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 static struct hlist_head event_hash[EVENT_HASHSIZE] __read_mostly;
20
21 static int next_event_type = __TRACE_LAST_TYPE + 1;
22
trace_print_seq(struct seq_file * m,struct trace_seq * s)23 int trace_print_seq(struct seq_file *m, struct trace_seq *s)
24 {
25 int len = s->len >= PAGE_SIZE ? PAGE_SIZE - 1 : s->len;
26 int ret;
27
28 ret = seq_write(m, s->buffer, len);
29
30 /*
31 * Only reset this buffer if we successfully wrote to the
32 * seq_file buffer.
33 */
34 if (!ret)
35 trace_seq_init(s);
36
37 return ret;
38 }
39
trace_print_bprintk_msg_only(struct trace_iterator * iter)40 enum print_line_t trace_print_bprintk_msg_only(struct trace_iterator *iter)
41 {
42 struct trace_seq *s = &iter->seq;
43 struct trace_entry *entry = iter->ent;
44 struct bprint_entry *field;
45 int ret;
46
47 trace_assign_type(field, entry);
48
49 ret = trace_seq_bprintf(s, field->fmt, field->buf);
50 if (!ret)
51 return TRACE_TYPE_PARTIAL_LINE;
52
53 return TRACE_TYPE_HANDLED;
54 }
55
trace_print_printk_msg_only(struct trace_iterator * iter)56 enum print_line_t trace_print_printk_msg_only(struct trace_iterator *iter)
57 {
58 struct trace_seq *s = &iter->seq;
59 struct trace_entry *entry = iter->ent;
60 struct print_entry *field;
61 int ret;
62
63 trace_assign_type(field, entry);
64
65 ret = trace_seq_printf(s, "%s", field->buf);
66 if (!ret)
67 return TRACE_TYPE_PARTIAL_LINE;
68
69 return TRACE_TYPE_HANDLED;
70 }
71
72 /**
73 * trace_seq_printf - sequence printing of trace information
74 * @s: trace sequence descriptor
75 * @fmt: printf format string
76 *
77 * It returns 0 if the trace oversizes the buffer's free
78 * space, 1 otherwise.
79 *
80 * The tracer may use either sequence operations or its own
81 * copy to user routines. To simplify formating of a trace
82 * trace_seq_printf is used to store strings into a special
83 * buffer (@s). Then the output may be either used by
84 * the sequencer or pulled into another buffer.
85 */
86 int
trace_seq_printf(struct trace_seq * s,const char * fmt,...)87 trace_seq_printf(struct trace_seq *s, const char *fmt, ...)
88 {
89 int len = (PAGE_SIZE - 1) - s->len;
90 va_list ap;
91 int ret;
92
93 if (s->full || !len)
94 return 0;
95
96 va_start(ap, fmt);
97 ret = vsnprintf(s->buffer + s->len, len, fmt, ap);
98 va_end(ap);
99
100 /* If we can't write it all, don't bother writing anything */
101 if (ret >= len) {
102 s->full = 1;
103 return 0;
104 }
105
106 s->len += ret;
107
108 return 1;
109 }
110 EXPORT_SYMBOL_GPL(trace_seq_printf);
111
112 /**
113 * trace_seq_vprintf - sequence printing of trace information
114 * @s: trace sequence descriptor
115 * @fmt: printf format string
116 *
117 * The tracer may use either sequence operations or its own
118 * copy to user routines. To simplify formating of a trace
119 * trace_seq_printf is used to store strings into a special
120 * buffer (@s). Then the output may be either used by
121 * the sequencer or pulled into another buffer.
122 */
123 int
trace_seq_vprintf(struct trace_seq * s,const char * fmt,va_list args)124 trace_seq_vprintf(struct trace_seq *s, const char *fmt, va_list args)
125 {
126 int len = (PAGE_SIZE - 1) - s->len;
127 int ret;
128
129 if (s->full || !len)
130 return 0;
131
132 ret = vsnprintf(s->buffer + s->len, len, fmt, args);
133
134 /* If we can't write it all, don't bother writing anything */
135 if (ret >= len) {
136 s->full = 1;
137 return 0;
138 }
139
140 s->len += ret;
141
142 return len;
143 }
144 EXPORT_SYMBOL_GPL(trace_seq_vprintf);
145
trace_seq_bprintf(struct trace_seq * s,const char * fmt,const u32 * binary)146 int trace_seq_bprintf(struct trace_seq *s, const char *fmt, const u32 *binary)
147 {
148 int len = (PAGE_SIZE - 1) - s->len;
149 int ret;
150
151 if (s->full || !len)
152 return 0;
153
154 ret = bstr_printf(s->buffer + s->len, len, fmt, binary);
155
156 /* If we can't write it all, don't bother writing anything */
157 if (ret >= len) {
158 s->full = 1;
159 return 0;
160 }
161
162 s->len += ret;
163
164 return len;
165 }
166
167 /**
168 * trace_seq_puts - trace sequence printing of simple string
169 * @s: trace sequence descriptor
170 * @str: simple string to record
171 *
172 * The tracer may use either the sequence operations or its own
173 * copy to user routines. This function records a simple string
174 * into a special buffer (@s) for later retrieval by a sequencer
175 * or other mechanism.
