov $0x14,%esi 51: mov $0x14,%esi 33: callq 0xffffffffe1021e31 56: callq 0xffffffffe102bd91 38: cmp $0x84,%eax 5b: cmp $0x84,%rax 3d: je 0x0000000000000049 62: je 0x0000000000000074 3f: cmp $0x6,%eax 64: cmp $0x6,%rax 42: je 0x0000000000000049 68: je 0x0000000000000074 44: cmp $0x11,%eax 6a: cmp $0x11,%rax 47: jne 0x00000000000000c6 6e: jne 0x0000000000000117 49: mov $0x36,%esi 74: mov $0x36,%esi 4e: callq 0xffffffffe1021e15 79: callq 0xffffffffe102bd75 53: cmp $0x16,%eax 7e: cmp $0x16,%rax 56: je 0x00000000000000bf 82: je 0x0000000000000110 58: mov $0x38,%esi 88: mov $0x38,%esi 5d: callq 0xffffffffe1021e15 8d: callq 0xffffffffe102bd75 62: cmp $0x16,%eax 92: cmp $0x16,%rax 65: je 0x00000000000000bf 96: je 0x0000000000000110 67: jmp 0x00000000000000c6 98: jmp 0x0000000000000117 69: cmp $0x800,%eax 9a: cmp $0x800,%rax 6e: jne 0x00000000000000c6 a1: jne 0x0000000000000117 70: mov $0x17,%esi a3: mov $0x17,%esi 75: callq 0xffffffffe1021e31 a8: callq 0xffffffffe102bd91 7a: cmp $0x84,%eax ad: cmp $0x84,%rax 7f: je 0x000000000000008b b4: je 0x00000000000000c2 81: cmp $0x6,%eax b6: cmp $0x6,%rax 84: je 0x000000000000008b ba: je 0x00000000000000c2 86: cmp $0x11,%eax bc: cmp $0x11,%rax 89: jne 0x00000000000000c6 c0: jne 0x0000000000000117 8b: mov $0x14,%esi c2: mov $0x14,%esi 90: callq 0xffffffffe1021e15 c7: callq 0xffffffffe102bd75 95: test $0x1fff,%ax cc: test $0x1fff,%rax 99: jne 0x00000000000000c6 d3: jne 0x0000000000000117 d5: mov %rax,%r14 9b: mov $0xe,%esi d8: mov $0xe,%esi a0: callq 0xffffffffe1021e44 dd: callq 0xffffffffe102bd91 // MSH e2: and $0xf,%eax e5: shl $0x2,%eax e8: mov %rax,%r13 eb: mov %r14,%rax ee: mov %r13,%rsi a5: lea 0xe(%rbx),%esi f1: add $0xe,%esi a8: callq 0xffffffffe1021e0d f4: callq 0xffffffffe102bd6d ad: cmp $0x16,%eax f9: cmp $0x16,%rax b0: je 0x00000000000000bf fd: je 0x0000000000000110 ff: mov %r13,%rsi b2: lea 0x10(%rbx),%esi 102: add $0x10,%esi b5: callq 0xffffffffe1021e0d 105: callq 0xffffffffe102bd6d ba: cmp $0x16,%eax 10a: cmp $0x16,%rax bd: jne 0x00000000000000c6 10e: jne 0x0000000000000117 bf: mov $0xffff,%eax 110: mov $0xffff,%eax c4: jmp 0x00000000000000c8 115: jmp 0x000000000000011c c6: xor %eax,%eax 117: mov $0x0,%eax c8: mov -0x8(%rbp),%rbx 11c: mov -0x228(%rbp),%rbx // epilogue cc: leaveq 123: mov -0x220(%rbp),%r13 cd: retq 12a: mov -0x218(%rbp),%r14 131: mov -0x210(%rbp),%r15 138: leaveq 139: retq On fully cached SKBs both JITed functions take 12 nsec to execute. BPF interpreter executes the program in 30 nsec. The difference in generated assembler is due to the following: Old BPF imlements LDX_MSH instruction via sk_load_byte_msh() helper function inside bpf_jit.S. New JIT removes the helper and does it explicitly, so ldx_msh cost is the same for both JITs, but generated code looks longer. New JIT has 4 registers to save, so prologue/epilogue are larger, but the cost is within noise on x64. Old JIT checks whether first insn clears A and if not emits 'xor %eax,%eax'. New JIT clears %rax unconditionally. 2. old BPF JIT doesn't support ANC_NLATTR, ANC_PAY_OFFSET, ANC_RANDOM extensions. New JIT supports all BPF extensions. Performance of such filters improves 2-4 times depending on a filter. The longer the filter the higher performance gain. Synthetic benchmarks with many ancillary loads see 20x speedup which seems to be the maximum gain from JIT Notes: . net.core.bpf_jit_enable=2 + tools/net/bpf_jit_disasm is still functional and can be used to see generated assembler . there are two jit_compile() functions and code flow for classic filters is: sk_attach_filter() - load classic BPF bpf_jit_compile() - try to JIT from classic BPF sk_convert_filter() - convert classic to internal bpf_int_jit_compile() - JIT from internal BPF seccomp and tracing filters will just call bpf_int_jit_compile() Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 20:50:46 -06:00
/* add %esi, imm8 */
net: filter: cleanup A/X name usage The macro 'A' used in internal BPF interpreter: #define A regs[insn->a_reg] was easily confused with the name of classic BPF register 'A', since 'A' would mean two different things depending on context. This patch is trying to clean up the naming and clarify its usage in the following way: - A and X are names of two classic BPF registers - BPF_REG_A denotes internal BPF register R0 used to map classic register A in internal BPF programs generated from classic - BPF_REG_X denotes internal BPF register R7 used to map classic register X in internal BPF programs generated from classic - internal BPF instruction format: struct sock_filter_int { __u8 code; /* opcode */ __u8 dst_reg:4; /* dest register */ __u8 src_reg:4; /* source register */ __s16 off; /* signed offset */ __s32 imm; /* signed immediate constant */ }; - BPF_X/BPF_K is 1 bit used to encode source operand of instruction In classic: BPF_X - means use register X as source operand BPF_K - means use 32-bit immediate as source operand In internal: BPF_X - means use 'src_reg' register as source operand BPF_K - means use 32-bit immediate as source operand Suggested-by: Chema Gonzalez <chema@google.com> Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Acked-by: Daniel Borkmann <dborkman@redhat.com> Acked-by: Chema Gonzalez <chema@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-06-06 15:46:06 -06:00
EMIT3(0x83, 0xC6, imm32);
net: filter: Just In Time compiler for x86-64 In order to speedup packet filtering, here is an implementation of a JIT compiler for x86_64 It is disabled by default, and must be enabled by the admin. echo 1 >/proc/sys/net/core/bpf_jit_enable It uses module_alloc() and module_free() to get memory in the 2GB text kernel range since we call helpers functions from the generated code. EAX : BPF A accumulator EBX : BPF X accumulator RDI : pointer to skb (first argument given to JIT function) RBP : frame pointer (even if CONFIG_FRAME_POINTER=n) r9d : skb->len - skb->data_len (headlen) r8 : skb->data To get a trace of generated code, use : echo 2 >/proc/sys/net/core/bpf_jit_enable Example of generated code : # tcpdump -p -n -s 0 -i eth1 host 192.168.20.0/24 flen=18 proglen=147 pass=3 image=ffffffffa00b5000 JIT code: ffffffffa00b5000: 55 48 89 e5 48 83 ec 60 48 89 5d f8 44 8b 4f 60 JIT code: ffffffffa00b5010: 44 2b 4f 64 4c 8b 87 b8 00 00 00 be 0c 00 00 00 JIT code: ffffffffa00b5020: e8 24 7b f7 e0 3d 00 08 00 00 75 28 be 1a 00 00 JIT code: ffffffffa00b5030: 00 e8 fe 7a f7 e0 24 00 3d 00 14 a8 c0 74 49 be JIT code: ffffffffa00b5040: 1e 00 00 00 e8 eb 7a f7 e0 24 00 3d 00 14 a8 c0 JIT code: ffffffffa00b5050: 74 36 eb 3b 3d 06 08 00 00 74 07 3d 35 80 00 00 JIT code: ffffffffa00b5060: 75 2d be 1c 00 00 00 e8 c8 7a f7 e0 24 00 3d 00 JIT code: ffffffffa00b5070: 14 a8 c0 74 13 be 26 00 00 00 e8 b5 7a f7 e0 24 JIT code: ffffffffa00b5080: 00 3d 00 14 a8 c0 75 07 b8 ff ff 00 00 eb 02 31 JIT code: ffffffffa00b5090: c0 c9 c3 BPF program is 144 bytes long, so native program is almost same size ;) (000) ldh [12] (001) jeq #0x800 jt 2 jf 8 (002) ld [26] (003) and #0xffffff00 (004) jeq #0xc0a81400 jt 16 jf 5 (005) ld [30] (006) and #0xffffff00 (007) jeq #0xc0a81400 jt 16 jf 17 (008) jeq #0x806 jt 10 jf 9 (009) jeq #0x8035 jt 10 jf 17 (010) ld [28] (011) and #0xffffff00 (012) jeq #0xc0a81400 jt 16 jf 13 (013) ld [38] (014) and #0xffffff00 (015) jeq #0xc0a81400 jt 16 jf 17 (016) ret #65535 (017) ret #0 Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Cc: Arnaldo Carvalho de Melo <acme@infradead.org> Cc: Ben Hutchings <bhutchings@solarflare.com> Cc: Hagen Paul Pfeifer <hagen@jauu.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-04-20 03:27:32 -06:00
else
net: filter: x86: internal BPF JIT Maps all internal BPF instructions into x86_64 instructions. This patch replaces original BPF x64 JIT with internal BPF x64 JIT. sysctl net.core.bpf_jit_enable is reused as on/off switch. Performance: 1. old BPF JIT and internal BPF JIT generate equivalent x86_64 code. No performance difference is observed for filters that were JIT-able before Example assembler code for BPF filter "tcpdump port 22" original BPF -> old JIT: original BPF -> internal BPF -> new JIT: 0: push %rbp 0: push %rbp 1: mov %rsp,%rbp 1: mov %rsp,%rbp 4: sub $0x60,%rsp 4: sub $0x228,%rsp 8: mov %rbx,-0x8(%rbp) b: mov %rbx,-0x228(%rbp) // prologue 12: mov %r13,-0x220(%rbp) 19: mov %r14,-0x218(%rbp) 20: mov %r15,-0x210(%rbp) 27: xor %eax,%eax // clear A c: xor %ebx,%ebx 29: xor %r13,%r13 // clear X e: mov 0x68(%rdi),%r9d 2c: mov 0x68(%rdi),%r9d 12: sub 0x6c(%rdi),%r9d 30: sub 0x6c(%rdi),%r9d 16: mov 0xd8(%rdi),%r8 34: mov 0xd8(%rdi),%r10 3b: mov %rdi,%rbx 1d: mov $0xc,%esi 3e: mov $0xc,%esi 22: callq 0xffffffffe1021e15 43: callq 0xffffffffe102bd75 27: cmp $0x86dd,%eax 48: cmp $0x86dd,%rax 2c: jne 0x0000000000000069 4f: jne 0x000000000000009a 2e: mov $0x14,%esi 51: mov $0x14,%esi 33: callq 0xffffffffe1021e31 56: callq 0xffffffffe102bd91 38: cmp $0x84,%eax 5b: cmp $0x84,%rax 3d: je 0x0000000000000049 62: je 0x0000000000000074 3f: cmp $0x6,%eax 64: cmp $0x6,%rax 42: je 0x0000000000000049 68: je 0x0000000000000074 44: cmp $0x11,%eax 6a: cmp $0x11,%rax 47: jne 0x00000000000000c6 6e: jne 0x0000000000000117 49: mov $0x36,%esi 74: mov $0x36,%esi 4e: callq 0xffffffffe1021e15 79: callq 0xffffffffe102bd75 53: cmp $0x16,%eax 7e: cmp $0x16,%rax 56: je 0x00000000000000bf 82: je 0x0000000000000110 58: mov $0x38,%esi 88: mov $0x38,%esi 5d: callq 0xffffffffe1021e15 8d: callq 0xffffffffe102bd75 62: cmp $0x16,%eax 92: cmp $0x16,%rax 65: je 0x00000000000000bf 96: je 0x0000000000000110 67: jmp 0x00000000000000c6 98: jmp 0x0000000000000117 69: cmp $0x800,%eax 9a: cmp $0x800,%rax 6e: jne 0x00000000000000c6 a1: jne 0x0000000000000117 70: mov $0x17,%esi a3: mov $0x17,%esi 75: callq 0xffffffffe1021e31 a8: callq 0xffffffffe102bd91 7a: cmp $0x84,%eax ad: cmp $0x84,%rax 7f: je 0x000000000000008b b4: je 0x00000000000000c2 81: cmp $0x6,%eax b6: cmp $0x6,%rax 84: je 0x000000000000008b ba: je 0x00000000000000c2 86: cmp $0x11,%eax bc: cmp $0x11,%rax 89: jne 0x00000000000000c6 c0: jne 0x0000000000000117 8b: mov $0x14,%esi c2: mov $0x14,%esi 90: callq 0xffffffffe1021e15 c7: callq 0xffffffffe102bd75 95: test $0x1fff,%ax cc: test $0x1fff,%rax 99: jne 0x00000000000000c6 d3: jne 0x0000000000000117 d5: mov %rax,%r14 9b: mov $0xe,%esi d8: mov $0xe,%esi a0: callq 0xffffffffe1021e44 dd: callq 0xffffffffe102bd91 // MSH e2: and $0xf,%eax e5: shl $0x2,%eax e8: mov %rax,%r13 eb: mov %r14,%rax ee: mov %r13,%rsi a5: lea 0xe(%rbx),%esi f1: add $0xe,%esi a8: callq 0xffffffffe1021e0d f4: callq 0xffffffffe102bd6d ad: cmp $0x16,%eax f9: cmp $0x16,%rax b0: je 0x00000000000000bf fd: je 0x0000000000000110 ff: mov %r13,%rsi b2: lea 0x10(%rbx),%esi 102: add $0x10,%esi b5: callq 0xffffffffe1021e0d 105: callq 0xffffffffe102bd6d ba: cmp $0x16,%eax 10a: cmp $0x16,%rax bd: jne 0x00000000000000c6 10e: jne 0x0000000000000117 bf: mov $0xffff,%eax 110: mov $0xffff,%eax c4: jmp 0x00000000000000c8 115: jmp 0x000000000000011c c6: xor %eax,%eax 117: mov $0x0,%eax c8: mov -0x8(%rbp),%rbx 11c: mov -0x228(%rbp),%rbx // epilogue cc: leaveq 123: mov -0x220(%rbp),%r13 cd: retq 12a: mov -0x218(%rbp),%r14 131: mov -0x210(%rbp),%r15 138: leaveq 139: retq On fully cached SKBs both JITed functions take 12 nsec to execute. BPF interpreter executes the program in 30 nsec. The difference in generated assembler is due to the following: Old BPF imlements LDX_MSH instruction via sk_load_byte_msh() helper function inside bpf_jit.S. New JIT removes the helper and does it explicitly, so ldx_msh cost is the same for both JITs, but generated code looks longer. New JIT has 4 registers to save, so prologue/epilogue are larger, but the cost is within noise on x64. Old JIT checks whether first insn clears A and if not emits 'xor %eax,%eax'. New JIT clears %rax unconditionally. 2. old BPF JIT doesn't support ANC_NLATTR, ANC_PAY_OFFSET, ANC_RANDOM extensions. New JIT supports all BPF extensions. Performance of such filters improves 2-4 times depending on a filter. The longer the filter the higher performance gain. Synthetic benchmarks with many ancillary loads see 20x speedup which seems to be the maximum gain from JIT Notes: . net.core.bpf_jit_enable=2 + tools/net/bpf_jit_disasm is still functional and can be used to see generated assembler . there are two jit_compile() functions and code flow for classic filters is: sk_attach_filter() - load classic BPF bpf_jit_compile() - try to JIT from classic BPF sk_convert_filter() - convert classic to internal bpf_int_jit_compile() - JIT from internal BPF seccomp and tracing filters will just call bpf_int_jit_compile() Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 20:50:46 -06:00
/* add %esi, imm32 */
net: filter: cleanup A/X name usage The macro 'A' used in internal BPF interpreter: #define A regs[insn->a_reg] was easily confused with the name of classic BPF register 'A', since 'A' would mean two different things depending on context. This patch is trying to clean up the naming and clarify its usage in the following way: - A and X are names of two classic BPF registers - BPF_REG_A denotes internal BPF register R0 used to map classic register A in internal BPF programs generated from classic - BPF_REG_X denotes internal BPF register R7 used to map classic register X in internal BPF programs generated from classic - internal BPF instruction format: struct sock_filter_int { __u8 code; /* opcode */ __u8 dst_reg:4; /* dest register */ __u8 src_reg:4; /* source register */ __s16 off; /* signed offset */ __s32 imm; /* signed immediate constant */ }; - BPF_X/BPF_K is 1 bit used to encode source operand of instruction In classic: BPF_X - means use register X as source operand BPF_K - means use 32-bit immediate as source operand In internal: BPF_X - means use 'src_reg' register as source operand BPF_K - means use 32-bit immediate as source operand Suggested-by: Chema Gonzalez <chema@google.com> Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Acked-by: Daniel Borkmann <dborkman@redhat.com> Acked-by: Chema Gonzalez <chema@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-06-06 15:46:06 -06:00
EMIT2_off32(0x81, 0xC6, imm32);
net: filter: Just In Time compiler for x86-64 In order to speedup packet filtering, here is an implementation of a JIT compiler for x86_64 It is disabled by default, and must be enabled by the admin. echo 1 >/proc/sys/net/core/bpf_jit_enable It uses module_alloc() and module_free() to get memory in the 2GB text kernel range since we call helpers functions from the generated code. EAX : BPF A accumulator EBX : BPF X accumulator RDI : pointer to skb (first argument given to JIT function) RBP : frame pointer (even if CONFIG_FRAME_POINTER=n) r9d : skb->len - skb->data_len (headlen) r8 : skb->data To get a trace of generated code, use : echo 2 >/proc/sys/net/core/bpf_jit_enable Example of generated code : # tcpdump -p -n -s 0 -i eth1 host 192.168.20.0/24 flen=18 proglen=147 pass=3 image=ffffffffa00b5000 JIT code: ffffffffa00b5000: 55 48 89 e5 48 83 ec 60 48 89 5d f8 44 8b 4f 60 JIT code: ffffffffa00b5010: 44 2b 4f 64 4c 8b 87 b8 00 00 00 be 0c 00 00 00 JIT code: ffffffffa00b5020: e8 24 7b f7 e0 3d 00 08 00 00 75 28 be 1a 00 00 JIT code: ffffffffa00b5030: 00 e8 fe 7a f7 e0 24 00 3d 00 14 a8 c0 74 49 be JIT code: ffffffffa00b5040: 1e 00 00 00 e8 eb 7a f7 e0 24 00 3d 00 14 a8 c0 JIT code: ffffffffa00b5050: 74 36 eb 3b 3d 06 08 00 00 74 07 3d 35 80 00 00 JIT code: ffffffffa00b5060: 75 2d be 1c 00 00 00 e8 c8 7a f7 e0 24 00 3d 00 JIT code: ffffffffa00b5070: 14 a8 c0 74 13 be 26 00 00 00 e8 b5 7a f7 e0 24 JIT code: ffffffffa00b5080: 00 3d 00 14 a8 c0 75 07 b8 ff ff 00 00 eb 02 31 JIT code: ffffffffa00b5090: c0 c9 c3 BPF program is 144 bytes long, so native program is almost same size ;) (000) ldh [12] (001) jeq #0x800 jt 2 jf 8 (002) ld [26] (003) and #0xffffff00 (004) jeq #0xc0a81400 jt 16 jf 5 (005) ld [30] (006) and #0xffffff00 (007) jeq #0xc0a81400 jt 16 jf 17 (008) jeq #0x806 jt 10 jf 9 (009) jeq #0x8035 jt 10 jf 17 (010) ld [28] (011) and #0xffffff00 (012) jeq #0xc0a81400 jt 16 jf 13 (013) ld [38] (014) and #0xffffff00 (015) jeq #0xc0a81400 jt 16 jf 17 (016) ret #65535 (017) ret #0 Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Cc: Arnaldo Carvalho de Melo <acme@infradead.org> Cc: Ben Hutchings <bhutchings@solarflare.com> Cc: Hagen Paul Pfeifer <hagen@jauu.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-04-20 03:27:32 -06:00
}
net: filter: x86: internal BPF JIT Maps all internal BPF instructions into x86_64 instructions. This patch replaces original BPF x64 JIT with internal BPF x64 JIT. sysctl net.core.bpf_jit_enable is reused as on/off switch. Performance: 1. old BPF JIT and internal BPF JIT generate equivalent x86_64 code. No performance difference is observed for filters that were JIT-able before Example assembler code for BPF filter "tcpdump port 22" original BPF -> old JIT: original BPF -> internal BPF -> new JIT: 0: push %rbp 0: push %rbp 1: mov %rsp,%rbp 1: mov %rsp,%rbp 4: sub $0x60,%rsp 4: sub $0x228,%rsp 8: mov %rbx,-0x8(%rbp) b: mov %rbx,-0x228(%rbp) // prologue 12: mov %r13,-0x220(%rbp) 19: mov %r14,-0x218(%rbp) 20: mov %r15,-0x210(%rbp) 27: xor %eax,%eax // clear A c: xor %ebx,%ebx 29: xor %r13,%r13 // clear X e: mov 0x68(%rdi),%r9d 2c: mov 0x68(%rdi),%r9d 12: sub 0x6c(%rdi),%r9d 30: sub 0x6c(%rdi),%r9d 16: mov 0xd8(%rdi),%r8 34: mov 0xd8(%rdi),%r10 3b: mov %rdi,%rbx 1d: mov $0xc,%esi 3e: mov $0xc,%esi 22: callq 0xffffffffe1021e15 43: callq 0xffffffffe102bd75 27: cmp $0x86dd,%eax 48: cmp $0x86dd,%rax 2c: jne 0x0000000000000069 4f: jne 0x000000000000009a 2e: mov $0x14,%esi 51: mov $0x14,%esi 33: callq 0xffffffffe1021e31 56: callq 0xffffffffe102bd91 38: cmp $0x84,%eax 5b: cmp $0x84,%rax 3d: je 0x0000000000000049 62: je 0x0000000000000074 3f: cmp $0x6,%eax 64: cmp $0x6,%rax 42: je 0x0000000000000049 68: je 0x0000000000000074 44: cmp $0x11,%eax 6a: cmp $0x11,%rax 47: jne 0x00000000000000c6 6e: jne 0x0000000000000117 49: mov $0x36,%esi 74: mov $0x36,%esi 4e: callq 0xffffffffe1021e15 79: callq 0xffffffffe102bd75 53: cmp $0x16,%eax 7e: cmp $0x16,%rax 56: je 0x00000000000000bf 82: je 0x0000000000000110 58: mov $0x38,%esi 88: mov $0x38,%esi 5d: callq 0xffffffffe1021e15 8d: callq 0xffffffffe102bd75 62: cmp $0x16,%eax 92: cmp $0x16,%rax 65: je 0x00000000000000bf 96: je 0x0000000000000110 67: jmp 0x00000000000000c6 98: jmp 0x0000000000000117 69: cmp $0x800,%eax 9a: cmp $0x800,%rax 6e: jne 0x00000000000000c6 a1: jne 0x0000000000000117 70: mov $0x17,%esi a3: mov $0x17,%esi 75: callq 0xffffffffe1021e31 a8: callq 0xffffffffe102bd91 7a: cmp $0x84,%eax ad: cmp $0x84,%rax 7f: je 0x000000000000008b b4: je 0x00000000000000c2 81: cmp $0x6,%eax b6: cmp $0x6,%rax 84: je 0x000000000000008b ba: je 0x00000000000000c2 86: cmp $0x11,%eax bc: cmp $0x11,%rax 89: jne 0x00000000000000c6 c0: jne 0x0000000000000117 8b: mov $0x14,%esi c2: mov $0x14,%esi 90: callq 0xffffffffe1021e15 c7: callq 0xffffffffe102bd75 95: test $0x1fff,%ax cc: test $0x1fff,%rax 99: jne 0x00000000000000c6 d3: jne 0x0000000000000117 d5: mov %rax,%r14 9b: mov $0xe,%esi d8: mov $0xe,%esi a0: callq 0xffffffffe1021e44 dd: callq 0xffffffffe102bd91 // MSH e2: and $0xf,%eax e5: shl $0x2,%eax e8: mov %rax,%r13 eb: mov %r14,%rax ee: mov %r13,%rsi a5: lea 0xe(%rbx),%esi f1: add $0xe,%esi a8: callq 0xffffffffe1021e0d f4: callq 0xffffffffe102bd6d ad: cmp $0x16,%eax f9: cmp $0x16,%rax b0: je 0x00000000000000bf fd: je 0x0000000000000110 ff: mov %r13,%rsi b2: lea 0x10(%rbx),%esi 102: add $0x10,%esi b5: callq 0xffffffffe1021e0d 105: callq 0xffffffffe102bd6d ba: cmp $0x16,%eax 10a: cmp $0x16,%rax bd: jne 0x00000000000000c6 10e: jne 0x0000000000000117 bf: mov $0xffff,%eax 110: mov $0xffff,%eax c4: jmp 0x00000000000000c8 115: jmp 0x000000000000011c c6: xor %eax,%eax 117: mov $0x0,%eax c8: mov -0x8(%rbp),%rbx 11c: mov -0x228(%rbp),%rbx // epilogue cc: leaveq 123: mov -0x220(%rbp),%r13 cd: retq 12a: mov -0x218(%rbp),%r14 131: mov -0x210(%rbp),%r15 138: leaveq 139: retq On fully cached SKBs both JITed functions take 12 nsec to execute. BPF interpreter executes the program in 30 nsec. The difference in generated assembler is due to the following: Old BPF imlements LDX_MSH instruction via sk_load_byte_msh() helper function inside bpf_jit.S. New JIT removes the helper and does it explicitly, so ldx_msh cost is the same for both JITs, but generated code looks longer. New JIT has 4 registers to save, so prologue/epilogue are larger, but the cost is within noise on x64. Old JIT checks whether first insn clears A and if not emits 'xor %eax,%eax'. New JIT clears %rax unconditionally. 2. old BPF JIT doesn't support ANC_NLATTR, ANC_PAY_OFFSET, ANC_RANDOM extensions. New JIT supports all BPF extensions. Performance of such filters improves 2-4 times depending on a filter. The longer the filter the higher performance gain. Synthetic benchmarks with many ancillary loads see 20x speedup which seems to be the maximum gain from JIT Notes: . net.core.bpf_jit_enable=2 + tools/net/bpf_jit_disasm is still functional and can be used to see generated assembler . there are two jit_compile() functions and code flow for classic filters is: sk_attach_filter() - load classic BPF bpf_jit_compile() - try to JIT from classic BPF sk_convert_filter() - convert classic to internal bpf_int_jit_compile() - JIT from internal BPF seccomp and tracing filters will just call bpf_int_jit_compile() Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 20:50:46 -06:00
}
/* skb pointer is in R6 (%rbx), it will be copied into
* %rdi if skb_copy_bits() call is necessary.
