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1// SPDX-License-Identifier: GPL-2.0
2/* Include in trace.c */
3
4#include <uapi/linux/sched/types.h>
5#include <linux/stringify.h>
6#include <linux/kthread.h>
7#include <linux/delay.h>
8#include <linux/slab.h>
9
10static inline int trace_valid_entry(struct trace_entry *entry)
11{
12 switch (entry->type) {
13 case TRACE_FN:
14 case TRACE_CTX:
15 case TRACE_WAKE:
16 case TRACE_STACK:
17 case TRACE_PRINT:
18 case TRACE_BRANCH:
19 case TRACE_GRAPH_ENT:
20 case TRACE_GRAPH_RET:
21 return 1;
22 }
23 return 0;
24}
25
26static int trace_test_buffer_cpu(struct 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
1// SPDX-License-Identifier: GPL-2.0
2/* Include in trace.c */
3
4#include <uapi/linux/sched/types.h>
5#include <linux/stringify.h>
6#include <linux/kthread.h>
7#include <linux/delay.h>
8#include <linux/slab.h>
9
10static inline int trace_valid_entry(struct trace_entry *entry)
11{
12 switch (entry->type) {
13 case TRACE_FN:
14 case TRACE_CTX:
15 case TRACE_WAKE:
16 case TRACE_STACK:
17 case TRACE_PRINT:
18 case TRACE_BRANCH:
19 case TRACE_GRAPH_ENT:
20 case TRACE_GRAPH_RET:
21 return 1;
22 }
23 return 0;
24}
25
26static int trace_test_buffer_cpu(struct array_buffer *buf, int cpu)
27{
28 struct ring_buffer_event *event;
29 struct trace_entry *entry;
30 unsigned int loops = 0;
31
32 while ((event = ring_buffer_consume(buf->buffer, cpu, NULL, NULL))) {
33 entry = ring_buffer_event_data(event);
34
35 /*
36 * The ring buffer is a size of trace_buf_size, if
37 * we loop more than the size, there's something wrong
38 * with the ring buffer.
39 */
40 if (loops++ > trace_buf_size) {
41 printk(KERN_CONT ".. bad ring buffer ");
42 goto failed;
43 }
44 if (!trace_valid_entry(entry)) {
45 printk(KERN_CONT ".. invalid entry %d ",
46 entry->type);
47 goto failed;
48 }
49 }
50 return 0;
51
52 failed:
53 /* disable tracing */
54 tracing_disabled = 1;
55 printk(KERN_CONT ".. corrupted trace buffer .. ");
56 return -1;
57}
58
59/*
60 * Test the trace buffer to see if all the elements
61 * are still sane.
62 */
63static int __maybe_unused trace_test_buffer(struct array_buffer *buf, unsigned long *count)
64{
65 unsigned long flags, cnt = 0;
66 int cpu, ret = 0;
67
68 /* Don't allow flipping of max traces now */
69 local_irq_save(flags);
70 arch_spin_lock(&buf->tr->max_lock);
71
72 cnt = ring_buffer_entries(buf->buffer);
73
74 /*
75 * The trace_test_buffer_cpu runs a while loop to consume all data.
76 * If the calling tracer is broken, and is constantly filling
77 * the buffer, this will run forever, and hard lock the box.
78 * We disable the ring buffer while we do this test to prevent
79 * a hard lock up.
