Messages in this thread | | | Date | Tue, 24 Sep 2013 19:04:11 +0200 | From | Thomas Hellstrom <> | Subject | Re: [RFC PATCH] drm/nouveau: fix nested locking in mmap handler |
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On 09/24/2013 01:32 PM, Maarten Lankhorst wrote: > Op 24-09-13 12:33, Thomas Hellstrom schreef: >> On 09/24/2013 12:11 PM, Maarten Lankhorst wrote: >>> >>> It seems userspace only updates offset and domain in nouveau. If it fails to update >>> it would result in the same affect as when the buffer gets moved around by TTM. >>> But hey maybe I'll have some fun, I'll lie to userspace, hardcode userspace offset >>> to 0x40000000, always force domain to be different and see what breaks. >>> >>> My guess is absolutely nothing, except it might expose some bugs where we forgot annotation.. >> I think that would certainly break if your return an -ERESTARTSYS after applying relocations but >> before submitting the command stream to hardware.... > The relocations are updated before submitting the command stream, but it's copied back to userspace > after submitting the command stream. I'm not sure what -ERESTARTSYS would change, the syscall > is not in an interruptible state. Hmm, I was assuming without looking at the code that there was an interruptible wait for pipe/ring space after relocation application.
/Thomas
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