xref: /openbmc/linux/kernel/trace/trace_output.c (revision e8e0929d)
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_mutex);
18 
19 DEFINE_PER_CPU(struct trace_seq, ftrace_event_seq);
20 EXPORT_PER_CPU_SYMBOL(ftrace_event_seq);
21 
22 static struct hlist_head event_hash[EVENT_HASHSIZE] __read_mostly;
23 
24 static int next_event_type = __TRACE_LAST_TYPE + 1;
25 
26 void trace_print_seq(struct seq_file *m, struct trace_seq *s)
27 {
28 	int len = s->len >= PAGE_SIZE ? PAGE_SIZE - 1 : s->len;
29 
30 	seq_write(m, s->buffer, len);
31 
32 	trace_seq_init(s);
33 }
34 
35 enum print_line_t trace_print_bprintk_msg_only(struct trace_iterator *iter)
36 {
37 	struct trace_seq *s = &iter->seq;
38 	struct trace_entry *entry = iter->ent;
39 	struct bprint_entry *field;
40 	int ret;
41 
42 	trace_assign_type(field, entry);
43 
44 	ret = trace_seq_bprintf(s, field->fmt, field->buf);
45 	if (!ret)
46 		return TRACE_TYPE_PARTIAL_LINE;
47 
48 	return TRACE_TYPE_HANDLED;
49 }
50 
51 enum print_line_t trace_print_printk_msg_only(struct trace_iterator *iter)
52 {
53 	struct trace_seq *s = &iter->seq;
54 	struct trace_entry *entry = iter->ent;
55 	struct print_entry *field;
56 	int ret;
57 
58 	trace_assign_type(field, entry);
59 
60 	ret = trace_seq_printf(s, "%s", field->buf);
61 	if (!ret)
62 		return TRACE_TYPE_PARTIAL_LINE;
63 
64 	return TRACE_TYPE_HANDLED;
65 }
66 
67 /**
68  * trace_seq_printf - sequence printing of trace information
69  * @s: trace sequence descriptor
70  * @fmt: printf format string
71  *
72  * The tracer may use either sequence operations or its own
73  * copy to user routines. To simplify formating of a trace
74  * trace_seq_printf is used to store strings into a special
75  * buffer (@s). Then the output may be either used by
76  * the sequencer or pulled into another buffer.
77  */
78 int
79 trace_seq_printf(struct trace_seq *s, const char *fmt, ...)
80 {
81 	int len = (PAGE_SIZE - 1) - s->len;
82 	va_list ap;
83 	int ret;
84 
85 	if (!len)
86 		return 0;
87 
88 	va_start(ap, fmt);
89 	ret = vsnprintf(s->buffer + s->len, len, fmt, ap);
90 	va_end(ap);
91 
92 	/* If we can't write it all, don't bother writing anything */
93 	if (ret >= len)
94 		return 0;
95 
96 	s->len += ret;
97 
98 	return len;
99 }
100 EXPORT_SYMBOL_GPL(trace_seq_printf);
101 
102 /**
103  * trace_seq_vprintf - sequence printing of trace information
104  * @s: trace sequence descriptor
105  * @fmt: printf format string
106  *
107  * The tracer may use either sequence operations or its own
108  * copy to user routines. To simplify formating of a trace
109  * trace_seq_printf is used to store strings into a special
110  * buffer (@s). Then the output may be either used by
111  * the sequencer or pulled into another buffer.
112  */
113 int
114 trace_seq_vprintf(struct trace_seq *s, const char *fmt, va_list args)
115 {
116 	int len = (PAGE_SIZE - 1) - s->len;
117 	int ret;
118 
119 	if (!len)
120 		return 0;
121 
122 	ret = vsnprintf(s->buffer + s->len, len, fmt, args);
123 
124 	/* If we can't write it all, don't bother writing anything */
125 	if (ret >= len)
126 		return 0;
127 
128 	s->len += ret;
129 
130 	return len;
131 }
132 EXPORT_SYMBOL_GPL(trace_seq_vprintf);
133 
134 int trace_seq_bprintf(struct trace_seq *s, const char *fmt, const u32 *binary)
135 {
136 	int len = (PAGE_SIZE - 1) - s->len;
137 	int ret;
138 
139 	if (!len)
140 		return 0;
141 
142 	ret = bstr_printf(s->buffer + s->len, len, fmt, binary);
143 
144 	/* If we can't write it all, don't bother writing anything */
145 	if (ret >= len)
146 		return 0;
147 
148 	s->len += ret;
149 
150 	return len;
151 }
152 
153 /**
154  * trace_seq_puts - trace sequence printing of simple string
155  * @s: trace sequence descriptor
156  * @str: simple string to record
157  *
158  * The tracer may use either the sequence operations or its own
159  * copy to user routines. This function records a simple string
160  * into a special buffer (@s) for later retrieval by a sequencer
161  * or other mechanism.
