From: Eric Dumazet Date: Thu, 16 Apr 2026 20:03:10 +0000 (+0000) Subject: tcp: annotate data-races around tp->delivered and tp->delivered_ce X-Git-Tag: v7.1-rc1~36^2~60^2~9 X-Git-Url: http://git.ipfire.org/gitweb/?a=commitdiff_plain;h=faa886ad3ce5fc8f5156493491fe189b2b726bc9;p=thirdparty%2Fkernel%2Flinux.git tcp: annotate data-races around tp->delivered and tp->delivered_ce tcp_get_timestamping_opt_stats() intentionally runs lockless, we must add READ_ONCE() and WRITE_ONCE() annotations to keep KCSAN happy. Fixes: feb5f2ec6464 ("tcp: export packets delivery info") Signed-off-by: Eric Dumazet Link: https://patch.msgid.link/20260416200319.3608680-6-edumazet@google.com Signed-off-by: Jakub Kicinski --- diff --git a/include/net/tcp_ecn.h b/include/net/tcp_ecn.h index e9a933641636..865d5c5a7718 100644 --- a/include/net/tcp_ecn.h +++ b/include/net/tcp_ecn.h @@ -181,7 +181,7 @@ static inline void tcp_accecn_third_ack(struct sock *sk, tcp_accecn_validate_syn_feedback(sk, ace, sent_ect)) { if ((tcp_accecn_extract_syn_ect(ace) == INET_ECN_CE) && !tp->delivered_ce) - tp->delivered_ce++; + WRITE_ONCE(tp->delivered_ce, 1); } break; } diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index 802a9ea05211..0aabd02d4496 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -4453,8 +4453,8 @@ struct sk_buff *tcp_get_timestamping_opt_stats(const struct sock *sk, READ_ONCE(inet_csk(sk)->icsk_retransmits)); nla_put_u8(stats, TCP_NLA_DELIVERY_RATE_APP_LMT, data_race(!!tp->rate_app_limited)); nla_put_u32(stats, TCP_NLA_SND_SSTHRESH, READ_ONCE(tp->snd_ssthresh)); - nla_put_u32(stats, TCP_NLA_DELIVERED, tp->delivered); - nla_put_u32(stats, TCP_NLA_DELIVERED_CE, tp->delivered_ce); + nla_put_u32(stats, TCP_NLA_DELIVERED, READ_ONCE(tp->delivered)); + nla_put_u32(stats, TCP_NLA_DELIVERED_CE, READ_ONCE(tp->delivered_ce)); nla_put_u32(stats, TCP_NLA_SNDQ_SIZE, tp->write_seq - tp->snd_una); nla_put_u8(stats, TCP_NLA_CA_STATE, inet_csk(sk)->icsk_ca_state); diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index c6361447535f..63ff89210a72 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -476,14 +476,14 @@ static bool tcp_accecn_process_option(struct tcp_sock *tp, static void tcp_count_delivered_ce(struct tcp_sock *tp, u32 ecn_count) { - tp->delivered_ce += ecn_count; + WRITE_ONCE(tp->delivered_ce, tp->delivered_ce + ecn_count); } /* Updates the delivered and delivered_ce counts */ static void tcp_count_delivered(struct tcp_sock *tp, u32 delivered, bool ece_ack) { - tp->delivered += delivered; + WRITE_ONCE(tp->delivered, tp->delivered + delivered); if (tcp_ecn_mode_rfc3168(tp) && ece_ack) tcp_count_delivered_ce(tp, delivered); } @@ -6779,7 +6779,7 @@ static bool tcp_rcv_fastopen_synack(struct sock *sk, struct sk_buff *synack, NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPFASTOPENACTIVE); /* SYN-data is counted as two separate packets in tcp_ack() */ if (tp->delivered > 1) - --tp->delivered; + WRITE_ONCE(tp->delivered, tp->delivered - 1); } tcp_fastopen_add_skb(sk, synack); @@ -7212,7 +7212,7 @@ tcp_rcv_state_process(struct sock *sk, struct sk_buff *skb) SKB_DR_SET(reason, NOT_SPECIFIED); switch (sk->sk_state) { case TCP_SYN_RECV: - tp->delivered++; /* SYN-ACK delivery isn't tracked in tcp_ack */ + WRITE_ONCE(tp->delivered, tp->delivered + 1); /* SYN-ACK delivery isn't tracked in tcp_ack */ if (!tp->srtt_us) tcp_synack_rtt_meas(sk, req);