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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 /* 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
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_array *tr, 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(tr->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_array *tr, 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(&ftrace_max_lock);
69
70 cnt = ring_buffer_entries(tr->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(tr, cpu);
82 if (ret)
83 break;
84 }
85 tracing_on();
86 arch_spin_unlock(&ftrace_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{
108 trace_selftest_test_probe1_cnt++;
109}
110
111static int trace_selftest_test_probe2_cnt;
112static void trace_selftest_test_probe2_func(unsigned long ip,
113 unsigned long pip)
114{
115 trace_selftest_test_probe2_cnt++;
116}
117
118static int trace_selftest_test_probe3_cnt;
119static void trace_selftest_test_probe3_func(unsigned long ip,
120 unsigned long pip)
121{
122 trace_selftest_test_probe3_cnt++;
123}
124
125static int trace_selftest_test_global_cnt;
126static void trace_selftest_test_global_func(unsigned long ip,
127 unsigned long pip)
128{
129 trace_selftest_test_global_cnt++;
130}
131
132static int trace_selftest_test_dyn_cnt;
133static void trace_selftest_test_dyn_func(unsigned long ip,
134 unsigned long pip)
135{
136 trace_selftest_test_dyn_cnt++;
137}
138
139static struct ftrace_ops test_probe1 = {
140 .func = trace_selftest_test_probe1_func,
141};
142
143static struct ftrace_ops test_probe2 = {
144 .func = trace_selftest_test_probe2_func,
145};
146
147static struct ftrace_ops test_probe3 = {
148 .func = trace_selftest_test_probe3_func,
149};
150
151static struct ftrace_ops test_global = {
152 .func = trace_selftest_test_global_func,
153 .flags = FTRACE_OPS_FL_GLOBAL,
154};
155
156static void print_counts(void)
157{
158 printk("(%d %d %d %d %d) ",
159 trace_selftest_test_probe1_cnt,
160 trace_selftest_test_probe2_cnt,
161 trace_selftest_test_probe3_cnt,
162 trace_selftest_test_global_cnt,
163 trace_selftest_test_dyn_cnt);
164}
165
166static void reset_counts(void)
167{
168 trace_selftest_test_probe1_cnt = 0;
169 trace_selftest_test_probe2_cnt = 0;
170 trace_selftest_test_probe3_cnt = 0;
171 trace_selftest_test_global_cnt = 0;
172 trace_selftest_test_dyn_cnt = 0;
173}
174
175static int trace_selftest_ops(int cnt)
176{
177 int save_ftrace_enabled = ftrace_enabled;
178 struct ftrace_ops *dyn_ops;
179 char *func1_name;
180 char *func2_name;
181 int len1;
182 int len2;
183 int ret = -1;
184
185 printk(KERN_CONT "PASSED\n");
186 pr_info("Testing dynamic ftrace ops #%d: ", cnt);
187
188 ftrace_enabled = 1;
189 reset_counts();
190
191 /* Handle PPC64 '.' name */
192 func1_name = "*" __stringify(DYN_FTRACE_TEST_NAME);
193 func2_name = "*" __stringify(DYN_FTRACE_TEST_NAME2);
194 len1 = strlen(func1_name);
195 len2 = strlen(func2_name);
196
197 /*
198 * Probe 1 will trace function 1.
199 * Probe 2 will trace function 2.
200 * Probe 3 will trace functions 1 and 2.
