aboutsummaryrefslogtreecommitdiff
path: root/kernel/test_kprobes.c
blob: f8b11a283171b65849c5ed3bc0e162397f76fbea (plain)
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
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
/*
 * test_kprobes.c - simple sanity test for *probes
 *
 * Copyright IBM Corp. 2008
 *
 * 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 would 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.
 */

#include <linux/kernel.h>
#include <linux/kprobes.h>
#include <linux/random.h>

#define div_factor 3

static u32 rand1, preh_val, posth_val, jph_val;
static int errors, handler_errors, num_tests;
static u32 (*target)(u32 value);
static u32 (*target2)(u32 value);

static noinline u32 kprobe_target(u32 value)
{
	return (value / div_factor);
}

static int kp_pre_handler(struct kprobe *p, struct pt_regs *regs)
{
	preh_val = (rand1 / div_factor);
	return 0;
}

static void kp_post_handler(struct kprobe *p, struct pt_regs *regs,
		unsigned long flags)
{
	if (preh_val != (rand1 / div_factor)) {
		handler_errors++;
		printk(KERN_ERR "Kprobe smoke test failed: "
				"incorrect value in post_handler\n");
	}
	posth_val = preh_val + div_factor;
}

static struct kprobe kp = {
	.symbol_name = "kprobe_target",
	.pre_handler = kp_pre_handler,
	.post_handler = kp_post_handler
};

static int test_kprobe(void)
{
	int ret;

	ret = register_kprobe(&kp);
	if (ret < 0) {
		printk(KERN_ERR "Kprobe smoke test failed: "
				"register_kprobe returned %d\n", ret);
		return ret;
	}

	ret = target(rand1);
	unregister_kprobe(&kp);

	if (preh_val == 0) {
		printk(KERN_ERR "Kprobe smoke test failed: "
				"kprobe pre_handler not called\n");
		handler_errors++;
	}

	if (posth_val == 0) {
		printk(KERN_ERR "Kprobe smoke test failed: "
				"kprobe post_handler not called\n");
		handler_errors++;
	}

	return 0;
}

static noinline u32 kprobe_target2(u32 value)
{
	return (value / div_factor) + 1;
}

static int kp_pre_handler2(struct kprobe *p, struct pt_regs *regs)
{
	preh_val = (rand1 / div_factor) + 1;
	return 0;
}

static void kp_post_handler2(struct kprobe *p, struct pt_regs *regs,
		unsigned long flags)
{
	if (preh_val != (rand1 / div_factor) + 1) {
		handler_errors++;
		printk(KERN_ERR "Kprobe smoke test failed: "
				"incorrect value in post_handler2\n");
	}
	posth_val = preh_val + div_factor;
}

static struct kprobe kp2 = {
	.symbol_name = "kprobe_target2",
	.pre_handler = kp_pre_handler2,
	.post_handler = kp_post_handler2
};

static int test_kprobes(void)
{
	int ret;
	struct kprobe *kps[2] = {&kp, &kp2};

	/* addr and flags should be cleard for reusing kprobe. */
	kp.addr = NULL;
	kp.flags = 0;
	ret = register_kprobes(kps, 2);
	if (ret < 0) {
		printk(KERN_ERR "Kprobe smoke test failed: "
				"register_kprobes returned %d\n", ret);
		return ret;
	}

	preh_val = 0;
	posth_val = 0;
	ret = target(rand1);

	if (preh_val == 0) {
		printk(KERN_ERR "Kprobe smoke test failed: "
				"kprobe pre_handler not called\n");
		handler_errors++;
	}

	if (posth_val == 0) {
		printk(KERN_ERR "Kprobe smoke test failed: "
				"kprobe post_handler not called\n");
		handler_errors++;
	}

	preh_val = 0;
	posth_val = 0;
	ret = target2(rand1);

	if (preh_val == 0) {
		printk(KERN_ERR "Kprobe smoke test failed: "
				"kprobe pre_handler2 not called\n");
		handler_errors++;
	}

	if (posth_val == 0) {
		printk(KERN_ERR "Kprobe smoke test failed: "
				"kprobe post_handler2 not called\n");
		handler_errors++;
	}

	unregister_kprobes(kps, 2);
	return 0;

}

static u32 j_kprobe_target(u32 value)
{
	if (value != rand1) {
		handler_errors++;
		printk(KERN_ERR "Kprobe smoke test failed: "
				"incorrect value in jprobe handler\n");
	}

	jph_val = rand1;
	jprobe_return();
	return 0;
}

static struct jprobe jp = {
	.entry		= j_kprobe_target,
	.kp.symbol_name = "kprobe_target"
};

static int test_jprobe(void)
{
	int ret;

	ret = register_jprobe(&jp);
	if (ret < 0) {
		printk(KERN_ERR "Kprobe smoke test failed: "
				"register_jprobe returned %d\n", ret);
		return ret;
	}

	ret = target(rand1);
	unregister_jprobe(&jp);
	if (jph_val == 0) {
		printk(KERN_ERR "Kprobe smoke test failed: "
				"jprobe handler not called\n");
		handler_errors++;
	}

	return 0;
}

static struct jprobe jp2 = {
	.entry          = j_kprobe_target,
	.kp.symbol_name = "kprobe_target2"
};

static int test_jprobes(void)
{
	int ret;
	struct jprobe *jps[2] = {&jp, &jp2};

