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1/* Include in trace.c */
2
3#include <linux/stringify.h>
4#include <linux/kthread.h>
5#include <linux/delay.h>
6#include <linux/slab.h>
7
8static inline int trace_valid_entry(struct trace_entry *entry)
9{
10 switch (entry->type) {
11 case TRACE_FN:
12 case TRACE_CTX:
13 case TRACE_WAKE:
14 case TRACE_STACK:
15 case TRACE_PRINT:
16 case TRACE_BRANCH:
17 case TRACE_GRAPH_ENT:
18 case TRACE_GRAPH_RET:
19 return 1;
20 }
21 return 0;
22}
23
24static int trace_test_buffer_cpu(struct trace_buffer *buf, int cpu)
25{
26 struct ring_buffer_event *event;
27 struct trace_entry *entry;
28 unsigned int loops = 0;
29
30 while ((event = ring_buffer_consume(buf->buffer, cpu, NULL, NULL))) {
31 entry = ring_buffer_event_data(event);
32
33 /*
34 * The ring buffer is a size of trace_buf_size, if
35 * we loop more than the size, there's something wrong
36 * with the ring buffer.
37 */
38 if (loops++ > trace_buf_size) {
39 printk(KERN_CONT ".. bad ring buffer ");
40 goto failed;
41 }
42 if (!trace_valid_entry(entry)) {
43 printk(KERN_CONT ".. invalid entry %d ",
44 entry->type);
45 goto failed;
46 }
47 }
48 return 0;
49
50 failed:
51 /* disable tracing */
52 tracing_disabled = 1;
53 printk(KERN_CONT ".. corrupted trace buffer .. ");
54 return -1;
55}
56
57/*
58 * Test the trace buffer to see if all the elements
59 * are still sane.
60 */
61static int trace_test_buffer(struct trace_buffer *buf, unsigned long *count)
62{
63 unsigned long flags, cnt = 0;
64 int cpu, ret = 0;
65
66 /* Don't allow flipping of max traces now */
67 local_irq_save(flags);
68 arch_spin_lock(&buf->tr->max_lock);
69
70 cnt = ring_buffer_entries(buf->buffer);
71
72 /*
73 * The trace_test_buffer_cpu runs a while loop to consume all data.
74 * If the calling tracer is broken, and is constantly filling
75 * the buffer, this will run forever, and hard lock the box.
76 * We disable the ring buffer while we do this test to prevent
77 * a hard lock up.
78 */
79 tracing_off();
80 for_each_possible_cpu(cpu) {
81 ret = trace_test_buffer_cpu(buf, cpu);
82 if (ret)
83 break;
84 }
85 tracing_on();
86 arch_spin_unlock(&buf->tr->max_lock);
87 local_irq_restore(flags);
88
89 if (count)
90 *count = cnt;
91
92 return ret;
93}
94
95static inline void warn_failed_init_tracer(struct tracer *trace, int init_ret)
96{
97 printk(KERN_WARNING "Failed to init %s tracer, init returned %d\n",
98 trace->name, init_ret);
99}
100#ifdef CONFIG_FUNCTION_TRACER
101
102#ifdef CONFIG_DYNAMIC_FTRACE
103
104static int trace_selftest_test_probe1_cnt;
105static void trace_selftest_test_probe1_func(unsigned long ip,
106 unsigned long pip,
107 struct ftrace_ops *op,
108 struct pt_regs *pt_regs)
109{
110 trace_selftest_test_probe1_cnt++;
111}
112
113static int trace_selftest_test_probe2_cnt;
114static void trace_selftest_test_probe2_func(unsigned long ip,
115 unsigned long pip,
116 struct ftrace_ops *op,
117 struct pt_regs *pt_regs)
118{
119 trace_selftest_test_probe2_cnt++;
120}
121
122static int trace_selftest_test_probe3_cnt;
123static void trace_selftest_test_probe3_func(unsigned long ip,
124 unsigned long pip,
125 struct ftrace_ops *op,
126 struct pt_regs *pt_regs)
127{
128 trace_selftest_test_probe3_cnt++;
129}
130
131static int trace_selftest_test_global_cnt;
132static void trace_selftest_test_global_func(unsigned long ip,
133 unsigned long pip,
134 struct ftrace_ops *op,
135 struct pt_regs *pt_regs)
136{
137 trace_selftest_test_global_cnt++;
138}
139
140static int trace_selftest_test_dyn_cnt;
141static void trace_selftest_test_dyn_func(unsigned long ip,
142 unsigned long pip,
143 struct ftrace_ops *op,
144 struct pt_regs *pt_regs)
145{
146 trace_selftest_test_dyn_cnt++;
147}
148
149static struct ftrace_ops test_probe1 = {
150 .func = trace_selftest_test_probe1_func,
151 .flags = FTRACE_OPS_FL_RECURSION_SAFE,
152};
153
154static struct ftrace_ops test_probe2 = {
155 .func = trace_selftest_test_probe2_func,
156 .flags = FTRACE_OPS_FL_RECURSION_SAFE,
157};
158
159static struct ftrace_ops test_probe3 = {
160 .func = trace_selftest_test_probe3_func,
161 .flags = FTRACE_OPS_FL_RECURSION_SAFE,
162};
163
164static 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
174static 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
183static 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;
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 ret = 0;
292 out_free:
293 unregister_ftrace_function(dyn_ops);
294 kfree(dyn_ops);
295
296 out:
297 /* Purposely unregister in the same order */
298 unregister_ftrace_function(&test_probe1);
299 unregister_ftrace_function(&test_probe2);
300 unregister_ftrace_function(&test_probe3);
301 if (cnt > 1)
302 unregister_ftrace_function(tr->ops);
303 ftrace_reset_array_ops(tr);
304
305 /* Make sure everything is off */
306 reset_counts();
307 DYN_FTRACE_TEST_NAME();
308 DYN_FTRACE_TEST_NAME();
309
310 if (trace_selftest_test_probe1_cnt ||
311 trace_selftest_test_probe2_cnt ||
312 trace_selftest_test_probe3_cnt ||
313 trace_selftest_test_global_cnt ||
314 trace_selftest_test_dyn_cnt)
315 ret = -1;
316
317 ftrace_enabled = save_ftrace_enabled;
318
319 return ret;
320}
321
322/* Test dynamic code modification and ftrace filters */
323static int trace_selftest_startup_dynamic_tracing(struct tracer *trace,
324 struct trace_array *tr,
325 int (*func)(void))
326{
327 int save_ftrace_enabled = ftrace_enabled;
328 unsigned long count;
329 char *func_name;
330 int ret;
331
332 /* The ftrace test PASSED */
333 printk(KERN_CONT "PASSED\n");
334 pr_info("Testing dynamic ftrace: ");
335
336 /* enable tracing, and record the filter function */
337 ftrace_enabled = 1;
338
339 /* passed in by parameter to fool gcc from optimizing */
340 func();
341
342 /*
343 * Some archs *cough*PowerPC*cough* add characters to the
344 * start of the function names. We simply put a '*' to
345 * accommodate them.
