Re: Panic "Fatal trap 18: integer divide fault while in kernel mode"

On Wed, Apr 29, 2009 at 09:16:26AM -0700, David Wolfskill wrote:
> My build machine had no trouble building & booting r191662, but my
> laptop's boot came to a screeching halt rather quickly.  Here's
> cut/paste for serial console of the single-user mode boot sequence:
> 
> 
> GDB: no debug ports present
> KDB: debugger backends: ddb
> KDB: current backend: ddb
> SMAP type=01 base=0000000000000000 len=000000000009fc00
> SMAP type=02 base=000000000009fc00 len=0000000000000400
> SMAP type=01 base=0000000000100000 len=000000002fee2800
> SMAP type=02 base=000000002ffe2800 len=000000000001d800
> SMAP type=02 base=00000000feda0000 len=0000000000060000
> SMAP type=02 base=00000000ffb80000 len=0000000000480000
> Copyright (c) 1992-2009 The FreeBSD Project.
> Copyright (c) 1979, 1980, 1983, 1986, 1988, 1989, 1991, 1992, 1993, 1994
>         The Regents of the University of California. All rights reserved.
> FreeBSD is a registered trademark of The FreeBSD Foundation.
> FreeBSD 8.0-CURRENT #1025 r191662: Wed Apr 29 08:28:59 PDT 2009
>     root_at_g1-37.catwhisker.org:/common/S4/obj/usr/src/sys/CANARY
> WARNING: WITNESS option enabled, expect reduced performance.
> Preloaded elf kernel "/boot/kernel/kernel" at 0xc1125000.
> Preloaded elf module "/boot/kernel/linux.ko" at 0xc112514c.
> Preloaded elf module "/boot/kernel/if_an.ko" at 0xc11251f8.
> Preloaded elf module "/boot/kernel/if_wi.ko" at 0xc11252a4.
> Preloaded elf module "/boot/kernel/radeon.ko" at 0xc1125350.
> Preloaded elf module "/boot/kernel/drm.ko" at 0xc11253fc.
> Timecounter "i8254" frequency 1193182 Hz quality 0
> Calibrating TSC clock ... TSC clock: 2392949196 Hz
> CPU: Mobile Intel(R) Pentium(R) 4 - M CPU 2.40GHz (2392.95-MHz 686-class CPU)
>   Origin = "GenuineIntel"  Id = 0xf27  Stepping = 7
>   Features=0xbfebf9ff<FPU,VME,DE,PSE,TSC,MSR,PAE,MCE,CX8,SEP,MTRR,PGE,MCA,CMOV,PAT,PSE36,CLFLUSH,DTS,ACPI,MMX,FXSR,SSE,SSE2,SS,HTT,TM,PBE>
>   Features2=0x400<CNXT-ID>
> 
> Instruction TLB: 4 KB, 2 MB or 4 MB pages, fully associative, 128 entries
> Data TLB: 4 KB or 4 MB pages, fully associative, 64 entries
> 1st-level data cache: 8 KB, 4-way set associative, sectored cache, 64 byte line size
> Trace cache: 12K-uops, 8-way set associative
> 2nd-level cache: 512 KB, 8-way set associative, sectored cache, 64 byte line size
> real memory  = 805306368 (768 MB)
> Physical memory chunk(s):
> 0x0000000000001000 - 0x000000000009efff, 647168 bytes (158 pages)
> 0x0000000000100000 - 0x00000000003fffff, 3145728 bytes (768 pages)
> 0x0000000001425000 - 0x000000002f2d9fff, 770396160 bytes (188085 pages)
> avail memory = 769642496 (733 MB)
> bios32: Found BIOS32 Service Directory header at 0xc00ffe80
> bios32: Entry = 0xffe90 (c00ffe90)  Rev = 0  Len = 1
> pcibios: PCI BIOS entry at 0xf0000+0xbfee
> pnpbios: Found PnP BIOS data at 0xc00fe2d0
> pnpbios: Entry = f0000:e2f4  Rev = 1.0
> pnpbios: Event flag at 4b4
> Other BIOS signatures found:
> 
> 
> Fatal trap 18: integer divide fault while in kernel mode
> cpuid = 0; apic id = 00
> instruction pointer     = 0x20:0xc0b34433
> stack pointer           = 0x28:0xc1420d00
> frame pointer           = 0x28:0xc1420d20
> 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         = 0 (swapper)
> [thread pid 0 tid 100000 ]
> Stopped at      cpu_topo+0x43:  idivl   %ecx,%eax
> db> 
> 
> 
> [Note: I've been in the habit of tracking head/CURRENT on a daily basis,
> and had no problems building today's while running yesterday's, which
> was r1916?? -- sorry; looks as if I'll need to boot from a different
> kernel to get that info.  (I've already powered off my build machine,
> and it's at home, while I'm at work.)]
> 
> Is there anything of use I might get from DDB?
> 

It seems it is r191648, cpu_cores or cpu_logical equal to 0.
cc to jeff_at_

-- 
Have fun!
chd