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

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Message-ID: <d2cb7f4d97d05036608c8b4324de17df2e2acfa7.camel@intel.com>
Date:   Thu, 13 Oct 2022 00:31:38 +0000
From:   "Edgecombe, Rick P" <rick.p.edgecombe@...el.com>
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Subject: Re: [PATCH v2 02/39] x86/cet/shstk: Add Kconfig option for Shadow
 Stack

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@...el.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.