Re: [PATCH 2/3] x86: Use -mindirect-branch-cs-prefix for RETPOLINE builds

[Kees Cook]

On Fri, Nov 19, 2021 at 05:50:25PM +0100, Peter Zijlstra wrote:
> In order to further enable commit:
> 
>   bbe2df3f6b6d ("x86/alternative: Try inline spectre_v2=retpoline,amd")
> 
> add the new GCC flag -mindirect-branch-cs-prefix:
> 
>   https://gcc.gnu.org/g:2196a681d7810ad8b227bf983f38ba716620545e
>   https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102952
>   https://bugs.llvm.org/show_bug.cgi?id=52323
> 
> to RETPOLINE=y builds. This should allow fully inlining retpoline,amd
> for GCC builds.
> 
> Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>

Reviewed-by: Kees Cook <keescook@xxxxxxxxxxxx>

-- 
Kees Cook