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=-15.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 5FA72C433DB for ; Wed, 3 Mar 2021 05:14:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1D68B64EC0 for ; Wed, 3 Mar 2021 05:14:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237421AbhCCFFV (ORCPT ); Wed, 3 Mar 2021 00:05:21 -0500 Received: from us-smtp-delivery-124.mimecast.com ([63.128.21.124]:23037 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1578680AbhCBP03 (ORCPT ); Tue, 2 Mar 2021 10:26:29 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1614698702; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc; bh=l1EErq2Ure6g3ZP+f0TqMild9A+xwG0o9pFCNJA33oM=; b=hohJ72qJ6SCH2lgBDShh8FDvh0FQatZkgD35Xyin7UeUVzTJ+nq7bu0BjN0H+7lh9Xl4N8 1PANOqCVzqyNWOVdSVjIfNbYkXvi9czqgJ1TwrRu6agboOY/U6TPr2ftJkF6z2GxrkuEkH vuQFeIUEoB4voqo5cj6Q20NTHyryXJg= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-91-tKaoDq7ZP0qfYu1fY9zQ2A-1; Tue, 02 Mar 2021 09:41:24 -0500 X-MC-Unique: tKaoDq7ZP0qfYu1fY9zQ2A-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 5BF0080197A for ; Tue, 2 Mar 2021 14:41:23 +0000 (UTC) Received: from Diego.redhat.com (unknown [10.40.208.49]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 4162C19C48; Tue, 2 Mar 2021 14:41:22 +0000 (UTC) From: Michael Petlan To: acme@redhat.com, linux-perf-users@vger.kernel.org Cc: jolsa@redhat.com Subject: [PATCH] perf trace: Fix race in signal handling Date: Tue, 2 Mar 2021 15:41:20 +0100 Message-Id: <20210302144120.17362-1-mpetlan@redhat.com> X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 Precedence: bulk List-ID: X-Mailing-List: linux-perf-users@vger.kernel.org Since a lot of stuff happens before the SIGINT signal handler is registered (scanning /proc/*, etc.), on bigger systems, such as Cavium Sabre CN99xx, it may happen that first interrupt signal is lost and perf isn't correctly terminated. The reproduction code might look like the following: perf trace -a & PERF_PID=$! sleep 4 kill -INT $PERF_PID The issue has been found on a CN99xx machine with RHEL-8 and the patch fixes it by registering the signal handlers earlier in the init stage. Suggested-by: Jiri Olsa Signed-off-by: Michael Petlan Tested-by: Michael Petlan --- tools/perf/builtin-trace.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/tools/perf/builtin-trace.c b/tools/perf/builtin-trace.c index 85b6a46e85b6..7ec18ff57fc4 100644 --- a/tools/perf/builtin-trace.c +++ b/tools/perf/builtin-trace.c @@ -3964,9 +3964,6 @@ static int trace__run(struct trace *trace, int argc, const char **argv) evlist__config(evlist, &trace->opts, &callchain_param); - signal(SIGCHLD, sig_handler); - signal(SIGINT, sig_handler); - if (forks) { err = evlist__prepare_workload(evlist, &trace->opts.target, argv, false, NULL); if (err < 0) { @@ -4827,6 +4824,8 @@ int cmd_trace(int argc, const char **argv) signal(SIGSEGV, sighandler_dump_stack); signal(SIGFPE, sighandler_dump_stack); + signal(SIGCHLD, sig_handler); + signal(SIGINT, sig_handler); trace.evlist = evlist__new(); trace.sctbl = syscalltbl__new(); -- 2.18.4