On Wed, Sep 02, 2020 at 12:43:48PM +0100, Mark Rutland wrote: > I'll see what I can do. > > At first glance it looks like we might need to flesh out or refactor the > arm64 kernel maccess routines first (since we want the user maccess > routines to use LDTR/STTR instructions that can't access kernel memory), > but after that I think the rest is largely mechanical.
Yes, the first thing is to implement __get_kernel_nofaul and __put_kernel_nofault. I think they should mostly look like the existing non-UAO versions of get_user and put_user with a fixed address space limit.
