Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752856Ab3JSP14 (ORCPT ); Sat, 19 Oct 2013 11:27:56 -0400 Received: from mail4.hitachi.co.jp ([133.145.228.5]:53227 "EHLO mail4.hitachi.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751299Ab3JSP1y (ORCPT ); Sat, 19 Oct 2013 11:27:54 -0400 Message-ID: <5262A4F6.3000609@hitachi.com> Date: Sun, 20 Oct 2013 00:27:50 +0900 From: Masami Hiramatsu Organization: Hitachi, Ltd., Japan User-Agent: Mozilla/5.0 (Windows NT 5.2; rv:13.0) Gecko/20120614 Thunderbird/13.0.1 MIME-Version: 1.0 To: Hemant Kumar Cc: linux-kernel@vger.kernel.org, srikar@linux.vnet.ibm.com, peterz@infradead.org, oleg@redhat.com, hegdevasant@linux.vnet.ibm.com, mingo@redhat.com, anton@redhat.com, systemtap@sourceware.org, namhyung@kernel.org, aravinda@linux.vnet.ibm.com Subject: Re: [PATCH v3 1/3] SDT markers listing by perf: References: <20131018143714.10452.83494.stgit@hemant-fedora> <20131018144231.10452.65885.stgit@hemant-fedora> In-Reply-To: <20131018144231.10452.65885.stgit@hemant-fedora> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 13739 Lines: 466 (2013/10/18 23:44), Hemant Kumar wrote: > This patch will enable perf to list all the sdt markers present > in an elf file. The markers are present in the .note.stapsdt section > of the elf. We can traverse through this section and collect the > required info about the markers. > We can use '-M/--markers' with perf to view the SDT notes. > > Currently, the sdt notes which have their semaphores enabled, are being > ignored silently. But, they will be supported soon. > > Wrapping this inside #ifdef LIBELF_SUPPORT pair is not required, > because, if NO_LIBELF = 1, then 'probe' command of perf is itself disabled. > > Usage: > perf probe --markers -x /lib64/libc.so.6 > > Output : > %libc:setjmp > %libc:longjmp > %libc:longjmp_target > %libc:lll_futex_wake > %libc:lll_lock_wait_private > %libc:longjmp > %libc:longjmp_target > %libc:lll_futex_wake > > Signed-off-by: Hemant Kumar Shaw > --- > tools/perf/builtin-probe.c | 41 ++++++++ > tools/perf/util/probe-event.c | 35 +++++++ > tools/perf/util/probe-event.h | 1 > tools/perf/util/symbol-elf.c | 211 +++++++++++++++++++++++++++++++++++++++++ > tools/perf/util/symbol.h | 18 +++ > 5 files changed, 304 insertions(+), 2 deletions(-) > > diff --git a/tools/perf/builtin-probe.c b/tools/perf/builtin-probe.c > index 89acc17..2450613 100644 > --- a/tools/perf/builtin-probe.c > +++ b/tools/perf/builtin-probe.c > @@ -55,6 +55,8 @@ static struct { > bool show_funcs; > bool mod_events; > bool uprobes; > + bool exec; > + bool sdt; > int nevents; > struct perf_probe_event events[MAX_PROBES]; > struct strlist *dellist; > @@ -171,8 +173,10 @@ static int opt_set_target(const struct option *opt, const char *str, > int ret = -ENOENT; > > if (str && !params.target) { > - if (!strcmp(opt->long_name, "exec")) > + if (!strcmp(opt->long_name, "exec")) { > params.uprobes = true; > + params.exec = true; > + } > #ifdef HAVE_DWARF_SUPPORT > else if (!strcmp(opt->long_name, "module")) > params.uprobes = false; > @@ -325,6 +329,7 @@ int cmd_probe(int argc, const char **argv, const char *prefix __maybe_unused) > opt_set_filter), > OPT_CALLBACK('x', "exec", NULL, "executable|path", > "target executable name or path", opt_set_target), > + OPT_BOOLEAN('M', "markers", ¶ms.sdt, "Show proba-able sdt notes"), > OPT_END() > }; > int ret; > @@ -347,7 +352,7 @@ int cmd_probe(int argc, const char **argv, const char *prefix __maybe_unused) > params.max_probe_points = MAX_PROBES; > > if ((!params.nevents && !params.dellist && !params.list_events && > - !params.show_lines && !params.show_funcs)) > + !params.show_lines && !params.show_funcs && !params.sdt)) > usage_with_options(probe_usage, options); > > /* > @@ -355,6 +360,38 @@ int cmd_probe(int argc, const char **argv, const char *prefix __maybe_unused) > */ > symbol_conf.try_vmlinux_path = (symbol_conf.vmlinux_name == NULL); > > + if (params.sdt) { > + if (params.show_lines) { > + pr_err("Error: Don't use --markers with --lines.\n"); > + usage_with_options(probe_usage, options); > + } > + if (params.show_vars) { > + pr_err("Error: Don't use --markers with --vars.\n"); > + usage_with_options(probe_usage, options); > + } > + if (params.show_funcs) { > + pr_err("Error: Don't use --markers with --funcs.\n"); > + usage_with_options(probe_usage, options); > + } > + if (params.mod_events) { > + pr_err("Error: Don't use --markers with --add/--del.\n"); > + usage_with_options(probe_usage, options); > + } > + if (!params.exec) { > + pr_err("Error: Always use --exec with --markers.\n"); > + usage_with_options(probe_usage, options); > + } > + if (!params.target) { > + pr_err("Error: Please specify a target binary!\n"); > + usage_with_options(probe_usage, options); > + } > + ret = show_sdt_notes(params.target); > + if (ret < 0) { > + pr_err(" Error : Failed to find SDT markers in %s !" > + " (%d)\n", params.target, ret); > + } > + return ret; > + } > if (params.list_events) { > if (params.mod_events) { > pr_err(" Error: Don't use --list with --add/--del.\n"); > diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c > index 779b2da..c228fe6 100644 > --- a/tools/perf/util/probe-event.c > +++ b/tools/perf/util/probe-event.c > @@ -1909,6 +1909,18 @@ static int __add_probe_trace_events(struct perf_probe_event *pev, > return ret; > } > > +static void cleanup_sdt_note_list(struct list_head *sdt_notes) > +{ > + struct sdt_note *tmp, *pos; > + > + list_for_each_entry_safe(pos, tmp, sdt_notes, note_list) { > + list_del(&pos->note_list); > + free(pos->name); > + free(pos->provider); > + free(pos); > + } > +} > + > static int convert_to_probe_trace_events(struct perf_probe_event *pev, > struct probe_trace_event **tevs, > int max_tevs, const char *target) > @@ -2372,3 +2384,26 @@ out: > free(name); > return ret; > } > + > +static void display_sdt_note_info(struct list_head *start) > +{ > + struct sdt_note *pos; > + > + list_for_each_entry(pos, start, note_list) { > + printf("%%%s:%s\n", pos->provider, pos->name); > + } > +} > + > +int show_sdt_notes(const char *target) > +{ > + int ret; > + LIST_HEAD(sdt_notes); > + > + ret = get_sdt_note_list(&sdt_notes, target); > + if (!list_empty(&sdt_notes)) { > + if (!ret) Hmm, why don't you check the ret first? And I think the empty check should be done in display_sdt_note_info() and cleanup_sdt_note_list() (anyway, since both uses list_for_each*() it is already done). > + display_sdt_note_info(&sdt_notes); > + cleanup_sdt_note_list(&sdt_notes); > + } > + return ret; > +} Others are good for me. :) Thank you! > diff --git a/tools/perf/util/probe-event.h b/tools/perf/util/probe-event.h > index f9f3de8..32de5a3 100644 > --- a/tools/perf/util/probe-event.h > +++ b/tools/perf/util/probe-event.h > @@ -133,6 +133,7 @@ extern int show_available_vars(struct perf_probe_event *pevs, int npevs, > struct strfilter *filter, bool externs); > extern int show_available_funcs(const char *module, struct strfilter *filter, > bool user); > +int