On 03/16/2012 07:53 AM, Jan Kiszka wrote:
> On 2012-03-16 13:46, Jason Wessel wrote:
>> On 03/16/2012 07:17 AM, Jan Kiszka wrote:
>>> Not all kgdb I/O drivers implement a flush operation. Adjust
>>> gdbstub_exit accordingly.
>> The flush is certainly optional.  The reason we never saw this bug is 
>> because it was only used by some code not in the mainline, where it is in 
>> fact patched.  The out of tree patch hooked into the reboot notifier.
>>
>> It makes me wonder if using the reboot notifier is enough vs the call backs 
>> you placed in the critical power off points in your patch [4/4].   I'll 
>> respond separately to that thread because there are other folks in the CC 
>> line.
> I looked at other (granted: not kgdb-) archs and found them hooking
> their machine_xxx handlers. Also, do we trigger the notifier on all
> reboot/shutdown types?

>From what I can tell, all the safe shutdown types go through notifier, however 
>if you do something like:

echo o > /proc/sysrq-trigger

This will avoid the reboot notifier hook.  It is a question of how aggressively 
you want to catch all these cases or patch the kernel such that these holes 
provide notifications.

>> If we decide to roll with this series, I will definitely merge this patch, 
>> else I will remove the code since it is not used except for out of tree 
>> patches.
> Even with a reboot notifier, you still need the logic of gdbstub_exit.
> So I doubt it makes sense to be removed, rather start to be used - finally.

You are correct about that, and it is actually used in the reboot notifier 
version.

Jason.

------------------------------------------------------------------------------
This SF email is sponsosred by:
Try Windows Azure free for 90 days Click Here 
http://p.sf.net/sfu/sfd2d-msazure
_______________________________________________
Kgdb-bugreport mailing list
[email protected]
https://lists.sourceforge.net/lists/listinfo/kgdb-bugreport

Reply via email to