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581 commits

Author SHA1 Message Date
Andrii Nakryiko 1f8e2bcb2c libbpf: Refactor relocation handling
Relocation handling code is convoluted and unnecessarily deeply nested. Split
out per-relocation logic into separate function. Also refactor the logic to be
more a sequence of per-relocation type checks and processing steps, making it
simpler to follow control flow. This makes it easier to further extends it to
new kinds of relocations (e.g., support for extern variables).

This patch also makes relocation's section verification more robust.
Previously relocations against not yet supported externs were silently ignored
because of obj->efile.text_shndx was zero, when all BPF programs had custom
section names and there was no .text section. Also, invalid LDIMM64 relocations
against non-map sections were passed through, if they were pointing to a .text
section (or 0, which is invalid section). All these bugs are fixed within this
refactoring and checks are made more appropriate for each type of relocation.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20191121070743.1309473-3-andriin@fb.com
2019-11-24 16:58:45 -08:00
Andrii Nakryiko a0d7da26ce libbpf: Fix call relocation offset calculation bug
When relocating subprogram call, libbpf doesn't take into account
relo->text_off, which comes from symbol's value. This generally works fine for
subprograms implemented as static functions, but breaks for global functions.

Taking a simplified test_pkt_access.c as an example:

__attribute__ ((noinline))
static int test_pkt_access_subprog1(volatile struct __sk_buff *skb)
{
        return skb->len * 2;
}

__attribute__ ((noinline))
static int test_pkt_access_subprog2(int val, volatile struct __sk_buff *skb)
{
        return skb->len + val;
}

SEC("classifier/test_pkt_access")
int test_pkt_access(struct __sk_buff *skb)
{
        if (test_pkt_access_subprog1(skb) != skb->len * 2)
                return TC_ACT_SHOT;
        if (test_pkt_access_subprog2(2, skb) != skb->len + 2)
                return TC_ACT_SHOT;
        return TC_ACT_UNSPEC;
}

When compiled, we get two relocations, pointing to '.text' symbol. .text has
st_value set to 0 (it points to the beginning of .text section):

0000000000000008  000000050000000a R_BPF_64_32            0000000000000000 .text
0000000000000040  000000050000000a R_BPF_64_32            0000000000000000 .text

test_pkt_access_subprog1 and test_pkt_access_subprog2 offsets (targets of two
calls) are encoded within call instruction's imm32 part as -1 and 2,
respectively:

0000000000000000 test_pkt_access_subprog1:
       0:       61 10 00 00 00 00 00 00 r0 = *(u32 *)(r1 + 0)
       1:       64 00 00 00 01 00 00 00 w0 <<= 1
       2:       95 00 00 00 00 00 00 00 exit

0000000000000018 test_pkt_access_subprog2:
       3:       61 10 00 00 00 00 00 00 r0 = *(u32 *)(r1 + 0)
       4:       04 00 00 00 02 00 00 00 w0 += 2
       5:       95 00 00 00 00 00 00 00 exit

0000000000000000 test_pkt_access:
       0:       bf 16 00 00 00 00 00 00 r6 = r1
===>   1:       85 10 00 00 ff ff ff ff call -1
       2:       bc 01 00 00 00 00 00 00 w1 = w0
       3:       b4 00 00 00 02 00 00 00 w0 = 2
       4:       61 62 00 00 00 00 00 00 r2 = *(u32 *)(r6 + 0)
       5:       64 02 00 00 01 00 00 00 w2 <<= 1
       6:       5e 21 08 00 00 00 00 00 if w1 != w2 goto +8 <LBB0_3>
       7:       bf 61 00 00 00 00 00 00 r1 = r6
===>   8:       85 10 00 00 02 00 00 00 call 2
       9:       bc 01 00 00 00 00 00 00 w1 = w0
      10:       61 62 00 00 00 00 00 00 r2 = *(u32 *)(r6 + 0)
      11:       04 02 00 00 02 00 00 00 w2 += 2
      12:       b4 00 00 00 ff ff ff ff w0 = -1
      13:       1e 21 01 00 00 00 00 00 if w1 == w2 goto +1 <LBB0_3>
      14:       b4 00 00 00 02 00 00 00 w0 = 2
0000000000000078 LBB0_3:
      15:       95 00 00 00 00 00 00 00 exit

Now, if we compile example with global functions, the setup changes.
Relocations are now against specifically test_pkt_access_subprog1 and
test_pkt_access_subprog2 symbols, with test_pkt_access_subprog2 pointing 24
bytes into its respective section (.text), i.e., 3 instructions in:

0000000000000008  000000070000000a R_BPF_64_32            0000000000000000 test_pkt_access_subprog1
0000000000000048  000000080000000a R_BPF_64_32            0000000000000018 test_pkt_access_subprog2

Calls instructions now encode offsets relative to function symbols and are both
set ot -1:

0000000000000000 test_pkt_access_subprog1:
       0:       61 10 00 00 00 00 00 00 r0 = *(u32 *)(r1 + 0)
       1:       64 00 00 00 01 00 00 00 w0 <<= 1
       2:       95 00 00 00 00 00 00 00 exit

0000000000000018 test_pkt_access_subprog2:
       3:       61 20 00 00 00 00 00 00 r0 = *(u32 *)(r2 + 0)
       4:       0c 10 00 00 00 00 00 00 w0 += w1
       5:       95 00 00 00 00 00 00 00 exit

0000000000000000 test_pkt_access:
       0:       bf 16 00 00 00 00 00 00 r6 = r1
===>   1:       85 10 00 00 ff ff ff ff call -1
       2:       bc 01 00 00 00 00 00 00 w1 = w0
       3:       b4 00 00 00 02 00 00 00 w0 = 2
       4:       61 62 00 00 00 00 00 00 r2 = *(u32 *)(r6 + 0)
       5:       64 02 00 00 01 00 00 00 w2 <<= 1
       6:       5e 21 09 00 00 00 00 00 if w1 != w2 goto +9 <LBB2_3>
       7:       b4 01 00 00 02 00 00 00 w1 = 2
       8:       bf 62 00 00 00 00 00 00 r2 = r6
===>   9:       85 10 00 00 ff ff ff ff call -1
      10:       bc 01 00 00 00 00 00 00 w1 = w0
      11:       61 62 00 00 00 00 00 00 r2 = *(u32 *)(r6 + 0)
      12:       04 02 00 00 02 00 00 00 w2 += 2
      13:       b4 00 00 00 ff ff ff ff w0 = -1
      14:       1e 21 01 00 00 00 00 00 if w1 == w2 goto +1 <LBB2_3>
      15:       b4 00 00 00 02 00 00 00 w0 = 2
0000000000000080 LBB2_3:
      16:       95 00 00 00 00 00 00 00 exit

Thus the right formula to calculate target call offset after relocation should
take into account relocation's target symbol value (offset within section),
call instruction's imm32 offset, and (subtracting, to get relative instruction
offset) instruction index of call instruction itself. All that is shifted by
number of instructions in main program, given all sub-programs are copied over
after main program.

Convert few selftests relying on bpf-to-bpf calls to use global functions
instead of static ones.

Fixes: 48cca7e44f ("libbpf: add support for bpf_call")
Reported-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20191119224447.3781271-1-andriin@fb.com
2019-11-19 15:00:12 -08:00
Luigi Rizzo 3de88c9113 net-af_xdp: Use correct number of channels from ethtool
Drivers use different fields to report the number of channels, so take
the maximum of all data channels (rx, tx, combined) when determining the
size of the xsk map. The current code used only 'combined' which was set
to 0 in some drivers e.g. mlx4.

Tested: compiled and run xdpsock -q 3 -r -S on mlx4

Signed-off-by: Luigi Rizzo <lrizzo@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Acked-by: Magnus Karlsson <magnus.karlsson@intel.com>
Link: https://lore.kernel.org/bpf/20191119001951.92930-1-lrizzo@google.com
2019-11-19 14:06:35 -08:00
Andrii Nakryiko 7fe74b4362 libbpf: Make global data internal arrays mmap()-able, if possible
Add detection of BPF_F_MMAPABLE flag support for arrays and add it as an extra
flag to internal global data maps, if supported by kernel. This allows users
to memory-map global data and use it without BPF map operations, greatly
simplifying user experience.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Song Liu <songliubraving@fb.com>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/20191117172806.2195367-5-andriin@fb.com
2019-11-18 11:41:59 +01:00
Alexei Starovoitov e7bf94dbb8 libbpf: Add support for attaching BPF programs to other BPF programs
Extend libbpf api to pass attach_prog_fd into bpf_object__open.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20191114185720.1641606-19-ast@kernel.org
2019-11-15 23:45:37 +01:00
Alexei Starovoitov 11d1e2eeff selftests/bpf: Add test for BPF trampoline
Add sanity test for BPF trampoline that checks kernel functions
with up to 6 arguments of different sizes.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20191114185720.1641606-10-ast@kernel.org
2019-11-15 23:43:15 +01:00
Alexei Starovoitov b8c54ea455 libbpf: Add support to attach to fentry/fexit tracing progs
Teach libbpf to recognize tracing programs types and attach them to
fentry/fexit.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Song Liu <songliubraving@fb.com>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20191114185720.1641606-7-ast@kernel.org
2019-11-15 23:42:31 +01:00
Alexei Starovoitov 1442e2871b libbpf: Introduce btf__find_by_name_kind()
Introduce btf__find_by_name_kind() helper to search BTF by name and kind, since
name alone can be ambiguous.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Song Liu <songliubraving@fb.com>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20191114185720.1641606-6-ast@kernel.org
2019-11-15 23:42:14 +01:00
Magnus Karlsson a68977d269 libbpf: Allow for creating Rx or Tx only AF_XDP sockets
The libbpf AF_XDP code is extended to allow for the creation of Rx
only or Tx only sockets. Previously it returned an error if the socket
was not initialized for both Rx and Tx.

Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Tested-by: William Tu <u9012063@gmail.com>
Acked-by: Jonathan Lemon <jonathan.lemon@gmail.com>
Link: https://lore.kernel.org/bpf/1573148860-30254-4-git-send-email-magnus.karlsson@intel.com
2019-11-10 19:30:46 -08:00
Magnus Karlsson cbf07409d0 libbpf: Support XDP_SHARED_UMEM with external XDP program
Add support in libbpf to create multiple sockets that share a single
umem. Note that an external XDP program need to be supplied that
routes the incoming traffic to the desired sockets. So you need to
supply the libbpf_flag XSK_LIBBPF_FLAGS__INHIBIT_PROG_LOAD and load
your own XDP program.

Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Tested-by: William Tu <u9012063@gmail.com>
Acked-by: Jonathan Lemon <jonathan.lemon@gmail.com>
Link: https://lore.kernel.org/bpf/1573148860-30254-2-git-send-email-magnus.karlsson@intel.com
2019-11-10 19:30:45 -08:00
Toke Høiland-Jørgensen 1a734efe06 libbpf: Add getter for program size
This adds a new getter for the BPF program size (in bytes). This is useful
for a caller that is trying to predict how much memory will be locked by
loading a BPF object into the kernel.

Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: David S. Miller <davem@davemloft.net>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/157333185272.88376.10996937115395724683.stgit@toke.dk
2019-11-10 19:26:30 -08:00
Toke Høiland-Jørgensen 473f4e133a libbpf: Add bpf_get_link_xdp_info() function to get more XDP information
Currently, libbpf only provides a function to get a single ID for the XDP
program attached to the interface. However, it can be useful to get the
full set of program IDs attached, along with the attachment mode, in one
go. Add a new getter function to support this, using an extendible
structure to carry the information. Express the old bpf_get_link_id()
function in terms of the new function.

Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: David S. Miller <davem@davemloft.net>
Acked-by: Song Liu <songliubraving@fb.com>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/157333185164.88376.7520653040667637246.stgit@toke.dk
2019-11-10 19:26:30 -08:00
Toke Høiland-Jørgensen b6e99b010e libbpf: Use pr_warn() when printing netlink errors
The netlink functions were using fprintf(stderr, ) directly to print out
error messages, instead of going through the usual logging macros. This
makes it impossible for the calling application to silence or redirect
those error messages. Fix this by switching to pr_warn() in nlattr.c and
netlink.c.

Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: David S. Miller <davem@davemloft.net>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/157333185055.88376.15999360127117901443.stgit@toke.dk
2019-11-10 19:26:30 -08:00
Toke Høiland-Jørgensen 4f33ddb4e3 libbpf: Propagate EPERM to caller on program load
When loading an eBPF program, libbpf overrides the return code for EPERM
errors instead of returning it to the caller. This makes it hard to figure
out what went wrong on load.

In particular, EPERM is returned when the system rlimit is too low to lock
the memory required for the BPF program. Previously, this was somewhat
obscured because the rlimit error would be hit on map creation (which does
return it correctly). However, since maps can now be reused, object load
can proceed all the way to loading programs without hitting the error;
propagating it even in this case makes it possible for the caller to react
appropriately (and, e.g., attempt to raise the rlimit before retrying).

Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: David S. Miller <davem@davemloft.net>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/157333184946.88376.11768171652794234561.stgit@toke.dk
2019-11-10 19:26:30 -08:00
Toke Høiland-Jørgensen ec6d5f47bf libbpf: Unpin auto-pinned maps if loading fails
Since the automatic map-pinning happens during load, it will leave pinned
maps around if the load fails at a later stage. Fix this by unpinning any
pinned maps on cleanup. To avoid unpinning pinned maps that were reused
rather than newly pinned, add a new boolean property on struct bpf_map to
keep track of whether that map was reused or not; and only unpin those maps
that were not reused.

Fixes: 57a00f4164 ("libbpf: Add auto-pinning of maps when loading BPF objects")
Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: David S. Miller <davem@davemloft.net>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/157333184731.88376.9992935027056165873.stgit@toke.dk
2019-11-10 19:26:30 -08:00
Andrii Nakryiko 98e527af30 libbpf: Improve handling of corrupted ELF during map initialization
If we get ELF file with "maps" section, but no symbols pointing to it, we'll
end up with division by zero. Add check against this situation and exit early
with error. Found by Coverity scan against Github libbpf sources.

Fixes: bf82927125 ("libbpf: refactor map initialization")
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20191107020855.3834758-6-andriin@fb.com
2019-11-07 16:20:38 +01:00
Andrii Nakryiko 994021a7e0 libbpf: Make btf__resolve_size logic always check size error condition
Perform size check always in btf__resolve_size. Makes the logic a bit more
robust against corrupted BTF and silences LGTM/Coverity complaining about
always true (size < 0) check.

Fixes: 69eaab04c6 ("btf: extract BTF type size calculation")
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20191107020855.3834758-5-andriin@fb.com
2019-11-07 16:20:38 +01:00
Andrii Nakryiko dd3ab12637 libbpf: Fix another potential overflow issue in bpf_prog_linfo
Fix few issues found by Coverity and LGTM.

Fixes: b053b439b7 ("bpf: libbpf: bpftool: Print bpf_line_info during prog dump")
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20191107020855.3834758-4-andriin@fb.com
2019-11-07 16:20:38 +01:00
Andrii Nakryiko 4ee1135615 libbpf: Fix potential overflow issue
Fix a potential overflow issue found by LGTM analysis, based on Github libbpf
source code.

Fixes: 3d65014146 ("bpf: libbpf: Add btf_line_info support to libbpf")
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20191107020855.3834758-3-andriin@fb.com
2019-11-07 16:20:37 +01:00
Andrii Nakryiko 3dc5e05982 libbpf: Fix memory leak/double free issue
Coverity scan against Github libbpf code found the issue of not freeing memory and
leaving already freed memory still referenced from bpf_program. Fix it by
re-assigning successfully reallocated memory sooner.

Fixes: 2993e0515b ("tools/bpf: add support to read .BTF.ext sections")
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20191107020855.3834758-2-andriin@fb.com
2019-11-07 16:20:37 +01:00
Andrii Nakryiko 9656b346b2 libbpf: Fix negative FD close() in xsk_setup_xdp_prog()
Fix issue reported by static analysis (Coverity). If bpf_prog_get_fd_by_id()
fails, xsk_lookup_bpf_maps() will fail as well and clean-up code will attempt
close() with fd=-1. Fix by checking bpf_prog_get_fd_by_id() return result and
exiting early.

Fixes: 10a13bb40e ("libbpf: remove qidconf and better support external bpf programs.")
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20191107054059.313884-1-andriin@fb.com
2019-11-07 16:15:27 +01:00
Andrii Nakryiko ed57802121 libbpf: Simplify BPF_CORE_READ_BITFIELD_PROBED usage
Streamline BPF_CORE_READ_BITFIELD_PROBED interface to follow
BPF_CORE_READ_BITFIELD (direct) and BPF_CORE_READ, in general, i.e., just
return read result or 0, if underlying bpf_probe_read() failed.

In practice, real applications rarely check bpf_probe_read() result, because
it has to always work or otherwise it's a bug. So propagating internal
bpf_probe_read() error from this macro hurts usability without providing real
benefits in practice. This patch fixes the issue and simplifies usage,
noticeable even in selftest itself.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20191106201500.2582438-1-andriin@fb.com
2019-11-06 13:54:59 -08:00
Andrii Nakryiko 94f060e984 libbpf: Add support for field size relocations
Add bpf_core_field_size() macro, capturing a relocation against field size.
Adjust bits of internal libbpf relocation logic to allow capturing size
relocations of various field types: arrays, structs/unions, enums, etc.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20191101222810.1246166-4-andriin@fb.com
2019-11-04 16:06:56 +01:00
Andrii Nakryiko ee26dade0e libbpf: Add support for relocatable bitfields
Add support for the new field relocation kinds, necessary to support
relocatable bitfield reads. Provide macro for abstracting necessary code doing
full relocatable bitfield extraction into u64 value. Two separate macros are
provided:
- BPF_CORE_READ_BITFIELD macro for direct memory read-enabled BPF programs
(e.g., typed raw tracepoints). It uses direct memory dereference to extract
bitfield backing integer value.
- BPF_CORE_READ_BITFIELD_PROBED macro for cases where bpf_probe_read() needs
to be used to extract same backing integer value.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20191101222810.1246166-3-andriin@fb.com
2019-11-04 16:06:56 +01:00
Toke Høiland-Jørgensen 57a00f4164 libbpf: Add auto-pinning of maps when loading BPF objects
This adds support to libbpf for setting map pinning information as part of
the BTF map declaration, to get automatic map pinning (and reuse) on load.
The pinning type currently only supports a single PIN_BY_NAME mode, where
each map will be pinned by its name in a path that can be overridden, but
defaults to /sys/fs/bpf.

Since auto-pinning only does something if any maps actually have a
'pinning' BTF attribute set, we default the new option to enabled, on the
assumption that seamless pinning is what most callers want.

When a map has a pin_path set at load time, libbpf will compare the map
pinned at that location (if any), and if the attributes match, will re-use
that map instead of creating a new one. If no existing map is found, the
newly created map will instead be pinned at the location.

Programs wanting to customise the pinning can override the pinning paths
using bpf_map__set_pin_path() before calling bpf_object__load() (including
setting it to NULL to disable pinning of a particular map).

Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/157269298092.394725.3966306029218559681.stgit@toke.dk
2019-11-02 12:35:07 -07:00
Toke Høiland-Jørgensen 196f8487f5 libbpf: Move directory creation into _pin() functions
The existing pin_*() functions all try to create the parent directory
before pinning. Move this check into the per-object _pin() functions
instead. This ensures consistent behaviour when auto-pinning is
added (which doesn't go through the top-level pin_maps() function), at the
cost of a few more calls to mkdir().

Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/157269297985.394725.5882630952992598610.stgit@toke.dk
2019-11-02 12:35:07 -07:00
Toke Høiland-Jørgensen 4580b25fce libbpf: Store map pin path and status in struct bpf_map
Support storing and setting a pin path in struct bpf_map, which can be used
for automatic pinning. Also store the pin status so we can avoid attempts
to re-pin a map that has already been pinned (or reused from a previous
pinning).

The behaviour of bpf_object__{un,}pin_maps() is changed so that if it is
called with a NULL path argument (which was previously illegal), it will
(un)pin only those maps that have a pin_path set.

Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/157269297876.394725.14782206533681896279.stgit@toke.dk
2019-11-02 12:35:07 -07:00
Toke Høiland-Jørgensen d1b4574a4b libbpf: Fix error handling in bpf_map__reuse_fd()
bpf_map__reuse_fd() was calling close() in the error path before returning
an error value based on errno. However, close can change errno, so that can
lead to potentially misleading error messages. Instead, explicitly store
errno in the err variable before each goto.

Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/157269297769.394725.12634985106772698611.stgit@toke.dk
2019-11-02 12:35:06 -07:00
Alexei Starovoitov 12a8654b2e libbpf: Add support for prog_tracing
Cleanup libbpf from expected_attach_type == attach_btf_id hack
and introduce BPF_PROG_TYPE_TRACING.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/20191030223212.953010-3-ast@kernel.org
2019-10-31 15:16:59 +01:00
Andrii Nakryiko a566e35f1e libbpf: Don't use kernel-side u32 type in xsk.c
u32 is a kernel-side typedef. User-space library is supposed to use __u32.
This breaks Github's projection of libbpf. Do u32 -> __u32 fix.

Fixes: 94ff9ebb49 ("libbpf: Fix compatibility for kernels without need_wakeup")
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Björn Töpel <bjorn.topel@intel.com>
Cc: Magnus Karlsson <magnus.karlsson@intel.com>
Link: https://lore.kernel.org/bpf/20191029055953.2461336-1-andriin@fb.com
2019-10-29 06:38:12 -07:00
Andrii Nakryiko d3a3aa0c59 libbpf: Fix off-by-one error in ELF sanity check
libbpf's bpf_object__elf_collect() does simple sanity check after iterating
over all ELF sections, if checks that .strtab index is correct. Unfortunately,
due to section indices being 1-based, the check breaks for cases when .strtab
ends up being the very last section in ELF.

Fixes: 77ba9a5b48 ("tools lib bpf: Fetch map names from correct strtab")
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20191028233727.1286699-1-andriin@fb.com
2019-10-28 20:27:40 -07:00
Magnus Karlsson 94ff9ebb49 libbpf: Fix compatibility for kernels without need_wakeup
When the need_wakeup flag was added to AF_XDP, the format of the
XDP_MMAP_OFFSETS getsockopt was extended. Code was added to the
kernel to take care of compatibility issues arrising from running
applications using any of the two formats. However, libbpf was
not extended to take care of the case when the application/libbpf
uses the new format but the kernel only supports the old
format. This patch adds support in libbpf for parsing the old
format, before the need_wakeup flag was added, and emulating a
set of static need_wakeup flags that will always work for the
application.

v2 -> v3:
* Incorporated code improvements suggested by Jonathan Lemon

v1 -> v2:
* Rebased to bpf-next
* Rewrote the code as the previous version made you blind

Fixes: a4500432c2 ("libbpf: add support for need_wakeup flag in AF_XDP part")
Reported-by: Eloy Degen <degeneloy@gmail.com>
Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Jonathan Lemon <jonathan.lemon@gmail.com>
Link: https://lore.kernel.org/bpf/1571995035-21889-1-git-send-email-magnus.karlsson@intel.com
2019-10-28 20:25:32 -07:00
David S. Miller 5b7fe93db0 Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next
Daniel Borkmann says:

====================
pull-request: bpf-next 2019-10-27

The following pull-request contains BPF updates for your *net-next* tree.

We've added 52 non-merge commits during the last 11 day(s) which contain
a total of 65 files changed, 2604 insertions(+), 1100 deletions(-).

The main changes are:

 1) Revolutionize BPF tracing by using in-kernel BTF to type check BPF
    assembly code. The work here teaches BPF verifier to recognize
    kfree_skb()'s first argument as 'struct sk_buff *' in tracepoints
    such that verifier allows direct use of bpf_skb_event_output() helper
    used in tc BPF et al (w/o probing memory access) that dumps skb data
    into perf ring buffer. Also add direct loads to probe memory in order
    to speed up/replace bpf_probe_read() calls, from Alexei Starovoitov.

 2) Big batch of changes to improve libbpf and BPF kselftests. Besides
    others: generalization of libbpf's CO-RE relocation support to now
    also include field existence relocations, revamp the BPF kselftest
    Makefile to add test runner concept allowing to exercise various
    ways to build BPF programs, and teach bpf_object__open() and friends
    to automatically derive BPF program type/expected attach type from
    section names to ease their use, from Andrii Nakryiko.

 3) Fix deadlock in stackmap's build-id lookup on rq_lock(), from Song Liu.

 4) Allow to read BTF as raw data from bpftool. Most notable use case
    is to dump /sys/kernel/btf/vmlinux through this, from Jiri Olsa.

 5) Use bpf_redirect_map() helper in libbpf's AF_XDP helper prog which
    manages to improve "rx_drop" performance by ~4%., from Björn Töpel.

 6) Fix to restore the flow dissector after reattach BPF test and also
    fix error handling in bpf_helper_defs.h generation, from Jakub Sitnicki.

 7) Improve verifier's BTF ctx access for use outside of raw_tp, from
    Martin KaFai Lau.

 8) Improve documentation for AF_XDP with new sections and to reflect
    latest features, from Magnus Karlsson.

 9) Add back 'version' section parsing to libbpf for old kernels, from
    John Fastabend.

10) Fix strncat bounds error in libbpf's libbpf_prog_type_by_name(),
    from KP Singh.

11) Turn on -mattr=+alu32 in LLVM by default for BPF kselftests in order
    to improve insn coverage for built BPF progs, from Yonghong Song.