show_sdt_notes(const char *target); > > /* Maximum index number of event-name postfix */ > #define MAX_EVENT_INDEX 1024 > diff --git a/tools/perf/util/symbol-elf.c b/tools/perf/util/symbol-elf.c > index eed0b96..828ecad 100644 > --- a/tools/perf/util/symbol-elf.c > +++ b/tools/perf/util/symbol-elf.c > @@ -1613,6 +1613,217 @@ void kcore_extract__delete(struct kcore_extract *kce) > unlink(kce->extract_filename); > } > > +/* > + * Populate the name, type, offset in the SDT note structure and > + * ignore the argument fields (for now) > + */ > +static int populate_sdt_note(Elf **elf, const char *data, size_t len, int type, > + struct sdt_note **note) > +{ > + const char *provider, *name; > + struct sdt_note *tmp = NULL; > + int ret = -1; > + > + /* > + * Three addresses need to be obtained : > + * Marker location, address of base section and semaphore location > + */ > + union { > + Elf64_Addr a64[3]; > + Elf32_Addr a32[3]; > + } buf; > + > + /* > + * dst and src are required for translation from file to memory > + * representation > + */ > + Elf_Data dst = { > + .d_buf = &buf, .d_type = ELF_T_ADDR, .d_version = EV_CURRENT, > + .d_size = gelf_fsize((*elf), ELF_T_ADDR, 3, EV_CURRENT), > + .d_off = 0, .d_align = 0 > + }; > + > + Elf_Data src = { > + .d_buf = (void *) data, .d_type = ELF_T_ADDR, > + .d_version = EV_CURRENT, .d_size = dst.d_size, .d_off = 0, > + .d_align = 0 > + }; > + > + /* Check the type of each of the notes */ > + if (type != SDT_NOTE_TYPE) > + goto out_err; > + > + tmp = (struct sdt_note *)zalloc(sizeof(struct sdt_note)); > + if (tmp == NULL) { > + ret = -ENOMEM; > + goto out_err; > + } > + INIT_LIST_HEAD(&tmp->note_list); > + > + if (len < dst.d_size + 3) > + goto out_free_note; > + > + /* Translation from file representation to memory representation */ > + if (gelf_xlatetom(*elf, &dst, &src, > + elf_getident(*elf, NULL)[EI_DATA]) == NULL) > + pr_debug("gelf_xlatetom : %s", elf_errmsg(-1)); > + > + /* Populate the fields of sdt_note */ > + provider = data + dst.d_size; > + > + name = (const char *)memchr(provider, '\0', data + len - provider); > + if (name++ == NULL) > + goto out_free_note; > + tmp->provider = strdup(provider); > + if (!tmp->provider) { > + ret = -ENOMEM; > + goto out_free_note; > + } > + tmp->name = strdup(name); > + if (!tmp->name) { > + ret = -ENOMEM; > + goto out_free_prov; > + } > + > + /* Obtain the addresses and ignore notes with semaphores set*/ > + if (gelf_getclass(*elf) == ELFCLASS32) { > + if (buf.a32[2] != 0) > + goto out_free_name; > + tmp->addr.a32[0] = buf.a32[0]; > + tmp->addr.a32[1] = buf.a32[1]; > + tmp->addr.a32[2] = buf.a32[2]; > + tmp->bit32 = true; > + } else { > + if (buf.a64[2] != 0) > + goto out_free_name; > + tmp->addr.a64[0] = buf.a64[0]; > + tmp->addr.a64[1] = buf.a64[1]; > + tmp->addr.a64[2] = buf.a64[2]; > + tmp->bit32 = false; > + } > + *note = tmp; > + return 0; > + > +out_free_name: > + free(tmp->name); > +out_free_prov: > + free(tmp->provider); > +out_free_note: > + free(tmp); > +out_err: > + return ret; > +} > + > +static int construct_sdt_notes_list(Elf *elf, struct list_head *sdt_notes) > +{ > + GElf_Ehdr ehdr; > + Elf_Scn *scn = NULL; > + Elf_Data *data; > + GElf_Shdr shdr; > + size_t shstrndx; > + size_t next; > + GElf_Nhdr nhdr; > + size_t name_off, desc_off, offset; > + struct sdt_note *tmp = NULL; > + int ret = 0, val = 0; > + > + if (gelf_getehdr(elf, &ehdr) == NULL) { > + ret = -EBADF; > + pr_debug("Can't get elf header!"); > + goto out_ret; > + } > + if (elf_getshdrstrndx(elf, &shstrndx) != 0) { > + ret = -EBADF; > + pr_debug("getshdrstrndx failed\n"); > + goto out_ret; > + } > + > + /* > + * Look for section type = SHT_NOTE, flags = no SHF_ALLOC > + * and name = .note.stapsdt > + */ > + scn = elf_section_by_name(elf, &ehdr, &shdr, SDT_NOTE_SCN, NULL); > + if (!scn) { > + ret = -ENOENT; > + pr_debug("Can't get section .note.stapsdt\n"); > + goto out_ret; > + } > + if (!