trace.c 86.1 KB
Newer Older
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
/*
 * ring buffer based function tracer
 *
 * Copyright (C) 2007-2008 Steven Rostedt <srostedt@redhat.com>
 * Copyright (C) 2008 Ingo Molnar <mingo@redhat.com>
 *
 * Originally taken from the RT patch by:
 *    Arnaldo Carvalho de Melo <acme@redhat.com>
 *
 * Based on code from the latency_tracer, that is:
 *  Copyright (C) 2004-2006 Ingo Molnar
 *  Copyright (C) 2004 William Lee Irwin III
 */
#include <linux/utsrelease.h>
#include <linux/kallsyms.h>
#include <linux/seq_file.h>
17
#include <linux/notifier.h>
18
#include <linux/debugfs.h>
19
#include <linux/pagemap.h>
20
21
22
23
24
25
#include <linux/hardirq.h>
#include <linux/linkage.h>
#include <linux/uaccess.h>
#include <linux/ftrace.h>
#include <linux/module.h>
#include <linux/percpu.h>
26
#include <linux/kdebug.h>
27
28
#include <linux/ctype.h>
#include <linux/init.h>
29
#include <linux/poll.h>
30
31
#include <linux/gfp.h>
#include <linux/fs.h>
32
#include <linux/kprobes.h>
33
#include <linux/seq_file.h>
Steven Rostedt's avatar
Steven Rostedt committed
34
#include <linux/writeback.h>
35

Ingo Molnar's avatar
Ingo Molnar committed
36
#include <linux/stacktrace.h>
37
#include <linux/ring_buffer.h>
38
#include <linux/irqflags.h>
Ingo Molnar's avatar
Ingo Molnar committed
39

40
41
#include "trace.h"

42
43
#define TRACE_BUFFER_FLAGS	(RB_FL_OVERWRITE)

44
45
46
unsigned long __read_mostly	tracing_max_latency = (cycle_t)ULONG_MAX;
unsigned long __read_mostly	tracing_thresh;

47
48
/*
 * We need to change this state when a selftest is running.
49
50
51
52
53
 * A selftest will lurk into the ring-buffer to count the
 * entries inserted during the selftest although some concurrent
 * insertions into the ring-buffer such as ftrace_printk could occurred
 * at the same time, giving false positive or negative results.
 */
54
static bool __read_mostly tracing_selftest_running;
55

56
57
58
59
60
61
62
63
64
65
66
67
68
69
/* For tracers that don't implement custom flags */
static struct tracer_opt dummy_tracer_opt[] = {
	{ }
};

static struct tracer_flags dummy_tracer_flags = {
	.val = 0,
	.opts = dummy_tracer_opt
};

static int dummy_set_flag(u32 old_flags, u32 bit, int set)
{
	return 0;
}
70
71
72
73
74
75
76
77
78

/*
 * Kill all tracing for good (never come back).
 * It is initialized to 1 but will turn to zero if the initialization
 * of the tracer is successful. But that is the only place that sets
 * this back to zero.
 */
int tracing_disabled = 1;

79
80
81
82
83
84
85
86
87
88
89
90
91
92
static DEFINE_PER_CPU(local_t, ftrace_cpu_disabled);

static inline void ftrace_disable_cpu(void)
{
	preempt_disable();
	local_inc(&__get_cpu_var(ftrace_cpu_disabled));
}

static inline void ftrace_enable_cpu(void)
{
	local_dec(&__get_cpu_var(ftrace_cpu_disabled));
	preempt_enable();
}

93
94
95
96
97
static cpumask_t __read_mostly		tracing_buffer_mask;

#define for_each_tracing_cpu(cpu)	\
	for_each_cpu_mask(cpu, tracing_buffer_mask)

98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
/*
 * ftrace_dump_on_oops - variable to dump ftrace buffer on oops
 *
 * If there is an oops (or kernel panic) and the ftrace_dump_on_oops
 * is set, then ftrace_dump is called. This will output the contents
 * of the ftrace buffers to the console.  This is very useful for
 * capturing traces that lead to crashes and outputing it to a
 * serial console.
 *
 * It is default off, but you can enable it with either specifying
 * "ftrace_dump_on_oops" in the kernel command line, or setting
 * /proc/sys/kernel/ftrace_dump_on_oops to true.
 */
int ftrace_dump_on_oops;

113
114
115
116
117
118
119
120
121
static int tracing_set_tracer(char *buf);

static int __init set_ftrace(char *str)
{
	tracing_set_tracer(str);
	return 1;
}
__setup("ftrace", set_ftrace);

122
123
124
125
126
127
128
static int __init set_ftrace_dump_on_oops(char *str)
{
	ftrace_dump_on_oops = 1;
	return 1;
}
__setup("ftrace_dump_on_oops", set_ftrace_dump_on_oops);

129
long
130
131
132
133
134
135
136
ns2usecs(cycle_t nsec)
{
	nsec += 500;
	do_div(nsec, 1000);
	return nsec;
}

Ingo Molnar's avatar
Ingo Molnar committed
137
cycle_t ftrace_now(int cpu)
138
{
139
140
141
	u64 ts = ring_buffer_time_stamp(cpu);
	ring_buffer_normalize_time_stamp(cpu, &ts);
	return ts;
142
143
}

Steven Rostedt's avatar
Steven Rostedt committed
144
145
146
147
148
149
150
151
152
153
154
155
/*
 * The global_trace is the descriptor that holds the tracing
 * buffers for the live tracing. For each CPU, it contains
 * a link list of pages that will store trace entries. The
 * page descriptor of the pages in the memory is used to hold
 * the link list by linking the lru item in the page descriptor
 * to each of the pages in the buffer per CPU.
 *
 * For each active CPU there is a data field that holds the
 * pages for the buffer for that CPU. Each CPU has the same number
 * of pages allocated for its buffer.
 */
156
157
158
159
static struct trace_array	global_trace;

static DEFINE_PER_CPU(struct trace_array_cpu, global_trace_cpu);

