1 /*
2 * test_kprobes.c - simple sanity test for *probes
3 *
4 * Copyright IBM Corp. 2008
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 *
11 * This program is distributed in the hope that it would be useful, but
12 * WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
14 * the GNU General Public License for more details.
15 */
16
17 #include <linux/kernel.h>
18 #include <linux/kprobes.h>
19 #include <linux/random.h>
20
21 #define div_factor 3
22
23 static u32 rand1, preh_val, posth_val, jph_val;
24 static int errors, handler_errors, num_tests;
25 static u32 (*target)(u32 value);
26 static u32 (*target2)(u32 value);
27
kprobe_target(u32 value)28 static noinline u32 kprobe_target(u32 value)
29 {
30 return (value / div_factor);
31 }
32
kp_pre_handler(struct kprobe * p,struct pt_regs * regs)33 static int kp_pre_handler(struct kprobe *p, struct pt_regs *regs)
34 {
35 preh_val = (rand1 / div_factor);
36 return 0;
37 }
38
kp_post_handler(struct kprobe * p,struct pt_regs * regs,unsigned long flags)39 static void kp_post_handler(struct kprobe *p, struct pt_regs *regs,
40 unsigned long flags)
41 {
42 if (preh_val != (rand1 / div_factor)) {
43 handler_errors++;
44 printk(KERN_ERR "Kprobe smoke test failed: "
45 "incorrect value in post_handler\n");
46 }
47 posth_val = preh_val + div_factor;
48 }
49
50 static struct kprobe kp = {
51 .symbol_name = "kprobe_target",
52 .pre_handler = kp_pre_handler,
53 .post_handler = kp_post_handler
54 };
55
test_kprobe(void)56 static int test_kprobe(void)
57 {
58 int ret;
59
60 ret = register_kprobe(&kp);
61 if (ret < 0) {
62 printk(KERN_ERR "Kprobe smoke test failed: "
63 "register_kprobe returned %d\n", ret);
64 return ret;
65 }
66
67 ret = target(rand1);
68 unregister_kprobe(&kp);
69
70 if (preh_val == 0) {
71 printk(KERN_ERR "Kprobe smoke test failed: "
72 "kprobe pre_handler not called\n");
73 handler_errors++;
74 }
75
76 if (posth_val == 0) {
77 printk(KERN_ERR "Kprobe smoke test failed: "
78 "kprobe post_handler not called\n");
79 handler_errors++;
80 }
81
82 return 0;
83 }
84
kprobe_target2(u32 value)85 static noinline u32 kprobe_target2(u32 value)
86 {
87 return (value / div_factor) + 1;
88 }
89
kp_pre_handler2(struct kprobe * p,struct pt_regs * regs)90 static int kp_pre_handler2(struct kprobe *p, struct pt_regs *regs)
91 {
92 preh_val = (rand1 / div_factor) + 1;
93 return 0;
94 }
95
kp_post_handler2(struct kprobe * p,struct pt_regs * regs,unsigned long flags)96 static void kp_post_handler2(struct kprobe *p, struct pt_regs *regs,
97 unsigned long flags)
98 {
99 if (preh_val != (rand1 / div_factor) + 1) {
100 handler_errors++;
101 printk(KERN_ERR "Kprobe smoke test failed: "
102 "incorrect value in post_handler2\n");
103 }
104 posth_val = preh_val + div_factor;
105 }
106
107 static struct kprobe kp2 = {
108 .symbol_name = "kprobe_target2",
109 .pre_handler = kp_pre_handler2,
110 .post_handler = kp_post_handler2
111 };
112
test_kprobes(void)113 static int test_kprobes(void)
114 {
115 int ret;
116 struct kprobe *kps[2] = {&kp, &kp2};
117
118 kp.addr = 0; /* addr should be cleard for reusing kprobe. */
119 ret = register_kprobes(kps, 2);
120 if (ret < 0) {
121 printk(KERN_ERR "Kprobe smoke test failed: "
122 "register_kprobes returned %d\n", ret);
123 return ret;
124 }
125
126 preh_val = 0;
127 posth_val = 0;
128 ret = target(rand1);
129
