Re: [PATCH 32/39] Annotate hardware config module parameters in drivers/tty/

From: Greg Kroah-Hartman
Date: Thu Dec 01 2016 - 10:02:49 EST


On Thu, Dec 01, 2016 at 12:33:54PM +0000, David Howells 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/tty/.
>
> Suggested-by: One Thousand Gnomes <gnomes@xxxxxxxxxxxxxxxxxxx>
> Signed-off-by: David Howells <dhowells@xxxxxxxxxx>
> cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
> cc: Jiri Slaby <jslaby@xxxxxxxx>
> cc: linux-serial@xxxxxxxxxxxxxxx
> ---
>
> drivers/tty/cyclades.c | 4 ++--
> drivers/tty/moxa.c | 2 +-
> drivers/tty/mxser.c | 2 +-
> drivers/tty/rocket.c | 10 +++++-----
> drivers/tty/serial/8250/8250_core.c | 4 ++--
> drivers/tty/synclink.c | 6 +++---
> 6 files changed, 14 insertions(+), 14 deletions(-)

NAK, see my response to patch 1 of this series.

thanks,

greg k-h