[GitHub/mt8127/android_kernel_alcatel_ttab.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, struct trace_array_cpu *data)
{
	struct trace_entry *entries;
	struct page *page;
	int idx = 0;
	int i;

	BUG_ON(list_empty(&data->trace_pages));
	page = list_entry(data->trace_pages.next, struct page, lru);
	entries = page_address(page);

	check_pages(data);
	if (head_page(data) != entries)
		goto failed;

	/*
	 * The starting trace buffer always has valid elements,
	 * if any element exists.
	 */
	entries = head_page(data);

	for (i = 0; i < tr->entries; i++) {

		if (i < data->trace_idx && !trace_valid_entry(&entries[idx])) {
			printk(KERN_CONT ".. invalid entry %d ",
				entries[idx].type);
			goto failed;
		}

		idx++;
		if (idx >= ENTRIES_PER_PAGE) {
			page = virt_to_page(entries);
			if (page->lru.next == &data->trace_pages) {
				if (i != tr->entries - 1) {
					printk(KERN_CONT ".. entries buffer mismatch");
					goto failed;
				}
			} else {
				page = list_entry(page->lru.next, struct page, lru);
				entries = page_address(page);
			}
			idx = 0;
		}
	}

	page = virt_to_page(entries);
	if (page->lru.next != &data->trace_pages) {
		printk(KERN_CONT ".. too many entries");
		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);
	for_each_possible_cpu(cpu) {
		if (!head_page(tr->data[cpu]))
			continue;

		cnt += tr->data[cpu]->trace_idx;

		ret = trace_test_buffer_cpu(tr, tr->data[cpu]);
		if (ret)
			break;
	}
	__raw_spin_unlock(&ftrace_max_lock);
	raw_local_irq_restore(flags);

	if (count)
		*count = cnt;

	return ret;
}

#ifdef CONFIG_FTRACE

#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();

	/* update the records */
	ret = ftrace_force_update();
	if (ret) {
		printk(KERN_CONT ".. ftraced failed .. ");
		return ret;
	}

	/*
	 * 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. */
	tr->ctrl = 0;
	trace->ctrl_update(tr);
	ftrace_enabled = 0;

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

	/* 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);

	/* force the recorded functions to be traced */
	ret = ftrace_force_update();
	if (ret) {
		printk(KERN_CONT ".. ftraced failed .. ");
		return ret;
	}

	/* 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. */
	tr->ctrl = 0;
	trace->ctrl_update(tr);
	ftrace_enabled = 0;

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

	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_FTRACE */

#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. */
	tr->ctrl = 0;
	trace->ctrl_update(tr);
	/* check both trace buffers */
	ret = trace_test_buffer(tr, NULL);
	if (!ret)
		ret = trace_test_buffer(&max_tr, &count);
	trace->reset(tr);

	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. */
	tr->ctrl = 0;
	trace->ctrl_update(tr);
	/* check both trace buffers */
	ret = trace_test_buffer(tr, NULL);
	if (!ret)
		ret = trace_test_buffer(&max_tr, &count);
	trace->reset(tr);

	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. */
	tr->ctrl = 0;
	trace->ctrl_update(tr);
	/* check both trace buffers */
	ret = trace_test_buffer(tr, NULL);
	if (ret)
		goto out;

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

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

	/* do the test by disabling interrupts first this time */
	tracing_max_latency = 0;
	tr->ctrl = 1;
	trace->ctrl_update(tr);
	preempt_disable();
	local_irq_disable();
	udelay(100);
	preempt_enable();
	/* reverse the order of preempt vs irqs */
	local_irq_enable();

	/* stop the tracing. */
	tr->ctrl = 0;
	trace->ctrl_update(tr);
	/* 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_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);

	/* stop the tracing. */
	tr->ctrl = 0;
	trace->ctrl_update(tr);
	/* check both trace buffers */
	ret = trace_test_buffer(tr, NULL);
	if (!ret)
		ret = trace_test_buffer(&max_tr, &count);


	trace->reset(tr);

	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. */
	tr->ctrl = 0;
	trace->ctrl_update(tr);
	/* check the trace buffer */
	ret = trace_test_buffer(tr, &count);
	trace->reset(tr);

	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. */
	tr->ctrl = 0;
	trace->ctrl_update(tr);
	/* check the trace buffer */
	ret = trace_test_buffer(tr, &count);
	trace->reset(tr);

	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
	21	static int
	22	trace_test_buffer_cpu(struct trace_array tr, struct trace_array_cpu data)
	23	{
60a11774	24	struct trace_entry *entries;
c7aafc54	25	struct page *page;
60a11774 SR	26	int idx = 0;
	27	int i;
	28
c7aafc54	29	BUG_ON(list_empty(&data->trace_pages));
60a11774 SR	30	page = list_entry(data->trace_pages.next, struct page, lru);
	31	entries = page_address(page);
	32
19384c03	33	check_pages(data);
c7aafc54	34	if (head_page(data) != entries)
60a11774 SR	35	goto failed;
	36
	37	/*
	38	* The starting trace buffer always has valid elements,
c7aafc54	39	* if any element exists.
60a11774	40	*/
c7aafc54	41	entries = head_page(data);
60a11774 SR	42
	43	for (i = 0; i < tr->entries; i++) {
	44
c7aafc54 IM	45	if (i < data->trace_idx && !trace_valid_entry(&entries[idx])) {
	46	printk(KERN_CONT ".. invalid entry %d ",
	47	entries[idx].type);
60a11774 SR	48	goto failed;
	49	}
	50
	51	idx++;
	52	if (idx >= ENTRIES_PER_PAGE) {
	53	page = virt_to_page(entries);
	54	if (page->lru.next == &data->trace_pages) {
	55	if (i != tr->entries - 1) {
	56	printk(KERN_CONT ".. entries buffer mismatch");
	57	goto failed;
	58	}
	59	} else {
	60	page = list_entry(page->lru.next, struct page, lru);
	61	entries = page_address(page);
	62	}
	63	idx = 0;
	64	}
	65	}
	66
	67	page = virt_to_page(entries);
	68	if (page->lru.next != &data->trace_pages) {
	69	printk(KERN_CONT ".. too many entries");
	70	goto failed;
	71	}
	72
	73	return 0;
	74
	75	failed:
08bafa0e SR	76	/* disable tracing */
08bafa0e SR	77	tracing_disabled = 1;
60a11774 SR	78	printk(KERN_CONT ".. corrupted trace buffer .. ");
	79	return -1;
	80	}
	81
	82	/*
	83	* Test the trace buffer to see if all the elements
	84	* are still sane.
	85	*/
	86	static int trace_test_buffer(struct trace_array tr, unsigned long count)
	87	{
30afdcb1 SR	88	unsigned long flags, cnt = 0;
30afdcb1 SR	89	int cpu, ret = 0;
60a11774	90
30afdcb1 SR	91	/* Don't allow flipping of max traces now */
	92	raw_local_irq_save(flags);
	93	__raw_spin_lock(&ftrace_max_lock);
60a11774	94	for_each_possible_cpu(cpu) {
c7aafc54	95	if (!head_page(tr->data[cpu]))
60a11774 SR	96	continue;
	97
	98	cnt += tr->data[cpu]->trace_idx;
60a11774 SR	99
	100	ret = trace_test_buffer_cpu(tr, tr->data[cpu]);
	101	if (ret)
	102	break;
	103	}
30afdcb1 SR	104	__raw_spin_unlock(&ftrace_max_lock);
30afdcb1 SR	105	raw_local_irq_restore(flags);
60a11774 SR	106
	107	if (count)
	108	*count = cnt;
	109
	110	return ret;
	111	}
	112
	113	#ifdef CONFIG_FTRACE
77a2b37d SR	114
	115	#ifdef CONFIG_DYNAMIC_FTRACE
	116
77a2b37d SR	117	#define __STR(x) #x
