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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 ret = 0;
291 out_free:
292 unregister_ftrace_function(dyn_ops);
293 kfree(dyn_ops);
294
295 out:
296 /* Purposely unregister in the same order */
297 unregister_ftrace_function(&test_probe1);
298 unregister_ftrace_function(&test_probe2);
299 unregister_ftrace_function(&test_probe3);
300 if (cnt > 1)
301 unregister_ftrace_function(tr->ops);
302 ftrace_reset_array_ops(tr);
303
304 /* Make sure everything is off */
305 reset_counts();
306 DYN_FTRACE_TEST_NAME();
307 DYN_FTRACE_TEST_NAME();
308
309 if (trace_selftest_test_probe1_cnt ||
310 trace_selftest_test_probe2_cnt ||
311 trace_selftest_test_probe3_cnt ||
312 trace_selftest_test_global_cnt ||
313 trace_selftest_test_dyn_cnt)
314 ret = -1;
315
316 ftrace_enabled = save_ftrace_enabled;
317
318 return ret;
319}
320
321/* Test dynamic code modification and ftrace filters */
322static int trace_selftest_startup_dynamic_tracing(struct tracer *trace,
323 struct trace_array *tr,
324 int (*func)(void))
325{
326 int save_ftrace_enabled = ftrace_enabled;
327 unsigned long count;
328 char *func_name;
329 int ret;
330
331 /* The ftrace test PASSED */
332 printk(KERN_CONT "PASSED\n");
333 pr_info("Testing dynamic ftrace: ");
334
335 /* enable tracing, and record the filter function */
336 ftrace_enabled = 1;
337
338 /* passed in by parameter to fool gcc from optimizing */
339 func();
340
341 /*
342 * Some archs *cough*PowerPC*cough* add characters to the
343 * start of the function names. We simply put a '*' to
344 * accommodate them.
345 */
346 func_name = "*" __stringify(DYN_FTRACE_TEST_NAME);
347
348 /* filter only on our function */
349 ftrace_set_global_filter(func_name, strlen(func_name), 1);
350
351 /* enable tracing */
352 ret = tracer_init(trace, tr);
353 if (ret) {
354 warn_failed_init_tracer(trace, ret);
355 goto out;
356 }
357
358 /* Sleep for a 1/10 of a second */
359 msleep(100);
360
361 /* we should have nothing in the buffer */
362 ret = trace_test_buffer(&tr->array_buffer, &count);
363 if (ret)
364 goto out;
365
366 if (count) {
367 ret = -1;
368 printk(KERN_CONT ".. filter did not filter .. ");
369 goto out;
370 }
371
372 /* call our function again */
373 func();
374
375 /* sleep again */
376 msleep(100);
377
378 /* stop the tracing. */
379 tracing_stop();
380 ftrace_enabled = 0;
381
382 /* check the trace buffer */
383 ret = trace_test_buffer(&tr->array_buffer, &count);
384
385 ftrace_enabled = 1;
386 tracing_start();
387
388 /* we should only have one item */
389 if (!ret && count != 1) {
390 trace->reset(tr);
391 printk(KERN_CONT ".. filter failed count=%ld ..", count);
392 ret = -1;
393 goto out;
394 }
395
396 /* Test the ops with global tracing running */
397 ret = trace_selftest_ops(tr, 1);
398 trace->reset(tr);
399
400 out:
401 ftrace_enabled = save_ftrace_enabled;
402
403 /* Enable tracing on all functions again */
404 ftrace_set_global_filter(NULL, 0, 1);
405
406 /* Test the ops with global tracing off */
407 if (!ret)
408 ret = trace_selftest_ops(tr, 2);
409
410 return ret;
411}
412
413static int trace_selftest_recursion_cnt;
414static void trace_selftest_test_recursion_func(unsigned long ip,
415 unsigned long pip,
416 struct ftrace_ops *op,
417 struct ftrace_regs *fregs)
418{
419 /*
420 * This function is registered without the recursion safe flag.
421 * The ftrace infrastructure should provide the recursion
422 * protection. If not, this will crash the kernel!
423 */
424 if (trace_selftest_recursion_cnt++ > 10)
425 return;
426 DYN_FTRACE_TEST_NAME();
427}
428
429static void trace_selftest_test_recursion_safe_func(unsigned long ip,
430 unsigned long pip,
431 struct ftrace_ops *op,
432 struct ftrace_regs *fregs)
433{
434 /*
435 * We said we would provide our own recursion. By calling
436 * this function again, we should recurse back into this function
437 * and count again. But this only happens if the arch supports
438 * all of ftrace features and nothing else is using the function
439 * tracing utility.
