On Wed, 24 Aug 2016 10:03:08 -0300 Arnaldo Carvalho de Melo <a...@kernel.org> wrote:
> Em Wed, Aug 24, 2016 at 02:58:41PM +0900, Masami Hiramatsu escreveu: > > 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: > > ----- > > $ mkdir tracing > > No need for the sudo here, right? > > > $ sudo perf probe --outdir=./tracing --vmlinux=./vmlinux-arm \ > > do_sys_open '$vars' Ah, actually, there might be something wrong processing path around kernel_get_ref_reloc_sym(), it calls map__load() to load symbols in the kernel, but it actually loads /proc/kallsyms, and if kptr_restrict is enabled fails to find reloc_sym, because all addresses are 0. I think it should not load the kallsyms if symbol_conf.vmlinux_name is given. But I'm not sure how. (Moreover, it is very strange why we could get the correct ref_reloc_sym address(_text) from kallsyms, I guess map__load() may load both of the kallsyms and given vmlinux) BTW, actually, the dso already loaded given vmlinux, so I would like to know how to load a map from dso. > Going with the --definition (or any other name that spits out what needs > to go to kprobes_events, this could be further short circuited, ie.: > > $ perf probe --vmlinux=./vmlinux-arm do_sys_open '$vars' > p:probe/do_sys_open _text+1282292 dfd=%r5:s32 filename=%r1:u32 > flags=%r6:s32 mode=%r3:u16 op=-60(%sp) fd=%r4:s32 tmp=%r7:u32 > $ > > Because in this case clearly the probe is not for the running kernel, > thus we could imply that this is to generate probes for running on > some other place. Hmm, but if user gives a file what he think it is running kernel vmlinux to --vmlinux, he might be upset. I would like to see the Buildid error in that case. If he gives --definition, we may be sure that user is done with his intention. Thanks, > Also perhaps even this could be made shorter: > > $ perf probe vmlinux-arm do_sys_open '$vars' > p:probe/do_sys_open _text+1282292 dfd=%r5:s32 filename=%r1:u32 > flags=%r6:s32 mode=%r3:u16 op=-60(%sp) fd=%r4:s32 tmp=%r7:u32 > $ > > As it can easily figure out the first argument _is_ a vmlinux :-) > > - Arnaldo > > > > Added new event: > > probe:do_sys_open (on do_sys_open with $vars) > > > > You can now use it in all perf tools, such as: > > > > perf record -e probe:do_sys_open -aR sleep 1 > > > > $ cat tracing/kprobe_events > > p:probe/do_sys_open _text+1282292 dfd=%r5:s32 filename=%r1:u32 > > flags=%r6:s32 mode=%r3:u16 op=-60(%sp) fd=%r4:s32 tmp=%r7:u32 > > ----- > > Here, we can get probe/do_sys_open event by "copy & paste" from > > ./tracing/kprobe_events to target-machine's debugfs/tracing/kprobe_events > > > > To make sure it is correct: > > ----- > > $ nm vmlinux-arm | grep "T _text" > > 80008000 T _text > > $ nm vmlinux-arm | grep "T do_sys_open" > > 801410f4 T do_sys_open > > $ expr `printf "%d + %d" 0x80008000 1282292` > > 2148798708 > > $ printf "%x\n" 2148798708 > > 801410f4 > > ----- > > So "_text+12882292" indicates do_sys_open on the target binary correctly. > > > > Signed-off-by: Masami Hiramatsu <mhira...@kernel.org> > > --- > > tools/perf/arch/arm/include/dwarf-regs-table.h | 9 +++ > > tools/perf/arch/arm64/include/dwarf-regs-table.h | 13 +++++ > > tools/perf/arch/powerpc/include/dwarf-regs-table.h | 27 ++++++++++ > > tools/perf/arch/s390/include/dwarf-regs-table.h | 8 +++ > > tools/perf/arch/sh/include/dwarf-regs-table.h | 25 +++++++++ > > tools/perf/arch/sparc/include/dwarf-regs-table.h | 18 +++++++ > > tools/perf/arch/x86/include/dwarf-regs-table.h | 14 +++++ > > tools/perf/arch/xtensa/include/dwarf-regs-table.h | 8 +++ > > tools/perf/util/Build | 1 > > tools/perf/util/dwarf-regs.c | 55 > > ++++++++++++++++++++ > > tools/perf/util/include/dwarf-regs.h | 6 ++ > > tools/perf/util/probe-finder.c | 27 ++++++---- > > tools/perf/util/probe-finder.h | 1 > > 13 files changed, 201 insertions(+), 11 deletions(-) > > create mode 100644 tools/perf/arch/arm/include/dwarf-regs-table.h > > create mode 100644 tools/perf/arch/arm64/include/dwarf-regs-table.h > > create mode 100644 tools/perf/arch/powerpc/include/dwarf-regs-table.h > > create mode 100644 tools/perf/arch/s390/include/dwarf-regs-table.h > > create mode 100644 tools/perf/arch/sh/include/dwarf-regs-table.h > > create mode 100644 