From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760893AbZFZSw0 (ORCPT ); Fri, 26 Jun 2009 14:52:26 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753820AbZFZSwS (ORCPT ); Fri, 26 Jun 2009 14:52:18 -0400 Received: from hera.kernel.org ([140.211.167.34]:49181 "EHLO hera.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752169AbZFZSwR (ORCPT ); Fri, 26 Jun 2009 14:52:17 -0400 Date: Fri, 26 Jun 2009 18:51:31 GMT From: tip-bot for Li Zefan To: linux-tip-commits@vger.kernel.org Cc: linux-kernel@vger.kernel.org, hpa@zytor.com, mingo@redhat.com, fweisbec@gmail.com, rostedt@goodmis.org, lizf@cn.fujitsu.com, tglx@linutronix.de, mingo@elte.hu Reply-To: mingo@redhat.com, hpa@zytor.com, linux-kernel@vger.kernel.org, fweisbec@gmail.com, lizf@cn.fujitsu.com, rostedt@goodmis.org, tglx@linutronix.de, mingo@elte.hu In-Reply-To: <4A448D17.9010305@cn.fujitsu.com> References: <4A448D17.9010305@cn.fujitsu.com> Subject: [tip:tracing/urgent] tracing: Fix stack tracer sysctl handling Message-ID: Git-Commit-ID: a32c7765e2796395aec49f699bd25c407155e9c5 X-Mailer: tip-git-log-daemon MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.0 (hera.kernel.org [127.0.0.1]); Fri, 26 Jun 2009 18:51:33 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: a32c7765e2796395aec49f699bd25c407155e9c5 Gitweb: http://git.kernel.org/tip/a32c7765e2796395aec49f699bd25c407155e9c5 Author: Li Zefan AuthorDate: Fri, 26 Jun 2009 16:55:51 +0800 Committer: Ingo Molnar CommitDate: Fri, 26 Jun 2009 20:48:39 +0200 tracing: Fix stack tracer sysctl handling This made my machine completely frozen: # echo 1 > /proc/sys/kernel/stack_tracer_enabled # echo 2 > /proc/sys/kernel/stack_tracer_enabled The cause is register_ftrace_function() was called twice. Also fix ftrace_enabled sysctl, though seems nothing bad happened as I tested it. Signed-off-by: Li Zefan Cc: Steven Rostedt Cc: Frederic Weisbecker LKML-Reference: <4A448D17.9010305@cn.fujitsu.com> Signed-off-by: Ingo Molnar --- kernel/trace/ftrace.c | 4 ++-- kernel/trace/trace_stack.c | 4 ++-- 2 files changed, 4 insertions(+), 4 deletions(-) diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index f3716bf..bce9e01 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -3160,10 +3160,10 @@ ftrace_enable_sysctl(struct ctl_table *table, int write, ret = proc_dointvec(table, write, file, buffer, lenp, ppos); - if (ret || !write || (last_ftrace_enabled == ftrace_enabled)) + if (ret || !write || (last_ftrace_enabled == !!ftrace_enabled)) goto out; - last_ftrace_enabled = ftrace_enabled; + last_ftrace_enabled = !!ftrace_enabled; if (ftrace_enabled) { diff --git a/kernel/trace/trace_stack.c b/kernel/trace/trace_stack.c index 2d7aebd..e644af9 100644 --- a/kernel/trace/trace_stack.c +++ b/kernel/trace/trace_stack.c @@ -326,10 +326,10 @@ stack_trace_sysctl(struct ctl_table *table, int write, ret = proc_dointvec(table, write, file, buffer, lenp, ppos); if (ret || !write || - (last_stack_tracer_enabled == stack_tracer_enabled)) + (last_stack_tracer_enabled == !!stack_tracer_enabled)) goto out; - last_stack_tracer_enabled = stack_tracer_enabled; + last_stack_tracer_enabled = !!stack_tracer_enabled; if (stack_tracer_enabled) register_ftrace_function(&trace_ops);