From f1617b40596cb341ee6602a9d969c5e4cebe9260 Mon Sep 17 00:00:00 2001 From: Arnaldo Carvalho de Melo Date: Wed, 18 Nov 2009 20:20:52 -0200 Subject: [PATCH] perf symbols: Record the build_ids of kernel modules too MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit [root@doppio linux-2.6-tip]# perf record -a sleep 2s;perf buildid-list|tail [ perf record: Woken up 1 times to write data ] [ perf record: Captured and wrote 0.162 MB perf.data (~7078 samples) ] 881588fa57b3c1696bc91e5e804a11304f093535 [cfg80211] 4d47ce1da9d16bad00c962c072451b7c681e82df [snd_page_alloc] 5146377e89a7caac617f9782f1a02e46263d3a31 [rfkill] 2153b937bff0d345fea83b63a2e1d3138569f83d [i915] 4e6fb1bb97362e3ee4d306988b9ad6912d5fb9ae [drm_kms_helper] f56ef2bf853e3a798f0d8d51f797622e5dc4420e [drm] b0d157a3b5c4e017329ffc07c64623cd6ad65e95 [i2c_algo_bit] 8125374b905ef9fa8b65d98e166b008ad952f198 [i2c_core] fc875c6e5a90e7b915e9d445d0efc859e1b2678c [video] 4b43c5006589f977e9762fdfc7ac1a92b72fca52 [output] [root@doppio linux-2.6-tip]# elfutils libdwfl/linux-kernel-modules.c was used as reference, as suggested by Roland McGrath. Signed-off-by: Arnaldo Carvalho de Melo Cc: Roland McGrath Cc: Frédéric Weisbecker Cc: Mike Galbraith Cc: Peter Zijlstra Cc: Paul Mackerras LKML-Reference: <1258582853-8579-3-git-send-email-acme@infradead.org> Signed-off-by: Ingo Molnar --- tools/perf/util/header.c | 5 ++++ tools/perf/util/symbol.c | 53 +++++++++++++++++++++++++++++++++++++++- tools/perf/util/symbol.h | 2 ++ 3 files changed, 59 insertions(+), 1 deletion(-) diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c index 31731f1606b2..d3d656f9a621 100644 --- a/tools/perf/util/header.c +++ b/tools/perf/util/header.c @@ -241,6 +241,11 @@ perf_header__adds_write(struct perf_header *self, int fd) buildid_sec = &feat_sec[idx++]; + /* + * Read the list of loaded modules with its build_ids + */ + dsos__load_modules(); + /* Write build-ids */ buildid_sec->offset = lseek(fd, 0, SEEK_CUR); if (dsos__write_buildid_table(fd) < 0) diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c index 946ec319568b..7b4cedeb3020 100644 --- a/tools/perf/util/symbol.c +++ b/tools/perf/util/symbol.c @@ -9,6 +9,7 @@ #include #include #include +#include #include enum dso_origin { @@ -943,6 +944,50 @@ out: return err; } +int sysfs__read_build_id(const char *filename, void *build_id, size_t size) +{ + int fd, err = -1; + + if (size < BUILD_ID_SIZE) + goto out; + + fd = open(filename, O_RDONLY); + if (fd < 0) + goto out; + + while (1) { + char bf[BUFSIZ]; + GElf_Nhdr nhdr; + int namesz, descsz; + + if (read(fd, &nhdr, sizeof(nhdr)) != sizeof(nhdr)) + break; + + namesz = (nhdr.n_namesz + 3) & -4U; + descsz = (nhdr.n_descsz + 3) & -4U; + if (nhdr.n_type == NT_GNU_BUILD_ID && + nhdr.n_namesz == sizeof("GNU")) { + if (read(fd, bf, namesz) != namesz) + break; + if (memcmp(bf, "GNU", sizeof("GNU")) == 0) { + if (read(fd, build_id, + BUILD_ID_SIZE) == BUILD_ID_SIZE) { + err = 0; + break; + } + } else if (read(fd, bf, descsz) != descsz) + break; + } else { + int n = namesz + descsz; + if (read(fd, bf, n) != n) + break; + } + } + close(fd); +out: + return err; +} + char dso__symtab_origin(const struct dso *self) { static const char origin[] = { @@ -1218,7 +1263,7 @@ static struct map *map__new2(u64 start, struct dso *dso) return self; } -static int dsos__load_modules(void) +int dsos__load_modules(void) { char *line = NULL; size_t n; @@ -1268,6 +1313,12 @@ static int dsos__load_modules(void) goto out_delete_line; } + snprintf(name, sizeof(name), + "/sys/module/%s/notes/.note.gnu.build-id", line); + if (sysfs__read_build_id(name, dso->build_id, + sizeof(dso->build_id)) == 0) + dso->has_build_id = true; + dso->origin = DSO__ORIG_KMODULE; kernel_maps__insert(map); dsos__add(dso); diff --git a/tools/perf/util/symbol.h b/tools/perf/util/symbol.h index 546eb766d81e..da7ec1af255a 100644 --- a/tools/perf/util/symbol.h +++ b/tools/perf/util/symbol.h @@ -78,6 +78,7 @@ void dso__delete(struct dso *self); struct symbol *dso__find_symbol(struct dso *self, u64 ip); int dsos__load_kernel(const char *vmlinux, symbol_filter_t filter, int modules); +int dsos__load_modules(void); struct dso *dsos__findnew(const char *name); int dso__load(struct dso *self, struct map *map, symbol_filter_t filter); void dsos__fprintf(FILE *fp); @@ -89,6 +90,7 @@ char dso__symtab_origin(const struct dso *self); void dso__set_build_id(struct dso *self, void *build_id); int filename__read_build_id(const char *filename, void *bf, size_t size); +int sysfs__read_build_id(const char *filename, void *bf, size_t size); bool dsos__read_build_ids(void); int build_id__sprintf(u8 *self, int len, char *bf); -- 2.30.2