Fwd: [CULLT:5590] Need some help, kernel crash without an apparent cause.
Sami Bel Hadj
From: Abdel <ghith.ab...@gmail.com>
Date: 2009/5/11
Subject: [CULLT:5590] Need some help, kernel crash without an apparent cause.
To: CULLT <CU...@googlegroups.com>
Trying to run busybox hush shell in xip mode due to a memory
restrinction cause a kernel crash.
any advices or suggestions are welcome, thanks in advance!
a dump of the crash is posted here : http://pastebin.ca/1419601
best regards,
Abdelhamid.
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Sami Bel Hadj
Ingénieur Système / DBA Oracle
Linux Certified LPIC-1
Centre National de l'Informatique
Tél : +216 97280182
http://www.linkedin.com/in/sbelhadj
http://sbelhadj.cullt.org
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(Imed Chihi) عماد الشيحي
2009/5/12 Sami Bel Hadj <sami.b...@gmail.com>:
> ---------- Forwarded message ----------
> From: Abdel <ghith.ab...@gmail.com>
> Date: 2009/5/11
> Subject: [CULLT:5590] Need some help, kernel crash without an apparent
> cause.
> To: CULLT <CU...@googlegroups.com>
>
> Trying to run busybox hush shell in xip mode due to a memory
> restrinction cause a kernel crash.
> any advices or suggestions are welcome, thanks in advance!
> a dump of the crash is posted here : http://pastebin.ca/1419601
Have you verified that the cramfs image was created with an mkcramfs
binary which does have XIP support included in it? Did you verify that
the busybox binary in the cramfs image has the sticky bit set? The
busybox binary has been mapped to a VMA which has all permissions in
vma->vm_page_prot cleared, do you have an idea why?
The crash occurred while executing the instruction at 0x641b4366, I
would suggest that you try to disassemble the busybox binary at offset
0x641b4366 - 0x641ad000 to see what the CPU was doing at the moment of
the crash.
Good luck,
-Imed
Abdel
Hi,
First I would like to thank you for your answer,
About the busybox Effectively the binary have been tagged with +t flag
(sticky bit set), also the mkcramfs include the -x option that allow
application xip (the busybox binary has been added uncompressed to the
file system image).
For the vma->vm_page_prot, it’s due to a little hack made to enable
the support of application xip with linear cramfs on 2.6.26 kernel
(there is no available patch for this version). I will take a look at
this and fix it.
After disassembling the last instruction executed when the crash
happen is “str R1, [sp, #28]” (and the stack pointer has a valid
address 0x680bff68).
I will send the full disassembly of the file.
Abdelhamid.