lkml.org 
[lkml]   [2018]   [Jul]   [11]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [RFC PATCH v2 16/27] mm: Modify can_follow_write_pte/pmd for shadow stack
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.

\
 
 \ /
  Last update: 2018-07-11 11:30    [W:0.219 / U:2.324 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site