From 4286cc2c953983d44d248c9de1c81d3a9643345c Mon Sep 17 00:00:00 2001 From: Tvrtko Ursulin Date: Fri, 13 Sep 2024 17:05:52 +0100 Subject: [PATCH] drm/sched: Add locking to drm_sched_entity_modify_sched MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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 Fixes: b37aced31eb0 ("drm/scheduler: implement a function to modify sched list") Cc: Christian König Cc: Alex Deucher Cc: Luben Tuikov Cc: Matthew Brost Cc: David Airlie Cc: Daniel Vetter Cc: dri-devel@lists.freedesktop.org Cc: Philipp Stanner Cc: # v5.7+ Reviewed-by: Christian König Link: https://patchwork.freedesktop.org/patch/msgid/20240913160559.49054-2-tursulin@igalia.com Signed-off-by: Christian König --- 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 567e5ace6d0c4..0e002c17fcb62 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);