Pileus Git - ~andy/linux/blob - 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 DEFINE_PER_CPU(struct trace_seq, ftrace_event_seq);
  20 EXPORT_PER_CPU_SYMBOL(ftrace_event_seq);
  21
  22 static struct hlist_head event_hash[EVENT_HASHSIZE] __read_mostly;
  23
  24 static int next_event_type = __TRACE_LAST_TYPE + 1;
  25
  26 int trace_print_seq(struct seq_file *m, struct trace_seq *s)
  27 {
  28         int len = s->len >= PAGE_SIZE ? PAGE_SIZE - 1 : s->len;
  29         int ret;
  30
  31         ret = seq_write(m, s->buffer, len);
  32
  33         /*
  34          * Only reset this buffer if we successfully wrote to the
  35          * seq_file buffer.
  36          */
  37         if (!ret)
  38                 trace_seq_init(s);
  39
  40         return ret;
  41 }
  42
  43 enum print_line_t trace_print_bprintk_msg_only(struct trace_iterator *iter)
  44 {
  45         struct trace_seq *s = &iter->seq;
  46         struct trace_entry *entry = iter->ent;
  47         struct bprint_entry *field;
  48         int ret;
  49
  50         trace_assign_type(field, entry);
  51
  52         ret = trace_seq_bprintf(s, field->fmt, field->buf);
  53         if (!ret)
  54                 return TRACE_TYPE_PARTIAL_LINE;
  55
  56         return TRACE_TYPE_HANDLED;
  57 }
  58
  59 enum print_line_t trace_print_printk_msg_only(struct trace_iterator *iter)
  60 {
  61         struct trace_seq *s = &iter->seq;
  62         struct trace_entry *entry = iter->ent;
  63         struct print_entry *field;
  64         int ret;
  65
  66         trace_assign_type(field, entry);
  67
  68         ret = trace_seq_printf(s, "%s", field->buf);
  69         if (!ret)
  70                 return TRACE_TYPE_PARTIAL_LINE;
  71
  72         return TRACE_TYPE_HANDLED;
  73 }
  74
  75 /**
  76  * trace_seq_printf - sequence printing of trace information
  77  * @s: trace sequence descriptor
  78  * @fmt: printf format string
  79  *
  80  * It returns 0 if the trace oversizes the buffer's free
  81  * space, 1 otherwise.
  82  *
  83  * The tracer may use either sequence operations or its own
  84  * copy to user routines. To simplify formating of a trace
  85  * trace_seq_printf is used to store strings into a special
  86  * buffer (@s). Then the output may be either used by
  87  * the sequencer or pulled into another buffer.
  88  */
  89 int
  90 trace_seq_printf(struct trace_seq *s, const char *fmt, ...)
  91 {
  92         int len = (PAGE_SIZE - 1) - s->len;
  93         va_list ap;
  94         int ret;
  95
  96         if (s->full || !len)
  97                 return 0;
  98
  99         va_start(ap, fmt);
 100         ret = vsnprintf(s->buffer + s->len, len, fmt, ap);
 101         va_end(ap);
 102
 103         /* If we can't write it all, don't bother writing anything */
 104         if (ret >= len) {
 105                 s->full = 1;
 106                 return 0;
 107         }
 108
 109         s->len += ret;
 110
 111         return 1;
 112 }
 113 EXPORT_SYMBOL_GPL(trace_seq_printf);
 114
 115 /**
 116  * trace_seq_vprintf - sequence printing of trace information
 117  * @s: trace sequence descriptor
 118  * @fmt: printf format string
 119  *
 120  * The tracer may use either sequence operations or its own
 121  * copy to user routines. To simplify formating of a trace
 122  * trace_seq_printf is used to store strings into a special
 123  * buffer (@s). Then the output may be either used by
 124  * the sequencer or pulled into another buffer.
 125  */
 126 int
 127 trace_seq_vprintf(struct trace_seq *s, const char *fmt, va_list args)
 128 {
 129         int len = (PAGE_SIZE - 1) - s->len;
 130         int ret;
 131
 132         if (s->full || !len)
 133                 return 0;
 134
 135         ret = vsnprintf(s->buffer + s->len, len, fmt, args);
 136
 137         /* If we can't write it all, don't bother writing anything */
 138         if (ret >= len) {
 139                 s->full = 1;
 140                 return 0;
 141         }
 142
 143         s->len += ret;
 144
 145         return len;
 146 }
 147 EXPORT_SYMBOL_GPL(trace_seq_vprintf);
 148
 149 int trace_seq_bprintf(struct trace_seq *s, const char *fmt, const u32 *binary)
 150 {
 151         int len = (PAGE_SIZE - 1) - s->len;
 152         int ret;
 153
 154         if (s->full || !len)
 155                 return 0;
 156
 157         ret = bstr_printf(s->buffer + s->len, len, fmt, binary);
 158
 159         /* If we can't write it all, don't bother writing anything */
 160         if (ret >= len) {
 161                 s->full = 1;
 162                 return 0;
 163         }
 164
 165         s->len += ret;
 166
 167         return len;
 168 }
 169
 170 /**
 171  * trace_seq_puts - trace sequence printing of simple string
 172  * @s: trace sequence descriptor
 173  * @str: simple string to record
 174  *
 175  * The tracer may use either the sequence operations or its own
 176  * copy to user routines. This function records a simple string
 177  * into a special buffer (@s) for later retrieval by a sequencer
 178  * or other mechanism.