346 */
347 func_name = "*" __stringify(DYN_FTRACE_TEST_NAME);
348
349 /* filter only on our function */
350 ftrace_set_global_filter(func_name, strlen(func_name), 1);
351
352 /* enable tracing */
353 ret = tracer_init(trace, tr);
354 if (ret) {
355 warn_failed_init_tracer(trace, ret);
356 goto out;
357 }
358
359 /* Sleep for a 1/10 of a second */
360 msleep(100);
361
362 /* we should have nothing in the buffer */
363 ret = trace_test_buffer(&tr->trace_buffer, &count);
364 if (ret)
365 goto out;
366
367 if (count) {
368 ret = -1;
369 printk(KERN_CONT ".. filter did not filter .. ");
370 goto out;
371 }
372
373 /* call our function again */
374 func();
375
376 /* sleep again */
377 msleep(100);
378
379 /* stop the tracing. */
380 tracing_stop();
381 ftrace_enabled = 0;
382
383 /* check the trace buffer */
384 ret = trace_test_buffer(&tr->trace_buffer, &count);
385
386 ftrace_enabled = 1;
387 tracing_start();
388
389 /* we should only have one item */
390 if (!ret && count != 1) {
391 trace->reset(tr);
392 printk(KERN_CONT ".. filter failed count=%ld ..", count);
393 ret = -1;
394 goto out;
395 }
396
397 /* Test the ops with global tracing running */
398 ret = trace_selftest_ops(tr, 1);
399 trace->reset(tr);
400
401 out:
402 ftrace_enabled = save_ftrace_enabled;
403
404 /* Enable tracing on all functions again */
405 ftrace_set_global_filter(NULL, 0, 1);
406
407 /* Test the ops with global tracing off */
408 if (!ret)
409 ret = trace_selftest_ops(tr, 2);
410
411 return ret;
412}
413
414static int trace_selftest_recursion_cnt;
415static void trace_selftest_test_recursion_func(unsigned long ip,
416 unsigned long pip,
417 struct ftrace_ops *op,
418 struct pt_regs *pt_regs)
419{
420 /*
421 * This function is registered without the recursion safe flag.
422 * The ftrace infrastructure should provide the recursion
423 * protection. If not, this will crash the kernel!
424 */
425 if (trace_selftest_recursion_cnt++ > 10)
426 return;
427 DYN_FTRACE_TEST_NAME();
428}
429
430static void trace_selftest_test_recursion_safe_func(unsigned long ip,
431 unsigned long pip,
432 struct ftrace_ops *op,
433 struct pt_regs *pt_regs)
434{
435 /*
436 * We said we would provide our own recursion. By calling
437 * this function again, we should recurse back into this function
438 * and count again. But this only happens if the arch supports
439 * all of ftrace features and nothing else is using the function
440 * tracing utility.
441 */
442 if (trace_selftest_recursion_cnt++)
443 return;
444 DYN_FTRACE_TEST_NAME();
445}
446
447static struct ftrace_ops test_rec_probe = {
448 .func = trace_selftest_test_recursion_func,
449};
450
451static struct ftrace_ops test_recsafe_probe = {
452 .func = trace_selftest_test_recursion_safe_func,
453 .flags = FTRACE_OPS_FL_RECURSION_SAFE,
454};
455
456static int
457trace_selftest_function_recursion(void)
458{
459 int save_ftrace_enabled = ftrace_enabled;
460 char *func_name;
461 int len;
462 int ret;
463
464 /* The previous test PASSED */
465 pr_cont("PASSED\n");
466 pr_info("Testing ftrace recursion: ");
467
468
469 /* enable tracing, and record the filter function */
470 ftrace_enabled = 1;
471
472 /* Handle PPC64 '.' name */
473 func_name = "*" __stringify(DYN_FTRACE_TEST_NAME);
474 len = strlen(func_name);
475
476 ret = ftrace_set_filter(&test_rec_probe, func_name, len, 1);
477 if (ret) {
478 pr_cont("*Could not set filter* ");
479 goto out;
480 }
481
482 ret = register_ftrace_function(&test_rec_probe);
483 if (ret) {
484 pr_cont("*could not register callback* ");
485 goto out;
486 }
487
488 DYN_FTRACE_TEST_NAME();
489
490 unregister_ftrace_function(&test_rec_probe);
491
492 ret = -1;
493 if (trace_selftest_recursion_cnt != 1) {
494 pr_cont("*callback not called once (%d)* ",
495 trace_selftest_recursion_cnt);
496 goto out;
497 }
498
499 trace_selftest_recursion_cnt = 1;
500
501 pr_cont("PASSED\n");
502 pr_info("Testing ftrace recursion safe: ");
503
504 ret = ftrace_set_filter(&test_recsafe_probe, func_name, len, 1);
505 if (ret) {
506 pr_cont("*Could not set filter* ");
507 goto out;
508 }
509
510 ret = register_ftrace_function(&test_recsafe_probe);
511 if (ret) {
512 pr_cont("*could not register callback* ");
513 goto out;
514 }
515
516 DYN_FTRACE_TEST_NAME();
517
518 unregister_ftrace_function(&test_recsafe_probe);
519
520 ret = -1;
521 if (trace_selftest_recursion_cnt != 2) {
522 pr_cont("*callback not called expected 2 times (%d)* ",
523 trace_selftest_recursion_cnt);
524 goto out;
525 }
526
527 ret = 0;
528out:
529 ftrace_enabled = save_ftrace_enabled;
530
531 return ret;
532}
533#else
534# define trace_selftest_startup_dynamic_tracing(trace, tr, func) ({ 0; })
535# define trace_selftest_function_recursion() ({ 0; })
536#endif /* CONFIG_DYNAMIC_FTRACE */
537
538static enum {
539 TRACE_SELFTEST_REGS_START,
540 TRACE_SELFTEST_REGS_FOUND,
541 TRACE_SELFTEST_REGS_NOT_FOUND,
542} trace_selftest_regs_stat;
543
544static void trace_selftest_test_regs_func(unsigned long ip,
545 unsigned long pip,
546 struct ftrace_ops *op,
547 struct pt_regs *pt_regs)
548{
549 if (pt_regs)
550 trace_selftest_regs_stat = TRACE_SELFTEST_REGS_FOUND;
551 else
552 trace_selftest_regs_stat = TRACE_SELFTEST_REGS_NOT_FOUND;
553}
554
555static struct ftrace_ops test_regs_probe = {
556 .func = trace_selftest_test_regs_func,
557 .flags = FTRACE_OPS_FL_RECURSION_SAFE | FTRACE_OPS_FL_SAVE_REGS,
558};
559
560static int
561trace_selftest_function_regs(void)
562{
563 int save_ftrace_enabled = ftrace_enabled;
564 char *func_name;
565 int len;
566 int ret;
567 int supported = 0;
568
569#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
570 supported = 1;
571#endif
572
573 /* The previous test PASSED */
574 pr_cont("PASSED\n");
575 pr_info("Testing ftrace regs%s: ",
576 !supported ? "(no arch support)" : "");
577
578 /* enable tracing, and record the filter function */
579 ftrace_enabled = 1;
580
581 /* Handle PPC64 '.' name */
582 func_name = "*" __stringify(DYN_FTRACE_TEST_NAME);
583 len = strlen(func_name);
584
585 ret = ftrace_set_filter(&test_regs_probe, func_name, len, 1);
586 /*
587 * If DYNAMIC_FTRACE is not set, then we just trace all functions.
