Page fault while in kernel mode

[Tom Evans]

Hi all.

I got this panic when our SMB server moved hostname. I still had the
drives mounted, so I wondered what would happen if I ls'ed the mount
point ('Doctor it hurts when I do this' 'Dont do that then..').

I'm running i386 RELENG_7 from mid October, so it is more than possible
that this has already been fixed, but best to report it as well. I still
have the vmcore if anyone wants more info from it.

Cheers

Tom

FreeBSD strangepork.mintel.co.uk 7.1-PRERELEASE FreeBSD 7.1-PRERELEASE
#0: Wed Oct 22 02:25:56 BST 2008
root at strangepork.mintel.co.uk:/usr/FreeBSD/RELENG_7/obj/usr/FreeBSD/RELENG_7/src/sys/STRANGEPORK  i386

> # kgdb /usr/obj/usr/FreeBSD/RELENG_7/src/sys/STRANGEPORK/kernel.debug /var/crash/vmcore.1
GNU gdb 6.1.1 [FreeBSD]
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This GDB was configured as "i386-marcel-freebsd"...

Unread portion of the kernel message buffer:
kernel trap 12 with interrupts disabled


Fatal trap 12: page fault while in kernel mode
cpuid = 0; apic id = 00
fault virtual address	= 0x18
fault code		= supervisor read, page not present
instruction pointer	= 0x20:0xc0817385
stack pointer	        = 0x28:0xe8276adc
frame pointer	        = 0x28:0xe8276af8
code segment		= base 0x0, limit 0xfffff, type 0x1b
			= DPL 0, pres 1, def32 1, gran 1
processor eflags	= resume, IOPL = 0
current process		= 1032 (smbiod0)
trap number		= 12
panic: page fault
cpuid = 0
Uptime: 20d23h21m41s
Physical memory: 1992 MB
Dumping 314 MB: 299 283 267 251 235 219 203 187 171 155 139 123 107 91 75 59 43 27 11