12) Misc minor cleanups and fixes, from various others.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2019-10-26 22:57:27 -07:00
KP Singh 58eeb2289a libbpf: Fix strncat bounds error in libbpf_prog_type_by_name
On compiling samples with this change, one gets an error:

 error: ‘strncat’ specified bound 118 equals destination size
  [-Werror=stringop-truncation]

    strncat(dst, name + section_names[i].len,
    ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
     sizeof(raw_tp_btf_name) - (dst - raw_tp_btf_name));
     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

strncat requires the destination to have enough space for the
terminating null byte.

Fixes: f75a697e09 ("libbpf: Auto-detect btf_id of BTF-based raw_tracepoint")
Signed-off-by: KP Singh <kpsingh@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20191023154038.24075-1-kpsingh@chromium.org
2019-10-23 10:17:28 -07:00
Björn Töpel d7d962a095 libbpf: Use implicit XSKMAP lookup from AF_XDP XDP program
In commit 43e74c0267 ("bpf_xdp_redirect_map: Perform map lookup in
eBPF helper") the bpf_redirect_map() helper learned to do map lookup,
which means that the explicit lookup in the XDP program for AF_XDP is
not needed for post-5.3 kernels.

This commit adds the implicit map lookup with default action, which
improves the performance for the "rx_drop" [1] scenario with ~4%.

For pre-5.3 kernels, the bpf_redirect_map() returns XDP_ABORTED, and a
fallback path for backward compatibility is entered, where explicit
lookup is still performed. This means a slight regression for older
kernels (an additional bpf_redirect_map() call), but I consider that a
fair punishment for users not upgrading their kernels. ;-)

v1->v2: Backward compatibility (Toke) [2]
v2->v3: Avoid masking/zero-extension by using JMP32 [3]

[1] # xdpsock -i eth0 -z -r
[2] https://lore.kernel.org/bpf/87pnirb3dc.fsf@toke.dk/
[3] https://lore.kernel.org/bpf/87v9sip0i8.fsf@toke.dk/

Suggested-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: Björn Töpel <bjorn.topel@intel.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Toke Høiland-Jørgensen <toke@redhat.com>
Link: https://lore.kernel.org/bpf/20191022072206.6318-1-bjorn.topel@gmail.com
2019-10-23 10:03:52 -07:00
Andrii Nakryiko e00aca65e6 libbpf: Make DECLARE_LIBBPF_OPTS macro strictly a variable declaration
LIBBPF_OPTS is implemented as a mix of field declaration and memset
+ assignment. This makes it neither variable declaration nor purely
statements, which is a problem, because you can't mix it with either
other variable declarations nor other function statements, because C90
compiler mode emits warning on mixing all that together.

This patch changes LIBBPF_OPTS into a strictly declaration of variable
and solves this problem, as can be seen in case of bpftool, which
previously would emit compiler warning, if done this way (LIBBPF_OPTS as
part of function variables declaration block).

This patch also renames LIBBPF_OPTS into DECLARE_LIBBPF_OPTS to follow
kernel convention for similar macros more closely.

v1->v2:
- rename LIBBPF_OPTS into DECLARE_LIBBPF_OPTS (Jakub Sitnicki).

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Toke Høiland-Jørgensen <toke@redhat.com>
Link: https://lore.kernel.org/bpf/20191022172100.3281465-1-andriin@fb.com
2019-10-22 21:35:03 +02:00
Andrii Nakryiko dd4436bb83 libbpf: Teach bpf_object__open to guess program types
Teach bpf_object__open how to guess program type and expected attach
type from section names, similar to what bpf_prog_load() does. This
seems like a really useful features and an oversight to not have this
done during bpf_object_open(). To preserver backwards compatible
behavior of bpf_prog_load(), its attr->prog_type is treated as an
override of bpf_object__open() decisions, if attr->prog_type is not
UNSPECIFIED.

There is a slight difference in behavior for bpf_prog_load().
Previously, if bpf_prog_load() was loading BPF object with more than one
program, first program's guessed program type and expected attach type
would determine corresponding attributes of all the subsequent program
types, even if their sections names suggest otherwise. That seems like
a rather dubious behavior and with this change it will behave more
sanely: each program's type is determined individually, unless they are
forced to uniformity through attr->prog_type.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20191021033902.3856966-5-andriin@fb.com
2019-10-21 14:49:12 +02:00
Andrii Nakryiko 32dff6db29 libbpf: Add uprobe/uretprobe and tp/raw_tp section suffixes
Map uprobe/uretprobe into KPROBE program type. tp/raw_tp are just an
alias for more verbose tracepoint/raw_tracepoint, respectively.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20191021033902.3856966-4-andriin@fb.com
2019-10-21 14:49:12 +02:00
Andrii Nakryiko f1eead9e3c libbpf: Add bpf_program__get_{type, expected_attach_type) APIs
There are bpf_program__set_type() and
bpf_program__set_expected_attach_type(), but no corresponding getters,
which seems rather incomplete. Fix this.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20191021033902.3856966-3-andriin@fb.com
2019-10-21 14:49:12 +02:00
Kefeng Wang be18010ea2 tools, bpf: Rename pr_warning to pr_warn to align with kernel logging
For kernel logging macros, pr_warning() is completely removed and
replaced by pr_warn(). By using pr_warn() in tools/lib/bpf/ for
symmetry to kernel logging macros, we could eventually drop the
use of pr_warning() in the whole kernel tree.

Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20191021055532.185245-1-wangkefeng.wang@huawei.com
2019-10-21 14:38:41 +02:00
Jakub Sitnicki ab81e203bc scripts/bpf: Print an error when known types list needs updating
Don't generate a broken bpf_helper_defs.h header if the helper script needs
updating because it doesn't recognize a newly added type. Instead print an
error that explains why the build is failing, clean up the partially
generated header and stop.

v1->v2:
- Switched from temporary file to .DELETE_ON_ERROR.

Fixes: 456a513bb5 ("scripts/bpf: Emit an #error directive known types list needs updating")
Suggested-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Jakub Sitnicki <jakub@cloudflare.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20191020112344.19395-1-jakub@cloudflare.com
2019-10-20 18:21:21 -07:00
David S. Miller 2f184393e0 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Several cases of overlapping changes which were for the most
part trivially resolvable.

Signed-off-by: David S. Miller <davem@davemloft.net>
2019-10-20 10:43:00 -07:00
John Fastabend 54b8625cd9 bpf, libbpf: Add kernel version section parsing back
With commit "libbpf: stop enforcing kern_version,..." we removed the
kernel version section parsing in favor of querying for the kernel
using uname() and populating the version using the result of the
query. After this any version sections were simply ignored.

Unfortunately, the world of kernels is not so friendly. I've found some
customized kernels where uname() does not match the in kernel version.
To fix this so programs can load in this environment this patch adds
back parsing the section and if it exists uses the user specified
kernel version to override the uname() result. However, keep most the
kernel uname() discovery bits so users are not required to insert the
version except in these odd cases.

Fixes: 5e61f27070 ("libbpf: stop enforcing kern_version, populate it for users")
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/157140968634.9073.6407090804163937103.stgit@john-XPS-13-9370
2019-10-18 20:59:10 +02:00
Alexei Starovoitov f75a697e09 libbpf: Auto-detect btf_id of BTF-based raw_tracepoints
It's a responsiblity of bpf program author to annotate the program
with SEC("tp_btf/name") where "name" is a valid raw tracepoint.
The libbpf will try to find "name" in vmlinux BTF and error out
in case vmlinux BTF is not available or "name" is not found.
If "name" is indeed a valid raw tracepoint then in-kernel BTF
will have "btf_trace_##name" typedef that points to function
prototype of that raw tracepoint. BTF description captures
exact argument the kernel C code is passing into raw tracepoint.
The kernel verifier will check the types while loading bpf program.

libbpf keeps BTF type id in expected_attach_type, but since
kernel ignores this attribute for tracing programs copy it
into attach_btf_id attribute before loading.

Later the kernel will use prog->attach_btf_id to select raw tracepoint
during bpf_raw_tracepoint_open syscall command.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/20191016032505.2089704-6-ast@kernel.org
2019-10-17 16:44:35 +02:00
Andrii Nakryiko 01340e3191 libbpf: Add BPF-side definitions of supported field relocation kinds
Add enum definition for Clang's __builtin_preserve_field_info()
second argument (info_kind). Currently only byte offset and existence
are supported. Corresponding Clang changes introducing this built-in can
be found at [0]

  [0] https://reviews.llvm.org/D67980

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20191015182849.3922287-5-andriin@fb.com
2019-10-15 16:06:05 -07:00
Andrii Nakryiko 62561eb442 libbpf: Add support for field existance CO-RE relocation
Add support for BPF_FRK_EXISTS relocation kind to detect existence of
captured field in a destination BTF, allowing conditional logic to
handle incompatible differences between kernels.

Also introduce opt-in relaxed CO-RE relocation handling option, which
makes libbpf emit warning for failed relocations, but proceed with other
relocations. Instruction, for which relocation failed, is patched with
(u32)-1 value.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20191015182849.3922287-4-andriin@fb.com
2019-10-15 16:06:05 -07:00
Andrii Nakryiko 291ee02b5e libbpf: Refactor bpf_object__open APIs to use common opts
Refactor all the various bpf_object__open variations to ultimately
specify common bpf_object_open_opts struct. This makes it easy to keep
extending this common struct w/ extra parameters without having to
update all the legacy APIs.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20191015182849.3922287-3-andriin@fb.com
2019-10-15 16:06:05 -07:00
Andrii Nakryiko 511bb0085c libbpf: Update BTF reloc support to latest Clang format
BTF offset reloc was generalized in recent Clang into field relocation,
capturing extra u32 field, specifying what aspect of captured field
needs to be relocated. This changes .BTF.ext's record size for this
relocation from 12 bytes to 16 bytes. Given these format changes
happened in Clang before official released version, it's ok to not
support outdated 12-byte record size w/o breaking ABI.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20191015182849.3922287-2-andriin@fb.com
2019-10-15 16:06:05 -07:00
Ivan Khoronzhuk 793a349cd8 libbpf: Add C/LDFLAGS to libbpf.so and test_libpf targets
In case of C/LDFLAGS there is no way to pass them correctly to build
command, for instance when --sysroot is used or external libraries
are used, like -lelf, wich can be absent in toolchain. This can be
used for samples/bpf cross-compiling allowing to get elf lib from
sysroot.

Signed-off-by: Ivan Khoronzhuk <ivan.khoronzhuk@linaro.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20191011002808.28206-13-ivan.khoronzhuk@linaro.org
2019-10-12 16:08:59 -07:00
Ivan Khoronzhuk 5c26f9a783 libbpf: Don't use cxx to test_libpf target
No need to use C++ for test_libbpf target when libbpf is on C and it
can be tested with C, after this change the CXXFLAGS in makefiles can
be avoided, at least in bpf samples, when sysroot is used, passing
same C/LDFLAGS as for lib.

Add "return 0" in test_libbpf to avoid warn, but also remove spaces at
start of the lines to keep same style and avoid warns while apply.

Signed-off-by: Ivan Khoronzhuk <ivan.khoronzhuk@linaro.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20191011002808.28206-12-ivan.khoronzhuk@linaro.org
2019-10-12 16:08:59 -07:00
Andrii Nakryiko e78dcbf414 libbpf: Handle invalid typedef emitted by old GCC
Old GCC versions are producing invalid typedef for __gnuc_va_list
pointing to void. Special-case this and emit valid:

typedef __builtin_va_list __gnuc_va_list;

Reported-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/20191011032901.452042-1-andriin@fb.com
2019-10-11 23:11:55 +02:00
Andrii Nakryiko 409017847d libbpf: Generate more efficient BPF_CORE_READ code
Existing BPF_CORE_READ() macro generates slightly suboptimal code. If
there are intermediate pointers to be read, initial source pointer is
going to be assigned into a temporary variable and then temporary
variable is going to be uniformly used as a "source" pointer for all
intermediate pointer reads. Schematically (ignoring all the type casts),
BPF_CORE_READ(s, a, b, c) is expanded into:
({
	const void *__t = src;
	bpf_probe_read(&__t, sizeof(*__t), &__t->a);
	bpf_probe_read(&__t, sizeof(*__t), &__t->b);

	typeof(s->a->b->c) __r;
	bpf_probe_read(&__r, sizeof(*__r), &__t->c);
})

This initial `__t = src` makes calls more uniform, but causes slightly
less optimal register usage sometimes when compiled with Clang. This can
cascase into, e.g., more register spills.

