This can be used to validate that an address range is mapped but without
being readable or writable.

It will be used by an updated implementation of mincore().

Signed-off-by: Thomas Weißschuh <thomas@t-8ch.de>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Message-Id: <20230422100314.1650-2-thomas@t-8ch.de>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>