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1/* Include in trace.c */
2
3#include <linux/stringify.h>
4#include <linux/kthread.h>
5#include <linux/delay.h>
6#include <linux/slab.h>
7
8static inline int trace_valid_entry(struct trace_entry *entry)
9{
10 switch (entry->type) {
11 case TRACE_FN:
12 case TRACE_CTX:
13 case TRACE_WAKE:
14 case TRACE_STACK:
15 case TRACE_PRINT:
16 case TRACE_BRANCH:
17 case TRACE_GRAPH_ENT:
18 case TRACE_GRAPH_RET:
19 return 1;
20 }
21 return 0;
22}
23
24static int trace_test_buffer_cpu(struct trace_buffer *buf, int cpu)
25{
26 struct ring_buffer_event *event;
27 struct trace_entry *entry;
28 unsigned int loops = 0;
29
30 while ((event = ring_buffer_consume(buf->buffer, cpu, NULL, NULL))) {
31 entry = ring_buffer_event_data(event);
32
33 /*
34 * The ring buffer is a size of trace_buf_size, if
35 * we loop more than the size, there's something wrong
36 * with the ring buffer.
37 */
38 if (loops++ > trace_buf_size) {
39 printk(KERN_CONT ".. bad ring buffer ");
40 goto failed;
41 }
42 if (!trace_valid_entry(entry)) {
43 printk(KERN_CONT ".. invalid entry %d ",
44 entry->type);
45 goto failed;
46 }
47 }
48 return 0;
49
50 failed:
51 /* disable tracing */
52 tracing_disabled = 1;
53 printk(KERN_CONT ".. corrupted trace buffer .. ");
54 return -1;
55}
56
57/*
58 * Test the trace buffer to see if all the elements
59 * are still sane.
60 */
61static int trace_test_buffer(struct trace_buffer *buf, unsigned long *count)
62{
63 unsigned long flags, cnt = 0;
64 int cpu, ret = 0;
65
66 /* Don't allow flipping of max traces now */
67 local_irq_save(flags);
68 arch_spin_lock(&buf->tr->max_lock);
69
70 cnt = ring_buffer_entries(buf->buffer);
71
72 /*
73 * The trace_test_buffer_cpu runs a while loop to consume all data.
74 * If the calling tracer is broken, and is constantly filling
75 * the buffer, this will run forever, and hard lock the box.
76 * We disable the ring buffer while we do this test to prevent
77 * a hard lock up.
78 */
79 tracing_off();
80 for_each_possible_cpu(cpu) {
81 ret = trace_test_buffer_cpu(buf, cpu);
82 if (ret)
83 break;
84 }
85 tracing_on();
86 arch_spin_unlock(&buf->tr->max_lock);
87 local_irq_restore(flags);
88
89 if (count)
90 *count = cnt;
91
92 return ret;
93}
94
95static inline void warn_failed_init_tracer(struct tracer *trace, int init_ret)
96{
97 printk(KERN_WARNING "Failed to init %s tracer, init returned %d\n",
98 trace->name, init_ret);
99}
100#ifdef CONFIG_FUNCTION_TRACER
101
102#ifdef CONFIG_DYNAMIC_FTRACE
103
104static int trace_selftest_test_probe1_cnt;
105static void trace_selftest_test_probe1_func(unsigned long ip,
106 unsigned long pip,
107 struct ftrace_ops *op,
108 struct pt_regs *pt_regs)
109{
110 trace_selftest_test_probe1_cnt++;
111}
112
113static int trace_selftest_test_probe2_cnt;
114static void trace_selftest_test_probe2_func(unsigned long ip,
115 unsigned long pip,
116 struct ftrace_ops *op,
117 struct pt_regs *pt_regs)
118{
119 trace_selftest_test_probe2_cnt++;
120}
121
122static int trace_selftest_test_probe3_cnt;
123static void trace_selftest_test_probe3_func(unsigned long ip,
124 unsigned long pip,
125 struct ftrace_ops *op,
126 struct pt_regs *pt_regs)
127{
128 trace_selftest_test_probe3_cnt++;
129}
130
131static int trace_selftest_test_global_cnt;
132static void trace_selftest_test_global_func(unsigned long ip,
133 unsigned long pip,
134 struct ftrace_ops *op,
135 struct pt_regs *pt_regs)
136{
137 trace_selftest_test_global_cnt++;
138}
139
140static int trace_selftest_test_dyn_cnt;
141static void trace_selftest_test_dyn_func(unsigned long ip,
142 unsigned long pip,
143 struct ftrace_ops *op,
144 struct pt_regs *pt_regs)
145{
146 trace_selftest_test_dyn_cnt++;
147}
148
149static struct ftrace_ops test_probe1 = {
150 .func = trace_selftest_test_probe1_func,
151 .flags = FTRACE_OPS_FL_RECURSION_SAFE,
152};
153
154static struct ftrace_ops test_probe2 = {
155 .func = trace_selftest_test_probe2_func,
156 .flags = FTRACE_OPS_FL_RECURSION_SAFE,
157};
158
159static struct ftrace_ops test_probe3 = {
160 .func = trace_selftest_test_probe3_func,
161 .flags = FTRACE_OPS_FL_RECURSION_SAFE,
162};
163
164static void print_counts(void)
165{
166 printk("(%d %d %d %d %d) ",
167 trace_selftest_test_probe1_cnt,
168 trace_selftest_test_probe2_cnt,
169 trace_selftest_test_probe3_cnt,
170 trace_selftest_test_global_cnt,
171 trace_selftest_test_dyn_cnt);
172}
173
174static void reset_counts(void)
175{
176 trace_selftest_test_probe1_cnt = 0;
177 trace_selftest_test_probe2_cnt = 0;
178 trace_selftest_test_probe3_cnt = 0;
179 trace_selftest_test_global_cnt = 0;
180 trace_selftest_test_dyn_cnt = 0;
181}
182
183static int trace_selftest_ops(struct trace_array *tr, int cnt)
184{
185 int save_ftrace_enabled = ftrace_enabled;
186 struct ftrace_ops *dyn_ops;
187 char *func1_name;
188 char *func2_name;
189 int len1;
190 int len2;
191 int ret = -1;
192
193 printk(KERN_CONT "PASSED\n");
194 pr_info("Testing dynamic ftrace ops #%d: ", cnt);
195
196 ftrace_enabled = 1;
197 reset_counts();
198
199 /* Handle PPC64 '.' name */
200 func1_name = "*" __stringify(DYN_FTRACE_TEST_NAME);
201 func2_name = "*" __stringify(DYN_FTRACE_TEST_NAME2);
202 len1 = strlen(func1_name);
203 len2 = strlen(func2_name);
204
205 /*
206 * Probe 1 will trace function 1.
207 * Probe 2 will trace function 2.
208 * Probe 3 will trace functions 1 and 2.
209 */
210 ftrace_set_filter(&test_probe1, func1_name, len1, 1);
211 ftrace_set_filter(&test_probe2, func2_name, len2, 1);
212 ftrace_set_filter(&test_probe3, func1_name, len1, 1);
213 ftrace_set_filter(&test_probe3, func2_name, len2, 0);
214
215 register_ftrace_function(&test_probe1);
216 register_ftrace_function(&test_probe2);
217 register_ftrace_function(&test_probe3);
218 /* First time we are running with main function */
219 if (cnt > 1) {
220 ftrace_init_array_ops(tr, trace_selftest_test_global_func);
221 register_ftrace_function(tr->ops);
222 }
223
224 DYN_FTRACE_TEST_NAME();
225
226 print_counts();
227
228 if (trace_selftest_test_probe1_cnt != 1)
229 goto out;
230 if (trace_selftest_test_probe2_cnt != 0)
231 goto out;
232 if (trace_selftest_test_probe3_cnt != 1)
233 goto out;
234 if (cnt > 1) {
235 if (trace_selftest_test_global_cnt == 0)
236 goto out;
237 }
238
239 DYN_FTRACE_TEST_NAME2();
240
241 print_counts();
242
243 if (trace_selftest_test_probe1_cnt != 1)
244 goto out;
245 if (trace_selftest_test_probe2_cnt != 1)
246 goto out;
247 if (trace_selftest_test_probe3_cnt != 2)
248 goto out;
249
250 /* Add a dynamic probe */
251 dyn_ops = kzalloc(sizeof(*dyn_ops), GFP_KERNEL);
252 if (!dyn_ops) {
253 printk("MEMORY ERROR ");
254 goto out;
255 }
256
257 dyn_ops->func = trace_selftest_test_dyn_func;
258
259 register_ftrace_function(dyn_ops);
260
261 trace_selftest_test_global_cnt = 0;
262
263 DYN_FTRACE_TEST_NAME();
264
265 print_counts();
266
267 if (trace_selftest_test_probe1_cnt != 2)
268 goto out_free;
269 if (trace_selftest_test_probe2_cnt != 1)
270 goto out_free;
271 if (trace_selftest_test_probe3_cnt != 3)
272 goto out_free;
273 if (cnt > 1) {
274 if (trace_selftest_test_global_cnt == 0)
275 goto out;
276 }
277 if (trace_selftest_test_dyn_cnt == 0)
278 goto out_free;
279
280 DYN_FTRACE_TEST_NAME2();
281
282 print_counts();
283
284 if (trace_selftest_test_probe1_cnt != 2)
285 goto out_free;
286 if (trace_selftest_test_probe2_cnt != 2)
287 goto out_free;
288 if (trace_selftest_test_probe3_cnt != 4)
289 goto out_free;
290
291 ret = 0;
292 out_free:
293 unregister_ftrace_function(dyn_ops);
294 kfree(dyn_ops);
295
296 out:
297 /* Purposely unregister in the same order */
