xref: /openbmc/linux/kernel/trace/trace_output.c (revision f3539c12)
1 /*
2  * trace_output.c
3  *
4  * Copyright (C) 2008 Red Hat Inc, Steven Rostedt <srostedt@redhat.com>
5  *
6  */
7 
8 #include <linux/module.h>
9 #include <linux/mutex.h>
10 #include <linux/ftrace.h>
11 
12 #include "trace_output.h"
13 
14 /* must be a power of 2 */
15 #define EVENT_HASHSIZE	128
16 
17 DECLARE_RWSEM(trace_event_sem);
18 
19 static struct hlist_head event_hash[EVENT_HASHSIZE] __read_mostly;
20 
21 static int next_event_type = __TRACE_LAST_TYPE + 1;
22 
23 enum print_line_t trace_print_bputs_msg_only(struct trace_iterator *iter)
24 {
25 	struct trace_seq *s = &iter->seq;
26 	struct trace_entry *entry = iter->ent;
27 	struct bputs_entry *field;
28 
29 	trace_assign_type(field, entry);
30 
31 	trace_seq_puts(s, field->str);
32 
33 	return trace_handle_return(s);
34 }
35 
36 enum print_line_t trace_print_bprintk_msg_only(struct trace_iterator *iter)
37 {
38 	struct trace_seq *s = &iter->seq;
39 	struct trace_entry *entry = iter->ent;
40 	struct bprint_entry *field;
41 
42 	trace_assign_type(field, entry);
43 
44 	trace_seq_bprintf(s, field->fmt, field->buf);
45 
46 	return trace_handle_return(s);
47 }
48 
49 enum print_line_t trace_print_printk_msg_only(struct trace_iterator *iter)
50 {
51 	struct trace_seq *s = &iter->seq;
52 	struct trace_entry *entry = iter->ent;
53 	struct print_entry *field;
54 
55 	trace_assign_type(field, entry);
56 
57 	trace_seq_puts(s, field->buf);
58 
59 	return trace_handle_return(s);
60 }
61 
62 const char *
63 trace_print_flags_seq(struct trace_seq *p, const char *delim,
64 		      unsigned long flags,
65 		      const struct trace_print_flags *flag_array)
66 {
67 	unsigned long mask;
68 	const char *str;
69 	const char *ret = trace_seq_buffer_ptr(p);
70 	int i, first = 1;
71 
72 	for (i = 0;  flag_array[i].name && flags; i++) {
73 
74 		mask = flag_array[i].mask;
75 		if ((flags & mask) != mask)
76 			continue;
77 
78 		str = flag_array[i].name;
79 		flags &= ~mask;
80 		if (!first && delim)
81 			trace_seq_puts(p, delim);
82 		else
83 			first = 0;
84 		trace_seq_puts(p, str);
85 	}
86 
87 	/* check for left over flags */
88 	if (flags) {
89 		if (!first && delim)
90 			trace_seq_puts(p, delim);
91 		trace_seq_printf(p, "0x%lx", flags);
92 	}
93 
94 	trace_seq_putc(p, 0);
95 
96 	return ret;
97 }
98 EXPORT_SYMBOL(trace_print_flags_seq);
99 
100 const char *
101 trace_print_symbols_seq(struct trace_seq *p, unsigned long val,
102 			const struct trace_print_flags *symbol_array)
103 {
104 	int i;
105 	const char *ret = trace_seq_buffer_ptr(p);
106 
107 	for (i = 0;  symbol_array[i].name; i++) {
108 
109 		if (val != symbol_array[i].mask)
110 			continue;
111 
112 		trace_seq_puts(p, symbol_array[i].name);
113 		break;
114 	}
115 
116 	if (ret == (const char *)(trace_seq_buffer_ptr(p)))
117 		trace_seq_printf(p, "0x%lx", val);
118 
119 	trace_seq_putc(p, 0);
120 
121 	return ret;
122 }
123 EXPORT_SYMBOL(trace_print_symbols_seq);
124 
125 #if BITS_PER_LONG == 32
126 const char *
127 trace_print_symbols_seq_u64(struct trace_seq *p, unsigned long long val,
128 			 const struct trace_print_flags_u64 *symbol_array)
129 {
130 	int i;
131 	const char *ret = trace_seq_buffer_ptr(p);
132 
133 	for (i = 0;  symbol_array[i].name; i++) {
134 
135 		if (val != symbol_array[i].mask)
136 			continue;
137 
138 		trace_seq_puts(p, symbol_array[i].name);
139 		break;
140 	}
141 
142 	if (ret == (const char *)(trace_seq_buffer_ptr(p)))
143 		trace_seq_printf(p, "0x%llx", val);
144 
145 	trace_seq_putc(p, 0);
146 
147 	return ret;
148 }
149 EXPORT_SYMBOL(trace_print_symbols_seq_u64);
150 #endif
151 
152 const char *
153 trace_print_bitmask_seq(struct trace_seq *p, void *bitmask_ptr,
154 			unsigned int bitmask_size)
155 {
156 	const char *ret = trace_seq_buffer_ptr(p);
157 
158 	trace_seq_bitmask(p, bitmask_ptr, bitmask_size * 8);
159 	trace_seq_putc(p, 0);
160 