176 */
trace_seq_puts(struct trace_seq * s,const char * str)177 int trace_seq_puts(struct trace_seq *s, const char *str)
178 {
179 int len = strlen(str);
180
181 if (s->full)
182 return 0;
183
184 if (len > ((PAGE_SIZE - 1) - s->len)) {
185 s->full = 1;
186 return 0;
187 }
188
189 memcpy(s->buffer + s->len, str, len);
190 s->len += len;
191
192 return len;
193 }
194
trace_seq_putc(struct trace_seq * s,unsigned char c)195 int trace_seq_putc(struct trace_seq *s, unsigned char c)
196 {
197 if (s->full)
198 return 0;
199
200 if (s->len >= (PAGE_SIZE - 1)) {
201 s->full = 1;
202 return 0;
203 }
204
205 s->buffer[s->len++] = c;
206
207 return 1;
208 }
209 EXPORT_SYMBOL(trace_seq_putc);
210
trace_seq_putmem(struct trace_seq * s,const void * mem,size_t len)211 int trace_seq_putmem(struct trace_seq *s, const void *mem, size_t len)
212 {
213 if (s->full)
214 return 0;
215
216 if (len > ((PAGE_SIZE - 1) - s->len)) {
217 s->full = 1;
218 return 0;
219 }
220
221 memcpy(s->buffer + s->len, mem, len);
222 s->len += len;
223
224 return len;
225 }
226
trace_seq_putmem_hex(struct trace_seq * s,const void * mem,size_t len)227 int trace_seq_putmem_hex(struct trace_seq *s, const void *mem, size_t len)
228 {
229 unsigned char hex[HEX_CHARS];
230 const unsigned char *data = mem;
231 int i, j;
232
233 if (s->full)
234 return 0;
235
236 #ifdef __BIG_ENDIAN
237 for (i = 0, j = 0; i < len; i++) {
238 #else
239 for (i = len-1, j = 0; i >= 0; i--) {
240 #endif
241 hex[j++] = hex_asc_hi(data[i]);
242 hex[j++] = hex_asc_lo(data[i]);
243 }
244 hex[j++] = ' ';
245
246 return trace_seq_putmem(s, hex, j);
247 }
248
249 void *trace_seq_reserve(struct trace_seq *s, size_t len)
250 {
251 void *ret;
252
253 if (s->full)
254 return NULL;
255
256 if (len > ((PAGE_SIZE - 1) - s->len)) {
257 s->full = 1;
258 return NULL;
259 }
260
261 ret = s->buffer + s->len;
262 s->len += len;
263
264 return ret;
265 }
266
267 int trace_seq_path(struct trace_seq *s, struct path *path)
268 {
269 unsigned char *p;
270
271 if (s->full)
272 return 0;
273
274 if (s->len >= (PAGE_SIZE - 1)) {
275 s->full = 1;
276 return 0;
277 }
278
279 p = d_path(path, s->buffer + s->len, PAGE_SIZE - s->len);
280 if (!IS_ERR(p)) {
281 p = mangle_path(s->buffer + s->len, p, "\n");
282 if (p) {
283 s->len = p - s->buffer;
284 return 1;
285 }
286 } else {
287 s->buffer[s->len++] = '?';
288 return 1;
289 }
290
291 s->full = 1;
292 return 0;
293 }
294
295 const char *
296 ftrace_print_flags_seq(struct trace_seq *p, const char *delim,
297 unsigned long flags,
298 const struct trace_print_flags *flag_array)
299 {
300 unsigned long mask;
301 const char *str;
302 const char *ret = p->buffer + p->len;
303 int i;
304
305 for (i = 0; flag_array[i].name && flags; i++) {
306
307 mask = flag_array[i].mask;
308 if ((flags & mask) != mask)
309 continue;
310
311 str = flag_array[i].name;
312 flags &= ~mask;
313 if (p->len && delim)
314 trace_seq_puts(p, delim);
315 trace_seq_puts(p, str);
316 }
317
318 /* check for left over flags */
319 if (flags) {
320 if (p->len && delim)
321 trace_seq_puts(p, delim);
322 trace_seq_printf(p, "0x%lx", flags);
323 }
324
325 trace_seq_putc(p, 0);
326
327 return ret;
328 }
329 EXPORT_SYMBOL(ftrace_print_flags_seq);
330
331 const char *
332 ftrace_print_symbols_seq(struct trace_seq *p, unsigned long val,
333 const struct trace_print_flags *symbol_array)
334 {
335 int i;
336 const char *ret = p->buffer + p->len;
337
338 for (i = 0; symbol_array[i].name; i++) {
339
340 if (val != symbol_array[i].mask)
341 continue;
342
343 trace_seq_puts(p, symbol_array[i].name);
344 break;
345 }
346
347 if (!p->len)
348 trace_seq_printf(p, "0x%lx", val);
349
350 trace_seq_putc(p, 0);
351
352 return ret;
353 }
354 EXPORT_SYMBOL(ftrace_print_symbols_seq);
355
356 #if BITS_PER_LONG == 32
357 const char *
358 ftrace_print_symbols_seq_u64(struct trace_seq *p, unsigned long long val,
359 const struct trace_print_flags_u64 *symbol_array)
360 {
361 int i;
362 const char *ret = p->buffer + p->len;
363
364 for (i = 0; symbol_array[i].name; i++) {
365
366 if (val != symbol_array[i].mask)
367 continue;
368
369 trace_seq_puts(p, symbol_array[i].name);
370 break;
371 }
372
373 if (!p->len)
374 trace_seq_printf(p, "0x%llx", val);
375
