Re: [PATCH v1 3/8] iio: core: Switch to krealloc_array()

Nuno Sá
2023-07-21T10:51:29Z

On Fri, 2023-07-21 at 13:14 +0300, Andy Shevchenko wrote:
> On Fri, Jul 21, 2023 at 09:59:37AM +0200, Nuno Sá wrote:
> > On Thu, 2023-07-20 at 23:53 +0300, Andy Shevchenko wrote:
>
> ...
>
> > > +       struct attribute **attrs, **attr, *clk = NULL;
> > >         struct iio_dev_attr *p;
> > > -       struct attribute **attr, *clk = NULL;
> > >
> > >         /* First count elements in any existing group */
> > > -       if (indio_dev->info->attrs) {
> > > -               attr = indio_dev->info->attrs->attrs;
> > > -               while (*attr++ != NULL)
> > > +       attrs = indio_dev->info->attrs ? indio_dev->info->attrs->attrs :
> > > NULL;
> > > +       if (attrs) {
> > > +               for (attr = attrs; *attr; attr++)
> > >                         attrcount_orig++;
>
> > not really related with the change... maybe just mention it in the commit?
>
> Hmm... It's related to make krealloc_array() to work as expected.
>

Hmm, I think it's arguable :). while() -> for() it's not really needed unless
I'm missing something. You could even initialize 'attrs' to NULL at declaration
and keep the above diff minimum.

That said, I actually prefer this style (even though some people don't like much
the ternary operator).

> > >         }
>
> ...
>
> > >         iio_dev_opaque->chan_attr_group.attrs =
> > > -               kcalloc(attrcount + 1,
> > > -                       sizeof(iio_dev_opaque->chan_attr_group.attrs[0]),
> > > -                       GFP_KERNEL);
> > > +               krealloc_array(attrs, attrcount + 1, sizeof(*attrs),
> > > GFP_KERNEL);
> > >         if (iio_dev_opaque->chan_attr_group.attrs == NULL) {
> >
> > since you're here and you also already did some style cleanups above, maybe
> > change it to 'if (!iio_dev_opaque->chan_attr_group.attrs)'?
>
> I don't think it's related (but you can tell that this check related to
> the allocator, and since we touch it, we may touch this), if Jonathan
> wants this, I definitely do.

Fair enough...

- Nuno Sá