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 const char *
 357 ftrace_print_hex_seq(struct trace_seq *p, const unsigned char *buf, int buf_len)
 358 {
 359         int i;
 360         const char *ret = p->buffer + p->len;
 361
 362         for (i = 0; i < buf_len; i++)
 363                 trace_seq_printf(p, "%s%2.2x", i == 0 ? "" : " ", buf[i]);
 364
 365         trace_seq_putc(p, 0);
 366
 367         return ret;
 368 }
 369 EXPORT_SYMBOL(ftrace_print_hex_seq);
 370
 371 #ifdef CONFIG_KRETPROBES
 372 static inline const char *kretprobed(const char *name)
 373 {
 374         static const char tramp_name[] = "kretprobe_trampoline";
 375         int size = sizeof(tramp_name);
 376
 377         if (strncmp(tramp_name, name, size) == 0)
 378                 return "[unknown/kretprobe'd]";
 379         return name;
 380 }
 381 #else
 382 static inline const char *kretprobed(const char *name)
 383 {
 384         return name;
 385 }
 386 #endif /* CONFIG_KRETPROBES */
 387
 388 static int
 389 seq_print_sym_short(struct trace_seq *s, const char *fmt, unsigned long address)
 390 {
 391 #ifdef CONFIG_KALLSYMS
 392         char str[KSYM_SYMBOL_LEN];
 393         const char *name;
 394
 395         kallsyms_lookup(address, NULL, NULL, NULL, str);
 396
 397         name = kretprobed(str);
 398
 399         return trace_seq_printf(s, fmt, name);
 400 #endif
 401         return 1;
 402 }
 403
 404 static int
 405 seq_print_sym_offset(struct trace_seq *s, const char *fmt,
 406                      unsigned long address)
 407 {
 408 #ifdef CONFIG_KALLSYMS
 409         char str[KSYM_SYMBOL_LEN];
 410         const char *name;
 411
 412         sprint_symbol(str, address);
 413         name = kretprobed(str);
 414
 415         return trace_seq_printf(s, fmt, name);
 416 #endif
 417         return 1;
 418 }
 419
 420 #ifndef CONFIG_64BIT
 421 # define IP_FMT "%08lx"
 422 #else
 423 # define IP_FMT "%016lx"
 424 #endif
 425
 426 int seq_print_user_ip(struct trace_seq *s, struct mm_struct *mm,
 427                       unsigned long ip, unsigned long sym_flags)
 428 {
 429         struct file *file = NULL;
 430         unsigned long vmstart = 0;
 431         int ret = 1;
 432
 433         if (s->full)
 434                 return 0;
 435
 436         if (mm) {
 437                 const struct vm_area_struct *vma;
 438
 439                 down_read(&mm->mmap_sem);
 440                 vma = find_vma(mm, ip);
 441                 if (vma) {
 442                         file = vma->vm_file;
 443                         vmstart = vma->vm_start;
 444                 }
 445                 if (file) {
 446                         ret = trace_seq_path(s, &file->f_path);
 447                         if (ret)
 448                                 ret = trace_seq_printf(s, "[+0x%lx]",
 449                                                        ip - vmstart);
 450                 }
 451                 up_read(&mm->mmap_sem);
 452         }
 453         if (ret && ((sym_flags & TRACE_ITER_SYM_ADDR) || !file))
 454                 ret = trace_seq_printf(s, " <" IP_FMT ">", ip);
 455         return ret;
 456 }
 457
 458 int
 459 seq_print_userip_objs(const struct userstack_entry *entry, struct trace_seq *s,
 460                       unsigned long sym_flags)
 461 {
 462         struct mm_struct *mm = NULL;
 463         int ret = 1;
 464         unsigned int i;
 465
 466         if (trace_flags & TRACE_ITER_SYM_USEROBJ) {
 467                 struct task_struct *task;
 468                 /*
 469                  * we do the lookup on the thread group leader,
 470                  * since individual threads might have already quit!
