[#6408] Xenomai applications emit warning "kernel is anterior to 2.5.2"?(2010)

[#6408] Xenomai applications emit warning "kernel is anterior to 2.5.2"?

Submitted By: Kolja Waschk

Open Date

2010-12-15 11:06:21

Priority:

Low Assignee:

Nobody

Status:

Open Fixed In Release:

N/A

Found In Release:

2010R1-RC5 Release:

2010R1-RC5

Category:

N/A Board:

Custom

Processor:

BF537 Silicon Revision:

0.3

Is this bug repeatable?:

Yes Resolution:

Assigned (Not Start)

Uboot version or rev.:

Toolchain version or rev.:

2010R1-RC4

App binary format:

FDPIC

Summary: Xenomai applications emit warning "kernel is anterior to 2.5.2"?

Details:

Applications utilizing Xenomai all (including switchtest etc.) emit a warning at startup:

Xenomai: WARNING, this version of Xenomai kernel is anterior to 2.5.2.

It can cause memory corruption on thread termination.

Upgrade is recommended.

However, the Xenomai kernel code that comes in 2010R1 is 2.5.3 which is certainly not "anterior to 2.5.2". The warning text is incorrect or the warning is given incorrectly.

Looking at the code I found that Xenomai library code in xenomai-2.5.3/src/skins/common/sem_heap.c triggers the warning as follows:

96 if (!xnvdso_test_feature(XNVDSO_FEAT_DROP_U_MODE))

97 xeno_current_warn_old();

The kernel sets this feature bit for sure. I found that the test actually misses XNVDSO_FEAT_DROP_U_MODE because it accesses some wrong location. Adding a line before the above code

96 fprintf(stderr, "Xenomai: VDSO features are %llu\n", nkvdso->features)

shows some arbitrary value other than "1". I conclude that it is accessing wrong memory or memory was corrupted.

Replacing Xenomai 2.5.3 by 2.5.5.2 made the warning go away for me. It has a number of lines changed in the sem_heap.c. Text indicates the change was necessary in particular for NOMMU targets.

However, once when stopping a particular application (cyclictest) I saw the warning again. I'm not sure if that was for the same or another reason...

Follow-ups

--- Sonic Zhang 2010-12-15 22:22:45

You'd better report this warning issue to Xenomai mailing list as well.

We are not the maintainer of Xenomai.

--- Kolja Waschk 2011-01-21 05:30:35

I've been told the warning in 2.5.5.2 actually should be printed on systems with

MMU, not NOMMU. The #ifdef logic there is wrong. I assume this will be fixed

upstream.

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