440 */
441 if (trace_selftest_recursion_cnt++)
442 return;
443 DYN_FTRACE_TEST_NAME();
444}
445
446static struct ftrace_ops test_rec_probe = {
447 .func = trace_selftest_test_recursion_func,
448 .flags = FTRACE_OPS_FL_RECURSION,
449};
450
451static struct ftrace_ops test_recsafe_probe = {
452 .func = trace_selftest_test_recursion_safe_func,
453};
454
455static int
456trace_selftest_function_recursion(void)
457{
458 int save_ftrace_enabled = ftrace_enabled;
459 char *func_name;
460 int len;
461 int ret;
462
463 /* The previous test PASSED */
464 pr_cont("PASSED\n");
465 pr_info("Testing ftrace recursion: ");
466
467
468 /* enable tracing, and record the filter function */
469 ftrace_enabled = 1;
470
471 /* Handle PPC64 '.' name */
472 func_name = "*" __stringify(DYN_FTRACE_TEST_NAME);
473 len = strlen(func_name);
474
475 ret = ftrace_set_filter(&test_rec_probe, func_name, len, 1);
476 if (ret) {
477 pr_cont("*Could not set filter* ");
478 goto out;
479 }
480
481 ret = register_ftrace_function(&test_rec_probe);
482 if (ret) {
483 pr_cont("*could not register callback* ");
484 goto out;
485 }
486
487 DYN_FTRACE_TEST_NAME();
488
489 unregister_ftrace_function(&test_rec_probe);
490
491 ret = -1;
492 /*
493 * Recursion allows for transitions between context,
494 * and may call the callback twice.
495 */
496 if (trace_selftest_recursion_cnt != 1 &&
497 trace_selftest_recursion_cnt != 2) {
498 pr_cont("*callback not called once (or twice) (%d)* ",
499 trace_selftest_recursion_cnt);
500 goto out;
501 }
502
503 trace_selftest_recursion_cnt = 1;
504
505 pr_cont("PASSED\n");
506 pr_info("Testing ftrace recursion safe: ");
507
508 ret = ftrace_set_filter(&test_recsafe_probe, func_name, len, 1);
509 if (ret) {
510 pr_cont("*Could not set filter* ");
511 goto out;
512 }
513
514 ret = register_ftrace_function(&test_recsafe_probe);
515 if (ret) {
516 pr_cont("*could not register callback* ");
517 goto out;
518 }
519
520 DYN_FTRACE_TEST_NAME();
521
522 unregister_ftrace_function(&test_recsafe_probe);
523
524 ret = -1;
525 if (trace_selftest_recursion_cnt != 2) {
526 pr_cont("*callback not called expected 2 times (%d)* ",
527 trace_selftest_recursion_cnt);
528 goto out;
529 }
530
531 ret = 0;
532out:
533 ftrace_enabled = save_ftrace_enabled;
534
535 return ret;
536}
537#else
538# define trace_selftest_startup_dynamic_tracing(trace, tr, func) ({ 0; })
539# define trace_selftest_function_recursion() ({ 0; })
540#endif /* CONFIG_DYNAMIC_FTRACE */
541
542static enum {
543 TRACE_SELFTEST_REGS_START,
544 TRACE_SELFTEST_REGS_FOUND,
545 TRACE_SELFTEST_REGS_NOT_FOUND,
546} trace_selftest_regs_stat;
547
548static void trace_selftest_test_regs_func(unsigned long ip,
549 unsigned long pip,
550 struct ftrace_ops *op,
551 struct ftrace_regs *fregs)
552{
553 struct pt_regs *regs = ftrace_get_regs(fregs);
554
555 if (regs)
556 trace_selftest_regs_stat = TRACE_SELFTEST_REGS_FOUND;
557 else
558 trace_selftest_regs_stat = TRACE_SELFTEST_REGS_NOT_FOUND;
559}
560
561static struct ftrace_ops test_regs_probe = {
562 .func = trace_selftest_test_regs_func,
563 .flags = FTRACE_OPS_FL_SAVE_REGS,
564};
565
566static int
567trace_selftest_function_regs(void)
568{
569 int save_ftrace_enabled = ftrace_enabled;
570 char *func_name;
571 int len;
572 int ret;
573 int supported = 0;
574
575#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
576 supported = 1;
577#endif
578
579 /* The previous test PASSED */
580 pr_cont("PASSED\n");
581 pr_info("Testing ftrace regs%s: ",
582 !supported ? "(no arch support)" : "");
583
584 /* enable tracing, and record the filter function */
585 ftrace_enabled = 1;
586
587 /* Handle PPC64 '.' name */
588 func_name = "*" __stringify(DYN_FTRACE_TEST_NAME);
589 len = strlen(func_name);
590
591 ret = ftrace_set_filter(&test_regs_probe, func_name, len, 1);
592 /*
593 * If DYNAMIC_FTRACE is not set, then we just trace all functions.
594 * This test really doesn't care.
595 */
596 if (ret && ret != -ENODEV) {
597 pr_cont("*Could not set filter* ");
598 goto out;
599 }
600
601 ret = register_ftrace_function(&test_regs_probe);
602 /*
603 * Now if the arch does not support passing regs, then this should
604 * have failed.
605 */
606 if (!supported) {
607 if (!ret) {
608 pr_cont("*registered save-regs without arch support* ");
609 goto out;
610 }
611 test_regs_probe.flags |= FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED;
612 ret = register_ftrace_function(&test_regs_probe);
613 }
614 if (ret) {
615 pr_cont("*could not register callback* ");
616 goto out;
617 }
618
619
620 DYN_FTRACE_TEST_NAME();
621
622 unregister_ftrace_function(&test_regs_probe);
623
624 ret = -1;
625
626 switch (trace_selftest_regs_stat) {
627 case TRACE_SELFTEST_REGS_START:
628 pr_cont("*callback never called* ");
629 goto out;
630
631 case TRACE_SELFTEST_REGS_FOUND:
632 if (supported)
633 break;
634 pr_cont("*callback received regs without arch support* ");
635 goto out;
636
637 case TRACE_SELFTEST_REGS_NOT_FOUND:
638 if (!supported)
639 break;
640 pr_cont("*callback received NULL regs* ");
641 goto out;
642 }
643
644 ret = 0;
645out:
646 ftrace_enabled = save_ftrace_enabled;
647
648 return ret;
649}
650
651/*
652 * Simple verification test of ftrace function tracer.
