-- The hang was not detected but the dump process could be started using the Sys Rq key

nexus:~# BUG: unable to handle kernel NULL pointer dereference at virtual address 00000000
 printing eip:
f8a2264d
*pde = 00000000
Oops: 0002 [#1]
PREEMPT SMP
Modules linked in: dtt hook ipv6 ext3 jbd rtc ide_cd cdrom eth1394 ohci1394 snd_intel8x0 snd_ac97_codec ieee1394 piix psmouse snd_ac97_bus ehci_hcd uhci_hcd evdev i2c_i801 hw_random snd_pcm snd_timer ide_core snd usbcore soundcore snd_page_alloc
CPU:    3
EIP:    0060:[<f8a2264d>]    Not tainted VLI
EFLAGS: 00010297   (2.6.17-rc4-dtt #2)
EIP is at cpoint_default_exit+0x4d/0x95 [dtt]
eax: 00000004   ebx: f7f9aa24   ecx: f7eda3e0   edx: 00000001
esi: f7095dec   edi: 00000000   ebp: 00000000   esp: f7095cd4
ds: 007b   es: 007b   ss: 0068
Process login (pid: 1728, threadinfo=f7095000 task=c3a40a50)
Stack: <0>f7f9aa24 c015cd16 c0309800 00000000 002980b4 f7fc2dec f7ae3900 f7095e34
       c01b0d3f 00000000 00000001 f7095dec c030aba8 c3a40a50 000200d2 00000000
       c01412f5 00000044 f7095d20 c38ffe40 00000246 000200d2 c030aba8 c037e060
Call Trace:
 <c015cd16> FS_DEVRW_hook+0x9d/0xa2   <c01b0d3f> search_by_key+0x15f/0x113b
 <c01412f5> __alloc_pages+0x53/0x2d1   <c013f6d0> __mod_page_state_offset+0x10/0x21
 <c0172718> __d_lookup+0x94/0x141   <c016894b> do_lookup+0x53/0x14f
 <c0171650> dput+0x90/0x143   <c0169362> __link_path_walk+0x91b/0xf23
 <c0172718> __d_lookup+0x94/0x141   <c019da12> reiserfs_update_sd_size+0x12c/0x32a
 <c01babb5> journal_begin+0x6c/0xff   <c01a7a93> reiserfs_dirty_inode+0x73/0x98
 <c017c523> __mark_inode_dirty+0x2d/0x197   <c013b3a5> generic_file_mmap+0x47/0x49
 <c014c7d2> do_mmap_pgoff+0x3f2/0x726   <c0107c34> sys_mmap2+0x67/0xb0
 <c0102e8b> syscall_call+0x7/0xb
Code: 77 ec ff 24 85 d0 31 a2 f8 c7 04 24 13 36 a2 f8 e8 9c 9b 6f c7 c7 04 24 1c 36 a2 f8 e8 f5 ac 6f c7 0f 0b 37 01 26 36 a2 f8 eb c3 <c7> 05 00 00 00 00 00 00 00 00 eb b7 c7 04 24 3a 36 a2 f8 e8 d3
EIP: [<f8a2264d>] cpoint_default_exit+0x4d/0x95 [dtt] SS:ESP 0068:f7095cd4
 BUG: warning at kernel/exit.c:855/do_exit()
 <c011f2af> do_exit+0x816/0x916   <c01046ba> do_simd_coprocessor_error+0x0/0x1b2 <c01141be> do_page_fault+0x3a7/0x6c1   <c0113e17> do_page_fault+0x0/0x6c1
 <c01039af> error_code+0x4f/0x54   <f8a2264d> cpoint_default_exit+0x4d/0x95 [dtt]
 <c015cd16> FS_DEVRW_hook+0x9d/0xa2   <c01b0d3f> search_by_key+0x15f/0x113b
 <c01412f5> __alloc_pages+0x53/0x2d1   <c013f6d0> __mod_page_state_offset+0x10/0x21
 <c0172718> __d_lookup+0x94/0x141   <c016894b> do_lookup+0x53/0x14f
 <c0171650> dput+0x90/0x143   <c0169362> __link_path_walk+0x91b/0xf23
 <c0172718> __d_lookup+0x94/0x141   <c019da12> reiserfs_update_sd_size+0x12c/0x32a
 <c01babb5> journal_begin+0x6c/0xff   <c01a7a93> reiserfs_dirty_inode+0x73/0x98
 <c017c523> __mark_inode_dirty+0x2d/0x197   <c013b3a5> generic_file_mmap+0x47/0x49
 <c014c7d2> do_mmap_pgoff+0x3f2/0x726   <c0107c34> sys_mmap2+0x67/0xb0
 <c0102e8b> syscall_call+0x7/0xb