1 /* Include in trace.c */
3 #include <linux/kthread.h>
4 #include <linux/delay.h>
6 static inline int trace_valid_entry(struct trace_entry *entry)
21 static int trace_test_buffer_cpu(struct trace_array *tr, int cpu)
23 struct ring_buffer_event *event;
24 struct trace_entry *entry;
26 while ((event = ring_buffer_consume(tr->buffer, cpu, NULL))) {
27 entry = ring_buffer_event_data(event);
29 if (!trace_valid_entry(entry)) {
30 printk(KERN_CONT ".. invalid entry %d ",
40 printk(KERN_CONT ".. corrupted trace buffer .. ");
45 * Test the trace buffer to see if all the elements
48 static int trace_test_buffer(struct trace_array *tr, unsigned long *count)
50 unsigned long flags, cnt = 0;
53 /* Don't allow flipping of max traces now */
54 local_irq_save(flags);
55 __raw_spin_lock(&ftrace_max_lock);
57 cnt = ring_buffer_entries(tr->buffer);
59 for_each_possible_cpu(cpu) {
60 ret = trace_test_buffer_cpu(tr, cpu);
64 __raw_spin_unlock(&ftrace_max_lock);
65 local_irq_restore(flags);
73 static inline void warn_failed_init_tracer(struct tracer *trace, int init_ret)
75 printk(KERN_WARNING "Failed to init %s tracer, init returned %d\n",
76 trace->name, init_ret);
78 #ifdef CONFIG_FUNCTION_TRACER
80 #ifdef CONFIG_DYNAMIC_FTRACE
83 #define STR(x) __STR(x)
85 /* Test dynamic code modification and ftrace filters */
86 int trace_selftest_startup_dynamic_tracing(struct tracer *trace,
87 struct trace_array *tr,
90 int save_ftrace_enabled = ftrace_enabled;
91 int save_tracer_enabled = tracer_enabled;
96 /* The ftrace test PASSED */
97 printk(KERN_CONT "PASSED\n");
98 pr_info("Testing dynamic ftrace: ");
100 /* enable tracing, and record the filter function */
104 /* passed in by parameter to fool gcc from optimizing */
108 * Some archs *cough*PowerPC*cough* add charachters to the
109 * start of the function names. We simply put a '*' to
112 func_name = "*" STR(DYN_FTRACE_TEST_NAME);
114 /* filter only on our function */
115 ftrace_set_filter(func_name, strlen(func_name), 1);
118 ret = trace->init(tr);
120 warn_failed_init_tracer(trace, ret);
124 /* Sleep for a 1/10 of a second */
127 /* we should have nothing in the buffer */
128 ret = trace_test_buffer(tr, &count);
134 printk(KERN_CONT ".. filter did not filter .. ");
138 /* call our function again */
144 /* stop the tracing. */
148 /* check the trace buffer */
149 ret = trace_test_buffer(tr, &count);
153 /* we should only have one item */
154 if (!ret && count != 1) {
155 printk(KERN_CONT ".. filter failed count=%ld ..", count);
161 ftrace_enabled = save_ftrace_enabled;
162 tracer_enabled = save_tracer_enabled;
164 /* Enable tracing on all functions again */
165 ftrace_set_filter(NULL, 0, 1);
170 # define trace_selftest_startup_dynamic_tracing(trace, tr, func) ({ 0; })
171 #endif /* CONFIG_DYNAMIC_FTRACE */
173 * Simple verification test of ftrace function tracer.
174 * Enable ftrace, sleep 1/10 second, and then read the trace
175 * buffer to see if all is in order.
