Commit cddb536a authored by Kefeng Wang's avatar Kefeng Wang Committed by Marc Zyngier
Browse files

irqchip/mbigen: Unify the error handling in mbigen_of_create_domain() 



Dan Carpenter reported that commit fea087fc "irqchip/mbigen: move
to use bus_get_dev_root()" leads to the following Smatch static checker
warning:

	drivers/irqchip/irq-mbigen.c:258 mbigen_of_create_domain()
	error: potentially dereferencing uninitialized 'child'.

It should not cause a problem on real hardware, but better to fix the
warning, let's move the bus_get_dev_root() out of the loop, and unify
the error handling to silence it.

Reported-by: default avatarDan Carpenter <dan.carpenter@linaro.org>
Signed-off-by: default avatarKefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: default avatarMarc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20230505090654.12793-1-wangkefeng.wang@huawei.com
parent 14130211

drivers/irqchip/irq-mbigen.c

+18 −13
Original line number Diff line number Diff line
@@ -240,26 +240,27 @@ static int mbigen_of_create_domain(struct platform_device *pdev, 
	struct irq_domain *domain;

	struct device_node *np;

	u32 num_pins;

	int ret = 0;



	parent = bus_get_dev_root(&platform_bus_type);

	if (!parent)

		return -ENODEV;



	for_each_child_of_node(pdev->dev.of_node, np) {

		if (!of_property_read_bool(np, "interrupt-controller"))

			continue;



		parent = bus_get_dev_root(&platform_bus_type);

		if (parent) {

		child = of_platform_device_create(np, NULL, parent);

			put_device(parent);

		if (!child) {

				of_node_put(np);

				return -ENOMEM;

			}

			ret = -ENOMEM;

			break;

		}



		if (of_property_read_u32(child->dev.of_node, "num-pins",

					 &num_pins) < 0) {

			dev_err(&pdev->dev, "No num-pins property\n");

			of_node_put(np);

			return -EINVAL;

			ret = -EINVAL;

			break;

		}



		domain = platform_msi_create_device_domain(&child->dev, num_pins,
@@ -267,12 +268,16 @@ static int mbigen_of_create_domain(struct platform_device *pdev, 
							   &mbigen_domain_ops,

							   mgn_chip);

		if (!domain) {

			of_node_put(np);

			return -ENOMEM;

			ret = -ENOMEM;

			break;

		}

	}



	return 0;

	put_device(parent);

	if (ret)

		of_node_put(np);



	return ret;

}



#ifdef CONFIG_ACPI