| Date | Sat, 8 Apr 2017 17:23:23 +0200 | From | Greg KH <> | Subject | Re: [PATCH 05/38] Annotate hardware config module parameters in drivers/char/ |
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On Wed, Apr 05, 2017 at 05:57:30PM +0100, 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/char/. > > Suggested-by: Alan Cox <gnomes@lxorguk.ukuu.org.uk> > Signed-off-by: David Howells <dhowells@redhat.com> > cc: Arnd Bergmann <arnd@arndb.de> > cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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