struct ctl_table_header *__register_sysctl_table(
	struct ctl_table_set *set,
	const char *path, struct ctl_table *table)
{
	struct ctl_table_root *root = set->dir.header.root;
	struct ctl_table_header *header;
	const char *name, *nextname;
	struct ctl_dir *dir;
	struct ctl_table *entry;
	struct ctl_node *node;
	int nr_entries = 0;

	for (entry = table; entry->procname; entry++)
		nr_entries++;

	header = kzalloc(sizeof(struct ctl_table_header) +
			 sizeof(struct ctl_node)*nr_entries, GFP_KERNEL);
	if (!header)
		return NULL;

	node = (struct ctl_node *)(header + 1);
	init_header(header, root, set, node, table);
	if (sysctl_check_table(path, table))
		goto fail;

	spin_lock(&sysctl_lock);
	dir = &set->dir;
	/* Reference moved down the diretory tree get_subdir */
	dir->header.nreg++;
	spin_unlock(&sysctl_lock);

	/* Find the directory for the ctl_table */
	for (name = path; name; name = nextname) {
		int namelen;
		nextname = strchr(name, '/');
		if (nextname) {
			namelen = nextname - name;
			nextname++;
		} else {
			namelen = strlen(name);
		}
		if (namelen == 0)
			continue;

		dir = get_subdir(dir, name, namelen);
		if (IS_ERR(dir))
			goto fail;
	}

	spin_lock(&sysctl_lock);
	if (insert_header(dir, header))
		goto fail_put_dir_locked;

	drop_sysctl_table(&dir->header);
	spin_unlock(&sysctl_lock);

	return header;

fail_put_dir_locked:
	drop_sysctl_table(&dir->header);
	spin_unlock(&sysctl_lock);
fail:
	kfree(header);
	dump_stack();
	return NULL;
}
Unknown