xref: /openbmc/linux/kernel/trace/trace_output.c (revision 4e1a33b1)
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_flags_seq_u64(struct trace_seq *p, const char *delim,
128 		      unsigned long long flags,
129 		      const struct trace_print_flags_u64 *flag_array)
130 {
131 	unsigned long long mask;
132 	const char *str;
133 	const char *ret = trace_seq_buffer_ptr(p);
134 	int i, first = 1;
135 
136 	for (i = 0;  flag_array[i].name && flags; i++) {
137 
138 		mask = flag_array[i].mask;
139 		if ((flags & mask) != mask)
140 			continue;
141 
142 		str = flag_array[i].name;
143 		flags &= ~mask;
144 		if (!first && delim)
145 			trace_seq_puts(p, delim);
146 		else
147 			first = 0;
148 		trace_seq_puts(p, str);
149 	}
150 
151 	/* check for left over flags */
152 	if (flags) {
153 		if (!first && delim)
154 			trace_seq_puts(p, delim);
155 		trace_seq_printf(p, "0x%llx", flags);
156 	}
157 
158 	trace_seq_putc(p, 0);
159 
160 	return ret;
161 }
162 EXPORT_SYMBOL(trace_print_flags_seq_u64);
163 
164 const char *
165 trace_print_symbols_seq_u64(struct trace_seq *p, unsigned long long val,
166 			 const struct trace_print_flags_u64 *symbol_array)
167 {
168 	int i;
169 	const char *ret = trace_seq_buffer_ptr(p);
170 
171 	for (i = 0;  symbol_array[i].name; i++) {
172 
173 		if (val != symbol_array[i].mask)
174 			continue;
175 
176 		trace_seq_puts(p, symbol_array[i].name);
177 		break;
178 	}
179 
180 	if (ret == (const char *)(trace_seq_buffer_ptr(p)))
181 		trace_seq_printf(p, "0x%llx", val);
182 
183 	trace_seq_putc(p, 0);
184 
185 	return ret;
186 }
187 EXPORT_SYMBOL(trace_print_symbols_seq_u64);
188 #endif
189 
190 const char *
191 trace_print_bitmask_seq(struct trace_seq *p, void *bitmask_ptr,
192 			unsigned int bitmask_size)
193 {
194 	const char *ret = trace_seq_buffer_ptr(p);
195 
196 	trace_seq_bitmask(p, bitmask_ptr, bitmask_size * 8);
197 	trace_seq_putc(p, 0);
198 
199 	return ret;
200 }
201 EXPORT_SYMBOL_GPL(trace_print_bitmask_seq);
202 
203 /**
204  * trace_print_hex_seq - print buffer as hex sequence
205  * @p: trace seq struct to write to
206  * @buf: The buffer to print
207  * @buf_len: Length of @buf in bytes
208  * @concatenate: Print @buf as single hex string or with spacing
209  *
210  * Prints the passed buffer as a hex sequence either as a whole,
211  * single hex string if @concatenate is true or with spacing after
212  * each byte in case @concatenate is false.
213  */
214 const char *
215 trace_print_hex_seq(struct trace_seq *p, const unsigned char *buf, int buf_len,
216 		    bool concatenate)
217 {
218 	int i;
219 	const char *ret = trace_seq_buffer_ptr(p);
220 
221 	for (i = 0; i < buf_len; i++)
222 		trace_seq_printf(p, "%s%2.2x", concatenate || i == 0 ? "" : " ",
223 				 buf[i]);
224 	trace_seq_putc(p, 0);
225 
226 	return ret;
227 }
228 EXPORT_SYMBOL(trace_print_hex_seq);
229 
230 const char *
231 trace_print_array_seq(struct trace_seq *p, const void *buf, int count,
232 		      size_t el_size)
233 {
234 	const char *ret = trace_seq_buffer_ptr(p);
235 	const char *prefix = "";
236 	void *ptr = (void *)buf;
237 	size_t buf_len = count * el_size;
238 
239 	trace_seq_putc(p, '{');
240 
241 	while (ptr < buf + buf_len) {
242 		switch (el_size) {
243 		case 1:
244 			trace_seq_printf(p, "%s0x%x", prefix,
245 					 *(u8 *)ptr);
246 			break;
247 		case 2:
248 			trace_seq_printf(p, "%s0x%x", prefix,
249 					 *(u16 *)ptr);
250 			break;
251 		case 4:
252 			trace_seq_printf(p, "%s0x%x", prefix,
253 					 *(u32 *)ptr);
254 			break;
255 		case 8:
256 			trace_seq_printf(p, "%s0x%llx", prefix,
257 					 *(u64 *)ptr);
258 			break;
259 		default:
260 			trace_seq_printf(p, "BAD SIZE:%zu 0x%x", el_size,
261 					 *(u8 *)ptr);
262 			el_size = 1;
263 		}
264 		prefix = ",";
265 		ptr += el_size;
266 	}
267 
268 	trace_seq_putc(p, '}');
269 	trace_seq_putc(p, 0);
270 
271 	return ret;
272 }
273 EXPORT_SYMBOL(trace_print_array_seq);
274 
275 int trace_raw_output_prep(struct trace_iterator *iter,
276 			  struct trace_event *trace_event)
277 {
278 	struct trace_event_call *event;
279 	struct trace_seq *s = &iter->seq;
280 	struct trace_seq *p = &iter->tmp_seq;
281 	struct trace_entry *entry;
282 
283 	event = container_of(trace_event, struct trace_event_call, event);
284 	entry = iter->ent;
285 
286 	if (entry->type != event->event.type) {
287 		WARN_ON_ONCE(1);
288 		return TRACE_TYPE_UNHANDLED;
289 	}
290 
291 	trace_seq_init(p);
292 	trace_seq_printf(s, "%s: ", trace_event_name(event));
293 
294 	return trace_handle_return(s);
295 }
296 EXPORT_SYMBOL(trace_raw_output_prep);
297 
298 static int trace_output_raw(struct trace_iterator *iter, char *name,
299 			    char *fmt, va_list ap)
300 {
301 	struct trace_seq *s = &iter->seq;
302 
303 	trace_seq_printf(s, "%s: ", name);
304 	trace_seq_vprintf(s, fmt, ap);
305 
306 	return trace_handle_return(s);
307 }
308 
309 int trace_output_call(struct trace_iterator *iter, char *name, char *fmt, ...)