* sk_load_* helpers also use %r10 and %r9d.
* See bpf_jit.S
*/
bpf, x86: add support for constant blinding This patch adds recently added constant blinding helpers into the x86 eBPF JIT. In the bpf_int_jit_compile() path, requirements are to utilize bpf_jit_blind_constants()/bpf_jit_prog_release_other() pair for rewriting the program into a blinded one, and to map the BPF_REG_AX register to a CPU register. The mapping of BPF_REG_AX is at non-callee saved register r10, and thus shared with cached skb->data used for ld_abs/ind and not in every program type needed. When blinding is not used, there's zero additional overhead in the generated image. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-05-13 11:08:33 -06:00
if (seen_ax_reg)
/* r10 = skb->data, mov %r10, off32(%rbx) */
EMIT3_off32(0x4c, 0x8b, 0x93,
offsetof(struct sk_buff, data));
net: filter: x86: internal BPF JIT Maps all internal BPF instructions into x86_64 instructions. This patch replaces original BPF x64 JIT with internal BPF x64 JIT. sysctl net.core.bpf_jit_enable is reused as on/off switch. Performance: 1. old BPF JIT and internal BPF JIT generate equivalent x86_64 code. No performance difference is observed for filters that were JIT-able before Example assembler code for BPF filter "tcpdump port 22" original BPF -> old JIT: original BPF -> internal BPF -> new JIT: 0: push %rbp 0: push %rbp 1: mov %rsp,%rbp 1: mov %rsp,%rbp 4: sub $0x60,%rsp 4: sub $0x228,%rsp 8: mov %rbx,-0x8(%rbp) b: mov %rbx,-0x228(%rbp) // prologue 12: mov %r13,-0x220(%rbp) 19: mov %r14,-0x218(%rbp) 20: mov %r15,-0x210(%rbp) 27: xor %eax,%eax // clear A c: xor %ebx,%ebx 29: xor %r13,%r13 // clear X e: mov 0x68(%rdi),%r9d 2c: mov 0x68(%rdi),%r9d 12: sub 0x6c(%rdi),%r9d 30: sub 0x6c(%rdi),%r9d 16: mov 0xd8(%rdi),%r8 34: mov 0xd8(%rdi),%r10 3b: mov %rdi,%rbx 1d: mov $0xc,%esi 3e: mov $0xc,%esi 22: callq 0xffffffffe1021e15 43: callq 0xffffffffe102bd75 27: cmp $0x86dd,%eax 48: cmp $0x86dd,%rax 2c: jne 0x0000000000000069 4f: jne 0x000000000000009a 2e: mov $0x14,%esi 51: mov $0x14,%esi 33: callq 0xffffffffe1021e31 56: callq 0xffffffffe102bd91 38: cmp $0x84,%eax 5b: cmp $0x84,%rax 3d: je 0x0000000000000049 62: je 0x0000000000000074 3f: cmp $0x6,%eax 64: cmp $0x6,%rax 42: je 0x0000000000000049 68: je 0x0000000000000074 44: cmp $0x11,%eax 6a: cmp $0x11,%rax 47: jne 0x00000000000000c6 6e: jne 0x0000000000000117 49: mov $0x36,%esi 74: mov $0x36,%esi 4e: callq 0xffffffffe1021e15 79: callq 0xffffffffe102bd75 53: cmp $0x16,%eax 7e: cmp $0x16,%rax 56: je 0x00000000000000bf 82: je 0x0000000000000110 58: mov $0x38,%esi 88: mov $0x38,%esi 5d: callq 0xffffffffe1021e15 8d: callq 0xffffffffe102bd75 62: cmp $0x16,%eax 92: cmp $0x16,%rax 65: je 0x00000000000000bf 96: je 0x0000000000000110 67: jmp 0x00000000000000c6 98: jmp 0x0000000000000117 69: cmp $0x800,%eax 9a: cmp $0x800,%rax 6e: jne 0x00000000000000c6 a1: jne 0x0000000000000117 70: mov $0x17,%esi a3: mov $0x17,%esi 75: callq 0xffffffffe1021e31 a8: callq 0xffffffffe102bd91 7a: cmp $0x84,%eax ad: cmp $0x84,%rax 7f: je 0x000000000000008b b4: je 0x00000000000000c2 81: cmp $0x6,%eax b6: cmp $0x6,%rax 84: je 0x000000000000008b ba: je 0x00000000000000c2 86: cmp $0x11,%eax bc: cmp $0x11,%rax 89: jne 0x00000000000000c6 c0: jne 0x0000000000000117 8b: mov $0x14,%esi c2: mov $0x14,%esi 90: callq 0xffffffffe1021e15 c7: callq 0xffffffffe102bd75 95: test $0x1fff,%ax cc: test $0x1fff,%rax 99: jne 0x00000000000000c6 d3: jne 0x0000000000000117 d5: mov %rax,%r14 9b: mov $0xe,%esi d8: mov $0xe,%esi a0: callq 0xffffffffe1021e44 dd: callq 0xffffffffe102bd91 // MSH e2: and $0xf,%eax e5: shl $0x2,%eax e8: mov %rax,%r13 eb: mov %r14,%rax ee: mov %r13,%rsi a5: lea 0xe(%rbx),%esi f1: add $0xe,%esi a8: callq 0xffffffffe1021e0d f4: callq 0xffffffffe102bd6d ad: cmp $0x16,%eax f9: cmp $0x16,%rax b0: je 0x00000000000000bf fd: je 0x0000000000000110 ff: mov %r13,%rsi b2: lea 0x10(%rbx),%esi 102: add $0x10,%esi b5: callq 0xffffffffe1021e0d 105: callq 0xffffffffe102bd6d ba: cmp $0x16,%eax 10a: cmp $0x16,%rax bd: jne 0x00000000000000c6 10e: jne 0x0000000000000117 bf: mov $0xffff,%eax 110: mov $0xffff,%eax c4: jmp 0x00000000000000c8 115: jmp 0x000000000000011c c6: xor %eax,%eax 117: mov $0x0,%eax c8: mov -0x8(%rbp),%rbx 11c: mov -0x228(%rbp),%rbx // epilogue cc: leaveq 123: mov -0x220(%rbp),%r13 cd: retq 12a: mov -0x218(%rbp),%r14 131: mov -0x210(%rbp),%r15 138: leaveq 139: retq On fully cached SKBs both JITed functions take 12 nsec to execute. BPF interpreter executes the program in 30 nsec. The difference in generated assembler is due to the following: Old BPF imlements LDX_MSH instruction via sk_load_byte_msh() helper function inside bpf_jit.S. New JIT removes the helper and does it explicitly, so ldx_msh cost is the same for both JITs, but generated code looks longer. New JIT has 4 registers to save, so prologue/epilogue are larger, but the cost is within noise on x64. Old JIT checks whether first insn clears A and if not emits 'xor %eax,%eax'. New JIT clears %rax unconditionally. 2. old BPF JIT doesn't support ANC_NLATTR, ANC_PAY_OFFSET, ANC_RANDOM extensions. New JIT supports all BPF extensions. Performance of such filters improves 2-4 times depending on a filter. The longer the filter the higher performance gain. Synthetic benchmarks with many ancillary loads see 20x speedup which seems to be the maximum gain from JIT Notes: . net.core.bpf_jit_enable=2 + tools/net/bpf_jit_disasm is still functional and can be used to see generated assembler . there are two jit_compile() functions and code flow for classic filters is: sk_attach_filter() - load classic BPF bpf_jit_compile() - try to JIT from classic BPF sk_convert_filter() - convert classic to internal bpf_int_jit_compile() - JIT from internal BPF seccomp and tracing filters will just call bpf_int_jit_compile() Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 20:50:46 -06:00
EMIT1_off32(0xE8, jmp_offset); /* call */
break;
case BPF_LD | BPF_IND | BPF_H:
func = sk_load_half;
goto common_load;
case BPF_LD | BPF_ABS | BPF_H:
net: filter: cleanup A/X name usage The macro 'A' used in internal BPF interpreter: #define A regs[insn->a_reg] was easily confused with the name of classic BPF register 'A', since 'A' would mean two different things depending on context. This patch is trying to clean up the naming and clarify its usage in the following way: - A and X are names of two classic BPF registers - BPF_REG_A denotes internal BPF register R0 used to map classic register A in internal BPF programs generated from classic - BPF_REG_X denotes internal BPF register R7 used to map classic register X in internal BPF programs generated from classic - internal BPF instruction format: struct sock_filter_int { __u8 code; /* opcode */ __u8 dst_reg:4; /* dest register */ __u8 src_reg:4; /* source register */ __s16 off; /* signed offset */ __s32 imm; /* signed immediate constant */ }; - BPF_X/BPF_K is 1 bit used to encode source operand of instruction In classic: BPF_X - means use register X as source operand BPF_K - means use 32-bit immediate as source operand In internal: BPF_X - means use 'src_reg' register as source operand BPF_K - means use 32-bit immediate as source operand Suggested-by: Chema Gonzalez <chema@google.com> Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Acked-by: Daniel Borkmann <dborkman@redhat.com> Acked-by: Chema Gonzalez <chema@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-06-06 15:46:06 -06:00
func = CHOOSE_LOAD_FUNC(imm32, sk_load_half);
net: filter: x86: internal BPF JIT Maps all internal BPF instructions into x86_64 instructions. This patch replaces original BPF x64 JIT with internal BPF x64 JIT. sysctl net.core.bpf_jit_enable is reused as on/off switch. Performance: 1. old BPF JIT and internal BPF JIT generate equivalent x86_64 code. No performance difference is observed for filters that were JIT-able before Example assembler code for BPF filter "tcpdump port 22" original BPF -> old JIT: original BPF -> internal BPF -> new JIT: 0: push %rbp 0: push %rbp 1: mov %rsp,%rbp 1: mov %rsp,%rbp 4: sub $0x60,%rsp 4: sub $0x228,%rsp 8: mov %rbx,-0x8(%rbp) b: mov %rbx,-0x228(%rbp) // prologue 12: mov %r13,-0x220(%rbp) 19: mov %r14,-0x218(%rbp) 20: mov %r15,-0x210(%rbp) 27: xor %eax,%eax // clear A c: xor %ebx,%ebx 29: xor %r13,%r13 // clear X e: mov 0x68(%rdi),%r9d 2c: mov 0x68(%rdi),%r9d 12: sub 0x6c(%rdi),%r9d 30: sub 0x6c(%rdi),%r9d 16: mov 0xd8(%rdi),%r8 34: mov 0xd8(%rdi),%r10 3b: mov %rdi,%rbx 1d: mov $0xc,%esi 3e: mov $0xc,%esi 22: callq 0xffffffffe1021e15 43: callq 0xffffffffe102bd75 27: cmp $0x86dd,%eax 48: cmp $0x86dd,%rax 2c: jne 0x0000000000000069 4f: jne 0x000000000000009a 2e: mov $0x14,%esi 51: mov $0x14,%esi 33: callq 0xffffffffe1021e31 56: callq 0xffffffffe102bd91 38: cmp $0x84,%eax 5b: cmp $0x84,%rax 3d: je 0x0000000000000049 62: je 0x0000000000000074 3f: cmp $0x6,%eax 64: cmp $0x6,%rax 42: je 0x0000000000000049 68: je 0x0000000000000074 44: cmp $0x11,%eax 6a: cmp $0x11,%rax 47: jne 0x00000000000000c6 6e: jne 0x0000000000000117 49: mov $0x36,%esi 74: mov $0x36,%esi 4e: callq 0xffffffffe1021e15 79: callq 0xffffffffe102bd75 53: cmp $0x16,%eax 7e: cmp $0x16,%rax 56: je 0x00000000000000bf 82: je 0x0000000000000110 58: mov $0x38,%esi 88: mov $0x38,%esi 5d: callq 0xffffffffe1021e15 8d: callq 0xffffffffe102bd75 62: cmp $0x16,%eax 92: cmp $0x16,%rax 65: je 0x00000000000000bf 96: je 0x0000000000000110 67: jmp 0x00000000000000c6 98: jmp 0x0000000000000117 69: cmp $0x800,%eax 9a: cmp $0x800,%rax 6e: jne 0x00000000000000c6 a1: jne 0x0000000000000117 70: mov $0x17,%esi a3: mov $0x17,%esi 75: callq 0xffffffffe1021e31 a8: callq 0xffffffffe102bd91 7a: cmp $0x84,%eax ad: cmp $0x84,%rax 7f: je 0x000000000000008b b4: je 0x00000000000000c2 81: cmp $0x6,%eax b6: cmp $0x6,%rax 84: je 0x000000000000008b ba: je 0x00000000000000c2 86: cmp $0x11,%eax bc: cmp $0x11,%rax 89: jne 0x00000000000000c6 c0: jne 0x0000000000000117 8b: mov $0x14,%esi c2: mov $0x14,%esi 90: callq 0xffffffffe1021e15 c7: callq 0xffffffffe102bd75 95: test $0x1fff,%ax cc: test $0x1fff,%rax 99: jne 0x00000000000000c6 d3: jne 0x0000000000000117 d5: mov %rax,%r14 9b: mov $0xe,%esi d8: mov $0xe,%esi a0: callq 0xffffffffe1021e44 dd: callq 0xffffffffe102bd91 // MSH e2: and $0xf,%eax e5: shl $0x2,%eax e8: mov %rax,%r13 eb: mov %r14,%rax ee: mov %r13,%rsi a5: lea 0xe(%rbx),%esi f1: add $0xe,%esi a8: callq 0xffffffffe1021e0d f4: callq 0xffffffffe102bd6d ad: cmp $0x16,%eax f9: cmp $0x16,%rax b0: je 0x00000000000000bf fd: je 0x0000000000000110 ff: mov %r13,%rsi b2: lea 0x10(%rbx),%esi 102: add $0x10,%esi b5: callq 0xffffffffe1021e0d 105: callq 0xffffffffe102bd6d ba: cmp $0x16,%eax 10a: cmp $0x16,%rax bd: jne 0x00000000000000c6 10e: jne 0x0000000000000117 bf: mov $0xffff,%eax 110: mov $0xffff,%eax c4: jmp 0x00000000000000c8 115: jmp 0x000000000000011c c6: xor %eax,%eax 117: mov $0x0,%eax c8: mov -0x8(%rbp),%rbx 11c: mov -0x228(%rbp),%rbx // epilogue cc: leaveq 123: mov -0x220(%rbp),%r13 cd: retq 12a: mov -0x218(%rbp),%r14 131: mov -0x210(%rbp),%r15 138: leaveq 139: retq On fully cached SKBs both JITed functions take 12 nsec to execute. BPF interpreter executes the program in 30 nsec. The difference in generated assembler is due to the following: Old BPF imlements LDX_MSH instruction via sk_load_byte_msh() helper function inside bpf_jit.S. New JIT removes the helper and does it explicitly, so ldx_msh cost is the same for both JITs, but generated code looks longer. New JIT has 4 registers to save, so prologue/epilogue are larger, but the cost is within noise on x64. Old JIT checks whether first insn clears A and if not emits 'xor %eax,%eax'. New JIT clears %rax unconditionally. 2. old BPF JIT doesn't support ANC_NLATTR, ANC_PAY_OFFSET, ANC_RANDOM extensions. New JIT supports all BPF extensions. Performance of such filters improves 2-4 times depending on a filter. The longer the filter the higher performance gain. Synthetic benchmarks with many ancillary loads see 20x speedup which seems to be the maximum gain from JIT Notes: . net.core.bpf_jit_enable=2 + tools/net/bpf_jit_disasm is still functional and can be used to see generated assembler . there are two jit_compile() functions and code flow for classic filters is: sk_attach_filter() - load classic BPF bpf_jit_compile() - try to JIT from classic BPF sk_convert_filter() - convert classic to internal bpf_int_jit_compile() - JIT from internal BPF seccomp and tracing filters will just call bpf_int_jit_compile() Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 20:50:46 -06:00
goto common_load;
case BPF_LD | BPF_IND | BPF_B:
func = sk_load_byte;
goto common_load;
case BPF_LD | BPF_ABS | BPF_B:
net: filter: cleanup A/X name usage The macro 'A' used in internal BPF interpreter: #define A regs[insn->a_reg] was easily confused with the name of classic BPF register 'A', since 'A' would mean two different things depending on context. This patch is trying to clean up the naming and clarify its usage in the following way: - A and X are names of two classic BPF registers - BPF_REG_A denotes internal BPF register R0 used to map classic register A in internal BPF programs generated from classic - BPF_REG_X denotes internal BPF register R7 used to map classic register X in internal BPF programs generated from classic - internal BPF instruction format: struct sock_filter_int { __u8 code; /* opcode */ __u8 dst_reg:4; /* dest register */ __u8 src_reg:4; /* source register */ __s16 off; /* signed offset */ __s32 imm; /* signed immediate constant */ }; - BPF_X/BPF_K is 1 bit used to encode source operand of instruction In classic: BPF_X - means use register X as source operand BPF_K - means use 32-bit immediate as source operand In internal: BPF_X - means use 'src_reg' register as source operand BPF_K - means use 32-bit immediate as source operand Suggested-by: Chema Gonzalez <chema@google.com> Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Acked-by: Daniel Borkmann <dborkman@redhat.com> Acked-by: Chema Gonzalez <chema@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-06-06 15:46:06 -06:00
func = CHOOSE_LOAD_FUNC(imm32, sk_load_byte);
net: filter: x86: internal BPF JIT Maps all internal BPF instructions into x86_64 instructions. This patch replaces original BPF x64 JIT with internal BPF x64 JIT. sysctl net.core.bpf_jit_enable is reused as on/off switch. Performance: 1. old BPF JIT and internal BPF JIT generate equivalent x86_64 code. No performance difference is observed for filters that were JIT-able before Example assembler code for BPF filter "tcpdump port 22" original BPF -> old JIT: original BPF -> internal BPF -> new JIT: 0: push %rbp 0: push %rbp 1: mov %rsp,%rbp 1: mov %rsp,%rbp 4: sub $0x60,%rsp 4: sub $0x228,%rsp 8: mov %rbx,-0x8(%rbp) b: mov %rbx,-0x228(%rbp) // prologue 12: mov %r13,-0x220(%rbp) 19: mov %r14,-0x218(%rbp) 20: mov %r15,-0x210(%rbp) 27: xor %eax,%eax // clear A c: xor %ebx,%ebx 29: xor %r13,%r13 // clear X e: mov 0x68(%rdi),%r9d 2c: mov 0x68(%rdi),%r9d 12: sub 0x6c(%rdi),%r9d 30: sub 0x6c(%rdi),%r9d 16: mov 0xd8(%rdi),%r8 34: mov 0xd8(%rdi),%r10 3b: mov %rdi,%rbx 1d: mov $0xc,%esi 3e: mov $0xc,%esi 22: callq 0xffffffffe1021e15 43: callq 0xffffffffe102bd75 27: cmp $0x86dd,%eax 48: cmp $0x86dd,%rax 2c: jne 0x0000000000000069 4f: jne 0x000000000000009a 2e: mov $0x14,%esi 51: mov $0x14,%esi 33: callq 0xffffffffe1021e31 56: callq 0xffffffffe102bd91 38: cmp $0x84,%eax 5b: cmp $0x84,%rax 3d: je 0x0000000000000049 62: je 0x0000000000000074 3f: cmp $0x6,%eax 64: cmp $0x6,%rax 42: je 0x0000000000000049 68: je 0x0000000000000074 44: cmp $0x11,%eax 6a: cmp $0x11,%rax 47: jne 0x00000000000000c6 6e: jne 0x0000000000000117 49: mov $0x36,%esi 74: mov $0x36,%esi 4e: callq 0xffffffffe1021e15 79: callq 0xffffffffe102bd75 53: cmp $0x16,%eax 7e: cmp $0x16,%rax 56: je 0x00000000000000bf 82: je 0x0000000000000110 58: mov $0x38,%esi 88: mov $0x38,%esi 5d: callq 0xffffffffe1021e15 8d: callq 0xffffffffe102bd75 62: cmp $0x16,%eax 92: cmp $0x16,%rax 65: je 0x00000000000000bf 96: je 0x0000000000000110 67: jmp 0x00000000000000c6 98: jmp 0x0000000000000117 69: cmp $0x800,%eax 9a: cmp $0x800,%rax 6e: jne 0x00000000000000c6 a1: jne 0x0000000000000117 70: mov $0x17,%esi a3: mov $0x17,%esi 75: callq 0xffffffffe1021e31 a8: callq 0xffffffffe102bd91 7a: cmp $0x84,%eax ad: cmp $0x84,%rax 7f: je 0x000000000000008b b4: je 0x00000000000000c2 81: cmp $0x6,%eax b6: cmp $0x6,%rax 84: je 0x000000000000008b ba: je 0x00000000000000c2 86: cmp $0x11,%eax bc: cmp $0x11,%rax 89: jne 0x00000000000000c6 c0: jne 0x0000000000000117 8b: mov $0x14,%esi c2: mov $0x14,%esi 90: callq 0xffffffffe1021e15 c7: callq 0xffffffffe102bd75 95: test $0x1fff,%ax cc: test $0x1fff,%rax 99: jne 0x00000000000000c6 d3: jne 0x0000000000000117 d5: mov %rax,%r14 9b: mov $0xe,%esi d8: mov $0xe,%esi a0: callq 0xffffffffe1021e44 dd: callq 0xffffffffe102bd91 // MSH e2: and $0xf,%eax e5: shl $0x2,%eax e8: mov %rax,%r13 eb: mov %r14,%rax ee: mov %r13,%rsi a5: lea 0xe(%rbx),%esi f1: add $0xe,%esi a8: callq 0xffffffffe1021e0d f4: callq 0xffffffffe102bd6d ad: cmp $0x16,%eax f9: cmp $0x16,%rax b0: je 0x00000000000000bf fd: je 0x0000000000000110 ff: mov %r13,%rsi b2: lea 0x10(%rbx),%esi 102: add $0x10,%esi b5: callq 0xffffffffe1021e0d 105: callq 0xffffffffe102bd6d ba: cmp $0x16,%eax 10a: cmp $0x16,%rax bd: jne 0x00000000000000c6 10e: jne 0x0000000000000117 bf: mov $0xffff,%eax 110: mov $0xffff,%eax c4: jmp 0x00000000000000c8 115: jmp 0x000000000000011c c6: xor %eax,%eax 117: mov $0x0,%eax c8: mov -0x8(%rbp),%rbx 11c: mov -0x228(%rbp),%rbx // epilogue cc: leaveq 123: mov -0x220(%rbp),%r13 cd: retq 12a: mov -0x218(%rbp),%r14 131: mov -0x210(%rbp),%r15 138: leaveq 139: retq On fully cached SKBs both JITed functions take 12 nsec to execute. BPF interpreter executes the program in 30 nsec. The difference in generated assembler is due to the following: Old BPF imlements LDX_MSH instruction via sk_load_byte_msh() helper function inside bpf_jit.S. New JIT removes the helper and does it explicitly, so ldx_msh cost is the same for both JITs, but generated code looks longer. New JIT has 4 registers to save, so prologue/epilogue are larger, but the cost is within noise on x64. Old JIT checks whether first insn clears A and if not emits 'xor %eax,%eax'. New JIT clears %rax unconditionally. 2. old BPF JIT doesn't support ANC_NLATTR, ANC_PAY_OFFSET, ANC_RANDOM extensions. New JIT supports all BPF extensions. Performance of such filters improves 2-4 times depending on a filter. The longer the filter the higher performance gain. Synthetic benchmarks with many ancillary loads see 20x speedup which seems to be the maximum gain from JIT Notes: . net.core.bpf_jit_enable=2 + tools/net/bpf_jit_disasm is still functional and can be used to see generated assembler . there are two jit_compile() functions and code flow for classic filters is: sk_attach_filter() - load classic BPF bpf_jit_compile() - try to JIT from classic BPF sk_convert_filter() - convert classic to internal bpf_int_jit_compile() - JIT from internal BPF seccomp and tracing filters will just call bpf_int_jit_compile() Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 20:50:46 -06:00
