[ICMP]: Allocate data for __icmp(v6)_sk dynamically.

Own __icmp(v6)_sk should be present in each namespace. So, it should be
allocated dynamically. Though, alloc_percpu does not fit the case as it
implies additional dereferrence for no bonus.

Allocate data for pointers just like __percpu_alloc_mask does and place
pointers to struct sock into this array.

Signed-off-by: Denis V. Lunev <den@openvz.org>
Acked-by: Daniel Lezcano <dlezcano@fr.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/ipv4/icmp.c

@@ -229,8 +229,8 @@ static const struct icmp_control icmp_pointers[NR_ICMP_TYPES+1];
  *
  *	On SMP we have one ICMP socket per-cpu.
  */
-static DEFINE_PER_CPU(struct sock *, __icmp_sk) = NULL;
-#define icmp_sk		__get_cpu_var(__icmp_sk)
+static struct sock **__icmp_sk = NULL;
+#define icmp_sk		(__icmp_sk[smp_processor_id()])
 
 static inline int icmp_xmit_lock(struct sock *sk)
 {
@@ -1149,18 +1149,23 @@ static void __exit icmp_exit(void)
 	for_each_possible_cpu(i) {
 		struct sock *sk;
 
-		sk = per_cpu(__icmp_sk, i);
+		sk = __icmp_sk[i];
 		if (sk == NULL)
 			continue;
-		per_cpu(__icmp_sk, i) = NULL;
 		sock_release(sk->sk_socket);
 	}
+	kfree(__icmp_sk);
+	__icmp_sk = NULL;
 }
 
 int __init icmp_init(void)
 {
 	int i, err;
 
+	__icmp_sk = kzalloc(nr_cpu_ids * sizeof(struct sock *), GFP_KERNEL);
+	if (__icmp_sk == NULL)
+		return -ENOMEM;
+
 	for_each_possible_cpu(i) {
 		struct sock *sk;
 		struct socket *sock;
@@ -1170,7 +1175,7 @@ int __init icmp_init(void)
 		if (err < 0)
 			goto fail;
 
-		per_cpu(__icmp_sk, i) = sk = sock->sk;
+		__icmp_sk[i] = sk = sock->sk;
 		sk->sk_allocation = GFP_ATOMIC;
 
 		/* Enough space for 2 64K ICMP packets, including

net/ipv6/icmp.c

@@ -80,8 +80,8 @@ EXPORT_SYMBOL(icmpv6msg_statistics);
  *
  *	On SMP we have one ICMP socket per-cpu.
  */
-static DEFINE_PER_CPU(struct sock *, __icmpv6_sk) = NULL;
-#define icmpv6_sk	__get_cpu_var(__icmpv6_sk)
+static struct sock **__icmpv6_sk = NULL;
+#define icmpv6_sk	(__icmpv6_sk[smp_processor_id()])
 
 static int icmpv6_rcv(struct sk_buff *skb);
 
@@ -785,6 +785,10 @@ int __init icmpv6_init(void)
 	struct sock *sk;
 	int err, i, j;
 
+	__icmpv6_sk = kzalloc(nr_cpu_ids * sizeof(struct sock *), GFP_KERNEL);
+	if (__icmpv6_sk == NULL)
+		return -ENOMEM;
+
 	for_each_possible_cpu(i) {
 		struct socket *sock;
 		err = sock_create_kern(PF_INET6, SOCK_RAW, IPPROTO_ICMPV6,
@@ -797,7 +801,7 @@ int __init icmpv6_init(void)
 			goto fail;
 		}
 
-		per_cpu(__icmpv6_sk, i) = sk = sock->sk;
+		__icmpv6_sk[i] = sk = sock->sk;
 		sk->sk_allocation = GFP_ATOMIC;
 		/*
 		 * Split off their lock-class, because sk->sk_dst_lock
@@ -830,7 +834,7 @@ int __init icmpv6_init(void)
 	for (j = 0; j < i; j++) {
 		if (!cpu_possible(j))
 			continue;
-		sock_release(per_cpu(__icmpv6_sk, j)->sk_socket);
+		sock_release(__icmpv6_sk[j]->sk_socket);
 	}
 
 	return err;
@@ -841,7 +845,7 @@ void icmpv6_cleanup(void)
 	int i;
 
 	for_each_possible_cpu(i) {
-		sock_release(per_cpu(__icmpv6_sk, i)->sk_socket);
+		sock_release(__icmpv6_sk[i]->sk_socket);
 	}
 	inet6_del_protocol(&icmpv6_protocol, IPPROTO_ICMPV6);
 }