On Fri, Jul 24, 2015 at 11:51:01AM +0100, Chris Wilson wrote: > On Fri, Jul 24, 2015 at 11:22:34AM +0200, Michał Winiarski wrote: > > From: Rafał Sapała <rafal.a.sapala@xxxxxxxxx> > > > > It is possible to hit a race condition in create_from_prime, when trying > > to import a BO that's currently being freed. In case of prime sharing > > we'll succesfully get a handle, but fail on get_tiling call, potentially > > confusing the caller (and requiring different locking scheme than with > > sharing using flink). Wrap fd_to_handle with struct_mutex to force > > a more consistent behaviour between prime/flink, convert fprintf to DBG > > when handling errors. > > The race is that the kernel returns us the same file-private handle as > the first thread, but that first thread is about to call gem_close > (thereby removing the handle from the file completely) and does so > between us acquiring the handle and taking the mutex. If we take > the mutex, then we acquire the refcnt on the bo prior to the first > thread completing its unref (and so preventing the early close). Or we > acquire the handle after the earlier close, in which case we are the new > owner. > > Reviewed-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> Thanks for the patch & review, pushed. -- Damien _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/intel-gfx