goto common_load;
case BPF_JMP | BPF_EXIT:
bpf: x86: fix epilogue generation for eBPF programs classic BPF has a restriction that last insn is always BPF_RET. eBPF doesn't have BPF_RET instruction and this restriction. It has BPF_EXIT insn which can appear anywhere in the program one or more times and it doesn't have to be last insn. Fix eBPF JIT to emit epilogue when first BPF_EXIT is seen and all other BPF_EXIT instructions will be emitted as jump. Since jump offset to epilogue is computed as: jmp_offset = ctx->cleanup_addr - addrs[i] we need to change type of cleanup_addr to signed to compute the offset as: (long long) ((int)20 - (int)30) instead of: (long long) ((unsigned int)20 - (int)30) Fixes: 622582786c9e ("net: filter: x86: internal BPF JIT") Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-11-29 15:46:13 -07:00
if (seen_exit) {
net: filter: x86: internal BPF JIT Maps all internal BPF instructions into x86_64 instructions. This patch replaces original BPF x64 JIT with internal BPF x64 JIT. sysctl net.core.bpf_jit_enable is reused as on/off switch. Performance: 1. old BPF JIT and internal BPF JIT generate equivalent x86_64 code. No performance difference is observed for filters that were JIT-able before Example assembler code for BPF filter "tcpdump port 22" original BPF -> old JIT: original BPF -> internal BPF -> new JIT: 0: push %rbp 0: push %rbp 1: mov %rsp,%rbp 1: mov %rsp,%rbp 4: sub $0x60,%rsp 4: sub $0x228,%rsp 8: mov %rbx,-0x8(%rbp) b: mov %rbx,-0x228(%rbp) // prologue 12: mov %r13,-0x220(%rbp) 19: mov %r14,-0x218(%rbp) 20: mov %r15,-0x210(%rbp) 27: xor %eax,%eax // clear A c: xor %ebx,%ebx 29: xor %r13,%r13 // clear X e: mov 0x68(%rdi),%r9d 2c: mov 0x68(%rdi),%r9d 12: sub 0x6c(%rdi),%r9d 30: sub 0x6c(%rdi),%r9d 16: mov 0xd8(%rdi),%r8 34: mov 0xd8(%rdi),%r10 3b: mov %rdi,%rbx 1d: mov $0xc,%esi 3e: mov $0xc,%esi 22: callq 0xffffffffe1021e15 43: callq 0xffffffffe102bd75 27: cmp $0x86dd,%eax 48: cmp $0x86dd,%rax 2c: jne 0x0000000000000069 4f: jne 0x000000000000009a 2e: mov $0x14,%esi 51: mov $0x14,%esi 33: callq 0xffffffffe1021e31 56: callq 0xffffffffe102bd91 38: cmp $0x84,%eax 5b: cmp $0x84,%rax 3d: je 0x0000000000000049 62: je 0x0000000000000074 3f: cmp $0x6,%eax 64: cmp $0x6,%rax 42: je 0x0000000000000049 68: je 0x0000000000000074 44: cmp $0x11,%eax 6a: cmp $0x11,%rax 47: jne 0x00000000000000c6 6e: jne 0x0000000000000117 49: mov $0x36,%esi 74: mov $0x36,%esi 4e: callq 0xffffffffe1021e15 79: callq 0xffffffffe102bd75 53: cmp $0x16,%eax 7e: cmp $0x16,%rax 56: je 0x00000000000000bf 82: je 0x0000000000000110 58: mov $0x38,%esi 88: mov $0x38,%esi 5d: callq 0xffffffffe1021e15 8d: callq 0xffffffffe102bd75 62: cmp $0x16,%eax 92: cmp $0x16,%rax 65: je 0x00000000000000bf 96: je 0x0000000000000110 67: jmp 0x00000000000000c6 98: jmp 0x0000000000000117 69: cmp $0x800,%eax 9a: cmp $0x800,%rax 6e: jne 0x00000000000000c6 a1: jne 0x0000000000000117 70: mov $0x17,%esi a3: mov $0x17,%esi 75: callq 0xffffffffe1021e31 a8: callq 0xffffffffe102bd91 7a: cmp $0x84,%eax ad: cmp $0x84,%rax 7f: je 0x000000000000008b b4: je 0x00000000000000c2 81: cmp $0x6,%eax b6: cmp $0x6,%rax 84: je 0x000000000000008b ba: je 0x00000000000000c2 86: cmp $0x11,%eax bc: cmp $0x11,%rax 89: jne 0x00000000000000c6 c0: jne 0x0000000000000117 8b: mov $0x14,%esi c2: mov $0x14,%esi 90: callq 0xffffffffe1021e15 c7: callq 0xffffffffe102bd75 95: test $0x1fff,%ax cc: test $0x1fff,%rax 99: jne 0x00000000000000c6 d3: jne 0x0000000000000117 d5: mov %rax,%r14 9b: mov $0xe,%esi d8: mov $0xe,%esi a0: callq 0xffffffffe1021e44 dd: callq 0xffffffffe102bd91 // MSH e2: and $0xf,%eax e5: shl $0x2,%eax e8: mov %rax,%r13 eb: mov %r14,%rax ee: mov %r13,%rsi a5: lea 0xe(%rbx),%esi f1: add $0xe,%esi a8: callq 0xffffffffe1021e0d f4: callq 0xffffffffe102bd6d ad: cmp $0x16,%eax f9: cmp $0x16,%rax b0: je 0x00000000000000bf fd: je 0x0000000000000110 ff: mov %r13,%rsi b2: lea 0x10(%rbx),%esi 102: add $0x10,%esi b5: callq 0xffffffffe1021e0d 105: callq 0xffffffffe102bd6d ba: cmp $0x16,%eax 10a: cmp $0x16,%rax bd: jne 0x00000000000000c6 10e: jne 0x0000000000000117 bf: mov $0xffff,%eax 110: mov $0xffff,%eax c4: jmp 0x00000000000000c8 115: jmp 0x000000000000011c c6: xor %eax,%eax 117: mov $0x0,%eax c8: mov -0x8(%rbp),%rbx 11c: mov -0x228(%rbp),%rbx // epilogue cc: leaveq 123: mov -0x220(%rbp),%r13 cd: retq 12a: mov -0x218(%rbp),%r14 131: mov -0x210(%rbp),%r15 138: leaveq 139: retq On fully cached SKBs both JITed functions take 12 nsec to execute. BPF interpreter executes the program in 30 nsec. The difference in generated assembler is due to the following: Old BPF imlements LDX_MSH instruction via sk_load_byte_msh() helper function inside bpf_jit.S. New JIT removes the helper and does it explicitly, so ldx_msh cost is the same for both JITs, but generated code looks longer. New JIT has 4 registers to save, so prologue/epilogue are larger, but the cost is within noise on x64. Old JIT checks whether first insn clears A and if not emits 'xor %eax,%eax'. New JIT clears %rax unconditionally. 2. old BPF JIT doesn't support ANC_NLATTR, ANC_PAY_OFFSET, ANC_RANDOM extensions. New JIT supports all BPF extensions. Performance of such filters improves 2-4 times depending on a filter. The longer the filter the higher performance gain. Synthetic benchmarks with many ancillary loads see 20x speedup which seems to be the maximum gain from JIT Notes: . net.core.bpf_jit_enable=2 + tools/net/bpf_jit_disasm is still functional and can be used to see generated assembler . there are two jit_compile() functions and code flow for classic filters is: sk_attach_filter() - load classic BPF bpf_jit_compile() - try to JIT from classic BPF sk_convert_filter() - convert classic to internal bpf_int_jit_compile() - JIT from internal BPF seccomp and tracing filters will just call bpf_int_jit_compile() Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 20:50:46 -06:00
jmp_offset = ctx->cleanup_addr - addrs[i];
goto emit_jmp;
}
bpf: x86: fix epilogue generation for eBPF programs classic BPF has a restriction that last insn is always BPF_RET. eBPF doesn't have BPF_RET instruction and this restriction. It has BPF_EXIT insn which can appear anywhere in the program one or more times and it doesn't have to be last insn. Fix eBPF JIT to emit epilogue when first BPF_EXIT is seen and all other BPF_EXIT instructions will be emitted as jump. Since jump offset to epilogue is computed as: jmp_offset = ctx->cleanup_addr - addrs[i] we need to change type of cleanup_addr to signed to compute the offset as: (long long) ((int)20 - (int)30) instead of: (long long) ((unsigned int)20 - (int)30) Fixes: 622582786c9e ("net: filter: x86: internal BPF JIT") Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-11-29 15:46:13 -07:00
seen_exit = true;
net: filter: x86: internal BPF JIT Maps all internal BPF instructions into x86_64 instructions. This patch replaces original BPF x64 JIT with internal BPF x64 JIT. sysctl net.core.bpf_jit_enable is reused as on/off switch. Performance: 1. old BPF JIT and internal BPF JIT generate equivalent x86_64 code. No performance difference is observed for filters that were JIT-able before Example assembler code for BPF filter "tcpdump port 22" original BPF -> old JIT: original BPF -> internal BPF -> new JIT: 0: push %rbp 0: push %rbp 1: mov %rsp,%rbp 1: mov %rsp,%rbp 4: sub $0x60,%rsp 4: sub $0x228,%rsp 8: mov %rbx,-0x8(%rbp) b: mov %rbx,-0x228(%rbp) // prologue 12: mov %r13,-0x220(%rbp) 19: mov %r14,-0x218(%rbp) 20: mov %r15,-0x210(%rbp) 27: xor %eax,%eax // clear A c: xor %ebx,%ebx 29: xor %r13,%r13 // clear X e: mov 0x68(%rdi),%r9d 2c: mov 0x68(%rdi),%r9d 12: sub 0x6c(%rdi),%r9d 30: sub 0x6c(%rdi),%r9d 16: mov 0xd8(%rdi),%r8 34: mov 0xd8(%rdi),%r10 3b: mov %rdi,%rbx 1d: mov $0xc,%esi 3e: mov $0xc,%esi 22: callq 0xffffffffe1021e15 43: callq 0xffffffffe102bd75 27: cmp $0x86dd,%eax 48: cmp $0x86dd,%rax 2c: jne 0x0000000000000069 4f: jne 0x000000000000009a 2e: mov $0x14,%esi 51: mov $0x14,%esi 33: callq 0xffffffffe1021e31 56: callq 0xffffffffe102bd91 38: cmp $0x84,%eax 5b: cmp $0x84,%rax 3d: je 0x0000000000000049 62: je 0x0000000000000074 3f: cmp $0x6,%eax 64: cmp $0x6,%rax 42: je 0x0000000000000049 68: je 0x0000000000000074 44: cmp $0x11,%eax 6a: cmp $0x11,%rax 47: jne 0x00000000000000c6 6e: jne 0x0000000000000117 49: mov $0x36,%esi 74: mov $0x36,%esi 4e: callq 0xffffffffe1021e15 79: callq 0xffffffffe102bd75 53: cmp $0x16,%eax 7e: cmp $0x16,%rax 56: je 0x00000000000000bf 82: je 0x0000000000000110 58: mov $0x38,%esi 88: mov $0x38,%esi 5d: callq 0xffffffffe1021e15 8d: callq 0xffffffffe102bd75 62: cmp $0x16,%eax 92: cmp $0x16,%rax 65: je 0x00000000000000bf 96: je 0x0000000000000110 67: jmp 0x00000000000000c6 98: jmp 0x0000000000000117 69: cmp $0x800,%eax 9a: cmp $0x800,%rax 6e: jne 0x00000000000000c6 a1: jne 0x0000000000000117 70: mov $0x17,%esi a3: mov $0x17,%esi 75: callq 0xffffffffe1021e31 a8: callq 0xffffffffe102bd91 7a: cmp $0x84,%eax ad: cmp $0x84,%rax 7f: je 0x000000000000008b b4: je 0x00000000000000c2 81: cmp $0x6,%eax b6: cmp $0x6,%rax 84: je 0x000000000000008b ba: je 0x00000000000000c2 86: cmp $0x11,%eax bc: cmp $0x11,%rax 89: jne 0x00000000000000c6 c0: jne 0x0000000000000117 8b: mov $0x14,%esi c2: mov $0x14,%esi 90: callq 0xffffffffe1021e15 c7: callq 0xffffffffe102bd75 95: test $0x1fff,%ax cc: test $0x1fff,%rax 99: jne 0x00000000000000c6 d3: jne 0x0000000000000117 d5: mov %rax,%r14 9b: mov $0xe,%esi d8: mov $0xe,%esi a0: callq 0xffffffffe1021e44 dd: callq 0xffffffffe102bd91 // MSH e2: and $0xf,%eax e5: shl $0x2,%eax e8: mov %rax,%r13 eb: mov %r14,%rax ee: mov %r13,%rsi a5: lea 0xe(%rbx),%esi f1: add $0xe,%esi a8: callq 0xffffffffe1021e0d f4: callq 0xffffffffe102bd6d ad: cmp $0x16,%eax f9: cmp $0x16,%rax b0: je 0x00000000000000bf fd: je 0x0000000000000110 ff: mov %r13,%rsi b2: lea 0x10(%rbx),%esi 102: add $0x10,%esi b5: callq 0xffffffffe1021e0d 105: callq 0xffffffffe102bd6d ba: cmp $0x16,%eax 10a: cmp $0x16,%rax bd: jne 0x00000000000000c6 10e: jne 0x0000000000000117 bf: mov $0xffff,%eax 110: mov $0xffff,%eax c4: jmp 0x00000000000000c8 115: jmp 0x000000000000011c c6: xor %eax,%eax 117: mov $0x0,%eax c8: mov -0x8(%rbp),%rbx 11c: mov -0x228(%rbp),%rbx // epilogue cc: leaveq 123: mov -0x220(%rbp),%r13 cd: retq 12a: mov -0x218(%rbp),%r14 131: mov -0x210(%rbp),%r15 138: leaveq 139: retq On fully cached SKBs both JITed functions take 12 nsec to execute. BPF interpreter executes the program in 30 nsec. The difference in generated assembler is due to the following: Old BPF imlements LDX_MSH instruction via sk_load_byte_msh() helper function inside bpf_jit.S. New JIT removes the helper and does it explicitly, so ldx_msh cost is the same for both JITs, but generated code looks longer. New JIT has 4 registers to save, so prologue/epilogue are larger, but the cost is within noise on x64. Old JIT checks whether first insn clears A and if not emits 'xor %eax,%eax'. New JIT clears %rax unconditionally. 2. old BPF JIT doesn't support ANC_NLATTR, ANC_PAY_OFFSET, ANC_RANDOM extensions. New JIT supports all BPF extensions. Performance of such filters improves 2-4 times depending on a filter. The longer the filter the higher performance gain. Synthetic benchmarks with many ancillary loads see 20x speedup which seems to be the maximum gain from JIT Notes: . net.core.bpf_jit_enable=2 + tools/net/bpf_jit_disasm is still functional and can be used to see generated assembler . there are two jit_compile() functions and code flow for classic filters is: sk_attach_filter() - load classic BPF bpf_jit_compile() - try to JIT from classic BPF sk_convert_filter() - convert classic to internal bpf_int_jit_compile() - JIT from internal BPF seccomp and tracing filters will just call bpf_int_jit_compile() Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 20:50:46 -06:00
/* update cleanup_addr */
ctx->cleanup_addr = proglen;
/* mov rbx, qword ptr [rbp-X] */
x86: bpf_jit: implement bpf_tail_call() helper bpf_tail_call() arguments: ctx - context pointer jmp_table - one of BPF_MAP_TYPE_PROG_ARRAY maps used as the jump table index - index in the jump table In this implementation x64 JIT bypasses stack unwind and jumps into the callee program after prologue, so the callee program reuses the same stack. The logic can be roughly expressed in C like: u32 tail_call_cnt; void *jumptable[2] = { &&label1, &&label2 }; int bpf_prog1(void *ctx) { label1: ... } int bpf_prog2(void *ctx) { label2: ... } int bpf_prog1(void *ctx) { ... if (tail_call_cnt++ < MAX_TAIL_CALL_CNT) goto *jumptable[index]; ... and pass my 'ctx' to callee ... ... fall through if no entry in jumptable ... } Note that 'skip current program epilogue and next program prologue' is an optimization. Other JITs don't have to do it the same way. >From safety point of view it's valid as well, since programs always initialize the stack before use, so any residue in the stack left by the current program is not going be read. The same verifier checks are done for the calls from the kernel into all bpf programs. Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-19 17:59:04 -06:00
EMIT3_off32(0x48, 0x8B, 0x9D, -STACKSIZE);
net: filter: x86: internal BPF JIT Maps all internal BPF instructions into x86_64 instructions. This patch replaces original BPF x64 JIT with internal BPF x64 JIT. sysctl net.core.bpf_jit_enable is reused as on/off switch. Performance: 1. old BPF JIT and internal BPF JIT generate equivalent x86_64 code. No performance difference is observed for filters that were JIT-able before Example assembler code for BPF filter "tcpdump port 22" original BPF -> old JIT: original BPF -> internal BPF -> new JIT: 0: push %rbp 0: push %rbp 1: mov %rsp,%rbp 1: mov %rsp,%rbp 4: sub $0x60,%rsp 4: sub $0x228,%rsp 8: mov %rbx,-0x8(%rbp) b: mov %rbx,-0x228(%rbp) // prologue 12: mov %r13,-0x220(%rbp) 19: mov %r14,-0x218(%rbp) 20: mov %r15,-0x210(%rbp) 27: xor %eax,%eax // clear A c: xor %ebx,%ebx 29: xor %r13,%r13 // clear X e: mov 0x68(%rdi),%r9d 2c: mov 0x68(%rdi),%r9d 12: sub 0x6c(%rdi),%r9d 30: sub 0x6c(%rdi),%r9d 16: mov 0xd8(%rdi),%r8 34: mov 0xd8(%rdi),%r10 3b: mov %rdi,%rbx 1d: mov $0xc,%esi 3e: mov $0xc,%esi 22: callq 0xffffffffe1021e15 43: callq 0xffffffffe102bd75 27: cmp $0x86dd,%eax 48: cmp $0x86dd,%rax 2c: jne 0x0000000000000069 4f: jne 0x000000000000009a 2e: mov $0x14,%esi 51: mov $0x14,%esi 33: callq 0xffffffffe1021e31 56: callq 0xffffffffe102bd91 38: cmp $0x84,%eax 5b: cmp $0x84,%rax 3d: je 0x0000000000000049 62: je 0x0000000000000074 3f: cmp $0x6,%eax 64: cmp $0x6,%rax 42: je 0x0000000000000049 68: je 0x0000000000000074 44: cmp $0x11,%eax 6a: cmp $0x11,%rax 47: jne 0x00000000000000c6 6e: jne 0x0000000000000117 49: mov $0x36,%esi 74: mov $0x36,%esi 4e: callq 0xffffffffe1021e15 79: callq 0xffffffffe102bd75 53: cmp $0x16,%eax 7e: cmp $0x16,%rax 56: je 0x00000000000000bf 82: je 0x0000000000000110 58: mov $0x38,%esi 88: mov $0x38,%esi 5d: callq 0xffffffffe1021e15 8d: callq 0xffffffffe102bd75 62: cmp $0x16,%eax 92: cmp $0x16,%rax 65: je 0x00000000000000bf 96: je 0x0000000000000110 67: jmp 0x00000000000000c6 98: jmp 0x0000000000000117 69: cmp $0x800,%eax 9a: cmp $0x800,%rax 6e: jne 0x00000000000000c6 a1: jne 0x0000000000000117 70: mov $0x17,%esi a3: mov $0x17,%esi 75: callq 0xffffffffe1021e31 a8: callq 0xffffffffe102bd91 7a: cmp $0x84,%eax ad: cmp $0x84,%rax 7f: je 0x000000000000008b b4: je 0x00000000000000c2 81: cmp $0x6,%eax b6: cmp $0x6,%rax 84: je 0x000000000000008b ba: je 0x00000000000000c2 86: cmp $0x11,%eax bc: cmp $0x11,%rax 89: jne 0x00000000000000c6 c0: jne 0x0000000000000117 8b: mov $0x14,%esi c2: mov $0x14,%esi 90: callq 0xffffffffe1021e15 c7: callq 0xffffffffe102bd75 95: test $0x1fff,%ax cc: test $0x1fff,%rax 99: jne 0x00000000000000c6 d3: jne 0x0000000000000117 d5: mov %rax,%r14 9b: mov $0xe,%esi d8: mov $0xe,%esi a0: callq 0xffffffffe1021e44 dd: callq 0xffffffffe102bd91 // MSH e2: and $0xf,%eax e5: shl $0x2,%eax e8: mov %rax,%r13 eb: mov %r14,%rax ee: mov %r13,%rsi a5: lea 0xe(%rbx),%esi f1: add $0xe,%esi a8: callq 0xffffffffe1021e0d f4: callq 0xffffffffe102bd6d ad: cmp $0x16,%eax f9: cmp $0x16,%rax b0: je 0x00000000000000bf fd: je 0x0000000000000110 ff: mov %r13,%rsi b2: lea 0x10(%rbx),%esi 102: add $0x10,%esi b5: callq 0xffffffffe1021e0d 105: callq 0xffffffffe102bd6d ba: cmp $0x16,%eax 10a: cmp $0x16,%rax bd: jne 0x00000000000000c6 10e: jne 0x0000000000000117 bf: mov $0xffff,%eax 110: mov $0xffff,%eax c4: jmp 0x00000000000000c8 115: jmp 0x000000000000011c c6: xor %eax,%eax 117: mov $0x0,%eax c8: mov -0x8(%rbp),%rbx 11c: mov -0x228(%rbp),%rbx // epilogue cc: leaveq 123: mov -0x220(%rbp),%r13 cd: retq 12a: mov -0x218(%rbp),%r14 131: mov -0x210(%rbp),%r15 138: leaveq 139: retq On fully cached SKBs both JITed functions take 12 nsec to execute. BPF interpreter executes the program in 30 nsec. The difference in generated assembler is due to the following: Old BPF imlements LDX_MSH instruction via sk_load_byte_msh() helper function inside bpf_jit.S. New JIT removes the helper and does it explicitly, so ldx_msh cost is the same for both JITs, but generated code looks longer. New JIT has 4 registers to save, so prologue/epilogue are larger, but the cost is within noise on x64. Old JIT checks whether first insn clears A and if not emits 'xor %eax,%eax'. New JIT clears %rax unconditionally. 2. old BPF JIT doesn't support ANC_NLATTR, ANC_PAY_OFFSET, ANC_RANDOM extensions. New JIT supports all BPF extensions. Performance of such filters improves 2-4 times depending on a filter. The longer the filter the higher performance gain. Synthetic benchmarks with many ancillary loads see 20x speedup which seems to be the maximum gain from JIT Notes: . net.core.bpf_jit_enable=2 + tools/net/bpf_jit_disasm is still functional and can be used to see generated assembler . there are two jit_compile() functions and code flow for classic filters is: sk_attach_filter() - load classic BPF bpf_jit_compile() - try to JIT from classic BPF sk_convert_filter() - convert classic to internal bpf_int_jit_compile() - JIT from internal BPF seccomp and tracing filters will just call bpf_int_jit_compile() Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 20:50:46 -06:00