Steven Rostedt's avatar
Steven Rostedt committed
160
161
162
163
164
165
166
167
168
169
/*
 * The max_tr is used to snapshot the global_trace when a maximum
 * latency is reached. Some tracers will use this to store a maximum
 * trace while it continues examining live traces.
 *
 * The buffers for the max_tr are set up the same as the global_trace.
 * When a snapshot is taken, the link list of the max_tr is swapped
 * with the link list of the global_trace and the buffers are reset for
 * the global_trace so the tracing can continue.
 */
170
171
172
173
static struct trace_array	max_tr;

static DEFINE_PER_CPU(struct trace_array_cpu, max_data);

Steven Rostedt's avatar
Steven Rostedt committed
174
/* tracer_enabled is used to toggle activation of a tracer */
175
static int			tracer_enabled = 1;
Steven Rostedt's avatar
Steven Rostedt committed
176

177
178
179
180
181
182
183
184
185
186
187
188
189
/**
 * tracing_is_enabled - return tracer_enabled status
 *
 * This function is used by other tracers to know the status
 * of the tracer_enabled flag.  Tracers may use this function
 * to know if it should enable their features when starting
 * up. See irqsoff tracer for an example (start_irqsoff_tracer).
 */
int tracing_is_enabled(void)
{
	return tracer_enabled;
}

190
191
192
/* function tracing enabled */
int				ftrace_function_enabled;

Steven Rostedt's avatar
Steven Rostedt committed
193
/*
194
195
196
 * trace_buf_size is the size in bytes that is allocated
 * for a buffer. Note, the number of bytes is always rounded
 * to page size.
197
198
199
200
201
 *
 * This number is purposely set to a low number of 16384.
 * If the dump on oops happens, it will be much appreciated
 * to not have to wait for all that output. Anyway this can be
 * boot time and run time configurable.
Steven Rostedt's avatar
Steven Rostedt committed
202
 */
203
#define TRACE_BUF_SIZE_DEFAULT	1441792UL /* 16384 * 88 (sizeof(entry)) */
204

205
static unsigned long		trace_buf_size = TRACE_BUF_SIZE_DEFAULT;
206

Steven Rostedt's avatar
Steven Rostedt committed
207
/* trace_types holds a link list of available tracers. */
208
static struct tracer		*trace_types __read_mostly;
Steven Rostedt's avatar
Steven Rostedt committed
209
210

/* current_trace points to the tracer that is currently active */
211
static struct tracer		*current_trace __read_mostly;
Steven Rostedt's avatar
Steven Rostedt committed
212
213
214
215
216
217

/*
 * max_tracer_type_len is used to simplify the allocating of
 * buffers to read userspace tracer names. We keep track of
 * the longest tracer name registered.
 */
218
219
static int			max_tracer_type_len;

Steven Rostedt's avatar
Steven Rostedt committed
220
221
222
223
224
225
/*
 * trace_types_lock is used to protect the trace_types list.
 * This lock is also used to keep user access serialized.
 * Accesses from userspace will grab this lock while userspace
 * activities happen inside the kernel.
 */
226
static DEFINE_MUTEX(trace_types_lock);
Steven Rostedt's avatar
Steven Rostedt committed
227
228

/* trace_wait is a waitqueue for tasks blocked on trace_poll */
229
230
static DECLARE_WAIT_QUEUE_HEAD(trace_wait);

231
/* trace_flags holds trace_options default values */
232
233
unsigned long trace_flags = TRACE_ITER_PRINT_PARENT | TRACE_ITER_PRINTK |
	TRACE_ITER_ANNOTATE;
234

Steven Rostedt's avatar
Steven Rostedt committed
235
236
237
238
239
240
/**
 * trace_wake_up - wake up tasks waiting for trace input
 *
 * Simply wakes up any task that is blocked on the trace_wait
 * queue. These is used with trace_poll for tasks polling the trace.
 */
241
242
void trace_wake_up(void)
{
Ingo Molnar's avatar
Ingo Molnar committed
243
244
245
246
247
	/*
	 * The runqueue_is_locked() can fail, but this is the best we
	 * have for now:
	 */
	if (!(trace_flags & TRACE_ITER_BLOCK) && !runqueue_is_locked())
248
249
		wake_up(&trace_wait);
}
250

251
static int __init set_buf_size(char *str)
252
{
253
	unsigned long buf_size;
254
255
	int ret;

256
257
	if (!str)
		return 0;
258
	ret = strict_strtoul(str, 0, &buf_size);
259
	/* nr_entries can not be zero */
260
	if (ret < 0 || buf_size == 0)
261
		return 0;
262
	trace_buf_size = buf_size;
263
264
	return 1;
}
265
__setup("trace_buf_size=", set_buf_size);
266

Steven Rostedt's avatar
Steven Rostedt committed
267
268
269
270
271
unsigned long nsecs_to_usecs(unsigned long nsecs)
{
	return nsecs / 1000;
}

Steven Rostedt's avatar
Steven Rostedt committed
272
/* These must match the bit postions in trace_iterator_flags */
273
274
275
276
277
static const char *trace_options[] = {
	"print-parent",
	"sym-offset",
	"sym-addr",
	"verbose",
Ingo Molnar's avatar
Ingo Molnar committed
278
	"raw",
279
	"hex",
Ingo Molnar's avatar
Ingo Molnar committed
280
	"bin",
281
	"block",
Ingo Molnar's avatar
Ingo Molnar committed
282
	"stacktrace",
Ingo Molnar's avatar
Ingo Molnar committed
283
	"sched-tree",
284
	"ftrace_printk",
285
	"ftrace_preempt",
286
	"branch",
287
	"annotate",
288
	"userstacktrace",
289
	"sym-userobj",
290
	"printk-msg-only",
291
292
293
	NULL
};

Steven Rostedt's avatar
Steven Rostedt committed
294
295
296
297
298
299
300
301
302
/*
 * ftrace_max_lock is used to protect the swapping of buffers
 * when taking a max snapshot. The buffers themselves are
 * protected by per_cpu spinlocks. But the action of the swap
 * needs its own lock.
 *
 * This is defined as a raw_spinlock_t in order to help
 * with performance when lockdep debugging is enabled.
 */
303
304
static raw_spinlock_t ftrace_max_lock =
	(raw_spinlock_t)__RAW_SPIN_LOCK_UNLOCKED;
305
306
307
308
309
310