310 {
311 	va_list ap;
312 	int ret;
313 
314 	va_start(ap, fmt);
315 	ret = trace_output_raw(iter, name, fmt, ap);
316 	va_end(ap);
317 
318 	return ret;
319 }
320 EXPORT_SYMBOL_GPL(trace_output_call);
321 
322 #ifdef CONFIG_KRETPROBES
323 static inline const char *kretprobed(const char *name)
324 {
325 	static const char tramp_name[] = "kretprobe_trampoline";
326 	int size = sizeof(tramp_name);
327 
328 	if (strncmp(tramp_name, name, size) == 0)
329 		return "[unknown/kretprobe'd]";
330 	return name;
331 }
332 #else
333 static inline const char *kretprobed(const char *name)
334 {
335 	return name;
336 }
337 #endif /* CONFIG_KRETPROBES */
338 
339 static void
340 seq_print_sym_short(struct trace_seq *s, const char *fmt, unsigned long address)
341 {
342 #ifdef CONFIG_KALLSYMS
343 	char str[KSYM_SYMBOL_LEN];
344 	const char *name;
345 
346 	kallsyms_lookup(address, NULL, NULL, NULL, str);
347 
348 	name = kretprobed(str);
349 
350 	trace_seq_printf(s, fmt, name);
351 #endif
352 }
353 
354 static void
355 seq_print_sym_offset(struct trace_seq *s, const char *fmt,
356 		     unsigned long address)
357 {
358 #ifdef CONFIG_KALLSYMS
359 	char str[KSYM_SYMBOL_LEN];
360 	const char *name;
361 
362 	sprint_symbol(str, address);
363 	name = kretprobed(str);
364 
365 	trace_seq_printf(s, fmt, name);
366 #endif
367 }
368 
369 #ifndef CONFIG_64BIT
370 # define IP_FMT "%08lx"
371 #else
372 # define IP_FMT "%016lx"
373 #endif
374 
375 static int seq_print_user_ip(struct trace_seq *s, struct mm_struct *mm,
376 			     unsigned long ip, unsigned long sym_flags)
377 {
378 	struct file *file = NULL;
379 	unsigned long vmstart = 0;
380 	int ret = 1;
381 
382 	if (s->full)
383 		return 0;
384 
385 	if (mm) {
386 		const struct vm_area_struct *vma;
387 
388 		down_read(&mm->mmap_sem);
389 		vma = find_vma(mm, ip);
390 		if (vma) {
391 			file = vma->vm_file;
392 			vmstart = vma->vm_start;
393 		}
394 		if (file) {
395 			ret = trace_seq_path(s, &file->f_path);
396 			if (ret)
397 				trace_seq_printf(s, "[+0x%lx]",
398 						 ip - vmstart);
399 		}
400 		up_read(&mm->mmap_sem);
401 	}
402 	if (ret && ((sym_flags & TRACE_ITER_SYM_ADDR) || !file))
403 		trace_seq_printf(s, " <" IP_FMT ">", ip);
404 	return !trace_seq_has_overflowed(s);
405 }
406 
407 int
408 seq_print_ip_sym(struct trace_seq *s, unsigned long ip, unsigned long sym_flags)
409 {
410 	if (!ip) {
411 		trace_seq_putc(s, '0');
412 		goto out;
413 	}
414 
415 	if (sym_flags & TRACE_ITER_SYM_OFFSET)
416 		seq_print_sym_offset(s, "%s", ip);
417 	else
418 		seq_print_sym_short(s, "%s", ip);
419 
420 	if (sym_flags & TRACE_ITER_SYM_ADDR)
421 		trace_seq_printf(s, " <" IP_FMT ">", ip);
422 
423  out:
424 	return !trace_seq_has_overflowed(s);
425 }
426 
427 /**
428  * trace_print_lat_fmt - print the irq, preempt and lockdep fields
429  * @s: trace seq struct to write to
430  * @entry: The trace entry field from the ring buffer
431  *
432  * Prints the generic fields of irqs off, in hard or softirq, preempt
433  * count.