588 * This test really doesn't care.
589 */
590 if (ret && ret != -ENODEV) {
591 pr_cont("*Could not set filter* ");
592 goto out;
593 }
594
595 ret = register_ftrace_function(&test_regs_probe);
596 /*
597 * Now if the arch does not support passing regs, then this should
598 * have failed.
599 */
600 if (!supported) {
601 if (!ret) {
602 pr_cont("*registered save-regs without arch support* ");
603 goto out;
604 }
605 test_regs_probe.flags |= FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED;
606 ret = register_ftrace_function(&test_regs_probe);
607 }
608 if (ret) {
609 pr_cont("*could not register callback* ");
610 goto out;
611 }
612
613
614 DYN_FTRACE_TEST_NAME();
615
616 unregister_ftrace_function(&test_regs_probe);
617
618 ret = -1;
619
620 switch (trace_selftest_regs_stat) {
621 case TRACE_SELFTEST_REGS_START:
622 pr_cont("*callback never called* ");
623 goto out;
624
625 case TRACE_SELFTEST_REGS_FOUND:
626 if (supported)
627 break;
628 pr_cont("*callback received regs without arch support* ");
629 goto out;
630
631 case TRACE_SELFTEST_REGS_NOT_FOUND:
632 if (!supported)
633 break;
634 pr_cont("*callback received NULL regs* ");
635 goto out;
636 }
637
638 ret = 0;
639out:
640 ftrace_enabled = save_ftrace_enabled;
641
642 return ret;
643}
644
645/*
646 * Simple verification test of ftrace function tracer.
647 * Enable ftrace, sleep 1/10 second, and then read the trace
648 * buffer to see if all is in order.
649 */
650__init int
651trace_selftest_startup_function(struct tracer *trace, struct trace_array *tr)
652{
653 int save_ftrace_enabled = ftrace_enabled;
654 unsigned long count;
655 int ret;
656
657#ifdef CONFIG_DYNAMIC_FTRACE
658 if (ftrace_filter_param) {
659 printk(KERN_CONT " ... kernel command line filter set: force PASS ... ");
660 return 0;
661 }
662#endif
663
664 /* make sure msleep has been recorded */
665 msleep(1);
666
667 /* start the tracing */
668 ftrace_enabled = 1;
669
670 ret = tracer_init(trace, tr);
671 if (ret) {
672 warn_failed_init_tracer(trace, ret);
673 goto out;
674 }
675
676 /* Sleep for a 1/10 of a second */
677 msleep(100);
678 /* stop the tracing. */
679 tracing_stop();
680 ftrace_enabled = 0;
681
682 /* check the trace buffer */
683 ret = trace_test_buffer(&tr->trace_buffer, &count);
684
685 ftrace_enabled = 1;
686 trace->reset(tr);
687 tracing_start();
688
689 if (!ret && !count) {
690 printk(KERN_CONT ".. no entries found ..");
691 ret = -1;
692 goto out;
693 }
694
695 ret = trace_selftest_startup_dynamic_tracing(trace, tr,
696 DYN_FTRACE_TEST_NAME);
697 if (ret)
698 goto out;
699
700 ret = trace_selftest_function_recursion();
701 if (ret)
702 goto out;
703
704 ret = trace_selftest_function_regs();
705 out:
706 ftrace_enabled = save_ftrace_enabled;
707
708 /* kill ftrace totally if we failed */
709 if (ret)
710 ftrace_kill();
711
712 return ret;
713}
714#endif /* CONFIG_FUNCTION_TRACER */
715
716
717#ifdef CONFIG_FUNCTION_GRAPH_TRACER
718
719/* Maximum number of functions to trace before diagnosing a hang */
720#define GRAPH_MAX_FUNC_TEST 100000000
721
722static unsigned int graph_hang_thresh;
723
724/* Wrap the real function entry probe to avoid possible hanging */
725static int trace_graph_entry_watchdog(struct ftrace_graph_ent *trace)
726{
727 /* This is harmlessly racy, we want to approximately detect a hang */
728 if (unlikely(++graph_hang_thresh > GRAPH_MAX_FUNC_TEST)) {
729 ftrace_graph_stop();
730 printk(KERN_WARNING "BUG: Function graph tracer hang!\n");
731 if (ftrace_dump_on_oops) {
732 ftrace_dump(DUMP_ALL);
733 /* ftrace_dump() disables tracing */
734 tracing_on();
735 }
736 return 0;
737 }
738
739 return trace_graph_entry(trace);
740}
741
742/*
743 * Pretty much the same than for the function tracer from which the selftest
744 * has been borrowed.
