cpufreq: CPPC: Don't set transition_latency

[mirror_ubuntu-bionic-kernel.git] / net / l2tp / l2tp_eth.c

diff --git a/net/l2tp/l2tp_eth.c b/net/l2tp/l2tp_eth.c
index 014a7bc2a872514cf4422302a92b692ecda31c27..5c366ecfa1cb0e2918c54f30d80ab30780f4cfdb 100644 (file)
--- a/net/l2tp/l2tp_eth.c
+++ b/net/l2tp/l2tp_eth.c
@@ -41,8 +41,6 @@
 
 /* via netdev_priv() */
 struct l2tp_eth {
-       struct net_device       *dev;
-       struct sock             *tunnel_sock;
        struct l2tp_session     *session;
        atomic_long_t           tx_bytes;
        atomic_long_t           tx_packets;
@@ -54,15 +52,12 @@ struct l2tp_eth {
 
 /* via l2tp_session_priv() */
 struct l2tp_eth_sess {
-       struct net_device       *dev;
+       struct net_device __rcu *dev;
 };
 
 
 static int l2tp_eth_dev_init(struct net_device *dev)
 {
-       struct l2tp_eth *priv = netdev_priv(dev);
-
-       priv->dev = dev;
        eth_hw_addr_random(dev);
        eth_broadcast_addr(dev->broadcast);
        netdev_lockdep_set_classes(dev);
@@ -72,7 +67,14 @@ static int l2tp_eth_dev_init(struct net_device *dev)
 
 static void l2tp_eth_dev_uninit(struct net_device *dev)
 {
-       dev_put(dev);
+       struct l2tp_eth *priv = netdev_priv(dev);
+       struct l2tp_eth_sess *spriv;
+
+       spriv = l2tp_session_priv(priv->session);
+       RCU_INIT_POINTER(spriv->dev, NULL);
+       /* No need for synchronize_net() here. We're called by
+        * unregister_netdev*(), which does the synchronisation for us.
+        */
 }
 
 static int l2tp_eth_dev_xmit(struct sk_buff *skb, struct net_device *dev)
@@ -130,8 +132,8 @@ static void l2tp_eth_dev_setup(struct net_device *dev)
 static void l2tp_eth_dev_recv(struct l2tp_session *session, struct sk_buff *skb, int data_len)
 {
        struct l2tp_eth_sess *spriv = l2tp_session_priv(session);
-       struct net_device *dev = spriv->dev;
-       struct l2tp_eth *priv = netdev_priv(dev);
+       struct net_device *dev;
+       struct l2tp_eth *priv;
 
        if (session->debug & L2TP_MSG_DATA) {
                unsigned int length;
@@ -155,16 +157,25 @@ static void l2tp_eth_dev_recv(struct l2tp_session *session, struct sk_buff *skb,
        skb_dst_drop(skb);
        nf_reset(skb);
 
+       rcu_read_lock();
+       dev = rcu_dereference(spriv->dev);
+       if (!dev)
+               goto error_rcu;
+
+       priv = netdev_priv(dev);
        if (dev_forward_skb(dev, skb) == NET_RX_SUCCESS) {
                atomic_long_inc(&priv->rx_packets);
                atomic_long_add(data_len, &priv->rx_bytes);
        } else {
                atomic_long_inc(&priv->rx_errors);
        }
+       rcu_read_unlock();
+
        return;
 
+error_rcu:
+       rcu_read_unlock();
 error:
-       atomic_long_inc(&priv->rx_errors);
        kfree_skb(skb);
 }
 
@@ -175,11 +186,15 @@ static void l2tp_eth_delete(struct l2tp_session *session)
 
        if (session) {
                spriv = l2tp_session_priv(session);
-               dev = spriv->dev;
+
+               rtnl_lock();
+               dev = rtnl_dereference(spriv->dev);
                if (dev) {
-                       unregister_netdev(dev);
-                       spriv->dev = NULL;
+                       unregister_netdevice(dev);
+                       rtnl_unlock();
                        module_put(THIS_MODULE);
+               } else {
+                       rtnl_unlock();
                }
        }
 }
@@ -189,9 +204,20 @@ static void l2tp_eth_show(struct seq_file *m, void *arg)
 {
        struct l2tp_session *session = arg;
        struct l2tp_eth_sess *spriv = l2tp_session_priv(session);
-       struct net_device *dev = spriv->dev;
+       struct net_device *dev;
+
+       rcu_read_lock();
+       dev = rcu_dereference(spriv->dev);
+       if (!dev) {
+               rcu_read_unlock();
+               return;
+       }
+       dev_hold(dev);
+       rcu_read_unlock();
 
        seq_printf(m, "   interface %s\n", dev->name);
+
+       dev_put(dev);
 }
 #endif
 
@@ -268,14 +294,14 @@ static int l2tp_eth_create(struct net *net, struct l2tp_tunnel *tunnel,
                                      peer_session_id, cfg);
        if (IS_ERR(session)) {
                rc = PTR_ERR(session);
-               goto out;
+               goto err;
        }
 
        dev = alloc_netdev(sizeof(*priv), name, name_assign_type,
                           l2tp_eth_dev_setup);
        if (!dev) {
                rc = -ENOMEM;
-               goto out_del_session;
+               goto err_sess;
        }
 
        dev_net_set(dev, net);
@@ -284,10 +310,8 @@ static int l2tp_eth_create(struct net *net, struct l2tp_tunnel *tunnel,
        l2tp_eth_adjust_mtu(tunnel, session, dev);
 
        priv = netdev_priv(dev);
-       priv->dev = dev;
        priv->session = session;
 
-       priv->tunnel_sock = tunnel->sock;
        session->recv_skb = l2tp_eth_dev_recv;
        session->session_close = l2tp_eth_delete;
 #if IS_ENABLED(CONFIG_L2TP_DEBUGFS)
@@ -295,26 +319,48 @@ static int l2tp_eth_create(struct net *net, struct l2tp_tunnel *tunnel,
 #endif
 
        spriv = l2tp_session_priv(session);
-       spriv->dev = dev;
 
-       rc = register_netdev(dev);
-       if (rc < 0)
-               goto out_del_dev;
+       l2tp_session_inc_refcount(session);
+
+       rtnl_lock();
+
+       /* Register both device and session while holding the rtnl lock. This
+        * ensures that l2tp_eth_delete() will see that there's a device to
+        * unregister, even if it happened to run before we assign spriv->dev.
+        */
+       rc = l2tp_session_register(session, tunnel);
+       if (rc < 0) {
+               rtnl_unlock();
+               goto err_sess_dev;
+       }
+
+       rc = register_netdevice(dev);
+       if (rc < 0) {
+               rtnl_unlock();
+               l2tp_session_delete(session);
+               l2tp_session_dec_refcount(session);
+               free_netdev(dev);
+
+               return rc;
+       }
 
-       __module_get(THIS_MODULE);
-       /* Must be done after register_netdev() */
        strlcpy(session->ifname, dev->name, IFNAMSIZ);
+       rcu_assign_pointer(spriv->dev, dev);
 
-       dev_hold(dev);
+       rtnl_unlock();
+
+       l2tp_session_dec_refcount(session);
+
+       __module_get(THIS_MODULE);
 
        return 0;
 
-out_del_dev:
+err_sess_dev:
+       l2tp_session_dec_refcount(session);
        free_netdev(dev);
-       spriv->dev = NULL;
-out_del_session:
-       l2tp_session_delete(session);
-out:
+err_sess:
+       kfree(session);
+err:
        return rc;
 }