/*
 * Copy the new maximum trace into the separate maximum-trace
 * structure. (this way the maximum trace is permanently saved,
 * for later retrieval via /debugfs/tracing/latency_trace)
 */
Ingo Molnar's avatar
Ingo Molnar committed
311
static void
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
__update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu)
{
	struct trace_array_cpu *data = tr->data[cpu];

	max_tr.cpu = cpu;
	max_tr.time_start = data->preempt_timestamp;

	data = max_tr.data[cpu];
	data->saved_latency = tracing_max_latency;

	memcpy(data->comm, tsk->comm, TASK_COMM_LEN);
	data->pid = tsk->pid;
	data->uid = tsk->uid;
	data->nice = tsk->static_prio - 20 - MAX_RT_PRIO;
	data->policy = tsk->policy;
	data->rt_priority = tsk->rt_priority;

	/* record this tasks comm */
	tracing_record_cmdline(current);
}

Steven Rostedt's avatar
Steven Rostedt committed
333
334
335
336
337
338
339
340
341
342
343
/**
 * trace_seq_printf - sequence printing of trace information
 * @s: trace sequence descriptor
 * @fmt: printf format string
 *
 * The tracer may use either sequence operations or its own
 * copy to user routines. To simplify formating of a trace
 * trace_seq_printf is used to store strings into a special
 * buffer (@s). Then the output may be either used by
 * the sequencer or pulled into another buffer.
 */
344
int
345
346
347
348
trace_seq_printf(struct trace_seq *s, const char *fmt, ...)
{
	int len = (PAGE_SIZE - 1) - s->len;
	va_list ap;
349
	int ret;
350
351
352
353
354

	if (!len)
		return 0;

	va_start(ap, fmt);
355
	ret = vsnprintf(s->buffer + s->len, len, fmt, ap);
356
357
	va_end(ap);

358
	/* If we can't write it all, don't bother writing anything */
359
	if (ret >= len)
360
361
362
		return 0;

	s->len += ret;
363
364
365
366

	return len;
}

Steven Rostedt's avatar
Steven Rostedt committed
367
368
369
370
371
372
373
374
375
376
/**
 * trace_seq_puts - trace sequence printing of simple string
 * @s: trace sequence descriptor
 * @str: simple string to record
 *
 * The tracer may use either the sequence operations or its own
 * copy to user routines. This function records a simple string
 * into a special buffer (@s) for later retrieval by a sequencer
 * or other mechanism.
 */
Ingo Molnar's avatar
Ingo Molnar committed
377
static int
378
379
380
381
382
trace_seq_puts(struct trace_seq *s, const char *str)
{
	int len = strlen(str);

	if (len > ((PAGE_SIZE - 1) - s->len))
383
		return 0;
384
385
386
387
388
389
390

	memcpy(s->buffer + s->len, str, len);
	s->len += len;

	return len;
}

Ingo Molnar's avatar
Ingo Molnar committed
391
static int
392
393
394
395
396
397
398
399
400
401
trace_seq_putc(struct trace_seq *s, unsigned char c)
{
	if (s->len >= (PAGE_SIZE - 1))
		return 0;

	s->buffer[s->len++] = c;

	return 1;
}

Ingo Molnar's avatar
Ingo Molnar committed
402
static int
Ingo Molnar's avatar
Ingo Molnar committed
403
404
405
406
407
408
409
410
411
412
413
trace_seq_putmem(struct trace_seq *s, void *mem, size_t len)
{
	if (len > ((PAGE_SIZE - 1) - s->len))
		return 0;

	memcpy(s->buffer + s->len, mem, len);
	s->len += len;

	return len;
}

414
415
#define MAX_MEMHEX_BYTES	8
#define HEX_CHARS		(MAX_MEMHEX_BYTES*2 + 1)
416

Ingo Molnar's avatar
Ingo Molnar committed
417
static int
418
419
420
trace_seq_putmem_hex(struct trace_seq *s, void *mem, size_t len)
{
	unsigned char hex[HEX_CHARS];
Thomas Gleixner's avatar
Thomas Gleixner committed
421
	unsigned char *data = mem;
422
423
424
425
426
427
428
	int i, j;

#ifdef __BIG_ENDIAN
	for (i = 0, j = 0; i < len; i++) {
#else
	for (i = len-1, j = 0; i >= 0; i--) {
#endif
429
430
		hex[j++] = hex_asc_hi(data[i]);
		hex[j++] = hex_asc_lo(data[i]);
431
	}
Thomas Gleixner's avatar
Thomas Gleixner committed
432
	hex[j++] = ' ';
433
434
435
436

	return trace_seq_putmem(s, hex, j);
}

437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
static int
trace_seq_path(struct trace_seq *s, struct path *path)
{
	unsigned char *p;

	if (s->len >= (PAGE_SIZE - 1))
		return 0;
	p = d_path(path, s->buffer + s->len, PAGE_SIZE - s->len);
	if (!IS_ERR(p)) {
		p = mangle_path(s->buffer + s->len, p, "\n");
		if (p) {
			s->len = p - s->buffer;
			return 1;
		}
	} else {
		s->buffer[s->len++] = '?';
		return 1;
	}

	return 0;
}

Ingo Molnar's avatar
Ingo Molnar committed
459
static void
460
461
462
trace_seq_reset(struct trace_seq *s)
{
	s->len = 0;
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
	s->readpos = 0;
}

ssize_t trace_seq_to_user(struct trace_seq *s, char __user *ubuf, size_t cnt)
{
	int len;
	int ret;

	if (s->len <= s->readpos)
		return -EBUSY;

	len = s->len - s->readpos;
	if (cnt > len)
		cnt = len;
	ret = copy_to_user(ubuf, s->buffer + s->readpos, cnt);
	if (ret)
		return -EFAULT;

	s->readpos += len;
	return cnt;
483
484
}

Ingo Molnar's avatar
Ingo Molnar committed
485
static void
486
487
488
489
490
491
492
493
494
495
trace_print_seq(struct seq_file *m, struct trace_seq *s)
{
	int len = s->len >= PAGE_SIZE ? PAGE_SIZE - 1 : s->len;

	s->buffer[len] = 0;
	seq_puts(m, s->buffer);

	trace_seq_reset(s);
}

Steven Rostedt's avatar
Steven Rostedt committed
496
497
498
499
500
501
502
503
504
/**
 * update_max_tr - snapshot all trace buffers from global_trace to max_tr
 * @tr: tracer
 * @tsk: the task with the latency
 * @cpu: The cpu that initiated the trace.
 *
 * Flip the buffers between the @tr and the max_tr and record information
 * about which task was the cause of this latency.
 */
Ingo Molnar's avatar
Ingo Molnar committed
505
void
506
507
update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu)
{
508
	struct ring_buffer *buf = tr->buffer;
509