745 */
746__init int
747trace_selftest_startup_function_graph(struct tracer *trace,
748 struct trace_array *tr)
749{
750 int ret;
751 unsigned long count;
752
753#ifdef CONFIG_DYNAMIC_FTRACE
754 if (ftrace_filter_param) {
755 printk(KERN_CONT " ... kernel command line filter set: force PASS ... ");
756 return 0;
757 }
758#endif
759
760 /*
761 * Simulate the init() callback but we attach a watchdog callback
762 * to detect and recover from possible hangs
763 */
764 tracing_reset_online_cpus(&tr->trace_buffer);
765 set_graph_array(tr);
766 ret = register_ftrace_graph(&trace_graph_return,
767 &trace_graph_entry_watchdog);
768 if (ret) {
769 warn_failed_init_tracer(trace, ret);
770 goto out;
771 }
772 tracing_start_cmdline_record();
773
774 /* Sleep for a 1/10 of a second */
775 msleep(100);
776
777 /* Have we just recovered from a hang? */
778 if (graph_hang_thresh > GRAPH_MAX_FUNC_TEST) {
779 tracing_selftest_disabled = true;
780 ret = -1;
781 goto out;
782 }
783
784 tracing_stop();
785
786 /* check the trace buffer */
787 ret = trace_test_buffer(&tr->trace_buffer, &count);
788
789 trace->reset(tr);
790 tracing_start();
791
792 if (!ret && !count) {
793 printk(KERN_CONT ".. no entries found ..");
794 ret = -1;
795 goto out;
796 }
797
798 /* Don't test dynamic tracing, the function tracer already did */
799
800out:
801 /* Stop it if we failed */
802 if (ret)
803 ftrace_graph_stop();
804
805 return ret;
806}
807#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
808
809
810#ifdef CONFIG_IRQSOFF_TRACER
811int
812trace_selftest_startup_irqsoff(struct tracer *trace, struct trace_array *tr)
813{
814 unsigned long save_max = tr->max_latency;
815 unsigned long count;
816 int ret;
817
818 /* start the tracing */
819 ret = tracer_init(trace, tr);
820 if (ret) {
821 warn_failed_init_tracer(trace, ret);
822 return ret;
823 }
824
825 /* reset the max latency */
826 tr->max_latency = 0;
827 /* disable interrupts for a bit */
828 local_irq_disable();
829 udelay(100);
830 local_irq_enable();
831
832 /*
833 * Stop the tracer to avoid a warning subsequent
834 * to buffer flipping failure because tracing_stop()
835 * disables the tr and max buffers, making flipping impossible
836 * in case of parallels max irqs off latencies.
837 */
838 trace->stop(tr);
839 /* stop the tracing. */
840 tracing_stop();
841 /* check both trace buffers */
842 ret = trace_test_buffer(&tr->trace_buffer, NULL);
843 if (!ret)
844 ret = trace_test_buffer(&tr->max_buffer, &count);
845 trace->reset(tr);
846 tracing_start();
847
848 if (!ret && !count) {
849 printk(KERN_CONT ".. no entries found ..");
850 ret = -1;
851 }
852
853 tr->max_latency = save_max;
854
855 return ret;
856}
857#endif /* CONFIG_IRQSOFF_TRACER */
858
859#ifdef CONFIG_PREEMPT_TRACER
860int
861trace_selftest_startup_preemptoff(struct tracer *trace, struct trace_array *tr)
862{
863 unsigned long save_max = tr->max_latency;
864 unsigned long count;
865 int ret;
866
867 /*
868 * Now that the big kernel lock is no longer preemptable,
869 * and this is called with the BKL held, it will always
870 * fail. If preemption is already disabled, simply
871 * pass the test. When the BKL is removed, or becomes
872 * preemptible again, we will once again test this,
873 * so keep it in.
874 */
875 if (preempt_count()) {
876 printk(KERN_CONT "can not test ... force ");
877 return 0;
878 }
879
880 /* start the tracing */
881 ret = tracer_init(trace, tr);
882 if (ret) {
883 warn_failed_init_tracer(trace, ret);
884 return ret;
885 }
886
887 /* reset the max latency */
888 tr->max_latency = 0;
889 /* disable preemption for a bit */
890 preempt_disable();
891 udelay(100);
892 preempt_enable();
893
894 /*
895 * Stop the tracer to avoid a warning subsequent
896 * to buffer flipping failure because tracing_stop()
897 * disables the tr and max buffers, making flipping impossible
898 * in case of parallels max preempt off latencies.
899 */
900 trace->stop(tr);
901 /* stop the tracing. */
902 tracing_stop();
903 /* check both trace buffers */
904 ret = trace_test_buffer(&tr->trace_buffer, NULL);
905 if (!ret)
906 ret = trace_test_buffer(&tr->max_buffer, &count);
907 trace->reset(tr);
908 tracing_start();
909
910 if (!ret && !count) {
911 printk(KERN_CONT ".. no entries found ..");
912 ret = -1;
913 }
914
915 tr->max_latency = save_max;
916
917 return ret;
918}
919#endif /* CONFIG_PREEMPT_TRACER */
920
921#if defined(CONFIG_IRQSOFF_TRACER) && defined(CONFIG_PREEMPT_TRACER)
922int
923trace_selftest_startup_preemptirqsoff(struct tracer *trace, struct trace_array *tr)
924{
925 unsigned long save_max = tr->max_latency;
926 unsigned long count;
927 int ret;
928
929 /*
930 * Now that the big kernel lock is no longer preemptable,
931 * and this is called with the BKL held, it will always
932 * fail. If preemption is already disabled, simply
933 * pass the test. When the BKL is removed, or becomes
934 * preemptible again, we will once again test this,
935 * so keep it in.
936 */
937 if (preempt_count()) {
938 printk(KERN_CONT "can not test ... force ");
939 return 0;
940 }
941
942 /* start the tracing */
943 ret = tracer_init(trace, tr);
944 if (ret) {
945 warn_failed_init_tracer(trace, ret);
946 goto out_no_start;
947 }
948
949 /* reset the max latency */
950 tr->max_latency = 0;
951
952 /* disable preemption and interrupts for a bit */
953 preempt_disable();
954 local_irq_disable();
955 udelay(100);
956 preempt_enable();
957 /* reverse the order of preempt vs irqs */
958 local_irq_enable();
959
960 /*
961 * Stop the tracer to avoid a warning subsequent
962 * to buffer flipping failure because tracing_stop()
963 * disables the tr and max buffers, making flipping impossible
964 * in case of parallels max irqs/preempt off latencies.
