Re: [PATCH v2 12/21] kconfig: show compiler version text in the top comment
From: Kees Cook
Date: Tue Mar 27 2018 - 23:26:30 EST
On Mon, Mar 26, 2018 at 10:29 PM, Masahiro Yamada
<yamada.masahiro@xxxxxxxxxxxxx> wrote:
> The kernel configuration phase is now tightly coupled with the compiler
> in use. It will be nice to show the compiler information in Kconfig.
>
> The compiler information will be displayed like this:
>
> $ make ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- config
> scripts/kconfig/conf --oldaskconfig Kconfig
> *
> * Linux/arm64 4.16.0-rc1 Kernel Configuration
> *
> *
> * Compiler: aarch64-linux-gnu-gcc (Linaro GCC 7.2-2017.11) 7.2.1 20171011
> *
> *
> * General setup
> *
> Compile also drivers which will not load (COMPILE_TEST) [N/y/?]
>
> If you use GUI methods such as menuconfig, it will be displayed in the
> top menu.
>
> This is simply implemented by using 'comment'. So, it will be saved
> into the .config file as well.
>
> This commit has a very important meaning. If the compiler is upgraded,
> Kconfig must be re-run since different compilers have different sets
> of supported options.
>
> All referenced environments are written to include/config/auto.conf.cmd
> so that any environment change triggers syncconfig, and prompt the user
> to input new values if needed.
>
> With this commit, something like follows will be added to
> include/config/auto.conf.cmd
>
> ifneq "$(CC_VERSION_TEXT)" "aarch64-linux-gnu-gcc (Linaro GCC 7.2-2017.11) 7.2.1 20171011"
> include/config/auto.conf: FORCE
> endif
>
> Signed-off-by: Masahiro Yamada <yamada.masahiro@xxxxxxxxxxxxx>
I like seeing this in the config. Good idea!
Reviewed-by: Kees Cook <keescook@xxxxxxxxxxxx>
-Kees
> ---
>
> Changes in v2: None
>
> Kconfig | 2 ++
> Makefile | 2 ++
> 2 files changed, 4 insertions(+)
>
> diff --git a/Kconfig b/Kconfig
> index e6ece5b..99ed4b8 100644
> --- a/Kconfig
> +++ b/Kconfig
> @@ -5,4 +5,6 @@
> #
> mainmenu "Linux/$ARCH $KERNELVERSION Kernel Configuration"
>
> +comment "Compiler: $CC_VERSION_TEXT"
> +
> source "arch/$SRCARCH/Kconfig"
> diff --git a/Makefile b/Makefile
> index 5cadffa..3dc9eb8 100644
> --- a/Makefile
> +++ b/Makefile
> @@ -450,6 +450,8 @@ export KBUILD_AFLAGS_MODULE KBUILD_CFLAGS_MODULE KBUILD_LDFLAGS_MODULE
> export KBUILD_AFLAGS_KERNEL KBUILD_CFLAGS_KERNEL
> export KBUILD_ARFLAGS
>
> +export CC_VERSION_TEXT := $(shell $(CC) --version | head -n 1)
> +
> # When compiling out-of-tree modules, put MODVERDIR in the module
> # tree rather than in the kernel tree. The kernel tree might
> # even be read-only.
> --
> 2.7.4
>
--
Kees Cook
Pixel Security