162  */
163 int trace_seq_puts(struct trace_seq *s, const char *str)
164 {
165 	int len = strlen(str);
166 
167 	if (len > ((PAGE_SIZE - 1) - s->len))
168 		return 0;
169 
170 	memcpy(s->buffer + s->len, str, len);
171 	s->len += len;
172 
173 	return len;
174 }
175 
176 int trace_seq_putc(struct trace_seq *s, unsigned char c)
177 {
178 	if (s->len >= (PAGE_SIZE - 1))
179 		return 0;
180 
181 	s->buffer[s->len++] = c;
182 
183 	return 1;
184 }
185 
186 int trace_seq_putmem(struct trace_seq *s, const void *mem, size_t len)
187 {
188 	if (len > ((PAGE_SIZE - 1) - s->len))
189 		return 0;
190 
191 	memcpy(s->buffer + s->len, mem, len);
192 	s->len += len;
193 
194 	return len;
195 }
196 
197 int trace_seq_putmem_hex(struct trace_seq *s, const void *mem, size_t len)
198 {
199 	unsigned char hex[HEX_CHARS];
200 	const unsigned char *data = mem;
201 	int i, j;
202 
203 #ifdef __BIG_ENDIAN
204 	for (i = 0, j = 0; i < len; i++) {
205 #else
206 	for (i = len-1, j = 0; i >= 0; i--) {
207 #endif
208 		hex[j++] = hex_asc_hi(data[i]);
209 		hex[j++] = hex_asc_lo(data[i]);
210 	}
211 	hex[j++] = ' ';
212 
213 	return trace_seq_putmem(s, hex, j);
214 }
215 
216 void *trace_seq_reserve(struct trace_seq *s, size_t len)
217 {
218 	void *ret;
219 
220 	if (len > ((PAGE_SIZE - 1) - s->len))
221 		return NULL;
222 
223 	ret = s->buffer + s->len;
224 	s->len += len;
225 
226 	return ret;
227 }
228 
229 int trace_seq_path(struct trace_seq *s, struct path *path)
230 {
231 	unsigned char *p;
232 
233 	if (s->len >= (PAGE_SIZE - 1))
234 		return 0;
235 	p = d_path(path, s->buffer + s->len, PAGE_SIZE - s->len);
236 	if (!IS_ERR(p)) {
237 		p = mangle_path(s->buffer + s->len, p, "\n");
238 		if (p) {
239 			s->len = p - s->buffer;
240 			return 1;
241 		}
242 	} else {
243 		s->buffer[s->len++] = '?';
244 		return 1;
245 	}
246 
247 	return 0;
248 }
249 
250 const char *
251 ftrace_print_flags_seq(struct trace_seq *p, const char *delim,
252 		       unsigned long flags,
253 		       const struct trace_print_flags *flag_array)
254 {
255 	unsigned long mask;
256 	const char *str;
257 	const char *ret = p->buffer + p->len;
258 	int i;
259 
260 	for (i = 0;  flag_array[i].name && flags; i++) {
261 
262 		mask = flag_array[i].mask;
263 		if ((flags & mask) != mask)
264 			continue;
265 
266 		str = flag_array[i].name;
267 		flags &= ~mask;
268 		if (p->len && delim)
269 			trace_seq_puts(p, delim);
270 		trace_seq_puts(p, str);
271 	}
272 
273 	/* check for left over flags */
274 	if (flags) {
275 		if (p->len && delim)
276 			trace_seq_puts(p, delim);
277 		trace_seq_printf(p, "0x%lx", flags);
278 	}
279 
280 	trace_seq_putc(p, 0);
281 
282 	return ret;
283 }
284 EXPORT_SYMBOL(ftrace_print_flags_seq);
285 
286 const char *
287 ftrace_print_symbols_seq(struct trace_seq *p, unsigned long val,
288 			 const struct trace_print_flags *symbol_array)
289 {
290 	int i;
291 	const char *ret = p->buffer + p->len;
292 
293 	for (i = 0;  symbol_array[i].name; i++) {
294 
295 		if (val != symbol_array[i].mask)
296 			continue;
297 
298 		trace_seq_puts(p, symbol_array[i].name);
299 		break;
300 	}
301 
302 	if (!p->len)
303 		trace_seq_printf(p, "0x%lx", val);
304 
305 	trace_seq_putc(p, 0);
306 
307 	return ret;
308 }
309 EXPORT_SYMBOL(ftrace_print_symbols_seq);
310 
311 #ifdef CONFIG_KRETPROBES
312 static inline const char *kretprobed(const char *name)
313 {
314 	static const char tramp_name[] = "kretprobe_trampoline";
315 	int size = sizeof(tramp_name);
316 
317 	if (strncmp(tramp_name, name, size) == 0)
318 		return "[unknown/kretprobe'd]";
319 	return name;
320 }
321 #else
322 static inline const char *kretprobed(const char *name)
323 {
324 	return name;
325 }
326 #endif /* CONFIG_KRETPROBES */
327 
328 static int
329 seq_print_sym_short(struct trace_seq *s, const char *fmt, unsigned long address)
330 {
331 #ifdef CONFIG_KALLSYMS
332 	char str[KSYM_SYMBOL_LEN];
333 	const char *name;
