From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 553433FE357 for ; Thu, 4 Jun 2026 09:11:41 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.129.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780564302; cv=none; b=kOb5jmdIEyRh84vj+orlRR42u3X/4tM8czbgk5f1rabtXUzqKAHbqfHakQoaVs9axgv1VJkZEYvZbwe1GqWiX1pORbTMzqzrPCKZuOntsKCGwU90oH/1+gYYEOCI47uqjAxxYByew7EDbuqB+tS9v/KjcBwrKDp5etDxVTuKmrU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780564302; c=relaxed/simple; bh=ENzABfFSnHZNTaseRBhTe76JslvG9/OVWebygGCYPMU=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=MP+77xhofIr4SAhwtvhCsj85IPrMpdUyrB+m4hE+yiAyV5HwkE1BHwRtn35ykwwzqWk7u+DrKRF4Nve5KtvjPcv7i0Tv8vtKxgtF+Kz3d8rC9Doa15s+yFAxRz+MCQ5hHCYRk+s4omkg4XPy0VNMgCQJqOJH7NrqEdidR9htdD8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=SnPPUjs3; dkim=pass (2048-bit key) header.d=redhat.com header.i=@redhat.com header.b=qApYtqVM; arc=none smtp.client-ip=170.10.129.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="SnPPUjs3"; dkim=pass (2048-bit key) header.d=redhat.com header.i=@redhat.com header.b="qApYtqVM" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1780564300; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=PocJ/NUTE4E0S5HeZhCaCIbuyAspIpMbmuzKuC8QEOE=; b=SnPPUjs3OASKpW7IIZOK9EoDaD/S6hCwr7J5eHyr0iluyRpqS+COiTqu1F8q3CSM5MhblS K6/gAa+Q8DVXsduqqP8KAX8X9nFQ5rGqK/QyaZtSAN/e4rFWWjoqawcEYc4nCzNZ0C4T6+ oJ9DiWMRHU6bwZEncopxgX1ilY1M6Ko= Received: from mail-wr1-f72.google.com (mail-wr1-f72.google.com [209.85.221.72]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-91-NIkNsO4MMB-IO3iP08KZGQ-1; Thu, 04 Jun 2026 05:11:39 -0400 X-MC-Unique: NIkNsO4MMB-IO3iP08KZGQ-1 X-Mimecast-MFC-AGG-ID: NIkNsO4MMB-IO3iP08KZGQ_1780564298 Received: by mail-wr1-f72.google.com with SMTP id ffacd0b85a97d-46010392f89so430528f8f.2 for ; Thu, 04 Jun 2026 02:11:38 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=google; t=1780564298; x=1781169098; darn=vger.kernel.org; h=content-transfer-encoding:in-reply-to:content-language:from :references:cc:to:subject:user-agent:mime-version:date:message-id :from:to:cc:subject:date:message-id:reply-to; bh=PocJ/NUTE4E0S5HeZhCaCIbuyAspIpMbmuzKuC8QEOE=; b=qApYtqVMLhtFBvZOMR8MvIo8M6U79xYT/EjHb308ZJo/P0dkjFK7ej4BRcb/wcnBJg aSgehy12ZhtNiYqc3VJrbWSUFRrQdhB42yeFTKsuONYdKnvPC6wea++7jFF/+2wfK9gG VOI2wIZ8J2yrT0xaeTsAaSb10OVP87hZQEnK2RmaRpjgYwv9Ic+HcQGOc4vrm+pien4Z j3YPbXTMtbrHmH0kn6+I5s+99oo4Bk/QzUq/a1awNKMP+9hX+KxiMQSq7pd1V4UEShWA w93FF4N6afAWLuumui81pQ1at2tcPFdsmz8hXZHJ8eZH07GBI81OcdBXbVKAeBGGLfcT 1c4Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1780564298; x=1781169098; h=content-transfer-encoding:in-reply-to:content-language:from :references:cc:to:subject:user-agent:mime-version:date:message-id :x-gm-gg:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=PocJ/NUTE4E0S5HeZhCaCIbuyAspIpMbmuzKuC8QEOE=; b=C0UURyejZz3Pm8cQxoumD/vGI2S2CMk5dxPiG9K5z4UOvE1uwp5RL9pInzuGaGxhhW kPl9fo5/AqiEH3jxVWnj6ukW2Js/KEH8FfhMgyFZ8t3ZGqK/o6mVqoLXJCKCeaveNOWh ITQDKLOMh7fwR7VALtoWgnc97STrubMIWpK+RDNT3frQx/FXoXbs1I8DPZTHfp5q9rrw 