965 */
966 trace->stop(tr);
967 /* stop the tracing. */
968 tracing_stop();
969 /* check both trace buffers */
970 ret = trace_test_buffer(&tr->trace_buffer, NULL);
971 if (ret)
972 goto out;
973
974 ret = trace_test_buffer(&tr->max_buffer, &count);
975 if (ret)
976 goto out;
977
978 if (!ret && !count) {
979 printk(KERN_CONT ".. no entries found ..");
980 ret = -1;
981 goto out;
982 }
983
984 /* do the test by disabling interrupts first this time */
985 tr->max_latency = 0;
986 tracing_start();
987 trace->start(tr);
988
989 preempt_disable();
990 local_irq_disable();
991 udelay(100);
992 preempt_enable();
993 /* reverse the order of preempt vs irqs */
994 local_irq_enable();
995
996 trace->stop(tr);
997 /* stop the tracing. */
998 tracing_stop();
999 /* check both trace buffers */
1000 ret = trace_test_buffer(&tr->trace_buffer, NULL);
1001 if (ret)
1002 goto out;
1003
1004 ret = trace_test_buffer(&tr->max_buffer, &count);
1005
1006 if (!ret && !count) {
1007 printk(KERN_CONT ".. no entries found ..");
1008 ret = -1;
1009 goto out;
1010 }
1011
1012out:
1013 tracing_start();
1014out_no_start:
1015 trace->reset(tr);
1016 tr->max_latency = save_max;
1017
1018 return ret;
1019}
1020#endif /* CONFIG_IRQSOFF_TRACER && CONFIG_PREEMPT_TRACER */
1021
1022#ifdef CONFIG_NOP_TRACER
1023int
1024trace_selftest_startup_nop(struct tracer *trace, struct trace_array *tr)
1025{
1026 /* What could possibly go wrong? */
1027 return 0;
1028}
1029#endif
1030
1031#ifdef CONFIG_SCHED_TRACER
1032
1033struct wakeup_test_data {
1034 struct completion is_ready;
1035 int go;
1036};
1037
1038static int trace_wakeup_test_thread(void *data)
1039{
1040 /* Make this a -deadline thread */
1041 static const struct sched_attr attr = {
1042 .sched_policy = SCHED_DEADLINE,
1043 .sched_runtime = 100000ULL,
1044 .sched_deadline = 10000000ULL,
1045 .sched_period = 10000000ULL
1046 };
1047 struct wakeup_test_data *x = data;
1048
1049 sched_setattr(current, &attr);
1050
1051 /* Make it know we have a new prio */
1052 complete(&x->is_ready);
1053
1054 /* now go to sleep and let the test wake us up */
1055 set_current_state(TASK_INTERRUPTIBLE);
1056 while (!x->go) {
1057 schedule();
1058 set_current_state(TASK_INTERRUPTIBLE);
1059 }
1060
1061 complete(&x->is_ready);
1062
1063 set_current_state(TASK_INTERRUPTIBLE);
1064
1065 /* we are awake, now wait to disappear */
1066 while (!kthread_should_stop()) {
1067 schedule();
1068 set_current_state(TASK_INTERRUPTIBLE);
1069 }
1070
1071 __set_current_state(TASK_RUNNING);
1072
1073 return 0;
1074}
1075int
1076trace_selftest_startup_wakeup(struct tracer *trace, struct trace_array *tr)
1077{
1078 unsigned long save_max = tr->max_latency;
1079 struct task_struct *p;
1080 struct wakeup_test_data data;
1081 unsigned long count;
1082 int ret;
1083
1084 memset(&data, 0, sizeof(data));
1085
1086 init_completion(&data.is_ready);
1087
1088 /* create a -deadline thread */
1089 p = kthread_run(trace_wakeup_test_thread, &data, "ftrace-test");
1090 if (IS_ERR(p)) {
1091 printk(KERN_CONT "Failed to create ftrace wakeup test thread ");
1092 return -1;
1093 }
1094
1095 /* make sure the thread is running at -deadline policy */
1096 wait_for_completion(&data.is_ready);
1097
1098 /* start the tracing */
1099 ret = tracer_init(trace, tr);
1100 if (ret) {
1101 warn_failed_init_tracer(trace, ret);
1102 return ret;
1103 }
1104
1105 /* reset the max latency */
1106 tr->max_latency = 0;
1107
1108 while (p->on_rq) {
1109 /*
1110 * Sleep to make sure the -deadline thread is asleep too.
1111 * On virtual machines we can't rely on timings,
1112 * but we want to make sure this test still works.