/* mov r13, qword ptr [rbp-X] */
x86: bpf_jit: implement bpf_tail_call() helper bpf_tail_call() arguments: ctx - context pointer jmp_table - one of BPF_MAP_TYPE_PROG_ARRAY maps used as the jump table index - index in the jump table In this implementation x64 JIT bypasses stack unwind and jumps into the callee program after prologue, so the callee program reuses the same stack. The logic can be roughly expressed in C like: u32 tail_call_cnt; void *jumptable[2] = { &&label1, &&label2 }; int bpf_prog1(void *ctx) { label1: ... } int bpf_prog2(void *ctx) { label2: ... } int bpf_prog1(void *ctx) { ... if (tail_call_cnt++ < MAX_TAIL_CALL_CNT) goto *jumptable[index]; ... and pass my 'ctx' to callee ... ... fall through if no entry in jumptable ... } Note that 'skip current program epilogue and next program prologue' is an optimization. Other JITs don't have to do it the same way. >From safety point of view it's valid as well, since programs always initialize the stack before use, so any residue in the stack left by the current program is not going be read. The same verifier checks are done for the calls from the kernel into all bpf programs. Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-19 17:59:04 -06:00
EMIT3_off32(0x4C, 0x8B, 0xAD, -STACKSIZE + 8);
net: filter: x86: internal BPF JIT Maps all internal BPF instructions into x86_64 instructions. This patch replaces original BPF x64 JIT with internal BPF x64 JIT. sysctl net.core.bpf_jit_enable is reused as on/off switch. Performance: 1. old BPF JIT and internal BPF JIT generate equivalent x86_64 code. No performance difference is observed for filters that were JIT-able before Example assembler code for BPF filter "tcpdump port 22" original BPF -> old JIT: original BPF -> internal BPF -> new JIT: 0: push %rbp 0: push %rbp 1: mov %rsp,%rbp 1: mov %rsp,%rbp 4: sub $0x60,%rsp 4: sub $0x228,%rsp 8: mov %rbx,-0x8(%rbp) b: mov %rbx,-0x228(%rbp) // prologue 12: mov %r13,-0x220(%rbp) 19: mov %r14,-0x218(%rbp) 20: mov %r15,-0x210(%rbp) 27: xor %eax,%eax // clear A c: xor %ebx,%ebx 29: xor %r13,%r13 // clear X e: mov 0x68(%rdi),%r9d 2c: mov 0x68(%rdi),%r9d 12: sub 0x6c(%rdi),%r9d 30: sub 0x6c(%rdi),%r9d 16: mov 0xd8(%rdi),%r8 34: mov 0xd8(%rdi),%r10 3b: mov %rdi,%rbx 1d: mov $0xc,%esi 3e: mov $0xc,%esi 22: callq 0xffffffffe1021e15 43: callq 0xffffffffe102bd75 27: cmp $0x86dd,%eax 48: cmp $0x86dd,%rax 2c: jne 0x0000000000000069 4f: jne 0x000000000000009a 2e: mov $0x14,%esi 51: mov $0x14,%esi 33: callq 0xffffffffe1021e31 56: callq 0xffffffffe102bd91 38: cmp $0x84,%eax 5b: cmp $0x84,%rax 3d: je 0x0000000000000049 62: je 0x0000000000000074 3f: cmp $0x6,%eax 64: cmp $0x6,%rax 42: je 0x0000000000000049 68: je 0x0000000000000074 44: cmp $0x11,%eax 6a: cmp $0x11,%rax 47: jne 0x00000000000000c6 6e: jne 0x0000000000000117 49: mov $0x36,%esi 74: mov $0x36,%esi 4e: callq 0xffffffffe1021e15 79: callq 0xffffffffe102bd75 53: cmp $0x16,%eax 7e: cmp $0x16,%rax 56: je 0x00000000000000bf 82: je 0x0000000000000110 58: mov $0x38,%esi 88: mov $0x38,%esi 5d: callq 0xffffffffe1021e15 8d: callq 0xffffffffe102bd75 62: cmp $0x16,%eax 92: cmp $0x16,%rax 65: je 0x00000000000000bf 96: je 0x0000000000000110 67: jmp 0x00000000000000c6 98: jmp 0x0000000000000117 69: cmp $0x800,%eax 9a: cmp $0x800,%rax 6e: jne 0x00000000000000c6 a1: jne 0x0000000000000117 70: mov $0x17,%esi a3: mov $0x17,%esi 75: callq 0xffffffffe1021e31 a8: callq 0xffffffffe102bd91 7a: cmp $0x84,%eax ad: cmp $0x84,%rax 7f: je 0x000000000000008b b4: je 0x00000000000000c2 81: cmp $0x6,%eax b6: cmp $0x6,%rax 84: je 0x000000000000008b ba: je 0x00000000000000c2 86: cmp $0x11,%eax bc: cmp $0x11,%rax 89: jne 0x00000000000000c6 c0: jne 0x0000000000000117 8b: mov $0x14,%esi c2: mov $0x14,%esi 90: callq 0xffffffffe1021e15 c7: callq 0xffffffffe102bd75 95: test $0x1fff,%ax cc: test $0x1fff,%rax 99: jne 0x00000000000000c6 d3: jne 0x0000000000000117 d5: mov %rax,%r14 9b: mov $0xe,%esi d8: mov $0xe,%esi a0: callq 0xffffffffe1021e44 dd: callq 0xffffffffe102bd91 // MSH e2: and $0xf,%eax e5: shl $0x2,%eax e8: mov %rax,%r13 eb: mov %r14,%rax ee: mov %r13,%rsi a5: lea 0xe(%rbx),%esi f1: add $0xe,%esi a8: callq 0xffffffffe1021e0d f4: callq 0xffffffffe102bd6d ad: cmp $0x16,%eax f9: cmp $0x16,%rax b0: je 0x00000000000000bf fd: je 0x0000000000000110 ff: mov %r13,%rsi b2: lea 0x10(%rbx),%esi 102: add $0x10,%esi b5: callq 0xffffffffe1021e0d 105: callq 0xffffffffe102bd6d ba: cmp $0x16,%eax 10a: cmp $0x16,%rax bd: jne 0x00000000000000c6 10e: jne 0x0000000000000117 bf: mov $0xffff,%eax 110: mov $0xffff,%eax c4: jmp 0x00000000000000c8 115: jmp 0x000000000000011c c6: xor %eax,%eax 117: mov $0x0,%eax c8: mov -0x8(%rbp),%rbx 11c: mov -0x228(%rbp),%rbx // epilogue cc: leaveq 123: mov -0x220(%rbp),%r13 cd: retq 12a: mov -0x218(%rbp),%r14 131: mov -0x210(%rbp),%r15 138: leaveq 139: retq On fully cached SKBs both JITed functions take 12 nsec to execute. BPF interpreter executes the program in 30 nsec. The difference in generated assembler is due to the following: Old BPF imlements LDX_MSH instruction via sk_load_byte_msh() helper function inside bpf_jit.S. New JIT removes the helper and does it explicitly, so ldx_msh cost is the same for both JITs, but generated code looks longer. New JIT has 4 registers to save, so prologue/epilogue are larger, but the cost is within noise on x64. Old JIT checks whether first insn clears A and if not emits 'xor %eax,%eax'. New JIT clears %rax unconditionally. 2. old BPF JIT doesn't support ANC_NLATTR, ANC_PAY_OFFSET, ANC_RANDOM extensions. New JIT supports all BPF extensions. Performance of such filters improves 2-4 times depending on a filter. The longer the filter the higher performance gain. Synthetic benchmarks with many ancillary loads see 20x speedup which seems to be the maximum gain from JIT Notes: . net.core.bpf_jit_enable=2 + tools/net/bpf_jit_disasm is still functional and can be used to see generated assembler . there are two jit_compile() functions and code flow for classic filters is: sk_attach_filter() - load classic BPF bpf_jit_compile() - try to JIT from classic BPF sk_convert_filter() - convert classic to internal bpf_int_jit_compile() - JIT from internal BPF seccomp and tracing filters will just call bpf_int_jit_compile() Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 20:50:46 -06:00
/* mov r14, qword ptr [rbp-X] */
x86: bpf_jit: implement bpf_tail_call() helper bpf_tail_call() arguments: ctx - context pointer jmp_table - one of BPF_MAP_TYPE_PROG_ARRAY maps used as the jump table index - index in the jump table In this implementation x64 JIT bypasses stack unwind and jumps into the callee program after prologue, so the callee program reuses the same stack. The logic can be roughly expressed in C like: u32 tail_call_cnt; void *jumptable[2] = { &&label1, &&label2 }; int bpf_prog1(void *ctx) { label1: ... } int bpf_prog2(void *ctx) { label2: ... } int bpf_prog1(void *ctx) { ... if (tail_call_cnt++ < MAX_TAIL_CALL_CNT) goto *jumptable[index]; ... and pass my 'ctx' to callee ... ... fall through if no entry in jumptable ... } Note that 'skip current program epilogue and next program prologue' is an optimization. Other JITs don't have to do it the same way. >From safety point of view it's valid as well, since programs always initialize the stack before use, so any residue in the stack left by the current program is not going be read. The same verifier checks are done for the calls from the kernel into all bpf programs. Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-19 17:59:04 -06:00
EMIT3_off32(0x4C, 0x8B, 0xB5, -STACKSIZE + 16);
net: filter: x86: internal BPF JIT Maps all internal BPF instructions into x86_64 instructions. This patch replaces original BPF x64 JIT with internal BPF x64 JIT. sysctl net.core.bpf_jit_enable is reused as on/off switch. Performance: 1. old BPF JIT and internal BPF JIT generate equivalent x86_64 code. No performance difference is observed for filters that were JIT-able before Example assembler code for BPF filter "tcpdump port 22" original BPF -> old JIT: original BPF -> internal BPF -> new JIT: 0: push %rbp 0: push %rbp 1: mov %rsp,%rbp 1: mov %rsp,%rbp 4: sub $0x60,%rsp 4: sub $0x228,%rsp 8: mov %rbx,-0x8(%rbp) b: mov %rbx,-0x228(%rbp) // prologue 12: mov %r13,-0x220(%rbp) 19: mov %r14,-0x218(%rbp) 20: mov %r15,-0x210(%rbp) 27: xor %eax,%eax // clear A c: xor %ebx,%ebx 29: xor %r13,%r13 // clear X e: mov 0x68(%rdi),%r9d 2c: mov 0x68(%rdi),%r9d 12: sub 0x6c(%rdi),%r9d 30: sub 0x6c(%rdi),%r9d 16: mov 0xd8(%rdi),%r8 34: mov 0xd8(%rdi),%r10 3b: mov %rdi,%rbx 1d: mov $0xc,%esi 3e: mov $0xc,%esi 22: callq 0xffffffffe1021e15 43: callq 0xffffffffe102bd75 27: cmp $0x86dd,%eax 48: cmp $0x86dd,%rax 2c: jne 0x0000000000000069 4f: jne 0x000000000000009a 2e: mov $0x14,%esi 51: mov $0x14,%esi 33: callq 0xffffffffe1021e31 56: callq 0xffffffffe102bd91 38: cmp $0x84,%eax 5b: cmp $0x84,%rax 3d: je 0x0000000000000049 62: je 0x0000000000000074 3f: cmp $0x6,%eax 64: cmp $0x6,%rax 42: je 0x0000000000000049 68: je 0x0000000000000074 44: cmp $0x11,%eax 6a: cmp $0x11,%rax 47: jne 0x00000000000000c6 6e: jne 0x0000000000000117 49: mov $0x36,%esi 74: mov $0x36,%esi 4e: callq 0xffffffffe1021e15 79: callq 0xffffffffe102bd75 53: cmp $0x16,%eax 7e: cmp $0x16,%rax 56: je 0x00000000000000bf 82: je 0x0000000000000110 58: mov $0x38,%esi 88: mov $0x38,%esi 5d: callq 0xffffffffe1021e15 8d: callq 0xffffffffe102bd75 62: cmp $0x16,%eax 92: cmp $0x16,%rax 65: je 0x00000000000000bf 96: je 0x0000000000000110 67: jmp 0x00000000000000c6 98: jmp 0x0000000000000117 69: cmp $0x800,%eax 9a: cmp $0x800,%rax 6e: jne 0x00000000000000c6 a1: jne 0x0000000000000117 70: mov $0x17,%esi a3: mov $0x17,%esi 75: callq 0xffffffffe1021e31 a8: callq 0xffffffffe102bd91 7a: cmp $0x84,%eax ad: cmp $0x84,%rax 7f: je 0x000000000000008b b4: je 0x00000000000000c2 81: cmp $0x6,%eax b6: cmp $0x6,%rax 84: je 0x000000000000008b ba: je 0x00000000000000c2 86: cmp $0x11,%eax bc: cmp $0x11,%rax 89: jne 0x00000000000000c6 c0: jne 0x0000000000000117 8b: mov $0x14,%esi c2: mov $0x14,%esi 90: callq 0xffffffffe1021e15 c7: callq 0xffffffffe102bd75 95: test $0x1fff,%ax cc: test $0x1fff,%rax 99: jne 0x00000000000000c6 d3: jne 0x0000000000000117 d5: mov %rax,%r14 9b: mov $0xe,%esi d8: mov $0xe,%esi a0: callq 0xffffffffe1021e44 dd: callq 0xffffffffe102bd91 // MSH e2: and $0xf,%eax e5: shl $0x2,%eax e8: mov %rax,%r13 eb: mov %r14,%rax ee: mov %r13,%rsi a5: lea 0xe(%rbx),%esi f1: add $0xe,%esi a8: callq 0xffffffffe1021e0d f4: callq 0xffffffffe102bd6d ad: cmp $0x16,%eax f9: cmp $0x16,%rax b0: je 0x00000000000000bf fd: je 0x0000000000000110 ff: mov %r13,%rsi b2: lea 0x10(%rbx),%esi 102: add $0x10,%esi b5: callq 0xffffffffe1021e0d 105: callq 0xffffffffe102bd6d ba: cmp $0x16,%eax 10a: cmp $0x16,%rax bd: jne 0x00000000000000c6 10e: jne 0x0000000000000117 bf: mov $0xffff,%eax 110: mov $0xffff,%eax c4: jmp 0x00000000000000c8 115: jmp 0x000000000000011c c6: xor %eax,%eax 117: mov $0x0,%eax c8: mov -0x8(%rbp),%rbx 11c: mov -0x228(%rbp),%rbx // epilogue cc: leaveq 123: mov -0x220(%rbp),%r13 cd: retq 12a: mov -0x218(%rbp),%r14 131: mov -0x210(%rbp),%r15 138: leaveq 139: retq On fully cached SKBs both JITed functions take 12 nsec to execute. BPF interpreter executes the program in 30 nsec. The difference in generated assembler is due to the following: Old BPF imlements LDX_MSH instruction via sk_load_byte_msh() helper function inside bpf_jit.S. New JIT removes the helper and does it explicitly, so ldx_msh cost is the same for both JITs, but generated code looks longer. New JIT has 4 registers to save, so prologue/epilogue are larger, but the cost is within noise on x64. Old JIT checks whether first insn clears A and if not emits 'xor %eax,%eax'. New JIT clears %rax unconditionally. 2. old BPF JIT doesn't support ANC_NLATTR, ANC_PAY_OFFSET, ANC_RANDOM extensions. New JIT supports all BPF extensions. Performance of such filters improves 2-4 times depending on a filter. The longer the filter the higher performance gain. Synthetic benchmarks with many ancillary loads see 20x speedup which seems to be the maximum gain from JIT Notes: . net.core.bpf_jit_enable=2 + tools/net/bpf_jit_disasm is still functional and can be used to see generated assembler . there are two jit_compile() functions and code flow for classic filters is: sk_attach_filter() - load classic BPF bpf_jit_compile() - try to JIT from classic BPF sk_convert_filter() - convert classic to internal bpf_int_jit_compile() - JIT from internal BPF seccomp and tracing filters will just call bpf_int_jit_compile() Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 20:50:46 -06:00
/* mov r15, qword ptr [rbp-X] */
x86: bpf_jit: implement bpf_tail_call() helper bpf_tail_call() arguments: ctx - context pointer jmp_table - one of BPF_MAP_TYPE_PROG_ARRAY maps used as the jump table index - index in the jump table In this implementation x64 JIT bypasses stack unwind and jumps into the callee program after prologue, so the callee program reuses the same stack. The logic can be roughly expressed in C like: u32 tail_call_cnt; void *jumptable[2] = { &&label1, &&label2 }; int bpf_prog1(void *ctx) { label1: ... } int bpf_prog2(void *ctx) { label2: ... } int bpf_prog1(void *ctx) { ... if (tail_call_cnt++ < MAX_TAIL_CALL_CNT) goto *jumptable[index]; ... and pass my 'ctx' to callee ... ... fall through if no entry in jumptable ... } Note that 'skip current program epilogue and next program prologue' is an optimization. Other JITs don't have to do it the same way. >From safety point of view it's valid as well, since programs always initialize the stack before use, so any residue in the stack left by the current program is not going be read. The same verifier checks are done for the calls from the kernel into all bpf programs. Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-19 17:59:04 -06:00
EMIT3_off32(0x4C, 0x8B, 0xBD, -STACKSIZE + 24);
