1 // SPDX-License-Identifier: GPL-2.0
2 /* Include in trace.c */
3
4 #include <uapi/linux/sched/types.h>
5 #include <linux/stringify.h>
6 #include <linux/kthread.h>
7 #include <linux/delay.h>
8 #include <linux/slab.h>
9
trace_valid_entry(struct trace_entry * entry)10 static inline int trace_valid_entry(struct trace_entry *entry)
11 {
12 switch (entry->type) {
13 case TRACE_FN:
14 case TRACE_CTX:
15 case TRACE_WAKE:
16 case TRACE_STACK:
17 case TRACE_PRINT:
18 case TRACE_BRANCH:
19 case TRACE_GRAPH_ENT:
20 case TRACE_GRAPH_RETADDR_ENT:
21 case TRACE_GRAPH_RET:
22 return 1;
23 }
24 return 0;
25 }
26
trace_test_buffer_cpu(struct array_buffer * buf,int cpu)27 static int trace_test_buffer_cpu(struct array_buffer *buf, int cpu)
28 {
29 struct ring_buffer_event *event;
30 struct trace_entry *entry;
31 unsigned int loops = 0;
32
33 while ((event = ring_buffer_consume(buf->buffer, cpu, NULL, NULL))) {
34 entry = ring_buffer_event_data(event);
35
36 /*
37 * The ring buffer is a size of trace_buf_size, if
38 * we loop more than the size, there's something wrong
39 * with the ring buffer.
40 */
41 if (loops++ > trace_buf_size) {
42 printk(KERN_CONT ".. bad ring buffer ");
43 goto failed;
44 }
45 if (!trace_valid_entry(entry)) {
46 printk(KERN_CONT ".. invalid entry %d ",
47 entry->type);
48 goto failed;
49 }
50 }
51 return 0;
52
53 failed:
54 /* disable tracing */
55 tracing_disabled = 1;
56 printk(KERN_CONT ".. corrupted trace buffer .. ");
57 return -1;
58 }
59
60 /*
61 * Test the trace buffer to see if all the elements
62 * are still sane.
63 */
trace_test_buffer(struct array_buffer * buf,unsigned long * count)64 static int __maybe_unused trace_test_buffer(struct array_buffer *buf, unsigned long *count)
65 {
66 unsigned long flags, cnt = 0;
67 int cpu, ret = 0;
68
69 /* Don't allow flipping of max traces now */
70 local_irq_save(flags);
71 arch_spin_lock(&buf->tr->max_lock);
72
73 cnt = ring_buffer_entries(buf->buffer);
74
75 /*
76 * The trace_test_buffer_cpu runs a while loop to consume all data.
77 * If the calling tracer is broken, and is constantly filling
78 * the buffer, this will run forever, and hard lock the box.
79 * We disable the ring buffer while we do this test to prevent
80 * a hard lock up.
81 */
82 tracing_off();
83 for_each_possible_cpu(cpu) {
84 ret = trace_test_buffer_cpu(buf, cpu);
85 if (ret)
86 break;
87 }
88 tracing_on();
89 arch_spin_unlock(&buf->tr->max_lock);
90 local_irq_restore(flags);
91
92 if (count)
93 *count = cnt;
94
95 return ret;
96 }
97
warn_failed_init_tracer(struct tracer * trace,int init_ret)98 static inline void warn_failed_init_tracer(struct tracer *trace, int init_ret)
99 {
100 printk(KERN_WARNING "Failed to init %s tracer, init returned %d\n",
101 trace->name, init_ret);
102 }
103 #ifdef CONFIG_FUNCTION_TRACER
104
105 #ifdef CONFIG_DYNAMIC_FTRACE
106
107 static int trace_selftest_test_probe1_cnt;
trace_selftest_test_probe1_func(unsigned long ip,unsigned long pip,struct ftrace_ops * op,struct ftrace_regs * fregs)108 static void trace_selftest_test_probe1_func(unsigned long ip,
109 unsigned long pip,
110 struct ftrace_ops *op,
111 struct ftrace_regs *fregs)
112 {
113 trace_selftest_test_probe1_cnt++;
114 }
115
116 static int trace_selftest_test_probe2_cnt;
trace_selftest_test_probe2_func(unsigned long ip,unsigned long pip,struct ftrace_ops * op,struct ftrace_regs * fregs)117 static void trace_selftest_test_probe2_func(unsigned long ip,
118 unsigned long pip,
119 struct ftrace_ops *op,
120 struct ftrace_regs *fregs)
121 {
122 trace_selftest_test_probe2_cnt++;
123 }
124
125 static int trace_selftest_test_probe3_cnt;
trace_selftest_test_probe3_func(unsigned long ip,unsigned long pip,struct ftrace_ops * op,struct ftrace_regs * fregs)126 static void trace_selftest_test_probe3_func(unsigned long ip,
127 unsigned long pip,
128 struct ftrace_ops *op,
129 struct ftrace_regs *fregs)
130 {
131 trace_selftest_test_probe3_cnt++;
132 }
133
134 static int trace_selftest_test_global_cnt;
trace_selftest_test_global_func(unsigned long ip,unsigned long pip,struct ftrace_ops * op,struct ftrace_regs * fregs)135 static void trace_selftest_test_global_func(unsigned long ip,
136 unsigned long pip,
137 struct ftrace_ops *op,
138 struct ftrace_regs *fregs)
139 {
140 trace_selftest_test_global_cnt++;
141 }
142
143 static int trace_selftest_test_dyn_cnt;
trace_selftest_test_dyn_func(unsigned long ip,unsigned long pip,struct ftrace_ops * op,struct ftrace_regs * fregs)144 static void trace_selftest_test_dyn_func(unsigned long ip,
145 unsigned long pip,
146 struct ftrace_ops *op,
147 struct ftrace_regs *fregs)
148 {
149 trace_selftest_test_dyn_cnt++;
150 }
151
152 static struct ftrace_ops test_probe1 = {
153 .func = trace_selftest_test_probe1_func,
154 };
155
156 static struct ftrace_ops test_probe2 = {
157 .func = trace_selftest_test_probe2_func,
158 };
159
160 static struct ftrace_ops test_probe3 = {
161 .func = trace_selftest_test_probe3_func,
162 };
163
print_counts(void)164 static void print_counts(void)
165 {
166 printk("(%d %d %d %d %d) ",
167 trace_selftest_test_probe1_cnt,
168 trace_selftest_test_probe2_cnt,
169 trace_selftest_test_probe3_cnt,
170 trace_selftest_test_global_cnt,
171 trace_selftest_test_dyn_cnt);
172 }
173
reset_counts(void)174 static void reset_counts(void)
175 {
176 trace_selftest_test_probe1_cnt = 0;
177 trace_selftest_test_probe2_cnt = 0;
178 trace_selftest_test_probe3_cnt = 0;
179 trace_selftest_test_global_cnt = 0;
180 trace_selftest_test_dyn_cnt = 0;
181 }
182
trace_selftest_ops(struct trace_array * tr,int cnt)183 static int trace_selftest_ops(struct trace_array *tr, int cnt)
184 {
185 int save_ftrace_enabled = ftrace_enabled;
186 struct ftrace_ops *dyn_ops;
187 char *func1_name;
188 char *func2_name;
189 int len1;
190 int len2;
191 int ret = -1;
192
193 printk(KERN_CONT "PASSED\n");
194 pr_info("Testing dynamic ftrace ops #%d: ", cnt);
195
196 ftrace_enabled = 1;
197 reset_counts();
198
199 /* Handle PPC64 '.' name */
200 func1_name = "*" __stringify(DYN_FTRACE_TEST_NAME);
201 func2_name = "*" __stringify(DYN_FTRACE_TEST_NAME2);
202 len1 = strlen(func1_name);
203 len2 = strlen(func2_name);
204
205 /*
206 * Probe 1 will trace function 1.