 471                  */
 472                 rcu_read_lock();
 473                 task = find_task_by_vpid(entry->tgid);
 474                 if (task)
 475                         mm = get_task_mm(task);
 476                 rcu_read_unlock();
 477         }
 478
 479         for (i = 0; i < FTRACE_STACK_ENTRIES; i++) {
 480                 unsigned long ip = entry->caller[i];
 481
 482                 if (ip == ULONG_MAX || !ret)
 483                         break;
 484                 if (ret)
 485                         ret = trace_seq_puts(s, " => ");
 486                 if (!ip) {
 487                         if (ret)
 488                                 ret = trace_seq_puts(s, "??");
 489                         if (ret)
 490                                 ret = trace_seq_puts(s, "\n");
 491                         continue;
 492                 }
 493                 if (!ret)
 494                         break;
 495                 if (ret)
 496                         ret = seq_print_user_ip(s, mm, ip, sym_flags);
 497                 ret = trace_seq_puts(s, "\n");
 498         }
 499
 500         if (mm)
 501                 mmput(mm);
 502         return ret;
 503 }
 504
 505 int
 506 seq_print_ip_sym(struct trace_seq *s, unsigned long ip, unsigned long sym_flags)
 507 {
 508         int ret;
 509
 510         if (!ip)
 511                 return trace_seq_printf(s, "0");
 512
 513         if (sym_flags & TRACE_ITER_SYM_OFFSET)
 514                 ret = seq_print_sym_offset(s, "%s", ip);
 515         else
 516                 ret = seq_print_sym_short(s, "%s", ip);
 517
 518         if (!ret)
 519                 return 0;
 520
 521         if (sym_flags & TRACE_ITER_SYM_ADDR)
 522                 ret = trace_seq_printf(s, " <" IP_FMT ">", ip);
 523         return ret;
 524 }
 525
 526 /**
 527  * trace_print_lat_fmt - print the irq, preempt and lockdep fields
 528  * @s: trace seq struct to write to
 529  * @entry: The trace entry field from the ring buffer
 530  *
 531  * Prints the generic fields of irqs off, in hard or softirq, preempt
 532  * count and lock depth.
 533  */
 534 int trace_print_lat_fmt(struct trace_seq *s, struct trace_entry *entry)
 535 {
 536         int hardirq, softirq;
 537         int ret;
 538
 539         hardirq = entry->flags & TRACE_FLAG_HARDIRQ;
 540         softirq = entry->flags & TRACE_FLAG_SOFTIRQ;
 541
 542         if (!trace_seq_printf(s, "%c%c%c",
 543                               (entry->flags & TRACE_FLAG_IRQS_OFF) ? 'd' :
 544                                 (entry->flags & TRACE_FLAG_IRQS_NOSUPPORT) ?
 545                                   'X' : '.',
 546                               (entry->flags & TRACE_FLAG_NEED_RESCHED) ?
 547                                 'N' : '.',
 548                               (hardirq && softirq) ? 'H' :
 549                                 hardirq ? 'h' : softirq ? 's' : '.'))