161 	return ret;
162 }
163 EXPORT_SYMBOL_GPL(trace_print_bitmask_seq);
164 
165 const char *
166 trace_print_hex_seq(struct trace_seq *p, const unsigned char *buf, int buf_len)
167 {
168 	int i;
169 	const char *ret = trace_seq_buffer_ptr(p);
170 
171 	for (i = 0; i < buf_len; i++)
172 		trace_seq_printf(p, "%s%2.2x", i == 0 ? "" : " ", buf[i]);
173 
174 	trace_seq_putc(p, 0);
175 
176 	return ret;
177 }
178 EXPORT_SYMBOL(trace_print_hex_seq);
179 
180 const char *
181 trace_print_array_seq(struct trace_seq *p, const void *buf, int count,
182 		      size_t el_size)
183 {
184 	const char *ret = trace_seq_buffer_ptr(p);
185 	const char *prefix = "";
186 	void *ptr = (void *)buf;
187 	size_t buf_len = count * el_size;
188 
189 	trace_seq_putc(p, '{');
190 
191 	while (ptr < buf + buf_len) {
192 		switch (el_size) {
193 		case 1:
194 			trace_seq_printf(p, "%s0x%x", prefix,
195 					 *(u8 *)ptr);
196 			break;
197 		case 2:
198 			trace_seq_printf(p, "%s0x%x", prefix,
199 					 *(u16 *)ptr);
200 			break;
201 		case 4:
202 			trace_seq_printf(p, "%s0x%x", prefix,
203 					 *(u32 *)ptr);
204 			break;
205 		case 8:
206 			trace_seq_printf(p, "%s0x%llx", prefix,
207 					 *(u64 *)ptr);
208 			break;
209 		default:
210 			trace_seq_printf(p, "BAD SIZE:%zu 0x%x", el_size,
211 					 *(u8 *)ptr);
212 			el_size = 1;
213 		}
214 		prefix = ",";
215 		ptr += el_size;
216 	}
217 
218 	trace_seq_putc(p, '}');
219 	trace_seq_putc(p, 0);
220 
221 	return ret;
222 }
223 EXPORT_SYMBOL(trace_print_array_seq);
224 
225 int trace_raw_output_prep(struct trace_iterator *iter,
226 			  struct trace_event *trace_event)
227 {
228 	struct trace_event_call *event;
229 	struct trace_seq *s = &iter->seq;
230 	struct trace_seq *p = &iter->tmp_seq;
231 	struct trace_entry *entry;
232 
233 	event = container_of(trace_event, struct trace_event_call, event);
234 	entry = iter->ent;
235 
236 	if (entry->type != event->event.type) {
237 		WARN_ON_ONCE(1);
238 		return TRACE_TYPE_UNHANDLED;
239 	}
240 
241 	trace_seq_init(p);
242 	trace_seq_printf(s, "%s: ", trace_event_name(event));
243 
244 	return trace_handle_return(s);
245 }
246 EXPORT_SYMBOL(trace_raw_output_prep);
247 
248 static int trace_output_raw(struct trace_iterator *iter, char *name,
249 			    char *fmt, va_list ap)
250 {
251 	struct trace_seq *s = &iter->seq;
252 
253 	trace_seq_printf(s, "%s: ", name);
254 	trace_seq_vprintf(s, fmt, ap);
255 
256 	return trace_handle_return(s);
257 }
258 
259 int trace_output_call(struct trace_iterator *iter, char *name, char *fmt, ...)
260 {
261 	va_list ap;
262 	int ret;
263 
264 	va_start(ap, fmt);
265 	ret = trace_output_raw(iter, name, fmt, ap);
266 	va_end(ap);
267 
268 	return ret;
269 }
270 EXPORT_SYMBOL_GPL(trace_output_call);
271 
272 #ifdef CONFIG_KRETPROBES
273 static inline const char *kretprobed(const char *name)
274 {
275 	static const char tramp_name[] = "kretprobe_trampoline";
276 	int size = sizeof(tramp_name);
277 
278 	if (strncmp(tramp_name, name, size) == 0)
279 		return "[unknown/kretprobe'd]";
280 	return name;
281 }
282 #else
283 static inline const char *kretprobed(const char *name)
284 {
285 	return name;
286 }
287 #endif /* CONFIG_KRETPROBES */
288 
289 static void
290 seq_print_sym_short(struct trace_seq *s, const char *fmt, unsigned long address)
291 {
292 #ifdef CONFIG_KALLSYMS
293 	char str[KSYM_SYMBOL_LEN];
294 	const char *name;
295 
296 	kallsyms_lookup(address, NULL, NULL, NULL, str);
297 
298 	name = kretprobed(str);
299 
300 	trace_seq_printf(s, fmt, name);
301 #endif
302 }
303 
304 static void
305 seq_print_sym_offset(struct trace_seq *s, const char *fmt,
306 		     unsigned long address)
307 {
308 #ifdef CONFIG_KALLSYMS
309 	char str[KSYM_SYMBOL_LEN];
310 	const char *name;
311 
312 	sprint_symbol(str, address);
313 	name = kretprobed(str);
314 
315 	trace_seq_printf(s, fmt, name);
316 #endif
317 }
318 
319 #ifndef CONFIG_64BIT
320 # define IP_FMT "%08lx"