201 */
202 ftrace_set_filter(&test_probe1, func1_name, len1, 1);
203 ftrace_set_filter(&test_probe2, func2_name, len2, 1);
204 ftrace_set_filter(&test_probe3, func1_name, len1, 1);
205 ftrace_set_filter(&test_probe3, func2_name, len2, 0);
206
207 register_ftrace_function(&test_probe1);
208 register_ftrace_function(&test_probe2);
209 register_ftrace_function(&test_probe3);
210 register_ftrace_function(&test_global);
211
212 DYN_FTRACE_TEST_NAME();
213
214 print_counts();
215
216 if (trace_selftest_test_probe1_cnt != 1)
217 goto out;
218 if (trace_selftest_test_probe2_cnt != 0)
219 goto out;
220 if (trace_selftest_test_probe3_cnt != 1)
221 goto out;
222 if (trace_selftest_test_global_cnt == 0)
223 goto out;
224
225 DYN_FTRACE_TEST_NAME2();
226
227 print_counts();
228
229 if (trace_selftest_test_probe1_cnt != 1)
230 goto out;
231 if (trace_selftest_test_probe2_cnt != 1)
232 goto out;
233 if (trace_selftest_test_probe3_cnt != 2)
234 goto out;
235
236 /* Add a dynamic probe */
237 dyn_ops = kzalloc(sizeof(*dyn_ops), GFP_KERNEL);
238 if (!dyn_ops) {
239 printk("MEMORY ERROR ");
240 goto out;
241 }
242
243 dyn_ops->func = trace_selftest_test_dyn_func;
244
245 register_ftrace_function(dyn_ops);
246
247 trace_selftest_test_global_cnt = 0;
248
249 DYN_FTRACE_TEST_NAME();
250
251 print_counts();
252
253 if (trace_selftest_test_probe1_cnt != 2)
254 goto out_free;
255 if (trace_selftest_test_probe2_cnt != 1)
256 goto out_free;
257 if (trace_selftest_test_probe3_cnt != 3)
258 goto out_free;
259 if (trace_selftest_test_global_cnt == 0)
260 goto out;
261 if (trace_selftest_test_dyn_cnt == 0)
262 goto out_free;
263
264 DYN_FTRACE_TEST_NAME2();
265
266 print_counts();
267
268 if (trace_selftest_test_probe1_cnt != 2)
269 goto out_free;
270 if (trace_selftest_test_probe2_cnt != 2)
271 goto out_free;
272 if (trace_selftest_test_probe3_cnt != 4)
273 goto out_free;
274
275 ret = 0;
276 out_free:
277 unregister_ftrace_function(dyn_ops);
278 kfree(dyn_ops);
279
280 out:
281 /* Purposely unregister in the same order */
282 unregister_ftrace_function(&test_probe1);
283 unregister_ftrace_function(&test_probe2);
284 unregister_ftrace_function(&test_probe3);
285 unregister_ftrace_function(&test_global);
286
287 /* Make sure everything is off */
288 reset_counts();
289 DYN_FTRACE_TEST_NAME();
290 DYN_FTRACE_TEST_NAME();
291
292 if (trace_selftest_test_probe1_cnt ||
293 trace_selftest_test_probe2_cnt ||
294 trace_selftest_test_probe3_cnt ||
295 trace_selftest_test_global_cnt ||
296 trace_selftest_test_dyn_cnt)
297 ret = -1;
298
299 ftrace_enabled = save_ftrace_enabled;
300
301 return ret;
302}
303
304/* Test dynamic code modification and ftrace filters */
305int trace_selftest_startup_dynamic_tracing(struct tracer *trace,
306 struct trace_array *tr,
307 int (*func)(void))
308{
309 int save_ftrace_enabled = ftrace_enabled;
310 int save_tracer_enabled = tracer_enabled;
311 unsigned long count;
312 char *func_name;
313 int ret;
314
315 /* The ftrace test PASSED */
316 printk(KERN_CONT "PASSED\n");
317 pr_info("Testing dynamic ftrace: ");
318
319 /* enable tracing, and record the filter function */
320 ftrace_enabled = 1;
321 tracer_enabled = 1;
322
323 /* passed in by parameter to fool gcc from optimizing */
324 func();
325
326 /*
327 * Some archs *cough*PowerPC*cough* add characters to the
328 * start of the function names. We simply put a '*' to
329 * accommodate them.