334 
335 	kallsyms_lookup(address, NULL, NULL, NULL, str);
336 
337 	name = kretprobed(str);
338 
339 	return trace_seq_printf(s, fmt, name);
340 #endif
341 	return 1;
342 }
343 
344 static int
345 seq_print_sym_offset(struct trace_seq *s, const char *fmt,
346 		     unsigned long address)
347 {
348 #ifdef CONFIG_KALLSYMS
349 	char str[KSYM_SYMBOL_LEN];
350 	const char *name;
351 
352 	sprint_symbol(str, address);
353 	name = kretprobed(str);
354 
355 	return trace_seq_printf(s, fmt, name);
356 #endif
357 	return 1;
358 }
359 
360 #ifndef CONFIG_64BIT
361 # define IP_FMT "%08lx"
362 #else
363 # define IP_FMT "%016lx"
364 #endif
365 
366 int seq_print_user_ip(struct trace_seq *s, struct mm_struct *mm,
367 		      unsigned long ip, unsigned long sym_flags)
368 {
369 	struct file *file = NULL;
370 	unsigned long vmstart = 0;
371 	int ret = 1;
372 
373 	if (mm) {
374 		const struct vm_area_struct *vma;
375 
376 		down_read(&mm->mmap_sem);
377 		vma = find_vma(mm, ip);
378 		if (vma) {
379 			file = vma->vm_file;
380 			vmstart = vma->vm_start;
381 		}
382 		if (file) {
383 			ret = trace_seq_path(s, &file->f_path);
384 			if (ret)
385 				ret = trace_seq_printf(s, "[+0x%lx]",
386 						       ip - vmstart);
387 		}
388 		up_read(&mm->mmap_sem);
389 	}
390 	if (ret && ((sym_flags & TRACE_ITER_SYM_ADDR) || !file))
391 		ret = trace_seq_printf(s, " <" IP_FMT ">", ip);
392 	return ret;
393 }
394 
395 int
396 seq_print_userip_objs(const struct userstack_entry *entry, struct trace_seq *s,
397 		      unsigned long sym_flags)
398 {
399 	struct mm_struct *mm = NULL;
400 	int ret = 1;
401 	unsigned int i;
402 
403 	if (trace_flags & TRACE_ITER_SYM_USEROBJ) {
404 		struct task_struct *task;
405 		/*
406 		 * we do the lookup on the thread group leader,
407 		 * since individual threads might have already quit!
408 		 */
409 		rcu_read_lock();
410 		task = find_task_by_vpid(entry->tgid);
411 		if (task)
412 			mm = get_task_mm(task);
413 		rcu_read_unlock();
414 	}
415 
416 	for (i = 0; i < FTRACE_STACK_ENTRIES; i++) {
417 		unsigned long ip = entry->caller[i];
418 
419 		if (ip == ULONG_MAX || !ret)
420 			break;
421 		if (ret)
422 			ret = trace_seq_puts(s, " => ");
423 		if (!ip) {
424 			if (ret)
425 				ret = trace_seq_puts(s, "??");
426 			if (ret)
427 				ret = trace_seq_puts(s, "\n");
428 			continue;
429 		}
430 		if (!ret)
431 			break;
432 		if (ret)
433 			ret = seq_print_user_ip(s, mm, ip, sym_flags);
434 		ret = trace_seq_puts(s, "\n");
435 	}
436 
437 	if (mm)
438 		mmput(mm);
439 	return ret;
440 }
441 
442 int
443 seq_print_ip_sym(struct trace_seq *s, unsigned long ip, unsigned long sym_flags)
444 {
445 	int ret;
446 
447 	if (!ip)
448 		return trace_seq_printf(s, "0");
449 
450 	if (sym_flags & TRACE_ITER_SYM_OFFSET)
451 		ret = seq_print_sym_offset(s, "%s", ip);
452 	else
453 		ret = seq_print_sym_short(s, "%s", ip);
454 
455 	if (!ret)
456 		return 0;
457 
458 	if (sym_flags & TRACE_ITER_SYM_ADDR)
459 		ret = trace_seq_printf(s, " <" IP_FMT ">", ip);
460 	return ret;
461 }
462 
463 /**
464  * trace_print_lat_fmt - print the irq, preempt and lockdep fields
465  * @s: trace seq struct to write to
466  * @entry: The trace entry field from the ring buffer
467  *
468  * Prints the generic fields of irqs off, in hard or softirq, preempt
469  * count and lock depth.
470  */
471 int trace_print_lat_fmt(struct trace_seq *s, struct trace_entry *entry)
472 {
473 	int hardirq, softirq;
474 	int ret;
475 
476 	hardirq = entry->flags & TRACE_FLAG_HARDIRQ;
477 	softirq = entry->flags & TRACE_FLAG_SOFTIRQ;
478 
479 	if (!trace_seq_printf(s, "%c%c%c",
480 			      (entry->flags & TRACE_FLAG_IRQS_OFF) ? 'd' :
481 				(entry->flags & TRACE_FLAG_IRQS_NOSUPPORT) ?
482 				  'X' : '.',
483 			      (entry->flags & TRACE_FLAG_NEED_RESCHED) ?
484 				'N' : '.',
485 			      (hardirq && softirq) ? 'H' :
486 				hardirq ? 'h' : softirq ? 's' : '.'))