207 * Probe 2 will trace function 2.
208 * Probe 3 will trace functions 1 and 2.
209 */
210 ftrace_set_filter(&test_probe1, func1_name, len1, 1);
211 ftrace_set_filter(&test_probe2, func2_name, len2, 1);
212 ftrace_set_filter(&test_probe3, func1_name, len1, 1);
213 ftrace_set_filter(&test_probe3, func2_name, len2, 0);
214
215 register_ftrace_function(&test_probe1);
216 register_ftrace_function(&test_probe2);
217 register_ftrace_function(&test_probe3);
218 /* First time we are running with main function */
219 if (cnt > 1) {
220 ftrace_init_array_ops(tr, trace_selftest_test_global_func);
221 register_ftrace_function(tr->ops);
222 }
223
224 DYN_FTRACE_TEST_NAME();
225
226 print_counts();
227
228 if (trace_selftest_test_probe1_cnt != 1)
229 goto out;
230 if (trace_selftest_test_probe2_cnt != 0)
231 goto out;
232 if (trace_selftest_test_probe3_cnt != 1)
233 goto out;
234 if (cnt > 1) {
235 if (trace_selftest_test_global_cnt == 0)
236 goto out;
237 }
238
239 DYN_FTRACE_TEST_NAME2();
240
241 print_counts();
242
243 if (trace_selftest_test_probe1_cnt != 1)
244 goto out;
245 if (trace_selftest_test_probe2_cnt != 1)
246 goto out;
247 if (trace_selftest_test_probe3_cnt != 2)
248 goto out;
249
250 /* Add a dynamic probe */
251 dyn_ops = kzalloc(sizeof(*dyn_ops), GFP_KERNEL);
252 if (!dyn_ops) {
253 printk("MEMORY ERROR ");
254 goto out;
255 }
256
257 dyn_ops->func = trace_selftest_test_dyn_func;
258
259 register_ftrace_function(dyn_ops);
260
261 trace_selftest_test_global_cnt = 0;
262
263 DYN_FTRACE_TEST_NAME();
264
265 print_counts();
266
267 if (trace_selftest_test_probe1_cnt != 2)
268 goto out_free;
269 if (trace_selftest_test_probe2_cnt != 1)
270 goto out_free;
271 if (trace_selftest_test_probe3_cnt != 3)
272 goto out_free;
273 if (cnt > 1) {
274 if (trace_selftest_test_global_cnt == 0)
275 goto out_free;
276 }
277 if (trace_selftest_test_dyn_cnt == 0)
278 goto out_free;
279
280 DYN_FTRACE_TEST_NAME2();
281
282 print_counts();
283
284 if (trace_selftest_test_probe1_cnt != 2)
285 goto out_free;
286 if (trace_selftest_test_probe2_cnt != 2)
287 goto out_free;
288 if (trace_selftest_test_probe3_cnt != 4)
289 goto out_free;
290
291 /* Remove trace function from probe 3 */
292 func1_name = "!" __stringify(DYN_FTRACE_TEST_NAME);
293 len1 = strlen(func1_name);
294
295 ftrace_set_filter(&test_probe3, func1_name, len1, 0);
296
297 DYN_FTRACE_TEST_NAME();
298
299 print_counts();
300
301 if (trace_selftest_test_probe1_cnt != 3)
302 goto out_free;
303 if (trace_selftest_test_probe2_cnt != 2)
304 goto out_free;
305 if (trace_selftest_test_probe3_cnt != 4)
306 goto out_free;
307 if (cnt > 1) {
308 if (trace_selftest_test_global_cnt == 0)
309 goto out_free;
310 }
311 if (trace_selftest_test_dyn_cnt == 0)
312 goto out_free;
313
314 DYN_FTRACE_TEST_NAME2();
315
316 print_counts();
317
318 if (trace_selftest_test_probe1_cnt != 3)
319 goto out_free;
320 if (trace_selftest_test_probe2_cnt != 3)
321 goto out_free;
322 if (trace_selftest_test_probe3_cnt != 5)
323 goto out_free;
324
325 ret = 0;
326 out_free:
327 unregister_ftrace_function(dyn_ops);
328 kfree(dyn_ops);
329
330 out:
331 /* Purposely unregister in the same order */
332 unregister_ftrace_function(&test_probe1);
333 unregister_ftrace_function(&test_probe2);
334 unregister_ftrace_function(&test_probe3);
335 if (cnt > 1)
336 unregister_ftrace_function(tr->ops);
337 ftrace_reset_array_ops(tr);
338
339 /* Make sure everything is off */
340 reset_counts();
341 DYN_FTRACE_TEST_NAME();
342 DYN_FTRACE_TEST_NAME();
343
344 if (trace_selftest_test_probe1_cnt ||
345 trace_selftest_test_probe2_cnt ||
346 trace_selftest_test_probe3_cnt ||
347 trace_selftest_test_global_cnt ||
348 trace_selftest_test_dyn_cnt)
349 ret = -1;
350
351 ftrace_enabled = save_ftrace_enabled;
352
353 return ret;
354 }
355
356 /* Test dynamic code modification and ftrace filters */
trace_selftest_startup_dynamic_tracing(struct tracer * trace,struct trace_array * tr,int (* func)(void))357 static int trace_selftest_startup_dynamic_tracing(struct tracer *trace,
358 struct trace_array *tr,
359 int (*func)(void))
360 {
361 int save_ftrace_enabled = ftrace_enabled;
362 unsigned long count;
363 char *func_name;
364 int ret;
365
366 /* The ftrace test PASSED */
367 printk(KERN_CONT "PASSED\n");
368 pr_info("Testing dynamic ftrace: ");
369
370 /* enable tracing, and record the filter function */
371 ftrace_enabled = 1;
372
373 /* passed in by parameter to fool gcc from optimizing */
374 func();
375
376 /*
377 * Some archs *cough*PowerPC*cough* add characters to the
378 * start of the function names. We simply put a '*' to
379 * accommodate them.