(shdr.sh_type == SHT_NOTE) || (shdr.sh_flags & SHF_ALLOC)) { > + ret = -ENOENT; > + goto out_ret; > + } > + > + data = elf_getdata(scn, NULL); > + > + /* Get the SDT notes */ > + for (offset = 0; (next = gelf_getnote(data, offset, &nhdr, &name_off, > + &desc_off)) > 0; offset = next) { > + if (nhdr.n_namesz == sizeof(SDT_NOTE_NAME) && > + !memcmp(data->d_buf + name_off, SDT_NOTE_NAME, > + sizeof(SDT_NOTE_NAME))) { > + val = populate_sdt_note(&elf, ((data->d_buf) + desc_off), > + nhdr.n_descsz, nhdr.n_type, > + &tmp); > + if (!val) > + list_add_tail(&tmp->note_list, sdt_notes); > + if (val == -ENOMEM) { > + ret = -ENOMEM; > + goto out_ret; > + } > + } > + } > + if (!sdt_notes) > + ret = -ENOENT; > + > +out_ret: > + return ret; > +} > + > +static int sdt_err(int val, const char *target) > +{ > + switch (-val) { > + case 0: > + break; > + case ENOENT: > + /* Absence of SDT markers isn't an error */ > + val = 0; > + printf("%s : No SDT markers found!\n", target); > + break; > + case EBADF: > + pr_err("%s : Bad file name\n", target); > + break; > + default: > + pr_err("%s\n", strerror(val)); > + } > + return val; > +} > + > +int get_sdt_note_list(struct list_head *head, const char *target) > +{ > + Elf *elf; > + int fd, ret; > + > + fd = open(target, O_RDONLY); > + if (fd < 0) { > + pr_err("%s : %s\n", target, strerror(errno)); > + return -errno; > + } > + > + symbol__elf_init(); > + elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL); > + if (!elf) { > + ret = -EBADF; > + pr_debug("%s : %s\n", target, elf_errmsg(elf_errno())); > + goto out_close; > + } > + ret = construct_sdt_notes_list(elf, head); > + elf_end(elf); > + > +out_close: > + close(fd); > + return sdt_err(ret, target); > +} > + > void symbol__elf_init(void) > { > elf_version(EV_CURRENT); > diff --git a/tools/perf/util/symbol.h b/tools/perf/util/symbol.h > index 07de8fe..b78397b 100644 > --- a/tools/perf/util/symbol.h > +++ b/tools/perf/util/symbol.h > @@ -198,6 +198,17 @@ struct symsrc { > #endif > }; > > +struct sdt_note { > + char *name; > + char *provider; > + bool bit32; /* 32 or 64 bit flag */ > + union { > + Elf64_Addr a64[3]; > + Elf32_Addr a32[3]; > + } addr; > + struct list_head note_list; > +}; > + > void symsrc__destroy(struct symsrc *ss); > int symsrc__init(struct symsrc *ss, struct dso *dso, const char *name, > enum dso_binary_type type); > @@ -273,4 +284,11 @@ void kcore_extract__delete(struct kcore_extract *kce); > int kcore_copy(const char *from_dir, const char *to_dir); > int compare_proc_modules(const char *from, const char *to); > > +/* Specific to SDT notes */ > +int get_sdt_note_list(struct list_head *head, const char *target); > + > +#define SDT_NOTE_TYPE 3 > +#define SDT_NOTE_SCN ".note.stapsdt" > +#define SDT_NOTE_NAME "stapsdt" > + > #endif /* __PERF_SYMBOL */ > > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ > -- Masami HIRAMATSU IT Management Research Dept. Linux Technology Center Hitachi, Ltd., Yokohama Research Laboratory E-mail: masami.hiramatsu.pt@hitachi.com -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/