Merge branch 'next' into for-linus

1 files changed, 24 insertions, 0 deletions

diff --git a/include/linux/genetlink.h b/include/linux/genetlink.h
index 61549b26ad6f..73c28dea10ae 100644
--- a/include/linux/genetlink.h
+++ b/include/linux/genetlink.h
@@ -85,6 +85,30 @@ enum {
 /* All generic netlink requests are serialized by a global lock.  */
 extern void genl_lock(void);
 extern void genl_unlock(void);
+#ifdef CONFIG_PROVE_LOCKING
+extern int lockdep_genl_is_held(void);
+#endif
+
+/**
+ * rcu_dereference_genl - rcu_dereference with debug checking
+ * @p: The pointer to read, prior to dereferencing
+ *
+ * Do an rcu_dereference(p), but check caller either holds rcu_read_lock()
+ * or genl mutex. Note : Please prefer genl_dereference() or rcu_dereference()
+ */
+#define rcu_dereference_genl(p)					\
+	rcu_dereference_check(p, lockdep_genl_is_held())
+
+/**
+ * genl_dereference - fetch RCU pointer when updates are prevented by genl mutex
+ * @p: The pointer to read, prior to dereferencing
+ *
+ * Return the value of the specified RCU-protected pointer, but omit
+ * both the smp_read_barrier_depends() and the ACCESS_ONCE(), because
+ * caller holds genl mutex.
+ */
+#define genl_dereference(p)					\
+	rcu_dereference_protected(p, lockdep_genl_is_held())
 
 #endif /* __KERNEL__ */