380 */
381 func_name = "*" __stringify(DYN_FTRACE_TEST_NAME);
382
383 /* filter only on our function */
384 ftrace_set_global_filter(func_name, strlen(func_name), 1);
385
386 /* enable tracing */
387 ret = tracer_init(trace, tr);
388 if (ret) {
389 warn_failed_init_tracer(trace, ret);
390 goto out;
391 }
392
393 /* Sleep for a 1/10 of a second */
394 msleep(100);
395
396 /* we should have nothing in the buffer */
397 ret = trace_test_buffer(&tr->array_buffer, &count);
398 if (ret)
399 goto out;
400
401 if (count) {
402 ret = -1;
403 printk(KERN_CONT ".. filter did not filter .. ");
404 goto out;
405 }
406
407 /* call our function again */
408 func();
409
410 /* sleep again */
411 msleep(100);
412
413 /* stop the tracing. */
414 tracing_stop();
415 ftrace_enabled = 0;
416
417 /* check the trace buffer */
418 ret = trace_test_buffer(&tr->array_buffer, &count);
419
420 ftrace_enabled = 1;
421 tracing_start();
422
423 /* we should only have one item */
424 if (!ret && count != 1) {
425 trace->reset(tr);
426 printk(KERN_CONT ".. filter failed count=%ld ..", count);
427 ret = -1;
428 goto out;
429 }
430
431 /* Test the ops with global tracing running */
432 ret = trace_selftest_ops(tr, 1);
433 trace->reset(tr);
434
435 out:
436 ftrace_enabled = save_ftrace_enabled;
437
438 /* Enable tracing on all functions again */
439 ftrace_set_global_filter(NULL, 0, 1);
440
441 /* Test the ops with global tracing off */
442 if (!ret)
443 ret = trace_selftest_ops(tr, 2);
444
445 return ret;
446 }
447
448 static int trace_selftest_recursion_cnt;
trace_selftest_test_recursion_func(unsigned long ip,unsigned long pip,struct ftrace_ops * op,struct ftrace_regs * fregs)449 static void trace_selftest_test_recursion_func(unsigned long ip,
450 unsigned long pip,
451 struct ftrace_ops *op,
452 struct ftrace_regs *fregs)
453 {
454 /*
455 * This function is registered without the recursion safe flag.
456 * The ftrace infrastructure should provide the recursion
457 * protection. If not, this will crash the kernel!
458 */
459 if (trace_selftest_recursion_cnt++ > 10)
460 return;
461 DYN_FTRACE_TEST_NAME();
462 }
463
trace_selftest_test_recursion_safe_func(unsigned long ip,unsigned long pip,struct ftrace_ops * op,struct ftrace_regs * fregs)464 static void trace_selftest_test_recursion_safe_func(unsigned long ip,
465 unsigned long pip,
466 struct ftrace_ops *op,
467 struct ftrace_regs *fregs)
468 {
469 /*
470 * We said we would provide our own recursion. By calling
471 * this function again, we should recurse back into this function
472 * and count again. But this only happens if the arch supports
473 * all of ftrace features and nothing else is using the function
474 * tracing utility.
475 */
476 if (trace_selftest_recursion_cnt++)
477 return;
478 DYN_FTRACE_TEST_NAME();
479 }
480
481 static struct ftrace_ops test_rec_probe = {
482 .func = trace_selftest_test_recursion_func,
483 .flags = FTRACE_OPS_FL_RECURSION,
484 };
485
486 static struct ftrace_ops test_recsafe_probe = {
487 .func = trace_selftest_test_recursion_safe_func,
488 };
489
490 static int
trace_selftest_function_recursion(void)491 trace_selftest_function_recursion(void)
492 {
493 int save_ftrace_enabled = ftrace_enabled;
494 char *func_name;
495 int len;
496 int ret;
497
498 /* The previous test PASSED */
499 pr_cont("PASSED\n");
500 pr_info("Testing ftrace recursion: ");
501
502
503 /* enable tracing, and record the filter function */
504 ftrace_enabled = 1;
505
506 /* Handle PPC64 '.' name */
507 func_name = "*" __stringify(DYN_FTRACE_TEST_NAME);
508 len = strlen(func_name);
509
510 ret = ftrace_set_filter(&test_rec_probe, func_name, len, 1);
511 if (ret) {
512 pr_cont("*Could not set filter* ");
513 goto out;
514 }
515
516 ret = register_ftrace_function(&test_rec_probe);
517 if (ret) {
518 pr_cont("*could not register callback* ");
519 goto out;
520 }
521
522 DYN_FTRACE_TEST_NAME();
523
524 unregister_ftrace_function(&test_rec_probe);
525
526 ret = -1;
527 /*
528 * Recursion allows for transitions between context,
529 * and may call the callback twice.