This patch fixes this issue by generating more optimal sequence:
({
	const void *__t;
	bpf_probe_read(&__t, sizeof(*__t), &src->a); /* <-- src here */
	bpf_probe_read(&__t, sizeof(*__t), &__t->b);

	typeof(s->a->b->c) __r;
	bpf_probe_read(&__r, sizeof(*__r), &__t->c);
})

Fixes: 7db3822ab9 ("libbpf: Add BPF_CORE_READ/BPF_CORE_READ_INTO helpers")
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20191011023847.275936-1-andriin@fb.com
2019-10-11 22:35:46 +02:00
Ilya Maximets 25bfef430e libbpf: Fix passing uninitialized bytes to setsockopt
'struct xdp_umem_reg' has 4 bytes of padding at the end that makes
valgrind complain about passing uninitialized stack memory to the
syscall:

  Syscall param socketcall.setsockopt() points to uninitialised byte(s)
    at 0x4E7AB7E: setsockopt (in /usr/lib64/libc-2.29.so)
    by 0x4BDE035: xsk_umem__create@@LIBBPF_0.0.4 (xsk.c:172)
  Uninitialised value was created by a stack allocation
    at 0x4BDDEBA: xsk_umem__create@@LIBBPF_0.0.4 (xsk.c:140)

Padding bytes appeared after introducing of a new 'flags' field.
memset() is required to clear them.

Fixes: 10d30e3017 ("libbpf: add flags to umem config")
Signed-off-by: Ilya Maximets <i.maximets@ovn.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20191009164929.17242-1-i.maximets@ovn.org
2019-10-09 15:45:37 -07:00
Andrii Nakryiko b4099769f3 libbpf: Fix struct end padding in btf_dump
Fix a case where explicit padding at the end of a struct is necessary
due to non-standart alignment requirements of fields (which BTF doesn't
capture explicitly).

Fixes: 351131b51c ("libbpf: add btf_dump API for BTF-to-C conversion")
Reported-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Tested-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/20191008231009.2991130-2-andriin@fb.com
2019-10-09 15:38:36 -07:00
Andrii Nakryiko 7db3822ab9 libbpf: Add BPF_CORE_READ/BPF_CORE_READ_INTO helpers
Add few macros simplifying BCC-like multi-level probe reads, while also
emitting CO-RE relocations for each read.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20191008175942.1769476-7-andriin@fb.com
2019-10-08 23:16:03 +02:00
Andrii Nakryiko e01a75c159 libbpf: Move bpf_{helpers, helper_defs, endian, tracing}.h into libbpf
Move bpf_helpers.h, bpf_tracing.h, and bpf_endian.h into libbpf. Move
bpf_helper_defs.h generation into libbpf's Makefile. Ensure all those
headers are installed along the other libbpf headers. Also, adjust
selftests and samples include path to include libbpf now.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20191008175942.1769476-6-andriin@fb.com
2019-10-08 23:16:03 +02:00
Toke Høiland-Jørgensen a9eb048d56 libbpf: Add cscope and tags targets to Makefile
Using cscope and/or TAGS files for navigating the source code is useful.
Add simple targets to the Makefile to generate the index files for both
tools.

Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Tested-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20191004153444.1711278-1-toke@redhat.com
2019-10-05 18:24:56 -07:00
Andrii Nakryiko c9e4c3010c libbpf: fix bpf_object__name() to actually return object name
bpf_object__name() was returning file path, not name. Fix this.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-10-05 18:09:48 -07:00
Andrii Nakryiko 2ce8450ef5 libbpf: add bpf_object__open_{file, mem} w/ extensible opts
Add new set of bpf_object__open APIs using new approach to optional
parameters extensibility allowing simpler ABI compatibility approach.

This patch demonstrates an approach to implementing libbpf APIs that
makes it easy to extend existing APIs with extra optional parameters in
such a way, that ABI compatibility is preserved without having to do
symbol versioning and generating lots of boilerplate code to handle it.
To facilitate succinct code for working with options, add OPTS_VALID,
OPTS_HAS, and OPTS_GET macros that hide all the NULL, size, and zero
checks.

Additionally, newly added libbpf APIs are encouraged to follow similar
pattern of having all mandatory parameters as formal function parameters
and always have optional (NULL-able) xxx_opts struct, which should
always have real struct size as a first field and the rest would be
optional parameters added over time, which tune the behavior of existing
API, if specified by user.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-10-05 18:09:47 -07:00
Andrii Nakryiko 5e61f27070 libbpf: stop enforcing kern_version, populate it for users
Kernel version enforcement for kprobes/kretprobes was removed from
5.0 kernel in 6c4fc209fc ("bpf: remove useless version check for prog load").
Since then, BPF programs were specifying SEC("version") just to please
libbpf. We should stop enforcing this in libbpf, if even kernel doesn't
care. Furthermore, libbpf now will pre-populate current kernel version
of the host system, in case we are still running on old kernel.

This patch also removes __bpf_object__open_xattr from libbpf.h, as
nothing in libbpf is relying on having it in that header. That function
was never exported as LIBBPF_API and even name suggests its internal
version. So this should be safe to remove, as it doesn't break ABI.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-10-05 18:09:47 -07:00
Andrii Nakryiko 03bd4773d8 libbpf: Bump current version to v0.0.6
New release cycle started, let's bump to v0.0.6 proactively.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20190930222503.519782-1-andriin@fb.com
2019-10-02 01:05:10 +02:00
Yonghong Song 1bd6352459 libbpf: handle symbol versioning properly for libbpf.a
bcc uses libbpf repo as a submodule. It brings in libbpf source
code and builds everything together to produce shared libraries.
With latest libbpf, I got the following errors:
  /bin/ld: libbcc_bpf.so.0.10.0: version node not found for symbol xsk_umem__create@LIBBPF_0.0.2
  /bin/ld: failed to set dynamic section sizes: Bad value
  collect2: error: ld returned 1 exit status
  make[2]: *** [src/cc/libbcc_bpf.so.0.10.0] Error 1

In xsk.c, we have
  asm(".symver xsk_umem__create_v0_0_2, xsk_umem__create@LIBBPF_0.0.2");
  asm(".symver xsk_umem__create_v0_0_4, xsk_umem__create@@LIBBPF_0.0.4");
The linker thinks the built is for LIBBPF but cannot find proper version
LIBBPF_0.0.2/4, so emit errors.

I also confirmed that using libbpf.a to produce a shared library also
has issues:
  -bash-4.4$ cat t.c
  extern void *xsk_umem__create;
  void * test() { return xsk_umem__create; }
  -bash-4.4$ gcc -c -fPIC t.c
  -bash-4.4$ gcc -shared t.o libbpf.a -o t.so
  /bin/ld: t.so: version node not found for symbol xsk_umem__create@LIBBPF_0.0.2
  /bin/ld: failed to set dynamic section sizes: Bad value
  collect2: error: ld returned 1 exit status
  -bash-4.4$

Symbol versioning does happens in commonly used libraries, e.g., elfutils
and glibc. For static libraries, for a versioned symbol, the old definitions
will be ignored, and the symbol will be an alias to the latest definition.
For example, glibc sched_setaffinity is versioned.
  -bash-4.4$ readelf -s /usr/lib64/libc.so.6 | grep sched_setaffinity
     756: 000000000013d3d0    13 FUNC    GLOBAL DEFAULT   13 sched_setaffinity@GLIBC_2.3.3
     757: 00000000000e2e70   455 FUNC    GLOBAL DEFAULT   13 sched_setaffinity@@GLIBC_2.3.4
    1800: 0000000000000000     0 FILE    LOCAL  DEFAULT  ABS sched_setaffinity.c
    4228: 00000000000e2e70   455 FUNC    LOCAL  DEFAULT   13 __sched_setaffinity_new
    4648: 000000000013d3d0    13 FUNC    LOCAL  DEFAULT   13 __sched_setaffinity_old
    7338: 000000000013d3d0    13 FUNC    GLOBAL DEFAULT   13 sched_setaffinity@GLIBC_2
    7380: 00000000000e2e70   455 FUNC    GLOBAL DEFAULT   13 sched_setaffinity@@GLIBC_
  -bash-4.4$
For static library, the definition of sched_setaffinity aliases to the new definition.
  -bash-4.4$ readelf -s /usr/lib64/libc.a | grep sched_setaffinity
  File: /usr/lib64/libc.a(sched_setaffinity.o)
     8: 0000000000000000   455 FUNC    GLOBAL DEFAULT    1 __sched_setaffinity_new
    12: 0000000000000000   455 FUNC    WEAK   DEFAULT    1 sched_setaffinity

For both elfutils and glibc, additional macros are used to control different handling
of symbol versioning w.r.t static and shared libraries.
For elfutils, the macro is SYMBOL_VERSIONING
(https://sourceware.org/git/?p=elfutils.git;a=blob;f=lib/eu-config.h).
For glibc, the macro is SHARED
(https://sourceware.org/git/?p=glibc.git;a=blob;f=include/shlib-compat.h;hb=refs/heads/master)

This patch used SHARED as the macro name. After this patch, the libbpf.a has
  -bash-4.4$ readelf -s libbpf.a | grep xsk_umem__create
     372: 0000000000017145  1190 FUNC    GLOBAL DEFAULT    1 xsk_umem__create_v0_0_4
     405: 0000000000017145  1190 FUNC    GLOBAL DEFAULT    1 xsk_umem__create
     499: 00000000000175eb   103 FUNC    GLOBAL DEFAULT    1 xsk_umem__create_v0_0_2
  -bash-4.4$
No versioned symbols for xsk_umem__create.
The libbpf.a can be used to build a shared library succesfully.
  -bash-4.4$ cat t.c
  extern void *xsk_umem__create;
  void * test() { return xsk_umem__create; }
  -bash-4.4$ gcc -c -fPIC t.c
  -bash-4.4$ gcc -shared t.o libbpf.a -o t.so
  -bash-4.4$

Fixes: 10d30e3017 ("libbpf: add flags to umem config")
Cc: Kevin Laatz <kevin.laatz@intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Andrii Nakryiko <andriin@fb.com>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-09-30 15:19:45 -07:00
Shuah Khan 55d554f5d1 tools: bpf: Use !building_out_of_srctree to determine srctree
make TARGETS=bpf kselftest fails with:

Makefile:127: tools/build/Makefile.include: No such file or directory

When the bpf tool make is invoked from tools Makefile, srctree is
cleared and the current logic check for srctree equals to empty
string to determine srctree location from CURDIR.

When the build in invoked from selftests/bpf Makefile, the srctree
is set to "." and the same logic used for srctree equals to empty is
needed to determine srctree.

Check building_out_of_srctree undefined as the condition for both
cases to fix "make TARGETS=bpf kselftest" build failure.

Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20190927011344.4695-1-skhan@linuxfoundation.org
2019-09-30 10:53:34 +02:00
Andrii Nakryiko 39529a9948 libbpf: Teach btf_dumper to emit stand-alone anonymous enum definitions
BTF-to-C converter previously skipped anonymous enums in an assumption
that those are embedded in struct's field definitions. This is not
always the case and a lot of kernel constants are defined as part of
anonymous enums. This change fixes the logic by eagerly marking all
types as either referenced by any other type or not. This is enough to
distinguish two classes of anonymous enums and emit previously omitted
enum definitions.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20190925203745.3173184-1-andriin@fb.com
2019-09-26 14:38:29 +02:00
Andrii Nakryiko aef70a1f44 libbpf: fix false uninitialized variable warning
Some compilers emit warning for potential uninitialized next_id usage.
The code is correct, but control flow is too complicated for some
compilers to figure this out. Re-initialize next_id to satisfy
compiler.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-09-25 22:15:02 +02:00
Toke Høiland-Jørgensen e0973a421c libbpf: Remove getsockopt() check for XDP_OPTIONS
The xsk_socket__create() function fails and returns an error if it cannot
get the XDP_OPTIONS through getsockopt(). However, support for XDP_OPTIONS
was not added until kernel 5.3, so this means that creating XSK sockets
always fails on older kernels.

Since the option is just used to set the zero-copy flag in the xsk struct,
and that flag is not really used for anything yet, just remove the
getsockopt() call until a proper use for it is introduced.

Suggested-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-09-19 14:22:18 +02:00
David S. Miller 1e46c09ec1 Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next
Daniel Borkmann says:

====================
The following pull-request contains BPF updates for your *net-next* tree.

The main changes are:

1) Add the ability to use unaligned chunks in the AF_XDP umem. By
   relaxing where the chunks can be placed, it allows to use an
   arbitrary buffer size and place whenever there is a free
   address in the umem. Helps more seamless DPDK AF_XDP driver
   integration. Support for i40e, ixgbe and mlx5e, from Kevin and
   Maxim.

2) Addition of a wakeup flag for AF_XDP tx and fill rings so the
   application can wake up the kernel for rx/tx processing which
   avoids busy-spinning of the latter, useful when app and driver
   is located on the same core. Support for i40e, ixgbe and mlx5e,
   from Magnus and Maxim.

3) bpftool fixes for printf()-like functions so compiler can actually
   enforce checks, bpftool build system improvements for custom output
   directories, and addition of 'bpftool map freeze' command, from Quentin.

4) Support attaching/detaching XDP programs from 'bpftool net' command,
   from Daniel.