321 #else
322 # define IP_FMT "%016lx"
323 #endif
324 
325 static int seq_print_user_ip(struct trace_seq *s, struct mm_struct *mm,
326 			     unsigned long ip, unsigned long sym_flags)
327 {
328 	struct file *file = NULL;
329 	unsigned long vmstart = 0;
330 	int ret = 1;
331 
332 	if (s->full)
333 		return 0;
334 
335 	if (mm) {
336 		const struct vm_area_struct *vma;
337 
338 		down_read(&mm->mmap_sem);
339 		vma = find_vma(mm, ip);
340 		if (vma) {
341 			file = vma->vm_file;
342 			vmstart = vma->vm_start;
343 		}
344 		if (file) {
345 			ret = trace_seq_path(s, &file->f_path);
346 			if (ret)
347 				trace_seq_printf(s, "[+0x%lx]",
348 						 ip - vmstart);
349 		}
350 		up_read(&mm->mmap_sem);
351 	}
352 	if (ret && ((sym_flags & TRACE_ITER_SYM_ADDR) || !file))
353 		trace_seq_printf(s, " <" IP_FMT ">", ip);
354 	return !trace_seq_has_overflowed(s);
355 }
356 
357 int
358 seq_print_ip_sym(struct trace_seq *s, unsigned long ip, unsigned long sym_flags)
359 {
360 	if (!ip) {
361 		trace_seq_putc(s, '0');
362 		goto out;
363 	}
364 
365 	if (sym_flags & TRACE_ITER_SYM_OFFSET)
366 		seq_print_sym_offset(s, "%s", ip);
367 	else
368 		seq_print_sym_short(s, "%s", ip);
369 
370 	if (sym_flags & TRACE_ITER_SYM_ADDR)
371 		trace_seq_printf(s, " <" IP_FMT ">", ip);
372 
373  out:
374 	return !trace_seq_has_overflowed(s);
375 }
376 
377 /**
378  * trace_print_lat_fmt - print the irq, preempt and lockdep fields
379  * @s: trace seq struct to write to
380  * @entry: The trace entry field from the ring buffer
381  *
382  * Prints the generic fields of irqs off, in hard or softirq, preempt
383  * count.
384  */
385 int trace_print_lat_fmt(struct trace_seq *s, struct trace_entry *entry)
386 {
387 	char hardsoft_irq;
388 	char need_resched;
389 	char irqs_off;
390 	int hardirq;
391 	int softirq;
392 	int nmi;
393 
394 	nmi = entry->flags & TRACE_FLAG_NMI;
395 	hardirq = entry->flags & TRACE_FLAG_HARDIRQ;
396 	softirq = entry->flags & TRACE_FLAG_SOFTIRQ;
397 
398 	irqs_off =
399 		(entry->flags & TRACE_FLAG_IRQS_OFF) ? 'd' :
400 		(entry->flags & TRACE_FLAG_IRQS_NOSUPPORT) ? 'X' :
401 		'.';
402 
403 	switch (entry->flags & (TRACE_FLAG_NEED_RESCHED |
404 				TRACE_FLAG_PREEMPT_RESCHED)) {
405 	case TRACE_FLAG_NEED_RESCHED | TRACE_FLAG_PREEMPT_RESCHED:
406 		need_resched = 'N';
407 		break;
408 	case TRACE_FLAG_NEED_RESCHED:
409 		need_resched = 'n';
410 		break;
411 	case TRACE_FLAG_PREEMPT_RESCHED:
412 		need_resched = 'p';
413 		break;
414 	default:
415 		need_resched = '.';
416 		break;
417 	}
418 
419 	hardsoft_irq =
420 		(nmi && hardirq)     ? 'Z' :
421 		nmi                  ? 'z' :
422 		(hardirq && softirq) ? 'H' :
423 		hardirq              ? 'h' :
424 		softirq              ? 's' :
425 		                       '.' ;
426 
427 	trace_seq_printf(s, "%c%c%c",
428 			 irqs_off, need_resched, hardsoft_irq);
429 
430 	if (entry->preempt_count)
431 		trace_seq_printf(s, "%x", entry->preempt_count);
432 	else
433 		trace_seq_putc(s, '.');
434 
435 	return !trace_seq_has_overflowed(s);
436 }
437 
438 static int
439 lat_print_generic(struct trace_seq *s, struct trace_entry *entry, int cpu)
440 {
441 	char comm[TASK_COMM_LEN];
442 
443 	trace_find_cmdline(entry->pid, comm);
444 
445 	trace_seq_printf(s, "%8.8s-%-5d %3d",
446 			 comm, entry->pid, cpu);
447 
448 	return trace_print_lat_fmt(s, entry);
449 }
450 
451 #undef MARK
452 #define MARK(v, s) {.val = v, .sym = s}
453 /* trace overhead mark */
454 static const struct trace_mark {
455 	unsigned long long	val; /* unit: nsec */
456 	char			sym;
457 } mark[] = {
458 	MARK(1000000000ULL	, '$'), /* 1 sec */
459 	MARK(100000000ULL	, '@'), /* 100 msec */
460 	MARK(10000000ULL	, '*'), /* 10 msec */
461 	MARK(1000000ULL		, '#'), /* 1000 usecs */
462 	MARK(100000ULL		, '!'), /* 100 usecs */
463 	MARK(10000ULL		, '+'), /* 10 usecs */
464 };
465 #undef MARK
466 
467 char trace_find_mark(unsigned long long d)
468 {
469 	int i;
