Re: [PATCH 3/4] pinctrl: Add checks for empty names in pinmux_search_function

[Tony Lindgren <tony@atomide.com>]

* Stephen Warren <swarren@nvidia.com> [120120 08:28]:
> Tony Lindgren wrote at Friday, January 20, 2012 9:18 AM:
> > Otherwise we can get the following when dealing with
> > buggy data in a pinmux driver:
> > 
> > Unable to handle kernel NULL pointer dereference at virtual address 00000000
> 
> > diff --git a/drivers/pinctrl/pinmux.c b/drivers/pinctrl/pinmux.c
> > index 06b8943..ffe633d 100644
> > --- a/drivers/pinctrl/pinmux.c
> > +++ b/drivers/pinctrl/pinmux.c
> > @@ -584,6 +584,13 @@ static int pinmux_search_function(struct pinctrl_dev *pctldev,
> >  							   selector);
> >  		int ret;
> > 
> > +		if (!fname) {
> > +			pr_warning("no name for function%i\n",
> > +				   selector);
> > +			selector++;
> > +			continue;
> > +		}
> > +
> >  		if (!strcmp(map->function, fname)) {
> >  			/* Found the function, check pin group */
> >  			ret = pinmux_check_pin_group(pctldev, selector,
> 
> Shouldn't this be BUG_ON(!fname)?
>
> There are lots of other places that pmxops->get_function_name() is
> called. Wouldn't it be better to enhance e.g. pinmux_check_ops() to
> validate that all functions have a name during pinctrl registration?

Maybe yeah. I'll take a look next week when I'm back home.

Tony