On Fri, Jul 15, 2022 at 09:45:37AM -0700, Axel Rasmussen wrote: > I agree we should either: > - Update the UFFD selftest to exercise this case > - Or, don't allow it, update vma_can_userfault() to also require VM_SHARED > for VM_UFFD_MINOR registration. > > The first one is unfortunately not completely straightforward as Peter > described. I would say it's probably not worth holding up this fix while we > wait for it to happen? Agreed, Andrew has already queued it. It actually is a real fix since we never forbid the user running private mappings upon minor faults, so it's literally a bug in kernel irrelevant of the kselftest. > > I don't really have a strong preference between the two. The second option > is what I originally proposed in the first version of the minor fault > series, so going back to that isn't a problem at least from my perspective. > If in the future we find a real use case for this, we could always easily > re-enable it and add selftests for it at that point. I'd go for fixing the test case if possible. Mike, would it be fine if we go back to /dev/hugepages path based approach in the test case? Thanks, -- Peter Xu
