Re: drivers/irqchip/irq-apple-aic.c:941 aic_of_ic_init() error: uninitialized symbol 'off'.

Dan Carpenter
2022-06-06T11:31:39Z

On Mon, Jun 06, 2022 at 12:16:22PM +0100, Marc Zyngier wrote:
> > dc97fd6fec0099 Hector Martin 2022-03-10 926 switch (irqc->info.version) {
> > dc97fd6fec0099 Hector Martin 2022-03-10 927 case 1: {
> > dc97fd6fec0099 Hector Martin 2022-03-10 928 u32 info;
> > dc97fd6fec0099 Hector Martin 2022-03-10 929
> > 76cde26394114f Hector Martin 2021-01-21 930 info = aic_ic_read(irqc, AIC_INFO);
> > 7c841f5f6fa3f9 Hector Martin 2022-03-10 931 irqc->nr_irq = FIELD_GET(AIC_INFO_NR_IRQ, info);
> > dc97fd6fec0099 Hector Martin 2022-03-10 932 irqc->max_irq = AIC_MAX_IRQ;
> > dc97fd6fec0099 Hector Martin 2022-03-10 933
> > dc97fd6fec0099 Hector Martin 2022-03-10 934 off = irqc->info.target_cpu;
> > dc97fd6fec0099 Hector Martin 2022-03-10 935 off += sizeof(u32) * irqc->max_irq; /* TARGET_CPU */
> > dc97fd6fec0099 Hector Martin 2022-03-10 936
> > dc97fd6fec0099 Hector Martin 2022-03-10 937 break;
> >
> > "off" uninitialized if irqc->info.version != 1.
>
> Which is pretty much impossible by construction, as as of this
> particular commit, all the possible implementations have version == 1.
>
> Subsequent patches do add cases where version == 2, and that gets
> covered too.
>
> So unless I'm missing something obvious, there is no bug here.

I assumed it was something like that. The kbuild bot doesn't do cross
function analysis. Neither does Clang really.

regards,
dan carpenter