Messages in this thread | | | From | Suren Baghdasaryan <> | Date | Mon, 23 Oct 2023 12:00:09 -0700 | Subject | Re: [PATCH v3 2/3] userfaultfd: UFFDIO_MOVE uABI |
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On Mon, Oct 23, 2023 at 8:53 AM David Hildenbrand <david@redhat.com> wrote: > > On 23.10.23 14:29, David Hildenbrand wrote: > >> + > >> + /* Only allow remapping if both are mlocked or both aren't */ > >> + if ((src_vma->vm_flags & VM_LOCKED) != (dst_vma->vm_flags & VM_LOCKED)) > >> + return -EINVAL; > >> + > >> + if (!(src_vma->vm_flags & VM_WRITE) || !(dst_vma->vm_flags & VM_WRITE)) > >> + return -EINVAL; > > > > Why does one of both need VM_WRITE? If one really needs it, then the > > destination (where we're moving stuff to). > > Just realized that we want both to be writable. > > If you have this in place, there is no need to use maybe*_mkwrite(), you > can use the non-maybe variants.
Ack.
> > I recall that for UFFDIO_COPY we even support PROT_NONE VMAs, is there > any reason why we want to have different semantics here?
I don't think so. At least not for the single-mm case.
> > -- > Cheers, > > David / dhildenb > > -- > To unsubscribe from this group and stop receiving emails from it, send an email to kernel-team+unsubscribe@android.com. >
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