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Diffstat (limited to 'kernel')
-rw-r--r--kernel/locking/lockdep.c19
1 files changed, 13 insertions, 6 deletions
diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c
index 21d84510e28f..28fbeb2a10cc 100644
--- a/kernel/locking/lockdep.c
+++ b/kernel/locking/lockdep.c
@@ -859,7 +859,8 @@ static struct lock_list *alloc_list_entry(void)
 /*
  * Add a new dependency to the head of the list:
  */
-static int add_lock_to_list(struct lock_class *this, struct list_head *head,
+static int add_lock_to_list(struct lock_class *this,
+			    struct lock_class *links_to, struct list_head *head,
 			    unsigned long ip, int distance,
 			    struct stack_trace *trace)
 {
@@ -873,6 +874,7 @@ static int add_lock_to_list(struct lock_class *this, struct list_head *head,
 		return 0;
 
 	entry->class = this;
+	entry->links_to = links_to;
 	entry->distance = distance;
 	entry->trace = *trace;
 	/*
@@ -1907,14 +1909,14 @@ check_prev_add(struct task_struct *curr, struct held_lock *prev,
 	 * Ok, all validations passed, add the new lock
 	 * to the previous lock's dependency list:
 	 */
-	ret = add_lock_to_list(hlock_class(next),
+	ret = add_lock_to_list(hlock_class(next), hlock_class(prev),
 			       &hlock_class(prev)->locks_after,
 			       next->acquire_ip, distance, trace);
 
 	if (!ret)
 		return 0;
 
-	ret = add_lock_to_list(hlock_class(prev),
+	ret = add_lock_to_list(hlock_class(prev), hlock_class(next),
 			       &hlock_class(next)->locks_before,
 			       next->acquire_ip, distance, trace);
 	if (!ret)
@@ -4107,15 +4109,20 @@ void lockdep_reset(void)
  */
 static void zap_class(struct lock_class *class)
 {
+	struct lock_list *entry;
 	int i;
 
 	/*
 	 * Remove all dependencies this lock is
 	 * involved in:
 	 */
-	for (i = 0; i < nr_list_entries; i++) {
-		if (list_entries[i].class == class)
-			list_del_rcu(&list_entries[i].entry);
+	for (i = 0, entry = list_entries; i < nr_list_entries; i++, entry++) {
+		if (entry->class != class && entry->links_to != class)
+			continue;
+		list_del_rcu(&entry->entry);
+		/* Clear .class and .links_to to avoid double removal. */
+		WRITE_ONCE(entry->class, NULL);
+		WRITE_ONCE(entry->links_to, NULL);
 	}
 	/*
 	 * Unhash the class and remove it from the all_lock_classes list: