Re: [PATCH v2 02/21] kbuild: remove CONFIG_CROSS_COMPILE support

From: Kees Cook
Date: Tue Mar 27 2018 - 23:28:44 EST


On Mon, Mar 26, 2018 at 10:29 PM, Masahiro Yamada
<yamada.masahiro@xxxxxxxxxxxxx> wrote:
> 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
> 4 defconfig files that specify CONFIG_CROSS_COMPILE.
> arch/arm/configs/lpc18xx_defconfig
> arch/hexagon/configs/comet_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>

-Kees

--
Kees Cook
Pixel Security