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=-8.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham 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 D271DC072B5 for ; Fri, 24 May 2019 10:35:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 29CB121773 for ; Fri, 24 May 2019 10:35:57 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=amarulasolutions.com header.i=@amarulasolutions.com header.b="Hru5M1+b" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2390531AbfEXKf4 (ORCPT ); Fri, 24 May 2019 06:35:56 -0400 Received: from mail-wr1-f65.google.com ([209.85.221.65]:33281 "EHLO mail-wr1-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2389448AbfEXKf4 (ORCPT ); Fri, 24 May 2019 06:35:56 -0400 Received: by mail-wr1-f65.google.com with SMTP id d9so9492152wrx.0 for ; Fri, 24 May 2019 03:35:55 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amarulasolutions.com; s=google; h=from:to:cc:subject:date:message-id; bh=njauMCJ2o1/GsnZ2mPeYOiP+YI83chYuXOrhyQtPV2M=; b=Hru5M1+bFuLqBXipwVL2/tEtOL/OtEx3FfYSgOWmgjXRA6dLOeH7ftsHBfQvooSUhW wOktU1Vsg7mrFiljLdYvYKym6cUf2gXXkBYQQghCH0Qek2YnYyzk65DxP/TLjWfClk2z d8QYG7bXQwnPbdm+nWcEhHjzEhyGYCbHF+UKQ= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id; bh=njauMCJ2o1/GsnZ2mPeYOiP+YI83chYuXOrhyQtPV2M=; b=Rj/BHauAMMWRNPl3XLKZ/Crsff5urySQBKxB4rDvCTA+mEL2p2ql1oruWl1a/EMNUv 3RFm+Fr4s7Cqg4JlLxhA4R+V/PisnI6z6qV2KYxAsZzUg3iLLRAJiovz93OFIDHdQXfB KRzq/WfADnzi7r+I15ACk0xEIJcEe3KaUWXMrF7E6cc77bynoDwFVATZGXKVhccAzYZc WA7YOi3ISn6n5Q8aWqmJr1ja2LpRONCcE2tblQexunmnvJi/w3MOtr8JbdlIY17MxhsW ZI8P4vfXdwDTkgDW0gvoSj+EFvvVLQD9wXx8h5zo3ouovmuDuD1u5pB/H9pvav/oNcEI OOnA== X-Gm-Message-State: APjAAAX8UoT2FeZtmnktFF/yFpKlIjIH8Y4wyutcu/PpWEsF8S7LO3gh c35ufi7CRpP7znpE5uyVMY6nUAn0/k2ojw== X-Google-Smtp-Source: APXvYqymSOvRTe+J1h7dpzi/nvT3l56pi2Q0/g+JC6fOANr4pHoOUwoVnNfxrnU18CWAomssiDGh2g== X-Received: by 2002:adf:f292:: with SMTP id k18mr37384267wro.321.1558694154076; Fri, 24 May 2019 03:35:54 -0700 (PDT) Received: from localhost.localdomain (86.100.broadband17.iol.cz. [109.80.100.86]) by smtp.gmail.com with ESMTPSA id n4sm2111272wrp.61.2019.05.24.03.35.52 (version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Fri, 24 May 2019 03:35:53 -0700 (PDT) From: Andrea Parri To: linux-kernel@vger.kernel.org Cc: Andrea Parri , Arnd Bergmann , Greg Kroah-Hartman , Jorgen Hansen , Peter Zijlstra , Will Deacon , Mark Rutland , "Paul E. McKenney" Subject: [PATCH 0/2] Prevent evaluation of WRITE_ONCE() Date: Fri, 24 May 2019 12:35:34 +0200 Message-Id: <1558694136-19226-1-git-send-email-andrea.parri@amarulasolutions.com> X-Mailer: git-send-email 2.7.4 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi all, This all started when we realized that atomic64_t v; ... typeof(v.counter) my_val = atomic64_set(&v, VAL); is a valid assignment on some architectures, but not on others [1]: in particular, the assignment is valid on all architectures #define -ing their atomic64_set() macro to WRITE_ONCE() (which is currently evaluated). Mark suggested to clean up all non-portable users of atomic*_set(), and to prevent WRITE_ONCE() from being evaluated [2]; this resulted in this first attempt/patchset based on Mark's atomics/type-cleanup branch [3]. Cheers Andrea [1] https://lkml.kernel.org/r/20190523083013.GA4616@andrea [2] https://lkml.kernel.org/r/20190523141851.GA7523@lakrids.cambridge.arm.com [3] git://git.kernel.org/pub/scm/linux/kernel/git/mark/linux.git atomics/type-cleanup Cc: Arnd Bergmann Cc: Greg Kroah-Hartman Cc: Jorgen Hansen Cc: Peter Zijlstra Cc: Will Deacon Cc: Mark Rutland Cc: "Paul E. McKenney" Andrea Parri (2): vmw_vmci: Clean up uses of atomic*_set() compiler: Prevent evaluation of WRITE_ONCE() include/linux/compiler.h | 5 ++--- include/linux/vmw_vmci_defs.h | 4 ++-- 2 files changed, 4 insertions(+), 5 deletions(-) -- 2.7.4