 179  */
 180 int trace_seq_puts(struct trace_seq *s, const char *str)
 181 {
 182         int len = strlen(str);
 183
 184         if (s->full)
 185                 return 0;
 186
 187         if (len > ((PAGE_SIZE - 1) - s->len)) {
 188                 s->full = 1;
 189                 return 0;
 190         }
 191
 192         memcpy(s->buffer + s->len, str, len);
 193         s->len += len;
 194
 195         return len;
 196 }
 197
 198 int trace_seq_putc(struct trace_seq *s, unsigned char c)
 199 {
 200         if (s->full)
 201                 return 0;
 202
 203         if (s->len >= (PAGE_SIZE - 1)) {
 204                 s->full = 1;
 205                 return 0;
 206         }
 207
 208         s->buffer[s->len++] = c;
 209
 210         return 1;
 211 }
 212
 213 int trace_seq_putmem(struct trace_seq *s, const void *mem, size_t len)
 214 {
 215         if (s->full)
 216                 return 0;
 217
 218         if (len > ((PAGE_SIZE - 1) - s->len)) {
 219                 s->full = 1;
 220                 return 0;
 221         }
 222
 223         memcpy(s->buffer + s->len, mem, len);
 224         s->len += len;
 225
 226         return len;
 227 }
 228
 229 int trace_seq_putmem_hex(struct trace_seq *s, const void *mem, size_t len)
 230 {
 231         unsigned char hex[HEX_CHARS];
 232         const unsigned char *data = mem;
 233         int i, j;
 234
 235         if (s->full)
 236                 return 0;
 237
 238 #ifdef __BIG_ENDIAN
 239         for (i = 0, j = 0; i < len; i++) {
 240 #else
 241         for (i = len-1, j = 0; i >= 0; i--) {
 242 #endif
 243                 hex[j++] = hex_asc_hi(data[i]);
 244                 hex[j++] = hex_asc_lo(data[i]);
 245         }
 246         hex[j++] = ' ';
 247
 248         return trace_seq_putmem(s, hex, j);
 249 }
 250
 251 void *trace_seq_reserve(struct trace_seq *s, size_t len)
 252 {
 253         void *ret;
 254
 255         if (s->full)
 256                 return 0;
 257
 258         if (len > ((PAGE_SIZE - 1) - s->len)) {
 259                 s->full = 1;
 260                 return NULL;
 261         }
 262
 263         ret = s->buffer + s->len;
 264         s->len += len;
 265
 266         return ret;
 267 }
 268
 269 int trace_seq_path(struct trace_seq *s, struct path *path)
 270 {
 271         unsigned char *p;
 272
 273         if (s->full)
 274                 return 0;
 275
 276         if (s->len >= (PAGE_SIZE - 1)) {
 277                 s->full = 1;
 278                 return 0;
 279         }
 280
 281         p = d_path(path, s->buffer + s->len, PAGE_SIZE - s->len);
 282         if (!IS_ERR(p)) {
 283                 p = mangle_path(s->buffer + s->len, p, "\n");
 284                 if (p) {
 285                         s->len = p - s->buffer;
 286                         return 1;
 287                 }
 288         } else {
 289                 s->buffer[s->len++] = '?';
 290                 return 1;
 291         }
 292
 293         s->full = 1;
 294         return 0;
 295 }
 296
 297 const char *
 298 ftrace_print_flags_seq(struct trace_seq *p, const char *delim,
 299                        unsigned long flags,
 300                        const struct trace_print_flags *flag_array)
 301 {
 302         unsigned long mask;
 303         const char *str;
 304         const char *ret = p->buffer + p->len;
 305         int i;
 306
 307         for (i = 0;  flag_array[i].name && flags; i++) {
 308
 309                 mask = flag_array[i].mask;
 310                 if ((flags & mask) != mask)
 311                         continue;
 312
 313                 str = flag_array[i].name;
 314                 flags &= ~mask;
 315                 if (p->len && delim)
 316                         trace_seq_puts(p, delim);
 317                 trace_seq_puts(p, str);
 318         }
 319
 320         /* check for left over flags */
 321         if (flags) {
 322                 if (p->len && delim)
 323                         trace_seq_puts(p, delim);
 324                 trace_seq_printf(p, "0x%lx", flags);
 325         }
 326
 327         trace_seq_putc(p, 0);
 328
 329         return ret;
 330 }
 331 EXPORT_SYMBOL(ftrace_print_flags_seq);
 332
 333 const char *
 334 ftrace_print_symbols_seq(struct trace_seq *p, unsigned long val,
 335                          const struct trace_print_flags *symbol_array)
 336 {
 337         int i;
 338         const char *ret = p->buffer + p->len;
 339
 340         for (i = 0;  symbol_array[i].name; i++) {
 341
 342                 if (val != symbol_array[i].mask)
 343                         continue;
 344
 345                 trace_seq_puts(p, symbol_array[i].name);
 346                 break;
 347         }
 348
 349         if (!p->len)
 350                 trace_seq_printf(p, "0x%lx", val);
 351
 352         trace_seq_putc(p, 0);
 353
 354         return ret;
 355 }
 356 EXPORT_SYMBOL(ftrace_print_symbols_seq);
 357
 358 const char *
 359 ftrace_print_hex_seq(struct trace_seq *p, const unsigned char *buf, int buf_len)
 360 {
 361         int i;
 362         const char *ret = p->buffer + p->len;
 363
 364         for (i = 0; i < buf_len; i++)
 365                 trace_seq_printf(p, "%s%2.2x", i == 0 ? "" : " ", buf[i]);
 366
 367         trace_seq_putc(p, 0);
 368
 369         return ret;
 370 }
 371 EXPORT_SYMBOL(ftrace_print_hex_seq);
