diff --git a/drivers/gpu/drm/drm_syncobj.c b/drivers/gpu/drm/drm_syncobj.c index 6e74e6745ecaeb21a864768d66dc07dfe7a11d82..9ecfec1e55677ccbf7660108e74369366dd1b869 100644 --- a/drivers/gpu/drm/drm_syncobj.c +++ b/drivers/gpu/drm/drm_syncobj.c @@ -387,6 +387,15 @@ int drm_syncobj_find_fence(struct drm_file *file_private, if (!syncobj) return -ENOENT; + /* Waiting for userspace with locks help is illegal cause that can + * trivial deadlock with page faults for example. Make lockdep complain + * about it early on. + */ + if (flags & DRM_SYNCOBJ_WAIT_FLAGS_WAIT_FOR_SUBMIT) { + might_sleep(); + lockdep_assert_none_held_once(); + } + *fence = drm_syncobj_fence_get(syncobj); drm_syncobj_put(syncobj); @@ -940,6 +949,9 @@ static signed long drm_syncobj_array_wait_timeout(struct drm_syncobj **syncobjs, uint64_t *points; uint32_t signaled_count, i; + if (flags & DRM_SYNCOBJ_WAIT_FLAGS_WAIT_FOR_SUBMIT) + lockdep_assert_none_held_once(); + points = kmalloc_array(count, sizeof(*points), GFP_KERNEL); if (points == NULL) return -ENOMEM; diff --git a/include/linux/lockdep.h b/include/linux/lockdep.h index b9e9adec73e8b098ff113335c2f966dce9a72d31..6eb117c0d0f320441c0a4153287b69c955b71d23 100644 --- a/include/linux/lockdep.h +++ b/include/linux/lockdep.h @@ -310,6 +310,10 @@ extern void lock_unpin_lock(struct lockdep_map *lock, struct pin_cookie); WARN_ON_ONCE(debug_locks && !lockdep_is_held(l)); \ } while (0) +#define lockdep_assert_none_held_once() do { \ + WARN_ON_ONCE(debug_locks && current->lockdep_depth); \ + } while (0) + #define lockdep_recursing(tsk) ((tsk)->lockdep_recursion) #define lockdep_pin_lock(l) lock_pin_lock(&(l)->dep_map) @@ -387,6 +391,7 @@ extern int lockdep_is_held(const void *); #define lockdep_assert_held_write(l) do { (void)(l); } while (0) #define lockdep_assert_held_read(l) do { (void)(l); } while (0) #define lockdep_assert_held_once(l) do { (void)(l); } while (0) +#define lockdep_assert_none_held_once() do { } while (0) #define lockdep_recursing(tsk) (0)