Re: [PATCH 03/35] x86/cpufeatures: Add CET CPU feature flags for Control-flow Enforcement Technology (CET)

Edgecombe, Rick P
2022-02-08T22:25:21Z

On Mon, 2022-02-07 at 14:45 -0800, Dave Hansen wrote:
> Please add a chunk to the changelog that explains the dependency.
> This
> would suffice:
>
> To protect shadow stack state from malicious modification,
> the
> registers are only accessible in supervisor mode. This
> implementation context-switches the registers with XSAVES.
> Make
> X86_FEATURE_SHSTK depend on XSAVES.

Thanks. Yea, I don't think that part of the design is really elaborated
on anywhere. It can be some foreshadowing for the signal stuff later
too.