Panic - snoop device related

Hi

I got this panic last week when exiting a 'watch -W' with ctrl-g.
It happened on 3 servers in the space of 10 minutes with the same
trigger.

I have saved the crashdump and kernel for further debugging that
you may want me to do.

Fatal trap 12: page fault while in kernel mode
cpuid = 1; apic id = 06
fault virtual address   = 0x24
fault code              = supervisor read, page not present
instruction pointer     = 0x20:0xc0498d48
stack pointer           = 0x28:0xe9629b14
frame pointer           = 0x28:0xe9629b34
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         = 38563 (bash)
trap number             = 12
panic: page fault
cpuid = 1
KDB: stack backtrace:
db_trace_self_wrapper(c0687a39,e96299d0,c04f335a,c069bb21,1,...) at db_trace_sel
f_wrapper+0x27
kdb_backtrace(c069bb21,1,c067a9fe,e96299dc,0,...) at kdb_backtrace+0x2f
panic(c067a9fe,c069cace,c52b3f30,1,1,...) at panic+0x11f
trap_fatal(e9629ad4,24,1,0,c4e58048,...) at trap_fatal+0x332
trap_pfault(e9629ad4,0,24,0,24,...) at trap_pfault+0x226
trap(e9629ad4) at trap+0x3cd
calltrap() at calltrap+0x6
--- trap 0xc, eip = 0xc0498d48, esp = 0xe9629b14, ebp = 0xe9629b34 ---
snp_in(0,c522bab0,1,0,c4e58014,...) at snp_in+0x22
snplwrite(c4e58000,e9629c60,0,e9629bb4,c04bea3e,...) at snplwrite+0x8c
ptswrite(cabf2600,e9629c60,0,0,e9629c60,...) at ptswrite+0x38
giant_write(cabf2600,e9629c60,0,cabf2600,c06bb440,...) at giant_write+0x68
devfs_write_f(c591e000,e9629c60,c5bf6b80,0,c5010bd0,...) at devfs_write_f+0x7c
dofilewrite(c5010bd0,2,c591e000,e9629c60,ffffffff,...) at dofilewrite+0x8d
kern_writev(c5010bd0,2,e9629c60,28420401,0,...) at kern_writev+0x61
write(c5010bd0,e9629d00,c,7,0,...) at write+0x4f
syscall(e9629d38) at syscall+0x329
Xint0x80_syscall() at Xint0x80_syscall+0x20
--- syscall (4, FreeBSD ELF32, write), eip = 0x2830ecd7, esp = 0xbfbfe74c, ebp =
 0xbfbfe768 ---

(kgdb) bt
#0  doadump () at pcpu.h:147
#1  0xc04f304d in boot (howto=260) at /usr/src/sys/kern/kern_shutdown.c:409
#2  0xc04f3416 in panic (fmt=0xc067a9fe "%s")
    at /usr/src/sys/kern/kern_shutdown.c:563
#3  0xc0654ad8 in trap_fatal (frame=0xe9629ad4, eva=36)
    at /usr/src/sys/i386/i386/trap.c:868
#4  0xc0654782 in trap_pfault (frame=0xe9629ad4, usermode=0, eva=36)
    at /usr/src/sys/i386/i386/trap.c:777
#5  0xc0654309 in trap (frame=0xe9629ad4) at /usr/src/sys/i386/i386/trap.c:462
#6  0xc063b9cb in calltrap () at /usr/src/sys/i386/i386/exception.s:139
#7  0xc0498d48 in snp_in (snp=0x0, buf=0x0, n=1)
    at /usr/src/sys/dev/snp/snp.c:338
#8  0xc04989db in snplwrite (tp=0xc4e58000, uio=0xe9629c60, flag=0)
    at /usr/src/sys/dev/snp/snp.c:176
#9  0xc0538e51 in ptswrite (dev=0x0, uio=0x0, flag=0) at linedisc.h:107
#10 0xc04bea3e in giant_write (dev=0xcabf2600, uio=0x0, ioflag=0)
    at /usr/src/sys/kern/kern_conf.c:330
#11 0xc04a6bea in devfs_write_f (fp=0xc591e000, uio=0xe9629c60, 
    cred=0xc5bf6b80, flags=0, td=0xc5010bd0)
    at /usr/src/sys/fs/devfs/devfs_vnops.c:1280
#12 0xc05259a5 in dofilewrite (td=0xc5010bd0, fd=0, fp=0xc591e000, 
    auio=0xe9629c60, offset=Unhandled dwarf expression opcode 0x93
) at file.h:254
#13 0xc05257db in kern_writev (td=0xc5010bd0, fd=2, auio=0x0)
---Type <return> to continue, or q <return> to quit--- 
    at /usr/src/sys/kern/sys_generic.c:381
#14 0xc05256b1 in write (td=0x0, uap=0x0)
    at /usr/src/sys/kern/sys_generic.c:311
#15 0xc0654e99 in syscall (frame=0xe9629d38)
    at /usr/src/sys/i386/i386/trap.c:1008
#16 0xc063ba30 in Xint0x80_syscall () at /usr/src/sys/i386/i386/exception.s:196
#17 0x00000033 in ?? ()
Previous frame inner to this frame (corrupt stack?)


--
Ian Freislich