From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751782AbbINSHX (ORCPT ); Mon, 14 Sep 2015 14:07:23 -0400 Received: from mail.kernel.org ([198.145.29.136]:44558 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750951AbbINSHW (ORCPT ); Mon, 14 Sep 2015 14:07:22 -0400 Date: Mon, 14 Sep 2015 15:07:14 -0300 From: Arnaldo Carvalho de Melo To: Wang Nan Cc: namhyung@kernel.org, linux-kernel@vger.kernel.org, lizefan@huawei.com, pi3orama@163.com Subject: Re: [PATCH v2] perf tools: Fix segfault in 'perf top' Message-ID: <20150914180714.GC5250@kernel.org> References: <20150911162207.GD3447@danjae.kornet> <1442226235-117265-1-git-send-email-wangnan0@huawei.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1442226235-117265-1-git-send-email-wangnan0@huawei.com> X-Url: http://acmel.wordpress.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 Em Mon, Sep 14, 2015 at 10:23:55AM +0000, Wang Nan escreveu: > 'perf top' segfaults with following operation: > > # perf top -e page-faults -p 11400 # 11400 never generates page-fault > > Then on the resulting empty interface, press right key: So, this happens in perf/urgent, so we need to apply it there first, which this patch doesn't. I am fixing it up this time, thanks for the patch! - Arnaldo > # ./perf top -e page-faults -p 11400 > perf: Segmentation fault > -------- backtrace -------- > ./perf[0x535428] > /lib64/libc.so.6(+0x3545f)[0x7f0dd360745f] > ./perf[0x531d46] > ./perf(perf_evlist__tui_browse_hists+0x96)[0x5340d6] > ./perf[0x44ba2f] > /lib64/libpthread.so.0(+0x81d0)[0x7f0dd49dc1d0] > /lib64/libc.so.6(clone+0x6c)[0x7f0dd36b90dc] > > The bug reside in perf_evsel__hists_browse() that, in the above circumstance > browser->selection can be NULL, but code after skip_annotation doesn't consider > it. > > This patch fix it by checking browser->selection before fetching > browser->selection->map. > > Signed-off-by: Wang Nan > Cc: Arnaldo Carvalho de Melo > Cc: Namhyung Kim > --- > tools/perf/ui/browsers/hists.c | 12 +++++++++++- > 1 file changed, 11 insertions(+), 1 deletion(-) > > diff --git a/tools/perf/ui/browsers/hists.c b/tools/perf/ui/browsers/hists.c > index e4fd40f..182b87a 100644 > --- a/tools/perf/ui/browsers/hists.c > +++ b/tools/perf/ui/browsers/hists.c > @@ -2017,7 +2017,8 @@ skip_annotation: > &options[nr_options], dso); > nr_options += add_map_opt(browser, &actions[nr_options], > &options[nr_options], > - browser->selection->map); > + browser->selection ? > + browser->selection->map : NULL); > nr_options += add_socket_opt(browser, &actions[nr_options], > &options[nr_options], > socket); > @@ -2027,6 +2028,15 @@ skip_annotation: > &actions[nr_options], > &options[nr_options], > thread, NULL); > + /* > + * Note that browser->selection != NULL > + * when browser->he_selection is not NULL, > + * so we don't need to check browser->selection > + * before fetching browser->selection->sym like what > + * we do before fetching browser->selection->map. > + * > + * See hist_browser__show_entry. > + */ > nr_options += add_script_opt(browser, > &actions[nr_options], > &options[nr_options], > -- > 1.8.3.4