Re: [PATCH v4] gpio: sim: fix an invalid __free() usage

Kent Gibson
2023-09-19T07:37:36Z

On Tue, Sep 19, 2023 at 12:31:36AM -0700, brgl@bgdev.pl wrote:
> On Mon, 18 Sep 2023 17:31:36 +0200, Andy Shevchenko
> <andriy.shevchenko@linux.intel.com> said:
> > On Mon, Sep 18, 2023 at 04:55:33PM +0200, Bartosz Golaszewski wrote:
> >> From: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
> >>
> >> gpio_sim_make_line_names() returns NULL or ERR_PTR() so we must not use
> >> __free(kfree) on the returned address. Split this function into two, one
> >> that determines the size of the "gpio-line-names" array to allocate and
> >> one that actually sets the names at correct offsets. The allocation and
> >> assignment of the managed pointer happens in between.
> >
> > ...
> >
> >> + unsigned int size = 0;
> >>
> >> list_for_each_entry(line, &bank->line_list, siblings) {
> >> + if (!line->name || (line->offset >= bank->num_lines))
> >> continue;
> >>
> >> + size = line->offset + 1;
> >> }
> >>
> >> + return size;
> >
> > So, now the function iterates over all lines and returns the size of the last
> > match, correct?
> >
> > Why not
> >
> > list_for_each_entry_reversed() {
> > if (line->name && ())
> > break;
> > }
> >
> > return size;
> >
> > ?
>
> Because the line objects are not sorted by offset. They are added at the end
> of the list in the order the user creates their corresponding configfs groups.
>

Then your patch is also broken as it uses the last named entry,
not the named entry with the greatest offset??

Cheers,
Kent.