510
	WARN_ON_ONCE(!irqs_disabled());
511
	__raw_spin_lock(&ftrace_max_lock);
512
513
514
515

	tr->buffer = max_tr.buffer;
	max_tr.buffer = buf;

516
	ftrace_disable_cpu();
517
	ring_buffer_reset(tr->buffer);
518
	ftrace_enable_cpu();
519
520

	__update_max_tr(tr, tsk, cpu);
521
	__raw_spin_unlock(&ftrace_max_lock);
522
523
524
525
526
527
528
}

/**
 * update_max_tr_single - only copy one trace over, and reset the rest
 * @tr - tracer
 * @tsk - task with the latency
 * @cpu - the cpu of the buffer to copy.
Steven Rostedt's avatar
Steven Rostedt committed
529
530
 *
 * Flip the trace of a single CPU buffer between the @tr and the max_tr.
531
 */
Ingo Molnar's avatar
Ingo Molnar committed
532
void
533
534
update_max_tr_single(struct trace_array *tr, struct task_struct *tsk, int cpu)
{
535
	int ret;
536

537
	WARN_ON_ONCE(!irqs_disabled());
538
	__raw_spin_lock(&ftrace_max_lock);
539

540
541
	ftrace_disable_cpu();

542
543
544
	ring_buffer_reset(max_tr.buffer);
	ret = ring_buffer_swap_cpu(max_tr.buffer, tr->buffer, cpu);

545
546
	ftrace_enable_cpu();

547
	WARN_ON_ONCE(ret);
548
549

	__update_max_tr(tr, tsk, cpu);
550
	__raw_spin_unlock(&ftrace_max_lock);
551
552
}

Steven Rostedt's avatar
Steven Rostedt committed
553
554
555
556
557
558
/**
 * register_tracer - register a tracer with the ftrace system.
 * @type - the plugin for the tracer
 *
 * Register a new plugin tracer.
 */
559
560
561
562
563
564
565
566
567
568
569
int register_tracer(struct tracer *type)
{
	struct tracer *t;
	int len;
	int ret = 0;

	if (!type->name) {
		pr_info("Tracer must have a name\n");
		return -1;
	}

Ingo Molnar's avatar
Ingo Molnar committed
570
571
572
573
574
575
576
	/*
	 * When this gets called we hold the BKL which means that
	 * preemption is disabled. Various trace selftests however
	 * need to disable and enable preemption for successful tests.
	 * So we drop the BKL here and grab it after the tests again.
	 */
	unlock_kernel();
577
	mutex_lock(&trace_types_lock);
Ingo Molnar's avatar
Ingo Molnar committed
578

579
580
	tracing_selftest_running = true;

581
582
583
584
585
586
587
588
589
590
	for (t = trace_types; t; t = t->next) {
		if (strcmp(type->name, t->name) == 0) {
			/* already found */
			pr_info("Trace %s already registered\n",
				type->name);
			ret = -1;
			goto out;
		}
	}

591
592
593
594
595
596
597
598
	if (!type->set_flag)
		type->set_flag = &dummy_set_flag;
	if (!type->flags)
		type->flags = &dummy_tracer_flags;
	else
		if (!type->flags->opts)
			type->flags->opts = dummy_tracer_opt;

Steven Rostedt's avatar
Steven Rostedt committed
599
600
601
602
603
#ifdef CONFIG_FTRACE_STARTUP_TEST
	if (type->selftest) {
		struct tracer *saved_tracer = current_trace;
		struct trace_array *tr = &global_trace;
		int i;
604

Steven Rostedt's avatar
Steven Rostedt committed
605
606
607
608
609
610
611
		/*
		 * Run a selftest on this tracer.
		 * Here we reset the trace buffer, and set the current
		 * tracer to be this tracer. The tracer can then run some
		 * internal tracing to verify that everything is in order.
		 * If we fail, we do not register this tracer.
		 */
Ingo Molnar's avatar
Ingo Molnar committed
612
		for_each_tracing_cpu(i)
613
			tracing_reset(tr, i);
Ingo Molnar's avatar
Ingo Molnar committed
614

Steven Rostedt's avatar
Steven Rostedt committed
615
616
617
618
619
620
621
622
623
624
		current_trace = type;
		/* the test is responsible for initializing and enabling */
		pr_info("Testing tracer %s: ", type->name);
		ret = type->selftest(type, tr);
		/* the test is responsible for resetting too */
		current_trace = saved_tracer;
		if (ret) {
			printk(KERN_CONT "FAILED!\n");
			goto out;
		}
Steven Rostedt's avatar
Steven Rostedt committed
625
		/* Only reset on passing, to avoid touching corrupted buffers */
Ingo Molnar's avatar
Ingo Molnar committed
626
		for_each_tracing_cpu(i)
627
			tracing_reset(tr, i);
Ingo Molnar's avatar
Ingo Molnar committed
628

Steven Rostedt's avatar
Steven Rostedt committed
629
630
631
632
		printk(KERN_CONT "PASSED\n");
	}
#endif

633
634
635
636
637
	type->next = trace_types;
	trace_types = type;
	len = strlen(type->name);
	if (len > max_tracer_type_len)
		max_tracer_type_len = len;
Steven Rostedt's avatar
Steven Rostedt committed
638

639
 out:
640
	tracing_selftest_running = false;
641
	mutex_unlock(&trace_types_lock);
Ingo Molnar's avatar
Ingo Molnar committed
642
	lock_kernel();
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674

	return ret;
}

void unregister_tracer(struct tracer *type)
{
	struct tracer **t;
	int len;

	mutex_lock(&trace_types_lock);
	for (t = &trace_types; *t; t = &(*t)->next) {
		if (*t == type)
			goto found;
	}
	pr_info("Trace %s not registered\n", type->name);
	goto out;

 found:
	*t = (*t)->next;
	if (strlen(type->name) != max_tracer_type_len)
		goto out;

	max_tracer_type_len = 0;
	for (t = &trace_types; *t; t = &(*t)->next) {
		len = strlen((*t)->name);
		if (len > max_tracer_type_len)
			max_tracer_type_len = len;
	}
 out:
	mutex_unlock(&trace_types_lock);
}