80 */
81 tracing_off();
82 for_each_possible_cpu(cpu) {
83 ret = trace_test_buffer_cpu(buf, cpu);
84 if (ret)
85 break;
86 }
87 tracing_on();
88 arch_spin_unlock(&buf->tr->max_lock);
89 local_irq_restore(flags);
90
91 if (count)
92 *count = cnt;
93
94 return ret;
95}
96
97static inline void warn_failed_init_tracer(struct tracer *trace, int init_ret)
98{
99 printk(KERN_WARNING "Failed to init %s tracer, init returned %d\n",
100 trace->name, init_ret);
101}
102#ifdef CONFIG_FUNCTION_TRACER
103
104#ifdef CONFIG_DYNAMIC_FTRACE
105
106static int trace_selftest_test_probe1_cnt;
107static void trace_selftest_test_probe1_func(unsigned long ip,
108 unsigned long pip,
109 struct ftrace_ops *op,
110 struct ftrace_regs *fregs)
111{
112 trace_selftest_test_probe1_cnt++;
113}
114
115static int trace_selftest_test_probe2_cnt;
116static void trace_selftest_test_probe2_func(unsigned long ip,
117 unsigned long pip,
118 struct ftrace_ops *op,
119 struct ftrace_regs *fregs)
120{
121 trace_selftest_test_probe2_cnt++;
122}
123
124static int trace_selftest_test_probe3_cnt;
125static void trace_selftest_test_probe3_func(unsigned long ip,
126 unsigned long pip,
127 struct ftrace_ops *op,
128 struct ftrace_regs *fregs)
129{
130 trace_selftest_test_probe3_cnt++;
131}
132
133static int trace_selftest_test_global_cnt;
134static void trace_selftest_test_global_func(unsigned long ip,
135 unsigned long pip,
136 struct ftrace_ops *op,
137 struct ftrace_regs *fregs)
138{
139 trace_selftest_test_global_cnt++;
140}
141
142static int trace_selftest_test_dyn_cnt;
143static void trace_selftest_test_dyn_func(unsigned long ip,
144 unsigned long pip,
145 struct ftrace_ops *op,
146 struct ftrace_regs *fregs)
147{
148 trace_selftest_test_dyn_cnt++;
149}
150
151static struct ftrace_ops test_probe1 = {
152 .func = trace_selftest_test_probe1_func,
153};
154
155static struct ftrace_ops test_probe2 = {
156 .func = trace_selftest_test_probe2_func,
157};
158
159static struct ftrace_ops test_probe3 = {
160 .func = trace_selftest_test_probe3_func,
161};
162
163static void print_counts(void)
164{
165 printk("(%d %d %d %d %d) ",
166 trace_selftest_test_probe1_cnt,
167 trace_selftest_test_probe2_cnt,
168 trace_selftest_test_probe3_cnt,
169 trace_selftest_test_global_cnt,
170 trace_selftest_test_dyn_cnt);
171}
172
173static void reset_counts(void)
174{
175 trace_selftest_test_probe1_cnt = 0;
176 trace_selftest_test_probe2_cnt = 0;
177 trace_selftest_test_probe3_cnt = 0;
178 trace_selftest_test_global_cnt = 0;
179 trace_selftest_test_dyn_cnt = 0;
180}
181
182static int trace_selftest_ops(struct trace_array *tr, int cnt)
183{
184 int save_ftrace_enabled = ftrace_enabled;
185 struct ftrace_ops *dyn_ops;
186 char *func1_name;
187 char *func2_name;
188 int len1;
189 int len2;
190 int ret = -1;
191
192 printk(KERN_CONT "PASSED\n");
193 pr_info("Testing dynamic ftrace ops #%d: ", cnt);
194
195 ftrace_enabled = 1;
196 reset_counts();
197
198 /* Handle PPC64 '.' name */
199 func1_name = "*" __stringify(DYN_FTRACE_TEST_NAME);
200 func2_name = "*" __stringify(DYN_FTRACE_TEST_NAME2);
201 len1 = strlen(func1_name);
202 len2 = strlen(func2_name);
203
204 /*
205 * Probe 1 will trace function 1.
206 * Probe 2 will trace function 2.
207 * Probe 3 will trace functions 1 and 2.
208 */
209 ftrace_set_filter(&test_probe1, func1_name, len1, 1);
210 ftrace_set_filter(&test_probe2, func2_name, len2, 1);
211 ftrace_set_filter(&test_probe3, func1_name, len1, 1);
212 ftrace_set_filter(&test_probe3, func2_name, len2, 0);
213
214 register_ftrace_function(&test_probe1);
215 register_ftrace_function(&test_probe2);
216 register_ftrace_function(&test_probe3);
217 /* First time we are running with main function */
218 if (cnt > 1) {
219 ftrace_init_array_ops(tr, trace_selftest_test_global_func);
220 register_ftrace_function(tr->ops);
221 }
222
223 DYN_FTRACE_TEST_NAME();
224
225 print_counts();
226
227 if (trace_selftest_test_probe1_cnt != 1)
228 goto out;
229 if (trace_selftest_test_probe2_cnt != 0)
230 goto out;
231 if (trace_selftest_test_probe3_cnt != 1)
232 goto out;
233 if (cnt > 1) {
234 if (trace_selftest_test_global_cnt == 0)
235 goto out;
236 }
237
238 DYN_FTRACE_TEST_NAME2();
239
240 print_counts();
241
242 if (trace_selftest_test_probe1_cnt != 1)
243 goto out;
244 if (trace_selftest_test_probe2_cnt != 1)
