[PATCH v2 35/57][B] Annotate hardware config module parameters in drivers/tty/

Seth Forshee seth.forshee at canonical.com
Fri Jun 19 16:15:59 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/tty/.

Suggested-by: Alan Cox <gnomes at lxorguk.ukuu.org.uk>
Signed-off-by: David Howells <dhowells at redhat.com>
Acked-by: Greg Kroah-Hartman <gregkh at linuxfoundation.org>
cc: Jiri Slaby <jslaby at suse.com>
cc: linux-serial at vger.kernel.org
(backported from commit 3b60daf86b133f0b15e3eb9b767c6c1752af2bd6)
Signed-off-by: Seth Forshee <seth.forshee at canonical.com>
---
 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(-)

diff --git a/drivers/tty/cyclades.c b/drivers/tty/cyclades.c
index d4a1331675ed..cfd1b7f5179c 100644
--- a/drivers/tty/cyclades.c
+++ b/drivers/tty/cyclades.c
@@ -158,8 +158,8 @@ 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 14c54e041065..2ff6a13062d8 100644
--- a/drivers/tty/moxa.c
+++ b/drivers/tty/moxa.c
@@ -180,7 +180,7 @@ 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 4c4a23674569..935e9a9fb020 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 0d3cc3324f46..e8a65ed4bb2c 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 39126460c1f5..3305b7b1e4cf 100644
--- a/drivers/tty/serial/8250/8250_core.c
+++ b/drivers/tty/serial/8250/8250_core.c
@@ -1173,7 +1173,7 @@ EXPORT_SYMBOL(serial8250_resume_port);
 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)");
 
@@ -1184,7 +1184,7 @@ 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 6188059fd523..0a4416b2ce63 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);
-- 
2.27.0




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