Re: Panic after "in_cksum_skip: out of data by 260"

Hi Eirik,

> Today I received this message on my serial console:
> 
> in_cksum_skip: out of data by 260
> Fatal trap 12: page fault while in kernel mode
> cpuid = 1; apic id = 00
> fault virtual address   = 0xc
> fault code              = supervisor read, page not present
> instruction pointer     = 0x8:0xc066ec33
> stack pointer           = 0x10:0xd5437974
> frame pointer           = 0x10:0xd5437998
> 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         = 36 (swi1: net)
> trap number             = 12
> panic: page fault
> cpuid = 1
> boot() called on cpu#0
> Uptime: 1d15h8m10s
> 
> This server has been very stable for a very long time. This crash surprises
> me somewhat.
> Uname output:
> FreeBSD carnen.net 5.3-STABLE FreeBSD 5.3-STABLE #0: Wed Feb  2 21:02:44 CET
> 2005     root_at_carnen.net:/usr/obj/usr/src/sys/CARNEN  i386
> 
> Any idea what could have caused this?

I have no idea about what could have caused this, but in this case, it
would be useful to have a crashdump and its associated kernel.debug file,
or at least a backtrace (but you must have enabled the break to debugger
on panic).  I guess you could also use addr2line(1) to determine which
function caused the panic from the instruction pointer, but it's likely
not enough to help understanding the problem.

In order to get a crashdump, your swap space must at least be as large
as your RAM and you will have to set the following variables :

  dumpdev="AUTO"
  dumpdir="/usr/space/crash"

Note that if dumpdir is not set, it defaults to /var/crash.

Best regards,
-- 
Jeremie Le Hen
< jeremie at le-hen dot org >< ttz at chchile dot org >