376 trace_seq_putc(p, 0);
377
378 return ret;
379 }
380 EXPORT_SYMBOL(ftrace_print_symbols_seq_u64);
381 #endif
382
383 const char *
384 ftrace_print_hex_seq(struct trace_seq *p, const unsigned char *buf, int buf_len)
385 {
386 int i;
387 const char *ret = p->buffer + p->len;
388
389 for (i = 0; i < buf_len; i++)
390 trace_seq_printf(p, "%s%2.2x", i == 0 ? "" : " ", buf[i]);
391
392 trace_seq_putc(p, 0);
393
394 return ret;
395 }
396 EXPORT_SYMBOL(ftrace_print_hex_seq);
397
398 #ifdef CONFIG_KRETPROBES
399 static inline const char *kretprobed(const char *name)
400 {
401 static const char tramp_name[] = "kretprobe_trampoline";
402 int size = sizeof(tramp_name);
403
404 if (strncmp(tramp_name, name, size) == 0)
405 return "[unknown/kretprobe'd]";
406 return name;
407 }
408 #else
409 static inline const char *kretprobed(const char *name)
410 {
411 return name;
412 }
413 #endif /* CONFIG_KRETPROBES */
414
415 static int
416 seq_print_sym_short(struct trace_seq *s, const char *fmt, unsigned long address)
417 {
418 #ifdef CONFIG_KALLSYMS
419 char str[KSYM_SYMBOL_LEN];
420 const char *name;
421
422 kallsyms_lookup(address, NULL, NULL, NULL, str);
423
424 name = kretprobed(str);
425
426 return trace_seq_printf(s, fmt, name);
427 #endif
428 return 1;
429 }
430
431 static int
432 seq_print_sym_offset(struct trace_seq *s, const char *fmt,
433 unsigned long address)
434 {
435 #ifdef CONFIG_KALLSYMS
436 char str[KSYM_SYMBOL_LEN];
437 const char *name;
438
439 sprint_symbol(str, address);
440 name = kretprobed(str);
441
442 return trace_seq_printf(s, fmt, name);
443 #endif
444 return 1;
445 }
446
447 #ifndef CONFIG_64BIT
448 # define IP_FMT "%08lx"
449 #else
450 # define IP_FMT "%016lx"
451 #endif
452
453 int seq_print_user_ip(struct trace_seq *s, struct mm_struct *mm,
454 unsigned long ip, unsigned long sym_flags)
455 {
456 struct file *file = NULL;
457 unsigned long vmstart = 0;
458 int ret = 1;
459
460 if (s->full)
461 return 0;
462
463 if (mm) {
464 const struct vm_area_struct *vma;
465
466 down_read(&mm->mmap_sem);
467 vma = find_vma(mm, ip);
468 if (vma) {
469 file = vma->vm_file;
470 vmstart = vma->vm_start;
471 }
472 if (file) {
473 ret = trace_seq_path(s, &file->f_path);
474 if (ret)
475 ret = trace_seq_printf(s, "[+0x%lx]",
476 ip - vmstart);
477 }
478 up_read(&mm->mmap_sem);
479 }
480 if (ret && ((sym_flags & TRACE_ITER_SYM_ADDR) || !file))
481 ret = trace_seq_printf(s, " <" IP_FMT ">", ip);
482 return ret;
483 }
484
485 int
486 seq_print_userip_objs(const struct userstack_entry *entry, struct trace_seq *s,
487 unsigned long sym_flags)
488 {
489 struct mm_struct *mm = NULL;
490 int ret = 1;
491 unsigned int i;
492
493 if (trace_flags & TRACE_ITER_SYM_USEROBJ) {
494 struct task_struct *task;
495 /*
496 * we do the lookup on the thread group leader,
497 * since individual threads might have already quit!
498 */
499 rcu_read_lock();
500 task = find_task_by_vpid(entry->tgid);
501 if (task)
502 mm = get_task_mm(task);
503 rcu_read_unlock();
504 }
505
506 for (i = 0; i < FTRACE_STACK_ENTRIES; i++) {
507 unsigned long ip = entry->caller[i];
508
509 if (ip == ULONG_MAX || !ret)
510 break;
511 if (ret)
512 ret = trace_seq_puts(s, " => ");
513 if (!ip) {
514 if (ret)
515 ret = trace_seq_puts(s, "??");
516 if (ret)
517 ret = trace_seq_puts(s, "\n");
518 continue;
519 }
520 if (!ret)
521 break;
522 if (ret)
523 ret = seq_print_user_ip(s, mm, ip, sym_flags);
524 ret = trace_seq_puts(s, "\n");
525 }
526
527 if (mm)
528 mmput(mm);
529 return ret;
530 }
531
532 int
533 seq_print_ip_sym(struct trace_seq *s, unsigned long ip, unsigned long sym_flags)
534 {
535 int ret;
536
537 if (!ip)
538 return trace_seq_printf(s, "0");
539
540 if (sym_flags & TRACE_ITER_SYM_OFFSET)
541 ret = seq_print_sym_offset(s, "%s", ip);
542 else
543 ret = seq_print_sym_short(s, "%s", ip);
544
545 if (!ret)
546 return 0;
547
548 if (sym_flags & TRACE_ITER_SYM_ADDR)
549 ret = trace_seq_printf(s, " <" IP_FMT ">", ip);
550 return ret;
551 }
552
553 /**
554 * trace_print_lat_fmt - print the irq, preempt and lockdep fields
555 * @s: trace seq struct to write to
556 * @entry: The trace entry field from the ring buffer
557 *
558 * Prints the generic fields of irqs off, in hard or softirq, preempt
559 * count.