245 goto out;
246 if (trace_selftest_test_probe3_cnt != 2)
247 goto out;
248
249 /* Add a dynamic probe */
250 dyn_ops = kzalloc(sizeof(*dyn_ops), GFP_KERNEL);
251 if (!dyn_ops) {
252 printk("MEMORY ERROR ");
253 goto out;
254 }
255
256 dyn_ops->func = trace_selftest_test_dyn_func;
257
258 register_ftrace_function(dyn_ops);
259
260 trace_selftest_test_global_cnt = 0;
261
262 DYN_FTRACE_TEST_NAME();
263
264 print_counts();
265
266 if (trace_selftest_test_probe1_cnt != 2)
267 goto out_free;
268 if (trace_selftest_test_probe2_cnt != 1)
269 goto out_free;
270 if (trace_selftest_test_probe3_cnt != 3)
271 goto out_free;
272 if (cnt > 1) {
273 if (trace_selftest_test_global_cnt == 0)
274 goto out_free;
275 }
276 if (trace_selftest_test_dyn_cnt == 0)
277 goto out_free;
278
279 DYN_FTRACE_TEST_NAME2();
280
281 print_counts();
282
283 if (trace_selftest_test_probe1_cnt != 2)
284 goto out_free;
285 if (trace_selftest_test_probe2_cnt != 2)
286 goto out_free;
287 if (trace_selftest_test_probe3_cnt != 4)
288 goto out_free;
289
290 ret = 0;
291 out_free:
292 unregister_ftrace_function(dyn_ops);
293 kfree(dyn_ops);
294
295 out:
296 /* Purposely unregister in the same order */
297 unregister_ftrace_function(&test_probe1);
298 unregister_ftrace_function(&test_probe2);
299 unregister_ftrace_function(&test_probe3);
300 if (cnt > 1)
301 unregister_ftrace_function(tr->ops);
302 ftrace_reset_array_ops(tr);
303
304 /* Make sure everything is off */
305 reset_counts();
306 DYN_FTRACE_TEST_NAME();
307 DYN_FTRACE_TEST_NAME();
308
309 if (trace_selftest_test_probe1_cnt ||
310 trace_selftest_test_probe2_cnt ||
311 trace_selftest_test_probe3_cnt ||
312 trace_selftest_test_global_cnt ||
313 trace_selftest_test_dyn_cnt)
314 ret = -1;
315
316 ftrace_enabled = save_ftrace_enabled;
317
318 return ret;
319}
320
321/* Test dynamic code modification and ftrace filters */
322static int trace_selftest_startup_dynamic_tracing(struct tracer *trace,
323 struct trace_array *tr,
324 int (*func)(void))
325{
326 int save_ftrace_enabled = ftrace_enabled;
327 unsigned long count;
328 char *func_name;
329 int ret;
330
331 /* The ftrace test PASSED */
332 printk(KERN_CONT "PASSED\n");
333 pr_info("Testing dynamic ftrace: ");
334
335 /* enable tracing, and record the filter function */
336 ftrace_enabled = 1;
337
338 /* passed in by parameter to fool gcc from optimizing */
339 func();
340
341 /*
342 * Some archs *cough*PowerPC*cough* add characters to the
343 * start of the function names. We simply put a '*' to
344 * accommodate them.
345 */
346 func_name = "*" __stringify(DYN_FTRACE_TEST_NAME);
347
348 /* filter only on our function */
349 ftrace_set_global_filter(func_name, strlen(func_name), 1);
350
351 /* enable tracing */
352 ret = tracer_init(trace, tr);
353 if (ret) {
354 warn_failed_init_tracer(trace, ret);
355 goto out;
356 }
357
358 /* Sleep for a 1/10 of a second */
359 msleep(100);
360
361 /* we should have nothing in the buffer */
362 ret = trace_test_buffer(&tr->array_buffer, &count);
363 if (ret)
364 goto out;
365
366 if (count) {
367 ret = -1;
368 printk(KERN_CONT ".. filter did not filter .. ");
369 goto out;
370 }
371
372 /* call our function again */
373 func();
374
375 /* sleep again */
376 msleep(100);
377
378 /* stop the tracing. */
379 tracing_stop();
380 ftrace_enabled = 0;
381
382 /* check the trace buffer */
383 ret = trace_test_buffer(&tr->array_buffer, &count);
384
385 ftrace_enabled = 1;
386 tracing_start();
387
388 /* we should only have one item */
389 if (!ret && count != 1) {
390 trace->reset(tr);
391 printk(KERN_CONT ".. filter failed count=%ld ..", count);
392 ret = -1;
393 goto out;
394 }
395
396 /* Test the ops with global tracing running */
397 ret = trace_selftest_ops(tr, 1);
398 trace->reset(tr);
399
400 out:
401 ftrace_enabled = save_ftrace_enabled;
402
403 /* Enable tracing on all functions again */
404 ftrace_set_global_filter(NULL, 0, 1);
405
406 /* Test the ops with global tracing off */
407 if (!ret)
408 ret = trace_selftest_ops(tr, 2);
409
410 return ret;
411}
412
413static int trace_selftest_recursion_cnt;
414static void trace_selftest_test_recursion_func(unsigned long ip,
415 unsigned long pip,
416 struct ftrace_ops *op,
417 struct ftrace_regs *fregs)
418{
419 /*
420 * This function is registered without the recursion safe flag.
