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=-2.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_MUTT 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 29802C2BCA1 for ; Fri, 7 Jun 2019 15:43:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id F36992146F for ; Fri, 7 Jun 2019 15:43:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730762AbfFGPnE (ORCPT ); Fri, 7 Jun 2019 11:43:04 -0400 Received: from foss.arm.com ([217.140.110.172]:43104 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730720AbfFGPnA (ORCPT ); Fri, 7 Jun 2019 11:43:00 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id C0CF280D; Fri, 7 Jun 2019 08:42:59 -0700 (PDT) Received: from e103592.cambridge.arm.com (usa-sjc-imap-foss1.foss.arm.com [10.121.207.14]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 86C973F718; Fri, 7 Jun 2019 08:42:58 -0700 (PDT) Date: Fri, 7 Jun 2019 16:42:56 +0100 From: Dave Martin To: Nathan Chancellor Cc: Qian Cai , linux-efi@vger.kernel.org, Ard Biesheuvel , Catalin Marinas , Will Deacon , "linux-kernel@vger.kernel.org" , clang-built-linux@googlegroups.com, linux-arm-kernel@lists.infradead.org Subject: Re: "arm64: Silence gcc warnings about arch ABI drift" breaks clang Message-ID: <20190607154256.GG28398@e103592.cambridge.arm.com> References: <1559920965.6132.56.camel@lca.pw> <20190607152517.GC19862@fuggles.cambridge.arm.com> <1559921171.6132.57.camel@lca.pw> <20190607154010.GA41392@archlinux-epyc> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190607154010.GA41392@archlinux-epyc> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Jun 07, 2019 at 08:40:10AM -0700, Nathan Chancellor wrote: > On Fri, Jun 07, 2019 at 11:26:11AM -0400, Qian Cai wrote: > > On Fri, 2019-06-07 at 16:25 +0100, Will Deacon wrote: > > > On Fri, Jun 07, 2019 at 11:22:45AM -0400, Qian Cai wrote: > > > > The linux-next commit "arm64: Silence gcc warnings about arch ABI drift" [1] > > > > breaks clang build where it screams that unknown option "-Wno-psabi" and > > > > generates errors below, > > > > > > So that can be easily fixed with cc-option... > > > > > > > [1] https://lore.kernel.org/linux-arm-kernel/1559817223-32585-1-git-send-ema > > > > il-D > > > > ave.Martin@arm.com/ > > > > > > > > ./drivers/firmware/efi/libstub/arm-stub.stub.o: In function > > > > `install_memreserve_table': > > > > ./linux/drivers/firmware/efi/libstub/arm-stub.c:73: undefined reference to > > > > `__efistub___stack_chk_guard' > > > > ./linux/drivers/firmware/efi/libstub/arm-stub.c:73: undefined reference to > > > > `__efistub___stack_chk_guard' > > > > ./linux/drivers/firmware/efi/libstub/arm-stub.c:93: undefined reference to > > > > `__efistub___stack_chk_guard' > > > > ./linux/drivers/firmware/efi/libstub/arm-stub.c:93: undefined reference to > > > > `__efistub___stack_chk_guard' > > > > ./linux/drivers/firmware/efi/libstub/arm-stub.c:94: undefined reference to > > > > `__efistub___stack_chk_fail > > > > > > ... but this looks unrelated. Are you saying you don't see these errors if > > > you revert Dave's patch? > > > > Yes. > > I suspect the reason for this is -Wunknown-warning-option causes > cc-option to fail. I see some disabled warnings like > -Waddress-of-packed-member and -Wunused-const-variable when -Wno-psabi > is unconditionally added. > > I'll do some further triage but I think the obvious fix as Will > suggested is to use cc-disable-warning. I'll send a patch. Thanks for that. Cheers ---Dave