Reproducible Panic with port iplog

Hello,

It seems that the port iplog, causes a panic when it is stopped. Oddly
enough it works fine when running. Below is the information i gathered, i
dont know what commands to feed the debugger to provide useful info, so
instructions are welcome. I have also defined dumpdev in rc.conf and
makeoptions DEBUG=-g" in kernel, but the system does not dump. I dont
understand why, even dmesg reports its setup.

kernel dumps on /dev/ad0s1b
swapon: adding /dev/ad0s1b as swap device

It just sits there after the panic message. And yes, the swap partition is
larger than physical memory. Anyways, here is what i gathered.

This happens on a 1 month old kernel, as well as a recently cvsuped one.

---

root_at_fbsd:~# sync
root_at_fbsd:~# /usr/local/etc/rc.d/iplog.sh stop
 iplogroot_at_fbsd:~# kernel trap 12 with interrupts disabled


Fatal trap 12: page fault while in kernel mode
fault virtual address   = 0x4
fault code              = supervisor read, page not present
instruction pointer     = 0x8:0xc051274f
stack pointer           = 0x10:0xd8a55b04
frame pointer           = 0x10:0xd8a55b2c
code segment            = base 0x0, limit 0xfffff, type 0x1b
                        = DPL 0, pres 1, def32 1, gran 1
processor eflags        = resume, IOPL = 0
current process         = 526 (iplog)
[thread pid 526 tid 100105 ]
Stopped at      propagate_priority+0x13f:       movl    0x4(%eax),%eax
db> trace
Tracing pid 526 tid 100105 td 0xc1b85730
propagate_priority(c1b85730,0,c0649a96,254,c0698620) at
propagate_priority+0x13f
turnstile_wait(c19a7858,c1b878a0,c0645f57,216,c19a7858) at
turnstile_wait+0x38b
_mtx_lock_sleep(c19a7858,c1b85730,0,c06495f9,206) at _mtx_lock_sleep+0x134
_mtx_lock_flags(c19a7858,0,c06495f9,206,1) at _mtx_lock_flags+0xbf
sleepq_calc_signal_retval(0,0,c0647242,da,0) at
sleepq_calc_signal_retval+0x38
msleep(c19ab400,c19ab468,11a,c064fdf9,0) at msleep+0x3de
bpfread(c19abd00,d8a55c80,0,3a2,8000) at bpfread+0x1bc
devfs_read_f(c1a16a20,d8a55c80,c1551d00,0,c1b85730) at devfs_read_f+0xa6
dofileread(c1b85730,c1a16a20,7,807d000,8000) at dofileread+0x9b
read(c1b85730,d8a55d14,c,3ff,3) at read+0x6b
syscall(2f,2f,2f,808f600,0) at syscall+0x245
Xint0x80_syscall() at Xint0x80_syscall+0x1f
--- syscall (3, FreeBSD ELF32, read), eip = 0x281133cf, esp = 0xbfabde0c,
ebp = 0xbfabde28 ---
db> continue
panic: blockable sleep lock (sleep mutex) process lock _at_
/usr/src/sys/i386/i386/trap.c:696
KDB: enter: panic
[thread pid 526 tid 100105 ]
Stopped at      kdb_enter+0x30: leave
db> trace
Tracing pid 526 tid 100105 td 0xc1b85730
kdb_enter(c0646b1d,c06937e0,c064a32c,d8a559f0,100) at kdb_enter+0x30
panic(c064a32c,c0657a46,c06461d5,c065d5e6,2b8) at panic+0xcc
witness_checkorder(c19a7858,9,c065d5e6,2b8,0) at witness_checkorder+0xc7
_mtx_lock_flags(c19a7858,0,c065d5e6,2b8,c1b85730) at _mtx_lock_flags+0x8a
trap_pfault(d8a55ac4,0,4,1ce,4) at trap_pfault+0xa1
trap(18,10,10,c1b86540,c1b85730) at trap+0x34d
calltrap() at calltrap+0x5
--- trap 0xc, eip = 0xc051274f, esp = 0xd8a55b04, ebp = 0xd8a55b2c ---
propagate_priority(c1b85730,0,c0649a96,254,c0698620) at
propagate_priority+0x13f
turnstile_wait(c19a7858,c1b878a0,c0645f57,216,c19a7858) at
turnstile_wait+0x38b
_mtx_lock_sleep(c19a7858,c1b85730,0,c06495f9,206) at _mtx_lock_sleep+0x134
_mtx_lock_flags(c19a7858,0,c06495f9,206,1) at _mtx_lock_flags+0xbf
sleepq_calc_signal_retval(0,0,c0647242,da,0) at
sleepq_calc_signal_retval+0x38
msleep(c19ab400,c19ab468,11a,c064fdf9,0) at msleep+0x3de
bpfread(c19abd00,d8a55c80,0,3a2,8000) at bpfread+0x1bc
devfs_read_f(c1a16a20,d8a55c80,c1551d00,0,c1b85730) at devfs_read_f+0xa6
dofileread(c1b85730,c1a16a20,7,807d000,8000) at dofileread+0x9b
read(c1b85730,d8a55d14,c,3ff,3) at read+0x6b
syscall(2f,2f,2f,808f600,0) at syscall+0x245
Xint0x80_syscall() at Xint0x80_syscall+0x1f
--- syscall (3, FreeBSD ELF32, read), eip = 0x281133cf, esp = 0xbfabde0c,
ebp = 0xbfabde28 ---
db> continue
Uptime: 33m37s