330 */
331 func_name = "*" __stringify(DYN_FTRACE_TEST_NAME);
332
333 /* filter only on our function */
334 ftrace_set_global_filter(func_name, strlen(func_name), 1);
335
336 /* enable tracing */
337 ret = tracer_init(trace, tr);
338 if (ret) {
339 warn_failed_init_tracer(trace, ret);
340 goto out;
341 }
342
343 /* Sleep for a 1/10 of a second */
344 msleep(100);
345
346 /* we should have nothing in the buffer */
347 ret = trace_test_buffer(tr, &count);
348 if (ret)
349 goto out;
350
351 if (count) {
352 ret = -1;
353 printk(KERN_CONT ".. filter did not filter .. ");
354 goto out;
355 }
356
357 /* call our function again */
358 func();
359
360 /* sleep again */
361 msleep(100);
362
363 /* stop the tracing. */
364 tracing_stop();
365 ftrace_enabled = 0;
366
367 /* check the trace buffer */
368 ret = trace_test_buffer(tr, &count);
369 tracing_start();
370
371 /* we should only have one item */
372 if (!ret && count != 1) {
373 trace->reset(tr);
374 printk(KERN_CONT ".. filter failed count=%ld ..", count);
375 ret = -1;
376 goto out;
377 }
378
379 /* Test the ops with global tracing running */
380 ret = trace_selftest_ops(1);
381 trace->reset(tr);
382
383 out:
384 ftrace_enabled = save_ftrace_enabled;
385 tracer_enabled = save_tracer_enabled;
386
387 /* Enable tracing on all functions again */
388 ftrace_set_global_filter(NULL, 0, 1);
389
390 /* Test the ops with global tracing off */
391 if (!ret)
392 ret = trace_selftest_ops(2);
393
394 return ret;
395}
396#else
397# define trace_selftest_startup_dynamic_tracing(trace, tr, func) ({ 0; })
398#endif /* CONFIG_DYNAMIC_FTRACE */
399
400/*
401 * Simple verification test of ftrace function tracer.
402 * Enable ftrace, sleep 1/10 second, and then read the trace
403 * buffer to see if all is in order.
404 */
405int
406trace_selftest_startup_function(struct tracer *trace, struct trace_array *tr)
407{
408 int save_ftrace_enabled = ftrace_enabled;
409 int save_tracer_enabled = tracer_enabled;
410 unsigned long count;
411 int ret;
412
413 /* make sure msleep has been recorded */
414 msleep(1);
415
416 /* start the tracing */
417 ftrace_enabled = 1;
418 tracer_enabled = 1;
419
420 ret = tracer_init(trace, tr);
421 if (ret) {
422 warn_failed_init_tracer(trace, ret);
423 goto out;
424 }
425
426 /* Sleep for a 1/10 of a second */
427 msleep(100);
428 /* stop the tracing. */
429 tracing_stop();
430 ftrace_enabled = 0;
431
432 /* check the trace buffer */
433 ret = trace_test_buffer(tr, &count);
434 trace->reset(tr);
435 tracing_start();
436
437 if (!ret && !count) {
438 printk(KERN_CONT ".. no entries found ..");
439 ret = -1;
440 goto out;
441 }
442
443 ret = trace_selftest_startup_dynamic_tracing(trace, tr,
444 DYN_FTRACE_TEST_NAME);
445
446 out:
447 ftrace_enabled = save_ftrace_enabled;
448 tracer_enabled = save_tracer_enabled;
449
450 /* kill ftrace totally if we failed */
451 if (ret)
452 ftrace_kill();
453
454 return ret;
455}
456#endif /* CONFIG_FUNCTION_TRACER */
457
458
459#ifdef CONFIG_FUNCTION_GRAPH_TRACER
460
461/* Maximum number of functions to trace before diagnosing a hang */
462#define GRAPH_MAX_FUNC_TEST 100000000
463
464static void
465__ftrace_dump(bool disable_tracing, enum ftrace_dump_mode oops_dump_mode);
466static unsigned int graph_hang_thresh;
467
468/* Wrap the real function entry probe to avoid possible hanging */
469static int trace_graph_entry_watchdog(struct ftrace_graph_ent *trace)
470{
471 /* This is harmlessly racy, we want to approximately detect a hang */
472 if (unlikely(++graph_hang_thresh > GRAPH_MAX_FUNC_TEST)) {
473 ftrace_graph_stop();
474 printk(KERN_WARNING "BUG: Function graph tracer hang!\n");
475 if (ftrace_dump_on_oops)
476 __ftrace_dump(false, DUMP_ALL);
477 return 0;
478 }
479
480 return trace_graph_entry(trace);
481}
482
483/*
484 * Pretty much the same than for the function tracer from which the selftest
485 * has been borrowed.
