ping: Convert hlist_nulls to plain hlist.

[ Upstream commit f1b5dfe ]

Since introduced in commit c319b4d ("net: ipv4: add IPPROTO_ICMP
socket kind"), ping socket does not use SLAB_TYPESAFE_BY_RCU nor check
nulls marker in loops.

Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Stable-dep-of: ad5dfde ("ping: annotate data-races in ping_lookup()")
Signed-off-by: Sasha Levin <sashal@kernel.org>

Author: q2ven

net/ipv4/ping.c

@@ -49,13 +49,8 @@
 #include <net/transp_v6.h>
 #endif
 
-#define ping_portaddr_for_each_entry(__sk, node, list) \
-	hlist_nulls_for_each_entry(__sk, node, list, sk_nulls_node)
-#define ping_portaddr_for_each_entry_rcu(__sk, node, list) \
-	hlist_nulls_for_each_entry_rcu(__sk, node, list, sk_nulls_node)
-
 struct ping_table {
-	struct hlist_nulls_head	hash[PING_HTABLE_SIZE];
+	struct hlist_head	hash[PING_HTABLE_SIZE];
 	spinlock_t		lock;
 };
 
@@ -74,17 +69,16 @@ static inline u32 ping_hashfn(const struct net *net, u32 num, u32 mask)
 }
 EXPORT_SYMBOL_GPL(ping_hash);
 
-static inline struct hlist_nulls_head *ping_hashslot(struct ping_table *table,
-					     struct net *net, unsigned int num)
+static inline struct hlist_head *ping_hashslot(struct ping_table *table,
+					       struct net *net, unsigned int num)
 {
 	return &table->hash[ping_hashfn(net, num, PING_HTABLE_MASK)];
 }
 
 int ping_get_port(struct sock *sk, unsigned short ident)
 {
-	struct hlist_nulls_node *node;
-	struct hlist_nulls_head *hlist;
 	struct inet_sock *isk, *isk2;
+	struct hlist_head *hlist;
 	struct sock *sk2 = NULL;
 
 	isk = inet_sk(sk);
@@ -98,7 +92,7 @@ int ping_get_port(struct sock *sk, unsigned short ident)
 				result++; /* avoid zero */
 			hlist = ping_hashslot(&ping_table, sock_net(sk),
 					    result);
-			ping_portaddr_for_each_entry(sk2, node, hlist) {
+			sk_for_each(sk2, hlist) {
 				isk2 = inet_sk(sk2);
 
 				if (isk2->inet_num == result)
@@ -115,7 +109,7 @@ int ping_get_port(struct sock *sk, unsigned short ident)
 			goto fail;
 	} else {
 		hlist = ping_hashslot(&ping_table, sock_net(sk), ident);
-		ping_portaddr_for_each_entry(sk2, node, hlist) {
+		sk_for_each(sk2, hlist) {
 			isk2 = inet_sk(sk2);
 
 			/* BUG? Why is this reuse and not reuseaddr? ping.c
@@ -133,9 +127,8 @@ int ping_get_port(struct sock *sk, unsigned short ident)
 	isk->inet_num = ident;
 	if (sk_unhashed(sk)) {
 		pr_debug("was not hashed\n");
-		sock_hold(sk);
+		sk_add_node_rcu(sk, hlist);
 		sock_set_flag(sk, SOCK_RCU_FREE);
-		hlist_nulls_add_head_rcu(&sk->sk_nulls_node, hlist);
 		sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
 	}
 	spin_unlock(&ping_table.lock);
@@ -161,9 +154,7 @@ void ping_unhash(struct sock *sk)
 
 	pr_debug("ping_unhash(isk=%p,isk->num=%u)\n", isk, isk->inet_num);
 	spin_lock(&ping_table.lock);
-	if (sk_hashed(sk)) {
-		hlist_nulls_del_init_rcu(&sk->sk_nulls_node);
-		sock_put(sk);
+	if (sk_del_node_init_rcu(sk)) {
 		isk->inet_num = 0;
 		isk->inet_sport = 0;
 		sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1);
@@ -175,10 +166,9 @@ EXPORT_SYMBOL_GPL(ping_unhash);
 /* Called under rcu_read_lock() */
 static struct sock *ping_lookup(struct net *net, struct sk_buff *skb, u16 ident)
 {
-	struct hlist_nulls_head *hslot = ping_hashslot(&ping_table, net, ident);
+	struct hlist_head *hslot = ping_hashslot(&ping_table, net, ident);
 	struct sock *sk = NULL;
 	struct inet_sock *isk;
-	struct hlist_nulls_node *hnode;
 	int dif, sdif;
 
 	if (skb->protocol == htons(ETH_P_IP)) {
@@ -197,7 +187,7 @@ static struct sock *ping_lookup(struct net *net, struct sk_buff *skb, u16 ident)
 		return NULL;
 	}
 
-	ping_portaddr_for_each_entry_rcu(sk, hnode, hslot) {
+	sk_for_each_rcu(sk, hslot) {
 		isk = inet_sk(sk);
 
 		pr_debug("iterate\n");
@@ -1043,15 +1033,14 @@ static struct sock *ping_get_first(struct seq_file *seq, int start)
 
 	for (state->bucket = start; state->bucket < PING_HTABLE_SIZE;
 	     ++state->bucket) {
-		struct hlist_nulls_node *node;
-		struct hlist_nulls_head *hslot;
+		struct hlist_head *hslot;
 
 		hslot = &ping_table.hash[state->bucket];
 
-		if (hlist_nulls_empty(hslot))
+		if (hlist_empty(hslot))
 			continue;
 
-		sk_nulls_for_each(sk, node, hslot) {
+		sk_for_each(sk, hslot) {
 			if (net_eq(sock_net(sk), net) &&
 			    sk->sk_family == state->family)
 				goto found;
@@ -1068,7 +1057,7 @@ static struct sock *ping_get_next(struct seq_file *seq, struct sock *sk)
 	struct net *net = seq_file_net(seq);
 
 	do {
-		sk = sk_nulls_next(sk);
+		sk = sk_next(sk);
 	} while (sk && (!net_eq(sock_net(sk), net)));
 
 	if (!sk)
@@ -1204,6 +1193,6 @@ void __init ping_init(void)
 	int i;
 
 	for (i = 0; i < PING_HTABLE_SIZE; i++)
-		INIT_HLIST_NULLS_HEAD(&ping_table.hash[i], i);
+		INIT_HLIST_HEAD(&ping_table.hash[i]);
 	spin_lock_init(&ping_table.lock);
 }