On 2023/5/4 15:34, Dan Carpenter wrote:
Hello Greg Kroah-Hartman,
The patch fea087fc291b: "irqchip/mbigen: move to use
bus_get_dev_root()" from Mar 13, 2023, leads to the following Smatch
static checker warning:
drivers/irqchip/irq-mbigen.c:258 mbigen_of_create_domain()
error: potentially dereferencing uninitialized 'child'.
drivers/irqchip/irq-mbigen.c
235 static int mbigen_of_create_domain(struct platform_device *pdev,
236 struct mbigen_device *mgn_chip)
237 {
238 struct device *parent;
239 struct platform_device *child;
240 struct irq_domain *domain;
241 struct device_node *np;
242 u32 num_pins;
243
244 for_each_child_of_node(pdev->dev.of_node, np) {
245 if (!of_property_read_bool(np, "interrupt-controller"))
246 continue;
247
248 parent = bus_get_dev_root(&platform_bus_type);
249 if (parent) {
Smatch is concerned that "parent" can be NULL. Probably unlikely in
real life.
How about move bus_get_dev_root() out of the loop.
diff --git a/drivers/irqchip/irq-mbigen.c b/drivers/irqchip/irq-mbigen.c
index eada5e0e3eb9..954a55ed1f2b 100644
--- a/drivers/irqchip/irq-mbigen.c
+++ b/drivers/irqchip/irq-mbigen.c
@@ -240,26 +240,25 @@ static int mbigen_of_create_domain(struct
platform_device *pdev,
struct irq_domain *domain;
struct device_node *np;
u32 num_pins;
+ int ret = -ENODEV;
+
+ parent = bus_get_dev_root(&platform_bus_type);
+ if (!parent)
+ return ret;
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;
- }
- }
+ child = of_platform_device_create(np, NULL, parent);
+ if (!child)
+ goto out_put;
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;
+ goto out_put;
}
domain = platform_msi_create_device_domain(&child->dev, num_pins,
@@ -267,12 +266,17 @@ 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;
+ goto out_put;
}
}
return 0;
+
+out_put:
+ of_node_put(np);
+ put_device(parent);
+ return ret;
}
regards,
dan carpenter
