Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758138AbbLCCUT (ORCPT ); Wed, 2 Dec 2015 21:20:19 -0500 Received: from szxga01-in.huawei.com ([58.251.152.64]:25157 "EHLO szxga01-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757719AbbLCCUQ (ORCPT ); Wed, 2 Dec 2015 21:20:16 -0500 Message-ID: <565FA6B8.7010501@huawei.com> Date: Thu, 3 Dec 2015 10:19:36 +0800 From: "Wangnan (F)" User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:31.0) Gecko/20100101 Thunderbird/31.6.0 MIME-Version: 1.0 To: Namhyung Kim CC: , , , , Arnaldo Carvalho de Melo Subject: Re: [PATCH] perf hists browser: Fix segfault if use symbol filter in cmdline References: <1449055732-235627-1-git-send-email-wangnan0@huawei.com> <20151202154942.GA27992@danjae.kornet> In-Reply-To: <20151202154942.GA27992@danjae.kornet> Content-Type: text/plain; charset="utf-8"; format=flowed Content-Transfer-Encoding: 7bit X-Originating-IP: [10.111.66.109] X-CFilter-Loop: Reflected X-Mirapoint-Virus-RAPID-Raw: score=unknown(0), refid=str=0001.0A090205.565FA6D2.00D7,ss=1,re=0.000,recu=0.000,reip=0.000,cl=1,cld=1,fgs=0, ip=0.0.0.0, so=2013-06-18 04:22:30, dmn=2013-03-21 17:37:32 X-Mirapoint-Loop-Id: 15d4d45c3b1843e590de1613ecaa4dd8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2571 Lines: 83 On 2015/12/2 23:49, Namhyung Kim wrote: > Hi, > > On Wed, Dec 02, 2015 at 11:28:52AM +0000, Wang Nan wrote: >> If feed perf a symbol filter in cmdline and the result is empty, >> pressing 'Enter' in the hist browser causes crash: >> >> # ./perf report perf.data <-- Common mistake for beginners >> >> Then press 'Enter': >> >> perf: Segmentation fault >> -------- backtrace -------- >> /home/wangnan/perf[0x53e578] >> /lib64/libc.so.6(+0x3545f)[0x7f76bafe045f] >> /home/wangnan/perf[0x539dd4] >> /home/wangnan/perf(perf_evlist__tui_browse_hists+0x96)[0x53d216] >> /home/wangnan/perf(cmd_report+0x1b9f)[0x442c7f] >> /home/wangnan/perf[0x47efa2] >> /home/wangnan/perf(main+0x5f5)[0x432fa5] >> /lib64/libc.so.6(__libc_start_main+0xf4)[0x7f76bafccbd4] >> /home/wangnan/perf[0x4330d4] >> >> This is because 'perf.data' is interperted as a symbol filter, and the >> result is empty, so selection is empty. However, >> hist_browser__toggle_fold() forgets to check it. >> >> This patch simply return faluse when selection is NULL. > s/faluse/false/ > >> Signed-off-by: Wang Nan >> Cc: Arnaldo Carvalho de Melo > Acked-by: Namhyung Kim > > One nitpick below.. > >> --- >> tools/perf/ui/browsers/hists.c | 5 ++++- >> 1 file changed, 4 insertions(+), 1 deletion(-) >> >> diff --git a/tools/perf/ui/browsers/hists.c b/tools/perf/ui/browsers/hists.c >> index dcdcbaf..33da341 100644 >> --- a/tools/perf/ui/browsers/hists.c >> +++ b/tools/perf/ui/browsers/hists.c >> @@ -337,9 +337,12 @@ static bool hist_browser__toggle_fold(struct hist_browser *browser) >> { >> struct hist_entry *he = browser->he_selection; >> struct map_symbol *ms = browser->selection; >> - struct callchain_list *cl = container_of(ms, struct callchain_list, ms); >> + struct callchain_list *cl = ms ? container_of(ms, struct callchain_list, ms) : NULL; > I think this line is not needed as container_of doesn't make a pointer > dereference by itself. Just checking below is enough IMHO. I know it. Add it only for correctness. Will be removed. Thank you. > Thanks, > Namhyung > > >> bool has_children; >> >> + if (!ms) >> + return false; >> + >> if (ms == &he->ms) >> has_children = hist_entry__toggle_fold(he); >> else >> -- >> 1.8.3.4 >> -- 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/