On Thu, Mar 31, 2022 at 05:20:21PM +0200, Daniel Vetter wrote: > The stuff never really worked, and leads to lots of fun because it > out-of-order frees atomic states. Which upsets KASAN, among other > things. > > For async updates we now have a more solid solution with the > ->atomic_async_check and ->atomic_async_commit hooks. Support for that > for msm and vc4 landed. nouveau and i915 have their own commit > routines, doing something similar. > > For everyone else it's probably better to remove the use-after-free > bug, and encourage folks to use the async support instead. The > affected drivers which register a legacy cursor plane and don't either > use the new async stuff or their own commit routine are: amdgpu, > atmel, mediatek, qxl, rockchip, sti, sun4i, tegra, virtio, and vmwgfx. > > Inspired by an amdgpu bug report. > > v2: Drop RFC, I think with amdgpu converted over to use > atomic_async_check/commit done in > > commit 674e78acae0dfb4beb56132e41cbae5b60f7d662 > Author: Nicholas Kazlauskas <nicholas.kazlauskas@xxxxxxx> > Date: Wed Dec 5 14:59:07 2018 -0500 > > drm/amd/display: Add fast path for cursor plane updates > > we don't have any driver anymore where we have userspace expecting > solid legacy cursor support _and_ they are using the atomic helpers in > their fully glory. So we can retire this. > > v3: Paper over msm and i915 regression. The complete_all is the only > thing missing afaict. > > v4: Fixup i915 fixup ... > > References: https://bugzilla.kernel.org/show_bug.cgi?id=199425 > References: https://lore.kernel.org/all/20220221134155.125447-9-maxime@xxxxxxxxxx/ > References: https://bugzilla.kernel.org/show_bug.cgi?id=199425 > Cc: Maxime Ripard <maxime@xxxxxxxxxx> > Tested-by: Maxime Ripard <maxime@xxxxxxxxxx> > Cc: mikita.lipski@xxxxxxx > Cc: Michel Dänzer <michel@xxxxxxxxxxx> > Cc: harry.wentland@xxxxxxx > Cc: Rob Clark <robdclark@xxxxxxxxx> > Cc: "Kazlauskas, Nicholas" <nicholas.kazlauskas@xxxxxxx> > Cc: Dmitry Osipenko <dmitry.osipenko@xxxxxxxxxxxxx> > Signed-off-by: Daniel Vetter <daniel.vetter@xxxxxxxxx> Acked-by: Maxime Ripard <maxime@xxxxxxxxxx> Maxime