560 */
561 int trace_print_lat_fmt(struct trace_seq *s, struct trace_entry *entry)
562 {
563 char hardsoft_irq;
564 char need_resched;
565 char irqs_off;
566 int hardirq;
567 int softirq;
568 int ret;
569
570 hardirq = entry->flags & TRACE_FLAG_HARDIRQ;
571 softirq = entry->flags & TRACE_FLAG_SOFTIRQ;
572
573 irqs_off =
574 (entry->flags & TRACE_FLAG_IRQS_OFF) ? 'd' :
575 (entry->flags & TRACE_FLAG_IRQS_NOSUPPORT) ? 'X' :
576 '.';
577 need_resched =
578 (entry->flags & TRACE_FLAG_NEED_RESCHED) ? 'N' : '.';
579 hardsoft_irq =
580 (hardirq && softirq) ? 'H' :
581 hardirq ? 'h' :
582 softirq ? 's' :
583 '.';
584
585 if (!trace_seq_printf(s, "%c%c%c",
586 irqs_off, need_resched, hardsoft_irq))
587 return 0;
588
589 if (entry->preempt_count)
590 ret = trace_seq_printf(s, "%x", entry->preempt_count);
591 else
592 ret = trace_seq_putc(s, '.');
593
594 return ret;
595 }
596
597 static int
598 lat_print_generic(struct trace_seq *s, struct trace_entry *entry, int cpu)
599 {
600 char comm[TASK_COMM_LEN];
601
602 trace_find_cmdline(entry->pid, comm);
603
604 if (!trace_seq_printf(s, "%8.8s-%-5d %3d",
605 comm, entry->pid, cpu))
606 return 0;
607
608 return trace_print_lat_fmt(s, entry);
609 }
610
611 static unsigned long preempt_mark_thresh = 100;
612
613 static int
614 lat_print_timestamp(struct trace_seq *s, u64 abs_usecs,
615 unsigned long rel_usecs)
616 {
617 return trace_seq_printf(s, " %4lldus%c: ", abs_usecs,
618 rel_usecs > preempt_mark_thresh ? '!' :
619 rel_usecs > 1 ? '+' : ' ');
620 }
621
622 int trace_print_context(struct trace_iterator *iter)
623 {
624 struct trace_seq *s = &iter->seq;
625 struct trace_entry *entry = iter->ent;
626 unsigned long long t = ns2usecs(iter->ts);
627 unsigned long usec_rem = do_div(t, USEC_PER_SEC);
628 unsigned long secs = (unsigned long)t;
629 char comm[TASK_COMM_LEN];
630 int ret;
631
632 trace_find_cmdline(entry->pid, comm);
633
634 ret = trace_seq_printf(s, "%16s-%-5d [%03d] ",
635 comm, entry->pid, iter->cpu);
636 if (!ret)
637 return 0;
638
639 if (trace_flags & TRACE_ITER_IRQ_INFO) {
640 ret = trace_print_lat_fmt(s, entry);
641 if (!ret)
642 return 0;
643 }
644
645 return trace_seq_printf(s, " %5lu.%06lu: ",
646 secs, usec_rem);
647 }
648
649 int trace_print_lat_context(struct trace_iterator *iter)
650 {
651 u64 next_ts;
652 int ret;
653 struct trace_seq *s = &iter->seq;
654 struct trace_entry *entry = iter->ent,
655 *next_entry = trace_find_next_entry(iter, NULL,
656 &next_ts);
657 unsigned long verbose = (trace_flags & TRACE_ITER_VERBOSE);
658 unsigned long abs_usecs = ns2usecs(iter->ts - iter->tr->time_start);
659 unsigned long rel_usecs;
660
661 if (!next_entry)
662 next_ts = iter->ts;
663 rel_usecs = ns2usecs(next_ts - iter->ts);
664
665 if (verbose) {
666 char comm[TASK_COMM_LEN];
667
668 trace_find_cmdline(entry->pid, comm);
669
670 ret = trace_seq_printf(s, "%16s %5d %3d %d %08x %08lx [%08llx]"
671 " %ld.%03ldms (+%ld.%03ldms): ", comm,
672 entry->pid, iter->cpu, entry->flags,
673 entry->preempt_count, iter->idx,
674 ns2usecs(iter->ts),
675 abs_usecs / USEC_PER_MSEC,
676 abs_usecs % USEC_PER_MSEC,
677 rel_usecs / USEC_PER_MSEC,
678 rel_usecs % USEC_PER_MSEC);
679 } else {
680 ret = lat_print_generic(s, entry, iter->cpu);
681 if (ret)
682 ret = lat_print_timestamp(s, abs_usecs, rel_usecs);
683 }
684
685 return ret;
686 }
687
688 static const char state_to_char[] = TASK_STATE_TO_CHAR_STR;
689
690 static int task_state_char(unsigned long state)
691 {
692 int bit = state ? __ffs(state) + 1 : 0;
693
694 return bit < sizeof(state_to_char) - 1 ? state_to_char[bit] : '?';
695 }
696
697 /**
698 * ftrace_find_event - find a registered event
699 * @type: the type of event to look for
700 *
701 * Returns an event of type @type otherwise NULL
702 * Called with trace_event_read_lock() held.
