static int init_overlay_changeset()

in overlay.c [732:846]

• 83 lines of code
• 13 McCabe index (conditional complexity)

static int init_overlay_changeset(struct overlay_changeset *ovcs,
		const void *fdt, struct device_node *tree)
{
	struct device_node *node, *overlay_node;
	struct fragment *fragment;
	struct fragment *fragments;
	int cnt, id, ret;

	/*
	 * Warn for some issues.  Can not return -EINVAL for these until
	 * of_unittest_apply_overlay() is fixed to pass these checks.
	 */
	if (!of_node_check_flag(tree, OF_DYNAMIC))
		pr_debug("%s() tree is not dynamic\n", __func__);

	if (!of_node_check_flag(tree, OF_DETACHED))
		pr_debug("%s() tree is not detached\n", __func__);

	if (!of_node_is_root(tree))
		pr_debug("%s() tree is not root\n", __func__);

	ovcs->overlay_tree = tree;
	ovcs->fdt = fdt;

	INIT_LIST_HEAD(&ovcs->ovcs_list);

	of_changeset_init(&ovcs->cset);

	id = idr_alloc(&ovcs_idr, ovcs, 1, 0, GFP_KERNEL);
	if (id <= 0)
		return id;

	cnt = 0;

	/* fragment nodes */
	for_each_child_of_node(tree, node) {
		overlay_node = of_get_child_by_name(node, "__overlay__");
		if (overlay_node) {
			cnt++;
			of_node_put(overlay_node);
		}
	}

	node = of_get_child_by_name(tree, "__symbols__");
	if (node) {
		cnt++;
		of_node_put(node);
	}

	fragments = kcalloc(cnt, sizeof(*fragments), GFP_KERNEL);
	if (!fragments) {
		ret = -ENOMEM;
		goto err_free_idr;
	}

	cnt = 0;
	for_each_child_of_node(tree, node) {
		overlay_node = of_get_child_by_name(node, "__overlay__");
		if (!overlay_node)
			continue;

		fragment = &fragments[cnt];
		fragment->overlay = overlay_node;
		fragment->target = find_target(node);
		if (!fragment->target) {
			of_node_put(fragment->overlay);
			ret = -EINVAL;
			of_node_put(node);
			goto err_free_fragments;
		}

		cnt++;
	}

	/*
	 * if there is a symbols fragment in ovcs->fragments[i] it is
	 * the final element in the array
	 */
	node = of_get_child_by_name(tree, "__symbols__");
	if (node) {
		ovcs->symbols_fragment = 1;
		fragment = &fragments[cnt];
		fragment->overlay = node;
		fragment->target = of_find_node_by_path("/__symbols__");

		if (!fragment->target) {
			pr_err("symbols in overlay, but not in live tree\n");
			ret = -EINVAL;
			goto err_free_fragments;
		}

		cnt++;
	}

	if (!cnt) {
		pr_err("no fragments or symbols in overlay\n");
		ret = -EINVAL;
		goto err_free_fragments;
	}

	ovcs->id = id;
	ovcs->count = cnt;
	ovcs->fragments = fragments;

	return 0;

err_free_fragments:
	kfree(fragments);
err_free_idr:
	idr_remove(&ovcs_idr, id);

	pr_err("%s() failed, ret = %d\n", __func__, ret);

	return ret;
}