Re: [Xenomai-help] RTDM driver hangs

[Jan Kiszka <jan.kiszka@domain.hid>]

Juan Antonio Garcia Redondo wrote:
> Hi all,
> 
> I've been invetigating further the problem and I've found that the
> crash occurs in the following situation (now just one process using a
> rtdm driver):
> 
> o A real time process call to rtdm_ioctl function.
> o The rtdm_ioctl function blocks at rtdm_task_sleep (or any other blocking
> system call).
> o Arrive a signal which switch the process to executable state. The
> blocking system call returns -EINTR.
> o Whithout exit the RTDM driver, call to another blocking system call
> (rtdm_task_timedwait for instance). This system call returns -EINTR and the
> rtdm_ioctl function retuns -EINTR.

This is most probably the primary error: You should return to userspace
quickly, without further blocking, if a signal is pending.

However, the following crash is not OK. Maybe some code path lacks a
robustness check, maybe something more seriously is broken. Will try to
debug this with your test once time permits.

Thanks for reporting,
Jan

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