 372
 373 #ifdef CONFIG_KRETPROBES
 374 static inline const char *kretprobed(const char *name)
 375 {
 376         static const char tramp_name[] = "kretprobe_trampoline";
 377         int size = sizeof(tramp_name);
 378
 379         if (strncmp(tramp_name, name, size) == 0)
 380                 return "[unknown/kretprobe'd]";
 381         return name;
 382 }
 383 #else
 384 static inline const char *kretprobed(const char *name)
 385 {
 386         return name;
 387 }
 388 #endif /* CONFIG_KRETPROBES */
 389
 390 static int
 391 seq_print_sym_short(struct trace_seq *s, const char *fmt, unsigned long address)
 392 {
 393 #ifdef CONFIG_KALLSYMS
 394         char str[KSYM_SYMBOL_LEN];
 395         const char *name;
 396
 397         kallsyms_lookup(address, NULL, NULL, NULL, str);
 398
 399         name = kretprobed(str);
 400
 401         return trace_seq_printf(s, fmt, name);
 402 #endif
 403         return 1;
 404 }
 405
 406 static int
 407 seq_print_sym_offset(struct trace_seq *s, const char *fmt,
 408                      unsigned long address)
 409 {
 410 #ifdef CONFIG_KALLSYMS
 411         char str[KSYM_SYMBOL_LEN];
 412         const char *name;
 413
 414         sprint_symbol(str, address);
 415         name = kretprobed(str);
 416
 417         return trace_seq_printf(s, fmt, name);
 418 #endif
 419         return 1;
 420 }
 421
 422 #ifndef CONFIG_64BIT
 423 # define IP_FMT "%08lx"
 424 #else
 425 # define IP_FMT "%016lx"
 426 #endif
 427
 428 int seq_print_user_ip(struct trace_seq *s, struct mm_struct *mm,
 429                       unsigned long ip, unsigned long sym_flags)
 430 {
 431         struct file *file = NULL;
 432         unsigned long vmstart = 0;
 433         int ret = 1;
 434
 435         if (s->full)
 436                 return 0;
 437
 438         if (mm) {
 439                 const struct vm_area_struct *vma;
 440
 441                 down_read(&mm->mmap_sem);
 442                 vma = find_vma(mm, ip);
 443                 if (vma) {
 444                         file = vma->vm_file;
 445                         vmstart = vma->vm_start;
 446                 }
 447                 if (file) {
 448                         ret = trace_seq_path(s, &file->f_path);
 449                         if (ret)
 450                                 ret = trace_seq_printf(s, "[+0x%lx]",
 451                                                        ip - vmstart);
 452                 }
 453                 up_read(&mm->mmap_sem);
 454         }
 455         if (ret && ((sym_flags & TRACE_ITER_SYM_ADDR) || !file))
 456                 ret = trace_seq_printf(s, " <" IP_FMT ">", ip);
 457         return ret;
 458 }
 459
 460 int
 461 seq_print_userip_objs(const struct userstack_entry *entry, struct trace_seq *s,
 462                       unsigned long sym_flags)
 463 {
 464         struct mm_struct *mm = NULL;
 465         int ret = 1;
 466         unsigned int i;
 467
 468         if (trace_flags & TRACE_ITER_SYM_USEROBJ) {
 469                 struct task_struct *task;
 470                 /*
 471                  * we do the lookup on the thread group leader,
 472                  * since individual threads might have already quit!
 473                  */
 474                 rcu_read_lock();
 475                 task = find_task_by_vpid(entry->tgid);
 476                 if (task)
 477                         mm = get_task_mm(task);
 478                 rcu_read_unlock();
 479         }
 480
 481         for (i = 0; i < FTRACE_STACK_ENTRIES; i++) {
 482                 unsigned long ip = entry->caller[i];
 483
 484                 if (ip == ULONG_MAX || !ret)
 485                         break;
 486                 if (ret)
 487                         ret = trace_seq_puts(s, " => ");
 488                 if (!ip) {
 489                         if (ret)
 490                                 ret = trace_seq_puts(s, "??");
 491                         if (ret)
 492                                 ret = trace_seq_puts(s, "\n");
 493                         continue;
 494                 }
 495                 if (!ret)
 496                         break;
 497                 if (ret)
 498                         ret = seq_print_user_ip(s, mm, ip, sym_flags);
 499                 ret = trace_seq_puts(s, "\n");
 500         }
 501
 502         if (mm)
 503                 mmput(mm);
 504         return ret;
 505 }
 506
 507 int
 508 seq_print_ip_sym(struct trace_seq *s, unsigned long ip, unsigned long sym_flags)
 509 {
 510         int ret;
 511
 512         if (!ip)
 513                 return trace_seq_printf(s, "0");
 514
 515         if (sym_flags & TRACE_ITER_SYM_OFFSET)
 516                 ret = seq_print_sym_offset(s, "%s", ip);
 517         else
 518                 ret = seq_print_sym_short(s, "%s", ip);
 519
 520         if (!ret)
 521                 return 0;
 522
 523         if (sym_flags & TRACE_ITER_SYM_ADDR)
 524                 ret = trace_seq_printf(s, " <" IP_FMT ">", ip);
 525         return ret;
 526 }
 527
 528 /**
 529  * trace_print_lat_fmt - print the irq, preempt and lockdep fields
 530  * @s: trace seq struct to write to
 531  * @entry: The trace entry field from the ring buffer
 532  *
 533  * Prints the generic fields of irqs off, in hard or softirq, preempt
 534  * count and lock depth.
