kernel/trace/trace_output.c

   1 /*
   2  * trace_output.c
   3  *
   4  * Copyright (C) 2008 Red Hat Inc, Steven Rostedt <[email protected]>
   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 EXPORT_SYMBOL(trace_seq_putc);
 213
 214 int trace_seq_putmem(struct trace_seq *s, const void *mem, size_t len)
 215 {
 216         if (s->full)
 217                 return 0;
 218
 219         if (len > ((PAGE_SIZE - 1) - s->len)) {
 220                 s->full = 1;
 221                 return 0;
 222         }
 223
 224         memcpy(s->buffer + s->len, mem, len);
 225         s->len += len;
 226
 227         return len;
 228 }
 229
 230 int trace_seq_putmem_hex(struct trace_seq *s, const void *mem, size_t len)
 231 {
 232         unsigned char hex[HEX_CHARS];
 233         const unsigned char *data = mem;
 234         int i, j;
 235
 236         if (s->full)
 237                 return 0;
 238
 239 #ifdef __BIG_ENDIAN
 240         for (i = 0, j = 0; i < len; i++) {
 241 #else
 242         for (i = len-1, j = 0; i >= 0; i--) {
 243 #endif
 244                 hex[j++] = hex_asc_hi(data[i]);
 245                 hex[j++] = hex_asc_lo(data[i]);
 246         }
 247         hex[j++] = ' ';
 248
 249         return trace_seq_putmem(s, hex, j);
 250 }
 251
 252 void *trace_seq_reserve(struct trace_seq *s, size_t len)
 253 {
 254         void *ret;
 255
 256         if (s->full)
 257                 return NULL;
 258
 259         if (len > ((PAGE_SIZE - 1) - s->len)) {
 260                 s->full = 1;
 261                 return NULL;
 262         }
 263
 264         ret = s->buffer + s->len;
 265         s->len += len;
 266
 267         return ret;
 268 }
 269
 270 int trace_seq_path(struct trace_seq *s, struct path *path)
 271 {
 272         unsigned char *p;
 273
 274         if (s->full)
 275                 return 0;
 276
 277         if (s->len >= (PAGE_SIZE - 1)) {
 278                 s->full = 1;
 279                 return 0;
 280         }
 281
 282         p = d_path(path, s->buffer + s->len, PAGE_SIZE - s->len);
 283         if (!IS_ERR(p)) {
 284                 p = mangle_path(s->buffer + s->len, p, "\n");
 285                 if (p) {
 286                         s->len = p - s->buffer;
 287                         return 1;
 288                 }
 289         } else {
 290                 s->buffer[s->len++] = '?';
 291                 return 1;
 292         }
 293
 294         s->full = 1;
 295         return 0;
 296 }
 297
 298 const char *
 299 ftrace_print_flags_seq(struct trace_seq *p, const char *delim,
 300                        unsigned long flags,
 301                        const struct trace_print_flags *flag_array)
 302 {
 303         unsigned long mask;
 304         const char *str;
 305         const char *ret = p->buffer + p->len;
 306         int i;
 307
 308         for (i = 0;  flag_array[i].name && flags; i++) {
 309
 310                 mask = flag_array[i].mask;
 311                 if ((flags & mask) != mask)
 312                         continue;
 313
 314                 str = flag_array[i].name;
 315                 flags &= ~mask;
 316                 if (p->len && delim)
 317                         trace_seq_puts(p, delim);
 318                 trace_seq_puts(p, str);
 319         }
 320
 321         /* check for left over flags */
 322         if (flags) {
 323                 if (p->len && delim)
 324                         trace_seq_puts(p, delim);
 325                 trace_seq_printf(p, "0x%lx", flags);
 326         }
 327
 328         trace_seq_putc(p, 0);
 329
 330         return ret;
 331 }
 332 EXPORT_SYMBOL(ftrace_print_flags_seq);
 333
 334 const char *
 335 ftrace_print_symbols_seq(struct trace_seq *p, unsigned long val,
 336                          const struct trace_print_flags *symbol_array)
 337 {
 338         int i;
 339         const char *ret = p->buffer + p->len;
 340
 341         for (i = 0;  symbol_array[i].name; i++) {
 342
 343                 if (val != symbol_array[i].mask)
