6.12-stable review patch. If anyone has any objections, please let me know.
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From: David Rosca david.rosca@amd.com
commit 9e8b3201c7302d5b522ba3535630bed21cc03c27 upstream.
The DRM scheduler tracks who last uses an entity and when that process is killed blocks all further submissions to that entity.
The problem is that we didn't track who initially created an entity, so when a process accidently leaked its file descriptor to a child and that child got killed, we killed the parent's entities.
Avoid that and instead initialize the entities last user on entity creation. This also allows to drop the extra NULL check.
Signed-off-by: David Rosca david.rosca@amd.com Signed-off-by: Christian König christian.koenig@amd.com Closes: https://gitlab.freedesktop.org/drm/amd/-/issues/4568 Reviewed-by: Alex Deucher alexander.deucher@amd.com CC: stable@vger.kernel.org Acked-by: Philipp Stanner phasta@kernel.org Link: https://lore.kernel.org/r/20251015140128.1470-1-christian.koenig@amd.com Signed-off-by: Philipp Stanner phasta@kernel.org Link: https://patch.msgid.link/20251015140128.1470-1-christian.koenig@amd.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/gpu/drm/scheduler/sched_entity.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
--- a/drivers/gpu/drm/scheduler/sched_entity.c +++ b/drivers/gpu/drm/scheduler/sched_entity.c @@ -71,6 +71,7 @@ int drm_sched_entity_init(struct drm_sch entity->guilty = guilty; entity->num_sched_list = num_sched_list; entity->priority = priority; + entity->last_user = current->group_leader; /* * It's perfectly valid to initialize an entity without having a valid * scheduler attached. It's just not valid to use the scheduler before it @@ -315,7 +316,7 @@ long drm_sched_entity_flush(struct drm_s
/* For killed process disable any more IBs enqueue right now */ last_user = cmpxchg(&entity->last_user, current->group_leader, NULL); - if ((!last_user || last_user == current->group_leader) && + if (last_user == current->group_leader && (current->flags & PF_EXITING) && (current->exit_code == SIGKILL)) drm_sched_entity_kill(entity);