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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>
This commit is contained in:
Eric Dumazet 2019-04-23 09:24:46 -07:00 committed by David S. Miller
parent a65120bae4
commit 4109a2c3b9
1 changed files with 3 additions and 6 deletions
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9
net/tipc/udp_media.c
View File

@ -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;