From: Henning Schild <henning.schild@siemens.com>
To: Jan Kiszka <jan.kiszka@siemens.com>, Philippe Gerum <rpm@xenomai.org>
Cc: Xenomai <xenomai@xenomai.org>
Subject: Re: [Xenomai] Heads up: some race condition fixes for Xenomai 3
Date: Tue, 7 Mar 2017 19:34:44 +0100 [thread overview]
Message-ID: <20170307193444.79df74cd@md1em3qc> (raw)
In-Reply-To: <558D5FAD.3060003@siemens.com>
Am Fri, 26 Jun 2015 16:20:29 +0200
schrieb Jan Kiszka <jan.kiszka@siemens.com>:
> Hi,
>
> just pushed 3 patches to git.xenomai.org/xenomai-jki.git for-forge
> that are supposed to fix race conditions while manipulating
> xnthread::state and info (both need to be nklock-protected). Please
> review if finding and fixes make sense.
>
> cobalt/kernel: Fix locking for xnthread info manipulations
> cobalt/kernel: Fix locking for setting XNFPU
> cobalt/kernel: Rework thread debugging helpers
>
> Maybe some of the issues also exist in Xenomai 2, didn't check yet.
After looking deeper into the the mysterious -EINTR i asked about a few
days ago we now got a trace that suggests something is going wrong. Jan
remembered the race in thread flag manipulation he found in Xeno3.
I did not do a thorough code analysis yet but instead just put two
asserts into xnthread_set_info and xnthread_clear_info.
1. !xnlock_is_owner(&nklock)
2. xnpod_current_thread() != thread_to_update
Both cases do happen. The flags are manipulated without holding the
lock and the flags are manipulated from another context. I guess that
suggests that the race found in xenomai3 is also in xenomai2.
Henning
next prev parent reply other threads:[~2017-03-07 18:34 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-06-26 14:20 [Xenomai] Heads up: some race condition fixes for Xenomai 3 Jan Kiszka
2015-06-26 15:07 ` Gilles Chanteperdrix
2015-06-26 15:24 ` Jan Kiszka
2017-03-07 18:34 ` Henning Schild [this message]
2017-03-08 8:54 ` Philippe Gerum
2017-03-08 11:25 ` Jan Kiszka
2017-03-08 11:29 ` Philippe Gerum
2017-03-08 11:32 ` Jan Kiszka
2017-03-08 11:42 ` Philippe Gerum
2017-03-08 11:48 ` Philippe Gerum
2017-03-09 9:05 ` Henning Schild
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