Re: [PATCH 08/39] Annotate hardware config module parameters in drivers/gpio/

[Linus Walleij]

On Thu, Dec 1, 2016 at 1:30 PM, David Howells <dhowells@xxxxxxxxxx> wrote:

> When the kernel is running in secure boot mode, we lock down the kernel to
> prevent userspace from modifying the running kernel image.  Whilst this
> includes prohibiting access to things like /dev/mem, it must also prevent
> access by means of configuring driver modules in such a way as to cause a
> device to access or modify the kernel image.
>
> To this end, annotate module_param* statements that refer to hardware
> configuration and indicate for future reference what type of parameter they
> specify.  The parameter parser in the core sees this information and can
> skip such parameters with an error message if the kernel is locked down.
> The module initialisation then runs as normal, but just sees whatever the
> default values for those parameters is.
>
> Note that we do still need to do the module initialisation because some
> drivers have viable defaults set in case parameters aren't specified and
> some drivers support automatic configuration (e.g. PNP or PCI) in addition
> to manually coded parameters.
>
> This patch annotates drivers in drivers/gpio/.
>
> Suggested-by: One Thousand Gnomes <gnomes@xxxxxxxxxxxxxxxxxxx>
> Signed-off-by: David Howells <dhowells@xxxxxxxxxx>
> cc: William Breathitt Gray <vilhelm.gray@xxxxxxxxx>
> cc: Linus Walleij <linus.walleij@xxxxxxxxxx>
> cc: Alexandre Courbot <gnurou@xxxxxxxxx>
> cc: linux-gpio@xxxxxxxxxxxxxxx

Acked-by: Linus Walleij <linus.walleij@xxxxxxxxxx>

Yours,
Linus Walleij