653 * Enable ftrace, sleep 1/10 second, and then read the trace
654 * buffer to see if all is in order.
655 */
656__init int
657trace_selftest_startup_function(struct tracer *trace, struct trace_array *tr)
658{
659 int save_ftrace_enabled = ftrace_enabled;
660 unsigned long count;
661 int ret;
662
663#ifdef CONFIG_DYNAMIC_FTRACE
664 if (ftrace_filter_param) {
665 printk(KERN_CONT " ... kernel command line filter set: force PASS ... ");
666 return 0;
667 }
668#endif
669
670 /* make sure msleep has been recorded */
671 msleep(1);
672
673 /* start the tracing */
674 ftrace_enabled = 1;
675
676 ret = tracer_init(trace, tr);
677 if (ret) {
678 warn_failed_init_tracer(trace, ret);
679 goto out;
680 }
681
682 /* Sleep for a 1/10 of a second */
683 msleep(100);
684 /* stop the tracing. */
685 tracing_stop();
686 ftrace_enabled = 0;
687
688 /* check the trace buffer */
689 ret = trace_test_buffer(&tr->array_buffer, &count);
690
691 ftrace_enabled = 1;
692 trace->reset(tr);
693 tracing_start();
694
695 if (!ret && !count) {
696 printk(KERN_CONT ".. no entries found ..");
697 ret = -1;
698 goto out;
699 }
700
701 ret = trace_selftest_startup_dynamic_tracing(trace, tr,
702 DYN_FTRACE_TEST_NAME);
703 if (ret)
704 goto out;
705
706 ret = trace_selftest_function_recursion();
707 if (ret)
708 goto out;
709
710 ret = trace_selftest_function_regs();
711 out:
712 ftrace_enabled = save_ftrace_enabled;
713
714 /* kill ftrace totally if we failed */
715 if (ret)
716 ftrace_kill();
717
718 return ret;
719}
720#endif /* CONFIG_FUNCTION_TRACER */
721
722
723#ifdef CONFIG_FUNCTION_GRAPH_TRACER
724
725/* Maximum number of functions to trace before diagnosing a hang */
726#define GRAPH_MAX_FUNC_TEST 100000000
727
728static unsigned int graph_hang_thresh;
729
730/* Wrap the real function entry probe to avoid possible hanging */
731static int trace_graph_entry_watchdog(struct ftrace_graph_ent *trace)
732{
733 /* This is harmlessly racy, we want to approximately detect a hang */
734 if (unlikely(++graph_hang_thresh > GRAPH_MAX_FUNC_TEST)) {
735 ftrace_graph_stop();
736 printk(KERN_WARNING "BUG: Function graph tracer hang!\n");
737 if (ftrace_dump_on_oops) {
738 ftrace_dump(DUMP_ALL);
739 /* ftrace_dump() disables tracing */
740 tracing_on();
741 }
742 return 0;
743 }
744
745 return trace_graph_entry(trace);
746}
747
748static struct fgraph_ops fgraph_ops __initdata = {
749 .entryfunc = &trace_graph_entry_watchdog,
750 .retfunc = &trace_graph_return,
751};
752
753/*
754 * Pretty much the same than for the function tracer from which the selftest
755 * has been borrowed.
756 */
757__init int
758trace_selftest_startup_function_graph(struct tracer *trace,
759 struct trace_array *tr)
760{
761 int ret;
762 unsigned long count;
763
764#ifdef CONFIG_DYNAMIC_FTRACE
765 if (ftrace_filter_param) {
766 printk(KERN_CONT " ... kernel command line filter set: force PASS ... ");
767 return 0;
768 }
769#endif
770
771 /*
772 * Simulate the init() callback but we attach a watchdog callback
773 * to detect and recover from possible hangs
774 */
775 tracing_reset_online_cpus(&tr->array_buffer);
776 set_graph_array(tr);
777 ret = register_ftrace_graph(&fgraph_ops);
778 if (ret) {
779 warn_failed_init_tracer(trace, ret);
780 goto out;
781 }
782 tracing_start_cmdline_record();
783
784 /* Sleep for a 1/10 of a second */
785 msleep(100);
786
787 /* Have we just recovered from a hang? */
788 if (graph_hang_thresh > GRAPH_MAX_FUNC_TEST) {
789 disable_tracing_selftest("recovering from a hang");
790 ret = -1;
791 goto out;
792 }
793
794 tracing_stop();
795
796 /* check the trace buffer */
797 ret = trace_test_buffer(&tr->array_buffer, &count);
798
799 /* Need to also simulate the tr->reset to remove this fgraph_ops */
800 tracing_stop_cmdline_record();
801 unregister_ftrace_graph(&fgraph_ops);
802
803 tracing_start();
804
805 if (!ret && !count) {
806 printk(KERN_CONT ".. no entries found ..");
807 ret = -1;
808 goto out;
809 }
810
811 /* Don't test dynamic tracing, the function tracer already did */
812
813out:
814 /* Stop it if we failed */
815 if (ret)
816 ftrace_graph_stop();
817
818 return ret;
819}
820#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
821
822
823#ifdef CONFIG_IRQSOFF_TRACER
824int
825trace_selftest_startup_irqsoff(struct tracer *trace, struct trace_array *tr)
826{
827 unsigned long save_max = tr->max_latency;
828 unsigned long count;
829 int ret;
830
831 /* start the tracing */
832 ret = tracer_init(trace, tr);
833 if (ret) {
834 warn_failed_init_tracer(trace, ret);
835 return ret;
836 }
837
838 /* reset the max latency */
839 tr->max_latency = 0;
840 /* disable interrupts for a bit */
841 local_irq_disable();
842 udelay(100);
843 local_irq_enable();
844
845 /*
846 * Stop the tracer to avoid a warning subsequent
847 * to buffer flipping failure because tracing_stop()
848 * disables the tr and max buffers, making flipping impossible
849 * in case of parallels max irqs off latencies.
