From 7b08c866d7f084a4277921b14c155e029c52a888 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Tue, 4 Dec 2012 07:40:39 -0800 Subject: [PATCH] workqueue: convert BUG_ON()s in __queue_delayed_work() to WARN_ON_ONCE()s commit fc4b514f2727f74a4587c31db87e0e93465518c3 upstream. 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, casted 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 [Shuah Khan: This change is back-ported from upstream change that converted BUG_ON()s in __queue_delayed_work() to WARN_ON_ONCE()s.] Tested on Stable Trees: 3.0.x, 3.4.x, 3.6.x Signed-off-by: Shuah Khan Signed-off-by: Ben Hutchings --- kernel/workqueue.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/kernel/workqueue.c b/kernel/workqueue.c index d551d5f53f09..7bf068a76357 100644 --- a/kernel/workqueue.c +++ b/kernel/workqueue.c @@ -1146,8 +1146,8 @@ int queue_delayed_work_on(int cpu, struct workqueue_struct *wq, if (!test_and_set_bit(WORK_STRUCT_PENDING_BIT, work_data_bits(work))) { unsigned int lcpu; - BUG_ON(timer_pending(timer)); - BUG_ON(!list_empty(&work->entry)); + WARN_ON_ONCE(timer_pending(timer)); + WARN_ON_ONCE(!list_empty(&work->entry)); timer_stats_timer_set_start_info(&dwork->timer); -- 2.39.2