 535  */
 536 int trace_print_lat_fmt(struct trace_seq *s, struct trace_entry *entry)
 537 {
 538         int hardirq, softirq;
 539         int ret;
 540
 541         hardirq = entry->flags & TRACE_FLAG_HARDIRQ;
 542         softirq = entry->flags & TRACE_FLAG_SOFTIRQ;
 543
 544         if (!trace_seq_printf(s, "%c%c%c",
 545                               (entry->flags & TRACE_FLAG_IRQS_OFF) ? 'd' :
 546                                 (entry->flags & TRACE_FLAG_IRQS_NOSUPPORT) ?
 547                                   'X' : '.',
 548                               (entry->flags & TRACE_FLAG_NEED_RESCHED) ?
 549                                 'N' : '.',
 550                               (hardirq && softirq) ? 'H' :
 551                                 hardirq ? 'h' : softirq ? 's' : '.'))
 552                 return 0;
 553
 554         if (entry->preempt_count)
 555                 ret = trace_seq_printf(s, "%x", entry->preempt_count);
 556         else
 557                 ret = trace_seq_putc(s, '.');
 558
 559         if (!ret)
 560                 return 0;
 561
 562         if (entry->lock_depth < 0)
 563                 return trace_seq_putc(s, '.');
 564
 565         return trace_seq_printf(s, "%d", entry->lock_depth);
 566 }
 567
 568 static int
 569 lat_print_generic(struct trace_seq *s, struct trace_entry *entry, int cpu)
 570 {
 571         char comm[TASK_COMM_LEN];
 572
 573         trace_find_cmdline(entry->pid, comm);
 574
 575         if (!trace_seq_printf(s, "%8.8s-%-5d %3d",
 576                               comm, entry->pid, cpu))
 577                 return 0;
 578
 579         return trace_print_lat_fmt(s, entry);
 580 }
 581
 582 static unsigned long preempt_mark_thresh = 100;
 583
 584 static int
 585 lat_print_timestamp(struct trace_seq *s, u64 abs_usecs,
 586                     unsigned long rel_usecs)
 587 {
 588         return trace_seq_printf(s, " %4lldus%c: ", abs_usecs,
 589                                 rel_usecs > preempt_mark_thresh ? '!' :
 590                                   rel_usecs > 1 ? '+' : ' ');
 591 }
 592
 593 int trace_print_context(struct trace_iterator *iter)
 594 {
 595         struct trace_seq *s = &iter->seq;
 596         struct trace_entry *entry = iter->ent;
 597         unsigned long long t = ns2usecs(iter->ts);
 598         unsigned long usec_rem = do_div(t, USEC_PER_SEC);
 599         unsigned long secs = (unsigned long)t;
 600         char comm[TASK_COMM_LEN];
 601
 602         trace_find_cmdline(entry->pid, comm);
 603
 604         return trace_seq_printf(s, "%16s-%-5d [%03d] %5lu.%06lu: ",
 605                                 comm, entry->pid, iter->cpu, secs, usec_rem);
 606 }
 607
 608 int trace_print_lat_context(struct trace_iterator *iter)
 609 {
 610         u64 next_ts;
 611         int ret;
 612         struct trace_seq *s = &iter->seq;
 613         struct trace_entry *entry = iter->ent,
 614                            *next_entry = trace_find_next_entry(iter, NULL,
 615                                                                &next_ts);
 616         unsigned long verbose = (trace_flags & TRACE_ITER_VERBOSE);
 617         unsigned long abs_usecs = ns2usecs(iter->ts - iter->tr->time_start);
 618         unsigned long rel_usecs;
 619
 620         if (!next_entry)
 621                 next_ts = iter->ts;
 622         rel_usecs = ns2usecs(next_ts - iter->ts);
 623
 624         if (verbose) {
 625                 char comm[TASK_COMM_LEN];
 626
 627                 trace_find_cmdline(entry->pid, comm);
 628
 629                 ret = trace_seq_printf(s, "%16s %5d %3d %d %08x %08lx [%08llx]"
 630                                        " %ld.%03ldms (+%ld.%03ldms): ", comm,
 631                                        entry->pid, iter->cpu, entry->flags,
 632                                        entry->preempt_count, iter->idx,
 633                                        ns2usecs(iter->ts),
 634                                        abs_usecs / USEC_PER_MSEC,
 635                                        abs_usecs % USEC_PER_MSEC,
 636                                        rel_usecs / USEC_PER_MSEC,
 637                                        rel_usecs % USEC_PER_MSEC);
 638         } else {
 639                 ret = lat_print_generic(s, entry, iter->cpu);
 640                 if (ret)
 641                         ret = lat_print_timestamp(s, abs_usecs, rel_usecs);
 642         }
 643
 644         return ret;
 645 }
 646
 647 static const char state_to_char[] = TASK_STATE_TO_CHAR_STR;
 648
 649 static int task_state_char(unsigned long state)
 650 {
 651         int bit = state ? __ffs(state) + 1 : 0;
 652
 653         return bit < sizeof(state_to_char) - 1 ? state_to_char[bit] : '?';
 654 }
 655
 656 /**
 657  * ftrace_find_event - find a registered event
 658  * @type: the type of event to look for
 659  *
 660  * Returns an event of type @type otherwise NULL
 661  * Called with trace_event_read_lock() held.
