From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 51111C10F14 for ; Thu, 10 Oct 2019 08:56:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2A53C21920 for ; Thu, 10 Oct 2019 08:56:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1570697775; bh=HtTLYwMSkuU1fMYDyowkG8fljK9blnV/vEYaAIVphrM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=PuPA+Oy+K+otc7DGnAzwv5fh8XqUhP+uh/7BYo/5ZFGHdwBqW2Wd9emcl6gCJ0UAN n2CmHENJ03tL+253+/240tmTEkHqS/OejZnmP21sOfD67j+BJHJ9yRCKRodqwS5FpR OyrP7PvZjeisbGCDIa2vM96n/H+M3n0LmTe0cUE8= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389643AbfJJIs1 (ORCPT ); Thu, 10 Oct 2019 04:48:27 -0400 Received: from mail.kernel.org ([198.145.29.99]:54462 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2389625AbfJJIsR (ORCPT ); Thu, 10 Oct 2019 04:48:17 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 54C4D21D7A; Thu, 10 Oct 2019 08:48:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1570697296; bh=HtTLYwMSkuU1fMYDyowkG8fljK9blnV/vEYaAIVphrM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=OIPLwsiOTRf3MMYpfnu8RLKUc5LUlMnkCCXFwQtsNXhcwbk1yAdL9syntluZ1TXVb SS4iTBpGur2Em87jCn/iBSNJ+dxaUAjecBws966CnEVjScegjk1SkXqngIfv4Pol69 E1QEhRc1+Cv5dx/26VZOhEWLCAsMUABm9RMhLufA= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Srikar Dronamraju , Jiri Olsa , Arnaldo Carvalho de Melo , Ravi Bangoria , Namhyung Kim , "Naveen N. Rao" Subject: [PATCH 4.19 036/114] perf stat: Fix a segmentation fault when using repeat forever Date: Thu, 10 Oct 2019 10:35:43 +0200 Message-Id: <20191010083602.596987082@linuxfoundation.org> X-Mailer: git-send-email 2.23.0 In-Reply-To: <20191010083544.711104709@linuxfoundation.org> References: <20191010083544.711104709@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Srikar Dronamraju commit 443f2d5ba13d65ccfd879460f77941875159d154 upstream. Observe a segmentation fault when 'perf stat' is asked to repeat forever with the interval option. Without fix: # perf stat -r 0 -I 5000 -e cycles -a sleep 10 # time counts unit events 5.000211692 3,13,89,82,34,157 cycles 10.000380119 1,53,98,52,22,294 cycles 10.040467280 17,16,79,265 cycles Segmentation fault This problem was only observed when we use forever option aka -r 0 and works with limited repeats. Calling print_counter with ts being set to NULL, is not a correct option when interval is set. Hence avoid print_counter(NULL,..) if interval is set. With fix: # perf stat -r 0 -I 5000 -e cycles -a sleep 10 # time counts unit events 5.019866622 3,15,14,43,08,697 cycles 10.039865756 3,15,16,31,95,261 cycles 10.059950628 1,26,05,47,158 cycles 5.009902655 3,14,52,62,33,932 cycles 10.019880228 3,14,52,22,89,154 cycles 10.030543876 66,90,18,333 cycles 5.009848281 3,14,51,98,25,437 cycles 10.029854402 3,15,14,93,04,918 cycles 5.009834177 3,14,51,95,92,316 cycles Committer notes: Did the 'git bisect' to find the cset introducing the problem to add the Fixes tag below, and at that time the problem reproduced as: (gdb) run stat -r0 -I500 sleep 1 Program received signal SIGSEGV, Segmentation fault. print_interval (prefix=prefix@entry=0x7fffffffc8d0 "", ts=ts@entry=0x0) at builtin-stat.c:866 866 sprintf(prefix, "%6lu.%09lu%s", ts->tv_sec, ts->tv_nsec, csv_sep); (gdb) bt #0 print_interval (prefix=prefix@entry=0x7fffffffc8d0 "", ts=ts@entry=0x0) at builtin-stat.c:866 #1 0x000000000041860a in print_counters (ts=ts@entry=0x0, argc=argc@entry=2, argv=argv@entry=0x7fffffffd640) at builtin-stat.c:938 #2 0x0000000000419a7f in cmd_stat (argc=2, argv=0x7fffffffd640, prefix=) at builtin-stat.c:1411 #3 0x000000000045c65a in run_builtin (p=p@entry=0x6291b8 , argc=argc@entry=5, argv=argv@entry=0x7fffffffd640) at perf.c:370 #4 0x000000000045c893 in handle_internal_command (argc=5, argv=0x7fffffffd640) at perf.c:429 #5 0x000000000045c8f1 in run_argv (argcp=argcp@entry=0x7fffffffd4ac, argv=argv@entry=0x7fffffffd4a0) at perf.c:473 #6 0x000000000045cac9 in main (argc=, argv=) at perf.c:588 (gdb) Mostly the same as just before this patch: Program received signal SIGSEGV, Segmentation fault. 0x00000000005874a7 in print_interval (config=0xa1f2a0 , evlist=0xbc9b90, prefix=0x7fffffffd1c0 "`", ts=0x0) at util/stat-display.c:964 964 sprintf(prefix, "%6lu.%09lu%s", ts->tv_sec, ts->tv_nsec, config->csv_sep); (gdb) bt #0 0x00000000005874a7 in print_interval (config=0xa1f2a0 , evlist=0xbc9b90, prefix=0x7fffffffd1c0 "`", ts=0x0) at util/stat-display.c:964 #1 0x0000000000588047 in perf_evlist__print_counters (evlist=0xbc9b90, config=0xa1f2a0 , _target=0xa1f0c0 , ts=0x0, argc=2, argv=0x7fffffffd670) at util/stat-display.c:1172 #2 0x000000000045390f in print_counters (ts=0x0, argc=2, argv=0x7fffffffd670) at builtin-stat.c:656 #3 0x0000000000456bb5 in cmd_stat (argc=2, argv=0x7fffffffd670) at builtin-stat.c:1960 #4 0x00000000004dd2e0 in run_builtin (p=0xa30e00 , argc=5, argv=0x7fffffffd670) at perf.c:310 #5 0x00000000004dd54d in handle_internal_command (argc=5, argv=0x7fffffffd670) at perf.c:362 #6 0x00000000004dd694 in run_argv (argcp=0x7fffffffd4cc, argv=0x7fffffffd4c0) at perf.c:406 #7 0x00000000004dda11 in main (argc=5, argv=0x7fffffffd670) at perf.c:531 (gdb) Fixes: d4f63a4741a8 ("perf stat: Introduce print_counters function") Signed-off-by: Srikar Dronamraju Acked-by: Jiri Olsa Tested-by: Arnaldo Carvalho de Melo Tested-by: Ravi Bangoria Cc: Namhyung Kim Cc: Naveen N. Rao Cc: stable@vger.kernel.org # v4.2+ Link: http://lore.kernel.org/lkml/20190904094738.9558-3-srikar@linux.vnet.ibm.com Signed-off-by: Arnaldo Carvalho de Melo Signed-off-by: Greg Kroah-Hartman --- tools/perf/builtin-stat.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/tools/perf/builtin-stat.c +++ b/tools/perf/builtin-stat.c @@ -3091,7 +3091,7 @@ int cmd_stat(int argc, const char **argv run_idx + 1); status = run_perf_stat(argc, argv, run_idx); - if (forever && status != -1) { + if (forever && status != -1 && !interval) { print_counters(NULL, argc, argv); perf_stat__reset_stats(); }