703 */
704 struct trace_event *ftrace_find_event(int type)
705 {
706 struct trace_event *event;
707 struct hlist_node *n;
708 unsigned key;
709
710 key = type & (EVENT_HASHSIZE - 1);
711
712 hlist_for_each_entry(event, n, &event_hash[key], node) {
713 if (event->type == type)
714 return event;
715 }
716
717 return NULL;
718 }
719
720 static LIST_HEAD(ftrace_event_list);
721
722 static int trace_search_list(struct list_head **list)
723 {
724 struct trace_event *e;
725 int last = __TRACE_LAST_TYPE;
726
727 if (list_empty(&ftrace_event_list)) {
728 *list = &ftrace_event_list;
729 return last + 1;
730 }
731
732 /*
733 * We used up all possible max events,
734 * lets see if somebody freed one.
735 */
736 list_for_each_entry(e, &ftrace_event_list, list) {
737 if (e->type != last + 1)
738 break;
739 last++;
740 }
741
742 /* Did we used up all 65 thousand events??? */
743 if ((last + 1) > FTRACE_MAX_EVENT)
744 return 0;
745
746 *list = &e->list;
747 return last + 1;
748 }
749
750 void trace_event_read_lock(void)
751 {
752 down_read(&trace_event_mutex);
753 }
754
755 void trace_event_read_unlock(void)
756 {
757 up_read(&trace_event_mutex);
758 }
759
760 /**
761 * register_ftrace_event - register output for an event type
762 * @event: the event type to register
763 *
764 * Event types are stored in a hash and this hash is used to
765 * find a way to print an event. If the @event->type is set
766 * then it will use that type, otherwise it will assign a
767 * type to use.
768 *
769 * If you assign your own type, please make sure it is added
770 * to the trace_type enum in trace.h, to avoid collisions
771 * with the dynamic types.
772 *
773 * Returns the event type number or zero on error.
774 */
775 int register_ftrace_event(struct trace_event *event)
776 {
777 unsigned key;
778 int ret = 0;
779
780 down_write(&trace_event_mutex);
781
782 if (WARN_ON(!event))
783 goto out;
784
785 if (WARN_ON(!event->funcs))
786 goto out;
787
788 INIT_LIST_HEAD(&event->list);
789
790 if (!event->type) {
791 struct list_head *list = NULL;
792
793 if (next_event_type > FTRACE_MAX_EVENT) {
794
795 event->type = trace_search_list(&list);
796 if (!event->type)
797 goto out;
798
799 } else {
800
801 event->type = next_event_type++;
802 list = &ftrace_event_list;
803 }
804
805 if (WARN_ON(ftrace_find_event(event->type)))
806 goto out;
807
808 list_add_tail(&event->list, list);
809
810 } else if (event->type > __TRACE_LAST_TYPE) {
811 printk(KERN_WARNING "Need to add type to trace.h\n");
812 WARN_ON(1);
813 goto out;
814 } else {
815 /* Is this event already used */
816 if (ftrace_find_event(event->type))
817 goto out;
818 }
819
820 if (event->funcs->trace == NULL)
821 event->funcs->trace = trace_nop_print;
822 if (event->funcs->raw == NULL)
823 event->funcs->raw = trace_nop_print;
824 if (event->funcs->hex == NULL)
825 event->funcs->hex = trace_nop_print;
826 if (event->funcs->binary == NULL)
827 event->funcs->binary = trace_nop_print;
828
829 key = event->type & (EVENT_HASHSIZE - 1);
830
831 hlist_add_head(&event->node, &event_hash[key]);
832
833 ret = event->type;
834 out:
835 up_write(&trace_event_mutex);
836
837 return ret;
838 }
839 EXPORT_SYMBOL_GPL(register_ftrace_event);
840
841 /*
842 * Used by module code with the trace_event_mutex held for write.
