[ICMP]: Pass proper ICMP socket into icmp(v6)_xmit_(un)lock.

We have to get socket lock inside icmp(v6)_xmit_lock/unlock. The socket
is get from global variable now. When this code became namespaces, one
should pass a namespace and get socket from it.

Though, above is useless. Socket is available in the caller, just pass
it inside. This saves a bit of code now and saves more later.

add/remove: 0/0 grow/shrink: 1/3 up/down: 1/-169 (-168)
function                                     old     new   delta
icmp_rcv                                     718     719      +1
icmpv6_rcv                                  2343    2303     -40
icmp_send                                   1566    1518     -48
icmp_reply                                   549     468     -81

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

@@ -232,11 +232,11 @@ static const struct icmp_control icmp_pointers[NR_ICMP_TYPES+1];
 static DEFINE_PER_CPU(struct sock *, __icmp_sk) = NULL;
 #define icmp_sk		__get_cpu_var(__icmp_sk)
 
-static inline int icmp_xmit_lock(void)
+static inline int icmp_xmit_lock(struct sock *sk)
 {
 	local_bh_disable();
 
-	if (unlikely(!spin_trylock(&icmp_sk->sk_lock.slock))) {
+	if (unlikely(!spin_trylock(&sk->sk_lock.slock))) {
 		/* This can happen if the output path signals a
 		 * dst_link_failure() for an outgoing ICMP packet.
 		 */
@@ -246,9 +246,9 @@ static inline int icmp_xmit_lock(void)
 	return 0;
 }
 
-static inline void icmp_xmit_unlock(void)
+static inline void icmp_xmit_unlock(struct sock *sk)
 {
-	spin_unlock_bh(&icmp_sk->sk_lock.slock);
+	spin_unlock_bh(&sk->sk_lock.slock);
 }
 
 /*
@@ -387,7 +387,7 @@ static void icmp_reply(struct icmp_bxm *icmp_param, struct sk_buff *skb)
 	if (ip_options_echo(&icmp_param->replyopts, skb))
 		return;
 
-	if (icmp_xmit_lock())
+	if (icmp_xmit_lock(sk))
 		return;
 
 	icmp_param->data.icmph.checksum = 0;
@@ -415,7 +415,7 @@ static void icmp_reply(struct icmp_bxm *icmp_param, struct sk_buff *skb)
 		icmp_push_reply(icmp_param, &ipc, rt);
 	ip_rt_put(rt);
 out_unlock:
-	icmp_xmit_unlock();
+	icmp_xmit_unlock(sk);
 }
 
 
@@ -440,6 +440,7 @@ void icmp_send(struct sk_buff *skb_in, int type, int code, __be32 info)
 	__be32 saddr;
 	u8  tos;
 	struct net *net;
+	struct sock *sk = icmp_sk;
 
 	if (!rt)
 		goto out;
@@ -507,7 +508,7 @@ void icmp_send(struct sk_buff *skb_in, int type, int code, __be32 info)
 		}
 	}
 
-	if (icmp_xmit_lock())
+	if (icmp_xmit_lock(sk))
 		return;
 
 	/*
@@ -546,7 +547,7 @@ void icmp_send(struct sk_buff *skb_in, int type, int code, __be32 info)
 	icmp_param.data.icmph.checksum	 = 0;
 	icmp_param.skb	  = skb_in;
 	icmp_param.offset = skb_network_offset(skb_in);
-	inet_sk(icmp_sk)->tos = tos;
+	inet_sk(sk)->tos = tos;
 	ipc.addr = iph->saddr;
 	ipc.opt = &icmp_param.replyopts;
 
@@ -654,7 +655,7 @@ route_done:
 ende:
 	ip_rt_put(rt);
 out_unlock:
-	icmp_xmit_unlock();
+	icmp_xmit_unlock(sk);
 out:;
 }
 

net/ipv6/icmp.c

@@ -90,11 +90,11 @@ static struct inet6_protocol icmpv6_protocol = {
 	.flags		=	INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
 };
 
-static __inline__ int icmpv6_xmit_lock(void)
+static __inline__ int icmpv6_xmit_lock(struct sock *sk)
 {
 	local_bh_disable();
 
-	if (unlikely(!spin_trylock(&icmpv6_sk->sk_lock.slock))) {
+	if (unlikely(!spin_trylock(&sk->sk_lock.slock))) {
 		/* This can happen if the output path (f.e. SIT or
 		 * ip6ip6 tunnel) signals dst_link_failure() for an
 		 * outgoing ICMP6 packet.
@@ -105,9 +105,9 @@ static __inline__ int icmpv6_xmit_lock(void)
 	return 0;
 }
 
-static __inline__ void icmpv6_xmit_unlock(void)
+static __inline__ void icmpv6_xmit_unlock(struct sock *sk)
 {
-	spin_unlock_bh(&icmpv6_sk->sk_lock.slock);
+	spin_unlock_bh(&sk->sk_lock.slock);
 }
 
 /*
@@ -389,12 +389,12 @@ void icmpv6_send(struct sk_buff *skb, int type, int code, __u32 info,
 	fl.fl_icmp_code = code;
 	security_skb_classify_flow(skb, &fl);
 
-	if (icmpv6_xmit_lock())
-		return;
-
 	sk = icmpv6_sk;
 	np = inet6_sk(sk);
 
+	if (icmpv6_xmit_lock(sk))
+		return;
+
 	if (!icmpv6_xrlim_allow(sk, type, &fl))
 		goto out;
 
@@ -498,7 +498,7 @@ out_put:
 out_dst_release:
 	dst_release(dst);
 out:
-	icmpv6_xmit_unlock();
+	icmpv6_xmit_unlock(sk);
 }
 
 EXPORT_SYMBOL(icmpv6_send);
@@ -535,12 +535,12 @@ static void icmpv6_echo_reply(struct sk_buff *skb)
 	fl.fl_icmp_type = ICMPV6_ECHO_REPLY;
 	security_skb_classify_flow(skb, &fl);
 
-	if (icmpv6_xmit_lock())
-		return;
-
 	sk = icmpv6_sk;
 	np = inet6_sk(sk);
 
+	if (icmpv6_xmit_lock(sk))
+		return;
+
 	if (!fl.oif && ipv6_addr_is_multicast(&fl.fl6_dst))
 		fl.oif = np->mcast_oif;
 
@@ -584,7 +584,7 @@ out_put:
 		in6_dev_put(idev);
 	dst_release(dst);
 out:
-	icmpv6_xmit_unlock();
+	icmpv6_xmit_unlock(sk);
 }
 
 static void icmpv6_notify(struct sk_buff *skb, int type, int code, __be32 info)