Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 fixes from Ingo Molnar:
 "Various fixes"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86-64, kcmp: The kcmp system call can be common
  arch/x86/kernel/kdebugfs.c: Ensure a consistent return value in error case
  x86/mce: Add quirk for instruction recovery on Sandy Bridge processors
  x86/mce: Move MCACOD defines from mce-severity.c to <asm/mce.h>
  x86/ioapic: Fix NULL pointer dereference on CPU hotplug after disabling irqs
  x86, nops: Missing break resulting in incorrect selection on Intel
  x86: CONFIG_CC_STACKPROTECTOR=y is no longer experimental