From patchwork Thu Aug 20 09:20:27 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 265414 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=-9.8 required=3.0 tests=BAYES_00,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=unavailable 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 D67EEC433DF for ; Thu, 20 Aug 2020 12:40:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id AAD84207DA for ; Thu, 20 Aug 2020 12:40:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1597927218; bh=deq8yjCJDG8hwhZ8bxTLDfbAbLOszTp7MSKDmQytPtc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=yRlgzPDvjTdMTFCQCAgoymACPUvCY7ol+jLDNUsposmw95bk2m26IafdpnjoJLK/7 zrgy4Eq3gpn7p4nMZXYLybcsEsCzcUWQsyl1QmATMhWTQLAtOjDiPMfh7EKp6x2Bmb le4cqWGNuao2nrE+0YlT4z10Fqg8tW5vd/teGUXY= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729390AbgHTJrG (ORCPT ); Thu, 20 Aug 2020 05:47:06 -0400 Received: from mail.kernel.org ([198.145.29.99]:50310 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729389AbgHTJrF (ORCPT ); Thu, 20 Aug 2020 05:47:05 -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 048AD20724; Thu, 20 Aug 2020 09:47:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1597916824; bh=deq8yjCJDG8hwhZ8bxTLDfbAbLOszTp7MSKDmQytPtc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=gpXjdeWeMrp430veB2dB+gxZK05IRYnsSt2Qi3WUtR70Tftzq2u/pCsayl95rwKVm +U94kECPG6lxOFQDLdRuz5dYP+HSkZaZ2LfqzgjzOX+C3w1xunejT64J0MexeJ4weN JIwtzNnv15/R9P+2jDkMSafs5Vi6OO5HMo3n+ICM= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Namhyung Kim , "Steven Rostedt (VMware)" Subject: [PATCH 5.4 060/152] tracing: Use trace_sched_process_free() instead of exit() for pid tracing Date: Thu, 20 Aug 2020 11:20:27 +0200 Message-Id: <20200820091556.794463417@linuxfoundation.org> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20200820091553.615456912@linuxfoundation.org> References: <20200820091553.615456912@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Steven Rostedt (VMware) commit afcab636657421f7ebfa0783a91f90256bba0091 upstream. On exit, if a process is preempted after the trace_sched_process_exit() tracepoint but before the process is done exiting, then when it gets scheduled in, the function tracers will not filter it properly against the function tracing pid filters. That is because the function tracing pid filters hooks to the sched_process_exit() tracepoint to remove the exiting task's pid from the filter list. Because the filtering happens at the sched_switch tracepoint, when the exiting task schedules back in to finish up the exit, it will no longer be in the function pid filtering tables. This was noticeable in the notrace self tests on a preemptable kernel, as the tests would fail as it exits and preempted after being taken off the notrace filter table and on scheduling back in it would not be in the notrace list, and then the ending of the exit function would trace. The test detected this and would fail. Cc: stable@vger.kernel.org Cc: Namhyung Kim Fixes: 1e10486ffee0a ("ftrace: Add 'function-fork' trace option") Fixes: c37775d57830a ("tracing: Add infrastructure to allow set_event_pid to follow children" Signed-off-by: Steven Rostedt (VMware) Signed-off-by: Greg Kroah-Hartman --- kernel/trace/ftrace.c | 4 ++-- kernel/trace/trace_events.c | 4 ++-- 2 files changed, 4 insertions(+), 4 deletions(-) --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -6462,12 +6462,12 @@ void ftrace_pid_follow_fork(struct trace if (enable) { register_trace_sched_process_fork(ftrace_pid_follow_sched_process_fork, tr); - register_trace_sched_process_exit(ftrace_pid_follow_sched_process_exit, + register_trace_sched_process_free(ftrace_pid_follow_sched_process_exit, tr); } else { unregister_trace_sched_process_fork(ftrace_pid_follow_sched_process_fork, tr); - unregister_trace_sched_process_exit(ftrace_pid_follow_sched_process_exit, + unregister_trace_sched_process_free(ftrace_pid_follow_sched_process_exit, tr); } } --- a/kernel/trace/trace_events.c +++ b/kernel/trace/trace_events.c @@ -527,12 +527,12 @@ void trace_event_follow_fork(struct trac if (enable) { register_trace_prio_sched_process_fork(event_filter_pid_sched_process_fork, tr, INT_MIN); - register_trace_prio_sched_process_exit(event_filter_pid_sched_process_exit, + register_trace_prio_sched_process_free(event_filter_pid_sched_process_exit, tr, INT_MAX); } else { unregister_trace_sched_process_fork(event_filter_pid_sched_process_fork, tr); - unregister_trace_sched_process_exit(event_filter_pid_sched_process_exit, + unregister_trace_sched_process_free(event_filter_pid_sched_process_exit, tr); } }