Merge tag 'v3.13-rc4' into core/locking

Merge Linux 3.13-rc4, to refresh this rather old tree with the latest fixes.

Signed-off-by: Ingo Molnar <mingo@kernel.org>

1 files changed, 67 insertions, 41 deletions

diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c
index 2e8286b47c28..88cfbc189558 100644
--- a/net/packet/af_packet.c
+++ b/net/packet/af_packet.c
@@ -237,6 +237,30 @@ struct packet_skb_cb {
 static void __fanout_unlink(struct sock *sk, struct packet_sock *po);
 static void __fanout_link(struct sock *sk, struct packet_sock *po);
 
+static struct net_device *packet_cached_dev_get(struct packet_sock *po)
+{
+        struct net_device *dev;
+
+        rcu_read_lock();
+        dev = rcu_dereference(po->cached_dev);
+        if (likely(dev))
+                dev_hold(dev);
+        rcu_read_unlock();
+
+        return dev;
+}
+
+static void packet_cached_dev_assign(struct packet_sock *po,
+                                     struct net_device *dev)
+{
+        rcu_assign_pointer(po->cached_dev, dev);
+}
+
+static void packet_cached_dev_reset(struct packet_sock *po)
+{
+        RCU_INIT_POINTER(po->cached_dev, NULL);
+}
+
 /* register_prot_hook must be invoked with the po->bind_lock held,
  * or from a context in which asynchronous accesses to the packet
  * socket is not possible (packet_create()).
@@ -244,11 +268,13 @@ static void __fanout_link(struct sock *sk, struct packet_sock *po);
 static void register_prot_hook(struct sock *sk)
 {
         struct packet_sock *po = pkt_sk(sk);
+
         if (!po->running) {
                 if (po->fanout)
                         __fanout_link(sk, po);
                 else
                         dev_add_pack(&po->prot_hook);
+
                 sock_hold(sk);
                 po->running = 1;
         }
@@ -266,10 +292,12 @@ static void __unregister_prot_hook(struct sock *sk, bool sync)
         struct packet_sock *po = pkt_sk(sk);
 
         po->running = 0;
+
         if (po->fanout)
                 __fanout_unlink(sk, po);
         else
                 __dev_remove_pack(&po->prot_hook);
+
         __sock_put(sk);
 
         if (sync) {
@@ -432,9 +460,9 @@ static void prb_shutdown_retire_blk_timer(struct packet_sock *po,
 
         pkc = tx_ring ? &po->tx_ring.prb_bdqc : &po->rx_ring.prb_bdqc;
 
-        spin_lock(&rb_queue->lock);
+        spin_lock_bh(&rb_queue->lock);
         pkc->delete_blk_timer = 1;
-        spin_unlock(&rb_queue->lock);
+        spin_unlock_bh(&rb_queue->lock);
 
         prb_del_retire_blk_timer(pkc);
 }
@@ -2057,7 +2085,6 @@ static int tpacket_snd(struct packet_sock *po, struct msghdr *msg)
         struct sk_buff *skb;
         struct net_device *dev;
         __be16 proto;
-        bool need_rls_dev = false;
         int err, reserve = 0;
         void *ph;
         struct sockaddr_ll *saddr = (struct sockaddr_ll *)msg->msg_name;
@@ -2069,8 +2096,8 @@ static int tpacket_snd(struct packet_sock *po, struct msghdr *msg)
 
         mutex_lock(&po->pg_vec_lock);
 
-        if (saddr == NULL) {
-                dev = po->prot_hook.dev;
+        if (likely(saddr == NULL)) {
+                dev     = packet_cached_dev_get(po);
                 proto   = po->num;
                 addr    = NULL;
         } else {
@@ -2084,19 +2111,17 @@ static int tpacket_snd(struct packet_sock *po, struct msghdr *msg)
                 proto   = saddr->sll_protocol;
                 addr    = saddr->sll_addr;
                 dev = dev_get_by_index(sock_net(&po->sk), saddr->sll_ifindex);
-                need_rls_dev = true;
         }
 
         err = -ENXIO;
         if (unlikely(dev == NULL))
                 goto out;
-
-        reserve = dev->hard_header_len;
-
         err = -ENETDOWN;
         if (unlikely(!(dev->flags & IFF_UP)))
                 goto out_put;
 
+        reserve = dev->hard_header_len;
+
         size_max = po->tx_ring.frame_size
                 - (po->tp_hdrlen - sizeof(struct sockaddr_ll));
 
@@ -2173,8 +2198,7 @@ out_status:
         __packet_set_status(po, ph, status);
         kfree_skb(skb);
 out_put:
-        if (need_rls_dev)
-                dev_put(dev);
+        dev_put(dev);
 out:
         mutex_unlock(&po->pg_vec_lock);
         return err;
@@ -2212,7 +2236,6 @@ static int packet_snd(struct socket *sock,
         struct sk_buff *skb;
         struct net_device *dev;
         __be16 proto;
-        bool need_rls_dev = false;
         unsigned char *addr;
         int err, reserve = 0;
         struct virtio_net_hdr vnet_hdr = { 0 };
@@ -2227,8 +2250,8 @@ static int packet_snd(struct socket *sock,
          *      Get and verify the address.
          */
 
-        if (saddr == NULL) {
-                dev = po->prot_hook.dev;
+        if (likely(saddr == NULL)) {
+                dev     = packet_cached_dev_get(po);
                 proto   = po->num;
                 addr    = NULL;
         } else {
@@ -2240,19 +2263,17 @@ static int packet_snd(struct socket *sock,
                 proto   = saddr->sll_protocol;
                 addr    = saddr->sll_addr;
                 dev = dev_get_by_index(sock_net(sk), saddr->sll_ifindex);
-                need_rls_dev = true;
         }
 
         err = -ENXIO;
-        if (dev == NULL)
+        if (unlikely(dev == NULL))
                 goto out_unlock;
-        if (sock->type == SOCK_RAW)
-                reserve = dev->hard_header_len;
-