From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752766Ab1AIVLx (ORCPT ); Sun, 9 Jan 2011 16:11:53 -0500 Received: from hera.kernel.org ([140.211.167.34]:38426 "EHLO hera.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751501Ab1AIVLv (ORCPT ); Sun, 9 Jan 2011 16:11:51 -0500 Date: Sun, 9 Jan 2011 21:11:37 GMT From: tip-bot for Li Zefan Cc: linux-kernel@vger.kernel.org, hpa@zytor.com, mingo@redhat.com, rostedt@goodmis.org, lizf@cn.fujitsu.com, stable@kernel.org, tglx@linutronix.de Reply-To: mingo@redhat.com, hpa@zytor.com, linux-kernel@vger.kernel.org, lizf@cn.fujitsu.com, rostedt@goodmis.org, stable@kernel.org, tglx@linutronix.de In-Reply-To: <4D0089AC.1020802@cn.fujitsu.com> References: <4D0089AC.1020802@cn.fujitsu.com> To: linux-tip-commits@vger.kernel.org Subject: [tip:perf/urgent] tracing: Fix preempt count leak Message-ID: Git-Commit-ID: 1dbd1951f39e13da579ffe879cce19586d0462de X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.2.3 (hera.kernel.org [127.0.0.1]); Sun, 09 Jan 2011 21:11:38 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: 1dbd1951f39e13da579ffe879cce19586d0462de Gitweb: http://git.kernel.org/tip/1dbd1951f39e13da579ffe879cce19586d0462de Author: Li Zefan AuthorDate: Thu, 9 Dec 2010 15:47:56 +0800 Committer: Steven Rostedt CommitDate: Fri, 7 Jan 2011 23:20:02 -0500 tracing: Fix preempt count leak While running my ftrace stress test, this showed up: BUG: sleeping function called from invalid context at mm/mmap.c:233 ... note: cat[3293] exited with preempt_count 1 The bug was introduced by commit 91e86e560d0b3ce4c5fc64fd2bbb99f856a30a4e ("tracing: Fix recursive user stack trace") Cc: Signed-off-by: Li Zefan LKML-Reference: <4D0089AC.1020802@cn.fujitsu.com> Signed-off-by: Steven Rostedt --- kernel/trace/trace.c | 6 ++---- 1 files changed, 2 insertions(+), 4 deletions(-) diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index f8cf959..dc53ecb 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -1313,12 +1313,10 @@ ftrace_trace_userstack(struct ring_buffer *buffer, unsigned long flags, int pc) __this_cpu_inc(user_stack_count); - - event = trace_buffer_lock_reserve(buffer, TRACE_USER_STACK, sizeof(*entry), flags, pc); if (!event) - return; + goto out_drop_count; entry = ring_buffer_event_data(event); entry->tgid = current->tgid; @@ -1333,8 +1331,8 @@ ftrace_trace_userstack(struct ring_buffer *buffer, unsigned long flags, int pc) if (!filter_check_discard(call, entry, buffer, event)) ring_buffer_unlock_commit(buffer, event); + out_drop_count: __this_cpu_dec(user_stack_count); - out: preempt_enable(); }