530 */
531 if (trace_selftest_recursion_cnt != 1 &&
532 trace_selftest_recursion_cnt != 2) {
533 pr_cont("*callback not called once (or twice) (%d)* ",
534 trace_selftest_recursion_cnt);
535 goto out;
536 }
537
538 trace_selftest_recursion_cnt = 1;
539
540 pr_cont("PASSED\n");
541 pr_info("Testing ftrace recursion safe: ");
542
543 ret = ftrace_set_filter(&test_recsafe_probe, func_name, len, 1);
544 if (ret) {
545 pr_cont("*Could not set filter* ");
546 goto out;
547 }
548
549 ret = register_ftrace_function(&test_recsafe_probe);
550 if (ret) {
551 pr_cont("*could not register callback* ");
552 goto out;
553 }
554
555 DYN_FTRACE_TEST_NAME();
556
557 unregister_ftrace_function(&test_recsafe_probe);
558
559 ret = -1;
560 if (trace_selftest_recursion_cnt != 2) {
561 pr_cont("*callback not called expected 2 times (%d)* ",
562 trace_selftest_recursion_cnt);
563 goto out;
564 }
565
566 ret = 0;
567 out:
568 ftrace_enabled = save_ftrace_enabled;
569
570 return ret;
571 }
572 #else
573 # define trace_selftest_startup_dynamic_tracing(trace, tr, func) ({ 0; })
574 # define trace_selftest_function_recursion() ({ 0; })
575 #endif /* CONFIG_DYNAMIC_FTRACE */
576
577 static enum {
578 TRACE_SELFTEST_REGS_START,
579 TRACE_SELFTEST_REGS_FOUND,
580 TRACE_SELFTEST_REGS_NOT_FOUND,
581 } trace_selftest_regs_stat;
582
trace_selftest_test_regs_func(unsigned long ip,unsigned long pip,struct ftrace_ops * op,struct ftrace_regs * fregs)583 static void trace_selftest_test_regs_func(unsigned long ip,
584 unsigned long pip,
585 struct ftrace_ops *op,
586 struct ftrace_regs *fregs)
587 {
588 struct pt_regs *regs = ftrace_get_regs(fregs);
589
590 if (regs)
591 trace_selftest_regs_stat = TRACE_SELFTEST_REGS_FOUND;
592 else
593 trace_selftest_regs_stat = TRACE_SELFTEST_REGS_NOT_FOUND;
594 }
595
596 static struct ftrace_ops test_regs_probe = {
597 .func = trace_selftest_test_regs_func,
598 .flags = FTRACE_OPS_FL_SAVE_REGS,
599 };
600
601 static int
trace_selftest_function_regs(void)602 trace_selftest_function_regs(void)
603 {
604 int save_ftrace_enabled = ftrace_enabled;
605 char *func_name;
606 int len;
607 int ret;
608 int supported = 0;
609
610 #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
611 supported = 1;
612 #endif
613
614 /* The previous test PASSED */
615 pr_cont("PASSED\n");
616 pr_info("Testing ftrace regs%s: ",
617 !supported ? "(no arch support)" : "");
618
619 /* enable tracing, and record the filter function */
620 ftrace_enabled = 1;
621
622 /* Handle PPC64 '.' name */
623 func_name = "*" __stringify(DYN_FTRACE_TEST_NAME);
624 len = strlen(func_name);
625
626 ret = ftrace_set_filter(&test_regs_probe, func_name, len, 1);
627 /*
628 * If DYNAMIC_FTRACE is not set, then we just trace all functions.
629 * This test really doesn't care.
630 */
631 if (ret && ret != -ENODEV) {
632 pr_cont("*Could not set filter* ");
633 goto out;
634 }
635
636 ret = register_ftrace_function(&test_regs_probe);
637 /*
638 * Now if the arch does not support passing regs, then this should
639 * have failed.
640 */
641 if (!supported) {
642 if (!ret) {
643 pr_cont("*registered save-regs without arch support* ");
644 goto out;
645 }
646 test_regs_probe.flags |= FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED;
647 ret = register_ftrace_function(&test_regs_probe);
648 }
649 if (ret) {
650 pr_cont("*could not register callback* ");
651 goto out;
652 }
653
654
655 DYN_FTRACE_TEST_NAME();
656
657 unregister_ftrace_function(&test_regs_probe);
658
659 ret = -1;
660
661 switch (trace_selftest_regs_stat) {
662 case TRACE_SELFTEST_REGS_START:
663 pr_cont("*callback never called* ");
664 goto out;
665
666 case TRACE_SELFTEST_REGS_FOUND:
667 if (supported)
668 break;
669 pr_cont("*callback received regs without arch support* ");
670 goto out;
671
672 case TRACE_SELFTEST_REGS_NOT_FOUND:
673 if (!supported)
674 break;
675 pr_cont("*callback received NULL regs* ");
676 goto out;
677 }
678
679 ret = 0;
680 out:
681 ftrace_enabled = save_ftrace_enabled;
682
683 return ret;
684 }
685
686 /*
687 * Simple verification test of ftrace function tracer.
688 * Enable ftrace, sleep 1/10 second, and then read the trace
689 * buffer to see if all is in order.
690 */
691 __init int
trace_selftest_startup_function(struct tracer * trace,struct trace_array * tr)692 trace_selftest_startup_function(struct tracer *trace, struct trace_array *tr)
693 {
694 int save_ftrace_enabled = ftrace_enabled;
695 unsigned long count;
696 int ret;
697
698 #ifdef CONFIG_DYNAMIC_FTRACE
699 if (ftrace_filter_param) {
700 printk(KERN_CONT " ... kernel command line filter set: force PASS ... ");
701 return 0;
702 }
703 #endif
704
705 /* make sure msleep has been recorded */
706 msleep(1);
707
708 /* start the tracing */
709 ftrace_enabled = 1;
710
711 ret = tracer_init(trace, tr);
712 if (ret) {
713 warn_failed_init_tracer(trace, ret);
714 goto out;
715 }
716
717 /* Sleep for a 1/10 of a second */
718 msleep(100);
719 /* stop the tracing. */
720 tracing_stop();
721 ftrace_enabled = 0;
722
723 /* check the trace buffer */
724 ret = trace_test_buffer(&tr->array_buffer, &count);
725
726 ftrace_enabled = 1;
727 trace->reset(tr);
728 tracing_start();
729
730 if (!ret && !count) {
731 printk(KERN_CONT ".. no entries found ..");
732 ret = -1;
733 goto out;
734 }
735
