From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755027Ab2GXAXs (ORCPT ); Mon, 23 Jul 2012 20:23:48 -0400 Received: from LGEMRELSE6Q.lge.com ([156.147.1.121]:62796 "EHLO LGEMRELSE6Q.lge.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754599Ab2GXAXr (ORCPT ); Mon, 23 Jul 2012 20:23:47 -0400 X-AuditID: 9c930179-b7bdcae000003d91-66-500deb11e359 From: Namhyung Kim To: Andrew Watts Cc: linux-kernel@vger.kernel.org Subject: Re: [SEGFAULT: perf] References: <20120723135214.GA14465@ymail.com> Date: Tue, 24 Jul 2012 09:18:24 +0900 In-Reply-To: <20120723135214.GA14465@ymail.com> (Andrew Watts's message of "Mon, 23 Jul 2012 08:52:17 -0500") Message-ID: <878vea6mgf.fsf@sejong.aot.lge.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/24.0.97 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain X-Brightmail-Tracker: AAAAAA== Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, Andrew On Mon, 23 Jul 2012 08:52:17 -0500, Andrew Watts wrote: > perf report on 3.4.6 segfaults when certain pointers are null. Attached is > a patch that applies cleanly @3.4.6 and addresses (A). I am not comfortable > suggesting fixes for (B) and (C). > (A) has a fix already in the tip tree [1], and maybe in mainline too. And yes, I think this sort thing needs some love. It's on my TODO list but not have time to do it yet. [1] http://www.spinics.net/lists/linux-tip-commits/msg15695.html Thanks, Namhyung > ~ Andy > > === > > (A) perf report with sort on comm/pid/parent/dso: > > (gdb) run report --sort=comm > Program received signal SIGSEGV, Segmentation fault. > 0x0805c00b in perf_evsel__add_hist_entry (evsel=0x81c56a8, al=0xbfffe9b0, > sample=0xbfffea84, machine=0x81c3fa8) at builtin-report.c:171 > 171 if (notes->src == NULL && symbol__alloc_hist(he->ms.sym) < 0) > #0 0x0805c00b in perf_evsel__add_hist_entry (evsel=0x81c56a8, al=0xbfffe9b0, > sample=0xbfffea84, machine=0x81c3fa8) at builtin-report.c:171 > #1 0x0805c234 in process_sample_event (tool=0xbffff27c, event=0xb6db1f38, > sample=0xbfffea84, evsel=0x81c56a8, machine=0x81c3fa8) > at builtin-report.c:216 > #2 0x080a3097 in perf_session_deliver_event (session=0x81c3f50, event= > 0xb6db1f38, sample=0xbfffea84, tool=0xbffff27c, file_offset=339768) > at util/session.c:885 > #3 0x080a24d1 in flush_sample_queue (s=0x81c3f50, tool=0xbffff27c) > at util/session.c:587 > #4 0x080a40e3 in __perf_session__process_events (session=0x81c3f50, > data_offset=280, data_size=419640, file_size=419920, tool=0xbffff27c) > at util/session.c:1257 > #5 0x080a41d3 in perf_session__process_events (self=0x81c3f50, tool= > 0xbffff27c) at util/session.c:1273 > (gdb) print he->ms.sym > $1 = (struct symbol *) 0x0 > > -- > > (B) perf report segfaults on sorts of symbol_from/symbol_to: > > (gdb) run report --sort=symbol_from > Program received signal SIGSEGV, Segmentation fault. > 0x080b8777 in sort__sym_from_cmp (left=0xbfffe878, right=0x84dfde0) > at util/sort.c:334 > 334 if (!from_l->sym && !from_r->sym > (gdb) bt > #0 0x080b8777 in sort__sym_from_cmp (left=0xbfffe878, right=0x84dfde0) > at util/sort.c:334 > #1 0x080ba0b8 in hist_entry__cmp (left=0xbfffe878, right=0x84dfde0) > at util/hist.c:345 > #2 0x080b9c31 in add_hist_entry (hists=0x81c571c, entry=0xbfffe878, al= > 0xbfffe9b0, period=333940) at util/hist.c:254 > #3 0x080ba04c in __hists__add_entry (self=0x81c571c, al=0xbfffe9b0, > sym_parent=0x0, period=333940) at util/hist.c:335 > #4 0x0805bf50 in perf_evsel__add_hist_entry (evsel=0x81c56a8, al=0xbfffe9b0, > sample=0xbfffea84, machine=0x81c3fa8) at builtin-report.c:149 > #5 0x0805c234 in process_sample_event (tool=0xbffff27c, event=0xb6db1840, > sample=0xbfffea84, evsel=0x81c56a8, machine=0x81c3fa8) > at builtin-report.c:216 > (gdb) print left->branch_info > $2 = (struct branch_info *) 0x0 > (gdb) print right->branch_info > $3 = (struct branch_info *) 0x0 > > -- > > (C) perf report segfaults with dso_from/dso_to: > > (gdb) run report --sort=dso_to > Program received signal SIGSEGV, Segmentation fault. > sort__dso_to_cmp (left=0xbfffe878, right=0x82346f0) at util/sort.c:317 > 317 return _sort__dso_cmp(left->branch_info->to.map, > (gdb) bt > #0 sort__dso_to_cmp (left=0xbfffe878, right=0x82346f0) at util/sort.c:317 > #1 0x080ba0c8 in hist_entry__cmp (left=0xbfffe878, right=0x82346f0) > at util/hist.c:345 > #2 0x080b9c41 in add_hist_entry (hists=0x81c571c, entry=0xbfffe878, al= > 0xbfffe9b0, period=333331) at util/hist.c:254 > #3 0x080ba05c in __hists__add_entry (self=0x81c571c, al=0xbfffe9b0, > sym_parent=0x0, period=333331) at util/hist.c:335 > #4 0x0805bf50 in perf_evsel__add_hist_entry (evsel=0x81c56a8, al=0xbfffe9b0, > sample=0xbfffea84, machine=0x81c3fa8) at builtin-report.c:149 > #5 0x0805c242 in process_sample_event (tool=0xbffff27c, event=0xb6dbf800, > sample=0xbfffea84, evsel=0x81c56a8, machine=0x81c3fa8) > at builtin-report.c:216 > (gdb) print left->branch_info > $4 = (struct branch_info *) 0x0 > (gdb) print right->branch_info > $5 = (struct branch_info *) 0x0 > > === > > > --- builtin-report.c.orig 2012-07-22 > +++ builtin-report.c 2012-07-22 > @@ -162,7 +162,7 @@ static int perf_evsel__add_hist_entry(st > * so we don't allocated the extra space needed because the stdio > * code will not use it. > */ > - if (al->sym != NULL && use_browser > 0) { > + if (al->sym != NULL && he->ms.sym != NULL && use_browser > 0) { > struct annotation *notes = symbol__annotation(he->ms.sym); > > assert(evsel != NULL);