Re: [PATCH v2 08/16] x86: replace arch macros from compiler with CONFIG_X86_{32,64}

From: Masahiro Yamada <masahiroy@kernel.org>
To: Linux Kbuild mailing list <linux-kbuild@vger.kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>,
	Nick Desaulniers <ndesaulniers@google.com>,
	Borislav Petkov <bp@alien8.de>,
	Peter Zijlstra <peterz@infradead.org>,
	"H . Peter Anvin" <hpa@zytor.com>, X86 ML <x86@kernel.org>,
	"Jason A . Donenfeld" <Jason@zx2c4.com>,
	clang-built-linux <clang-built-linux@googlegroups.com>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	Al Viro <viro@zeniv.linux.org.uk>,
	Randy Dunlap <rdunlap@infradead.org>
Subject: Re: [PATCH v2 08/16] x86: replace arch macros from compiler with CONFIG_X86_{32,64}
Date: Tue, 31 Mar 2020 11:40:57 +0900	[thread overview]
Message-ID: <CAK7LNARueG4wM-_z+xDjwHci=wwAad8CqP1UF5mFJpPf8Zg71Q@mail.gmail.com> (raw)
In-Reply-To: <20200326080104.27286-9-masahiroy@kernel.org>

On Thu, Mar 26, 2020 at 5:03 PM Masahiro Yamada <masahiroy@kernel.org> wrote:
>
> If the intention is to check i386/x86_64 excluding UML, testing
> CONFIG_X86_{32,64} is simpler.
>
> The reason for checking __i386__ / __x86_64__ was perhaps because
> lib/raid6/algos.c is built not only for the kernel but also for
> testing the library code from userspace.
>
> However, lib/raid6/test/Makefile passes -DCONFIG_X86_{32,64} for
> this case. So, I do not see a reason to not use CONFIG option here.
>
> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
> Acked-by: H. Peter Anvin (Intel) <hpa@zytor.com>
> ---

Sorry, this patch broke UML builds.

https://lkml.org/lkml/2020/3/27/618

I will drop this patch for tomorrow's linux-next.

CONFIG_X86 is not defined for ARCH=um.
So, I still think it is OK to replace one complicated line
in lib/raid6/x86.h

   #if (defined(__i386__) || defined(__x86_64__)) && !defined(__arch_um__)

with:

   #ifdef CONFIG_X86

Also, I slightly prefer

   #if defined(CONFIG_X86_32) && !defined(CONFIG_UML)

to

   #if defined(__i386__) && !defined(__arch_um__)

But, we do not need to rush this now.

This patch does not affect the rest of this series.

Thanks.

> Changes in v2: None
>
>  kernel/signal.c   | 2 +-
>  lib/raid6/algos.c | 4 ++--
>  2 files changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/kernel/signal.c b/kernel/signal.c
> index 5b2396350dd1..db557e1629e5 100644
> --- a/kernel/signal.c
> +++ b/kernel/signal.c
> @@ -1246,7 +1246,7 @@ static void print_fatal_signal(int signr)
>         struct pt_regs *regs = signal_pt_regs();
>         pr_info("potentially unexpected fatal signal %d.\n", signr);
>
> -#if defined(__i386__) && !defined(__arch_um__)
> +#ifdef CONFIG_X86_32
>         pr_info("code at %08lx: ", regs->ip);
>         {
>                 int i;
> diff --git a/lib/raid6/algos.c b/lib/raid6/algos.c
> index df08664d3432..b5a02326cfb7 100644
> --- a/lib/raid6/algos.c
> +++ b/lib/raid6/algos.c
> @@ -29,7 +29,7 @@ struct raid6_calls raid6_call;
>  EXPORT_SYMBOL_GPL(raid6_call);
>
>  const struct raid6_calls * const raid6_algos[] = {
> -#if defined(__i386__) && !defined(__arch_um__)
> +#ifdef CONFIG_X86_32
>  #ifdef CONFIG_AS_AVX512
>         &raid6_avx512x2,
>         &raid6_avx512x1,
> @@ -45,7 +45,7 @@ const struct raid6_calls * const raid6_algos[] = {
>         &raid6_mmxx2,
>         &raid6_mmxx1,
>  #endif
> -#if defined(__x86_64__) && !defined(__arch_um__)
> +#ifdef CONFIG_X86_64
>  #ifdef CONFIG_AS_AVX512
>         &raid6_avx512x4,
>         &raid6_avx512x2,
> --
> 2.17.1
>

-- 
Best Regards
Masahiro Yamada