Re: [PATCH V6 XRT Alveo 08/20] fpga: xrt: driver infrastructure

[Lizhi Hou]

On 05/13/2021 08:27 AM, Tom Rix wrote:
> On 5/11/21 6:53 PM, Lizhi Hou wrote:
> > Infrastructure code providing APIs for managing leaf driver instance
> > groups, facilitating inter-leaf driver calls and root calls.
> >
> > Signed-off-by: Sonal Santan <sonal.santan@xxxxxxxxxx>
> > Signed-off-by: Max Zhen <max.zhen@xxxxxxxxxx>
> > Signed-off-by: Lizhi Hou <lizhi.hou@xxxxxxxxxx>
> > Reviewed-by: Tom Rix <trix@xxxxxxxxxx>
>
> > +
> > +int xrt_subdev_root_request(struct xrt_device *self, u32 cmd, void 
> > *arg)
> > +{
> > +     struct device *dev = DEV(self);
> > +     struct xrt_subdev_platdata *pdata = DEV_PDATA(self);
> > +
> > +     WARN_ON(!pdata->xsp_root_cb);
> > +     return (*pdata->xsp_root_cb)(dev->parent, 
> > pdata->xsp_root_cb_arg, cmd, arg);
>
> I am running v6 through clang's static analyzer.
>
> It reports this problem
>
> drivers/fpga/xrt/lib/subdev.c:72:9: warning: Called function pointer is
> null (null dereference)
>         return (*pdata->xsp_root_cb)(dev->parent,
> pdata->xsp_root_cb_arg, cmd, arg);
> ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> Though there is a warn_on, can you also add a
>
> return -EINVAL;
>
> To cover this case?
Sure. I will run through clang myself to check the fix.

Thanks,
Lizhi
> Tom
>
> > +}