Reading symbols from /boot/kernel/snd_hda.ko...done.
Loaded symbols for /boot/kernel/snd_hda.ko
Reading symbols from /boot/kernel/sound.ko...Reading symbols from /boot/kernel/sound.ko.symbols...done.
done.
Loaded symbols for /boot/kernel/sound.ko
Reading symbols from /boot/modules/nvidia.ko...done.
Loaded symbols for /boot/modules/nvidia.ko
Reading symbols from /boot/kernel/linux.ko...Reading symbols from /boot/kernel/linux.ko.symbols...done.
done.
Loaded symbols for /boot/kernel/linux.ko
Reading symbols from /boot/kernel/acpi.ko...Reading symbols from /boot/kernel/acpi.ko.symbols...done.
done.
Loaded symbols for /boot/kernel/acpi.ko
Reading symbols from /boot/kernel/linprocfs.ko...Reading symbols from /boot/kernel/linprocfs.ko.symbols...done.
done.
Loaded symbols for /boot/kernel/linprocfs.ko
Reading symbols from /boot/kernel/smbfs.ko...Reading symbols from /boot/kernel/smbfs.ko.symbols...done.
done.
Loaded symbols for /boot/kernel/smbfs.ko
Reading symbols from /boot/kernel/libiconv.ko...Reading symbols from /boot/kernel/libiconv.ko.symbols...done.
done.
Loaded symbols for /boot/kernel/libiconv.ko
Reading symbols from /boot/kernel/libmchain.ko...Reading symbols from /boot/kernel/libmchain.ko.symbols...done.
done.
Loaded symbols for /boot/kernel/libmchain.ko
Reading symbols from /boot/kernel/nullfs.ko...Reading symbols from /boot/kernel/nullfs.ko.symbols...done.
done.
Loaded symbols for /boot/kernel/nullfs.ko
Reading symbols from /boot/kernel/fdescfs.ko...Reading symbols from /boot/kernel/fdescfs.ko.symbols...done.
done.
Loaded symbols for /boot/kernel/fdescfs.ko
#0  doadump () at pcpu.h:196
196	pcpu.h: No such file or directory.
	in pcpu.h
(kgdb) bt full
#0  doadump () at pcpu.h:196
No locals.
#1  0xc07e2047 in boot (howto=260) at /usr/FreeBSD/RELENG_7/src/sys/kern/kern_shutdown.c:418
	_giantcnt = Variable "_giantcnt" is not available.
(kgdb) bt
#0  doadump () at pcpu.h:196
#1  0xc07e2047 in boot (howto=260) at /usr/FreeBSD/RELENG_7/src/sys/kern/kern_shutdown.c:418
#2  0xc07e2319 in panic (fmt=Variable "fmt" is not available.
) at /usr/FreeBSD/RELENG_7/src/sys/kern/kern_shutdown.c:574
#3  0xc0b1b45c in trap_fatal (frame=0xe8276a9c, eva=24) at /usr/FreeBSD/RELENG_7/src/sys/i386/i386/trap.c:939
#4  0xc0b1bdcf in trap (frame=0xe8276a9c) at /usr/FreeBSD/RELENG_7/src/sys/i386/i386/trap.c:320
#5  0xc0b028fb in calltrap () at /usr/FreeBSD/RELENG_7/src/sys/i386/i386/exception.s:159
#6  0xc0817385 in turnstile_broadcast (ts=0x0, queue=0) at /usr/FreeBSD/RELENG_7/src/sys/kern/subr_turnstile.c:836
#7  0xc07d4b12 in _mtx_unlock_sleep (m=0xc6457494, opts=0, file=0xc631c718 "/usr/FreeBSD/RELENG_7/src/sys/modules/smbfs/../../netsmb/smb_iod.c", line=97)
    at /usr/FreeBSD/RELENG_7/src/sys/kern/kern_mutex.c:619
#8  0xc07d4e72 in _mtx_unlock_flags (m=0xc6457494, opts=0, file=0xc631c718 "/usr/FreeBSD/RELENG_7/src/sys/modules/smbfs/../../netsmb/smb_iod.c", line=97)
    at /usr/FreeBSD/RELENG_7/src/sys/kern/kern_mutex.c:210
#9  0xc630fb73 in smb_iod_invrq (iod=Variable "iod" is not available.
) at /usr/FreeBSD/RELENG_7/src/sys/modules/smbfs/../../netsmb/smb_iod.c:97
#10 0xc6310d57 in smb_iod_addrq (rqp=0xc6457400) at /usr/FreeBSD/RELENG_7/src/sys/modules/smbfs/../../netsmb/smb_iod.c:424
#11 0xc630d28c in smb_rq_enqueue (rqp=0xc6457400) at /usr/FreeBSD/RELENG_7/src/sys/modules/smbfs/../../netsmb/smb_rq.c:193
#12 0xc630d6d8 in smb_rq_simple (rqp=0xc6457400) at /usr/FreeBSD/RELENG_7/src/sys/modules/smbfs/../../netsmb/smb_rq.c:174
#13 0xc630b9e4 in smb_smb_treeconnect (ssp=0xc5ee6100, scred=0xc5e9b4c4) at /usr/FreeBSD/RELENG_7/src/sys/modules/smbfs/../../netsmb/smb_smb.c:561
#14 0xc63108b8 in smb_iod_thread (arg=0xc5e9b480) at /usr/FreeBSD/RELENG_7/src/sys/modules/smbfs/../../netsmb/smb_iod.c:212
#15 0xc07be9a9 in fork_exit (callout=0xc63105c0 <smb_iod_thread>, arg=0xc5e9b480, frame=0xe8276d38) at /usr/FreeBSD/RELENG_7/src/sys/kern/kern_fork.c:804
#16 0xc0b02970 in fork_trampoline () at /usr/FreeBSD/RELENG_7/src/sys/i386/i386/exception.s:264
(kgdb)