net: filter: x86: internal BPF JIT Maps all internal BPF instructions into x86_64 instructions. This patch replaces original BPF x64 JIT with internal BPF x64 JIT. sysctl net.core.bpf_jit_enable is reused as on/off switch. Performance: 1. old BPF JIT and internal BPF JIT generate equivalent x86_64 code. No performance difference is observed for filters that were JIT-able before Example assembler code for BPF filter "tcpdump port 22" original BPF -> old JIT: original BPF -> internal BPF -> new JIT: 0: push %rbp 0: push %rbp 1: mov %rsp,%rbp 1: mov %rsp,%rbp 4: sub $0x60,%rsp 4: sub $0x228,%rsp 8: mov %rbx,-0x8(%rbp) b: mov %rbx,-0x228(%rbp) // prologue 12: mov %r13,-0x220(%rbp) 19: mov %r14,-0x218(%rbp) 20: mov %r15,-0x210(%rbp) 27: xor %eax,%eax // clear A c: xor %ebx,%ebx 29: xor %r13,%r13 // clear X e: mov 0x68(%rdi),%r9d 2c: mov 0x68(%rdi),%r9d 12: sub 0x6c(%rdi),%r9d 30: sub 0x6c(%rdi),%r9d 16: mov 0xd8(%rdi),%r8 34: mov 0xd8(%rdi),%r10 3b: mov %rdi,%rbx 1d: mov $0xc,%esi 3e: mov $0xc,%esi 22: callq 0xffffffffe1021e15 43: callq 0xffffffffe102bd75 27: cmp $0x86dd,%eax 48: cmp $0x86dd,%rax 2c: jne 0x0000000000000069 4f: jne 0x000000000000009a 2e: mov $0x14,%esi 51: mov $0x14,%esi 33: callq 0xffffffffe1021e31 56: callq 0xffffffffe102bd91 38: cmp $0x84,%eax 5b: cmp $0x84,%rax 3d: je 0x0000000000000049 62: je 0x0000000000000074 3f: cmp $0x6,%eax 64: cmp $0x6,%rax 42: je 0x0000000000000049 68: je 0x0000000000000074 44: cmp $0x11,%eax 6a: cmp $0x11,%rax 47: jne 0x00000000000000c6 6e: jne 0x0000000000000117 49: mov $0x36,%esi 74: mov $0x36,%esi 4e: callq 0xffffffffe1021e15 79: callq 0xffffffffe102bd75 53: cmp $0x16,%eax 7e: cmp $0x16,%rax 56: je 0x00000000000000bf 82: je 0x0000000000000110 58: mov $0x38,%esi 88: mov $0x38,%esi 5d: callq 0xffffffffe1021e15 8d: callq 0xffffffffe102bd75 62: cmp $0x16,%eax 92: cmp $0x16,%rax 65: je 0x00000000000000bf 96: je 0x0000000000000110 67: jmp 0x00000000000000c6 98: jmp 0x0000000000000117 69: cmp $0x800,%eax 9a: cmp $0x800,%rax 6e: jne 0x00000000000000c6 a1: jne 0x0000000000000117 70: mov $0x17,%esi a3: mov $0x17,%esi 75: callq 0xffffffffe1021e31 a8: callq 0xffffffffe102bd91 7a: cmp $0x84,%eax ad: cmp $0x84,%rax 7f: je 0x000000000000008b b4: je 0x00000000000000c2 81: cmp $0x6,%eax b6: cmp $0x6,%rax 84: je 0x000000000000008b ba: je 0x00000000000000c2 86: cmp $0x11,%eax bc: cmp $0x11,%rax 89: jne 0x00000000000000c6 c0: jne 0x0000000000000117 8b: mov $0x14,%esi c2: mov $0x14,%esi 90: callq 0xffffffffe1021e15 c7: callq 0xffffffffe102bd75 95: test $0x1fff,%ax cc: test $0x1fff,%rax 99: jne 0x00000000000000c6 d3: jne 0x0000000000000117 d5: mov %rax,%r14 9b: mov $0xe,%esi d8: mov $0xe,%esi a0: callq 0xffffffffe1021e44 dd: callq 0xffffffffe102bd91 // MSH e2: and $0xf,%eax e5: shl $0x2,%eax e8: mov %rax,%r13 eb: mov %r14,%rax ee: mov %r13,%rsi a5: lea 0xe(%rbx),%esi f1: add $0xe,%esi a8: callq 0xffffffffe1021e0d f4: callq 0xffffffffe102bd6d ad: cmp $0x16,%eax f9: cmp $0x16,%rax b0: je 0x00000000000000bf fd: je 0x0000000000000110 ff: mov %r13,%rsi b2: lea 0x10(%rbx),%esi 102: add $0x10,%esi b5: callq 0xffffffffe1021e0d 105: callq 0xffffffffe102bd6d ba: cmp $0x16,%eax 10a: cmp $0x16,%rax bd: jne 0x00000000000000c6 10e: jne 0x0000000000000117 bf: mov $0xffff,%eax 110: mov $0xffff,%eax c4: jmp 0x00000000000000c8 115: jmp 0x000000000000011c c6: xor %eax,%eax 117: mov $0x0,%eax c8: mov -0x8(%rbp),%rbx 11c: mov -0x228(%rbp),%rbx // epilogue cc: leaveq 123: mov -0x220(%rbp),%r13 cd: retq 12a: mov -0x218(%rbp),%r14 131: mov -0x210(%rbp),%r15 138: leaveq 139: retq On fully cached SKBs both JITed functions take 12 nsec to execute. BPF interpreter executes the program in 30 nsec. The difference in generated assembler is due to the following: Old BPF imlements LDX_MSH instruction via sk_load_byte_msh() helper function inside bpf_jit.S. New JIT removes the helper and does it explicitly, so ldx_msh cost is the same for both JITs, but generated code looks longer. New JIT has 4 registers to save, so prologue/epilogue are larger, but the cost is within noise on x64. Old JIT checks whether first insn clears A and if not emits 'xor %eax,%eax'. New JIT clears %rax unconditionally. 2. old BPF JIT doesn't support ANC_NLATTR, ANC_PAY_OFFSET, ANC_RANDOM extensions. New JIT supports all BPF extensions. Performance of such filters improves 2-4 times depending on a filter. The longer the filter the higher performance gain. Synthetic benchmarks with many ancillary loads see 20x speedup which seems to be the maximum gain from JIT Notes: . net.core.bpf_jit_enable=2 + tools/net/bpf_jit_disasm is still functional and can be used to see generated assembler . there are two jit_compile() functions and code flow for classic filters is: sk_attach_filter() - load classic BPF bpf_jit_compile() - try to JIT from classic BPF sk_convert_filter() - convert classic to internal bpf_int_jit_compile() - JIT from internal BPF seccomp and tracing filters will just call bpf_int_jit_compile() Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 20:50:46 -06:00
EMIT1(0xC9); /* leave */
EMIT1(0xC3); /* ret */
break;
net: filter: x86: split bpf_jit_compile() Split bpf_jit_compile() into two functions to improve readability of for(pass++) loop. The change follows similar style of JIT compilers for arm, powerpc, s390 The body of new do_jit() was not reformatted to reduce noise in this patch, since the following patch replaces most of it. Tested with BPF testsuite. Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 20:50:45 -06:00
default:
net: filter: x86: internal BPF JIT Maps all internal BPF instructions into x86_64 instructions. This patch replaces original BPF x64 JIT with internal BPF x64 JIT. sysctl net.core.bpf_jit_enable is reused as on/off switch. Performance: 1. old BPF JIT and internal BPF JIT generate equivalent x86_64 code. No performance difference is observed for filters that were JIT-able before Example assembler code for BPF filter "tcpdump port 22" original BPF -> old JIT: original BPF -> internal BPF -> new JIT: 0: push %rbp 0: push %rbp 1: mov %rsp,%rbp 1: mov %rsp,%rbp 4: sub $0x60,%rsp 4: sub $0x228,%rsp 8: mov %rbx,-0x8(%rbp) b: mov %rbx,-0x228(%rbp) // prologue 12: mov %r13,-0x220(%rbp) 19: mov %r14,-0x218(%rbp) 20: mov %r15,-0x210(%rbp) 27: xor %eax,%eax // clear A c: xor %ebx,%ebx 29: xor %r13,%r13 // clear X e: mov 0x68(%rdi),%r9d 2c: mov 0x68(%rdi),%r9d 12: sub 0x6c(%rdi),%r9d 30: sub 0x6c(%rdi),%r9d 16: mov 0xd8(%rdi),%r8 34: mov 0xd8(%rdi),%r10 3b: mov %rdi,%rbx 1d: mov $0xc,%esi 3e: mov $0xc,%esi 22: callq 0xffffffffe1021e15 43: callq 0xffffffffe102bd75 27: cmp $0x86dd,%eax 48: cmp $0x86dd,%rax 2c: jne 0x0000000000000069 4f: jne 0x000000000000009a 2e: mov $0x14,%esi 51: mov $0x14,%esi 33: callq 0xffffffffe1021e31 56: callq 0xffffffffe102bd91 38: cmp $0x84,%eax 5b: cmp $0x84,%rax 3d: je 0x0000000000000049 62: je 0x0000000000000074 3f: cmp $0x6,%eax 64: cmp $0x6,%rax 42: je 0x0000000000000049 68: je 0x0000000000000074 44: cmp $0x11,%eax 6a: cmp $0x11,%rax 47: jne 0x00000000000000c6 6e: jne 0x0000000000000117 49: mov $0x36,%esi 74: mov $0x36,%esi 4e: callq 0xffffffffe1021e15 79: callq 0xffffffffe102bd75 53: cmp $0x16,%eax 7e: cmp $0x16,%rax 56: je 0x00000000000000bf 82: je 0x0000000000000110 58: mov $0x38,%esi 88: mov $0x38,%esi 5d: callq 0xffffffffe1021e15 8d: callq 0xffffffffe102bd75 62: cmp $0x16,%eax 92: cmp $0x16,%rax 65: je 0x00000000000000bf 96: je 0x0000000000000110 67: jmp 0x00000000000000c6 98: jmp 0x0000000000000117 69: cmp $0x800,%eax 9a: cmp $0x800,%rax 6e: jne 0x00000000000000c6 a1: jne 0x0000000000000117 70: mov $0x17,%esi a3: mov $0x17,%esi 75: callq 0xffffffffe1021e31 a8: callq 0xffffffffe102bd91 7a: cmp $0x84,%eax ad: cmp $0x84,%rax 7f: je 0x000000000000008b b4: je 0x00000000000000c2 81: cmp $0x6,%eax b6: cmp $0x6,%rax 84: je 0x000000000000008b ba: je 0x00000000000000c2 86: cmp $0x11,%eax bc: cmp $0x11,%rax 89: jne 0x00000000000000c6 c0: jne 0x0000000000000117 8b: mov $0x14,%esi c2: mov $0x14,%esi 90: callq 0xffffffffe1021e15 c7: callq 0xffffffffe102bd75 95: test $0x1fff,%ax cc: test $0x1fff,%rax 99: jne 0x00000000000000c6 d3: jne 0x0000000000000117 d5: mov %rax,%r14 9b: mov $0xe,%esi d8: mov $0xe,%esi a0: callq 0xffffffffe1021e44 dd: callq 0xffffffffe102bd91 // MSH e2: and $0xf,%eax e5: shl $0x2,%eax e8: mov %rax,%r13 eb: mov %r14,%rax ee: mov %r13,%rsi a5: lea 0xe(%rbx),%esi f1: add $0xe,%esi a8: callq 0xffffffffe1021e0d f4: callq 0xffffffffe102bd6d ad: cmp $0x16,%eax f9: cmp $0x16,%rax b0: je 0x00000000000000bf fd: je 0x0000000000000110 ff: mov %r13,%rsi b2: lea 0x10(%rbx),%esi 102: add $0x10,%esi b5: callq 0xffffffffe1021e0d 105: callq 0xffffffffe102bd6d ba: cmp $0x16,%eax 10a: cmp $0x16,%rax bd: jne 0x00000000000000c6 10e: jne 0x0000000000000117 bf: mov $0xffff,%eax 110: mov $0xffff,%eax c4: jmp 0x00000000000000c8 115: jmp 0x000000000000011c c6: xor %eax,%eax 117: mov $0x0,%eax c8: mov -0x8(%rbp),%rbx 11c: mov -0x228(%rbp),%rbx // epilogue cc: leaveq 123: mov -0x220(%rbp),%r13 cd: retq 12a: mov -0x218(%rbp),%r14 131: mov -0x210(%rbp),%r15 138: leaveq 139: retq On fully cached SKBs both JITed functions take 12 nsec to execute. BPF interpreter executes the program in 30 nsec. The difference in generated assembler is due to the following: Old BPF imlements LDX_MSH instruction via sk_load_byte_msh() helper function inside bpf_jit.S. New JIT removes the helper and does it explicitly, so ldx_msh cost is the same for both JITs, but generated code looks longer. New JIT has 4 registers to save, so prologue/epilogue are larger, but the cost is within noise on x64. Old JIT checks whether first insn clears A and if not emits 'xor %eax,%eax'. New JIT clears %rax unconditionally. 2. old BPF JIT doesn't support ANC_NLATTR, ANC_PAY_OFFSET, ANC_RANDOM extensions. New JIT supports all BPF extensions. Performance of such filters improves 2-4 times depending on a filter. The longer the filter the higher performance gain. Synthetic benchmarks with many ancillary loads see 20x speedup which seems to be the maximum gain from JIT Notes: . net.core.bpf_jit_enable=2 + tools/net/bpf_jit_disasm is still functional and can be used to see generated assembler . there are two jit_compile() functions and code flow for classic filters is: sk_attach_filter() - load classic BPF bpf_jit_compile() - try to JIT from classic BPF sk_convert_filter() - convert classic to internal bpf_int_jit_compile() - JIT from internal BPF seccomp and tracing filters will just call bpf_int_jit_compile() Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 20:50:46 -06:00
/* By design x64 JIT should support all BPF instructions
* This error will be seen if new instruction was added
* to interpreter, but not to JIT
net: filter: split 'struct sk_filter' into socket and bpf parts clean up names related to socket filtering and bpf in the following way: - everything that deals with sockets keeps 'sk_*' prefix - everything that is pure BPF is changed to 'bpf_*' prefix split 'struct sk_filter' into struct sk_filter { atomic_t refcnt; struct rcu_head rcu; struct bpf_prog *prog; }; and struct bpf_prog { u32 jited:1, len:31; struct sock_fprog_kern *orig_prog; unsigned int (*bpf_func)(const struct sk_buff *skb, const struct bpf_insn *filter); union { struct sock_filter insns[0]; struct bpf_insn insnsi[0]; struct work_struct work; }; }; so that 'struct bpf_prog' can be used independent of sockets and cleans up 'unattached' bpf use cases split SK_RUN_FILTER macro into: SK_RUN_FILTER to be used with 'struct sk_filter *' and BPF_PROG_RUN to be used with 'struct bpf_prog *' __sk_filter_release(struct sk_filter *) gains __bpf_prog_release(struct bpf_prog *) helper function also perform related renames for the functions that work with 'struct bpf_prog *', since they're on the same lines: sk_filter_size -> bpf_prog_size sk_filter_select_runtime -> bpf_prog_select_runtime sk_filter_free -> bpf_prog_free sk_unattached_filter_create -> bpf_prog_create sk_unattached_filter_destroy -> bpf_prog_destroy sk_store_orig_filter -> bpf_prog_store_orig_filter sk_release_orig_filter -> bpf_release_orig_filter __sk_migrate_filter -> bpf_migrate_filter __sk_prepare_filter -> bpf_prepare_filter API for attaching classic BPF to a socket stays the same: sk_attach_filter(prog, struct sock *)/sk_detach_filter(struct sock *) and SK_RUN_FILTER(struct sk_filter *, ctx) to execute a program which is used by sockets, tun, af_packet API for 'unattached' BPF programs becomes: bpf_prog_create(struct bpf_prog **)/bpf_prog_destroy(struct bpf_prog *) and BPF_PROG_RUN(struct bpf_prog *, ctx) to execute a program which is used by isdn, ppp, team, seccomp, ptp, xt_bpf, cls_bpf, test_bpf Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-07-30 21:34:16 -06:00
* or if there is junk in bpf_prog
net: filter: x86: internal BPF JIT Maps all internal BPF instructions into x86_64 instructions. This patch replaces original BPF x64 JIT with internal BPF x64 JIT. sysctl net.core.bpf_jit_enable is reused as on/off switch. Performance: 1. old BPF JIT and internal BPF JIT generate equivalent x86_64 code. No performance difference is observed for filters that were JIT-able before Example assembler code for BPF filter "tcpdump port 22" original BPF -> old JIT: original BPF -> internal BPF -> new JIT: 0: push %rbp 0: push %rbp 1: mov %rsp,%rbp 1: mov %rsp,%rbp 4: sub $0x60,%rsp 4: sub $0x228,%rsp 8: mov %rbx,-0x8(%rbp) b: mov %rbx,-0x228(%rbp) // prologue 12: mov %r13,-0x220(%rbp) 19: mov %r14,-0x218(%rbp) 20: mov %r15,-0x210(%rbp) 27: xor %eax,%eax // clear A c: xor %ebx,%ebx 29: xor %r13,%r13 // clear X e: mov 0x68(%rdi),%r9d 2c: mov 0x68(%rdi),%r9d 12: sub 0x6c(%rdi),%r9d 30: sub 0x6c(%rdi),%r9d 16: mov 0xd8(%rdi),%r8 34: mov 0xd8(%rdi),%r10 3b: mov %rdi,%rbx 1d: mov $0xc,%esi 3e: mov $0xc,%esi 22: callq 0xffffffffe1021e15 43: callq 0xffffffffe102bd75 27: cmp $0x86dd,%eax 48: cmp $0x86dd,%rax 2c: jne 0x0000000000000069 4f: jne 0x000000000000009a 2e: mov $0x14,%esi 51: mov $0x14,%esi 33: callq 0xffffffffe1021e31 56: callq 0xffffffffe102bd91 38: cmp $0x84,%eax 5b: cmp $0x84,%rax 3d: je 0x0000000000000049 62: je 0x0000000000000074 3f: cmp $0x6,%eax 64: cmp $0x6,%rax 42: je 0x0000000000000049 68: je 0x0000000000000074 44: cmp $0x11,%eax 6a: cmp $0x11,%rax 47: jne 0x00000000000000c6 6e: jne 0x0000000000000117 49: mov $0x36,%esi 74: mov $0x36,%esi 4e: callq 0xffffffffe1021e15 79: callq 0xffffffffe102bd75 53: cmp $0x16,%eax 7e: cmp $0x16,%rax 56: je 0x00000000000000bf 82: je 0x0000000000000110 58: mov $0x38,%esi 88: mov $0x38,%esi 5d: callq 0xffffffffe1021e15 8d: callq 0xffffffffe102bd75 62: cmp $0x16,%eax 92: cmp $0x16,%rax 65: je 0x00000000000000bf 96: je 0x0000000000000110 67: jmp 0x00000000000000c6 98: jmp 0x0000000000000117 69: cmp $0x800,%eax 9a: cmp $0x800,%rax 6e: jne 0x00000000000000c6 a1: jne 0x0000000000000117 70: mov $0x17,%esi a3: mov $0x17,%esi 75: callq 0xffffffffe1021e31 a8: callq 0xffffffffe102bd91 7a: cmp $0x84,%eax ad: cmp $0x84,%rax 7f: je 0x000000000000008b b4: je 0x00000000000000c2 81: cmp $0x6,%eax b6: cmp $0x6,%rax 84: je 0x000000000000008b ba: je 0x00000000000000c2 86: cmp $0x11,%eax bc: cmp $0x11,%rax 89: jne 0x00000000000000c6 c0: jne 0x0000000000000117 8b: mov $0x14,%esi c2: mov $0x14,%esi 90: callq 0xffffffffe1021e15 c7: callq 0xffffffffe102bd75 95: test $0x1fff,%ax cc: test $0x1fff,%rax 99: jne 0x00000000000000c6 d3: jne 0x0000000000000117 d5: mov %rax,%r14 9b: mov $0xe,%esi d8: mov $0xe,%esi a0: callq 0xffffffffe1021e44 dd: callq 0xffffffffe102bd91 // MSH e2: and $0xf,%eax e5: shl $0x2,%eax e8: mov %rax,%r13 eb: mov %r14,%rax ee: mov %r13,%rsi a5: lea 0xe(%rbx),%esi f1: add $0xe,%esi a8: callq 0xffffffffe1021e0d f4: callq 0xffffffffe102bd6d ad: cmp $0x16,%eax f9: cmp $0x16,%rax b0: je 0x00000000000000bf fd: je 0x0000000000000110 ff: mov %r13,%rsi b2: lea 0x10(%rbx),%esi 102: add $0x10,%esi b5: callq 0xffffffffe1021e0d 105: callq 0xffffffffe102bd6d ba: cmp $0x16,%eax 10a: cmp $0x16,%rax bd: jne 0x00000000000000c6 10e: jne 0x0000000000000117 bf: mov $0xffff,%eax 110: mov $0xffff,%eax c4: jmp 0x00000000000000c8 115: jmp 0x000000000000011c c6: xor %eax,%eax 117: mov $0x0,%eax c8: mov -0x8(%rbp),%rbx 11c: mov -0x228(%rbp),%rbx // epilogue cc: leaveq 123: mov -0x220(%rbp),%r13 cd: retq 12a: mov -0x218(%rbp),%r14 131: mov -0x210(%rbp),%r15 138: leaveq 139: retq On fully cached SKBs both JITed functions take 12 nsec to execute. BPF interpreter executes the program in 30 nsec. The difference in generated assembler is due to the following: Old BPF imlements LDX_MSH instruction via sk_load_byte_msh() helper function inside bpf_jit.S. New JIT removes the helper and does it explicitly, so ldx_msh cost is the same for both JITs, but generated code looks longer. New JIT has 4 registers to save, so prologue/epilogue are larger, but the cost is within noise on x64. Old JIT checks whether first insn clears A and if not emits 'xor %eax,%eax'. New JIT clears %rax unconditionally. 2. old BPF JIT doesn't support ANC_NLATTR, ANC_PAY_OFFSET, ANC_RANDOM extensions. New JIT supports all BPF extensions. Performance of such filters improves 2-4 times depending on a filter. The longer the filter the higher performance gain. Synthetic benchmarks with many ancillary loads see 20x speedup which seems to be the maximum gain from JIT Notes: . net.core.bpf_jit_enable=2 + tools/net/bpf_jit_disasm is still functional and can be used to see generated assembler . there are two jit_compile() functions and code flow for classic filters is: sk_attach_filter() - load classic BPF bpf_jit_compile() - try to JIT from classic BPF sk_convert_filter() - convert classic to internal bpf_int_jit_compile() - JIT from internal BPF seccomp and tracing filters will just call bpf_int_jit_compile() Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 20:50:46 -06:00
*/
pr_err("bpf_jit: unknown opcode %02x\n", insn->code);
net: filter: x86: split bpf_jit_compile() Split bpf_jit_compile() into two functions to improve readability of for(pass++) loop. The change follows similar style of JIT compilers for arm, powerpc, s390 The body of new do_jit() was not reformatted to reduce noise in this patch, since the following patch replaces most of it. Tested with BPF testsuite. Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 20:50:45 -06:00
return -EINVAL;
}