5) Automatic xskmap cleanup when AF_XDP socket is released, and several
   barrier/{read,write}_once fixes in AF_XDP code, from Björn.

6) Relicense of bpf_helpers.h/bpf_endian.h for future libbpf
   inclusion as well as libbpf versioning improvements, from Andrii.

7) Several new BPF kselftests for verifier precision tracking, from Alexei.

8) Several BPF kselftest fixes wrt endianess to run on s390x, from Ilya.

9) And more BPF kselftest improvements all over the place, from Stanislav.

10) Add simple BPF map op cache for nfp driver to batch dumps, from Jakub.

11) AF_XDP socket umem mapping improvements for 32bit archs, from Ivan.

12) Add BPF-to-BPF call and BTF line info support for s390x JIT, from Yauheni.

13) Small optimization in arm64 JIT to spare 1 insns for BPF_MOD, from Jerin.

14) Fix an error check in bpf_tcp_gen_syncookie() helper, from Petar.

15) Various minor fixes and cleanups, from Nathan, Masahiro, Masanari,
    Peter, Wei, Yue.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2019-09-06 16:49:17 +02:00
Kevin Laatz 10d30e3017 libbpf: add flags to umem config
This patch adds a 'flags' field to the umem_config and umem_reg structs.
This will allow for more options to be added for configuring umems.

The first use for the flags field is to add a flag for unaligned chunks
mode. These flags can either be user-provided or filled with a default.

Since we change the size of the xsk_umem_config struct, we need to version
the ABI. This patch includes the ABI versioning for xsk_umem__create. The
Makefile was also updated to handle multiple function versions in
check-abi.

Signed-off-by: Kevin Laatz <kevin.laatz@intel.com>
Signed-off-by: Ciara Loftus <ciara.loftus@intel.com>
Acked-by: Jonathan Lemon <jonathan.lemon@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-08-31 01:08:26 +02:00
Ivan Khoronzhuk 71dd77fd4b libbpf: use LFS (_FILE_OFFSET_BITS) instead of direct mmap2 syscall
Drop __NR_mmap2 fork in flavor of LFS, that is _FILE_OFFSET_BITS=64
(glibc & bionic) / LARGEFILE64_SOURCE (for musl) decision. It allows
mmap() to use 64bit offset that is passed to mmap2 syscall. As result
pgoff is not truncated and no need to use direct access to mmap2 for
32 bits systems.

Signed-off-by: Ivan Khoronzhuk <ivan.khoronzhuk@linaro.org>
Acked-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-08-21 14:31:17 +02:00
Quentin Monnet 09d7c2e32b libbpf: add bpf_btf_get_next_id() to cycle through BTF objects
Add an API function taking a BTF object id and providing the id of the
next BTF object in the kernel. This can be used to list all BTF objects
loaded on the system.

v2:
- Rebase on top of Andrii's changes regarding libbpf versioning.

Signed-off-by: Quentin Monnet <quentin.monnet@netronome.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-08-20 09:51:06 -07:00
Quentin Monnet a6e130c420 libbpf: refactor bpf_*_get_next_id() functions
In preparation for the introduction of a similar function for retrieving
the id of the next BTF object, consolidate the code from
bpf_prog_get_next_id() and bpf_map_get_next_id() in libbpf.

Signed-off-by: Quentin Monnet <quentin.monnet@netronome.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-08-20 09:51:06 -07:00
David S. Miller 446bf64b61 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Merge conflict of mlx5 resolved using instructions in merge
commit 9566e650bf.

Signed-off-by: David S. Miller <davem@davemloft.net>
2019-08-19 11:54:03 -07:00
Magnus Karlsson a4500432c2 libbpf: add support for need_wakeup flag in AF_XDP part
This commit adds support for the new need_wakeup flag in AF_XDP. The
xsk_socket__create function is updated to handle this and a new
function is introduced called xsk_ring_prod__needs_wakeup(). This
function can be used by the application to check if Rx and/or Tx
processing needs to be explicitly woken up.

Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com>
Acked-by: Jonathan Lemon <jonathan.lemon@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-08-17 23:07:32 +02:00
Andrii Nakryiko dadb81d0af libbpf: make libbpf.map source of truth for libbpf version
Currently libbpf version is specified in 2 places: libbpf.map and
Makefile. They easily get out of sync and it's very easy to update one,
but forget to update another one. In addition, Github projection of
libbpf has to maintain its own version which has to be remembered to be
kept in sync manually, which is very error-prone approach.

This patch makes libbpf.map a source of truth for libbpf version and
uses shell invocation to parse out correct full and major libbpf version
to use during build. Now we need to make sure that once new release
cycle starts, we need to add (initially) empty section to libbpf.map
with correct latest version.

This also will make it possible to keep Github projection consistent
with kernel sources version of libbpf by adopting similar parsing of
version from libbpf.map.

v2->v3:
- grep -o + sort -rV (Andrey);

v1->v2:
- eager version vars evaluation (Jakub);
- simplified version regex (Andrey);

Cc: Andrey Ignatov <rdna@fb.com>
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: Andrey Ignatov <rdna@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-08-15 17:03:26 -07:00
Jakub Kicinski 708852dcac Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next
Daniel Borkmann says:

====================
The following pull-request contains BPF updates for your *net-next* tree.

There is a small merge conflict in libbpf (Cc Andrii so he's in the loop
as well):

        for (i = 1; i <= btf__get_nr_types(btf); i++) {
                t = (struct btf_type *)btf__type_by_id(btf, i);

                if (!has_datasec && btf_is_var(t)) {
                        /* replace VAR with INT */
                        t->info = BTF_INFO_ENC(BTF_KIND_INT, 0, 0);
  <<<<<<< HEAD
                        /*
                         * using size = 1 is the safest choice, 4 will be too
                         * big and cause kernel BTF validation failure if
                         * original variable took less than 4 bytes
                         */
                        t->size = 1;
                        *(int *)(t+1) = BTF_INT_ENC(0, 0, 8);
                } else if (!has_datasec && kind == BTF_KIND_DATASEC) {
  =======
                        t->size = sizeof(int);
                        *(int *)(t + 1) = BTF_INT_ENC(0, 0, 32);
                } else if (!has_datasec && btf_is_datasec(t)) {
  >>>>>>> 72ef80b5ee
                        /* replace DATASEC with STRUCT */

Conflict is between the two commits 1d4126c4e1 ("libbpf: sanitize VAR to
conservative 1-byte INT") and b03bc6853c ("libbpf: convert libbpf code to
use new btf helpers"), so we need to pick the sanitation fixup as well as
use the new btf_is_datasec() helper and the whitespace cleanup. Looks like
the following:

  [...]
                if (!has_datasec && btf_is_var(t)) {
                        /* replace VAR with INT */
                        t->info = BTF_INFO_ENC(BTF_KIND_INT, 0, 0);
                        /*
                         * using size = 1 is the safest choice, 4 will be too
                         * big and cause kernel BTF validation failure if
                         * original variable took less than 4 bytes
                         */
                        t->size = 1;
                        *(int *)(t + 1) = BTF_INT_ENC(0, 0, 8);
                } else if (!has_datasec && btf_is_datasec(t)) {
                        /* replace DATASEC with STRUCT */
  [...]

The main changes are:

1) Addition of core parts of compile once - run everywhere (co-re) effort,
   that is, relocation of fields offsets in libbpf as well as exposure of
   kernel's own BTF via sysfs and loading through libbpf, from Andrii.

   More info on co-re: http://vger.kernel.org/bpfconf2019.html#session-2
   and http://vger.kernel.org/lpc-bpf2018.html#session-2

2) Enable passing input flags to the BPF flow dissector to customize parsing
   and allowing it to stop early similar to the C based one, from Stanislav.

3) Add a BPF helper function that allows generating SYN cookies from XDP and
   tc BPF, from Petar.

4) Add devmap hash-based map type for more flexibility in device lookup for
   redirects, from Toke.

5) Improvements to XDP forwarding sample code now utilizing recently enabled
   devmap lookups, from Jesper.

6) Add support for reporting the effective cgroup progs in bpftool, from Jakub
   and Takshak.

7) Fix reading kernel config from bpftool via /proc/config.gz, from Peter.

8) Fix AF_XDP umem pages mapping for 32 bit architectures, from Ivan.

9) Follow-up to add two more BPF loop tests for the selftest suite, from Alexei.

10) Add perf event output helper also for other skb-based program types, from Allan.

11) Fix a co-re related compilation error in selftests, from Yonghong.
====================

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
2019-08-13 16:24:57 -07:00
Andrii Nakryiko a1916a153c libbpf: attempt to load kernel BTF from sysfs first
Add support for loading kernel BTF from sysfs (/sys/kernel/btf/vmlinux)
as a target BTF. Also extend the list of on disk search paths for
vmlinux ELF image with entries that perf is searching for.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-08-13 23:19:42 +02:00
David S. Miller 9481382b36 Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf
Daniel Borkmann says:

====================
pull-request: bpf 2019-08-11

The following pull-request contains BPF updates for your *net* tree.

The main changes are:

1) x64 JIT code generation fix for backward-jumps to 1st insn, from Alexei.

2) Fix buggy multi-closing of BTF file descriptor in libbpf, from Andrii.

3) Fix libbpf_num_possible_cpus() to make it thread safe, from Takshak.

4) Fix bpftool to dump an error if pinning fails, from Jakub.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2019-08-11 14:49:34 -07:00
Andrii Nakryiko ddc7c30426 libbpf: implement BPF CO-RE offset relocation algorithm
This patch implements the core logic for BPF CO-RE offsets relocations.
Every instruction that needs to be relocated has corresponding
bpf_offset_reloc as part of BTF.ext. Relocations are performed by trying
to match recorded "local" relocation spec against potentially many
compatible "target" types, creating corresponding spec. Details of the
algorithm are noted in corresponding comments in the code.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-08-07 14:43:49 -07:00
Andrii Nakryiko 4cedc0dad9 libbpf: add .BTF.ext offset relocation section loading
Add support for BPF CO-RE offset relocations. Add section/record
iteration macros for .BTF.ext. These macro are useful for iterating over
each .BTF.ext record, either for dumping out contents or later for BPF
CO-RE relocation handling.

To enable other parts of libbpf to work with .BTF.ext contents, moved
a bunch of type definitions into libbpf_internal.h.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-08-07 14:43:49 -07:00
Andrii Nakryiko b03bc6853c libbpf: convert libbpf code to use new btf helpers
Simplify code by relying on newly added BTF helper functions.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-08-07 14:43:49 -07:00
Andrii Nakryiko ef20a9b27c libbpf: add helpers for working with BTF types
Add lots of frequently used helpers that simplify working with BTF
types.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-08-07 14:43:49 -07:00
Linus Torvalds 33920f1ec5 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Pull networking fixes from David Miller:
 "Yeah I should have sent a pull request last week, so there is a lot
  more here than usual:

   1) Fix memory leak in ebtables compat code, from Wenwen Wang.

   2) Several kTLS bug fixes from Jakub Kicinski (circular close on
      disconnect etc.)

   3) Force slave speed check on link state recovery in bonding 802.3ad
      mode, from Thomas Falcon.

   4) Clear RX descriptor bits before assigning buffers to them in
      stmmac, from Jose Abreu.

   5) Several missing of_node_put() calls, mostly wrt. for_each_*() OF
      loops, from Nishka Dasgupta.

   6) Double kfree_skb() in peak_usb can driver, from Stephane Grosjean.

   7) Need to hold sock across skb->destructor invocation, from Cong
      Wang.

   8) IP header length needs to be validated in ipip tunnel xmit, from
      Haishuang Yan.

   9) Use after free in ip6 tunnel driver, also from Haishuang Yan.

  10) Do not use MSI interrupts on r8169 chips before RTL8168d, from
      Heiner Kallweit.

  11) Upon bridge device init failure, we need to delete the local fdb.
      From Nikolay Aleksandrov.

  12) Handle erros from of_get_mac_address() properly in stmmac, from
      Martin Blumenstingl.

  13) Handle concurrent rename vs. dump in netfilter ipset, from Jozsef
      Kadlecsik.

  14) Setting NETIF_F_LLTX on mac80211 causes complete breakage with
      some devices, so revert. From Johannes Berg.

  15) Fix deadlock in rxrpc, from David Howells.

  16) Fix Kconfig deps of enetc driver, we must have PHYLIB. From Yue
      Haibing.

  17) Fix mvpp2 crash on module removal, from Matteo Croce.

  18) Fix race in genphy_update_link, from Heiner Kallweit.

  19) bpf_xdp_adjust_head() stopped working with generic XDP when we
      fixes generic XDP to support stacked devices properly, fix from
      Jesper Dangaard Brouer.

  20) Unbalanced RCU locking in rt6_update_exception_stamp_rt(), from
      David Ahern.