850 */
851 trace->stop(tr);
852 /* stop the tracing. */
853 tracing_stop();
854 /* check both trace buffers */
855 ret = trace_test_buffer(&tr->array_buffer, NULL);
856 if (!ret)
857 ret = trace_test_buffer(&tr->max_buffer, &count);
858 trace->reset(tr);
859 tracing_start();
860
861 if (!ret && !count) {
862 printk(KERN_CONT ".. no entries found ..");
863 ret = -1;
864 }
865
866 tr->max_latency = save_max;
867
868 return ret;
869}
870#endif /* CONFIG_IRQSOFF_TRACER */
871
872#ifdef CONFIG_PREEMPT_TRACER
873int
874trace_selftest_startup_preemptoff(struct tracer *trace, struct trace_array *tr)
875{
876 unsigned long save_max = tr->max_latency;
877 unsigned long count;
878 int ret;
879
880 /*
881 * Now that the big kernel lock is no longer preemptible,
882 * and this is called with the BKL held, it will always
883 * fail. If preemption is already disabled, simply
884 * pass the test. When the BKL is removed, or becomes
885 * preemptible again, we will once again test this,
886 * so keep it in.
887 */
888 if (preempt_count()) {
889 printk(KERN_CONT "can not test ... force ");
890 return 0;
891 }
892
893 /* start the tracing */
894 ret = tracer_init(trace, tr);
895 if (ret) {
896 warn_failed_init_tracer(trace, ret);
897 return ret;
898 }
899
900 /* reset the max latency */
901 tr->max_latency = 0;
902 /* disable preemption for a bit */
903 preempt_disable();
904 udelay(100);
905 preempt_enable();
906
907 /*
908 * Stop the tracer to avoid a warning subsequent
909 * to buffer flipping failure because tracing_stop()
910 * disables the tr and max buffers, making flipping impossible
911 * in case of parallels max preempt off latencies.
912 */
913 trace->stop(tr);
914 /* stop the tracing. */
915 tracing_stop();
916 /* check both trace buffers */
917 ret = trace_test_buffer(&tr->array_buffer, NULL);
918 if (!ret)
919 ret = trace_test_buffer(&tr->max_buffer, &count);
920 trace->reset(tr);
921 tracing_start();
922
923 if (!ret && !count) {
924 printk(KERN_CONT ".. no entries found ..");
925 ret = -1;
926 }
927
928 tr->max_latency = save_max;
929
930 return ret;
931}
932#endif /* CONFIG_PREEMPT_TRACER */
933
934#if defined(CONFIG_IRQSOFF_TRACER) && defined(CONFIG_PREEMPT_TRACER)
935int
936trace_selftest_startup_preemptirqsoff(struct tracer *trace, struct trace_array *tr)
937{
938 unsigned long save_max = tr->max_latency;
939 unsigned long count;
940 int ret;
941
942 /*
943 * Now that the big kernel lock is no longer preemptible,
944 * and this is called with the BKL held, it will always
945 * fail. If preemption is already disabled, simply
946 * pass the test. When the BKL is removed, or becomes
947 * preemptible again, we will once again test this,
948 * so keep it in.
949 */
950 if (preempt_count()) {
951 printk(KERN_CONT "can not test ... force ");
952 return 0;
953 }
954
955 /* start the tracing */
956 ret = tracer_init(trace, tr);
957 if (ret) {
958 warn_failed_init_tracer(trace, ret);
959 goto out_no_start;
960 }
961
962 /* reset the max latency */
963 tr->max_latency = 0;
964
965 /* disable preemption and interrupts for a bit */
966 preempt_disable();
967 local_irq_disable();
968 udelay(100);
969 preempt_enable();
970 /* reverse the order of preempt vs irqs */
971 local_irq_enable();
972
973 /*
974 * Stop the tracer to avoid a warning subsequent
975 * to buffer flipping failure because tracing_stop()
976 * disables the tr and max buffers, making flipping impossible
977 * in case of parallels max irqs/preempt off latencies.