 344                         continue;
 345
 346                 trace_seq_puts(p, symbol_array[i].name);
 347                 break;
 348         }
 349
 350         if (!p->len)
 351                 trace_seq_printf(p, "0x%lx", val);
 352
 353         trace_seq_putc(p, 0);
 354
 355         return ret;
 356 }
 357 EXPORT_SYMBOL(ftrace_print_symbols_seq);
 358
 359 const char *
 360 ftrace_print_hex_seq(struct trace_seq *p, const unsigned char *buf, int buf_len)
 361 {
 362         int i;
 363         const char *ret = p->buffer + p->len;
 364
 365         for (i = 0; i < buf_len; i++)
 366                 trace_seq_printf(p, "%s%2.2x", i == 0 ? "" : " ", buf[i]);
 367
 368         trace_seq_putc(p, 0);
 369
 370         return ret;
 371 }
 372 EXPORT_SYMBOL(ftrace_print_hex_seq);
 373
 374 #ifdef CONFIG_KRETPROBES
 375 static inline const char *kretprobed(const char *name)
 376 {
 377         static const char tramp_name[] = "kretprobe_trampoline";
 378         int size = sizeof(tramp_name);
 379
 380         if (strncmp(tramp_name, name, size) == 0)
 381                 return "[unknown/kretprobe'd]";
 382         return name;
 383 }
 384 #else
 385 static inline const char *kretprobed(const char *name)
 386 {
 387         return name;
 388 }
 389 #endif /* CONFIG_KRETPROBES */
 390
 391 static int
 392 seq_print_sym_short(struct trace_seq *s, const char *fmt, unsigned long address)
 393 {
 394 #ifdef CONFIG_KALLSYMS
 395         char str[KSYM_SYMBOL_LEN];
 396         const char *name;
 397
 398         kallsyms_lookup(address, NULL, NULL, NULL, str);
 399
 400         name = kretprobed(str);
 401
 402         return trace_seq_printf(s, fmt, name);
 403 #endif
 404         return 1;
 405 }
 406
 407 static int
 408 seq_print_sym_offset(struct trace_seq *s, const char *fmt,
 409                      unsigned long address)
 410 {
 411 #ifdef CONFIG_KALLSYMS
 412         char str[KSYM_SYMBOL_LEN];
 413         const char *name;
 414
 415         sprint_symbol(str, address);
 416         name = kretprobed(str);
 417
 418         return trace_seq_printf(s, fmt, name);
 419 #endif
 420         return 1;
 421 }
 422
 423 #ifndef CONFIG_64BIT
 424 # define IP_FMT "%08lx"
 425 #else
 426 # define IP_FMT "%016lx"
 427 #endif
 428
 429 int seq_print_user_ip(struct trace_seq *s, struct mm_struct *mm,
 430                       unsigned long ip, unsigned long sym_flags)
 431 {
 432         struct file *file = NULL;
 433         unsigned long vmstart = 0;
 434         int ret = 1;
 435
 436         if (s->full)
 437                 return 0;
 438
 439         if (mm) {
 440                 const struct vm_area_struct *vma;
 441
 442                 down_read(&mm->mmap_sem);
 443                 vma = find_vma(mm, ip);
 444                 if (vma) {
 445                         file = vma->vm_file;
 446                         vmstart = vma->vm_start;
 447                 }
 448                 if (file) {
 449                         ret = trace_seq_path(s, &file->f_path);
 450                         if (ret)
 451                                 ret = trace_seq_printf(s, "[+0x%lx]",
 452                                                        ip - vmstart);
 453                 }
 454                 up_read(&mm->mmap_sem);
 455         }
 456         if (ret && ((sym_flags & TRACE_ITER_SYM_ADDR) || !file))
 457                 ret = trace_seq_printf(s, " <" IP_FMT ">", ip);
 458         return ret;
 459 }
 460
 461 int
 462 seq_print_userip_objs(const struct userstack_entry *entry, struct trace_seq *s,
 463                       unsigned long sym_flags)
 464 {
 465         struct mm_struct *mm = NULL;
 466         int ret = 1;
 467         unsigned int i;
 468
 469         if (trace_flags & TRACE_ITER_SYM_USEROBJ) {
 470                 struct task_struct *task;
 471                 /*
 472                  * we do the lookup on the thread group leader,
 473                  * since individual threads might have already quit!