434  */
435 int trace_print_lat_fmt(struct trace_seq *s, struct trace_entry *entry)
436 {
437 	char hardsoft_irq;
438 	char need_resched;
439 	char irqs_off;
440 	int hardirq;
441 	int softirq;
442 	int nmi;
443 
444 	nmi = entry->flags & TRACE_FLAG_NMI;
445 	hardirq = entry->flags & TRACE_FLAG_HARDIRQ;
446 	softirq = entry->flags & TRACE_FLAG_SOFTIRQ;
447 
448 	irqs_off =
449 		(entry->flags & TRACE_FLAG_IRQS_OFF) ? 'd' :
450 		(entry->flags & TRACE_FLAG_IRQS_NOSUPPORT) ? 'X' :
451 		'.';
452 
453 	switch (entry->flags & (TRACE_FLAG_NEED_RESCHED |
454 				TRACE_FLAG_PREEMPT_RESCHED)) {
455 	case TRACE_FLAG_NEED_RESCHED | TRACE_FLAG_PREEMPT_RESCHED:
456 		need_resched = 'N';
457 		break;
458 	case TRACE_FLAG_NEED_RESCHED:
459 		need_resched = 'n';
460 		break;
461 	case TRACE_FLAG_PREEMPT_RESCHED:
462 		need_resched = 'p';
463 		break;
464 	default:
465 		need_resched = '.';
466 		break;
467 	}
468 
469 	hardsoft_irq =
470 		(nmi && hardirq)     ? 'Z' :
471 		nmi                  ? 'z' :
472 		(hardirq && softirq) ? 'H' :
473 		hardirq              ? 'h' :
474 		softirq              ? 's' :
475 		                       '.' ;
476 
477 	trace_seq_printf(s, "%c%c%c",
478 			 irqs_off, need_resched, hardsoft_irq);
479 
480 	if (entry->preempt_count)
481 		trace_seq_printf(s, "%x", entry->preempt_count);
482 	else
483 		trace_seq_putc(s, '.');
484 
485 	return !trace_seq_has_overflowed(s);
486 }
487 
488 static int
489 lat_print_generic(struct trace_seq *s, struct trace_entry *entry, int cpu)
490 {
491 	char comm[TASK_COMM_LEN];
492 
493 	trace_find_cmdline(entry->pid, comm);
494 
495 	trace_seq_printf(s, "%8.8s-%-5d %3d",
496 			 comm, entry->pid, cpu);
497 
498 	return trace_print_lat_fmt(s, entry);
499 }
500 
501 #undef MARK
502 #define MARK(v, s) {.val = v, .sym = s}
503 /* trace overhead mark */
504 static const struct trace_mark {
505 	unsigned long long	val; /* unit: nsec */
506 	char			sym;
507 } mark[] = {
508 	MARK(1000000000ULL	, '$'), /* 1 sec */
509 	MARK(100000000ULL	, '@'), /* 100 msec */
510 	MARK(10000000ULL	, '*'), /* 10 msec */
511 	MARK(1000000ULL		, '#'), /* 1000 usecs */
512 	MARK(100000ULL		, '!'), /* 100 usecs */
513 	MARK(10000ULL		, '+'), /* 10 usecs */
514 };
515 #undef MARK
516 
517 char trace_find_mark(unsigned long long d)
518 {
519 	int i;
520 	int size = ARRAY_SIZE(mark);
521 
522 	for (i = 0; i < size; i++) {
523 		if (d > mark[i].val)
524 			break;
525 	}
526 
527 	return (i == size) ? ' ' : mark[i].sym;
528 }
529 
530 static int
531 lat_print_timestamp(struct trace_iterator *iter, u64 next_ts)
532 {
533 	struct trace_array *tr = iter->tr;
534 	unsigned long verbose = tr->trace_flags & TRACE_ITER_VERBOSE;
535 	unsigned long in_ns = iter->iter_flags & TRACE_FILE_TIME_IN_NS;
536 	unsigned long long abs_ts = iter->ts - iter->trace_buffer->time_start;
537 	unsigned long long rel_ts = next_ts - iter->ts;
538 	struct trace_seq *s = &iter->seq;
539 
540 	if (in_ns) {
541 		abs_ts = ns2usecs(abs_ts);
542 		rel_ts = ns2usecs(rel_ts);
543 	}
544 
545 	if (verbose && in_ns) {
546 		unsigned long abs_usec = do_div(abs_ts, USEC_PER_MSEC);
547 		unsigned long abs_msec = (unsigned long)abs_ts;
548 		unsigned long rel_usec = do_div(rel_ts, USEC_PER_MSEC);
549 		unsigned long rel_msec = (unsigned long)rel_ts;
550 
551 		trace_seq_printf(
552 			s, "[%08llx] %ld.%03ldms (+%ld.%03ldms): ",
553 			ns2usecs(iter->ts),
554 			abs_msec, abs_usec,
555 			rel_msec, rel_usec);
556 
557 	} else if (verbose && !in_ns) {
558 		trace_seq_printf(
559 			s, "[%016llx] %lld (+%lld): ",
560 			iter->ts, abs_ts, rel_ts);
561 
562 	} else if (!verbose && in_ns) {
563 		trace_seq_printf(
564 			s, " %4lldus%c: ",
565 			abs_ts,
566 			trace_find_mark(rel_ts * NSEC_PER_USEC));
567 
568 	} else { /* !verbose && !in_ns */
569 		trace_seq_printf(s, " %4lld: ", abs_ts);
570 	}
571 
572 	return !trace_seq_has_overflowed(s);
573 }
574 
575 int trace_print_context(struct trace_iterator *iter)
576 {
577 	struct trace_array *tr = iter->tr;
578 	struct trace_seq *s = &iter->seq;
579 	struct trace_entry *entry = iter->ent;
580 	unsigned long long t;
581 	unsigned long secs, usec_rem;
582 	char comm[TASK_COMM_LEN];
583 
584 	trace_find_cmdline(entry->pid, comm);
585 
586 	trace_seq_printf(s, "%16s-%-5d [%03d] ",
587 			       comm, entry->pid, iter->cpu);
588 
589 	if (tr->trace_flags & TRACE_ITER_IRQ_INFO)
590 		trace_print_lat_fmt(s, entry);
591 
592 	if (iter->iter_flags & TRACE_FILE_TIME_IN_NS) {
593 		t = ns2usecs(iter->ts);
594 		usec_rem = do_div(t, USEC_PER_SEC);
595 		secs = (unsigned long)t;
596 		trace_seq_printf(s, " %5lu.%06lu: ", secs, usec_rem);
597 	} else
598 		trace_seq_printf(s, " %12llu: ", iter->ts);
599 
600 	return !trace_seq_has_overflowed(s);
601 }
602 
603 int trace_print_lat_context(struct trace_iterator *iter)
604 {
