aboutsummaryrefslogtreecommitdiff
path: root/kernel/trace/trace_output.c
blob: 306fef84c503b86439c18fc44ff8f34460900881 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
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
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
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
784
785
786
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
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
/*
 * trace_output.c
 *
 * Copyright (C) 2008 Red Hat Inc, Steven Rostedt <srostedt@redhat.com>
 *
 */

#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/ftrace.h>

#include "trace_output.h"

/* must be a power of 2 */
#define EVENT_HASHSIZE	128

static DEFINE_MUTEX(trace_event_mutex);
static struct hlist_head event_hash[EVENT_HASHSIZE] __read_mostly;

static int next_event_type = __TRACE_LAST_TYPE + 1;

/**
 * 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.
 */
int
trace_seq_printf(struct trace_seq *s, const char *fmt, ...)
{
	int len = (PAGE_SIZE - 1) - s->len;
	va_list ap;
	int ret;

	if (!len)
		return 0;

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

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

	s->len += ret;

	return len;
}

/**
 * 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.
 */
int trace_seq_puts(struct trace_seq *s, const char *str)
{
	int len = strlen(str);

	if (len > ((PAGE_SIZE - 1) - s->len))
		return 0;

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

	return len;
}

int 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;
}

int 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;
}

int trace_seq_putmem_hex(struct trace_seq *s, void *mem, size_t len)
{
	unsigned char hex[HEX_CHARS];
	unsigned char *data = mem;
	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
		hex[j++] = hex_asc_hi(data[i]);
		hex[j++] = hex_asc_lo(data[i]);
	}
	hex[j++] = ' ';

	return trace_seq_putmem(s, hex, j);
}

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;
}

#ifdef CONFIG_KRETPROBES
static inline const char *kretprobed(const char *name)
{
	static const char tramp_name[] = "kretprobe_trampoline";
	int size = sizeof(tramp_name);

	if (strncmp(tramp_name, name, size) == 0)
		return "[unknown/kretprobe'd]";
	return name;
}
#else
static inline const char *kretprobed(const char *name)
{
	return name;
}
#endif /* CONFIG_KRETPROBES */

static int
seq_print_sym_short(struct trace_seq *s, const char *fmt, unsigned long address)
{
#ifdef CONFIG_KALLSYMS
	char str[KSYM_SYMBOL_LEN];
	const char *name;

	kallsyms_lookup(address, NULL, NULL, NULL, str);

	name = kretprobed(str);

	return trace_seq_printf(s, fmt, name);
#endif
	return 1;
}

static int
seq_print_sym_offset(struct trace_seq *s, const char *fmt,
		     unsigned long address)
{
#ifdef CONFIG_KALLSYMS
	char str[KSYM_SYMBOL_LEN];
	const char *name;

	sprint_symbol(str, address);
	name = kretprobed(str);

	return trace_seq_printf(s, fmt, name);
#endif
	return 1;
}

#ifndef CONFIG_64BIT
# define IP_FMT "%08lx"
#else
# define IP_FMT "%016lx"
#endif

int seq_print_user_ip(struct trace_seq *s, struct mm_struct *mm,
		      unsigned long ip, unsigned long sym_flags)
{
	struct file *file = NULL;
	unsigned long vmstart = 0;
	int ret = 1;

	if (mm) {
		const struct vm_area_struct *vma;

		down_read(&mm->mmap_sem);
		vma = find_vma(mm, ip);
		if (vma) {
			file = vma->vm_file;
			vmstart = vma->vm_start;
		}
		if (file) {
			ret = trace_seq_path(s, &file->f_path);
			if (ret)
				ret = trace_seq_printf(s, "[+0x%lx]",
						       ip - vmstart);
		}
		up_read(&mm->mmap_sem);
	}
	if (ret && ((sym_flags & TRACE_ITER_SYM_ADDR) || !file))
		ret = trace_seq_printf(s, " <" IP_FMT ">", ip);
	return ret;
}