 550                 return 0;
 551
 552         if (entry->preempt_count)
 553                 ret = trace_seq_printf(s, "%x", entry->preempt_count);
 554         else
 555                 ret = trace_seq_putc(s, '.');
 556
 557         if (!ret)
 558                 return 0;
 559
 560         if (entry->lock_depth < 0)
 561                 return trace_seq_putc(s, '.');
 562
 563         return trace_seq_printf(s, "%d", entry->lock_depth);
 564 }
 565
 566 static int
 567 lat_print_generic(struct trace_seq *s, struct trace_entry *entry, int cpu)
 568 {
 569         char comm[TASK_COMM_LEN];
 570
 571         trace_find_cmdline(entry->pid, comm);
 572
 573         if (!trace_seq_printf(s, "%8.8s-%-5d %3d",
 574                               comm, entry->pid, cpu))
 575                 return 0;
 576
 577         return trace_print_lat_fmt(s, entry);
 578 }
 579
 580 static unsigned long preempt_mark_thresh = 100;
 581
 582 static int
 583 lat_print_timestamp(struct trace_seq *s, u64 abs_usecs,
 584                     unsigned long rel_usecs)
 585 {
 586         return trace_seq_printf(s, " %4lldus%c: ", abs_usecs,
 587                                 rel_usecs > preempt_mark_thresh ? '!' :
 588                                   rel_usecs > 1 ? '+' : ' ');
 589 }
 590
 591 int trace_print_context(struct trace_iterator *iter)
 592 {
 593         struct trace_seq *s = &iter->seq;
 594         struct trace_entry *entry = iter->ent;
 595         unsigned long long t = ns2usecs(iter->ts);
 596         unsigned long usec_rem = do_div(t, USEC_PER_SEC);
 597         unsigned long secs = (unsigned long)t;
 598         char comm[TASK_COMM_LEN];
 599
 600         trace_find_cmdline(entry->pid, comm);
 601
 602         return trace_seq_printf(s, "%16s-%-5d [%03d] %5lu.%06lu: ",
 603                                 comm, entry->pid, iter->cpu, secs, usec_rem);
 604 }
 605
 606 int trace_print_lat_context(struct trace_iterator *iter)
 607 {
 608         u64 next_ts;
 609         int ret;
 610         struct trace_seq *s = &iter->seq;
 611         struct trace_entry *entry = iter->ent,
 612                            *next_entry = trace_find_next_entry(iter, NULL,
 613                                                                &next_ts);
 614         unsigned long verbose = (trace_flags & TRACE_ITER_VERBOSE);
 615         unsigned long abs_usecs = ns2usecs(iter->ts - iter->tr->time_start);
 616         unsigned long rel_usecs;
 617
 618         if (!next_entry)
 619                 next_ts = iter->ts;
 620         rel_usecs = ns2usecs(next_ts - iter->ts);
 621
 622         if (verbose) {
 623                 char comm[TASK_COMM_LEN];
 624
 625                 trace_find_cmdline(entry->pid, comm);
 626
 627                 ret = trace_seq_printf(s, "%16s %5d %3d %d %08x %08lx [%08llx]"
 628                                        " %ld.%03ldms (+%ld.%03ldms): ", comm,
 629                                        entry->pid, iter->cpu, entry->flags,
 630                                        entry->preempt_count, iter->idx,
 631                                        ns2usecs(iter->ts),
 632                                        abs_usecs / USEC_PER_MSEC,
 633                                        abs_usecs % USEC_PER_MSEC,
 634                                        rel_usecs / USEC_PER_MSEC,
 635                                        rel_usecs % USEC_PER_MSEC);
 636         } else {
 637                 ret = lat_print_generic(s, entry, iter->cpu);
 638                 if (ret)
 639                         ret = lat_print_timestamp(s, abs_usecs, rel_usecs);
 640         }
 641
 642         return ret;
 643 }
 644
 645 static const char state_to_char[] = TASK_STATE_TO_CHAR_STR;
 646
 647 static int task_state_char(unsigned long state)
 648 {
 649         int bit = state ? __ffs(state) + 1 : 0;
 650
 651         return bit < sizeof(state_to_char) - 1 ? state_to_char[bit] : '?';
 652 }
 653
 654 /**
 655  * ftrace_find_event - find a registered event
 656  * @type: the type of event to look for
 657  *
 658  * Returns an event of type @type otherwise NULL
 659  * Called with trace_event_read_lock() held.
 660  */
 661 struct trace_event *ftrace_find_event(int type)
 662 {
 663         struct trace_event *event;
 664         struct hlist_node *n;
 665         unsigned key;
 666
 667         key = type & (EVENT_HASHSIZE - 1);
 668
 669         hlist_for_each_entry(event, n, &event_hash[key], node) {
 670                 if (event->type == type)
 671                         return event;
 672         }
 673
 674         return NULL;
 675 }
 676
 677 static LIST_HEAD(ftrace_event_list);
 678
 679 static int trace_search_list(struct list_head **list)
 680 {
 681         struct trace_event *e;
 682         int last = __TRACE_LAST_TYPE;
 683
 684         if (list_empty(&ftrace_event_list)) {
 685                 *list = &ftrace_event_list;
 686                 return last + 1;
 687         }
 688
 689         /*
 690          * We used up all possible max events,
 691          * lets see if somebody freed one.
