Re: [PATCH v3 3/4] driver property: constify property arrays values

Rafael J. Wysocki
2017-02-02T11:29:08Z

On Wednesday, February 01, 2017 03:30:03 PM Joe Perches wrote:
> On Wed, 2017-02-01 at 09:31 -0800, Dmitry Torokhov wrote:
> > Data that is fed into property arrays should not be modified, so let's mark
> > relevant pointers as const. This will allow us making source arrays as
> > const/__initconst.
>
> trivia:
>
> > diff --git a/drivers/base/property.c b/drivers/base/property.c
> []
> > @@ -682,44 +682,66 @@ int fwnode_property_match_string(struct fwnode_handle *fwnode,
> > }
> > EXPORT_SYMBOL_GPL(fwnode_property_match_string);
> >
> > +static int property_copy_string_array(struct property_entry *dst,
> > + const struct property_entry *src)
> > +{
> > + char **d;
> > + size_t nval = src->length / sizeof(*d);
> > + size_t i;
> > +
> > + d = kcalloc(nval, sizeof(*d), GFP_KERNEL);
> > + if (!d)
> > + return -ENOMEM;
> > +
> > + for (i = 0; i < nval; i++) {
> > + d[i] = kstrdup(src->pointer.str[i], GFP_KERNEL);
> > + if (!d[i] && src->pointer.str[i]) {
> > + while (--i >= 0)
> > + kfree(d[i]);
> > + kfree(d);
> > + return -ENOMEM;
> > + }
> > + }
> > +
> > + dst->pointer.str = (void *)d;
> > + return 0;
> > +}
> > +
> > static int property_entry_copy(struct property_entry *dst,
> > const struct property_entry *src)
> > {
> > - const char **d, **s;
> > - size_t i, nval;
> > + int error;
> >
> > dst->name = kstrdup(src->name, GFP_KERNEL);
> > if (!dst->name)
> > return -ENOMEM;
> >
> > if (src->is_array) {
> > - if (!src->length)
> > - return -ENODATA;
> > + if (!src->length) {
> > + error = -ENODATA;
> > + goto out_free_name;
> > + }
> >
> > if (src->is_string) {
> > - nval = src->length / sizeof(const char *);
> > - dst->pointer.str = kcalloc(nval, sizeof(const char *),
> > - GFP_KERNEL);
> > - if (!dst->pointer.str)
> > - return -ENOMEM;
> > -
> > - d = dst->pointer.str;
> > - s = src->pointer.str;
> > - for (i = 0; i < nval; i++) {
> > - d[i] = kstrdup(s[i], GFP_KERNEL);
> > - if (!d[i] && s[i])
> > - return -ENOMEM;
> > + error = property_copy_string_array(dst, src);
> > + if (error) {
> > + error = -ENOMEM;
>
> An unnecessary set as the return from the above
> property_copy_string_array is either 0 or -ENOMEM

Even if it is not -ENOMEM, it still can be propagated to the caller.

I can fix this up unless Dmitry wants to send an updated patch.

Thanks,
Rafael