[PATCH v2] powerpc/64s: support nospectre_v2 cmdline option

[Michael Ellerman]

"Christopher M. Riedl" <cmr at informatik.wtf> writes:
> diff --git a/arch/powerpc/kernel/security.c b/arch/powerpc/kernel/security.c
> index b33bafb8fcea..d775da9b9227 100644
> --- a/arch/powerpc/kernel/security.c
> +++ b/arch/powerpc/kernel/security.c
> @@ -391,6 +394,15 @@ static void toggle_count_cache_flush(bool enable)
>  
>  void setup_count_cache_flush(void)
>  {
> +	if (no_spectrev2) {
> +		if (security_ftr_enabled(SEC_FTR_BCCTRL_SERIALISED)
> +		    || security_ftr_enabled(SEC_FTR_COUNT_CACHE_DISABLED))
> +			pr_warn("Spectre v2 mitigations not under software control, can't disable\n");
> +
> +		toggle_count_cache_flush(false);
> +		return;
> +	}
> +
>  	toggle_count_cache_flush(true);
>  }

I'm nit-picking, but would it be better as:

void setup_count_cache_flush(void)
{
	bool enable = true;

	if (no_spectrev2) {
		if (security_ftr_enabled(SEC_FTR_BCCTRL_SERIALISED)
		    || security_ftr_enabled(SEC_FTR_COUNT_CACHE_DISABLED))
			pr_warn("Spectre v2 mitigations not under software control, can't disable\n");

		enable = false;
	}

	toggle_count_cache_flush(enable);
}

???

cheers