Pull x86 fixes from Thomas Gleixner:
 "A set of fixes for x86:

   - Make the unwinder more robust when it encounters a NULL pointer
     call, so the backtrace becomes more useful

   - Fix the bogus ORC unwind table alignment

   - Prevent kernel panic during kexec on HyperV caused by a cleared but
     not disabled hypercall page.

   - Remove the now pointless stacksize increase for KASAN_EXTRA, as
     KASAN_EXTRA is gone.

   - Remove unused variables from the x86 memory management code"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/hyperv: Fix kernel panic when kexec on HyperV
  x86/mm: Remove unused variable 'old_pte'
  x86/mm: Remove unused variable 'cpu'
  Revert "x86_64: Increase stack size for KASAN_EXTRA"
  x86/unwind: Add hardcoded ORC entry for NULL
  x86/unwind: Handle NULL pointer calls better in frame unwinder
  x86/unwind/orc: Fix ORC unwind table alignment