1The lkdtm module provides an interface to crash or injure the kernel at 2predefined crashpoints to evaluate the reliability of crash dumps obtained 3using different dumping solutions. The module uses KPROBEs to instrument 4crashing points, but can also crash the kernel directly without KRPOBE 5support. 6 7 8You can provide the way either through module arguments when inserting 9the module, or through a debugfs interface. 10 11Usage: insmod lkdtm.ko [recur_count={>0}] cpoint_name=<> cpoint_type=<> 12 [cpoint_count={>0}] 13 14 recur_count : Recursion level for the stack overflow test. Default is 10. 15 16 cpoint_name : Crash point where the kernel is to be crashed. It can be 17 one of INT_HARDWARE_ENTRY, INT_HW_IRQ_EN, INT_TASKLET_ENTRY, 18 FS_DEVRW, MEM_SWAPOUT, TIMERADD, SCSI_DISPATCH_CMD, 19 IDE_CORE_CP, DIRECT 20 21 cpoint_type : Indicates the action to be taken on hitting the crash point. 22 It can be one of PANIC, BUG, EXCEPTION, LOOP, OVERFLOW, 23 CORRUPT_STACK, UNALIGNED_LOAD_STORE_WRITE, OVERWRITE_ALLOCATION, 24 WRITE_AFTER_FREE, 25 26 cpoint_count : Indicates the number of times the crash point is to be hit 27 to trigger an action. The default is 10. 28 29You can also induce failures by mounting debugfs and writing the type to 30<mountpoint>/provoke-crash/<crashpoint>. E.g., 31 32 mount -t debugfs debugfs /mnt 33 echo EXCEPTION > /mnt/provoke-crash/INT_HARDWARE_ENTRY 34 35 36A special file is `DIRECT' which will induce the crash directly without 37KPROBE instrumentation. This mode is the only one available when the module 38is built on a kernel without KPROBEs support. 39