Re: [PATCH v2 1/9] compiler_types.h: Move __nocfi out of compiler-specific header

Nathan Chancellor
2025-09-04T20:45:34Z

On Wed, Sep 03, 2025 at 08:46:40PM -0700, Kees Cook wrote:
> Prepare for GCC KCFI support and move the __nocfi attribute from
> compiler-clang.h to compiler_types.h. This was already gated by
> CONFIG_CFI_CLANG, so this remains safe for non-KCFI GCC builds.
>
> Signed-off-by: Kees Cook <kees@kernel.org>
> ---

I reviewed this on v1:

https://lore.kernel.org/20250827194657.GA3572128@ax162/

but just to make sure it sticks :)

Reviewed-by: Nathan Chancellor <nathan@kernel.org>

> ---
> include/linux/compiler-clang.h | 5 -----
> include/linux/compiler_types.h | 4 +++-
> 2 files changed, 3 insertions(+), 6 deletions(-)
>
> diff --git a/include/linux/compiler-clang.h b/include/linux/compiler-clang.h
> index fa4ffe037bc7..7a4568e421dc 100644
> --- a/include/linux/compiler-clang.h
> +++ b/include/linux/compiler-clang.h
> @@ -96,11 +96,6 @@
> # define __noscs __attribute__((__no_sanitize__("shadow-call-stack")))
> #endif
>
> -#if __has_feature(kcfi)
> -/* Disable CFI checking inside a function. */
> -#define __nocfi __attribute__((__no_sanitize__("kcfi")))
> -#endif
> -
> /*
> * Turn individual warnings and errors on and off locally, depending
> * on version.
> diff --git a/include/linux/compiler_types.h b/include/linux/compiler_types.h
> index 16755431fc11..a910f9fa5341 100644
> --- a/include/linux/compiler_types.h
> +++ b/include/linux/compiler_types.h
> @@ -432,7 +432,9 @@ struct ftrace_likely_data {
> # define __noscs
> #endif
>
> -#ifndef __nocfi
> +#if defined(CONFIG_CFI_CLANG)
> +# define __nocfi __attribute__((__no_sanitize__("kcfi")))
> +#else
> # define __nocfi
> #endif
>
> --
> 2.34.1
>