Re: [PATCH 2/2] auxdisplay: charlcd: checking for pointer reference before dereferencing

[Miguel Ojeda]

On Sun, Nov 7, 2021 at 4:03 PM Luiz Sampaio <sampaio.ime@xxxxxxxxx> wrote:
>
> Check if the pointer lcd->ops->init_display exists before dereferencing it.
> If a driver called charlcd_init() without defining the ops, this would
> return segmentation fault, as happened to me when implementing a charlcd
> driver.  Checking the pointer before dereferencing protects from
> segmentation fault.

It can't hurt -- thanks! I think `EINVAL` makes more sense here, also
we could use `WARN_ON`:

    if (WARN_ON(!lcd->ops->init_display))
        return -EINVAL;

Cheers,
Miguel