Re: [PATCH] gpio: sim: quietly ignore configured lines outside the bank

[Bartosz Golaszewski]

On Wed, Jun 7, 2023 at 8:50 AM Kent Gibson <warthog618@xxxxxxxxx> wrote:
>
> The user-space policy of the gpio-sim is that configuration for lines
> with offsets outside the bounds of the corresponding bank is ignored,
> but gpio-sim is still using that configuration when constructing the
> sim.  In the case of named lines this results in temporarily allocating
> space for names that are not used, and for hogs results in errors being
> logged when the gpio-sim attempts to register the out of range hog with
> gpiolib:
>
> gpiochip_machine_hog: unable to get GPIO desc: -22
>
> Add checks to filter out any line configuration outside the bounds
> of the bank when constructing the sim.
>
> Signed-off-by: Kent Gibson <warthog618@xxxxxxxxx>
> ---
>
> This is based on for-next patched with my recent memory corruption fix,
> as it touches a bit of the same code.
>
> Cheers,
> Kent.
>
>  drivers/gpio/gpio-sim.c | 12 ++++++++++++
>  1 file changed, 12 insertions(+)
>
> diff --git a/drivers/gpio/gpio-sim.c b/drivers/gpio/gpio-sim.c
> index fab67a5785d7..8b49b0abacd5 100644
> --- a/drivers/gpio/gpio-sim.c
> +++ b/drivers/gpio/gpio-sim.c
> @@ -696,6 +696,9 @@ static char **gpio_sim_make_line_names(struct gpio_sim_bank *bank,
>         char **line_names;
>
>         list_for_each_entry(line, &bank->line_list, siblings) {
> +               if (line->offset >= bank->num_lines)
> +                       continue;
> +
>                 if (line->name) {
>                         if (line->offset > max_offset)
>                                 max_offset = line->offset;
> @@ -722,6 +725,9 @@ static char **gpio_sim_make_line_names(struct gpio_sim_bank *bank,
>                 return ERR_PTR(-ENOMEM);
>
>         list_for_each_entry(line, &bank->line_list, siblings) {
> +               if (line->offset >= bank->num_lines)
> +                       continue;
> +
>                 if (line->name && (line->offset <= max_offset))
>                         line_names[line->offset] = line->name;
>         }
> @@ -756,6 +762,9 @@ static int gpio_sim_add_hogs(struct gpio_sim_device *dev)
>
>         list_for_each_entry(bank, &dev->bank_list, siblings) {
>                 list_for_each_entry(line, &bank->line_list, siblings) {
> +                       if (line->offset >= bank->num_lines)
> +                               continue;
> +
>                         if (line->hog)
>                                 num_hogs++;
>                 }
> @@ -771,6 +780,9 @@ static int gpio_sim_add_hogs(struct gpio_sim_device *dev)
>
>         list_for_each_entry(bank, &dev->bank_list, siblings) {
>                 list_for_each_entry(line, &bank->line_list, siblings) {
> +                       if (line->offset >= bank->num_lines)
> +                               continue;
> +
>                         if (!line->hog)
>                                 continue;
>
>
> base-commit: ba65c79fbb813423e7d42d99375e2045b27958a6
> prerequisite-patch-id: d89da2e3b7511c5b8132a379b12e4996256ac214
> --
> 2.40.1
>

I queued this for fixes, thanks!

Bart