int
seq_print_userip_objs(const struct userstack_entry *entry, struct trace_seq *s,
		      unsigned long sym_flags)
{
	struct mm_struct *mm = NULL;
	int ret = 1;
	unsigned int i;

	if (trace_flags & TRACE_ITER_SYM_USEROBJ) {
		struct task_struct *task;
		/*
		 * we do the lookup on the thread group leader,
		 * since individual threads might have already quit!
		 */
		rcu_read_lock();
		task = find_task_by_vpid(entry->ent.tgid);
		if (task)
			mm = get_task_mm(task);
		rcu_read_unlock();
	}

	for (i = 0; i < FTRACE_STACK_ENTRIES; i++) {
		unsigned long ip = entry->caller[i];

		if (ip == ULONG_MAX || !ret)
			break;
		if (i && ret)
			ret = trace_seq_puts(s, " <- ");
		if (!ip) {
			if (ret)
				ret = trace_seq_puts(s, "??");
			continue;
		}
		if (!ret)
			break;
		if (ret)
			ret = seq_print_user_ip(s, mm, ip, sym_flags);
	}

	if (mm)
		mmput(mm);
	return ret;
}

int
seq_print_ip_sym(struct trace_seq *s, unsigned long ip, unsigned long sym_flags)
{
	int ret;

	if (!ip)
		return trace_seq_printf(s, "0");

	if (sym_flags & TRACE_ITER_SYM_OFFSET)
		ret = seq_print_sym_offset(s, "%s", ip);
	else
		ret = seq_print_sym_short(s, "%s", ip);

	if (!ret)
		return 0;

	if (sym_flags & TRACE_ITER_SYM_ADDR)
		ret = trace_seq_printf(s, " <" IP_FMT ">", ip);
	return ret;
}

static int
lat_print_generic(struct trace_seq *s, struct trace_entry *entry, int cpu)
{
	int hardirq, softirq;
	char *comm;

	comm = trace_find_cmdline(entry->pid);
	hardirq = entry->flags & TRACE_FLAG_HARDIRQ;
	softirq = entry->flags & TRACE_FLAG_SOFTIRQ;

	if (!trace_seq_printf(s, "%8.8s-%-5d %3d%c%c%c",
			      comm, entry->pid, cpu,
			      (entry->flags & TRACE_FLAG_IRQS_OFF) ? 'd' :
				(entry->flags & TRACE_FLAG_IRQS_NOSUPPORT) ?
				  'X' : '.',
			      (entry->flags & TRACE_FLAG_NEED_RESCHED) ?
				'N' : '.',
			      (hardirq && softirq) ? 'H' :
				hardirq ? 'h' : softirq ? 's' : '.'))
		return 0;

	if (entry->preempt_count)
		return trace_seq_printf(s, "%x", entry->preempt_count);
	return trace_seq_puts(s, ".");
}

static unsigned long preempt_mark_thresh = 100;

static int
lat_print_timestamp(struct trace_seq *s, u64 abs_usecs,
		    unsigned long rel_usecs)
{
	return trace_seq_printf(s, " %4lldus%c: ", abs_usecs,
				rel_usecs > preempt_mark_thresh ? '!' :
				  rel_usecs > 1 ? '+' : ' ');
}

int trace_print_context(struct trace_iterator *iter)
{
	struct trace_seq *s = &iter->seq;
	struct trace_entry *entry = iter->ent;
	char *comm = trace_find_cmdline(entry->pid);
	unsigned long long t = ns2usecs(iter->ts);
	unsigned long usec_rem = do_div(t, USEC_PER_SEC);
	unsigned long secs = (unsigned long)t;

	return trace_seq_printf(s, "%16s-%-5d [%03d] %5lu.%06lu: ",
				comm, entry->pid, iter->cpu, secs, usec_rem);
}