470 	int size = ARRAY_SIZE(mark);
471 
472 	for (i = 0; i < size; i++) {
473 		if (d > mark[i].val)
474 			break;
475 	}
476 
477 	return (i == size) ? ' ' : mark[i].sym;
478 }
479 
480 static int
481 lat_print_timestamp(struct trace_iterator *iter, u64 next_ts)
482 {
483 	struct trace_array *tr = iter->tr;
484 	unsigned long verbose = tr->trace_flags & TRACE_ITER_VERBOSE;
485 	unsigned long in_ns = iter->iter_flags & TRACE_FILE_TIME_IN_NS;
486 	unsigned long long abs_ts = iter->ts - iter->trace_buffer->time_start;
487 	unsigned long long rel_ts = next_ts - iter->ts;
488 	struct trace_seq *s = &iter->seq;
489 
490 	if (in_ns) {
491 		abs_ts = ns2usecs(abs_ts);
492 		rel_ts = ns2usecs(rel_ts);
493 	}
494 
495 	if (verbose && in_ns) {
496 		unsigned long abs_usec = do_div(abs_ts, USEC_PER_MSEC);
497 		unsigned long abs_msec = (unsigned long)abs_ts;
498 		unsigned long rel_usec = do_div(rel_ts, USEC_PER_MSEC);
499 		unsigned long rel_msec = (unsigned long)rel_ts;
500 
501 		trace_seq_printf(
502 			s, "[%08llx] %ld.%03ldms (+%ld.%03ldms): ",
503 			ns2usecs(iter->ts),
504 			abs_msec, abs_usec,
505 			rel_msec, rel_usec);
506 
507 	} else if (verbose && !in_ns) {
508 		trace_seq_printf(
509 			s, "[%016llx] %lld (+%lld): ",
510 			iter->ts, abs_ts, rel_ts);
511 
512 	} else if (!verbose && in_ns) {
513 		trace_seq_printf(
514 			s, " %4lldus%c: ",
515 			abs_ts,
516 			trace_find_mark(rel_ts * NSEC_PER_USEC));
517 
518 	} else { /* !verbose && !in_ns */
519 		trace_seq_printf(s, " %4lld: ", abs_ts);
520 	}
521 
522 	return !trace_seq_has_overflowed(s);
523 }
524 
525 int trace_print_context(struct trace_iterator *iter)
526 {
527 	struct trace_array *tr = iter->tr;
528 	struct trace_seq *s = &iter->seq;
529 	struct trace_entry *entry = iter->ent;
530 	unsigned long long t;
531 	unsigned long secs, usec_rem;
532 	char comm[TASK_COMM_LEN];
533 
534 	trace_find_cmdline(entry->pid, comm);
535 
536 	trace_seq_printf(s, "%16s-%-5d [%03d] ",
537 			       comm, entry->pid, iter->cpu);
538 
539 	if (tr->trace_flags & TRACE_ITER_IRQ_INFO)
540 		trace_print_lat_fmt(s, entry);
541 
542 	if (iter->iter_flags & TRACE_FILE_TIME_IN_NS) {
543 		t = ns2usecs(iter->ts);
544 		usec_rem = do_div(t, USEC_PER_SEC);
545 		secs = (unsigned long)t;
546 		trace_seq_printf(s, " %5lu.%06lu: ", secs, usec_rem);
547 	} else
548 		trace_seq_printf(s, " %12llu: ", iter->ts);
549 
550 	return !trace_seq_has_overflowed(s);
551 }
552 
553 int trace_print_lat_context(struct trace_iterator *iter)
554 {
555 	struct trace_array *tr = iter->tr;
556 	/* trace_find_next_entry will reset ent_size */
557 	int ent_size = iter->ent_size;
558 	struct trace_seq *s = &iter->seq;
559 	u64 next_ts;
560 	struct trace_entry *entry = iter->ent,
561 			   *next_entry = trace_find_next_entry(iter, NULL,
562 							       &next_ts);
563 	unsigned long verbose = (tr->trace_flags & TRACE_ITER_VERBOSE);
564 
565 	/* Restore the original ent_size */
566 	iter->ent_size = ent_size;
567 
568 	if (!next_entry)
569 		next_ts = iter->ts;
570 
571 	if (verbose) {
572 		char comm[TASK_COMM_LEN];
573 
574 		trace_find_cmdline(entry->pid, comm);
575 
576 		trace_seq_printf(
577 			s, "%16s %5d %3d %d %08x %08lx ",
578 			comm, entry->pid, iter->cpu, entry->flags,
579 			entry->preempt_count, iter->idx);
580 	} else {
581 		lat_print_generic(s, entry, iter->cpu);
582 	}
583 
584 	lat_print_timestamp(iter, next_ts);
585 
586 	return !trace_seq_has_overflowed(s);
587 }
588 
589 static const char state_to_char[] = TASK_STATE_TO_CHAR_STR;
590 
591 static int task_state_char(unsigned long state)
592 {
593 	int bit = state ? __ffs(state) + 1 : 0;
594 
595 	return bit < sizeof(state_to_char) - 1 ? state_to_char[bit] : '?';
596 }
597 
598 /**
599  * ftrace_find_event - find a registered event
600  * @type: the type of event to look for
601  *
602  * Returns an event of type @type otherwise NULL
603  * Called with trace_event_read_lock() held.