298 unregister_ftrace_function(&test_probe1);
299 unregister_ftrace_function(&test_probe2);
300 unregister_ftrace_function(&test_probe3);
301 if (cnt > 1)
302 unregister_ftrace_function(tr->ops);
303 ftrace_reset_array_ops(tr);
304
305 /* Make sure everything is off */
306 reset_counts();
307 DYN_FTRACE_TEST_NAME();
308 DYN_FTRACE_TEST_NAME();
309
310 if (trace_selftest_test_probe1_cnt ||
311 trace_selftest_test_probe2_cnt ||
312 trace_selftest_test_probe3_cnt ||
313 trace_selftest_test_global_cnt ||
314 trace_selftest_test_dyn_cnt)
315 ret = -1;
316
317 ftrace_enabled = save_ftrace_enabled;
318
319 return ret;
320}
321
322/* Test dynamic code modification and ftrace filters */
323static int trace_selftest_startup_dynamic_tracing(struct tracer *trace,
324 struct trace_array *tr,
325 int (*func)(void))
326{
327 int save_ftrace_enabled = ftrace_enabled;
328 unsigned long count;
329 char *func_name;
330 int ret;
331
332 /* The ftrace test PASSED */
333 printk(KERN_CONT "PASSED\n");
334 pr_info("Testing dynamic ftrace: ");
335
336 /* enable tracing, and record the filter function */
337 ftrace_enabled = 1;
338
339 /* passed in by parameter to fool gcc from optimizing */
340 func();
341
342 /*
343 * Some archs *cough*PowerPC*cough* add characters to the
344 * start of the function names. We simply put a '*' to
345 * accommodate them.
346 */
347 func_name = "*" __stringify(DYN_FTRACE_TEST_NAME);
348
349 /* filter only on our function */
350 ftrace_set_global_filter(func_name, strlen(func_name), 1);
351
352 /* enable tracing */
353 ret = tracer_init(trace, tr);
354 if (ret) {
355 warn_failed_init_tracer(trace, ret);
356 goto out;
357 }
358
359 /* Sleep for a 1/10 of a second */
360 msleep(100);
361
362 /* we should have nothing in the buffer */
363 ret = trace_test_buffer(&tr->trace_buffer, &count);
364 if (ret)
365 goto out;
366
367 if (count) {
368 ret = -1;
369 printk(KERN_CONT ".. filter did not filter .. ");
370 goto out;
371 }
372
373 /* call our function again */
374 func();
375
376 /* sleep again */
377 msleep(100);
378
379 /* stop the tracing. */
380 tracing_stop();
381 ftrace_enabled = 0;
382
383 /* check the trace buffer */
384 ret = trace_test_buffer(&tr->trace_buffer, &count);
385
386 ftrace_enabled = 1;
387 tracing_start();
388
389 /* we should only have one item */
390 if (!ret && count != 1) {
391 trace->reset(tr);
392 printk(KERN_CONT ".. filter failed count=%ld ..", count);
393 ret = -1;
394 goto out;
395 }
396
397 /* Test the ops with global tracing running */
398 ret = trace_selftest_ops(tr, 1);
399 trace->reset(tr);
400
401 out:
402 ftrace_enabled = save_ftrace_enabled;
403
404 /* Enable tracing on all functions again */
405 ftrace_set_global_filter(NULL, 0, 1);
406
407 /* Test the ops with global tracing off */
408 if (!ret)
409 ret = trace_selftest_ops(tr, 2);
410
411 return ret;
412}
413
414static int trace_selftest_recursion_cnt;
415static void trace_selftest_test_recursion_func(unsigned long ip,
416 unsigned long pip,
417 struct ftrace_ops *op,
418 struct pt_regs *pt_regs)
419{
420 /*
421 * This function is registered without the recursion safe flag.
422 * The ftrace infrastructure should provide the recursion
423 * protection. If not, this will crash the kernel!
424 */
425 if (trace_selftest_recursion_cnt++ > 10)
426 return;
427 DYN_FTRACE_TEST_NAME();
428}
429
430static void trace_selftest_test_recursion_safe_func(unsigned long ip,
431 unsigned long pip,
432 struct ftrace_ops *op,
433 struct pt_regs *pt_regs)
434{
435 /*
436 * We said we would provide our own recursion. By calling
437 * this function again, we should recurse back into this function
438 * and count again. But this only happens if the arch supports
439 * all of ftrace features and nothing else is using the function
440 * tracing utility.
