Merge remote-tracking branch 'torvalds/master' into perf/core

[linux-2.6-microblaze.git] / net / packet / af_packet.c

diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c
index ae906eb..330ba68 100644 (file)
--- a/net/packet/af_packet.c
+++ b/net/packet/af_packet.c
@@ -2683,7 +2683,7 @@ static int tpacket_snd(struct packet_sock *po, struct msghdr *msg)
        }
        if (likely(saddr == NULL)) {
                dev     = packet_cached_dev_get(po);
-               proto   = po->num;
+               proto   = READ_ONCE(po->num);
        } else {
                err = -EINVAL;
                if (msg->msg_namelen < sizeof(struct sockaddr_ll))
@@ -2896,7 +2896,7 @@ static int packet_snd(struct socket *sock, struct msghdr *msg, size_t len)
 
        if (likely(saddr == NULL)) {
                dev     = packet_cached_dev_get(po);
-               proto   = po->num;
+               proto   = READ_ONCE(po->num);
        } else {
                err = -EINVAL;
                if (msg->msg_namelen < sizeof(struct sockaddr_ll))
@@ -3034,10 +3034,13 @@ static int packet_sendmsg(struct socket *sock, struct msghdr *msg, size_t len)
        struct sock *sk = sock->sk;
        struct packet_sock *po = pkt_sk(sk);
 
-       if (po->tx_ring.pg_vec)
+       /* Reading tx_ring.pg_vec without holding pg_vec_lock is racy.
+        * tpacket_snd() will redo the check safely.
+        */
+       if (data_race(po->tx_ring.pg_vec))
                return tpacket_snd(po, msg);
-       else
-               return packet_snd(sock, msg, len);
+
+       return packet_snd(sock, msg, len);
 }
 
 /*
@@ -3168,7 +3171,7 @@ static int packet_do_bind(struct sock *sk, const char *name, int ifindex,
                        /* prevents packet_notifier() from calling
                         * register_prot_hook()
                         */
-                       po->num = 0;
+                       WRITE_ONCE(po->num, 0);
                        __unregister_prot_hook(sk, true);
                        rcu_read_lock();
                        dev_curr = po->prot_hook.dev;
@@ -3178,17 +3181,17 @@ static int packet_do_bind(struct sock *sk, const char *name, int ifindex,
                }
 
                BUG_ON(po->running);
-               po->num = proto;
+               WRITE_ONCE(po->num, proto);
                po->prot_hook.type = proto;
 
                if (unlikely(unlisted)) {
                        dev_put(dev);
                        po->prot_hook.dev = NULL;
-                       po->ifindex = -1;
+                       WRITE_ONCE(po->ifindex, -1);
                        packet_cached_dev_reset(po);
                } else {
                        po->prot_hook.dev = dev;
-                       po->ifindex = dev ? dev->ifindex : 0;
+                       WRITE_ONCE(po->ifindex, dev ? dev->ifindex : 0);
                        packet_cached_dev_assign(po, dev);
                }
        }
@@ -3502,7 +3505,7 @@ static int packet_getname_spkt(struct socket *sock, struct sockaddr *uaddr,
        uaddr->sa_family = AF_PACKET;
        memset(uaddr->sa_data, 0, sizeof(uaddr->sa_data));
        rcu_read_lock();
-       dev = dev_get_by_index_rcu(sock_net(sk), pkt_sk(sk)->ifindex);
+       dev = dev_get_by_index_rcu(sock_net(sk), READ_ONCE(pkt_sk(sk)->ifindex));
        if (dev)
                strlcpy(uaddr->sa_data, dev->name, sizeof(uaddr->sa_data));
        rcu_read_unlock();
@@ -3517,16 +3520,18 @@ static int packet_getname(struct socket *sock, struct sockaddr *uaddr,
        struct sock *sk = sock->sk;
        struct packet_sock *po = pkt_sk(sk);
        DECLARE_SOCKADDR(struct sockaddr_ll *, sll, uaddr);
+       int ifindex;
 
        if (peer)
                return -EOPNOTSUPP;
 
+       ifindex = READ_ONCE(po->ifindex);
        sll->sll_family = AF_PACKET;
-       sll->sll_ifindex = po->ifindex;
-       sll->sll_protocol = po->num;
+       sll->sll_ifindex = ifindex;
+       sll->sll_protocol = READ_ONCE(po->num);
        sll->sll_pkttype = 0;
        rcu_read_lock();
-       dev = dev_get_by_index_rcu(sock_net(sk), po->ifindex);
+       dev = dev_get_by_index_rcu(sock_net(sk), ifindex);
        if (dev) {
                sll->sll_hatype = dev->type;
                sll->sll_halen = dev->addr_len;
@@ -4105,7 +4110,7 @@ static int packet_notifier(struct notifier_block *this,
                                }
                                if (msg == NETDEV_UNREGISTER) {
                                        packet_cached_dev_reset(po);
-                                       po->ifindex = -1;
+                                       WRITE_ONCE(po->ifindex, -1);
                                        if (po->prot_hook.dev)
                                                dev_put(po->prot_hook.dev);
                                        po->prot_hook.dev = NULL;
@@ -4411,7 +4416,7 @@ static int packet_set_ring(struct sock *sk, union tpacket_req_u *req_u,
        was_running = po->running;
        num = po->num;
        if (was_running) {
-               po->num = 0;
+               WRITE_ONCE(po->num, 0);
                __unregister_prot_hook(sk, false);
        }
        spin_unlock(&po->bind_lock);
@@ -4446,7 +4451,7 @@ static int packet_set_ring(struct sock *sk, union tpacket_req_u *req_u,
 
        spin_lock(&po->bind_lock);
        if (was_running) {
-               po->num = num;
+               WRITE_ONCE(po->num, num);
                register_prot_hook(sk);
        }
        spin_unlock(&po->bind_lock);
@@ -4616,8 +4621,8 @@ static int packet_seq_show(struct seq_file *seq, void *v)
                           s,
                           refcount_read(&s->sk_refcnt),
                           s->sk_type,
-                          ntohs(po->num),
-                          po->ifindex,
+                          ntohs(READ_ONCE(po->num)),
+                          READ_ONCE(po->ifindex),
                           po->running,
                           atomic_read(&s->sk_rmem_alloc),
                           from_kuid_munged(seq_user_ns(seq), sock_i_uid(s)),