  21) Several memory leaks in new sja1105 driver, from Vladimir Oltean"

* git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (214 commits)
  net: dsa: sja1105: Fix memory leak on meta state machine error path
  net: dsa: sja1105: Fix memory leak on meta state machine normal path
  net: dsa: sja1105: Really fix panic on unregistering PTP clock
  net: dsa: sja1105: Use the LOCKEDS bit for SJA1105 E/T as well
  net: dsa: sja1105: Fix broken learning with vlan_filtering disabled
  net: dsa: qca8k: Add of_node_put() in qca8k_setup_mdio_bus()
  net: sched: sample: allow accessing psample_group with rtnl
  net: sched: police: allow accessing police->params with rtnl
  net: hisilicon: Fix dma_map_single failed on arm64
  net: hisilicon: fix hip04-xmit never return TX_BUSY
  net: hisilicon: make hip04_tx_reclaim non-reentrant
  tc-testing: updated vlan action tests with batch create/delete
  net sched: update vlan action for batched events operations
  net: stmmac: tc: Do not return a fragment entry
  net: stmmac: Fix issues when number of Queues >= 4
  net: stmmac: xgmac: Fix XGMAC selftests
  be2net: disable bh with spin_lock in be_process_mcc
  net: cxgb3_main: Fix a resource leak in a error path in 'init_one()'
  net: ethernet: sun4i-emac: Support phy-handle property for finding PHYs
  net: bridge: move default pvid init/deinit to NETDEV_REGISTER/UNREGISTER
  ...
2019-08-06 17:11:59 -07:00
Andrii Nakryiko 3415ec643e libbpf: set BTF FD for prog only when there is supported .BTF.ext data
5d01ab7bac ("libbpf: fix erroneous multi-closing of BTF FD")
introduced backwards-compatibility issue, manifesting itself as -E2BIG
error returned on program load due to unknown non-zero btf_fd attribute
value for BPF_PROG_LOAD sys_bpf() sub-command.

This patch fixes bug by ensuring that we only ever associate BTF FD with
program if there is a BTF.ext data that was successfully loaded into
kernel, which automatically means kernel supports func_info/line_info
and associated BTF FD for progs (checked and ensured also by BTF
sanitization code).

Fixes: 5d01ab7bac ("libbpf: fix erroneous multi-closing of BTF FD")
Reported-by: Andrey Ignatov <rdna@fb.com>
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-08-01 13:10:45 -07:00
Takshak Chahande 56fbc24116 libbpf : make libbpf_num_possible_cpus function thread safe
Having static variable `cpus` in libbpf_num_possible_cpus function
without guarding it with mutex makes this function thread-unsafe.

If multiple threads accessing this function, in the current form; it
leads to incrementing the static variable value `cpus` in the multiple
of total available CPUs.

Used local stack variable to calculate the number of possible CPUs and
then updated the static variable using WRITE_ONCE().

Changes since v1:
 * added stack variable to calculate cpus
 * serialized static variable update using WRITE_ONCE()
 * fixed Fixes tag

Fixes: 6446b31555 ("bpf: add a new API libbpf_num_possible_cpus()")
Signed-off-by: Takshak Chahande <ctakshak@fb.com>
Acked-by: Andrey Ignatov <rdna@fb.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-07-31 20:35:19 -07:00
Toke Høiland-Jørgensen e42346192c tools/libbpf_probes: Add new devmap_hash type
This adds the definition for BPF_MAP_TYPE_DEVMAP_HASH to libbpf_probes.c in
tools/lib/bpf.

Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Acked-by: Yonghong Song <yhs@fb.com>
Acked-by: Jesper Dangaard Brouer <brouer@redhat.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-07-29 13:50:48 -07:00
Andrii Nakryiko 8aa259b10a libbpf: fix missing __WORDSIZE definition
hashmap.h depends on __WORDSIZE being defined. It is defined by
glibc/musl in different headers. It's an explicit goal for musl to be
"non-detectable" at compilation time, so instead include glibc header if
glibc is explicitly detected and fall back to musl header otherwise.

Reported-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Alexei Starovoitov <ast@fb.com>
Cc: Andrii Nakryiko <andrii.nakryiko@gmail.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Fixes: e3b9242240 ("libbpf: add resizable non-thread safe internal hashmap")
Link: https://lkml.kernel.org/r/20190718173021.2418606-1-andriin@fb.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2019-07-29 10:18:08 -03:00
Andrii Nakryiko e87fd8bae4 libbpf: return previous print callback from libbpf_set_print
By returning previously set print callback from libbpf_set_print, it's
possible to restore it, eventually. This is useful when running many
independent test with one default print function, but overriding log
verbosity for particular subset of tests.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-07-27 22:36:19 -07:00
Andrii Nakryiko 5d01ab7bac libbpf: fix erroneous multi-closing of BTF FD
Libbpf stores associated BTF FD per each instance of bpf_program. When
program is unloaded, that FD is closed. This is wrong, because leads to
a race and possibly closing of unrelated files, if application
simultaneously opens new files while bpf_programs are unloaded.

It's also unnecessary, because struct btf "owns" that FD, and
btf__free(), called from bpf_object__close() will close it. Thus the fix
is to never have per-program BTF FD and fetch it from obj->btf, when
necessary.

Fixes: 2993e0515b ("tools/bpf: add support to read .BTF.ext sections")
Reported-by: Andrey Ignatov <rdna@fb.com>
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-07-26 17:23:16 -07:00
Andrii Nakryiko cb8ffde569 libbpf: silence GCC8 warning about string truncation
Despite a proper NULL-termination after strncpy(..., ..., IFNAMSIZ - 1),
GCC8 still complains about *expected* string truncation:

  xsk.c:330:2: error: 'strncpy' output may be truncated copying 15 bytes
  from a string of length 15 [-Werror=stringop-truncation]
    strncpy(ifr.ifr_name, xsk->ifname, IFNAMSIZ - 1);

This patch gets rid of the issue altogether by using memcpy instead.
There is no performance regression, as strncpy will still copy and fill
all of the bytes anyway.

v1->v2:
- rebase against bpf tree.

Cc: Magnus Karlsson <magnus.karlsson@intel.com>
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: Magnus Karlsson <magnus.karlsson@intel.com>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-07-25 10:13:31 -07:00
Andrii Nakryiko f2a3e4e95f libbpf: provide more helpful message on uninitialized global var
When BPF program defines uninitialized global variable, it's put into
a special COMMON section. Libbpf will reject such programs, but will
provide very unhelpful message with garbage-looking section index.

This patch detects special section cases and gives more explicit error
message.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-07-23 15:59:12 -07:00
Ilya Maximets decb705e01 libbpf: fix using uninitialized ioctl results
'channels.max_combined' initialized only on ioctl success and
errno is only valid on ioctl failure.

The code doesn't produce any runtime issues, but makes memory
sanitizers angry:

 Conditional jump or move depends on uninitialised value(s)
    at 0x55C056F: xsk_get_max_queues (xsk.c:336)
    by 0x55C05B2: xsk_create_bpf_maps (xsk.c:354)
    by 0x55C089F: xsk_setup_xdp_prog (xsk.c:447)
    by 0x55C0E57: xsk_socket__create (xsk.c:601)
  Uninitialised value was created by a stack allocation
    at 0x55C04CD: xsk_get_max_queues (xsk.c:318)

Additionally fixed warning on uninitialized bytes in ioctl arguments:

 Syscall param ioctl(SIOCETHTOOL) points to uninitialised byte(s)
    at 0x648D45B: ioctl (in /usr/lib64/libc-2.28.so)
    by 0x55C0546: xsk_get_max_queues (xsk.c:330)
    by 0x55C05B2: xsk_create_bpf_maps (xsk.c:354)
    by 0x55C089F: xsk_setup_xdp_prog (xsk.c:447)
    by 0x55C0E57: xsk_socket__create (xsk.c:601)
  Address 0x1ffefff378 is on thread 1's stack
  in frame #1, created by xsk_get_max_queues (xsk.c:318)
  Uninitialised value was created by a stack allocation
    at 0x55C04CD: xsk_get_max_queues (xsk.c:318)

CC: Magnus Karlsson <magnus.karlsson@intel.com>
Fixes: 1cad078842 ("libbpf: add support for using AF_XDP sockets")
Signed-off-by: Ilya Maximets <i.maximets@samsung.com>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-07-23 15:14:35 -07:00
Arnaldo Carvalho de Melo 4be6e05c4d libbpf: Avoid designated initializers for unnamed union members
As it fails to build in some systems with:

  libbpf.c: In function 'perf_buffer__new':
  libbpf.c:4515: error: unknown field 'sample_period' specified in initializer
  libbpf.c:4516: error: unknown field 'wakeup_events' specified in initializer

Doing as:

    attr.sample_period = 1;

I.e. not as a designated initializer makes it build everywhere.

Cc: Andrii Nakryiko <andriin@fb.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Fixes: fb84b82246 ("libbpf: add perf buffer API")
Link: https://lkml.kernel.org/n/tip-hnlmch8qit1ieksfppmr32si@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-07-22 16:14:43 +02:00
Arnaldo Carvalho de Melo cdb2f92071 libbpf: Fix endianness macro usage for some compilers
Using endian.h and its endianness macros makes this code build in a
wider range of compilers, as some don't have those macros
(__BYTE_ORDER__, __ORDER_LITTLE_ENDIAN__, __ORDER_BIG_ENDIAN__),
so use instead endian.h's macros (__BYTE_ORDER, __LITTLE_ENDIAN,
__BIG_ENDIAN) which makes this code even shorter :-)

Acked-by: Andrii Nakryiko <andriin@fb.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Fixes: 12ef5634a8 ("libbpf: simplify endianness check")
Fixes: e6c64855fd ("libbpf: add btf__parse_elf API to load .BTF and .BTF.ext")
Link: https://lkml.kernel.org/n/tip-eep5n8vgwcdphw3uc058k03u@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-07-22 16:14:43 +02:00
Andrii Nakryiko 1d4126c4e1 libbpf: sanitize VAR to conservative 1-byte INT
If VAR in non-sanitized BTF was size less than 4, converting such VAR
into an INT with size=4 will cause BTF validation failure due to
violationg of STRUCT (into which DATASEC was converted) member size.
Fix by conservatively using size=1.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-07-19 12:48:55 -07:00
Andrii Nakryiko 04efe5911f libbpf: fix SIGSEGV when BTF loading fails, but .BTF.ext exists
In case when BTF loading fails despite sanitization, but BPF object has
.BTF.ext loaded as well, we free and null obj->btf, but not
obj->btf_ext. This leads to an attempt to relocate .BTF.ext later on
during bpf_object__load(), which assumes obj->btf is present. This leads
to SIGSEGV on null pointer access. Fix bug by freeing and nulling
obj->btf_ext as well.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-07-19 12:37:18 -07:00
Andrii Nakryiko 763ff0e7d9 libbpf: fix another GCC8 warning for strncpy
Similar issue was fixed in cdfc7f888c ("libbpf: fix GCC8 warning for
strncpy") already. This one was missed. Fixing now.

Cc: Magnus Karlsson <magnus.karlsson@intel.com>
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: Magnus Karlsson <magnus.karlsson@intel.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-07-16 10:34:31 -07:00
Andrii Nakryiko 36db2a94f1 libbpf: fix ptr to u64 conversion warning on 32-bit platforms
On 32-bit platforms compiler complains about conversion:

libbpf.c: In function ‘perf_event_open_probe’:
libbpf.c:4112:17: error: cast from pointer to integer of different
size [-Werror=pointer-to-int-cast]
  attr.config1 = (uint64_t)(void *)name; /* kprobe_func or uprobe_path */
                 ^

Reported-by: Matt Hart <matthew.hart@linaro.org>
Fixes: b265002747 ("libbpf: add kprobe/uprobe attach API")
Tested-by: Matt Hart <matthew.hart@linaro.org>
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-07-12 14:51:03 +02:00
Andrii Nakryiko cd07a95f9b libbpf: add perf_buffer_ prefix to README
perf_buffer "object" is part of libbpf API now, add it to the list of
libbpf function prefixes.

Suggested-by: Daniel Borkman <daniel@iogearbox.net>
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-07-08 15:35:43 +02:00
Andrii Nakryiko d7ff34d5fb libbpf: auto-set PERF_EVENT_ARRAY size to number of CPUs
For BPF_MAP_TYPE_PERF_EVENT_ARRAY typically correct size is number of
possible CPUs. This is impossible to specify at compilation time. This
change adds automatic setting of PERF_EVENT_ARRAY size to number of
system CPUs, unless non-zero size is specified explicitly. This allows
to adjust size for advanced specific cases, while providing convenient
and logical defaults.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: Song Liu <songliubraving@fb.com>
Acked-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-07-08 15:35:43 +02:00
Andrii Nakryiko fb84b82246 libbpf: add perf buffer API
BPF_MAP_TYPE_PERF_EVENT_ARRAY map is often used to send data from BPF program
to user space for additional processing. libbpf already has very low-level API
to read single CPU perf buffer, bpf_perf_event_read_simple(), but it's hard to
use and requires a lot of code to set everything up. This patch adds
perf_buffer abstraction on top of it, abstracting setting up and polling
per-CPU logic into simple and convenient API, similar to what BCC provides.

perf_buffer__new() sets up per-CPU ring buffers and updates corresponding BPF
map entries. It accepts two user-provided callbacks: one for handling raw
samples and one for get notifications of lost samples due to buffer overflow.

perf_buffer__new_raw() is similar, but provides more control over how
perf events are set up (by accepting user-provided perf_event_attr), how
they are handled (perf_event_header pointer is passed directly to
user-provided callback), and on which CPUs ring buffers are created
(it's possible to provide a list of CPUs and corresponding map keys to
update). This API allows advanced users fuller control.

perf_buffer__poll() is used to fetch ring buffer data across all CPUs,
utilizing epoll instance.

perf_buffer__free() does corresponding clean up and unsets FDs from BPF map.