441 */
442 if (trace_selftest_recursion_cnt++)
443 return;
444 DYN_FTRACE_TEST_NAME();
445}
446
447static struct ftrace_ops test_rec_probe = {
448 .func = trace_selftest_test_recursion_func,
449};
450
451static struct ftrace_ops test_recsafe_probe = {
452 .func = trace_selftest_test_recursion_safe_func,
453 .flags = FTRACE_OPS_FL_RECURSION_SAFE,
454};
455
456static int
457trace_selftest_function_recursion(void)
458{
459 int save_ftrace_enabled = ftrace_enabled;
460 char *func_name;
461 int len;
462 int ret;
463
464 /* The previous test PASSED */
465 pr_cont("PASSED\n");
466 pr_info("Testing ftrace recursion: ");
467
468
469 /* enable tracing, and record the filter function */
470 ftrace_enabled = 1;
471
472 /* Handle PPC64 '.' name */
473 func_name = "*" __stringify(DYN_FTRACE_TEST_NAME);
474 len = strlen(func_name);
475
476 ret = ftrace_set_filter(&test_rec_probe, func_name, len, 1);
477 if (ret) {
478 pr_cont("*Could not set filter* ");
479 goto out;
480 }
481
482 ret = register_ftrace_function(&test_rec_probe);
483 if (ret) {
484 pr_cont("*could not register callback* ");
485 goto out;
486 }
487
488 DYN_FTRACE_TEST_NAME();
489
490 unregister_ftrace_function(&test_rec_probe);
491
492 ret = -1;
493 if (trace_selftest_recursion_cnt != 1) {
494 pr_cont("*callback not called once (%d)* ",
495 trace_selftest_recursion_cnt);
496 goto out;
497 }
498
499 trace_selftest_recursion_cnt = 1;
500
501 pr_cont("PASSED\n");
502 pr_info("Testing ftrace recursion safe: ");
503
504 ret = ftrace_set_filter(&test_recsafe_probe, func_name, len, 1);
505 if (ret) {
506 pr_cont("*Could not set filter* ");
507 goto out;
508 }
509
510 ret = register_ftrace_function(&test_recsafe_probe);
511 if (ret) {
512 pr_cont("*could not register callback* ");
513 goto out;
514 }
515
516 DYN_FTRACE_TEST_NAME();
517
518 unregister_ftrace_function(&test_recsafe_probe);
519
520 ret = -1;
521 if (trace_selftest_recursion_cnt != 2) {
522 pr_cont("*callback not called expected 2 times (%d)* ",
523 trace_selftest_recursion_cnt);
524 goto out;
525 }
526
527 ret = 0;
528out:
529 ftrace_enabled = save_ftrace_enabled;
530
531 return ret;
532}
533#else
534# define trace_selftest_startup_dynamic_tracing(trace, tr, func) ({ 0; })
535# define trace_selftest_function_recursion() ({ 0; })
536#endif /* CONFIG_DYNAMIC_FTRACE */
537
538static enum {
539 TRACE_SELFTEST_REGS_START,
540 TRACE_SELFTEST_REGS_FOUND,
541 TRACE_SELFTEST_REGS_NOT_FOUND,
542} trace_selftest_regs_stat;
543
544static void trace_selftest_test_regs_func(unsigned long ip,
545 unsigned long pip,
546 struct ftrace_ops *op,
547 struct pt_regs *pt_regs)
548{
549 if (pt_regs)
550 trace_selftest_regs_stat = TRACE_SELFTEST_REGS_FOUND;
551 else
552 trace_selftest_regs_stat = TRACE_SELFTEST_REGS_NOT_FOUND;
553}
554
555static struct ftrace_ops test_regs_probe = {
556 .func = trace_selftest_test_regs_func,
557 .flags = FTRACE_OPS_FL_RECURSION_SAFE | FTRACE_OPS_FL_SAVE_REGS,
558};
559
560static int
561trace_selftest_function_regs(void)
562{
563 int save_ftrace_enabled = ftrace_enabled;
564 char *func_name;
565 int len;
566 int ret;
567 int supported = 0;
568
569#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
570 supported = 1;
571#endif
572
573 /* The previous test PASSED */
574 pr_cont("PASSED\n");
575 pr_info("Testing ftrace regs%s: ",
576 !supported ? "(no arch support)" : "");
577
578 /* enable tracing, and record the filter function */
579 ftrace_enabled = 1;
580
581 /* Handle PPC64 '.' name */
582 func_name = "*" __stringify(DYN_FTRACE_TEST_NAME);
583 len = strlen(func_name);
584
585 ret = ftrace_set_filter(&test_regs_probe, func_name, len, 1);
586 /*
587 * If DYNAMIC_FTRACE is not set, then we just trace all functions.
