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perf probe: Support probing on offline cross-arch binary

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Support probing on offline cross-architecture binary by adding getting
the target machine arch from ELF and choose correct register string for
the machine.

Here is an example:
  -----
  $ perf probe --vmlinux=./vmlinux-arm --definition 'do_sys_open $params'
  p:probe/do_sys_open do_sys_open+0 dfd=%r5:s32 filename=%r1:u32 flags=%r6:s32 mode=%r3:u16
  -----

Here, we can get probe/do_sys_open from above and append it to to the target
machine's tracing/kprobe_events file in the tracefs mountput, usually
/sys/kernel/debug/tracing/kprobe_events (or /sys/kernel/tracing/kprobe_events).

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/147214229717.23638.6440579792548044658.stgit@devbox
[ Add definition for EM_AARCH64 to fix the build on at least centos 6, debian 7 & ubuntu 12.04.5 ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This commit is contained in:
Masami Hiramatsu 2016-08-26 01:24:57 +09:00 committed by Arnaldo Carvalho de Melo
parent 428aff82e9
commit 293d5b4394
13 changed files with 205 additions and 11 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

9
tools/perf/arch/arm/include/dwarf-regs-table.h Normal file
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@ -0,0 +1,9 @@
#ifdef DEFINE_DWARF_REGSTR_TABLE
/* This is included in perf/util/dwarf-regs.c */
static const char * const arm_regstr_tbl[] = {
"%r0", "%r1", "%r2", "%r3", "%r4",
"%r5", "%r6", "%r7", "%r8", "%r9", "%r10",
"%fp", "%ip", "%sp", "%lr", "%pc",
};
#endif

13
tools/perf/arch/arm64/include/dwarf-regs-table.h Normal file
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@ -0,0 +1,13 @@
#ifdef DEFINE_DWARF_REGSTR_TABLE
/* This is included in perf/util/dwarf-regs.c */
static const char * const aarch64_regstr_tbl[] = {
"%r0", "%r1", "%r2", "%r3", "%r4",
"%r5", "%r6", "%r7", "%r8", "%r9",
"%r10", "%r11", "%r12", "%r13", "%r14",
"%r15", "%r16", "%r17", "%r18", "%r19",
"%r20", "%r21", "%r22", "%r23", "%r24",
"%r25", "%r26", "%r27", "%r28", "%r29",
"%lr", "%sp",
};
#endif

27
tools/perf/arch/powerpc/include/dwarf-regs-table.h Normal file
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@ -0,0 +1,27 @@
#ifdef DEFINE_DWARF_REGSTR_TABLE
/* This is included in perf/util/dwarf-regs.c */
/*
* Reference:
* http://refspecs.linuxfoundation.org/ELF/ppc64/PPC-elf64abi-1.9.html
* http://refspecs.linux-foundation.org/elf/elfspec_ppc.pdf
*/
#define REG_DWARFNUM_NAME(reg, idx) [idx] = "%" #reg
static const char * const powerpc_regstr_tbl[] = {
"%gpr0", "%gpr1", "%gpr2", "%gpr3", "%gpr4",
"%gpr5", "%gpr6", "%gpr7", "%gpr8", "%gpr9",
"%gpr10", "%gpr11", "%gpr12", "%gpr13", "%gpr14",
"%gpr15", "%gpr16", "%gpr17", "%gpr18", "%gpr19",
"%gpr20", "%gpr21", "%gpr22", "%gpr23", "%gpr24",
"%gpr25", "%gpr26", "%gpr27", "%gpr28", "%gpr29",
"%gpr30", "%gpr31",
REG_DWARFNUM_NAME(msr, 66),
REG_DWARFNUM_NAME(ctr, 109),
REG_DWARFNUM_NAME(link, 108),
REG_DWARFNUM_NAME(xer, 101),
REG_DWARFNUM_NAME(dar, 119),
REG_DWARFNUM_NAME(dsisr, 118),
};
#endif

8
tools/perf/arch/s390/include/dwarf-regs-table.h Normal file
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@ -0,0 +1,8 @@
#ifdef DEFINE_DWARF_REGSTR_TABLE
/* This is included in perf/util/dwarf-regs.c */
static const char * const s390_regstr_tbl[] = {
"%r0", "%r1", "%r2", "%r3", "%r4", "%r5", "%r6", "%r7",
"%r8", "%r9", "%r10", "%r11", "%r12", "%r13", "%r14", "%r15",
};
#endif

25
tools/perf/arch/sh/include/dwarf-regs-table.h Normal file
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@ -0,0 +1,25 @@
#ifdef DEFINE_DWARF_REGSTR_TABLE
/* This is included in perf/util/dwarf-regs.c */
const char * const sh_regstr_tbl[] = {
"r0",
"r1",
"r2",
"r3",
"r4",
"r5",
"r6",
"r7",
"r8",
"r9",
"r10",
"r11",
"r12",
"r13",
"r14",
"r15",
"pc",
"pr",
};
#endif