486 */
487int
488trace_selftest_startup_function_graph(struct tracer *trace,
489 struct trace_array *tr)
490{
491 int ret;
492 unsigned long count;
493
494 /*
495 * Simulate the init() callback but we attach a watchdog callback
496 * to detect and recover from possible hangs
497 */
498 tracing_reset_online_cpus(tr);
499 set_graph_array(tr);
500 ret = register_ftrace_graph(&trace_graph_return,
501 &trace_graph_entry_watchdog);
502 if (ret) {
503 warn_failed_init_tracer(trace, ret);
504 goto out;
505 }
506 tracing_start_cmdline_record();
507
508 /* Sleep for a 1/10 of a second */
509 msleep(100);
510
511 /* Have we just recovered from a hang? */
512 if (graph_hang_thresh > GRAPH_MAX_FUNC_TEST) {
513 tracing_selftest_disabled = true;
514 ret = -1;
515 goto out;
516 }
517
518 tracing_stop();
519
520 /* check the trace buffer */
521 ret = trace_test_buffer(tr, &count);
522
523 trace->reset(tr);
524 tracing_start();
525
526 if (!ret && !count) {
527 printk(KERN_CONT ".. no entries found ..");
528 ret = -1;
529 goto out;
530 }
531
532 /* Don't test dynamic tracing, the function tracer already did */
533
534out:
535 /* Stop it if we failed */
536 if (ret)
537 ftrace_graph_stop();
538
539 return ret;
540}
541#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
542
543
544#ifdef CONFIG_IRQSOFF_TRACER
545int
546trace_selftest_startup_irqsoff(struct tracer *trace, struct trace_array *tr)
547{
548 unsigned long save_max = tracing_max_latency;
549 unsigned long count;
550 int ret;
551
552 /* start the tracing */
553 ret = tracer_init(trace, tr);
554 if (ret) {
555 warn_failed_init_tracer(trace, ret);
556 return ret;
557 }
558
559 /* reset the max latency */
560 tracing_max_latency = 0;
561 /* disable interrupts for a bit */
562 local_irq_disable();
563 udelay(100);
564 local_irq_enable();
565
566 /*
567 * Stop the tracer to avoid a warning subsequent
568 * to buffer flipping failure because tracing_stop()
569 * disables the tr and max buffers, making flipping impossible
570 * in case of parallels max irqs off latencies.
571 */
572 trace->stop(tr);
573 /* stop the tracing. */
574 tracing_stop();
575 /* check both trace buffers */
576 ret = trace_test_buffer(tr, NULL);
577 if (!ret)
578 ret = trace_test_buffer(&max_tr, &count);
579 trace->reset(tr);
580 tracing_start();
581
582 if (!ret && !count) {
583 printk(KERN_CONT ".. no entries found ..");
584 ret = -1;
585 }
586
587 tracing_max_latency = save_max;
588
589 return ret;
590}
591#endif /* CONFIG_IRQSOFF_TRACER */
592
593#ifdef CONFIG_PREEMPT_TRACER
594int
595trace_selftest_startup_preemptoff(struct tracer *trace, struct trace_array *tr)
596{
597 unsigned long save_max = tracing_max_latency;
598 unsigned long count;
599 int ret;
600
601 /*
602 * Now that the big kernel lock is no longer preemptable,
603 * and this is called with the BKL held, it will always
604 * fail. If preemption is already disabled, simply
605 * pass the test. When the BKL is removed, or becomes
606 * preemptible again, we will once again test this,
607 * so keep it in.
608 */
609 if (preempt_count()) {
610 printk(KERN_CONT "can not test ... force ");
611 return 0;
612 }
613
614 /* start the tracing */
615 ret = tracer_init(trace, tr);
616 if (ret) {
617 warn_failed_init_tracer(trace, ret);
618 return ret;
619 }
620
621 /* reset the max latency */
622 tracing_max_latency = 0;
623 /* disable preemption for a bit */
624 preempt_disable();
625 udelay(100);
626 preempt_enable();
627
628 /*
629 * Stop the tracer to avoid a warning subsequent
630 * to buffer flipping failure because tracing_stop()
631 * disables the tr and max buffers, making flipping impossible
632 * in case of parallels max preempt off latencies.
