tracing: Have stack_tracer use a separate list of functions
[linux-2.6.git] / kernel / trace / trace_output.c
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
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
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
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
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
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
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  */
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
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
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
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);