From: Stephen Chandler Paul <cpaul@xxxxxxxxxx> A big problem with the current i8042 debugging option is that it outputs data going to and from the keyboard by default. As a result, many dmesg logs uploaded by users will unintentionally contain sensitive information such as their password, as such it's probably a good idea not to output data coming from the keyboard unless specifically enabled by the user. Signed-off-by: Stephen Chandler Paul <cpaul@xxxxxxxxxx> --- Changes * Remove #ifdefs around notifier code * Rename i8042_port.filter_dbg to i8042.driver_bound * Instead of checking the parent of the current device, compare serio against i8042_ports[I8042_KBD_PORT_NO].serio * Use a switch case instead of an if-else when checking the action in the bus notifier * Export serio_bus into serio.h, register the bus notifiers at module load time as opposed to port registration time Documentation/kernel-parameters.txt | 3 +++ drivers/input/serio/i8042.c | 43 +++++++++++++++++++++++++++++++++---- drivers/input/serio/i8042.h | 13 +++++++++++ drivers/input/serio/serio.c | 4 +--- include/linux/serio.h | 2 ++ 5 files changed, 58 insertions(+), 7 deletions(-) diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index ae44749..a9d2b19 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -1304,6 +1304,9 @@ bytes respectively. Such letter suffixes can also be entirely omitted. <bus_id>,<clkrate> i8042.debug [HW] Toggle i8042 debug mode + i8042.debug_kbd [HW] Enable printing of interrupt data from the KBD port + (disabled by default, requires that i8042.debug=1 + be enabled) i8042.direct [HW] Put keyboard port into non-translated mode i8042.dumbkbd [HW] Pretend that controller can only read data from keyboard and cannot control its state diff --git a/drivers/input/serio/i8042.c b/drivers/input/serio/i8042.c index cb5ece7..e29d6a4 100644 --- a/drivers/input/serio/i8042.c +++ b/drivers/input/serio/i8042.c @@ -88,6 +88,10 @@ MODULE_PARM_DESC(nopnp, "Do not use PNP to detect controller settings"); static bool i8042_debug; module_param_named(debug, i8042_debug, bool, 0600); MODULE_PARM_DESC(debug, "Turn i8042 debugging mode on and off"); + +static bool i8042_debug_kbd; +module_param_named(debug_kbd, i8042_debug_kbd, bool, 0600); +MODULE_PARM_DESC(i8042_kbd, "Turn i8042 kbd debugging output on or off (requires i8042.debug=1)"); #endif static bool i8042_bypass_aux_irq_test; @@ -116,6 +120,7 @@ struct i8042_port { struct serio *serio; int irq; bool exists; + bool driver_bound; signed char mux; }; @@ -133,6 +138,7 @@ static bool i8042_kbd_irq_registered; static bool i8042_aux_irq_registered; static unsigned char i8042_suppress_kbd_ack; static struct platform_device *i8042_platform_device; +static struct notifier_block i8042_kbd_bind_notifier_block; static irqreturn_t i8042_interrupt(int irq, void *dev_id); static bool (*i8042_platform_filter)(unsigned char data, unsigned char str, @@ -528,10 +534,10 @@ static irqreturn_t i8042_interrupt(int irq, void *dev_id) port = &i8042_ports[port_no]; serio = port->exists ? port->serio : NULL; - dbg("%02x <- i8042 (interrupt, %d, %d%s%s)\n", - data, port_no, irq, - dfl & SERIO_PARITY ? ", bad parity" : "", - dfl & SERIO_TIMEOUT ? ", timeout" : ""); + filter_dbg(port->driver_bound, data, "<- i8042 (interrupt, %d, %d%s%s)\n", + port_no, irq, + dfl & SERIO_PARITY ? ", bad parity" : "", + dfl & SERIO_TIMEOUT ? ", timeout" : ""); filtered = i8042_filter(data, str, serio); @@ -1438,6 +1444,29 @@ static int __init i8042_setup_kbd(void) return error; } +static int i8042_kbd_bind_notifier(struct notifier_block *nb, + unsigned long action, void *data) +{ + struct device *dev = data; + struct serio *serio = to_serio_port(dev); + struct i8042_port *port = serio->port_data; + + if (serio != i8042_ports[I8042_KBD_PORT_NO].serio) + return 0; + + switch (action) { + case BUS_NOTIFY_BOUND_DRIVER: + port->driver_bound = true; + break; + + case BUS_NOTIFY_UNBOUND_DRIVER: + port->driver_bound = false; + break; + } + + return 0; +} + static int __init i8042_probe(struct platform_device *dev) { int error; @@ -1507,6 +1536,10 @@ static struct platform_driver i8042_driver = { .shutdown = i8042_shutdown, }; +static struct notifier_block i8042_kbd_bind_notifier_block = { + .notifier_call = i8042_kbd_bind_notifier, +}; + static int __init i8042_init(void) { struct platform_device *pdev; @@ -1528,6 +1561,7 @@ static int __init i8042_init(void) goto err_platform_exit; } + bus_register_notifier(&serio_bus, &i8042_kbd_bind_notifier_block); panic_blink = i8042_panic_blink; return 0; @@ -1543,6 +1577,7 @@ static void __exit i8042_exit(void) platform_driver_unregister(&i8042_driver); i8042_platform_exit(); + bus_unregister_notifier(&serio_bus, &i8042_kbd_bind_notifier_block); panic_blink = NULL; } diff --git a/drivers/input/serio/i8042.h b/drivers/input/serio/i8042.h index fc080be..a198f0d 100644 --- a/drivers/input/serio/i8042.h +++ b/drivers/input/serio/i8042.h @@ -73,6 +73,17 @@ static unsigned long i8042_start_time; printk(KERN_DEBUG KBUILD_MODNAME ": [%d] " format, \ (int) (jiffies - i8042_start_time), ##arg); \ } while (0) + +#define filter_dbg(filter, data, format, args...) \ + do { \ + if (!i8042_debug) \ + break; \ + \ + if (!filter || i8042_debug_kbd) \ + dbg("%02x " format, data, ##args); \ + else \ + dbg("** " format, ##args); \ + } while (0) #else #define dbg_init() do { } while (0) #define dbg(format, arg...) \ @@ -80,6 +91,8 @@ static unsigned long i8042_start_time; if (0) \ printk(KERN_DEBUG pr_fmt(format), ##arg); \ } while (0) + +#define filter_dbg(filter, data, format, args...) do { } while (0) #endif #endif /* _I8042_H */ diff --git a/drivers/input/serio/serio.c b/drivers/input/serio/serio.c index a05a517..63422d2 100644 --- a/drivers/input/serio/serio.c +++ b/drivers/input/serio/serio.c @@ -49,8 +49,6 @@ static DEFINE_MUTEX(serio_mutex); static LIST_HEAD(serio_list); -static struct bus_type serio_bus; - static void serio_add_port(struct serio *serio); static int serio_reconnect_port(struct serio *serio); static void serio_disconnect_port(struct serio *serio); @@ -1017,7 +1015,7 @@ irqreturn_t serio_interrupt(struct serio *serio, } EXPORT_SYMBOL(serio_interrupt); -static struct bus_type serio_bus = { +struct bus_type serio_bus = { .name = "serio", .drv_groups = serio_driver_groups, .match = serio_bus_match, diff --git a/include/linux/serio.h b/include/linux/serio.h index 9f779c7..df4ab5d 100644 --- a/include/linux/serio.h +++ b/include/linux/serio.h @@ -18,6 +18,8 @@ #include <linux/mod_devicetable.h> #include <uapi/linux/serio.h> +extern struct bus_type serio_bus; + struct serio { void *port_data; -- 2.4.3 -- To unsubscribe from this list: send the line "unsubscribe linux-input" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html