Assert that the protection of a new map entry is a subset of the max

protection.

Noted and reviewed by:	alc
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week

sys/vm/vm_map.c

@@ -1190,6 +1190,8 @@ vm_map_insert(vm_map_t map, vm_object_t object, vm_ooffset_t offset,
 	    ("vm_map_insert: kmem or kernel object and COW"));
 	KASSERT(object == NULL || (cow & MAP_NOFAULT) == 0,
 	    ("vm_map_insert: paradoxical MAP_NOFAULT request"));
+	KASSERT((prot & ~max) == 0,
+	    ("prot %#x is not subset of max_prot %#x", prot, max));
 
 	/*
 	 * Check that the start and end points are not bogus.