parisc: add dynamic ftrace
This patch implements dynamic ftrace for PA-RISC. The required mcount call sequences can get pretty long, so instead of patching the whole call sequence out of the functions, we are using -fpatchable-function-entry from gcc. This puts a configurable amount of NOPS before/at the start of the function. Taking do_sys_open() as example, which would look like this when the call is patched out: 1036b248: 08 00 02 40 nop 1036b24c: 08 00 02 40 nop 1036b250: 08 00 02 40 nop 1036b254: 08 00 02 40 nop 1036b258 <do_sys_open>: 1036b258: 08 00 02 40 nop 1036b25c: 08 03 02 41 copy r3,r1 1036b260: 6b c2 3f d9 stw rp,-14(sp) 1036b264: 08 1e 02 43 copy sp,r3 1036b268: 6f c1 01 00 stw,ma r1,80(sp) When ftrace gets enabled for this function the kernel will patch these NOPs to: 1036b248: 10 19 57 20 <address of ftrace> 1036b24c: 6f c1 00 80 stw,ma r1,40(sp) 1036b250: 48 21 3f d1 ldw -18(r1),r1 1036b254: e8 20 c0 02 bv,n r0(r1) 1036b258 <do_sys_open>: 1036b258: e8 3f 1f df b,l,n .-c,r1 1036b25c: 08 03 02 41 copy r3,r1 1036b260: 6b c2 3f d9 stw rp,-14(sp) 1036b264: 08 1e 02 43 copy sp,r3 1036b268: 6f c1 01 00 stw,ma r1,80(sp) So the first NOP in do_sys_open() will be patched to jump backwards into some minimal trampoline code which pushes a stackframe, saves r1 which holds the return address, loads the address of the real ftrace function, and branches to that location. For 64 Bit things are getting a bit more complicated (and longer) because we must make sure that the address of ftrace location is 8 byte aligned, and the offset passed to ldd for fetching the address is 8 byte aligned as well. Note that gcc has a bug which misplaces the function label, and needs a patch to make dynamic ftrace work. See https://gcc.gnu.org/bugzilla/show_bug.cgi?id=90751 for details. Signed-off-by: Sven Schnelle <svens@stackframe.org> Signed-off-by: Helge Deller <deller@gmx.de>alistair/sunxi64-5.4-dsi
Sven Schnelle
Helge Deller
parent
2809b392a6
commit
6ca6366220
|
|
@ -59,6 +59,8 @@ config PARISC
|
|||
select HAVE_ARCH_KGDB
|
||||
select HAVE_KPROBES
|
||||
select HAVE_KRETPROBES
|
||||
select HAVE_DYNAMIC_FTRACE if $(cc-option,-fpatchable-function-entry=1,1)
|
||||
select HAVE_FTRACE_MCOUNT_RECORD if HAVE_DYNAMIC_FTRACE
|
||||
|
||||
help
|
||||
The PA-RISC microprocessor is designed by Hewlett-Packard and used
|
||||
|
|
|
|||
|
|
@ -47,6 +47,24 @@ ifneq ($(SUBARCH),$(UTS_MACHINE))
|
|||
endif
|
||||
endif
|
||||
|
||||
ifdef CONFIG_DYNAMIC_FTRACE
|
||||
ifdef CONFIG_64BIT
|
||||
NOP_COUNT := 8
|
||||
else
|
||||
NOP_COUNT := 5
|
||||
endif
|
||||
|
||||
export CC_USING_RECORD_MCOUNT:=1
|
||||
export CC_USING_PATCHABLE_FUNCTION_ENTRY:=1
|
||||
|
||||
KBUILD_AFLAGS += -DCC_USING_PATCHABLE_FUNCTION_ENTRY=1
|
||||
KBUILD_CFLAGS += -DCC_USING_PATCHABLE_FUNCTION_ENTRY=1 \
|
||||
-DFTRACE_PATCHABLE_FUNCTION_SIZE=$(NOP_COUNT)
|
||||
|
||||
CC_FLAGS_FTRACE := -fpatchable-function-entry=$(NOP_COUNT),$(shell echo $$(($(NOP_COUNT)-1)))
|
||||
KBUILD_LDFLAGS_MODULE += -T $(srctree)/arch/parisc/kernel/module.lds
