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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 181B5C77B73 for ; Mon, 24 Apr 2023 17:03:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231542AbjDXRDJ (ORCPT ); Mon, 24 Apr 2023 13:03:09 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41730 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231974AbjDXRDI (ORCPT ); Mon, 24 Apr 2023 13:03:08 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0233C4C1E; Mon, 24 Apr 2023 10:03:06 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 3FAF561F22; Mon, 24 Apr 2023 17:03:06 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 297D2C433D2; Mon, 24 Apr 2023 17:03:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1682355785; bh=VEVvVZ8+SlsEh9PFAshPWT7wBg1WEd2nNfTgDFp1BYo=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=eXuxW1vKbdgSWII8dvlWMbJ9Ck/G2tsLsG+xxW1eDaz1FFdVRlBlyNDIybSzYtp+J 8kJaCk1Sa2vMRA5I26+0u1q1q5cWgf7n8b3R09muHCWMvmZOjCDK9lXp3WP02n4zGi ymWWXUKwSVcPAZj3UXF5ngbq9+YqenmUKkhjDkETrh8sMqKQjVVsYAFK5HMLVJ2Fkr acMi4r1vqfmbdXEdwluFi9S4O7rCE6Ji9b4MeqazSmmEx1zKCZj+9KJb+UlZytVvKe Ah8ldBTPY5bRvP9si+4b7HHAlqgsCwnuD/8V6WAPBDu4wt9b4/iSmqcqNPFut9VTJp oaiCLdGkGU9iw== Date: Mon, 24 Apr 2023 10:03:03 -0700 From: Nathan Chancellor To: Jiaxun Yang Cc: Nick Desaulniers , Thomas Bogendoerfer , "linux-mips@vger.kernel.org" , llvm@lists.linux.dev, Borislav Petkov , Linux Kbuild mailing list , Masahiro Yamada Subject: Re: [PATCH v2 2/7] MIPS: Add toolchain feature dependency for microMIPS smartMIPS Message-ID: <20230424170303.GA1255815@dev-arch.thelio-3990X> References: <20230414080701.15503-1-jiaxun.yang@flygoat.com> <20230414080701.15503-3-jiaxun.yang@flygoat.com> <20230418130823.GA12456@alpha.franken.de> <77F56166-265A-4653-ADF4-B0057604A539@flygoat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <77F56166-265A-4653-ADF4-B0057604A539@flygoat.com> Precedence: bulk List-ID: X-Mailing-List: linux-mips@vger.kernel.org On Thu, Apr 20, 2023 at 08:41:07PM +0100, Jiaxun Yang wrote: > > > > 2023年4月20日 00:01，Nick Desaulniers 写道： > > > > On Tue, Apr 18, 2023 at 6:13 AM Thomas Bogendoerfer > > wrote: > >> > >> On Fri, Apr 14, 2023 at 09:06:56AM +0100, Jiaxun Yang wrote: > >>> microMIPS smartMIPS kernel can only be compiled if they are supported > >>> by toolchain. > >>> > >>> Signed-off-by: Jiaxun Yang > >>> Reviewed-by: Nick Desaulniers > > > > Question: won't the lack of this (patch and rest of the series) hurt > > our ability to test randconfig builds of ARCH=mips with clang? See > > also the 0day report from Boris: > > https://lore.kernel.org/llvm/202304170748.Fg9VIgGd-lkp@intel.com/ > > Kconfig experts, Is there any way to generate warning based on Kconfig options? > So we can let users know there are something went wrong but still allow build to happen. I do not think there is a way that this can be done within Kconfig itself but you could do something like arch/x86/Makefile does for RETPOLINE during archprepare and warn when an option is selected without a dependency. I envision something like the following but it has not even been compile tested: diff --git a/arch/mips/Makefile b/arch/mips/Makefile index 04e46ec24319..2c3be65ce3cc 100644 --- a/arch/mips/Makefile +++ b/arch/mips/Makefile @@ -399,6 +399,11 @@ ifdef CONFIG_MIPS32_O32 @$(kecho) ' Checking missing-syscalls for O32' $(Q)$(MAKE) $(build)=. missing-syscalls missing_syscalls_flags="-mabi=32" endif +ifdef CONFIG_CPU_HAS_SMARTMIPS +ifndef CC_HAS_SMARTMIPS + $(warning CONFIG_CPU_HAS_SMARTMIPS selected without supported compiler, build may not work) +endif +endif install: $(Q)install -D -m 755 vmlinux $(INSTALL_PATH)/vmlinux-$(KERNELRELEASE) You could also make that depend on !CONFIG_COMPILE_TEST, as that is a signal that the user does not intend to run this kernel. Masahiro might have other comments. Cheers, Nathan