Messages in this thread | | | From | Linus Torvalds <> | Date | Wed, 13 Dec 2017 10:23:59 -0800 | Subject | Re: [patch 05/16] mm: Allow special mappings with user access cleared |
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On Wed, Dec 13, 2017 at 10:21 AM, Dave Hansen <dave.hansen@intel.com> wrote: > On 12/13/2017 10:08 AM, Linus Torvalds wrote: >> On Wed, Dec 13, 2017 at 7:54 AM, Peter Zijlstr <peterz@infradead.org> wrote: >>> Which is why get_user_pages() _should_ enforce this. >>> >>> What use are protection keys if you can trivially circumvent them? >> No, we will *not* worry about protection keys in get_user_pages(). > > We did introduce some support for it here: > >> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=33a709b25a760b91184bb335cf7d7c32b8123013
Ugh. I never realized.
We should revert that, I feel. It's literally extra complexity for no actual real gain, and there is a real downside: the extra complexity that will cause people to get things wrong.
This thread about us getting it wrong is just the proof. I vote for not trying to "fix" this case, let's just remove it.
Linus
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