[BUG] Deadlock in Fiasco kernel

[Daniel Vandersee]

Hi there,

I noticed that the Fiasco kernel hangs under some circumstances so the
whole system stops working. Unfortunately I wasn't even able to enter
the kernel debugger via a serial cable in this case. The error is
reproducible on different plattforms (e.g. Thinkpad T43, 1GB RAM,
Pentium M 1.8 GHz or Thinkpad T41) even though it only appears from time
to time (probability ~50% or even better). Within VMWare or Qemu this
deadlock does *not* appear. Furthermore this error does not occur if the
kernel was started using the "-esc" option. I wasn't able to reproduce
this bug on a HP nx7400 (Dual Core T2300, 1GB RAM).
We use an own dynamic loader to load some L4 tasks whereas other L4
tasks, as the mGUI, are loaded by GRUB.

The bug can be reproduced on real hardware using the iso-image which I
will upload to the SLOX server (deadlock.iso). You have to choose GRUB
entry two or three. If the error occurs the system hangs in text mode
otherwise a graphical mode is entered. Sometimes you have to reboot up
to 20 times but it usually occurs immediately.

Kind regards
Daniel