On Thu, May 04, 2023 at 07:56:07PM +0800, Kefeng Wang wrote:
>
>
> 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.
>
Sounds good to me, but I don't know this code at all.
regards,
dan carpenter
