From: Eric Dumazet Date: Thu, 16 Apr 2026 20:03:12 +0000 (+0000) Subject: tcp: annotate data-races around tp->bytes_sent X-Git-Tag: v7.1-rc1~36^2~60^2~7 X-Git-Url: http://git.ipfire.org/gitweb/?a=commitdiff_plain;h=ee43e957ce2ec77b2ec47fef28f3c0df6ab01a31;p=thirdparty%2Fkernel%2Flinux.git tcp: annotate data-races around tp->bytes_sent tcp_get_timestamping_opt_stats() intentionally runs lockless, we must add READ_ONCE() and WRITE_ONCE() annotations to keep KCSAN happy. Fixes: ba113c3aa79a ("tcp: add data bytes sent stats") Signed-off-by: Eric Dumazet Link: https://patch.msgid.link/20260416200319.3608680-8-edumazet@google.com Signed-off-by: Jakub Kicinski --- diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index 729936d13a5c..f999b86851cd 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -4461,7 +4461,7 @@ struct sk_buff *tcp_get_timestamping_opt_stats(const struct sock *sk, READ_ONCE(tp->write_seq) - READ_ONCE(tp->snd_una))); nla_put_u8(stats, TCP_NLA_CA_STATE, inet_csk(sk)->icsk_ca_state); - nla_put_u64_64bit(stats, TCP_NLA_BYTES_SENT, tp->bytes_sent, + nla_put_u64_64bit(stats, TCP_NLA_BYTES_SENT, READ_ONCE(tp->bytes_sent), TCP_NLA_PAD); nla_put_u64_64bit(stats, TCP_NLA_BYTES_RETRANS, tp->bytes_retrans, TCP_NLA_PAD); diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c index 9f83c7e4acab..87af4731df87 100644 --- a/net/ipv4/tcp_output.c +++ b/net/ipv4/tcp_output.c @@ -1690,7 +1690,8 @@ static int __tcp_transmit_skb(struct sock *sk, struct sk_buff *skb, tcp_event_data_sent(tp, sk); WRITE_ONCE(tp->data_segs_out, tp->data_segs_out + tcp_skb_pcount(skb)); - tp->bytes_sent += skb->len - tcp_header_size; + WRITE_ONCE(tp->bytes_sent, + tp->bytes_sent + skb->len - tcp_header_size); } if (after(tcb->end_seq, tp->snd_nxt) || tcb->seq == tcb->end_seq)