 662  */
 663 struct trace_event *ftrace_find_event(int type)
 664 {
 665         struct trace_event *event;
 666         struct hlist_node *n;
 667         unsigned key;
 668
 669         key = type & (EVENT_HASHSIZE - 1);
 670
 671         hlist_for_each_entry(event, n, &event_hash[key], node) {
 672                 if (event->type == type)
 673                         return event;
 674         }
 675
 676         return NULL;
 677 }
 678
 679 static LIST_HEAD(ftrace_event_list);
 680
 681 static int trace_search_list(struct list_head **list)
 682 {
 683         struct trace_event *e;
 684         int last = __TRACE_LAST_TYPE;
 685
 686         if (list_empty(&ftrace_event_list)) {
 687                 *list = &ftrace_event_list;
 688                 return last + 1;
 689         }
 690
 691         /*
 692          * We used up all possible max events,
 693          * lets see if somebody freed one.
 694          */
 695         list_for_each_entry(e, &ftrace_event_list, list) {
 696                 if (e->type != last + 1)
 697                         break;
 698                 last++;
 699         }
 700
 701         /* Did we used up all 65 thousand events??? */
 702         if ((last + 1) > FTRACE_MAX_EVENT)
 703                 return 0;
 704
 705         *list = &e->list;
 706         return last + 1;
 707 }
 708
 709 void trace_event_read_lock(void)
 710 {
 711         down_read(&trace_event_mutex);
 712 }
 713
 714 void trace_event_read_unlock(void)
 715 {
 716         up_read(&trace_event_mutex);
 717 }
 718
 719 /**
 720  * register_ftrace_event - register output for an event type
 721  * @event: the event type to register
 722  *
 723  * Event types are stored in a hash and this hash is used to
 724  * find a way to print an event. If the @event->type is set
 725  * then it will use that type, otherwise it will assign a
 726  * type to use.
 727  *
 728  * If you assign your own type, please make sure it is added
 729  * to the trace_type enum in trace.h, to avoid collisions
 730  * with the dynamic types.
 731  *
 732  * Returns the event type number or zero on error.
 733  */
 734 int register_ftrace_event(struct trace_event *event)
 735 {
 736         unsigned key;
 737         int ret = 0;
 738
 739         down_write(&trace_event_mutex);
 740
 741         if (WARN_ON(!event))
 742                 goto out;
 743
 744         INIT_LIST_HEAD(&event->list);
 745
 746         if (!event->type) {
 747                 struct list_head *list = NULL;
 748
 749                 if (next_event_type > FTRACE_MAX_EVENT) {
 750
 751                         event->type = trace_search_list(&list);
 752                         if (!event->type)
 753                                 goto out;
 754
 755                 } else {
 756
 757                         event->type = next_event_type++;
 758                         list = &ftrace_event_list;
 759                 }
 760
 761                 if (WARN_ON(ftrace_find_event(event->type)))
 762                         goto out;
 763
 764                 list_add_tail(&event->list, list);
 765
 766         } else if (event->type > __TRACE_LAST_TYPE) {
 767                 printk(KERN_WARNING "Need to add type to trace.h\n");
 768                 WARN_ON(1);
 769                 goto out;
 770         } else {
 771                 /* Is this event already used */
 772                 if (ftrace_find_event(event->type))
 773                         goto out;
 774         }
 775
 776         if (event->trace == NULL)
 777                 event->trace = trace_nop_print;
 778         if (event->raw == NULL)
 779                 event->raw = trace_nop_print;
 780         if (event->hex == NULL)
 781                 event->hex = trace_nop_print;
 782         if (event->binary == NULL)
 783                 event->binary = trace_nop_print;
 784
 785         key = event->type & (EVENT_HASHSIZE - 1);
 786
 787         hlist_add_head(&event->node, &event_hash[key]);
 788
 789         ret = event->type;
 790  out:
 791         up_write(&trace_event_mutex);
 792
 793         return ret;
 794 }
 795 EXPORT_SYMBOL_GPL(register_ftrace_event);
 796
 797 /*
 798  * Used by module code with the trace_event_mutex held for write.