77a2b37d SR	118	#define STR(x) __STR(x)
77a2b37d SR	119
	120	/* Test dynamic code modification and ftrace filters */
	121	int trace_selftest_startup_dynamic_tracing(struct tracer *trace,
	122	struct trace_array *tr,
	123	int (*func)(void))
	124	{
77a2b37d SR	125	int save_ftrace_enabled = ftrace_enabled;
77a2b37d SR	126	int save_tracer_enabled = tracer_enabled;
dd0e545f	127	unsigned long count;
4e491d14	128	char *func_name;
dd0e545f	129	int ret;
77a2b37d SR	130
	131	/* The ftrace test PASSED */
	132	printk(KERN_CONT "PASSED\n");
	133	pr_info("Testing dynamic ftrace: ");
	134
	135	/* enable tracing, and record the filter function */
	136	ftrace_enabled = 1;
	137	tracer_enabled = 1;
	138
	139	/* passed in by parameter to fool gcc from optimizing */
	140	func();
	141
	142	/* update the records */
	143	ret = ftrace_force_update();
	144	if (ret) {
	145	printk(KERN_CONT ".. ftraced failed .. ");
	146	return ret;
	147	}
	148
4e491d14 SR	149	/*
	150	* Some archs coughPowerPCcough add charachters to the
	151	* start of the function names. We simply put a '*' to
	152	* accomodate them.
	153	*/
	154	func_name = "*" STR(DYN_FTRACE_TEST_NAME);
	155
77a2b37d	156	/* filter only on our function */
4e491d14	157	ftrace_set_filter(func_name, strlen(func_name), 1);
77a2b37d SR	158
	159	/* enable tracing */
	160	tr->ctrl = 1;
	161	trace->init(tr);
dd0e545f	162
77a2b37d SR	163	/* Sleep for a 1/10 of a second */
	164	msleep(100);
	165
	166	/* we should have nothing in the buffer */
	167	ret = trace_test_buffer(tr, &count);
	168	if (ret)
	169	goto out;
	170
	171	if (count) {
	172	ret = -1;
	173	printk(KERN_CONT ".. filter did not filter .. ");
	174	goto out;
	175	}
	176
	177	/* call our function again */
	178	func();
	179
	180	/* sleep again */
	181	msleep(100);
	182
	183	/* stop the tracing. */
	184	tr->ctrl = 0;
	185	trace->ctrl_update(tr);
	186	ftrace_enabled = 0;
	187
	188	/* check the trace buffer */
	189	ret = trace_test_buffer(tr, &count);
	190	trace->reset(tr);
	191
	192	/* we should only have one item */
	193	if (!ret && count != 1) {
06fa75ab	194	printk(KERN_CONT ".. filter failed count=%ld ..", count);
77a2b37d SR	195	ret = -1;
	196	goto out;
	197	}
	198	out:
	199	ftrace_enabled = save_ftrace_enabled;
	200	tracer_enabled = save_tracer_enabled;
	201
	202	/* Enable tracing on all functions again */
	203	ftrace_set_filter(NULL, 0, 1);
	204
	205	return ret;
	206	}
	207	#else
	208	# define trace_selftest_startup_dynamic_tracing(trace, tr, func) ({ 0; })
	209	#endif /* CONFIG_DYNAMIC_FTRACE */
60a11774 SR	210	/*
	211	* Simple verification test of ftrace function tracer.
	212	* Enable ftrace, sleep 1/10 second, and then read the trace
	213	* buffer to see if all is in order.
	214	*/
	215	int
	216	trace_selftest_startup_function(struct tracer trace, struct trace_array tr)
	217	{
77a2b37d SR	218	int save_ftrace_enabled = ftrace_enabled;
77a2b37d SR	219	int save_tracer_enabled = tracer_enabled;
dd0e545f SR	220	unsigned long count;
