tcp: annotate data-races around tp->timeout_rehash

tcp_get_timestamping_opt_stats() intentionally runs lockless, we must
add READ_ONCE() and WRITE_ONCE() annotations to keep KCSAN happy.

Fixes: 32efcc06d2 ("tcp: export count for rehash attempts")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20260416200319.3608680-13-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This commit is contained in:
Eric Dumazet 2026-04-16 20:03:17 +00:00 committed by Jakub Kicinski
parent 290b693ce7
commit 71c675358b
2 changed files with 3 additions and 2 deletions

View File

@ -4469,7 +4469,8 @@ struct sk_buff *tcp_get_timestamping_opt_stats(const struct sock *sk,
nla_put_u32(stats, TCP_NLA_DSACK_DUPS, READ_ONCE(tp->dsack_dups));
nla_put_u32(stats, TCP_NLA_REORD_SEEN, READ_ONCE(tp->reord_seen));
nla_put_u32(stats, TCP_NLA_SRTT, READ_ONCE(tp->srtt_us) >> 3);
nla_put_u16(stats, TCP_NLA_TIMEOUT_REHASH, tp->timeout_rehash);
nla_put_u16(stats, TCP_NLA_TIMEOUT_REHASH,
READ_ONCE(tp->timeout_rehash));
nla_put_u32(stats, TCP_NLA_BYTES_NOTSENT,
max_t(int, 0, tp->write_seq - tp->snd_nxt));
nla_put_u64_64bit(stats, TCP_NLA_EDT, orig_skb->skb_mstamp_ns,

View File

@ -297,7 +297,7 @@ static int tcp_write_timeout(struct sock *sk)
}
if (sk_rethink_txhash(sk)) {
tp->timeout_rehash++;
WRITE_ONCE(tp->timeout_rehash, tp->timeout_rehash + 1);
__NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPTIMEOUTREHASH);
}