Merge branch 'for-2.6.37/barrier' of git://git.kernel.dk/linux-2.6-block

[pandora-kernel.git] / kernel / lockdep.c

diff --git a/kernel/lockdep.c b/kernel/lockdep.c
index f2852a5..42ba65d 100644 (file)
--- a/kernel/lockdep.c
+++ b/kernel/lockdep.c
@@ -639,6 +639,16 @@ look_up_lock_class(struct lockdep_map *lock, unsigned int subclass)
        }
 #endif
 
+       if (unlikely(subclass >= MAX_LOCKDEP_SUBCLASSES)) {
+               debug_locks_off();
+               printk(KERN_ERR
+                       "BUG: looking up invalid subclass: %u\n", subclass);
+               printk(KERN_ERR
+                       "turning off the locking correctness validator.\n");
+               dump_stack();
+               return NULL;
+       }
+
        /*
         * Static locks do not have their class-keys yet - for them the key
         * is the lock object itself:
@@ -774,7 +784,9 @@ out_unlock_set:
        raw_local_irq_restore(flags);
 
        if (!subclass || force)
-               lock->class_cache = class;
+               lock->class_cache[0] = class;
+       else if (subclass < NR_LOCKDEP_CACHING_CLASSES)
+               lock->class_cache[subclass] = class;
 
        if (DEBUG_LOCKS_WARN_ON(class->subclass != subclass))
                return NULL;
@@ -2679,7 +2691,11 @@ static int mark_lock(struct task_struct *curr, struct held_lock *this,
 void lockdep_init_map(struct lockdep_map *lock, const char *name,
                      struct lock_class_key *key, int subclass)
 {
-       lock->class_cache = NULL;
+       int i;
+
+       for (i = 0; i < NR_LOCKDEP_CACHING_CLASSES; i++)
+               lock->class_cache[i] = NULL;
+
 #ifdef CONFIG_LOCK_STAT
        lock->cpu = raw_smp_processor_id();
 #endif
@@ -2739,21 +2755,13 @@ static int __lock_acquire(struct lockdep_map *lock, unsigned int subclass,
        if (DEBUG_LOCKS_WARN_ON(!irqs_disabled()))
                return 0;
 
-       if (unlikely(subclass >= MAX_LOCKDEP_SUBCLASSES)) {
-               debug_locks_off();
-               printk("BUG: MAX_LOCKDEP_SUBCLASSES too low!\n");
-               printk("turning off the locking correctness validator.\n");
-               dump_stack();
-               return 0;
-       }
-
        if (lock->key == &__lockdep_no_validate__)
                check = 1;
 
-       if (!subclass)
-               class = lock->class_cache;
+       if (subclass < NR_LOCKDEP_CACHING_CLASSES)
+               class = lock->class_cache[subclass];
        /*
-        * Not cached yet or subclass?
+        * Not cached?
         */
        if (unlikely(!class)) {
                class = register_lock_class(lock, subclass, 0);
@@ -2918,7 +2926,7 @@ static int match_held_lock(struct held_lock *hlock, struct lockdep_map *lock)
                return 1;
 
        if (hlock->references) {
-               struct lock_class *class = lock->class_cache;
+               struct lock_class *class = lock->class_cache[0];
 
                if (!class)
                        class = look_up_lock_class(lock, 0);
@@ -3559,7 +3567,12 @@ void lockdep_reset_lock(struct lockdep_map *lock)
                if (list_empty(head))
                        continue;
                list_for_each_entry_safe(class, next, head, hash_entry) {
-                       if (unlikely(class == lock->class_cache)) {
+                       int match = 0;
+
+                       for (j = 0; j < NR_LOCKDEP_CACHING_CLASSES; j++)
+                               match |= class == lock->class_cache[j];
+
+                       if (unlikely(match)) {
                                if (debug_locks_off_graph_unlock())
                                        WARN_ON(1);
                                goto out_restore;
@@ -3775,7 +3788,7 @@ EXPORT_SYMBOL_GPL(debug_show_all_locks);
  * Careful: only use this function if you are sure that
  * the task cannot run in parallel!
  */
-void __debug_show_held_locks(struct task_struct *task)
+void debug_show_held_locks(struct task_struct *task)
 {
        if (unlikely(!debug_locks)) {
                printk("INFO: lockdep is turned off.\n");
@@ -3783,12 +3796,6 @@ void __debug_show_held_locks(struct task_struct *task)
        }
        lockdep_print_held_locks(task);
 }
-EXPORT_SYMBOL_GPL(__debug_show_held_locks);
-
-void debug_show_held_locks(struct task_struct *task)
-{
-               __debug_show_held_locks(task);
-}
 EXPORT_SYMBOL_GPL(debug_show_held_locks);
 
 void lockdep_sys_exit(void)