kernel crash ...

Vincent Blondel
Wed, 15 Nov 2006 20:11:15 -0000

Hello all,

-- System: FreeBSD-6.2-BETA3 | Tyan S2468GN --

I got a kernel crash on my web server this evening. I am now trying to
debug the crash image generated on /var/crash/vmcore.0 but I am not
comfortable with this procedure.

As far as I can see it seems process httpd crashed but I do not know
what I have to do to obtain precise info on this crash.

I give you below a snapshot of I what I tried until now.

So, could somebody help me debugging this crash ?

Many thanks for your help.

Regards
Vincent.

--

root@sbepfkaa [/usr/obj/usr/src/sys/S2468GN] # kgdb
kernel.debug /var/crash/vmcore.0
[GDB will not be able to debug user-mode
threads: /usr/lib/libthread_db.so: Undefined symbol
"ps_pglobal_lookup"]
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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 = 01
fault virtual address   = 0x27675eda
fault code              = supervisor write, page not present
instruction pointer     = 0x20:0xc062a143
stack pointer           = 0x28:0xe7063988
frame pointer           = 0x28:0xe70639a4
code segment            = base 0x0, limit 0xfffff, type 0x1b
                        = DPL 0, pres 1, def32 1, gran 1
processor eflags        = resume, IOPL = 0
current process         = 1213 (httpd)
trap number             = 12
panic: page fault
cpuid = 0
Uptime: 4d0h17m19s
Dumping 1023 MB (2 chunks)
  chunk 0: 1MB (159 pages) ... ok
  chunk 1: 1023MB (261760 pages) 1007 991 975 959 943 927 911 895 879
863 847 831 815 799 783 767 751 735 719 703 687 671 655 639 623 607 591
575 559 543 527 511 495 479 463 447 431 415 399 383 367 351 335 319 303
287 271 255 239 223 207 191 175 159 143 127 111 95 79 63 47 31 15

#0  doadump () at pcpu.h:165
165     pcpu.h: No such file or directory.
        in pcpu.h
(kgdb) list*0xc062a143
0xc062a143 is at /usr/src/sys/i386/i386/swtch.s:108.
103     /usr/src/sys/i386/i386/swtch.s: No such file or directory.
        in /usr/src/sys/i386/i386/swtch.s
(kgdb) backtrace
#0  doadump () at pcpu.h:165
#1  0xc04e3436 in boot (howto=260)
at /usr/src/sys/kern/kern_shutdown.c:409
#2  0xc04e375d in panic (fmt=0xc064447a "%s")
at /usr/src/sys/kern/kern_shutdown.c:565
#3  0xc062bd30 in trap_fatal (frame=0xe7063948, eva=661085914)
at /usr/src/sys/i386/i386/trap.c:837
#4  0xc062b4e6 in trap (frame      {tf_fs = 8, tf_es = 40, tf_ds = 40, tf_edi =
-990658024, tf_esi -992064896, tf_ebp = -419022428, tf_isp = -419022476, tf_ebx
-999450368, tf_edx = -419021423, tf_ecx = -992064896, tf_eax -1068542761,
tf_trapno = 12, tf_err = 2, tf_eip = -1067278013, tf_cs 32, tf_eflags = 65666,
tf_esp = -1068542761, tf_ss = -1068542761})
at /usr/src/sys/i386/i386/trap.c:270
#5  0xc061810a in calltrap () at /usr/src/sys/i386/i386/exception.s:139
#6  0xc062a143 in cpu_switch () at /usr/src/sys/i386/i386/swtch.s:108
Previous frame inner to this frame (corrupt stack?)
(kgdb) quit
root@sbepfkaa [/usr/obj/usr/src/sys/S2468GN] #