From: Kirill Smelkov Date: Wed, 3 Feb 2010 18:52:07 +0000 (-0200) Subject: perf annotate: Fix it for non-prelinked *.so X-Git-Tag: v2.6.34-rc1~197^2~53 X-Git-Url: https://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=7a2b6209863626cf8362e5ff4653491558f91e67;p=pandora-kernel.git perf annotate: Fix it for non-prelinked *.so The problem was we were incorrectly calculating objdump addresses for sym->start and sym->end, look: For simple ET_DYN type DSO (*.so) with one function, objdump -dS output is something like this: 000004ac : int my_strlen(const char *s) 4ac: 55 push %ebp 4ad: 89 e5 mov %esp,%ebp 4af: 83 ec 10 sub $0x10,%esp { i.e. we have relative-to-dso-mapping IPs (=RIP) there. For ET_EXEC type and probably for prelinked libs as well (sorry can't test - I don't use prelink) objdump outputs absolute IPs, e.g. 08048604 : extern "C" int zz_strlen(const char *s) 8048604: 55 push %ebp 8048605: 89 e5 mov %esp,%ebp 8048607: 83 ec 10 sub $0x10,%esp { So, if sym->start is always relative to dso mapping(*), we'll have to unmap it for ET_EXEC like cases, and leave as is for ET_DYN cases. (*) and it is - we've explicitely made it relative. Look for adjust_symbols handling in dso__load_sym() Previously we were always unmapping sym->start and for ET_DYN dsos resulting addresses were wrong, and so objdump output was empty. The end result was that perf annotate output for symbols from non-prelinked *.so had always 0.00% percents only, which is wrong. To fix it, let's introduce a helper for converting rip to objdump address, and also let's document what map_ip() and unmap_ip() do -- I had to study sources for several hours to understand it. Signed-off-by: Kirill Smelkov Signed-off-by: Arnaldo Carvalho de Melo Cc: Mike Galbraith LKML-Reference: <1265223128-11786-8-git-send-email-acme@infradead.org> Signed-off-by: Ingo Molnar --- diff --git a/tools/perf/builtin-annotate.c b/tools/perf/builtin-annotate.c index 4fc3899bf83a..28ea4e0c3658 100644 --- a/tools/perf/builtin-annotate.c +++ b/tools/perf/builtin-annotate.c @@ -189,7 +189,7 @@ static int parse_line(FILE *file, struct hist_entry *he, u64 len) line_ip = -1; } - start = he->map->unmap_ip(he->map, sym->start); + start = map__rip_2objdump(he->map, sym->start); if (line_ip != -1) { const char *path = NULL; @@ -397,7 +397,8 @@ static void annotate_sym(struct hist_entry *he) dso, dso->long_name, sym, sym->name); sprintf(command, "objdump --start-address=0x%016Lx --stop-address=0x%016Lx -dS %s|grep -v %s", - map->unmap_ip(map, sym->start), map->unmap_ip(map, sym->end), + map__rip_2objdump(map, sym->start), + map__rip_2objdump(map, sym->end), filename, filename); if (verbose >= 3) diff --git a/tools/perf/util/map.c b/tools/perf/util/map.c index f6626cc3df2e..af5805f51314 100644 --- a/tools/perf/util/map.c +++ b/tools/perf/util/map.c @@ -210,3 +210,15 @@ size_t map__fprintf(struct map *self, FILE *fp) return fprintf(fp, " %Lx-%Lx %Lx %s\n", self->start, self->end, self->pgoff, self->dso->name); } + +/* + * objdump wants/reports absolute IPs for ET_EXEC, and RIPs for ET_DYN. + * map->dso->adjust_symbols==1 for ET_EXEC-like cases. + */ +u64 map__rip_2objdump(struct map *map, u64 rip) +{ + u64 addr = map->dso->adjust_symbols ? + map->unmap_ip(map, rip) : /* RIP -> IP */ + rip; + return addr; +} diff --git a/tools/perf/util/map.h b/tools/perf/util/map.h index de048399d776..9cee9c788dbf 100644 --- a/tools/perf/util/map.h +++ b/tools/perf/util/map.h @@ -26,8 +26,12 @@ struct map { u64 end; enum map_type type; u64 pgoff; + + /* ip -> dso rip */ u64 (*map_ip)(struct map *, u64); + /* dso rip -> ip */ u64 (*unmap_ip)(struct map *, u64); + struct dso *dso; }; @@ -56,6 +60,11 @@ static inline u64 identity__map_ip(struct map *map __used, u64 ip) return ip; } + +/* rip -> addr suitable for passing to `objdump --start-address=` */ +u64 map__rip_2objdump(struct map *map, u64 rip); + + struct symbol; struct mmap_event;