Re: [Workqueue] crash in process_one_work

[Tejun Heo]

Hello, Arun.

On Wed, Oct 08, 2014 at 05:30:20PM +0530, Arun KS wrote:
> > I sure hope not.  How reproducible is the issue?  Can you try w/
> > CONFIG_DEBUG_OBJECTS_WORK enabled?
> 
> Thanks for replying.
> That was a problem with one of our driver. It was freeing the
> memory(struct work) without flushing workqueue.
> We caught faulty driver by adding a BUG_ON() in INIT_WORK and looking
> at the func pointer in work_struct( which will be pointing to the
> faulty driver work function)
> 
> 1) faulty driver queue_work to system_unbownded_wq
> 2) free work_struct memory, but it is still queued in the work queue.
> 3) another driver request the memory from SLAB, go the same memory, it INIT_WORK
> 4) process work try to execute the work queued by the faulty driver,
> result in a crash.

Ah, good to hear.  I think bugs like the above should be detectable
with CONFIG_DEBUG_OBJECTS_WORK, so if you see something similar next
time, please try it out.

Thanks.

-- 
tejun
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/