2 * Kprobe module for testing crash dumps
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation; either version 2 of the License, or
7 * (at your option) any later version.
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write to the Free Software
16 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
18 * Copyright (C) IBM Corporation, 2006
20 * Author: Ankita Garg <ankita@in.ibm.com>
22 * This module induces system failures at predefined crashpoints to
23 * evaluate the reliability of crash dumps obtained using different dumping
26 * It is adapted from the Linux Kernel Dump Test Tool by
27 * Fernando Luis Vazquez Cao <http://lkdtt.sourceforge.net>
29 * Usage : insmod lkdtm.ko [recur_count={>0}] cpoint_name=<> cpoint_type=<>
32 * recur_count : Recursion level for the stack overflow test. Default is 10.
34 * cpoint_name : Crash point where the kernel is to be crashed. It can be
35 * one of INT_HARDWARE_ENTRY, INT_HW_IRQ_EN, INT_TASKLET_ENTRY,
36 * FS_DEVRW, MEM_SWAPOUT, TIMERADD, SCSI_DISPATCH_CMD,
39 * cpoint_type : Indicates the action to be taken on hitting the crash point.
40 * It can be one of PANIC, BUG, EXCEPTION, LOOP, OVERFLOW
42 * cpoint_count : Indicates the number of times the crash point is to be hit
43 * to trigger an action. The default is 10.
46 #include <linux/kernel.h>
48 #include <linux/module.h>
49 #include <linux/buffer_head.h>
50 #include <linux/kprobes.h>
51 #include <linux/list.h>
52 #include <linux/init.h>
53 #include <linux/interrupt.h>
54 #include <linux/hrtimer.h>
55 #include <scsi/scsi_cmnd.h>
58 #include <linux/ide.h>
62 #define NUM_CPOINT_TYPES 5
63 #define DEFAULT_COUNT 10
64 #define REC_NUM_DEFAULT 10
87 static char* cp_name[] = {
98 static char* cp_type[] = {
106 static struct jprobe lkdtm;
108 static int lkdtm_parse_commandline(void);
109 static void lkdtm_handler(void);
111 static char* cpoint_name;
112 static char* cpoint_type;
113 static int cpoint_count = DEFAULT_COUNT;
114 static int recur_count = REC_NUM_DEFAULT;
116 static enum cname cpoint = INVALID;
117 static enum ctype cptype = NONE;
118 static int count = DEFAULT_COUNT;
120 module_param(recur_count, int, 0644);
121 MODULE_PARM_DESC(recur_count, " Recursion level for the stack overflow test, "\
123 module_param(cpoint_name, charp, 0644);
124 MODULE_PARM_DESC(cpoint_name, " Crash Point, where kernel is to be crashed");
125 module_param(cpoint_type, charp, 0644);
126 MODULE_PARM_DESC(cpoint_type, " Crash Point Type, action to be taken on "\
127 "hitting the crash point");
128 module_param(cpoint_count, int, 0644);
129 MODULE_PARM_DESC(cpoint_count, " Crash Point Count, number of times the "\
130 "crash point is to be hit to trigger action");
132 static unsigned int jp_do_irq(unsigned int irq)
139 static irqreturn_t jp_handle_irq_event(unsigned int irq,
140 struct irqaction *action)
147 static void jp_tasklet_action(struct softirq_action *a)
153 static void jp_ll_rw_block(int rw, int nr, struct buffer_head *bhs[])
161 static unsigned long jp_shrink_inactive_list(unsigned long max_scan,
163 struct scan_control *sc)
170 static int jp_hrtimer_start(struct hrtimer *timer, ktime_t tim,
171 const enum hrtimer_mode mode)
178 static int jp_scsi_dispatch_cmd(struct scsi_cmnd *cmd)
186 int jp_generic_ide_ioctl(ide_drive_t *drive, struct file *file,
187 struct block_device *bdev, unsigned int cmd,
196 static int lkdtm_parse_commandline(void)
200 if (cpoint_name == NULL || cpoint_type == NULL ||
201 cpoint_count < 1 || recur_count < 1)
204 for (i = 0; i < NUM_CPOINTS; ++i) {
205 if (!strcmp(cpoint_name, cp_name[i])) {
211 for (i = 0; i < NUM_CPOINT_TYPES; ++i) {
212 if (!strcmp(cpoint_type, cp_type[i])) {
218 if (cpoint == INVALID || cptype == NONE)
221 count = cpoint_count;
226 static int recursive_loop(int a)
230 memset(buf,0xFF,1024);
235 return recursive_loop(a);
238 void lkdtm_handler(void)
240 printk(KERN_INFO "lkdtm : Crash point %s of type %s hit\n",
241 cpoint_name, cpoint_type);
249 printk(KERN_INFO "lkdtm : PANIC\n");
253 printk(KERN_INFO "lkdtm : BUG\n");
257 printk(KERN_INFO "lkdtm : EXCEPTION\n");
261 printk(KERN_INFO "lkdtm : LOOP\n");
265 printk(KERN_INFO "lkdtm : OVERFLOW\n");
266 (void) recursive_loop(0);
271 count = cpoint_count;
275 static int __init lkdtm_module_init(void)
279 if (lkdtm_parse_commandline() == -EINVAL) {
280 printk(KERN_INFO "lkdtm : Invalid command\n");
285 case INT_HARDWARE_ENTRY:
286 lkdtm.kp.symbol_name = "do_IRQ";
287 lkdtm.entry = (kprobe_opcode_t*) jp_do_irq;
290 lkdtm.kp.symbol_name = "handle_IRQ_event";
291 lkdtm.entry = (kprobe_opcode_t*) jp_handle_irq_event;
293 case INT_TASKLET_ENTRY:
294 lkdtm.kp.symbol_name = "tasklet_action";
295 lkdtm.entry = (kprobe_opcode_t*) jp_tasklet_action;
298 lkdtm.kp.symbol_name = "ll_rw_block";
299 lkdtm.entry = (kprobe_opcode_t*) jp_ll_rw_block;
302 lkdtm.kp.symbol_name = "shrink_inactive_list";
303 lkdtm.entry = (kprobe_opcode_t*) jp_shrink_inactive_list;
306 lkdtm.kp.symbol_name = "hrtimer_start";
307 lkdtm.entry = (kprobe_opcode_t*) jp_hrtimer_start;
309 case SCSI_DISPATCH_CMD:
310 lkdtm.kp.symbol_name = "scsi_dispatch_cmd";
311 lkdtm.entry = (kprobe_opcode_t*) jp_scsi_dispatch_cmd;
315 lkdtm.kp.symbol_name = "generic_ide_ioctl";
316 lkdtm.entry = (kprobe_opcode_t*) jp_generic_ide_ioctl;
318 printk(KERN_INFO "lkdtm : Crash point not available\n");
322 printk(KERN_INFO "lkdtm : Invalid Crash Point\n");
326 if ((ret = register_jprobe(&lkdtm)) < 0) {
327 printk(KERN_INFO "lkdtm : Couldn't register jprobe\n");
331 printk(KERN_INFO "lkdtm : Crash point %s of type %s registered\n",
332 cpoint_name, cpoint_type);
336 static void __exit lkdtm_module_exit(void)
338 unregister_jprobe(&lkdtm);
339 printk(KERN_INFO "lkdtm : Crash point unregistered\n");
342 module_init(lkdtm_module_init);
343 module_exit(lkdtm_module_exit);
345 MODULE_LICENSE("GPL");