On Sat, Jan 19, 2019 at 02:04:58AM +0900, Tetsuo Handa wrote: > syzbot found a flush_work() caller who forgot to call INIT_WORK() > because that work_struct was allocated by kzalloc(). But the message > > INFO: trying to register non-static key. > the code is fine but needs lockdep annotation. > turning off the locking correctness validator. > > by lock_map_acquire() is failing to tell that INIT_WORK() is missing. > > Since flush_work() without INIT_WORK() is a bug, and INIT_WORK() should > set ->func field to non-zero, let's warn if ->func field is zero.
Agree that it's a good idea to catch this. So the caller did flush_work without queueing it beforehand? Out of curiosity, what situation leads to this? Link to the report might be helpful. > diff --git a/kernel/workqueue.c b/kernel/workqueue.c > index 392be4b..a503ad9 100644 > --- a/kernel/workqueue.c > +++ b/kernel/workqueue.c > @@ -2908,6 +2908,9 @@ static bool __flush_work(struct work_struct *work, bool > from_cancel) > if (WARN_ON(!wq_online)) > return false; > > + if (WARN_ON(!work->func)) > + return false; > + __queue_work has a sanity check already for work, but using list_empty. Seems slightly better to be consistent?