675
void tracing_reset(struct trace_array *tr, int cpu)
676
{
677
	ftrace_disable_cpu();
678
	ring_buffer_reset_cpu(tr->buffer, cpu);
679
	ftrace_enable_cpu();
680
681
682
683
684
685
686
687
}

#define SAVED_CMDLINES 128
static unsigned map_pid_to_cmdline[PID_MAX_DEFAULT+1];
static unsigned map_cmdline_to_pid[SAVED_CMDLINES];
static char saved_cmdlines[SAVED_CMDLINES][TASK_COMM_LEN];
static int cmdline_idx;
static DEFINE_SPINLOCK(trace_cmdline_lock);
688
689
690

/* temporary disable recording */
atomic_t trace_record_cmdline_disabled __read_mostly;
691
692
693
694
695
696
697
698

static void trace_init_cmdlines(void)
{
	memset(&map_pid_to_cmdline, -1, sizeof(map_pid_to_cmdline));
	memset(&map_cmdline_to_pid, -1, sizeof(map_cmdline_to_pid));
	cmdline_idx = 0;
}

699
700
701
static int trace_stop_count;
static DEFINE_SPINLOCK(tracing_start_lock);

702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
/**
 * ftrace_off_permanent - disable all ftrace code permanently
 *
 * This should only be called when a serious anomally has
 * been detected.  This will turn off the function tracing,
 * ring buffers, and other tracing utilites. It takes no
 * locks and can be called from any context.
 */
void ftrace_off_permanent(void)
{
	tracing_disabled = 1;
	ftrace_stop();
	tracing_off_permanent();
}

717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
/**
 * tracing_start - quick start of the tracer
 *
 * If tracing is enabled but was stopped by tracing_stop,
 * this will start the tracer back up.
 */
void tracing_start(void)
{
	struct ring_buffer *buffer;
	unsigned long flags;

	if (tracing_disabled)
		return;

	spin_lock_irqsave(&tracing_start_lock, flags);
	if (--trace_stop_count)
		goto out;

	if (trace_stop_count < 0) {
		/* Someone screwed up their debugging */
		WARN_ON_ONCE(1);
		trace_stop_count = 0;
		goto out;
	}


	buffer = global_trace.buffer;
	if (buffer)
		ring_buffer_record_enable(buffer);

	buffer = max_tr.buffer;
	if (buffer)
		ring_buffer_record_enable(buffer);

	ftrace_start();
 out:
	spin_unlock_irqrestore(&tracing_start_lock, flags);
}

/**
 * tracing_stop - quick stop of the tracer
 *
 * Light weight way to stop tracing. Use in conjunction with
 * tracing_start.
 */
void tracing_stop(void)
{
	struct ring_buffer *buffer;
	unsigned long flags;

	ftrace_stop();
	spin_lock_irqsave(&tracing_start_lock, flags);
	if (trace_stop_count++)
		goto out;

	buffer = global_trace.buffer;
	if (buffer)
		ring_buffer_record_disable(buffer);

	buffer = max_tr.buffer;
	if (buffer)
		ring_buffer_record_disable(buffer);

 out:
	spin_unlock_irqrestore(&tracing_start_lock, flags);
}

Ingo Molnar's avatar
Ingo Molnar committed
784
void trace_stop_cmdline_recording(void);
785

Ingo Molnar's avatar
Ingo Molnar committed
786
static void trace_save_cmdline(struct task_struct *tsk)
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
{
	unsigned map;
	unsigned idx;

	if (!tsk->pid || unlikely(tsk->pid > PID_MAX_DEFAULT))
		return;

	/*
	 * It's not the end of the world if we don't get
	 * the lock, but we also don't want to spin
	 * nor do we want to disable interrupts,
	 * so if we miss here, then better luck next time.
	 */
	if (!spin_trylock(&trace_cmdline_lock))
		return;

	idx = map_pid_to_cmdline[tsk->pid];
	if (idx >= SAVED_CMDLINES) {
		idx = (cmdline_idx + 1) % SAVED_CMDLINES;

		map = map_cmdline_to_pid[idx];
		if (map <= PID_MAX_DEFAULT)
			map_pid_to_cmdline[map] = (unsigned)-1;

		map_pid_to_cmdline[tsk->pid] = idx;

		cmdline_idx = idx;
	}

	memcpy(&saved_cmdlines[idx], tsk->comm, TASK_COMM_LEN);

	spin_unlock(&trace_cmdline_lock);
}

821
char *trace_find_cmdline(int pid)
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
{
	char *cmdline = "<...>";
	unsigned map;

	if (!pid)
		return "<idle>";

	if (pid > PID_MAX_DEFAULT)
		goto out;

	map = map_pid_to_cmdline[pid];
	if (map >= SAVED_CMDLINES)
		goto out;

	cmdline = saved_cmdlines[map];

 out:
	return cmdline;
}

Ingo Molnar's avatar
Ingo Molnar committed
842
void tracing_record_cmdline(struct task_struct *tsk)
843
844
845
846
847
848
849
{
	if (atomic_read(&trace_record_cmdline_disabled))
		return;

	trace_save_cmdline(tsk);
}

850
void
851
852
tracing_generic_entry_update(struct trace_entry *entry, unsigned long flags,
			     int pc)
853
854
855
{
	struct task_struct *tsk = current;

856
857
	entry->preempt_count		= pc & 0xff;
	entry->pid			= (tsk) ? tsk->pid : 0;
858
	entry->tgid               	= (tsk) ? tsk->tgid : 0;
859
	entry->flags =
860
#ifdef CONFIG_TRACE_IRQFLAGS_SUPPORT
861
		(irqs_disabled_flags(flags) ? TRACE_FLAG_IRQS_OFF : 0) |
862
863
864
#else
		TRACE_FLAG_IRQS_NOSUPPORT |
#endif
865
866
867
868
869
		((pc & HARDIRQ_MASK) ? TRACE_FLAG_HARDIRQ : 0) |
		((pc & SOFTIRQ_MASK) ? TRACE_FLAG_SOFTIRQ : 0) |
		(need_resched() ? TRACE_FLAG_NEED_RESCHED : 0);
}

