From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753826AbcJEN2H (ORCPT ); Wed, 5 Oct 2016 09:28:07 -0400 Received: from smtprelay0033.hostedemail.com ([216.40.44.33]:59591 "EHLO smtprelay.hostedemail.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752164AbcJEN2F (ORCPT ); Wed, 5 Oct 2016 09:28:05 -0400 X-Session-Marker: 726F737465647440676F6F646D69732E6F7267 X-Spam-Summary: 2,0,0,,d41d8cd98f00b204,rostedt@goodmis.org,:::::::::::,RULES_HIT:41:355:379:541:599:800:960:973:988:989:1260:1277:1311:1313:1314:1345:1359:1437:1515:1516:1518:1534:1541:1593:1594:1711:1730:1747:1777:1792:2393:2553:2559:2562:3138:3139:3140:3141:3142:3352:3622:3865:3867:3871:3872:3874:4321:5007:6261:7875:10004:10400:10848:10967:11026:11232:11658:11914:12043:12114:12438:12555:12740:12760:13069:13311:13357:13439:14096:14097:14181:14659:14721:21080:21451:30054:30070:30090:30091,0,RBL:none,CacheIP:none,Bayesian:0.5,0.5,0.5,Netcheck:none,DomainCache:0,MSF:not bulk,SPF:fn,MSBL:0,DNSBL:none,Custom_rules:0:0:0,LFtime:2,LUA_SUMMARY:none X-HE-Tag: glove63_c13766248002 X-Filterd-Recvd-Size: 2130 Date: Wed, 5 Oct 2016 09:28:01 -0400 From: Steven Rostedt To: Namhyung Kim Cc: Arnaldo Carvalho de Melo , Ingo Molnar , Peter Zijlstra , Jiri Olsa , LKML Subject: Re: [PATCH] tools lib traceevent: Fix kbuffer_read_at_offset() Message-ID: <20161005092801.3a8e9166@gandalf.local.home> In-Reply-To: <20161001101700.29146-1-namhyung@kernel.org> References: <20161001101700.29146-1-namhyung@kernel.org> X-Mailer: Claws Mail 3.13.2 (GTK+ 2.24.30; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, 1 Oct 2016 19:17:00 +0900 Namhyung Kim wrote: > When it's called with an offset less than or equal to the first event, > it'll return a garbage value since the data is not initialized. Well, it can at most be equal to (unless offset is negative) because kbuffer_load_subbuffer() sets kbuf->curr to zero. But that said, it looks like offset == 0 is buggy. Acked-by: Steven Rostedt -- Steve > > Cc: Steven Rostedt > Signed-off-by: Namhyung Kim > --- > tools/lib/traceevent/kbuffer-parse.c | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/tools/lib/traceevent/kbuffer-parse.c b/tools/lib/traceevent/kbuffer-parse.c > index 3bcada3ae05a..65984f1c2974 100644 > --- a/tools/lib/traceevent/kbuffer-parse.c > +++ b/tools/lib/traceevent/kbuffer-parse.c > @@ -622,6 +622,7 @@ void *kbuffer_read_at_offset(struct kbuffer *kbuf, int offset, > > /* Reset the buffer */ > kbuffer_load_subbuffer(kbuf, kbuf->subbuffer); > + data = kbuffer_read_event(kbuf, ts); > > while (kbuf->curr < offset) { > data = kbuffer_next_event(kbuf, ts);