 474                  */
 475                 rcu_read_lock();
 476                 task = find_task_by_vpid(entry->tgid);
 477                 if (task)
 478                         mm = get_task_mm(task);
 479                 rcu_read_unlock();
 480         }
 481
 482         for (i = 0; i < FTRACE_STACK_ENTRIES; i++) {
 483                 unsigned long ip = entry->caller[i];
 484
 485                 if (ip == ULONG_MAX || !ret)
 486                         break;
 487                 if (ret)
 488                         ret = trace_seq_puts(s, " => ");
 489                 if (!ip) {
 490                         if (ret)
 491                                 ret = trace_seq_puts(s, "??");
 492                         if (ret)
 493                                 ret = trace_seq_puts(s, "\n");
 494                         continue;
 495                 }
 496                 if (!ret)
 497                         break;
 498                 if (ret)
 499                         ret = seq_print_user_ip(s, mm, ip, sym_flags);
 500                 ret = trace_seq_puts(s, "\n");
 501         }
 502
 503         if (mm)
 504                 mmput(mm);
 505         return ret;
 506 }
 507
 508 int
 509 seq_print_ip_sym(struct trace_seq *s, unsigned long ip, unsigned long sym_flags)
 510 {
 511         int ret;
 512
 513         if (!ip)
 514                 return trace_seq_printf(s, "0");
 515
 516         if (sym_flags & TRACE_ITER_SYM_OFFSET)
 517                 ret = seq_print_sym_offset(s, "%s", ip);
 518         else
 519                 ret = seq_print_sym_short(s, "%s", ip);
 520
 521         if (!ret)
 522                 return 0;
 523
 524         if (sym_flags & TRACE_ITER_SYM_ADDR)
 525                 ret = trace_seq_printf(s, " <" IP_FMT ">", ip);
 526         return ret;
 527 }
 528
 529 /**
 530  * trace_print_lat_fmt - print the irq, preempt and lockdep fields
 531  * @s: trace seq struct to write to
 532  * @entry: The trace entry field from the ring buffer
 533  *
 534  * Prints the generic fields of irqs off, in hard or softirq, preempt
 535  * count and lock depth.
 536  */
 537 int trace_print_lat_fmt(struct trace_seq *s, struct trace_entry *entry)
 538 {
 539         int hardirq, softirq;
 540         int ret;
 541
 542         hardirq = entry->flags & TRACE_FLAG_HARDIRQ;
 543         softirq = entry->flags & TRACE_FLAG_SOFTIRQ;
 544
 545         if (!trace_seq_printf(s, "%c%c%c",
 546                               (entry->flags & TRACE_FLAG_IRQS_OFF) ? 'd' :
 547                                 (entry->flags & TRACE_FLAG_IRQS_NOSUPPORT) ?
 548                                   'X' : '.',
 549                               (entry->flags & TRACE_FLAG_NEED_RESCHED) ?
 550                                 'N' : '.',
 551                               (hardirq && softirq) ? 'H' :
 552                                 hardirq ? 'h' : softirq ? 's' : '.'))
