From 293d5b43948309434568f4dcbb36cce4c3c51bd5 Mon Sep 17 00:00:00 2001 From: Masami Hiramatsu Date: Fri, 26 Aug 2016 01:24:57 +0900 Subject: perf probe: Support probing on offline cross-arch binary 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 $params' p:probe/do_sys_open do_sys_open+0 dfd=%r5:s32 filename=%r1:u32 flags=%r6:s32 mode=%r3:u16 ----- Here, we can get probe/do_sys_open from above and append it to to the target machine's tracing/kprobe_events file in the tracefs mountput, usually /sys/kernel/debug/tracing/kprobe_events (or /sys/kernel/tracing/kprobe_events). Signed-off-by: Masami Hiramatsu Cc: Jiri Olsa Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/147214229717.23638.6440579792548044658.stgit@devbox [ Add definition for EM_AARCH64 to fix the build on at least centos 6, debian 7 & ubuntu 12.04.5 ] Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/util/Build | 1 + tools/perf/util/dwarf-regs.c | 59 ++++++++++++++++++++++++++++++++++++ tools/perf/util/include/dwarf-regs.h | 6 ++++ tools/perf/util/probe-finder.c | 27 ++++++++++------- tools/perf/util/probe-finder.h | 1 + 5 files changed, 83 insertions(+), 11 deletions(-) create mode 100644 tools/perf/util/dwarf-regs.c (limited to 'tools/perf/util') diff --git a/tools/perf/util/Build b/tools/perf/util/Build index 91c5f6e1af59..f1a6d17c5a37 100644 --- a/tools/perf/util/Build +++ b/tools/perf/util/Build @@ -98,6 +98,7 @@ endif libperf-$(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 diff --git a/tools/perf/util/dwarf-regs.c b/tools/perf/util/dwarf-regs.c new file mode 100644 index 000000000000..62bc4a86a970 --- /dev/null +++ b/tools/perf/util/dwarf-regs.c @@ -0,0 +1,59 @@ +/* + * dwarf-regs.c : Mapping of DWARF debug register numbers into register names. + * + * Written by: Masami Hiramatsu + */ + +#include +#include +#include +#include + +#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; +} diff --git a/tools/perf/util/include/dwarf-regs.h b/tools/perf/util/include/dwarf-regs.h index 07c644ed64c4..43bfd8da7919 100644 --- a/tools/perf/util/include/dwarf-regs.h +++ b/tools/perf/util/include/dwarf-regs.h @@ -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 diff --git a/tools/perf/util/probe-finder.c b/tools/perf/util/probe-finder.c index ac4740f8ee3a..508b61c6e5fb 100644 --- a/tools/perf/util/probe-finder.c +++ b/tools/perf/util/probe-finder.c @@ -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; + +#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); + 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; diff --git a/tools/perf/util/probe-finder.h b/tools/perf/util/probe-finder.h index 51137fccb9c8..f1d8558f498e 100644 --- a/tools/perf/util/probe-finder.h +++ b/tools/perf/util/probe-finder.h @@ -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 */ }; -- cgit v1.2.3-59-g8ed1b