487 		return 0;
488 
489 	if (entry->lock_depth < 0)
490 		ret = trace_seq_putc(s, '.');
491 	else
492 		ret = trace_seq_printf(s, "%d", entry->lock_depth);
493 	if (!ret)
494 		return 0;
495 
496 	if (entry->preempt_count)
497 		return trace_seq_printf(s, "%x", entry->preempt_count);
498 	return trace_seq_putc(s, '.');
499 }
500 
501 static int
502 lat_print_generic(struct trace_seq *s, struct trace_entry *entry, int cpu)
503 {
504 	char comm[TASK_COMM_LEN];
505 
506 	trace_find_cmdline(entry->pid, comm);
507 
508 	if (!trace_seq_printf(s, "%8.8s-%-5d %3d",
509 			      comm, entry->pid, cpu))
510 		return 0;
511 
512 	return trace_print_lat_fmt(s, entry);
513 }
514 
515 static unsigned long preempt_mark_thresh = 100;
516 
517 static int
518 lat_print_timestamp(struct trace_seq *s, u64 abs_usecs,
519 		    unsigned long rel_usecs)
520 {
521 	return trace_seq_printf(s, " %4lldus%c: ", abs_usecs,
522 				rel_usecs > preempt_mark_thresh ? '!' :
523 				  rel_usecs > 1 ? '+' : ' ');
524 }
525 
526 int trace_print_context(struct trace_iterator *iter)
527 {
528 	struct trace_seq *s = &iter->seq;
529 	struct trace_entry *entry = iter->ent;
530 	unsigned long long t = ns2usecs(iter->ts);
531 	unsigned long usec_rem = do_div(t, USEC_PER_SEC);
532 	unsigned long secs = (unsigned long)t;
533 	char comm[TASK_COMM_LEN];
534 
535 	trace_find_cmdline(entry->pid, comm);
536 
537 	return trace_seq_printf(s, "%16s-%-5d [%03d] %5lu.%06lu: ",
538 				comm, entry->pid, iter->cpu, secs, usec_rem);
539 }
540 
541 int trace_print_lat_context(struct trace_iterator *iter)
542 {
543 	u64 next_ts;
544 	int ret;
545 	struct trace_seq *s = &iter->seq;
546 	struct trace_entry *entry = iter->ent,
547 			   *next_entry = trace_find_next_entry(iter, NULL,
548 							       &next_ts);
549 	unsigned long verbose = (trace_flags & TRACE_ITER_VERBOSE);
550 	unsigned long abs_usecs = ns2usecs(iter->ts - iter->tr->time_start);
551 	unsigned long rel_usecs;
552 
553 	if (!next_entry)
554 		next_ts = iter->ts;
555 	rel_usecs = ns2usecs(next_ts - iter->ts);
556 
557 	if (verbose) {
558 		char comm[TASK_COMM_LEN];
559 
560 		trace_find_cmdline(entry->pid, comm);
561 
562 		ret = trace_seq_printf(s, "%16s %5d %3d %d %08x %08lx [%08llx]"
563 				       " %ld.%03ldms (+%ld.%03ldms): ", comm,
564 				       entry->pid, iter->cpu, entry->flags,
565 				       entry->preempt_count, iter->idx,
566 				       ns2usecs(iter->ts),
567 				       abs_usecs / USEC_PER_MSEC,
568 				       abs_usecs % USEC_PER_MSEC,
569 				       rel_usecs / USEC_PER_MSEC,
570 				       rel_usecs % USEC_PER_MSEC);
571 	} else {
572 		ret = lat_print_generic(s, entry, iter->cpu);
573 		if (ret)
574 			ret = lat_print_timestamp(s, abs_usecs, rel_usecs);
575 	}
576 
577 	return ret;
578 }
579 
580 static const char state_to_char[] = TASK_STATE_TO_CHAR_STR;
581 
582 static int task_state_char(unsigned long state)
583 {
584 	int bit = state ? __ffs(state) + 1 : 0;
585 
586 	return bit < sizeof(state_to_char) - 1 ? state_to_char[bit] : '?';
587 }
588 
589 /**
590  * ftrace_find_event - find a registered event
591  * @type: the type of event to look for
592  *
593  * Returns an event of type @type otherwise NULL
594  * Called with trace_event_read_lock() held.
595  */
596 struct trace_event *ftrace_find_event(int type)
597 {
598 	struct trace_event *event;
599 	struct hlist_node *n;
600 	unsigned key;
601 
602 	key = type & (EVENT_HASHSIZE - 1);
603 
604 	hlist_for_each_entry(event, n, &event_hash[key], node) {
605 		if (event->type == type)
606 			return event;
607 	}
608 
609 	return NULL;
610 }
611 
612 static LIST_HEAD(ftrace_event_list);
613 
614 static int trace_search_list(struct list_head **list)
615 {
616 	struct trace_event *e;
617 	int last = __TRACE_LAST_TYPE;
618 
619 	if (list_empty(&ftrace_event_list)) {
620 		*list = &ftrace_event_list;
621 		return last + 1;
622 	}
623 
624 	/*
625 	 * We used up all possible max events,
626 	 * lets see if somebody freed one.