All APIs are not thread-safe. User should ensure proper locking/coordination if
used in multi-threaded set up.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-07-08 15:35:43 +02:00
Andrii Nakryiko ef99b02b23 libbpf: capture value in BTF type info for BTF-defined map defs
Change BTF-defined map definitions to capture compile-time integer
values as part of BTF type definition, to avoid split of key/value type
information and actual type/size/flags initialization for maps.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: Song Liu <songliubraving@fb.com>
Acked-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-07-05 22:52:25 +02:00
Andrii Nakryiko 84bf5e1f4f libbpf: add raw tracepoint attach API
Add a wrapper utilizing bpf_link "infrastructure" to allow attaching BPF
programs to raw tracepoints.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: Song Liu <songliubraving@fb.com>
Reviewed-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-07-05 22:37:30 +02:00
Andrii Nakryiko f6de59c17f libbpf: add tracepoint attach API
Allow attaching BPF programs to kernel tracepoint BPF hooks specified by
category and name.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: Song Liu <songliubraving@fb.com>
Reviewed-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-07-05 22:37:30 +02:00
Andrii Nakryiko b265002747 libbpf: add kprobe/uprobe attach API
Add ability to attach to kernel and user probes and retprobes.
Implementation depends on perf event support for kprobes/uprobes.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Reviewed-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-07-05 22:37:30 +02:00
Andrii Nakryiko 63f2f5ee85 libbpf: add ability to attach/detach BPF program to perf event
bpf_program__attach_perf_event allows to attach BPF program to existing
perf event hook, providing most generic and most low-level way to attach BPF
programs. It returns struct bpf_link, which should be passed to
bpf_link__destroy to detach and free resources, associated with a link.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Reviewed-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-07-05 22:37:30 +02:00
Andrii Nakryiko 1c2e9efc26 libbpf: introduce concept of bpf_link
bpf_link is an abstraction of an association of a BPF program and one of
many possible BPF attachment points (hooks). This allows to have uniform
interface for detaching BPF programs regardless of the nature of link
and how it was created. Details of creation and setting up of a specific
bpf_link is handled by corresponding attachment methods
(bpf_program__attach_xxx) added in subsequent commits. Once successfully
created, bpf_link has to be eventually destroyed with
bpf_link__destroy(), at which point BPF program is disassociated from
a hook and all the relevant resources are freed.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: Song Liu <songliubraving@fb.com>
Reviewed-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-07-05 22:37:30 +02:00
Andrii Nakryiko d66f43666a libbpf: make libbpf_strerror_r agnostic to sign of error
It's often inconvenient to switch sign of error when passing it into
libbpf_strerror_r. It's better for it to handle that automatically.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Reviewed-by: Stanislav Fomichev <sdf@google.com>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-07-05 22:37:30 +02:00
Leo Yan 33bae185f7 bpf, libbpf, smatch: Fix potential NULL pointer dereference
Based on the following report from Smatch, fix the potential NULL
pointer dereference check:

  tools/lib/bpf/libbpf.c:3493
  bpf_prog_load_xattr() warn: variable dereferenced before check 'attr'
  (see line 3483)

  3479 int bpf_prog_load_xattr(const struct bpf_prog_load_attr *attr,
  3480                         struct bpf_object **pobj, int *prog_fd)
  3481 {
  3482         struct bpf_object_open_attr open_attr = {
  3483                 .file           = attr->file,
  3484                 .prog_type      = attr->prog_type,
                                         ^^^^^^
  3485         };

At the head of function, it directly access 'attr' without checking
if it's NULL pointer. This patch moves the values assignment after
validating 'attr' and 'attr->file'.

Signed-off-by: Leo Yan <leo.yan@linaro.org>
Acked-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-07-03 12:17:29 +02:00
Andrii Nakryiko cdfc7f888c libbpf: fix GCC8 warning for strncpy
GCC8 started emitting warning about using strncpy with number of bytes
exactly equal destination size, which is generally unsafe, as can lead
to non-zero terminated string being copied. Use IFNAMSIZ - 1 as number
of bytes to ensure name is always zero-terminated.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Cc: Magnus Karlsson <magnus.karlsson@intel.com>
Acked-by: Yonghong Song <yhs@fb.com>
Acked-by: Magnus Karlsson <magnus.karlsson@intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-07-03 11:52:45 +02:00
Stanislav Fomichev 4cdbfb59c4 libbpf: support sockopt hooks
Make libbpf aware of new sockopt hooks so it can derive prog type
and hook point from the section names.

Cc: Andrii Nakryiko <andriin@fb.com>
Cc: Martin Lau <kafai@fb.com>
Signed-off-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-06-27 15:25:17 -07:00
Maxim Mikityanskiy 123e8da1d3 xsk: Change the default frame size to 4096 and allow controlling it
The typical XDP memory scheme is one packet per page. Change the AF_XDP
frame size in libbpf to 4096, which is the page size on x86, to allow
libbpf to be used with the drivers with the packet-per-page scheme.

Add a command line option -f to xdpsock to allow to specify a custom
frame size.

Signed-off-by: Maxim Mikityanskiy <maximmi@mellanox.com>
Signed-off-by: Tariq Toukan <tariqt@mellanox.com>
Acked-by: Saeed Mahameed <saeedm@mellanox.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-06-27 22:53:26 +02:00
Maxim Mikityanskiy 2761ed4b6e libbpf: Support getsockopt XDP_OPTIONS
Query XDP_OPTIONS in libbpf to determine if the zero-copy mode is active
or not.

Signed-off-by: Maxim Mikityanskiy <maximmi@mellanox.com>
Signed-off-by: Tariq Toukan <tariqt@mellanox.com>
Acked-by: Saeed Mahameed <saeedm@mellanox.com>
Acked-by: Björn Töpel <bjorn.topel@intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-06-27 22:53:26 +02:00
Ivan Khoronzhuk 950649791b libbpf: fix max() type mismatch for 32bit
It fixes build error for 32bit caused by type mismatch
size_t/unsigned long.

Fixes: bf82927125 ("libbpf: refactor map initialization")
Acked-by: Song Liu <songliubraving@fb.com>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Ivan Khoronzhuk <ivan.khoronzhuk@linaro.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-06-26 14:41:20 +02:00
Colin Ian King 900de4ac49 libbpf: fix spelling mistake "conflictling" -> "conflicting"
There are several spelling mistakes in pr_warning messages. Fix these.

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-06-24 18:18:30 -07:00
David S. Miller dca73a65a6 Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next
Alexei Starovoitov says:

====================
pull-request: bpf-next 2019-06-19

The following pull-request contains BPF updates for your *net-next* tree.

The main changes are:

1) new SO_REUSEPORT_DETACH_BPF setsocktopt, from Martin.

2) BTF based map definition, from Andrii.

3) support bpf_map_lookup_elem for xskmap, from Jonathan.

4) bounded loops and scalar precision logic in the verifier, from Alexei.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2019-06-20 00:06:27 -04:00
Andrii Nakryiko a324aae32f libbpf: constify getter APIs
Add const qualifiers to bpf_object/bpf_program/bpf_map arguments for
getter APIs. There is no need for them to not be const pointers.

Verified that

make -C tools/lib/bpf
make -C tools/testing/selftests/bpf
make -C tools/perf

all build without warnings.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-06-19 02:21:02 +02:00
David S. Miller 13091aa305 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Honestly all the conflicts were simple overlapping changes,
nothing really interesting to report.

Signed-off-by: David S. Miller <davem@davemloft.net>
2019-06-17 20:20:36 -07:00
Andrii Nakryiko abd29c9314 libbpf: allow specifying map definitions using BTF
This patch adds support for a new way to define BPF maps. It relies on
BTF to describe mandatory and optional attributes of a map, as well as
captures type information of key and value naturally. This eliminates
the need for BPF_ANNOTATE_KV_PAIR hack and ensures key/value sizes are
always in sync with the key/value type.

Relying on BTF, this approach allows for both forward and backward
compatibility w.r.t. extending supported map definition features. By
default, any unrecognized attributes are treated as an error, but it's
possible relax this using MAPS_RELAX_COMPAT flag. New attributes, added
in the future will need to be optional.

The outline of the new map definition (short, BTF-defined maps) is as follows:
1. All the maps should be defined in .maps ELF section. It's possible to
   have both "legacy" map definitions in `maps` sections and BTF-defined
   maps in .maps sections. Everything will still work transparently.
2. The map declaration and initialization is done through
   a global/static variable of a struct type with few mandatory and
   extra optional fields:
   - type field is mandatory and specified type of BPF map;
   - key/value fields are mandatory and capture key/value type/size information;
   - max_entries attribute is optional; if max_entries is not specified or
     initialized, it has to be provided in runtime through libbpf API
     before loading bpf_object;
   - map_flags is optional and if not defined, will be assumed to be 0.
3. Key/value fields should be **a pointer** to a type describing
   key/value. The pointee type is assumed (and will be recorded as such
   and used for size determination) to be a type describing key/value of
   the map. This is done to save excessive amounts of space allocated in
   corresponding ELF sections for key/value of big size.
4. As some maps disallow having BTF type ID associated with key/value,
   it's possible to specify key/value size explicitly without
   associating BTF type ID with it. Use key_size and value_size fields
   to do that (see example below).

Here's an example of simple ARRAY map defintion:

struct my_value { int x, y, z; };

struct {
	int type;
	int max_entries;
	int *key;
	struct my_value *value;
} btf_map SEC(".maps") = {
	.type = BPF_MAP_TYPE_ARRAY,
	.max_entries = 16,
};

This will define BPF ARRAY map 'btf_map' with 16 elements. The key will
be of type int and thus key size will be 4 bytes. The value is struct
my_value of size 12 bytes. This map can be used from C code exactly the
same as with existing maps defined through struct bpf_map_def.

Here's an example of STACKMAP definition (which currently disallows BTF type
IDs for key/value):

struct {
	__u32 type;
	__u32 max_entries;
	__u32 map_flags;
	__u32 key_size;
	__u32 value_size;
} stackmap SEC(".maps") = {
	.type = BPF_MAP_TYPE_STACK_TRACE,
	.max_entries = 128,
	.map_flags = BPF_F_STACK_BUILD_ID,
	.key_size = sizeof(__u32),
	.value_size = PERF_MAX_STACK_DEPTH * sizeof(struct bpf_stack_build_id),
};

This approach is naturally extended to support map-in-map, by making a value
field to be another struct that describes inner map. This feature is not
implemented yet. It's also possible to incrementally add features like pinning
with full backwards and forward compatibility. Support for static
initialization of BPF_MAP_TYPE_PROG_ARRAY using pointers to BPF programs
is also on the roadmap.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-06-18 00:10:41 +02:00
Andrii Nakryiko 063183bf04 libbpf: split initialization and loading of BTF
Libbpf does sanitization of BTF before loading it into kernel, if kernel
doesn't support some of newer BTF features. This removes some of the
important information from BTF (e.g., DATASEC and VAR description),
which will be used for map construction. This patch splits BTF
processing into initialization step, in which BTF is initialized from
ELF and all the original data is still preserved; and
sanitization/loading step, which ensures that BTF is safe to load into
kernel. This allows to use full BTF information to construct maps, while
still loading valid BTF into older kernels.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-06-18 00:10:41 +02:00
Andrii Nakryiko db48814bd2 libbpf: identify maps by section index in addition to offset
To support maps to be defined in multiple sections, it's important to
identify map not just by offset within its section, but section index as
well. This patch adds tracking of section index.