978 */
979 trace->stop(tr);
980 /* stop the tracing. */
981 tracing_stop();
982 /* check both trace buffers */
983 ret = trace_test_buffer(&tr->array_buffer, NULL);
984 if (ret)
985 goto out;
986
987 ret = trace_test_buffer(&tr->max_buffer, &count);
988 if (ret)
989 goto out;
990
991 if (!ret && !count) {
992 printk(KERN_CONT ".. no entries found ..");
993 ret = -1;
994 goto out;
995 }
996
997 /* do the test by disabling interrupts first this time */
998 tr->max_latency = 0;
999 tracing_start();
1000 trace->start(tr);
1001
1002 preempt_disable();
1003 local_irq_disable();
1004 udelay(100);
1005 preempt_enable();
1006 /* reverse the order of preempt vs irqs */
1007 local_irq_enable();
1008
1009 trace->stop(tr);
1010 /* stop the tracing. */
1011 tracing_stop();
1012 /* check both trace buffers */
1013 ret = trace_test_buffer(&tr->array_buffer, NULL);
1014 if (ret)
1015 goto out;
1016
1017 ret = trace_test_buffer(&tr->max_buffer, &count);
1018
1019 if (!ret && !count) {
1020 printk(KERN_CONT ".. no entries found ..");
1021 ret = -1;
1022 goto out;
1023 }
1024
1025out:
1026 tracing_start();
1027out_no_start:
1028 trace->reset(tr);
1029 tr->max_latency = save_max;
1030
1031 return ret;
1032}
1033#endif /* CONFIG_IRQSOFF_TRACER && CONFIG_PREEMPT_TRACER */
1034
1035#ifdef CONFIG_NOP_TRACER
1036int
1037trace_selftest_startup_nop(struct tracer *trace, struct trace_array *tr)
1038{
1039 /* What could possibly go wrong? */
1040 return 0;
1041}
1042#endif
1043
1044#ifdef CONFIG_SCHED_TRACER
1045
1046struct wakeup_test_data {
1047 struct completion is_ready;
1048 int go;
1049};
1050
1051static int trace_wakeup_test_thread(void *data)
1052{
1053 /* Make this a -deadline thread */
1054 static const struct sched_attr attr = {
1055 .sched_policy = SCHED_DEADLINE,
1056 .sched_runtime = 100000ULL,
1057 .sched_deadline = 10000000ULL,
1058 .sched_period = 10000000ULL
1059 };
1060 struct wakeup_test_data *x = data;
1061
1062 sched_setattr(current, &attr);
1063
1064 /* Make it know we have a new prio */
1065 complete(&x->is_ready);
1066
1067 /* now go to sleep and let the test wake us up */
1068 set_current_state(TASK_INTERRUPTIBLE);
1069 while (!x->go) {
1070 schedule();
1071 set_current_state(TASK_INTERRUPTIBLE);
1072 }
1073
1074 complete(&x->is_ready);
1075
1076 set_current_state(TASK_INTERRUPTIBLE);
1077
1078 /* we are awake, now wait to disappear */
1079 while (!kthread_should_stop()) {
1080 schedule();
1081 set_current_state(TASK_INTERRUPTIBLE);
1082 }
1083
1084 __set_current_state(TASK_RUNNING);
1085
1086 return 0;
1087}
1088int
1089trace_selftest_startup_wakeup(struct tracer *trace, struct trace_array *tr)
1090{
1091 unsigned long save_max = tr->max_latency;
1092 struct task_struct *p;
1093 struct wakeup_test_data data;
1094 unsigned long count;
1095 int ret;
1096
1097 memset(&data, 0, sizeof(data));
1098
1099 init_completion(&data.is_ready);
1100
1101 /* create a -deadline thread */
1102 p = kthread_run(trace_wakeup_test_thread, &data, "ftrace-test");
1103 if (IS_ERR(p)) {
1104 printk(KERN_CONT "Failed to create ftrace wakeup test thread ");
1105 return -1;
1106 }
1107
1108 /* make sure the thread is running at -deadline policy */
1109 wait_for_completion(&data.is_ready);
1110
1111 /* start the tracing */
1112 ret = tracer_init(trace, tr);
1113 if (ret) {
1114 warn_failed_init_tracer(trace, ret);
1115 return ret;
1116 }
1117
1118 /* reset the max latency */
1119 tr->max_latency = 0;
1120
1121 while (p->on_rq) {
1122 /*
1123 * Sleep to make sure the -deadline thread is asleep too.
1124 * On virtual machines we can't rely on timings,
1125 * but we want to make sure this test still works.
1126 */
1127 msleep(100);
1128 }
1129
1130 init_completion(&data.is_ready);
1131
1132 data.go = 1;
1133 /* memory barrier is in the wake_up_process() */
1134
1135 wake_up_process(p);
1136
1137 /* Wait for the task to wake up */
1138 wait_for_completion(&data.is_ready);
1139
1140 /* stop the tracing. */
1141 tracing_stop();
1142 /* check both trace buffers */
1143 ret = trace_test_buffer(&tr->array_buffer, NULL);
1144 if (!ret)
1145 ret = trace_test_buffer(&tr->max_buffer, &count);
1146
1147
1148 trace->reset(tr);
1149 tracing_start();
1150
1151 tr->max_latency = save_max;
1152
1153 /* kill the thread */
1154 kthread_stop(p);
1155
1156 if (!ret && !count) {
1157 printk(KERN_CONT ".. no entries found ..");
1158 ret = -1;
1159 }
1160
1161 return ret;
1162}
1163#endif /* CONFIG_SCHED_TRACER */
1164
1165#ifdef CONFIG_BRANCH_TRACER
1166int
1167trace_selftest_startup_branch(struct tracer *trace, struct trace_array *tr)
1168{
1169 unsigned long count;
1170 int ret;
1171
1172 /* start the tracing */
1173 ret = tracer_init(trace, tr);
1174 if (ret) {
1175 warn_failed_init_tracer(trace, ret);
1176 return ret;
1177 }
1178
1179 /* Sleep for a 1/10 of a second */
1180 msleep(100);
1181 /* stop the tracing. */
1182 tracing_stop();
1183 /* check the trace buffer */
1184 ret = trace_test_buffer(&tr->array_buffer, &count);
1185 trace->reset(tr);
1186 tracing_start();
1187
1188 if (!ret && !count) {
1189 printk(KERN_CONT ".. no entries found ..");
1190 ret = -1;
1191 }
1192
1193 return ret;
1194}
1195#endif /* CONFIG_BRANCH_TRACER */
1196
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
788#ifndef CALL_DEPTH_ACCOUNT
789#define CALL_DEPTH_ACCOUNT ""
790#endif
791
792noinline __noclone static void trace_direct_tramp(void)
793{
794 asm(CALL_DEPTH_ACCOUNT);
795}
796#endif
797
798/*
799 * Pretty much the same than for the function tracer from which the selftest
800 * has been borrowed.