 799  */
 800 int __unregister_ftrace_event(struct trace_event *event)
 801 {
 802         hlist_del(&event->node);
 803         list_del(&event->list);
 804         return 0;
 805 }
 806
 807 /**
 808  * unregister_ftrace_event - remove a no longer used event
 809  * @event: the event to remove
 810  */
 811 int unregister_ftrace_event(struct trace_event *event)
 812 {
 813         down_write(&trace_event_mutex);
 814         __unregister_ftrace_event(event);
 815         up_write(&trace_event_mutex);
 816
 817         return 0;
 818 }
 819 EXPORT_SYMBOL_GPL(unregister_ftrace_event);
 820
 821 /*
 822  * Standard events
 823  */
 824
 825 enum print_line_t trace_nop_print(struct trace_iterator *iter, int flags)
 826 {
 827         return TRACE_TYPE_HANDLED;
 828 }
 829
 830 /* TRACE_FN */
 831 static enum print_line_t trace_fn_trace(struct trace_iterator *iter, int flags)
 832 {
 833         struct ftrace_entry *field;
 834         struct trace_seq *s = &iter->seq;
 835
 836         trace_assign_type(field, iter->ent);
 837
 838         if (!seq_print_ip_sym(s, field->ip, flags))
 839                 goto partial;
 840
 841         if ((flags & TRACE_ITER_PRINT_PARENT) && field->parent_ip) {
 842                 if (!trace_seq_printf(s, " <-"))
 843                         goto partial;
 844                 if (!seq_print_ip_sym(s,
 845                                       field->parent_ip,
 846                                       flags))
 847                         goto partial;
 848         }
 849         if (!trace_seq_printf(s, "\n"))
 850                 goto partial;
 851
 852         return TRACE_TYPE_HANDLED;
 853
 854  partial:
 855         return TRACE_TYPE_PARTIAL_LINE;
 856 }
 857
 858 static enum print_line_t trace_fn_raw(struct trace_iterator *iter, int flags)
 859 {
 860         struct ftrace_entry *field;
 861
 862         trace_assign_type(field, iter->ent);
 863
 864         if (!trace_seq_printf(&iter->seq, "%lx %lx\n",
 865                               field->ip,
 866                               field->parent_ip))
 867                 return TRACE_TYPE_PARTIAL_LINE;
 868
 869         return TRACE_TYPE_HANDLED;
 870 }
 871
 872 static enum print_line_t trace_fn_hex(struct trace_iterator *iter, int flags)
 873 {
 874         struct ftrace_entry *field;
 875         struct trace_seq *s = &iter->seq;
 876
 877         trace_assign_type(field, iter->ent);
 878
 879         SEQ_PUT_HEX_FIELD_RET(s, field->ip);
 880         SEQ_PUT_HEX_FIELD_RET(s, field->parent_ip);
 881
 882         return TRACE_TYPE_HANDLED;
 883 }
 884
 885 static enum print_line_t trace_fn_bin(struct trace_iterator *iter, int flags)
 886 {
 887         struct ftrace_entry *field;
 888         struct trace_seq *s = &iter->seq;
 889
 890         trace_assign_type(field, iter->ent);
 891
 892         SEQ_PUT_FIELD_RET(s, field->ip);
 893         SEQ_PUT_FIELD_RET(s, field->parent_ip);
 894
 895         return TRACE_TYPE_HANDLED;
 896 }
 897
 898 static struct trace_event trace_fn_event = {
 899         .type           = TRACE_FN,
 900         .trace          = trace_fn_trace,
 901         .raw            = trace_fn_raw,
 902         .hex            = trace_fn_hex,
 903         .binary         = trace_fn_bin,
 904 };
 905
 906 /* TRACE_CTX an TRACE_WAKE */
 907 static enum print_line_t trace_ctxwake_print(struct trace_iterator *iter,
 908                                              char *delim)
 909 {
 910         struct ctx_switch_entry *field;
 911         char comm[TASK_COMM_LEN];
 912         int S, T;
 913
 914
 915         trace_assign_type(field, iter->ent);
 916
 917         T = task_state_char(field->next_state);
 918         S = task_state_char(field->prev_state);
 919         trace_find_cmdline(field->next_pid, comm);
 920         if (!trace_seq_printf(&iter->seq,
 921                               " %5d:%3d:%c %s [%03d] %5d:%3d:%c %s\n",
 922                               field->prev_pid,
 923                               field->prev_prio,
 924                               S, delim,
 925                               field->next_cpu,
 926                               field->next_pid,
 927                               field->next_prio,
 928                               T, comm))
 929                 return TRACE_TYPE_PARTIAL_LINE;
 930
 931         return TRACE_TYPE_HANDLED;
 932 }
 933
 934 static enum print_line_t trace_ctx_print(struct trace_iterator *iter, int flags)
 935 {
 936         return trace_ctxwake_print(iter, "==>");
 937 }
 938
 939 static enum print_line_t trace_wake_print(struct trace_iterator *iter,
 940                                           int flags)
 941 {
 942         return trace_ctxwake_print(iter, "  +");
 943 }
 944
 945 static int trace_ctxwake_raw(struct trace_iterator *iter, char S)
 946 {
 947         struct ctx_switch_entry *field;
 948         int T;
 949
 950         trace_assign_type(field, iter->ent);
 951
 952         if (!S)
 953                 S = task_state_char(field->prev_state);
 954         T = task_state_char(field->next_state);
 955         if (!trace_seq_printf(&iter->seq, "%d %d %c %d %d %d %c\n",
 956                               field->prev_pid,
 957                               field->prev_prio,
 958                               S,
 959                               field->next_cpu,
 960                               field->next_pid,
