[apw@shadowen.org: generalise pattern and add tests]
Signed-off-by: NMichael Ellerman <michael@ellerman.id.au>
Signed-off-by: NAndy Whitcroft <apw@shadowen.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>