This verifies virtual address mapping below and above the 128TB range
and makes sure that address returned are within the expected range
depending upon the hint passed from the user space.

Link: http://lkml.kernel.org/r/20170418095252.20533-1-khandual@linux.vnet.ibm.comSigned-off-by: NAnshuman Khandual <khandual@linux.vnet.ibm.com>
Cc: Michal Suchanek <msuchanek@suse.de>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Cc: Shuah Khan <shuahkh@osg.samsung.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>