[PATCH 6/7] mm/x86: Add missing pud helpers

[Edgecombe, Rick P]

On Fri, 2024-06-21 at 07:51 -0700, Dave Hansen wrote:
> 
> But, still, what if you take a Dirty=1,Write=1 pud and pud_modify() it
> to make it Dirty=1,Write=0?  What prevents that from being
> misinterpreted by the hardware as being a valid 1G shadow stack mapping?

Hmm, it looks like we could use an arch_check_zapped_pud() that does a warning
like arch_check_zapped_pte/pmd() too. Not that we had no use for one before
this.