[31/38] Annotate hardware config module parameters in drivers/tty/

Commit Message

David Howells April 5, 2017, 5:01 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/tty/.

Suggested-by: Alan Cox <[e-mail]>
Signed-off-by: David Howells <[e-mail]>
cc: Greg Kroah-Hartman <[e-mail]>
cc: Jiri Slaby <[e-mail]>
cc: [e-mail]
---

 drivers/tty/cyclades.c              |    4 ++--
 drivers/tty/moxa.c                  |    2 +-
 drivers/tty/mxser.c                 |    2 +-
 drivers/tty/rocket.c                |   10 +++++-----
 drivers/tty/serial/8250/8250_core.c |    4 ++--
 drivers/tty/synclink.c              |    6 +++---
 6 files changed, 14 insertions(+), 14 deletions(-)


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Comments

Greg Kroah-Hartman April 8, 2017, 3:19 p.m. UTC | #1

On Wed, Apr 05, 2017 at 06:01:26PM +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/tty/.
> 
> Suggested-by: Alan Cox <[e-mail]>
> Signed-off-by: David Howells <[e-mail]>
> cc: Greg Kroah-Hartman <[e-mail]>
> cc: Jiri Slaby <[e-mail]>
> cc: [e-mail]


Acked-by: Greg Kroah-Hartman <[e-mail]>
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Patch

diff --git a/drivers/tty/cyclades.c b/drivers/tty/cyclades.c
index 5e4fa9206861..104f09c58163 100644
--- a/drivers/tty/cyclades.c
+++ b/drivers/tty/cyclades.c
@@ -156,8 +156,8 @@  static unsigned int cy_isa_addresses[] = {
 static long maddr[NR_CARDS];
 static int irq[NR_CARDS];
 
-module_param_array(maddr, long, NULL, 0);
-module_param_array(irq, int, NULL, 0);
+module_param_hw_array(maddr, long, iomem, NULL, 0);
+module_param_hw_array(irq, int, irq, NULL, 0);
 
 #endif				/* CONFIG_ISA */
 
diff --git a/drivers/tty/moxa.c b/drivers/tty/moxa.c
index 4caf0c3b1f99..3b251f4e5df0 100644
--- a/drivers/tty/moxa.c
+++ b/drivers/tty/moxa.c
@@ -179,7 +179,7 @@  MODULE_FIRMWARE("c320tunx.cod");
 
 module_param_array(type, uint, NULL, 0);
 MODULE_PARM_DESC(type, "card type: C218=2, C320=4");
-module_param_array(baseaddr, ulong, NULL, 0);
+module_param_hw_array(baseaddr, ulong, ioport, NULL, 0);
 MODULE_PARM_DESC(baseaddr, "base address");
 module_param_array(numports, uint, NULL, 0);
 MODULE_PARM_DESC(numports, "numports (ignored for C218)");
diff --git a/drivers/tty/mxser.c b/drivers/tty/mxser.c
index 7b8f383fb090..8bd6fb6d9391 100644
--- a/drivers/tty/mxser.c
+++ b/drivers/tty/mxser.c
@@ -183,7 +183,7 @@  static int ttymajor = MXSERMAJOR;
 
 MODULE_AUTHOR("Casper Yang");
 MODULE_DESCRIPTION("MOXA Smartio/Industio Family Multiport Board Device Driver");
-module_param_array(ioaddr, ulong, NULL, 0);
+module_param_hw_array(ioaddr, ulong, ioport, NULL, 0);
 MODULE_PARM_DESC(ioaddr, "ISA io addresses to look for a moxa board");
 module_param(ttymajor, int, 0);
 MODULE_LICENSE("GPL");
diff --git a/drivers/tty/rocket.c b/drivers/tty/rocket.c
index d66c1edd9892..b51a877da986 100644
--- a/drivers/tty/rocket.c
+++ b/drivers/tty/rocket.c
@@ -250,15 +250,15 @@  static int sReadAiopNumChan(WordIO_t io);
 
 MODULE_AUTHOR("Theodore Ts'o");
 MODULE_DESCRIPTION("Comtrol RocketPort driver");
-module_param(board1, ulong, 0);
+module_param_hw(board1, ulong, ioport, 0);
 MODULE_PARM_DESC(board1, "I/O port for (ISA) board #1");
-module_param(board2, ulong, 0);
+module_param_hw(board2, ulong, ioport, 0);
 MODULE_PARM_DESC(board2, "I/O port for (ISA) board #2");
-module_param(board3, ulong, 0);
+module_param_hw(board3, ulong, ioport, 0);
 MODULE_PARM_DESC(board3, "I/O port for (ISA) board #3");
-module_param(board4, ulong, 0);
+module_param_hw(board4, ulong, ioport, 0);
 MODULE_PARM_DESC(board4, "I/O port for (ISA) board #4");
-module_param(controller, ulong, 0);
+module_param_hw(controller, ulong, ioport, 0);
 MODULE_PARM_DESC(controller, "I/O port for (ISA) rocketport controller");
 module_param(support_low_speed, bool, 0);
 MODULE_PARM_DESC(support_low_speed, "1 means support 50 baud, 0 means support 460400 baud");
diff --git a/drivers/tty/serial/8250/8250_core.c b/drivers/tty/serial/8250/8250_core.c
index 76e03a7de9cc..89fde17d9617 100644
--- a/drivers/tty/serial/8250/8250_core.c
+++ b/drivers/tty/serial/8250/8250_core.c
@@ -1191,7 +1191,7 @@  module_exit(serial8250_exit);
 MODULE_LICENSE("GPL");
 MODULE_DESCRIPTION("Generic 8250/16x50 serial driver");
 
-module_param(share_irqs, uint, 0644);
+module_param_hw(share_irqs, uint, other, 0644);
 MODULE_PARM_DESC(share_irqs, "Share IRQs with other non-8250/16x50 devices (unsafe)");
 
 module_param(nr_uarts, uint, 0644);
@@ -1201,7 +1201,7 @@  module_param(skip_txen_test, uint, 0644);
 MODULE_PARM_DESC(skip_txen_test, "Skip checking for the TXEN bug at init time");
 
 #ifdef CONFIG_SERIAL_8250_RSA
-module_param_array(probe_rsa, ulong, &probe_rsa_count, 0444);
+module_param_hw_array(probe_rsa, ulong, ioport, &probe_rsa_count, 0444);
 MODULE_PARM_DESC(probe_rsa, "Probe I/O ports for RSA");
 #endif
 MODULE_ALIAS_CHARDEV_MAJOR(TTY_MAJOR);
diff --git a/drivers/tty/synclink.c b/drivers/tty/synclink.c
index 657eed82eeb3..a2c308f7d637 100644
--- a/drivers/tty/synclink.c
+++ b/drivers/tty/synclink.c
@@ -869,9 +869,9 @@  static int txholdbufs[MAX_TOTAL_DEVICES];
 	
 module_param(break_on_load, bool, 0);
 module_param(ttymajor, int, 0);
-module_param_array(io, int, NULL, 0);
-module_param_array(irq, int, NULL, 0);
-module_param_array(dma, int, NULL, 0);
+module_param_hw_array(io, int, ioport, NULL, 0);
+module_param_hw_array(irq, int, irq, NULL, 0);
+module_param_hw_array(dma, int, dma, NULL, 0);
 module_param(debug_level, int, 0);
 module_param_array(maxframe, int, NULL, 0);
 module_param_array(txdmabufs, int, NULL, 0);