Re: [usb-gadget-udc] question about null check after calling phys_to_virt() function

[Gustavo A. R. Silva]

Hi Felipe,

Quoting Felipe Balbi <balbi@xxxxxxxxxx>:

> Hi,
>
> "Gustavo A. R. Silva" <garsilva@xxxxxxxxxxxxxx> writes:
> > Hello everybody,
> >
> > While looking into Coverity ID 145958 I ran into the following piece
> > of code at drivers/usb/gadget/udc/amd5536udc.c:852:
> >
> > } else if (i == buf_len) {
> >          /* first td */
> >          td = (struct udc_data_dma *)phys_to_virt(
> >                                  req->td_data->next);
> >          td->status = 0;
> > } else {
> >          td = (struct udc_data_dma *)phys_to_virt(last->next);
> >          td->status = 0;
> > }
> >
> > if (td)
> >          td->bufptr = req->req.dma + i; /* assign buffer */
> > else
> >          break;
> >
> > The issue here is that _td_ pointer is being dereferenced before null check.
> >
> > After searching for calls to phys_to_virt() function, I've noticed
> > that is not common at all to test the returned address value.
> >
> > So either the null check at line 862 is not needed or a null check
> > before each td->status = 0; needs to be added.
>
> just remove the previous null check

I get it.

Thanks!
--
Gustavo A. R. Silva