LOR from vm_map_lookup() leads to fatal trap:

I have not seen this before, from -current built from 6/31/2005.  This was
NOT found on the LOR page (http://sources.zabbadoz.net/freebsd/lor.html),
so I'm posting it here.

lock order reversal
 1st 0xc15f8e68 process lock (process lock)
_at_ /usr/src/sys/kern/kern_time.c:595
 2nd 0xc0a00a64 user map (user map) _at_ /usr/src/sys/vm/vm_map.c:2997
KDB: stack backtrace:
kdb_backtrace(c093c54a,c0a00a64,c0954678,c0954678,c09546f8) at
kdb_backtrace+0x2e
witness_checkorder(c0a00a64,9,c09546f8,bb5,c151fd80) at
witness_checkorder+0x6ba
_sx_xlock(c0a00a64,c09546f8,bb5,c06a1a26,cc01b9f0) at _sx_xlock+0x7e
_vm_map_lock_read(c0a00a20,c09546f8,bb5,15101dd,0) at _vm_map_lock_read+0x4a
vm_map_lookup(cc01ba88,0,1,cc01ba8c,cc01ba7c) at vm_map_lookup+0x38
vm_fault(c0a00a20,0,1,0,c151fd80) at vm_fault+0x7f
trap_pfault(cc01bb70,0,aa8,c0a33a80,aa8) at trap_pfault+0xf1
trap(c0a10008,c0a10028,28,c0938bcb,6ab) at trap+0x35e
calltrap() at calltrap+0x5
--- trap 0xc, eip = 0xc068fc66, esp = 0xcc01bbb0, ebp = 0xcc01bbd0 ---
_mtx_lock_flags(aa8,0,c0938bcb,6ab,c15f8f38) at _mtx_lock_flags+0x46
do_tdsignal(c1547c00,e,0,0,c0938bcb) at do_tdsignal+0x119
tdsignal(c1547c00,e,0,654) at tdsignal+0x4d
psignal(c15f8e00,e,c0939794,253,cc01bc88) at psignal+0x83
realitexpire(c15f8e00,0,c093992c,105,c06a7ed0) at realitexpire+0x3f
softclock(0,0,c093620e,256,c0a02780) at softclock+0x24e
ithread_loop(c1517780,cc01bd38,c0935ff9,30d,0) at ithread_loop+0x172
fork_exit(c0682920,c1517780,cc01bd38) at fork_exit+0xc1
fork_trampoline() at fork_trampoline+0x8
--- trap 0x1, eip = 0, esp = 0xcc01bd6c, ebp = 0 ---


Fatal trap 12: page fault while in kernel mode
cpuid = 0; apic id = 00
fault virtual address   = 0xaa8
fault code              = supervisor read, page not present
instruction pointer     = 0x20:0xc068fc66
stack pointer           = 0x28:0xcc01bbb0
frame pointer           = 0x28:0xcc01bbd0
code segment            = base 0x0, limit 0xfffff, type 0x1b
                        = DPL 0, pres 1, def32 1, gran 1
processor eflags        = interrupt enabled, resume, IOPL = 0
current process         = 28 (swi4: clock sio)
[thread pid 28 tid 100029 ]
Stopped at      _mtx_lock_flags+0x46:   cmpl    $0xc099d624,0(%ebx)
db> show alllocks
Process 28 (swi4: clock sio) thread 0xc151fd80 (100029)
exclusive sleep mutex process lock r = 0 (0xc15f8e68) locked
_at_ /usr/src/sys/kern/kern_time.c:595



-- 
othermark
atkin901 at nospam dot yahoo dot com
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