|
||||
endif
|
||||
|
||||
OBJCOPY_FLAGS =-O binary -R .note -R .comment -S
|
||||
|
||||
cflags-y := -pipe
|
||||
|
|
|
|||
|
|
@ -5,12 +5,23 @@
|
|||
#ifndef __ASSEMBLY__
|
||||
extern void mcount(void);
|
||||
|
||||
#define MCOUNT_INSN_SIZE 4
|
||||
|
||||
#define MCOUNT_ADDR ((unsigned long)mcount)
|
||||
#define MCOUNT_INSN_SIZE 4
|
||||
#define CC_USING_NOP_MCOUNT
|
||||
extern unsigned long sys_call_table[];
|
||||
|
||||
extern unsigned long return_address(unsigned int);
|
||||
|
||||
#ifdef CONFIG_DYNAMIC_FTRACE
|
||||
extern void ftrace_caller(void);
|
||||
|
||||
struct dyn_arch_ftrace {
|
||||
};
|
||||
|
||||
unsigned long ftrace_call_adjust(unsigned long addr);
|
||||
|
||||
#endif
|
||||
|
||||
#define ftrace_return_address(n) return_address(n)
|
||||
|
||||
#endif /* __ASSEMBLY__ */
|
||||
|
|
|
|||
|
|
@ -14,10 +14,11 @@ obj-y := cache.o pacache.o setup.o pdt.o traps.o time.o irq.o \
|
|||
|
||||
ifdef CONFIG_FUNCTION_TRACER
|
||||
# Do not profile debug and lowlevel utilities
|
||||
CFLAGS_REMOVE_ftrace.o = -pg
|
||||
CFLAGS_REMOVE_cache.o = -pg
|
||||
CFLAGS_REMOVE_perf.o = -pg
|
||||
CFLAGS_REMOVE_unwind.o = -pg
|
||||
CFLAGS_REMOVE_ftrace.o = $(CC_FLAGS_FTRACE)
|
||||
CFLAGS_REMOVE_cache.o = $(CC_FLAGS_FTRACE)
|
||||
CFLAGS_REMOVE_perf.o = $(CC_FLAGS_FTRACE)
|
||||
CFLAGS_REMOVE_unwind.o = $(CC_FLAGS_FTRACE)
|
||||
CFLAGS_REMOVE_patch.o = $(CC_FLAGS_FTRACE)
|
||||
endif
|
||||
|
||||
obj-$(CONFIG_SMP) += smp.o
|
||||
|
|
|
|||
|
|
@ -2012,6 +2012,70 @@ ftrace_stub:
|
|||
#endif
|
||||
ENDPROC_CFI(mcount)
|
||||
|
||||
#ifdef CONFIG_DYNAMIC_FTRACE
|
||||
|
||||
#ifdef CONFIG_64BIT
|
||||
#define FTRACE_FRAME_SIZE (2*FRAME_SIZE)
|
||||
#else
|
||||
#define FTRACE_FRAME_SIZE FRAME_SIZE
|
||||
#endif
|
||||
ENTRY_CFI(ftrace_caller, caller,frame=FTRACE_FRAME_SIZE,CALLS,SAVE_RP,SAVE_SP)
|
||||
ftrace_caller:
|
||||
.global ftrace_caller
|
||||
|
||||
STREG %r3, -FTRACE_FRAME_SIZE+1*REG_SZ(%sp)
|
||||
ldo -FTRACE_FRAME_SIZE(%sp), %r3
|
||||
STREG %rp, -RP_OFFSET(%r3)
|
||||
|
||||
/* Offset 0 is already allocated for %r1 */
|
||||
STREG %r23, 2*REG_SZ(%r3)
|
||||
STREG %r24, 3*REG_SZ(%r3)
|
||||
STREG %r25, 4*REG_SZ(%r3)
|
||||
STREG %r26, 5*REG_SZ(%r3)
|
||||
STREG %r28, 6*REG_SZ(%r3)
|
||||
STREG %r29, 7*REG_SZ(%r3)
|
||||
#ifdef CONFIG_64BIT
|
||||
STREG %r19, 8*REG_SZ(%r3)
|
||||
STREG %r20, 9*REG_SZ(%r3)
|
||||
STREG %r21, 10*REG_SZ(%r3)
|
||||
STREG %r22, 11*REG_SZ(%r3)
|
||||
STREG %r27, 12*REG_SZ(%r3)
|
||||
STREG %r31, 13*REG_SZ(%r3)
|
||||
loadgp
|
||||
ldo -16(%sp),%r29
|
||||
#endif
|
||||
LDREG 0(%r3), %r25
|
||||
copy %rp, %r26
|
||||
ldo -8(%r25), %r25
|
||||
b,l ftrace_function_trampoline, %rp
|
||||
copy %r3, %r24
|
||||
|
||||
LDREG -RP_OFFSET(%r3), %rp
|
||||
LDREG 2*REG_SZ(%r3), %r23
|
||||
LDREG 3*REG_SZ(%r3), %r24
|
||||
LDREG 4*REG_SZ(%r3), %r25
|
||||
LDREG 5*REG_SZ(%r3), %r26
|
||||
LDREG 6*REG_SZ(%r3), %r28
|
||||
LDREG 7*REG_SZ(%r3), %r29
|
||||
#ifdef CONFIG_64BIT
|
||||
LDREG 8*REG_SZ(%r3), %r19
|
||||
LDREG 9*REG_SZ(%r3), %r20
