From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751683AbbCJGHF (ORCPT ); Tue, 10 Mar 2015 02:07:05 -0400 Received: from lgeamrelo01.lge.com ([156.147.1.125]:60291 "EHLO lgeamrelo01.lge.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750769AbbCJGHB (ORCPT ); Tue, 10 Mar 2015 02:07:01 -0400 X-Original-SENDERIP: 10.177.220.203 X-Original-MAILFROM: namhyung@kernel.org Date: Tue, 10 Mar 2015 15:01:12 +0900 From: Namhyung Kim To: He Kuang Cc: acme@kernel.org, a.p.zijlstra@chello.nl, mingo@redhat.com, paulus@samba.org, jolsa@kernel.org, wangnan0@huawei.com, linux-kernel@vger.kernel.org Subject: Re: [PATCH] perf hists browser: Fix segfault when all entries be filtered Message-ID: <20150310060112.GB943@sejong> References: <1425442416-29035-1-git-send-email-hekuang@huawei.com> <54FE6753.8090703@huawei.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <54FE6753.8090703@huawei.com> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, On Tue, Mar 10, 2015 at 11:38:59AM +0800, He Kuang wrote: > ping.. > On 2015/3/4 12:13, He Kuang wrote: > >When all perf report entries be filtered, the result of > >hists__filter_entries() can be NULL, check the result before processing. In that case, browser->nr_entries should be zero IMHO. But it seems there's a place missing to update the number. Thanks, Namhyung > > > >Miss this checking will cause segmentation fault like this: > > > > $ perf report > > > >(filter all entries and left nothing, then zoom in/out) > > perf: Segmentation fault > > -------- backtrace -------- > > ../bin/perf[0x4d1858] > > ../lib64/libc.so.6(+0x3545f)[0x7fe72fc1145f] > > ../bin/perf[0x4cd9f5] > > ../bin/perf[0x4ce176] > > ../bin/perf[0x4d0506] > > ../bin/perf[0x41a94f] > > ../bin/perf[0x408cf2] > > ../bin/perf[0x408455] > > ../lib64/libc.so.6(__libc_start_main+0xf4)[0x7fe72fbfdbd4] > > ../bin/perf[0x408584] > > > >Signed-off-by: He Kuang > >--- > > tools/perf/ui/browsers/hists.c | 3 +++ > > 1 file changed, 3 insertions(+) > > > >diff --git a/tools/perf/ui/browsers/hists.c b/tools/perf/ui/browsers/hists.c > >index 788506e..1106bb8 100644 > >--- a/tools/perf/ui/browsers/hists.c > >+++ b/tools/perf/ui/browsers/hists.c > >@@ -992,6 +992,9 @@ static void ui_browser__hists_seek(struct ui_browser *browser, > > * and stop when we printed enough lines to fill the screen. > > */ > > do_offset: > >+ if (!nd) > >+ return; > >+ > > if (offset > 0) { > > do { > > h = rb_entry(nd, struct hist_entry, rb_node); > > > -- > 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/