801 */
802__init int
803trace_selftest_startup_function_graph(struct tracer *trace,
804 struct trace_array *tr)
805{
806 int ret;
807 unsigned long count;
808 char *func_name __maybe_unused;
809
810#ifdef CONFIG_DYNAMIC_FTRACE
811 if (ftrace_filter_param) {
812 printk(KERN_CONT " ... kernel command line filter set: force PASS ... ");
813 return 0;
814 }
815#endif
816
817 /*
818 * Simulate the init() callback but we attach a watchdog callback
819 * to detect and recover from possible hangs
820 */
821 tracing_reset_online_cpus(&tr->array_buffer);
822 set_graph_array(tr);
823 ret = register_ftrace_graph(&fgraph_ops);
824 if (ret) {
825 warn_failed_init_tracer(trace, ret);
826 goto out;
827 }
828 tracing_start_cmdline_record();
829
830 /* Sleep for a 1/10 of a second */
831 msleep(100);
832
833 /* Have we just recovered from a hang? */
834 if (graph_hang_thresh > GRAPH_MAX_FUNC_TEST) {
835 disable_tracing_selftest("recovering from a hang");
836 ret = -1;
837 goto out;
838 }
839
840 tracing_stop();
841
842 /* check the trace buffer */
843 ret = trace_test_buffer(&tr->array_buffer, &count);
844
845 /* Need to also simulate the tr->reset to remove this fgraph_ops */
846 tracing_stop_cmdline_record();
847 unregister_ftrace_graph(&fgraph_ops);
848
849 tracing_start();
850
851 if (!ret && !count) {
852 printk(KERN_CONT ".. no entries found ..");
853 ret = -1;
854 goto out;
855 }
856
857#ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
858 tracing_reset_online_cpus(&tr->array_buffer);
859 set_graph_array(tr);
860
861 /*
862 * Some archs *cough*PowerPC*cough* add characters to the
863 * start of the function names. We simply put a '*' to
864 * accommodate them.
865 */
866 func_name = "*" __stringify(DYN_FTRACE_TEST_NAME);
867 ftrace_set_global_filter(func_name, strlen(func_name), 1);
868
869 /*
870 * Register direct function together with graph tracer
871 * and make sure we get graph trace.
872 */
873 ret = register_ftrace_direct((unsigned long) DYN_FTRACE_TEST_NAME,
874 (unsigned long) trace_direct_tramp);
875 if (ret)
876 goto out;
877
878 ret = register_ftrace_graph(&fgraph_ops);
879 if (ret) {
880 warn_failed_init_tracer(trace, ret);
881 goto out;
882 }
883
884 DYN_FTRACE_TEST_NAME();
885
886 count = 0;
887
888 tracing_stop();
889 /* check the trace buffer */
890 ret = trace_test_buffer(&tr->array_buffer, &count);
891
892 unregister_ftrace_graph(&fgraph_ops);
893
894 ret = unregister_ftrace_direct((unsigned long) DYN_FTRACE_TEST_NAME,
895 (unsigned long) trace_direct_tramp);
896 if (ret)
897 goto out;
898
899 tracing_start();
900
901 if (!ret && !count) {
902 ret = -1;
903 goto out;
904 }
905
906 /* Enable tracing on all functions again */
907 ftrace_set_global_filter(NULL, 0, 1);
908#endif
909
910 /* Don't test dynamic tracing, the function tracer already did */
911out:
912 /* Stop it if we failed */
913 if (ret)
914 ftrace_graph_stop();
915
916 return ret;
917}
918#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
919
920
921#ifdef CONFIG_IRQSOFF_TRACER
922int
923trace_selftest_startup_irqsoff(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 /* start the tracing */
930 ret = tracer_init(trace, tr);
931 if (ret) {
932 warn_failed_init_tracer(trace, ret);
933 return ret;
934 }
935
936 /* reset the max latency */
937 tr->max_latency = 0;
938 /* disable interrupts for a bit */
939 local_irq_disable();
940 udelay(100);
941 local_irq_enable();
942
943 /*
944 * Stop the tracer to avoid a warning subsequent
945 * to buffer flipping failure because tracing_stop()
946 * disables the tr and max buffers, making flipping impossible
947 * in case of parallels max irqs off latencies.
