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