[mirror_ubuntu-zesty-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:
	case TRACE_BRANCH:
		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 */
	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;

	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 */
	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;

	/*
	 * Now that the big kernel lock is no longer preemptable,
	 * and this is called with the BKL held, it will always
	 * fail. If preemption is already disabled, simply
	 * pass the test. When the BKL is removed, or becomes
	 * preemptible again, we will once again test this,
	 * so keep it in.
	 */
	if (preempt_count()) {
		printk(KERN_CONT "can not test ... force ");
		return 0;
	}

	/* start the tracing */
	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;

	/*
	 * Now that the big kernel lock is no longer preemptable,
	 * and this is called with the BKL held, it will always
	 * fail. If preemption is already disabled, simply
	 * pass the test. When the BKL is removed, or becomes
	 * preemptible again, we will once again test this,
	 * so keep it in.
	 */
	if (preempt_count()) {
		printk(KERN_CONT "can not test ... force ");
		return 0;
	}

	/* start the tracing */
	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 */
	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 */
	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 */
	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 */

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

	/* start the tracing */
	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_BRANCH_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:
80e5ea45	16	case TRACE_BRANCH:
60a11774 SR	17	return 1;
	18	}
	19	return 0;
	20	}
	21
3928a8a2	22	static int trace_test_buffer_cpu(struct trace_array *tr, int cpu)
60a11774	23	{
3928a8a2 SR	24	struct ring_buffer_event *event;
3928a8a2 SR	25	struct trace_entry *entry;
60a11774	26
3928a8a2 SR	27	while ((event = ring_buffer_consume(tr->buffer, cpu, NULL))) {
3928a8a2 SR	28	entry = ring_buffer_event_data(event);
60a11774	29
3928a8a2	30	if (!trace_valid_entry(entry)) {
c7aafc54	31	printk(KERN_CONT ".. invalid entry %d ",
3928a8a2	32	entry->type);
60a11774 SR	33	goto failed;
60a11774 SR	34	}
60a11774	35	}
60a11774 SR	36	return 0;
	37
	38	failed:
08bafa0e SR	39	/* disable tracing */
08bafa0e SR	40	tracing_disabled = 1;
60a11774 SR	41	printk(KERN_CONT ".. corrupted trace buffer .. ");
	42	return -1;
	43	}
	44
	45	/*
	46	* Test the trace buffer to see if all the elements
	47	* are still sane.
	48	*/
	49	static int trace_test_buffer(struct trace_array tr, unsigned long count)
	50	{
30afdcb1 SR	51	unsigned long flags, cnt = 0;
30afdcb1 SR	52	int cpu, ret = 0;
60a11774	53
30afdcb1 SR	54	/* Don't allow flipping of max traces now */
	55	raw_local_irq_save(flags);
	56	__raw_spin_lock(&ftrace_max_lock);
60a11774	57
3928a8a2	58	cnt = ring_buffer_entries(tr->buffer);
60a11774	59
3928a8a2 SR	60	for_each_possible_cpu(cpu) {
3928a8a2 SR	61	ret = trace_test_buffer_cpu(tr, cpu);
60a11774 SR	62	if (ret)
	63	break;
	64	}
30afdcb1 SR	65	__raw_spin_unlock(&ftrace_max_lock);
30afdcb1 SR	66	raw_local_irq_restore(flags);
60a11774 SR	67
	68	if (count)
	69	*count = cnt;
	70
	71	return ret;
	72	}
	73
606576ce	74	#ifdef CONFIG_FUNCTION_TRACER
77a2b37d SR	75
	76	#ifdef CONFIG_DYNAMIC_FTRACE
	77
77a2b37d SR	78	#define __STR(x) #x
77a2b37d SR	79	#define STR(x) __STR(x)
77a2b37d SR	80
	81	/* Test dynamic code modification and ftrace filters */
	82	int trace_selftest_startup_dynamic_tracing(struct tracer *trace,
	83	struct trace_array *tr,
	84	int (*func)(void))
	85	{
77a2b37d SR	86	int save_ftrace_enabled = ftrace_enabled;
77a2b37d SR	87	int save_tracer_enabled = tracer_enabled;
dd0e545f	88	unsigned long count;
4e491d14	89	char *func_name;
dd0e545f	90	int ret;