 961                               field->next_prio,
 962                               T))
 963                 return TRACE_TYPE_PARTIAL_LINE;
 964
 965         return TRACE_TYPE_HANDLED;
 966 }
 967
 968 static enum print_line_t trace_ctx_raw(struct trace_iterator *iter, int flags)
 969 {
 970         return trace_ctxwake_raw(iter, 0);
 971 }
 972
 973 static enum print_line_t trace_wake_raw(struct trace_iterator *iter, int flags)
 974 {
 975         return trace_ctxwake_raw(iter, '+');
 976 }
 977
 978
 979 static int trace_ctxwake_hex(struct trace_iterator *iter, char S)
 980 {
 981         struct ctx_switch_entry *field;
 982         struct trace_seq *s = &iter->seq;
 983         int T;
 984
 985         trace_assign_type(field, iter->ent);
 986
 987         if (!S)
 988                 S = task_state_char(field->prev_state);
 989         T = task_state_char(field->next_state);
 990
 991         SEQ_PUT_HEX_FIELD_RET(s, field->prev_pid);
 992         SEQ_PUT_HEX_FIELD_RET(s, field->prev_prio);
 993         SEQ_PUT_HEX_FIELD_RET(s, S);
 994         SEQ_PUT_HEX_FIELD_RET(s, field->next_cpu);
 995         SEQ_PUT_HEX_FIELD_RET(s, field->next_pid);
 996         SEQ_PUT_HEX_FIELD_RET(s, field->next_prio);
 997         SEQ_PUT_HEX_FIELD_RET(s, T);
 998
 999         return TRACE_TYPE_HANDLED;
1000 }
1001
1002 static enum print_line_t trace_ctx_hex(struct trace_iterator *iter, int flags)
1003 {
1004         return trace_ctxwake_hex(iter, 0);
1005 }
1006
1007 static enum print_line_t trace_wake_hex(struct trace_iterator *iter, int flags)
1008 {
1009         return trace_ctxwake_hex(iter, '+');
1010 }
1011
1012 static enum print_line_t trace_ctxwake_bin(struct trace_iterator *iter,
1013                                            int flags)
1014 {
1015         struct ctx_switch_entry *field;
1016         struct trace_seq *s = &iter->seq;
1017
1018         trace_assign_type(field, iter->ent);
1019
1020         SEQ_PUT_FIELD_RET(s, field->prev_pid);
1021         SEQ_PUT_FIELD_RET(s, field->prev_prio);
1022         SEQ_PUT_FIELD_RET(s, field->prev_state);
1023         SEQ_PUT_FIELD_RET(s, field->next_pid);
1024         SEQ_PUT_FIELD_RET(s, field->next_prio);
1025         SEQ_PUT_FIELD_RET(s, field->next_state);
1026
1027         return TRACE_TYPE_HANDLED;
1028 }
1029
1030 static struct trace_event trace_ctx_event = {
1031         .type           = TRACE_CTX,
1032         .trace          = trace_ctx_print,
1033         .raw            = trace_ctx_raw,
1034         .hex            = trace_ctx_hex,
1035         .binary         = trace_ctxwake_bin,
1036 };
1037
1038 static struct trace_event trace_wake_event = {
1039         .type           = TRACE_WAKE,
1040         .trace          = trace_wake_print,
1041         .raw            = trace_wake_raw,
1042         .hex            = trace_wake_hex,
1043         .binary         = trace_ctxwake_bin,
1044 };
1045
1046 /* TRACE_SPECIAL */
1047 static enum print_line_t trace_special_print(struct trace_iterator *iter,
1048                                              int flags)
1049 {
1050         struct special_entry *field;
1051
1052         trace_assign_type(field, iter->ent);
1053
1054         if (!trace_seq_printf(&iter->seq, "# %ld %ld %ld\n",
1055                               field->arg1,
1056                               field->arg2,
1057                               field->arg3))
1058                 return TRACE_TYPE_PARTIAL_LINE;
1059
1060         return TRACE_TYPE_HANDLED;
1061 }
1062
1063 static enum print_line_t trace_special_hex(struct trace_iterator *iter,
1064                                            int flags)
1065 {
1066         struct special_entry *field;
1067         struct trace_seq *s = &iter->seq;
1068
1069         trace_assign_type(field, iter->ent);
1070
1071         SEQ_PUT_HEX_FIELD_RET(s, field->arg1);
1072         SEQ_PUT_HEX_FIELD_RET(s, field->arg2);
1073         SEQ_PUT_HEX_FIELD_RET(s, field->arg3);
1074
1075         return TRACE_TYPE_HANDLED;
1076 }
1077
1078 static enum print_line_t trace_special_bin(struct trace_iterator *iter,
1079                                            int flags)
1080 {
1081         struct special_entry *field;
1082         struct trace_seq *s = &iter->seq;
1083
1084         trace_assign_type(field, iter->ent);
1085
1086         SEQ_PUT_FIELD_RET(s, field->arg1);
1087         SEQ_PUT_FIELD_RET(s, field->arg2);
1088         SEQ_PUT_FIELD_RET(s, field->arg3);
1089
1090         return TRACE_TYPE_HANDLED;
1091 }
1092
1093 static struct trace_event trace_special_event = {
1094         .type           = TRACE_SPECIAL,
1095         .trace          = trace_special_print,
1096         .raw            = trace_special_print,
1097         .hex            = trace_special_hex,
1098         .binary         = trace_special_bin,
1099 };
1100
1101 /* TRACE_STACK */
1102
1103 static enum print_line_t trace_stack_print(struct trace_iterator *iter,
1104                                            int flags)
1105 {
1106         struct stack_entry *field;
1107         struct trace_seq *s = &iter->seq;
1108         int i;
1109
1110         trace_assign_type(field, iter->ent);
1111
1112         if (!trace_seq_puts(s, "<stack trace>\n"))
1113                 goto partial;
1114         for (i = 0; i < FTRACE_STACK_ENTRIES; i++) {
1115                 if (!field->caller[i] || (field->caller[i] == ULONG_MAX))
1116                         break;
1117                 if (!trace_seq_puts(s, " => "))
