Re: [PATCH] gpio: sim: set a limit on the number of GPIOs

[Bartosz Golaszewski]

On Mon, Dec 12, 2022 at 2:07 PM Bartosz Golaszewski <brgl@xxxxxxxx> wrote:
>
> From: Bartosz Golaszewski <bartosz.golaszewski@xxxxxxxxxx>
>
> With the removal of ARCH_NR_GPIOS in commit 7b61212f2a07 ("gpiolib: Get
> rid of ARCH_NR_GPIOS") the gpiolib core no longer sanitizes the number
> of GPIOs for us. This causes the gpio-sim selftests to now fail when
> setting the number of GPIOs to 99999 and expecting the probe() to fail.
>
> Set a sane limit of 1024 on the number of simulated GPIOs and bail out
> of probe if it's exceeded.
>
> Reported-by: kernel test robot <oliver.sang@xxxxxxxxx>
> Link: https://lore.kernel.org/oe-lkp/202212112236.756f5db9-oliver.sang@xxxxxxxxx
> Fixes: 7b61212f2a07 ("gpiolib: Get rid of ARCH_NR_GPIOS")
> Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@xxxxxxxxxx>
> ---
>  drivers/gpio/gpio-sim.c | 4 ++++
>  1 file changed, 4 insertions(+)
>
> diff --git a/drivers/gpio/gpio-sim.c b/drivers/gpio/gpio-sim.c
> index 1020c2feb249..60514bc5454f 100644
> --- a/drivers/gpio/gpio-sim.c
> +++ b/drivers/gpio/gpio-sim.c
> @@ -31,6 +31,7 @@
>
>  #include "gpiolib.h"
>
> +#define GPIO_SIM_NGPIO_MAX     1024
>  #define GPIO_SIM_PROP_MAX      4 /* Max 3 properties + sentinel. */
>  #define GPIO_SIM_NUM_ATTRS     3 /* value, pull and sentinel */
>
> @@ -371,6 +372,9 @@ static int gpio_sim_add_bank(struct fwnode_handle *swnode, struct device *dev)
>         if (ret)
>                 return ret;
>
> +       if (num_lines > GPIO_SIM_NGPIO_MAX)
> +               return -ERANGE;
> +
>         ret = fwnode_property_read_string(swnode, "gpio-sim,label", &label);
>         if (ret) {
>                 label = devm_kasprintf(dev, GFP_KERNEL, "%s-%s",
> --
> 2.37.2
>

Applied this, as it needs to go into the big PR for this merge window.

Bart