diff mbox series

[RFC,3/4] drm/sched: Keep module reference while there are active fences

Message ID 20250418164246.72426-4-tvrtko.ursulin@igalia.com (mailing list archive)
State New
Headers show
Series Some (drm_sched_|dma_)fence lifetime issues | expand

Commit Message

Tvrtko Ursulin April 18, 2025, 4:42 p.m. UTC
Continuing the theme from previous patches. This time round we deal with
the problem that it is possible to unbind the driver from the PCI device
with an active sync file fence.

Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@igalia.com>
Cc: Christian König <christian.koenig@amd.com>
Cc: Danilo Krummrich <dakr@kernel.org>
Cc: Lucas De Marchi <lucas.demarchi@intel.com>
Cc: Matthew Brost <matthew.brost@intel.com>
Cc: Philipp Stanner <phasta@kernel.org>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
---
 drivers/gpu/drm/scheduler/sched_fence.c | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)
diff mbox series

Patch

diff --git a/drivers/gpu/drm/scheduler/sched_fence.c b/drivers/gpu/drm/scheduler/sched_fence.c
index e971528504a5..178077f03e44 100644
--- a/drivers/gpu/drm/scheduler/sched_fence.c
+++ b/drivers/gpu/drm/scheduler/sched_fence.c
@@ -115,8 +115,10 @@  static void drm_sched_fence_free_rcu(struct rcu_head *rcu)
 void drm_sched_fence_free(struct drm_sched_fence *fence)
 {
 	/* This function should not be called if the fence has been initialized. */
-	if (!WARN_ON_ONCE(fence->sched))
+	if (!WARN_ON_ONCE(fence->sched)) {
 		kmem_cache_free(sched_fence_slab, fence);
+		module_put(THIS_MODULE);
+	}
 }
 
 /**
@@ -133,6 +135,7 @@  static void drm_sched_fence_release_scheduled(struct dma_fence *f)
 
 	dma_fence_put(fence->parent);
 	call_rcu(&fence->finished.rcu, drm_sched_fence_free_rcu);
+	module_put(THIS_MODULE);
 }
 
 /**
@@ -210,9 +213,14 @@  struct drm_sched_fence *drm_sched_fence_alloc(struct drm_sched_entity *entity,
 {
 	struct drm_sched_fence *fence = NULL;
 
+	if (!try_module_get(THIS_MODULE))
+		return NULL;
+
 	fence = kmem_cache_zalloc(sched_fence_slab, GFP_KERNEL);
-	if (fence == NULL)
+	if (!fence) {
+		module_put(THIS_MODULE);
 		return NULL;
+	}
 
 	fence->owner = owner;
 	spin_lock_init(&fence->lock);