From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-3.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0ABA5C4360C for ; Thu, 10 Oct 2019 04:51:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C7A2520B7C for ; Thu, 10 Oct 2019 04:51:53 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=netronome-com.20150623.gappssmtp.com header.i=@netronome-com.20150623.gappssmtp.com header.b="scvBLN3n" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732813AbfJJEvx (ORCPT ); Thu, 10 Oct 2019 00:51:53 -0400 Received: from mail-pg1-f194.google.com ([209.85.215.194]:46081 "EHLO mail-pg1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726201AbfJJEvw (ORCPT ); Thu, 10 Oct 2019 00:51:52 -0400 Received: by mail-pg1-f194.google.com with SMTP id b8so2830095pgm.13 for ; Wed, 09 Oct 2019 21:51:52 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=netronome-com.20150623.gappssmtp.com; s=20150623; h=date:from:to:cc:subject:message-id:in-reply-to:references :organization:mime-version:content-transfer-encoding; bh=7SAEt83MVuHB2RYl8EVswDTFl2nsqnZqWSL/7jMoTHE=; b=scvBLN3nqHptKuJ1LuItcT3kbN73lQQ+4Rd3j3JI2jdRYN/pOMBy5vNLweI7S+5vfz ilxnBX2hDOfZuAwCRIDUg2wvKqpvqXh+NJMsBNzS0aD7dCNLnWEltnRPERhV6Yqnji7p dGuB0UjBJJHI/p1ape6zmOaH+6XVGwMcabMS8f/6q29IOKb2wIHfiZuBqr73ZDg3NfJu zLpelb9cwDMvs/fDzInNx/Tu/f0wy//L5zFrDm1gVqGlvz4PizMkDAMhXU20HzoJA//m 9a0ekL4vMBBdHhKNu7mzy0HKtuHzMFllk9/rqooPgWCg6VF0kf1jG5ODGbtxFSH5vvx8 uj8Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:in-reply-to :references:organization:mime-version:content-transfer-encoding; bh=7SAEt83MVuHB2RYl8EVswDTFl2nsqnZqWSL/7jMoTHE=; b=JdcYUX2BcTtvAM9JftzTOR9ki2Aoxn0amENK2k6eStXiVGoHmUw1376LnYRD11E3zZ ahnnbAfQj/vZZHJlmy7Dm1z/47UgV7qIXFMCrWY1VLTGQo6e+fkLK0Uu+VuAcd+d/jHx cbiK+E/154x0MYuThFJIU1KU5hC6r1PHnwEtK3BHNC7anJB0BUpDwojbXnPNLSd2vAUE utZWif+fl/A+bk/6RKOfKB86Yjz5wRQhVY2g9goCuLt7JdivxS/dywFxa8kJO1ZMFfO8 lWPoyGxUs4IOTbH7Th3doF0exkTT7Pjp3BZPVHKIOMLyRJdrGwXWiJZy6D5JF+TebAkR T6uA== X-Gm-Message-State: APjAAAUFh4mfZHSi1q88COri/qYp+NheXhUr8+0hpf5pxwcf2vHaHw+z LPThu2fVA2OWUdEAc25HFzo+eeoZLP0= X-Google-Smtp-Source: APXvYqxZiNzs7te1GtQVrv98saq1DWP9Xwi8Wkv3PEntWaVFq+gkMQ9voFd1fh8TrbGIHa+C2VHXZA== X-Received: by 2002:a63:eb08:: with SMTP id t8mr8916105pgh.49.1570683112020; Wed, 09 Oct 2019 21:51:52 -0700 (PDT) Received: from cakuba.netronome.com (c-73-202-202-92.hsd1.ca.comcast.net. [73.202.202.92]) by smtp.gmail.com with ESMTPSA id o185sm4545933pfg.136.2019.10.09.21.51.51 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 09 Oct 2019 21:51:51 -0700 (PDT) Date: Wed, 9 Oct 2019 21:51:39 -0700 From: Jakub Kicinski To: Eric Dumazet Cc: "David S . Miller" , netdev , Eric Dumazet Subject: Re: [PATCH net] net: annotate sk->sk_rcvlowat lockless reads Message-ID: <20191009215139.314608b6@cakuba.netronome.com> In-Reply-To: <20191009223235.92999-1-edumazet@google.com> References: <20191009223235.92999-1-edumazet@google.com> Organization: Netronome Systems, Ltd. MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Wed, 9 Oct 2019 15:32:35 -0700, Eric Dumazet wrote: > sock_rcvlowat() or int_sk_rcvlowat() might be called without the socket > lock for example from tcp_poll(). > > Use READ_ONCE() to document the fact that other cpus might change > sk->sk_rcvlowat under us and avoid KCSAN splats. > > Use WRITE_ONCE() on write sides too. > > Signed-off-by: Eric Dumazet Applied, thanks!