 692          */
 693         list_for_each_entry(e, &ftrace_event_list, list) {
 694                 if (e->type != last + 1)
 695                         break;
 696                 last++;
 697         }
 698
 699         /* Did we used up all 65 thousand events??? */
 700         if ((last + 1) > FTRACE_MAX_EVENT)
 701                 return 0;
 702
 703         *list = &e->list;
 704         return last + 1;
 705 }
 706
 707 void trace_event_read_lock(void)
 708 {
 709         down_read(&trace_event_mutex);
 710 }
 711
 712 void trace_event_read_unlock(void)
 713 {
 714         up_read(&trace_event_mutex);
 715 }
 716
 717 /**
 718  * register_ftrace_event - register output for an event type
 719  * @event: the event type to register
 720  *
 721  * Event types are stored in a hash and this hash is used to
 722  * find a way to print an event. If the @event->type is set
 723  * then it will use that type, otherwise it will assign a
 724  * type to use.
 725  *
 726  * If you assign your own type, please make sure it is added
 727  * to the trace_type enum in trace.h, to avoid collisions
 728  * with the dynamic types.
 729  *
 730  * Returns the event type number or zero on error.
 731  */
 732 int register_ftrace_event(struct trace_event *event)
 733 {
 734         unsigned key;
 735         int ret = 0;
 736
 737         down_write(&trace_event_mutex);
 738
 739         if (WARN_ON(!event))
 740                 goto out;
 741
 742         if (WARN_ON(!event->funcs))
 743                 goto out;
 744
 745         INIT_LIST_HEAD(&event->list);
 746
 747         if (!event->type) {
 748                 struct list_head *list = NULL;
 749
 750                 if (next_event_type > FTRACE_MAX_EVENT) {
 751
 752                         event->type = trace_search_list(&list);
 753                         if (!event->type)
 754                                 goto out;
 755
 756                 } else {
 757
 758                         event->type = next_event_type++;
 759                         list = &ftrace_event_list;
 760                 }
 761
 762                 if (WARN_ON(ftrace_find_event(event->type)))
 763                         goto out;
 764
 765                 list_add_tail(&event->list, list);
 766
 767         } else if (event->type > __TRACE_LAST_TYPE) {
 768                 printk(KERN_WARNING "Need to add type to trace.h\n");
 769                 WARN_ON(1);
 770                 goto out;
 771         } else {
 772                 /* Is this event already used */
 773                 if (ftrace_find_event(event->type))
 774                         goto out;
 775         }
 776
 777         if (event->funcs->trace == NULL)
 778                 event->funcs->trace = trace_nop_print;
 779         if (event->funcs->raw == NULL)
 780                 event->funcs->raw = trace_nop_print;
 781         if (event->funcs->hex == NULL)
 782                 event->funcs->hex = trace_nop_print;
 783         if (event->funcs->binary == NULL)
 784                 event->funcs->binary = trace_nop_print;
 785
 786         key = event->type & (EVENT_HASHSIZE - 1);
 787
 788         hlist_add_head(&event->node, &event_hash[key]);
 789
 790         ret = event->type;
 791  out:
 792         up_write(&trace_event_mutex);
 793
 794         return ret;
 795 }
 796 EXPORT_SYMBOL_GPL(register_ftrace_event);
 797
 798 /*
 799  * Used by module code with the trace_event_mutex held for write.