77a2b37d SR	91
	92	/* The ftrace test PASSED */
	93	printk(KERN_CONT "PASSED\n");
	94	pr_info("Testing dynamic ftrace: ");
	95
	96	/* enable tracing, and record the filter function */
	97	ftrace_enabled = 1;
	98	tracer_enabled = 1;
	99
	100	/* passed in by parameter to fool gcc from optimizing */
	101	func();
	102
4e491d14 SR	103	/*
	104	* Some archs coughPowerPCcough add charachters to the
	105	* start of the function names. We simply put a '*' to
	106	* accomodate them.
	107	*/
	108	func_name = "*" STR(DYN_FTRACE_TEST_NAME);
	109
77a2b37d	110	/* filter only on our function */
4e491d14	111	ftrace_set_filter(func_name, strlen(func_name), 1);
77a2b37d SR	112
77a2b37d SR	113	/* enable tracing */
77a2b37d	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	trace->init(tr);
	185	/* Sleep for a 1/10 of a second */
	186	msleep(100);
	187	/* stop the tracing. */
bbf5b1a0	188	tracing_stop();
c7aafc54 IM	189	ftrace_enabled = 0;
c7aafc54 IM	190
60a11774 SR	191	/* check the trace buffer */
	192	ret = trace_test_buffer(tr, &count);
	193	trace->reset(tr);
bbf5b1a0	194	tracing_start();
60a11774 SR	195
	196	if (!ret && !count) {
	197	printk(KERN_CONT ".. no entries found ..");
	198	ret = -1;
77a2b37d	199	goto out;
60a11774 SR	200	}
60a11774 SR	201
77a2b37d SR	202	ret = trace_selftest_startup_dynamic_tracing(trace, tr,
	203	DYN_FTRACE_TEST_NAME);
	204
	205	out:
	206	ftrace_enabled = save_ftrace_enabled;
	207	tracer_enabled = save_tracer_enabled;
	208
4eebcc81 SR	209	/* kill ftrace totally if we failed */
	210	if (ret)
	211	ftrace_kill();
	212
60a11774 SR	213	return ret;
60a11774 SR	214	}
606576ce	215	#endif /* CONFIG_FUNCTION_TRACER */
60a11774 SR	216
	217	#ifdef CONFIG_IRQSOFF_TRACER
	218	int
	219	trace_selftest_startup_irqsoff(struct tracer trace, struct trace_array tr)
	220	{
	221	unsigned long save_max = tracing_max_latency;
	222	unsigned long count;
	223	int ret;
	224
	225	/* start the tracing */
60a11774 SR	226	trace->init(tr);
	227	/* reset the max latency */
	228	tracing_max_latency = 0;
	229	/* disable interrupts for a bit */
	230	local_irq_disable();
	231	udelay(100);
	232	local_irq_enable();
	233	/* stop the tracing. */
bbf5b1a0	234	tracing_stop();
60a11774 SR	235	/* check both trace buffers */
	236	ret = trace_test_buffer(tr, NULL);
	237	if (!ret)
	238	ret = trace_test_buffer(&max_tr, &count);
	239	trace->reset(tr);
bbf5b1a0	240	tracing_start();
60a11774 SR	241
	242	if (!ret && !count) {
	243	printk(KERN_CONT ".. no entries found ..");
	244	ret = -1;
	245	}
	246
	247	tracing_max_latency = save_max;
	248
	249	return ret;
	250	}
	251	#endif /* CONFIG_IRQSOFF_TRACER */
	252
	253	#ifdef CONFIG_PREEMPT_TRACER
	254	int
	255	trace_selftest_startup_preemptoff(struct tracer trace, struct trace_array tr)
	256	{
	257	unsigned long save_max = tracing_max_latency;
	258	unsigned long count;
	259	int ret;
	260
769c48eb SR	261	/*
	262	* Now that the big kernel lock is no longer preemptable,
	263	* and this is called with the BKL held, it will always
	264	* fail. If preemption is already disabled, simply
	265	* pass the test. When the BKL is removed, or becomes
	266	* preemptible again, we will once again test this,
	267	* so keep it in.
	268	*/
	269	if (preempt_count()) {
	270	printk(KERN_CONT "can not test ... force ");
	271	return 0;
	272	}
	273
60a11774	274	/* start the tracing */
60a11774 SR	275	trace->init(tr);
	276	/* reset the max latency */
	277	tracing_max_latency = 0;
	278	/* disable preemption for a bit */
	279	preempt_disable();
	280	udelay(100);
	281	preempt_enable();
	282	/* stop the tracing. */
bbf5b1a0	283	tracing_stop();
60a11774 SR	284	/* check both trace buffers */
	285	ret = trace_test_buffer(tr, NULL);
	286	if (!ret)
	287	ret = trace_test_buffer(&max_tr, &count);
	288	trace->reset(tr);
bbf5b1a0	289	tracing_start();
