Messages in this thread Patch in this message | | | From | Greg Kroah-Hartman <> | Subject | [ 10/37] workqueue: convert BUG_ON()s in __queue_delayed_work() to WARN_ON_ONCE()s | Date | Fri, 14 Dec 2012 15:00:47 -0800 |
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3.6-stable review patch. If anyone has any objections, please let me know.
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From: Tejun Heo <tj@kernel.org>
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 <tj@kernel.org> Cc: Xiaotian Feng <xtfeng@gmail.com> Signed-off-by: Shuah Khan <shuah.khan@hp.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
--- kernel/workqueue.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
--- a/kernel/workqueue.c +++ b/kernel/workqueue.c @@ -1143,8 +1143,8 @@ int queue_delayed_work_on(int cpu, struc 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);
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