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

From: Linus Walleij
Date: Thu Jul 04 2019 - 04:13:45 EST


On Tue, Jun 25, 2019 at 11:04 PM Nick Desaulniers
<ndesaulniers@xxxxxxxxxx> 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@xxxxxxxx>
> Signed-off-by: Nick Desaulniers <ndesaulniers@xxxxxxxxxx>

As reflecting the state of things with CLANG it's:
Reviewed-by: Linus Walleij <linus.walleij@xxxxxxxxxx>

But I think we in general need to have some discussion on how to
proceed with OABI userspaces.

I am well aware of distributions like OpenWrt using EABI even
on ARMv4 with "tricks" like this:
https://github.com/openwrt/openwrt/blob/master/toolchain/gcc/patches/9.1.0/840-armv4_pass_fix-v4bx_to_ld.patch

I have one OABI that I can think of would be nice to live on
and it's the RedHat derivative on my Foorbridge NetWinder.
OK I wouldn't cry if we have to kill it because it is too hard to
keep supporting it, but it has been running the latest kernels
all along so if it's not a huge effort I'd be interested in knowing
the options.

Yours,
Linus Walleij