 800  */
 801 int __unregister_ftrace_event(struct trace_event *event)
 802 {
 803         hlist_del(&event->node);
 804         list_del(&event->list);
 805         return 0;
 806 }
 807
 808 /**
 809  * unregister_ftrace_event - remove a no longer used event
 810  * @event: the event to remove
 811  */
 812 int unregister_ftrace_event(struct trace_event *event)
 813 {
 814         down_write(&trace_event_mutex);
 815         __unregister_ftrace_event(event);
 816         up_write(&trace_event_mutex);
 817
 818         return 0;
 819 }
 820 EXPORT_SYMBOL_GPL(unregister_ftrace_event);
 821
 822 /*
 823  * Standard events
 824  */
 825
 826 enum print_line_t trace_nop_print(struct trace_iterator *iter, int flags,
 827                                   struct trace_event *event)
 828 {
 829         return TRACE_TYPE_HANDLED;
 830 }
 831
 832 /* TRACE_FN */
 833 static enum print_line_t trace_fn_trace(struct trace_iterator *iter, int flags,
 834                                         struct trace_event *event)
 835 {
 836         struct ftrace_entry *field;
 837         struct trace_seq *s = &iter->seq;
 838
 839         trace_assign_type(field, iter->ent);
 840
 841         if (!seq_print_ip_sym(s, field->ip, flags))
 842                 goto partial;
 843
 844         if ((flags & TRACE_ITER_PRINT_PARENT) && field->parent_ip) {
 845                 if (!trace_seq_printf(s, " <-"))
 846                         goto partial;
 847                 if (!seq_print_ip_sym(s,
 848                                       field->parent_ip,
 849                                       flags))
 850                         goto partial;
 851         }
 852         if (!trace_seq_printf(s, "\n"))
 853                 goto partial;
 854
 855         return TRACE_TYPE_HANDLED;
 856
 857  partial:
 858         return TRACE_TYPE_PARTIAL_LINE;
 859 }
 860
 861 static enum print_line_t trace_fn_raw(struct trace_iterator *iter, int flags,
 862                                       struct trace_event *event)
 863 {
 864         struct ftrace_entry *field;
 865
 866         trace_assign_type(field, iter->ent);
 867
 868         if (!trace_seq_printf(&iter->seq, "%lx %lx\n",
 869                               field->ip,
 870                               field->parent_ip))
 871                 return TRACE_TYPE_PARTIAL_LINE;
 872
 873         return TRACE_TYPE_HANDLED;
 874 }
 875
 876 static enum print_line_t trace_fn_hex(struct trace_iterator *iter, int flags,
 877                                       struct trace_event *event)
 878 {
 879         struct ftrace_entry *field;
 880         struct trace_seq *s = &iter->seq;
 881
 882         trace_assign_type(field, iter->ent);
 883
 884         SEQ_PUT_HEX_FIELD_RET(s, field->ip);
 885         SEQ_PUT_HEX_FIELD_RET(s, field->parent_ip);
 886
 887         return TRACE_TYPE_HANDLED;
 888 }
 889
 890 static enum print_line_t trace_fn_bin(struct trace_iterator *iter, int flags,
 891                                       struct trace_event *event)
 892 {
 893         struct ftrace_entry *field;
 894         struct trace_seq *s = &iter->seq;
 895
 896         trace_assign_type(field, iter->ent);
 897
 898         SEQ_PUT_FIELD_RET(s, field->ip);
 899         SEQ_PUT_FIELD_RET(s, field->parent_ip);
 900
 901         return TRACE_TYPE_HANDLED;
 902 }
 903
 904 static struct trace_event_functions trace_fn_funcs = {
 905         .trace          = trace_fn_trace,
 906         .raw            = trace_fn_raw,
 907         .hex            = trace_fn_hex,
 908         .binary         = trace_fn_bin,
 909 };
 910
 911 static struct trace_event trace_fn_event = {
 912         .type           = TRACE_FN,
 913         .funcs          = &trace_fn_funcs,
 914 };
 915
 916 /* TRACE_CTX an TRACE_WAKE */
 917 static enum print_line_t trace_ctxwake_print(struct trace_iterator *iter,
 918                                              char *delim)
 919 {