18
tools/perf/arch/sparc/include/dwarf-regs-table.h Normal file
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@ -0,0 +1,18 @@
#ifdef DEFINE_DWARF_REGSTR_TABLE
/* This is included in perf/util/dwarf-regs.c */
static const char * const sparc_regstr_tbl[] = {
"%g0", "%g1", "%g2", "%g3", "%g4", "%g5", "%g6", "%g7",
"%o0", "%o1", "%o2", "%o3", "%o4", "%o5", "%sp", "%o7",
"%l0", "%l1", "%l2", "%l3", "%l4", "%l5", "%l6", "%l7",
"%i0", "%i1", "%i2", "%i3", "%i4", "%i5", "%fp", "%i7",
"%f0", "%f1", "%f2", "%f3", "%f4", "%f5", "%f6", "%f7",
"%f8", "%f9", "%f10", "%f11", "%f12", "%f13", "%f14", "%f15",
"%f16", "%f17", "%f18", "%f19", "%f20", "%f21", "%f22", "%f23",
"%f24", "%f25", "%f26", "%f27", "%f28", "%f29", "%f30", "%f31",
"%f32", "%f33", "%f34", "%f35", "%f36", "%f37", "%f38", "%f39",
"%f40", "%f41", "%f42", "%f43", "%f44", "%f45", "%f46", "%f47",
"%f48", "%f49", "%f50", "%f51", "%f52", "%f53", "%f54", "%f55",
"%f56", "%f57", "%f58", "%f59", "%f60", "%f61", "%f62", "%f63",
};
#endif

14
tools/perf/arch/x86/include/dwarf-regs-table.h Normal file
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@ -0,0 +1,14 @@
#ifdef DEFINE_DWARF_REGSTR_TABLE
/* This is included in perf/util/dwarf-regs.c */
static const char * const x86_32_regstr_tbl[] = {
"%ax", "%cx", "%dx", "%bx", "$stack",/* Stack address instead of %sp */
"%bp", "%si", "%di",
};
static const char * const x86_64_regstr_tbl[] = {
"%ax", "dx", "%cx", "%bx", "%si", "%di",
"%bp", "%sp", "%r8", "%r9", "%r10", "%r11",
"%r12", "%r13", "%r14", "%r15",
};
#endif

8
tools/perf/arch/xtensa/include/dwarf-regs-table.h Normal file
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@ -0,0 +1,8 @@
#ifdef DEFINE_DWARF_REGSTR_TABLE
/* This is included in perf/util/dwarf-regs.c */
static const char * const xtensa_regstr_tbl[] = {
"a0", "a1", "a2", "a3", "a4", "a5", "a6", "a7",
"a8", "a9", "a10", "a11", "a12", "a13", "a14", "a15",
};
#endif

1
tools/perf/util/Build
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@ -98,6 +98,7 @@ endif
libperf-$(CONFIG_DWARF) += probe-finder.o
libperf-$(CONFIG_DWARF) += dwarf-aux.o
libperf-$(CONFIG_DWARF) += dwarf-regs.o
libperf-$(CONFIG_LIBDW_DWARF_UNWIND) += unwind-libdw.o
libperf-$(CONFIG_LOCAL_LIBUNWIND) += unwind-libunwind-local.o

59
tools/perf/util/dwarf-regs.c Normal file
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@ -0,0 +1,59 @@
/*
* dwarf-regs.c : Mapping of DWARF debug register numbers into register names.
*
* Written by: Masami Hiramatsu <mhiramat@kernel.org>
*/
#include <util.h>
#include <debug.h>
#include <dwarf-regs.h>
#include <elf.h>
#ifndef EM_AARCH64
#define EM_AARCH64 183 /* ARM 64 bit */
#endif
/* Define const char * {arch}_register_tbl[] */
#define DEFINE_DWARF_REGSTR_TABLE
#include "../arch/x86/include/dwarf-regs-table.h"
#include "../arch/arm/include/dwarf-regs-table.h"
#include "../arch/arm64/include/dwarf-regs-table.h"
#include "../arch/sh/include/dwarf-regs-table.h"
#include "../arch/powerpc/include/dwarf-regs-table.h"
#include "../arch/s390/include/dwarf-regs-table.h"
#include "../arch/sparc/include/dwarf-regs-table.h"
#include "../arch/xtensa/include/dwarf-regs-table.h"
#define __get_dwarf_regstr(tbl, n) (((n) < ARRAY_SIZE(tbl)) ? (tbl)[(n)] : NULL)
/* Return architecture dependent register string (for kprobe-tracer) */
const char *get_dwarf_regstr(unsigned int n, unsigned int machine)
{
switch (machine) {
case EM_NONE: /* Generic arch - use host arch */
return get_arch_regstr(n);
case EM_386:
return __get_dwarf_regstr(x86_32_regstr_tbl, n);
case EM_X86_64:
return __get_dwarf_regstr(x86_64_regstr_tbl, n);
case EM_ARM:
return __get_dwarf_regstr(arm_regstr_tbl, n);
case EM_AARCH64:
return __get_dwarf_regstr(aarch64_regstr_tbl, n);
case EM_SH:
return __get_dwarf_regstr(sh_regstr_tbl, n);
case EM_S390:
return __get_dwarf_regstr(s390_regstr_tbl, n);
case EM_PPC:
case EM_PPC64:
return __get_dwarf_regstr(powerpc_regstr_tbl, n);
case EM_SPARC:
case EM_SPARCV9:
return __get_dwarf_regstr(sparc_regstr_tbl, n);
case EM_XTENSA:
return __get_dwarf_regstr(xtensa_regstr_tbl, n);
default:
pr_err("ELF MACHINE %x is not supported.\n", machine);
}
return NULL;
}

