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 /* addr and flags should be cleard for reusing kprobe. */
119 kp.addr = NULL;
120 kp.flags = 0;
121 ret = register_kprobes(kps, 2);
122 if (ret < 0) {
123 printk(KERN_ERR "Kprobe smoke test failed: "
124 "register_kprobes returned %d\n", ret);
125 return ret;
126 }
127
128 preh_val = 0;
129 posth_val = 0;
130 ret = target(rand1);
131
132 if (preh_val == 0) {
133 printk(KERN_ERR "Kprobe smoke test failed: "
134 "kprobe pre_handler not called\n");
135 handler_errors++;
136 }
137
138 if (posth_val == 0) {
139 printk(KERN_ERR "Kprobe smoke test failed: "
140 "kprobe post_handler not called\n");
141 handler_errors++;
142 }
143
144 preh_val = 0;
145 posth_val = 0;
146 ret = target2(rand1);
147
148 if (preh_val == 0) {
149 printk(KERN_ERR "Kprobe smoke test failed: "
150 "kprobe pre_handler2 not called\n");
151 handler_errors++;
152 }
153
154 if (posth_val == 0) {
155 printk(KERN_ERR "Kprobe smoke test failed: "
156 "kprobe post_handler2 not called\n");
157 handler_errors++;
158 }
159
160 unregister_kprobes(kps, 2);
161 return 0;
162
163 }
164
j_kprobe_target(u32 value)165 static u32 j_kprobe_target(u32 value)
166 {
167 if (value != rand1) {
168 handler_errors++;
169 printk(KERN_ERR "Kprobe smoke test failed: "
170 "incorrect value in jprobe handler\n");
171 }
172
173 jph_val = rand1;
174 jprobe_return();
175 return 0;
176 }
177
178 static struct jprobe jp = {
179 .entry = j_kprobe_target,
180 .kp.symbol_name = "kprobe_target"
181 };
182
test_jprobe(void)183 static int test_jprobe(void)
184 {
185 int ret;
186
187 ret = register_jprobe(&jp);
188 if (ret < 0) {
189 printk(KERN_ERR "Kprobe smoke test failed: "
190 "register_jprobe returned %d\n", ret);
191 return ret;
192 }
193
194 ret = target(rand1);
195 unregister_jprobe(&jp);
196 if (jph_val == 0) {
197 printk(KERN_ERR "Kprobe smoke test failed: "
198 "jprobe handler not called\n");
199 handler_errors++;
200 }
201
202 return 0;
203 }
204
205 static struct jprobe jp2 = {
206 .entry = j_kprobe_target,
207 .kp.symbol_name = "kprobe_target2"
208 };
209
test_jprobes(void)210 static int test_jprobes(void)
211 {
212 int ret;
213 struct jprobe *jps[2] = {&jp, &jp2};
214
215 /* addr and flags should be cleard for reusing kprobe. */
216 jp.kp.addr = NULL;
217 jp.kp.flags = 0;
218 ret = register_jprobes(jps, 2);
219 if (ret < 0) {
220 printk(KERN_ERR "Kprobe smoke test failed: "
221 "register_jprobes returned %d\n", ret);
222 return ret;
223 }
224
225 jph_val = 0;
226 ret = target(rand1);
227 if (jph_val == 0) {
228 printk(KERN_ERR "Kprobe smoke test failed: "
229 "jprobe handler not called\n");
230 handler_errors++;
231 }
232
233 jph_val = 0;
234 ret = target2(rand1);
235 if (jph_val == 0) {
236 printk(KERN_ERR "Kprobe smoke test failed: "
237 "jprobe handler2 not called\n");
238 handler_errors++;
239 }
240 unregister_jprobes(jps, 2);
241
242 return 0;
243 }
244 #ifdef CONFIG_KRETPROBES
245 static u32 krph_val;
246
entry_handler(struct kretprobe_instance * ri,struct pt_regs * regs)247 static int entry_handler(struct kretprobe_instance *ri, struct pt_regs *regs)
248 {
249 krph_val = (rand1 / div_factor);
250 return 0;
251 }
252
return_handler(struct kretprobe_instance * ri,struct pt_regs * regs)253 static int return_handler(struct kretprobe_instance *ri, struct pt_regs *regs)
254 {
255 unsigned long ret = regs_return_value(regs);
256
257 if (ret != (rand1 / div_factor)) {
258 handler_errors++;
259 printk(KERN_ERR "Kprobe smoke test failed: "
260 "incorrect value in kretprobe handler\n");
261 }
262 if (krph_val == 0) {