736 ret = trace_selftest_startup_dynamic_tracing(trace, tr,
737 DYN_FTRACE_TEST_NAME);
738 if (ret)
739 goto out;
740
741 ret = trace_selftest_function_recursion();
742 if (ret)
743 goto out;
744
745 ret = trace_selftest_function_regs();
746 out:
747 ftrace_enabled = save_ftrace_enabled;
748
749 /* kill ftrace totally if we failed */
750 if (ret)
751 ftrace_kill();
752
753 return ret;
754 }
755 #endif /* CONFIG_FUNCTION_TRACER */
756
757
758 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
759
760 #ifdef CONFIG_DYNAMIC_FTRACE
761
762 #define CHAR_NUMBER 123
763 #define SHORT_NUMBER 12345
764 #define WORD_NUMBER 1234567890
765 #define LONG_NUMBER 1234567890123456789LL
766 #define ERRSTR_BUFLEN 128
767
768 struct fgraph_fixture {
769 struct fgraph_ops gops;
770 int store_size;
771 const char *store_type_name;
772 char error_str_buf[ERRSTR_BUFLEN];
773 char *error_str;
774 };
775
store_entry(struct ftrace_graph_ent * trace,struct fgraph_ops * gops)776 static __init int store_entry(struct ftrace_graph_ent *trace,
777 struct fgraph_ops *gops)
778 {
779 struct fgraph_fixture *fixture = container_of(gops, struct fgraph_fixture, gops);
780 const char *type = fixture->store_type_name;
781 int size = fixture->store_size;
782 void *p;
783
784 p = fgraph_reserve_data(gops->idx, size);
785 if (!p) {
786 snprintf(fixture->error_str_buf, ERRSTR_BUFLEN,
787 "Failed to reserve %s\n", type);
788 return 0;
789 }
790
791 switch (size) {
792 case 1:
793 *(char *)p = CHAR_NUMBER;
794 break;
795 case 2:
796 *(short *)p = SHORT_NUMBER;
797 break;
798 case 4:
799 *(int *)p = WORD_NUMBER;
800 break;
801 case 8:
802 *(long long *)p = LONG_NUMBER;
803 break;
804 }
805
806 return 1;
807 }
808
store_return(struct ftrace_graph_ret * trace,struct fgraph_ops * gops)809 static __init void store_return(struct ftrace_graph_ret *trace,
810 struct fgraph_ops *gops)
811 {
812 struct fgraph_fixture *fixture = container_of(gops, struct fgraph_fixture, gops);
813 const char *type = fixture->store_type_name;
814 long long expect = 0;
815 long long found = -1;
816 int size;
817 char *p;
818
819 p = fgraph_retrieve_data(gops->idx, &size);
820 if (!p) {
821 snprintf(fixture->error_str_buf, ERRSTR_BUFLEN,
822 "Failed to retrieve %s\n", type);
823 return;
824 }
825 if (fixture->store_size > size) {
826 snprintf(fixture->error_str_buf, ERRSTR_BUFLEN,
827 "Retrieved size %d is smaller than expected %d\n",
828 size, (int)fixture->store_size);
829 return;
830 }
831
832 switch (fixture->store_size) {
833 case 1:
834 expect = CHAR_NUMBER;
835 found = *(char *)p;
836 break;
837 case 2:
838 expect = SHORT_NUMBER;
839 found = *(short *)p;
840 break;
841 case 4:
842 expect = WORD_NUMBER;
843 found = *(int *)p;
844 break;
845 case 8:
846 expect = LONG_NUMBER;
847 found = *(long long *)p;
848 break;
849 }
850
851 if (found != expect) {
852 snprintf(fixture->error_str_buf, ERRSTR_BUFLEN,
853 "%s returned not %lld but %lld\n", type, expect, found);
854 return;
855 }
856 fixture->error_str = NULL;
857 }
858
init_fgraph_fixture(struct fgraph_fixture * fixture)859 static int __init init_fgraph_fixture(struct fgraph_fixture *fixture)
860 {
861 char *func_name;
862 int len;
863
864 snprintf(fixture->error_str_buf, ERRSTR_BUFLEN,
865 "Failed to execute storage %s\n", fixture->store_type_name);
866 fixture->error_str = fixture->error_str_buf;
867
868 func_name = "*" __stringify(DYN_FTRACE_TEST_NAME);
869 len = strlen(func_name);
870
871 return ftrace_set_filter(&fixture->gops.ops, func_name, len, 1);
872 }
873
874 /* Test fgraph storage for each size */
test_graph_storage_single(struct fgraph_fixture * fixture)875 static int __init test_graph_storage_single(struct fgraph_fixture *fixture)
876 {
877 int size = fixture->store_size;
878 int ret;
879
880 pr_cont("PASSED\n");
881 pr_info("Testing fgraph storage of %d byte%s: ", size, str_plural(size));
882
883 ret = init_fgraph_fixture(fixture);
884 if (ret && ret != -ENODEV) {
885 pr_cont("*Could not set filter* ");
886 return -1;
887 }
888
889 ret = register_ftrace_graph(&fixture->gops);
890 if (ret) {
891 pr_warn("Failed to init store_bytes fgraph tracing\n");
892 return -1;
893 }
894
895 DYN_FTRACE_TEST_NAME();
896
897 unregister_ftrace_graph(&fixture->gops);
898
899 if (fixture->error_str) {
900 pr_cont("*** %s ***", fixture->error_str);
901 return -1;
902 }
903
904 return 0;
905 }
906
907 static struct fgraph_fixture store_bytes[4] __initdata = {
908 [0] = {
909 .gops = {
910 .entryfunc = store_entry,
911 .retfunc = store_return,
912 },
913 .store_size = 1,
914 .store_type_name = "byte",
915 },
916 [1] = {
917 .gops = {
918 .entryfunc = store_entry,
919 .retfunc = store_return,
920 },
921 .store_size = 2,
922 .store_type_name = "short",
923 },
924 [2] = {
925 .gops = {
926 .entryfunc = store_entry,
927 .retfunc = store_return,
928 },
929 .store_size = 4,
930 .store_type_name = "word",
931 },
932 [3] = {
933 .gops = {
934 .entryfunc = store_entry,
935 .retfunc = store_return,
936 },
937 .store_size = 8,
938 .store_type_name = "long long",
939 },
940 };
941
test_graph_storage_multi(void)942 static __init int test_graph_storage_multi(void)
943 {
944 struct fgraph_fixture *fixture;
945 bool printed = false;
946 int i, j, ret;
947
948 pr_cont("PASSED\n");
949 pr_info("Testing multiple fgraph storage on a function: ");
950
