From 7dff59efbb0e8b0f81c95fd40379c0d0c757c808 Mon Sep 17 00:00:00 2001
From: Eric Dumazet <eric.dumazet@gmail.com>
Date: Wed, 15 Sep 2010 11:07:15 +0000
Subject: [PATCH] net: add rtnl_dereference()

We sometime want to dereference an rcu protected pointer while
holding RTNL. Use a macro to hide all lockdep details.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
 include/linux/rtnetlink.h | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/include/linux/rtnetlink.h b/include/linux/rtnetlink.h
index 263690d991a8..68c436bddc88 100644
--- a/include/linux/rtnetlink.h
+++ b/include/linux/rtnetlink.h
@@ -760,6 +760,15 @@ extern int lockdep_rtnl_is_held(void);
 	rcu_dereference_check(p, rcu_read_lock_held() ||	\
 				 lockdep_rtnl_is_held())
 
+/**
+ * rtnl_dereference - rcu_dereference with debug checking
+ * @p: The pointer to read, prior to dereferencing
+ *
+ * Do an rcu_dereference(p), but check caller holds RTNL
+ */
+#define rtnl_dereference(p)					\
+	rcu_dereference_check(p, lockdep_rtnl_is_held())
+
 extern void rtnetlink_init(void);
 extern void __rtnl_unlock(void);
 
-- 
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