843 */
844 int __unregister_ftrace_event(struct trace_event *event)
845 {
846 hlist_del(&event->node);
847 list_del(&event->list);
848 return 0;
849 }
850
851 /**
852 * unregister_ftrace_event - remove a no longer used event
853 * @event: the event to remove
854 */
855 int unregister_ftrace_event(struct trace_event *event)
856 {
857 down_write(&trace_event_mutex);
858 __unregister_ftrace_event(event);
859 up_write(&trace_event_mutex);
860
861 return 0;
862 }
863 EXPORT_SYMBOL_GPL(unregister_ftrace_event);
864
865 /*
866 * Standard events
867 */
868
869 enum print_line_t trace_nop_print(struct trace_iterator *iter, int flags,
870 struct trace_event *event)
871 {
872 if (!trace_seq_printf(&iter->seq, "type: %d\n", iter->ent->type))
873 return TRACE_TYPE_PARTIAL_LINE;
874
875 return TRACE_TYPE_HANDLED;
876 }
877
878 /* TRACE_FN */
879 static enum print_line_t trace_fn_trace(struct trace_iterator *iter, int flags,
880 struct trace_event *event)
881 {
882 struct ftrace_entry *field;
883 struct trace_seq *s = &iter->seq;
884
885 trace_assign_type(field, iter->ent);
886
887 if (!seq_print_ip_sym(s, field->ip, flags))
888 goto partial;
889
890 if ((flags & TRACE_ITER_PRINT_PARENT) && field->parent_ip) {
891 if (!trace_seq_printf(s, " <-"))
892 goto partial;
893 if (!seq_print_ip_sym(s,
894 field->parent_ip,
895 flags))
896 goto partial;
897 }
898 if (!trace_seq_printf(s, "\n"))
899 goto partial;
900
901 return TRACE_TYPE_HANDLED;
902
903 partial:
904 return TRACE_TYPE_PARTIAL_LINE;
905 }
906
907 static enum print_line_t trace_fn_raw(struct trace_iterator *iter, int flags,
908 struct trace_event *event)
909 {
910 struct ftrace_entry *field;
911
912 trace_assign_type(field, iter->ent);
913
914 if (!trace_seq_printf(&iter->seq, "%lx %lx\n",
915 field->ip,
916 field->parent_ip))
917 return TRACE_TYPE_PARTIAL_LINE;
918
919 return TRACE_TYPE_HANDLED;
920 }
921
922 static enum print_line_t trace_fn_hex(struct trace_iterator *iter, int flags,
923 struct trace_event *event)
924 {
925 struct ftrace_entry *field;
926 struct trace_seq *s = &iter->seq;
927
928 trace_assign_type(field, iter->ent);
929
930 SEQ_PUT_HEX_FIELD_RET(s, field->ip);
931 SEQ_PUT_HEX_FIELD_RET(s, field->parent_ip);
932
933 return TRACE_TYPE_HANDLED;
934 }
935
936 static enum print_line_t trace_fn_bin(struct trace_iterator *iter, int flags,
937 struct trace_event *event)
938 {
939 struct ftrace_entry *field;
940 struct trace_seq *s = &iter->seq;
941
942 trace_assign_type(field, iter->ent);
943
944 SEQ_PUT_FIELD_RET(s, field->ip);
945 SEQ_PUT_FIELD_RET(s, field->parent_ip);
946
947 return TRACE_TYPE_HANDLED;
948 }
949
950 static struct trace_event_functions trace_fn_funcs = {
951 .trace = trace_fn_trace,
952 .raw = trace_fn_raw,
953 .hex = trace_fn_hex,
954 .binary = trace_fn_bin,
955 };
956
957 static struct trace_event trace_fn_event = {
958 .type = TRACE_FN,
959 .funcs = &trace_fn_funcs,
960 };
961
962 /* TRACE_CTX an TRACE_WAKE */
963 static enum print_line_t trace_ctxwake_print(struct trace_iterator *iter,
964 char *delim)
965 {
966 struct ctx_switch_entry *field;
967 char comm[TASK_COMM_LEN];
968 int S, T;
969
970
971 trace_assign_type(field, iter->ent);
972
973 T = task_state_char(field->next_state);
974 S = task_state_char(field->prev_state);
975 trace_find_cmdline(field->next_pid, comm);
976 if (!trace_seq_printf(&iter->seq,
977 " %5d:%3d:%c %s [%03d] %5d:%3d:%c %s\n",
978 field->prev_pid,
979 field->prev_prio,
980 S, delim,
981 field->next_cpu,
982 field->next_pid,
983 field->next_prio,
984 T, comm))
985 return TRACE_TYPE_PARTIAL_LINE;
986
987 return TRACE_TYPE_HANDLED;
988 }
989
990 static enum print_line_t trace_ctx_print(struct trace_iterator *iter, int flags,
991 struct trace_event *event)
992 {
993 return trace_ctxwake_print(iter, "==>");
994 }
995
996 static enum print_line_t trace_wake_print(struct trace_iterator *iter,
997 int flags, struct trace_event *event)
998 {
999 return trace_ctxwake_print(iter, " +");
1000 }
1001
1002 static int trace_ctxwake_raw(struct trace_iterator *iter, char S)
1003 {
1004 struct ctx_switch_entry *field;
1005 int T;
