Re: [PATCH v2 1/2] retpolines: Only enable retpoline support when compiler support it

[Ingo Molnar]

* Zhenzhong Duan <zhenzhong.duan@xxxxxxxxxx> wrote:

> Since retpoline capable compilers are widely available, make
> CONFIG_RETPOLINE hard depend on it.
> 
> The check of RETPOLINE is changed to CONFIG_RETPOLINE.
> 
> This change is based on suggestion in https://lkml.org/lkml/2018/9/18/1016
>
> Signed-off-by: Zhenzhong Duan <zhenzhong.duan@xxxxxxxxxx>
> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>

Please turn such 'based on suggestions' into proper tags as well, i.e. 
something like:

  Suggested-by: David Woodhouse <dwmw2@xxxxxxxxxxxxx>

>  config RETPOLINE
>  	bool "Avoid speculative indirect branches in kernel"
> +	depends on $(cc-option,-mindirect-branch=thunk-extern -mindirect-branch-register) || \
> +                    $(cc-option,-mretpoline-external-thunk)

At least a comment should be added that this is the retpoline feature 
check for GCC and Clang.

Also, whitespace damage plus the two options should align vertically.

Thanks,

	Ingo