[PATCH 36/47][X] Annotate hardware config module parameters in drivers/video/

Seth Forshee seth.forshee at canonical.com
Thu Jun 18 23:12:47 UTC 2020


From: David Howells <dhowells at redhat.com>

BugLink: https://bugs.launchpad.net/bugs/1884159

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/video/.

Suggested-by: Alan Cox <gnomes at lxorguk.ukuu.org.uk>
Signed-off-by: David Howells <dhowells at redhat.com>
Acked-by: Bartlomiej Zolnierkiewicz <b.zolnierkie at samsung.com>
cc: Tomi Valkeinen <tomi.valkeinen at ti.com>
cc: linux-fbdev at vger.kernel.org
(cherry picked from commit c729203defa7e6672ff6a5e503066351ac3928cb)
Signed-off-by: Seth Forshee <seth.forshee at canonical.com>
---
 drivers/video/fbdev/arcfb.c | 8 ++++----
 drivers/video/fbdev/n411.c  | 6 +++---
 2 files changed, 7 insertions(+), 7 deletions(-)

diff --git a/drivers/video/fbdev/arcfb.c b/drivers/video/fbdev/arcfb.c
index 1b0b233b8b39..875496d277cd 100644
--- a/drivers/video/fbdev/arcfb.c
+++ b/drivers/video/fbdev/arcfb.c
@@ -645,17 +645,17 @@ module_param(nosplash, uint, 0);
 MODULE_PARM_DESC(nosplash, "Disable doing the splash screen");
 module_param(arcfb_enable, uint, 0);
 MODULE_PARM_DESC(arcfb_enable, "Enable communication with Arc board");
-module_param(dio_addr, ulong, 0);
+module_param_hw(dio_addr, ulong, ioport, 0);
 MODULE_PARM_DESC(dio_addr, "IO address for data, eg: 0x480");
-module_param(cio_addr, ulong, 0);
+module_param_hw(cio_addr, ulong, ioport, 0);
 MODULE_PARM_DESC(cio_addr, "IO address for control, eg: 0x400");
-module_param(c2io_addr, ulong, 0);
+module_param_hw(c2io_addr, ulong, ioport, 0);
 MODULE_PARM_DESC(c2io_addr, "IO address for secondary control, eg: 0x408");
 module_param(splashval, ulong, 0);
 MODULE_PARM_DESC(splashval, "Splash pattern: 0xFF is black, 0x00 is green");
 module_param(tuhold, ulong, 0);
 MODULE_PARM_DESC(tuhold, "Time to hold between strobing data to Arc board");
-module_param(irq, uint, 0);
+module_param_hw(irq, uint, irq, 0);
 MODULE_PARM_DESC(irq, "IRQ for the Arc board");
 
 module_init(arcfb_init);
diff --git a/drivers/video/fbdev/n411.c b/drivers/video/fbdev/n411.c
index 935830fea7b6..5383d70f0ce7 100644
--- a/drivers/video/fbdev/n411.c
+++ b/drivers/video/fbdev/n411.c
@@ -187,11 +187,11 @@ module_exit(n411_exit);
 
 module_param(nosplash, uint, 0);
 MODULE_PARM_DESC(nosplash, "Disable doing the splash screen");
-module_param(dio_addr, ulong, 0);
+module_param_hw(dio_addr, ulong, ioport, 0);
 MODULE_PARM_DESC(dio_addr, "IO address for data, eg: 0x480");
-module_param(cio_addr, ulong, 0);
+module_param_hw(cio_addr, ulong, ioport, 0);
 MODULE_PARM_DESC(cio_addr, "IO address for control, eg: 0x400");
-module_param(c2io_addr, ulong, 0);
+module_param_hw(c2io_addr, ulong, ioport, 0);
 MODULE_PARM_DESC(c2io_addr, "IO address for secondary control, eg: 0x408");
 module_param(splashval, ulong, 0);
 MODULE_PARM_DESC(splashval, "Splash pattern: 0x00 is black, 0x01 is white");
-- 
2.27.0




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