diff --git a/kernel/rcupdate.c b/kernel/rcupdate.c
index 8e79513..4a189ea 100644
--- a/kernel/rcupdate.c
+++ b/kernel/rcupdate.c
@@ -46,6 +46,13 @@
 #include <linux/module.h>
 #include <linux/kernel_stat.h>
 
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+static struct lock_class_key rcu_lock_key;
+struct lockdep_map rcu_lock_map =
+	STATIC_LOCKDEP_MAP_INIT("rcu_read_lock", &rcu_lock_key);
+EXPORT_SYMBOL_GPL(rcu_lock_map);
+#endif
+
 enum rcu_barrier {
 	RCU_BARRIER_STD,
 	RCU_BARRIER_BH,