mptcp: diag: switch to context structure

Raw access to cb->arg[] is deprecated, use a context structure.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/mptcp/mptcp_diag.c

@@ -66,20 +66,28 @@ static int mptcp_diag_dump_one(struct netlink_callback *cb,
 	return err;
 }
 
+struct mptcp_diag_ctx {
+	long s_slot;
+	long s_num;
+};
+
 static void mptcp_diag_dump(struct sk_buff *skb, struct netlink_callback *cb,
 			    const struct inet_diag_req_v2 *r)
 {
 	bool net_admin = netlink_net_capable(cb->skb, CAP_NET_ADMIN);
+	struct mptcp_diag_ctx *diag_ctx = (void *)cb->ctx;
 	struct net *net = sock_net(skb->sk);
 	struct inet_diag_dump_data *cb_data;
 	struct mptcp_sock *msk;
 	struct nlattr *bc;
 
+	BUILD_BUG_ON(sizeof(cb->ctx) < sizeof(*diag_ctx));
+
 	cb_data = cb->data;
 	bc = cb_data->inet_diag_nla_bc;
 
-	while ((msk = mptcp_token_iter_next(net, &cb->args[0], &cb->args[1])) !=
-	       NULL) {
+	while ((msk = mptcp_token_iter_next(net, &diag_ctx->s_slot,
+					    &diag_ctx->s_num)) != NULL) {
 		struct inet_sock *inet = (struct inet_sock *)msk;
 		struct sock *sk = (struct sock *)msk;
 		int ret = 0;
@@ -101,7 +109,7 @@ static void mptcp_diag_dump(struct sk_buff *skb, struct netlink_callback *cb,
 		sock_put(sk);
 		if (ret < 0) {
 			/* will retry on the same position */
-			cb->args[1]--;
+			diag_ctx->s_num--;
 			break;
 		}
 		cond_resched();