Re: [PATCH v2 11/17] selftests/x86/ldt_gdt: Prepare for access bit forced

From: Peter Zijlstra
Date: Thu Dec 14 2017 - 17:02:49 EST


On Thu, Dec 14, 2017 at 01:48:50PM -0800, Linus Torvalds wrote:
> Actually, just clearing PAGE_USER should make gup avoid it automatically.

_Should_ being the operative word, because I cannot currently see it
DTRT. But maybe I'm missing the obvious -- I tend to do that at times.

We don't appear to have pte_bad() and pte_access_permitted() is
currently all sorts of wrong.