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=-10.6 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 2E3B2C2D0A3 for ; Mon, 9 Nov 2020 23:25:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D41A92074F for ; Mon, 9 Nov 2020 23:25:58 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="w2aOvisN" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730520AbgKIXZ5 (ORCPT ); Mon, 9 Nov 2020 18:25:57 -0500 Received: from mail.kernel.org ([198.145.29.99]:40304 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727311AbgKIXZ5 (ORCPT ); Mon, 9 Nov 2020 18:25:57 -0500 Received: from willie-the-truck (236.31.169.217.in-addr.arpa [217.169.31.236]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 15471206A1; Mon, 9 Nov 2020 23:25:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1604964356; bh=OVysUOvCr5fa7OosTb0TzgoRDvZFoVbKaYZCwm1QTRY=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=w2aOvisNwjlGcG/pAQgMRKhxwbCZf46d0fOIN6SDjqsTiaBe/0z7ovwxKtsT7F2rY sv7faSNqBH29uftJkCaXIqSVbpSWzoAlUd+YMG3XYt2P77UBkABhwVz0CnuCEpbKfn +L/GLCjiBQsJiMeqEtQWQDjSaaqxQSuGNTWDCD8E= Date: Mon, 9 Nov 2020 23:25:51 +0000 From: Will Deacon To: linux-arm-kernel@lists.infradead.org Cc: Kees Cook , Catalin Marinas , Sami Tolvanen , Masahiro Yamada , Peter Zijlstra , linux-kernel@vger.kernel.org Subject: Re: [PATCH v4 0/4] Upgrade READ_ONCE() to RCpc acquire on arm64 with LTO Message-ID: <20201109232551.GA15385@willie-the-truck> References: <20201103121721.5166-1-will@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20201103121721.5166-1-will@kernel.org> User-Agent: Mutt/1.10.1 (2018-07-13) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Nov 03, 2020 at 12:17:17PM +0000, Will Deacon wrote: > Hi all, > > These patches were previously posted as part of a larger series enabling > architectures to override __READ_ONCE(): > > v3: https://lore.kernel.org/lkml/20200710165203.31284-1-will@kernel.org/ > > With the bulk of that merged, the four patches here override READ_ONCE() > so that it gains RCpc acquire semantics on arm64 when LTO is enabled. We > can revisit this as and when the compiler provides a means for us to reason > about the result of dependency-breaking optimisations. In the meantime, > this unblocks LTO for arm64, which I would really like to see merged so > that we can focus on enabling CFI. > > I plan to queue these on their own branch in the arm64 tree for 5.11 at > -rc3. Now pushed to for-next/lto: https://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git/log/?h=for-next/lto with Mark's comments addressed. Will