tcp: annotate data-races around tp->keepalive_time

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

Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20230719212857.3943972-4-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This commit is contained in:
Eric Dumazet 2023-07-19 21:28:49 +00:00 committed by Jakub Kicinski
parent dd23c9f1e8
commit 4164245c76
2 changed files with 7 additions and 3 deletions

View File

@ -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)

View File

@ -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);