633 */
634 trace->stop(tr);
635 /* stop the tracing. */
636 tracing_stop();
637 /* check both trace buffers */
638 ret = trace_test_buffer(tr, NULL);
639 if (!ret)
640 ret = trace_test_buffer(&max_tr, &count);
641 trace->reset(tr);
642 tracing_start();
643
644 if (!ret && !count) {
645 printk(KERN_CONT ".. no entries found ..");
646 ret = -1;
647 }
648
649 tracing_max_latency = save_max;
650
651 return ret;
652}
653#endif /* CONFIG_PREEMPT_TRACER */
654
655#if defined(CONFIG_IRQSOFF_TRACER) && defined(CONFIG_PREEMPT_TRACER)
656int
657trace_selftest_startup_preemptirqsoff(struct tracer *trace, struct trace_array *tr)
658{
659 unsigned long save_max = tracing_max_latency;
660 unsigned long count;
661 int ret;
662
663 /*
664 * Now that the big kernel lock is no longer preemptable,
665 * and this is called with the BKL held, it will always
666 * fail. If preemption is already disabled, simply
667 * pass the test. When the BKL is removed, or becomes
668 * preemptible again, we will once again test this,
669 * so keep it in.
670 */
671 if (preempt_count()) {
672 printk(KERN_CONT "can not test ... force ");
673 return 0;
674 }
675
676 /* start the tracing */
677 ret = tracer_init(trace, tr);
678 if (ret) {
679 warn_failed_init_tracer(trace, ret);
680 goto out_no_start;
681 }
682
683 /* reset the max latency */
684 tracing_max_latency = 0;
685
686 /* disable preemption and interrupts for a bit */
687 preempt_disable();
688 local_irq_disable();
689 udelay(100);
690 preempt_enable();
691 /* reverse the order of preempt vs irqs */
692 local_irq_enable();
693
694 /*
695 * Stop the tracer to avoid a warning subsequent
696 * to buffer flipping failure because tracing_stop()
697 * disables the tr and max buffers, making flipping impossible
698 * in case of parallels max irqs/preempt off latencies.
699 */
700 trace->stop(tr);
701 /* stop the tracing. */
702 tracing_stop();
703 /* check both trace buffers */
704 ret = trace_test_buffer(tr, NULL);
705 if (ret)
706 goto out;
707
708 ret = trace_test_buffer(&max_tr, &count);
709 if (ret)
710 goto out;
711
712 if (!ret && !count) {
713 printk(KERN_CONT ".. no entries found ..");
714 ret = -1;
715 goto out;
716 }
717
718 /* do the test by disabling interrupts first this time */
719 tracing_max_latency = 0;
720 tracing_start();
721 trace->start(tr);
722
723 preempt_disable();
724 local_irq_disable();
725 udelay(100);
726 preempt_enable();
727 /* reverse the order of preempt vs irqs */
728 local_irq_enable();
729
730 trace->stop(tr);
731 /* stop the tracing. */
732 tracing_stop();
733 /* check both trace buffers */
734 ret = trace_test_buffer(tr, NULL);
735 if (ret)
736 goto out;
737
738 ret = trace_test_buffer(&max_tr, &count);
739
740 if (!ret && !count) {
741 printk(KERN_CONT ".. no entries found ..");
742 ret = -1;
743 goto out;
744 }
745
746out:
747 tracing_start();
748out_no_start:
749 trace->reset(tr);
750 tracing_max_latency = save_max;
751
752 return ret;
753}
754#endif /* CONFIG_IRQSOFF_TRACER && CONFIG_PREEMPT_TRACER */
755
756#ifdef CONFIG_NOP_TRACER
757int
758trace_selftest_startup_nop(struct tracer *trace, struct trace_array *tr)
759{
760 /* What could possibly go wrong? */
761 return 0;
762}
763#endif
764
765#ifdef CONFIG_SCHED_TRACER
766static int trace_wakeup_test_thread(void *data)
767{
768 /* Make this a RT thread, doesn't need to be too high */
769 static const struct sched_param param = { .sched_priority = 5 };
770 struct completion *x = data;
771
772 sched_setscheduler(current, SCHED_FIFO, ¶m);
773
774 /* Make it know we have a new prio */
775 complete(x);
776
777 /* now go to sleep and let the test wake us up */
778 set_current_state(TASK_INTERRUPTIBLE);
779 schedule();
780
781 /* we are awake, now wait to disappear */
782 while (!kthread_should_stop()) {
783 /*
784 * This is an RT task, do short sleeps to let
785 * others run.
