From: Leopold Palomo-Avellaneda <leo@alaxarxa.net>
To: xenomai@xenomai.org
Cc: Jan Kiszka <jan.kiszka@siemens.com>
Subject: [Xenomai] About SMAP (was Re: Xenomai 3.0.3 is broken in my system)
Date: Thu, 06 Oct 2016 11:51:15 +0200 [thread overview]
Message-ID: <2013828.8eEOvBkU4r@soho> (raw)
In-Reply-To: <9025a424-109a-8db1-a523-695ed43664ca@siemens.com>
Hi,
lasts weeks I have been in a trouble with Xenomai and RTnet. Finally it was
solved disabling some parameters in kernel (nosmap) Thanks again Jan.
That parameter is an interesting feature of the Intel processors [1,2], that
IMHO affects all the RTnet code and I hope that nothing more of Xenomai.
It seems that fix it is could be easy, but it must be done (a boring task ;-)
In the middle, I would propose that some note could be added to the FAQ, or
"Troubleshooting a dual kernel configuration" page. Something like this in the
"Common kernel configuration issues":
CONFIG_X86_SMAP
On modern Intel processors with SMAP-enabled systems, kernel is not allowed to
access to userspace memory, it must be done in a special way. So, until all
Xenomai code was updated, specially RTnet, if you find crashes with " unable to
handle kernel paging request at " disable this feature neither in kernel
configuration or in boot with nosmap.
Best regards,
Leopold
[1] https://en.wikipedia.org/wiki/Supervisor_Mode_Access_Prevention
[2] https://lwn.net/Articles/517475/
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next prev parent reply other threads:[~2016-10-06 9:51 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-10-03 16:12 [Xenomai] Xenomai 3.0.3 is broken in my system (was Regarding Xenomai and RTNET) Leopold Palomo-Avellaneda
2016-10-04 15:36 ` Leopold Palomo-Avellaneda
2016-10-05 10:39 ` Jan Kiszka
2016-10-05 12:42 ` Leopold Palomo-Avellaneda
2016-10-05 12:45 ` Jan Kiszka
2016-10-05 13:00 ` Leopold Palomo-Avellaneda
2016-10-05 13:12 ` Jan Kiszka
2016-10-06 9:51 ` Leopold Palomo-Avellaneda [this message]
2016-10-06 11:50 ` [Xenomai] About SMAP (was Re: Xenomai 3.0.3 is broken in my system) Jan Kiszka
2016-10-06 17:24 ` Leopold Palomo-Avellaneda
2016-10-06 17:30 ` Philippe Gerum
2016-10-06 17:44 ` Leopold Palomo-Avellaneda
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