421 * The ftrace infrastructure should provide the recursion
422 * protection. If not, this will crash the kernel!
423 */
424 if (trace_selftest_recursion_cnt++ > 10)
425 return;
426 DYN_FTRACE_TEST_NAME();
427}
428
429static void trace_selftest_test_recursion_safe_func(unsigned long ip,
430 unsigned long pip,
431 struct ftrace_ops *op,
432 struct ftrace_regs *fregs)
433{
434 /*
435 * We said we would provide our own recursion. By calling
436 * this function again, we should recurse back into this function
437 * and count again. But this only happens if the arch supports
438 * all of ftrace features and nothing else is using the function
439 * tracing utility.
440 */
441 if (trace_selftest_recursion_cnt++)
442 return;
443 DYN_FTRACE_TEST_NAME();
444}
445
446static struct ftrace_ops test_rec_probe = {
447 .func = trace_selftest_test_recursion_func,
448 .flags = FTRACE_OPS_FL_RECURSION,
449};
450
451static struct ftrace_ops test_recsafe_probe = {
452 .func = trace_selftest_test_recursion_safe_func,
453};
454
455static int
456trace_selftest_function_recursion(void)
457{
458 int save_ftrace_enabled = ftrace_enabled;
459 char *func_name;
460 int len;
461 int ret;
462
463 /* The previous test PASSED */
464 pr_cont("PASSED\n");
465 pr_info("Testing ftrace recursion: ");
466
467
468 /* enable tracing, and record the filter function */
469 ftrace_enabled = 1;
470
471 /* Handle PPC64 '.' name */
472 func_name = "*" __stringify(DYN_FTRACE_TEST_NAME);
473 len = strlen(func_name);
474
475 ret = ftrace_set_filter(&test_rec_probe, func_name, len, 1);
476 if (ret) {
477 pr_cont("*Could not set filter* ");
478 goto out;
479 }
480
481 ret = register_ftrace_function(&test_rec_probe);
482 if (ret) {
483 pr_cont("*could not register callback* ");
484 goto out;
485 }
486
487 DYN_FTRACE_TEST_NAME();
488
489 unregister_ftrace_function(&test_rec_probe);
490
491 ret = -1;
492 /*
493 * Recursion allows for transitions between context,
494 * and may call the callback twice.
495 */
496 if (trace_selftest_recursion_cnt != 1 &&
497 trace_selftest_recursion_cnt != 2) {
498 pr_cont("*callback not called once (or twice) (%d)* ",
499 trace_selftest_recursion_cnt);
500 goto out;
501 }
502
503 trace_selftest_recursion_cnt = 1;
504
505 pr_cont("PASSED\n");
506 pr_info("Testing ftrace recursion safe: ");
507
508 ret = ftrace_set_filter(&test_recsafe_probe, func_name, len, 1);
509 if (ret) {
510 pr_cont("*Could not set filter* ");
511 goto out;
512 }
513
514 ret = register_ftrace_function(&test_recsafe_probe);
515 if (ret) {
516 pr_cont("*could not register callback* ");
517 goto out;
518 }
519
520 DYN_FTRACE_TEST_NAME();
521
522 unregister_ftrace_function(&test_recsafe_probe);
523
524 ret = -1;
525 if (trace_selftest_recursion_cnt != 2) {
526 pr_cont("*callback not called expected 2 times (%d)* ",
527 trace_selftest_recursion_cnt);
528 goto out;
529 }
530
531 ret = 0;
532out:
533 ftrace_enabled = save_ftrace_enabled;
534
535 return ret;
536}
537#else
538# define trace_selftest_startup_dynamic_tracing(trace, tr, func) ({ 0; })
539# define trace_selftest_function_recursion() ({ 0; })
540#endif /* CONFIG_DYNAMIC_FTRACE */
541
542static enum {
543 TRACE_SELFTEST_REGS_START,
544 TRACE_SELFTEST_REGS_FOUND,
545 TRACE_SELFTEST_REGS_NOT_FOUND,
546} trace_selftest_regs_stat;
547
548static void trace_selftest_test_regs_func(unsigned long ip,
549 unsigned long pip,
550 struct ftrace_ops *op,
551 struct ftrace_regs *fregs)
552{
553 struct pt_regs *regs = ftrace_get_regs(fregs);
554
555 if (regs)
556 trace_selftest_regs_stat = TRACE_SELFTEST_REGS_FOUND;
557 else
558 trace_selftest_regs_stat = TRACE_SELFTEST_REGS_NOT_FOUND;
559}
560
561static struct ftrace_ops test_regs_probe = {
562 .func = trace_selftest_test_regs_func,
563 .flags = FTRACE_OPS_FL_SAVE_REGS,
564};
565
566static int
567trace_selftest_function_regs(void)
568{
569 int save_ftrace_enabled = ftrace_enabled;
570 char *func_name;
571 int len;
572 int ret;
573 int supported = 0;
574
575#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
576 supported = 1;
577#endif
578
579 /* The previous test PASSED */
580 pr_cont("PASSED\n");
581 pr_info("Testing ftrace regs%s: ",
582 !supported ? "(no arch support)" : "");
583
584 /* enable tracing, and record the filter function */
585 ftrace_enabled = 1;
586
587 /* Handle PPC64 '.' name */
588 func_name = "*" __stringify(DYN_FTRACE_TEST_NAME);
589 len = strlen(func_name);
590
591 ret = ftrace_set_filter(&test_regs_probe, func_name, len, 1);
592 /*
593 * If DYNAMIC_FTRACE is not set, then we just trace all functions.
