[NET]: Move some core sock setup into sk_prot_alloc

The security_sk_alloc() and the module_get is a part of the
object allocations - move it in the proper place.

Note, that since we do not reset the newly allocated sock
in the sk_alloc() (memset() is removed with the previous
patch) we can safely do this.

Also fix the error path in sk_prot_alloc() - release the security
context if needed.
Signed-off-by: NPavel Emelyanov <xemul@openvz.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net/core/sock.c

@@ -870,7 +870,8 @@ static void sock_copy(struct sock *nsk, const struct sock *osk)
 #endif
 }
 
-static struct sock *sk_prot_alloc(struct proto *prot, gfp_t priority)
+static struct sock *sk_prot_alloc(struct proto *prot, gfp_t priority,
+		int family)
 {
 	struct sock *sk;
 	struct kmem_cache *slab;
@@ -881,18 +882,40 @@ static struct sock *sk_prot_alloc(struct proto *prot, gfp_t priority)
 	else
 		sk = kmalloc(prot->obj_size, priority);
 
+	if (sk != NULL) {
+		if (security_sk_alloc(sk, family, priority))
+			goto out_free;
+
+		if (!try_module_get(prot->owner))
+			goto out_free_sec;
+	}
+
 	return sk;
+
+out_free_sec:
+	security_sk_free(sk);
+out_free:
+	if (slab != NULL)
+		kmem_cache_free(slab, sk);
+	else
+		kfree(sk);
+	return NULL;
 }
 
 static void sk_prot_free(struct proto *prot, struct sock *sk)
 {
 	struct kmem_cache *slab;
+	struct module *owner;
 
+	owner = prot->owner;
 	slab = prot->slab;
+
+	security_sk_free(sk);
 	if (slab != NULL)
 		kmem_cache_free(slab, sk);
 	else
 		kfree(sk);
+	module_put(owner);
 }
 
 /**
@@ -911,7 +934,7 @@ struct sock *sk_alloc(struct net *net, int family, gfp_t priority,
 	if (zero_it)
 		priority |= __GFP_ZERO;
 
-	sk = sk_prot_alloc(prot, priority);
+	sk = sk_prot_alloc(prot, priority, family);
 	if (sk) {
 		if (zero_it) {
 			sk->sk_family = family;
@@ -923,24 +946,14 @@ struct sock *sk_alloc(struct net *net, int family, gfp_t priority,
 			sock_lock_init(sk);
 			sk->sk_net = get_net(net);
 		}
-
-		if (security_sk_alloc(sk, family, priority))
-			goto out_free;
-
-		if (!try_module_get(prot->owner))
-			goto out_free;
 	}
-	return sk;
 
-out_free:
-	sk_prot_free(prot, sk);
-	return NULL;
+	return sk;
 }
 
 void sk_free(struct sock *sk)
 {
 	struct sk_filter *filter;
-	struct module *owner = sk->sk_prot_creator->owner;
 
 	if (sk->sk_destruct)
 		sk->sk_destruct(sk);
@@ -957,10 +970,8 @@ void sk_free(struct sock *sk)
 		printk(KERN_DEBUG "%s: optmem leakage (%d bytes) detected.\n",
 		       __FUNCTION__, atomic_read(&sk->sk_omem_alloc));
 
-	security_sk_free(sk);
 	put_net(sk->sk_net);
 	sk_prot_free(sk->sk_prot_creator, sk);
-	module_put(owner);
 }
 
 struct sock *sk_clone(const struct sock *sk, const gfp_t priority)