1113 */
1114 msleep(100);
1115 }
1116
1117 init_completion(&data.is_ready);
1118
1119 data.go = 1;
1120 /* memory barrier is in the wake_up_process() */
1121
1122 wake_up_process(p);
1123
1124 /* Wait for the task to wake up */
1125 wait_for_completion(&data.is_ready);
1126
1127 /* stop the tracing. */
1128 tracing_stop();
1129 /* check both trace buffers */
1130 ret = trace_test_buffer(&tr->trace_buffer, NULL);
1131 if (!ret)
1132 ret = trace_test_buffer(&tr->max_buffer, &count);
1133
1134
1135 trace->reset(tr);
1136 tracing_start();
1137
1138 tr->max_latency = save_max;
1139
1140 /* kill the thread */
1141 kthread_stop(p);
1142
1143 if (!ret && !count) {
1144 printk(KERN_CONT ".. no entries found ..");
1145 ret = -1;
1146 }
1147
1148 return ret;
1149}
1150#endif /* CONFIG_SCHED_TRACER */
1151
1152#ifdef CONFIG_CONTEXT_SWITCH_TRACER
1153int
1154trace_selftest_startup_sched_switch(struct tracer *trace, struct trace_array *tr)
1155{
1156 unsigned long count;
1157 int ret;
1158
1159 /* start the tracing */
1160 ret = tracer_init(trace, tr);
1161 if (ret) {
1162 warn_failed_init_tracer(trace, ret);
1163 return ret;
1164 }
1165
1166 /* Sleep for a 1/10 of a second */
1167 msleep(100);
1168 /* stop the tracing. */
1169 tracing_stop();
1170 /* check the trace buffer */
1171 ret = trace_test_buffer(&tr->trace_buffer, &count);
1172 trace->reset(tr);
1173 tracing_start();
1174
1175 if (!ret && !count) {
1176 printk(KERN_CONT ".. no entries found ..");
1177 ret = -1;
1178 }
1179
1180 return ret;
1181}
1182#endif /* CONFIG_CONTEXT_SWITCH_TRACER */
1183
1184#ifdef CONFIG_BRANCH_TRACER
1185int
1186trace_selftest_startup_branch(struct tracer *trace, struct trace_array *tr)
1187{
1188 unsigned long count;
1189 int ret;
1190
1191 /* start the tracing */
1192 ret = tracer_init(trace, tr);
1193 if (ret) {
1194 warn_failed_init_tracer(trace, ret);
1195 return ret;
1196 }
1197
1198 /* Sleep for a 1/10 of a second */
1199 msleep(100);
1200 /* stop the tracing. */
1201 tracing_stop();
1202 /* check the trace buffer */
1203 ret = trace_test_buffer(&tr->trace_buffer, &count);
1204 trace->reset(tr);
1205 tracing_start();
1206
1207 if (!ret && !count) {
1208 printk(KERN_CONT ".. no entries found ..");
1209 ret = -1;
1210 }
1211
1212 return ret;
1213}
1214#endif /* CONFIG_BRANCH_TRACER */
1215
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
10static 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
26static 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 */
63static 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
97static 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
106static int trace_selftest_test_probe1_cnt;
107static 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
115static int trace_selftest_test_probe2_cnt;
116static 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
124static int trace_selftest_test_probe3_cnt;
125static 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
133static int trace_selftest_test_global_cnt;
134static 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
142static int trace_selftest_test_dyn_cnt;
143static 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
151static struct ftrace_ops test_probe1 = {
152 .func = trace_selftest_test_probe1_func,
153};
154
155static struct ftrace_ops test_probe2 = {
156 .func = trace_selftest_test_probe2_func,
157};
158
159static struct ftrace_ops test_probe3 = {
160 .func = trace_selftest_test_probe3_func,
161};
162
163static 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
173static 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
182static 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 */
356static 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
447static int trace_selftest_recursion_cnt;
448static 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
463static 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
480static struct ftrace_ops test_rec_probe = {
481 .func = trace_selftest_test_recursion_func,
482 .flags = FTRACE_OPS_FL_RECURSION,
483};
484
485static struct ftrace_ops test_recsafe_probe = {
486 .func = trace_selftest_test_recursion_safe_func,
487};
488
489static int
490trace_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;
566out:
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
576static enum {
577 TRACE_SELFTEST_REGS_START,
578 TRACE_SELFTEST_REGS_FOUND,
579 TRACE_SELFTEST_REGS_NOT_FOUND,
580} trace_selftest_regs_stat;
581
582static 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
595static struct ftrace_ops test_regs_probe = {
596 .func = trace_selftest_test_regs_func,
597 .flags = FTRACE_OPS_FL_SAVE_REGS,
598};
599
600static int
601trace_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;
679out:
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
691trace_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/* Maximum number of functions to trace before diagnosing a hang */
760#define GRAPH_MAX_FUNC_TEST 100000000
761
762static unsigned int graph_hang_thresh;
763
764/* Wrap the real function entry probe to avoid possible hanging */
765static int trace_graph_entry_watchdog(struct ftrace_graph_ent *trace)
766{
767 /* This is harmlessly racy, we want to approximately detect a hang */
768 if (unlikely(++graph_hang_thresh > GRAPH_MAX_FUNC_TEST)) {
769 ftrace_graph_stop();
770 printk(KERN_WARNING "BUG: Function graph tracer hang!\n");
771 if (ftrace_dump_on_oops) {
772 ftrace_dump(DUMP_ALL);
773 /* ftrace_dump() disables tracing */
774 tracing_on();
775 }
776 return 0;
777 }
778
779 return trace_graph_entry(trace);
780}
781
782static struct fgraph_ops fgraph_ops __initdata = {
783 .entryfunc = &trace_graph_entry_watchdog,
784 .retfunc = &trace_graph_return,
785};
786
787#ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
788static struct ftrace_ops direct;
789#endif
790
791/*
792 * Pretty much the same than for the function tracer from which the selftest
793 * has been borrowed.
794 */
795__init int
796trace_selftest_startup_function_graph(struct tracer *trace,
797 struct trace_array *tr)
798{
799 int ret;
800 unsigned long count;
801 char *func_name __maybe_unused;
802
803#ifdef CONFIG_DYNAMIC_FTRACE
804 if (ftrace_filter_param) {
805 printk(KERN_CONT " ... kernel command line filter set: force PASS ... ");
806 return 0;
807 }
808#endif
809
810 /*
811 * Simulate the init() callback but we attach a watchdog callback
812 * to detect and recover from possible hangs
813 */
814 tracing_reset_online_cpus(&tr->array_buffer);
815 set_graph_array(tr);
816 ret = register_ftrace_graph(&fgraph_ops);
817 if (ret) {
818 warn_failed_init_tracer(trace, ret);
819 goto out;
820 }
821 tracing_start_cmdline_record();
822
823 /* Sleep for a 1/10 of a second */
824 msleep(100);
825
826 /* Have we just recovered from a hang? */
827 if (graph_hang_thresh > GRAPH_MAX_FUNC_TEST) {
828 disable_tracing_selftest("recovering from a hang");
829 ret = -1;
830 goto out;
831 }
832
833 tracing_stop();
834
835 /* check the trace buffer */
836 ret = trace_test_buffer(&tr->array_buffer, &count);
837
838 /* Need to also simulate the tr->reset to remove this fgraph_ops */
839 tracing_stop_cmdline_record();
840 unregister_ftrace_graph(&fgraph_ops);
841
842 tracing_start();
843
844 if (!ret && !count) {
845 printk(KERN_CONT ".. no entries found ..");
846 ret = -1;
847 goto out;
848 }
849
850#ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
851 /*
852 * These tests can take some time to run. Make sure on non PREEMPT
853 * kernels, we do not trigger the softlockup detector.
854 */
855 cond_resched();
856
857 tracing_reset_online_cpus(&tr->array_buffer);
858 set_graph_array(tr);
859
860 /*
861 * Some archs *cough*PowerPC*cough* add characters to the
862 * start of the function names. We simply put a '*' to
863 * accommodate them.
864 */
865 func_name = "*" __stringify(DYN_FTRACE_TEST_NAME);
866 ftrace_set_global_filter(func_name, strlen(func_name), 1);
867
868 /*
869 * Register direct function together with graph tracer
870 * and make sure we get graph trace.
