static int of_overlay_apply()

in overlay.c [916:1015]

• 70 lines of code
• 12 McCabe index (conditional complexity)

static int of_overlay_apply(const void *fdt, struct device_node *tree,
		int *ovcs_id)
{
	struct overlay_changeset *ovcs;
	int ret = 0, ret_revert, ret_tmp;

	/*
	 * As of this point, fdt and tree belong to the overlay changeset.
	 * overlay changeset code is responsible for freeing them.
	 */

	if (devicetree_corrupt()) {
		pr_err("devicetree state suspect, refuse to apply overlay\n");
		kfree(fdt);
		kfree(tree);
		ret = -EBUSY;
		goto out;
	}

	ovcs = kzalloc(sizeof(*ovcs), GFP_KERNEL);
	if (!ovcs) {
		kfree(fdt);
		kfree(tree);
		ret = -ENOMEM;
		goto out;
	}

	of_overlay_mutex_lock();
	mutex_lock(&of_mutex);

	ret = of_resolve_phandles(tree);
	if (ret)
		goto err_free_tree;

	ret = init_overlay_changeset(ovcs, fdt, tree);
	if (ret)
		goto err_free_tree;

	/*
	 * after overlay_notify(), ovcs->overlay_tree related pointers may have
	 * leaked to drivers, so can not kfree() tree, aka ovcs->overlay_tree;
	 * and can not free memory containing aligned fdt.  The aligned fdt
	 * is contained within the memory at ovcs->fdt, possibly at an offset
	 * from ovcs->fdt.
	 */
	ret = overlay_notify(ovcs, OF_OVERLAY_PRE_APPLY);
	if (ret) {
		pr_err("overlay changeset pre-apply notify error %d\n", ret);
		goto err_free_overlay_changeset;
	}

	ret = build_changeset(ovcs);
	if (ret)
		goto err_free_overlay_changeset;

	ret_revert = 0;
	ret = __of_changeset_apply_entries(&ovcs->cset, &ret_revert);
	if (ret) {
		if (ret_revert) {
			pr_debug("overlay changeset revert error %d\n",
				 ret_revert);
			devicetree_state_flags |= DTSF_APPLY_FAIL;
		}
		goto err_free_overlay_changeset;
	}

	ret = __of_changeset_apply_notify(&ovcs->cset);
	if (ret)
		pr_err("overlay apply changeset entry notify error %d\n", ret);
	/* notify failure is not fatal, continue */

	list_add_tail(&ovcs->ovcs_list, &ovcs_list);
	*ovcs_id = ovcs->id;

	ret_tmp = overlay_notify(ovcs, OF_OVERLAY_POST_APPLY);
	if (ret_tmp) {
		pr_err("overlay changeset post-apply notify error %d\n",
		       ret_tmp);
		if (!ret)
			ret = ret_tmp;
	}

	goto out_unlock;

err_free_tree:
	kfree(fdt);
	kfree(tree);

err_free_overlay_changeset:
	free_overlay_changeset(ovcs);

out_unlock:
	mutex_unlock(&of_mutex);
	of_overlay_mutex_unlock();

out:
	pr_debug("%s() err=%d\n", __func__, ret);

	return ret;
}