[PATCH v2 28/57][B] Annotate hardware config module parameters in drivers/parport/

Seth Forshee seth.forshee at canonical.com
Fri Jun 19 16:15:52 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/parport/.

Suggested-by: Alan Cox <gnomes at lxorguk.ukuu.org.uk>
Signed-off-by: David Howells <dhowells at redhat.com>
cc: Sudip Mukherjee <sudipm.mukherjee at gmail.com>
(cherry picked from commit c8fc074dd388112890684b614be1e58335890b27)
Signed-off-by: Seth Forshee <seth.forshee at canonical.com>
---
 drivers/parport/parport_pc.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/parport/parport_pc.c b/drivers/parport/parport_pc.c
index 02e6485c1ed5..6520c4041bf7 100644
--- a/drivers/parport/parport_pc.c
+++ b/drivers/parport/parport_pc.c
@@ -3154,13 +3154,13 @@ static char *irq[PARPORT_PC_MAX_PORTS];
 static char *dma[PARPORT_PC_MAX_PORTS];
 
 MODULE_PARM_DESC(io, "Base I/O address (SPP regs)");
-module_param_array(io, int, NULL, 0);
+module_param_hw_array(io, int, ioport, NULL, 0);
 MODULE_PARM_DESC(io_hi, "Base I/O address (ECR)");
-module_param_array(io_hi, int, NULL, 0);
+module_param_hw_array(io_hi, int, ioport, NULL, 0);
 MODULE_PARM_DESC(irq, "IRQ line");
-module_param_array(irq, charp, NULL, 0);
+module_param_hw_array(irq, charp, irq, NULL, 0);
 MODULE_PARM_DESC(dma, "DMA channel");
-module_param_array(dma, charp, NULL, 0);
+module_param_hw_array(dma, charp, dma, NULL, 0);
 #if defined(CONFIG_PARPORT_PC_SUPERIO) || \
        (defined(CONFIG_PARPORT_1284) && defined(CONFIG_PARPORT_PC_FIFO))
 MODULE_PARM_DESC(verbose_probing, "Log chit-chat during initialisation");
-- 
2.27.0




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