dd0e545f SR	221	int ret;
60a11774	222
77a2b37d SR	223	/* make sure msleep has been recorded */
	224	msleep(1);
	225
	226	/* force the recorded functions to be traced */
60a11774 SR	227	ret = ftrace_force_update();
	228	if (ret) {
	229	printk(KERN_CONT ".. ftraced failed .. ");
	230	return ret;
	231	}
	232
	233	/* start the tracing */
c7aafc54	234	ftrace_enabled = 1;
77a2b37d	235	tracer_enabled = 1;
c7aafc54	236
60a11774 SR	237	tr->ctrl = 1;
	238	trace->init(tr);
	239	/* Sleep for a 1/10 of a second */
	240	msleep(100);
	241	/* stop the tracing. */
	242	tr->ctrl = 0;
	243	trace->ctrl_update(tr);
c7aafc54 IM	244	ftrace_enabled = 0;
c7aafc54 IM	245
60a11774 SR	246	/* check the trace buffer */
	247	ret = trace_test_buffer(tr, &count);
	248	trace->reset(tr);
	249
	250	if (!ret && !count) {
	251	printk(KERN_CONT ".. no entries found ..");
	252	ret = -1;
77a2b37d	253	goto out;
60a11774 SR	254	}
60a11774 SR	255
77a2b37d SR	256	ret = trace_selftest_startup_dynamic_tracing(trace, tr,
	257	DYN_FTRACE_TEST_NAME);
	258
	259	out:
	260	ftrace_enabled = save_ftrace_enabled;
	261	tracer_enabled = save_tracer_enabled;
	262
4eebcc81 SR	263	/* kill ftrace totally if we failed */
	264	if (ret)
	265	ftrace_kill();
	266
60a11774 SR	267	return ret;
	268	}
	269	#endif /* CONFIG_FTRACE */
	270
	271	#ifdef CONFIG_IRQSOFF_TRACER
	272	int
	273	trace_selftest_startup_irqsoff(struct tracer trace, struct trace_array tr)
	274	{
	275	unsigned long save_max = tracing_max_latency;
	276	unsigned long count;
	277	int ret;
	278
	279	/* start the tracing */
	280	tr->ctrl = 1;
	281	trace->init(tr);
	282	/* reset the max latency */
	283	tracing_max_latency = 0;
	284	/* disable interrupts for a bit */
	285	local_irq_disable();
	286	udelay(100);
	287	local_irq_enable();
	288	/* stop the tracing. */
	289	tr->ctrl = 0;
	290	trace->ctrl_update(tr);
	291	/* check both trace buffers */
	292	ret = trace_test_buffer(tr, NULL);
	293	if (!ret)
	294	ret = trace_test_buffer(&max_tr, &count);
	295	trace->reset(tr);
	296
	297	if (!ret && !count) {
	298	printk(KERN_CONT ".. no entries found ..");
	299	ret = -1;
	300	}
	301
	302	tracing_max_latency = save_max;
	303
	304	return ret;
	305	}
	306	#endif /* CONFIG_IRQSOFF_TRACER */
	307
	308	#ifdef CONFIG_PREEMPT_TRACER
	309	int
	310	trace_selftest_startup_preemptoff(struct tracer trace, struct trace_array tr)
	311	{
	312	unsigned long save_max = tracing_max_latency;
	313	unsigned long count;
	314	int ret;
	315
	316	/* start the tracing */
	317	tr->ctrl = 1;
	318	trace->init(tr);
	319	/* reset the max latency */
	320	tracing_max_latency = 0;
	321	/* disable preemption for a bit */
	322	preempt_disable();
	323	udelay(100);
	324	preempt_enable();
	325	/* stop the tracing. */
	326	tr->ctrl = 0;
	327	trace->ctrl_update(tr);
	328	/* check both trace buffers */
	329	ret = trace_test_buffer(tr, NULL);
	330	if (!ret)
331	ret = trace_test_buffer(&max_tr, &count);
332	trace->reset(tr);
333
334	if (!ret && !count) {
