[PATCH 2.6.27-rc3 19/28] mdb: adding notify_die handler for keyboard debugger entry

[PATCH 2.6.27-rc3 19/28] mdb: adding notify_die handler for keyboard debugger entry

[jmerkey]

added module support for keyboard debugger entry point and
notify_die entry point.

Signed-off-by: Jeffrey Vernon Merkey (jmerkey@wolfmountaingroup.com)

--- a/drivers/char/keyboard.c	2008-08-15 21:26:13.000000000 -0600
+++ b/drivers/char/keyboard.c	2008-08-15 15:41:57.000000000 -0600
@@ -44,6 +44,10 @@
 #include <linux/notifier.h>
 #include <linux/jiffies.h>
 
+#if defined(CONFIG_MDB) || defined(CONFIG_MDB_MODULE)
+#include <linux/kdebug.h>
+#endif
+
 extern void ctrl_alt_del(void);
 
 #define to_handle_h(n) container_of(n, struct input_handle, h_node)
@@ -1180,6 +1184,15 @@
 			if (keycode < BTN_MISC && printk_ratelimit())
 				printk(KERN_WARNING "keyboard.c: can't emulate rawmode for keycode %d\n", keycode);
 
+#if defined(CONFIG_MDB) || defined(CONFIG_MDB_MODULE)
+	if (down && !rep && keycode == KEY_PAUSE)
+        {
+	   if (notify_die(DIE_KERNELDEBUG, NULL, get_irq_regs(),
+                          0, -1, SIGINT) == NOTIFY_STOP)
+	      return;
+	}
+#endif
+
 #ifdef CONFIG_MAGIC_SYSRQ	       /* Handle the SysRq Hack */
 	if (keycode == KEY_SYSRQ && (sysrq_down || (down == 1 && sysrq_alt))) {
 		if (!sysrq_down) {

Re: [PATCH 2.6.27-rc3 19/28] mdb: adding notify_die handler for keyboard debugger entry

[Andi Kleen]

jmerkey@wolfmountaingroup.com writes:
 
> +#if defined(CONFIG_MDB) || defined(CONFIG_MDB_MODULE)
> +	if (down && !rep && keycode == KEY_PAUSE)
> +        {
> +	   if (notify_die(DIE_KERNELDEBUG, NULL, get_irq_regs(),
> +                          0, -1, SIGINT) == NOTIFY_STOP)
> +	      return;
> +	}
> +#endif
> +
>  #ifdef CONFIG_MAGIC_SYSRQ	       /* Handle the SysRq Hack */
>  	if (keycode == KEY_SYSRQ && (sysrq_down || (down == 1 && sysrq_alt))) {
>  		if (!sysrq_down) {

A nicer alternative to adding an hook here would be to use 
register_sysrq_key() to register a sysrq key that triggers
the debugger.  That function is also already exported.

-Andi

Re: [PATCH 2.6.27-rc3 19/28] mdb: adding notify_die handler for keyboard debugger entry

[jmerkey]

> jmerkey@wolfmountaingroup.com writes:
>
>> +#if defined(CONFIG_MDB) || defined(CONFIG_MDB_MODULE)
>> +	if (down && !rep && keycode == KEY_PAUSE)
>> +        {
>> +	   if (notify_die(DIE_KERNELDEBUG, NULL, get_irq_regs(),
>> +                          0, -1, SIGINT) == NOTIFY_STOP)
>> +	      return;
>> +	}
>> +#endif
>> +
>>  #ifdef CONFIG_MAGIC_SYSRQ	       /* Handle the SysRq Hack */
>>  	if (keycode == KEY_SYSRQ && (sysrq_down || (down == 1 && sysrq_alt)))
>> {
>>  		if (!sysrq_down) {
>
> A nicer alternative to adding an hook here would be to use
> register_sysrq_key() to register a sysrq key that triggers
> the debugger.  That function is also already exported.
>
> -Andi
>

Got it.  Added to the list.  I will Instrument it.

Jeff