Re: [PATCH 2/2] gpiolib: cdev: export the consumer's PID

From: Andy Shevchenko
Date: Fri Sep 09 2022 - 09:48:12 EST


On Fri, Sep 09, 2022 at 02:13:29PM +0200, Bartosz Golaszewski wrote:
> It's useful for user-space to be able to know the PIDs of processes
> holding GPIO lines in case they have the permissions and need to kill
> them.
>
> Extend the gpio_v2_line_info structure with the consumer_pid field
> that's set to the PID of the user-space process or 0 if the user lives
> in the kernel.

...

> +int gpiod_request(struct gpio_desc *desc, const char *label)
> +{
> + return gpiod_request_with_pid(desc, label, 0);

Why not -1? I would expect this is the usual way of telling
"don't use this PID".

> +}

...

> + desc_set_pid(desc, 0);

Ditto.

...

> + ret = gpiod_request_commit(desc, label, 0);

Ditto.

--
With Best Regards,
Andy Shevchenko