 920         struct ctx_switch_entry *field;
 921         char comm[TASK_COMM_LEN];
 922         int S, T;
 923
 924
 925         trace_assign_type(field, iter->ent);
 926
 927         T = task_state_char(field->next_state);
 928         S = task_state_char(field->prev_state);
 929         trace_find_cmdline(field->next_pid, comm);
 930         if (!trace_seq_printf(&iter->seq,
 931                               " %5d:%3d:%c %s [%03d] %5d:%3d:%c %s\n",
 932                               field->prev_pid,
 933                               field->prev_prio,
 934                               S, delim,
 935                               field->next_cpu,
 936                               field->next_pid,
 937                               field->next_prio,
 938                               T, comm))
 939                 return TRACE_TYPE_PARTIAL_LINE;
 940
 941         return TRACE_TYPE_HANDLED;
 942 }
 943
 944 static enum print_line_t trace_ctx_print(struct trace_iterator *iter, int flags,
 945                                          struct trace_event *event)
 946 {
 947         return trace_ctxwake_print(iter, "==>");
 948 }
 949
 950 static enum print_line_t trace_wake_print(struct trace_iterator *iter,
 951                                           int flags, struct trace_event *event)
 952 {
 953         return trace_ctxwake_print(iter, "  +");
 954 }
 955
 956 static int trace_ctxwake_raw(struct trace_iterator *iter, char S)
 957 {
 958         struct ctx_switch_entry *field;
 959         int T;
 960
 961         trace_assign_type(field, iter->ent);
 962
 963         if (!S)
 964                 S = task_state_char(field->prev_state);
 965         T = task_state_char(field->next_state);
 966         if (!trace_seq_printf(&iter->seq, "%d %d %c %d %d %d %c\n",
 967                               field->prev_pid,
 968                               field->prev_prio,
 969                               S,
 970                               field->next_cpu,
 971                               field->next_pid,
 972                               field->next_prio,
 973                               T))
 974                 return TRACE_TYPE_PARTIAL_LINE;
 975
 976         return TRACE_TYPE_HANDLED;
 977 }
 978
 979 static enum print_line_t trace_ctx_raw(struct trace_iterator *iter, int flags,
 980                                        struct trace_event *event)
 981 {
 982         return trace_ctxwake_raw(iter, 0);
 983 }
 984
 985 static enum print_line_t trace_wake_raw(struct trace_iterator *iter, int flags,
 986                                         struct trace_event *event)
 987 {
 988         return trace_ctxwake_raw(iter, '+');
 989 }
 990
 991
 992 static int trace_ctxwake_hex(struct trace_iterator *iter, char S)
 993 {
 994         struct ctx_switch_entry *field;
 995         struct trace_seq *s = &iter->seq;
 996         int T;
 997
 998         trace_assign_type(field, iter->ent);
 999
1000         if (!S)
1001                 S = task_state_char(field->prev_state);
1002         T = task_state_char(field->next_state);
1003
1004         SEQ_PUT_HEX_FIELD_RET(s, field->prev_pid);
1005         SEQ_PUT_HEX_FIELD_RET(s, field->prev_prio);
1006         SEQ_PUT_HEX_FIELD_RET(s, S);
1007         SEQ_PUT_HEX_FIELD_RET(s, field->next_cpu);
1008         SEQ_PUT_HEX_FIELD_RET(s, field->next_pid);
1009         SEQ_PUT_HEX_FIELD_RET(s, field->next_prio);
1010         SEQ_PUT_HEX_FIELD_RET(s, T);
1011
1012         return TRACE_TYPE_HANDLED;
1013 }
1014
1015 static enum print_line_t trace_ctx_hex(struct trace_iterator *iter, int flags,
1016                                        struct trace_event *event)
1017 {
1018         return trace_ctxwake_hex(iter, 0);
1019 }
1020
1021 static enum print_line_t trace_wake_hex(struct trace_iterator *iter, int flags,
1022                                         struct trace_event *event)
1023 {
1024         return trace_ctxwake_hex(iter, '+');