178 trace_selftest_startup_function(struct tracer *trace, struct trace_array *tr)
180 int save_ftrace_enabled = ftrace_enabled;
181 int save_tracer_enabled = tracer_enabled;
185 /* make sure msleep has been recorded */
188 /* start the tracing */
192 ret = trace->init(tr);
194 warn_failed_init_tracer(trace, ret);
198 /* Sleep for a 1/10 of a second */
200 /* stop the tracing. */
204 /* check the trace buffer */
205 ret = trace_test_buffer(tr, &count);
209 if (!ret && !count) {
210 printk(KERN_CONT ".. no entries found ..");
215 ret = trace_selftest_startup_dynamic_tracing(trace, tr,
216 DYN_FTRACE_TEST_NAME);
219 ftrace_enabled = save_ftrace_enabled;
220 tracer_enabled = save_tracer_enabled;
222 /* kill ftrace totally if we failed */
228 #endif /* CONFIG_FUNCTION_TRACER */
230 #ifdef CONFIG_IRQSOFF_TRACER
232 trace_selftest_startup_irqsoff(struct tracer *trace, struct trace_array *tr)
234 unsigned long save_max = tracing_max_latency;
238 /* start the tracing */
239 ret = trace->init(tr);
241 warn_failed_init_tracer(trace, ret);
245 /* reset the max latency */
246 tracing_max_latency = 0;
247 /* disable interrupts for a bit */
251 /* stop the tracing. */
253 /* check both trace buffers */
254 ret = trace_test_buffer(tr, NULL);
256 ret = trace_test_buffer(&max_tr, &count);
260 if (!ret && !count) {
261 printk(KERN_CONT ".. no entries found ..");
265 tracing_max_latency = save_max;
269 #endif /* CONFIG_IRQSOFF_TRACER */
271 #ifdef CONFIG_PREEMPT_TRACER
273 trace_selftest_startup_preemptoff(struct tracer *trace, struct trace_array *tr)
275 unsigned long save_max = tracing_max_latency;
280 * Now that the big kernel lock is no longer preemptable,
281 * and this is called with the BKL held, it will always
282 * fail. If preemption is already disabled, simply
283 * pass the test. When the BKL is removed, or becomes
284 * preemptible again, we will once again test this,
287 if (preempt_count()) {
288 printk(KERN_CONT "can not test ... force ");
292 /* start the tracing */
293 ret = trace->init(tr);
295 warn_failed_init_tracer(trace, ret);
299 /* reset the max latency */
300 tracing_max_latency = 0;
301 /* disable preemption for a bit */
305 /* stop the tracing. */
307 /* check both trace buffers */
308 ret = trace_test_buffer(tr, NULL);
310 ret = trace_test_buffer(&max_tr, &count);
314 if (!ret && !count) {
315 printk(KERN_CONT ".. no entries found ..");
319 tracing_max_latency = save_max;
323 #endif /* CONFIG_PREEMPT_TRACER */
325 #if defined(CONFIG_IRQSOFF_TRACER) && defined(CONFIG_PREEMPT_TRACER)
327 trace_selftest_startup_preemptirqsoff(struct tracer *trace, struct trace_array *tr)
329 unsigned long save_max = tracing_max_latency;
334 * Now that the big kernel lock is no longer preemptable,
335 * and this is called with the BKL held, it will always
336 * fail. If preemption is already disabled, simply
337 * pass the test. When the BKL is removed, or becomes
338 * preemptible again, we will once again test this,
341 if (preempt_count()) {
342 printk(KERN_CONT "can not test ... force ");
346 /* start the tracing */
347 ret = trace->init(tr);
349 warn_failed_init_tracer(trace, ret);
353 /* reset the max latency */
354 tracing_max_latency = 0;
356 /* disable preemption and interrupts for a bit */
361 /* reverse the order of preempt vs irqs */
364 /* stop the tracing. */
366 /* check both trace buffers */
367 ret = trace_test_buffer(tr, NULL);
373 ret = trace_test_buffer(&max_tr, &count);
379 if (!ret && !count) {
380 printk(KERN_CONT ".. no entries found ..");
386 /* do the test by disabling interrupts first this time */
387 tracing_max_latency = 0;
393 /* reverse the order of preempt vs irqs */
396 /* stop the tracing. */
398 /* check both trace buffers */