786 */
787 msleep(100);
788 }
789
790 return 0;
791}
792
793int
794trace_selftest_startup_wakeup(struct tracer *trace, struct trace_array *tr)
795{
796 unsigned long save_max = tracing_max_latency;
797 struct task_struct *p;
798 struct completion isrt;
799 unsigned long count;
800 int ret;
801
802 init_completion(&isrt);
803
804 /* create a high prio thread */
805 p = kthread_run(trace_wakeup_test_thread, &isrt, "ftrace-test");
806 if (IS_ERR(p)) {
807 printk(KERN_CONT "Failed to create ftrace wakeup test thread ");
808 return -1;
809 }
810
811 /* make sure the thread is running at an RT prio */
812 wait_for_completion(&isrt);
813
814 /* start the tracing */
815 ret = tracer_init(trace, tr);
816 if (ret) {
817 warn_failed_init_tracer(trace, ret);
818 return ret;
819 }
820
821 /* reset the max latency */
822 tracing_max_latency = 0;
823
824 /* sleep to let the RT thread sleep too */
825 msleep(100);
826
827 /*
828 * Yes this is slightly racy. It is possible that for some
829 * strange reason that the RT thread we created, did not
830 * call schedule for 100ms after doing the completion,
831 * and we do a wakeup on a task that already is awake.
832 * But that is extremely unlikely, and the worst thing that
833 * happens in such a case, is that we disable tracing.
834 * Honestly, if this race does happen something is horrible
835 * wrong with the system.
836 */
837
838 wake_up_process(p);
839
840 /* give a little time to let the thread wake up */
841 msleep(100);
842
843 /* stop the tracing. */
844 tracing_stop();
845 /* check both trace buffers */
846 ret = trace_test_buffer(tr, NULL);
847 if (!ret)
848 ret = trace_test_buffer(&max_tr, &count);
849
850
851 trace->reset(tr);
852 tracing_start();
853
854 tracing_max_latency = save_max;
855
856 /* kill the thread */
857 kthread_stop(p);
858
859 if (!ret && !count) {
860 printk(KERN_CONT ".. no entries found ..");
861 ret = -1;
862 }
863
864 return ret;
865}
866#endif /* CONFIG_SCHED_TRACER */
867
868#ifdef CONFIG_CONTEXT_SWITCH_TRACER
869int
870trace_selftest_startup_sched_switch(struct tracer *trace, struct trace_array *tr)
871{
872 unsigned long count;
873 int ret;
874
875 /* start the tracing */
876 ret = tracer_init(trace, tr);
877 if (ret) {
878 warn_failed_init_tracer(trace, ret);
879 return ret;
880 }
881
882 /* Sleep for a 1/10 of a second */
883 msleep(100);
884 /* stop the tracing. */
885 tracing_stop();
886 /* check the trace buffer */
887 ret = trace_test_buffer(tr, &count);
888 trace->reset(tr);
889 tracing_start();
890
891 if (!ret && !count) {
892 printk(KERN_CONT ".. no entries found ..");
893 ret = -1;
894 }
895
896 return ret;
897}
898#endif /* CONFIG_CONTEXT_SWITCH_TRACER */
899
900#ifdef CONFIG_BRANCH_TRACER
901int
902trace_selftest_startup_branch(struct tracer *trace, struct trace_array *tr)
903{
904 unsigned long count;
905 int ret;
906
907 /* start the tracing */
908 ret = tracer_init(trace, tr);
909 if (ret) {
910 warn_failed_init_tracer(trace, ret);
911 return ret;
912 }
913
914 /* Sleep for a 1/10 of a second */
915 msleep(100);
916 /* stop the tracing. */
917 tracing_stop();
918 /* check the trace buffer */
919 ret = trace_test_buffer(tr, &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 return ret;
929}
930#endif /* CONFIG_BRANCH_TRACER */
931