588 * This test really doesn't care.
589 */
590 if (ret && ret != -ENODEV) {
591 pr_cont("*Could not set filter* ");
592 goto out;
593 }
594
595 ret = register_ftrace_function(&test_regs_probe);
596 /*
597 * Now if the arch does not support passing regs, then this should
598 * have failed.
599 */
600 if (!supported) {
601 if (!ret) {
602 pr_cont("*registered save-regs without arch support* ");
603 goto out;
604 }
605 test_regs_probe.flags |= FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED;
606 ret = register_ftrace_function(&test_regs_probe);
607 }
608 if (ret) {
609 pr_cont("*could not register callback* ");
610 goto out;
611 }
612
613
614 DYN_FTRACE_TEST_NAME();
615
616 unregister_ftrace_function(&test_regs_probe);
617
618 ret = -1;
619
620 switch (trace_selftest_regs_stat) {
621 case TRACE_SELFTEST_REGS_START:
622 pr_cont("*callback never called* ");
623 goto out;
624
625 case TRACE_SELFTEST_REGS_FOUND:
626 if (supported)
627 break;
628 pr_cont("*callback received regs without arch support* ");
629 goto out;
630
631 case TRACE_SELFTEST_REGS_NOT_FOUND:
632 if (!supported)
633 break;
634 pr_cont("*callback received NULL regs* ");
635 goto out;
636 }
637
638 ret = 0;
639out:
640 ftrace_enabled = save_ftrace_enabled;
641
642 return ret;
643}
644
645/*
646 * Simple verification test of ftrace function tracer.
647 * Enable ftrace, sleep 1/10 second, and then read the trace
648 * buffer to see if all is in order.
649 */
650__init int
651trace_selftest_startup_function(struct tracer *trace, struct trace_array *tr)
652{
653 int save_ftrace_enabled = ftrace_enabled;
654 unsigned long count;
655 int ret;
656
657#ifdef CONFIG_DYNAMIC_FTRACE
658 if (ftrace_filter_param) {
659 printk(KERN_CONT " ... kernel command line filter set: force PASS ... ");
660 return 0;
661 }
662#endif
663
664 /* make sure msleep has been recorded */
665 msleep(1);
666
667 /* start the tracing */
668 ftrace_enabled = 1;
669
670 ret = tracer_init(trace, tr);
671 if (ret) {
672 warn_failed_init_tracer(trace, ret);
673 goto out;
674 }
675
676 /* Sleep for a 1/10 of a second */
677 msleep(100);
678 /* stop the tracing. */
679 tracing_stop();
680 ftrace_enabled = 0;
681
682 /* check the trace buffer */
683 ret = trace_test_buffer(&tr->trace_buffer, &count);
684
685 ftrace_enabled = 1;
686 trace->reset(tr);
687 tracing_start();
688
689 if (!ret && !count) {
690 printk(KERN_CONT ".. no entries found ..");
691 ret = -1;
692 goto out;
693 }
694
695 ret = trace_selftest_startup_dynamic_tracing(trace, tr,
696 DYN_FTRACE_TEST_NAME);
697 if (ret)
698 goto out;
699
700 ret = trace_selftest_function_recursion();
701 if (ret)
702 goto out;
703
704 ret = trace_selftest_function_regs();
705 out:
706 ftrace_enabled = save_ftrace_enabled;
707
708 /* kill ftrace totally if we failed */
709 if (ret)
710 ftrace_kill();
711
712 return ret;
713}
714#endif /* CONFIG_FUNCTION_TRACER */
715
716
717#ifdef CONFIG_FUNCTION_GRAPH_TRACER
718
719/* Maximum number of functions to trace before diagnosing a hang */
720#define GRAPH_MAX_FUNC_TEST 100000000
721
722static unsigned int graph_hang_thresh;
723
724/* Wrap the real function entry probe to avoid possible hanging */
725static int trace_graph_entry_watchdog(struct ftrace_graph_ent *trace)
726{
727 /* This is harmlessly racy, we want to approximately detect a hang */
728 if (unlikely(++graph_hang_thresh > GRAPH_MAX_FUNC_TEST)) {
729 ftrace_graph_stop();
730 printk(KERN_WARNING "BUG: Function graph tracer hang!\n");
731 if (ftrace_dump_on_oops) {
732 ftrace_dump(DUMP_ALL);
733 /* ftrace_dump() disables tracing */
734 tracing_on();
735 }
736 return 0;
737 }
738
739 return trace_graph_entry(trace);
740}
741
742/*
743 * Pretty much the same than for the function tracer from which the selftest
744 * has been borrowed.
