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