skmsg: Update saved hooks only once

					 struct sk_psock *psock,

					 struct proto *ops)

{

	psock->saved_unhash = sk->sk_prot->unhash;

	psock->saved_close = sk->sk_prot->close;

	/* Initialize saved callbacks and original proto only once, since this

	 * function may be called multiple times for a psock, e.g. when

	 * psock->progs.msg_parser is updated.

	 *

	 * Since we've not installed the new proto, psock is not yet in use and

	 * we can initialize it without synchronization.

	 */

	if (!psock->sk_proto) {

		struct proto *orig = READ_ONCE(sk->sk_prot);

		psock->saved_unhash = orig->unhash;

		psock->saved_close = orig->close;

		psock->saved_write_space = sk->sk_write_space;

	psock->sk_proto = sk->sk_prot;

		psock->sk_proto = orig;

	}

	/* Pairs with lockless read in sk_clone_lock() */

	WRITE_ONCE(sk->sk_prot, ops);

}

	sk_psock_update_proto(sk, psock, &tcp_bpf_prots[family][config]);

}

static void tcp_bpf_reinit_sk_prot(struct sock *sk, struct sk_psock *psock)

{

	int family = sk->sk_family == AF_INET6 ? TCP_BPF_IPV6 : TCP_BPF_IPV4;

	int config = psock->progs.msg_parser   ? TCP_BPF_TX   : TCP_BPF_BASE;

	/* Reinit occurs when program types change e.g. TCP_BPF_TX is removed

	 * or added requiring sk_prot hook updates. We keep original saved

	 * hooks in this case.

	 *

	 * Pairs with lockless read in sk_clone_lock().

	 */

	WRITE_ONCE(sk->sk_prot, &tcp_bpf_prots[family][config]);

}

static int tcp_bpf_assert_proto_ops(struct proto *ops)

{

	/* In order to avoid retpoline, we make assumptions when we call

	rcu_read_lock();

	psock = sk_psock(sk);

	tcp_bpf_reinit_sk_prot(sk, psock);

	tcp_bpf_update_sk_prot(sk, psock);

	rcu_read_unlock();

}