---

yaml --- r: 362068 b: refs/heads/master c: 00cfec3 h: refs/heads/master v: v3
git-mirror · Mar 29, 2013 · 66eaafd · 66eaafd
1 parent 1b1ce13
commit 66eaafd
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Showing 2 changed files with 7 additions and 1 deletion.
diff --git a/[refs] b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 8622315e0142eba78ec0a8075b5a6fd481a059a4
+refs/heads/master: 00cfec37484761a44a3b6f4675a54caa618210ae
diff --git a/trunk/net/core/dev.c b/trunk/net/core/dev.c
@@ -3313,6 +3313,7 @@ int netdev_rx_handler_register(struct net_device *dev,
 	if (dev->rx_handler)
 		return -EBUSY;
 
+	/* Note: rx_handler_data must be set before rx_handler */
 	rcu_assign_pointer(dev->rx_handler_data, rx_handler_data);
 	rcu_assign_pointer(dev->rx_handler, rx_handler);
 
@@ -3333,6 +3334,11 @@ void netdev_rx_handler_unregister(struct net_device *dev)
 
 	ASSERT_RTNL();
 	RCU_INIT_POINTER(dev->rx_handler, NULL);
+	/* a reader seeing a non NULL rx_handler in a rcu_read_lock()
+	 * section has a guarantee to see a non NULL rx_handler_data
+	 * as well.
+	 */
+	synchronize_net();
 	RCU_INIT_POINTER(dev->rx_handler_data, NULL);
 }
 EXPORT_SYMBOL_GPL(netdev_rx_handler_unregister);