For global data, we record section index of corresponding
.data/.bss/.rodata ELF section for uniformity, and thus don't need
a special value of offset for those maps.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-06-18 00:10:40 +02:00
Andrii Nakryiko bf82927125 libbpf: refactor map initialization
User and global data maps initialization has gotten pretty complicated
and unnecessarily convoluted. This patch splits out the logic for global
data map and user-defined map initialization. It also removes the
restriction of pre-calculating how many maps will be initialized,
instead allowing to keep adding new maps as they are discovered, which
will be used later for BTF-defined map definitions.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-06-18 00:10:39 +02:00
Andrii Nakryiko 01b29d1dc9 libbpf: streamline ELF parsing error-handling
Simplify ELF parsing logic by exiting early, as there is no common clean
up path to execute. That makes it unnecessary to track when err was set
and when it was cleared. It also reduces nesting in some places.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-06-18 00:10:39 +02:00
Andrii Nakryiko 9c6660d040 libbpf: extract BTF loading logic
As a preparation for adding BTF-based BPF map loading, extract .BTF and
.BTF.ext loading logic.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-06-18 00:10:12 +02:00
Andrii Nakryiko d7fe74f940 libbpf: add common min/max macro to libbpf_internal.h
Multiple files in libbpf redefine their own definitions for min/max.
Let's define them in libbpf_internal.h and use those everywhere.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-06-18 00:08:54 +02:00
Andrii Nakryiko e55d54f43d libbpf: fix check for presence of associated BTF for map creation
Kernel internally checks that either key or value type ID is specified,
before using btf_fd. Do the same in libbpf's map creation code for
determining when to retry map creation w/o BTF.

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Fixes: fba01a0689 ("libbpf: use negative fd to specify missing BTF")
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-06-15 01:14:08 +02:00
Hechao Li 6446b31555 bpf: add a new API libbpf_num_possible_cpus()
Adding a new API libbpf_num_possible_cpus() that helps user with
per-CPU map operations.

Signed-off-by: Hechao Li <hechaol@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-06-11 10:36:02 +02:00
Jonathan Lemon 10a13bb40e libbpf: remove qidconf and better support external bpf programs.
Use the recent change to XSKMAP bpf_map_lookup_elem() to test if
there is a xsk present in the map instead of duplicating the work
with qidconf.

Fix things so callers using XSK_LIBBPF_FLAGS__INHIBIT_PROG_LOAD
bypass any internal bpf maps, so xsk_socket__{create|delete} works
properly.

Clean up error handling path.

Signed-off-by: Jonathan Lemon <jonathan.lemon@gmail.com>
Acked-by: Song Liu <songliubraving@fb.com>
Tested-by: Björn Töpel <bjorn.topel@intel.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-06-10 23:31:26 -07:00
Daniel Borkmann 9bb59ac1f6 bpf, libbpf: enable recvmsg attach types
Another trivial patch to libbpf in order to enable identifying and
attaching programs to BPF_CGROUP_UDP{4,6}_RECVMSG by section name.

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-06-06 16:53:12 -07:00
Michal Rostecki cfd4921049 libbpf: Return btf_fd for load_sk_storage_btf
Before this change, function load_sk_storage_btf expected that
libbpf__probe_raw_btf was returning a BTF descriptor, but in fact it was
returning an information about whether the probe was successful (0 or
1). load_sk_storage_btf was using that value as an argument of the close
function, which was resulting in closing stdout and thus terminating the
process which called that function.

That bug was visible in bpftool. `bpftool feature` subcommand was always
exiting too early (because of closed stdout) and it didn't display all
requested probes. `bpftool -j feature` or `bpftool -p feature` were not
returning a valid json object.

This change renames the libbpf__probe_raw_btf function to
libbpf__load_raw_btf, which now returns a BTF descriptor, as expected in
load_sk_storage_btf.

v2:
- Fix typo in the commit message.

v3:
- Simplify BTF descriptor handling in bpf_object__probe_btf_* functions.
- Rename libbpf__probe_raw_btf function to libbpf__load_raw_btf and
return a BTF descriptor.

v4:
- Fix typo in the commit message.

Fixes: d7c4b3980c ("libbpf: detect supported kernel BTF features and sanitize BTF")
Signed-off-by: Michal Rostecki <mrostecki@opensuse.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-05-31 17:03:39 -07:00
Andrii Nakryiko 399dc65e9c libbpf: reduce unnecessary line wrapping
There are a bunch of lines of code or comments that are unnecessary
wrapped into multi-lines. Fix that without violating any code
guidelines.

Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-05-30 01:23:35 +02:00
Andrii Nakryiko 76e1022b96 libbpf: typo and formatting fixes
A bunch of typo and formatting fixes.

Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-05-30 01:23:35 +02:00
Andrii Nakryiko 7e8c328c4e libbpf: simplify two pieces of logic
Extra check for type is unnecessary in first case.

Extra zeroing is unnecessary, as snprintf guarantees that it will
zero-terminate string.

Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-05-30 01:23:35 +02:00
Andrii Nakryiko fba01a0689 libbpf: use negative fd to specify missing BTF
0 is a valid FD, so it's better to initialize it to -1, as is done in
other places. Also, technically, BTF type ID 0 is valid (it's a VOID
type), so it's more reliable to check btf_fd, instead of
btf_key_type_id, to determine if there is any BTF associated with a map.

Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-05-30 01:23:35 +02:00
Andrii Nakryiko f102154d31 libbpf: fix error code returned on corrupted ELF
All of libbpf errors are negative, except this one. Fix it.

Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-05-30 01:23:35 +02:00
Andrii Nakryiko c51829bb6e libbpf: check map name retrieved from ELF
Validate there was no error retrieving symbol name corresponding to
a BPF map.

Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-05-30 01:23:35 +02:00
Andrii Nakryiko 12ef5634a8 libbpf: simplify endianness check
Rewrite endianness check to use "more canonical" way, using
compiler-defined macros, similar to few other places in libbpf. It also
is more obvious and shorter.

Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-05-30 01:23:35 +02:00
Andrii Nakryiko be5c5d4e9d libbpf: preserve errno before calling into user callback
pr_warning ultimately may call into user-provided callback function,
which can clobber errno value, so we need to save it before that.

Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-05-30 01:23:34 +02:00
Andrii Nakryiko 8ca990ce0d libbpf: fix detection of corrupted BPF instructions section
Ensure that size of a section w/ BPF instruction is exactly a multiple
of BPF instruction size.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-05-30 01:23:34 +02:00
Quentin Monnet 501b125a29 libbpf: prevent overwriting of log_level in bpf_object__load_progs()
There are two functions in libbpf that support passing a log_level
parameter for the verifier for loading programs:
bpf_object__load_xattr() and bpf_prog_load_xattr(). Both accept an
attribute object containing the log_level, and apply it to the programs
to load.

It turns out that to effectively load the programs, the latter function
eventually relies on the former. This was not taken into account when
adding support for log_level in bpf_object__load_xattr(), and the
log_level passed to bpf_prog_load_xattr() later gets overwritten with a
zero value, thus disabling verifier logs for the program in all cases:

bpf_prog_load_xattr()             // prog->log_level = attr1->log_level;
-> bpf_object__load()             // attr2->log_level = 0;
   -> bpf_object__load_xattr()    // <pass prog and attr2>
      -> bpf_object__load_progs() // prog->log_level = attr2->log_level;

Fix this by OR-ing the log_level in bpf_object__load_progs(), instead of
overwriting it.

v2: Fix commit log description (confusion on function names in v1).

Fixes: 60276f9849 ("libbpf: add bpf_object__load_xattr() API function to pass log_level")
Reported-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Quentin Monnet <quentin.monnet@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-05-29 19:36:55 +02:00
Quentin Monnet 60276f9849 libbpf: add bpf_object__load_xattr() API function to pass log_level
libbpf was recently made aware of the log_level attribute for programs,
used to specify the level of information expected to be dumped by the
verifier. Function bpf_prog_load_xattr() got support for this log_level
parameter.

But some applications using libbpf rely on another function to load
programs, bpf_object__load(), which does accept any parameter for log
level. Create an API function based on bpf_object__load(), but accepting
an "attr" object as a parameter. Then add a log_level field to that
object, so that applications calling the new bpf_object__load_xattr()
can pick the desired log level.

v3:
- Rewrite commit log.

v2:
- We are in a new cycle, bump libbpf extraversion number.

Signed-off-by: Quentin Monnet <quentin.monnet@netronome.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-05-28 11:03:26 +02:00
Hariprasad Kelam d98363b510 libbpf: fix warning that PTR_ERR_OR_ZERO can be used
Fix below warning reported by coccicheck:

/tools/lib/bpf/libbpf.c:3461:1-3: WARNING: PTR_ERR_OR_ZERO can be used

Signed-off-by: Hariprasad Kelam <hariprasad.kelam@gmail.com>
Acked-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-05-28 10:56:05 +02:00
Jiong Wang 046561981b libbpf: add "prog_flags" to bpf_program/bpf_prog_load_attr/bpf_load_program_attr
libbpf doesn't allow passing "prog_flags" during bpf program load in a
couple of load related APIs, "bpf_load_program_xattr", "load_program" and
"bpf_prog_load_xattr".

It makes sense to allow passing "prog_flags" which is useful for
customizing program loading.

Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Jiong Wang <jiong.wang@netronome.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-05-24 18:58:37 -07:00
Andrii Nakryiko 351131b51c libbpf: add btf_dump API for BTF-to-C conversion
BTF contains enough type information to allow generating valid
compilable C header w/ correct layout of structs/unions and all the
typedef/enum definitions. This patch adds a new "object" - btf_dump to
facilitate dumping BTF as valid C. btf_dump__dump_type() is the main API
which takes care of dumping out (through user-provided printf-like
callback function) C definitions for given type ID and it's required
dependencies. This allows for not just dumping out entirety of BTF types,
but also selective filtering based on user-provided criterias w/ minimal
set of dependent types.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-05-24 14:05:58 -07:00
Andrii Nakryiko 2fc3fc0bcd libbpf: switch btf_dedup() to hashmap for dedup table
Utilize libbpf's hashmap as a multimap fof dedup_table implementation.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-05-24 14:05:58 -07:00
Andrii Nakryiko e3b9242240 libbpf: add resizable non-thread safe internal hashmap
There is a need for fast point lookups inside libbpf for multiple use
cases (e.g., name resolution for BTF-to-C conversion, by-name lookups in
BTF for upcoming BPF CO-RE relocation support, etc). This patch
implements simple resizable non-thread safe hashmap using single linked
list chains.

Four different insert strategies are supported:
 - HASHMAP_ADD - only add key/value if key doesn't exist yet;
 - HASHMAP_SET - add key/value pair if key doesn't exist yet; otherwise,
   update value;
 - HASHMAP_UPDATE - update value, if key already exists; otherwise, do
   nothing and return -ENOENT;
 - HASHMAP_APPEND - always add key/value pair, even if key already exists.
   This turns hashmap into a multimap by allowing multiple values to be
   associated with the same key. Most useful read API for such hashmap is
   hashmap__for_each_key_entry() iteration. If hashmap__find() is still
   used, it will return last inserted key/value entry (first in a bucket
   chain).

For HASHMAP_SET and HASHMAP_UPDATE, old key/value pair is returned, so
that calling code can handle proper memory management, if necessary.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-05-24 14:05:57 -07:00
Andrii Nakryiko e6c64855fd libbpf: add btf__parse_elf API to load .BTF and .BTF.ext
Loading BTF and BTF.ext from ELF file is a common need. Instead of
requiring every user to re-implement it, let's provide this API from
libbpf itself. It's mostly copy/paste from `bpftool btf dump`
implementation, which will be switched to libbpf's version in next
patch. btf__parse_elf allows to load BTF and optionally BTF.ext.
This is also useful for tests that need to load/work with BTF, loaded
from test ELF files.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-05-24 14:05:57 -07:00
Andrii Nakryiko 1d7a08b3bd libbpf: ensure libbpf.h is included along libbpf_internal.h
libbpf_internal.h expects a bunch of stuff defined in libbpf.h to be
defined. This patch makes sure that libbpf.h is always included.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-05-24 14:05:57 -07:00
Andrii Nakryiko 9efc779449 libbpf: emit diff of mismatched public API, if any
It's easy to have a mismatch of "intended to be public" vs really
exposed API functions. While Makefile does check for this mismatch, if
it actually occurs it's not trivial to determine which functions are
accidentally exposed. This patch dumps out a diff showing what's not
supposed to be exposed facilitating easier fixing.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-05-22 18:34:01 -07:00
Andrii Nakryiko d72386fe7a libbpf: move logging helpers into libbpf_internal.h
libbpf_util.h header was recently exposed as public as a dependency of
xsk.h. In addition to memory barriers, it contained logging helpers,
which are not supposed to be exposed. This patch moves those into
libbpf_internal.h, which is kept as an internal header.

Cc: Stanislav Fomichev <sdf@google.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Fixes: 7080da8909 ("libbpf: add libbpf_util.h to header install.")
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-05-16 12:47:47 -07:00
Stanislav Fomichev 15ea164ef1 libbpf: don't fail when feature probing fails
Otherwise libbpf is unusable from unprivileged process with
kernel.kernel.unprivileged_bpf_disabled=1.
All I get is EPERM from the probes, even if I just want to
open an ELF object and look at what progs/maps it has.

Instead of dying on probes, let's just pr_debug the error and
try to continue.

Signed-off-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-05-16 01:32:19 +02:00