tipc: tipc_udp_recv() cleanup vs rcu verbs

First thing tipc_udp_recv() does is to use rcu_dereference_sk_user_data(),
and this is really hinting we already own rcu_read_lock() from the caller
(UDP stack).

No need to add another rcu_read_lock()/rcu_read_unlock() pair.

Also use rcu_dereference() instead of rcu_dereference_rtnl()
in the data path.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Jon Maloy <jon.maloy@ericsson.com>
Cc: Ying Xue <ying.xue@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 3 insertions, 6 deletions

diff --git a/net/tipc/udp_media.c b/net/tipc/udp_media.c
index 6f166fbbfff1..7413cbc9b638 100644
--- a/net/tipc/udp_media.c
+++ b/net/tipc/udp_media.c
@@ -354,10 +354,9 @@ static int tipc_udp_recv(struct sock *sk, struct sk_buff *skb)
         skb_pull(skb, sizeof(struct udphdr));
         hdr = buf_msg(skb);
 
-        rcu_read_lock();
-        b = rcu_dereference_rtnl(ub->bearer);
+        b = rcu_dereference(ub->bearer);
         if (!b)
-                goto rcu_out;
+                goto out;
 
         if (b && test_bit(0, &b->up)) {
                 tipc_rcv(sock_net(sk), skb, b);
@@ -368,11 +367,9 @@ static int tipc_udp_recv(struct sock *sk, struct sk_buff *skb)
         if (unlikely(msg_user(hdr) == LINK_CONFIG)) {
                 err = tipc_udp_rcast_disc(b, skb);
                 if (err)
-                        goto rcu_out;
+                        goto out;
         }
 
-rcu_out:
-        rcu_read_unlock();
 out:
         kfree_skb(skb);
         return 0;