From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757507AbaEPNwp (ORCPT ); Fri, 16 May 2014 09:52:45 -0400 Received: from mx1.redhat.com ([209.132.183.28]:33836 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757480AbaEPNwn (ORCPT ); Fri, 16 May 2014 09:52:43 -0400 Date: Fri, 16 May 2014 15:51:37 +0200 From: Oleg Nesterov To: Andrew Morton , Peter Zijlstra , David Howells Cc: Mel Gorman , Johannes Weiner , Vlastimil Babka , Jan Kara , Michal Hocko , Hugh Dickins , Dave Hansen , Linux Kernel , Linux-MM , Linux-FSDevel , Paul McKenney , Linus Torvalds Subject: [PATCH 1/1] ptrace: task_clear_jobctl_trapping()->wake_up_bit() needs mb() Message-ID: <20140516135137.GB19210@redhat.com> References: <1399974350-11089-1-git-send-email-mgorman@suse.de> <1399974350-11089-20-git-send-email-mgorman@suse.de> <20140513125313.GR23991@suse.de> <20140513141748.GD2485@laptop.programming.kicks-ass.net> <20140514161152.GA2615@redhat.com> <20140514161755.GQ30445@twins.programming.kicks-ass.net> <20140516135116.GA19210@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20140516135116.GA19210@redhat.com> User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org __wake_up_bit() checks waitqueue_active() and thus the caller needs mb() as wake_up_bit() documents, fix task_clear_jobctl_trapping(). Signed-off-by: Oleg Nesterov --- kernel/signal.c | 1 + 1 files changed, 1 insertions(+), 0 deletions(-) diff --git a/kernel/signal.c b/kernel/signal.c index c2a8542..f4c4119 100644 --- a/kernel/signal.c +++ b/kernel/signal.c @@ -277,6 +277,7 @@ void task_clear_jobctl_trapping(struct task_struct *task) { if (unlikely(task->jobctl & JOBCTL_TRAPPING)) { task->jobctl &= ~JOBCTL_TRAPPING; + smp_mb(); /* advised by wake_up_bit() */ wake_up_bit(&task->jobctl, JOBCTL_TRAPPING_BIT); } } -- 1.5.5.1