Hello:
When i use the ex_regs system call to trigger the exception ipc
it seems to be frozed in the do_ipc stange. I use jdb to debug this
current thread lists is like this:

9.04 l4ertl.exceptio 10 9.03 rcv,ipc_progr
9.03 l4ertl.timer0 10 9.02 rcv,ipc_progr
9.02 domain2.main 10 9.04 rcv,ipc_progr,exc_progr

l4ertl.exceptio is the pager of domain2.main. And now l4ertl.timer0
is executing ex_regs system to trigger exception for domain2.main.
l4ertl.exceptio is waiting for the exception ipc from the l4ertl2.main2.
In detail l4ertl.exceptio is in ipc (user level registers). l4ertl.timer0
is in ipc (user level registers), too. domain2.main is in the exception 255.
It seems to be dead lock in the kernel. Very strange.
Thanks.
Cheng Guanghui