745 */
746__init int
747trace_selftest_startup_function_graph(struct tracer *trace,
748 struct trace_array *tr)
749{
750 int ret;
751 unsigned long count;
752
753#ifdef CONFIG_DYNAMIC_FTRACE
754 if (ftrace_filter_param) {
755 printk(KERN_CONT " ... kernel command line filter set: force PASS ... ");
756 return 0;
757 }
758#endif
759
760 /*
761 * Simulate the init() callback but we attach a watchdog callback
762 * to detect and recover from possible hangs
763 */
764 tracing_reset_online_cpus(&tr->trace_buffer);
765 set_graph_array(tr);
766 ret = register_ftrace_graph(&trace_graph_return,
767 &trace_graph_entry_watchdog);
768 if (ret) {
769 warn_failed_init_tracer(trace, ret);
770 goto out;
771 }
772 tracing_start_cmdline_record();
773
774 /* Sleep for a 1/10 of a second */
775 msleep(100);
776
777 /* Have we just recovered from a hang? */
778 if (graph_hang_thresh > GRAPH_MAX_FUNC_TEST) {
779 tracing_selftest_disabled = true;
780 ret = -1;
781 goto out;
782 }
783
784 tracing_stop();
785
786 /* check the trace buffer */
787 ret = trace_test_buffer(&tr->trace_buffer, &count);
788
789 trace->reset(tr);
790 tracing_start();
791
792 if (!ret && !count) {
793 printk(KERN_CONT ".. no entries found ..");
794 ret = -1;
795 goto out;
796 }
797
798 /* Don't test dynamic tracing, the function tracer already did */
799
800out:
801 /* Stop it if we failed */
802 if (ret)
803 ftrace_graph_stop();
804
805 return ret;
806}
807#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
808
809
810#ifdef CONFIG_IRQSOFF_TRACER
811int
812trace_selftest_startup_irqsoff(struct tracer *trace, struct trace_array *tr)
813{
814 unsigned long save_max = tr->max_latency;
815 unsigned long count;
816 int ret;
817
818 /* start the tracing */
819 ret = tracer_init(trace, tr);
820 if (ret) {
821 warn_failed_init_tracer(trace, ret);
822 return ret;
823 }
824
825 /* reset the max latency */
826 tr->max_latency = 0;
827 /* disable interrupts for a bit */
828 local_irq_disable();
829 udelay(100);
830 local_irq_enable();
831
832 /*
833 * Stop the tracer to avoid a warning subsequent
834 * to buffer flipping failure because tracing_stop()
835 * disables the tr and max buffers, making flipping impossible
836 * in case of parallels max irqs off latencies.
837 */
838 trace->stop(tr);
839 /* stop the tracing. */
840 tracing_stop();
841 /* check both trace buffers */
842 ret = trace_test_buffer(&tr->trace_buffer, NULL);
843 if (!ret)
844 ret = trace_test_buffer(&tr->max_buffer, &count);
845 trace->reset(tr);
846 tracing_start();
847
848 if (!ret && !count) {
849 printk(KERN_CONT ".. no entries found ..");
850 ret = -1;
851 }
852
853 tr->max_latency = save_max;
854
855 return ret;
856}
857#endif /* CONFIG_IRQSOFF_TRACER */
858
859#ifdef CONFIG_PREEMPT_TRACER
860int
861trace_selftest_startup_preemptoff(struct tracer *trace, struct trace_array *tr)
862{
863 unsigned long save_max = tr->max_latency;
864 unsigned long count;
865 int ret;
866
867 /*
868 * Now that the big kernel lock is no longer preemptable,
869 * and this is called with the BKL held, it will always
870 * fail. If preemption is already disabled, simply
871 * pass the test. When the BKL is removed, or becomes
872 * preemptible again, we will once again test this,
873 * so keep it in.
874 */
875 if (preempt_count()) {
876 printk(KERN_CONT "can not test ... force ");
877 return 0;
878 }
879
880 /* start the tracing */
881 ret = tracer_init(trace, tr);
882 if (ret) {
883 warn_failed_init_tracer(trace, ret);
884 return ret;
885 }
886
887 /* reset the max latency */
888 tr->max_latency = 0;
889 /* disable preemption for a bit */
890 preempt_disable();
891 udelay(100);
892 preempt_enable();
893
894 /*
895 * Stop the tracer to avoid a warning subsequent
896 * to buffer flipping failure because tracing_stop()
897 * disables the tr and max buffers, making flipping impossible
898 * in case of parallels max preempt off latencies.