335	printk(KERN_CONT ".. no entries found ..");
336	ret = -1;
337	}
338
339	tracing_max_latency = save_max;
340
341	return ret;
342	}
343	#endif /* CONFIG_PREEMPT_TRACER */
344
345	#if defined(CONFIG_IRQSOFF_TRACER) && defined(CONFIG_PREEMPT_TRACER)
346	int
347	trace_selftest_startup_preemptirqsoff(struct tracer trace, struct trace_array tr)
348	{
349	unsigned long save_max = tracing_max_latency;
350	unsigned long count;
351	int ret;
352
353	/* start the tracing */
354	tr->ctrl = 1;
355	trace->init(tr);
356
357	/* reset the max latency */
358	tracing_max_latency = 0;
359
360	/* disable preemption and interrupts for a bit */
361	preempt_disable();
362	local_irq_disable();
363	udelay(100);
364	preempt_enable();
365	/* reverse the order of preempt vs irqs */
366	local_irq_enable();
367
368	/* stop the tracing. */
369	tr->ctrl = 0;
370	trace->ctrl_update(tr);
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	if (ret)
378	goto out;
379
380	if (!ret && !count) {
381	printk(KERN_CONT ".. no entries found ..");
382	ret = -1;
383	goto out;
384	}
385
386	/* do the test by disabling interrupts first this time */
387	tracing_max_latency = 0;
388	tr->ctrl = 1;
389	trace->ctrl_update(tr);
390	preempt_disable();
391	local_irq_disable();
392	udelay(100);
393	preempt_enable();
394	/* reverse the order of preempt vs irqs */
395	local_irq_enable();
396
397	/* stop the tracing. */
398	tr->ctrl = 0;
399	trace->ctrl_update(tr);
400	/* check both trace buffers */
401	ret = trace_test_buffer(tr, NULL);
402	if (ret)
403	goto out;
404
405	ret = trace_test_buffer(&max_tr, &count);
406
407	if (!ret && !count) {
408	printk(KERN_CONT ".. no entries found ..");
409	ret = -1;
410	goto out;
411	}
412
413	out:
414	trace->reset(tr);
415	tracing_max_latency = save_max;
416
417	return ret;
418	}
419	#endif /* CONFIG_IRQSOFF_TRACER && CONFIG_PREEMPT_TRACER */
420
fb1b6d8b SN	421	#ifdef CONFIG_NOP_TRACER
	422	int
	423	trace_selftest_startup_nop(struct tracer trace, struct trace_array tr)
	424	{
	425	/* What could possibly go wrong? */
	426	return 0;
	427	}
	428	#endif
	429
60a11774 SR	430	#ifdef CONFIG_SCHED_TRACER
	431	static int trace_wakeup_test_thread(void *data)
	432	{
60a11774	433	/* Make this a RT thread, doesn't need to be too high */
05bd68c5 SR	434	struct sched_param param = { .sched_priority = 5 };
05bd68c5 SR	435	struct completion *x = data;
60a11774	436
05bd68c5	437	sched_setscheduler(current, SCHED_FIFO, &param);
60a11774 SR	438
	439	/* Make it know we have a new prio */
	440	complete(x);
	441
	442	/* now go to sleep and let the test wake us up */
	443	set_current_state(TASK_INTERRUPTIBLE);
	444	schedule();
	445
	446	/* we are awake, now wait to disappear */
	447	while (!kthread_should_stop()) {
	448	/*
	449	* This is an RT task, do short sleeps to let
	450	* others run.
	451	*/
	452	msleep(100);
	453	}
	454
	455	return 0;
	456	}
	457
	458	int
	459	trace_selftest_startup_wakeup(struct tracer trace, struct trace_array tr)
	460	{