60a11774 SR	290
	291	if (!ret && !count) {
	292	printk(KERN_CONT ".. no entries found ..");
	293	ret = -1;
	294	}
	295
	296	tracing_max_latency = save_max;
	297
	298	return ret;
	299	}
	300	#endif /* CONFIG_PREEMPT_TRACER */
	301
	302	#if defined(CONFIG_IRQSOFF_TRACER) && defined(CONFIG_PREEMPT_TRACER)
	303	int
	304	trace_selftest_startup_preemptirqsoff(struct tracer trace, struct trace_array tr)
	305	{
	306	unsigned long save_max = tracing_max_latency;
	307	unsigned long count;
	308	int ret;
	309
769c48eb SR	310	/*
	311	* Now that the big kernel lock is no longer preemptable,
	312	* and this is called with the BKL held, it will always
	313	* fail. If preemption is already disabled, simply
	314	* pass the test. When the BKL is removed, or becomes
	315	* preemptible again, we will once again test this,
	316	* so keep it in.
	317	*/
	318	if (preempt_count()) {
	319	printk(KERN_CONT "can not test ... force ");
	320	return 0;
	321	}
	322
60a11774	323	/* start the tracing */
60a11774 SR	324	trace->init(tr);
	325
	326	/* reset the max latency */
	327	tracing_max_latency = 0;
	328
	329	/* disable preemption and interrupts for a bit */
	330	preempt_disable();
	331	local_irq_disable();
	332	udelay(100);
	333	preempt_enable();
	334	/* reverse the order of preempt vs irqs */
	335	local_irq_enable();
	336
	337	/* stop the tracing. */
bbf5b1a0	338	tracing_stop();
60a11774 SR	339	/* check both trace buffers */
60a11774 SR	340	ret = trace_test_buffer(tr, NULL);
bbf5b1a0 SR	341	if (ret) {
bbf5b1a0 SR	342	tracing_start();
60a11774	343	goto out;
bbf5b1a0	344	}
60a11774 SR	345
60a11774 SR	346	ret = trace_test_buffer(&max_tr, &count);
bbf5b1a0 SR	347	if (ret) {
bbf5b1a0 SR	348	tracing_start();
60a11774	349	goto out;
bbf5b1a0	350	}
60a11774 SR	351
	352	if (!ret && !count) {
	353	printk(KERN_CONT ".. no entries found ..");
	354	ret = -1;
bbf5b1a0	355	tracing_start();
60a11774 SR	356	goto out;
	357	}
	358
	359	/* do the test by disabling interrupts first this time */
	360	tracing_max_latency = 0;
bbf5b1a0	361	tracing_start();
60a11774 SR	362	preempt_disable();
	363	local_irq_disable();
	364	udelay(100);
	365	preempt_enable();
	366	/* reverse the order of preempt vs irqs */
	367	local_irq_enable();
	368
	369	/* stop the tracing. */
bbf5b1a0	370	tracing_stop();
60a11774 SR	371	/* check both trace buffers */
	372	ret = trace_test_buffer(tr, NULL);
	373	if (ret)
	374	goto out;
	375
	376	ret = trace_test_buffer(&max_tr, &count);
	377
	378	if (!ret && !count) {
	379	printk(KERN_CONT ".. no entries found ..");
	380	ret = -1;
	381	goto out;
	382	}
	383
	384	out:
	385	trace->reset(tr);
bbf5b1a0	386	tracing_start();
60a11774 SR	387	tracing_max_latency = save_max;
	388
	389	return ret;
	390	}
	391	#endif /* CONFIG_IRQSOFF_TRACER && CONFIG_PREEMPT_TRACER */
	392
fb1b6d8b SN	393	#ifdef CONFIG_NOP_TRACER
	394	int
	395	trace_selftest_startup_nop(struct tracer trace, struct trace_array tr)
	396	{
	397	/* What could possibly go wrong? */
	398	return 0;
	399	}
	400	#endif
	401
60a11774 SR	402	#ifdef CONFIG_SCHED_TRACER
	403	static int trace_wakeup_test_thread(void *data)
	404	{
60a11774	405	/* Make this a RT thread, doesn't need to be too high */
05bd68c5 SR	406	struct sched_param param = { .sched_priority = 5 };
05bd68c5 SR	407	struct completion *x = data;
60a11774	408
05bd68c5	409	sched_setscheduler(current, SCHED_FIFO, &param);
60a11774 SR	410
	411	/* Make it know we have a new prio */
	412	complete(x);
	413
	414	/* now go to sleep and let the test wake us up */
	415	set_current_state(TASK_INTERRUPTIBLE);
	416	schedule();
	417
	418	/* we are awake, now wait to disappear */
	419	while (!kthread_should_stop()) {
	420	/*
	421	* This is an RT task, do short sleeps to let
	422	* others run.
	423	*/
	424	msleep(100);
	425	}
	426
	427	return 0;
	428	}
	429
	430	int
