Commit 4164245c authored by Eric Dumazet's avatar Eric Dumazet Committed by Jakub Kicinski
Browse files

tcp: annotate data-races around tp->keepalive_time 



do_tcp_getsockopt() reads tp->keepalive_time while another cpu
might change its value.

Fixes: 1da177e4 ("Linux-2.6.12-rc2")
Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20230719212857.3943972-4-edumazet@google.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent dd23c9f1

include/net/tcp.h

+5 −2
Original line number Diff line number Diff line
@@ -1517,9 +1517,12 @@ static inline int keepalive_intvl_when(const struct tcp_sock *tp) 
static inline int keepalive_time_when(const struct tcp_sock *tp)

{

	struct net *net = sock_net((struct sock *)tp);

	int val;



	return tp->keepalive_time ? :

		READ_ONCE(net->ipv4.sysctl_tcp_keepalive_time);

	/* Paired with WRITE_ONCE() in tcp_sock_set_keepidle_locked() */

	val = READ_ONCE(tp->keepalive_time);



	return val ? : READ_ONCE(net->ipv4.sysctl_tcp_keepalive_time);

}



static inline int keepalive_probes(const struct tcp_sock *tp)

net/ipv4/tcp.c

+2 −1
Original line number Diff line number Diff line
@@ -3312,7 +3312,8 @@ int tcp_sock_set_keepidle_locked(struct sock *sk, int val) 
	if (val < 1 || val > MAX_TCP_KEEPIDLE)

		return -EINVAL;



	tp->keepalive_time = val * HZ;

	/* Paired with WRITE_ONCE() in keepalive_time_when() */

	WRITE_ONCE(tp->keepalive_time, val * HZ);

	if (sock_flag(sk, SOCK_KEEPOPEN) &&

	    !((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_LISTEN))) {

		u32 elapsed = keepalive_time_elapsed(tp);