[RFC PATCH v2 3/3] arm64: implement dynamic shadow call stack for Clang

[Kees Cook]

On Thu, May 05, 2022 at 06:10:11PM +0200, Ard Biesheuvel wrote:
> [...]
> +	/*
> +	 * We only enable the shadow call stack dynamically if we are running
> +	 * on a system that does not implement PAC or BTI. PAC and SCS roughly
> +	 * provide the same level of protection, and BTI relies on the PACIASP
> +	 * instructions serving as landing pads, preventing us from patching
> +	 * those instructions into something else.
> +	 */

If BTI relies on PAC, then we only need to check for PAC, yes? I.e.
there isn't going to be a device with BTI but without PAC.

-- 
Kees Cook