Re: [RFC PATCH 1/7] x86/entry: Move PUSH_AND_CLEAR_REGS out of paranoid_entry

[Peter Zijlstra]

On Mon, Apr 03, 2023 at 10:05:59PM +0800, Lai Jiangshan wrote:
> @@ -915,11 +922,8 @@ SYM_CODE_END(xen_failsafe_callback)
>   * R14 - old CR3
>   * R15 - old SPEC_CTRL
>   */
> -SYM_CODE_START(paranoid_entry)
> +SYM_FUNC_START(paranoid_entry)
>  	ANNOTATE_NOENDBR
> -	UNWIND_HINT_FUNC

That isn't quite equivalent. SYM_FUNC_START() gets you ENDBR, while the
SYM_CODE_START(); ANNOTATE_NOENDBR; UNWIND_HINT_FUNC is
explicitly no ENDBR.


> -	PUSH_AND_CLEAR_REGS save_ret=1
> -	ENCODE_FRAME_POINTER 8
>  
>  	/*
>  	 * Always stash CR3 in %r14.  This value will be restored,