130 if (preh_val == 0) {
131 printk(KERN_ERR "Kprobe smoke test failed: "
132 "kprobe pre_handler not called\n");
133 handler_errors++;
134 }
135
136 if (posth_val == 0) {
137 printk(KERN_ERR "Kprobe smoke test failed: "
138 "kprobe post_handler not called\n");
139 handler_errors++;
140 }
141
142 preh_val = 0;
143 posth_val = 0;
144 ret = target2(rand1);
145
146 if (preh_val == 0) {
147 printk(KERN_ERR "Kprobe smoke test failed: "
148 "kprobe pre_handler2 not called\n");
149 handler_errors++;
150 }
151
152 if (posth_val == 0) {
153 printk(KERN_ERR "Kprobe smoke test failed: "
154 "kprobe post_handler2 not called\n");
155 handler_errors++;
156 }
157
158 unregister_kprobes(kps, 2);
159 return 0;
160
161 }
162
j_kprobe_target(u32 value)163 static u32 j_kprobe_target(u32 value)
164 {
165 if (value != rand1) {
166 handler_errors++;
167 printk(KERN_ERR "Kprobe smoke test failed: "
168 "incorrect value in jprobe handler\n");
169 }
170
171 jph_val = rand1;
172 jprobe_return();
173 return 0;
174 }
175
176 static struct jprobe jp = {
177 .entry = j_kprobe_target,
178 .kp.symbol_name = "kprobe_target"
179 };
180
test_jprobe(void)181 static int test_jprobe(void)
182 {
183 int ret;
184
185 ret = register_jprobe(&jp);
186 if (ret < 0) {
187 printk(KERN_ERR "Kprobe smoke test failed: "
188 "register_jprobe returned %d\n", ret);
189 return ret;
190 }
191
192 ret = target(rand1);
193 unregister_jprobe(&jp);
194 if (jph_val == 0) {
195 printk(KERN_ERR "Kprobe smoke test failed: "
196 "jprobe handler not called\n");
197 handler_errors++;
198 }
199
200 return 0;
201 }
202
203 static struct jprobe jp2 = {
204 .entry = j_kprobe_target,
205 .kp.symbol_name = "kprobe_target2"
206 };
207
test_jprobes(void)208 static int test_jprobes(void)
209 {
210 int ret;
211 struct jprobe *jps[2] = {&jp, &jp2};
212
213 jp.kp.addr = 0; /* addr should be cleard for reusing kprobe. */
214 ret = register_jprobes(jps, 2);
215 if (ret < 0) {
216 printk(KERN_ERR "Kprobe smoke test failed: "
217 "register_jprobes returned %d\n", ret);
218 return ret;
219 }
220
221 jph_val = 0;
222 ret = target(rand1);
223 if (jph_val == 0) {
224 printk(KERN_ERR "Kprobe smoke test failed: "
225 "jprobe handler not called\n");
226 handler_errors++;
227 }
228
229 jph_val = 0;
230 ret = target2(rand1);
231 if (jph_val == 0) {
232 printk(KERN_ERR "Kprobe smoke test failed: "
233 "jprobe handler2 not called\n");
234 handler_errors++;
235 }
236 unregister_jprobes(jps, 2);
237
238 return 0;
239 }
240 #ifdef CONFIG_KRETPROBES
241 static u32 krph_val;
242
entry_handler(struct kretprobe_instance * ri,struct pt_regs * regs)243 static int entry_handler(struct kretprobe_instance *ri, struct pt_regs *regs)
244 {
245 krph_val = (rand1 / div_factor);
246 return 0;
247 }
248
return_handler(struct kretprobe_instance * ri,struct pt_regs * regs)249 static int return_handler(struct kretprobe_instance *ri, struct pt_regs *regs)
250 {
251 unsigned long ret = regs_return_value(regs);
252
253 if (ret != (rand1 / div_factor)) {
254 handler_errors++;
255 printk(KERN_ERR "Kprobe smoke test failed: "
256 "incorrect value in kretprobe handler\n");
257 }
258 if (krph_val == 0) {
259 handler_errors++;
260 printk(KERN_ERR "Kprobe smoke test failed: "
261 "call to kretprobe entry handler failed\n");
262 }
263
264 krph_val = rand1;
265 return 0;
266 }
267
268 static struct kretprobe rp = {
