• David Howells's avatar
    Annotate hardware config module parameters in drivers/misc/ · 4f1927dc
    David Howells authored
    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/misc/.
    Suggested-by: default avatarAlan Cox <gnomes@lxorguk.ukuu.org.uk>
    Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
    Acked-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
    cc: Arnd Bergmann <arnd@arndb.de>
    4f1927dc
dummy-irq.c 1.51 KB