627 	 */
628 	list_for_each_entry(e, &ftrace_event_list, list) {
629 		if (e->type != last + 1)
630 			break;
631 		last++;
632 	}
633 
634 	/* Did we used up all 65 thousand events??? */
635 	if ((last + 1) > FTRACE_MAX_EVENT)
636 		return 0;
637 
638 	*list = &e->list;
639 	return last + 1;
640 }
641 
642 void trace_event_read_lock(void)
643 {
644 	down_read(&trace_event_mutex);
645 }
646 
647 void trace_event_read_unlock(void)
648 {
649 	up_read(&trace_event_mutex);
650 }
651 
652 /**
653  * register_ftrace_event - register output for an event type
654  * @event: the event type to register
655  *
656  * Event types are stored in a hash and this hash is used to
657  * find a way to print an event. If the @event->type is set
658  * then it will use that type, otherwise it will assign a
659  * type to use.
660  *
661  * If you assign your own type, please make sure it is added
662  * to the trace_type enum in trace.h, to avoid collisions
663  * with the dynamic types.
664  *
665  * Returns the event type number or zero on error.
666  */
667 int register_ftrace_event(struct trace_event *event)
668 {
669 	unsigned key;
670 	int ret = 0;
671 
672 	down_write(&trace_event_mutex);
673 
674 	if (WARN_ON(!event))
675 		goto out;
676 
677 	INIT_LIST_HEAD(&event->list);
678 
679 	if (!event->type) {
680 		struct list_head *list = NULL;
681 
682 		if (next_event_type > FTRACE_MAX_EVENT) {
683 
684 			event->type = trace_search_list(&list);
685 			if (!event->type)
686 				goto out;
687 
688 		} else {
689 
690 			event->type = next_event_type++;
691 			list = &ftrace_event_list;
692 		}
693 
694 		if (WARN_ON(ftrace_find_event(event->type)))
695 			goto out;
696 
697 		list_add_tail(&event->list, list);
698 
699 	} else if (event->type > __TRACE_LAST_TYPE) {
700 		printk(KERN_WARNING "Need to add type to trace.h\n");
701 		WARN_ON(1);
702 		goto out;
703 	} else {
704 		/* Is this event already used */
705 		if (ftrace_find_event(event->type))
706 			goto out;
707 	}
708 
709 	if (event->trace == NULL)
710 		event->trace = trace_nop_print;
711 	if (event->raw == NULL)
712 		event->raw = trace_nop_print;
713 	if (event->hex == NULL)
714 		event->hex = trace_nop_print;
715 	if (event->binary == NULL)
716 		event->binary = trace_nop_print;
717 
718 	key = event->type & (EVENT_HASHSIZE - 1);
719 
720 	hlist_add_head(&event->node, &event_hash[key]);
721 
722 	ret = event->type;
723  out:
724 	up_write(&trace_event_mutex);
725 
726 	return ret;
727 }
728 EXPORT_SYMBOL_GPL(register_ftrace_event);
729 
730 /*
731  * Used by module code with the trace_event_mutex held for write.
732  */
733 int __unregister_ftrace_event(struct trace_event *event)
734 {
735 	hlist_del(&event->node);
736 	list_del(&event->list);
737 	return 0;
738 }
739 
740 /**
741  * unregister_ftrace_event - remove a no longer used event
742  * @event: the event to remove
743  */
744 int unregister_ftrace_event(struct trace_event *event)
745 {
746 	down_write(&trace_event_mutex);
747 	__unregister_ftrace_event(event);
748 	up_write(&trace_event_mutex);
749 
750 	return 0;
751 }
752 EXPORT_SYMBOL_GPL(unregister_ftrace_event);
753 
754 /*
755  * Standard events
756  */
757 
758 enum print_line_t trace_nop_print(struct trace_iterator *iter, int flags)
759 {
760 	return TRACE_TYPE_HANDLED;
761 }
762 
763 /* TRACE_FN */
764 static enum print_line_t trace_fn_trace(struct trace_iterator *iter, int flags)
765 {
766 	struct ftrace_entry *field;
767 	struct trace_seq *s = &iter->seq;
768 
769 	trace_assign_type(field, iter->ent);
770 
771 	if (!seq_print_ip_sym(s, field->ip, flags))
772 		goto partial;
773 
774 	if ((flags & TRACE_ITER_PRINT_PARENT) && field->parent_ip) {
775 		if (!trace_seq_printf(s, " <-"))
776 			goto partial;
777 		if (!seq_print_ip_sym(s,
778 				      field->parent_ip,
779 				      flags))
780 			goto partial;
781 	}
782 	if (!trace_seq_printf(s, "\n"))
783 		goto partial;
784 
