Messages in this thread | | | Date | Fri, 16 Aug 2013 18:38:58 +0200 | From | Richard Weinberger <> | Subject | Re: [PATCH] print_worker_info: Handle pointer with more care |
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Am 16.08.2013 18:28, schrieb Tejun Heo: > 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()?
You are already talking to UML people. ;) Anyway, I'll investigate into that. What I see so far is that pwq is NULL after probe_kernel_read().
Thanks, //richard
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