[mirror_ubuntu-bionic-kernel.git] / kernel / trace / trace_selftest.c

/* Include in trace.c */

#include <linux/kthread.h>
#include <linux/delay.h>

static inline int trace_valid_entry(struct trace_entry *entry)
{
	switch (entry->type) {
	case TRACE_FN:
	case TRACE_CTX:
	case TRACE_WAKE:
	case TRACE_CONT:
	case TRACE_STACK:
	case TRACE_PRINT:
	case TRACE_SPECIAL:
		return 1;
	}
	return 0;
}

static int trace_test_buffer_cpu(struct trace_array *tr, int cpu)
{
	struct ring_buffer_event *event;
	struct trace_entry *entry;

	while ((event = ring_buffer_consume(tr->buffer, cpu, NULL))) {
		entry = ring_buffer_event_data(event);

		if (!trace_valid_entry(entry)) {
			printk(KERN_CONT ".. invalid entry %d ",
				entry->type);
			goto failed;
		}
	}
	return 0;

 failed:
	/* disable tracing */
	tracing_disabled = 1;
	printk(KERN_CONT ".. corrupted trace buffer .. ");
	return -1;
}

/*
 * Test the trace buffer to see if all the elements
 * are still sane.
 */
static int trace_test_buffer(struct trace_array *tr, unsigned long *count)
{
	unsigned long flags, cnt = 0;
	int cpu, ret = 0;

	/* Don't allow flipping of max traces now */
	raw_local_irq_save(flags);
	__raw_spin_lock(&ftrace_max_lock);

	cnt = ring_buffer_entries(tr->buffer);

	for_each_possible_cpu(cpu) {
		ret = trace_test_buffer_cpu(tr, cpu);
		if (ret)
			break;
	}
	__raw_spin_unlock(&ftrace_max_lock);
	raw_local_irq_restore(flags);

	if (count)
		*count = cnt;

	return ret;
}

#ifdef CONFIG_FUNCTION_TRACER

#ifdef CONFIG_DYNAMIC_FTRACE

#define __STR(x) #x
#define STR(x) __STR(x)

/* Test dynamic code modification and ftrace filters */
int trace_selftest_startup_dynamic_tracing(struct tracer *trace,
					   struct trace_array *tr,
					   int (*func)(void))
{
	int save_ftrace_enabled = ftrace_enabled;
	int save_tracer_enabled = tracer_enabled;
	unsigned long count;
	char *func_name;
	int ret;

	/* The ftrace test PASSED */
	printk(KERN_CONT "PASSED\n");
	pr_info("Testing dynamic ftrace: ");

	/* enable tracing, and record the filter function */
	ftrace_enabled = 1;
	tracer_enabled = 1;

	/* passed in by parameter to fool gcc from optimizing */
	func();

	/*
	 * Some archs *cough*PowerPC*cough* add charachters to the
	 * start of the function names. We simply put a '*' to
	 * accomodate them.
	 */
	func_name = "*" STR(DYN_FTRACE_TEST_NAME);

	/* filter only on our function */
	ftrace_set_filter(func_name, strlen(func_name), 1);

	/* enable tracing */
	tr->ctrl = 1;
	trace->init(tr);

	/* Sleep for a 1/10 of a second */
	msleep(100);

	/* we should have nothing in the buffer */
	ret = trace_test_buffer(tr, &count);
	if (ret)
		goto out;

	if (count) {
		ret = -1;
		printk(KERN_CONT ".. filter did not filter .. ");
		goto out;
	}

	/* call our function again */
	func();

	/* sleep again */
	msleep(100);

	/* stop the tracing. */
	tracing_stop();
	ftrace_enabled = 0;

	/* check the trace buffer */
	ret = trace_test_buffer(tr, &count);
	trace->reset(tr);
	tracing_start();

	/* we should only have one item */
	if (!ret && count != 1) {
		printk(KERN_CONT ".. filter failed count=%ld ..", count);
		ret = -1;
		goto out;
	}

 out:
	ftrace_enabled = save_ftrace_enabled;
	tracer_enabled = save_tracer_enabled;