int trace_print_lat_context(struct trace_iterator *iter)
{
	u64 next_ts;
	int ret;
	struct trace_seq *s = &iter->seq;
	struct trace_entry *entry = iter->ent,
			   *next_entry = trace_find_next_entry(iter, NULL,
							       &next_ts);
	unsigned long verbose = (trace_flags & TRACE_ITER_VERBOSE);
	unsigned long abs_usecs = ns2usecs(iter->ts - iter->tr->time_start);
	unsigned long rel_usecs;

	if (!next_entry)
		next_ts = iter->ts;
	rel_usecs = ns2usecs(next_ts - iter->ts);

	if (verbose) {
		char *comm = trace_find_cmdline(entry->pid);
		ret = trace_seq_printf(s, "%16s %5d %3d %d %08x %08lx [%08lx]"
				       " %ld.%03ldms (+%ld.%03ldms): ", comm,
				       entry->pid, iter->cpu, entry->flags,
				       entry->preempt_count, iter->idx,
				       ns2usecs(iter->ts),
				       abs_usecs / USEC_PER_MSEC,
				       abs_usecs % USEC_PER_MSEC,
				       rel_usecs / USEC_PER_MSEC,
				       rel_usecs % USEC_PER_MSEC);
	} else {
		ret = lat_print_generic(s, entry, iter->cpu);
		if (ret)
			ret = lat_print_timestamp(s, abs_usecs, rel_usecs);
	}

	return ret;
}

static const char state_to_char[] = TASK_STATE_TO_CHAR_STR;

static int task_state_char(unsigned long state)
{
	int bit = state ? __ffs(state) + 1 : 0;

	return bit < sizeof(state_to_char) - 1 ? state_to_char[bit] : '?';
}

/**
 * ftrace_find_event - find a registered event
 * @type: the type of event to look for
 *
 * Returns an event of type @type otherwise NULL
 */
struct trace_event *ftrace_find_event(int type)
{
	struct trace_event *event;
	struct hlist_node *n;
	unsigned key;

	key = type & (EVENT_HASHSIZE - 1);

	hlist_for_each_entry_rcu(event, n, &event_hash[key], node) {
		if (event->type == type)
			return event;
	}

	return NULL;
}

/**
 * register_ftrace_event - register output for an event type
 * @event: the event type to register
 *
 * Event types are stored in a hash and this hash is used to
 * find a way to print an event. If the @event->type is set
 * then it will use that type, otherwise it will assign a
 * type to use.
 *
 * If you assign your own type, please make sure it is added
 * to the trace_type enum in trace.h, to avoid collisions
 * with the dynamic types.
 *
 * Returns the event type number or zero on error.
 */
int register_ftrace_event(struct trace_event *event)
{
	unsigned key;
	int ret = 0;

	mutex_lock(&trace_event_mutex);

	if (!event->type)
		event->type = next_event_type++;
	else if (event->type > __TRACE_LAST_TYPE) {
		printk(KERN_WARNING "Need to add type to trace.h\n");
		WARN_ON(1);
	}

	if (ftrace_find_event(event->type))
		goto out;

	if (event->trace == NULL)
		event->trace = trace_nop_print;
	if (event->raw == NULL)
		event->raw = trace_nop_print;
	if (event->hex == NULL)
		event->hex = trace_nop_print;
	if (event->binary == NULL)
		event->binary = trace_nop_print;

	key = event->type & (EVENT_HASHSIZE - 1);

	hlist_add_head_rcu(&event->node, &event_hash[key]);

	ret = event->type;
 out:
	mutex_unlock(&trace_event_mutex);

	return ret;
}

/**
 * unregister_ftrace_event - remove a no longer used event
 * @event: the event to remove
 */
int unregister_ftrace_event(struct trace_event *event)
{
	mutex_lock(&trace_event_mutex);
	hlist_del(&event->node);
	mutex_unlock(&trace_event_mutex);

	return 0;
}

/*
 * Standard events
 */

enum print_line_t trace_nop_print(struct trace_iterator *iter, int flags)
{
	return TRACE_TYPE_HANDLED;
}

