Merge tag 's390-5.2-4' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux

Merge tag 's390-5.2-4' of git://git./linux/kernel/git/s390/linux

Pull s390 fixes from Heiko Carstens:

 - fix stack unwinder: the stack unwinder rework has on off-by-one bug
   which prevents following stack backchains over more than one context
   (e.g. irq -> process).

 - fix address space detection in exception handler: if user space
   switches to access register mode, which is not supported anymore, the
   exception handler may resolve to the wrong address space.

* tag 's390-5.2-4' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
  s390/unwind: correct stack switching during unwind
  s390/mm: fix address space detection in exception handling