Re: [PATCH 28/38] Annotate hardware config module parameters in drivers/staging/media/

[Mauro Carvalho Chehab]

Em Wed, 05 Apr 2017 18:01:01 +0100
David Howells  escreveu:

> 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/staging/media/.
> 
> Suggested-by: Alan Cox 
> Signed-off-by: David Howells 
> cc: Mauro Carvalho Chehab 

Acked-by: Mauro Carvalho Chehab 

> cc: Greg Kroah-Hartman 
> cc: linux-media@vger.kernel.org
> cc: de...@driverdev.osuosl.org
> ---
> 
>  drivers/staging/media/lirc/lirc_sir.c |4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/staging/media/lirc/lirc_sir.c 
> b/drivers/staging/media/lirc/lirc_sir.c
> index c6c3de94adaa..dde46dd8cabb 100644
> --- a/drivers/staging/media/lirc/lirc_sir.c
> +++ b/drivers/staging/media/lirc/lirc_sir.c
> @@ -826,10 +826,10 @@ MODULE_AUTHOR("Milan Pikula");
>  #endif
>  MODULE_LICENSE("GPL");
>  
> -module_param(io, int, S_IRUGO);
> +module_param_hw(io, int, ioport, S_IRUGO);
>  MODULE_PARM_DESC(io, "I/O address base (0x3f8 or 0x2f8)");
>  
> -module_param(irq, int, S_IRUGO);
> +module_param_hw(irq, int, irq, S_IRUGO);
>  MODULE_PARM_DESC(irq, "Interrupt (4 or 3)");
>  
>  module_param(threshold, int, S_IRUGO);
> 



Thanks,
Mauro

Re: [PATCH 28/38] Annotate hardware config module parameters in drivers/staging/media/

[Greg KH]

On Wed, Apr 05, 2017 at 06:01:01PM +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/staging/media/.
> 
> Suggested-by: Alan Cox 
> Signed-off-by: David Howells 
> cc: Mauro Carvalho Chehab 
> cc: Greg Kroah-Hartman 
> cc: linux-media@vger.kernel.org
> cc: de...@driverdev.osuosl.org

Acked-by: Greg Kroah-Hartman 

[PATCH 28/38] Annotate hardware config module parameters in drivers/staging/media/

[David Howells]

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/staging/media/.

Suggested-by: Alan Cox 
Signed-off-by: David Howells 
cc: Mauro Carvalho Chehab 
cc: Greg Kroah-Hartman 
cc: linux-media@vger.kernel.org
cc: de...@driverdev.osuosl.org
---

 drivers/staging/media/lirc/lirc_sir.c |4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/staging/media/lirc/lirc_sir.c 
b/drivers/staging/media/lirc/lirc_sir.c
index c6c3de94adaa..dde46dd8cabb 100644
--- a/drivers/staging/media/lirc/lirc_sir.c
+++ b/drivers/staging/media/lirc/lirc_sir.c
@@ -826,10 +826,10 @@ MODULE_AUTHOR("Milan Pikula");
 #endif
 MODULE_LICENSE("GPL");
 
-module_param(io, int, S_IRUGO);
+module_param_hw(io, int, ioport, S_IRUGO);
 MODULE_PARM_DESC(io, "I/O address base (0x3f8 or 0x2f8)");
 
-module_param(irq, int, S_IRUGO);
+module_param_hw(irq, int, irq, S_IRUGO);
 MODULE_PARM_DESC(irq, "Interrupt (4 or 3)");
 
 module_param(threshold, int, S_IRUGO);