From: Stephen Chandler Paul <cp...@redhat.com>

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 <cp...@redhat.com>
Reviewed-by: Benjamin Tissoires <benjamin.tissoi...@redhat.com>
---
 Documentation/kernel-parameters.txt |  7 +++++++
 drivers/input/serio/i8042.c         | 25 +++++++++++++++++++++----
 2 files changed, 28 insertions(+), 4 deletions(-)

diff --git a/Documentation/kernel-parameters.txt 
b/Documentation/kernel-parameters.txt
index ae44749..9e00234 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -1304,6 +1304,13 @@ 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
+                            As a side effect, this option will mask some of the
+                            interrupts sent back from the keyboard during the
+                            initialization of the KBD port on the i8042, if you
+                            need to see this, you will need to enable this
+                            option.
+                            (disabled by default)
        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..084fc05 100644
--- a/drivers/input/serio/i8042.c
+++ b/drivers/input/serio/i8042.c
@@ -88,6 +88,23 @@ 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");
+
+#define str_dbg(str, data, format, args...)                    \
+       do {                                                    \
+               if (!i8042_debug)                               \
+                       break;                                  \
+                                                               \
+               if (str & I8042_STR_AUXDATA || i8042_debug_kbd) \
+                       dbg("%02x " format, data, ##args);      \
+               else                                            \
+                       dbg("** " format, ##args);              \
+       } while (0)
+#else
+#define str_dbg(str, data, format, args...) do { } while (0)
 #endif
 
 static bool i8042_bypass_aux_irq_test;
@@ -528,10 +545,10 @@ 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" : "");
+       str_dbg(str, 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);
 
-- 
2.4.3

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