871 */
872 ftrace_set_filter_ip(&direct, (unsigned long)DYN_FTRACE_TEST_NAME, 0, 0);
873 ret = register_ftrace_direct(&direct,
874 (unsigned long)ftrace_stub_direct_tramp);
875 if (ret)
876 goto out;
877
878 cond_resched();
879
880 ret = register_ftrace_graph(&fgraph_ops);
881 if (ret) {
882 warn_failed_init_tracer(trace, ret);
883 goto out;
884 }
885
886 DYN_FTRACE_TEST_NAME();
887
888 count = 0;
889
890 tracing_stop();
891 /* check the trace buffer */
892 ret = trace_test_buffer(&tr->array_buffer, &count);
893
894 unregister_ftrace_graph(&fgraph_ops);
895
896 ret = unregister_ftrace_direct(&direct,
897 (unsigned long)ftrace_stub_direct_tramp,
898 true);
899 if (ret)
900 goto out;
901
902 cond_resched();
903
904 tracing_start();
905
906 if (!ret && !count) {
907 ret = -1;
908 goto out;
909 }
910
911 /* Enable tracing on all functions again */
912 ftrace_set_global_filter(NULL, 0, 1);
913#endif
914
915 /* Don't test dynamic tracing, the function tracer already did */
916out:
917 /* Stop it if we failed */
918 if (ret)
919 ftrace_graph_stop();
920
921 return ret;
922}
923#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
924
925
926#ifdef CONFIG_IRQSOFF_TRACER
927int
928trace_selftest_startup_irqsoff(struct tracer *trace, struct trace_array *tr)
929{
930 unsigned long save_max = tr->max_latency;
931 unsigned long count;
932 int ret;
933
934 /* start the tracing */
935 ret = tracer_init(trace, tr);
936 if (ret) {
937 warn_failed_init_tracer(trace, ret);
938 return ret;
939 }
940
941 /* reset the max latency */
942 tr->max_latency = 0;
943 /* disable interrupts for a bit */
944 local_irq_disable();
945 udelay(100);
946 local_irq_enable();
947
948 /*
949 * Stop the tracer to avoid a warning subsequent
950 * to buffer flipping failure because tracing_stop()
951 * disables the tr and max buffers, making flipping impossible
952 * in case of parallels max irqs off latencies.
953 */
954 trace->stop(tr);
955 /* stop the tracing. */
956 tracing_stop();
957 /* check both trace buffers */
958 ret = trace_test_buffer(&tr->array_buffer, NULL);
959 if (!ret)
960 ret = trace_test_buffer(&tr->max_buffer, &count);
961 trace->reset(tr);
962 tracing_start();
963
964 if (!ret && !count) {
965 printk(KERN_CONT ".. no entries found ..");
966 ret = -1;
967 }
968
969 tr->max_latency = save_max;
970
971 return ret;
972}
973#endif /* CONFIG_IRQSOFF_TRACER */
974
975#ifdef CONFIG_PREEMPT_TRACER
976int
977trace_selftest_startup_preemptoff(struct tracer *trace, struct trace_array *tr)
978{
979 unsigned long save_max = tr->max_latency;
980 unsigned long count;
981 int ret;
982
983 /*
984 * Now that the big kernel lock is no longer preemptible,
985 * and this is called with the BKL held, it will always
986 * fail. If preemption is already disabled, simply
987 * pass the test. When the BKL is removed, or becomes
988 * preemptible again, we will once again test this,
989 * so keep it in.
990 */
991 if (preempt_count()) {
992 printk(KERN_CONT "can not test ... force ");
993 return 0;
994 }
995
996 /* start the tracing */
997 ret = tracer_init(trace, tr);
998 if (ret) {
999 warn_failed_init_tracer(trace, ret);
1000 return ret;
1001 }
1002
1003 /* reset the max latency */
1004 tr->max_latency = 0;
1005 /* disable preemption for a bit */
1006 preempt_disable();
1007 udelay(100);
1008 preempt_enable();
1009
1010 /*
1011 * Stop the tracer to avoid a warning subsequent
1012 * to buffer flipping failure because tracing_stop()
1013 * disables the tr and max buffers, making flipping impossible
1014 * in case of parallels max preempt off latencies.
1015 */
1016 trace->stop(tr);
1017 /* stop the tracing. */
1018 tracing_stop();
1019 /* check both trace buffers */
1020 ret = trace_test_buffer(&tr->array_buffer, NULL);
1021 if (!ret)
1022 ret = trace_test_buffer(&tr->max_buffer, &count);
1023 trace->reset(tr);
1024 tracing_start();
1025
1026 if (!ret && !count) {
1027 printk(KERN_CONT ".. no entries found ..");
1028 ret = -1;
1029 }
1030
1031 tr->max_latency = save_max;
1032
1033 return ret;
1034}
1035#endif /* CONFIG_PREEMPT_TRACER */
1036
1037#if defined(CONFIG_IRQSOFF_TRACER) && defined(CONFIG_PREEMPT_TRACER)
1038int
1039trace_selftest_startup_preemptirqsoff(struct tracer *trace, struct trace_array *tr)
1040{
1041 unsigned long save_max = tr->max_latency;
1042 unsigned long count;
1043 int ret;
1044
1045 /*
1046 * Now that the big kernel lock is no longer preemptible,
1047 * and this is called with the BKL held, it will always
1048 * fail. If preemption is already disabled, simply
1049 * pass the test. When the BKL is removed, or becomes
1050 * preemptible again, we will once again test this,
1051 * so keep it in.
1052 */
1053 if (preempt_count()) {
1054 printk(KERN_CONT "can not test ... force ");
1055 return 0;
1056 }
1057
1058 /* start the tracing */
1059 ret = tracer_init(trace, tr);
1060 if (ret) {
1061 warn_failed_init_tracer(trace, ret);
1062 goto out_no_start;
1063 }
1064
1065 /* reset the max latency */
1066 tr->max_latency = 0;
1067
1068 /* disable preemption and interrupts for a bit */
1069 preempt_disable();
1070 local_irq_disable();
1071 udelay(100);
1072 preempt_enable();
1073 /* reverse the order of preempt vs irqs */
1074 local_irq_enable();
1075
1076 /*
1077 * Stop the tracer to avoid a warning subsequent
1078 * to buffer flipping failure because tracing_stop()
1079 * disables the tr and max buffers, making flipping impossible
1080 * in case of parallels max irqs/preempt off latencies.