Ingo Molnar's avatar
Ingo Molnar committed
870
void
871
trace_function(struct trace_array *tr, struct trace_array_cpu *data,
872
873
	       unsigned long ip, unsigned long parent_ip, unsigned long flags,
	       int pc)
874
{
875
	struct ring_buffer_event *event;
876
	struct ftrace_entry *entry;
Ingo Molnar's avatar
Ingo Molnar committed
877
	unsigned long irq_flags;
878

879
880
881
882
	/* If we are reading the ring buffer, don't trace */
	if (unlikely(local_read(&__get_cpu_var(ftrace_cpu_disabled))))
		return;

883
884
885
886
887
	event = ring_buffer_lock_reserve(tr->buffer, sizeof(*entry),
					 &irq_flags);
	if (!event)
		return;
	entry	= ring_buffer_event_data(event);
888
	tracing_generic_entry_update(&entry->ent, flags, pc);
889
890
891
	entry->ent.type			= TRACE_FN;
	entry->ip			= ip;
	entry->parent_ip		= parent_ip;
892
	ring_buffer_unlock_commit(tr->buffer, event, irq_flags);
893
894
}

895
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
static void __trace_graph_entry(struct trace_array *tr,
				struct trace_array_cpu *data,
				struct ftrace_graph_ent *trace,
				unsigned long flags,
				int pc)
{
	struct ring_buffer_event *event;
	struct ftrace_graph_ent_entry *entry;
	unsigned long irq_flags;

	if (unlikely(local_read(&__get_cpu_var(ftrace_cpu_disabled))))
		return;

	event = ring_buffer_lock_reserve(global_trace.buffer, sizeof(*entry),
					 &irq_flags);
	if (!event)
		return;
	entry	= ring_buffer_event_data(event);
	tracing_generic_entry_update(&entry->ent, flags, pc);
	entry->ent.type			= TRACE_GRAPH_ENT;
	entry->graph_ent			= *trace;
	ring_buffer_unlock_commit(global_trace.buffer, event, irq_flags);
}

static void __trace_graph_return(struct trace_array *tr,
921
				struct trace_array_cpu *data,
922
				struct ftrace_graph_ret *trace,
923
924
925
926
				unsigned long flags,
				int pc)
{
	struct ring_buffer_event *event;
927
	struct ftrace_graph_ret_entry *entry;
928
929
930
931
932
933
934
935
936
937
938
	unsigned long irq_flags;

	if (unlikely(local_read(&__get_cpu_var(ftrace_cpu_disabled))))
		return;

	event = ring_buffer_lock_reserve(global_trace.buffer, sizeof(*entry),
					 &irq_flags);
	if (!event)
		return;
	entry	= ring_buffer_event_data(event);
	tracing_generic_entry_update(&entry->ent, flags, pc);
939
940
	entry->ent.type			= TRACE_GRAPH_RET;
	entry->ret				= *trace;
941
942
943
944
	ring_buffer_unlock_commit(global_trace.buffer, event, irq_flags);
}
#endif

Ingo Molnar's avatar
Ingo Molnar committed
945
void
Ingo Molnar's avatar
Ingo Molnar committed
946
ftrace(struct trace_array *tr, struct trace_array_cpu *data,
947
948
       unsigned long ip, unsigned long parent_ip, unsigned long flags,
       int pc)
Ingo Molnar's avatar
Ingo Molnar committed
949
950
{
	if (likely(!atomic_read(&data->disabled)))
951
		trace_function(tr, data, ip, parent_ip, flags, pc);
Ingo Molnar's avatar
Ingo Molnar committed
952
953
}

954
955
956
957
static void ftrace_trace_stack(struct trace_array *tr,
			       struct trace_array_cpu *data,
			       unsigned long flags,
			       int skip, int pc)
Ingo Molnar's avatar
Ingo Molnar committed
958
{
959
#ifdef CONFIG_STACKTRACE
960
	struct ring_buffer_event *event;
961
	struct stack_entry *entry;
Ingo Molnar's avatar
Ingo Molnar committed
962
	struct stack_trace trace;
963
	unsigned long irq_flags;
Ingo Molnar's avatar
Ingo Molnar committed
964
965
966
967

	if (!(trace_flags & TRACE_ITER_STACKTRACE))
		return;

968
969
970
971
972
	event = ring_buffer_lock_reserve(tr->buffer, sizeof(*entry),
					 &irq_flags);
	if (!event)
		return;
	entry	= ring_buffer_event_data(event);
973
	tracing_generic_entry_update(&entry->ent, flags, pc);
974
	entry->ent.type		= TRACE_STACK;
Ingo Molnar's avatar
Ingo Molnar committed
975

976
	memset(&entry->caller, 0, sizeof(entry->caller));
Ingo Molnar's avatar
Ingo Molnar committed
977
978
979
980

	trace.nr_entries	= 0;
	trace.max_entries	= FTRACE_STACK_ENTRIES;
	trace.skip		= skip;
981
	trace.entries		= entry->caller;
Ingo Molnar's avatar
Ingo Molnar committed
982
983

	save_stack_trace(&trace);
984
	ring_buffer_unlock_commit(tr->buffer, event, irq_flags);
985
#endif
Ingo Molnar's avatar
Ingo Molnar committed
986
987
}

988
989
990
991
992
993
994
995
void __trace_stack(struct trace_array *tr,
		   struct trace_array_cpu *data,
		   unsigned long flags,
		   int skip)
{
	ftrace_trace_stack(tr, data, flags, skip, preempt_count());
}