tools/perf/arch/sparc/include/dwarf-regs-table.h > > create mode 100644 tools/perf/arch/x86/include/dwarf-regs-table.h > > create mode 100644 tools/perf/arch/xtensa/include/dwarf-regs-table.h > > create mode 100644 tools/perf/util/dwarf-regs.c > > > > diff --git a/tools/perf/arch/arm/include/dwarf-regs-table.h > > b/tools/perf/arch/arm/include/dwarf-regs-table.h > > new file mode 100644 > > index 0000000..f298d03 > > --- /dev/null > > +++ b/tools/perf/arch/arm/include/dwarf-regs-table.h > > @@ -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 > > diff --git a/tools/perf/arch/arm64/include/dwarf-regs-table.h > > b/tools/perf/arch/arm64/include/dwarf-regs-table.h > > new file mode 100644 > > index 0000000..2675936 > > --- /dev/null > > +++ b/tools/perf/arch/arm64/include/dwarf-regs-table.h > > @@ -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 > > diff --git a/tools/perf/arch/powerpc/include/dwarf-regs-table.h > > b/tools/perf/arch/powerpc/include/dwarf-regs-table.h > > new file mode 100644 > > index 0000000..db4730f > > --- /dev/null > > +++ b/tools/perf/arch/powerpc/include/dwarf-regs-table.h > > @@ -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 > > diff --git a/tools/perf/arch/s390/include/dwarf-regs-table.h > > b/tools/perf/arch/s390/include/dwarf-regs-table.h > > new file mode 100644 > > index 0000000..9da74a9 > > --- /dev/null > > +++ b/tools/perf/arch/s390/include/dwarf-regs-table.h > > @@ -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 > > diff --git a/tools/perf/arch/sh/include/dwarf-regs-table.h > > b/tools/perf/arch/sh/include/dwarf-regs-table.h > > new file mode 100644 > > index 0000000..3a2deaf > > --- /dev/null > > +++ b/tools/perf/arch/sh/include/dwarf-regs-table.h > > @@ -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 > > diff --git a/tools/perf/arch/sparc/include/dwarf-regs-table.h > > b/tools/perf/arch/sparc/include/dwarf-regs-table.h > > new file mode 100644 > > index 0000000..12c0761 > > --- /dev/null > > +++ b/tools/perf/arch/sparc/include/dwarf-regs-table.h > > @@ -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 > > diff --git a/tools/perf/arch/x86/include/dwarf-regs-table.h > > b/tools/perf/arch/x86/include/dwarf-regs-table.h > > new file mode 100644 > > index 0000000..39ac7cb > > --- /dev/null > > +++ b/tools/perf/arch/x86/include/dwarf-regs-table.h > > @@ -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", "$stack",/* Stack address instead of %sp */ > > + "%bp", "%si", "%di", > > +}; > > + > > +static const char * const x86_64_regstr_tbl[] = { > > + "%ax", "dx", "%cx", "%bx", "%si", "%di", > > + "%bp", "%sp", "%r8", "%r9", "%r10", "%r11", > > + "%r12", "%r13", "%r14", "%r15", > > +}; > > +#endif > > diff --git a/tools/perf/arch/xtensa/include/dwarf-regs-table.h > > b/tools/perf/arch/xtensa/include/dwarf-regs-table.h > > new file mode 100644 > > index 0000000..aa0444a > > --- /dev/null > > +++ b/tools/perf/arch/xtensa/include/dwarf-regs-table.h > > @@ -0,0 +1,8 @@ > > +#ifdef DEFINE_DWARF_REGSTR_TABLE > > +/* This is included in perf/util/dwarf-regs.c */ > > + > > +static const char * const xtensa_regstr_tbl[] = { > > + "a0", "a1", "a2", "a3", "a4", "a5", "a6", "a7", > > + "a8", "a9", "a10", "a11", "a12", "a13", "a14", "a15", > > +}; > > +#endif > > diff --git a/tools/perf/util/Build b/tools/perf/util/Build > > index 91c5f6e..f1a6d17 100644 > > --- a/tools/perf/util/Build > > +++ b/tools/perf/util/Build > > @@ -98,6 +98,7 @@ endif > > > > libperf-$(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 0000000..ce15816 > > --- /dev/null > > +++ b/tools/perf/util/dwarf-regs.c > > @@ -0,0 +1,55 @@ > > +/* > > + * dwarf-regs.c : Mapping of DWARF debug register numbers into register > > names. > > + * > > + * Written by: Masami Hiramatsu <mhira...@kernel.org> > > + */ > > + > > +#include <util.h> > > +#include <debug.h> > > +#include <dwarf-regs.h> > > +#include <elf.h> > > + > > +/* 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 07c644e..43bfd8d 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 ac4740f..508b61c 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 51137fc..f1d8558 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 */ > > }; -- Masami Hiramatsu <mhira...@kernel.org>