1025 }
1026
1027 static enum print_line_t trace_ctxwake_bin(struct trace_iterator *iter,
1028                                            int flags, struct trace_event *event)
1029 {
1030         struct ctx_switch_entry *field;
1031         struct trace_seq *s = &iter->seq;
1032
1033         trace_assign_type(field, iter->ent);
1034
1035         SEQ_PUT_FIELD_RET(s, field->prev_pid);
1036         SEQ_PUT_FIELD_RET(s, field->prev_prio);
1037         SEQ_PUT_FIELD_RET(s, field->prev_state);
1038         SEQ_PUT_FIELD_RET(s, field->next_pid);
1039         SEQ_PUT_FIELD_RET(s, field->next_prio);
1040         SEQ_PUT_FIELD_RET(s, field->next_state);
1041
1042         return TRACE_TYPE_HANDLED;
1043 }
1044
1045 static struct trace_event_functions trace_ctx_funcs = {
1046         .trace          = trace_ctx_print,
1047         .raw            = trace_ctx_raw,
1048         .hex            = trace_ctx_hex,
1049         .binary         = trace_ctxwake_bin,
1050 };
1051
1052 static struct trace_event trace_ctx_event = {
1053         .type           = TRACE_CTX,
1054         .funcs          = &trace_ctx_funcs,
1055 };
1056
1057 static struct trace_event_functions trace_wake_funcs = {
1058         .trace          = trace_wake_print,
1059         .raw            = trace_wake_raw,
1060         .hex            = trace_wake_hex,
1061         .binary         = trace_ctxwake_bin,
1062 };
1063
1064 static struct trace_event trace_wake_event = {
1065         .type           = TRACE_WAKE,
1066         .funcs          = &trace_wake_funcs,
1067 };
1068
1069 /* TRACE_STACK */
1070
1071 static enum print_line_t trace_stack_print(struct trace_iterator *iter,
1072                                            int flags, struct trace_event *event)
1073 {
1074         struct stack_entry *field;
1075         struct trace_seq *s = &iter->seq;
1076         int i;
1077
1078         trace_assign_type(field, iter->ent);
1079
1080         if (!trace_seq_puts(s, "<stack trace>\n"))
1081                 goto partial;
1082         for (i = 0; i < FTRACE_STACK_ENTRIES; i++) {
1083                 if (!field->caller[i] || (field->caller[i] == ULONG_MAX))
1084                         break;
1085                 if (!trace_seq_puts(s, " => "))
1086                         goto partial;
1087
1088                 if (!seq_print_ip_sym(s, field->caller[i], flags))
1089                         goto partial;
1090                 if (!trace_seq_puts(s, "\n"))
1091                         goto partial;
1092         }
1093
1094         return TRACE_TYPE_HANDLED;
1095
1096  partial:
1097         return TRACE_TYPE_PARTIAL_LINE;
1098 }
1099
1100 static struct trace_event_functions trace_stack_funcs = {
1101         .trace          = trace_stack_print,
1102 };
1103
1104 static struct trace_event trace_stack_event = {
1105         .type           = TRACE_STACK,
1106         .funcs          = &trace_stack_funcs,
1107 };
1108
1109 /* TRACE_USER_STACK */
1110 static enum print_line_t trace_user_stack_print(struct trace_iterator *iter,
1111                                                 int flags, struct trace_event *event)
1112 {
1113         struct userstack_entry *field;
1114         struct trace_seq *s = &iter->seq;
1115
1116         trace_assign_type(field, iter->ent);
1117
1118         if (!trace_seq_puts(s, "<user stack trace>\n"))
1119                 goto partial;
1120
1121         if (!seq_print_userip_objs(field, s, flags))
1122                 goto partial;
1123
1124         return TRACE_TYPE_HANDLED;
1125
1126  partial:
1127         return TRACE_TYPE_PARTIAL_LINE;
1128 }
1129
1130 static struct trace_event_functions trace_user_stack_funcs = {
1131         .trace          = trace_user_stack_print,
1132 };
1133
1134 static struct trace_event trace_user_stack_event = {
1135         .type           = TRACE_USER_STACK,
1136         .funcs          = &trace_user_stack_funcs,
1137 };
1138
1139 /* TRACE_BPRINT */
