From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-yw1-f201.google.com (mail-yw1-f201.google.com [209.85.128.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 610463537EA for ; Thu, 16 Apr 2026 20:03:45 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.128.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776369830; cv=none; b=NKHLGG40MQF5DJ5EMJ2T99DNhoNdUQpe3yeja0BtKbMnl47YFuLOkVA8fWHaY0XzbrK1HPDTn5abmaKEWSAU6I7b4Eu3YHEZPrDl0ePOS2KeVZiTCKsuljWVy2lDYbaZ+PJ1Kxqgn6sM0WKrDfybJBCvdI2uOd3hmzAWXGaJTd8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776369830; c=relaxed/simple; bh=QqOs/THqfii59khCeoTMZOPtKFPFLV2Y5odetbyhFO8=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=ECxDK834DmRAnMOu4wtksNIJLxEwMY6F/mNgizeQAviI7J3RzvIiJz/fq6zIAUIpIr0x0XqJWsSBdxb4zk46BwE609AMFbzpvPYglTciBVTzPe848QpvgituVlX5nZQDUWGmdvRpf4gYcgrmIrFwS2J7ZzrLbclI4HKLOiXG724= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--edumazet.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=Vp9FTgAT; arc=none smtp.client-ip=209.85.128.201 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--edumazet.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="Vp9FTgAT" Received: by mail-yw1-f201.google.com with SMTP id 00721157ae682-790afc07667so205946647b3.0 for ; Thu, 16 Apr 2026 13:03:45 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1776369822; x=1776974622; darn=vger.kernel.org; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=k8EuQvM8AiGSLEO1UUgTVNhEY05Q2B79NY1zW1zF9Oo=; b=Vp9FTgAT6k2wAZH0zdwvfEAaligl8v0Cx8NkQFcPfpNM5Y3Xqq5IckSwqOElU05NYY Tm9SC7sJFm9J3SlMZVzLA+QZvmSdVO78WD0+uIypgDt+4iXG0czQmmwu3F3S0exRmFpl qVh8ACHT0ogUpfzC7p4kQll9dv8uvLkLt21fIhyM9cIBUub+D12aQst7gt43ZFsmFmAc 9hNQp9HKaGnkaSm57cNlsB4RRB0mjH+W9QkvSr+xKs0/6YP8vrXhHRb7eTL4SKqm1IZ6 DgxcOdQ9YdKQckFNR4sIcwzwki3xfmKfowOhVA6d57/RhFBG9hYDaH3k48OafZ2urWym Nvug== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1776369822; x=1776974622; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=k8EuQvM8AiGSLEO1UUgTVNhEY05Q2B79NY1zW1zF9Oo=; b=GGjrpXmQ35mgkqXgY76cKMzYslG8MRG6o+waNhILRsM3WLW5ElTBI9iqVCQGXcYuyT yY5VjoiSx17qEo/C+qBXGDMh3Gny+Z6/WkyJvPcfBPLLv0HR7no6waFUweAfuu+TFD3v T1pAnXT7dHJC8GdKCM4UUGA8aa+6wPBNjFCPFZfGye3gK66SW2xzfzsSrpKee0+NuHtS CECW2m8MzIab3uIFhFJNyC623qC+pQr1m0c+5/vBtBBoAn4SXCe0sdUzuEI+K/iR5gKn uOkZHgSOEBmaeYFLwRh+BLY7ner8ZTJc1C3Ju15EVaDW2OJv9o7EEBqukPqgvHTmOknK E4GQ== X-Forwarded-Encrypted: i=1; AFNElJ8TFuk6dmoKniwun0JVZnUSqAdQKH1HvKmX9KFShckZz4pTMwX2zXcJdt3jUS+SgKv3wcUpJeA=@vger.kernel.org X-Gm-Message-State: AOJu0YxU01C31wXO8wH11tYpgTKQey4J6ZXp13CCyuZSMmc2mjOqJD2P kGT2mRtnnUyIEvWBxXSQJxhWbA+8u6iLR2my3wwXflYXxY29cz62hpJndoIVT6bLSlxZTldLogW cIA9Ut/RFemnCuA== X-Received: from ywbgn17.prod.google.com ([2002:a05:690c:4391:b0:7b6:65b2:1d31]) (user=edumazet job=prod-delivery.src-stubby-dispatcher) by 2002:a05:690c:ed4:b0:79a:c40d:b701 with SMTP id 00721157ae682-7b9e1405e01mr6568117b3.13.1776369821912; Thu, 16 Apr 2026 13:03:41 -0700 (PDT) Date: Thu, 16 Apr 2026 20:03:18 +0000 In-Reply-To: <20260416200319.3608680-1-edumazet@google.com> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20260416200319.3608680-1-edumazet@google.com> X-Mailer: git-send-email 2.54.0.rc1.513.gad8abe7a5a-goog Message-ID: <20260416200319.3608680-14-edumazet@google.com> Subject: [PATCH net 13/14] tcp: annotate data-races around (tp->write_seq - tp->snd_nxt) From: Eric Dumazet To: "David S . Miller" , Jakub Kicinski , Paolo Abeni Cc: Simon Horman , Neal Cardwell , Kuniyuki Iwashima , netdev@vger.kernel.org, eric.dumazet@gmail.com, Eric Dumazet Content-Type: text/plain; charset="UTF-8" tcp_get_timestamping_opt_stats() intentionally runs lockless, we must add READ_ONCE() annotations to keep KCSAN happy. WRITE_ONCE() annotations are already present. Fixes: e08ab0b377a1 ("tcp: add bytes not sent to SCM_TIMESTAMPING_OPT_STATS") Signed-off-by: Eric Dumazet --- net/ipv4/tcp.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index 192e95b71ce9868980a809184be83398d8740427..68894c03f2622d1a08fd747ff4c5e32be8579d2c 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -4472,7 +4472,8 @@ struct sk_buff *tcp_get_timestamping_opt_stats(const struct sock *sk, 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)); + max_t(int, 0, + READ_ONCE(tp->write_seq) - READ_ONCE(tp->snd_nxt))); nla_put_u64_64bit(stats, TCP_NLA_EDT, orig_skb->skb_mstamp_ns, TCP_NLA_PAD); if (ack_skb) -- 2.54.0.rc1.513.gad8abe7a5a-goog