899 */
900 trace->stop(tr);
901 /* stop the tracing. */
902 tracing_stop();
903 /* check both trace buffers */
904 ret = trace_test_buffer(&tr->trace_buffer, NULL);
905 if (!ret)
906 ret = trace_test_buffer(&tr->max_buffer, &count);
907 trace->reset(tr);
908 tracing_start();
909
910 if (!ret && !count) {
911 printk(KERN_CONT ".. no entries found ..");
912 ret = -1;
913 }
914
915 tr->max_latency = save_max;
916
917 return ret;
918}
919#endif /* CONFIG_PREEMPT_TRACER */
920
921#if defined(CONFIG_IRQSOFF_TRACER) && defined(CONFIG_PREEMPT_TRACER)
922int
923trace_selftest_startup_preemptirqsoff(struct tracer *trace, struct trace_array *tr)
924{
925 unsigned long save_max = tr->max_latency;
926 unsigned long count;
927 int ret;
928
929 /*
930 * Now that the big kernel lock is no longer preemptable,
931 * and this is called with the BKL held, it will always
932 * fail. If preemption is already disabled, simply
933 * pass the test. When the BKL is removed, or becomes
934 * preemptible again, we will once again test this,
935 * so keep it in.
936 */
937 if (preempt_count()) {
938 printk(KERN_CONT "can not test ... force ");
939 return 0;
940 }
941
942 /* start the tracing */
943 ret = tracer_init(trace, tr);
944 if (ret) {
945 warn_failed_init_tracer(trace, ret);
946 goto out_no_start;
947 }
948
949 /* reset the max latency */
950 tr->max_latency = 0;
951
952 /* disable preemption and interrupts for a bit */
953 preempt_disable();
954 local_irq_disable();
955 udelay(100);
956 preempt_enable();
957 /* reverse the order of preempt vs irqs */
958 local_irq_enable();
959
960 /*
961 * Stop the tracer to avoid a warning subsequent
962 * to buffer flipping failure because tracing_stop()
963 * disables the tr and max buffers, making flipping impossible
964 * in case of parallels max irqs/preempt off latencies.
965 */
966 trace->stop(tr);
967 /* stop the tracing. */
968 tracing_stop();
969 /* check both trace buffers */
970 ret = trace_test_buffer(&tr->trace_buffer, NULL);
971 if (ret)
972 goto out;
973
974 ret = trace_test_buffer(&tr->max_buffer, &count);
975 if (ret)
976 goto out;
977
978 if (!ret && !count) {
979 printk(KERN_CONT ".. no entries found ..");
980 ret = -1;
981 goto out;
982 }
983
984 /* do the test by disabling interrupts first this time */
985 tr->max_latency = 0;
986 tracing_start();
987 trace->start(tr);
988
989 preempt_disable();
990 local_irq_disable();
991 udelay(100);
992 preempt_enable();
993 /* reverse the order of preempt vs irqs */
994 local_irq_enable();
995
996 trace->stop(tr);
997 /* stop the tracing. */
998 tracing_stop();
999 /* check both trace buffers */
1000 ret = trace_test_buffer(&tr->trace_buffer, NULL);
1001 if (ret)
1002 goto out;
1003
1004 ret = trace_test_buffer(&tr->max_buffer, &count);
1005
1006 if (!ret && !count) {
1007 printk(KERN_CONT ".. no entries found ..");
1008 ret = -1;
1009 goto out;
1010 }
1011
1012out:
1013 tracing_start();
1014out_no_start:
1015 trace->reset(tr);
1016 tr->max_latency = save_max;
1017
1018 return ret;
1019}
1020#endif /* CONFIG_IRQSOFF_TRACER && CONFIG_PREEMPT_TRACER */
1021
1022#ifdef CONFIG_NOP_TRACER
1023int
1024trace_selftest_startup_nop(struct tracer *trace, struct trace_array *tr)
1025{
1026 /* What could possibly go wrong? */
1027 return 0;
1028}
1029#endif
1030
1031#ifdef CONFIG_SCHED_TRACER
1032
1033struct wakeup_test_data {
1034 struct completion is_ready;
1035 int go;
1036};
1037
1038static int trace_wakeup_test_thread(void *data)
1039{
1040 /* Make this a -deadline thread */
1041 static const struct sched_attr attr = {
1042 .sched_policy = SCHED_DEADLINE,
1043 .sched_runtime = 100000ULL,
1044 .sched_deadline = 10000000ULL,
1045 .sched_period = 10000000ULL
1046 };
1047 struct wakeup_test_data *x = data;
1048
1049 sched_setattr(current, &attr);
1050
1051 /* Make it know we have a new prio */
1052 complete(&x->is_ready);
1053
1054 /* now go to sleep and let the test wake us up */
