Re: [PATCH] kbuild: move -fzero-init-padding-bits=all to the top-level Makefile

From: Nathan Chancellor
Date: Sat Feb 15 2025 - 15:37:45 EST


On Sun, Feb 16, 2025 at 01:15:52AM +0900, Masahiro Yamada wrote:
> The -fzero-init-padding-bits=all option is not a warning flag, so
> defining it in scripts/Makefile.extrawarn is inconsistent.
>
> Move it to the top-level Makefile for consistency.
>
> Signed-off-by: Masahiro Yamada <masahiroy@xxxxxxxxxx>

Whoops, I will have to watch for that in the future.

Reviewed-by: Nathan Chancellor <nathan@xxxxxxxxxx>

> ---
>
> Makefile | 3 +++
> scripts/Makefile.extrawarn | 3 ---
> 2 files changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/Makefile b/Makefile
> index 89628e354ca7..4a36864dd4bd 100644
> --- a/Makefile
> +++ b/Makefile
> @@ -928,6 +928,9 @@ KBUILD_CFLAGS += $(CC_AUTO_VAR_INIT_ZERO_ENABLER)
> endif
> endif
>
> +# Explicitly clear padding bits during variable initialization
> +KBUILD_CFLAGS += $(call cc-option,-fzero-init-padding-bits=all)
> +
> # While VLAs have been removed, GCC produces unreachable stack probes
> # for the randomize_kstack_offset feature. Disable it for all compilers.
> KBUILD_CFLAGS += $(call cc-option, -fno-stack-clash-protection)
> diff --git a/scripts/Makefile.extrawarn b/scripts/Makefile.extrawarn
> index dc081cf46d21..d75897559d18 100644
> --- a/scripts/Makefile.extrawarn
> +++ b/scripts/Makefile.extrawarn
> @@ -82,9 +82,6 @@ KBUILD_CFLAGS += $(call cc-option,-Werror=designated-init)
> # Warn if there is an enum types mismatch
> KBUILD_CFLAGS += $(call cc-option,-Wenum-conversion)
>
> -# Explicitly clear padding bits during variable initialization
> -KBUILD_CFLAGS += $(call cc-option,-fzero-init-padding-bits=all)
> -
> KBUILD_CFLAGS += -Wextra
> KBUILD_CFLAGS += -Wunused
>
> --
> 2.43.0
>