 553                 return 0;
 554
 555         if (entry->preempt_count)
 556                 ret = trace_seq_printf(s, "%x", entry->preempt_count);
 557         else
 558                 ret = trace_seq_putc(s, '.');
 559
 560         if (!ret)
 561                 return 0;
 562
 563         if (entry->lock_depth < 0)
 564                 return trace_seq_putc(s, '.');
 565
 566         return trace_seq_printf(s, "%d", entry->lock_depth);
 567 }
 568
 569 static int
 570 lat_print_generic(struct trace_seq *s, struct trace_entry *entry, int cpu)
 571 {
 572         char comm[TASK_COMM_LEN];
 573
 574         trace_find_cmdline(entry->pid, comm);
 575
 576         if (!trace_seq_printf(s, "%8.8s-%-5d %3d",
 577                               comm, entry->pid, cpu))
 578                 return 0;
 579
 580         return trace_print_lat_fmt(s, entry);
 581 }
 582
 583 static unsigned long preempt_mark_thresh = 100;
 584
 585 static int
 586 lat_print_timestamp(struct trace_seq *s, u64 abs_usecs,
 587                     unsigned long rel_usecs)
 588 {
 589         return trace_seq_printf(s, " %4lldus%c: ", abs_usecs,
 590                                 rel_usecs > preempt_mark_thresh ? '!' :
 591                                   rel_usecs > 1 ? '+' : ' ');
 592 }
 593
 594 int trace_print_context(struct trace_iterator *iter)
 595 {
 596         struct trace_seq *s = &iter->seq;
 597         struct trace_entry *entry = iter->ent;
 598         unsigned long long t = ns2usecs(iter->ts);
 599         unsigned long usec_rem = do_div(t, USEC_PER_SEC);
 600         unsigned long secs = (unsigned long)t;
 601         char comm[TASK_COMM_LEN];
 602
 603         trace_find_cmdline(entry->pid, comm);
 604
 605         return trace_seq_printf(s, "%16s-%-5d [%03d] %5lu.%06lu: ",
 606                                 comm, entry->pid, iter->cpu, secs, usec_rem);
 607 }
 608
 609 int trace_print_lat_context(struct trace_iterator *iter)
 610 {
 611         u64 next_ts;
 612         int ret;
 613         struct trace_seq *s = &iter->seq;
 614         struct trace_entry *entry = iter->ent,
 615                            *next_entry = trace_find_next_entry(iter, NULL,
 616                                                                &next_ts);
 617         unsigned long verbose = (trace_flags & TRACE_ITER_VERBOSE);
 618         unsigned long abs_usecs = ns2usecs(iter->ts - iter->tr->time_start);
 619         unsigned long rel_usecs;
 620
 621         if (!next_entry)
 622                 next_ts = iter->ts;
 623         rel_usecs = ns2usecs(next_ts - iter->ts);
 624
 625         if (verbose) {
 626                 char comm[TASK_COMM_LEN];
 627
 628                 trace_find_cmdline(entry->pid, comm);
 629
 630                 ret = trace_seq_printf(s, "%16s %5d %3d %d %08x %08lx [%08llx]"
 631                                        " %ld.%03ldms (+%ld.%03ldms): ", comm,
 632                                        entry->pid, iter->cpu, entry->flags,
 633                                        entry->preempt_count, iter->idx,
 634                                        ns2usecs(iter->ts),
 635                                        abs_usecs / USEC_PER_MSEC,
 636                                        abs_usecs % USEC_PER_MSEC,
 637                                        rel_usecs / USEC_PER_MSEC,
 638                                        rel_usecs % USEC_PER_MSEC);
 639         } else {
 640                 ret = lat_print_generic(s, entry, iter->cpu);
 641                 if (ret)
 642                         ret = lat_print_timestamp(s, abs_usecs, rel_usecs);
 643         }
 644
 645         return ret;
 646 }
 647
 648 static const char state_to_char[] = TASK_STATE_TO_CHAR_STR;
 649
 650 static int task_state_char(unsigned long state)
 651 {
 652         int bit = state ? __ffs(state) + 1 : 0;
 653
 654         return bit < sizeof(state_to_char) - 1 ? state_to_char[bit] : '?';
 655 }
 656
 657 /**
 658  * ftrace_find_event - find a registered event
 659  * @type: the type of event to look for
 660  *
 661  * Returns an event of type @type otherwise NULL
 662  * Called with trace_event_read_lock() held.
 663  */
 664 struct trace_event *ftrace_find_event(int type)
 665 {
 666         struct trace_event *event;
 667         struct hlist_node *n;
 668         unsigned key;
 669
 670         key = type & (EVENT_HASHSIZE - 1);
 671
 672         hlist_for_each_entry(event, n, &event_hash[key], node) {
 673                 if (event->type == type)
 674                         return event;
 675         }
 676
 677         return NULL;
 678 }
 679
 680 static LIST_HEAD(ftrace_event_list);
 681
 682 static int trace_search_list(struct list_head **list)
 683 {
 684         struct trace_event *e;
 685         int last = __TRACE_LAST_TYPE;
 686
 687         if (list_empty(&ftrace_event_list)) {
 688                 *list = &ftrace_event_list;
 689                 return last + 1;
 690         }
 691
 692         /*
 693          * We used up all possible max events,
 694          * lets see if somebody freed one.
