Re: [GIT PULL 2/2] Kconfig updates for v4.18

[Eric W. Biederman]

Masahiro Yamada <yamada.masahiro@xxxxxxxxxxxxx> writes:

> - drop CONFIG_CROSS_COMPILE support

aka
> commit f1089c92da791034af73478159626007cba7f092
> Author: Masahiro Yamada <yamada.masahiro@xxxxxxxxxxxxx>
> Date:   Mon May 28 18:21:39 2018 +0900
> 
>     kbuild: remove CONFIG_CROSS_COMPILE support
>     
>     Kbuild provides a couple of ways to specify CROSS_COMPILE:
>     
>     [1] Command line
>     [2] Environment
>     [3] arch/*/Makefile (only some architectures)
>     [4] CONFIG_CROSS_COMPILE
>     
>     [4] is problematic for the compiler capability tests in Kconfig.
>     CONFIG_CROSS_COMPILE allows users to change the compiler prefix from
>     'make menuconfig', etc.  It means, the compiler options would have
>     to be all re-calculated everytime CONFIG_CROSS_COMPILE is changed.
>     
>     To avoid complexity and performance issues, I'd like to evaluate
>     the shell commands statically, i.e. only parsing Kconfig files.
>     
>     I guess the majority is [1] or [2].  Currently, there are only
>     5 defconfig files that specify CONFIG_CROSS_COMPILE.
>       arch/arm/configs/lpc18xx_defconfig
>       arch/hexagon/configs/comet_defconfig
>       arch/nds32/configs/defconfig
>       arch/openrisc/configs/or1ksim_defconfig
>       arch/openrisc/configs/simple_smp_defconfig
>     
>     Signed-off-by: Masahiro Yamada <yamada.masahiro@xxxxxxxxxxxxx>
>     Reviewed-by: Kees Cook <keescook@xxxxxxxxxxxx>
> 

I just started working against 4.18-rc1 and discovered this.

This has broken my setup for building and testing changes on other
architectures.  I have to put the name of the compiler prefix somewhere.
The mapping between the prefix to gcc and the linux architecture is
non-trivial.  Especially with a lot of architectures in the test pool.

I am tired and frustrated this morning as this is going to keep me from
getting done what I had planned today.

This is a regression pure and simple.  It breaks my workflow.  Please
fix it.

Eric