1055 set_current_state(TASK_INTERRUPTIBLE);
1056 while (!x->go) {
1057 schedule();
1058 set_current_state(TASK_INTERRUPTIBLE);
1059 }
1060
1061 complete(&x->is_ready);
1062
1063 set_current_state(TASK_INTERRUPTIBLE);
1064
1065 /* we are awake, now wait to disappear */
1066 while (!kthread_should_stop()) {
1067 schedule();
1068 set_current_state(TASK_INTERRUPTIBLE);
1069 }
1070
1071 __set_current_state(TASK_RUNNING);
1072
1073 return 0;
1074}
1075int
1076trace_selftest_startup_wakeup(struct tracer *trace, struct trace_array *tr)
1077{
1078 unsigned long save_max = tr->max_latency;
1079 struct task_struct *p;
1080 struct wakeup_test_data data;
1081 unsigned long count;
1082 int ret;
1083
1084 memset(&data, 0, sizeof(data));
1085
1086 init_completion(&data.is_ready);
1087
1088 /* create a -deadline thread */
1089 p = kthread_run(trace_wakeup_test_thread, &data, "ftrace-test");
1090 if (IS_ERR(p)) {
1091 printk(KERN_CONT "Failed to create ftrace wakeup test thread ");
1092 return -1;
1093 }
1094
1095 /* make sure the thread is running at -deadline policy */
1096 wait_for_completion(&data.is_ready);
1097
1098 /* start the tracing */
1099 ret = tracer_init(trace, tr);
1100 if (ret) {
1101 warn_failed_init_tracer(trace, ret);
1102 return ret;
1103 }
1104
1105 /* reset the max latency */
1106 tr->max_latency = 0;
1107
1108 while (p->on_rq) {
1109 /*
1110 * Sleep to make sure the -deadline thread is asleep too.
1111 * On virtual machines we can't rely on timings,
1112 * but we want to make sure this test still works.
1113 */
1114 msleep(100);
1115 }
1116
1117 init_completion(&data.is_ready);
1118
1119 data.go = 1;
1120 /* memory barrier is in the wake_up_process() */
1121
1122 wake_up_process(p);
1123
1124 /* Wait for the task to wake up */
1125 wait_for_completion(&data.is_ready);
1126
1127 /* stop the tracing. */
1128 tracing_stop();
1129 /* check both trace buffers */
1130 ret = trace_test_buffer(&tr->trace_buffer, NULL);
1131 if (!ret)
1132 ret = trace_test_buffer(&tr->max_buffer, &count);
1133
1134
1135 trace->reset(tr);
1136 tracing_start();
1137
1138 tr->max_latency = save_max;
1139
1140 /* kill the thread */
1141 kthread_stop(p);
1142
1143 if (!ret && !count) {
1144 printk(KERN_CONT ".. no entries found ..");
1145 ret = -1;
1146 }
1147
1148 return ret;
1149}
1150#endif /* CONFIG_SCHED_TRACER */
1151
1152#ifdef CONFIG_CONTEXT_SWITCH_TRACER
1153int
1154trace_selftest_startup_sched_switch(struct tracer *trace, struct trace_array *tr)
1155{
1156 unsigned long count;
1157 int ret;
1158
1159 /* start the tracing */
1160 ret = tracer_init(trace, tr);
1161 if (ret) {
1162 warn_failed_init_tracer(trace, ret);
1163 return ret;
1164 }
1165
1166 /* Sleep for a 1/10 of a second */
1167 msleep(100);
1168 /* stop the tracing. */
1169 tracing_stop();
1170 /* check the trace buffer */
1171 ret = trace_test_buffer(&tr->trace_buffer, &count);
1172 trace->reset(tr);
1173 tracing_start();
1174
1175 if (!ret && !count) {
1176 printk(KERN_CONT ".. no entries found ..");
1177 ret = -1;
1178 }
1179
1180 return ret;
1181}
1182#endif /* CONFIG_CONTEXT_SWITCH_TRACER */
1183
1184#ifdef CONFIG_BRANCH_TRACER
1185int
1186trace_selftest_startup_branch(struct tracer *trace, struct trace_array *tr)
1187{
1188 unsigned long count;
1189 int ret;
1190
1191 /* start the tracing */
1192 ret = tracer_init(trace, tr);
1193 if (ret) {
1194 warn_failed_init_tracer(trace, ret);
1195 return ret;
1196 }
1197
1198 /* Sleep for a 1/10 of a second */
1199 msleep(100);
1200 /* stop the tracing. */
1201 tracing_stop();
1202 /* check the trace buffer */
1203 ret = trace_test_buffer(&tr->trace_buffer, &count);
1204 trace->reset(tr);
1205 tracing_start();
1206
1207 if (!ret && !count) {
1208 printk(KERN_CONT ".. no entries found ..");
1209 ret = -1;
1210 }
1211
1212 return ret;
1213}
1214#endif /* CONFIG_BRANCH_TRACER */
1215
1/* 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