	/* Enable tracing on all functions again */
	ftrace_set_filter(NULL, 0, 1);

	return ret;
}
#else
# define trace_selftest_startup_dynamic_tracing(trace, tr, func) ({ 0; })
#endif /* CONFIG_DYNAMIC_FTRACE */
/*
 * Simple verification test of ftrace function tracer.
 * Enable ftrace, sleep 1/10 second, and then read the trace
 * buffer to see if all is in order.
 */
int
trace_selftest_startup_function(struct tracer *trace, struct trace_array *tr)
{
	int save_ftrace_enabled = ftrace_enabled;
	int save_tracer_enabled = tracer_enabled;
	unsigned long count;
	int ret;

	/* make sure msleep has been recorded */
	msleep(1);

	/* start the tracing */
	ftrace_enabled = 1;
	tracer_enabled = 1;

	tr->ctrl = 1;
	trace->init(tr);
	/* Sleep for a 1/10 of a second */
	msleep(100);
	/* stop the tracing. */
	tracing_stop();
	ftrace_enabled = 0;

	/* check the trace buffer */
	ret = trace_test_buffer(tr, &count);
	trace->reset(tr);
	tracing_start();

	if (!ret && !count) {
		printk(KERN_CONT ".. no entries found ..");
		ret = -1;
		goto out;
	}

	ret = trace_selftest_startup_dynamic_tracing(trace, tr,
						     DYN_FTRACE_TEST_NAME);

 out:
	ftrace_enabled = save_ftrace_enabled;
	tracer_enabled = save_tracer_enabled;

	/* kill ftrace totally if we failed */
	if (ret)
		ftrace_kill();

	return ret;
}
#endif /* CONFIG_FUNCTION_TRACER */

#ifdef CONFIG_IRQSOFF_TRACER
int
trace_selftest_startup_irqsoff(struct tracer *trace, struct trace_array *tr)
{
	unsigned long save_max = tracing_max_latency;
	unsigned long count;
	int ret;

	/* start the tracing */
	tr->ctrl = 1;
	trace->init(tr);
	/* reset the max latency */
	tracing_max_latency = 0;
	/* disable interrupts for a bit */
	local_irq_disable();
	udelay(100);
	local_irq_enable();
	/* stop the tracing. */
	tracing_stop();
	/* check both trace buffers */
	ret = trace_test_buffer(tr, NULL);
	if (!ret)
		ret = trace_test_buffer(&max_tr, &count);
	trace->reset(tr);
	tracing_start();

	if (!ret && !count) {
		printk(KERN_CONT ".. no entries found ..");
		ret = -1;
	}

	tracing_max_latency = save_max;

	return ret;
}
#endif /* CONFIG_IRQSOFF_TRACER */

#ifdef CONFIG_PREEMPT_TRACER
int
trace_selftest_startup_preemptoff(struct tracer *trace, struct trace_array *tr)
{
	unsigned long save_max = tracing_max_latency;
	unsigned long count;
	int ret;

	/* start the tracing */
	tr->ctrl = 1;
	trace->init(tr);
	/* reset the max latency */
	tracing_max_latency = 0;
	/* disable preemption for a bit */
	preempt_disable();
	udelay(100);
	preempt_enable();
	/* stop the tracing. */
	tracing_stop();
	/* check both trace buffers */
	ret = trace_test_buffer(tr, NULL);
	if (!ret)
		ret = trace_test_buffer(&max_tr, &count);
	trace->reset(tr);
	tracing_start();

	if (!ret && !count) {
		printk(KERN_CONT ".. no entries found ..");
		ret = -1;
	}

	tracing_max_latency = save_max;

	return ret;
}
#endif /* CONFIG_PREEMPT_TRACER */

#if defined(CONFIG_IRQSOFF_TRACER) && defined(CONFIG_PREEMPT_TRACER)
int
trace_selftest_startup_preemptirqsoff(struct tracer *trace, struct trace_array *tr)
{
	unsigned long save_max = tracing_max_latency;
	unsigned long count;
	int ret;

	/* start the tracing */
	tr->ctrl = 1;
	trace->init(tr);

	/* reset the max latency */
	tracing_max_latency = 0;

	/* disable preemption and interrupts for a bit */
	preempt_disable();
	local_irq_disable();
	udelay(100);
	preempt_enable();
	/* reverse the order of preempt vs irqs */
	local_irq_enable();

	/* stop the tracing. */
	tracing_stop();
	/* check both trace buffers */
	ret = trace_test_buffer(tr, NULL);
	if (ret) {
		tracing_start();
		goto out;
	}

	ret = trace_test_buffer(&max_tr, &count);
	if (ret) {
		tracing_start();
		goto out;
	}

	if (!ret && !count) {
		printk(KERN_CONT ".. no entries found ..");
		ret = -1;
		tracing_start();
		goto out;
	}

	/* do the test by disabling interrupts first this time */
	tracing_max_latency = 0;
	tracing_start();
	preempt_disable();
	local_irq_disable();
	udelay(100);
	preempt_enable();
	/* reverse the order of preempt vs irqs */
	local_irq_enable();

	/* stop the tracing. */
	tracing_stop();
	/* check both trace buffers */
	ret = trace_test_buffer(tr, NULL);
	if (ret)
		goto out;

	ret = trace_test_buffer(&max_tr, &count);

	if (!ret && !count) {
		printk(KERN_CONT ".. no entries found ..");
		ret = -1;
		goto out;
	}

 out:
	trace->reset(tr);
	tracing_start();
	tracing_max_latency = save_max;

	return ret;
}
#endif /* CONFIG_IRQSOFF_TRACER && CONFIG_PREEMPT_TRACER */

#ifdef CONFIG_NOP_TRACER
int
trace_selftest_startup_nop(struct tracer *trace, struct trace_array *tr)
{
	/* What could possibly go wrong? */
	return 0;
}
#endif

#ifdef CONFIG_SCHED_TRACER
static int trace_wakeup_test_thread(void *data)
{
	/* Make this a RT thread, doesn't need to be too high */
	struct sched_param param = { .sched_priority = 5 };
	struct completion *x = data;

	sched_setscheduler(current, SCHED_FIFO, &param);

	/* Make it know we have a new prio */
	complete(x);

	/* now go to sleep and let the test wake us up */
	set_current_state(TASK_INTERRUPTIBLE);
	schedule();

	/* we are awake, now wait to disappear */
	while (!kthread_should_stop()) {
		/*
		 * This is an RT task, do short sleeps to let
		 * others run.
		 */
		msleep(100);
	}

	return 0;
}

int
trace_selftest_startup_wakeup(struct tracer *trace, struct trace_array *tr)
{
	unsigned long save_max = tracing_max_latency;
	struct task_struct *p;
	struct completion isrt;
	unsigned long count;
	int ret;

	init_completion(&isrt);

	/* create a high prio thread */
	p = kthread_run(trace_wakeup_test_thread, &isrt, "ftrace-test");
	if (IS_ERR(p)) {
		printk(KERN_CONT "Failed to create ftrace wakeup test thread ");
		return -1;
	}

	/* make sure the thread is running at an RT prio */
	wait_for_completion(&isrt);

	/* start the tracing */
	tr->ctrl = 1;
	trace->init(tr);
	/* reset the max latency */
	tracing_max_latency = 0;

	/* sleep to let the RT thread sleep too */
	msleep(100);

	/*
	 * Yes this is slightly racy. It is possible that for some
	 * strange reason that the RT thread we created, did not
	 * call schedule for 100ms after doing the completion,
	 * and we do a wakeup on a task that already is awake.
	 * But that is extremely unlikely, and the worst thing that
	 * happens in such a case, is that we disable tracing.
	 * Honestly, if this race does happen something is horrible
	 * wrong with the system.
	 */

	wake_up_process(p);

	/* give a little time to let the thread wake up */
	msleep(100);

	/* stop the tracing. */
	tracing_stop();
	/* check both trace buffers */
	ret = trace_test_buffer(tr, NULL);
	if (!ret)
		ret = trace_test_buffer(&max_tr, &count);


	trace->reset(tr);
	tracing_start();

	tracing_max_latency = save_max;

	/* kill the thread */
	kthread_stop(p);

	if (!ret && !count) {
		printk(KERN_CONT ".. no entries found ..");
		ret = -1;
	}

	return ret;
}
#endif /* CONFIG_SCHED_TRACER */

#ifdef CONFIG_CONTEXT_SWITCH_TRACER
int
trace_selftest_startup_sched_switch(struct tracer *trace, struct trace_array *tr)
{
	unsigned long count;
	int ret;

	/* start the tracing */
	tr->ctrl = 1;
	trace->init(tr);
	/* Sleep for a 1/10 of a second */
	msleep(100);
	/* stop the tracing. */
	tracing_stop();
	/* check the trace buffer */
	ret = trace_test_buffer(tr, &count);
	trace->reset(tr);
	tracing_start();

	if (!ret && !count) {
		printk(KERN_CONT ".. no entries found ..");
		ret = -1;
	}

	return ret;
}
#endif /* CONFIG_CONTEXT_SWITCH_TRACER */

#ifdef CONFIG_SYSPROF_TRACER
int
trace_selftest_startup_sysprof(struct tracer *trace, struct trace_array *tr)
{
	unsigned long count;
	int ret;

	/* start the tracing */
	tr->ctrl = 1;
	trace->init(tr);
	/* Sleep for a 1/10 of a second */
	msleep(100);
	/* stop the tracing. */
	tracing_stop();
	/* check the trace buffer */
	ret = trace_test_buffer(tr, &count);
	trace->reset(tr);
	tracing_start();

	return ret;
}
#endif /* CONFIG_SYSPROF_TRACER */
Commit	Line	Data
60a11774 SR	1	/* Include in trace.c */
	2
	3	#include <linux/kthread.h>
c7aafc54	4	#include <linux/delay.h>
60a11774	5
e309b41d	6	static inline int trace_valid_entry(struct trace_entry *entry)
60a11774 SR	7	{
	8	switch (entry->type) {
	9	case TRACE_FN:
	10	case TRACE_CTX:
57422797	11	case TRACE_WAKE:
dd0e545f	12	case TRACE_CONT:
06fa75ab	13	case TRACE_STACK:
dd0e545f	14	case TRACE_PRINT:
06fa75ab	15	case TRACE_SPECIAL:
60a11774 SR	16	return 1;
	17	}
	18	return 0;
	19	}
	20
3928a8a2	21	static int trace_test_buffer_cpu(struct trace_array *tr, int cpu)
60a11774	22	{
3928a8a2 SR	23	struct ring_buffer_event *event;
3928a8a2 SR	24	struct trace_entry *entry;
60a11774	25
3928a8a2 SR	26	while ((event = ring_buffer_consume(tr->buffer, cpu, NULL))) {
3928a8a2 SR	27	entry = ring_buffer_event_data(event);
60a11774	28
3928a8a2	29	if (!trace_valid_entry(entry)) {
c7aafc54	30	printk(KERN_CONT ".. invalid entry %d ",
3928a8a2	31	entry->type);
60a11774 SR	32	goto failed;
60a11774 SR	33	}
60a11774	34	}
60a11774 SR	35	return 0;
	36
	37	failed:
08bafa0e SR	38	/* disable tracing */
08bafa0e SR	39	tracing_disabled = 1;
60a11774 SR	40	printk(KERN_CONT ".. corrupted trace buffer .. ");
	41	return -1;
	42	}
	43
	44	/*
	45	* Test the trace buffer to see if all the elements
	46	* are still sane.
	47	*/
	48	static int trace_test_buffer(struct trace_array tr, unsigned long count)
	49	{
30afdcb1 SR	50	unsigned long flags, cnt = 0;
30afdcb1 SR	51	int cpu, ret = 0;
60a11774	52
30afdcb1 SR	53	/* Don't allow flipping of max traces now */
	54	raw_local_irq_save(flags);
	55	__raw_spin_lock(&ftrace_max_lock);
60a11774	56
3928a8a2	57	cnt = ring_buffer_entries(tr->buffer);
60a11774	58
3928a8a2 SR	59	for_each_possible_cpu(cpu) {
3928a8a2 SR	60	ret = trace_test_buffer_cpu(tr, cpu);
60a11774 SR	61	if (ret)
	62	break;
	63	}
30afdcb1 SR	64	__raw_spin_unlock(&ftrace_max_lock);
30afdcb1 SR	65	raw_local_irq_restore(flags);
60a11774 SR	66
	67	if (count)
	68	*count = cnt;
	69
	70	return ret;
	71	}
	72
606576ce	73	#ifdef CONFIG_FUNCTION_TRACER
77a2b37d SR	74
	75	#ifdef CONFIG_DYNAMIC_FTRACE
	76
77a2b37d SR	77	#define __STR(x) #x
77a2b37d SR	78	#define STR(x) __STR(x)
77a2b37d SR	79
