Bug 15707

this panic was caused while running an electric fenced program under gdb.

Current directory is /usr/src/sys/compile/HUNAHPU/
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This GDB was configured as "i386-unknown-freebsd"...
(kgdb) cd /var/crash
Working directory /var/crash
 (canonically /usr/crash).
(kgdb) exec-file kernel.9
(kgdb) core-file vmcore.9
SMP 2 cpus
IdlePTD 3489792
initial pcb at 2d3640
panicstr: page fault
panic messages:
---
Fatal trap 12: page fault while in kernel mode
mp_lock = 01000002; cpuid = 1; lapic.id = 00000000
fault virtual address	= 0xcc962bb8
fault code		= supervisor read, page not present
instruction pointer	= 0x8:0xc0229790
stack pointer	        = 0x10:0xc875df08
frame pointer	        = 0x10:0xc875df1c
code segment		= base rx0, limit 0xfffff, type 0x1b
			= DPL 0, pres 1, def32 1, gran 1
processor eflags	= interrupt enabled, resume, IOPL = 0
current process		= 47908 (arlad)
interrupt mask		= none <- SMP: XXX
trap number		= 12
panic: page fault
mp_lock = 01000002; cpuid = 1; lapic.id = 00000000
boot() called on cpu#1

syncing disks... 11 
done
Uptime: 20h7m54s

dumping to dev #ad/0x20001, offset 0
dump ata0: resetting devices .. done
128 127 126 125 124 123 122 121 120 119 118 117 116 115 114 113 112 111 110 109 108 107 106 105 104 103 102 101 100 99 98 97 96 95 94 93 92 91 90 89 88 87 86 85 84 83 82 81 80 79 78 77 76 75 74 73 72 71 70 69 68 67 66 65 64 63 62 61 60 59 58 57 56 55 54 53 52 51 50 49 48 47 46 45 44 43 42 41 40 39 38 37 36 35 34 33 32 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 
---
#0  boot (howto=256) at ../../kern/kern_shutdown.c:303
(kgdb) bt
#0  boot (howto=256) at ../../kern/kern_shutdown.c:303
#1  0xc01423b9 in panic (fmt=0xc02a8dcf "page fault")
    at ../../kern/kern_shutdown.c:553
#2  0xc026a6ac in trap_fatal (frame=0xc875dec8, eva=3432393656)
    at ../../i386/i386/trap.c:908
#3  0xc026a31d in trap_pfault (frame=0xc875dec8, usermode=0, eva=3432393656)
    at ../../i386/i386/trap.c:801
#4  0xc0269ef7 in trap (frame={tf_fs = -931856360, tf_es = -1072496624, 
      tf_ds = -942800880, tf_edi = 715091968, tf_esi = -942784384, 
      tf_ebp = -931799268, tf_isp = -931799308, tf_ebx = -862573648, 
      tf_edx = -928955492, tf_ecx = 715083776, tf_eax = -929682688, 
      tf_trapno = 12, tf_err = 0, tf_eip = -1071474800, tf_cs = 8, 
      tf_eflags = 66054, tf_esp = -942803456, tf_ss = -1070906348})
    at ../../i386/i386/trap.c:425
#5  0xc0229790 in vm_map_protect (map=0xc7ce4080, start=715083776, 
    end=715091968, new_prot=0 '\000', set_max=0) at ../../vm/vm_map.c:959
#6  0xc022c661 in mprotect (p=0xc7cdf680, uap=0xc875df80)
    at ../../vm/vm_mmap.c:563
#7  0xc026a952 in syscall (frame={tf_fs = -1071316945, tf_es = 47, tf_ds = 47, 
      tf_edi = 726413168, tf_esi = 755155100, tf_ebp = 726518952, 
      tf_isp = -931799084, tf_ebx = 755155120, tf_edx = 755155140, 
      tf_ecx = 715091968, tf_eax = 74, tf_trapno = 12, tf_err = 2, 
      tf_eip = 672540064, tf_cs = 31, tf_eflags = 519, tf_esp = 726518924, 
      tf_ss = 47}) at ../../i386/i386/trap.c:1057
#8  0xc02580f1 in Xint0x80_syscall ()
cannot read proc at 0

Fix: 

no fix known :-(
How-To-Repeat: 
run a large program with efence for a while.