996
997
998
999
static void ftrace_trace_userstack(struct trace_array *tr,
		   struct trace_array_cpu *data,
		   unsigned long flags, int pc)
{
1000
#ifdef CONFIG_STACKTRACE
1001
	struct ring_buffer_event *event;
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
	struct userstack_entry *entry;
	struct stack_trace trace;
	unsigned long irq_flags;

	if (!(trace_flags & TRACE_ITER_USERSTACKTRACE))
		return;

	event = ring_buffer_lock_reserve(tr->buffer, sizeof(*entry),
					 &irq_flags);
	if (!event)
		return;
	entry	= ring_buffer_event_data(event);
	tracing_generic_entry_update(&entry->ent, flags, pc);
	entry->ent.type		= TRACE_USER_STACK;

	memset(&entry->caller, 0, sizeof(entry->caller));

	trace.nr_entries	= 0;
	trace.max_entries	= FTRACE_STACK_ENTRIES;
	trace.skip		= 0;
	trace.entries		= entry->caller;

	save_stack_trace_user(&trace);
	ring_buffer_unlock_commit(tr->buffer, event, irq_flags);
1026
#endif
1027
1028
1029
1030
1031
1032
1033
1034
1035
}

void __trace_userstack(struct trace_array *tr,
		   struct trace_array_cpu *data,
		   unsigned long flags)
{
	ftrace_trace_userstack(tr, data, flags, preempt_count());
}

1036
1037
1038
1039
static void
ftrace_trace_special(void *__tr, void *__data,
		     unsigned long arg1, unsigned long arg2, unsigned long arg3,
		     int pc)
Ingo Molnar's avatar
Ingo Molnar committed
1040
{
1041
	struct ring_buffer_event *event;
Ingo Molnar's avatar
Ingo Molnar committed
1042
1043
	struct trace_array_cpu *data = __data;
	struct trace_array *tr = __tr;
1044
	struct special_entry *entry;
Ingo Molnar's avatar
Ingo Molnar committed
1045
1046
	unsigned long irq_flags;

1047
1048
1049
1050
1051
	event = ring_buffer_lock_reserve(tr->buffer, sizeof(*entry),
					 &irq_flags);
	if (!event)
		return;
	entry	= ring_buffer_event_data(event);
1052
	tracing_generic_entry_update(&entry->ent, 0, pc);
1053
1054
1055
1056
	entry->ent.type			= TRACE_SPECIAL;
	entry->arg1			= arg1;
	entry->arg2			= arg2;
	entry->arg3			= arg3;
1057
	ring_buffer_unlock_commit(tr->buffer, event, irq_flags);
1058
	ftrace_trace_stack(tr, data, irq_flags, 4, pc);
1059
	ftrace_trace_userstack(tr, data, irq_flags, pc);
Ingo Molnar's avatar
Ingo Molnar committed
1060
1061
1062
1063

	trace_wake_up();
}

1064
1065
1066
1067
1068
1069
1070
void
__trace_special(void *__tr, void *__data,
		unsigned long arg1, unsigned long arg2, unsigned long arg3)
{
	ftrace_trace_special(__tr, __data, arg1, arg2, arg3, preempt_count());
}

Ingo Molnar's avatar
Ingo Molnar committed
1071
void
1072
1073
tracing_sched_switch_trace(struct trace_array *tr,
			   struct trace_array_cpu *data,
Ingo Molnar's avatar
Ingo Molnar committed
1074
1075
			   struct task_struct *prev,
			   struct task_struct *next,
1076
			   unsigned long flags, int pc)
1077
{
1078
	struct ring_buffer_event *event;
1079
	struct ctx_switch_entry *entry;
Ingo Molnar's avatar
Ingo Molnar committed
1080
	unsigned long irq_flags;
1081

1082
1083
1084
1085
1086
	event = ring_buffer_lock_reserve(tr->buffer, sizeof(*entry),
					   &irq_flags);
	if (!event)
		return;
	entry	= ring_buffer_event_data(event);
1087
	tracing_generic_entry_update(&entry->ent, flags, pc);
1088
1089
1090
1091
1092
1093
1094
1095
	entry->ent.type			= TRACE_CTX;
	entry->prev_pid			= prev->pid;
	entry->prev_prio		= prev->prio;
	entry->prev_state		= prev->state;
	entry->next_pid			= next->pid;
	entry->next_prio		= next->prio;
	entry->next_state		= next->state;
	entry->next_cpu	= task_cpu(next);
1096
	ring_buffer_unlock_commit(tr->buffer, event, irq_flags);
1097
	ftrace_trace_stack(tr, data, flags, 5, pc);
1098
	ftrace_trace_userstack(tr, data, flags, pc);
1099
1100
}

1101
1102
1103
void
tracing_sched_wakeup_trace(struct trace_array *tr,
			   struct trace_array_cpu *data,
Ingo Molnar's avatar
Ingo Molnar committed
1104
1105
			   struct task_struct *wakee,
			   struct task_struct *curr,
1106
			   unsigned long flags, int pc)
1107
{
1108
	struct ring_buffer_event *event;
1109
	struct ctx_switch_entry *entry;
1110
1111
	unsigned long irq_flags;

1112
1113
1114
1115
1116
	event = ring_buffer_lock_reserve(tr->buffer, sizeof(*entry),
					   &irq_flags);
	if (!event)
		return;
	entry	= ring_buffer_event_data(event);
1117
	tracing_generic_entry_update(&entry->ent, flags, pc);
1118
1119
1120
1121
1122
1123
1124
1125
	entry->ent.type			= TRACE_WAKE;
	entry->prev_pid			= curr->pid;
	entry->prev_prio		= curr->prio;
	entry->prev_state		= curr->state;
	entry->next_pid			= wakee->pid;
	entry->next_prio		= wakee->prio;
	entry->next_state		= wakee->state;
	entry->next_cpu			= task_cpu(wakee);
1126
	ring_buffer_unlock_commit(tr->buffer, event, irq_flags);
1127
	ftrace_trace_stack(tr, data, flags, 6, pc);
1128
	ftrace_trace_userstack(tr, data, flags, pc);
Ingo Molnar's avatar
Ingo Molnar committed
1129
1130

	trace_wake_up();
1131
1132
}

1133
1134
1135
1136
1137
void
ftrace_special(unsigned long arg1, unsigned long arg2, unsigned long arg3)
{
	struct trace_array *tr = &global_trace;
	struct trace_array_cpu *data;
1138
	unsigned long flags;
1139
	int cpu;
1140
	int pc;
1141

1142
	if (tracing_disabled)
1143
1144
		return;