605 	struct trace_array *tr = iter->tr;
606 	/* trace_find_next_entry will reset ent_size */
607 	int ent_size = iter->ent_size;
608 	struct trace_seq *s = &iter->seq;
609 	u64 next_ts;
610 	struct trace_entry *entry = iter->ent,
611 			   *next_entry = trace_find_next_entry(iter, NULL,
612 							       &next_ts);
613 	unsigned long verbose = (tr->trace_flags & TRACE_ITER_VERBOSE);
614 
615 	/* Restore the original ent_size */
616 	iter->ent_size = ent_size;
617 
618 	if (!next_entry)
619 		next_ts = iter->ts;
620 
621 	if (verbose) {
622 		char comm[TASK_COMM_LEN];
623 
624 		trace_find_cmdline(entry->pid, comm);
625 
626 		trace_seq_printf(
627 			s, "%16s %5d %3d %d %08x %08lx ",
628 			comm, entry->pid, iter->cpu, entry->flags,
629 			entry->preempt_count, iter->idx);
630 	} else {
631 		lat_print_generic(s, entry, iter->cpu);
632 	}
633 
634 	lat_print_timestamp(iter, next_ts);
635 
636 	return !trace_seq_has_overflowed(s);
637 }
638 
639 static const char state_to_char[] = TASK_STATE_TO_CHAR_STR;
640 
641 static int task_state_char(unsigned long state)
642 {
643 	int bit = state ? __ffs(state) + 1 : 0;
644 
645 	return bit < sizeof(state_to_char) - 1 ? state_to_char[bit] : '?';
646 }
647 
648 /**
649  * ftrace_find_event - find a registered event
650  * @type: the type of event to look for
651  *
652  * Returns an event of type @type otherwise NULL
653  * Called with trace_event_read_lock() held.
654  */
655 struct trace_event *ftrace_find_event(int type)
656 {
657 	struct trace_event *event;
658 	unsigned key;
659 
660 	key = type & (EVENT_HASHSIZE - 1);
661 
662 	hlist_for_each_entry(event, &event_hash[key], node) {
663 		if (event->type == type)
664 			return event;
665 	}
666 
667 	return NULL;
668 }
669 
670 static LIST_HEAD(ftrace_event_list);
671 
672 static int trace_search_list(struct list_head **list)
673 {
674 	struct trace_event *e;
675 	int last = __TRACE_LAST_TYPE;
676 
677 	if (list_empty(&ftrace_event_list)) {
678 		*list = &ftrace_event_list;
679 		return last + 1;
680 	}
681 
682 	/*
683 	 * We used up all possible max events,
684 	 * lets see if somebody freed one.
685 	 */
686 	list_for_each_entry(e, &ftrace_event_list, list) {
687 		if (e->type != last + 1)
688 			break;
689 		last++;
690 	}
691 
692 	/* Did we used up all 65 thousand events??? */
693 	if ((last + 1) > TRACE_EVENT_TYPE_MAX)
694 		return 0;
695 
696 	*list = &e->list;
697 	return last + 1;
698 }
699 
700 void trace_event_read_lock(void)
701 {
702 	down_read(&trace_event_sem);
703 }
704 
705 void trace_event_read_unlock(void)
706 {
707 	up_read(&trace_event_sem);
708 }
709 
710 /**
711  * register_trace_event - register output for an event type
712  * @event: the event type to register
713  *
714  * Event types are stored in a hash and this hash is used to
715  * find a way to print an event. If the @event->type is set
716  * then it will use that type, otherwise it will assign a
717  * type to use.
718  *
719  * If you assign your own type, please make sure it is added
720  * to the trace_type enum in trace.h, to avoid collisions
721  * with the dynamic types.
722  *
723  * Returns the event type number or zero on error.
724  */
725 int register_trace_event(struct trace_event *event)
726 {
727 	unsigned key;
728 	int ret = 0;
729 
730 	down_write(&trace_event_sem);
731 
732 	if (WARN_ON(!event))
733 		goto out;
734 
735 	if (WARN_ON(!event->funcs))
736 		goto out;
737 
738 	INIT_LIST_HEAD(&event->list);
739 
740 	if (!event->type) {
741 		struct list_head *list = NULL;
742 
743 		if (next_event_type > TRACE_EVENT_TYPE_MAX) {
744 
745 			event->type = trace_search_list(&list);
746 			if (!event->type)
747 				goto out;
748 
749 		} else {
750 
751 			event->type = next_event_type++;
752 			list = &ftrace_event_list;
753 		}
754 
755 		if (WARN_ON(ftrace_find_event(event->type)))
756 			goto out;
757 
758 		list_add_tail(&event->list, list);
759 
760 	} else if (event->type > __TRACE_LAST_TYPE) {
761 		printk(KERN_WARNING "Need to add type to trace.h\n");
762 		WARN_ON(1);
763 		goto out;
764 	} else {
765 		/* Is this event already used */
766 		if (ftrace_find_event(event->type))
767 			goto out;
768 	}
769 
770 	if (event->funcs->trace == NULL)
771 		event->funcs->trace = trace_nop_print;
772 	if (event->funcs->raw == NULL)
773 		event->funcs->raw = trace_nop_print;
774 	if (event->funcs->hex == NULL)
775 		event->funcs->hex = trace_nop_print;
776 	if (event->funcs->binary == NULL)
777 		event->funcs->binary = trace_nop_print;
778 
779 	key = event->type & (EVENT_HASHSIZE - 1);
780 
781 	hlist_add_head(&event->node, &event_hash[key]);
782 
783 	ret = event->type;
784  out:
785 	up_write(&trace_event_sem);
786 
787 	return ret;
788 }
789 EXPORT_SYMBOL_GPL(register_trace_event);
790 
791 /*
792  * Used by module code with the trace_event_sem held for write.
