Re: [PATCH v2 02/39] x86/cet/shstk: Add Kconfig option for Shadow Stack

Edgecombe, Rick P
2022-10-13T01:02:15Z

On Wed, 2022-10-12 at 22:04 +0200, Borislav Petkov wrote:
> On Thu, Sep 29, 2022 at 03:28:59PM -0700, Rick Edgecombe wrote:
> > From: Yu-cheng Yu <yu-cheng.yu@intel.com>
> > Subject: Re: [PATCH v2 02/39] x86/cet/shstk: Add Kconfig option for
> > Shadow Stack
>
> Please remove all "CET", "cet", etc strings from the text as that is
> confusing. We should use either shadow stack or IBT and not CET.

Good point, I'll remove it. Thanks.

>
> > +config ARCH_HAS_SHADOW_STACK
>
> Do I see it correctly that this thing is needed only once in
> show_smap_vma_flags()?
>
> If so, can we do a arch_show_smap_vma_flags(), call it at the end of
> former function and avoid adding yet another Kconfig symbol?

Yea, I was thinking to maybe just change it to
CONFIG_X86_USER_SHADOW_STACK in show_smap_vma_flags(). In that function
there is already CONFIG_ARM64_BTI and CONFIG_ARM64_MTE.

I'm not sure if there is any aversion to having arch CONFIGs in core
code, but it's kind of nice to have all of the potentially conflicting
strings in once place.