Re: [PATCH v5 0/5] gpio: Add GPIO Aggregator

From: Geert Uytterhoeven
Date: Fri Feb 21 2020 - 11:39:34 EST

Hi Linus and Bartosz,

On Tue, Feb 18, 2020 at 4:18 PM Geert Uytterhoeven
<geert+renesas@xxxxxxxxx> wrote:
> GPIO controllers are exported to userspace using /dev/gpiochip*
> character devices. Access control to these devices is provided by
> standard UNIX file system permissions, on an all-or-nothing basis:
> either a GPIO controller is accessible for a user, or it is not.
> Currently no mechanism exists to control access to individual GPIOs.
> Hence this adds a GPIO driver to aggregate existing GPIOs, and expose
> them as a new gpiochip. This is useful for implementing access control,
> and assigning a set of GPIOs to a specific user. Furthermore, this
> simplifies and hardens exporting GPIOs to a virtual machine, as the VM
> can just grab the full GPIO controller, and no longer needs to care
> about which GPIOs to grab and which not, reducing the attack surface.

Do you have any more comments, before I respin and post v6?

Thanks, and have a niec weekend!



Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds