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- From 144ec5e1ce3bd238723a259c09f635b84fda423e Mon Sep 17 00:00:00 2001
- From: =?UTF-8?q?Christian=20K=C3=B6nig?= <christian.koenig@amd.com>
- 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 <christian.koenig@amd.com>
- Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
- Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
- 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 <sashal@kernel.org>
- ---
- 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
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