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.
250 child = of_platform_device_create(np, NULL, parent);
251 put_device(parent);
252 if (!child) {
253 of_node_put(np);
254 return -ENOMEM;
255 }
256 }
257
--> 258 if (of_property_read_u32(child->dev.of_node, "num-pins",
259 &num_pins) < 0) {
260 dev_err(&pdev->dev, "No num-pins property\n");
261 of_node_put(np);
262 return -EINVAL;
263 }
264
265 domain = platform_msi_create_device_domain(&child->dev, num_pins,
266 mbigen_write_msg,
267 &mbigen_domain_ops,
268 mgn_chip);
269 if (!domain) {
270 of_node_put(np);
271 return -ENOMEM;
272 }
273 }
274
275 return 0;
276 }
regards,
dan carpenter
