From 144ec5e1ce3bd238723a259c09f635b84fda423e Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Christian=20K=C3=B6nig?= Date: Fri, 15 Jan 2021 14:32:39 +0100 Subject: [PATCH] lockdep: add lockdep_assert_none_held_once() macro [ Upstream commit 7621350c6bb20fb6ab7eb988833ab96eac3dcbef ] DRM_SYNCOBJ_WAIT_FLAGS_WAIT_FOR_SUBMIT can't be used when we hold locks since we are basically waiting for userspace to do something. Holding a lock while doing so can trivial deadlock with page faults etc... So make lockdep complain when a driver tries to do this. v2: Add lockdep_assert_none_held() macro. v3: Add might_sleep() and also use lockdep_assert_none_held() in the IOCTL path. Signed-off-by: Christian König Reviewed-by: Daniel Vetter Acked-by: Peter Zijlstra (Intel) Link: https://patchwork.freedesktop.org/patch/414944/ Stable-dep-of: 3c43177ffb54 ("drm/syncobj: call drm_syncobj_fence_add_wait when WAIT_AVAILABLE flag is set") Signed-off-by: Sasha Levin --- include/linux/lockdep.h | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/include/linux/lockdep.h b/include/linux/lockdep.h index 2c2586312b44..3eca9f91b9a5 100644 --- a/include/linux/lockdep.h +++ b/include/linux/lockdep.h @@ -321,6 +321,10 @@ 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) @@ -394,6 +398,7 @@ static inline void lockdep_unregister_key(struct lock_class_key *key) #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) -- 2.55.0