	461	unsigned long save_max = tracing_max_latency;
	462	struct task_struct *p;
	463	struct completion isrt;
	464	unsigned long count;
	465	int ret;
	466
	467	init_completion(&isrt);
	468
	469	/* create a high prio thread */
	470	p = kthread_run(trace_wakeup_test_thread, &isrt, "ftrace-test");
c7aafc54	471	if (IS_ERR(p)) {
60a11774 SR	472	printk(KERN_CONT "Failed to create ftrace wakeup test thread ");
	473	return -1;
	474	}
	475
	476	/* make sure the thread is running at an RT prio */
	477	wait_for_completion(&isrt);
	478
	479	/* start the tracing */
	480	tr->ctrl = 1;
	481	trace->init(tr);
	482	/* reset the max latency */
	483	tracing_max_latency = 0;
	484
	485	/* sleep to let the RT thread sleep too */
	486	msleep(100);
	487
	488	/*
	489	* Yes this is slightly racy. It is possible that for some
	490	* strange reason that the RT thread we created, did not
	491	* call schedule for 100ms after doing the completion,
	492	* and we do a wakeup on a task that already is awake.
	493	* But that is extremely unlikely, and the worst thing that
	494	* happens in such a case, is that we disable tracing.
	495	* Honestly, if this race does happen something is horrible
	496	* wrong with the system.
	497	*/
	498
	499	wake_up_process(p);
	500
	501	/* stop the tracing. */
	502	tr->ctrl = 0;
	503	trace->ctrl_update(tr);
	504	/* check both trace buffers */
	505	ret = trace_test_buffer(tr, NULL);
	506	if (!ret)
	507	ret = trace_test_buffer(&max_tr, &count);
	508
	509
	510	trace->reset(tr);
	511
	512	tracing_max_latency = save_max;
	513
	514	/* kill the thread */
	515	kthread_stop(p);
	516
	517	if (!ret && !count) {
	518	printk(KERN_CONT ".. no entries found ..");
	519	ret = -1;
	520	}
	521
	522	return ret;
	523	}
	524	#endif /* CONFIG_SCHED_TRACER */
	525
	526	#ifdef CONFIG_CONTEXT_SWITCH_TRACER
	527	int
	528	trace_selftest_startup_sched_switch(struct tracer trace, struct trace_array tr)
	529	{
	530	unsigned long count;
	531	int ret;
	532
	533	/* start the tracing */
	534	tr->ctrl = 1;
	535	trace->init(tr);
536	/* Sleep for a 1/10 of a second */
537	msleep(100);
538	/* stop the tracing. */
539	tr->ctrl = 0;
540	trace->ctrl_update(tr);
541	/* check the trace buffer */
542	ret = trace_test_buffer(tr, &count);
543	trace->reset(tr);
544
545	if (!ret && !count) {
546	printk(KERN_CONT ".. no entries found ..");
547	ret = -1;
548	}
549
550	return ret;
551	}
552	#endif /* CONFIG_CONTEXT_SWITCH_TRACER */
a6dd24f8 IM	553
	554	#ifdef CONFIG_SYSPROF_TRACER
	555	int
	556	trace_selftest_startup_sysprof(struct tracer trace, struct trace_array tr)
	557	{
	558	unsigned long count;
	559	int ret;
	560
	561	/* start the tracing */
	562	tr->ctrl = 1;
	563	trace->init(tr);
	564	/* Sleep for a 1/10 of a second */
	565	msleep(100);
	566	/* stop the tracing. */
	567	tr->ctrl = 0;
	568	trace->ctrl_update(tr);
	569	/* check the trace buffer */
	570	ret = trace_test_buffer(tr, &count);
	571	trace->reset(tr);
	572
a6dd24f8 IM	573	return ret;
	574	}
	575	#endif /* CONFIG_SYSPROF_TRACER */