From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <504C7797.8040201@xenomai.org> Date: Sun, 09 Sep 2012 13:03:51 +0200 From: Philippe Gerum MIME-Version: 1.0 References: <50483A49.5090100@ebus.com> In-Reply-To: <50483A49.5090100@ebus.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Subject: Re: [Xenomai] Queue corruption from XDDP in Xenomai 2.6.1 List-Id: Discussions about the Xenomai project List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Doug Brunner Cc: xenomai@xenomai.org On 09/06/2012 07:53 AM, Doug Brunner wrote: > It looks like the bug I wrote about back in June still exists in Xenomai > 2.6.1 (with Linux 3.2.21). I ran the same test case (an RT thread opens > an XDDP socket, then a Linux thread opens its end of the pipe, then the > RT thread stops, then with the Linux thread still holding its end of the > pipe another RT thread tries to open an XDDP socket with the same minor > number). With Xenomai queue and I-pipe debugging enabled, I got a report > of a corrupted queue. I've attached my config, test case, and serial > console log. > > So far I haven't found anything in the XDDP or underlying xnpipe_* code > that would suggest why this is happening. However something is > definitely going wrong, since xnpipe_minor_free should not be called > until my Linux task closes its end of the pipe, so the call by the > second RT thread to open the pipe should fail with -EBUSY. Any thoughts > on why this might be happening? > Yes, please have a look at the commit log there: http://git.xenomai.org/?p=xenomai-2.6.git;a=commit;h=283c5f6eae1d1d7c65073e2f30fd40abdcf2c1ca This patch should fix the issue raised by the test case you sent (actually, it does, it was very useful to spot the problem - thanks for this). -- Philippe.