Re: [PATCH] ARM: Kconfig: default to AEABI w/ Clang

From: Arnd Bergmann <arnd@arndb.de>
To: Nick Desaulniers <ndesaulniers@google.com>
Cc: Russell King - ARM Linux <linux@armlinux.org.uk>,
	clang-built-linux <clang-built-linux@googlegroups.com>,
	Mark Brown <broonie@kernel.org>,
	Masahiro Yamada <yamada.masahiro@socionext.com>,
	Linus Walleij <linus.walleij@linaro.org>,
	Paul Burton <paul.burton@mips.com>,
	Mike Rapoport <rppt@linux.ibm.com>,
	Ard Biesheuvel <ard.biesheuvel@linaro.org>,
	Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>,
	Palmer Dabbelt <palmer@sifive.com>,
	Linux ARM <linux-arm-kernel@lists.infradead.org>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] ARM: Kconfig: default to AEABI w/ Clang
Date: Thu, 4 Jul 2019 09:24:24 +0200	[thread overview]
Message-ID: <CAK8P3a2uW+a_=siusLTt=rq-erw1tyJfU8PDGaXuVcJoKHjpRw@mail.gmail.com> (raw)
In-Reply-To: <20190625210441.199514-1-ndesaulniers@google.com>

On Tue, Jun 25, 2019 at 11:04 PM 'Nick Desaulniers' via Clang Built
Linux <clang-built-linux@googlegroups.com> wrote:
>
> Clang produces references to __aeabi_uidivmod and __aeabi_idivmod for
> arm-linux-gnueabi and arm-linux-gnueabihf targets incorrectly when AEABI
> is not selected (such as when OABI_COMPAT is selected).
>
> While this means that OABI userspaces wont be able to upgraded to
> kernels built with Clang, it means that boards that don't enable AEABI
> like s3c2410_defconfig will stop failing to link in KernelCI when built
> with Clang.
>
> Link: https://github.com/ClangBuiltLinux/linux/issues/482
> Link: https://groups.google.com/forum/#!msg/clang-built-linux/yydsAAux5hk/GxjqJSW-AQAJ
> Suggested-by: Arnd Bergmann <arnd@arndb.de>
> Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>

Looks good to me,

Reviewed-by: Arnd Bergmann <arnd@arndb.de>

Please add it to Russell's patch tracker if you haven't already.

Most of the .config files that don't set AEABI (and a lot of the others
as well) have likely never been booted on real hardware with a modern
kernel in a long time. There have not been any distros using OABI in
a long time (Debian Lenny was released in 2009), and gcc dropped
support for it a few years later.

We could probably change most of these to use OABI_COMPAT
instead, aside from any ones that Russell wants to keep building as
OABI for his own machines.

       Arnd