Re: [PATCH 08/39] Annotate hardware config module parameters in drivers/gpio/

[William Breathitt Gray]

On Thu, Dec 01, 2016 at 12:30:40PM +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/gpio/.
>
>Suggested-by: One Thousand Gnomes <gnomes@xxxxxxxxxxxxxxxxxxx>
>Signed-off-by: David Howells <dhowells@xxxxxxxxxx>
>cc: William Breathitt Gray <vilhelm.gray@xxxxxxxxx>
>cc: Linus Walleij <linus.walleij@xxxxxxxxxx>
>cc: Alexandre Courbot <gnurou@xxxxxxxxx>
>cc: linux-gpio@xxxxxxxxxxxxxxx

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

>---
>
> drivers/gpio/gpio-104-dio-48e.c |    4 ++--
> drivers/gpio/gpio-104-idi-48.c  |    4 ++--
> drivers/gpio/gpio-104-idio-16.c |    4 ++--
> drivers/gpio/gpio-gpio-mm.c     |    2 +-
> drivers/gpio/gpio-ws16c48.c     |    4 ++--
> 5 files changed, 9 insertions(+), 9 deletions(-)
>
>diff --git a/drivers/gpio/gpio-104-dio-48e.c b/drivers/gpio/gpio-104-dio-48e.c
>index fcf776971ca9..1c334eed5821 100644
>--- a/drivers/gpio/gpio-104-dio-48e.c
>+++ b/drivers/gpio/gpio-104-dio-48e.c
>@@ -33,11 +33,11 @@
> 
> static unsigned int base[MAX_NUM_DIO48E];
> static unsigned int num_dio48e;
>-module_param_array(base, uint, &num_dio48e, 0);
>+module_param_hw_array(base, uint, ioport, &num_dio48e, 0);
> MODULE_PARM_DESC(base, "ACCES 104-DIO-48E base addresses");
> 
> static unsigned int irq[MAX_NUM_DIO48E];
>-module_param_array(irq, uint, NULL, 0);
>+module_param_hw_array(irq, uint, irq, NULL, 0);
> MODULE_PARM_DESC(irq, "ACCES 104-DIO-48E interrupt line numbers");
> 
> /**
>diff --git a/drivers/gpio/gpio-104-idi-48.c b/drivers/gpio/gpio-104-idi-48.c
>index 2d2763ea1a68..6639920b3299 100644
>--- a/drivers/gpio/gpio-104-idi-48.c
>+++ b/drivers/gpio/gpio-104-idi-48.c
>@@ -33,11 +33,11 @@
> 
> static unsigned int base[MAX_NUM_IDI_48];
> static unsigned int num_idi_48;
>-module_param_array(base, uint, &num_idi_48, 0);
>+module_param_hw_array(base, uint, ioport, &num_idi_48, 0);
> MODULE_PARM_DESC(base, "ACCES 104-IDI-48 base addresses");
> 
> static unsigned int irq[MAX_NUM_IDI_48];
>-module_param_array(irq, uint, NULL, 0);
>+module_param_hw_array(irq, uint, irq, NULL, 0);
> MODULE_PARM_DESC(irq, "ACCES 104-IDI-48 interrupt line numbers");
> 
> /**
>diff --git a/drivers/gpio/gpio-104-idio-16.c b/drivers/gpio/gpio-104-idio-16.c
>index 6787b8fcf0d8..6d7024ac2689 100644
>--- a/drivers/gpio/gpio-104-idio-16.c
>+++ b/drivers/gpio/gpio-104-idio-16.c
>@@ -33,11 +33,11 @@
> 
> static unsigned int base[MAX_NUM_IDIO_16];
> static unsigned int num_idio_16;
>-module_param_array(base, uint, &num_idio_16, 0);
>+module_param_hw_array(base, uint, ioport, &num_idio_16, 0);
> MODULE_PARM_DESC(base, "ACCES 104-IDIO-16 base addresses");
> 
> static unsigned int irq[MAX_NUM_IDIO_16];
>-module_param_array(irq, uint, NULL, 0);
>+module_param_hw_array(irq, uint, irq, NULL, 0);
> MODULE_PARM_DESC(irq, "ACCES 104-IDIO-16 interrupt line numbers");
> 
> /**
>diff --git a/drivers/gpio/gpio-gpio-mm.c b/drivers/gpio/gpio-gpio-mm.c
>index 1e7def9449ce..4ac2179b96ad 100644
>--- a/drivers/gpio/gpio-gpio-mm.c
>+++ b/drivers/gpio/gpio-gpio-mm.c
>@@ -31,7 +31,7 @@
> 
> static unsigned int base[MAX_NUM_GPIOMM];
> static unsigned int num_gpiomm;
>-module_param_array(base, uint, &num_gpiomm, 0);
>+module_param_hw_array(base, uint, ioport, &num_gpiomm, 0);
> MODULE_PARM_DESC(base, "Diamond Systems GPIO-MM base addresses");
> 
> /**
>diff --git a/drivers/gpio/gpio-ws16c48.c b/drivers/gpio/gpio-ws16c48.c
>index eaa71d440ccf..c84d600a8bb0 100644
>--- a/drivers/gpio/gpio-ws16c48.c
>+++ b/drivers/gpio/gpio-ws16c48.c
>@@ -30,11 +30,11 @@
> 
> static unsigned int base[MAX_NUM_WS16C48];
> static unsigned int num_ws16c48;
>-module_param_array(base, uint, &num_ws16c48, 0);
>+module_param_hw_array(base, uint, ioport, &num_ws16c48, 0);
> MODULE_PARM_DESC(base, "WinSystems WS16C48 base addresses");
> 
> static unsigned int irq[MAX_NUM_WS16C48];
>-module_param_array(irq, uint, NULL, 0);
>+module_param_hw_array(irq, uint, irq, NULL, 0);
> MODULE_PARM_DESC(irq, "WinSystems WS16C48 interrupt line numbers");
> 
> /**
>