604  */
605 struct trace_event *ftrace_find_event(int type)
606 {
607 	struct trace_event *event;
608 	unsigned key;
609 
610 	key = type & (EVENT_HASHSIZE - 1);
611 
612 	hlist_for_each_entry(event, &event_hash[key], node) {
613 		if (event->type == type)
614 			return event;
615 	}
616 
617 	return NULL;
618 }
619 
620 static LIST_HEAD(ftrace_event_list);
621 
622 static int trace_search_list(struct list_head **list)
623 {
624 	struct trace_event *e;
625 	int last = __TRACE_LAST_TYPE;
626 
627 	if (list_empty(&ftrace_event_list)) {
628 		*list = &ftrace_event_list;
629 		return last + 1;
630 	}
631 
632 	/*
633 	 * We used up all possible max events,
634 	 * lets see if somebody freed one.
635 	 */
636 	list_for_each_entry(e, &ftrace_event_list, list) {
637 		if (e->type != last + 1)
638 			break;
639 		last++;
640 	}
641 
642 	/* Did we used up all 65 thousand events??? */
643 	if ((last + 1) > TRACE_EVENT_TYPE_MAX)
644 		return 0;
645 
646 	*list = &e->list;
647 	return last + 1;
648 }
649 
650 void trace_event_read_lock(void)
651 {
652 	down_read(&trace_event_sem);
653 }
654 
655 void trace_event_read_unlock(void)
656 {
657 	up_read(&trace_event_sem);
658 }
659 
660 /**
661  * register_trace_event - register output for an event type
662  * @event: the event type to register
663  *
664  * Event types are stored in a hash and this hash is used to
665  * find a way to print an event. If the @event->type is set
666  * then it will use that type, otherwise it will assign a
667  * type to use.
668  *
669  * If you assign your own type, please make sure it is added
670  * to the trace_type enum in trace.h, to avoid collisions
671  * with the dynamic types.
672  *
673  * Returns the event type number or zero on error.
674  */
675 int register_trace_event(struct trace_event *event)
676 {
677 	unsigned key;
678 	int ret = 0;
679 
680 	down_write(&trace_event_sem);
681 
682 	if (WARN_ON(!event))
683 		goto out;
684 
685 	if (WARN_ON(!event->funcs))
686 		goto out;
687 
688 	INIT_LIST_HEAD(&event->list);
689 
690 	if (!event->type) {
691 		struct list_head *list = NULL;
692 
693 		if (next_event_type > TRACE_EVENT_TYPE_MAX) {
694 
695 			event->type = trace_search_list(&list);
696 			if (!event->type)
697 				goto out;
698 
699 		} else {
700 
701 			event->type = next_event_type++;
702 			list = &ftrace_event_list;
703 		}
704 
705 		if (WARN_ON(ftrace_find_event(event->type)))
706 			goto out;
707 
708 		list_add_tail(&event->list, list);
709 
710 	} else if (event->type > __TRACE_LAST_TYPE) {
711 		printk(KERN_WARNING "Need to add type to trace.h\n");
712 		WARN_ON(1);
713 		goto out;
714 	} else {
715 		/* Is this event already used */
716 		if (ftrace_find_event(event->type))
717 			goto out;
718 	}
719 
720 	if (event->funcs->trace == NULL)
721 		event->funcs->trace = trace_nop_print;
722 	if (event->funcs->raw == NULL)
723 		event->funcs->raw = trace_nop_print;
724 	if (event->funcs->hex == NULL)
725 		event->funcs->hex = trace_nop_print;
726 	if (event->funcs->binary == NULL)
727 		event->funcs->binary = trace_nop_print;
728 
729 	key = event->type & (EVENT_HASHSIZE - 1);
730 
731 	hlist_add_head(&event->node, &event_hash[key]);
732 
733 	ret = event->type;
734  out:
735 	up_write(&trace_event_sem);
736 
737 	return ret;
738 }
739 EXPORT_SYMBOL_GPL(register_trace_event);
740 
741 /*
742  * Used by module code with the trace_event_sem held for write.
743  */
744 int __unregister_trace_event(struct trace_event *event)
745 {
746 	hlist_del(&event->node);
747 	list_del(&event->list);
748 	return 0;
749 }
750 
751 /**
752  * unregister_trace_event - remove a no longer used event
753  * @event: the event to remove
754  */
755 int unregister_trace_event(struct trace_event *event)
756 {
757 	down_write(&trace_event_sem);
758 	__unregister_trace_event(event);
759 	up_write(&trace_event_sem);
760 
761 	return 0;
762 }
763 EXPORT_SYMBOL_GPL(unregister_trace_event);
764 
765 /*
766  * Standard events
767  */
768 
769 enum print_line_t trace_nop_print(struct trace_iterator *iter, int flags,