951 for (i = 0; i < ARRAY_SIZE(store_bytes); i++) {
952 fixture = &store_bytes[i];
953 ret = init_fgraph_fixture(fixture);
954 if (ret && ret != -ENODEV) {
955 pr_cont("*Could not set filter* ");
956 printed = true;
957 goto out2;
958 }
959 }
960
961 for (j = 0; j < ARRAY_SIZE(store_bytes); j++) {
962 fixture = &store_bytes[j];
963 ret = register_ftrace_graph(&fixture->gops);
964 if (ret) {
965 pr_warn("Failed to init store_bytes fgraph tracing\n");
966 printed = true;
967 goto out1;
968 }
969 }
970
971 DYN_FTRACE_TEST_NAME();
972 out1:
973 while (--j >= 0) {
974 fixture = &store_bytes[j];
975 unregister_ftrace_graph(&fixture->gops);
976
977 if (fixture->error_str && !printed) {
978 pr_cont("*** %s ***", fixture->error_str);
979 printed = true;
980 }
981 }
982 out2:
983 while (--i >= 0) {
984 fixture = &store_bytes[i];
985 ftrace_free_filter(&fixture->gops.ops);
986
987 if (fixture->error_str && !printed) {
988 pr_cont("*** %s ***", fixture->error_str);
989 printed = true;
990 }
991 }
992 return printed ? -1 : 0;
993 }
994
995 /* Test the storage passed across function_graph entry and return */
test_graph_storage(void)996 static __init int test_graph_storage(void)
997 {
998 int ret;
999
1000 ret = test_graph_storage_single(&store_bytes[0]);
1001 if (ret)
1002 return ret;
1003 ret = test_graph_storage_single(&store_bytes[1]);
1004 if (ret)
1005 return ret;
1006 ret = test_graph_storage_single(&store_bytes[2]);
1007 if (ret)
1008 return ret;
1009 ret = test_graph_storage_single(&store_bytes[3]);
1010 if (ret)
1011 return ret;
1012 ret = test_graph_storage_multi();
1013 if (ret)
1014 return ret;
1015 return 0;
1016 }
1017 #else
test_graph_storage(void)1018 static inline int test_graph_storage(void) { return 0; }
1019 #endif /* CONFIG_DYNAMIC_FTRACE */
1020
1021 /* Maximum number of functions to trace before diagnosing a hang */
1022 #define GRAPH_MAX_FUNC_TEST 100000000
1023
1024 static unsigned int graph_hang_thresh;
1025
1026 /* Wrap the real function entry probe to avoid possible hanging */
trace_graph_entry_watchdog(struct ftrace_graph_ent * trace,struct fgraph_ops * gops)1027 static int trace_graph_entry_watchdog(struct ftrace_graph_ent *trace,
1028 struct fgraph_ops *gops)
1029 {
1030 /* This is harmlessly racy, we want to approximately detect a hang */
1031 if (unlikely(++graph_hang_thresh > GRAPH_MAX_FUNC_TEST)) {
1032 ftrace_graph_stop();
1033 printk(KERN_WARNING "BUG: Function graph tracer hang!\n");
1034 if (ftrace_dump_on_oops_enabled()) {
1035 ftrace_dump(DUMP_ALL);
1036 /* ftrace_dump() disables tracing */
1037 tracing_on();
1038 }
1039 return 0;
1040 }
1041
1042 return trace_graph_entry(trace, gops);
1043 }
1044
1045 static struct fgraph_ops fgraph_ops __initdata = {
1046 .entryfunc = &trace_graph_entry_watchdog,
1047 .retfunc = &trace_graph_return,
1048 };
1049
1050 #ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
1051 static struct ftrace_ops direct;
1052 #endif
1053
1054 /*
1055 * Pretty much the same than for the function tracer from which the selftest
1056 * has been borrowed.
1057 */
1058 __init int
trace_selftest_startup_function_graph(struct tracer * trace,struct trace_array * tr)1059 trace_selftest_startup_function_graph(struct tracer *trace,
1060 struct trace_array *tr)
1061 {
1062 int ret;
1063 unsigned long count;
1064 char *func_name __maybe_unused;
1065
1066 #ifdef CONFIG_DYNAMIC_FTRACE
1067 if (ftrace_filter_param) {
1068 printk(KERN_CONT " ... kernel command line filter set: force PASS ... ");
1069 return 0;
1070 }
1071 #endif
1072
1073 /*
1074 * Simulate the init() callback but we attach a watchdog callback
1075 * to detect and recover from possible hangs
1076 */
1077 tracing_reset_online_cpus(&tr->array_buffer);
1078 fgraph_ops.private = tr;
1079 ret = register_ftrace_graph(&fgraph_ops);
1080 if (ret) {
1081 warn_failed_init_tracer(trace, ret);
1082 goto out;
1083 }
1084 tracing_start_cmdline_record();
1085
1086 /* Sleep for a 1/10 of a second */
1087 msleep(100);
1088
1089 /* Have we just recovered from a hang? */
1090 if (graph_hang_thresh > GRAPH_MAX_FUNC_TEST) {
1091 disable_tracing_selftest("recovering from a hang");
1092 ret = -1;
1093 goto out;
1094 }
1095
1096 tracing_stop();
1097
1098 /* check the trace buffer */
1099 ret = trace_test_buffer(&tr->array_buffer, &count);
1100
1101 /* Need to also simulate the tr->reset to remove this fgraph_ops */
1102 tracing_stop_cmdline_record();
1103 unregister_ftrace_graph(&fgraph_ops);
1104
1105 tracing_start();
1106
1107 if (!ret && !count) {
1108 printk(KERN_CONT ".. no entries found ..");
1109 ret = -1;
1110 goto out;
1111 }
1112
1113 #ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
1114 /*
1115 * These tests can take some time to run. Make sure on non PREEMPT
1116 * kernels, we do not trigger the softlockup detector.
1117 */
1118 cond_resched();
1119
1120 tracing_reset_online_cpus(&tr->array_buffer);
1121 fgraph_ops.private = tr;
1122
1123 /*
1124 * Some archs *cough*PowerPC*cough* add characters to the
1125 * start of the function names. We simply put a '*' to
1126 * accommodate them.
1127 */
1128 func_name = "*" __stringify(DYN_FTRACE_TEST_NAME);
1129 ftrace_set_global_filter(func_name, strlen(func_name), 1);
1130
1131 /*
1132 * Register direct function together with graph tracer
1133 * and make sure we get graph trace.