|
||||
LDREG 10*REG_SZ(%r3), %r21
|
||||
LDREG 11*REG_SZ(%r3), %r22
|
||||
LDREG 12*REG_SZ(%r3), %r27
|
||||
LDREG 13*REG_SZ(%r3), %r31
|
||||
#endif
|
||||
LDREG 1*REG_SZ(%r3), %r3
|
||||
|
||||
LDREGM -FTRACE_FRAME_SIZE(%sp), %r1
|
||||
/* Adjust return point to jump back to beginning of traced function */
|
||||
ldo -4(%r1), %r1
|
||||
bv,n (%r1)
|
||||
|
||||
ENDPROC_CFI(ftrace_caller)
|
||||
|
||||
#endif
|
||||
|
||||
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
|
||||
.align 8
|
||||
ENTRY_CFI(return_to_handler, caller,frame=FRAME_SIZE)
|
||||
|
|
|
|||
|
|
@ -7,17 +7,17 @@
|
|||
* Copyright (C) 2007-2008 Steven Rostedt <srostedt@redhat.com>
|
||||
*
|
||||
* future possible enhancements:
|
||||
* - add CONFIG_DYNAMIC_FTRACE
|
||||
* - add CONFIG_STACK_TRACER
|
||||
*/
|
||||
|
||||
#include <linux/init.h>
|
||||
#include <linux/ftrace.h>
|
||||
#include <linux/uaccess.h>
|
||||
|
||||
#include <asm/assembly.h>
|
||||
#include <asm/sections.h>
|
||||
#include <asm/ftrace.h>
|
||||
|
||||
#include <asm/patch.h>
|
||||
|
||||
#define __hot __attribute__ ((__section__ (".text.hot")))
|
||||
|
||||
|
|
@ -50,13 +50,11 @@ void notrace __hot ftrace_function_trampoline(unsigned long parent,
|
|||
unsigned long self_addr,
|
||||
unsigned long org_sp_gr3)
|
||||
{
|
||||
extern ftrace_func_t ftrace_trace_function; /* depends on CONFIG_DYNAMIC_FTRACE */
|
||||
|
||||
if (ftrace_trace_function != ftrace_stub) {
|
||||
/* struct ftrace_ops *op, struct pt_regs *regs); */
|
||||
ftrace_trace_function(parent, self_addr, NULL, NULL);
|
||||
return;
|
||||
}
|
||||
#ifndef CONFIG_DYNAMIC_FTRACE
|
||||
extern ftrace_func_t ftrace_trace_function;
|
||||
#endif
|
||||
if (ftrace_trace_function != ftrace_stub)
|
||||
ftrace_trace_function(self_addr, parent, NULL, NULL);
|
||||
|
||||
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
|
||||
if (ftrace_graph_return != (trace_func_graph_ret_t) ftrace_stub ||
|
||||
|
|
@ -75,3 +73,116 @@ void notrace __hot ftrace_function_trampoline(unsigned long parent,
|
|||
#endif
|
||||
}
|
||||
|
||||
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
|
||||
int ftrace_enable_ftrace_graph_caller(void)
|
||||
{
|
||||
return 0;
|
||||
}
|
||||
|
||||
int ftrace_disable_ftrace_graph_caller(void)
|
||||
{
|
||||
return 0;
|
||||
}
|
||||
#endif
|
||||
|
||||
#ifdef CONFIG_DYNAMIC_FTRACE
|
||||
|
||||
int __init ftrace_dyn_arch_init(void)
|
||||
{
|
||||
return 0;
|
||||
}
|
||||
int ftrace_update_ftrace_func(ftrace_func_t func)
|
||||
{
|
||||
return 0;
|
||||
}
|
||||
|
||||
unsigned long ftrace_call_adjust(unsigned long addr)
|
||||
{
|
||||
return addr+(FTRACE_PATCHABLE_FUNCTION_SIZE-1)*4;
|
||||
}
|
||||
|
||||
int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr)
|
||||
{
|
||||
u32 insn[FTRACE_PATCHABLE_FUNCTION_SIZE];
|
||||
u32 *tramp;
|
||||
int size, ret, i;
|
||||
void *ip;
|
||||
|
||||
#ifdef CONFIG_64BIT
|
||||
unsigned long addr2 =
|
||||
(unsigned long)dereference_function_descriptor((void *)addr);
|
||||
|
||||
