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.
