From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932687AbbAIMcL (ORCPT ); Fri, 9 Jan 2015 07:32:11 -0500 Received: from terminus.zytor.com ([198.137.202.10]:60155 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932142AbbAIMcI (ORCPT ); Fri, 9 Jan 2015 07:32:08 -0500 Date: Fri, 9 Jan 2015 04:31:27 -0800 From: tip-bot for Namhyung Kim Message-ID: Cc: eranian@google.com, namhyung@kernel.org, mingo@kernel.org, fweisbec@gmail.com, andi@firstfloor.org, adrian.hunter@intel.com, linux-kernel@vger.kernel.org, acme@redhat.com, hpa@zytor.com, jolsa@redhat.com, tglx@linutronix.de, a.p.zijlstra@chello.nl Reply-To: hpa@zytor.com, jolsa@redhat.com, a.p.zijlstra@chello.nl, tglx@linutronix.de, acme@redhat.com, linux-kernel@vger.kernel.org, adrian.hunter@intel.com, andi@firstfloor.org, namhyung@kernel.org, eranian@google.com, fweisbec@gmail.com, mingo@kernel.org In-Reply-To: <1419401076-21700-1-git-send-email-namhyung@kernel.org> References: <1419401076-21700-1-git-send-email-namhyung@kernel.org> To: linux-tip-commits@vger.kernel.org Subject: [tip:perf/urgent] perf hists browser: Fix segfault when showing callchain Git-Commit-ID: c09e31cc128cf1aec3a6cd47203508fbf0082873 X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: c09e31cc128cf1aec3a6cd47203508fbf0082873 Gitweb: http://git.kernel.org/tip/c09e31cc128cf1aec3a6cd47203508fbf0082873 Author: Namhyung Kim AuthorDate: Wed, 24 Dec 2014 15:04:36 +0900 Committer: Arnaldo Carvalho de Melo CommitDate: Thu, 8 Jan 2015 11:59:16 -0300 perf hists browser: Fix segfault when showing callchain When perf report on TUI shows callchain it checks first node has siblings to determine whether it needs to print percentage value. But it missed a case that first node is NULL. So sometimes it segfaults like below: $ perf top -g perf: Segmentation fault -------- backtrace -------- perf[0x4fcefb] /usr/lib/libc.so.6(+0x33b20)[0x7f2a35839b20] perf(rb_next+0x8)[0x47d3d8] perf[0x4f6058] perf[0x4f833b] perf[0x4f8610] perf[0x4f209e] perf(ui_browser__run+0x3a)[0x4f2e6a] perf[0x4f94ee] perf(perf_evlist__tui_browse_hists+0x94)[0x4fbbf4] perf[0x444d10] /usr/lib/libpthread.so.0(+0x7314)[0x7f2a37070314] /usr/lib/libc.so.6(clone+0x6d)[0x7f2a358ee5bd] $ addr2line -e `which perf` 0x4f6058 /home/namhyung/project/linux/tools/perf/ui/browsers/hists.c:553 I don't know why the backtrace didn't print some symbols.. Signed-off-by: Namhyung Kim Fixes: 4087d11cd945 ("perf hists browser: Print overhead percent value for first-level callchain") Cc: Adrian Hunter Cc: Andi Kleen Cc: Frederic Weisbecker Cc: Ingo Molnar Cc: Jiri Olsa Cc: Peter Zijlstra Cc: Stephane Eranian Link: http://lkml.kernel.org/r/1419401076-21700-1-git-send-email-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/ui/browsers/hists.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/tools/perf/ui/browsers/hists.c b/tools/perf/ui/browsers/hists.c index e6bb04b..788506e 100644 --- a/tools/perf/ui/browsers/hists.c +++ b/tools/perf/ui/browsers/hists.c @@ -550,7 +550,7 @@ static int hist_browser__show_callchain(struct hist_browser *browser, bool need_percent; node = rb_first(root); - need_percent = !!rb_next(node); + need_percent = node && rb_next(node); while (node) { struct callchain_node *child = rb_entry(node, struct callchain_node, rb_node);