	80	/* Test dynamic code modification and ftrace filters */
	81	int trace_selftest_startup_dynamic_tracing(struct tracer *trace,
	82	struct trace_array *tr,
	83	int (*func)(void))
	84	{
77a2b37d SR	85	int save_ftrace_enabled = ftrace_enabled;
77a2b37d SR	86	int save_tracer_enabled = tracer_enabled;
dd0e545f	87	unsigned long count;
4e491d14	88	char *func_name;
dd0e545f	89	int ret;
77a2b37d SR	90
	91	/* The ftrace test PASSED */
	92	printk(KERN_CONT "PASSED\n");
	93	pr_info("Testing dynamic ftrace: ");
	94
	95	/* enable tracing, and record the filter function */
	96	ftrace_enabled = 1;
	97	tracer_enabled = 1;
	98
	99	/* passed in by parameter to fool gcc from optimizing */
	100	func();
	101
4e491d14 SR	102	/*
	103	* Some archs coughPowerPCcough add charachters to the
	104	* start of the function names. We simply put a '*' to
	105	* accomodate them.
	106	*/
	107	func_name = "*" STR(DYN_FTRACE_TEST_NAME);
	108
77a2b37d	109	/* filter only on our function */
4e491d14	110	ftrace_set_filter(func_name, strlen(func_name), 1);
77a2b37d SR	111
	112	/* enable tracing */
	113	tr->ctrl = 1;
	114	trace->init(tr);
dd0e545f	115
77a2b37d SR	116	/* Sleep for a 1/10 of a second */
	117	msleep(100);
	118
	119	/* we should have nothing in the buffer */
	120	ret = trace_test_buffer(tr, &count);
	121	if (ret)
	122	goto out;
	123
	124	if (count) {
	125	ret = -1;
	126	printk(KERN_CONT ".. filter did not filter .. ");
	127	goto out;
	128	}
	129
	130	/* call our function again */
	131	func();
	132
	133	/* sleep again */
	134	msleep(100);
	135
	136	/* stop the tracing. */
bbf5b1a0	137	tracing_stop();
77a2b37d SR	138	ftrace_enabled = 0;
	139
	140	/* check the trace buffer */
	141	ret = trace_test_buffer(tr, &count);
	142	trace->reset(tr);
bbf5b1a0	143	tracing_start();
77a2b37d SR	144
	145	/* we should only have one item */
	146	if (!ret && count != 1) {
06fa75ab	147	printk(KERN_CONT ".. filter failed count=%ld ..", count);
77a2b37d SR	148	ret = -1;
	149	goto out;
	150	}
bbf5b1a0	151
77a2b37d SR	152	out:
	153	ftrace_enabled = save_ftrace_enabled;
	154	tracer_enabled = save_tracer_enabled;
	155
	156	/* Enable tracing on all functions again */
	157	ftrace_set_filter(NULL, 0, 1);
	158
	159	return ret;
	160	}
	161	#else
	162	# define trace_selftest_startup_dynamic_tracing(trace, tr, func) ({ 0; })
	163	#endif /* CONFIG_DYNAMIC_FTRACE */
60a11774 SR	164	/*
	165	* Simple verification test of ftrace function tracer.
	166	* Enable ftrace, sleep 1/10 second, and then read the trace
	167	* buffer to see if all is in order.
	168	*/
	169	int
	170	trace_selftest_startup_function(struct tracer trace, struct trace_array tr)
	171	{
77a2b37d SR	172	int save_ftrace_enabled = ftrace_enabled;
77a2b37d SR	173	int save_tracer_enabled = tracer_enabled;
dd0e545f SR	174	unsigned long count;
dd0e545f SR	175	int ret;
60a11774	176
77a2b37d SR	177	/* make sure msleep has been recorded */
	178	msleep(1);
	179
60a11774	180	/* start the tracing */
c7aafc54	181	ftrace_enabled = 1;
77a2b37d	182	tracer_enabled = 1;
c7aafc54	183
60a11774 SR	184	tr->ctrl = 1;
	185	trace->init(tr);