793  */
794 int __unregister_trace_event(struct trace_event *event)
795 {
796 	hlist_del(&event->node);
797 	list_del(&event->list);
798 	return 0;
799 }
800 
801 /**
802  * unregister_trace_event - remove a no longer used event
803  * @event: the event to remove
804  */
805 int unregister_trace_event(struct trace_event *event)
806 {
807 	down_write(&trace_event_sem);
808 	__unregister_trace_event(event);
809 	up_write(&trace_event_sem);
810 
811 	return 0;
812 }
813 EXPORT_SYMBOL_GPL(unregister_trace_event);
814 
815 /*
816  * Standard events
817  */
818 
819 enum print_line_t trace_nop_print(struct trace_iterator *iter, int flags,
820 				  struct trace_event *event)
821 {
822 	trace_seq_printf(&iter->seq, "type: %d\n", iter->ent->type);
823 
824 	return trace_handle_return(&iter->seq);
825 }
826 
827 /* TRACE_FN */
828 static enum print_line_t trace_fn_trace(struct trace_iterator *iter, int flags,
829 					struct trace_event *event)
830 {
831 	struct ftrace_entry *field;
832 	struct trace_seq *s = &iter->seq;
833 
834 	trace_assign_type(field, iter->ent);
835 
836 	seq_print_ip_sym(s, field->ip, flags);
837 
838 	if ((flags & TRACE_ITER_PRINT_PARENT) && field->parent_ip) {
839 		trace_seq_puts(s, " <-");
840 		seq_print_ip_sym(s, field->parent_ip, flags);
841 	}
842 
843 	trace_seq_putc(s, '\n');
844 
845 	return trace_handle_return(s);
846 }
847 
848 static enum print_line_t trace_fn_raw(struct trace_iterator *iter, int flags,
849 				      struct trace_event *event)
850 {
851 	struct ftrace_entry *field;
852 
853 	trace_assign_type(field, iter->ent);
854 
855 	trace_seq_printf(&iter->seq, "%lx %lx\n",
856 			 field->ip,
857 			 field->parent_ip);
858 
859 	return trace_handle_return(&iter->seq);
860 }
861 
862 static enum print_line_t trace_fn_hex(struct trace_iterator *iter, int flags,
863 				      struct trace_event *event)
864 {
865 	struct ftrace_entry *field;
866 	struct trace_seq *s = &iter->seq;
867 
868 	trace_assign_type(field, iter->ent);
869 
870 	SEQ_PUT_HEX_FIELD(s, field->ip);
871 	SEQ_PUT_HEX_FIELD(s, field->parent_ip);
872 
873 	return trace_handle_return(s);
874 }
875 
876 static enum print_line_t trace_fn_bin(struct trace_iterator *iter, int flags,
877 				      struct trace_event *event)
878 {
879 	struct ftrace_entry *field;
880 	struct trace_seq *s = &iter->seq;
881 
882 	trace_assign_type(field, iter->ent);
883 
884 	SEQ_PUT_FIELD(s, field->ip);
885 	SEQ_PUT_FIELD(s, field->parent_ip);
886 
887 	return trace_handle_return(s);
888 }
889 
890 static struct trace_event_functions trace_fn_funcs = {
891 	.trace		= trace_fn_trace,
892 	.raw		= trace_fn_raw,
893 	.hex		= trace_fn_hex,
894 	.binary		= trace_fn_bin,
895 };
896 
897 static struct trace_event trace_fn_event = {
898 	.type		= TRACE_FN,
899 	.funcs		= &trace_fn_funcs,
900 };
901 
902 /* TRACE_CTX an TRACE_WAKE */
903 static enum print_line_t trace_ctxwake_print(struct trace_iterator *iter,
904 					     char *delim)
905 {
906 	struct ctx_switch_entry *field;
907 	char comm[TASK_COMM_LEN];
908 	int S, T;
909 
910 
911 	trace_assign_type(field, iter->ent);
912 
913 	T = task_state_char(field->next_state);
914 	S = task_state_char(field->prev_state);
915 	trace_find_cmdline(field->next_pid, comm);
916 	trace_seq_printf(&iter->seq,
917 			 " %5d:%3d:%c %s [%03d] %5d:%3d:%c %s\n",
918 			 field->prev_pid,
919 			 field->prev_prio,
920 			 S, delim,
921 			 field->next_cpu,
922 			 field->next_pid,
923 			 field->next_prio,
924 			 T, comm);
925 
926 	return trace_handle_return(&iter->seq);
927 }
928 
929 static enum print_line_t trace_ctx_print(struct trace_iterator *iter, int flags,
930 					 struct trace_event *event)
931 {
932 	return trace_ctxwake_print(iter, "==>");
933 }
934 
935 static enum print_line_t trace_wake_print(struct trace_iterator *iter,
936 					  int flags, struct trace_event *event)
937 {
938 	return trace_ctxwake_print(iter, "  +");
939 }
940 
941 static int trace_ctxwake_raw(struct trace_iterator *iter, char S)
942 {
943 	struct ctx_switch_entry *field;
944 	int T;
945 
946 	trace_assign_type(field, iter->ent);
947 
948 	if (!S)
949 		S = task_state_char(field->prev_state);
950 	T = task_state_char(field->next_state);
951 	trace_seq_printf(&iter->seq, "%d %d %c %d %d %d %c\n",
952 			 field->prev_pid,
953 			 field->prev_prio,
954 			 S,
955 			 field->next_cpu,
956 			 field->next_pid,
957 			 field->next_prio,
958 			 T);