net: filter: x86: internal BPF JIT Maps all internal BPF instructions into x86_64 instructions. This patch replaces original BPF x64 JIT with internal BPF x64 JIT. sysctl net.core.bpf_jit_enable is reused as on/off switch. Performance: 1. old BPF JIT and internal BPF JIT generate equivalent x86_64 code. No performance difference is observed for filters that were JIT-able before Example assembler code for BPF filter "tcpdump port 22" original BPF -> old JIT: original BPF -> internal BPF -> new JIT: 0: push %rbp 0: push %rbp 1: mov %rsp,%rbp 1: mov %rsp,%rbp 4: sub $0x60,%rsp 4: sub $0x228,%rsp 8: mov %rbx,-0x8(%rbp) b: mov %rbx,-0x228(%rbp) // prologue 12: mov %r13,-0x220(%rbp) 19: mov %r14,-0x218(%rbp) 20: mov %r15,-0x210(%rbp) 27: xor %eax,%eax // clear A c: xor %ebx,%ebx 29: xor %r13,%r13 // clear X e: mov 0x68(%rdi),%r9d 2c: mov 0x68(%rdi),%r9d 12: sub 0x6c(%rdi),%r9d 30: sub 0x6c(%rdi),%r9d 16: mov 0xd8(%rdi),%r8 34: mov 0xd8(%rdi),%r10 3b: mov %rdi,%rbx 1d: mov $0xc,%esi 3e: mov $0xc,%esi 22: callq 0xffffffffe1021e15 43: callq 0xffffffffe102bd75 27: cmp $0x86dd,%eax 48: cmp $0x86dd,%rax 2c: jne 0x0000000000000069 4f: jne 0x000000000000009a 2e: mov $0x14,%esi 51: mov $0x14,%esi 33: callq 0xffffffffe1021e31 56: callq 0xffffffffe102bd91 38: cmp $0x84,%eax 5b: cmp $0x84,%rax 3d: je 0x0000000000000049 62: je 0x0000000000000074 3f: cmp $0x6,%eax 64: cmp $0x6,%rax 42: je 0x0000000000000049 68: je 0x0000000000000074 44: cmp $0x11,%eax 6a: cmp $0x11,%rax 47: jne 0x00000000000000c6 6e: jne 0x0000000000000117 49: mov $0x36,%esi 74: mov $0x36,%esi 4e: callq 0xffffffffe1021e15 79: callq 0xffffffffe102bd75 53: cmp $0x16,%eax 7e: cmp $0x16,%rax 56: je 0x00000000000000bf 82: je 0x0000000000000110 58: mov $0x38,%esi 88: mov $0x38,%esi 5d: callq 0xffffffffe1021e15 8d: callq 0xffffffffe102bd75 62: cmp $0x16,%eax 92: cmp $0x16,%rax 65: je 0x00000000000000bf 96: je 0x0000000000000110 67: jmp 0x00000000000000c6 98: jmp 0x0000000000000117 69: cmp $0x800,%eax 9a: cmp $0x800,%rax 6e: jne 0x00000000000000c6 a1: jne 0x0000000000000117 70: mov $0x17,%esi a3: mov $0x17,%esi 75: callq 0xffffffffe1021e31 a8: callq 0xffffffffe102bd91 7a: cmp $0x84,%eax ad: cmp $0x84,%rax 7f: je 0x000000000000008b b4: je 0x00000000000000c2 81: cmp $0x6,%eax b6: cmp $0x6,%rax 84: je 0x000000000000008b ba: je 0x00000000000000c2 86: cmp $0x11,%eax bc: cmp $0x11,%rax 89: jne 0x00000000000000c6 c0: jne 0x0000000000000117 8b: mov $0x14,%esi c2: mov $0x14,%esi 90: callq 0xffffffffe1021e15 c7: callq 0xffffffffe102bd75 95: test $0x1fff,%ax cc: test $0x1fff,%rax 99: jne 0x00000000000000c6 d3: jne 0x0000000000000117 d5: mov %rax,%r14 9b: mov $0xe,%esi d8: mov $0xe,%esi a0: callq 0xffffffffe1021e44 dd: callq 0xffffffffe102bd91 // MSH e2: and $0xf,%eax e5: shl $0x2,%eax e8: mov %rax,%r13 eb: mov %r14,%rax ee: mov %r13,%rsi a5: lea 0xe(%rbx),%esi f1: add $0xe,%esi a8: callq 0xffffffffe1021e0d f4: callq 0xffffffffe102bd6d ad: cmp $0x16,%eax f9: cmp $0x16,%rax b0: je 0x00000000000000bf fd: je 0x0000000000000110 ff: mov %r13,%rsi b2: lea 0x10(%rbx),%esi 102: add $0x10,%esi b5: callq 0xffffffffe1021e0d 105: callq 0xffffffffe102bd6d ba: cmp $0x16,%eax 10a: cmp $0x16,%rax bd: jne 0x00000000000000c6 10e: jne 0x0000000000000117 bf: mov $0xffff,%eax 110: mov $0xffff,%eax c4: jmp 0x00000000000000c8 115: jmp 0x000000000000011c c6: xor %eax,%eax 117: mov $0x0,%eax c8: mov -0x8(%rbp),%rbx 11c: mov -0x228(%rbp),%rbx // epilogue cc: leaveq 123: mov -0x220(%rbp),%r13 cd: retq 12a: mov -0x218(%rbp),%r14 131: mov -0x210(%rbp),%r15 138: leaveq 139: retq On fully cached SKBs both JITed functions take 12 nsec to execute. BPF interpreter executes the program in 30 nsec. The difference in generated assembler is due to the following: Old BPF imlements LDX_MSH instruction via sk_load_byte_msh() helper function inside bpf_jit.S. New JIT removes the helper and does it explicitly, so ldx_msh cost is the same for both JITs, but generated code looks longer. New JIT has 4 registers to save, so prologue/epilogue are larger, but the cost is within noise on x64. Old JIT checks whether first insn clears A and if not emits 'xor %eax,%eax'. New JIT clears %rax unconditionally. 2. old BPF JIT doesn't support ANC_NLATTR, ANC_PAY_OFFSET, ANC_RANDOM extensions. New JIT supports all BPF extensions. Performance of such filters improves 2-4 times depending on a filter. The longer the filter the higher performance gain. Synthetic benchmarks with many ancillary loads see 20x speedup which seems to be the maximum gain from JIT Notes: . net.core.bpf_jit_enable=2 + tools/net/bpf_jit_disasm is still functional and can be used to see generated assembler . there are two jit_compile() functions and code flow for classic filters is: sk_attach_filter() - load classic BPF bpf_jit_compile() - try to JIT from classic BPF sk_convert_filter() - convert classic to internal bpf_int_jit_compile() - JIT from internal BPF seccomp and tracing filters will just call bpf_int_jit_compile() Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 20:50:46 -06:00
net: filter: x86: split bpf_jit_compile() Split bpf_jit_compile() into two functions to improve readability of for(pass++) loop. The change follows similar style of JIT compilers for arm, powerpc, s390 The body of new do_jit() was not reformatted to reduce noise in this patch, since the following patch replaces most of it. Tested with BPF testsuite. Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 20:50:45 -06:00
ilen = prog - temp;
x86: bpf_jit: fix two bugs in eBPF JIT compiler 1. JIT compiler using multi-pass approach to converge to final image size, since x86 instructions are variable length. It starts with large gaps between instructions (so some jumps may use imm32 instead of imm8) and iterates until total program size is the same as in previous pass. This algorithm works only if program size is strictly decreasing. Programs that use LD_ABS insn need additional code in prologue, but it was not emitted during 1st pass, so there was a chance that 2nd pass would adjust imm32->imm8 jump offsets to the same number of bytes as increase in prologue, which may cause algorithm to erroneously decide that size converged. Fix it by always emitting largest prologue in the first pass which is detected by oldproglen==0 check. Also change error check condition 'proglen != oldproglen' to fail gracefully. 2. while staring at the code realized that 64-byte buffer may not be enough when 1st insn is large, so increase it to 128 to avoid buffer overflow (theoretical maximum size of prologue+div is 109) and add runtime check. Fixes: 622582786c9e ("net: filter: x86: internal BPF JIT") Reported-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Tested-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-10-10 21:30:23 -06:00
if (ilen > BPF_MAX_INSN_SIZE) {
bpf: remove stubs for cBPF from arch code Remove the dummy bpf_jit_compile() stubs for eBPF JITs and make that a single __weak function in the core that can be overridden similarly to the eBPF one. Also remove stale pr_err() mentions of bpf_jit_compile. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-02-16 14:24:49 -07:00
pr_err("bpf_jit: fatal insn size error\n");
x86: bpf_jit: fix two bugs in eBPF JIT compiler 1. JIT compiler using multi-pass approach to converge to final image size, since x86 instructions are variable length. It starts with large gaps between instructions (so some jumps may use imm32 instead of imm8) and iterates until total program size is the same as in previous pass. This algorithm works only if program size is strictly decreasing. Programs that use LD_ABS insn need additional code in prologue, but it was not emitted during 1st pass, so there was a chance that 2nd pass would adjust imm32->imm8 jump offsets to the same number of bytes as increase in prologue, which may cause algorithm to erroneously decide that size converged. Fix it by always emitting largest prologue in the first pass which is detected by oldproglen==0 check. Also change error check condition 'proglen != oldproglen' to fail gracefully. 2. while staring at the code realized that 64-byte buffer may not be enough when 1st insn is large, so increase it to 128 to avoid buffer overflow (theoretical maximum size of prologue+div is 109) and add runtime check. Fixes: 622582786c9e ("net: filter: x86: internal BPF JIT") Reported-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Tested-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-10-10 21:30:23 -06:00
return -EFAULT;
}
net: filter: x86: split bpf_jit_compile() Split bpf_jit_compile() into two functions to improve readability of for(pass++) loop. The change follows similar style of JIT compilers for arm, powerpc, s390 The body of new do_jit() was not reformatted to reduce noise in this patch, since the following patch replaces most of it. Tested with BPF testsuite. Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 20:50:45 -06:00
if (image) {
if (unlikely(proglen + ilen > oldproglen)) {
bpf: remove stubs for cBPF from arch code Remove the dummy bpf_jit_compile() stubs for eBPF JITs and make that a single __weak function in the core that can be overridden similarly to the eBPF one. Also remove stale pr_err() mentions of bpf_jit_compile. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-02-16 14:24:49 -07:00
pr_err("bpf_jit: fatal error\n");
net: filter: x86: split bpf_jit_compile() Split bpf_jit_compile() into two functions to improve readability of for(pass++) loop. The change follows similar style of JIT compilers for arm, powerpc, s390 The body of new do_jit() was not reformatted to reduce noise in this patch, since the following patch replaces most of it. Tested with BPF testsuite. Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 20:50:45 -06:00
return -EFAULT;
net: filter: Just In Time compiler for x86-64 In order to speedup packet filtering, here is an implementation of a JIT compiler for x86_64 It is disabled by default, and must be enabled by the admin. echo 1 >/proc/sys/net/core/bpf_jit_enable It uses module_alloc() and module_free() to get memory in the 2GB text kernel range since we call helpers functions from the generated code. EAX : BPF A accumulator EBX : BPF X accumulator RDI : pointer to skb (first argument given to JIT function) RBP : frame pointer (even if CONFIG_FRAME_POINTER=n) r9d : skb->len - skb->data_len (headlen) r8 : skb->data To get a trace of generated code, use : echo 2 >/proc/sys/net/core/bpf_jit_enable Example of generated code : # tcpdump -p -n -s 0 -i eth1 host 192.168.20.0/24 flen=18 proglen=147 pass=3 image=ffffffffa00b5000 JIT code: ffffffffa00b5000: 55 48 89 e5 48 83 ec 60 48 89 5d f8 44 8b 4f 60 JIT code: ffffffffa00b5010: 44 2b 4f 64 4c 8b 87 b8 00 00 00 be 0c 00 00 00 JIT code: ffffffffa00b5020: e8 24 7b f7 e0 3d 00 08 00 00 75 28 be 1a 00 00 JIT code: ffffffffa00b5030: 00 e8 fe 7a f7 e0 24 00 3d 00 14 a8 c0 74 49 be JIT code: ffffffffa00b5040: 1e 00 00 00 e8 eb 7a f7 e0 24 00 3d 00 14 a8 c0 JIT code: ffffffffa00b5050: 74 36 eb 3b 3d 06 08 00 00 74 07 3d 35 80 00 00 JIT code: ffffffffa00b5060: 75 2d be 1c 00 00 00 e8 c8 7a f7 e0 24 00 3d 00 JIT code: ffffffffa00b5070: 14 a8 c0 74 13 be 26 00 00 00 e8 b5 7a f7 e0 24 JIT code: ffffffffa00b5080: 00 3d 00 14 a8 c0 75 07 b8 ff ff 00 00 eb 02 31 JIT code: ffffffffa00b5090: c0 c9 c3 BPF program is 144 bytes long, so native program is almost same size ;) (000) ldh [12] (001) jeq #0x800 jt 2 jf 8 (002) ld [26] (003) and #0xffffff00 (004) jeq #0xc0a81400 jt 16 jf 5 (005) ld [30] (006) and #0xffffff00 (007) jeq #0xc0a81400 jt 16 jf 17 (008) jeq #0x806 jt 10 jf 9 (009) jeq #0x8035 jt 10 jf 17 (010) ld [28] (011) and #0xffffff00 (012) jeq #0xc0a81400 jt 16 jf 13 (013) ld [38] (014) and #0xffffff00 (015) jeq #0xc0a81400 jt 16 jf 17 (016) ret #65535 (017) ret #0 Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Cc: Arnaldo Carvalho de Melo <acme@infradead.org> Cc: Ben Hutchings <bhutchings@solarflare.com> Cc: Hagen Paul Pfeifer <hagen@jauu.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-04-20 03:27:32 -06:00
}
net: filter: x86: split bpf_jit_compile() Split bpf_jit_compile() into two functions to improve readability of for(pass++) loop. The change follows similar style of JIT compilers for arm, powerpc, s390 The body of new do_jit() was not reformatted to reduce noise in this patch, since the following patch replaces most of it. Tested with BPF testsuite. Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 20:50:45 -06:00
memcpy(image + proglen, temp, ilen);
net: filter: Just In Time compiler for x86-64 In order to speedup packet filtering, here is an implementation of a JIT compiler for x86_64 It is disabled by default, and must be enabled by the admin. echo 1 >/proc/sys/net/core/bpf_jit_enable It uses module_alloc() and module_free() to get memory in the 2GB text kernel range since we call helpers functions from the generated code. EAX : BPF A accumulator EBX : BPF X accumulator RDI : pointer to skb (first argument given to JIT function) RBP : frame pointer (even if CONFIG_FRAME_POINTER=n) r9d : skb->len - skb->data_len (headlen) r8 : skb->data To get a trace of generated code, use : echo 2 >/proc/sys/net/core/bpf_jit_enable Example of generated code : # tcpdump -p -n -s 0 -i eth1 host 192.168.20.0/24 flen=18 proglen=147 pass=3 image=ffffffffa00b5000 JIT code: ffffffffa00b5000: 55 48 89 e5 48 83 ec 60 48 89 5d f8 44 8b 4f 60 JIT code: ffffffffa00b5010: 44 2b 4f 64 4c 8b 87 b8 00 00 00 be 0c 00 00 00 JIT code: ffffffffa00b5020: e8 24 7b f7 e0 3d 00 08 00 00 75 28 be 1a 00 00 JIT code: ffffffffa00b5030: 00 e8 fe 7a f7 e0 24 00 3d 00 14 a8 c0 74 49 be JIT code: ffffffffa00b5040: 1e 00 00 00 e8 eb 7a f7 e0 24 00 3d 00 14 a8 c0 JIT code: ffffffffa00b5050: 74 36 eb 3b 3d 06 08 00 00 74 07 3d 35 80 00 00 JIT code: ffffffffa00b5060: 75 2d be 1c 00 00 00 e8 c8 7a f7 e0 24 00 3d 00 JIT code: ffffffffa00b5070: 14 a8 c0 74 13 be 26 00 00 00 e8 b5 7a f7 e0 24 JIT code: ffffffffa00b5080: 00 3d 00 14 a8 c0 75 07 b8 ff ff 00 00 eb 02 31 JIT code: ffffffffa00b5090: c0 c9 c3 BPF program is 144 bytes long, so native program is almost same size ;) (000) ldh [12] (001) jeq #0x800 jt 2 jf 8 (002) ld [26] (003) and #0xffffff00 (004) jeq #0xc0a81400 jt 16 jf 5 (005) ld [30] (006) and #0xffffff00 (007) jeq #0xc0a81400 jt 16 jf 17 (008) jeq #0x806 jt 10 jf 9 (009) jeq #0x8035 jt 10 jf 17 (010) ld [28] (011) and #0xffffff00 (012) jeq #0xc0a81400 jt 16 jf 13 (013) ld [38] (014) and #0xffffff00 (015) jeq #0xc0a81400 jt 16 jf 17 (016) ret #65535 (017) ret #0 Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Cc: Arnaldo Carvalho de Melo <acme@infradead.org> Cc: Ben Hutchings <bhutchings@solarflare.com> Cc: Hagen Paul Pfeifer <hagen@jauu.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-04-20 03:27:32 -06:00
}
net: filter: x86: split bpf_jit_compile() Split bpf_jit_compile() into two functions to improve readability of for(pass++) loop. The change follows similar style of JIT compilers for arm, powerpc, s390 The body of new do_jit() was not reformatted to reduce noise in this patch, since the following patch replaces most of it. Tested with BPF testsuite. Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 20:50:45 -06:00
proglen += ilen;
addrs[i] = proglen;
prog = temp;
}
return proglen;
}
bpf: prepare bpf_int_jit_compile/bpf_prog_select_runtime apis Since the blinding is strictly only called from inside eBPF JITs, we need to change signatures for bpf_int_jit_compile() and bpf_prog_select_runtime() first in order to prepare that the eBPF program we're dealing with can change underneath. Hence, for call sites, we need to return the latest prog. No functional change in this patch. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-05-13 11:08:31 -06:00
struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog)
net: filter: x86: split bpf_jit_compile() Split bpf_jit_compile() into two functions to improve readability of for(pass++) loop. The change follows similar style of JIT compilers for arm, powerpc, s390 The body of new do_jit() was not reformatted to reduce noise in this patch, since the following patch replaces most of it. Tested with BPF testsuite. Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 20:50:45 -06:00
{
struct bpf_binary_header *header = NULL;
bpf, x86: add support for constant blinding This patch adds recently added constant blinding helpers into the x86 eBPF JIT. In the bpf_int_jit_compile() path, requirements are to utilize bpf_jit_blind_constants()/bpf_jit_prog_release_other() pair for rewriting the program into a blinded one, and to map the BPF_REG_AX register to a CPU register. The mapping of BPF_REG_AX is at non-callee saved register r10, and thus shared with cached skb->data used for ld_abs/ind and not in every program type needed. When blinding is not used, there's zero additional overhead in the generated image. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-05-13 11:08:33 -06:00
struct bpf_prog *tmp, *orig_prog = prog;
net: filter: x86: split bpf_jit_compile() Split bpf_jit_compile() into two functions to improve readability of for(pass++) loop. The change follows similar style of JIT compilers for arm, powerpc, s390 The body of new do_jit() was not reformatted to reduce noise in this patch, since the following patch replaces most of it. Tested with BPF testsuite. Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 20:50:45 -06:00
int proglen, oldproglen = 0;
struct jit_context ctx = {};
bpf, x86: add support for constant blinding This patch adds recently added constant blinding helpers into the x86 eBPF JIT. In the bpf_int_jit_compile() path, requirements are to utilize bpf_jit_blind_constants()/bpf_jit_prog_release_other() pair for rewriting the program into a blinded one, and to map the BPF_REG_AX register to a CPU register. The mapping of BPF_REG_AX is at non-callee saved register r10, and thus shared with cached skb->data used for ld_abs/ind and not in every program type needed. When blinding is not used, there's zero additional overhead in the generated image. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-05-13 11:08:33 -06:00
bool tmp_blinded = false;
net: filter: x86: split bpf_jit_compile() Split bpf_jit_compile() into two functions to improve readability of for(pass++) loop. The change follows similar style of JIT compilers for arm, powerpc, s390 The body of new do_jit() was not reformatted to reduce noise in this patch, since the following patch replaces most of it. Tested with BPF testsuite. Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 20:50:45 -06:00
u8 *image = NULL;
int *addrs;
int pass;
int i;
if (!bpf_jit_enable)
bpf, x86: add support for constant blinding This patch adds recently added constant blinding helpers into the x86 eBPF JIT. In the bpf_int_jit_compile() path, requirements are to utilize bpf_jit_blind_constants()/bpf_jit_prog_release_other() pair for rewriting the program into a blinded one, and to map the BPF_REG_AX register to a CPU register. The mapping of BPF_REG_AX is at non-callee saved register r10, and thus shared with cached skb->data used for ld_abs/ind and not in every program type needed. When blinding is not used, there's zero additional overhead in the generated image. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-05-13 11:08:33 -06:00
return orig_prog;
tmp = bpf_jit_blind_constants(prog);
/* If blinding was requested and we failed during blinding,
* we must fall back to the interpreter.