	186	/* Sleep for a 1/10 of a second */
	187	msleep(100);
	188	/* stop the tracing. */
bbf5b1a0	189	tracing_stop();
c7aafc54 IM	190	ftrace_enabled = 0;
c7aafc54 IM	191
60a11774 SR	192	/* check the trace buffer */
	193	ret = trace_test_buffer(tr, &count);
	194	trace->reset(tr);
bbf5b1a0	195	tracing_start();
60a11774 SR	196
	197	if (!ret && !count) {
	198	printk(KERN_CONT ".. no entries found ..");
	199	ret = -1;
77a2b37d	200	goto out;
60a11774 SR	201	}
60a11774 SR	202
77a2b37d SR	203	ret = trace_selftest_startup_dynamic_tracing(trace, tr,
	204	DYN_FTRACE_TEST_NAME);
	205
	206	out:
	207	ftrace_enabled = save_ftrace_enabled;
	208	tracer_enabled = save_tracer_enabled;
	209
4eebcc81 SR	210	/* kill ftrace totally if we failed */
	211	if (ret)
	212	ftrace_kill();
	213
60a11774 SR	214	return ret;
60a11774 SR	215	}
606576ce	216	#endif /* CONFIG_FUNCTION_TRACER */
60a11774 SR	217
	218	#ifdef CONFIG_IRQSOFF_TRACER
	219	int
	220	trace_selftest_startup_irqsoff(struct tracer trace, struct trace_array tr)
	221	{
	222	unsigned long save_max = tracing_max_latency;
	223	unsigned long count;
	224	int ret;
	225
	226	/* start the tracing */
	227	tr->ctrl = 1;
	228	trace->init(tr);
	229	/* reset the max latency */
	230	tracing_max_latency = 0;
	231	/* disable interrupts for a bit */
	232	local_irq_disable();
	233	udelay(100);
	234	local_irq_enable();
	235	/* stop the tracing. */
bbf5b1a0	236	tracing_stop();
60a11774 SR	237	/* check both trace buffers */
	238	ret = trace_test_buffer(tr, NULL);
	239	if (!ret)
	240	ret = trace_test_buffer(&max_tr, &count);
	241	trace->reset(tr);
bbf5b1a0	242	tracing_start();
60a11774 SR	243
	244	if (!ret && !count) {
	245	printk(KERN_CONT ".. no entries found ..");
	246	ret = -1;
	247	}
	248
	249	tracing_max_latency = save_max;
	250
	251	return ret;
	252	}
	253	#endif /* CONFIG_IRQSOFF_TRACER */
	254
	255	#ifdef CONFIG_PREEMPT_TRACER
	256	int
	257	trace_selftest_startup_preemptoff(struct tracer trace, struct trace_array tr)
	258	{
	259	unsigned long save_max = tracing_max_latency;
	260	unsigned long count;
	261	int ret;
	262
	263	/* start the tracing */
	264	tr->ctrl = 1;
	265	trace->init(tr);
	266	/* reset the max latency */
	267	tracing_max_latency = 0;
	268	/* disable preemption for a bit */
	269	preempt_disable();
	270	udelay(100);
	271	preempt_enable();
	272	/* stop the tracing. */
bbf5b1a0	273	tracing_stop();
60a11774 SR	274	/* check both trace buffers */
	275	ret = trace_test_buffer(tr, NULL);
	276	if (!ret)
	277	ret = trace_test_buffer(&max_tr, &count);
	278	trace->reset(tr);
bbf5b1a0	279	tracing_start();
60a11774 SR	280
	281	if (!ret && !count) {
	282	printk(KERN_CONT ".. no entries found ..");
	283	ret = -1;
	284	}
	285
	286	tracing_max_latency = save_max;
	287
	288	return ret;
	289	}
	290	#endif /* CONFIG_PREEMPT_TRACER */
	291
	292	#if defined(CONFIG_IRQSOFF_TRACER) && defined(CONFIG_PREEMPT_TRACER)
	293	int
	294	trace_selftest_startup_preemptirqsoff(struct tracer trace, struct trace_array tr)
	295	{
	296	unsigned long save_max = tracing_max_latency;
	297	unsigned long count;
	298	int ret;
	299