770 				  struct trace_event *event)
771 {
772 	trace_seq_printf(&iter->seq, "type: %d\n", iter->ent->type);
773 
774 	return trace_handle_return(&iter->seq);
775 }
776 
777 /* TRACE_FN */
778 static enum print_line_t trace_fn_trace(struct trace_iterator *iter, int flags,
779 					struct trace_event *event)
780 {
781 	struct ftrace_entry *field;
782 	struct trace_seq *s = &iter->seq;
783 
784 	trace_assign_type(field, iter->ent);
785 
786 	seq_print_ip_sym(s, field->ip, flags);
787 
788 	if ((flags & TRACE_ITER_PRINT_PARENT) && field->parent_ip) {
789 		trace_seq_puts(s, " <-");
790 		seq_print_ip_sym(s, field->parent_ip, flags);
791 	}
792 
793 	trace_seq_putc(s, '\n');
794 
795 	return trace_handle_return(s);
796 }
797 
798 static enum print_line_t trace_fn_raw(struct trace_iterator *iter, int flags,
799 				      struct trace_event *event)
800 {
801 	struct ftrace_entry *field;
802 
803 	trace_assign_type(field, iter->ent);
804 
805 	trace_seq_printf(&iter->seq, "%lx %lx\n",
806 			 field->ip,
807 			 field->parent_ip);
808 
809 	return trace_handle_return(&iter->seq);
810 }
811 
812 static enum print_line_t trace_fn_hex(struct trace_iterator *iter, int flags,
813 				      struct trace_event *event)
814 {
815 	struct ftrace_entry *field;
816 	struct trace_seq *s = &iter->seq;
817 
818 	trace_assign_type(field, iter->ent);
819 
820 	SEQ_PUT_HEX_FIELD(s, field->ip);
821 	SEQ_PUT_HEX_FIELD(s, field->parent_ip);
822 
823 	return trace_handle_return(s);
824 }
825 
826 static enum print_line_t trace_fn_bin(struct trace_iterator *iter, int flags,
827 				      struct trace_event *event)
828 {
829 	struct ftrace_entry *field;
830 	struct trace_seq *s = &iter->seq;
831 
832 	trace_assign_type(field, iter->ent);
833 
834 	SEQ_PUT_FIELD(s, field->ip);
835 	SEQ_PUT_FIELD(s, field->parent_ip);
836 
837 	return trace_handle_return(s);
838 }
839 
840 static struct trace_event_functions trace_fn_funcs = {
841 	.trace		= trace_fn_trace,
842 	.raw		= trace_fn_raw,
843 	.hex		= trace_fn_hex,
844 	.binary		= trace_fn_bin,
845 };
846 
847 static struct trace_event trace_fn_event = {
848 	.type		= TRACE_FN,
849 	.funcs		= &trace_fn_funcs,
850 };
851 
852 /* TRACE_CTX an TRACE_WAKE */
853 static enum print_line_t trace_ctxwake_print(struct trace_iterator *iter,
854 					     char *delim)
855 {
856 	struct ctx_switch_entry *field;
857 	char comm[TASK_COMM_LEN];
858 	int S, T;
859 
860 
861 	trace_assign_type(field, iter->ent);
862 
863 	T = task_state_char(field->next_state);
864 	S = task_state_char(field->prev_state);
865 	trace_find_cmdline(field->next_pid, comm);
866 	trace_seq_printf(&iter->seq,
867 			 " %5d:%3d:%c %s [%03d] %5d:%3d:%c %s\n",
868 			 field->prev_pid,
869 			 field->prev_prio,
870 			 S, delim,
871 			 field->next_cpu,
872 			 field->next_pid,
873 			 field->next_prio,
874 			 T, comm);
875 
876 	return trace_handle_return(&iter->seq);
877 }
878 
879 static enum print_line_t trace_ctx_print(struct trace_iterator *iter, int flags,
880 					 struct trace_event *event)
881 {
882 	return trace_ctxwake_print(iter, "==>");
883 }
884 
885 static enum print_line_t trace_wake_print(struct trace_iterator *iter,
886 					  int flags, struct trace_event *event)
887 {
888 	return trace_ctxwake_print(iter, "  +");
889 }
890 
891 static int trace_ctxwake_raw(struct trace_iterator *iter, char S)
892 {
893 	struct ctx_switch_entry *field;
894 	int T;
895 
896 	trace_assign_type(field, iter->ent);
897 
898 	if (!S)
899 		S = task_state_char(field->prev_state);
900 	T = task_state_char(field->next_state);
901 	trace_seq_printf(&iter->seq, "%d %d %c %d %d %d %c\n",
902 			 field->prev_pid,
903 			 field->prev_prio,
904 			 S,
905 			 field->next_cpu,
906 			 field->next_pid,
907 			 field->next_prio,
908 			 T);
909 
910 	return trace_handle_return(&iter->seq);
911 }
912 
913 static enum print_line_t trace_ctx_raw(struct trace_iterator *iter, int flags,
914 				       struct trace_event *event)
915 {
916 	return trace_ctxwake_raw(iter, 0);
917 }
918 
919 static enum print_line_t trace_wake_raw(struct trace_iterator *iter, int flags,
