[PATCH 1/2] locking/lockdep: Provide lockdep_assert{, _once}() helpers

Desmond Cheong Zhi Xi desmondcheongzx at gmail.com
Fri Jul 30 04:15:14 UTC 2021


From: Peter Zijlstra <peterz at infradead.org>

Extract lockdep_assert{,_once}() helpers to more easily write composite
assertions like, for example:

	lockdep_assert(lockdep_is_held(&drm_device.master_mutex) ||
		       lockdep_is_held(&drm_file.master_lookup_lock));

Signed-off-by: Peter Zijlstra (Intel) <peterz at infradead.org>
Signed-off-by: Desmond Cheong Zhi Xi <desmondcheongzx at gmail.com>
---
 include/linux/lockdep.h | 41 +++++++++++++++++++++--------------------
 1 file changed, 21 insertions(+), 20 deletions(-)

diff --git a/include/linux/lockdep.h b/include/linux/lockdep.h
index 5cf387813754..9fe165beb0f9 100644
--- a/include/linux/lockdep.h
+++ b/include/linux/lockdep.h
@@ -306,31 +306,29 @@ extern void lock_unpin_lock(struct lockdep_map *lock, struct pin_cookie);
 
 #define lockdep_depth(tsk)	(debug_locks ? (tsk)->lockdep_depth : 0)
 
-#define lockdep_assert_held(l)	do {					\
-		WARN_ON(debug_locks &&					\
-			lockdep_is_held(l) == LOCK_STATE_NOT_HELD);	\
-	} while (0)
+#define lockdep_assert(cond)		\
+	do { WARN_ON(debug_locks && !(cond)); } while (0)
 
-#define lockdep_assert_not_held(l)	do {				\
-		WARN_ON(debug_locks &&					\
-			lockdep_is_held(l) == LOCK_STATE_HELD);		\
-	} while (0)
+#define lockdep_assert_once(cond)	\
+	do { WARN_ON_ONCE(debug_locks && !(cond)); } while (0)
 
-#define lockdep_assert_held_write(l)	do {			\
-		WARN_ON(debug_locks && !lockdep_is_held_type(l, 0));	\
-	} while (0)
+#define lockdep_assert_held(l)		\
+	lockdep_assert(lockdep_is_held(l) != LOCK_STATE_NOT_HELD)
 
-#define lockdep_assert_held_read(l)	do {				\
-		WARN_ON(debug_locks && !lockdep_is_held_type(l, 1));	\
-	} while (0)
+#define lockdep_assert_not_held(l)	\
+	lockdep_assert(lockdep_is_held(l) != LOCK_STATE_HELD)
 
-#define lockdep_assert_held_once(l)	do {				\
-		WARN_ON_ONCE(debug_locks && !lockdep_is_held(l));	\
-	} while (0)
+#define lockdep_assert_held_write(l)	\
+	lockdep_assert(lockdep_is_held_type(l, 0))
 
-#define lockdep_assert_none_held_once()	do {				\
-		WARN_ON_ONCE(debug_locks && current->lockdep_depth);	\
-	} while (0)
+#define lockdep_assert_held_read(l)	\
+	lockdep_assert(lockdep_is_held_type(l, 1))
+
+#define lockdep_assert_held_once(l)		\
+	lockdep_assert_once(lockdep_is_held(l) != LOCK_STATE_NOT_HELD)
+
+#define lockdep_assert_none_held_once()		\
+	lockdep_assert_once(!current->lockdep_depth)
 
 #define lockdep_recursing(tsk)	((tsk)->lockdep_recursion)
 
@@ -407,6 +405,9 @@ extern int lock_is_held(const void *);
 extern int lockdep_is_held(const void *);
 #define lockdep_is_held_type(l, r)		(1)
 
+#define lockdep_assert(c)			do { } while (0)
+#define lockdep_assert_once(c)			do { } while (0)
+
 #define lockdep_assert_held(l)			do { (void)(l); } while (0)
 #define lockdep_assert_not_held(l)		do { (void)(l); } while (0)
 #define lockdep_assert_held_write(l)		do { (void)(l); } while (0)
-- 
2.25.1



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