	300	/* start the tracing */
	301	tr->ctrl = 1;
	302	trace->init(tr);
	303
	304	/* reset the max latency */
	305	tracing_max_latency = 0;
	306
	307	/* disable preemption and interrupts for a bit */
	308	preempt_disable();
	309	local_irq_disable();
	310	udelay(100);
	311	preempt_enable();
	312	/* reverse the order of preempt vs irqs */
	313	local_irq_enable();
	314
	315	/* stop the tracing. */
bbf5b1a0	316	tracing_stop();
60a11774 SR	317	/* check both trace buffers */
60a11774 SR	318	ret = trace_test_buffer(tr, NULL);
bbf5b1a0 SR	319	if (ret) {
bbf5b1a0 SR	320	tracing_start();
60a11774	321	goto out;
bbf5b1a0	322	}
60a11774 SR	323
60a11774 SR	324	ret = trace_test_buffer(&max_tr, &count);
bbf5b1a0 SR	325	if (ret) {
bbf5b1a0 SR	326	tracing_start();
60a11774	327	goto out;
bbf5b1a0	328	}
60a11774 SR	329
	330	if (!ret && !count) {
	331	printk(KERN_CONT ".. no entries found ..");
	332	ret = -1;
bbf5b1a0	333	tracing_start();
60a11774 SR	334	goto out;
	335	}
	336
	337	/* do the test by disabling interrupts first this time */
	338	tracing_max_latency = 0;
bbf5b1a0	339	tracing_start();
60a11774 SR	340	preempt_disable();
	341	local_irq_disable();
	342	udelay(100);
	343	preempt_enable();
	344	/* reverse the order of preempt vs irqs */
	345	local_irq_enable();
	346
	347	/* stop the tracing. */
bbf5b1a0	348	tracing_stop();
60a11774 SR	349	/* check both trace buffers */
	350	ret = trace_test_buffer(tr, NULL);
	351	if (ret)
	352	goto out;
	353
	354	ret = trace_test_buffer(&max_tr, &count);
	355
	356	if (!ret && !count) {
	357	printk(KERN_CONT ".. no entries found ..");
	358	ret = -1;
	359	goto out;
	360	}
	361
	362	out:
	363	trace->reset(tr);
bbf5b1a0	364	tracing_start();
60a11774 SR	365	tracing_max_latency = save_max;
	366
	367	return ret;
	368	}
	369	#endif /* CONFIG_IRQSOFF_TRACER && CONFIG_PREEMPT_TRACER */
	370
fb1b6d8b SN	371	#ifdef CONFIG_NOP_TRACER
	372	int
	373	trace_selftest_startup_nop(struct tracer trace, struct trace_array tr)
	374	{
	375	/* What could possibly go wrong? */
	376	return 0;
	377	}
	378	#endif
	379
60a11774 SR	380	#ifdef CONFIG_SCHED_TRACER
	381	static int trace_wakeup_test_thread(void *data)
	382	{
60a11774	383	/* Make this a RT thread, doesn't need to be too high */
05bd68c5 SR	384	struct sched_param param = { .sched_priority = 5 };
05bd68c5 SR	385	struct completion *x = data;
60a11774	386
05bd68c5	387	sched_setscheduler(current, SCHED_FIFO, &param);
60a11774 SR	388
	389	/* Make it know we have a new prio */
	390	complete(x);
	391
	392	/* now go to sleep and let the test wake us up */
	393	set_current_state(TASK_INTERRUPTIBLE);
	394	schedule();
	395
	396	/* we are awake, now wait to disappear */
	397	while (!kthread_should_stop()) {
	398	/*
	399	* This is an RT task, do short sleeps to let
	400	* others run.
	401	*/
	402	msleep(100);
	403	}
	404
	405	return 0;
	406	}
	407
	408	int
	409	trace_selftest_startup_wakeup(struct tracer trace, struct trace_array tr)
	410	{
	411	unsigned long save_max = tracing_max_latency;
	412	struct task_struct *p;
	413	struct completion isrt;
	414	unsigned long count;
	415	int ret;