6
tools/perf/util/include/dwarf-regs.h
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@ -3,6 +3,12 @@
#ifdef HAVE_DWARF_SUPPORT
const char *get_arch_regstr(unsigned int n);
/*
* get_dwarf_regstr - Returns ftrace register string from DWARF regnum
* n: DWARF register number
* machine: ELF machine signature (EM_*)
*/
const char *get_dwarf_regstr(unsigned int n, unsigned int machine);
#endif
#ifdef HAVE_ARCH_REGS_QUERY_REGISTER_OFFSET

27
tools/perf/util/probe-finder.c
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@ -171,6 +171,7 @@ static struct probe_trace_arg_ref *alloc_trace_arg_ref(long offs)
*/
static int convert_variable_location(Dwarf_Die *vr_die, Dwarf_Addr addr,
Dwarf_Op *fb_ops, Dwarf_Die *sp_die,
unsigned int machine,
struct probe_trace_arg *tvar)
{
Dwarf_Attribute attr;
@ -266,7 +267,7 @@ static_var:
if (!tvar)
return ret2;
regs = get_arch_regstr(regn);
regs = get_dwarf_regstr(regn, machine);
if (!regs) {
/* This should be a bug in DWARF or this tool */
pr_warning("Mapping for the register number %u "
@ -543,7 +544,7 @@ static int convert_variable(Dwarf_Die *vr_die, struct probe_finder *pf)
dwarf_diename(vr_die));
ret = convert_variable_location(vr_die, pf->addr, pf->fb_ops,
&pf->sp_die, pf->tvar);
&pf->sp_die, pf->machine, pf->tvar);
if (ret == -ENOENT || ret == -EINVAL) {
pr_err("Failed to find the location of the '%s' variable at this address.\n"
" Perhaps it has been optimized out.\n"
@ -1106,11 +1107,8 @@ static int debuginfo__find_probes(struct debuginfo *dbg,
struct probe_finder *pf)
{
int ret = 0;
#if _ELFUTILS_PREREQ(0, 142)
Elf *elf;
GElf_Ehdr ehdr;
GElf_Shdr shdr;
if (pf->cfi_eh || pf->cfi_dbg)
return debuginfo__find_probe_location(dbg, pf);
@ -1123,11 +1121,18 @@ static int debuginfo__find_probes(struct debuginfo *dbg,
if (gelf_getehdr(elf, &ehdr) == NULL)
return -EINVAL;
if (elf_section_by_name(elf, &ehdr, &shdr, ".eh_frame", NULL) &&
shdr.sh_type == SHT_PROGBITS)
pf->cfi_eh = dwarf_getcfi_elf(elf);
pf->machine = ehdr.e_machine;
pf->cfi_dbg = dwarf_getcfi(dbg->dbg);
#if _ELFUTILS_PREREQ(0, 142)
do {
GElf_Shdr shdr;
if (elf_section_by_name(elf, &ehdr, &shdr, ".eh_frame", NULL) &&
shdr.sh_type == SHT_PROGBITS)
pf->cfi_eh = dwarf_getcfi_elf(elf);
pf->cfi_dbg = dwarf_getcfi(dbg->dbg);
} while (0);
#endif
ret = debuginfo__find_probe_location(dbg, pf);
@ -1155,7 +1160,7 @@ static int copy_variables_cb(Dwarf_Die *die_mem, void *data)
(tag == DW_TAG_variable && vf->vars)) {
if (convert_variable_location(die_mem, vf->pf->addr,
vf->pf->fb_ops, &pf->sp_die,
NULL) == 0) {
pf->machine, NULL) == 0) {
vf->args[vf->nargs].var = (char *)dwarf_diename(die_mem);
if (vf->args[vf->nargs].var == NULL) {
vf->ret = -ENOMEM;
@ -1318,7 +1323,7 @@ static int collect_variables_cb(Dwarf_Die *die_mem, void *data)
tag == DW_TAG_variable) {
ret = convert_variable_location(die_mem, af->pf.addr,
af->pf.fb_ops, &af->pf.sp_die,
NULL);
af->pf.machine, NULL);
if (ret == 0 || ret == -ERANGE) {
int ret2;
bool externs = !af->child;

1
tools/perf/util/probe-finder.h
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@ -80,6 +80,7 @@ struct probe_finder {
Dwarf_CFI *cfi_dbg;
#endif
Dwarf_Op *fb_ops; /* Frame base attribute */
unsigned int machine; /* Target machine arch */
struct perf_probe_arg *pvar; /* Current target variable */
struct probe_trace_arg *tvar; /* Current result variable */
};