785 	return TRACE_TYPE_HANDLED;
786 
787  partial:
788 	return TRACE_TYPE_PARTIAL_LINE;
789 }
790 
791 static enum print_line_t trace_fn_raw(struct trace_iterator *iter, int flags)
792 {
793 	struct ftrace_entry *field;
794 
795 	trace_assign_type(field, iter->ent);
796 
797 	if (!trace_seq_printf(&iter->seq, "%lx %lx\n",
798 			      field->ip,
799 			      field->parent_ip))
800 		return TRACE_TYPE_PARTIAL_LINE;
801 
802 	return TRACE_TYPE_HANDLED;
803 }
804 
805 static enum print_line_t trace_fn_hex(struct trace_iterator *iter, int flags)
806 {
807 	struct ftrace_entry *field;
808 	struct trace_seq *s = &iter->seq;
809 
810 	trace_assign_type(field, iter->ent);
811 
812 	SEQ_PUT_HEX_FIELD_RET(s, field->ip);
813 	SEQ_PUT_HEX_FIELD_RET(s, field->parent_ip);
814 
815 	return TRACE_TYPE_HANDLED;
816 }
817 
818 static enum print_line_t trace_fn_bin(struct trace_iterator *iter, int flags)
819 {
820 	struct ftrace_entry *field;
821 	struct trace_seq *s = &iter->seq;
822 
823 	trace_assign_type(field, iter->ent);
824 
825 	SEQ_PUT_FIELD_RET(s, field->ip);
826 	SEQ_PUT_FIELD_RET(s, field->parent_ip);
827 
828 	return TRACE_TYPE_HANDLED;
829 }
830 
831 static struct trace_event trace_fn_event = {
832 	.type		= TRACE_FN,
833 	.trace		= trace_fn_trace,
834 	.raw		= trace_fn_raw,
835 	.hex		= trace_fn_hex,
836 	.binary		= trace_fn_bin,
837 };
838 
839 /* TRACE_CTX an TRACE_WAKE */
840 static enum print_line_t trace_ctxwake_print(struct trace_iterator *iter,
841 					     char *delim)
842 {
843 	struct ctx_switch_entry *field;
844 	char comm[TASK_COMM_LEN];
845 	int S, T;
846 
847 
848 	trace_assign_type(field, iter->ent);
849 
850 	T = task_state_char(field->next_state);
851 	S = task_state_char(field->prev_state);
852 	trace_find_cmdline(field->next_pid, comm);
853 	if (!trace_seq_printf(&iter->seq,
854 			      " %5d:%3d:%c %s [%03d] %5d:%3d:%c %s\n",
855 			      field->prev_pid,
856 			      field->prev_prio,
857 			      S, delim,
858 			      field->next_cpu,
859 			      field->next_pid,
860 			      field->next_prio,
861 			      T, comm))
862 		return TRACE_TYPE_PARTIAL_LINE;
863 
864 	return TRACE_TYPE_HANDLED;
865 }
866 
867 static enum print_line_t trace_ctx_print(struct trace_iterator *iter, int flags)
868 {
869 	return trace_ctxwake_print(iter, "==>");
870 }
871 
872 static enum print_line_t trace_wake_print(struct trace_iterator *iter,
873 					  int flags)
874 {
875 	return trace_ctxwake_print(iter, "  +");
876 }
877 
878 static int trace_ctxwake_raw(struct trace_iterator *iter, char S)
879 {
880 	struct ctx_switch_entry *field;
881 	int T;
882 
883 	trace_assign_type(field, iter->ent);
884 
885 	if (!S)
886 		task_state_char(field->prev_state);
887 	T = task_state_char(field->next_state);
888 	if (!trace_seq_printf(&iter->seq, "%d %d %c %d %d %d %c\n",
889 			      field->prev_pid,
890 			      field->prev_prio,
891 			      S,
892 			      field->next_cpu,
893 			      field->next_pid,
894 			      field->next_prio,
895 			      T))
896 		return TRACE_TYPE_PARTIAL_LINE;
897 
898 	return TRACE_TYPE_HANDLED;
899 }
900 
901 static enum print_line_t trace_ctx_raw(struct trace_iterator *iter, int flags)
902 {
903 	return trace_ctxwake_raw(iter, 0);
904 }
905 
906 static enum print_line_t trace_wake_raw(struct trace_iterator *iter, int flags)
907 {
908 	return trace_ctxwake_raw(iter, '+');
909 }
910 
911 
912 static int trace_ctxwake_hex(struct trace_iterator *iter, char S)
913 {
914 	struct ctx_switch_entry *field;
915 	struct trace_seq *s = &iter->seq;
916 	int T;
917 
918 	trace_assign_type(field, iter->ent);
919 
920 	if (!S)
921 		task_state_char(field->prev_state);
922 	T = task_state_char(field->next_state);
923 
924 	SEQ_PUT_HEX_FIELD_RET(s, field->prev_pid);
925 	SEQ_PUT_HEX_FIELD_RET(s, field->prev_prio);
926 	SEQ_PUT_HEX_FIELD_RET(s, S);
927 	SEQ_PUT_HEX_FIELD_RET(s, field->next_cpu);
928 	SEQ_PUT_HEX_FIELD_RET(s, field->next_pid);
