[OpenAFS] UML kernel panic

[Arjen Meek]

Hi,

I'm having problems with the OpenAFS client software in User Mode Linux.
The setup currently consists of 3 UML systems running on the same host:
an AFS server, succesfully installed & configured, a working Kerberos
KDC+admin server and a system with the AFS client software.

Software versions:
All systems run the same 2.4.23 UML kernel, in SKAS mode.
The AFS server runs Debian stable, the afs packages are compiled from
Debian testing source packages (version 1.2.11-1).
The client runs Debian testing and uses default binary packages (also
1.2.11-1). I tried compiling the kernel module using the debian build
tools ( using "make-kpkg module_image --arch um", compiled UML kernel
tree present with "ARCH = um" in makefile and debian/rules edited to use
i386_umlinux24 instead of i386_linux24) but can't get it to work.
Compiling the non-debian 1.2.11 source tarball from www.openafs.org did
work however, and the module loads into the UML kernel without errors.

All three systems can see each other through the tuntap based network
(routing done by host), and I can succesfully kinit on each of them.

However, starting afsd (either with /etc/init.d/openafs-client start or
just runnig "afsd") causes the UML client kernel to panic. The UML
console shows:

Starting AFS cache scan...<0>Kernel panic: Kernel mode fault at addr
0x0, ip 0x4010206d

Running afsd under strace shows the last thing that happens is:

afs_syscall(0x1c, 0x7, 0x8071d80, 0xbfffed00, 0xbfffc8b0
(incomplete line since the kernel panic occurs here and strace runs on
the UML as well)

As far as I can see, this is the first afs_syscall that takes place. And
the last, unfortunately.

Can anyone tell me what might be going wrong here, and more importantly,
what I can do about it? tcpdump shows that no AFS-traffic ever leaves
the client, so I'm pretty sure that the AFS server plays no role in
this. Just to make sure, I configured the host system as AFS+Kerberos
client, and this runs fine, using exactly the same configuration files
(host=Debian stable with the original 1.2.3final2-6 packages).

Keep in mind that I'm an OpenAFS newbie and might be overlooking
something very obvious...

Arjen