1081 */
1082 trace->stop(tr);
1083 /* stop the tracing. */
1084 tracing_stop();
1085 /* check both trace buffers */
1086 ret = trace_test_buffer(&tr->array_buffer, NULL);
1087 if (ret)
1088 goto out;
1089
1090 ret = trace_test_buffer(&tr->max_buffer, &count);
1091 if (ret)
1092 goto out;
1093
1094 if (!ret && !count) {
1095 printk(KERN_CONT ".. no entries found ..");
1096 ret = -1;
1097 goto out;
1098 }
1099
1100 /* do the test by disabling interrupts first this time */
1101 tr->max_latency = 0;
1102 tracing_start();
1103 trace->start(tr);
1104
1105 preempt_disable();
1106 local_irq_disable();
1107 udelay(100);
1108 preempt_enable();
1109 /* reverse the order of preempt vs irqs */
1110 local_irq_enable();
1111
1112 trace->stop(tr);
1113 /* stop the tracing. */
1114 tracing_stop();
1115 /* check both trace buffers */
1116 ret = trace_test_buffer(&tr->array_buffer, NULL);
1117 if (ret)
1118 goto out;
1119
1120 ret = trace_test_buffer(&tr->max_buffer, &count);
1121
1122 if (!ret && !count) {
1123 printk(KERN_CONT ".. no entries found ..");
1124 ret = -1;
1125 goto out;
1126 }
1127
1128out:
1129 tracing_start();
1130out_no_start:
1131 trace->reset(tr);
1132 tr->max_latency = save_max;
1133
1134 return ret;
1135}
1136#endif /* CONFIG_IRQSOFF_TRACER && CONFIG_PREEMPT_TRACER */
1137
1138#ifdef CONFIG_NOP_TRACER
1139int
1140trace_selftest_startup_nop(struct tracer *trace, struct trace_array *tr)
1141{
1142 /* What could possibly go wrong? */
1143 return 0;
1144}
1145#endif
1146
1147#ifdef CONFIG_SCHED_TRACER
1148
1149struct wakeup_test_data {
1150 struct completion is_ready;
1151 int go;
1152};
1153
1154static int trace_wakeup_test_thread(void *data)
1155{
1156 /* Make this a -deadline thread */
1157 static const struct sched_attr attr = {
1158 .sched_policy = SCHED_DEADLINE,
1159 .sched_runtime = 100000ULL,
1160 .sched_deadline = 10000000ULL,
1161 .sched_period = 10000000ULL
1162 };
1163 struct wakeup_test_data *x = data;
1164
1165 sched_setattr(current, &attr);
1166
1167 /* Make it know we have a new prio */
1168 complete(&x->is_ready);
1169
1170 /* now go to sleep and let the test wake us up */
1171 set_current_state(TASK_INTERRUPTIBLE);
1172 while (!x->go) {
1173 schedule();
1174 set_current_state(TASK_INTERRUPTIBLE);
1175 }
1176
1177 complete(&x->is_ready);
1178
1179 set_current_state(TASK_INTERRUPTIBLE);
1180
1181 /* we are awake, now wait to disappear */
1182 while (!kthread_should_stop()) {
1183 schedule();
1184 set_current_state(TASK_INTERRUPTIBLE);
1185 }
1186
1187 __set_current_state(TASK_RUNNING);
1188
1189 return 0;
1190}
1191int
1192trace_selftest_startup_wakeup(struct tracer *trace, struct trace_array *tr)
1193{
1194 unsigned long save_max = tr->max_latency;
1195 struct task_struct *p;
1196 struct wakeup_test_data data;
1197 unsigned long count;
1198 int ret;
1199
1200 memset(&data, 0, sizeof(data));
1201
1202 init_completion(&data.is_ready);
1203
1204 /* create a -deadline thread */
1205 p = kthread_run(trace_wakeup_test_thread, &data, "ftrace-test");
1206 if (IS_ERR(p)) {
1207 printk(KERN_CONT "Failed to create ftrace wakeup test thread ");
1208 return -1;
1209 }
1210
1211 /* make sure the thread is running at -deadline policy */
1212 wait_for_completion(&data.is_ready);
1213
1214 /* start the tracing */
1215 ret = tracer_init(trace, tr);
1216 if (ret) {
1217 warn_failed_init_tracer(trace, ret);
1218 return ret;
1219 }
1220
1221 /* reset the max latency */
1222 tr->max_latency = 0;
1223
1224 while (p->on_rq) {
1225 /*
1226 * Sleep to make sure the -deadline thread is asleep too.
1227 * On virtual machines we can't rely on timings,
1228 * but we want to make sure this test still works.
1229 */
1230 msleep(100);
1231 }
1232
1233 init_completion(&data.is_ready);
1234
1235 data.go = 1;
1236 /* memory barrier is in the wake_up_process() */
1237
1238 wake_up_process(p);
1239
1240 /* Wait for the task to wake up */
1241 wait_for_completion(&data.is_ready);
1242
1243 /* stop the tracing. */
1244 tracing_stop();
1245 /* check both trace buffers */
1246 ret = trace_test_buffer(&tr->array_buffer, NULL);
1247 if (!ret)
1248 ret = trace_test_buffer(&tr->max_buffer, &count);
1249
1250
1251 trace->reset(tr);
1252 tracing_start();
1253
1254 tr->max_latency = save_max;
1255
1256 /* kill the thread */
1257 kthread_stop(p);
1258
1259 if (!ret && !count) {
1260 printk(KERN_CONT ".. no entries found ..");
1261 ret = -1;
1262 }
1263
1264 return ret;
1265}
1266#endif /* CONFIG_SCHED_TRACER */
1267
1268#ifdef CONFIG_BRANCH_TRACER
1269int
1270trace_selftest_startup_branch(struct tracer *trace, struct trace_array *tr)
1271{
1272 unsigned long count;
1273 int ret;
1274
1275 /* start the tracing */
1276 ret = tracer_init(trace, tr);
1277 if (ret) {
1278 warn_failed_init_tracer(trace, ret);
1279 return ret;
1280 }
1281
1282 /* Sleep for a 1/10 of a second */
1283 msleep(100);
1284 /* stop the tracing. */
1285 tracing_stop();
1286 /* check the trace buffer */
1287 ret = trace_test_buffer(&tr->array_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 return ret;
1297}
1298#endif /* CONFIG_BRANCH_TRACER */
1299