 695          */
 696         list_for_each_entry(e, &ftrace_event_list, list) {
 697                 if (e->type != last + 1)
 698                         break;
 699                 last++;
 700         }
 701
 702         /* Did we used up all 65 thousand events??? */
 703         if ((last + 1) > FTRACE_MAX_EVENT)
 704                 return 0;
 705
 706         *list = &e->list;
 707         return last + 1;
 708 }
 709
 710 void trace_event_read_lock(void)
 711 {
 712         down_read(&trace_event_mutex);
 713 }
 714
 715 void trace_event_read_unlock(void)
 716 {
 717         up_read(&trace_event_mutex);
 718 }
 719
 720 /**
 721  * register_ftrace_event - register output for an event type
 722  * @event: the event type to register
 723  *
 724  * Event types are stored in a hash and this hash is used to
 725  * find a way to print an event. If the @event->type is set
 726  * then it will use that type, otherwise it will assign a
 727  * type to use.
 728  *
 729  * If you assign your own type, please make sure it is added
 730  * to the trace_type enum in trace.h, to avoid collisions
 731  * with the dynamic types.
 732  *
 733  * Returns the event type number or zero on error.
 734  */
 735 int register_ftrace_event(struct trace_event *event)
 736 {
 737         unsigned key;
 738         int ret = 0;
 739
 740         down_write(&trace_event_mutex);
 741
 742         if (WARN_ON(!event))
 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->trace == NULL)
 778                 event->trace = trace_nop_print;
 779         if (event->raw == NULL)
 780                 event->raw = trace_nop_print;
 781         if (event->hex == NULL)
 782                 event->hex = trace_nop_print;
 783         if (event->binary == NULL)
 784                 event->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 {
 828         return TRACE_TYPE_HANDLED;
 829 }
 830
 831 /* TRACE_FN */
 832 static enum print_line_t trace_fn_trace(struct trace_iterator *iter, int flags)
 833 {
 834         struct ftrace_entry *field;
 835         struct trace_seq *s = &iter->seq;
 836
 837         trace_assign_type(field, iter->ent);
 838
 839         if (!seq_print_ip_sym(s, field->ip, flags))
 840                 goto partial;
 841
 842         if ((flags & TRACE_ITER_PRINT_PARENT) && field->parent_ip) {
 843                 if (!trace_seq_printf(s, " <-"))
 844                         goto partial;
 845                 if (!seq_print_ip_sym(s,
 846                                       field->parent_ip,
 847                                       flags))
 848                         goto partial;
 849         }
 850         if (!trace_seq_printf(s, "\n"))
 851                 goto partial;
 852
 853         return TRACE_TYPE_HANDLED;
 854
 855  partial:
 856         return TRACE_TYPE_PARTIAL_LINE;
 857 }
 858
 859 static enum print_line_t trace_fn_raw(struct trace_iterator *iter, int flags)
 860 {
 861         struct ftrace_entry *field;
 862
 863         trace_assign_type(field, iter->ent);
 864
 865         if (!trace_seq_printf(&iter->seq, "%lx %lx\n",
 866                               field->ip,
 867                               field->parent_ip))
 868                 return TRACE_TYPE_PARTIAL_LINE;
 869
 870         return TRACE_TYPE_HANDLED;
 871 }
 872
 873 static enum print_line_t trace_fn_hex(struct trace_iterator *iter, int flags)
 874 {
 875         struct ftrace_entry *field;
 876         struct trace_seq *s = &iter->seq;
 877
 878         trace_assign_type(field, iter->ent);
 879
 880         SEQ_PUT_HEX_FIELD_RET(s, field->ip);
 881         SEQ_PUT_HEX_FIELD_RET(s, field->parent_ip);
 882
 883         return TRACE_TYPE_HANDLED;
 884 }
 885
 886 static enum print_line_t trace_fn_bin(struct trace_iterator *iter, int flags)
 887 {
 888         struct ftrace_entry *field;
 889         struct trace_seq *s = &iter->seq;
 890
 891         trace_assign_type(field, iter->ent);
 892
 893         SEQ_PUT_FIELD_RET(s, field->ip);
 894         SEQ_PUT_FIELD_RET(s, field->parent_ip);
 895
 896         return TRACE_TYPE_HANDLED;
 897 }
 898
 899 static struct trace_event trace_fn_event = {
