Re: [patch 02/15] x86/cpu: Uninline CR4 accessors

[Christoph Hellwig]

> --- a/arch/x86/kernel/cpu/common.c
> +++ b/arch/x86/kernel/cpu/common.c
> @@ -387,7 +387,30 @@ void native_write_cr4(unsigned long val)
>  			  bits_missing);
>  	}
>  }
> -EXPORT_SYMBOL(native_write_cr4);
> +#if IS_MODULE(CONFIG_LKDTM)
> +EXPORT_SYMBOL_GPL(native_write_cr4);
> +#endif

While this is better than what we had before we really need to have
a discussion on lkdtm - it needs a lot of crap that otherwise wouldn't
be exported, and I'm really worried about people enabling it and thus
adding exports even if they are conditional.  Can we force the code
to be built in require a boot option for it to be activated?