diff mbox

[10/39] Annotate hardware config module parameters in drivers/iio/

Message ID 148059545558.31612.1279403857733187213.stgit@warthog.procyon.org.uk
State New
Headers show

Commit Message

David Howells Dec. 1, 2016, 12:30 p.m. UTC
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/iio/.

Suggested-by: One Thousand Gnomes <gnomes@lxorguk.ukuu.org.uk>
Signed-off-by: David Howells <dhowells@redhat.com>
cc: William Breathitt Gray <vilhelm.gray@gmail.com>
cc: Jonathan Cameron <jic23@kernel.org>
cc: linux-iio@vger.kernel.org
---

 drivers/iio/adc/stx104.c  |    2 +-
 drivers/iio/dac/cio-dac.c |    2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)


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Comments

William Breathitt Gray Dec. 1, 2016, 1:50 p.m. UTC | #1
On Thu, Dec 01, 2016 at 12:30:55PM +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/iio/.
>
>Suggested-by: One Thousand Gnomes <gnomes@lxorguk.ukuu.org.uk>
>Signed-off-by: David Howells <dhowells@redhat.com>
>cc: William Breathitt Gray <vilhelm.gray@gmail.com>
>cc: Jonathan Cameron <jic23@kernel.org>
>cc: linux-iio@vger.kernel.org

Acked-by: William Breathitt Gray <vilhelm.gray@gmail.com>

>---
>
> drivers/iio/adc/stx104.c  |    2 +-
> drivers/iio/dac/cio-dac.c |    2 +-
> 2 files changed, 2 insertions(+), 2 deletions(-)
>
>diff --git a/drivers/iio/adc/stx104.c b/drivers/iio/adc/stx104.c
>index 7e3645749eaf..a805bd543acb 100644
>--- a/drivers/iio/adc/stx104.c
>+++ b/drivers/iio/adc/stx104.c
>@@ -49,7 +49,7 @@
> 
> static unsigned int base[max_num_isa_dev(STX104_EXTENT)];
> static unsigned int num_stx104;
>-module_param_array(base, uint, &num_stx104, 0);
>+module_param_hw_array(base, uint, ioport, &num_stx104, 0);
> MODULE_PARM_DESC(base, "Apex Embedded Systems STX104 base addresses");
> 
> /**
>diff --git a/drivers/iio/dac/cio-dac.c b/drivers/iio/dac/cio-dac.c
>index 5a743e2a779d..dac086129edf 100644
>--- a/drivers/iio/dac/cio-dac.c
>+++ b/drivers/iio/dac/cio-dac.c
>@@ -39,7 +39,7 @@
> 
> static unsigned int base[max_num_isa_dev(CIO_DAC_EXTENT)];
> static unsigned int num_cio_dac;
>-module_param_array(base, uint, &num_cio_dac, 0);
>+module_param_hw_array(base, uint, ioport, &num_cio_dac, 0);
> MODULE_PARM_DESC(base, "Measurement Computing CIO-DAC base addresses");
> 
> /**
>
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Jonathan Cameron Dec. 3, 2016, 9:05 a.m. UTC | #2
On 01/12/16 13:50, William Breathitt Gray wrote:
> On Thu, Dec 01, 2016 at 12:30:55PM +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/iio/.
>>
>> Suggested-by: One Thousand Gnomes <gnomes@lxorguk.ukuu.org.uk>
>> Signed-off-by: David Howells <dhowells@redhat.com>
>> cc: William Breathitt Gray <vilhelm.gray@gmail.com>
>> cc: Jonathan Cameron <jic23@kernel.org>
>> cc: linux-iio@vger.kernel.org
> 
> Acked-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Hi David,

I'm on a train so can't check the original thread right now (and will probably
forget to do so later!). I am guessing the new functions are introduced
earlier in the series?  Hence for now I'll assume you want to merge
this lot in one go.

Acked-by: Jonathan Cameron <jic23@kernel.org>

Shout if you want me to take this via the IIO tree after the merge window
closes.

Thanks,

Jonathan
> 
>> ---
>>
>> drivers/iio/adc/stx104.c  |    2 +-
>> drivers/iio/dac/cio-dac.c |    2 +-
>> 2 files changed, 2 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/iio/adc/stx104.c b/drivers/iio/adc/stx104.c
>> index 7e3645749eaf..a805bd543acb 100644
>> --- a/drivers/iio/adc/stx104.c
>> +++ b/drivers/iio/adc/stx104.c
>> @@ -49,7 +49,7 @@
>>
>> static unsigned int base[max_num_isa_dev(STX104_EXTENT)];
>> static unsigned int num_stx104;
>> -module_param_array(base, uint, &num_stx104, 0);
>> +module_param_hw_array(base, uint, ioport, &num_stx104, 0);
>> MODULE_PARM_DESC(base, "Apex Embedded Systems STX104 base addresses");
>>
>> /**
>> diff --git a/drivers/iio/dac/cio-dac.c b/drivers/iio/dac/cio-dac.c
>> index 5a743e2a779d..dac086129edf 100644
>> --- a/drivers/iio/dac/cio-dac.c
>> +++ b/drivers/iio/dac/cio-dac.c
>> @@ -39,7 +39,7 @@
>>
>> static unsigned int base[max_num_isa_dev(CIO_DAC_EXTENT)];
>> static unsigned int num_cio_dac;
>> -module_param_array(base, uint, &num_cio_dac, 0);
>> +module_param_hw_array(base, uint, ioport, &num_cio_dac, 0);
>> MODULE_PARM_DESC(base, "Measurement Computing CIO-DAC base addresses");
>>
>> /**
>>
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David Howells Dec. 7, 2016, 1:43 p.m. UTC | #3
Jonathan Cameron <jic23@kernel.org> wrote:

> I'm on a train so can't check the original thread right now (and will probably
> forget to do so later!). I am guessing the new functions are introduced
> earlier in the series?

Yeah, patch 1 is a prerequisite for all the subsequent patches.

> Hence for now I'll assume you want to merge this lot in one go.

I'll see if I can get patch 1 in and then distribute the other patches.

David
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diff mbox

Patch

diff --git a/drivers/iio/adc/stx104.c b/drivers/iio/adc/stx104.c
index 7e3645749eaf..a805bd543acb 100644
--- a/drivers/iio/adc/stx104.c
+++ b/drivers/iio/adc/stx104.c
@@ -49,7 +49,7 @@ 
 
 static unsigned int base[max_num_isa_dev(STX104_EXTENT)];
 static unsigned int num_stx104;
-module_param_array(base, uint, &num_stx104, 0);
+module_param_hw_array(base, uint, ioport, &num_stx104, 0);
 MODULE_PARM_DESC(base, "Apex Embedded Systems STX104 base addresses");
 
 /**
diff --git a/drivers/iio/dac/cio-dac.c b/drivers/iio/dac/cio-dac.c
index 5a743e2a779d..dac086129edf 100644
--- a/drivers/iio/dac/cio-dac.c
+++ b/drivers/iio/dac/cio-dac.c
@@ -39,7 +39,7 @@ 
 
 static unsigned int base[max_num_isa_dev(CIO_DAC_EXTENT)];
 static unsigned int num_cio_dac;
-module_param_array(base, uint, &num_cio_dac, 0);
+module_param_hw_array(base, uint, ioport, &num_cio_dac, 0);
 MODULE_PARM_DESC(base, "Measurement Computing CIO-DAC base addresses");
 
 /**