|  | The lkdtm module provides an interface to crash or injure the kernel at | 
|  | predefined crashpoints to evaluate the reliability of crash dumps obtained | 
|  | using different dumping solutions. The module uses KPROBEs to instrument | 
|  | crashing points, but can also crash the kernel directly without KRPOBE | 
|  | support. | 
|  |  | 
|  |  | 
|  | You can provide the way either through module arguments when inserting | 
|  | the module, or through a debugfs interface. | 
|  |  | 
|  | Usage: insmod lkdtm.ko [recur_count={>0}] cpoint_name=<> cpoint_type=<> | 
|  | [cpoint_count={>0}] | 
|  |  | 
|  | recur_count : Recursion level for the stack overflow test. Default is 10. | 
|  |  | 
|  | cpoint_name : Crash point where the kernel is to be crashed. It can be | 
|  | one of INT_HARDWARE_ENTRY, INT_HW_IRQ_EN, INT_TASKLET_ENTRY, | 
|  | FS_DEVRW, MEM_SWAPOUT, TIMERADD, SCSI_DISPATCH_CMD, | 
|  | IDE_CORE_CP, DIRECT | 
|  |  | 
|  | cpoint_type : Indicates the action to be taken on hitting the crash point. | 
|  | It can be one of PANIC, BUG, EXCEPTION, LOOP, OVERFLOW, | 
|  | CORRUPT_STACK, UNALIGNED_LOAD_STORE_WRITE, OVERWRITE_ALLOCATION, | 
|  | WRITE_AFTER_FREE, | 
|  |  | 
|  | cpoint_count : Indicates the number of times the crash point is to be hit | 
|  | to trigger an action. The default is 10. | 
|  |  | 
|  | You can also induce failures by mounting debugfs and writing the type to | 
|  | <mountpoint>/provoke-crash/<crashpoint>. E.g., | 
|  |  | 
|  | mount -t debugfs debugfs /mnt | 
|  | echo EXCEPTION > /mnt/provoke-crash/INT_HARDWARE_ENTRY | 
|  |  | 
|  |  | 
|  | A special file is `DIRECT' which will induce the crash directly without | 
|  | KPROBE instrumentation. This mode is the only one available when the module | 
|  | is built on a kernel without KPROBEs support. |