948 */
949 trace->stop(tr);
950 /* stop the tracing. */
951 tracing_stop();
952 /* check both trace buffers */
953 ret = trace_test_buffer(&tr->array_buffer, NULL);
954 if (!ret)
955 ret = trace_test_buffer(&tr->max_buffer, &count);
956 trace->reset(tr);
957 tracing_start();
958
959 if (!ret && !count) {
960 printk(KERN_CONT ".. no entries found ..");
961 ret = -1;
962 }
963
964 tr->max_latency = save_max;
965
966 return ret;
967}
968#endif /* CONFIG_IRQSOFF_TRACER */
969
970#ifdef CONFIG_PREEMPT_TRACER
971int
972trace_selftest_startup_preemptoff(struct tracer *trace, struct trace_array *tr)
973{
974 unsigned long save_max = tr->max_latency;
975 unsigned long count;
976 int ret;
977
978 /*
979 * Now that the big kernel lock is no longer preemptible,
980 * and this is called with the BKL held, it will always
981 * fail. If preemption is already disabled, simply
982 * pass the test. When the BKL is removed, or becomes
983 * preemptible again, we will once again test this,
984 * so keep it in.
985 */
986 if (preempt_count()) {
987 printk(KERN_CONT "can not test ... force ");
988 return 0;
989 }
990
991 /* start the tracing */
992 ret = tracer_init(trace, tr);
993 if (ret) {
994 warn_failed_init_tracer(trace, ret);
995 return ret;
996 }
997
998 /* reset the max latency */
999 tr->max_latency = 0;
1000 /* disable preemption for a bit */
1001 preempt_disable();
1002 udelay(100);
1003 preempt_enable();
1004
1005 /*
1006 * Stop the tracer to avoid a warning subsequent
1007 * to buffer flipping failure because tracing_stop()
1008 * disables the tr and max buffers, making flipping impossible
1009 * in case of parallels max preempt off latencies.
1010 */
1011 trace->stop(tr);
1012 /* stop the tracing. */
1013 tracing_stop();
1014 /* check both trace buffers */
1015 ret = trace_test_buffer(&tr->array_buffer, NULL);
1016 if (!ret)
1017 ret = trace_test_buffer(&tr->max_buffer, &count);
1018 trace->reset(tr);
1019 tracing_start();
1020
1021 if (!ret && !count) {
1022 printk(KERN_CONT ".. no entries found ..");
1023 ret = -1;
1024 }
1025
1026 tr->max_latency = save_max;
1027
1028 return ret;
1029}
1030#endif /* CONFIG_PREEMPT_TRACER */
1031
1032#if defined(CONFIG_IRQSOFF_TRACER) && defined(CONFIG_PREEMPT_TRACER)
1033int
1034trace_selftest_startup_preemptirqsoff(struct tracer *trace, struct trace_array *tr)
1035{
1036 unsigned long save_max = tr->max_latency;
1037 unsigned long count;
1038 int ret;
1039
1040 /*
1041 * Now that the big kernel lock is no longer preemptible,
1042 * and this is called with the BKL held, it will always
1043 * fail. If preemption is already disabled, simply
1044 * pass the test. When the BKL is removed, or becomes
1045 * preemptible again, we will once again test this,
1046 * so keep it in.
1047 */
1048 if (preempt_count()) {
1049 printk(KERN_CONT "can not test ... force ");
1050 return 0;
1051 }
1052
1053 /* start the tracing */
1054 ret = tracer_init(trace, tr);
1055 if (ret) {
1056 warn_failed_init_tracer(trace, ret);
1057 goto out_no_start;
1058 }
1059
1060 /* reset the max latency */
1061 tr->max_latency = 0;
1062
1063 /* disable preemption and interrupts for a bit */
1064 preempt_disable();
1065 local_irq_disable();
1066 udelay(100);
1067 preempt_enable();
1068 /* reverse the order of preempt vs irqs */
1069 local_irq_enable();
1070
1071 /*
1072 * Stop the tracer to avoid a warning subsequent
1073 * to buffer flipping failure because tracing_stop()
1074 * disables the tr and max buffers, making flipping impossible
1075 * in case of parallels max irqs/preempt off latencies.
