Messages in this thread | | | Date | Fri, 16 Aug 2013 12:28:44 -0400 | From | Tejun Heo <> | Subject | Re: [PATCH] print_worker_info: Handle pointer with more care |
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On Fri, Aug 16, 2013 at 06:15:07PM +0200, Richard Weinberger wrote: > On UML I hit the case that pwq is NULL. > Then we oops at &pwq->wq...
Hmmm? I'm confused. &pwq->wq is pwq's pointer + wq's offset in pwq. It doesn't involve dereferencing pwq->wq. Maybe uml isn't implementing probe_kernel_thread()? Now that I think about it, I'm not sure how it could.
cc'ing uml people. Hey, guys, workqueue uses proble_kernel_read() to print out workqueue related information during oops because those events are completely asynchronous and workqueue states may not be consistently accessible. It seems like uml doesn't implement probe_kernel_read() and tries direct derference of incorrect pointers leading to its own oops. Maybe uml should check whether the memory is mapped from probe_kernel_read()?
Thanks.
-- tejun
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