Commit dd23c9f1 authored by Eric Dumazet's avatar Eric Dumazet Committed by Jakub Kicinski
Browse files

tcp: annotate data-races around tp->tsoffset 



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

Fixes: 93be6ce0 ("tcp: set and get per-socket timestamp")
Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20230719212857.3943972-3-edumazet@google.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent 348b81b6

net/ipv4/tcp.c

+2 −2
Original line number Diff line number Diff line
@@ -3656,7 +3656,7 @@ int do_tcp_setsockopt(struct sock *sk, int level, int optname, 
		if (!tp->repair)

			err = -EPERM;

		else

			tp->tsoffset = val - tcp_time_stamp_raw();

			WRITE_ONCE(tp->tsoffset, val - tcp_time_stamp_raw());

		break;

	case TCP_REPAIR_WINDOW:

		err = tcp_repair_set_window(tp, optval, optlen);
@@ -4158,7 +4158,7 @@ int do_tcp_getsockopt(struct sock *sk, int level, 
		break;



	case TCP_TIMESTAMP:

		val = tcp_time_stamp_raw() + tp->tsoffset;

		val = tcp_time_stamp_raw() + READ_ONCE(tp->tsoffset);

		break;

	case TCP_NOTSENT_LOWAT:

		val = tp->notsent_lowat;

net/ipv4/tcp_ipv4.c

+3 −2
Original line number Diff line number Diff line
@@ -307,8 +307,9 @@ int tcp_v4_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len) 
						  inet->inet_daddr,

						  inet->inet_sport,

						  usin->sin_port));

		tp->tsoffset = secure_tcp_ts_off(net, inet->inet_saddr,

						 inet->inet_daddr);

		WRITE_ONCE(tp->tsoffset,

			   secure_tcp_ts_off(net, inet->inet_saddr,

					     inet->inet_daddr));

	}



	inet->inet_id = get_random_u16();