1118                         goto partial;
1119
1120                 if (!seq_print_ip_sym(s, field->caller[i], flags))
1121                         goto partial;
1122                 if (!trace_seq_puts(s, "\n"))
1123                         goto partial;
1124         }
1125
1126         return TRACE_TYPE_HANDLED;
1127
1128  partial:
1129         return TRACE_TYPE_PARTIAL_LINE;
1130 }
1131
1132 static struct trace_event trace_stack_event = {
1133         .type           = TRACE_STACK,
1134         .trace          = trace_stack_print,
1135         .raw            = trace_special_print,
1136         .hex            = trace_special_hex,
1137         .binary         = trace_special_bin,
1138 };
1139
1140 /* TRACE_USER_STACK */
1141 static enum print_line_t trace_user_stack_print(struct trace_iterator *iter,
1142                                                 int flags)
1143 {
1144         struct userstack_entry *field;
1145         struct trace_seq *s = &iter->seq;
1146
1147         trace_assign_type(field, iter->ent);
1148
1149         if (!trace_seq_puts(s, "<user stack trace>\n"))
1150                 goto partial;
1151
1152         if (!seq_print_userip_objs(field, s, flags))
1153                 goto partial;
1154
1155         return TRACE_TYPE_HANDLED;
1156
1157  partial:
1158         return TRACE_TYPE_PARTIAL_LINE;
1159 }
1160
1161 static struct trace_event trace_user_stack_event = {
1162         .type           = TRACE_USER_STACK,
1163         .trace          = trace_user_stack_print,
1164         .raw            = trace_special_print,
1165         .hex            = trace_special_hex,
1166         .binary         = trace_special_bin,
1167 };
1168
1169 /* TRACE_BPRINT */
1170 static enum print_line_t
1171 trace_bprint_print(struct trace_iterator *iter, int flags)
1172 {
1173         struct trace_entry *entry = iter->ent;
1174         struct trace_seq *s = &iter->seq;
1175         struct bprint_entry *field;
1176
1177         trace_assign_type(field, entry);
1178
1179         if (!seq_print_ip_sym(s, field->ip, flags))
1180                 goto partial;
1181
1182         if (!trace_seq_puts(s, ": "))
1183                 goto partial;
1184
1185         if (!trace_seq_bprintf(s, field->fmt, field->buf))
1186                 goto partial;
1187
1188         return TRACE_TYPE_HANDLED;
1189
1190  partial:
1191         return TRACE_TYPE_PARTIAL_LINE;
1192 }
1193
1194
1195 static enum print_line_t
1196 trace_bprint_raw(struct trace_iterator *iter, int flags)
1197 {
1198         struct bprint_entry *field;
1199         struct trace_seq *s = &iter->seq;
1200
1201         trace_assign_type(field, iter->ent);
1202
1203         if (!trace_seq_printf(s, ": %lx : ", field->ip))
1204                 goto partial;
1205
1206         if (!trace_seq_bprintf(s, field->fmt, field->buf))
1207                 goto partial;
1208
1209         return TRACE_TYPE_HANDLED;
1210
1211  partial:
1212         return TRACE_TYPE_PARTIAL_LINE;
1213 }
1214
1215
1216 static struct trace_event trace_bprint_event = {
1217         .type           = TRACE_BPRINT,
1218         .trace          = trace_bprint_print,
1219         .raw            = trace_bprint_raw,
1220 };
1221
1222 /* TRACE_PRINT */
1223 static enum print_line_t trace_print_print(struct trace_iterator *iter,
1224                                            int flags)
1225 {
1226         struct print_entry *field;
1227         struct trace_seq *s = &iter->seq;
1228
1229         trace_assign_type(field, iter->ent);
1230
1231         if (!seq_print_ip_sym(s, field->ip, flags))
1232                 goto partial;
1233
1234         if (!trace_seq_printf(s, ": %s", field->buf))
1235                 goto partial;
1236
1237         return TRACE_TYPE_HANDLED;
1238
1239  partial:
1240         return TRACE_TYPE_PARTIAL_LINE;
1241 }
1242
1243 static enum print_line_t trace_print_raw(struct trace_iterator *iter, int flags)
1244 {
1245         struct print_entry *field;
1246
1247         trace_assign_type(field, iter->ent);
1248
1249         if (!trace_seq_printf(&iter->seq, "# %lx %s", field->ip, field->buf))
1250                 goto partial;
1251
1252         return TRACE_TYPE_HANDLED;
1253
1254  partial:
1255         return TRACE_TYPE_PARTIAL_LINE;
1256 }
1257
1258 static struct trace_event trace_print_event = {
1259         .type           = TRACE_PRINT,
1260         .trace          = trace_print_print,
1261         .raw            = trace_print_raw,
1262 };
1263
1264
1265 static struct trace_event *events[] __initdata = {
1266         &trace_fn_event,
1267         &trace_ctx_event,
1268         &trace_wake_event,
1269         &trace_special_event,
1270         &trace_stack_event,
1271         &trace_user_stack_event,
1272         &trace_bprint_event,
1273         &trace_print_event,
1274         NULL
1275 };
1276
1277 __init static int init_events(void)
1278 {
1279         struct trace_event *event;
1280         int i, ret;
1281
1282         for (i = 0; events[i]; i++) {
1283                 event = events[i];
1284
1285                 ret = register_ftrace_event(event);
1286                 if (!ret) {
1287                         printk(KERN_WARNING "event %d failed to register\n",
1288                                event->type);
1289                         WARN_ON_ONCE(1);
1290                 }
1291         }
1292
1293         return 0;
1294 }
1295 device_initcall(init_events);