From: Tvrtko Ursulin <tvrtko.ursulin@xxxxxxxxxx> Without the locking amdgpu currently can race between amdgpu_ctx_set_entity_priority() (via drm_sched_entity_modify_sched()) and drm_sched_job_arm(), leading to the latter accesing potentially inconsitent entity->sched_list and entity->num_sched_list pair. v2: * Improve commit message. (Philipp) Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@xxxxxxxxxx> Fixes: b37aced31eb0 ("drm/scheduler: implement a function to modify sched list") Cc: Christian König <christian.koenig@xxxxxxx> Cc: Alex Deucher <alexander.deucher@xxxxxxx> Cc: Luben Tuikov <ltuikov89@xxxxxxxxx> Cc: Matthew Brost <matthew.brost@xxxxxxxxx> Cc: David Airlie <airlied@xxxxxxxxx> Cc: Daniel Vetter <daniel@xxxxxxxx> Cc: dri-devel@xxxxxxxxxxxxxxxxxxxxx Cc: Philipp Stanner <pstanner@xxxxxxxxxx> Cc: <stable@xxxxxxxxxxxxxxx> # v5.7+ Reviewed-by: Christian König <christian.koenig@xxxxxxx> --- drivers/gpu/drm/scheduler/sched_entity.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/gpu/drm/scheduler/sched_entity.c b/drivers/gpu/drm/scheduler/sched_entity.c index 58c8161289fe..ae8be30472cd 100644 --- a/drivers/gpu/drm/scheduler/sched_entity.c +++ b/drivers/gpu/drm/scheduler/sched_entity.c @@ -133,8 +133,10 @@ void drm_sched_entity_modify_sched(struct drm_sched_entity *entity, { WARN_ON(!num_sched_list || !sched_list); + spin_lock(&entity->rq_lock); entity->sched_list = sched_list; entity->num_sched_list = num_sched_list; + spin_unlock(&entity->rq_lock); } EXPORT_SYMBOL(drm_sched_entity_modify_sched); -- 2.46.0