920 					struct trace_event *event)
921 {
922 	return trace_ctxwake_raw(iter, '+');
923 }
924 
925 
926 static int trace_ctxwake_hex(struct trace_iterator *iter, char S)
927 {
928 	struct ctx_switch_entry *field;
929 	struct trace_seq *s = &iter->seq;
930 	int T;
931 
932 	trace_assign_type(field, iter->ent);
933 
934 	if (!S)
935 		S = task_state_char(field->prev_state);
936 	T = task_state_char(field->next_state);
937 
938 	SEQ_PUT_HEX_FIELD(s, field->prev_pid);
939 	SEQ_PUT_HEX_FIELD(s, field->prev_prio);
940 	SEQ_PUT_HEX_FIELD(s, S);
941 	SEQ_PUT_HEX_FIELD(s, field->next_cpu);
942 	SEQ_PUT_HEX_FIELD(s, field->next_pid);
943 	SEQ_PUT_HEX_FIELD(s, field->next_prio);
944 	SEQ_PUT_HEX_FIELD(s, T);
945 
946 	return trace_handle_return(s);
947 }
948 
949 static enum print_line_t trace_ctx_hex(struct trace_iterator *iter, int flags,
950 				       struct trace_event *event)
951 {
952 	return trace_ctxwake_hex(iter, 0);
953 }
954 
955 static enum print_line_t trace_wake_hex(struct trace_iterator *iter, int flags,
956 					struct trace_event *event)
957 {
958 	return trace_ctxwake_hex(iter, '+');
959 }
960 
961 static enum print_line_t trace_ctxwake_bin(struct trace_iterator *iter,
962 					   int flags, struct trace_event *event)
963 {
964 	struct ctx_switch_entry *field;
965 	struct trace_seq *s = &iter->seq;
966 
967 	trace_assign_type(field, iter->ent);
968 
969 	SEQ_PUT_FIELD(s, field->prev_pid);
970 	SEQ_PUT_FIELD(s, field->prev_prio);
971 	SEQ_PUT_FIELD(s, field->prev_state);
972 	SEQ_PUT_FIELD(s, field->next_cpu);
973 	SEQ_PUT_FIELD(s, field->next_pid);
974 	SEQ_PUT_FIELD(s, field->next_prio);
975 	SEQ_PUT_FIELD(s, field->next_state);
976 
977 	return trace_handle_return(s);
978 }
979 
980 static struct trace_event_functions trace_ctx_funcs = {
981 	.trace		= trace_ctx_print,
982 	.raw		= trace_ctx_raw,
983 	.hex		= trace_ctx_hex,
984 	.binary		= trace_ctxwake_bin,
985 };
986 
987 static struct trace_event trace_ctx_event = {
988 	.type		= TRACE_CTX,
989 	.funcs		= &trace_ctx_funcs,
990 };
991 
992 static struct trace_event_functions trace_wake_funcs = {
993 	.trace		= trace_wake_print,
994 	.raw		= trace_wake_raw,
995 	.hex		= trace_wake_hex,
996 	.binary		= trace_ctxwake_bin,
997 };
998 
999 static struct trace_event trace_wake_event = {
1000 	.type		= TRACE_WAKE,
1001 	.funcs		= &trace_wake_funcs,
1002 };
1003 
1004 /* TRACE_STACK */
1005 
1006 static enum print_line_t trace_stack_print(struct trace_iterator *iter,
1007 					   int flags, struct trace_event *event)
1008 {
1009 	struct stack_entry *field;
1010 	struct trace_seq *s = &iter->seq;
1011 	unsigned long *p;
1012 	unsigned long *end;
1013 
1014 	trace_assign_type(field, iter->ent);
1015 	end = (unsigned long *)((long)iter->ent + iter->ent_size);
1016 
1017 	trace_seq_puts(s, "<stack trace>\n");
1018 
1019 	for (p = field->caller; p && *p != ULONG_MAX && p < end; p++) {
1020 
1021 		if (trace_seq_has_overflowed(s))
1022 			break;
1023 
1024 		trace_seq_puts(s, " => ");
1025 		seq_print_ip_sym(s, *p, flags);
1026 		trace_seq_putc(s, '\n');
1027 	}
1028 
1029 	return trace_handle_return(s);
1030 }
1031 
1032 static struct trace_event_functions trace_stack_funcs = {
1033 	.trace		= trace_stack_print,
1034 };
1035 
1036 static struct trace_event trace_stack_event = {
1037 	.type		= TRACE_STACK,
1038 	.funcs		= &trace_stack_funcs,
1039 };
1040 
1041 /* TRACE_USER_STACK */
1042 static enum print_line_t trace_user_stack_print(struct trace_iterator *iter,
1043 						int flags, struct trace_event *event)
1044 {
1045 	struct trace_array *tr = iter->tr;
1046 	struct userstack_entry *field;
1047 	struct trace_seq *s = &iter->seq;
1048 	struct mm_struct *mm = NULL;
1049 	unsigned int i;
1050 
1051 	trace_assign_type(field, iter->ent);
1052 
1053 	trace_seq_puts(s, "<user stack trace>\n");
1054 
1055 	if (tr->trace_flags & TRACE_ITER_SYM_USEROBJ) {
1056 		struct task_struct *task;
1057 		/*
1058 		 * we do the lookup on the thread group leader,
1059 		 * since individual threads might have already quit!