1006
1007 trace_assign_type(field, iter->ent);
1008
1009 if (!S)
1010 S = task_state_char(field->prev_state);
1011 T = task_state_char(field->next_state);
1012 if (!trace_seq_printf(&iter->seq, "%d %d %c %d %d %d %c\n",
1013 field->prev_pid,
1014 field->prev_prio,
1015 S,
1016 field->next_cpu,
1017 field->next_pid,
1018 field->next_prio,
1019 T))
1020 return TRACE_TYPE_PARTIAL_LINE;
1021
1022 return TRACE_TYPE_HANDLED;
1023 }
1024
1025 static enum print_line_t trace_ctx_raw(struct trace_iterator *iter, int flags,
1026 struct trace_event *event)
1027 {
1028 return trace_ctxwake_raw(iter, 0);
1029 }
1030
1031 static enum print_line_t trace_wake_raw(struct trace_iterator *iter, int flags,
1032 struct trace_event *event)
1033 {
1034 return trace_ctxwake_raw(iter, '+');
1035 }
1036
1037
1038 static int trace_ctxwake_hex(struct trace_iterator *iter, char S)
1039 {
1040 struct ctx_switch_entry *field;
1041 struct trace_seq *s = &iter->seq;
1042 int T;
1043
1044 trace_assign_type(field, iter->ent);
1045
1046 if (!S)
1047 S = task_state_char(field->prev_state);
1048 T = task_state_char(field->next_state);
1049
1050 SEQ_PUT_HEX_FIELD_RET(s, field->prev_pid);
1051 SEQ_PUT_HEX_FIELD_RET(s, field->prev_prio);
1052 SEQ_PUT_HEX_FIELD_RET(s, S);
1053 SEQ_PUT_HEX_FIELD_RET(s, field->next_cpu);
1054 SEQ_PUT_HEX_FIELD_RET(s, field->next_pid);
1055 SEQ_PUT_HEX_FIELD_RET(s, field->next_prio);
1056 SEQ_PUT_HEX_FIELD_RET(s, T);
1057
1058 return TRACE_TYPE_HANDLED;
1059 }
1060
1061 static enum print_line_t trace_ctx_hex(struct trace_iterator *iter, int flags,
1062 struct trace_event *event)
1063 {
1064 return trace_ctxwake_hex(iter, 0);
1065 }
1066
1067 static enum print_line_t trace_wake_hex(struct trace_iterator *iter, int flags,
1068 struct trace_event *event)
1069 {
1070 return trace_ctxwake_hex(iter, '+');
1071 }
1072
1073 static enum print_line_t trace_ctxwake_bin(struct trace_iterator *iter,
1074 int flags, struct trace_event *event)
1075 {
1076 struct ctx_switch_entry *field;
1077 struct trace_seq *s = &iter->seq;
1078
1079 trace_assign_type(field, iter->ent);
1080
1081 SEQ_PUT_FIELD_RET(s, field->prev_pid);
1082 SEQ_PUT_FIELD_RET(s, field->prev_prio);
1083 SEQ_PUT_FIELD_RET(s, field->prev_state);
1084 SEQ_PUT_FIELD_RET(s, field->next_pid);
1085 SEQ_PUT_FIELD_RET(s, field->next_prio);
1086 SEQ_PUT_FIELD_RET(s, field->next_state);
1087
1088 return TRACE_TYPE_HANDLED;
1089 }
1090
1091 static struct trace_event_functions trace_ctx_funcs = {
1092 .trace = trace_ctx_print,
1093 .raw = trace_ctx_raw,
1094 .hex = trace_ctx_hex,
1095 .binary = trace_ctxwake_bin,
1096 };
1097
1098 static struct trace_event trace_ctx_event = {
1099 .type = TRACE_CTX,
1100 .funcs = &trace_ctx_funcs,
1101 };
1102
1103 static struct trace_event_functions trace_wake_funcs = {
1104 .trace = trace_wake_print,
1105 .raw = trace_wake_raw,
1106 .hex = trace_wake_hex,
1107 .binary = trace_ctxwake_bin,
1108 };
1109
1110 static struct trace_event trace_wake_event = {
1111 .type = TRACE_WAKE,
1112 .funcs = &trace_wake_funcs,
1113 };
1114
1115 /* TRACE_STACK */
1116
1117 static enum print_line_t trace_stack_print(struct trace_iterator *iter,
1118 int flags, struct trace_event *event)
1119 {
1120 struct stack_entry *field;
1121 struct trace_seq *s = &iter->seq;
1122 unsigned long *p;
1123 unsigned long *end;
1124
1125 trace_assign_type(field, iter->ent);
1126 end = (unsigned long *)((long)iter->ent + iter->ent_size);
1127
1128 if (!trace_seq_puts(s, "<stack trace>\n"))
1129 goto partial;
1130
1131 for (p = field->caller; p && *p != ULONG_MAX && p < end; p++) {
1132 if (!trace_seq_puts(s, " => "))
1133 goto partial;
1134
1135 if (!seq_print_ip_sym(s, *p, flags))
1136 goto partial;
1137 if (!trace_seq_puts(s, "\n"))
1138 goto partial;
1139 }
1140
1141 return TRACE_TYPE_HANDLED;
1142
1143 partial:
1144 return TRACE_TYPE_PARTIAL_LINE;
1145 }
1146
1147 static struct trace_event_functions trace_stack_funcs = {
1148 .trace = trace_stack_print,
1149 };
1150
1151 static struct trace_event trace_stack_event = {
1152 .type = TRACE_STACK,
1153 .funcs = &trace_stack_funcs,
