Re: [PATCH 05/29] x86: Base IBT bits

[Joao Moreira]

> +config CC_HAS_IBT
> +	# GCC >= 9 and binutils >= 2.29
> +	# Retpoline check to work around
> https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93654
> +	def_bool $(cc-option, -fcf-protection=branch
> -mindirect-branch-register) && $(as-instr,endbr64)
> +
Is -mindirect-branch-register breaks compiling with clang. Maybe we 
should we do instead?

+       def_bool ($(cc-option, -fcf-protection=branch 
-mindirect-branch-register) || $(cc-option, -mretpoline-external-thunk)) 
&& $(as-instr,endbr64)