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=-8.4 required=3.0 tests=DKIMWL_WL_MED,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_IN_DEF_DKIM_WL 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 4D9D2C433DF for ; Thu, 21 May 2020 09:38:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1F78120721 for ; Thu, 21 May 2020 09:38:09 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="HmNGNwT0" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728934AbgEUJiI (ORCPT ); Thu, 21 May 2020 05:38:08 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37730 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728719AbgEUJiH (ORCPT ); Thu, 21 May 2020 05:38:07 -0400 Received: from mail-oo1-xc43.google.com (mail-oo1-xc43.google.com [IPv6:2607:f8b0:4864:20::c43]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BEACCC061A0E for ; Thu, 21 May 2020 02:38:07 -0700 (PDT) Received: by mail-oo1-xc43.google.com with SMTP id p67so1312427ooa.11 for ; Thu, 21 May 2020 02:38:07 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=XRRenhNm9RcrMGaLaFDRHCMDiaKFzvbNFCQExEVcZEI=; b=HmNGNwT0/nTNwhk2QkQq2ieaY4fXPKzgGc6i93+BrNIwF1AtkKSu77TWtbfKwcwSc6 dT/v4sy6DWT5wDaNmoJdoIAMrvhkxh2HNpgz8Hc2Vmu48egXDLCOqlFeI1mXEjLC/rb+ APGPTYy2+DgT65Pc3waqCCRCvynp0Wbb3L5+UO+XfRz1RdirUXPJo9l8QPU4ylGmnxHp fJnleaCszpokXvQmkjyQuIjofri9zb8Pv2tjn3gaesbANbJzORgc/3wOTDWewar+37kF zlKDEVAHiOoKaaRAeVZZmW+ZKx7fqyCgVv6bS6xR9SGAr/PR/W8BIXM3MPItVGOW/6WM f72Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=XRRenhNm9RcrMGaLaFDRHCMDiaKFzvbNFCQExEVcZEI=; b=U+wQ0bBD3F9MeaMYt9yx1zi7A0aXRD+GXv4wXvT+KT60Z0nnFkIg8T4Sn8fghIqfxD AR/8Qi3ZvaUhtV6QTDenTiYPoqFPuQjEXmjcoJ1WFSQRS2ZjWLlgIAb2UnmyAts1285G taSDHDm++VrxRAnEyhuiUMKsuw3mfh/e5OhF4uU8caRiTyxnRg694fHNbPaoUBPtjNN1 +zVTEp8r5e8iyshtne/Al2zAIM5obA1LG2iEk0Fka8VPOeAJIx+Vt34IsMnuxY2oxZ4d 9SSyTzc9+lAN667s7z5GllrTViEnTrVtYD0ZpyU6cwpEXWR/iJSUCFq0A5LP1hbHTm5H 69ww== X-Gm-Message-State: AOAM530voA3aRpqctUYOk8DY+dbO/bXk9NsbWqxL9r5P3H1fwz+Tp/5t 5v40YZ/8R9o9NSb7K2sXf+GWSGMIwycBSDIYnsfYog== X-Google-Smtp-Source: ABdhPJyw2BNtuFy9oINuCcU/aMPLnbDEf9QicF1fHmI3WsLhnZXh08jAfH1GiPiA2HkJL+Omfvf9ZHnVgwW65spkedY= X-Received: by 2002:a4a:e836:: with SMTP id d22mr6691371ood.54.1590053886935; Thu, 21 May 2020 02:38:06 -0700 (PDT) MIME-Version: 1.0 References: <20200511204150.27858-18-will@kernel.org> <158929421358.390.2138794300247844367.tip-bot2@tip-bot2> <20200520221712.GA21166@zn.tnic> <20200521072557.GA10099@zn.tnic> In-Reply-To: <20200521072557.GA10099@zn.tnic> From: Marco Elver Date: Thu, 21 May 2020 11:37:54 +0200 Message-ID: Subject: Re: [tip: locking/kcsan] READ_ONCE: Use data_race() to avoid KCSAN instrumentation To: Borislav Petkov Cc: Will Deacon , "Peter Zijlstra (Intel)" , LKML , linux-tip-commits@vger.kernel.org, Thomas Gleixner , x86 Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 21 May 2020 at 09:26, Borislav Petkov wrote: > > On Thu, May 21, 2020 at 12:30:39AM +0200, Marco Elver wrote: > > This should be fixed when the series that includes this commit is applied: > > https://lore.kernel.org/lkml/20200515150338.190344-9-elver@google.com/ > > Yap, that fixes it. > > Thx. Thanks for confirming. I think Peter also mentioned that nested statement expressions caused issues. This probably also means we shouldn't have a nested "data_race()" macro, to avoid any kind of nested statement expressions where possible. I will send a v2 of the above series to add that patch. Thanks, -- Marco