*/
if (IS_ERR(tmp))
return orig_prog;
if (tmp != prog) {
tmp_blinded = true;
prog = tmp;
}
net: filter: Just In Time compiler for x86-64 In order to speedup packet filtering, here is an implementation of a JIT compiler for x86_64 It is disabled by default, and must be enabled by the admin. echo 1 >/proc/sys/net/core/bpf_jit_enable It uses module_alloc() and module_free() to get memory in the 2GB text kernel range since we call helpers functions from the generated code. EAX : BPF A accumulator EBX : BPF X accumulator RDI : pointer to skb (first argument given to JIT function) RBP : frame pointer (even if CONFIG_FRAME_POINTER=n) r9d : skb->len - skb->data_len (headlen) r8 : skb->data To get a trace of generated code, use : echo 2 >/proc/sys/net/core/bpf_jit_enable Example of generated code : # tcpdump -p -n -s 0 -i eth1 host 192.168.20.0/24 flen=18 proglen=147 pass=3 image=ffffffffa00b5000 JIT code: ffffffffa00b5000: 55 48 89 e5 48 83 ec 60 48 89 5d f8 44 8b 4f 60 JIT code: ffffffffa00b5010: 44 2b 4f 64 4c 8b 87 b8 00 00 00 be 0c 00 00 00 JIT code: ffffffffa00b5020: e8 24 7b f7 e0 3d 00 08 00 00 75 28 be 1a 00 00 JIT code: ffffffffa00b5030: 00 e8 fe 7a f7 e0 24 00 3d 00 14 a8 c0 74 49 be JIT code: ffffffffa00b5040: 1e 00 00 00 e8 eb 7a f7 e0 24 00 3d 00 14 a8 c0 JIT code: ffffffffa00b5050: 74 36 eb 3b 3d 06 08 00 00 74 07 3d 35 80 00 00 JIT code: ffffffffa00b5060: 75 2d be 1c 00 00 00 e8 c8 7a f7 e0 24 00 3d 00 JIT code: ffffffffa00b5070: 14 a8 c0 74 13 be 26 00 00 00 e8 b5 7a f7 e0 24 JIT code: ffffffffa00b5080: 00 3d 00 14 a8 c0 75 07 b8 ff ff 00 00 eb 02 31 JIT code: ffffffffa00b5090: c0 c9 c3 BPF program is 144 bytes long, so native program is almost same size ;) (000) ldh [12] (001) jeq #0x800 jt 2 jf 8 (002) ld [26] (003) and #0xffffff00 (004) jeq #0xc0a81400 jt 16 jf 5 (005) ld [30] (006) and #0xffffff00 (007) jeq #0xc0a81400 jt 16 jf 17 (008) jeq #0x806 jt 10 jf 9 (009) jeq #0x8035 jt 10 jf 17 (010) ld [28] (011) and #0xffffff00 (012) jeq #0xc0a81400 jt 16 jf 13 (013) ld [38] (014) and #0xffffff00 (015) jeq #0xc0a81400 jt 16 jf 17 (016) ret #65535 (017) ret #0 Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Cc: Arnaldo Carvalho de Melo <acme@infradead.org> Cc: Ben Hutchings <bhutchings@solarflare.com> Cc: Hagen Paul Pfeifer <hagen@jauu.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-04-20 03:27:32 -06:00
net: filter: x86: split bpf_jit_compile() Split bpf_jit_compile() into two functions to improve readability of for(pass++) loop. The change follows similar style of JIT compilers for arm, powerpc, s390 The body of new do_jit() was not reformatted to reduce noise in this patch, since the following patch replaces most of it. Tested with BPF testsuite. Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 20:50:45 -06:00
addrs = kmalloc(prog->len * sizeof(*addrs), GFP_KERNEL);
bpf, x86: add support for constant blinding This patch adds recently added constant blinding helpers into the x86 eBPF JIT. In the bpf_int_jit_compile() path, requirements are to utilize bpf_jit_blind_constants()/bpf_jit_prog_release_other() pair for rewriting the program into a blinded one, and to map the BPF_REG_AX register to a CPU register. The mapping of BPF_REG_AX is at non-callee saved register r10, and thus shared with cached skb->data used for ld_abs/ind and not in every program type needed. When blinding is not used, there's zero additional overhead in the generated image. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-05-13 11:08:33 -06:00
if (!addrs) {
prog = orig_prog;
goto out;
}
net: filter: x86: split bpf_jit_compile() Split bpf_jit_compile() into two functions to improve readability of for(pass++) loop. The change follows similar style of JIT compilers for arm, powerpc, s390 The body of new do_jit() was not reformatted to reduce noise in this patch, since the following patch replaces most of it. Tested with BPF testsuite. Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 20:50:45 -06:00
/* Before first pass, make a rough estimation of addrs[]
* each bpf instruction is translated to less than 64 bytes
*/
for (proglen = 0, i = 0; i < prog->len; i++) {
proglen += 64;
addrs[i] = proglen;
}
ctx.cleanup_addr = proglen;
x86: bpf_jit: fix compilation of large bpf programs x86 has variable length encoding. x86 JIT compiler is trying to pick the shortest encoding for given bpf instruction. While doing so the jump targets are changing, so JIT is doing multiple passes over the program. Typical program needs 3 passes. Some very short programs converge with 2 passes. Large programs may need 4 or 5. But specially crafted bpf programs may hit the pass limit and if the program converges on the last iteration the JIT compiler will be producing an image full of 'int 3' insns. Fix this corner case by doing final iteration over bpf program. Fixes: 0a14842f5a3c ("net: filter: Just In Time compiler for x86-64") Reported-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Tested-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-22 16:42:55 -06:00
/* JITed image shrinks with every pass and the loop iterates
* until the image stops shrinking. Very large bpf programs
* may converge on the last pass. In such case do one more
* pass to emit the final image
*/
for (pass = 0; pass < 10 || image; pass++) {
net: filter: x86: split bpf_jit_compile() Split bpf_jit_compile() into two functions to improve readability of for(pass++) loop. The change follows similar style of JIT compilers for arm, powerpc, s390 The body of new do_jit() was not reformatted to reduce noise in this patch, since the following patch replaces most of it. Tested with BPF testsuite. Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 20:50:45 -06:00
proglen = do_jit(prog, addrs, image, oldproglen, &ctx);
if (proglen <= 0) {
image = NULL;
if (header)
net: bpf: consolidate JIT binary allocator Introduced in commit 314beb9bcabf ("x86: bpf_jit_comp: secure bpf jit against spraying attacks") and later on replicated in aa2d2c73c21f ("s390/bpf,jit: address randomize and write protect jit code") for s390 architecture, write protection for BPF JIT images got added and a random start address of the JIT code, so that it's not on a page boundary anymore. Since both use a very similar allocator for the BPF binary header, we can consolidate this code into the BPF core as it's mostly JIT independant anyway. This will also allow for future archs that support DEBUG_SET_MODULE_RONX to just reuse instead of reimplementing it. JIT tested on x86_64 and s390x with BPF test suite. Signed-off-by: Daniel Borkmann <dborkman@redhat.com> Acked-by: Alexei Starovoitov <ast@plumgrid.com> Cc: Eric Dumazet <edumazet@google.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-08 00:04:47 -06:00
bpf_jit_binary_free(header);
bpf, x86: add support for constant blinding This patch adds recently added constant blinding helpers into the x86 eBPF JIT. In the bpf_int_jit_compile() path, requirements are to utilize bpf_jit_blind_constants()/bpf_jit_prog_release_other() pair for rewriting the program into a blinded one, and to map the BPF_REG_AX register to a CPU register. The mapping of BPF_REG_AX is at non-callee saved register r10, and thus shared with cached skb->data used for ld_abs/ind and not in every program type needed. When blinding is not used, there's zero additional overhead in the generated image. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-05-13 11:08:33 -06:00
prog = orig_prog;
goto out_addrs;
net: filter: x86: split bpf_jit_compile() Split bpf_jit_compile() into two functions to improve readability of for(pass++) loop. The change follows similar style of JIT compilers for arm, powerpc, s390 The body of new do_jit() was not reformatted to reduce noise in this patch, since the following patch replaces most of it. Tested with BPF testsuite. Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 20:50:45 -06:00
}
net: filter: Just In Time compiler for x86-64 In order to speedup packet filtering, here is an implementation of a JIT compiler for x86_64 It is disabled by default, and must be enabled by the admin. echo 1 >/proc/sys/net/core/bpf_jit_enable It uses module_alloc() and module_free() to get memory in the 2GB text kernel range since we call helpers functions from the generated code. EAX : BPF A accumulator EBX : BPF X accumulator RDI : pointer to skb (first argument given to JIT function) RBP : frame pointer (even if CONFIG_FRAME_POINTER=n) r9d : skb->len - skb->data_len (headlen) r8 : skb->data To get a trace of generated code, use : echo 2 >/proc/sys/net/core/bpf_jit_enable Example of generated code : # tcpdump -p -n -s 0 -i eth1 host 192.168.20.0/24 flen=18 proglen=147 pass=3 image=ffffffffa00b5000 JIT code: ffffffffa00b5000: 55 48 89 e5 48 83 ec 60 48 89 5d f8 44 8b 4f 60 JIT code: ffffffffa00b5010: 44 2b 4f 64 4c 8b 87 b8 00 00 00 be 0c 00 00 00 JIT code: ffffffffa00b5020: e8 24 7b f7 e0 3d 00 08 00 00 75 28 be 1a 00 00 JIT code: ffffffffa00b5030: 00 e8 fe 7a f7 e0 24 00 3d 00 14 a8 c0 74 49 be JIT code: ffffffffa00b5040: 1e 00 00 00 e8 eb 7a f7 e0 24 00 3d 00 14 a8 c0 JIT code: ffffffffa00b5050: 74 36 eb 3b 3d 06 08 00 00 74 07 3d 35 80 00 00 JIT code: ffffffffa00b5060: 75 2d be 1c 00 00 00 e8 c8 7a f7 e0 24 00 3d 00 JIT code: ffffffffa00b5070: 14 a8 c0 74 13 be 26 00 00 00 e8 b5 7a f7 e0 24 JIT code: ffffffffa00b5080: 00 3d 00 14 a8 c0 75 07 b8 ff ff 00 00 eb 02 31 JIT code: ffffffffa00b5090: c0 c9 c3 BPF program is 144 bytes long, so native program is almost same size ;) (000) ldh [12] (001) jeq #0x800 jt 2 jf 8 (002) ld [26] (003) and #0xffffff00 (004) jeq #0xc0a81400 jt 16 jf 5 (005) ld [30] (006) and #0xffffff00 (007) jeq #0xc0a81400 jt 16 jf 17 (008) jeq #0x806 jt 10 jf 9 (009) jeq #0x8035 jt 10 jf 17 (010) ld [28] (011) and #0xffffff00 (012) jeq #0xc0a81400 jt 16 jf 13 (013) ld [38] (014) and #0xffffff00 (015) jeq #0xc0a81400 jt 16 jf 17 (016) ret #65535 (017) ret #0 Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Cc: Arnaldo Carvalho de Melo <acme@infradead.org> Cc: Ben Hutchings <bhutchings@solarflare.com> Cc: Hagen Paul Pfeifer <hagen@jauu.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-04-20 03:27:32 -06:00
if (image) {
x86: bpf_jit: fix two bugs in eBPF JIT compiler 1. JIT compiler using multi-pass approach to converge to final image size, since x86 instructions are variable length. It starts with large gaps between instructions (so some jumps may use imm32 instead of imm8) and iterates until total program size is the same as in previous pass. This algorithm works only if program size is strictly decreasing. Programs that use LD_ABS insn need additional code in prologue, but it was not emitted during 1st pass, so there was a chance that 2nd pass would adjust imm32->imm8 jump offsets to the same number of bytes as increase in prologue, which may cause algorithm to erroneously decide that size converged. Fix it by always emitting largest prologue in the first pass which is detected by oldproglen==0 check. Also change error check condition 'proglen != oldproglen' to fail gracefully. 2. while staring at the code realized that 64-byte buffer may not be enough when 1st insn is large, so increase it to 128 to avoid buffer overflow (theoretical maximum size of prologue+div is 109) and add runtime check. Fixes: 622582786c9e ("net: filter: x86: internal BPF JIT") Reported-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Tested-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-10-10 21:30:23 -06:00
if (proglen != oldproglen) {
net: filter: x86: split bpf_jit_compile() Split bpf_jit_compile() into two functions to improve readability of for(pass++) loop. The change follows similar style of JIT compilers for arm, powerpc, s390 The body of new do_jit() was not reformatted to reduce noise in this patch, since the following patch replaces most of it. Tested with BPF testsuite. Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 20:50:45 -06:00
pr_err("bpf_jit: proglen=%d != oldproglen=%d\n",
proglen, oldproglen);
bpf, x86: add support for constant blinding This patch adds recently added constant blinding helpers into the x86 eBPF JIT. In the bpf_int_jit_compile() path, requirements are to utilize bpf_jit_blind_constants()/bpf_jit_prog_release_other() pair for rewriting the program into a blinded one, and to map the BPF_REG_AX register to a CPU register. The mapping of BPF_REG_AX is at non-callee saved register r10, and thus shared with cached skb->data used for ld_abs/ind and not in every program type needed. When blinding is not used, there's zero additional overhead in the generated image. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-05-13 11:08:33 -06:00
prog = orig_prog;
goto out_addrs;
x86: bpf_jit: fix two bugs in eBPF JIT compiler 1. JIT compiler using multi-pass approach to converge to final image size, since x86 instructions are variable length. It starts with large gaps between instructions (so some jumps may use imm32 instead of imm8) and iterates until total program size is the same as in previous pass. This algorithm works only if program size is strictly decreasing. Programs that use LD_ABS insn need additional code in prologue, but it was not emitted during 1st pass, so there was a chance that 2nd pass would adjust imm32->imm8 jump offsets to the same number of bytes as increase in prologue, which may cause algorithm to erroneously decide that size converged. Fix it by always emitting largest prologue in the first pass which is detected by oldproglen==0 check. Also change error check condition 'proglen != oldproglen' to fail gracefully. 2. while staring at the code realized that 64-byte buffer may not be enough when 1st insn is large, so increase it to 128 to avoid buffer overflow (theoretical maximum size of prologue+div is 109) and add runtime check. Fixes: 622582786c9e ("net: filter: x86: internal BPF JIT") Reported-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Tested-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-10-10 21:30:23 -06:00
}
net: filter: Just In Time compiler for x86-64 In order to speedup packet filtering, here is an implementation of a JIT compiler for x86_64 It is disabled by default, and must be enabled by the admin. echo 1 >/proc/sys/net/core/bpf_jit_enable It uses module_alloc() and module_free() to get memory in the 2GB text kernel range since we call helpers functions from the generated code. EAX : BPF A accumulator EBX : BPF X accumulator RDI : pointer to skb (first argument given to JIT function) RBP : frame pointer (even if CONFIG_FRAME_POINTER=n) r9d : skb->len - skb->data_len (headlen) r8 : skb->data To get a trace of generated code, use : echo 2 >/proc/sys/net/core/bpf_jit_enable Example of generated code : # tcpdump -p -n -s 0 -i eth1 host 192.168.20.0/24 flen=18 proglen=147 pass=3 image=ffffffffa00b5000 JIT code: ffffffffa00b5000: 55 48 89 e5 48 83 ec 60 48 89 5d f8 44 8b 4f 60 JIT code: ffffffffa00b5010: 44 2b 4f 64 4c 8b 87 b8 00 00 00 be 0c 00 00 00 JIT code: ffffffffa00b5020: e8 24 7b f7 e0 3d 00 08 00 00 75 28 be 1a 00 00 JIT code: ffffffffa00b5030: 00 e8 fe 7a f7 e0 24 00 3d 00 14 a8 c0 74 49 be JIT code: ffffffffa00b5040: 1e 00 00 00 e8 eb 7a f7 e0 24 00 3d 00 14 a8 c0 JIT code: ffffffffa00b5050: 74 36 eb 3b 3d 06 08 00 00 74 07 3d 35 80 00 00 JIT code: ffffffffa00b5060: 75 2d be 1c 00 00 00 e8 c8 7a f7 e0 24 00 3d 00 JIT code: ffffffffa00b5070: 14 a8 c0 74 13 be 26 00 00 00 e8 b5 7a f7 e0 24 JIT code: ffffffffa00b5080: 00 3d 00 14 a8 c0 75 07 b8 ff ff 00 00 eb 02 31 JIT code: ffffffffa00b5090: c0 c9 c3 BPF program is 144 bytes long, so native program is almost same size ;) (000) ldh [12] (001) jeq #0x800 jt 2 jf 8 (002) ld [26] (003) and #0xffffff00 (004) jeq #0xc0a81400 jt 16 jf 5 (005) ld [30] (006) and #0xffffff00 (007) jeq #0xc0a81400 jt 16 jf 17 (008) jeq #0x806 jt 10 jf 9 (009) jeq #0x8035 jt 10 jf 17 (010) ld [28] (011) and #0xffffff00 (012) jeq #0xc0a81400 jt 16 jf 13 (013) ld [38] (014) and #0xffffff00 (015) jeq #0xc0a81400 jt 16 jf 17 (016) ret #65535 (017) ret #0 Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Cc: Arnaldo Carvalho de Melo <acme@infradead.org> Cc: Ben Hutchings <bhutchings@solarflare.com> Cc: Hagen Paul Pfeifer <hagen@jauu.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-04-20 03:27:32 -06:00
break;
}
if (proglen == oldproglen) {
net: bpf: consolidate JIT binary allocator Introduced in commit 314beb9bcabf ("x86: bpf_jit_comp: secure bpf jit against spraying attacks") and later on replicated in aa2d2c73c21f ("s390/bpf,jit: address randomize and write protect jit code") for s390 architecture, write protection for BPF JIT images got added and a random start address of the JIT code, so that it's not on a page boundary anymore. Since both use a very similar allocator for the BPF binary header, we can consolidate this code into the BPF core as it's mostly JIT independant anyway. This will also allow for future archs that support DEBUG_SET_MODULE_RONX to just reuse instead of reimplementing it. JIT tested on x86_64 and s390x with BPF test suite. Signed-off-by: Daniel Borkmann <dborkman@redhat.com> Acked-by: Alexei Starovoitov <ast@plumgrid.com> Cc: Eric Dumazet <edumazet@google.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-08 00:04:47 -06:00
header = bpf_jit_binary_alloc(proglen, &image,
1, jit_fill_hole);
bpf, x86: add support for constant blinding This patch adds recently added constant blinding helpers into the x86 eBPF JIT. In the bpf_int_jit_compile() path, requirements are to utilize bpf_jit_blind_constants()/bpf_jit_prog_release_other() pair for rewriting the program into a blinded one, and to map the BPF_REG_AX register to a CPU register. The mapping of BPF_REG_AX is at non-callee saved register r10, and thus shared with cached skb->data used for ld_abs/ind and not in every program type needed. When blinding is not used, there's zero additional overhead in the generated image. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-05-13 11:08:33 -06:00
if (!header) {
prog = orig_prog;
goto out_addrs;
}