	416
	417	init_completion(&isrt);
	418
	419	/* create a high prio thread */
	420	p = kthread_run(trace_wakeup_test_thread, &isrt, "ftrace-test");
c7aafc54	421	if (IS_ERR(p)) {
60a11774 SR	422	printk(KERN_CONT "Failed to create ftrace wakeup test thread ");
	423	return -1;
	424	}
	425
	426	/* make sure the thread is running at an RT prio */
	427	wait_for_completion(&isrt);
	428
	429	/* start the tracing */
	430	tr->ctrl = 1;
	431	trace->init(tr);
	432	/* reset the max latency */
	433	tracing_max_latency = 0;
	434
	435	/* sleep to let the RT thread sleep too */
	436	msleep(100);
	437
	438	/*
	439	* Yes this is slightly racy. It is possible that for some
	440	* strange reason that the RT thread we created, did not
	441	* call schedule for 100ms after doing the completion,
	442	* and we do a wakeup on a task that already is awake.
	443	* But that is extremely unlikely, and the worst thing that
	444	* happens in such a case, is that we disable tracing.
	445	* Honestly, if this race does happen something is horrible
	446	* wrong with the system.
	447	*/
	448
	449	wake_up_process(p);
	450
5aa60c60 SR	451	/* give a little time to let the thread wake up */
	452	msleep(100);
	453
60a11774	454	/* stop the tracing. */
bbf5b1a0	455	tracing_stop();
60a11774 SR	456	/* check both trace buffers */
	457	ret = trace_test_buffer(tr, NULL);
	458	if (!ret)
	459	ret = trace_test_buffer(&max_tr, &count);
	460
	461
	462	trace->reset(tr);
bbf5b1a0	463	tracing_start();
60a11774 SR	464
	465	tracing_max_latency = save_max;
	466
	467	/* kill the thread */
	468	kthread_stop(p);
	469
	470	if (!ret && !count) {
	471	printk(KERN_CONT ".. no entries found ..");
	472	ret = -1;
	473	}
	474
	475	return ret;
	476	}
	477	#endif /* CONFIG_SCHED_TRACER */
	478
	479	#ifdef CONFIG_CONTEXT_SWITCH_TRACER
	480	int
	481	trace_selftest_startup_sched_switch(struct tracer trace, struct trace_array tr)
	482	{
	483	unsigned long count;
	484	int ret;
	485
	486	/* start the tracing */
	487	tr->ctrl = 1;
	488	trace->init(tr);
	489	/* Sleep for a 1/10 of a second */
	490	msleep(100);
	491	/* stop the tracing. */
bbf5b1a0	492	tracing_stop();
60a11774 SR	493	/* check the trace buffer */
	494	ret = trace_test_buffer(tr, &count);
	495	trace->reset(tr);
bbf5b1a0	496	tracing_start();
60a11774 SR	497
	498	if (!ret && !count) {
	499	printk(KERN_CONT ".. no entries found ..");
	500	ret = -1;
	501	}
	502
	503	return ret;
	504	}
	505	#endif /* CONFIG_CONTEXT_SWITCH_TRACER */
a6dd24f8 IM	506
	507	#ifdef CONFIG_SYSPROF_TRACER
	508	int
	509	trace_selftest_startup_sysprof(struct tracer trace, struct trace_array tr)
	510	{
	511	unsigned long count;
	512	int ret;
	513
	514	/* start the tracing */
	515	tr->ctrl = 1;
	516	trace->init(tr);
	517	/* Sleep for a 1/10 of a second */
	518	msleep(100);
	519	/* stop the tracing. */
bbf5b1a0	520	tracing_stop();
a6dd24f8 IM	521	/* check the trace buffer */
	522	ret = trace_test_buffer(tr, &count);
	523	trace->reset(tr);
bbf5b1a0	524	tracing_start();
a6dd24f8	525
a6dd24f8 IM	526	return ret;
	527	}
	528	#endif /* CONFIG_SYSPROF_TRACER */