# kgdb /boot/kernel/kernel vmcore.10 
..

Unread portion of the kernel message buffer:


Fatal trap 12: page fault while in kernel mode
cpuid = 1; apic id = 01
fault virtual address	= 0xaaaaab4
fault code		= supervisor write, page not present
instruction pointer	= 0x20:0xc07d2c78
stack pointer	        = 0x28:0xc57e4900
frame pointer	        = 0x28:0xc57e4914
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		= 19885 (sh)
trap number		= 12
panic: page fault
cpuid = 1
Uptime: 1d17h8m52s
Physical memory: 2031 MB
Dumping 273 MB: 258 242 226 210 194 178 162 146 130 114 98 82 66 50 34 18 2

Reading symbols from /boot/kernel/linux.ko...Reading symbols from /boot/kernel/linux.ko.symbols...done.
done.
Loaded symbols for /boot/kernel/linux.ko
Reading symbols from /boot/modules/nvidia.ko...done.
Loaded symbols for /boot/modules/nvidia.ko
Reading symbols from /boot/kernel/acpi.ko...Reading symbols from /boot/kernel/acpi.ko.symbols...done.
done.
Loaded symbols for /boot/kernel/acpi.ko
Reading symbols from /boot/kernel/linprocfs.ko...Reading symbols from /boot/kernel/linprocfs.ko.symbols...done.
done.
Loaded symbols for /boot/kernel/linprocfs.ko
Reading symbols from /boot/kernel/logo_saver.ko...Reading symbols from /boot/kernel/logo_saver.ko.symbols...done.
done.
Loaded symbols for /boot/kernel/logo_saver.ko
Reading symbols from /boot/kernel/aio.ko...Reading symbols from /boot/kernel/aio.ko.symbols...done.
done.
Loaded symbols for /boot/kernel/aio.ko
Reading symbols from /boot/modules/kqemu.ko...done.
Loaded symbols for /boot/modules/kqemu.ko
#0  doadump () at pcpu.h:196
196	pcpu.h: No such file or directory.
	in pcpu.h
(kgdb) bt
#0  doadump () at pcpu.h:196
#1  0xc0597f17 in boot (howto=260) at /usr/src/sys/kern/kern_shutdown.c:418
#2  0xc05981ec in panic (fmt=Variable "fmt" is not available.
) at /usr/src/sys/kern/kern_shutdown.c:574
#3  0xc07daccc in trap_fatal (frame=0xc57e48c0, eva=178956980) at /usr/src/sys/i386/i386/trap.c:939
#4  0xc07daf30 in trap_pfault (frame=0xc57e48c0, usermode=0, eva=178956980) at /usr/src/sys/i386/i386/trap.c:852
#5  0xc07db8f9 in trap (frame=0xc57e48c0) at /usr/src/sys/i386/i386/trap.c:530
#6  0xc07c0c8b in calltrap () at /usr/src/sys/i386/i386/exception.s:159
#7  0xc07d2c78 in free_pv_entry (pmap=0xc72a1528, pv=Variable "pv" is not available.
) at /usr/src/sys/i386/i386/pmap.c:1973
#8  0xc07d2dd3 in pmap_pvh_free (pvh=0xc2ff1300, pmap=0xc72a1528, va=Variable "va" is not available.
) at /usr/src/sys/i386/i386/pmap.c:2175
#9  0xc07d2dfa in pmap_remove_entry (pmap=Variable "pmap" is not available.
) at /usr/src/sys/i386/i386/pmap.c:2184
#10 0xc07d4f4c in pmap_remove_pte (pmap=0xc72a1528, ptq=0x10, va=671502336, free=0xc57e4980) at /usr/src/sys/i386/i386/pmap.c:2471
#11 0xc07d6b47 in pmap_remove (pmap=0xc72a1528, sva=671502336, eva=671645696) at /usr/src/sys/i386/i386/pmap.c:2597
#12 0xc078bb1c in vm_map_delete (map=0xc72a149c, start=0, end=3217031168) at /usr/src/sys/vm/vm_map.c:2400
#13 0xc078bd55 in vm_map_remove (map=0xc72a149c, start=0, end=Variable "end" is not available.
) at /usr/src/sys/vm/vm_map.c:2427
#14 0xc056ea00 in exec_new_vmspace (imgp=0xc57e4be0, sv=0xc087dd80) at /usr/src/sys/kern/kern_exec.c:962
#15 0xc055567f in exec_elf32_imgact (imgp=0xc57e4be0) at /usr/src/sys/kern/imgact_elf.c:702
#16 0xc056ee44 in kern_execve (td=0xc6b7aaf0, args=0xc57e4c5c, mac_p=0x0) at /usr/src/sys/kern/kern_exec.c:433
#17 0xc056fdfc in execve (td=0xc6b7aaf0, uap=0xc57e4cfc) at /usr/src/sys/kern/kern_exec.c:202
#18 0xc07db295 in syscall (frame=0xc57e4d38) at /usr/src/sys/i386/i386/trap.c:1090
#19 0xc07c0cf0 in Xint0x80_syscall () at /usr/src/sys/i386/i386/exception.s:255
#20 0x00000033 in ?? ()
Previous frame inner to this frame (corrupt stack?)
(kgdb) frame 7
#7  0xc07d2c78 in free_pv_entry (pmap=0xc72a1528, pv=Variable "pv" is not available.
) at /usr/src/sys/i386/i386/pmap.c:1973
1973		pc->pc_map[field] |= 1ul << bit;
(kgdb) list
1968		pv_entry_count--;
1969		pc = pv_to_chunk(pv);
1970		idx = pv - &pc->pc_pventry[0];
1971		field = idx / 32;
1972		bit = idx % 32;
1973		pc->pc_map[field] |= 1ul << bit;
1974		/* move to head of list */
1975		TAILQ_REMOVE(&pmap->pm_pvchunk, pc, pc_list);
1976		for (idx = 0; idx < _NPCM; idx++)
1977			if (pc->pc_map[idx] != pc_freemask[idx]) {