On Wed, Dec 13, 2017 at 10:21 AM, Dave Hansen <dave.hansen@xxxxxxxxx> wrote: > On 12/13/2017 10:08 AM, Linus Torvalds wrote: >> On Wed, Dec 13, 2017 at 7:54 AM, Peter Zijlstr <peterz@xxxxxxxxxxxxx> 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 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>
