Hi,

on NetBSD/i386 1.5.1, I had a crash probably at the end of a program
running in Linux emulation. This is a stack trace of the netbsd.core file:

(gdb) where
#0  0x2 in ?? ()
#1  0xc02761f3 in cpu_reboot (howto=256, bootstr=0x0)
    at /usr/src/sys/arch/i386/i386/machdep.c:1175
#2  0xc011ffad in db_sync_cmd () at /usr/src/sys/ddb/db_command.c:720
#3  0xc011fb12 in db_command (last_cmdp=0xc02fdcc8, cmd_table=0x0)
    at /usr/src/sys/ddb/db_command.c:320
#4  0xc011fe5e in db_command_loop () at /usr/src/sys/ddb/db_command.c:555
#5  0xc012334e in db_trap (type=6, code=0) at /usr/src/sys/ddb/db_trap.c:78
#6  0xc027313e in kdb_trap (type=6, code=0, regs=0xd2beabd0)
    at /usr/src/sys/arch/i386/i386/db_interface.c:119
#7  0xc0279c7c in trap (frame={tf_gs = 16, tf_fs = 16, tf_es = 16, tf_ds = 16,
      tf_edi = -1, tf_esi = -992548444, tf_ebp = -759256040,
      tf_ebx = -992548444, tf_edx = -1073682620, tf_ecx = 0, tf_eax = 0,
      tf_trapno = 6, tf_err = 0, tf_eip = -1072266756, tf_cs = 8,
      tf_eflags = 66118, tf_esp = 0, tf_ss = -992548444,
      tf_vm86_es = -759256000, tf_vm86_ds = -1072287248, tf_vm86_fs = 0,
      tf_vm86_gs = -992548444}) at /usr/src/sys/arch/i386/i386/trap.c:299
#8  0xc0100c57 in calltrap ()
#9  0xc01631f0 in getblk (vp=0x0, blkno=516160, size=8192, slpflag=0,
    slptimeo=0) at /usr/src/sys/kern/vfs_bio.c:705
#10 0xc01639cd in bread (vp=0x0, blkno=516160, size=8192, cred=0xffffffff,
    bpp=0xd2beacb0) at /usr/src/sys/kern/vfs_bio.c:196
#11 0xc0241d08 in softdep_setup_freeblocks (ip=0xd2ab3b60, length=0)
    at /usr/src/sys/ufs/ffs/ffs_softdep.c:1593
#12 0xc023e9e3 in ffs_truncate (v=0xd2beae48)
    at /usr/src/sys/ufs/ffs/ffs_inode.c:244
#13 0xc0258900 in ufs_inactive (v=0xd2beae7c)
    at /usr/src/sys/sys/vnode_if.h:1039
#14 0xc016a6ad in vrele (vp=0xd2b8bddc) at /usr/src/sys/sys/vnode_if.h:723
#15 0xc0270646 in uvn_detach (uobj=0xd2b8bddc)
    at /usr/src/sys/uvm/uvm_vnode.c:495
#16 0xc0268d34 in uvm_unmap_detach (first_entry=0xd2961bd0, 
amap_unref_flags=0)
    at /usr/src/sys/uvm/uvm_map.c:1129
#17 0xc0268cdf in uvm_unmap (map=0xd2acda54, start=0, end=3217022976)
    at /usr/src/sys/uvm/uvm_map_i.h:183
#18 0xc026f324 in uvm_deallocate (map=0xd2acda54, start=0, size=3217022976)
    at /usr/src/sys/uvm/uvm_user.c:66
#19 0xc013bb2f in exit1 (p=0xd2c744e8, rv=0)
    at /usr/src/sys/kern/kern_exit.c:206
#20 0xc013c180 in sys_exit (p=0xd2c744e8, v=0xd2beaf80, retval=0xd2beaf78)
    at /usr/src/sys/kern/kern_exit.c:138
#21 0xc027a2d4 in syscall (frame={tf_gs = 31, tf_fs = 31, tf_es = 43,
      tf_ds = 43, tf_edi = 0, tf_esi = 1210680220, tf_ebp = 1309707860,
      tf_ebx = 0, tf_edx = 1210680888, tf_ecx = 1208450525, tf_eax = 1,
      tf_trapno = 3, tf_err = 2, tf_eip = 1210300461, tf_cs = 35,
      tf_eflags = 535, tf_esp = 1309707816, tf_ss = 43, tf_vm86_es = 0,
      tf_vm86_ds = 0, tf_vm86_fs = 0, tf_vm86_gs = 0})
    at /usr/src/sys/arch/i386/i386/trap.c:801
#22 0xc0100cc3 in syscall1 ()
can not access 0x4e108e54, invalid translation (invalid PDE)
can not access 0x4e108e54, invalid translation (invalid PDE)
Cannot access memory at address 0x4e108e54.

Is it possible to find out with gdb what process was running at that moment?

Regards
    Ingolf