Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757530Ab0BCSw6 (ORCPT ); Wed, 3 Feb 2010 13:52:58 -0500 Received: from casper.infradead.org ([85.118.1.10]:53465 "EHLO casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756565Ab0BCSwf (ORCPT ); Wed, 3 Feb 2010 13:52:35 -0500 From: Arnaldo Carvalho de Melo To: Ingo Molnar Cc: linux-kernel@vger.kernel.org, Kirill Smelkov , Mike Galbraith , Arnaldo Carvalho de Melo Subject: [PATCH 8/9] perf annotate: fix it for non-prelinked *.so Date: Wed, 3 Feb 2010 16:52:07 -0200 Message-Id: <1265223128-11786-8-git-send-email-acme@infradead.org> X-Mailer: git-send-email 1.6.2.5 In-Reply-To: <1265223128-11786-1-git-send-email-acme@infradead.org> References: <1265223128-11786-1-git-send-email-acme@infradead.org> X-SRS-Rewrite: SMTP reverse-path rewritten from by casper.infradead.org See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4349 Lines: 133 From: Kirill Smelkov 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. Cc: Mike Galbraith Signed-off-by: Kirill Smelkov Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/builtin-annotate.c | 5 +++-- tools/perf/util/map.c | 12 ++++++++++++ tools/perf/util/map.h | 9 +++++++++ 3 files changed, 24 insertions(+), 2 deletions(-) diff --git a/tools/perf/builtin-annotate.c b/tools/perf/builtin-annotate.c index 4fc3899..28ea4e0 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 f6626cc..af5805f 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 de04839..9cee9c7 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; -- 1.6.2.5 -- 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/