net: filter: Just In Time compiler for x86-64 In order to speedup packet filtering, here is an implementation of a JIT compiler for x86_64 It is disabled by default, and must be enabled by the admin. echo 1 >/proc/sys/net/core/bpf_jit_enable It uses module_alloc() and module_free() to get memory in the 2GB text kernel range since we call helpers functions from the generated code. EAX : BPF A accumulator EBX : BPF X accumulator RDI : pointer to skb (first argument given to JIT function) RBP : frame pointer (even if CONFIG_FRAME_POINTER=n) r9d : skb->len - skb->data_len (headlen) r8 : skb->data To get a trace of generated code, use : echo 2 >/proc/sys/net/core/bpf_jit_enable Example of generated code : # tcpdump -p -n -s 0 -i eth1 host 192.168.20.0/24 flen=18 proglen=147 pass=3 image=ffffffffa00b5000 JIT code: ffffffffa00b5000: 55 48 89 e5 48 83 ec 60 48 89 5d f8 44 8b 4f 60 JIT code: ffffffffa00b5010: 44 2b 4f 64 4c 8b 87 b8 00 00 00 be 0c 00 00 00 JIT code: ffffffffa00b5020: e8 24 7b f7 e0 3d 00 08 00 00 75 28 be 1a 00 00 JIT code: ffffffffa00b5030: 00 e8 fe 7a f7 e0 24 00 3d 00 14 a8 c0 74 49 be JIT code: ffffffffa00b5040: 1e 00 00 00 e8 eb 7a f7 e0 24 00 3d 00 14 a8 c0 JIT code: ffffffffa00b5050: 74 36 eb 3b 3d 06 08 00 00 74 07 3d 35 80 00 00 JIT code: ffffffffa00b5060: 75 2d be 1c 00 00 00 e8 c8 7a f7 e0 24 00 3d 00 JIT code: ffffffffa00b5070: 14 a8 c0 74 13 be 26 00 00 00 e8 b5 7a f7 e0 24 JIT code: ffffffffa00b5080: 00 3d 00 14 a8 c0 75 07 b8 ff ff 00 00 eb 02 31 JIT code: ffffffffa00b5090: c0 c9 c3 BPF program is 144 bytes long, so native program is almost same size ;) (000) ldh [12] (001) jeq #0x800 jt 2 jf 8 (002) ld [26] (003) and #0xffffff00 (004) jeq #0xc0a81400 jt 16 jf 5 (005) ld [30] (006) and #0xffffff00 (007) jeq #0xc0a81400 jt 16 jf 17 (008) jeq #0x806 jt 10 jf 9 (009) jeq #0x8035 jt 10 jf 17 (010) ld [28] (011) and #0xffffff00 (012) jeq #0xc0a81400 jt 16 jf 13 (013) ld [38] (014) and #0xffffff00 (015) jeq #0xc0a81400 jt 16 jf 17 (016) ret #65535 (017) ret #0 Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Cc: Arnaldo Carvalho de Melo <acme@infradead.org> Cc: Ben Hutchings <bhutchings@solarflare.com> Cc: Hagen Paul Pfeifer <hagen@jauu.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-04-20 03:27:32 -06:00
}
oldproglen = proglen;
}
filter: bpf_jit_comp: refactor and unify BPF JIT image dump output If bpf_jit_enable > 1, then we dump the emitted JIT compiled image after creation. Currently, only SPARC and PowerPC has similar output as in the reference implementation on x86_64. Make a small helper function in order to reduce duplicated code and make the dump output uniform across architectures x86_64, SPARC, PPC, ARM (e.g. on ARM flen, pass and proglen are currently not shown, but would be interesting to know as well), also for future BPF JIT implementations on other archs. Cc: Mircea Gherzan <mgherzan@gmail.com> Cc: Matt Evans <matt@ozlabs.org> Cc: Eric Dumazet <eric.dumazet@google.com> Cc: David S. Miller <davem@davemloft.net> Signed-off-by: Daniel Borkmann <dborkman@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-03-21 15:22:03 -06:00
net: filter: Just In Time compiler for x86-64 In order to speedup packet filtering, here is an implementation of a JIT compiler for x86_64 It is disabled by default, and must be enabled by the admin. echo 1 >/proc/sys/net/core/bpf_jit_enable It uses module_alloc() and module_free() to get memory in the 2GB text kernel range since we call helpers functions from the generated code. EAX : BPF A accumulator EBX : BPF X accumulator RDI : pointer to skb (first argument given to JIT function) RBP : frame pointer (even if CONFIG_FRAME_POINTER=n) r9d : skb->len - skb->data_len (headlen) r8 : skb->data To get a trace of generated code, use : echo 2 >/proc/sys/net/core/bpf_jit_enable Example of generated code : # tcpdump -p -n -s 0 -i eth1 host 192.168.20.0/24 flen=18 proglen=147 pass=3 image=ffffffffa00b5000 JIT code: ffffffffa00b5000: 55 48 89 e5 48 83 ec 60 48 89 5d f8 44 8b 4f 60 JIT code: ffffffffa00b5010: 44 2b 4f 64 4c 8b 87 b8 00 00 00 be 0c 00 00 00 JIT code: ffffffffa00b5020: e8 24 7b f7 e0 3d 00 08 00 00 75 28 be 1a 00 00 JIT code: ffffffffa00b5030: 00 e8 fe 7a f7 e0 24 00 3d 00 14 a8 c0 74 49 be JIT code: ffffffffa00b5040: 1e 00 00 00 e8 eb 7a f7 e0 24 00 3d 00 14 a8 c0 JIT code: ffffffffa00b5050: 74 36 eb 3b 3d 06 08 00 00 74 07 3d 35 80 00 00 JIT code: ffffffffa00b5060: 75 2d be 1c 00 00 00 e8 c8 7a f7 e0 24 00 3d 00 JIT code: ffffffffa00b5070: 14 a8 c0 74 13 be 26 00 00 00 e8 b5 7a f7 e0 24 JIT code: ffffffffa00b5080: 00 3d 00 14 a8 c0 75 07 b8 ff ff 00 00 eb 02 31 JIT code: ffffffffa00b5090: c0 c9 c3 BPF program is 144 bytes long, so native program is almost same size ;) (000) ldh [12] (001) jeq #0x800 jt 2 jf 8 (002) ld [26] (003) and #0xffffff00 (004) jeq #0xc0a81400 jt 16 jf 5 (005) ld [30] (006) and #0xffffff00 (007) jeq #0xc0a81400 jt 16 jf 17 (008) jeq #0x806 jt 10 jf 9 (009) jeq #0x8035 jt 10 jf 17 (010) ld [28] (011) and #0xffffff00 (012) jeq #0xc0a81400 jt 16 jf 13 (013) ld [38] (014) and #0xffffff00 (015) jeq #0xc0a81400 jt 16 jf 17 (016) ret #65535 (017) ret #0 Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Cc: Arnaldo Carvalho de Melo <acme@infradead.org> Cc: Ben Hutchings <bhutchings@solarflare.com> Cc: Hagen Paul Pfeifer <hagen@jauu.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-04-20 03:27:32 -06:00
if (bpf_jit_enable > 1)
bpf, x86/sparc: show actual number of passes in bpf_jit_dump When bpf_jit_compile() got split into two functions via commit f3c2af7ba17a ("net: filter: x86: split bpf_jit_compile()"), bpf_jit_dump() was changed to always show 0 as number of compiler passes. Change it to dump the actual number. Also on sparc, we count passes starting from 0, so add 1 for the debug dump as well. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-30 04:42:48 -06:00
bpf_jit_dump(prog->len, proglen, pass + 1, image);
net: filter: Just In Time compiler for x86-64 In order to speedup packet filtering, here is an implementation of a JIT compiler for x86_64 It is disabled by default, and must be enabled by the admin. echo 1 >/proc/sys/net/core/bpf_jit_enable It uses module_alloc() and module_free() to get memory in the 2GB text kernel range since we call helpers functions from the generated code. EAX : BPF A accumulator EBX : BPF X accumulator RDI : pointer to skb (first argument given to JIT function) RBP : frame pointer (even if CONFIG_FRAME_POINTER=n) r9d : skb->len - skb->data_len (headlen) r8 : skb->data To get a trace of generated code, use : echo 2 >/proc/sys/net/core/bpf_jit_enable Example of generated code : # tcpdump -p -n -s 0 -i eth1 host 192.168.20.0/24 flen=18 proglen=147 pass=3 image=ffffffffa00b5000 JIT code: ffffffffa00b5000: 55 48 89 e5 48 83 ec 60 48 89 5d f8 44 8b 4f 60 JIT code: ffffffffa00b5010: 44 2b 4f 64 4c 8b 87 b8 00 00 00 be 0c 00 00 00 JIT code: ffffffffa00b5020: e8 24 7b f7 e0 3d 00 08 00 00 75 28 be 1a 00 00 JIT code: ffffffffa00b5030: 00 e8 fe 7a f7 e0 24 00 3d 00 14 a8 c0 74 49 be JIT code: ffffffffa00b5040: 1e 00 00 00 e8 eb 7a f7 e0 24 00 3d 00 14 a8 c0 JIT code: ffffffffa00b5050: 74 36 eb 3b 3d 06 08 00 00 74 07 3d 35 80 00 00 JIT code: ffffffffa00b5060: 75 2d be 1c 00 00 00 e8 c8 7a f7 e0 24 00 3d 00 JIT code: ffffffffa00b5070: 14 a8 c0 74 13 be 26 00 00 00 e8 b5 7a f7 e0 24 JIT code: ffffffffa00b5080: 00 3d 00 14 a8 c0 75 07 b8 ff ff 00 00 eb 02 31 JIT code: ffffffffa00b5090: c0 c9 c3 BPF program is 144 bytes long, so native program is almost same size ;) (000) ldh [12] (001) jeq #0x800 jt 2 jf 8 (002) ld [26] (003) and #0xffffff00 (004) jeq #0xc0a81400 jt 16 jf 5 (005) ld [30] (006) and #0xffffff00 (007) jeq #0xc0a81400 jt 16 jf 17 (008) jeq #0x806 jt 10 jf 9 (009) jeq #0x8035 jt 10 jf 17 (010) ld [28] (011) and #0xffffff00 (012) jeq #0xc0a81400 jt 16 jf 13 (013) ld [38] (014) and #0xffffff00 (015) jeq #0xc0a81400 jt 16 jf 17 (016) ret #65535 (017) ret #0 Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Cc: Arnaldo Carvalho de Melo <acme@infradead.org> Cc: Ben Hutchings <bhutchings@solarflare.com> Cc: Hagen Paul Pfeifer <hagen@jauu.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-04-20 03:27:32 -06:00
if (image) {
x86: bpf_jit_comp: secure bpf jit against spraying attacks hpa bringed into my attention some security related issues with BPF JIT on x86. This patch makes sure the bpf generated code is marked read only, as other kernel text sections. It also splits the unused space (we vmalloc() and only use a fraction of the page) in two parts, so that the generated bpf code not starts at a known offset in the page, but a pseudo random one. Refs: http://mainisusuallyafunction.blogspot.com/2012/11/attacking-hardened-linux-systems-with.html Reported-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Daniel Borkmann <dborkman@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-05-17 10:37:03 -06:00
bpf_flush_icache(header, image + proglen);
bpf: fix unlocking of jited image when module ronx not set Eric and Willem reported that they recently saw random crashes when JIT was in use and bisected this to 74451e66d516 ("bpf: make jited programs visible in traces"). Issue was that the consolidation part added bpf_jit_binary_unlock_ro() that would unlock previously made read-only memory back to read-write. However, DEBUG_SET_MODULE_RONX cannot be used for this to test for presence of set_memory_*() functions. We need to use ARCH_HAS_SET_MEMORY instead to fix this; also add the corresponding bpf_jit_binary_lock_ro() to filter.h. Fixes: 74451e66d516 ("bpf: make jited programs visible in traces") Reported-by: Eric Dumazet <edumazet@google.com> Reported-by: Willem de Bruijn <willemb@google.com> Bisected-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Tested-by: Willem de Bruijn <willemb@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-02-21 08:09:34 -07:00
bpf_jit_binary_lock_ro(header);
net: filter: x86: split bpf_jit_compile() Split bpf_jit_compile() into two functions to improve readability of for(pass++) loop. The change follows similar style of JIT compilers for arm, powerpc, s390 The body of new do_jit() was not reformatted to reduce noise in this patch, since the following patch replaces most of it. Tested with BPF testsuite. Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 20:50:45 -06:00
prog->bpf_func = (void *)image;
ebpf: migrate bpf_prog's flags to bitfield As we need to add further flags to the bpf_prog structure, lets migrate both bools to a bitfield representation. The size of the base structure (excluding insns) remains unchanged at 40 bytes. Add also tags for the kmemchecker, so that it doesn't throw false positives. Even in case gcc would generate suboptimal code, it's not being accessed in performance critical paths. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-09-29 17:41:50 -06:00
prog->jited = 1;
bpf: change back to orig prog on too many passes If after too many passes still no image could be emitted, then swap back to the original program as we do in all other cases and don't use the one with blinding. Fixes: 959a75791603 ("bpf, x86: add support for constant blinding") Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-01-06 16:26:33 -07:00
} else {
prog = orig_prog;
net: filter: Just In Time compiler for x86-64 In order to speedup packet filtering, here is an implementation of a JIT compiler for x86_64 It is disabled by default, and must be enabled by the admin. echo 1 >/proc/sys/net/core/bpf_jit_enable It uses module_alloc() and module_free() to get memory in the 2GB text kernel range since we call helpers functions from the generated code. EAX : BPF A accumulator EBX : BPF X accumulator RDI : pointer to skb (first argument given to JIT function) RBP : frame pointer (even if CONFIG_FRAME_POINTER=n) r9d : skb->len - skb->data_len (headlen) r8 : skb->data To get a trace of generated code, use : echo 2 >/proc/sys/net/core/bpf_jit_enable Example of generated code : # tcpdump -p -n -s 0 -i eth1 host 192.168.20.0/24 flen=18 proglen=147 pass=3 image=ffffffffa00b5000 JIT code: ffffffffa00b5000: 55 48 89 e5 48 83 ec 60 48 89 5d f8 44 8b 4f 60 JIT code: ffffffffa00b5010: 44 2b 4f 64 4c 8b 87 b8 00 00 00 be 0c 00 00 00 JIT code: ffffffffa00b5020: e8 24 7b f7 e0 3d 00 08 00 00 75 28 be 1a 00 00 JIT code: ffffffffa00b5030: 00 e8 fe 7a f7 e0 24 00 3d 00 14 a8 c0 74 49 be JIT code: ffffffffa00b5040: 1e 00 00 00 e8 eb 7a f7 e0 24 00 3d 00 14 a8 c0 JIT code: ffffffffa00b5050: 74 36 eb 3b 3d 06 08 00 00 74 07 3d 35 80 00 00 JIT code: ffffffffa00b5060: 75 2d be 1c 00 00 00 e8 c8 7a f7 e0 24 00 3d 00 JIT code: ffffffffa00b5070: 14 a8 c0 74 13 be 26 00 00 00 e8 b5 7a f7 e0 24 JIT code: ffffffffa00b5080: 00 3d 00 14 a8 c0 75 07 b8 ff ff 00 00 eb 02 31 JIT code: ffffffffa00b5090: c0 c9 c3 BPF program is 144 bytes long, so native program is almost same size ;) (000) ldh [12] (001) jeq #0x800 jt 2 jf 8 (002) ld [26] (003) and #0xffffff00 (004) jeq #0xc0a81400 jt 16 jf 5 (005) ld [30] (006) and #0xffffff00 (007) jeq #0xc0a81400 jt 16 jf 17 (008) jeq #0x806 jt 10 jf 9 (009) jeq #0x8035 jt 10 jf 17 (010) ld [28] (011) and #0xffffff00 (012) jeq #0xc0a81400 jt 16 jf 13 (013) ld [38] (014) and #0xffffff00 (015) jeq #0xc0a81400 jt 16 jf 17 (016) ret #65535 (017) ret #0 Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Cc: Arnaldo Carvalho de Melo <acme@infradead.org> Cc: Ben Hutchings <bhutchings@solarflare.com> Cc: Hagen Paul Pfeifer <hagen@jauu.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-04-20 03:27:32 -06:00
}
bpf, x86: add support for constant blinding This patch adds recently added constant blinding helpers into the x86 eBPF JIT. In the bpf_int_jit_compile() path, requirements are to utilize bpf_jit_blind_constants()/bpf_jit_prog_release_other() pair for rewriting the program into a blinded one, and to map the BPF_REG_AX register to a CPU register. The mapping of BPF_REG_AX is at non-callee saved register r10, and thus shared with cached skb->data used for ld_abs/ind and not in every program type needed. When blinding is not used, there's zero additional overhead in the generated image. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-05-13 11:08:33 -06:00
out_addrs:
net: filter: Just In Time compiler for x86-64 In order to speedup packet filtering, here is an implementation of a JIT compiler for x86_64 It is disabled by default, and must be enabled by the admin. echo 1 >/proc/sys/net/core/bpf_jit_enable It uses module_alloc() and module_free() to get memory in the 2GB text kernel range since we call helpers functions from the generated code. EAX : BPF A accumulator EBX : BPF X accumulator RDI : pointer to skb (first argument given to JIT function) RBP : frame pointer (even if CONFIG_FRAME_POINTER=n) r9d : skb->len - skb->data_len (headlen) r8 : skb->data To get a trace of generated code, use : echo 2 >/proc/sys/net/core/bpf_jit_enable Example of generated code : # tcpdump -p -n -s 0 -i eth1 host 192.168.20.0/24 flen=18 proglen=147 pass=3 image=ffffffffa00b5000 JIT code: ffffffffa00b5000: 55 48 89 e5 48 83 ec 60 48 89 5d f8 44 8b 4f 60 JIT code: ffffffffa00b5010: 44 2b 4f 64 4c 8b 87 b8 00 00 00 be 0c 00 00 00 JIT code: ffffffffa00b5020: e8 24 7b f7 e0 3d 00 08 00 00 75 28 be 1a 00 00 JIT code: ffffffffa00b5030: 00 e8 fe 7a f7 e0 24 00 3d 00 14 a8 c0 74 49 be JIT code: ffffffffa00b5040: 1e 00 00 00 e8 eb 7a f7 e0 24 00 3d 00 14 a8 c0 JIT code: ffffffffa00b5050: 74 36 eb 3b 3d 06 08 00 00 74 07 3d 35 80 00 00 JIT code: ffffffffa00b5060: 75 2d be 1c 00 00 00 e8 c8 7a f7 e0 24 00 3d 00 JIT code: ffffffffa00b5070: 14 a8 c0 74 13 be 26 00 00 00 e8 b5 7a f7 e0 24 JIT code: ffffffffa00b5080: 00 3d 00 14 a8 c0 75 07 b8 ff ff 00 00 eb 02 31 JIT code: ffffffffa00b5090: c0 c9 c3 BPF program is 144 bytes long, so native program is almost same size ;) (000) ldh [12] (001) jeq #0x800 jt 2 jf 8 (002) ld [26] (003) and #0xffffff00 (004) jeq #0xc0a81400 jt 16 jf 5 (005) ld [30] (006) and #0xffffff00 (007) jeq #0xc0a81400 jt 16 jf 17 (008) jeq #0x806 jt 10 jf 9 (009) jeq #0x8035 jt 10 jf 17 (010) ld [28] (011) and #0xffffff00 (012) jeq #0xc0a81400 jt 16 jf 13 (013) ld [38] (014) and #0xffffff00 (015) jeq #0xc0a81400 jt 16 jf 17 (016) ret #65535 (017) ret #0 Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Cc: Arnaldo Carvalho de Melo <acme@infradead.org> Cc: Ben Hutchings <bhutchings@solarflare.com> Cc: Hagen Paul Pfeifer <hagen@jauu.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-04-20 03:27:32 -06:00
kfree(addrs);
bpf, x86: add support for constant blinding This patch adds recently added constant blinding helpers into the x86 eBPF JIT. In the bpf_int_jit_compile() path, requirements are to utilize bpf_jit_blind_constants()/bpf_jit_prog_release_other() pair for rewriting the program into a blinded one, and to map the BPF_REG_AX register to a CPU register. The mapping of BPF_REG_AX is at non-callee saved register r10, and thus shared with cached skb->data used for ld_abs/ind and not in every program type needed. When blinding is not used, there's zero additional overhead in the generated image. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-05-13 11:08:33 -06:00
out:
if (tmp_blinded)
bpf_jit_prog_release_other(prog, prog == orig_prog ?
tmp : orig_prog);
bpf: prepare bpf_int_jit_compile/bpf_prog_select_runtime apis Since the blinding is strictly only called from inside eBPF JITs, we need to change signatures for bpf_int_jit_compile() and bpf_prog_select_runtime() first in order to prepare that the eBPF program we're dealing with can change underneath. Hence, for call sites, we need to return the latest prog. No functional change in this patch. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-05-13 11:08:31 -06:00
return prog;
net: filter: Just In Time compiler for x86-64 In order to speedup packet filtering, here is an implementation of a JIT compiler for x86_64 It is disabled by default, and must be enabled by the admin. echo 1 >/proc/sys/net/core/bpf_jit_enable It uses module_alloc() and module_free() to get memory in the 2GB text kernel range since we call helpers functions from the generated code. EAX : BPF A accumulator EBX : BPF X accumulator RDI : pointer to skb (first argument given to JIT function) RBP : frame pointer (even if CONFIG_FRAME_POINTER=n) r9d : skb->len - skb->data_len (headlen) r8 : skb->data To get a trace of generated code, use : echo 2 >/proc/sys/net/core/bpf_jit_enable Example of generated code : # tcpdump -p -n -s 0 -i eth1 host 192.168.20.0/24 flen=18 proglen=147 pass=3 image=ffffffffa00b5000 JIT code: ffffffffa00b5000: 55 48 89 e5 48 83 ec 60 48 89 5d f8 44 8b 4f 60 JIT code: ffffffffa00b5010: 44 2b 4f 64 4c 8b 87 b8 00 00 00 be 0c 00 00 00 JIT code: ffffffffa00b5020: e8 24 7b f7 e0 3d 00 08 00 00 75 28 be 1a 00 00 JIT code: ffffffffa00b5030: 00 e8 fe 7a f7 e0 24 00 3d 00 14 a8 c0 74 49 be JIT code: ffffffffa00b5040: 1e 00 00 00 e8 eb 7a f7 e0 24 00 3d 00 14 a8 c0 JIT code: ffffffffa00b5050: 74 36 eb 3b 3d 06 08 00 00 74 07 3d 35 80 00 00 JIT code: ffffffffa00b5060: 75 2d be 1c 00 00 00 e8 c8 7a f7 e0 24 00 3d 00 JIT code: ffffffffa00b5070: 14 a8 c0 74 13 be 26 00 00 00 e8 b5 7a f7 e0 24 JIT code: ffffffffa00b5080: 00 3d 00 14 a8 c0 75 07 b8 ff ff 00 00 eb 02 31 JIT code: ffffffffa00b5090: c0 c9 c3 BPF program is 144 bytes long, so native program is almost same size ;) (000) ldh [12] (001) jeq #0x800 jt 2 jf 8 (002) ld [26] (003) and #0xffffff00 (004) jeq #0xc0a81400 jt 16 jf 5 (005) ld [30] (006) and #0xffffff00 (007) jeq #0xc0a81400 jt 16 jf 17 (008) jeq #0x806 jt 10 jf 9 (009) jeq #0x8035 jt 10 jf 17 (010) ld [28] (011) and #0xffffff00 (012) jeq #0xc0a81400 jt 16 jf 13 (013) ld [38] (014) and #0xffffff00 (015) jeq #0xc0a81400 jt 16 jf 17 (016) ret #65535 (017) ret #0 Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Cc: Arnaldo Carvalho de Melo <acme@infradead.org> Cc: Ben Hutchings <bhutchings@solarflare.com> Cc: Hagen Paul Pfeifer <hagen@jauu.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-04-20 03:27:32 -06:00
}