[PATCH] lockdep: prove spinlock rwlock locking correctness

Use the lock validator framework to prove spinlock and rwlock locking
correctness.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

2 files changed, 42 insertions, 1 deletions

diff --git a/lib/kernel_lock.c b/lib/kernel_lock.c
index e713e86811ae..e0fdfddb406e 100644
--- a/lib/kernel_lock.c
+++ b/lib/kernel_lock.c
@@ -177,7 +177,12 @@ static inline void __lock_kernel(void)
 
 static inline void __unlock_kernel(void)
 {
-        spin_unlock(&kernel_flag);
+        /*
+         * the BKL is not covered by lockdep, so we open-code the
+         * unlocking sequence (and thus avoid the dep-chain ops):
+         */
+        _raw_spin_unlock(&kernel_flag);
+        preempt_enable();
 }
 
 /*
diff --git a/lib/spinlock_debug.c b/lib/spinlock_debug.c
index 3de2ccf48ac6..3d9c4dc965ed 100644
--- a/lib/spinlock_debug.c
+++ b/lib/spinlock_debug.c
@@ -12,6 +12,42 @@
 #include <linux/delay.h>
 #include <linux/module.h>
 
+void __spin_lock_init(spinlock_t *lock, const char *name,
+                      struct lock_class_key *key)
+{
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+        /*
+         * Make sure we are not reinitializing a held lock:
+         */
+        debug_check_no_locks_freed((void *)lock, sizeof(*lock));
+        lockdep_init_map(&lock->dep_map, name, key);
+#endif
+        lock->raw_lock = (raw_spinlock_t)__RAW_SPIN_LOCK_UNLOCKED;
+        lock->magic = SPINLOCK_MAGIC;
+        lock->owner = SPINLOCK_OWNER_INIT;
+        lock->owner_cpu = -1;
+}
+
+EXPORT_SYMBOL(__spin_lock_init);
+
+void __rwlock_init(rwlock_t *lock, const char *name,
+                   struct lock_class_key *key)
+{
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+        /*
+         * Make sure we are not reinitializing a held lock:
+         */
+        debug_check_no_locks_freed((void *)lock, sizeof(*lock));
+        lockdep_init_map(&lock->dep_map, name, key);
+#endif
+        lock->raw_lock = (raw_rwlock_t) __RAW_RW_LOCK_UNLOCKED;
+        lock->magic = RWLOCK_MAGIC;
+        lock->owner = SPINLOCK_OWNER_INIT;
+        lock->owner_cpu = -1;
+}
+
+EXPORT_SYMBOL(__rwlock_init);
+
 static void spin_bug(spinlock_t *lock, const char *msg)
 {
         struct task_struct *owner = NULL;