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=-9.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,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 507D0C072B5 for ; Fri, 24 May 2019 10:36:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 23B9F21773 for ; Fri, 24 May 2019 10:36:21 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=amarulasolutions.com header.i=@amarulasolutions.com header.b="EVlS01Zr" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2390570AbfEXKgU (ORCPT ); Fri, 24 May 2019 06:36:20 -0400 Received: from mail-wm1-f66.google.com ([209.85.128.66]:54838 "EHLO mail-wm1-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2389448AbfEXKgT (ORCPT ); Fri, 24 May 2019 06:36:19 -0400 Received: by mail-wm1-f66.google.com with SMTP id i3so8822645wml.4 for ; Fri, 24 May 2019 03:36:18 -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:in-reply-to:references; bh=2QncBY+O8HWHusWpmG3TvATwMEVVOER+jDNcjQdf6X8=; b=EVlS01ZrOUW4y5TgcO5PW42Ys40ozEuuGxT/VlB+ZHdDPVKs4LX29n9Jkr/8Z6PNse UOegy/cIjxDtwK5VzIY7E10zeWFGG8tTsr5lP2bUds+aMR5zF6msMBfDOuzwMsAVKFkQ gU27fdfkz+KNgVoLDEVbPC0ybAaS2opAbZtLg= 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:in-reply-to :references; bh=2QncBY+O8HWHusWpmG3TvATwMEVVOER+jDNcjQdf6X8=; b=NWTkUBCAqfnj5kNwlchrZsE4Wl4cU9tW4LbT8XcDldMFALweDnnrYAUkTA1GfSojFf GzQvcc1JyNOtUUlhu1wlDg29USc+kmZG7DOIXOIrA5ELKq9dswjZ2kAaRcUbql/CrXzw qbCKRyL02ky7gfS0iFWGQICQrSJpL4W1/ATO3q+l4OOsRETfFxn6JmtqdJ1qiUyv0rlA 4fthaNZaX8ll3pYhibm5vxf30xehLBxu881dmYfmJRN/2w9SxCjdFzvrIp9KF/WwWXnu YKHhJrWFLcqsHNPmBrX/P8N0+egqdRYZCzfuUWCDtlD/DjlOuzp1E8kRVhyxsnBcJHHo 9kLA== X-Gm-Message-State: APjAAAXFgtSOqrl2sV9NHJnjzMK/VLAeX0g0hPJzlMmDaVbwmgtxgtlW hv+xUYy5woqqOGMYZLamz0msUEJuvpxIog== X-Google-Smtp-Source: APXvYqws0A2pqR2pfzJ8O/T2RqNMUG9rXolT5X554i6CeJ//OGuyEyIYbdY/Bl3oqqrJuBL1+d3ltQ== X-Received: by 2002:a1c:f909:: with SMTP id x9mr16477369wmh.12.1558694177408; Fri, 24 May 2019 03:36:17 -0700 (PDT) Received: from localhost.localdomain (86.100.broadband17.iol.cz. [109.80.100.86]) by smtp.gmail.com with ESMTPSA id n4sm2111272wrp.61.2019.05.24.03.36.16 (version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Fri, 24 May 2019 03:36:16 -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 2/2] compiler: Prevent evaluation of WRITE_ONCE() Date: Fri, 24 May 2019 12:35:36 +0200 Message-Id: <1558694136-19226-3-git-send-email-andrea.parri@amarulasolutions.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1558694136-19226-1-git-send-email-andrea.parri@amarulasolutions.com> References: <1558694136-19226-1-git-send-email-andrea.parri@amarulasolutions.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Now that there's no single use of the value of WRITE_ONCE(), change the implementation to eliminate it. Suggested-by: Mark Rutland Signed-off-by: Andrea Parri Cc: Arnd Bergmann Cc: Greg Kroah-Hartman Cc: Jorgen Hansen Cc: Peter Zijlstra Cc: Will Deacon Cc: Mark Rutland Cc: "Paul E. McKenney" --- include/linux/compiler.h | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/include/linux/compiler.h b/include/linux/compiler.h index 8aaf7cd026b06..4024c809a6c63 100644 --- a/include/linux/compiler.h +++ b/include/linux/compiler.h @@ -277,12 +277,11 @@ unsigned long read_word_at_a_time(const void *addr) } #define WRITE_ONCE(x, val) \ -({ \ +do { \ union { typeof(x) __val; char __c[1]; } __u = \ { .__val = (__force typeof(x)) (val) }; \ __write_once_size(&(x), __u.__c, sizeof(x)); \ - __u.__val; \ -}) +} while (0) #endif /* __KERNEL__ */ -- 2.7.4