269 .handler = return_handler,
270 .entry_handler = entry_handler,
271 .kp.symbol_name = "kprobe_target"
272 };
273
test_kretprobe(void)274 static int test_kretprobe(void)
275 {
276 int ret;
277
278 ret = register_kretprobe(&rp);
279 if (ret < 0) {
280 printk(KERN_ERR "Kprobe smoke test failed: "
281 "register_kretprobe returned %d\n", ret);
282 return ret;
283 }
284
285 ret = target(rand1);
286 unregister_kretprobe(&rp);
287 if (krph_val != rand1) {
288 printk(KERN_ERR "Kprobe smoke test failed: "
289 "kretprobe handler not called\n");
290 handler_errors++;
291 }
292
293 return 0;
294 }
295
return_handler2(struct kretprobe_instance * ri,struct pt_regs * regs)296 static int return_handler2(struct kretprobe_instance *ri, struct pt_regs *regs)
297 {
298 unsigned long ret = regs_return_value(regs);
299
300 if (ret != (rand1 / div_factor) + 1) {
301 handler_errors++;
302 printk(KERN_ERR "Kprobe smoke test failed: "
303 "incorrect value in kretprobe handler2\n");
304 }
305 if (krph_val == 0) {
306 handler_errors++;
307 printk(KERN_ERR "Kprobe smoke test failed: "
308 "call to kretprobe entry handler failed\n");
309 }
310
311 krph_val = rand1;
312 return 0;
313 }
314
315 static struct kretprobe rp2 = {
316 .handler = return_handler2,
317 .entry_handler = entry_handler,
318 .kp.symbol_name = "kprobe_target2"
319 };
320
test_kretprobes(void)321 static int test_kretprobes(void)
322 {
323 int ret;
324 struct kretprobe *rps[2] = {&rp, &rp2};
325
326 rp.kp.addr = 0; /* addr should be cleard for reusing kprobe. */
327 ret = register_kretprobes(rps, 2);
328 if (ret < 0) {
329 printk(KERN_ERR "Kprobe smoke test failed: "
330 "register_kretprobe returned %d\n", ret);
331 return ret;
332 }
333
334 krph_val = 0;
335 ret = target(rand1);
336 if (krph_val != rand1) {
337 printk(KERN_ERR "Kprobe smoke test failed: "
338 "kretprobe handler not called\n");
339 handler_errors++;
340 }
341
342 krph_val = 0;
343 ret = target2(rand1);
344 if (krph_val != rand1) {
345 printk(KERN_ERR "Kprobe smoke test failed: "
346 "kretprobe handler2 not called\n");
347 handler_errors++;
348 }
349 unregister_kretprobes(rps, 2);
350 return 0;
351 }
352 #endif /* CONFIG_KRETPROBES */
353
init_test_probes(void)354 int init_test_probes(void)
355 {
356 int ret;
357
358 target = kprobe_target;
359 target2 = kprobe_target2;
360
361 do {
362 rand1 = random32();
363 } while (rand1 <= div_factor);
364
365 printk(KERN_INFO "Kprobe smoke test started\n");
366 num_tests++;
367 ret = test_kprobe();
368 if (ret < 0)
369 errors++;
370
371 num_tests++;
372 ret = test_kprobes();
373 if (ret < 0)
374 errors++;
375
376 num_tests++;
377 ret = test_jprobe();
378 if (ret < 0)
379 errors++;
380
381 num_tests++;
382 ret = test_jprobes();
383 if (ret < 0)
384 errors++;
385
386 #ifdef CONFIG_KRETPROBES
387 num_tests++;
388 ret = test_kretprobe();
389 if (ret < 0)
390 errors++;
391
392 num_tests++;
393 ret = test_kretprobes();
394 if (ret < 0)
395 errors++;
396 #endif /* CONFIG_KRETPROBES */
397
398 if (errors)
399 printk(KERN_ERR "BUG: Kprobe smoke test: %d out of "
400 "%d tests failed\n", errors, num_tests);
401 else if (handler_errors)
402 printk(KERN_ERR "BUG: Kprobe smoke test: %d error(s) "
403 "running handlers\n", handler_errors);
404 else
405 printk(KERN_INFO "Kprobe smoke test passed successfully\n");
406
407 return 0;
408 }
409