From f1dfa0b1c1a90d4d3bf515ab04a6b6222e086293 Mon Sep 17 00:00:00 2001 From: Arnaldo Carvalho de Melo Date: Fri, 11 Dec 2009 14:50:39 -0200 Subject: [PATCH] perf symbols: Add support for 'variable' symtabs MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Example: { u64 addr = strtoull(sym_filter, NULL, 16); struct map *map = map_groups__find(kmaps, MAP__VARIABLE, addr); if (map == NULL) pr_err("couldn't find map!\n"); else { struct symbol *sym = map__find_symbol(map, addr, NULL); if (sym == NULL) pr_err("couldn't find addr!\n"); else pr_info("addr %#Lx is in %s global var\n", addr, sym->name); } exit(0); } Added just after symbol__init() call in 'perf top', then: { u64 addr = strtoull(sym_filter, NULL, 16); struct map *map = map_groups__find(kmaps, MAP__VARIABLE, addr); if (map == NULL) pr_err("couldn't find map!\n"); else { struct symbol *sym = map__find_symbol(map, addr, NULL); if (sym == NULL) pr_err("couldn't find addr!\n"); else pr_info("addr %#Lx is in %s global var\n", addr, sym->name); } exit(0); } [root@doppio linux-2.6-tip]# grep ' [dD] ' /proc/kallsyms | grep ' sched' ffffffff817827d8 d sched_nr_latency ffffffff81782ce0 d sched_domains_mutex ffffffff8178c070 d schedstr.22423 ffffffff817909a0 d sched_register_mutex ffffffff81823490 d sched_feat_names ffffffff81823558 d scheduler_running ffffffff818235b8 d sched_clock_running ffffffff818235bc D sched_clock_stable ffffffff81824f00 d sched_switch_trace [root@doppio linux-2.6-tip]# perf top -s 0xffffffff817827d9 addr 0xffffffff817827d9 is in sched_nr_latency global var [root@doppio linux-2.6-tip]# perf top -s ffffffff81782ce0 addr 0xffffffff81782ce0 is in sched_domains_mutex global var [root@doppio linux-2.6-tip]# [root@doppio linux-2.6-tip]# perf top -s ffffffff81782ce0 --vmlinux OFF The file OFF cannot be used, trying to use /proc/kallsyms...addr 0xffffffff81782ce0 is in sched_domains_mutex global var [root@doppio linux-2.6-tip]# perf top -s ffffffff818235bc --vmlinux OFF The file OFF cannot be used, trying to use /proc/kallsyms...addr 0xffffffff818235bc is in sched_clock_stable global var [root@doppio linux-2.6-tip]# So it works with both /proc/kallsyms and with ELF symtabs, either the one on the vmlinux explicitely passed via --vmlinux or in one in the vmlinux_path that matches the buildid for the running kernel or the one found in the buildid header section in a perf.data file. Signed-off-by: Arnaldo Carvalho de Melo Cc: Frédéric Weisbecker Cc: Mike Galbraith Cc: Peter Zijlstra Cc: Paul Mackerras LKML-Reference: <1260550239-5372-4-git-send-email-acme@infradead.org> Signed-off-by: Ingo Molnar --- tools/perf/util/event.h | 3 ++- tools/perf/util/symbol.c | 66 +++++++++++++++++++++++++++++++++++++----------- 2 files changed, 53 insertions(+), 16 deletions(-) diff --git a/tools/perf/util/event.h b/tools/perf/util/event.h index d9a65d91e925..56640946b5a9 100644 --- a/tools/perf/util/event.h +++ b/tools/perf/util/event.h @@ -103,9 +103,10 @@ void event__print_totals(void); enum map_type { MAP__FUNCTION = 0, + MAP__VARIABLE, }; -#define MAP__NR_TYPES (MAP__FUNCTION + 1) +#define MAP__NR_TYPES (MAP__VARIABLE + 1) struct map { union { diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c index db8dc97b548b..e63ddb469de7 100644 --- a/tools/perf/util/symbol.c +++ b/tools/perf/util/symbol.c @@ -61,6 +61,8 @@ static bool symbol_type__is_a(char symbol_type, enum map_type map_type) switch (map_type) { case MAP__FUNCTION: return symbol_type == 'T' || symbol_type == 'W'; + case MAP__VARIABLE: + return symbol_type == 'D' || symbol_type == 'd'; default: return false; } @@ -551,6 +553,13 @@ static inline int elf_sym__is_function(const GElf_Sym *sym) sym->st_shndx != SHN_UNDEF; } +static inline bool elf_sym__is_object(const GElf_Sym *sym) +{ + return elf_sym__type(sym) == STT_OBJECT && + sym->st_name != 0 && + sym->st_shndx != SHN_UNDEF; +} + static inline int elf_sym__is_label(const GElf_Sym *sym) { return elf_sym__type(sym) == STT_NOTYPE && @@ -571,6 +580,12 @@ static inline int elf_sec__is_text(const GElf_Shdr *shdr, return strstr(elf_sec__name(shdr, secstrs), "text") != NULL; } +static inline bool elf_sec__is_data(const GElf_Shdr *shdr, + const Elf_Data *secstrs) +{ + return strstr(elf_sec__name(shdr, secstrs), "data") != NULL; +} + static inline const char *elf_sym__name(const GElf_Sym *sym, const Elf_Data *symstrs) { @@ -756,6 +771,8 @@ static bool elf_sym__is_a(GElf_Sym *self, enum map_type type) switch (type) { case MAP__FUNCTION: return elf_sym__is_function(self); + case MAP__VARIABLE: + return elf_sym__is_object(self); default: return false; } @@ -766,6 +783,8 @@ static bool elf_sec__is_a(GElf_Shdr *self, Elf_Data *secstrs, enum map_type type switch (type) { case MAP__FUNCTION: return elf_sec__is_text(self, secstrs); + case MAP__VARIABLE: + return elf_sec__is_data(self, secstrs); default: return false; } @@ -1536,42 +1555,59 @@ size_t dsos__fprintf_buildid(FILE *fp) __dsos__fprintf_buildid(&dsos__user, fp)); } -static int map_groups__create_kernel_map(struct map_groups *self, const char *vmlinux) +static struct dso *dsos__create_kernel( const char *vmlinux) { - struct map *kmap; struct dso *kernel = dso__new(vmlinux ?: "[kernel.kallsyms]"); if (kernel == NULL) - return -1; - - kmap = map__new2(0, kernel, MAP__FUNCTION); - if (kmap == NULL) - goto out_delete_kernel_dso; + return NULL; - kmap->map_ip = kmap->unmap_ip = identity__map_ip; kernel->short_name = "[kernel]"; kernel->kernel = 1; vdso = dso__new("[vdso]"); if (vdso == NULL) - goto out_delete_kernel_map; + goto out_delete_kernel_dso; dso__set_loaded(vdso, MAP__FUNCTION); if (sysfs__read_build_id("/sys/kernel/notes", kernel->build_id, sizeof(kernel->build_id)) == 0) kernel->has_build_id = true; - map_groups__insert(self, kmap); dsos__add(&dsos__kernel, kernel); dsos__add(&dsos__user, vdso); - return 0; + return kernel; -out_delete_kernel_map: - map__delete(kmap); out_delete_kernel_dso: dso__delete(kernel); - return -1; + return NULL; +} + +static int map_groups__create_kernel_maps(struct map_groups *self, const char *vmlinux) +{ + struct map *functions, *variables; + struct dso *kernel = dsos__create_kernel(vmlinux); + + if (kernel == NULL) + return -1; + + functions = map__new2(0, kernel, MAP__FUNCTION); + if (functions == NULL) + return -1; + + variables = map__new2(0, kernel, MAP__VARIABLE); + if (variables == NULL) { + map__delete(functions); + return -1; + } + + functions->map_ip = functions->unmap_ip = + variables->map_ip = variables->unmap_ip = identity__map_ip; + map_groups__insert(self, functions); + map_groups__insert(self, variables); + + return 0; } static void vmlinux_path__exit(void) @@ -1640,7 +1676,7 @@ int symbol__init(struct symbol_conf *conf) if (pconf->try_vmlinux_path && vmlinux_path__init() < 0) return -1; - if (map_groups__create_kernel_map(kmaps, pconf->vmlinux_name) < 0) { + if (map_groups__create_kernel_maps(kmaps, pconf->vmlinux_name) < 0) { vmlinux_path__exit(); return -1; } -- 2.11.0