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