On Tue, Aug 30, 2016 at 09:13:32PM +0100, Al Viro wrote: > On Tue, Aug 30, 2016 at 02:15:58PM -0400, Kees Cook wrote: > > > First, some current API usage which we'll need to maintain at least > > for now: __copy_*_user() is just copy_*_user() without the access_ok() > > checks. Unfortunately, some arch implement different copying methods > > depending on if the entry is via copy...() or __copy..() (e.g. see > > x86's use of _copy...() -- single underscore??) There doesn't seem to > > be a good reason for this, and I think it would make sense to extract > > the actual per-arch implementation that performs the real copy into > > something like arm64's __arch_copy_*_user(), which only does the copy > > itself and nothing else. > > No. __arch_copy_from_user() is a bloody bad idea; the real primitive > is what's currently called __copy_from_user_inatomic(), and I'm planning > to rename it to raw_copy_from_user().
Great! FWIW, my plan with the arch_* forms was to follow the convention set by the spinlock code and have raw_* forms build atop of these, where common debug and/or hardening checks would live. >From my PoV, anything to make this more consistent cross-architecture is good, especially if we can pull the duplicated logic into common code. Thanks, Mark.
