posix/munmap: Use mmap to obtain valid and safe address range

Avoid accidentally un-mapping memory used internally by malloc by creating a
new mapping and then un-mapping it twice.

Signed-off-by: Richard Palethorpe <rpalethorpe@suse.com>
Signed-off-by: Cyril Hrubis <chrubis@suse.cz>
1 file changed