Commit 5282de17 authored by Eric Dumazet's avatar Eric Dumazet Committed by Jakub Kicinski
Browse files

tcp: remove READ_ONCE(req->ts_recent) 



After commit 8d52da23 ("tcp: Defer ts_recent changes
until req is owned"), req->ts_recent is not changed anymore.

It is set once in tcp_openreq_init(), bpf_sk_assign_tcp_reqsk()
or cookie_tcp_reqsk_alloc() before the req can be seen by other
cpus/threads.

This completes the revert of eba20811 ("tcp: annotate
data-races around tcp_rsk(req)->ts_recent").

Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
Cc: Wang Hai <wanghai38@huawei.com>
Reviewed-by: default avatarJason Xing <kerneljasonxing@gmail.com>
Reviewed-by: default avatarKuniyuki Iwashima <kuniyu@amazon.com>
Link: https://patch.msgid.link/20250301201424.2046477-6-edumazet@google.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent 9b49f57c

net/ipv4/tcp_ipv4.c

+1 −1
Original line number Diff line number Diff line
@@ -1155,7 +1155,7 @@ static void tcp_v4_reqsk_send_ack(const struct sock *sk, struct sk_buff *skb, 
			tcp_rsk(req)->rcv_nxt,

			tcp_synack_window(req) >> inet_rsk(req)->rcv_wscale,

			tcp_rsk_tsval(tcp_rsk(req)),

			READ_ONCE(req->ts_recent),

			req->ts_recent,

			0, &key,

			inet_rsk(req)->no_srccheck ? IP_REPLY_ARG_NOSRCCHECK : 0,

			ip_hdr(skb)->tos,

net/ipv4/tcp_minisocks.c

+2 −2
Original line number Diff line number Diff line
@@ -585,7 +585,7 @@ struct sock *tcp_create_openreq_child(const struct sock *sk, 


	if (newtp->rx_opt.tstamp_ok) {

		newtp->tcp_usec_ts = treq->req_usec_ts;

		newtp->rx_opt.ts_recent = READ_ONCE(req->ts_recent);

		newtp->rx_opt.ts_recent = req->ts_recent;

		newtp->rx_opt.ts_recent_stamp = ktime_get_seconds();

		newtp->tcp_header_len = sizeof(struct tcphdr) + TCPOLEN_TSTAMP_ALIGNED;

	} else {
@@ -673,7 +673,7 @@ struct sock *tcp_check_req(struct sock *sk, struct sk_buff *skb, 
		tcp_parse_options(sock_net(sk), skb, &tmp_opt, 0, NULL);



		if (tmp_opt.saw_tstamp) {

			tmp_opt.ts_recent = READ_ONCE(req->ts_recent);

			tmp_opt.ts_recent = req->ts_recent;

			if (tmp_opt.rcv_tsecr) {

				if (inet_rsk(req)->tstamp_ok && !fastopen)

					tsecr_reject = !between(tmp_opt.rcv_tsecr,

net/ipv4/tcp_output.c

+1 −1
Original line number Diff line number Diff line
@@ -949,7 +949,7 @@ static unsigned int tcp_synack_options(const struct sock *sk, 
			tcp_rsk(req)->snt_tsval_first = opts->tsval;

		}

		WRITE_ONCE(tcp_rsk(req)->snt_tsval_last, opts->tsval);

		opts->tsecr = READ_ONCE(req->ts_recent);

		opts->tsecr = req->ts_recent;

		remaining -= TCPOLEN_TSTAMP_ALIGNED;

	}

	if (likely(ireq->sack_ok)) {

net/ipv6/tcp_ipv6.c

+1 −1
Original line number Diff line number Diff line
@@ -1279,7 +1279,7 @@ static void tcp_v6_reqsk_send_ack(const struct sock *sk, struct sk_buff *skb, 
			tcp_rsk(req)->rcv_nxt,

			tcp_synack_window(req) >> inet_rsk(req)->rcv_wscale,

			tcp_rsk_tsval(tcp_rsk(req)),

			READ_ONCE(req->ts_recent), sk->sk_bound_dev_if,

			req->ts_recent, sk->sk_bound_dev_if,

			&key, ipv6_get_dsfield(ipv6_hdr(skb)), 0,

			READ_ONCE(sk->sk_priority),

			READ_ONCE(tcp_rsk(req)->txhash));