929 	SEQ_PUT_HEX_FIELD_RET(s, field->next_prio);
930 	SEQ_PUT_HEX_FIELD_RET(s, T);
931 
932 	return TRACE_TYPE_HANDLED;
933 }
934 
935 static enum print_line_t trace_ctx_hex(struct trace_iterator *iter, int flags)
936 {
937 	return trace_ctxwake_hex(iter, 0);
938 }
939 
940 static enum print_line_t trace_wake_hex(struct trace_iterator *iter, int flags)
941 {
942 	return trace_ctxwake_hex(iter, '+');
943 }
944 
945 static enum print_line_t trace_ctxwake_bin(struct trace_iterator *iter,
946 					   int flags)
947 {
948 	struct ctx_switch_entry *field;
949 	struct trace_seq *s = &iter->seq;
950 
951 	trace_assign_type(field, iter->ent);
952 
953 	SEQ_PUT_FIELD_RET(s, field->prev_pid);
954 	SEQ_PUT_FIELD_RET(s, field->prev_prio);
955 	SEQ_PUT_FIELD_RET(s, field->prev_state);
956 	SEQ_PUT_FIELD_RET(s, field->next_pid);
957 	SEQ_PUT_FIELD_RET(s, field->next_prio);
958 	SEQ_PUT_FIELD_RET(s, field->next_state);
959 
960 	return TRACE_TYPE_HANDLED;
961 }
962 
963 static struct trace_event trace_ctx_event = {
964 	.type		= TRACE_CTX,
965 	.trace		= trace_ctx_print,
966 	.raw		= trace_ctx_raw,
967 	.hex		= trace_ctx_hex,
968 	.binary		= trace_ctxwake_bin,
969 };
970 
971 static struct trace_event trace_wake_event = {
972 	.type		= TRACE_WAKE,
973 	.trace		= trace_wake_print,
974 	.raw		= trace_wake_raw,
975 	.hex		= trace_wake_hex,
976 	.binary		= trace_ctxwake_bin,
977 };
978 
979 /* TRACE_SPECIAL */
980 static enum print_line_t trace_special_print(struct trace_iterator *iter,
981 					     int flags)
982 {
983 	struct special_entry *field;
984 
985 	trace_assign_type(field, iter->ent);
986 
987 	if (!trace_seq_printf(&iter->seq, "# %ld %ld %ld\n",
988 			      field->arg1,
989 			      field->arg2,
990 			      field->arg3))
991 		return TRACE_TYPE_PARTIAL_LINE;
992 
993 	return TRACE_TYPE_HANDLED;
994 }
995 
996 static enum print_line_t trace_special_hex(struct trace_iterator *iter,
997 					   int flags)
998 {
999 	struct special_entry *field;
1000 	struct trace_seq *s = &iter->seq;
1001 
1002 	trace_assign_type(field, iter->ent);
1003 
1004 	SEQ_PUT_HEX_FIELD_RET(s, field->arg1);
1005 	SEQ_PUT_HEX_FIELD_RET(s, field->arg2);
1006 	SEQ_PUT_HEX_FIELD_RET(s, field->arg3);
1007 
1008 	return TRACE_TYPE_HANDLED;
1009 }
1010 
1011 static enum print_line_t trace_special_bin(struct trace_iterator *iter,
1012 					   int flags)
1013 {
1014 	struct special_entry *field;
1015 	struct trace_seq *s = &iter->seq;
1016 
1017 	trace_assign_type(field, iter->ent);
1018 
1019 	SEQ_PUT_FIELD_RET(s, field->arg1);
1020 	SEQ_PUT_FIELD_RET(s, field->arg2);
1021 	SEQ_PUT_FIELD_RET(s, field->arg3);
1022 
1023 	return TRACE_TYPE_HANDLED;
1024 }
1025 
1026 static struct trace_event trace_special_event = {
1027 	.type		= TRACE_SPECIAL,
1028 	.trace		= trace_special_print,
1029 	.raw		= trace_special_print,
1030 	.hex		= trace_special_hex,
1031 	.binary		= trace_special_bin,
1032 };
1033 
1034 /* TRACE_STACK */
1035 
1036 static enum print_line_t trace_stack_print(struct trace_iterator *iter,
1037 					   int flags)
1038 {
1039 	struct stack_entry *field;
1040 	struct trace_seq *s = &iter->seq;
1041 	int i;
1042 
1043 	trace_assign_type(field, iter->ent);
1044 
1045 	if (!trace_seq_puts(s, "<stack trace>\n"))
1046 		goto partial;
1047 	for (i = 0; i < FTRACE_STACK_ENTRIES; i++) {
1048 		if (!field->caller[i] || (field->caller[i] == ULONG_MAX))
1049 			break;
1050 		if (!trace_seq_puts(s, " => "))
1051 			goto partial;
1052 
1053 		if (!seq_print_ip_sym(s, field->caller[i], flags))
1054 			goto partial;
1055 		if (!trace_seq_puts(s, "\n"))
1056 			goto partial;
1057 	}
1058 
1059 	return TRACE_TYPE_HANDLED;
1060 
1061  partial:
1062 	return TRACE_TYPE_PARTIAL_LINE;
1063 }
1064 
1065 static struct trace_event trace_stack_event = {
1066 	.type		= TRACE_STACK,
1067 	.trace		= trace_stack_print,
1068 	.raw		= trace_special_print,
1069 	.hex		= trace_special_hex,
1070 	.binary		= trace_special_bin,