	431	trace_selftest_startup_wakeup(struct tracer trace, struct trace_array tr)
	432	{
	433	unsigned long save_max = tracing_max_latency;
	434	struct task_struct *p;
	435	struct completion isrt;
	436	unsigned long count;
	437	int ret;
	438
	439	init_completion(&isrt);
	440
	441	/* create a high prio thread */
	442	p = kthread_run(trace_wakeup_test_thread, &isrt, "ftrace-test");
c7aafc54	443	if (IS_ERR(p)) {
60a11774 SR	444	printk(KERN_CONT "Failed to create ftrace wakeup test thread ");
	445	return -1;
	446	}
	447
	448	/* make sure the thread is running at an RT prio */
	449	wait_for_completion(&isrt);
	450
	451	/* start the tracing */
60a11774 SR	452	trace->init(tr);
	453	/* reset the max latency */
	454	tracing_max_latency = 0;
	455
	456	/* sleep to let the RT thread sleep too */
	457	msleep(100);
	458
	459	/*
	460	* Yes this is slightly racy. It is possible that for some
	461	* strange reason that the RT thread we created, did not
	462	* call schedule for 100ms after doing the completion,
	463	* and we do a wakeup on a task that already is awake.
	464	* But that is extremely unlikely, and the worst thing that
	465	* happens in such a case, is that we disable tracing.
	466	* Honestly, if this race does happen something is horrible
	467	* wrong with the system.
	468	*/
	469
	470	wake_up_process(p);
	471
5aa60c60 SR	472	/* give a little time to let the thread wake up */
	473	msleep(100);
	474
60a11774	475	/* stop the tracing. */
bbf5b1a0	476	tracing_stop();
60a11774 SR	477	/* check both trace buffers */
	478	ret = trace_test_buffer(tr, NULL);
	479	if (!ret)
	480	ret = trace_test_buffer(&max_tr, &count);
	481
	482
	483	trace->reset(tr);
bbf5b1a0	484	tracing_start();
60a11774 SR	485
	486	tracing_max_latency = save_max;
	487
	488	/* kill the thread */
	489	kthread_stop(p);
	490
	491	if (!ret && !count) {
	492	printk(KERN_CONT ".. no entries found ..");
	493	ret = -1;
	494	}
	495
	496	return ret;
	497	}
	498	#endif /* CONFIG_SCHED_TRACER */
	499
	500	#ifdef CONFIG_CONTEXT_SWITCH_TRACER
	501	int
	502	trace_selftest_startup_sched_switch(struct tracer trace, struct trace_array tr)
	503	{
	504	unsigned long count;
	505	int ret;
	506
	507	/* start the tracing */
60a11774 SR	508	trace->init(tr);
	509	/* Sleep for a 1/10 of a second */
	510	msleep(100);
	511	/* stop the tracing. */
bbf5b1a0	512	tracing_stop();
60a11774 SR	513	/* check the trace buffer */
	514	ret = trace_test_buffer(tr, &count);
	515	trace->reset(tr);
bbf5b1a0	516	tracing_start();
60a11774 SR	517
	518	if (!ret && !count) {
	519	printk(KERN_CONT ".. no entries found ..");
	520	ret = -1;
	521	}
	522
	523	return ret;
	524	}
	525	#endif /* CONFIG_CONTEXT_SWITCH_TRACER */
a6dd24f8 IM	526
	527	#ifdef CONFIG_SYSPROF_TRACER
	528	int
	529	trace_selftest_startup_sysprof(struct tracer trace, struct trace_array tr)
	530	{
	531	unsigned long count;
	532	int ret;
	533
	534	/* start the tracing */
a6dd24f8 IM	535	trace->init(tr);
	536	/* Sleep for a 1/10 of a second */
	537	msleep(100);
	538	/* stop the tracing. */
bbf5b1a0	539	tracing_stop();
a6dd24f8 IM	540	/* check the trace buffer */
	541	ret = trace_test_buffer(tr, &count);
	542	trace->reset(tr);
bbf5b1a0	543	tracing_start();
a6dd24f8	544
a6dd24f8 IM	545	return ret;
	546	}
	547	#endif /* CONFIG_SYSPROF_TRACER */
80e5ea45 SR	548
	549	#ifdef CONFIG_BRANCH_TRACER
	550	int
	551	trace_selftest_startup_branch(struct tracer trace, struct trace_array tr)
	552	{
	553	unsigned long count;
	554	int ret;
	555
	556	/* start the tracing */
	557	trace->init(tr);
	558	/* Sleep for a 1/10 of a second */
	559	msleep(100);
	560	/* stop the tracing. */
	561	tracing_stop();
	562	/* check the trace buffer */
	563	ret = trace_test_buffer(tr, &count);
	564	trace->reset(tr);
	565	tracing_start();
	566
	567	return ret;
	568	}
	569	#endif /* CONFIG_BRANCH_TRACER */