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-rw-r--r--include/linux/lockdep.h21
1 files changed, 18 insertions, 3 deletions
diff --git a/include/linux/lockdep.h b/include/linux/lockdep.h
index 619ec3f26cdc..43fb35bd7baf 100644
--- a/include/linux/lockdep.h
+++ b/include/linux/lockdep.h
@@ -46,15 +46,19 @@ extern int lock_stat;
#define NR_LOCKDEP_CACHING_CLASSES 2
/*
- * Lock-classes are keyed via unique addresses, by embedding the
- * lockclass-key into the kernel (or module) .data section. (For
- * static locks we use the lock address itself as the key.)
+ * A lockdep key is associated with each lock object. For static locks we use
+ * the lock address itself as the key. Dynamically allocated lock objects can
+ * have a statically or dynamically allocated key. Dynamically allocated lock
+ * keys must be registered before being used and must be unregistered before
+ * the key memory is freed.
*/
struct lockdep_subclass_key {
char __one_byte;
} __attribute__ ((__packed__));
+/* hash_entry is used to keep track of dynamically allocated keys. */
struct lock_class_key {
+ struct hlist_node hash_entry;
struct lockdep_subclass_key subkeys[MAX_LOCKDEP_SUBCLASSES];
};
@@ -273,6 +277,9 @@ extern void lockdep_set_selftest_task(struct task_struct *task);
extern void lockdep_off(void);
extern void lockdep_on(void);
+extern void lockdep_register_key(struct lock_class_key *key);
+extern void lockdep_unregister_key(struct lock_class_key *key);
+
/*
* These methods are used by specific locking variants (spinlocks,
* rwlocks, mutexes and rwsems) to pass init/acquire/release events
@@ -434,6 +441,14 @@ static inline void lockdep_set_selftest_task(struct task_struct *task)
*/
struct lock_class_key { };
+static inline void lockdep_register_key(struct lock_class_key *key)
+{
+}
+
+static inline void lockdep_unregister_key(struct lock_class_key *key)
+{
+}
+
/*
* The lockdep_map takes no space if lockdep is disabled:
*/