[ICMP]: Optimize icmp_socket usage.

Use this macro only once in a function to save a bit of space.

add/remove: 0/0 grow/shrink: 0/3 up/down: 0/-98 (-98)
function                                     old     new   delta
icmp_reply                                   562     561      -1
icmp_push_reply                              305     258     -47
icmp_init                                    273     223     -50
Signed-off-by: NDenis V. Lunev <den@openvz.org>
Acked-by: NDaniel Lezcano <dlezcano@fr.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net/ipv4/icmp.c

@@ -346,19 +346,21 @@ static int icmp_glue_bits(void *from, char *to, int offset, int len, int odd,
 static void icmp_push_reply(struct icmp_bxm *icmp_param,
 			    struct ipcm_cookie *ipc, struct rtable *rt)
 {
+	struct sock *sk;
 	struct sk_buff *skb;
 
-	if (ip_append_data(icmp_socket->sk, icmp_glue_bits, icmp_param,
+	sk = icmp_socket->sk;
+	if (ip_append_data(sk, icmp_glue_bits, icmp_param,
 			   icmp_param->data_len+icmp_param->head_len,
 			   icmp_param->head_len,
 			   ipc, rt, MSG_DONTWAIT) < 0)
-		ip_flush_pending_frames(icmp_socket->sk);
-	else if ((skb = skb_peek(&icmp_socket->sk->sk_write_queue)) != NULL) {
+		ip_flush_pending_frames(sk);
+	else if ((skb = skb_peek(&sk->sk_write_queue)) != NULL) {
 		struct icmphdr *icmph = icmp_hdr(skb);
 		__wsum csum = 0;
 		struct sk_buff *skb1;
 
-		skb_queue_walk(&icmp_socket->sk->sk_write_queue, skb1) {
+		skb_queue_walk(&sk->sk_write_queue, skb1) {
 			csum = csum_add(csum, skb1->csum);
 		}
 		csum = csum_partial_copy_nocheck((void *)&icmp_param->data,
@@ -366,7 +368,7 @@ static void icmp_push_reply(struct icmp_bxm *icmp_param,
 						 icmp_param->head_len, csum);
 		icmph->checksum = csum_fold(csum);
 		skb->ip_summed = CHECKSUM_NONE;
-		ip_push_pending_frames(icmp_socket->sk);
+		ip_push_pending_frames(sk);
 	}
 }
 
@@ -1156,25 +1158,28 @@ static void __exit icmp_exit(void)
 
 int __init icmp_init(void)
 {
-	struct inet_sock *inet;
 	int i, err;
 
 	for_each_possible_cpu(i) {
-		err = sock_create_kern(PF_INET, SOCK_RAW, IPPROTO_ICMP,
-				       &per_cpu(__icmp_socket, i));
+		struct sock *sk;
+		struct socket *sock;
+		struct inet_sock *inet;
 
+		err = sock_create_kern(PF_INET, SOCK_RAW, IPPROTO_ICMP, &sock);
 		if (err < 0)
 			goto fail;
 
-		per_cpu(__icmp_socket, i)->sk->sk_allocation = GFP_ATOMIC;
+		per_cpu(__icmp_socket, i) = sock;
+		sk = sock->sk;
+		sk->sk_allocation = GFP_ATOMIC;
 
 		/* Enough space for 2 64K ICMP packets, including
 		 * sk_buff struct overhead.
 		 */
-		per_cpu(__icmp_socket, i)->sk->sk_sndbuf =
+		sk->sk_sndbuf =
 			(2 * ((64 * 1024) + sizeof(struct sk_buff)));
 
-		inet = inet_sk(per_cpu(__icmp_socket, i)->sk);
+		inet = inet_sk(sk);
 		inet->uc_ttl = -1;
 		inet->pmtudisc = IP_PMTUDISC_DONT;
 
@@ -1182,7 +1187,7 @@ int __init icmp_init(void)
 		 * see it, we do not wish this socket to see incoming
 		 * packets.
 		 */
-		per_cpu(__icmp_socket, i)->sk->sk_prot->unhash(per_cpu(__icmp_socket, i)->sk);
+		sk->sk_prot->unhash(sk);
 	}
 	return 0;