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 70763C001B0 for ; Tue, 27 Jun 2023 21:28:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229923AbjF0V2o (ORCPT ); Tue, 27 Jun 2023 17:28:44 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36116 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229488AbjF0V2n (ORCPT ); Tue, 27 Jun 2023 17:28:43 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3AECBF5; Tue, 27 Jun 2023 14:28:42 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id BDA3061233; Tue, 27 Jun 2023 21:28:41 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id B3A61C433CC; Tue, 27 Jun 2023 21:28:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1687901321; bh=OafCvthRtEiRdBBCDx7oq4YlYCXLBNwqs0QHZRTmIb8=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=WNHnNPwyINedj0Xi/GK/WRVtr+QPUA7zgH7xzT1SFoagTucmdMlTvsqCW6fqS0J+t C+GmRxWpRP9iyvzeA11fYrpBqRbOujdmp9Oyj34AsMyV6uuFVB0YFvVsKymL78/d6R a5/2PISHZv6bFkuZvwUh7GQZ+GheCZoTPl22bq1V/rhGNfMV4UgLhawCtDOcXjxnFx Y5EDw4ySZ+iYmXyrhGxi+YtrlW+sCQA1uTCiwCoGa0ArdJ+IUsJET7rEDhRZsJvqZ9 kDhte2YL4t2YHYg+7KVdYD2+UG/wTNu3rj2zym/vhdDOGHKb41d2I6y7xeecZBlaql NTp6PFrId9O5A== Date: Tue, 27 Jun 2023 14:28:39 -0700 From: Nathan Chancellor To: Huacai Chen Cc: Huacai Chen , Thomas Bogendoerfer , linux-mips@vger.kernel.org, Jiaxun Yang , stable@vger.kernel.org, Nick Desaulniers Subject: Re: [PATCH] MIPS: Loongson: Fix build error when make modules_install Message-ID: <20230627212839.GA1806408@dev-arch.thelio-3990X> References: <20230626075047.1872818-1-chenhuacai@loongson.cn> <20230626160720.GA2174263@dev-arch.thelio-3990X> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org Hi Huacai, + Masahiro On Tue, Jun 27, 2023 at 11:11:27AM +0800, Huacai Chen wrote: > Hi, Nathan, > > On Tue, Jun 27, 2023 at 12:07 AM Nathan Chancellor wrote: > > > > On Mon, Jun 26, 2023 at 03:50:47PM +0800, Huacai Chen wrote: > > > After commit 0e96ea5c3eb5904e5dc2f ("MIPS: Loongson64: Clean up use of > > > cc-ifversion") we get a build error when make modules_install: > > > > > > cc1: error: '-mloongson-mmi' must be used with '-mhard-float' > > > > > > The reason is when make modules_install, 'call cc-option' doesn't work > > > in $(KBUILD_CFLAGS) of 'CHECKFLAGS'. Then there is no -mno-loongson-mmi > > > applied and -march=loongson3a enable MMI instructions. > > > > The first sentence does not make much sense to me, specifically "in > > $(KBUILD_CFLAGS) of 'CHECKFLAGS'". What configuration and build command > > reproduces this? I do not see how '-mno-loongson-mmi' would fail to get > > added to cflags-y after 0e96ea5c3eb5, which should have had no > > functional change... I don't want to hang this change up since there is > > real breakage but I want to make sure we fully understand why > > 0e96ea5c3eb5 broke things and why this patch resolves it. > Please use loongson3_defconfig to build a loongson kernel with > toolchains from here [1]: > 'make' will succeed, but there is a build error when 'make > modules_install'. And you should be careful because 'make > modules_install' doesn't stop when the error occurs. Excellent, thank you! I understand what is going on here and your patch should work to resolve it (although I think the commit message should be flushed out a little more with the following details) but I am curious if Masahiro has any thoughts around this. As you note, the error message comes from the CHECKFLAGS invocation of $(CC) but it has no impact on the final result of modules_install, it is purely a cosmetic issue from what I can tell. The error occurs because cc-option is defined in scripts/Makefile.compiler, which is not included in Makefile when running modules_install, as install targets are not supposed to require the compiler; see commit 805b2e1d427a ("kbuild: include Makefile.compiler only when compiler is needed"). As a result, the call to check for '-mno-loongson-mmi' just never happens. It would nice if '-mno-loongson-mmi' could be added unconditionally when using GCC but I can see that the flag has only existed since 9.x, so we do need to keep the cc-option call. I am fine with your change as long as it includes some of the above information (basically noting that while the original change should have been equivalent, the requirement of '-mno-loongson-mmi' when using certain Loongson '-march=' values with '-msoft-float' means that those Loongson '-march=' values need to be called with cc-option as well), even if clang will incur two more cc-option calls as a result (not the end of the world). Additionally, it seems like the same issue will occur when running modules_install when CONFIG_CPU_LOONGSON2E or CONFIG_CPU_LOONGSON2F are enabled, which I guess I also broke in commit 13ceb48bc19c ("MIPS: Loongson2ef: Remove unnecessary {as,cc}-option calls") :/ Sorry again for the breakage and thanks for the fix! Cheers, Nathan > > > Fix this by partially reverting to the old logic, use 'call cc-option' > > > to conditionally apply -march=loongson3a and -march=mips64r2. > > > > > > Fixes: 0e96ea5c3eb5904e5dc2f ("MIPS: Loongson64: Clean up use of cc-ifversion") > > > Cc: stable@vger.kernel.org > > > Cc: Nathan Chancellor > > > Cc: Nick Desaulniers > > > Signed-off-by: Huacai Chen > > > --- > > > arch/mips/Makefile | 5 +---- > > > 1 file changed, 1 insertion(+), 4 deletions(-) > > > > > > diff --git a/arch/mips/Makefile b/arch/mips/Makefile > > > index a7a4ee66a9d3..7fb76d12829e 100644 > > > --- a/arch/mips/Makefile > > > +++ b/arch/mips/Makefile > > > @@ -186,11 +186,8 @@ cflags-$(CONFIG_CPU_LOONGSON2F) += -march=loongson2f -Wa,--trap > > > # Some -march= flags enable MMI instructions, and GCC complains about that > > > # support being enabled alongside -msoft-float. Thus explicitly disable MMI. > > > cflags-$(CONFIG_CPU_LOONGSON2EF) += $(call cc-option,-mno-loongson-mmi) > > > -ifdef CONFIG_CPU_LOONGSON64 > > > cflags-$(CONFIG_CPU_LOONGSON64) += -Wa,--trap > > > -cflags-$(CONFIG_CC_IS_GCC) += -march=loongson3a > > > -cflags-$(CONFIG_CC_IS_CLANG) += -march=mips64r2 > > > -endif > > > +cflags-$(CONFIG_CPU_LOONGSON64) += $(call cc-option,-march=loongson3a,-march=mips64r2) > > > cflags-$(CONFIG_CPU_LOONGSON64) += $(call cc-option,-mno-loongson-mmi) > > > > > > cflags-$(CONFIG_CPU_R4000_WORKAROUNDS) += $(call cc-option,-mfix-r4000,) > > > -- > > > 2.39.3 > > >