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Date: Mon, 09 Nov 2009 19:12:05 +0100
From: Gilles Chanteperdrix <gilles.chanteperdrix@xenomai.org>
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Subject: Re: [Adeos-main] Unchecked ipipe_test_pipeline_from
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To: Jan Kiszka <jan.kiszka@domain.hid>
Cc: adeos-main <adeos-main@gna.org>, Philippe Gerum <rpm@xenomai.org>

Jan Kiszka wrote:
> Hi Philippe,
> 
> just noticed: The __ipipe_check_percpu_access of __ipipe_get_cpu_var,
> added in 2.6.29, makes ipipe_test_pipeline_from unusable for debugging
> purposes. It now triggers a false positive warning if the caller did not
> disabled interrupts or stalled its pipeline. One such user under Xenomai
> is rthal_local_irq_disabled, and that is used to check RTDM driver
> handlers /wrt leaking IRQ masks.

It does not look like a false positive. If the task issuing the call to
rthal_local_irq_disabled function was migrated at the wrong time, it
could check the stall flag on the wrong cpu. So, it looks like
rthal_local_irq_disabled should be fixed to turn off irqs during the check.

-- 
                                          Gilles