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From: Philippe Gerum <rpm@xenomai.org>
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Date: Thu, 14 Jan 2016 09:46:09 +0100
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Subject: Re: [Xenomai] [Xenomai-git] Jan Kiszka : cobalt/kernel: Fix
 invalidation of cond shadow
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To: Jan Kiszka <jan.kiszka@siemens.com>
Cc: xenomai@xenomai.org

On 01/13/2016 08:42 PM, Jan Kiszka wrote:
> On 2016-01-13 19:44, Philippe Gerum wrote:
>> On 01/13/2016 07:33 PM, git repository hosting wrote:
>>> Module: xenomai-jki
>>> Branch: for-forge
>>> Commit: b7d37dab571df0c0cd42aae094c3d5d1bc71db80
>>> URL:    http://git.xenomai.org/?p=xenomai-jki.git;a=commit;h=b7d37dab571df0c0cd42aae094c3d5d1bc71db80
>>>
>>> Author: Jan Kiszka <jan.kiszka@siemens.com>
>>> Date:   Wed Jan 13 19:31:23 2016 +0100
>>>
>>> cobalt/kernel: Fix invalidation of cond shadow
>>>
>>> pthread_cond_destroy fails to invalidate also the shadow object. This
>>> can cause spurious -EBUSY errors on re-initialization of the very same
>>> shadow as condition variable later on.
>>>
>>> Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
>>>
>>> ---
>>>
>>>  kernel/cobalt/posix/cond.c |    2 ++
>>>  1 file changed, 2 insertions(+)
>>>
>>> diff --git a/kernel/cobalt/posix/cond.c b/kernel/cobalt/posix/cond.c
>>> index 7e115cf..84ae8fd 100644
>>> --- a/kernel/cobalt/posix/cond.c
>>> +++ b/kernel/cobalt/posix/cond.c
>>> @@ -117,6 +117,8 @@ static inline int pthread_cond_destroy(struct cobalt_cond_shadow *cnd)
>>>  
>>>  	cobalt_cond_reclaim(&cond->resnode, s); /* drops lock */
>>>  
>>> +	cobalt_mark_deleted(cnd);
>>> +
>>>  	return 0;
>>>  }
>>>  
>>>
>>
>> cobalt_cond_reclaim() invalidates the shadow object already. Did you
> 
> Nope, it only invalidates cond->magic, i.e. the object itself. We also
> need to invalidate cnd->magic here. See also mutex.c, it has the same
> pattern.
> 

Ack, I misread the patch. This is a regression compared to 2.x, we need
both descriptors to be invalidated indeed.

-- 
Philippe.