594 * This test really doesn't care.
595 */
596 if (ret && ret != -ENODEV) {
597 pr_cont("*Could not set filter* ");
598 goto out;
599 }
600
601 ret = register_ftrace_function(&test_regs_probe);
602 /*
603 * Now if the arch does not support passing regs, then this should
604 * have failed.
605 */
606 if (!supported) {
607 if (!ret) {
608 pr_cont("*registered save-regs without arch support* ");
609 goto out;
610 }
611 test_regs_probe.flags |= FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED;
612 ret = register_ftrace_function(&test_regs_probe);
613 }
614 if (ret) {
615 pr_cont("*could not register callback* ");
616 goto out;
617 }
618
619
620 DYN_FTRACE_TEST_NAME();
621
622 unregister_ftrace_function(&test_regs_probe);
623
624 ret = -1;
625
626 switch (trace_selftest_regs_stat) {
627 case TRACE_SELFTEST_REGS_START:
628 pr_cont("*callback never called* ");
629 goto out;
630
631 case TRACE_SELFTEST_REGS_FOUND:
632 if (supported)
633 break;
634 pr_cont("*callback received regs without arch support* ");
635 goto out;
636
637 case TRACE_SELFTEST_REGS_NOT_FOUND:
638 if (!supported)
639 break;
640 pr_cont("*callback received NULL regs* ");
641 goto out;
642 }
643
644 ret = 0;
645out:
646 ftrace_enabled = save_ftrace_enabled;
647
648 return ret;
649}
650
651/*
652 * Simple verification test of ftrace function tracer.
653 * Enable ftrace, sleep 1/10 second, and then read the trace
654 * buffer to see if all is in order.
655 */
656__init int
657trace_selftest_startup_function(struct tracer *trace, struct trace_array *tr)
658{
659 int save_ftrace_enabled = ftrace_enabled;
660 unsigned long count;
661 int ret;
662
663#ifdef CONFIG_DYNAMIC_FTRACE
664 if (ftrace_filter_param) {
665 printk(KERN_CONT " ... kernel command line filter set: force PASS ... ");
666 return 0;
667 }
668#endif
669
670 /* make sure msleep has been recorded */
671 msleep(1);
672
673 /* start the tracing */
674 ftrace_enabled = 1;
675
676 ret = tracer_init(trace, tr);
677 if (ret) {
678 warn_failed_init_tracer(trace, ret);
679 goto out;
680 }
681
682 /* Sleep for a 1/10 of a second */
683 msleep(100);
684 /* stop the tracing. */
685 tracing_stop();
686 ftrace_enabled = 0;
687
688 /* check the trace buffer */
689 ret = trace_test_buffer(&tr->array_buffer, &count);
690
691 ftrace_enabled = 1;
692 trace->reset(tr);
693 tracing_start();
694
695 if (!ret && !count) {
696 printk(KERN_CONT ".. no entries found ..");
697 ret = -1;
698 goto out;
699 }
700
701 ret = trace_selftest_startup_dynamic_tracing(trace, tr,
702 DYN_FTRACE_TEST_NAME);
703 if (ret)
704 goto out;
705
706 ret = trace_selftest_function_recursion();
707 if (ret)
708 goto out;
709
710 ret = trace_selftest_function_regs();
711 out:
712 ftrace_enabled = save_ftrace_enabled;
713
714 /* kill ftrace totally if we failed */
715 if (ret)
716 ftrace_kill();
717
718 return ret;
719}
720#endif /* CONFIG_FUNCTION_TRACER */
721
722
723#ifdef CONFIG_FUNCTION_GRAPH_TRACER
724
725/* Maximum number of functions to trace before diagnosing a hang */
726#define GRAPH_MAX_FUNC_TEST 100000000
727
728static unsigned int graph_hang_thresh;
729
730/* Wrap the real function entry probe to avoid possible hanging */
731static int trace_graph_entry_watchdog(struct ftrace_graph_ent *trace)
732{
733 /* This is harmlessly racy, we want to approximately detect a hang */
734 if (unlikely(++graph_hang_thresh > GRAPH_MAX_FUNC_TEST)) {
735 ftrace_graph_stop();
736 printk(KERN_WARNING "BUG: Function graph tracer hang!\n");
737 if (ftrace_dump_on_oops) {
738 ftrace_dump(DUMP_ALL);
739 /* ftrace_dump() disables tracing */
740 tracing_on();
741 }
742 return 0;
743 }
744
745 return trace_graph_entry(trace);
746}
747
748static struct fgraph_ops fgraph_ops __initdata = {
749 .entryfunc = &trace_graph_entry_watchdog,
750 .retfunc = &trace_graph_return,
751};
752
753/*
754 * Pretty much the same than for the function tracer from which the selftest
755 * has been borrowed.
