From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752071Ab1AHUSJ (ORCPT ); Sat, 8 Jan 2011 15:18:09 -0500 Received: from hrndva-omtalb.mail.rr.com ([71.74.56.125]:49711 "EHLO hrndva-omtalb.mail.rr.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751455Ab1AHUQr (ORCPT ); Sat, 8 Jan 2011 15:16:47 -0500 X-Authority-Analysis: v=1.1 cv=+c36koQ5Dcj/1qolKHjtkYAGXvrVJRRiKMp+84F5sLg= c=1 sm=0 a=qTKyyP81ZpcA:10 a=bbbx4UPp9XUA:10 a=OPBmh+XkhLl+Enan7BmTLg==:17 a=omOdbC7AAAAA:8 a=VwQbUJbxAAAA:8 a=meVymXHHAAAA:8 a=b7Hv58zx8xWRB-HYK-MA:9 a=UCRDLsGb3T3r8Upl5S6ezSR8OrIA:4 a=LI9Vle30uBYA:10 a=jeBq3FmKZ4MA:10 a=OPBmh+XkhLl+Enan7BmTLg==:117 X-Cloudmark-Score: 0 X-Originating-IP: 67.242.120.143 Message-Id: <20110108201645.768731043@goodmis.org> User-Agent: quilt/0.48-1 Date: Sat, 08 Jan 2011 15:16:04 -0500 From: Steven Rostedt To: linux-kernel@vger.kernel.org Cc: Ingo Molnar , Andrew Morton , Frederic Weisbecker , , Li Zefan Subject: [PATCH 5/7] tracing: Fix preempt count leak References: <20110108201559.130182944@goodmis.org> Content-Disposition: inline; filename=0005-tracing-Fix-preempt-count-leak.patch Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Li Zefan 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(); } -- 1.7.2.3