u32 ftrace_trampoline[] = {
|
||||
0x73c10208, /* std,ma r1,100(sp) */
|
||||
0x0c2110c1, /* ldd -10(r1),r1 */
|
||||
0xe820d002, /* bve,n (r1) */
|
||||
addr2 >> 32,
|
||||
addr2 & 0xffffffff,
|
||||
0xe83f1fd7, /* b,l,n .-14,r1 */
|
||||
};
|
||||
|
||||
u32 ftrace_trampoline_unaligned[] = {
|
||||
addr2 >> 32,
|
||||
addr2 & 0xffffffff,
|
||||
0x37de0200, /* ldo 100(sp),sp */
|
||||
0x73c13e01, /* std r1,-100(sp) */
|
||||
0x34213ff9, /* ldo -4(r1),r1 */
|
||||
0x50213fc1, /* ldd -20(r1),r1 */
|
||||
0xe820d002, /* bve,n (r1) */
|
||||
0xe83f1fcf, /* b,l,n .-20,r1 */
|
||||
};
|
||||
|
||||
BUILD_BUG_ON(ARRAY_SIZE(ftrace_trampoline_unaligned) >
|
||||
FTRACE_PATCHABLE_FUNCTION_SIZE);
|
||||
#else
|
||||
u32 ftrace_trampoline[] = {
|
||||
(u32)addr,
|
||||
0x6fc10080, /* stw,ma r1,40(sp) */
|
||||
0x48213fd1, /* ldw -18(r1),r1 */
|
||||
0xe820c002, /* bv,n r0(r1) */
|
||||
0xe83f1fdf, /* b,l,n .-c,r1 */
|
||||
};
|
||||
#endif
|
||||
|
||||
BUILD_BUG_ON(ARRAY_SIZE(ftrace_trampoline) >
|
||||
FTRACE_PATCHABLE_FUNCTION_SIZE);
|
||||
|
||||
size = sizeof(ftrace_trampoline);
|
||||
tramp = ftrace_trampoline;
|
||||
|
||||
#ifdef CONFIG_64BIT
|
||||
if (rec->ip & 0x4) {
|
||||
size = sizeof(ftrace_trampoline_unaligned);
|
||||
tramp = ftrace_trampoline_unaligned;
|
||||
}
|
||||
#endif
|
||||
|
||||
ip = (void *)(rec->ip + 4 - size);
|
||||
|
||||
ret = probe_kernel_read(insn, ip, size);
|
||||
if (ret)
|
||||
return ret;
|
||||
|
||||
for (i = 0; i < size / 4; i++) {
|
||||
if (insn[i] != INSN_NOP)
|
||||
return -EINVAL;
|
||||
}
|
||||
|
||||
__patch_text_multiple(ip, tramp, size);
|
||||
return 0;
|
||||
}
|
||||
|
||||
int ftrace_make_nop(struct module *mod, struct dyn_ftrace *rec,
|
||||
unsigned long addr)
|
||||
{
|
||||
u32 insn[FTRACE_PATCHABLE_FUNCTION_SIZE];
|
||||
int i;
|
||||
|
||||
for (i = 0; i < ARRAY_SIZE(insn); i++)
|
||||
insn[i] = INSN_NOP;
|
||||
|
||||
__patch_text_multiple((void *)rec->ip + 4 - sizeof(insn),
|
||||
insn, sizeof(insn));
|
||||
return 0;
|
||||
}
|
||||
#endif
|
||||
|
|
|
|||
|
|
@ -858,6 +858,7 @@ int module_finalize(const Elf_Ehdr *hdr,
|
|||
const char *strtab = NULL;
|
||||
const Elf_Shdr *s;
|
||||
char *secstrings;
|
||||
int err, symindex = -1;
|
||||
Elf_Sym *newptr, *oldptr;
|
||||
Elf_Shdr *symhdr = NULL;
|
||||
#ifdef DEBUG
|
||||
|
|
@ -884,6 +885,7 @@ int module_finalize(const Elf_Ehdr *hdr,
|
|||
if(sechdrs[i].sh_type == SHT_SYMTAB
|
||||
&& (sechdrs[i].sh_flags & SHF_ALLOC)) {
|
||||
int strindex = sechdrs[i].sh_link;
|
||||
symindex = i;
|
||||
/* FIXME: AWFUL HACK
|
||||
* The cast is to drop the const from
|
||||
* the sechdrs pointer */
|
||||
|
|
@ -939,8 +941,24 @@ int module_finalize(const Elf_Ehdr *hdr,
|
|||
if (!strcmp(".altinstructions", secname))
|
||||
/* patch .altinstructions */
|
||||
apply_alternatives(aseg, aseg + s->sh_size, me->name);
|
||||
}
|
||||
|
||||
/* For 32 bit kernels we're compiling modules with
|
||||
* -ffunction-sections so we must relocate the addresses in the
|
||||
*__mcount_loc section.