1071 };
1072 
1073 /* TRACE_USER_STACK */
1074 static enum print_line_t trace_user_stack_print(struct trace_iterator *iter,
1075 						int flags)
1076 {
1077 	struct userstack_entry *field;
1078 	struct trace_seq *s = &iter->seq;
1079 
1080 	trace_assign_type(field, iter->ent);
1081 
1082 	if (!trace_seq_puts(s, "<user stack trace>\n"))
1083 		goto partial;
1084 
1085 	if (!seq_print_userip_objs(field, s, flags))
1086 		goto partial;
1087 
1088 	return TRACE_TYPE_HANDLED;
1089 
1090  partial:
1091 	return TRACE_TYPE_PARTIAL_LINE;
1092 }
1093 
1094 static struct trace_event trace_user_stack_event = {
1095 	.type		= TRACE_USER_STACK,
1096 	.trace		= trace_user_stack_print,
1097 	.raw		= trace_special_print,
1098 	.hex		= trace_special_hex,
1099 	.binary		= trace_special_bin,
1100 };
1101 
1102 /* TRACE_BPRINT */
1103 static enum print_line_t
1104 trace_bprint_print(struct trace_iterator *iter, int flags)
1105 {
1106 	struct trace_entry *entry = iter->ent;
1107 	struct trace_seq *s = &iter->seq;
1108 	struct bprint_entry *field;
1109 
1110 	trace_assign_type(field, entry);
1111 
1112 	if (!seq_print_ip_sym(s, field->ip, flags))
1113 		goto partial;
1114 
1115 	if (!trace_seq_puts(s, ": "))
1116 		goto partial;
1117 
1118 	if (!trace_seq_bprintf(s, field->fmt, field->buf))
1119 		goto partial;
1120 
1121 	return TRACE_TYPE_HANDLED;
1122 
1123  partial:
1124 	return TRACE_TYPE_PARTIAL_LINE;
1125 }
1126 
1127 
1128 static enum print_line_t
1129 trace_bprint_raw(struct trace_iterator *iter, int flags)
1130 {
1131 	struct bprint_entry *field;
1132 	struct trace_seq *s = &iter->seq;
1133 
1134 	trace_assign_type(field, iter->ent);
1135 
1136 	if (!trace_seq_printf(s, ": %lx : ", field->ip))
1137 		goto partial;
1138 
1139 	if (!trace_seq_bprintf(s, field->fmt, field->buf))
1140 		goto partial;
1141 
1142 	return TRACE_TYPE_HANDLED;
1143 
1144  partial:
1145 	return TRACE_TYPE_PARTIAL_LINE;
1146 }
1147 
1148 
1149 static struct trace_event trace_bprint_event = {
1150 	.type		= TRACE_BPRINT,
1151 	.trace		= trace_bprint_print,
1152 	.raw		= trace_bprint_raw,
1153 };
1154 
1155 /* TRACE_PRINT */
1156 static enum print_line_t trace_print_print(struct trace_iterator *iter,
1157 					   int flags)
1158 {
1159 	struct print_entry *field;
1160 	struct trace_seq *s = &iter->seq;
1161 
1162 	trace_assign_type(field, iter->ent);
1163 
1164 	if (!seq_print_ip_sym(s, field->ip, flags))
1165 		goto partial;
1166 
1167 	if (!trace_seq_printf(s, ": %s", field->buf))
1168 		goto partial;
1169 
1170 	return TRACE_TYPE_HANDLED;
1171 
1172  partial:
1173 	return TRACE_TYPE_PARTIAL_LINE;
1174 }
1175 
1176 static enum print_line_t trace_print_raw(struct trace_iterator *iter, int flags)
1177 {
1178 	struct print_entry *field;
1179 
1180 	trace_assign_type(field, iter->ent);
1181 
1182 	if (!trace_seq_printf(&iter->seq, "# %lx %s", field->ip, field->buf))
1183 		goto partial;
1184 
1185 	return TRACE_TYPE_HANDLED;
1186 
1187  partial:
1188 	return TRACE_TYPE_PARTIAL_LINE;
1189 }
1190 
1191 static struct trace_event trace_print_event = {
1192 	.type	 	= TRACE_PRINT,
1193 	.trace		= trace_print_print,
1194 	.raw		= trace_print_raw,
1195 };
1196 
1197 
1198 static struct trace_event *events[] __initdata = {
1199 	&trace_fn_event,
1200 	&trace_ctx_event,
1201 	&trace_wake_event,
1202 	&trace_special_event,
1203 	&trace_stack_event,
1204 	&trace_user_stack_event,
1205 	&trace_bprint_event,
1206 	&trace_print_event,
1207 	NULL
1208 };
1209 
1210 __init static int init_events(void)
1211 {
1212 	struct trace_event *event;
1213 	int i, ret;
1214 
1215 	for (i = 0; events[i]; i++) {
1216 		event = events[i];
1217 
1218 		ret = register_ftrace_event(event);
1219 		if (!ret) {
1220 			printk(KERN_WARNING "event %d failed to register\n",
1221 			       event->type);
1222 			WARN_ON_ONCE(1);
1223 		}
1224 	}
1225 
1226 	return 0;
1227 }
1228 device_initcall(init_events);
1229