From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758476AbZCMCox (ORCPT ); Thu, 12 Mar 2009 22:44:53 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1758169AbZCMCin (ORCPT ); Thu, 12 Mar 2009 22:38:43 -0400 Received: from hrndva-omtalb.mail.rr.com ([71.74.56.124]:48839 "EHLO hrndva-omtalb.mail.rr.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757760AbZCMCia (ORCPT ); Thu, 12 Mar 2009 22:38:30 -0400 Message-Id: <20090313023827.790845257@goodmis.org> References: <20090313023704.971438367@goodmis.org> User-Agent: quilt/0.46-1 Date: Thu, 12 Mar 2009 22:37:18 -0400 From: Steven Rostedt To: linux-kernel@vger.kernel.org Cc: Ingo Molnar , Andrew Morton , Peter Zijlstra , Frederic Weisbecker , Lai Jiangshan , KOSAKI Motohiro , Steven Rostedt Subject: [PATCH 14/16] tracing: Dont use tracing_record_cmdline() in workqueue tracer fix Content-Disposition: inline; filename=0014-tracing-Don-t-use-tracing_record_cmdline-in-workq.patch Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: KOSAKI Motohiro commit c3ffc7a40b7e94b094efe1c8ab4e24370a782b65 "Don't use tracing_record_cmdline() in workqueue tracer" has a race window. find_task_by_vpid() requires task_list_lock(). LKML-Reference: <20090313090042.43CD.A69D9226@jp.fujitsu.com> Signed-off-by: KOSAKI Motohiro Signed-off-by: Steven Rostedt --- kernel/trace/trace_workqueue.c | 20 ++++++++++++++------ 1 files changed, 14 insertions(+), 6 deletions(-) diff --git a/kernel/trace/trace_workqueue.c b/kernel/trace/trace_workqueue.c index fb5ccac..9ab035b 100644 --- a/kernel/trace/trace_workqueue.c +++ b/kernel/trace/trace_workqueue.c @@ -193,12 +193,20 @@ static int workqueue_stat_show(struct seq_file *s, void *p) struct cpu_workqueue_stats *cws = p; unsigned long flags; int cpu = cws->cpu; - struct task_struct *tsk = find_task_by_vpid(cws->pid); - - seq_printf(s, "%3d %6d %6u %s\n", cws->cpu, - atomic_read(&cws->inserted), - cws->executed, - tsk ? tsk->comm : "<...>"); + struct pid *pid; + struct task_struct *tsk; + + pid = find_get_pid(cws->pid); + if (pid) { + tsk = get_pid_task(pid, PIDTYPE_PID); + if (tsk) { + seq_printf(s, "%3d %6d %6u %s\n", cws->cpu, + atomic_read(&cws->inserted), cws->executed, + tsk->comm); + put_task_struct(tsk); + } + put_pid(pid); + } spin_lock_irqsave(&workqueue_cpu_stat(cpu)->lock, flags); if (&cws->list == workqueue_cpu_stat(cpu)->list.next) -- 1.6.1.3 --