6.6-stable review patch. If anyone has any objections, please let me know.
------------------
From: Tvrtko Ursulin <tvrtko.ursulin@xxxxxxxxxx>
commit 4286cc2c953983d44d248c9de1c81d3a9643345c upstream.
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>
Link: https://patchwork.freedesktop.org/patch/msgid/20240913160559.49054-2-tursulin@xxxxxxxxxx
Signed-off-by: Christian König <christian.koenig@xxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/gpu/drm/scheduler/sched_entity.c | 2 ++
1 file changed, 2 insertions(+)
--- a/drivers/gpu/drm/scheduler/sched_entity.c
+++ b/drivers/gpu/drm/scheduler/sched_entity.c
@@ -111,8 +111,10 @@ void drm_sched_entity_modify_sched(struc
{
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);
