kernel/linux.git/drivers/gpu/drm/scheduler, branch v6.18.21

drm/sched: Fix kernel-doc warning for drm_sched_job_done()

2026-03-12T11:09:56+00:00

[ Upstream commit 61ded1083b264ff67ca8c2de822c66b6febaf9a8 ] There is a kernel-doc warning for the scheduler: Warning: drivers/gpu/drm/scheduler/sched_main.c:367 function parameter 'result' not described in 'drm_sched_job_done' Fix the warning by describing the undocumented error code. Fixes: 539f9ee4b52a ("drm/scheduler: properly forward fence errors") Signed-off-by: Yujie Liu [phasta: Flesh out commit message] Signed-off-by: Philipp Stanner Link: https://patch.msgid.link/20260227082452.1802922-1-yujie.liu@intel.com Signed-off-by: Sasha Levin

drm/sched: Fix deadlock in drm_sched_entity_kill_jobs_cb

2025-11-05T11:29:52+00:00

The Mesa issue referenced below pointed out a possible deadlock: [ 1231.611031] Possible interrupt unsafe locking scenario: [ 1231.611033] CPU0 CPU1 [ 1231.611034] ---- ---- [ 1231.611035] lock(&xa->xa_lock#17); [ 1231.611038] local_irq_disable(); [ 1231.611039] lock(&fence->lock); [ 1231.611041] lock(&xa->xa_lock#17); [ 1231.611044] [ 1231.611045] lock(&fence->lock); [ 1231.611047] *** DEADLOCK *** In this example, CPU0 would be any function accessing job->dependencies through the xa_* functions that don't disable interrupts (eg: drm_sched_job_add_dependency(), drm_sched_entity_kill_jobs_cb()). CPU1 is executing drm_sched_entity_kill_jobs_cb() as a fence signalling callback so in an interrupt context. It will deadlock when trying to grab the xa_lock which is already held by CPU0. Replacing all xa_* usage by their xa_*_irq counterparts would fix this issue, but Christian pointed out another issue: dma_fence_signal takes fence.lock and so does dma_fence_add_callback. dma_fence_signal() // locks f1.lock -> drm_sched_entity_kill_jobs_cb() -> foreach dependencies -> dma_fence_add_callback() // locks f2.lock This will deadlock if f1 and f2 share the same spinlock. To fix both issues, the code iterating on dependencies and re-arming them is moved out to drm_sched_entity_kill_jobs_work(). Cc: stable@vger.kernel.org # v6.2+ Fixes: 2fdb8a8f07c2 ("drm/scheduler: rework entity flush, kill and fini") Link: https://gitlab.freedesktop.org/mesa/mesa/-/issues/13908 Reported-by: Mikhail Gavrilov Suggested-by: Christian König Reviewed-by: Christian König Signed-off-by: Pierre-Eric Pelloux-Prayer [phasta: commit message nits] Signed-off-by: Philipp Stanner Link: https://patch.msgid.link/20251104095358.15092-1-pierre-eric.pelloux-prayer@amd.com

drm/sched: avoid killing parent entity on child SIGKILL

2025-10-28T13:11:42+00:00

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 Signed-off-by: Christian König Closes: https://gitlab.freedesktop.org/drm/amd/-/issues/4568 Reviewed-by: Alex Deucher CC: stable@vger.kernel.org Acked-by: Philipp Stanner Link: https://lore.kernel.org/r/20251015140128.1470-1-christian.koenig@amd.com Signed-off-by: Philipp Stanner Link: https://patch.msgid.link/20251015140128.1470-1-christian.koenig@amd.com

drm/sched: Fix race in drm_sched_entity_select_rq()

2025-10-27T12:48:46+00:00

In a past bug fix it was forgotten that entity access must be protected by the entity lock. That's a data race and potentially UB. Move the spin_unlock() to the appropriate position. Cc: stable@vger.kernel.org # v5.13+ Fixes: ac4eb83ab255 ("drm/sched: select new rq even if there is only one v3") Reviewed-by: Tvrtko Ursulin Signed-off-by: Philipp Stanner Link: https://patch.msgid.link/20251022063402.87318-2-phasta@kernel.org