1076 */
1077 trace->stop(tr);
1078 /* stop the tracing. */
1079 tracing_stop();
1080 /* check both trace buffers */
1081 ret = trace_test_buffer(&tr->array_buffer, NULL);
1082 if (ret)
1083 goto out;
1084
1085 ret = trace_test_buffer(&tr->max_buffer, &count);
1086 if (ret)
1087 goto out;
1088
1089 if (!ret && !count) {
1090 printk(KERN_CONT ".. no entries found ..");
1091 ret = -1;
1092 goto out;
1093 }
1094
1095 /* do the test by disabling interrupts first this time */
1096 tr->max_latency = 0;
1097 tracing_start();
1098 trace->start(tr);
1099
1100 preempt_disable();
1101 local_irq_disable();
1102 udelay(100);
1103 preempt_enable();
1104 /* reverse the order of preempt vs irqs */
1105 local_irq_enable();
1106
1107 trace->stop(tr);
1108 /* stop the tracing. */
1109 tracing_stop();
1110 /* check both trace buffers */
1111 ret = trace_test_buffer(&tr->array_buffer, NULL);
1112 if (ret)
1113 goto out;
1114
1115 ret = trace_test_buffer(&tr->max_buffer, &count);
1116
1117 if (!ret && !count) {
1118 printk(KERN_CONT ".. no entries found ..");
1119 ret = -1;
1120 goto out;
1121 }
1122
1123out:
1124 tracing_start();
1125out_no_start:
1126 trace->reset(tr);
1127 tr->max_latency = save_max;
1128
1129 return ret;
1130}
1131#endif /* CONFIG_IRQSOFF_TRACER && CONFIG_PREEMPT_TRACER */
1132
1133#ifdef CONFIG_NOP_TRACER
1134int
1135trace_selftest_startup_nop(struct tracer *trace, struct trace_array *tr)
1136{
1137 /* What could possibly go wrong? */
1138 return 0;
1139}
1140#endif
1141
1142#ifdef CONFIG_SCHED_TRACER
1143
1144struct wakeup_test_data {
1145 struct completion is_ready;
1146 int go;
1147};
1148
1149static int trace_wakeup_test_thread(void *data)
1150{
1151 /* Make this a -deadline thread */
1152 static const struct sched_attr attr = {
1153 .sched_policy = SCHED_DEADLINE,
1154 .sched_runtime = 100000ULL,
1155 .sched_deadline = 10000000ULL,
1156 .sched_period = 10000000ULL
1157 };
1158 struct wakeup_test_data *x = data;
1159
1160 sched_setattr(current, &attr);
1161
1162 /* Make it know we have a new prio */
1163 complete(&x->is_ready);
1164
1165 /* now go to sleep and let the test wake us up */
1166 set_current_state(TASK_INTERRUPTIBLE);
1167 while (!x->go) {
1168 schedule();
1169 set_current_state(TASK_INTERRUPTIBLE);
1170 }
1171
1172 complete(&x->is_ready);
1173
1174 set_current_state(TASK_INTERRUPTIBLE);
1175
1176 /* we are awake, now wait to disappear */
1177 while (!kthread_should_stop()) {
1178 schedule();
1179 set_current_state(TASK_INTERRUPTIBLE);
1180 }
1181
1182 __set_current_state(TASK_RUNNING);
1183
1184 return 0;
1185}
1186int
1187trace_selftest_startup_wakeup(struct tracer *trace, struct trace_array *tr)
1188{
1189 unsigned long save_max = tr->max_latency;
1190 struct task_struct *p;
1191 struct wakeup_test_data data;
1192 unsigned long count;
1193 int ret;
1194
1195 memset(&data, 0, sizeof(data));
1196
1197 init_completion(&data.is_ready);
1198
1199 /* create a -deadline thread */
1200 p = kthread_run(trace_wakeup_test_thread, &data, "ftrace-test");
1201 if (IS_ERR(p)) {
1202 printk(KERN_CONT "Failed to create ftrace wakeup test thread ");
1203 return -1;
1204 }
1205
1206 /* make sure the thread is running at -deadline policy */
1207 wait_for_completion(&data.is_ready);
1208
1209 /* start the tracing */
1210 ret = tracer_init(trace, tr);
1211 if (ret) {
1212 warn_failed_init_tracer(trace, ret);
1213 return ret;
1214 }
1215
1216 /* reset the max latency */
1217 tr->max_latency = 0;
1218
1219 while (p->on_rq) {
1220 /*
1221 * Sleep to make sure the -deadline thread is asleep too.
1222 * On virtual machines we can't rely on timings,
1223 * but we want to make sure this test still works.
1224 */
1225 msleep(100);
1226 }
1227
1228 init_completion(&data.is_ready);
1229
1230 data.go = 1;
1231 /* memory barrier is in the wake_up_process() */
1232
1233 wake_up_process(p);
1234
1235 /* Wait for the task to wake up */
1236 wait_for_completion(&data.is_ready);
1237
1238 /* stop the tracing. */
1239 tracing_stop();
1240 /* check both trace buffers */
1241 ret = trace_test_buffer(&tr->array_buffer, NULL);
1242 if (!ret)
1243 ret = trace_test_buffer(&tr->max_buffer, &count);
1244
1245
1246 trace->reset(tr);
1247 tracing_start();
1248
1249 tr->max_latency = save_max;
1250
1251 /* kill the thread */
1252 kthread_stop(p);
1253
1254 if (!ret && !count) {
1255 printk(KERN_CONT ".. no entries found ..");
1256 ret = -1;
1257 }
1258
1259 return ret;
1260}
1261#endif /* CONFIG_SCHED_TRACER */
1262
1263#ifdef CONFIG_BRANCH_TRACER
1264int
1265trace_selftest_startup_branch(struct tracer *trace, struct trace_array *tr)
1266{
1267 unsigned long count;
1268 int ret;
1269
1270 /* start the tracing */
1271 ret = tracer_init(trace, tr);
1272 if (ret) {
1273 warn_failed_init_tracer(trace, ret);
1274 return ret;
1275 }
1276
1277 /* Sleep for a 1/10 of a second */
1278 msleep(100);
1279 /* stop the tracing. */
1280 tracing_stop();
1281 /* check the trace buffer */
1282 ret = trace_test_buffer(&tr->array_buffer, &count);
1283 trace->reset(tr);
1284 tracing_start();
1285
1286 if (!ret && !count) {
1287 printk(KERN_CONT ".. no entries found ..");
1288 ret = -1;
1289 }
1290
1291 return ret;
1292}
1293#endif /* CONFIG_BRANCH_TRACER */
1294