On Wed, Dec 13, 2017 at 10:08 AM, Linus Torvalds <[email protected]> wrote: > On Wed, Dec 13, 2017 at 7:54 AM, Peter Zijlstra <[email protected]> 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(). >
Hmm. If I goof some pointer and pass that bogus pointer to read(2), and I'm using pkey to protect my mmapped database, I think i'd rather that read(2) fail. Sure, pkey is trivially circumventable using wrpkru or mprotect, but those are obvious dangerous functions.
