aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/misc/lkdtm.c
blob: e689ee94ac3da71450c7d03c66feda8457fe14f8 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
/*
 * Kprobe module for testing crash dumps
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 *
 * Copyright (C) IBM Corporation, 2006
 *
 * Author: Ankita Garg <ankita@in.ibm.com>
 *
 * This module induces system failures at predefined crashpoints to
 * evaluate the reliability of crash dumps obtained using different dumping
 * solutions.
 *
 * It is adapted from the Linux Kernel Dump Test Tool by
 * Fernando Luis Vazquez Cao <http://lkdtt.sourceforge.net>
 *
 * 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
 *
 * cpoint_type : Indicates the action to be taken on hitting the crash point.
 *		 It can be one of PANIC, BUG, EXCEPTION, LOOP, OVERFLOW
 *
 * cpoint_count : Indicates the number of times the crash point is to be hit
 *		  to trigger an action. The default is 10.
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/kprobes.h>
#include <linux/kallsyms.h>
#include <linux/init.h>
#include <linux/irq.h>
#include <linux/interrupt.h>
#include <scsi/scsi_cmnd.h>

#ifdef CONFIG_IDE
#include <linux/ide.h>
#endif

#define NUM_CPOINTS 8
#define NUM_CPOINT_TYPES 5
#define DEFAULT_COUNT 10
#define REC_NUM_DEFAULT 10

enum cname {
	INVALID,
	INT_HARDWARE_ENTRY,
	INT_HW_IRQ_EN,
	INT_TASKLET_ENTRY,
	FS_DEVRW,
	MEM_SWAPOUT,
	TIMERADD,
	SCSI_DISPATCH_CMD,
	IDE_CORE_CP
};

enum ctype {
	NONE,
	PANIC,
	BUG,
	EXCEPTION,
	LOOP,
	OVERFLOW
};

static char* cp_name[] = {
	"INT_HARDWARE_ENTRY",
	"INT_HW_IRQ_EN",
	"INT_TASKLET_ENTRY",
	"FS_DEVRW",
	"MEM_SWAPOUT",
	"TIMERADD",
	"SCSI_DISPATCH_CMD",
	"IDE_CORE_CP"
};

static char* cp_type[] = {
	"PANIC",
	"BUG",
	"EXCEPTION",
	"LOOP",
	"OVERFLOW"
};

static struct jprobe lkdtm;

static int lkdtm_parse_commandline(void);
static void lkdtm_handler(void);

static char* cpoint_name = INVALID;
static char* cpoint_type = NONE;
static int cpoint_count = DEFAULT_COUNT;
static int recur_count = REC_NUM_DEFAULT;

static enum cname cpoint = INVALID;
static enum ctype cptype = NONE;
static int count = DEFAULT_COUNT;

module_param(recur_count, int, 0644);
MODULE_PARM_DESC(recur_count, "Recurcion level for the stack overflow test,\
				 default is 10");
module_param(cpoint_name, charp, 0644);
MODULE_PARM_DESC(cpoint_name, "Crash Point, where kernel is to be crashed");
module_param(cpoint_type, charp, 06444);
MODULE_PARM_DESC(cpoint_type, "Crash Point Type, action to be taken on\
				hitting the crash point");
module_param(cpoint_count, int, 06444);
MODULE_PARM_DESC(cpoint_count, "Crash Point Count, number of times the \
				crash point is to be hit to trigger action");

unsigned int jp_do_irq(unsigned int irq, struct pt_regs *regs)
{
	lkdtm_handler();
	jprobe_return();
	return 0;
}

irqreturn_t jp_handle_irq_event(unsigned int irq, struct pt_regs *regs,
			struct irqaction *action)
{
	lkdtm_handler();
	jprobe_return();
	return 0;
}

void jp_tasklet_action(struct softirq_action *a)
{
	lkdtm_handler();
	jprobe_return();
}

void jp_ll_rw_block(int rw, int nr, struct buffer_head *bhs[])
{
	lkdtm_handler();
	jprobe_return();
}

struct scan_control;

unsigned long jp_shrink_page_list(struct list_head *page_list,
                                        struct scan_control *sc)
{
	lkdtm_handler();
	jprobe_return();
	return 0;
}

int jp_hrtimer_start(struct hrtimer *timer, ktime_t tim,
				const enum hrtimer_mode mode)
{
	lkdtm_handler();
	jprobe_return();
	return 0;
}

int jp_scsi_dispatch_cmd(struct scsi_cmnd *cmd)
{
	lkdtm_handler();
	jprobe_return();
	return 0;
}

