[NET]: Memory barrier cleanups

I believe all the below memory barriers only matter on SMP so
therefore the smp_* variant of the barrier should be used.

I'm wondering if the barrier in net/ipv4/inet_timewait_sock.c should be
dropped entirely.  schedule_work's implementation currently implies a
memory barrier and I think sane semantics of schedule_work() should imply
a memory barrier, as needed so the caller shouldn't have to worry.
It's not quite obvious why the barrier in net/packet/af_packet.c is
needed; maybe it should be implied through flush_dcache_page?

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

4 files changed, 6 insertions, 6 deletions

diff --git a/net/core/wireless.c b/net/core/wireless.c
index cb1b8728d7ee..f69ab7b4408e 100644
--- a/net/core/wireless.c
+++ b/net/core/wireless.c
@@ -2130,7 +2130,7 @@ int iw_handler_set_spy(struct net_device *	dev,
          * The rtnl_lock() make sure we don't race with the other iw_handlers.
          * This make sure wireless_spy_update() "see" that the spy list
          * is temporarily disabled. */
-        wmb();
+        smp_wmb();
 
         /* Are there are addresses to copy? */
         if(wrqu->data.length > 0) {
@@ -2159,7 +2159,7 @@ int iw_handler_set_spy(struct net_device *	dev,
         }
 
         /* Make sure above is updated before re-enabling */
-        wmb();
+        smp_wmb();
 
         /* Enable addresses */
         spydata->spy_number = wrqu->data.length;
diff --git a/net/ipv4/inet_timewait_sock.c b/net/ipv4/inet_timewait_sock.c
index 8c74f9168b7d..75373f35383f 100644
--- a/net/ipv4/inet_timewait_sock.c
+++ b/net/ipv4/inet_timewait_sock.c
@@ -178,7 +178,7 @@ void inet_twdr_hangman(unsigned long data)
         need_timer = 0;
         if (inet_twdr_do_twkill_work(twdr, twdr->slot)) {
                 twdr->thread_slots |= (1 << twdr->slot);
-                mb();
+                smp_mb();
                 schedule_work(&twdr->twkill_work);
                 need_timer = 1;
         } else {
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index 9304034c0c47..c701f6abbfc1 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -4235,7 +4235,7 @@ static int tcp_rcv_synsent_state_process(struct sock *sk, struct sk_buff *skb,
                  * Change state from SYN-SENT only after copied_seq
                  * is initialized. */
                 tp->copied_seq = tp->rcv_nxt;
-                mb();
+                smp_mb();
                 tcp_set_state(sk, TCP_ESTABLISHED);
 
                 security_inet_conn_established(sk, skb);
@@ -4483,7 +4483,7 @@ int tcp_rcv_state_process(struct sock *sk, struct sk_buff *skb,
                 case TCP_SYN_RECV:
                         if (acceptable) {
                                 tp->copied_seq = tp->rcv_nxt;
-                                mb();
+                                smp_mb();
                                 tcp_set_state(sk, TCP_ESTABLISHED);
                                 sk->sk_state_change(sk);
 
diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c
index 08e68b67bbf6..da73e8a8c18d 100644
--- a/net/packet/af_packet.c
+++ b/net/packet/af_packet.c
@@ -660,7 +660,7 @@ static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev, struct packe
         sll->sll_ifindex = dev->ifindex;
 
         h->tp_status = status;
-        mb();
+        smp_mb();
 
         {
                 struct page *p_start, *p_end;