From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tejun Heo Subject: [PATCH 2/2] workqueue: convert BUG_ON()s in __queue_delayed_work() to WARN_ON_ONCE()s Date: Tue, 4 Dec 2012 07:55:06 -0800 Message-ID: <20121204155506.GF3885@mtj.dyndns.org> References: <1354620834-2953-1-git-send-email-xtfeng@gmail.com> <20121204155434.GE3885@mtj.dyndns.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <20121204155434.GE3885@mtj.dyndns.org> Sender: linux-kernel-owner@vger.kernel.org To: Xiaotian Feng Cc: linux-kernel@vger.kernel.org, Xiaotian Feng , Neela Syam Kolli , "James E.J. Bottomley" , linux-scsi@vger.kernel.org List-Id: linux-scsi@vger.kernel.org >>From 87aa1e796ff6d491b5ed4e5663e5a4e449ac513b Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Tue, 4 Dec 2012 07:40:39 -0800 8852aac25e ("workqueue: mod_delayed_work_on() shouldn't queue timer on 0 delay") unexpectedly uncovered a very nasty abuse of delayed_work in megaraid - it allocated work_struct, used container_of() to cast it to delayed_work and then pass that into queue_delayed_work(). Previously, this was okay because 0 @delay short-circuited to queue_work() before doing anything with delayed_work. 8852aac25e moved 0 @delay test into __queue_delayed_work() after sanity check on delayed_work making megaraid trigger BUG_ON(). Although megaraid is already fixed by c1d390d8e6 ("megaraid: fix BUG_ON() from incorrect use of delayed work"), this patch converts BUG_ON()s in __queue_delayed_work() to WARN_ON_ONCE()s so that such abusers, if there are more, trigger warning but don't crash the machine. Signed-off-by: Tejun Heo Cc: Xiaotian Feng --- kernel/workqueue.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/kernel/workqueue.c b/kernel/workqueue.c index 084aa47..1dae900 100644 --- a/kernel/workqueue.c +++ b/kernel/workqueue.c @@ -1361,8 +1361,8 @@ static void __queue_delayed_work(int cpu, struct workqueue_struct *wq, WARN_ON_ONCE(timer->function != delayed_work_timer_fn || timer->data != (unsigned long)dwork); - BUG_ON(timer_pending(timer)); - BUG_ON(!list_empty(&work->entry)); + WARN_ON_ONCE(timer_pending(timer)); + WARN_ON_ONCE(!list_empty(&work->entry)); /* * If @delay is 0, queue @dwork->work immediately. This is for -- 1.7.11.7