Unable to Debug following kernel crash triggered via SysRq

Unable to Debug following kernel crash triggered via SysRq

I am getting following Oops message while testing on a device which is
running on Linux Kernel 3.4.5 and ARM processor.I am unable to trace the
issue. If you look at call stack , you would see it starting from
ret_fast_syscall() , now actually sysrq for Crash has been triggered
inside the code but i am not getting from where.How can i find that. I
have Lauterbach installed but no idea from where to find which part of
kernel code has actually triggered this SysRq.
[50728.239318] C0 [ sh] SysRq : Trigger a crash [50728.239501] C0 [ sh]
******** READ GIC status [50728.239654] C0 [ sh] Unable to handle kernel
NULL pointer dereference at virtual address 00000000 [50728.239776] C0 [
sh] pgd = ebc9c000 [50728.239929] C0 [ sh] [00000000] *pgd=00000000
[50728.240081] C0 [ sh] Internal error: Oops: 805 [#1] PREEMPT SMP ARM
[50728.240234] C0 [ sh] kona_fb: die notifier invoked [50728.240356] C0 [
sh] Modules linked in: bcmdhd dm_crypt(O) moc_crypto(PO)
moc_platform_mod(O) texfat(PO) [50728.241088] C0 [ sh] CPU: 0 Tainted: P W
O (3.4.5-g4192471-dirty #116) [50728.241271] C0 [ sh] PC is at
sysrq_handle_crash+0x14/0x20 [50728.241424] C0 [ sh] LR is at
__handle_sysrq+0xa0/0x14c [50728.241516] C0 [ sh] pc : [] lr : [] psr:
60000093 [50728.241516] C0 [ sh] sp : ebd0ff20 ip : 0000000c fp : 4003a404
[50728.241821] C0 [ sh] r10: 4070002c r9 : edbc2f0c r8 : 00000000
[50728.241912] C0 [ sh] r7 : 60000013 r6 : 00000063 r5 : 00000007 r4 :
c0a26b90 [50728.242065] C0 [ sh] r3 : 00000001 r2 : 00000000 r1 : c07ab3a2
r0 : 00000063 [50728.242248] C0 [ sh] Flags: nZCv IRQs off FIQs on Mode
SVC_32 ISA ARM Segment user [50728.242401] C0 [ sh] Control: 10c53c7d
Table: adc9c06a DAC: 00000015 [50728.242492] C0 [ sh] ..................
(Register Contents(............. [50728.284851] C0 [ sh] Stack:
(0xebd0ff20 to 0xebd10000) [50728.284942] C0 [ sh] ff20: 00000002 c026b2bc
ec2a4ef0 ebd0ff88 00000002 c026b2e0 edbc2ec0 c014c840 [50728.285125] C0 [
sh] ff40: 00000002 ec2a4ef0 4070002c ebd0ff88 00000002 ebd0e000 00000000
c0109d24 [50728.285308] C0 [ sh] ff60: ec2a4ef0 4070002c ec2a4ef0 4070002c
00000000 00000000 00000002 c0109f5c [50728.285491] C0 [ sh] ff80: 00000001
00000000 00000000 00000000 00000003 00000002 00000001 00000004
[50728.285675] C0 [ sh] ffa0: c000e304 c000e140 00000003 00000002 00000001
4070002c 00000002 ffffffff [50728.285858] C0 [ sh] ffc0: 00000003 00000002
00000001 00000004 4070002c 00000000 406ffc84 4003a404 [50728.286010] C0 [
sh] ffe0: 40035f38 bea5e710 40020257 40150e44 20000010 00000001 00000000
00000000 [50728.286224] C0 [ sh] [] (sysrq_handle_crash+0x14/0x20) from []
(__handle_sysrq+0xa0/0x14c) [50728.286376] C0 [ sh] []
(__handle_sysrq+0xa0/0x14c) from [] (write_sysrq_trigger+0x24/0x34)
[50728.286560] C0 [ sh] [] (write_sysrq_trigger+0x24/0x34) from []
(proc_reg_write+0x80/0x94) [50728.286682] C0 [ sh] []
(proc_reg_write+0x80/0x94) from [] (vfs_write+0xb0/0x128) [50728.286865]
C0 [ sh] [] (vfs_write+0xb0/0x128) from [] (sys_write+0x38/0x64)
[50728.287048] C0 [ sh] [] (sys_write+0x38/0x64) from []
(ret_fast_syscall+0x0/0x48) [50728.287200] C0 [ sh] Code: e3a03001
e5823000 f57ff04f e3a02000 (e5c23000) [50728.287384] C0 [ sh] ---[ end
trace 1b75b31a2719ed7e ]--- [50728.287475] C0 [ sh] Kernel panic - not
syncing: Fatal exception