Panic: "Fatal trap 12: page fault while in kernel mode"

[Francois Tigeot <ftigeot@xxxxxxxxxxxx>]

I have just been bitten by this panic on a 4 cores Xeon server running
DragonFly 2.6.3/i386.
It is usually lightly loaded and mainly used for mail services.

I have also setup a local chroot with a devfs mount of /dev and a nullfs
mount of /usr/pkgsrc/distfiles to build packages.
The panic occurred just after I exited a chrooted root shell.

I wasn't able to get a core dump: the keyboard was completely unresponsive
in the debugger and I had to reboot the machine with the reset switch.

Details of the crash follow:

Fatal trap 12: page fault while in kernel mode
mp_lock = 00000002; cpuid = 2; lapic.id = 04000000
fault virtual address   = 0
fault code              = supervisor read, page not present
instruction pointer     = 0x8:0xc02d0a55
stack pointer           = 0x10:0xe30729ac
frame pointer           = 0x10:0xe3072a40
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         = 89056 (zsh)
current thread          = pri 6
 <- SMP: XXX
kernel: type 12 trap, code=0

CPU2 stopping CPUs: 0x0000000b
 stopped
Stopped at      devfs_getattr+0x1b:    movl    0(%edi),%edx
db>


-- 
Francois Tigeot