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=-19.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,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 ACA93C433EF for ; Thu, 16 Sep 2021 18:42:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 927C4610A6 for ; Thu, 16 Sep 2021 18:42:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1350330AbhIPSnz (ORCPT ); Thu, 16 Sep 2021 14:43:55 -0400 Received: from mail.kernel.org ([198.145.29.99]:44938 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1349179AbhIPSnn (ORCPT ); Thu, 16 Sep 2021 14:43:43 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 9E065610A6; Thu, 16 Sep 2021 18:42:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1631817742; bh=W8lmbPG+Y7dzqY16kJIWhu7Hte7q4CpDtoM8X9UOKiM=; h=Subject:To:Cc:References:From:Date:In-Reply-To:From; b=naUyEq4E5gf3apJKSzndPpK7/aIAe+JSS11lI1ZBRDlVSeotuOczaxJ43zzK02LCa rD3zGSc2Lt9KEmwk6RQu+UkOMlTQV3sRshuH5PhUWy/lrT2A2CpGegUCx7um3fzi38 RF9IbCMzODaL9mRzNiW3jG90gQL3l4SZqKVnvSR0weYqu50gEIHWshudMnbxMbpm8y hiwGHnyfCFhuudQvDt5AxlfqDL4syXomLcCqritQb7WuhdDR/9rTsJwMC9D5jPaXsY MmJOhQdSp3koJVBFRx6b4cgp3fbUnfXHUsvqtRXwk2HYpWwpMNt+8B9lW1qzbdXT2I WDdzk2HDk0KVw== Subject: Re: [PATCH 1/2] x86: Do not add -falign flags unconditionally for clang To: Borislav Petkov Cc: Thomas Gleixner , Ingo Molnar , x86@kernel.org, Masahiro Yamada , "H. Peter Anvin" , Nick Desaulniers , linux-kernel@vger.kernel.org, linux-kbuild@vger.kernel.org, clang-built-linux@googlegroups.com, llvm@lists.linux.dev, kernel test robot References: <20210824022640.2170859-1-nathan@kernel.org> <20210824022640.2170859-2-nathan@kernel.org> From: Nathan Chancellor Message-ID: <4d88e0ed-422d-447a-ea8f-36e54b38fac1@kernel.org> Date: Thu, 16 Sep 2021 11:42:19 -0700 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.14.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kbuild@vger.kernel.org On 9/16/2021 10:18 AM, Borislav Petkov wrote: > On Mon, Aug 23, 2021 at 07:26:39PM -0700, Nathan Chancellor wrote: > > A couple of nitpicks: > >> Subject: [PATCH 1/2] x86: Do not add -falign flags unconditionally for clang > > Make that prefix into "x86/build: " Done, I'll be sure to keep that prefix in mind for future flag-based changes. >> clang does not support -falign-jumps and only recently gained support >> for -falign-loops. When one of the configuration options that adds these >> flags is enabled, clang warns and all cc-{disable-warning,option} that >> follow fail because -Werror gets added to test for the presence of this >> warning: >> >> clang-14: warning: optimization flag '-falign-jumps=0' is not supported >> [-Wignored-optimization-argument] >> >> To resolve this, add a couple of cc-option calls when building with >> clang; gcc has supported these options since 3.2 so there is no point in >> testing for their support. -falign-functions was implemented in clang-7, >> -falign-loops was implemented in clang-14, and -falign-jumps has not >> been implemented yet. >> >> Link: https://lore.kernel.org/r/YSQE2f5teuvKLkON@Ryzen-9-3900X.localdomain/ > > Also, there should be a second Link: tag which points to this mail > thread so that we can find it later, when we dig for the "why we did > that" question :) > > I.e., > > Link: 20210824022640.2170859-2-nathan@kernel.org Sure thing, kind of hard to do that on the initial submission but I will do it for the v2 shortly :) >> Reported-by: kernel test robot >> Signed-off-by: Nathan Chancellor >> --- >> arch/x86/Makefile_32.cpu | 12 +++++++++--- >> 1 file changed, 9 insertions(+), 3 deletions(-) > > with that: > > Acked-by: Borislav Petkov Thank you for the ack. The conflicting changes that I mentioned in the cover letter have been merged in 5.15-rc1 so if you guys want to take these changes via -tip, just holler for an ack from Masahiro on the second patch on v2 (but I am going with the assumption this will be merged via the kbuild tree). Cheers, Nathan