1060 		 */
1061 		rcu_read_lock();
1062 		task = find_task_by_vpid(field->tgid);
1063 		if (task)
1064 			mm = get_task_mm(task);
1065 		rcu_read_unlock();
1066 	}
1067 
1068 	for (i = 0; i < FTRACE_STACK_ENTRIES; i++) {
1069 		unsigned long ip = field->caller[i];
1070 
1071 		if (ip == ULONG_MAX || trace_seq_has_overflowed(s))
1072 			break;
1073 
1074 		trace_seq_puts(s, " => ");
1075 
1076 		if (!ip) {
1077 			trace_seq_puts(s, "??");
1078 			trace_seq_putc(s, '\n');
1079 			continue;
1080 		}
1081 
1082 		seq_print_user_ip(s, mm, ip, flags);
1083 		trace_seq_putc(s, '\n');
1084 	}
1085 
1086 	if (mm)
1087 		mmput(mm);
1088 
1089 	return trace_handle_return(s);
1090 }
1091 
1092 static struct trace_event_functions trace_user_stack_funcs = {
1093 	.trace		= trace_user_stack_print,
1094 };
1095 
1096 static struct trace_event trace_user_stack_event = {
1097 	.type		= TRACE_USER_STACK,
1098 	.funcs		= &trace_user_stack_funcs,
1099 };
1100 
1101 /* TRACE_BPUTS */
1102 static enum print_line_t
1103 trace_bputs_print(struct trace_iterator *iter, int flags,
1104 		   struct trace_event *event)
1105 {
1106 	struct trace_entry *entry = iter->ent;
1107 	struct trace_seq *s = &iter->seq;
1108 	struct bputs_entry *field;
1109 
1110 	trace_assign_type(field, entry);
1111 
1112 	seq_print_ip_sym(s, field->ip, flags);
1113 	trace_seq_puts(s, ": ");
1114 	trace_seq_puts(s, field->str);
1115 
1116 	return trace_handle_return(s);
1117 }
1118 
1119 
1120 static enum print_line_t
1121 trace_bputs_raw(struct trace_iterator *iter, int flags,
1122 		struct trace_event *event)
1123 {
1124 	struct bputs_entry *field;
1125 	struct trace_seq *s = &iter->seq;
1126 
1127 	trace_assign_type(field, iter->ent);
1128 
1129 	trace_seq_printf(s, ": %lx : ", field->ip);
1130 	trace_seq_puts(s, field->str);
1131 
1132 	return trace_handle_return(s);
1133 }
1134 
1135 static struct trace_event_functions trace_bputs_funcs = {
1136 	.trace		= trace_bputs_print,
1137 	.raw		= trace_bputs_raw,
1138 };
1139 
1140 static struct trace_event trace_bputs_event = {
1141 	.type		= TRACE_BPUTS,
1142 	.funcs		= &trace_bputs_funcs,
1143 };
1144 
1145 /* TRACE_BPRINT */
1146 static enum print_line_t
1147 trace_bprint_print(struct trace_iterator *iter, int flags,
1148 		   struct trace_event *event)
1149 {
1150 	struct trace_entry *entry = iter->ent;
1151 	struct trace_seq *s = &iter->seq;
1152 	struct bprint_entry *field;
1153 
1154 	trace_assign_type(field, entry);
1155 
1156 	seq_print_ip_sym(s, field->ip, flags);
1157 	trace_seq_puts(s, ": ");
1158 	trace_seq_bprintf(s, field->fmt, field->buf);
1159 
1160 	return trace_handle_return(s);
1161 }
1162 
1163 
1164 static enum print_line_t
1165 trace_bprint_raw(struct trace_iterator *iter, int flags,
1166 		 struct trace_event *event)
1167 {
1168 	struct bprint_entry *field;
1169 	struct trace_seq *s = &iter->seq;
1170 
1171 	trace_assign_type(field, iter->ent);
1172 
1173 	trace_seq_printf(s, ": %lx : ", field->ip);
1174 	trace_seq_bprintf(s, field->fmt, field->buf);
1175 
1176 	return trace_handle_return(s);
1177 }
1178 
1179 static struct trace_event_functions trace_bprint_funcs = {
1180 	.trace		= trace_bprint_print,
1181 	.raw		= trace_bprint_raw,
1182 };
1183 
1184 static struct trace_event trace_bprint_event = {
1185 	.type		= TRACE_BPRINT,
1186 	.funcs		= &trace_bprint_funcs,
1187 };
1188 
1189 /* TRACE_PRINT */
1190 static enum print_line_t trace_print_print(struct trace_iterator *iter,
1191 					   int flags, struct trace_event *event)
1192 {
1193 	struct print_entry *field;
1194 	struct trace_seq *s = &iter->seq;
1195 
1196 	trace_assign_type(field, iter->ent);
1197 
1198 	seq_print_ip_sym(s, field->ip, flags);
1199 	trace_seq_printf(s, ": %s", field->buf);
1200 
1201 	return trace_handle_return(s);
1202 }
1203 
1204 static enum print_line_t trace_print_raw(struct trace_iterator *iter, int flags,
1205 					 struct trace_event *event)
1206 {
1207 	struct print_entry *field;
1208 
1209 	trace_assign_type(field, iter->ent);
1210 
1211 	trace_seq_printf(&iter->seq, "# %lx %s", field->ip, field->buf);
1212 
1213 	return trace_handle_return(&iter->seq);
1214 }
1215 
1216 static struct trace_event_functions trace_print_funcs = {
1217 	.trace		= trace_print_print,
1218 	.raw		= trace_print_raw,
1219 };
1220 
1221 static struct trace_event trace_print_event = {
1222 	.type	 	= TRACE_PRINT,
1223 	.funcs		= &trace_print_funcs,
1224 };
1225 
1226 
1227 static struct trace_event *events[] __initdata = {
1228 	&trace_fn_event,
1229 	&trace_ctx_event,
1230 	&trace_wake_event,
1231 	&trace_stack_event,
1232 	&trace_user_stack_event,
1233 	&trace_bputs_event,
1234 	&trace_bprint_event,
1235 	&trace_print_event,
1236 	NULL
1237 };
1238 
1239 __init static int init_events(void)
1240 {
1241 	struct trace_event *event;
1242 	int i, ret;
1243 
1244 	for (i = 0; events[i]; i++) {
1245 		event = events[i];
1246 
1247 		ret = register_trace_event(event);
1248 		if (!ret) {
1249 			printk(KERN_WARNING "event %d failed to register\n",
1250 			       event->type);
1251 			WARN_ON_ONCE(1);
1252 		}
1253 	}
1254 
1255 	return 0;
1256 }
1257 early_initcall(init_events);
1258