Commit 84485080 authored by Eric Dumazet's avatar Eric Dumazet Committed by David S. Miller
Browse files

tcp: set TCP_KEEPCNT locklessly 



tp->keepalive_probes can be set locklessly, readers
are already taking care of this field being potentially
set by other threads.

Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
Acked-by: default avatarSoheil Hassas Yeganeh <soheil@google.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 6fd70a6b

net/ipv4/tcp.c

+2 −8
Original line number Diff line number Diff line
@@ -3358,10 +3358,8 @@ int tcp_sock_set_keepcnt(struct sock *sk, int val) 
	if (val < 1 || val > MAX_TCP_KEEPCNT)

		return -EINVAL;



	lock_sock(sk);

	/* Paired with READ_ONCE() in keepalive_probes() */

	WRITE_ONCE(tcp_sk(sk)->keepalive_probes, val);

	release_sock(sk);

	return 0;

}

EXPORT_SYMBOL(tcp_sock_set_keepcnt);
@@ -3471,6 +3469,8 @@ int do_tcp_setsockopt(struct sock *sk, int level, int optname, 
		return tcp_sock_set_user_timeout(sk, val);

	case TCP_KEEPINTVL:

		return tcp_sock_set_keepintvl(sk, val);

	case TCP_KEEPCNT:

		return tcp_sock_set_keepcnt(sk, val);

	}



	sockopt_lock_sock(sk);
@@ -3568,12 +3568,6 @@ int do_tcp_setsockopt(struct sock *sk, int level, int optname, 
	case TCP_KEEPIDLE:

		err = tcp_sock_set_keepidle_locked(sk, val);

		break;

	case TCP_KEEPCNT:

		if (val < 1 || val > MAX_TCP_KEEPCNT)

			err = -EINVAL;

		else

			WRITE_ONCE(tp->keepalive_probes, val);

		break;

	case TCP_SAVE_SYN:

		/* 0: disable, 1: enable, 2: start from ether_header */

		if (val < 0 || val > 2)