Re: [(take 2)patch 6/7] Kprobes registers for notify page fault

[Keshavamurthy Anil S <anil.s.keshavamurthy@intel.com>]

On Fri, Apr 21, 2006 at 10:53:29AM +1000, Keith Owens wrote:
> Keshavamurthy Anil S (on Thu, 20 Apr 2006 17:38:47 -0700) wrote:
> >On Fri, Apr 21, 2006 at 10:14:04AM +1000, Keith Owens wrote:
> >> Anil S Keshavamurthy (on Thu, 20 Apr 2006 16:25:02 -0700) wrote:
> >> >---
> >> >@@ -654,6 +659,9 @@ static int __init init_kprobes(void)
> >> > 	if (!err)
> >> > 		err = register_die_notifier(&kprobe_exceptions_nb);
> >> > 
> >> >+	if (!err)
> >> >+		err = register_page_fault_notifier(&kprobe_page_fault_nb);
> >> >+
> >> > 	return err;
> >> > }
> >> > 
> >> 
> >> The rest of the patches look OK, but this one does not.  init_kprobes()
> >> registers the main kprobe exception handler, not the page fault
> >> handler.
> >I am registering for register_page_fault_notifier() and as you can see
> >I am not deleting the old register_die_notifier() which is also required
> >for getting notified on int3/break and single-step traps. 
> >So no issues here.
> 
> Patch 7 conditionally registers a page fault handler, plus an
> unregister when there are no user space probes.  Why does patch 6
> unconditionally register a page fault handler?
Patch 7 is the improvement of patch 6, so in other words the patch
7 removes the patch 6's unconditional registration and adds
conditional registration support. 

-Anil