ipv6: udp: remove udp_v6_clear_sk()

Now RCU lookups of ipv6 udp sockets no longer dereference
pinet6 field, we can get rid of udp_v6_clear_sk() helper.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/ipv6/udp.c

@@ -1424,17 +1424,6 @@ void udp6_proc_exit(struct net *net)
 }
 #endif /* CONFIG_PROC_FS */
 
-void udp_v6_clear_sk(struct sock *sk, int size)
-{
-	struct inet_sock *inet = inet_sk(sk);
-
-	/* we do not want to clear pinet6 field, because of RCU lookups */
-	sk_prot_clear_portaddr_nulls(sk, offsetof(struct inet_sock, pinet6));
-
-	size -= offsetof(struct inet_sock, pinet6) + sizeof(inet->pinet6);
-	memset(&inet->pinet6 + 1, 0, size);
-}
-
 /* ------------------------------------------------------------------------ */
 
 struct proto udpv6_prot = {
@@ -1466,7 +1455,6 @@ struct proto udpv6_prot = {
 	.compat_setsockopt = compat_udpv6_setsockopt,
 	.compat_getsockopt = compat_udpv6_getsockopt,
 #endif
-	.clear_sk	   = udp_v6_clear_sk,
 	.diag_destroy      = udp_abort,
 };
 

net/ipv6/udp_impl.h

@@ -29,8 +29,6 @@ int udpv6_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int noblock,
 int udpv6_queue_rcv_skb(struct sock *sk, struct sk_buff *skb);
 void udpv6_destroy_sock(struct sock *sk);
 
-void udp_v6_clear_sk(struct sock *sk, int size);
-
 #ifdef CONFIG_PROC_FS
 int udp6_seq_show(struct seq_file *seq, void *v);
 #endif

net/ipv6/udplite.c

@@ -56,7 +56,7 @@ struct proto udplitev6_prot = {
 	.compat_setsockopt = compat_udpv6_setsockopt,
 	.compat_getsockopt = compat_udpv6_getsockopt,
 #endif
-	.clear_sk	   = udp_v6_clear_sk,
+	.clear_sk	   = sk_prot_clear_portaddr_nulls,
 };
 
 static struct inet_protosw udplite6_protosw = {