959 
960 	return trace_handle_return(&iter->seq);
961 }
962 
963 static enum print_line_t trace_ctx_raw(struct trace_iterator *iter, int flags,
964 				       struct trace_event *event)
965 {
966 	return trace_ctxwake_raw(iter, 0);
967 }
968 
969 static enum print_line_t trace_wake_raw(struct trace_iterator *iter, int flags,
970 					struct trace_event *event)
971 {
972 	return trace_ctxwake_raw(iter, '+');
973 }
974 
975 
976 static int trace_ctxwake_hex(struct trace_iterator *iter, char S)
977 {
978 	struct ctx_switch_entry *field;
979 	struct trace_seq *s = &iter->seq;
980 	int T;
981 
982 	trace_assign_type(field, iter->ent);
983 
984 	if (!S)
985 		S = task_state_char(field->prev_state);
986 	T = task_state_char(field->next_state);
987 
988 	SEQ_PUT_HEX_FIELD(s, field->prev_pid);
989 	SEQ_PUT_HEX_FIELD(s, field->prev_prio);
990 	SEQ_PUT_HEX_FIELD(s, S);
991 	SEQ_PUT_HEX_FIELD(s, field->next_cpu);
992 	SEQ_PUT_HEX_FIELD(s, field->next_pid);
993 	SEQ_PUT_HEX_FIELD(s, field->next_prio);
994 	SEQ_PUT_HEX_FIELD(s, T);
995 
996 	return trace_handle_return(s);
997 }
998 
999 static enum print_line_t trace_ctx_hex(struct trace_iterator *iter, int flags,
1000 				       struct trace_event *event)
1001 {
1002 	return trace_ctxwake_hex(iter, 0);
1003 }
1004 
1005 static enum print_line_t trace_wake_hex(struct trace_iterator *iter, int flags,
1006 					struct trace_event *event)
1007 {
1008 	return trace_ctxwake_hex(iter, '+');
1009 }
1010 
1011 static enum print_line_t trace_ctxwake_bin(struct trace_iterator *iter,
1012 					   int flags, struct trace_event *event)
1013 {
1014 	struct ctx_switch_entry *field;
1015 	struct trace_seq *s = &iter->seq;
1016 
1017 	trace_assign_type(field, iter->ent);
1018 
1019 	SEQ_PUT_FIELD(s, field->prev_pid);
1020 	SEQ_PUT_FIELD(s, field->prev_prio);
1021 	SEQ_PUT_FIELD(s, field->prev_state);
1022 	SEQ_PUT_FIELD(s, field->next_cpu);
1023 	SEQ_PUT_FIELD(s, field->next_pid);
1024 	SEQ_PUT_FIELD(s, field->next_prio);
1025 	SEQ_PUT_FIELD(s, field->next_state);
1026 
1027 	return trace_handle_return(s);
1028 }
1029 
1030 static struct trace_event_functions trace_ctx_funcs = {
1031 	.trace		= trace_ctx_print,
1032 	.raw		= trace_ctx_raw,
1033 	.hex		= trace_ctx_hex,
1034 	.binary		= trace_ctxwake_bin,
1035 };
1036 
1037 static struct trace_event trace_ctx_event = {
1038 	.type		= TRACE_CTX,
1039 	.funcs		= &trace_ctx_funcs,
1040 };
1041 
1042 static struct trace_event_functions trace_wake_funcs = {
1043 	.trace		= trace_wake_print,
1044 	.raw		= trace_wake_raw,
1045 	.hex		= trace_wake_hex,
1046 	.binary		= trace_ctxwake_bin,
1047 };
1048 
1049 static struct trace_event trace_wake_event = {
1050 	.type		= TRACE_WAKE,
1051 	.funcs		= &trace_wake_funcs,
1052 };
1053 
1054 /* TRACE_STACK */
1055 
1056 static enum print_line_t trace_stack_print(struct trace_iterator *iter,
1057 					   int flags, struct trace_event *event)
1058 {
1059 	struct stack_entry *field;
1060 	struct trace_seq *s = &iter->seq;
1061 	unsigned long *p;
1062 	unsigned long *end;
1063 
1064 	trace_assign_type(field, iter->ent);
1065 	end = (unsigned long *)((long)iter->ent + iter->ent_size);
1066 
1067 	trace_seq_puts(s, "<stack trace>\n");
1068 
1069 	for (p = field->caller; p && *p != ULONG_MAX && p < end; p++) {
1070 
1071 		if (trace_seq_has_overflowed(s))
1072 			break;
1073 
1074 		trace_seq_puts(s, " => ");
1075 		seq_print_ip_sym(s, *p, flags);
1076 		trace_seq_putc(s, '\n');
1077 	}
1078 
1079 	return trace_handle_return(s);
1080 }
1081 
1082 static struct trace_event_functions trace_stack_funcs = {
1083 	.trace		= trace_stack_print,
1084 };
1085 
1086 static struct trace_event trace_stack_event = {
1087 	.type		= TRACE_STACK,
1088 	.funcs		= &trace_stack_funcs,
1089 };
1090 
1091 /* TRACE_USER_STACK */
1092 static enum print_line_t trace_user_stack_print(struct trace_iterator *iter,
1093 						int flags, struct trace_event *event)
1094 {
1095 	struct trace_array *tr = iter->tr;
1096 	struct userstack_entry *field;
1097 	struct trace_seq *s = &iter->seq;
1098 	struct mm_struct *mm = NULL;
1099 	unsigned int i;
1100 
1101 	trace_assign_type(field, iter->ent);
1102 
1103 	trace_seq_puts(s, "<user stack trace>\n");
1104 
1105 	if (tr->trace_flags & TRACE_ITER_SYM_USEROBJ) {
1106 		struct task_struct *task;
1107 		/*
1108 		 * we do the lookup on the thread group leader,
1109 		 * since individual threads might have already quit!
