From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751010AbcFXGnu (ORCPT ); Fri, 24 Jun 2016 02:43:50 -0400 Received: from mx1.redhat.com ([209.132.183.28]:47797 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750833AbcFXGnt (ORCPT ); Fri, 24 Jun 2016 02:43:49 -0400 Date: Fri, 24 Jun 2016 08:43:45 +0200 From: Jiri Olsa To: Marc Kleine-Budde Cc: Peter Zijlstra , Ingo Molnar , linux-kernel@vger.kernel.org, Jiri Olsa Subject: Re: [PATCH] perf: symbols: dso__load(): remove check of file on uninitialized memory Message-ID: <20160624064345.GB32753@krava> References: <1466691621-29488-1-git-send-email-mkl@pengutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1466691621-29488-1-git-send-email-mkl@pengutronix.de> User-Agent: Mutt/1.6.1 (2016-04-27) X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.28]); Fri, 24 Jun 2016 06:43:48 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jun 23, 2016 at 04:20:21PM +0200, Marc Kleine-Budde wrote: > In commit "403567217d3f perf symbols: Do not read symbols/data from > device files" a check to uninitialzied memory was added. This leads to > the following valgrind output: > > ==24515== Syscall param stat(file_name) points to uninitialised byte(s) > ==24515== at 0x75B26D5: _xstat (in /lib/x86_64-linux-gnu/libc-2.22.so) > ==24515== by 0x4E548D: stat (stat.h:454) > ==24515== by 0x4E548D: is_regular_file (util.c:687) > ==24515== by 0x4A5BEE: dso__load (symbol.c:1435) > ==24515== by 0x4BB1AE: map__load (map.c:289) > ==24515== by 0x4BB1AE: map__find_symbol (map.c:333) > ==24515== by 0x4835B3: thread__find_addr_location (event.c:1300) > ==24515== by 0x4B5342: add_callchain_ip (machine.c:1652) > ==24515== by 0x4B5342: thread__resolve_callchain_sample (machine.c:1906) > ==24515== by 0x4B9E7D: thread__resolve_callchain (machine.c:1958) > ==24515== by 0x441B3E: process_event (builtin-script.c:795) > ==24515== by 0x441B3E: process_sample_event (builtin-script.c:920) > ==24515== by 0x4BEE29: perf_evlist__deliver_sample (session.c:1192) > ==24515== by 0x4BEE29: machines__deliver_event (session.c:1229) > ==24515== by 0x4BF770: perf_session__deliver_event (session.c:1286) > ==24515== by 0x4BF770: ordered_events__deliver_event (session.c:114) > ==24515== by 0x4C1D17: __ordered_events__flush (ordered-events.c:207) > ==24515== by 0x4C1D17: ordered_events__flush.part.3 (ordered-events.c:274) > ==24515== by 0x4BF44C: perf_session__process_user_event (session.c:1325) > ==24515== by 0x4BF44C: perf_session__process_event (session.c:1451) > ==24515== Address 0x807c6a0 is 0 bytes inside a block of size 4,096 alloc'd > ==24515== at 0x4C29C0F: malloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so) > ==24515== by 0x4A5BCB: dso__load (symbol.c:1421) > ==24515== by 0x4BB1AE: map__load (map.c:289) > ==24515== by 0x4BB1AE: map__find_symbol (map.c:333) > ==24515== by 0x4835B3: thread__find_addr_location (event.c:1300) > ==24515== by 0x4B5342: add_callchain_ip (machine.c:1652) > ==24515== by 0x4B5342: thread__resolve_callchain_sample (machine.c:1906) > ==24515== by 0x4B9E7D: thread__resolve_callchain (machine.c:1958) > ==24515== by 0x441B3E: process_event (builtin-script.c:795) > ==24515== by 0x441B3E: process_sample_event (builtin-script.c:920) > ==24515== by 0x4BEE29: perf_evlist__deliver_sample (session.c:1192) > ==24515== by 0x4BEE29: machines__deliver_event (session.c:1229) > ==24515== by 0x4BF770: perf_session__deliver_event (session.c:1286) > ==24515== by 0x4BF770: ordered_events__deliver_event (session.c:114) > ==24515== by 0x4C1D17: __ordered_events__flush (ordered-events.c:207) > ==24515== by 0x4C1D17: ordered_events__flush.part.3 (ordered-events.c:274) > ==24515== by 0x4BF44C: perf_session__process_user_event (session.c:1325) > ==24515== by 0x4BF44C: perf_session__process_event (session.c:1451) > ==24515== by 0x4C0EAC: __perf_session__process_events (session.c:1804) > ==24515== by 0x4C0EAC: perf_session__process_events (session.c:1858) > > This patch fixes the problem by removing the check. > > Fixes: 403567217d3f perf symbols: Do not read symbols/data from device files > Signed-off-by: Marc Kleine-Budde > --- > tools/perf/util/symbol.c | 3 +-- > 1 file changed, 1 insertion(+), 2 deletions(-) > > diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c > index 8a747dc6cf86..b4070daeb17f 100644 > --- a/tools/perf/util/symbol.c > +++ b/tools/perf/util/symbol.c > @@ -1432,8 +1432,7 @@ int dso__load(struct dso *dso, struct map *map, symbol_filter_t filter) > * Read the build id if possible. This is required for > * DSO_BINARY_TYPE__BUILDID_DEBUGINFO to work > */ > - if (is_regular_file(name) && > - filename__read_build_id(dso->long_name, build_id, BUILD_ID_SIZE) > 0) > + if (filename__read_build_id(dso->long_name, build_id, BUILD_ID_SIZE) > 0) > dso__set_build_id(dso, build_id); ouch copy&paste error.. we better fix it properly, could you please check attached patch? thanks, jirka --- diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c index b044f1a32d16..37e8d20ae03e 100644 --- a/tools/perf/util/symbol.c +++ b/tools/perf/util/symbol.c @@ -1430,7 +1430,7 @@ int dso__load(struct dso *dso, struct map *map, symbol_filter_t filter) * Read the build id if possible. This is required for * DSO_BINARY_TYPE__BUILDID_DEBUGINFO to work */ - if (is_regular_file(name) && + if (is_regular_file(dso->long_name) && filename__read_build_id(dso->long_name, build_id, BUILD_ID_SIZE) > 0) dso__set_build_id(dso, build_id);