0c4MxfhMhyiNBhAj9CWtjfLbn7huImkbVX/MZG51WxRhCvKWWuRlzAlnJrEjaMUlSU1v X9oIUM75dMX1txaxiscES/Rdkg/sNV4ZEK9dTVHrbb4JLlJRmiEagIe8ou8PcwjE7h70 EeRA== X-Forwarded-Encrypted: i=1; AFNElJ/hMQH6+Vo+zeWn+DVo8Dhp3al6eMBg7cHzb/QM9VPOJzEX7iyGk5fa0HUUptrSAFthR3PVubo=@vger.kernel.org X-Gm-Message-State: AOJu0YzAsZ6yazhm8R/js5h64PpgC/f5jK7WydBuZhQOtBtgio5tMcj+ TURHXGzQdc1q6L1H3L9638tjGwIha/OTKO9HXpMLX0nAAJg5jpKlhIXPM3/FcTmdeAOU6mgy2oI uB4HDKrM4QEhqJoHYgYVDMWdb/Rk7jRYjo4BaV/mRrfGUlfhgxz+Gtwq9DQ== X-Gm-Gg: Acq92OH/mAnEJdqIFcgpfLu2pHldTFXNLh82qHxBkBtcTAfvyP/Zv66gY3Tr3gpSt20 IONyoW2H9q9vQQoWE4zgz7Go+92wLrRt7Uiqsin5lmY6rBcgqhfj/0lHwGHJMqRjTpRpoHk3jog xyTh2BcCQRyOq6cjlq7FE4mn18PE2gQ3FPyfojMeH1MUwtp2/RTs3VzvIs/nqH66Q/yQQ6iprYo DB85oy34IZ4tlZE2hYaGrQMHmllQU0i+WK2TDkZbd1NqLdrsvBXMQ3nnobIrsaN7K3guoLFOfbx SkzG2CE4HPlPcTPgOFW5LO4RcJ/kxf/H04kFcEx2fOjweYlULgbGlVjPGUKYZLg1DyL/bbuezxZ zyeMNvn6smrG3IkGVCyZXhRjaAWrD9bFDKOmLpDODa9ftUo9aio8Oy2wtbcu7ZLK3dY0= X-Received: by 2002:a05:6000:491d:b0:45e:edcc:f6dc with SMTP id ffacd0b85a97d-460216bd84cmr10725913f8f.6.1780564297741; Thu, 04 Jun 2026 02:11:37 -0700 (PDT) X-Received: by 2002:a05:6000:491d:b0:45e:edcc:f6dc with SMTP id ffacd0b85a97d-460216bd84cmr10725848f8f.6.1780564297247; Thu, 04 Jun 2026 02:11:37 -0700 (PDT) Received: from [192.168.88.32] ([212.105.155.59]) by smtp.gmail.com with ESMTPSA id ffacd0b85a97d-4601f0a43e9sm14825452f8f.0.2026.06.04.02.11.36 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 04 Jun 2026 02:11:36 -0700 (PDT) Message-ID: <95adff35-ee56-49d3-8567-382ac17810b3@redhat.com> Date: Thu, 4 Jun 2026 11:11:30 +0200 Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 1/2] ipv4: igmp: annotate data-races around in_dev->mc_count To: Yuyang Huang Cc: "David S. Miller" , David Ahern , Eric Dumazet , Ido Schimmel , Jakub Kicinski , Simon Horman , linux-kernel@vger.kernel.org, netdev@vger.kernel.org References: <20260531030705.3754389-1-yuyanghuang@google.com> <20260531030705.3754389-2-yuyanghuang@google.com> From: Paolo Abeni Content-Language: en-US In-Reply-To: <20260531030705.3754389-2-yuyanghuang@google.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 5/31/26 5:07 AM, Yuyang Huang wrote: > @@ -1922,7 +1923,7 @@ void ip_mc_destroy_dev(struct in_device *in_dev) > > while ((i = rtnl_dereference(in_dev->mc_list)) != NULL) { > in_dev->mc_list = i->next_rcu; > - in_dev->mc_count--; > + WRITE_ONCE(in_dev->mc_count, in_dev->mc_count - 1); > ip_mc_clear_src(i); > ip_ma_put(i); The patch LGTM, but note that sashiko has identified a pre-existing issue which could deserve a follow-up: https://sashiko.dev/#/patchset/20260531030705.3754389-1-yuyanghuang%40google.com /P > } > @@ -2974,7 +2975,9 @@ static int igmp_mc_seq_show(struct seq_file *seq, void *v) > > if (rcu_access_pointer(state->in_dev->mc_list) == im) { > seq_printf(seq, "%d\t%-10s: %5d %7s\n", > - state->dev->ifindex, state->dev->name, state->in_dev->mc_count, querier); > + state->dev->ifindex, state->dev->name, > + READ_ONCE(state->in_dev->mc_count), > + querier); > } > > delta = im->timer.expires - jiffies;