Re: [PATCH v2 04/12] software node: Implement .get_reference_args fwnode operation

[Heikki Krogerus <heikki.krogerus@linux.intel.com>]

On Fri, Apr 12, 2019 at 10:48:41AM +0200, Rafael J. Wysocki wrote:
> On Wed, Apr 10, 2019 at 5:26 PM Heikki Krogerus
> <heikki.krogerus@linux.intel.com> wrote:
> >
> > This makes it possible to support drivers that use
> > fwnode_property_get_reference_args() function.
> >
> > Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
> > ---
> >  drivers/base/swnode.c | 56 +++++++++++++++++++++++++++++++++++++++++++
> >  1 file changed, 56 insertions(+)
> >
> > diff --git a/drivers/base/swnode.c b/drivers/base/swnode.c
> > index 39b8f8f35cfe..d6a9b56cb073 100644
> > --- a/drivers/base/swnode.c
> > +++ b/drivers/base/swnode.c
> > @@ -534,6 +534,61 @@ software_node_get_named_child_node(const struct fwnode_handle *fwnode,
> >         return NULL;
> >  }
> >
> > +static int
> > +software_node_get_reference_args(const struct fwnode_handle *fwnode,
> > +                                const char *propname, const char *nargs_prop,
> > +                                unsigned int nargs, unsigned int index,
> > +                                struct fwnode_reference_args *args)
> > +{
> > +       struct software_node *swnode = to_software_node(fwnode);
> > +       struct software_node_reference *ref;
> > +       const struct property_entry *prop;
> > +       int ret = -ENOENT;
> > +       int i;
> > +
> > +       mutex_lock(&swnode->lock);
> > +
> > +       if (!swnode || list_empty(&swnode->references))
> > +               goto err_unlock;
> > +
> > +       if (nargs_prop) {
> > +               prop = property_entry_get(swnode->properties, nargs_prop);
> > +               if (!prop) {
> > +                       ret = -EINVAL;
> > +                       goto err_unlock;
> > +               }
> > +
> > +               nargs = prop->value.u32_data;
> > +       }
> > +
> > +       if (nargs > NR_FWNODE_REFERENCE_ARGS) {
                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
note

> > +               ret = -EINVAL;
> > +               goto err_unlock;
> > +       }
> > +
> > +       list_for_each_entry(ref, &swnode->references, list) {
> > +               if (strcmp(ref->name, propname))
> > +                       continue;
> > +
> > +               if (index > (ref->nrefs - 1))
> > +                       break;
> > +
> > +               args->nargs = nargs;
> > +               args->fwnode = software_node_get(ref->args[index].fwnode);
> > +
> > +               for (i = 0; i < nargs; i++)
> > +                       args->args[i] = ref->args[index].args[i];
> 
> If nargs is provided by the caller, can't it be greater than the
> number of args[index].args[] entries?

No. They have NR_FWNODE_REREFECE_ARGS elements, and we check above
that nargs is not greater then that.


thanks,

-- 
heikki