On Mon, Jan 27, 2014 at 10:41:57PM +0100, Daniel Vetter wrote: > On Mon, Jan 27, 2014 at 10:26 PM, Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> wrote: > > On Mon, Jan 27, 2014 at 09:49:47PM +0100, Daniel Vetter wrote: > >> Userspace can currently provoke this when e.g. trying to use a pinned > >> scanout as a cursor or overlay target. Later on that might lead to > >> some fun fence pin count mayhem. > >> > >> Spurred by Ville's report that something goes wrong here and > >> originally I've thought that this might slip through the pwrite gtt > >> fastpath. But that one checks of obj tiling, so should be ok. > >> > >> But one thing that _does_ blow up is the vma unbinding with more than > >> one address space. The next patch will fix this. > > > > It's buggy behaviour, so if (WARN_ON(fence->pin_count) return -EBUSY; > > > > I did worry that we would then have some unexpected failure, a new EBUSY > > returning to userspace, but I think along the paths that can trigger it, > > we have already returned EBUSY in the (dim and distant) past. > > Indeed we seem to have the required tiling checks everywhere. At first > I've had the WARN but then though userspace could sneak in through the > cursor/overlay code, but it can't. I'll update the patch. I've tested these (+ Chris's WARN_ON) and the issue looks to be fixed. Tested-by: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx> -- Ville Syrjälä Intel OTC _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/intel-gfx