1140 static enum print_line_t
1141 trace_bprint_print(struct trace_iterator *iter, int flags,
1142                    struct trace_event *event)
1143 {
1144         struct trace_entry *entry = iter->ent;
1145         struct trace_seq *s = &iter->seq;
1146         struct bprint_entry *field;
1147
1148         trace_assign_type(field, entry);
1149
1150         if (!seq_print_ip_sym(s, field->ip, flags))
1151                 goto partial;
1152
1153         if (!trace_seq_puts(s, ": "))
1154                 goto partial;
1155
1156         if (!trace_seq_bprintf(s, field->fmt, field->buf))
1157                 goto partial;
1158
1159         return TRACE_TYPE_HANDLED;
1160
1161  partial:
1162         return TRACE_TYPE_PARTIAL_LINE;
1163 }
1164
1165
1166 static enum print_line_t
1167 trace_bprint_raw(struct trace_iterator *iter, int flags,
1168                  struct trace_event *event)
1169 {
1170         struct bprint_entry *field;
1171         struct trace_seq *s = &iter->seq;
1172
1173         trace_assign_type(field, iter->ent);
1174
1175         if (!trace_seq_printf(s, ": %lx : ", field->ip))
1176                 goto partial;
1177
1178         if (!trace_seq_bprintf(s, field->fmt, field->buf))
1179                 goto partial;
1180
1181         return TRACE_TYPE_HANDLED;
1182
1183  partial:
1184         return TRACE_TYPE_PARTIAL_LINE;
1185 }
1186
1187 static struct trace_event_functions trace_bprint_funcs = {
1188         .trace          = trace_bprint_print,
1189         .raw            = trace_bprint_raw,
1190 };
1191
1192 static struct trace_event trace_bprint_event = {
1193         .type           = TRACE_BPRINT,
1194         .funcs          = &trace_bprint_funcs,
1195 };
1196
1197 /* TRACE_PRINT */
1198 static enum print_line_t trace_print_print(struct trace_iterator *iter,
1199                                            int flags, struct trace_event *event)
1200 {
1201         struct print_entry *field;
1202         struct trace_seq *s = &iter->seq;
1203
1204         trace_assign_type(field, iter->ent);
1205
1206         if (!seq_print_ip_sym(s, field->ip, flags))
1207                 goto partial;
1208
1209         if (!trace_seq_printf(s, ": %s", field->buf))
1210                 goto partial;
1211
1212         return TRACE_TYPE_HANDLED;
1213
1214  partial:
1215         return TRACE_TYPE_PARTIAL_LINE;
1216 }
1217
1218 static enum print_line_t trace_print_raw(struct trace_iterator *iter, int flags,
1219                                          struct trace_event *event)
1220 {
1221         struct print_entry *field;
1222
1223         trace_assign_type(field, iter->ent);
1224
1225         if (!trace_seq_printf(&iter->seq, "# %lx %s", field->ip, 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_print_funcs = {
1235         .trace          = trace_print_print,
1236         .raw            = trace_print_raw,
1237 };
1238
1239 static struct trace_event trace_print_event = {
1240         .type           = TRACE_PRINT,
1241         .funcs          = &trace_print_funcs,
1242 };
1243
1244
1245 static struct trace_event *events[] __initdata = {
1246         &trace_fn_event,
1247         &trace_ctx_event,
1248         &trace_wake_event,
1249         &trace_stack_event,
1250         &trace_user_stack_event,
1251         &trace_bprint_event,
1252         &trace_print_event,
1253         NULL
1254 };
1255
1256 __init static int init_events(void)
1257 {
1258         struct trace_event *event;
1259         int i, ret;
1260
1261         for (i = 0; events[i]; i++) {
1262                 event = events[i];
1263
1264                 ret = register_ftrace_event(event);
1265                 if (!ret) {
1266                         printk(KERN_WARNING "event %d failed to register\n",
1267                                event->type);
1268                         WARN_ON_ONCE(1);
1269                 }
1270         }
1271
1272         return 0;
1273 }
1274 device_initcall(init_events);