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=-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 46BAFC433DF for ; Thu, 20 Aug 2020 12:25:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1E36122B4B for ; Thu, 20 Aug 2020 12:25:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1597926322; bh=Ppm1C6MX9zQmNg+5iS5ogBkLzVjwjFP12u3V1FrqDlU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=ntnnSIiLtTokiv9US5AGgnUb8bk3N4zNcaw53gvfmz7VhQoGwL/OBwoytMsxs+d3t fxpZduFXtjigAsx4A6p4Mir2H5PqYi5zmTOXwP5bKy74ufT2EJVe+dfRhIp7qs3Glh 3b3dZerLCHkUeq9pxpLN21UUNT2HUxHyIA3jtsAE= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730054AbgHTJxc (ORCPT ); Thu, 20 Aug 2020 05:53:32 -0400 Received: from mail.kernel.org ([198.145.29.99]:35248 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729942AbgHTJx1 (ORCPT ); Thu, 20 Aug 2020 05:53:27 -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 DAD45207FB; Thu, 20 Aug 2020 09:53:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1597917205; bh=Ppm1C6MX9zQmNg+5iS5ogBkLzVjwjFP12u3V1FrqDlU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=pmOr/mx7hR+w7Y43dei+8YBo/qwz+FcYhJAhO8ZJrRzaILq5Vx43tzX/b6Q8RULmN yEkEs0k2okRbbo24GnVnR9hFF6JWEhcfBgG9LPyKTIuqogbF8wBh7Nt5Lh5ahe28X2 hh7ynUxITXFKqr2CHDKdKJwHaUNzk7Ty/u/6u93M= 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 4.19 40/92] tracing: Use trace_sched_process_free() instead of exit() for pid tracing Date: Thu, 20 Aug 2020 11:21:25 +0200 Message-Id: <20200820091539.716867117@linuxfoundation.org> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20200820091537.490965042@linuxfoundation.org> References: <20200820091537.490965042@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: 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 @@ -6450,12 +6450,12 @@ 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 @@ -534,12 +534,12 @@ 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); } }