1134 */
1135 ftrace_set_filter_ip(&direct, (unsigned long)DYN_FTRACE_TEST_NAME, 0, 0);
1136 ret = register_ftrace_direct(&direct,
1137 (unsigned long)ftrace_stub_direct_tramp);
1138 if (ret)
1139 goto out;
1140
1141 cond_resched();
1142
1143 ret = register_ftrace_graph(&fgraph_ops);
1144 if (ret) {
1145 warn_failed_init_tracer(trace, ret);
1146 goto out;
1147 }
1148
1149 DYN_FTRACE_TEST_NAME();
1150
1151 count = 0;
1152
1153 tracing_stop();
1154 /* check the trace buffer */
1155 ret = trace_test_buffer(&tr->array_buffer, &count);
1156
1157 unregister_ftrace_graph(&fgraph_ops);
1158
1159 ret = unregister_ftrace_direct(&direct,
1160 (unsigned long)ftrace_stub_direct_tramp,
1161 true);
1162 if (ret)
1163 goto out;
1164
1165 cond_resched();
1166
1167 tracing_start();
1168
1169 if (!ret && !count) {
1170 ret = -1;
1171 goto out;
1172 }
1173
1174 /* Enable tracing on all functions again */
1175 ftrace_set_global_filter(NULL, 0, 1);
1176 #endif
1177
1178 ret = test_graph_storage();
1179
1180 /* Don't test dynamic tracing, the function tracer already did */
1181 out:
1182 /* Stop it if we failed */
1183 if (ret)
1184 ftrace_graph_stop();
1185
1186 return ret;
1187 }
1188 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
1189
1190
1191 #ifdef CONFIG_IRQSOFF_TRACER
1192 int
trace_selftest_startup_irqsoff(struct tracer * trace,struct trace_array * tr)1193 trace_selftest_startup_irqsoff(struct tracer *trace, struct trace_array *tr)
1194 {
1195 unsigned long save_max = tr->max_latency;
1196 unsigned long count;
1197 int ret;
1198
1199 /* start the tracing */
1200 ret = tracer_init(trace, tr);
1201 if (ret) {
1202 warn_failed_init_tracer(trace, ret);
1203 return ret;
1204 }
1205
1206 /* reset the max latency */
1207 tr->max_latency = 0;
1208 /* disable interrupts for a bit */
1209 local_irq_disable();
1210 udelay(100);
1211 local_irq_enable();
1212
1213 /*
1214 * Stop the tracer to avoid a warning subsequent
1215 * to buffer flipping failure because tracing_stop()
1216 * disables the tr and max buffers, making flipping impossible
1217 * in case of parallels max irqs off latencies.
1218 */
1219 trace->stop(tr);
1220 /* stop the tracing. */
1221 tracing_stop();
1222 /* check both trace buffers */
1223 ret = trace_test_buffer(&tr->array_buffer, NULL);
1224 if (!ret)
1225 ret = trace_test_buffer(&tr->max_buffer, &count);
1226 trace->reset(tr);
1227 tracing_start();
1228
1229 if (!ret && !count) {
1230 printk(KERN_CONT ".. no entries found ..");
1231 ret = -1;
1232 }
1233
1234 tr->max_latency = save_max;
1235
1236 return ret;
1237 }
1238 #endif /* CONFIG_IRQSOFF_TRACER */
1239
1240 #ifdef CONFIG_PREEMPT_TRACER
1241 int
trace_selftest_startup_preemptoff(struct tracer * trace,struct trace_array * tr)1242 trace_selftest_startup_preemptoff(struct tracer *trace, struct trace_array *tr)
1243 {
1244 unsigned long save_max = tr->max_latency;
1245 unsigned long count;
1246 int ret;
1247
1248 /*
1249 * Now that the big kernel lock is no longer preemptible,
1250 * and this is called with the BKL held, it will always
1251 * fail. If preemption is already disabled, simply
1252 * pass the test. When the BKL is removed, or becomes
1253 * preemptible again, we will once again test this,
1254 * so keep it in.
1255 */
1256 if (preempt_count()) {
1257 printk(KERN_CONT "can not test ... force ");
1258 return 0;
1259 }
1260
1261 /* start the tracing */
1262 ret = tracer_init(trace, tr);
1263 if (ret) {
1264 warn_failed_init_tracer(trace, ret);
1265 return ret;
1266 }
1267
1268 /* reset the max latency */
1269 tr->max_latency = 0;
1270 /* disable preemption for a bit */
1271 preempt_disable();
1272 udelay(100);
1273 preempt_enable();
1274
1275 /*
1276 * Stop the tracer to avoid a warning subsequent
1277 * to buffer flipping failure because tracing_stop()
1278 * disables the tr and max buffers, making flipping impossible
1279 * in case of parallels max preempt off latencies.
1280 */
1281 trace->stop(tr);
1282 /* stop the tracing. */
1283 tracing_stop();
1284 /* check both trace buffers */
1285 ret = trace_test_buffer(&tr->array_buffer, NULL);
1286 if (!ret)
1287 ret = trace_test_buffer(&tr->max_buffer, &count);
1288 trace->reset(tr);
1289 tracing_start();
1290
1291 if (!ret && !count) {
1292 printk(KERN_CONT ".. no entries found ..");
1293 ret = -1;
1294 }
1295
1296 tr->max_latency = save_max;
1297
1298 return ret;
1299 }
1300 #endif /* CONFIG_PREEMPT_TRACER */
1301
1302 #if defined(CONFIG_IRQSOFF_TRACER) && defined(CONFIG_PREEMPT_TRACER)
1303 int
trace_selftest_startup_preemptirqsoff(struct tracer * trace,struct trace_array * tr)1304 trace_selftest_startup_preemptirqsoff(struct tracer *trace, struct trace_array *tr)
1305 {
1306 unsigned long save_max = tr->max_latency;
1307 unsigned long count;
1308 int ret;
1309
1310 /*
1311 * Now that the big kernel lock is no longer preemptible,
1312 * and this is called with the BKL held, it will always
1313 * fail. If preemption is already disabled, simply
1314 * pass the test. When the BKL is removed, or becomes
1315 * preemptible again, we will once again test this,
1316 * so keep it in.
1317 */
1318 if (preempt_count()) {
1319 printk(KERN_CONT "can not test ... force ");
1320 return 0;
1321 }
1322
1323 /* start the tracing */
1324 ret = tracer_init(trace, tr);
1325 if (ret) {
1326 warn_failed_init_tracer(trace, ret);
1327 goto out_no_start;
1328 }
1329
1330 /* reset the max latency */
1331 tr->max_latency = 0;
1332
1333 /* disable preemption and interrupts for a bit */
1334 preempt_disable();
1335 local_irq_disable();
1336 udelay(100);
1337 preempt_enable();
1338 /* reverse the order of preempt vs irqs */
1339 local_irq_enable();
1340
1341 /*
1342 * Stop the tracer to avoid a warning subsequent
1343 * to buffer flipping failure because tracing_stop()
1344 * disables the tr and max buffers, making flipping impossible
1345 * in case of parallels max irqs/preempt off latencies.
