Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel os linux

drm/gem: Properly annotate WW context on drm_gem_lock_reservations() error

Use ww_acquire_fini() in the error code paths. Otherwise lockdep
thinks that lock is held when lock's memory is freed after the
drm_gem_lock_reservations() error. The ww_acquire_context needs to be
annotated as "released", which fixes the noisy "WARNING: held lock freed!"
splat of VirtIO-GPU driver with CONFIG_DEBUG_MUTEXES=y and enabled lockdep.

Cc: stable@vger.kernel.org
Fixes: 7edc3e3b975b5 ("drm: Add helpers for locking an array of BO reservations.")
Reviewed-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20220630200405.1883897-2-dmitry.osipenko@collabora.com

authored by

Dmitry Osipenko and committed by
Daniel Vetter
2939deac df4aaf01

+2 -2
+2 -2
drivers/gpu/drm/drm_gem.c
··· 1226 1226 ret = dma_resv_lock_slow_interruptible(obj->resv, 1227 1227 acquire_ctx); 1228 1228 if (ret) { 1229 - ww_acquire_done(acquire_ctx); 1229 + ww_acquire_fini(acquire_ctx); 1230 1230 return ret; 1231 1231 } 1232 1232 } ··· 1251 1251 goto retry; 1252 1252 } 1253 1253 1254 - ww_acquire_done(acquire_ctx); 1254 + ww_acquire_fini(acquire_ctx); 1255 1255 return ret; 1256 1256 } 1257 1257 }