Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754283AbbDMQEG (ORCPT ); Mon, 13 Apr 2015 12:04:06 -0400 Received: from mail7.hitachi.co.jp ([133.145.228.42]:53824 "EHLO mail7.hitachi.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754127AbbDMQED (ORCPT ); Mon, 13 Apr 2015 12:04:03 -0400 Message-ID: <552BE8EB.2000502@hitachi.com> Date: Tue, 14 Apr 2015 01:03:55 +0900 From: Masami Hiramatsu Organization: Hitachi, Ltd., Japan User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:13.0) Gecko/20120614 Thunderbird/13.0.1 MIME-Version: 1.0 To: He Kuang CC: acme@kernel.org, a.p.zijlstra@chello.nl, mingo@redhat.com, namhyung@kernel.org, wangnan0@huawei.com, linux-kernel@vger.kernel.org Subject: Re: [PATCH 3/3] perf probe: Fix segfault when probe with lazy_line to file References: <1428925290-5623-1-git-send-email-hekuang@huawei.com> <1428925290-5623-3-git-send-email-hekuang@huawei.com> In-Reply-To: <1428925290-5623-3-git-send-email-hekuang@huawei.com> Content-Type: text/plain; charset=ISO-2022-JP Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2070 Lines: 61 (2015/04/13 20:41), He Kuang wrote: > The first argument passed to find_probe_point_lazy() should be CU die, > which will be passed to die_walk_lines() when lazy_line > matches. Currently, when we probe with lazy_line pattern to file without > function name, NULL pointer is passed and causes a segment fault. > > Can be repoduced as following: > > $ perf probe -k vmlinux --add='fs/super.c;s->s_count=1;' > [ 1958.984658] perf[1020]: segfault at 10 ip 00007fc6e10d8c71 sp > 00007ffcbfaaf900 error 4 in libdw-0.161.so[7fc6e10ce000+34000] > Segmentation fault > > After this patch: > > $ perf probe -k vmlinux --add='fs/super.c;s->s_count=1;' > Added new event: > probe:_stext (on @fs/super.c) > > You can now use it in all perf tools, such as: > perf record -e probe:_stext -aR sleep 1 > Acked-by: Masami Hiramatsu Thanks! > Signed-off-by: He Kuang > --- > tools/perf/util/probe-finder.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/tools/perf/util/probe-finder.c b/tools/perf/util/probe-finder.c > index 431c12d..e91101b 100644 > --- a/tools/perf/util/probe-finder.c > +++ b/tools/perf/util/probe-finder.c > @@ -1067,7 +1067,7 @@ static int debuginfo__find_probes(struct debuginfo *dbg, > if (pp->function) > ret = find_probe_point_by_func(pf); > else if (pp->lazy_line) > - ret = find_probe_point_lazy(NULL, pf); > + ret = find_probe_point_lazy(&pf->cu_die, pf); > else { > pf->lno = pp->line; > ret = find_probe_point_by_line(pf); > -- Masami HIRAMATSU Linux Technology Research Center, System Productivity Research Dept. Center for Technology Innovation - Systems Engineering Hitachi, Ltd., Research & Development Group E-mail: masami.hiramatsu.pt@hitachi.com -- 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/