dcons kldunload panic

This is probably one of those "don't do that" problems.  I can 
reliably panic my -CURRENT system by having dcons setup then doing 
the following:
kldunload fireware
kldunload dcons
<At this point there is a message on the console that a process is 
still in use, so I go to kill the process ;) >
kill <dcons getty pid>

And then I get this panic, the message seems corrupt and adding the 
dcons symbols file doesn't seem to help.
#0  doadump () at pcpu.h:166
#1  0xc0444e2a in db_fncall (dummy1=-1068514612, dummy2=0, dummy3=1, 
    dummy4=0xcc82e908 "") at /usr/src/sys/ddb/db_command.c:486
#2  0xc0445105 in db_command_loop () 
at /usr/src/sys/ddb/db_command.c:401
#3  0xc0446d13 in db_trap (type=3, code=0) 
at /usr/src/sys/ddb/db_main.c:222
#4  0xc04fc6eb in kdb_trap (type=3, code=0, tf=0x0)
    at /usr/src/sys/kern/subr_kdb.c:502
#5  0xc061207c in trap (frame=
      {tf_fs = 8, tf_es = 40, tf_ds = 40, tf_edi = -1038531312, tf_esi 
= -1067202952, tf_ebp = -863835460, tf_isp = -863835480, tf_ebx 
= -863835420, tf_edx = -1067199496, tf_ecx = -1056878592, tf_eax 
= -1067189541, tf_trapno = 3, tf_err = 0, tf_eip = -1068514612, tf_cs 
= 32, tf_eflags = 646, tf_esp = -863835432, tf_ss = -1068646766}) 
at /usr/src/sys/i386/i386/trap.c:622
#6  0xc060244a in calltrap () 
at /usr/src/sys/i386/i386/exception.s:138
#7  0xc04fc2cc in kdb_enter (msg=0xc063fadb "KDB: enter: %s\n") at 
cpufunc.h:60
#8  0xc04dbe92 in panic (
    fmt=0xc063c678 "_mtx_lock_sleep: recursed on non-recursive 
mutex %s _at_ %s:%d\n") at /usr/src/sys/kern/kern_shutdown.c:551
#9  0xc04d3746 in _mtx_lock_sleep (m=0xc06a4284, tid=3227783745, 
opts=0, 
    file=0xc0641241 "/usr/src/sys/kern/subr_unit.c", line=719)
    at /usr/src/sys/kern/kern_mutex.c:294
#10 0xc04d37c3 in _mtx_lock_flags (m=0xc1015000, opts=0, 
    file=0xc0641241 "/usr/src/sys/kern/subr_unit.c", line=719)
---Type <return> to continue, or q <return> to quit---
    at /usr/src/sys/kern/kern_mutex.c:138
#11 0xc05076e9 in free_unr (uh=0xc1c08d00, item=31)
    at /usr/src/sys/kern/subr_unit.c:719
#12 0xc0486612 in devfs_free (cdev=0xc063fadb)
    at /usr/src/sys/fs/devfs/devfs_devs.c:144
#13 0xc04b4d54 in destroy_devl (dev=0xc1c4d800)
    at /usr/src/sys/kern/kern_conf.c:712
#14 0xc04b4db3 in destroy_dev (dev=0xc1c4d800)
    at /usr/src/sys/kern/kern_conf.c:721
#15 0xc093d7b3 in ?? ()
#16 0xc1c4d800 in ?? ()
#17 0xc093ed20 in ?? ()
#18 0x00000000 in ?? ()
#19 0x0000005c in ?? ()
#20 0xc093da21 in ?? ()
#21 0x00000019 in ?? ()
#22 0x00000000 in ?? ()
#23 0xc1bfab80 in ?? ()
#24 0xcc82ec04 in ?? ()
#25 0xc093d92a in ?? ()
#26 0xc093eae0 in ?? ()
#27 0xc093ed88 in ?? ()
#28 0x00000000 in ?? ()
---Type <return> to continue, or q <return> to quit---
#29 0xc093da42 in ?? ()
#30 0x00000000 in ?? ()
#31 0xc1bfab80 in ?? ()
#32 0xcc82ec20 in ?? ()
#33 0xc04d2d72 in module_unload (mod=0xc1c4d800, flags=-1064047224)
    at /usr/src/sys/kern/kern_module.c:244
Previous frame inner to this frame (corrupt stack?)

-- 
Anish Mistry
amistry_at_am-productions.biz
AM Productions http://am-productions.biz/