Re: [PATCH v2 01/17] mm/gup: Fixup p*_access_permitted()

From: Peter Zijlstra
Date: Fri Dec 15 2017 - 02:52:33 EST


On Thu, Dec 14, 2017 at 10:09:24PM -0800, Linus Torvalds wrote:
> On Dec 14, 2017 21:04, "Dave Hansen" <dave.hansen@xxxxxxxxx> wrote:
> Can we please just undo that broken crap instead of trying to "fix" it?
>
> It was wrong. We absolutely do not want to complicate the gup path.
>
> Let's fet rid of those broken p??_access_permited() things.

So we actually need the pte_access_permitted() stuff if we want to
ensure we're not stepping on !PAGE_USER things.