1154 };
1155
1156 /* TRACE_USER_STACK */
1157 static enum print_line_t trace_user_stack_print(struct trace_iterator *iter,
1158 int flags, struct trace_event *event)
1159 {
1160 struct userstack_entry *field;
1161 struct trace_seq *s = &iter->seq;
1162
1163 trace_assign_type(field, iter->ent);
1164
1165 if (!trace_seq_puts(s, "<user stack trace>\n"))
1166 goto partial;
1167
1168 if (!seq_print_userip_objs(field, s, flags))
1169 goto partial;
1170
1171 return TRACE_TYPE_HANDLED;
1172
1173 partial:
1174 return TRACE_TYPE_PARTIAL_LINE;
1175 }
1176
1177 static struct trace_event_functions trace_user_stack_funcs = {
1178 .trace = trace_user_stack_print,
1179 };
1180
1181 static struct trace_event trace_user_stack_event = {
1182 .type = TRACE_USER_STACK,
1183 .funcs = &trace_user_stack_funcs,
1184 };
1185
1186 /* TRACE_BPRINT */
1187 static enum print_line_t
1188 trace_bprint_print(struct trace_iterator *iter, int flags,
1189 struct trace_event *event)
1190 {
1191 struct trace_entry *entry = iter->ent;
1192 struct trace_seq *s = &iter->seq;
1193 struct bprint_entry *field;
1194
1195 trace_assign_type(field, entry);
1196
1197 if (!seq_print_ip_sym(s, field->ip, flags))
1198 goto partial;
1199
1200 if (!trace_seq_puts(s, ": "))
1201 goto partial;
1202
1203 if (!trace_seq_bprintf(s, field->fmt, field->buf))
1204 goto partial;
1205
1206 return TRACE_TYPE_HANDLED;
1207
1208 partial:
1209 return TRACE_TYPE_PARTIAL_LINE;
1210 }
1211
1212
1213 static enum print_line_t
1214 trace_bprint_raw(struct trace_iterator *iter, int flags,
1215 struct trace_event *event)
1216 {
1217 struct bprint_entry *field;
1218 struct trace_seq *s = &iter->seq;
1219
1220 trace_assign_type(field, iter->ent);
1221
1222 if (!trace_seq_printf(s, ": %lx : ", field->ip))
1223 goto partial;
1224
1225 if (!trace_seq_bprintf(s, field->fmt, field->buf))
1226 goto partial;
1227
1228 return TRACE_TYPE_HANDLED;
1229
1230 partial:
1231 return TRACE_TYPE_PARTIAL_LINE;
1232 }
1233
1234 static struct trace_event_functions trace_bprint_funcs = {
1235 .trace = trace_bprint_print,
1236 .raw = trace_bprint_raw,
1237 };
1238
1239 static struct trace_event trace_bprint_event = {
1240 .type = TRACE_BPRINT,
1241 .funcs = &trace_bprint_funcs,
1242 };
1243
1244 /* TRACE_PRINT */
1245 static enum print_line_t trace_print_print(struct trace_iterator *iter,
1246 int flags, struct trace_event *event)
1247 {
1248 struct print_entry *field;
1249 struct trace_seq *s = &iter->seq;
1250
1251 trace_assign_type(field, iter->ent);
1252
1253 if (!seq_print_ip_sym(s, field->ip, flags))
1254 goto partial;
1255
1256 if (!trace_seq_printf(s, ": %s", field->buf))
1257 goto partial;
1258
1259 return TRACE_TYPE_HANDLED;
1260
1261 partial:
1262 return TRACE_TYPE_PARTIAL_LINE;
1263 }
1264
1265 static enum print_line_t trace_print_raw(struct trace_iterator *iter, int flags,
1266 struct trace_event *event)
1267 {
1268 struct print_entry *field;
1269
1270 trace_assign_type(field, iter->ent);
1271
1272 if (!trace_seq_printf(&iter->seq, "# %lx %s", field->ip, field->buf))
1273 goto partial;
1274
1275 return TRACE_TYPE_HANDLED;
1276
1277 partial:
1278 return TRACE_TYPE_PARTIAL_LINE;
1279 }
1280
1281 static struct trace_event_functions trace_print_funcs = {
1282 .trace = trace_print_print,
1283 .raw = trace_print_raw,
1284 };
1285
1286 static struct trace_event trace_print_event = {
1287 .type = TRACE_PRINT,
1288 .funcs = &trace_print_funcs,
1289 };
1290
1291
1292 static struct trace_event *events[] __initdata = {
1293 &trace_fn_event,
1294 &trace_ctx_event,
1295 &trace_wake_event,
1296 &trace_stack_event,
1297 &trace_user_stack_event,
1298 &trace_bprint_event,
1299 &trace_print_event,
1300 NULL
1301 };
1302
1303 __init static int init_events(void)
1304 {
1305 struct trace_event *event;
1306 int i, ret;
1307
1308 for (i = 0; events[i]; i++) {
1309 event = events[i];
1310
1311 ret = register_ftrace_event(event);
1312 if (!ret) {
1313 printk(KERN_WARNING "event %d failed to register\n",
1314 event->type);
1315 WARN_ON_ONCE(1);
1316 }
1317 }
1318
1319 return 0;
1320 }
1321 device_initcall(init_events);
1322