Re: [PATCH v2 18/39] x86/ibt: Add IBT feature, MSR and #CP handling

[Peter Zijlstra]

On Wed, Mar 02, 2022 at 01:59:46AM +0000, Edgecombe, Rick P wrote:
> As for pinning strength, I'm not understanding this kexec asm enough to
> say for sure how much better it is than just removing the bit from the
> pinning mask. I think some future hardening around preventing turning
> off IBT might still be worthwhile.
> 
> Kees, I think you brought up the pinning, what do you think of this?

IIRC the whole purpose of that was to ensure that the
cr4_update_irqsoff() function itself isn't a useful gadget to manipulate
CR4 with.