1110 		 */
1111 		rcu_read_lock();
1112 		task = find_task_by_vpid(field->tgid);
1113 		if (task)
1114 			mm = get_task_mm(task);
1115 		rcu_read_unlock();
1116 	}
1117 
1118 	for (i = 0; i < FTRACE_STACK_ENTRIES; i++) {
1119 		unsigned long ip = field->caller[i];
1120 
1121 		if (ip == ULONG_MAX || trace_seq_has_overflowed(s))
1122 			break;
1123 
1124 		trace_seq_puts(s, " => ");
1125 
1126 		if (!ip) {
1127 			trace_seq_puts(s, "??");
1128 			trace_seq_putc(s, '\n');
1129 			continue;
1130 		}
1131 
1132 		seq_print_user_ip(s, mm, ip, flags);
1133 		trace_seq_putc(s, '\n');
1134 	}
1135 
1136 	if (mm)
1137 		mmput(mm);
1138 
1139 	return trace_handle_return(s);
1140 }
1141 
1142 static struct trace_event_functions trace_user_stack_funcs = {
1143 	.trace		= trace_user_stack_print,
1144 };
1145 
1146 static struct trace_event trace_user_stack_event = {
1147 	.type		= TRACE_USER_STACK,
1148 	.funcs		= &trace_user_stack_funcs,
1149 };
1150 
1151 /* TRACE_HWLAT */
1152 static enum print_line_t
1153 trace_hwlat_print(struct trace_iterator *iter, int flags,
1154 		  struct trace_event *event)
1155 {
1156 	struct trace_entry *entry = iter->ent;
1157 	struct trace_seq *s = &iter->seq;
1158 	struct hwlat_entry *field;
1159 
1160 	trace_assign_type(field, entry);
1161 
1162 	trace_seq_printf(s, "#%-5u inner/outer(us): %4llu/%-5llu ts:%ld.%09ld",
1163 			 field->seqnum,
1164 			 field->duration,
1165 			 field->outer_duration,
1166 			 field->timestamp.tv_sec,
1167 			 field->timestamp.tv_nsec);
1168 
1169 	if (field->nmi_count) {
1170 		/*
1171 		 * The generic sched_clock() is not NMI safe, thus
1172 		 * we only record the count and not the time.
1173 		 */
1174 		if (!IS_ENABLED(CONFIG_GENERIC_SCHED_CLOCK))
1175 			trace_seq_printf(s, " nmi-total:%llu",
1176 					 field->nmi_total_ts);
1177 		trace_seq_printf(s, " nmi-count:%u",
1178 				 field->nmi_count);
1179 	}
1180 
1181 	trace_seq_putc(s, '\n');
1182 
1183 	return trace_handle_return(s);
1184 }
1185 
1186 
1187 static enum print_line_t
1188 trace_hwlat_raw(struct trace_iterator *iter, int flags,
1189 		struct trace_event *event)
1190 {
1191 	struct hwlat_entry *field;
1192 	struct trace_seq *s = &iter->seq;
1193 
1194 	trace_assign_type(field, iter->ent);
1195 
1196 	trace_seq_printf(s, "%llu %lld %ld %09ld %u\n",
1197 			 field->duration,
1198 			 field->outer_duration,
1199 			 field->timestamp.tv_sec,
1200 			 field->timestamp.tv_nsec,
1201 			 field->seqnum);
1202 
1203 	return trace_handle_return(s);
1204 }
1205 
1206 static struct trace_event_functions trace_hwlat_funcs = {
1207 	.trace		= trace_hwlat_print,
1208 	.raw		= trace_hwlat_raw,
1209 };
1210 
1211 static struct trace_event trace_hwlat_event = {
1212 	.type		= TRACE_HWLAT,
1213 	.funcs		= &trace_hwlat_funcs,
1214 };
1215 
1216 /* TRACE_BPUTS */
1217 static enum print_line_t
1218 trace_bputs_print(struct trace_iterator *iter, int flags,
1219 		   struct trace_event *event)
1220 {
1221 	struct trace_entry *entry = iter->ent;
1222 	struct trace_seq *s = &iter->seq;
1223 	struct bputs_entry *field;
1224 
1225 	trace_assign_type(field, entry);
1226 
1227 	seq_print_ip_sym(s, field->ip, flags);
1228 	trace_seq_puts(s, ": ");
1229 	trace_seq_puts(s, field->str);
1230 
1231 	return trace_handle_return(s);
1232 }
1233 
1234 
1235 static enum print_line_t
1236 trace_bputs_raw(struct trace_iterator *iter, int flags,
1237 		struct trace_event *event)
1238 {
1239 	struct bputs_entry *field;
1240 	struct trace_seq *s = &iter->seq;
1241 
1242 	trace_assign_type(field, iter->ent);
1243 
1244 	trace_seq_printf(s, ": %lx : ", field->ip);
1245 	trace_seq_puts(s, field->str);
1246 
1247 	return trace_handle_return(s);
1248 }
1249 
1250 static struct trace_event_functions trace_bputs_funcs = {
1251 	.trace		= trace_bputs_print,
1252 	.raw		= trace_bputs_raw,
1253 };
1254 
1255 static struct trace_event trace_bputs_event = {
1256 	.type		= TRACE_BPUTS,
1257 	.funcs		= &trace_bputs_funcs,