1145
	pc = preempt_count();
1146
	local_irq_save(flags);
1147
1148
1149
	cpu = raw_smp_processor_id();
	data = tr->data[cpu];

1150
	if (likely(atomic_inc_return(&data->disabled) == 1))
1151
		ftrace_trace_special(tr, data, arg1, arg2, arg3, pc);
1152

1153
1154
	atomic_dec(&data->disabled);
	local_irq_restore(flags);
1155
1156
}

1157
#ifdef CONFIG_FUNCTION_TRACER
Ingo Molnar's avatar
Ingo Molnar committed
1158
static void
1159
function_trace_call_preempt_only(unsigned long ip, unsigned long parent_ip)
Ingo Molnar's avatar
Ingo Molnar committed
1160
1161
1162
1163
1164
{
	struct trace_array *tr = &global_trace;
	struct trace_array_cpu *data;
	unsigned long flags;
	long disabled;
1165
1166
	int cpu, resched;
	int pc;
Ingo Molnar's avatar
Ingo Molnar committed
1167

1168
	if (unlikely(!ftrace_function_enabled))
Ingo Molnar's avatar
Ingo Molnar committed
1169
1170
		return;

1171
	pc = preempt_count();
1172
	resched = ftrace_preempt_disable();
1173
	local_save_flags(flags);
Ingo Molnar's avatar
Ingo Molnar committed
1174
1175
1176
1177
1178
	cpu = raw_smp_processor_id();
	data = tr->data[cpu];
	disabled = atomic_inc_return(&data->disabled);

	if (likely(disabled == 1))
1179
		trace_function(tr, data, ip, parent_ip, flags, pc);
Ingo Molnar's avatar
Ingo Molnar committed
1180
1181

	atomic_dec(&data->disabled);
1182
	ftrace_preempt_enable(resched);
Ingo Molnar's avatar
Ingo Molnar committed
1183
1184
}

1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
static void
function_trace_call(unsigned long ip, unsigned long parent_ip)
{
	struct trace_array *tr = &global_trace;
	struct trace_array_cpu *data;
	unsigned long flags;
	long disabled;
	int cpu;
	int pc;

	if (unlikely(!ftrace_function_enabled))
		return;

	/*
	 * Need to use raw, since this must be called before the
	 * recursive protection is performed.
	 */
1202
	local_irq_save(flags);
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
	cpu = raw_smp_processor_id();
	data = tr->data[cpu];
	disabled = atomic_inc_return(&data->disabled);

	if (likely(disabled == 1)) {
		pc = preempt_count();
		trace_function(tr, data, ip, parent_ip, flags, pc);
	}

	atomic_dec(&data->disabled);
1213
	local_irq_restore(flags);
1214
1215
}

1216
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
1217
int trace_graph_entry(struct ftrace_graph_ent *trace)
1218
1219
1220
1221
1222
1223
1224
1225
{
	struct trace_array *tr = &global_trace;
	struct trace_array_cpu *data;
	unsigned long flags;
	long disabled;
	int cpu;
	int pc;

1226
1227
1228
	if (!ftrace_trace_task(current))
		return 0;

1229
1230
1231
	if (!ftrace_graph_addr(trace->func))
		return 0;

1232
	local_irq_save(flags);
1233
1234
1235
1236
1237
	cpu = raw_smp_processor_id();
	data = tr->data[cpu];
	disabled = atomic_inc_return(&data->disabled);
	if (likely(disabled == 1)) {
		pc = preempt_count();
1238
1239
		__trace_graph_entry(tr, data, trace, flags, pc);
	}
1240
1241
1242
	/* Only do the atomic if it is not already set */
	if (!test_tsk_trace_graph(current))
		set_tsk_trace_graph(current);
1243
	atomic_dec(&data->disabled);
1244
	local_irq_restore(flags);
1245
1246

	return 1;
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
}

void trace_graph_return(struct ftrace_graph_ret *trace)
{
	struct trace_array *tr = &global_trace;
	struct trace_array_cpu *data;
	unsigned long flags;
	long disabled;
	int cpu;
	int pc;

1258
	local_irq_save(flags);
1259
1260
1261
1262
1263
1264
	cpu = raw_smp_processor_id();
	data = tr->data[cpu];
	disabled = atomic_inc_return(&data->disabled);
	if (likely(disabled == 1)) {
		pc = preempt_count();
		__trace_graph_return(tr, data, trace, flags, pc);
1265
	}
1266
1267
	if (!trace->depth)
		clear_tsk_trace_graph(current);
1268
	atomic_dec(&data->disabled);
1269
	local_irq_restore(flags);
1270
}
1271
#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
1272

Ingo Molnar's avatar
Ingo Molnar committed
1273
1274
1275
1276
1277
static struct ftrace_ops trace_ops __read_mostly =
{
	.func = function_trace_call,
};

Ingo Molnar's avatar
Ingo Molnar committed
1278
void tracing_start_function_trace(void)
Ingo Molnar's avatar
Ingo Molnar committed
1279
{
1280
	ftrace_function_enabled = 0;
1281
1282
1283
1284
1285
1286

	if (trace_flags & TRACE_ITER_PREEMPTONLY)
		trace_ops.func = function_trace_call_preempt_only;
	else
		trace_ops.func = function_trace_call;

Ingo Molnar's avatar
Ingo Molnar committed
1287
	register_ftrace_function(&trace_ops);
1288
	ftrace_function_enabled = 1;
Ingo Molnar's avatar
Ingo Molnar committed
1289
1290
}

Ingo Molnar's avatar
Ingo Molnar committed
1291
void tracing_stop_function_trace(void)
Ingo Molnar's avatar
Ingo Molnar committed
1292
{
1293
	ftrace_function_enabled = 0;
Ingo Molnar's avatar
Ingo Molnar committed
1294
1295
1296
1297
	unregister_ftrace_function(&trace_ops);
}
#endif

1298
1299
enum trace_file_type {
	TRACE_FILE_LAT_FMT	= 1,
1300
	TRACE_FILE_ANNOTATE	= 2,
1301
1302
};

1303
1304
static void trace_iterator_increment(struct trace_iterator *iter, int cpu)
{
1305
1306
1307
	/* Don't allow ftrace to trace into the ring buffers */
	ftrace_disable_cpu();