Gilles Chanteperdrix wrote:
> Philippe Gerum wrote:
>> On Fri, 2010-01-22 at 17:58 +0100, Jan Kiszka wrote: 
>>> Hi guys,
>>> we are currently trying to catch an ugly Linux pipeline state corruption
>>> on x86-64.
>>> Conceptual question: If a Xenomai task causes a fault, we enter
>>> ipipe_trap_notify over the primary domain and leave it over the root
>>> domain, right? Now, if the root domain happened to be stalled when the
>>> exception happened, where should it normally be unstalled again,
>>> *for_that_task*? Our problem is that we generate a code path where this
>>> does not happen.
>> xnhadow_relax -> ipipe_reenter_root -> finish_task_switch ->
>> finish_lock_switch -> unstall
>> Since xnshadow_relax is called on behalf the event dispatcher, we should
>> expect it to return with the root domain unstalled after a domain
>> downgrade, from primary to root.
> Ok, but what about local_irq_restore_nosync at the end of the function ?

That is, IMO, our problem: It replays the root state on fault entry, but
that one is totally unrelated to the (Xenomai) task that caused the fault.


Siemens AG, Corporate Technology, CT T DE IT 1
Corporate Competence Center Embedded Linux

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