1===============
2Provoke crashes
3===============
4
5The lkdtm module provides an interface to crash or injure the kernel at
6predefined crashpoints to evaluate the reliability of crash dumps obtained
7using different dumping solutions. The module uses KPROBEs to instrument
8crashing points, but can also crash the kernel directly without KRPOBE
9support.
10
11
12You can provide the way either through module arguments when inserting
13the module, or through a debugfs interface.
14
15Usage::
16
17	insmod lkdtm.ko [recur_count={>0}] cpoint_name=<> cpoint_type=<>
18			[cpoint_count={>0}]
19
20recur_count
21	Recursion level for the stack overflow test. Default is 10.
22
23cpoint_name
24	Crash point where the kernel is to be crashed. It can be
25	one of INT_HARDWARE_ENTRY, INT_HW_IRQ_EN, INT_TASKLET_ENTRY,
26	FS_DEVRW, MEM_SWAPOUT, TIMERADD, SCSI_DISPATCH_CMD,
27	IDE_CORE_CP, DIRECT
28
29cpoint_type
30	Indicates the action to be taken on hitting the crash point.
31	It can be one of PANIC, BUG, EXCEPTION, LOOP, OVERFLOW,
32	CORRUPT_STACK, UNALIGNED_LOAD_STORE_WRITE, OVERWRITE_ALLOCATION,
33	WRITE_AFTER_FREE,
34
35cpoint_count
36	Indicates the number of times the crash point is to be hit
37	to trigger an action. The default is 10.
38
39You can also induce failures by mounting debugfs and writing the type to
40<mountpoint>/provoke-crash/<crashpoint>. E.g.::
41
42  mount -t debugfs debugfs /mnt
43  echo EXCEPTION > /mnt/provoke-crash/INT_HARDWARE_ENTRY
44
45
46A special file is `DIRECT` which will induce the crash directly without
47KPROBE instrumentation. This mode is the only one available when the module
48is built on a kernel without KPROBEs support.
49