756 */
757__init int
758trace_selftest_startup_function_graph(struct tracer *trace,
759 struct trace_array *tr)
760{
761 int ret;
762 unsigned long count;
763
764#ifdef CONFIG_DYNAMIC_FTRACE
765 if (ftrace_filter_param) {
766 printk(KERN_CONT " ... kernel command line filter set: force PASS ... ");
767 return 0;
768 }
769#endif
770
771 /*
772 * Simulate the init() callback but we attach a watchdog callback
773 * to detect and recover from possible hangs
774 */
775 tracing_reset_online_cpus(&tr->array_buffer);
776 set_graph_array(tr);
777 ret = register_ftrace_graph(&fgraph_ops);
778 if (ret) {
779 warn_failed_init_tracer(trace, ret);
780 goto out;
781 }
782 tracing_start_cmdline_record();
783
784 /* Sleep for a 1/10 of a second */
785 msleep(100);
786
787 /* Have we just recovered from a hang? */
788 if (graph_hang_thresh > GRAPH_MAX_FUNC_TEST) {
789 disable_tracing_selftest("recovering from a hang");
790 ret = -1;
791 goto out;
792 }
793
794 tracing_stop();
795
796 /* check the trace buffer */
797 ret = trace_test_buffer(&tr->array_buffer, &count);
798
799 /* Need to also simulate the tr->reset to remove this fgraph_ops */
800 tracing_stop_cmdline_record();
801 unregister_ftrace_graph(&fgraph_ops);
802
803 tracing_start();
804
805 if (!ret && !count) {
806 printk(KERN_CONT ".. no entries found ..");
807 ret = -1;
808 goto out;
809 }
810
811 /* Don't test dynamic tracing, the function tracer already did */
812
813out:
814 /* Stop it if we failed */
815 if (ret)
816 ftrace_graph_stop();
817
818 return ret;
819}
820#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
821
822
823#ifdef CONFIG_IRQSOFF_TRACER
824int
825trace_selftest_startup_irqsoff(struct tracer *trace, struct trace_array *tr)
826{
827 unsigned long save_max = tr->max_latency;
828 unsigned long count;
829 int ret;
830
831 /* start the tracing */
832 ret = tracer_init(trace, tr);
833 if (ret) {
834 warn_failed_init_tracer(trace, ret);
835 return ret;
836 }
837
838 /* reset the max latency */
839 tr->max_latency = 0;
840 /* disable interrupts for a bit */
841 local_irq_disable();
842 udelay(100);
843 local_irq_enable();
844
845 /*
846 * Stop the tracer to avoid a warning subsequent
847 * to buffer flipping failure because tracing_stop()
848 * disables the tr and max buffers, making flipping impossible
849 * in case of parallels max irqs off latencies.
850 */
851 trace->stop(tr);
852 /* stop the tracing. */
853 tracing_stop();
854 /* check both trace buffers */
855 ret = trace_test_buffer(&tr->array_buffer, NULL);
856 if (!ret)
857 ret = trace_test_buffer(&tr->max_buffer, &count);
858 trace->reset(tr);
859 tracing_start();
860
861 if (!ret && !count) {
862 printk(KERN_CONT ".. no entries found ..");
863 ret = -1;
864 }
865
866 tr->max_latency = save_max;
867
868 return ret;
869}
870#endif /* CONFIG_IRQSOFF_TRACER */
871
872#ifdef CONFIG_PREEMPT_TRACER
873int
874trace_selftest_startup_preemptoff(struct tracer *trace, struct trace_array *tr)
875{
876 unsigned long save_max = tr->max_latency;
877 unsigned long count;
878 int ret;
879
880 /*
881 * Now that the big kernel lock is no longer preemptible,
882 * and this is called with the BKL held, it will always
883 * fail. If preemption is already disabled, simply
884 * pass the test. When the BKL is removed, or becomes
885 * preemptible again, we will once again test this,
886 * so keep it in.