	/* addr and flags should be cleard for reusing kprobe. */
	jp.kp.addr = NULL;
	jp.kp.flags = 0;
	ret = register_jprobes(jps, 2);
	if (ret < 0) {
		printk(KERN_ERR "Kprobe smoke test failed: "
				"register_jprobes returned %d\n", ret);
		return ret;
	}

	jph_val = 0;
	ret = target(rand1);
	if (jph_val == 0) {
		printk(KERN_ERR "Kprobe smoke test failed: "
				"jprobe handler not called\n");
		handler_errors++;
	}

	jph_val = 0;
	ret = target2(rand1);
	if (jph_val == 0) {
		printk(KERN_ERR "Kprobe smoke test failed: "
				"jprobe handler2 not called\n");
		handler_errors++;
	}
	unregister_jprobes(jps, 2);

	return 0;
}
#ifdef CONFIG_KRETPROBES
static u32 krph_val;

static int entry_handler(struct kretprobe_instance *ri, struct pt_regs *regs)
{
	krph_val = (rand1 / div_factor);
	return 0;
}

static int return_handler(struct kretprobe_instance *ri, struct pt_regs *regs)
{
	unsigned long ret = regs_return_value(regs);

	if (ret != (rand1 / div_factor)) {
		handler_errors++;
		printk(KERN_ERR "Kprobe smoke test failed: "
				"incorrect value in kretprobe handler\n");
	}
	if (krph_val == 0) {
		handler_errors++;
		printk(KERN_ERR "Kprobe smoke test failed: "
				"call to kretprobe entry handler failed\n");
	}

	krph_val = rand1;
	return 0;
}

static struct kretprobe rp = {
	.handler	= return_handler,
	.entry_handler  = entry_handler,
	.kp.symbol_name = "kprobe_target"
};

static int test_kretprobe(void)
{
	int ret;

	ret = register_kretprobe(&rp);
	if (ret < 0) {
		printk(KERN_ERR "Kprobe smoke test failed: "
				"register_kretprobe returned %d\n", ret);
		return ret;
	}

	ret = target(rand1);
	unregister_kretprobe(&rp);
	if (krph_val != rand1) {
		printk(KERN_ERR "Kprobe smoke test failed: "
				"kretprobe handler not called\n");
		handler_errors++;
	}

	return 0;
}

static int return_handler2(struct kretprobe_instance *ri, struct pt_regs *regs)
{
	unsigned long ret = regs_return_value(regs);

	if (ret != (rand1 / div_factor) + 1) {
		handler_errors++;
		printk(KERN_ERR "Kprobe smoke test failed: "
				"incorrect value in kretprobe handler2\n");
	}
	if (krph_val == 0) {
		handler_errors++;
		printk(KERN_ERR "Kprobe smoke test failed: "
				"call to kretprobe entry handler failed\n");
	}

	krph_val = rand1;
	return 0;
}

static struct kretprobe rp2 = {
	.handler	= return_handler2,
	.entry_handler  = entry_handler,
	.kp.symbol_name = "kprobe_target2"
};

static int test_kretprobes(void)
{
	int ret;
	struct kretprobe *rps[2] = {&rp, &rp2};

	/* addr and flags should be cleard for reusing kprobe. */
	rp.kp.addr = NULL;
	rp.kp.flags = 0;
	ret = register_kretprobes(rps, 2);
	if (ret < 0) {
		printk(KERN_ERR "Kprobe smoke test failed: "
				"register_kretprobe returned %d\n", ret);
		return ret;
	}

	krph_val = 0;
	ret = target(rand1);
	if (krph_val != rand1) {
		printk(KERN_ERR "Kprobe smoke test failed: "
				"kretprobe handler not called\n");
		handler_errors++;
	}

	krph_val = 0;
	ret = target2(rand1);
	if (krph_val != rand1) {
		printk(KERN_ERR "Kprobe smoke test failed: "
				"kretprobe handler2 not called\n");
		handler_errors++;
	}
	unregister_kretprobes(rps, 2);
	return 0;
}
#endif /* CONFIG_KRETPROBES */

int init_test_probes(void)
{
	int ret;

	target = kprobe_target;
	target2 = kprobe_target2;

	do {
		rand1 = random32();
	} while (rand1 <= div_factor);

	printk(KERN_INFO "Kprobe smoke test started\n");
	num_tests++;
	ret = test_kprobe();
	if (ret < 0)
		errors++;

	num_tests++;
	ret = test_kprobes();
	if (ret < 0)
		errors++;

	num_tests++;
	ret = test_jprobe();
	if (ret < 0)
		errors++;

	num_tests++;
	ret = test_jprobes();
	if (ret < 0)
		errors++;

#ifdef CONFIG_KRETPROBES
	num_tests++;
	ret = test_kretprobe();
	if (ret < 0)
		errors++;

	num_tests++;
	ret = test_kretprobes();
	if (ret < 0)
		errors++;
#endif /* CONFIG_KRETPROBES */

	if (errors)
		printk(KERN_ERR "BUG: Kprobe smoke test: %d out of "
				"%d tests failed\n", errors, num_tests);
	else if (handler_errors)
		printk(KERN_ERR "BUG: Kprobe smoke test: %d error(s) "
				"running handlers\n", handler_errors);
	else
		printk(KERN_INFO "Kprobe smoke test passed successfully\n");

	return 0;
}