dev: Hold per-netns RTNL in (un)?register_netdev().

Let's hold per-netns RTNL of dev_net(dev) in register_netdev()
and unregister_netdev().

Signed-off-by: Kuniyuki Iwashima <[email protected]>
Reviewed-by: Eric Dumazet <[email protected]>
Signed-off-by: Paolo Abeni <[email protected]>

Author: q2ven

net/core/dev.c

@@ -10731,12 +10731,16 @@ EXPORT_SYMBOL_GPL(init_dummy_netdev);
  */
 int register_netdev(struct net_device *dev)
 {
+	struct net *net = dev_net(dev);
 	int err;
 
-	if (rtnl_lock_killable())
+	if (rtnl_net_lock_killable(net))
 		return -EINTR;
+
 	err = register_netdevice(dev);
-	rtnl_unlock();
+
+	rtnl_net_unlock(net);
+
 	return err;
 }
 EXPORT_SYMBOL(register_netdev);
@@ -11606,9 +11610,11 @@ EXPORT_SYMBOL(unregister_netdevice_many);
  */
 void unregister_netdev(struct net_device *dev)
 {
-	rtnl_lock();
+	struct net *net = dev_net(dev);
+
+	rtnl_net_lock(net);
 	unregister_netdevice(dev);
-	rtnl_unlock();
+	rtnl_net_unlock(net);
 }
 EXPORT_SYMBOL(unregister_netdev);