Messages in this thread | | | Date | Mon, 10 Apr 2017 16:03:16 +0530 | From | Viresh Kumar <> | Subject | Re: [PATCH 07/38] Annotate hardware config module parameters in drivers/cpufreq/ |
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On 05-04-17, 17:57, 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/cpufreq/. > > Suggested-by: Alan Cox <gnomes@lxorguk.ukuu.org.uk> > Signed-off-by: David Howells <dhowells@redhat.com> > Acked-by: "Rafael J. Wysocki" <rjw@rjwysocki.net> > cc: Viresh Kumar <viresh.kumar@linaro.org> > cc: linux-pm@vger.kernel.org > --- > > drivers/cpufreq/speedstep-smi.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/cpufreq/speedstep-smi.c b/drivers/cpufreq/speedstep-smi.c > index 770a9ae1999a..37b30071c220 100644 > --- a/drivers/cpufreq/speedstep-smi.c > +++ b/drivers/cpufreq/speedstep-smi.c > @@ -378,7 +378,7 @@ static void __exit speedstep_exit(void) > cpufreq_unregister_driver(&speedstep_driver); > } > > -module_param(smi_port, int, 0444); > +module_param_hw(smi_port, int, ioport, 0444); > module_param(smi_cmd, int, 0444); > module_param(smi_sig, uint, 0444); >
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
-- viresh
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