ps "Bus error" under jail

[Edwin]

Hi,

The machine is running FreeBSD 6.0-RELEASE and i am trying out jails on it
I have followed the tutorial in jail's man page and everythings seems
working fine, except the ps command.
When I execute ps, it say "Bus error"
Here is the gdb output:

GNU gdb 6.1.1 [FreeBSD]
Copyright 2004 Free Software Foundation, Inc.
GDB is free software, covered by the GNU General Public License, and you are
welcome to change it and/or distribute copies of it under certain conditions.
Type "show copying" to see the conditions.
There is absolutely no warranty for GDB.  Type "show warranty" for details.
This GDB was configured as "i386-marcel-freebsd"...(no debugging
symbols found)...
Core was generated by `ps'.
Program terminated with signal 10, Bus error.
Reading symbols from /lib/libm.so.4...(no debugging symbols found)...done.
Loaded symbols for /lib/libm.so.4
Reading symbols from /lib/libkvm.so.3...(no debugging symbols found)...done.
Loaded symbols for /lib/libkvm.so.3
Reading symbols from /lib/libc.so.6...(no debugging symbols found)...done.
Loaded symbols for /lib/libc.so.6
Reading symbols from /libexec/ld-elf.so.1...(no debugging symbols found)...done.
Loaded symbols for /libexec/ld-elf.so.1
#0  0x28092398 in _kvm_initvtop () from /lib/libkvm.so.3
(gdb) backtrace
#0  0x28092398 in _kvm_initvtop () from /lib/libkvm.so.3
Cannot access memory at address 0xbfbfdc6c

Thanks
Edwin