On Tue, Jul 10, 2018 at 03:26:28PM -0700, Yu-cheng Yu wrote: > There are three possible shadow stack PTE settings: > > Normal SHSTK PTE: (R/O + DIRTY_HW) > SHSTK PTE COW'ed: (R/O + DIRTY_HW) > SHSTK PTE shared as R/O data: (R/O + DIRTY_SW) I count _2_ distinct states there. > Update can_follow_write_pte/pmd for the shadow stack. So the below disallows can_follow_write when shstk && _PAGE_DIRTY_SW, but this here Changelog doesn't explain why. Doesn't even get close. Also, the code is a right mess :/ Can't we try harder to not let this shadow stack stuff escape arch code.