Re: [PATCH v8 09/12] arm64: disable SCS for hypervisor code

[Kees Cook]

On Tue, Feb 18, 2020 at 04:08:14PM -0800, Sami Tolvanen wrote:
> Disable SCS for code that runs at a different exception level by
> adding __noscs to __hyp_text.
> 
> Suggested-by: James Morse <james.morse@xxxxxxx>
> Signed-off-by: Sami Tolvanen <samitolvanen@xxxxxxxxxx>

Reviewed-by: Kees Cook <keescook@xxxxxxxxxxxx>

-Kees

> ---
>  arch/arm64/include/asm/kvm_hyp.h | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/arch/arm64/include/asm/kvm_hyp.h b/arch/arm64/include/asm/kvm_hyp.h
> index a3a6a2ba9a63..0f0603f55ea0 100644
> --- a/arch/arm64/include/asm/kvm_hyp.h
> +++ b/arch/arm64/include/asm/kvm_hyp.h
> @@ -13,7 +13,7 @@
>  #include <asm/kvm_mmu.h>
>  #include <asm/sysreg.h>
>  
> -#define __hyp_text __section(.hyp.text) notrace
> +#define __hyp_text __section(.hyp.text) notrace __noscs
>  
>  #define read_sysreg_elx(r,nvh,vh)					\
>  	({								\
> -- 
> 2.25.0.265.gbab2e86ba0-goog
> 

-- 
Kees Cook