Merge tag 'drm-misc-next-2023-04-12' of git://anongit.freedesktop.org/drm/drm-misc into drm-next

drm-misc-next for v6.4-rc1:

Cross-subsystem Changes:
- Convert MIPI DSIM bridge dt to yaml.

Core Changes:
- Fix UAF race in drm scheduler.

Driver Changes:
- Add primary plane positioning support to VKMS.
- Convert omapdrm fbdev emulation to in-kernel client.
- Assorted small fixes to vkms, vc4, nouveau, vmwgfx.

Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
From: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/b7c37d4e-8f16-85dc-0f5f-3bd98f961395@linux.intel.com

1 files changed, 9 insertions, 2 deletions

diff --git a/drivers/gpu/drm/scheduler/sched_entity.c b/drivers/gpu/drm/scheduler/sched_entity.c
index 15d04a0ec623..e0a8890a62e2 100644
--- a/drivers/gpu/drm/scheduler/sched_entity.c
+++ b/drivers/gpu/drm/scheduler/sched_entity.c
@@ -507,12 +507,19 @@ void drm_sched_entity_push_job(struct drm_sched_job *sched_job)
 {
 	struct drm_sched_entity *entity = sched_job->entity;
 	bool first;
+	ktime_t submit_ts;
 
 	trace_drm_sched_job(sched_job, entity);
 	atomic_inc(entity->rq->sched->score);
 	WRITE_ONCE(entity->last_user, current->group_leader);
+
+	/*
+	 * After the sched_job is pushed into the entity queue, it may be
+	 * completed and freed up at any time. We can no longer access it.
+	 * Make sure to set the submit_ts first, to avoid a race.
+	 */
+	sched_job->submit_ts = submit_ts = ktime_get();
 	first = spsc_queue_push(&entity->job_queue, &sched_job->queue_node);
-	sched_job->submit_ts = ktime_get();
 
 	/* first job wakes up scheduler */
 	if (first) {
@@ -529,7 +536,7 @@ void drm_sched_entity_push_job(struct drm_sched_job *sched_job)
 		spin_unlock(&entity->rq_lock);
 
 		if (drm_sched_policy == DRM_SCHED_POLICY_FIFO)
-			drm_sched_rq_update_fifo(entity, sched_job->submit_ts);
+			drm_sched_rq_update_fifo(entity, submit_ts);
 
 		drm_sched_wakeup(entity->rq->sched);
 	}