On Tue, Apr 16, 2019 at 5:08 AM Martin Schwidefsky <schwidefsky@xxxxxxxxxx> wrote: > > This is not nice, would a patch like the following be acceptable? Umm. We actually already *have* this function. It's called "gup_fast_permitted()" and it's used by x86-64 to verify the proper address range. Exactly like s390 needs.. Could you please use that instead? Linus