drm/sched: Fix potential double free in drm_sched_job_add_resv_dependencies

2025-10-16T12:26:05+00:00

When adding dependencies with drm_sched_job_add_dependency(), that function consumes the fence reference both on success and failure, so in the latter case the dma_fence_put() on the error path (xarray failed to expand) is a double free. Interestingly this bug appears to have been present ever since commit ebd5f74255b9 ("drm/sched: Add dependency tracking"), since the code back then looked like this: drm_sched_job_add_implicit_dependencies(): ... for (i = 0; i < fence_count; i++) { ret = drm_sched_job_add_dependency(job, fences[i]); if (ret) break; } for (; i < fence_count; i++) dma_fence_put(fences[i]); Which means for the failing 'i' the dma_fence_put was already a double free. Possibly there were no users at that time, or the test cases were insufficient to hit it. The bug was then only noticed and fixed after commit 9c2ba265352a ("drm/scheduler: use new iterator in drm_sched_job_add_implicit_dependencies v2") landed, with its fixup of commit 4eaf02d6076c ("drm/scheduler: fix drm_sched_job_add_implicit_dependencies"). At that point it was a slightly different flavour of a double free, which commit 963d0b356935 ("drm/scheduler: fix drm_sched_job_add_implicit_dependencies harder") noticed and attempted to fix. But it only moved the double free from happening inside the drm_sched_job_add_dependency(), when releasing the reference not yet obtained, to the caller, when releasing the reference already released by the former in the failure case. As such it is not easy to identify the right target for the fixes tag so lets keep it simple and just continue the chain. While fixing we also improve the comment and explain the reason for taking the reference and not dropping it. Signed-off-by: Tvrtko Ursulin Fixes: 963d0b356935 ("drm/scheduler: fix drm_sched_job_add_implicit_dependencies harder") Reported-by: Dan Carpenter Closes: https://lore.kernel.org/dri-devel/aNFbXq8OeYl3QSdm@stanley.mountain/ Cc: Christian König Cc: Rob Clark Cc: Daniel Vetter Cc: Matthew Brost Cc: Danilo Krummrich Cc: Philipp Stanner Cc: Christian König Cc: dri-devel@lists.freedesktop.org Cc: stable@vger.kernel.org # v5.16+ Signed-off-by: Philipp Stanner Link: https://lore.kernel.org/r/20251015084015.6273-1-tvrtko.ursulin@igalia.com

drm/sched: Fix racy access to drm_sched_entity.dependency

2025-09-02T07:25:51+00:00

The drm_sched_job_unschedulable trace point can access entity->dependency after it was cleared by the callback installed in drm_sched_entity_add_dependency_cb, causing: BUG: kernel NULL pointer dereference, address: 0000000000000020 [...] Workqueue: comp_1.1.0 drm_sched_run_job_work [gpu_sched] RIP: 0010:trace_event_raw_event_drm_sched_job_unschedulable+0x70/0xd0 [gpu_sched] To fix this we either need to keep a reference to the fence before setting up the callbacks, or move the trace_drm_sched_job_unschedulable calls into drm_sched_entity_add_dependency_cb where they can be done earlier. Fixes: 76d97c870f29 ("drm/sched: Trace dependencies for GPU jobs") Signed-off-by: Pierre-Eric Pelloux-Prayer Reviewed-by: Tvrtko Ursulin Signed-off-by: Philipp Stanner Link: https://lore.kernel.org/r/20250901124032.1955-1-pierre-eric.pelloux-prayer@amd.com

drm/sched: Document race condition in drm_sched_fini()

2025-08-28T08:27:18+00:00

In drm_sched_fini() all entities are marked as stopped - without taking the appropriate lock, because that would deadlock. That means that drm_sched_fini() and drm_sched_entity_push_job() can race against each other. This should most likely be fixed by establishing the rule that all entities associated with a scheduler must be torn down first. Then, however, the locking should be removed from drm_sched_fini() alltogether with an appropriate comment. Reported-by: James Flowers Link: https://lore.kernel.org/dri-devel/20250720235748.2798-1-bold.zone2373@fastmail.com/ Reviewed-by: Christian König Signed-off-by: Philipp Stanner Link: https://lore.kernel.org/r/20250813085654.102504-2-phasta@kernel.org

drm/sched/tests: Remove redundant header files

2025-08-28T08:13:56+00:00

The header file is already included on line 8. Remove the redundant include. Fixes: 5a99350794fec ("drm/sched: Add scheduler unit testing infrastructure and some basic tests") Signed-off-by: Liao Yuanhong Reviewed-by: Tvrtko Ursulin Signed-off-by: Philipp Stanner Link: https://lore.kernel.org/r/20250819142630.368796-1-liaoyuanhong@vivo.com

drm/sched: Remove mention of indirect buffers

2025-08-28T08:09:12+00:00

Indirect buffers are an AMD term describing essentialy a job submitted to the scheduler, just a lower level one. Since scheduler was promoted to be generic long ago, lets replace those references with jobs. Signed-off-by: Tvrtko Ursulin Cc: Christian König Cc: Danilo Krummrich Cc: Matthew Brost Cc: Philipp Stanner Reviewed-by: Christian König Reviewed-by: Alex Deucher Signed-off-by: Philipp Stanner Link: https://lore.kernel.org/r/20250814133627.2550-1-tvrtko.ursulin@igalia.com

Merge drm/drm-next into drm-misc-n

2025-08-11T12:37:45+00:00

Updating drm-misc-next to the state of v6.17-rc1. Begins a new release cycle. Signed-off-by: Thomas Zimmermann