/* TRACE_FN */
static enum print_line_t trace_fn_trace(struct trace_iterator *iter, int flags)
{
	struct ftrace_entry *field;
	struct trace_seq *s = &iter->seq;

	trace_assign_type(field, iter->ent);

	if (!seq_print_ip_sym(s, field->ip, flags))
		goto partial;

	if ((flags & TRACE_ITER_PRINT_PARENT) && field->parent_ip) {
		if (!trace_seq_printf(s, " <-"))
			goto partial;
		if (!seq_print_ip_sym(s,
				      field->parent_ip,
				      flags))
			goto partial;
	}
	if (!trace_seq_printf(s, "\n"))
		goto partial;

	return TRACE_TYPE_HANDLED;

 partial:
	return TRACE_TYPE_PARTIAL_LINE;
}

static enum print_line_t trace_fn_raw(struct trace_iterator *iter, int flags)
{
	struct ftrace_entry *field;

	trace_assign_type(field, iter->ent);

	if (!trace_seq_printf(&iter->seq, "%lx %lx\n",
			      field->ip,
			      field->parent_ip))
		return TRACE_TYPE_PARTIAL_LINE;

	return TRACE_TYPE_HANDLED;
}

static enum print_line_t trace_fn_hex(struct trace_iterator *iter, int flags)
{
	struct ftrace_entry *field;
	struct trace_seq *s = &iter->seq;

	trace_assign_type(field, iter->ent);

	SEQ_PUT_HEX_FIELD_RET(s, field->ip);
	SEQ_PUT_HEX_FIELD_RET(s, field->parent_ip);

	return TRACE_TYPE_HANDLED;
}

static enum print_line_t trace_fn_bin(struct trace_iterator *iter, int flags)
{
	struct ftrace_entry *field;
	struct trace_seq *s = &iter->seq;

	trace_assign_type(field, iter->ent);

	SEQ_PUT_FIELD_RET(s, field->ip);
	SEQ_PUT_FIELD_RET(s, field->parent_ip);

	return TRACE_TYPE_HANDLED;
}

static struct trace_event trace_fn_event = {
	.type	 	= TRACE_FN,
	.trace		= trace_fn_trace,
	.raw		= trace_fn_raw,
	.hex		= trace_fn_hex,
	.binary		= trace_fn_bin,
};

/* TRACE_CTX an TRACE_WAKE */
static enum print_line_t trace_ctxwake_print(struct trace_iterator *iter,
					     char *delim)
{
	struct ctx_switch_entry *field;
	char *comm;
	int S, T;

	trace_assign_type(field, iter->ent);

	T = task_state_char(field->next_state);
	S = task_state_char(field->prev_state);
	comm = trace_find_cmdline(field->next_pid);
	if (!trace_seq_printf(&iter->seq,
			      " %5d:%3d:%c %s [%03d] %5d:%3d:%c %s\n",
			      field->prev_pid,
			      field->prev_prio,
			      S, delim,
			      field->next_cpu,
			      field->next_pid,
			      field->next_prio,
			      T, comm))
		return TRACE_TYPE_PARTIAL_LINE;

	return TRACE_TYPE_HANDLED;
}

static enum print_line_t trace_ctx_print(struct trace_iterator *iter, int flags)
{
	return trace_ctxwake_print(iter, "==>");
}

static enum print_line_t trace_wake_print(struct trace_iterator *iter,
					  int flags)
{
	return trace_ctxwake_print(iter, "  +");
}

static int trace_ctxwake_raw(struct trace_iterator *iter, char S)
{
	struct ctx_switch_entry *field;
	int T;

	trace_assign_type(field, iter->ent);

	if (!S)
		task_state_char(field->prev_state);
	T = task_state_char(field->next_state);
	if (!trace_seq_printf(&iter->seq, "%d %d %c %d %d %d %c\n",
			      field->prev_pid,
			      field->prev_prio,
			      S,
			      field->next_cpu,
			      field->next_pid,
			      field->next_prio,
			      T))
		return TRACE_TYPE_PARTIAL_LINE;