1258 };
1259 
1260 /* TRACE_BPRINT */
1261 static enum print_line_t
1262 trace_bprint_print(struct trace_iterator *iter, int flags,
1263 		   struct trace_event *event)
1264 {
1265 	struct trace_entry *entry = iter->ent;
1266 	struct trace_seq *s = &iter->seq;
1267 	struct bprint_entry *field;
1268 
1269 	trace_assign_type(field, entry);
1270 
1271 	seq_print_ip_sym(s, field->ip, flags);
1272 	trace_seq_puts(s, ": ");
1273 	trace_seq_bprintf(s, field->fmt, field->buf);
1274 
1275 	return trace_handle_return(s);
1276 }
1277 
1278 
1279 static enum print_line_t
1280 trace_bprint_raw(struct trace_iterator *iter, int flags,
1281 		 struct trace_event *event)
1282 {
1283 	struct bprint_entry *field;
1284 	struct trace_seq *s = &iter->seq;
1285 
1286 	trace_assign_type(field, iter->ent);
1287 
1288 	trace_seq_printf(s, ": %lx : ", field->ip);
1289 	trace_seq_bprintf(s, field->fmt, field->buf);
1290 
1291 	return trace_handle_return(s);
1292 }
1293 
1294 static struct trace_event_functions trace_bprint_funcs = {
1295 	.trace		= trace_bprint_print,
1296 	.raw		= trace_bprint_raw,
1297 };
1298 
1299 static struct trace_event trace_bprint_event = {
1300 	.type		= TRACE_BPRINT,
1301 	.funcs		= &trace_bprint_funcs,
1302 };
1303 
1304 /* TRACE_PRINT */
1305 static enum print_line_t trace_print_print(struct trace_iterator *iter,
1306 					   int flags, struct trace_event *event)
1307 {
1308 	struct print_entry *field;
1309 	struct trace_seq *s = &iter->seq;
1310 
1311 	trace_assign_type(field, iter->ent);
1312 
1313 	seq_print_ip_sym(s, field->ip, flags);
1314 	trace_seq_printf(s, ": %s", field->buf);
1315 
1316 	return trace_handle_return(s);
1317 }
1318 
1319 static enum print_line_t trace_print_raw(struct trace_iterator *iter, int flags,
1320 					 struct trace_event *event)
1321 {
1322 	struct print_entry *field;
1323 
1324 	trace_assign_type(field, iter->ent);
1325 
1326 	trace_seq_printf(&iter->seq, "# %lx %s", field->ip, field->buf);
1327 
1328 	return trace_handle_return(&iter->seq);
1329 }
1330 
1331 static struct trace_event_functions trace_print_funcs = {
1332 	.trace		= trace_print_print,
1333 	.raw		= trace_print_raw,
1334 };
1335 
1336 static struct trace_event trace_print_event = {
1337 	.type	 	= TRACE_PRINT,
1338 	.funcs		= &trace_print_funcs,
1339 };
1340 
1341 static enum print_line_t trace_raw_data(struct trace_iterator *iter, int flags,
1342 					 struct trace_event *event)
1343 {
1344 	struct raw_data_entry *field;
1345 	int i;
1346 
1347 	trace_assign_type(field, iter->ent);
1348 
1349 	trace_seq_printf(&iter->seq, "# %x buf:", field->id);
1350 
1351 	for (i = 0; i < iter->ent_size - offsetof(struct raw_data_entry, buf); i++)
1352 		trace_seq_printf(&iter->seq, " %02x",
1353 				 (unsigned char)field->buf[i]);
1354 
1355 	trace_seq_putc(&iter->seq, '\n');
1356 
1357 	return trace_handle_return(&iter->seq);
1358 }
1359 
1360 static struct trace_event_functions trace_raw_data_funcs = {
1361 	.trace		= trace_raw_data,
1362 	.raw		= trace_raw_data,
1363 };
1364 
1365 static struct trace_event trace_raw_data_event = {
1366 	.type	 	= TRACE_RAW_DATA,
1367 	.funcs		= &trace_raw_data_funcs,
1368 };
1369 
1370 
1371 static struct trace_event *events[] __initdata = {
1372 	&trace_fn_event,
1373 	&trace_ctx_event,
1374 	&trace_wake_event,
1375 	&trace_stack_event,
1376 	&trace_user_stack_event,
1377 	&trace_bputs_event,
1378 	&trace_bprint_event,
1379 	&trace_print_event,
1380 	&trace_hwlat_event,
1381 	&trace_raw_data_event,
1382 	NULL
1383 };
1384 
1385 __init static int init_events(void)
1386 {
1387 	struct trace_event *event;
1388 	int i, ret;
1389 
1390 	for (i = 0; events[i]; i++) {
1391 		event = events[i];
1392 
1393 		ret = register_trace_event(event);
1394 		if (!ret) {
1395 			printk(KERN_WARNING "event %d failed to register\n",
1396 			       event->type);
1397 			WARN_ON_ONCE(1);
1398 		}
1399 	}
1400 
1401 	return 0;
1402 }
1403 early_initcall(init_events);
1404