Fixed broken x86_64

Fixed broken x86_64

[Amit S. Kale]

Hi,

I am attempting to fix broken x86_64: kgdb_connected is zero when kgdb 
connects to gdb. This comes through a debug exception.

I am checking in this patch to fix it for uniprocessor systems. I still have 
to think about smp system.
-Amit

@@ -556,13 +566,15 @@
 +{
 +        struct die_args *d = ptr;
 +
-+        if (!kgdb_connected || (cmd == DIE_DEBUG && user_mode(d->regs)))
++        if (cmd == DIE_DEBUG && user_mode(d->regs))
 +                return NOTIFY_DONE;
 +        if (cmd == DIE_NMI_IPI) {
-+                if (atomic_read(debugger_active))
++                if (atomic_read(&debugger_active))
 +                        return NOTIFY_BAD;
-+        } else if ((*linux_debug_hook)(d->trapnr, d->signr, d->err, 
d->regs))
-+                return NOTIFY_BAD; /* skip */
++        } else {
++              CHK_DEBUGGER(d->trapnr, d->signr, d->err, d->regs,);
++              return NOTIFY_BAD;
++      }
 +
 +        return NOTIFY_DONE;
 +}