1346 */
1347 trace->stop(tr);
1348 /* stop the tracing. */
1349 tracing_stop();
1350 /* check both trace buffers */
1351 ret = trace_test_buffer(&tr->array_buffer, NULL);
1352 if (ret)
1353 goto out;
1354
1355 ret = trace_test_buffer(&tr->max_buffer, &count);
1356 if (ret)
1357 goto out;
1358
1359 if (!ret && !count) {
1360 printk(KERN_CONT ".. no entries found ..");
1361 ret = -1;
1362 goto out;
1363 }
1364
1365 /* do the test by disabling interrupts first this time */
1366 tr->max_latency = 0;
1367 tracing_start();
1368 trace->start(tr);
1369
1370 preempt_disable();
1371 local_irq_disable();
1372 udelay(100);
1373 preempt_enable();
1374 /* reverse the order of preempt vs irqs */
1375 local_irq_enable();
1376
1377 trace->stop(tr);
1378 /* stop the tracing. */
1379 tracing_stop();
1380 /* check both trace buffers */
1381 ret = trace_test_buffer(&tr->array_buffer, NULL);
1382 if (ret)
1383 goto out;
1384
1385 ret = trace_test_buffer(&tr->max_buffer, &count);
1386
1387 if (!ret && !count) {
1388 printk(KERN_CONT ".. no entries found ..");
1389 ret = -1;
1390 goto out;
1391 }
1392
1393 out:
1394 tracing_start();
1395 out_no_start:
1396 trace->reset(tr);
1397 tr->max_latency = save_max;
1398
1399 return ret;
1400 }
1401 #endif /* CONFIG_IRQSOFF_TRACER && CONFIG_PREEMPT_TRACER */
1402
1403 #ifdef CONFIG_NOP_TRACER
1404 int
trace_selftest_startup_nop(struct tracer * trace,struct trace_array * tr)1405 trace_selftest_startup_nop(struct tracer *trace, struct trace_array *tr)
1406 {
1407 /* What could possibly go wrong? */
1408 return 0;
1409 }
1410 #endif
1411
1412 #ifdef CONFIG_SCHED_TRACER
1413
1414 struct wakeup_test_data {
1415 struct completion is_ready;
1416 int go;
1417 };
1418
trace_wakeup_test_thread(void * data)1419 static int trace_wakeup_test_thread(void *data)
1420 {
1421 /* Make this a -deadline thread */
1422 static const struct sched_attr attr = {
1423 .sched_policy = SCHED_DEADLINE,
1424 .sched_runtime = 100000ULL,
1425 .sched_deadline = 10000000ULL,
1426 .sched_period = 10000000ULL
1427 };
1428 struct wakeup_test_data *x = data;
1429
1430 sched_setattr(current, &attr);
1431
1432 /* Make it know we have a new prio */
1433 complete(&x->is_ready);
1434
1435 /* now go to sleep and let the test wake us up */
1436 set_current_state(TASK_INTERRUPTIBLE);
1437 while (!x->go) {
1438 schedule();
1439 set_current_state(TASK_INTERRUPTIBLE);
1440 }
1441
1442 complete(&x->is_ready);
1443
1444 set_current_state(TASK_INTERRUPTIBLE);
1445
1446 /* we are awake, now wait to disappear */
1447 while (!kthread_should_stop()) {
1448 schedule();
1449 set_current_state(TASK_INTERRUPTIBLE);
1450 }
1451
1452 __set_current_state(TASK_RUNNING);
1453
1454 return 0;
1455 }
1456 int
trace_selftest_startup_wakeup(struct tracer * trace,struct trace_array * tr)1457 trace_selftest_startup_wakeup(struct tracer *trace, struct trace_array *tr)
1458 {
1459 unsigned long save_max = tr->max_latency;
1460 struct task_struct *p;
1461 struct wakeup_test_data data;
1462 unsigned long count;
1463 int ret;
1464
1465 memset(&data, 0, sizeof(data));
1466
1467 init_completion(&data.is_ready);
1468
1469 /* create a -deadline thread */
1470 p = kthread_run(trace_wakeup_test_thread, &data, "ftrace-test");
1471 if (IS_ERR(p)) {
1472 printk(KERN_CONT "Failed to create ftrace wakeup test thread ");
1473 return -1;
1474 }
1475
1476 /* make sure the thread is running at -deadline policy */
1477 wait_for_completion(&data.is_ready);
1478
1479 /* start the tracing */
1480 ret = tracer_init(trace, tr);
1481 if (ret) {
1482 warn_failed_init_tracer(trace, ret);
1483 return ret;
1484 }
1485
1486 /* reset the max latency */
1487 tr->max_latency = 0;
1488
1489 while (task_is_runnable(p)) {
1490 /*
1491 * Sleep to make sure the -deadline thread is asleep too.
1492 * On virtual machines we can't rely on timings,
1493 * but we want to make sure this test still works.
1494 */
1495 msleep(100);
1496 }
1497
1498 init_completion(&data.is_ready);
1499
1500 data.go = 1;
1501 /* memory barrier is in the wake_up_process() */
1502
1503 wake_up_process(p);
1504
1505 /* Wait for the task to wake up */
1506 wait_for_completion(&data.is_ready);
1507
1508 /* stop the tracing. */
1509 tracing_stop();
1510 /* check both trace buffers */
1511 ret = trace_test_buffer(&tr->array_buffer, NULL);
1512 if (!ret)
1513 ret = trace_test_buffer(&tr->max_buffer, &count);
1514
1515
1516 trace->reset(tr);
1517 tracing_start();
1518
1519 tr->max_latency = save_max;
1520
1521 /* kill the thread */
1522 kthread_stop(p);
1523
1524 if (!ret && !count) {
1525 printk(KERN_CONT ".. no entries found ..");
1526 ret = -1;
1527 }
1528
1529 return ret;
1530 }
1531 #endif /* CONFIG_SCHED_TRACER */
1532
1533 #ifdef CONFIG_BRANCH_TRACER
1534 int
trace_selftest_startup_branch(struct tracer * trace,struct trace_array * tr)1535 trace_selftest_startup_branch(struct tracer *trace, struct trace_array *tr)
1536 {
1537 unsigned long count;
1538 int ret;
1539
1540 /* start the tracing */
1541 ret = tracer_init(trace, tr);
1542 if (ret) {
1543 warn_failed_init_tracer(trace, ret);
1544 return ret;
1545 }
1546
1547 /* Sleep for a 1/10 of a second */
1548 msleep(100);
1549 /* stop the tracing. */
1550 tracing_stop();
1551 /* check the trace buffer */
1552 ret = trace_test_buffer(&tr->array_buffer, &count);
1553 trace->reset(tr);
1554 tracing_start();
1555
1556 if (!ret && !count) {
1557 printk(KERN_CONT ".. no entries found ..");
1558 ret = -1;
1559 }
1560
1561 return ret;
1562 }
1563 #endif /* CONFIG_BRANCH_TRACER */
1564
1565