|
||||
*/
|
||||
if (symindex != -1 && !strcmp(secname, "__mcount_loc")) {
|
||||
if (s->sh_type == SHT_REL)
|
||||
err = apply_relocate((Elf_Shdr *)sechdrs,
|
||||
strtab, symindex,
|
||||
s - sechdrs, me);
|
||||
else if (s->sh_type == SHT_RELA)
|
||||
err = apply_relocate_add((Elf_Shdr *)sechdrs,
|
||||
strtab, symindex,
|
||||
s - sechdrs, me);
|
||||
if (err)
|
||||
return err;
|
||||
}
|
||||
}
|
||||
return 0;
|
||||
}
|
||||
|
||||
|
|
|
|||
|
|
@ -0,0 +1,7 @@
|
|||
/* SPDX-License-Identifier: GPL-2.0 */
|
||||
|
||||
SECTIONS {
|
||||
__mcount_loc : {
|
||||
*(__patchable_function_entries)
|
||||
}
|
||||
}
|
||||
|
|
@ -18,6 +18,8 @@
|
|||
*(.data..vm0.pgd) \
|
||||
*(.data..vm0.pte)
|
||||
|
||||
#define CC_USING_PATCHABLE_FUNCTION_ENTRY
|
||||
|
||||
#include <asm-generic/vmlinux.lds.h>
|
||||
|
||||
/* needed for the processor specific cache alignment size */
|
||||
|
|
|
|||
|
|
@ -10,7 +10,7 @@
|
|||
#include <asm/cacheflush.h>
|
||||
#include <asm/fixmap.h>
|
||||
|
||||
void set_fixmap(enum fixed_addresses idx, phys_addr_t phys)
|
||||
void notrace set_fixmap(enum fixed_addresses idx, phys_addr_t phys)
|
||||
{
|
||||
unsigned long vaddr = __fix_to_virt(idx);
|
||||
pgd_t *pgd = pgd_offset_k(vaddr);
|
||||
|
|
@ -28,7 +28,7 @@ void set_fixmap(enum fixed_addresses idx, phys_addr_t phys)
|
|||
flush_tlb_kernel_range(vaddr, vaddr + PAGE_SIZE);
|
||||
}
|
||||
|
||||
void clear_fixmap(enum fixed_addresses idx)
|
||||
void notrace clear_fixmap(enum fixed_addresses idx)
|
||||
{
|
||||
unsigned long vaddr = __fix_to_virt(idx);
|
||||
pgd_t *pgd = pgd_offset_k(vaddr);
|
||||
|
|
|
|||
|
|
@ -110,10 +110,17 @@
|
|||
#endif
|
||||
|
||||
#ifdef CONFIG_FTRACE_MCOUNT_RECORD
|
||||
#ifdef CC_USING_PATCHABLE_FUNCTION_ENTRY
|
||||
#define MCOUNT_REC() . = ALIGN(8); \
|
||||
__start_mcount_loc = .; \
|
||||
KEEP(*(__patchable_function_entries)) \
|
||||
__stop_mcount_loc = .;
|
||||
#else
|
||||
#define MCOUNT_REC() . = ALIGN(8); \
|
||||
__start_mcount_loc = .; \
|
||||
KEEP(*(__mcount_loc)) \
|
||||
__stop_mcount_loc = .;
|
||||
#endif
|
||||
#else
|
||||
#define MCOUNT_REC()
|
||||
#endif
|
||||
|
|
|
|||
Loading…
Reference in New Issue