1 files changed, 30 insertions, 20 deletions

diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c
index b5c8fcb6c070..81388d028ac7 100644
--- a/kernel/locking/lockdep.c
+++ b/kernel/locking/lockdep.c
@@ -4201,13 +4201,33 @@ void lockdep_free_key_range(void *start, unsigned long size)
          */
 }
 
-void lockdep_reset_lock(struct lockdep_map *lock)
+/*
+ * Check whether any element of the @lock->class_cache[] array refers to a
+ * registered lock class. The caller must hold either the graph lock or the
+ * RCU read lock.
+ */
+static bool lock_class_cache_is_registered(struct lockdep_map *lock)
 {
         struct lock_class *class;
         struct hlist_head *head;
-        unsigned long flags;
         int i, j;
-        int locked;
+
+        for (i = 0; i < CLASSHASH_SIZE; i++) {
+                head = classhash_table + i;
+                hlist_for_each_entry_rcu(class, head, hash_entry) {
+                        for (j = 0; j < NR_LOCKDEP_CACHING_CLASSES; j++)
+                                if (lock->class_cache[j] == class)
+                                        return true;
+                }
+        }
+        return false;
+}
+
+void lockdep_reset_lock(struct lockdep_map *lock)
+{
+        struct lock_class *class;
+        unsigned long flags;
+        int j, locked;
 
         raw_local_irq_save(flags);
 
@@ -4227,24 +4247,14 @@ void lockdep_reset_lock(struct lockdep_map *lock)
          * be gone.
          */
         locked = graph_lock();
-        for (i = 0; i < CLASSHASH_SIZE; i++) {
-                head = classhash_table + i;
-                hlist_for_each_entry_rcu(class, head, hash_entry) {
-                        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()) {
-                                        /*
-                                         * We all just reset everything, how did it match?
-                                         */
-                                        WARN_ON(1);
-                                }
-                                goto out_restore;
-                        }
+        if (unlikely(lock_class_cache_is_registered(lock))) {
+                if (debug_locks_off_graph_unlock()) {
+                        /*
+                         * We all just reset everything, how did it match?
+                         */
+                        WARN_ON(1);
                 }
+                goto out_restore;
         }
         if (locked)
                 graph_unlock();