887 */
888 if (preempt_count()) {
889 printk(KERN_CONT "can not test ... force ");
890 return 0;
891 }
892
893 /* start the tracing */
894 ret = tracer_init(trace, tr);
895 if (ret) {
896 warn_failed_init_tracer(trace, ret);
897 return ret;
898 }
899
900 /* reset the max latency */
901 tr->max_latency = 0;
902 /* disable preemption for a bit */
903 preempt_disable();
904 udelay(100);
905 preempt_enable();
906
907 /*
908 * Stop the tracer to avoid a warning subsequent
909 * to buffer flipping failure because tracing_stop()
910 * disables the tr and max buffers, making flipping impossible
911 * in case of parallels max preempt off latencies.
912 */
913 trace->stop(tr);
914 /* stop the tracing. */
915 tracing_stop();
916 /* check both trace buffers */
917 ret = trace_test_buffer(&tr->array_buffer, NULL);
918 if (!ret)
919 ret = trace_test_buffer(&tr->max_buffer, &count);
920 trace->reset(tr);
921 tracing_start();
922
923 if (!ret && !count) {
924 printk(KERN_CONT ".. no entries found ..");
925 ret = -1;
926 }
927
928 tr->max_latency = save_max;
929
930 return ret;
931}
932#endif /* CONFIG_PREEMPT_TRACER */
933
934#if defined(CONFIG_IRQSOFF_TRACER) && defined(CONFIG_PREEMPT_TRACER)
935int
936trace_selftest_startup_preemptirqsoff(struct tracer *trace, struct trace_array *tr)
937{
938 unsigned long save_max = tr->max_latency;
939 unsigned long count;
940 int ret;
941
942 /*
943 * Now that the big kernel lock is no longer preemptible,
944 * and this is called with the BKL held, it will always
945 * fail. If preemption is already disabled, simply
946 * pass the test. When the BKL is removed, or becomes
947 * preemptible again, we will once again test this,
948 * so keep it in.
949 */
950 if (preempt_count()) {
951 printk(KERN_CONT "can not test ... force ");
952 return 0;
953 }
954
955 /* start the tracing */
956 ret = tracer_init(trace, tr);
957 if (ret) {
958 warn_failed_init_tracer(trace, ret);
959 goto out_no_start;
960 }
961
962 /* reset the max latency */
963 tr->max_latency = 0;
964
965 /* disable preemption and interrupts for a bit */
966 preempt_disable();
967 local_irq_disable();
968 udelay(100);
969 preempt_enable();
970 /* reverse the order of preempt vs irqs */
971 local_irq_enable();
972
973 /*
974 * Stop the tracer to avoid a warning subsequent
975 * to buffer flipping failure because tracing_stop()
976 * disables the tr and max buffers, making flipping impossible
977 * in case of parallels max irqs/preempt off latencies.
978 */
979 trace->stop(tr);
980 /* stop the tracing. */
981 tracing_stop();
982 /* check both trace buffers */
983 ret = trace_test_buffer(&tr->array_buffer, NULL);
984 if (ret)
985 goto out;
986
987 ret = trace_test_buffer(&tr->max_buffer, &count);
988 if (ret)
989 goto out;
990
991 if (!ret && !count) {
992 printk(KERN_CONT ".. no entries found ..");
993 ret = -1;
994 goto out;
995 }
996
997 /* do the test by disabling interrupts first this time */
998 tr->max_latency = 0;
999 tracing_start();
1000 trace->start(tr);
1001
1002 preempt_disable();
1003 local_irq_disable();
1004 udelay(100);
1005 preempt_enable();
1006 /* reverse the order of preempt vs irqs */
1007 local_irq_enable();
1008
1009 trace->stop(tr);
1010 /* stop the tracing. */
1011 tracing_stop();
1012 /* check both trace buffers */
1013 ret = trace_test_buffer(&tr->array_buffer, NULL);
1014 if (ret)
1015 goto out;
1016
1017 ret = trace_test_buffer(&tr->max_buffer, &count);
1018
1019 if (!ret && !count) {
1020 printk(KERN_CONT ".. no entries found ..");
1021 ret = -1;
1022 goto out;
1023 }
1024
1025out:
1026 tracing_start();
1027out_no_start:
1028 trace->reset(tr);
1029 tr->max_latency = save_max;
1030
1031 return ret;
1032}
1033#endif /* CONFIG_IRQSOFF_TRACER && CONFIG_PREEMPT_TRACER */
1034
1035#ifdef CONFIG_NOP_TRACER
1036int
1037trace_selftest_startup_nop(struct tracer *trace, struct trace_array *tr)
