Gilles Chanteperdrix wrote:
> Jan Kiszka wrote:
>> Gilles Chanteperdrix wrote:
>>> Jan Kiszka wrote:
>>>> Gilles Chanteperdrix wrote:
>>>>> Gilles Chanteperdrix wrote:
>>>>>> Jan Kiszka wrote:
>>>>>>> Gilles Chanteperdrix wrote:
>>>>>>>> Gilles Chanteperdrix wrote:
>>>>>>>>> Jan Kiszka wrote:
>>>>>>>>>> Gilles Chanteperdrix wrote:
>>>>>>>>>>> I get this warning when compiling trunk:
>>>>>>>>>>>
>>>>>>>>>>> checking for __thread... rm: cannot remove `conftest1.dir': Is a directory
>>>>>>>>>>> yes
>>>>>>>>>>>
>>>>>>>>>> That simple, it's a typo in this line:
>>>>>>>>>>
>>>>>>>>>> http://www.rts.uni-hannover.de/xenomai/lxr/source/configure.in?v=SVN-trunk#394
>>>>>>>>>>
>>>>>>>>>> Also, that rm should be done outside the if block to play safe.
>>>>>>>>> Ok. But once this is fixed, I get a segmentation fault with __thread on
>>>>>>>>> ARM in rt_task_trampoline. I am currently testing the SIGWINCH thing,
>>>>>>>>> and if __thread is disabled, there is no segfault.
>>>>>>>> If a #ifdef 0 xeno_set_current, there is no segfault.
>>>>>>>>
>>>>>>> Interesting. What about removing the initial-exec attributes? Is
>>>>>>> __thread otherwise know to work on your platform?
>>>>>> Yes. This is a race condition, the real bug is, IMHO:
>>>>>> 	__native_self = *iargs->task;
>>>>>> When the segfault happens iargs->task is NULL. I suspect you are not
>>>>>> supposed to use iargs after the __native_task_create syscall.
>>>>> Yes, that was the problem.
>>>> What did you change? Can you explain the why to me?
>>> Because I guess iargs is no longer valid at this point. So, I saved the
>>> task pointer and reused it.
>>>
>> Sorry, makes no sense to me: *iargs is on the stack of the
>> rt_task_create caller, and that one is not expected to proceed until we
>> issue __xn_sys_barrier.
> 
> Well I am busy with the ARM FCSE now. Do you want my test case ?

Yes, hoping that it triggers on x86 as well. And is toolchain independent.

Jan