263 handler_errors++;
264 printk(KERN_ERR "Kprobe smoke test failed: "
265 "call to kretprobe entry handler failed\n");
266 }
267
268 krph_val = rand1;
269 return 0;
270 }
271
272 static struct kretprobe rp = {
273 .handler = return_handler,
274 .entry_handler = entry_handler,
275 .kp.symbol_name = "kprobe_target"
276 };
277
test_kretprobe(void)278 static int test_kretprobe(void)
279 {
280 int ret;
281
282 ret = register_kretprobe(&rp);
283 if (ret < 0) {
284 printk(KERN_ERR "Kprobe smoke test failed: "
285 "register_kretprobe returned %d\n", ret);
286 return ret;
287 }
288
289 ret = target(rand1);
290 unregister_kretprobe(&rp);
291 if (krph_val != rand1) {
292 printk(KERN_ERR "Kprobe smoke test failed: "
293 "kretprobe handler not called\n");
294 handler_errors++;
295 }
296
297 return 0;
298 }
299
return_handler2(struct kretprobe_instance * ri,struct pt_regs * regs)300 static int return_handler2(struct kretprobe_instance *ri, struct pt_regs *regs)
301 {
302 unsigned long ret = regs_return_value(regs);
303
304 if (ret != (rand1 / div_factor) + 1) {
305 handler_errors++;
306 printk(KERN_ERR "Kprobe smoke test failed: "
307 "incorrect value in kretprobe handler2\n");
308 }
309 if (krph_val == 0) {
310 handler_errors++;
311 printk(KERN_ERR "Kprobe smoke test failed: "
312 "call to kretprobe entry handler failed\n");
313 }
314
315 krph_val = rand1;
316 return 0;
317 }
318
319 static struct kretprobe rp2 = {
320 .handler = return_handler2,
321 .entry_handler = entry_handler,
322 .kp.symbol_name = "kprobe_target2"
323 };
324
test_kretprobes(void)325 static int test_kretprobes(void)
326 {
327 int ret;
328 struct kretprobe *rps[2] = {&rp, &rp2};
329
330 /* addr and flags should be cleard for reusing kprobe. */
331 rp.kp.addr = NULL;
332 rp.kp.flags = 0;
333 ret = register_kretprobes(rps, 2);
334 if (ret < 0) {
335 printk(KERN_ERR "Kprobe smoke test failed: "
336 "register_kretprobe returned %d\n", ret);
337 return ret;
338 }
339
340 krph_val = 0;
341 ret = target(rand1);
342 if (krph_val != rand1) {
343 printk(KERN_ERR "Kprobe smoke test failed: "
344 "kretprobe handler not called\n");
345 handler_errors++;
346 }
347
348 krph_val = 0;
349 ret = target2(rand1);
350 if (krph_val != rand1) {
351 printk(KERN_ERR "Kprobe smoke test failed: "
352 "kretprobe handler2 not called\n");
353 handler_errors++;
354 }
355 unregister_kretprobes(rps, 2);
356 return 0;
357 }
358 #endif /* CONFIG_KRETPROBES */
359
init_test_probes(void)360 int init_test_probes(void)
361 {
362 int ret;
363
364 target = kprobe_target;
365 target2 = kprobe_target2;
366
367 do {
368 rand1 = random32();
369 } while (rand1 <= div_factor);
370
371 printk(KERN_INFO "Kprobe smoke test started\n");
372 num_tests++;
373 ret = test_kprobe();
374 if (ret < 0)
375 errors++;
376
377 num_tests++;
378 ret = test_kprobes();
379 if (ret < 0)
380 errors++;
381
382 num_tests++;
383 ret = test_jprobe();
384 if (ret < 0)
385 errors++;
386
387 num_tests++;
388 ret = test_jprobes();
389 if (ret < 0)
390 errors++;
391
392 #ifdef CONFIG_KRETPROBES
393 num_tests++;
394 ret = test_kretprobe();
395 if (ret < 0)
396 errors++;
397
398 num_tests++;
399 ret = test_kretprobes();
400 if (ret < 0)
401 errors++;
402 #endif /* CONFIG_KRETPROBES */
403
404 if (errors)
405 printk(KERN_ERR "BUG: Kprobe smoke test: %d out of "
406 "%d tests failed\n", errors, num_tests);
407 else if (handler_errors)
408 printk(KERN_ERR "BUG: Kprobe smoke test: %d error(s) "
409 "running handlers\n", handler_errors);
410 else
411 printk(KERN_INFO "Kprobe smoke test passed successfully\n");
412
413 return 0;
414 }
415