1038{
1039 /* What could possibly go wrong? */
1040 return 0;
1041}
1042#endif
1043
1044#ifdef CONFIG_SCHED_TRACER
1045
1046struct wakeup_test_data {
1047 struct completion is_ready;
1048 int go;
1049};
1050
1051static int trace_wakeup_test_thread(void *data)
1052{
1053 /* Make this a -deadline thread */
1054 static const struct sched_attr attr = {
1055 .sched_policy = SCHED_DEADLINE,
1056 .sched_runtime = 100000ULL,
1057 .sched_deadline = 10000000ULL,
1058 .sched_period = 10000000ULL
1059 };
1060 struct wakeup_test_data *x = data;
1061
1062 sched_setattr(current, &attr);
1063
1064 /* Make it know we have a new prio */
1065 complete(&x->is_ready);
1066
1067 /* now go to sleep and let the test wake us up */
1068 set_current_state(TASK_INTERRUPTIBLE);
1069 while (!x->go) {
1070 schedule();
1071 set_current_state(TASK_INTERRUPTIBLE);
1072 }
1073
1074 complete(&x->is_ready);
1075
1076 set_current_state(TASK_INTERRUPTIBLE);
1077
1078 /* we are awake, now wait to disappear */
1079 while (!kthread_should_stop()) {
1080 schedule();
1081 set_current_state(TASK_INTERRUPTIBLE);
1082 }
1083
1084 __set_current_state(TASK_RUNNING);
1085
1086 return 0;
1087}
1088int
1089trace_selftest_startup_wakeup(struct tracer *trace, struct trace_array *tr)
1090{
1091 unsigned long save_max = tr->max_latency;
1092 struct task_struct *p;
1093 struct wakeup_test_data data;
1094 unsigned long count;
1095 int ret;
1096
1097 memset(&data, 0, sizeof(data));
1098
1099 init_completion(&data.is_ready);
1100
1101 /* create a -deadline thread */
1102 p = kthread_run(trace_wakeup_test_thread, &data, "ftrace-test");
1103 if (IS_ERR(p)) {
1104 printk(KERN_CONT "Failed to create ftrace wakeup test thread ");
1105 return -1;
1106 }
1107
1108 /* make sure the thread is running at -deadline policy */
1109 wait_for_completion(&data.is_ready);
1110
1111 /* start the tracing */
1112 ret = tracer_init(trace, tr);
1113 if (ret) {
1114 warn_failed_init_tracer(trace, ret);
1115 return ret;
1116 }
1117
1118 /* reset the max latency */
1119 tr->max_latency = 0;
1120
1121 while (p->on_rq) {
1122 /*
1123 * Sleep to make sure the -deadline thread is asleep too.
1124 * On virtual machines we can't rely on timings,
1125 * but we want to make sure this test still works.
1126 */
1127 msleep(100);
1128 }
1129
1130 init_completion(&data.is_ready);
1131
1132 data.go = 1;
1133 /* memory barrier is in the wake_up_process() */
1134
1135 wake_up_process(p);
1136
1137 /* Wait for the task to wake up */
1138 wait_for_completion(&data.is_ready);
1139
1140 /* stop the tracing. */
1141 tracing_stop();
1142 /* check both trace buffers */
1143 ret = trace_test_buffer(&tr->array_buffer, NULL);
1144 if (!ret)
1145 ret = trace_test_buffer(&tr->max_buffer, &count);
1146
1147
1148 trace->reset(tr);
1149 tracing_start();
1150
1151 tr->max_latency = save_max;
1152
1153 /* kill the thread */
1154 kthread_stop(p);
1155
1156 if (!ret && !count) {
1157 printk(KERN_CONT ".. no entries found ..");
1158 ret = -1;
1159 }
1160
1161 return ret;
1162}
1163#endif /* CONFIG_SCHED_TRACER */
1164
1165#ifdef CONFIG_BRANCH_TRACER
1166int
1167trace_selftest_startup_branch(struct tracer *trace, struct trace_array *tr)
1168{
1169 unsigned long count;
1170 int ret;
1171
1172 /* start the tracing */
1173 ret = tracer_init(trace, tr);
1174 if (ret) {
1175 warn_failed_init_tracer(trace, ret);
1176 return ret;
1177 }
1178
1179 /* Sleep for a 1/10 of a second */
1180 msleep(100);
1181 /* stop the tracing. */
1182 tracing_stop();
1183 /* check the trace buffer */
1184 ret = trace_test_buffer(&tr->array_buffer, &count);
1185 trace->reset(tr);
1186 tracing_start();
1187
1188 if (!ret && !count) {
1189 printk(KERN_CONT ".. no entries found ..");
1190 ret = -1;
1191 }
1192
1193 return ret;
1194}
1195#endif /* CONFIG_BRANCH_TRACER */
1196