Function vm_map_delete

freebsd/vm/vm_map.c:3931–4016

* vm_map_delete: [ internal use only ] * * Deallocates the given address range from the target * map. */

 *	map.
 */
int
vm_map_delete(vm_map_t map, vm_offset_t start, vm_offset_t end)
{
	vm_map_entry_t entry, next_entry, scratch_entry;
	int rv;

	VM_MAP_ASSERT_LOCKED(map);

	if (start == end)
		return (KERN_SUCCESS);

	/*
	 * Find the start of the region, and clip it.
	 * Step through all entries in this region.
	 */
	rv = vm_map_lookup_clip_start(map, start, &entry, &scratch_entry);
	if (rv != KERN_SUCCESS)
		return (rv);
	for (; entry->start < end; entry = next_entry) {
		/*
		 * Wait for wiring or unwiring of an entry to complete.
		 * Also wait for any system wirings to disappear on
		 * user maps.
		 */
		if ((entry->eflags & MAP_ENTRY_IN_TRANSITION) != 0 ||
		    (vm_map_pmap(map) != kernel_pmap &&
		    vm_map_entry_system_wired_count(entry) != 0)) {
			unsigned int last_timestamp;
			vm_offset_t saved_start;

			saved_start = entry->start;
			entry->eflags |= MAP_ENTRY_NEEDS_WAKEUP;
			last_timestamp = map->timestamp;
			(void) vm_map_unlock_and_wait(map, 0);
			vm_map_lock(map);
			if (last_timestamp + 1 != map->timestamp) {
				/*
				 * Look again for the entry because the map was
				 * modified while it was unlocked.
				 * Specifically, the entry may have been
				 * clipped, merged, or deleted.
				 */
				rv = vm_map_lookup_clip_start(map, saved_start,
				    &next_entry, &scratch_entry);
				if (rv != KERN_SUCCESS)
					break;
			} else
				next_entry = entry;
			continue;
		}

		/* XXXKIB or delete to the upper superpage boundary ? */
		rv = vm_map_clip_end(map, entry, end);
		if (rv != KERN_SUCCESS)
			break;
		next_entry = vm_map_entry_succ(entry);

		/*