#ifdef CONFIG_IDE
int jp_generic_ide_ioctl(ide_drive_t *drive, struct file *file,
			struct block_device *bdev, unsigned int cmd,
			unsigned long arg)
{
	lkdtm_handler();
	jprobe_return();
	return 0;
}
#endif

static int lkdtm_parse_commandline(void)
{
	int i;

	if (cpoint_name == INVALID || cpoint_type == NONE ||
					cpoint_count < 1 || recur_count < 1)
		return -EINVAL;

	for (i = 0; i < NUM_CPOINTS; ++i) {
		if (!strcmp(cpoint_name, cp_name[i])) {
			cpoint = i + 1;
			break;
		}
	}

	for (i = 0; i < NUM_CPOINT_TYPES; ++i) {
		if (!strcmp(cpoint_type, cp_type[i])) {
			cptype = i + 1;
			break;
		}
	}

	if (cpoint == INVALID || cptype == NONE)
                return -EINVAL;

	count = cpoint_count;

	return 0;
}

static int recursive_loop(int a)
{
	char buf[1024];

	memset(buf,0xFF,1024);
	recur_count--;
	if (!recur_count)
		return 0;
	else
        	return recursive_loop(a);
}

void lkdtm_handler(void)
{
	printk(KERN_INFO "lkdtm : Crash point %s of type %s hit\n",
					 cpoint_name, cpoint_type);
	--count;

	if (count == 0) {
		switch (cptype) {
		case NONE:
			break;
		case PANIC:
			printk(KERN_INFO "lkdtm : PANIC\n");
			panic("dumptest");
			break;
		case BUG:
			printk(KERN_INFO "lkdtm : BUG\n");
			BUG();
			break;
		case EXCEPTION:
			printk(KERN_INFO "lkdtm : EXCEPTION\n");
			*((int *) 0) = 0;
			break;
		case LOOP:
			printk(KERN_INFO "lkdtm : LOOP\n");
			for (;;);
			break;
		case OVERFLOW:
			printk(KERN_INFO "lkdtm : OVERFLOW\n");
			(void) recursive_loop(0);
			break;
		default:
			break;
		}
		count = cpoint_count;
	}
}

int lkdtm_module_init(void)
{
	int ret;

	if (lkdtm_parse_commandline() == -EINVAL) {
		printk(KERN_INFO "lkdtm : Invalid command\n");
		return -EINVAL;
	}

	switch (cpoint) {
	case INT_HARDWARE_ENTRY:
		lkdtm.kp.symbol_name = "__do_IRQ";
		lkdtm.entry = (kprobe_opcode_t*) jp_do_irq;
		break;
	case INT_HW_IRQ_EN:
		lkdtm.kp.symbol_name = "handle_IRQ_event";
		lkdtm.entry = (kprobe_opcode_t*) jp_handle_irq_event;
		break;
	case INT_TASKLET_ENTRY:
		lkdtm.kp.symbol_name = "tasklet_action";
		lkdtm.entry = (kprobe_opcode_t*) jp_tasklet_action;
		break;
	case FS_DEVRW:
		lkdtm.kp.symbol_name = "ll_rw_block";
		lkdtm.entry = (kprobe_opcode_t*) jp_ll_rw_block;
		break;
	case MEM_SWAPOUT:
		lkdtm.kp.symbol_name = "shrink_page_list";
		lkdtm.entry = (kprobe_opcode_t*) jp_shrink_page_list;
		break;
	case TIMERADD:
		lkdtm.kp.symbol_name = "hrtimer_start";
		lkdtm.entry = (kprobe_opcode_t*) jp_hrtimer_start;
		break;
	case SCSI_DISPATCH_CMD:
		lkdtm.kp.symbol_name = "scsi_dispatch_cmd";
		lkdtm.entry = (kprobe_opcode_t*) jp_scsi_dispatch_cmd;
		break;
	case IDE_CORE_CP:
#ifdef CONFIG_IDE
		lkdtm.kp.symbol_name = "generic_ide_ioctl";
		lkdtm.entry = (kprobe_opcode_t*) jp_generic_ide_ioctl;
#else
		printk(KERN_INFO "lkdtm : Crash point not available\n");
#endif
		break;
	default:
		printk(KERN_INFO "lkdtm : Invalid Crash Point\n");
		break;
	}

	if ((ret = register_jprobe(&lkdtm)) < 0) {
                printk(KERN_INFO "lkdtm : Couldn't register jprobe\n");
                return ret;
	}

	printk(KERN_INFO "lkdtm : Crash point %s of type %s registered\n",
						cpoint_name, cpoint_type);
	return 0;
}

void lkdtm_module_exit(void)
{
        unregister_jprobe(&lkdtm);
        printk(KERN_INFO "lkdtm : Crash point unregistered\n");
}

module_init(lkdtm_module_init);
module_exit(lkdtm_module_exit);

MODULE_LICENSE("GPL");