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authorSimon Kagstrom <simon.kagstrom@netinsight.net>2010-03-05 13:42:49 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2010-03-06 11:26:32 -0800
commit0347af4ee3922220f6bfe74b87b526aa709a0365 (patch)
tree6b1f860991e3dae3fc110e02a1a838eb291b94ee /Documentation/fault-injection
parent33fd797b3e2c6a7663b9331150da0acdb31990a2 (diff)
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lkdtm: add debugfs access and loosen KPROBE ties
Add adds a debugfs interface and additional failure modes to LKDTM to provide similar functionality to the provoke-crash driver submitted here: http://lwn.net/Articles/371208/ Crashes can now be induced either through module parameters (as before) or through the debugfs interface as in provoke-crash. The patch also provides a new "direct" interface, where KPROBES are not used, i.e., the crash is invoked directly upon write to the debugfs file. When built without KPROBES configured, only this mode is available. Signed-off-by: Simon Kagstrom <simon.kagstrom@netinsight.net> Cc: M. Mohan Kumar <mohan@in.ibm.com> Cc: Americo Wang <xiyou.wangcong@gmail.com> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Ingo Molnar <mingo@elte.hu> Cc: "Eric W. Biederman" <ebiederm@xmission.com>, Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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+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.