	return TRACE_TYPE_HANDLED;
}

static enum print_line_t trace_ctx_raw(struct trace_iterator *iter, int flags)
{
	return trace_ctxwake_raw(iter, 0);
}

static enum print_line_t trace_wake_raw(struct trace_iterator *iter, int flags)
{
	return trace_ctxwake_raw(iter, '+');
}


static int trace_ctxwake_hex(struct trace_iterator *iter, char S)
{
	struct ctx_switch_entry *field;
	struct trace_seq *s = &iter->seq;
	int T;

	trace_assign_type(field, iter->ent);

	if (!S)
		task_state_char(field->prev_state);
	T = task_state_char(field->next_state);

	SEQ_PUT_HEX_FIELD_RET(s, field->prev_pid);
	SEQ_PUT_HEX_FIELD_RET(s, field->prev_prio);
	SEQ_PUT_HEX_FIELD_RET(s, S);
	SEQ_PUT_HEX_FIELD_RET(s, field->next_cpu);
	SEQ_PUT_HEX_FIELD_RET(s, field->next_pid);
	SEQ_PUT_HEX_FIELD_RET(s, field->next_prio);
	SEQ_PUT_HEX_FIELD_RET(s, T);

	return TRACE_TYPE_HANDLED;
}

static enum print_line_t trace_ctx_hex(struct trace_iterator *iter, int flags)
{
	return trace_ctxwake_hex(iter, 0);
}

static enum print_line_t trace_wake_hex(struct trace_iterator *iter, int flags)
{
	return trace_ctxwake_hex(iter, '+');
}

static enum print_line_t trace_ctxwake_bin(struct trace_iterator *iter,
					   int flags)
{
	struct ctx_switch_entry *field;
	struct trace_seq *s = &iter->seq;

	trace_assign_type(field, iter->ent);

	SEQ_PUT_FIELD_RET(s, field->prev_pid);
	SEQ_PUT_FIELD_RET(s, field->prev_prio);
	SEQ_PUT_FIELD_RET(s, field->prev_state);
	SEQ_PUT_FIELD_RET(s, field->next_pid);
	SEQ_PUT_FIELD_RET(s, field->next_prio);
	SEQ_PUT_FIELD_RET(s, field->next_state);

	return TRACE_TYPE_HANDLED;
}

static struct trace_event trace_ctx_event = {
	.type	 	= TRACE_CTX,
	.trace		= trace_ctx_print,
	.raw		= trace_ctx_raw,
	.hex		= trace_ctx_hex,
	.binary		= trace_ctxwake_bin,
};

static struct trace_event trace_wake_event = {
	.type	 	= TRACE_WAKE,
	.trace		= trace_wake_print,
	.raw		= trace_wake_raw,
	.hex		= trace_wake_hex,
	.binary		= trace_ctxwake_bin,
};

/* TRACE_SPECIAL */
static enum print_line_t trace_special_print(struct trace_iterator *iter,
					     int flags)
{
	struct special_entry *field;

	trace_assign_type(field, iter->ent);

	if (!trace_seq_printf(&iter->seq, "# %ld %ld %ld\n",
			      field->arg1,
			      field->arg2,
			      field->arg3))
		return TRACE_TYPE_PARTIAL_LINE;

	return TRACE_TYPE_HANDLED;
}

static enum print_line_t trace_special_hex(struct trace_iterator *iter,
					   int flags)
{
	struct special_entry *field;
	struct trace_seq *s = &iter->seq;

	trace_assign_type(field, iter->ent);

	SEQ_PUT_HEX_FIELD_RET(s, field->arg1);
	SEQ_PUT_HEX_FIELD_RET(s, field->arg2);
	SEQ_PUT_HEX_FIELD_RET(s, field->arg3);

	return TRACE_TYPE_HANDLED;
}

static enum print_line_t trace_special_bin(struct trace_iterator *iter,
					   int flags)
{
	struct special_entry *field;
	struct trace_seq *s = &iter->seq;

	trace_assign_type(field, iter->ent);