399 ret = trace_test_buffer(tr, NULL);
403 ret = trace_test_buffer(&max_tr, &count);
405 if (!ret && !count) {
406 printk(KERN_CONT ".. no entries found ..");
414 tracing_max_latency = save_max;
418 #endif /* CONFIG_IRQSOFF_TRACER && CONFIG_PREEMPT_TRACER */
420 #ifdef CONFIG_NOP_TRACER
422 trace_selftest_startup_nop(struct tracer *trace, struct trace_array *tr)
424 /* What could possibly go wrong? */
429 #ifdef CONFIG_SCHED_TRACER
430 static int trace_wakeup_test_thread(void *data)
432 /* Make this a RT thread, doesn't need to be too high */
433 struct sched_param param = { .sched_priority = 5 };
434 struct completion *x = data;
436 sched_setscheduler(current, SCHED_FIFO, ¶m);
438 /* Make it know we have a new prio */
441 /* now go to sleep and let the test wake us up */
442 set_current_state(TASK_INTERRUPTIBLE);
445 /* we are awake, now wait to disappear */
446 while (!kthread_should_stop()) {
448 * This is an RT task, do short sleeps to let
458 trace_selftest_startup_wakeup(struct tracer *trace, struct trace_array *tr)
460 unsigned long save_max = tracing_max_latency;
461 struct task_struct *p;
462 struct completion isrt;
466 init_completion(&isrt);
468 /* create a high prio thread */
469 p = kthread_run(trace_wakeup_test_thread, &isrt, "ftrace-test");
471 printk(KERN_CONT "Failed to create ftrace wakeup test thread ");
475 /* make sure the thread is running at an RT prio */
476 wait_for_completion(&isrt);
478 /* start the tracing */
479 ret = trace->init(tr);
481 warn_failed_init_tracer(trace, ret);
485 /* reset the max latency */
486 tracing_max_latency = 0;
488 /* sleep to let the RT thread sleep too */
492 * Yes this is slightly racy. It is possible that for some
493 * strange reason that the RT thread we created, did not
494 * call schedule for 100ms after doing the completion,
495 * and we do a wakeup on a task that already is awake.
496 * But that is extremely unlikely, and the worst thing that
497 * happens in such a case, is that we disable tracing.
498 * Honestly, if this race does happen something is horrible
499 * wrong with the system.
504 /* give a little time to let the thread wake up */
507 /* stop the tracing. */
509 /* check both trace buffers */
510 ret = trace_test_buffer(tr, NULL);
512 ret = trace_test_buffer(&max_tr, &count);
518 tracing_max_latency = save_max;
520 /* kill the thread */
523 if (!ret && !count) {
524 printk(KERN_CONT ".. no entries found ..");
530 #endif /* CONFIG_SCHED_TRACER */
532 #ifdef CONFIG_CONTEXT_SWITCH_TRACER
534 trace_selftest_startup_sched_switch(struct tracer *trace, struct trace_array *tr)
539 /* start the tracing */
540 ret = trace->init(tr);
542 warn_failed_init_tracer(trace, ret);
546 /* Sleep for a 1/10 of a second */
548 /* stop the tracing. */
550 /* check the trace buffer */
551 ret = trace_test_buffer(tr, &count);
555 if (!ret && !count) {
556 printk(KERN_CONT ".. no entries found ..");
562 #endif /* CONFIG_CONTEXT_SWITCH_TRACER */
564 #ifdef CONFIG_SYSPROF_TRACER
566 trace_selftest_startup_sysprof(struct tracer *trace, struct trace_array *tr)
571 /* start the tracing */
572 ret = trace->init(tr);
574 warn_failed_init_tracer(trace, ret);
578 /* Sleep for a 1/10 of a second */
580 /* stop the tracing. */
582 /* check the trace buffer */
583 ret = trace_test_buffer(tr, &count);
589 #endif /* CONFIG_SYSPROF_TRACER */
591 #ifdef CONFIG_BRANCH_TRACER
593 trace_selftest_startup_branch(struct tracer *trace, struct trace_array *tr)
598 /* start the tracing */
599 ret = trace->init(tr);
601 warn_failed_init_tracer(trace, ret);
605 /* Sleep for a 1/10 of a second */
607 /* stop the tracing. */
609 /* check the trace buffer */
610 ret = trace_test_buffer(tr, &count);
616 #endif /* CONFIG_BRANCH_TRACER */