	SEQ_PUT_FIELD_RET(s, field->arg1);
	SEQ_PUT_FIELD_RET(s, field->arg2);
	SEQ_PUT_FIELD_RET(s, field->arg3);

	return TRACE_TYPE_HANDLED;
}

static struct trace_event trace_special_event = {
	.type	 	= TRACE_SPECIAL,
	.trace		= trace_special_print,
	.raw		= trace_special_print,
	.hex		= trace_special_hex,
	.binary		= trace_special_bin,
};

/* TRACE_STACK */

static enum print_line_t trace_stack_print(struct trace_iterator *iter,
					   int flags)
{
	struct stack_entry *field;
	struct trace_seq *s = &iter->seq;
	int i;

	trace_assign_type(field, iter->ent);

	for (i = 0; i < FTRACE_STACK_ENTRIES; i++) {
		if (i) {
			if (!trace_seq_puts(s, " <= "))
				goto partial;

			if (!seq_print_ip_sym(s, field->caller[i], flags))
				goto partial;
		}
		if (!trace_seq_puts(s, "\n"))
			goto partial;
	}

	return TRACE_TYPE_HANDLED;

 partial:
	return TRACE_TYPE_PARTIAL_LINE;
}

static struct trace_event trace_stack_event = {
	.type	 	= TRACE_STACK,
	.trace		= trace_stack_print,
	.raw		= trace_special_print,
	.hex		= trace_special_hex,
	.binary		= trace_special_bin,
};

/* TRACE_USER_STACK */
static enum print_line_t trace_user_stack_print(struct trace_iterator *iter,
						int flags)
{
	struct userstack_entry *field;
	struct trace_seq *s = &iter->seq;

	trace_assign_type(field, iter->ent);

	if (!seq_print_userip_objs(field, s, flags))
		goto partial;

	if (!trace_seq_putc(s, '\n'))
		goto partial;

	return TRACE_TYPE_HANDLED;

 partial:
	return TRACE_TYPE_PARTIAL_LINE;
}

static struct trace_event trace_user_stack_event = {
	.type	 	= TRACE_USER_STACK,
	.trace		= trace_user_stack_print,
	.raw		= trace_special_print,
	.hex		= trace_special_hex,
	.binary		= trace_special_bin,
};

/* TRACE_PRINT */
static enum print_line_t trace_print_print(struct trace_iterator *iter,
					   int flags)
{
	struct print_entry *field;
	struct trace_seq *s = &iter->seq;

	trace_assign_type(field, iter->ent);

	if (!seq_print_ip_sym(s, field->ip, flags))
		goto partial;

	if (!trace_seq_printf(s, ": %s", field->buf))
		goto partial;

	return TRACE_TYPE_HANDLED;

 partial:
	return TRACE_TYPE_PARTIAL_LINE;
}

static enum print_line_t trace_print_raw(struct trace_iterator *iter, int flags)
{
	struct print_entry *field;

	trace_assign_type(field, iter->ent);

	if (!trace_seq_printf(&iter->seq, "# %lx %s", field->ip, field->buf))
		goto partial;

	return TRACE_TYPE_HANDLED;

 partial:
	return TRACE_TYPE_PARTIAL_LINE;
}

static struct trace_event trace_print_event = {
	.type	 	= TRACE_PRINT,
	.trace		= trace_print_print,
	.raw		= trace_print_raw,
};

static struct trace_event *events[] __initdata = {
	&trace_fn_event,
	&trace_ctx_event,
	&trace_wake_event,
	&trace_special_event,
	&trace_stack_event,
	&trace_user_stack_event,
	&trace_print_event,
	NULL
};

__init static int init_events(void)
{
	struct trace_event *event;
	int i, ret;

	for (i = 0; events[i]; i++) {
		event = events[i];

		ret = register_ftrace_event(event);
		if (!ret) {
			printk(KERN_WARNING "event %d failed to register\n",
			       event->type);
			WARN_ON_ONCE(1);
		}
	}

	return 0;
}
device_initcall(init_events);