 900         .type           = TRACE_FN,
 901         .trace          = trace_fn_trace,
 902         .raw            = trace_fn_raw,
 903         .hex            = trace_fn_hex,
 904         .binary         = trace_fn_bin,
 905 };
 906
 907 /* TRACE_CTX an TRACE_WAKE */
 908 static enum print_line_t trace_ctxwake_print(struct trace_iterator *iter,
 909                                              char *delim)
 910 {
 911         struct ctx_switch_entry *field;
 912         char comm[TASK_COMM_LEN];
 913         int S, T;
 914
 915
 916         trace_assign_type(field, iter->ent);
 917
 918         T = task_state_char(field->next_state);
 919         S = task_state_char(field->prev_state);
 920         trace_find_cmdline(field->next_pid, comm);
 921         if (!trace_seq_printf(&iter->seq,
 922                               " %5d:%3d:%c %s [%03d] %5d:%3d:%c %s\n",
 923                               field->prev_pid,
 924                               field->prev_prio,
 925                               S, delim,
 926                               field->next_cpu,
 927                               field->next_pid,
 928                               field->next_prio,
 929                               T, comm))
 930                 return TRACE_TYPE_PARTIAL_LINE;
 931
 932         return TRACE_TYPE_HANDLED;
 933 }
 934
 935 static enum print_line_t trace_ctx_print(struct trace_iterator *iter, int flags)
 936 {
 937         return trace_ctxwake_print(iter, "==>");
 938 }
 939
 940 static enum print_line_t trace_wake_print(struct trace_iterator *iter,
 941                                           int flags)
 942 {
 943         return trace_ctxwake_print(iter, "  +");
 944 }
 945
 946 static int trace_ctxwake_raw(struct trace_iterator *iter, char S)
 947 {
 948         struct ctx_switch_entry *field;
 949         int T;
 950
 951         trace_assign_type(field, iter->ent);
 952
 953         if (!S)
 954                 S = task_state_char(field->prev_state);
 955         T = task_state_char(field->next_state);
 956         if (!trace_seq_printf(&iter->seq, "%d %d %c %d %d %d %c\n",
 957                               field->prev_pid,
 958                               field->prev_prio,
 959                               S,
 960                               field->next_cpu,
 961                               field->next_pid,
 962                               field->next_prio,
 963                               T))
 964                 return TRACE_TYPE_PARTIAL_LINE;
 965
 966         return TRACE_TYPE_HANDLED;
 967 }
 968
 969 static enum print_line_t trace_ctx_raw(struct trace_iterator *iter, int flags)
 970 {
 971         return trace_ctxwake_raw(iter, 0);
 972 }
 973
 974 static enum print_line_t trace_wake_raw(struct trace_iterator *iter, int flags)
 975 {
 976         return trace_ctxwake_raw(iter, '+');
 977 }
 978
 979
 980 static int trace_ctxwake_hex(struct trace_iterator *iter, char S)
 981 {
 982         struct ctx_switch_entry *field;
 983         struct trace_seq *s = &iter->seq;
 984         int T;
 985
 986         trace_assign_type(field, iter->ent);
 987
 988         if (!S)
 989                 S = task_state_char(field->prev_state);
 990         T = task_state_char(field->next_state);
 991
 992         SEQ_PUT_HEX_FIELD_RET(s, field->prev_pid);
 993         SEQ_PUT_HEX_FIELD_RET(s, field->prev_prio);
 994         SEQ_PUT_HEX_FIELD_RET(s, S);
 995         SEQ_PUT_HEX_FIELD_RET(s, field->next_cpu);
 996         SEQ_PUT_HEX_FIELD_RET(s, field->next_pid);
 997         SEQ_PUT_HEX_FIELD_RET(s, field->next_prio);
 998         SEQ_PUT_HEX_FIELD_RET(s, T);
 999
1000         return TRACE_TYPE_HANDLED;
1001 }
1002
1003 static enum print_line_t trace_ctx_hex(struct trace_iterator *iter, int flags)
1004 {
1005         return trace_ctxwake_hex(iter, 0);
1006 }
1007
1008 static enum print_line_t trace_wake_hex(struct trace_iterator *iter, int flags)
1009 {
1010         return trace_ctxwake_hex(iter, '+');
1011 }
1012
1013 static enum print_line_t trace_ctxwake_bin(struct trace_iterator *iter,
1014                                            int flags)
1015 {
1016         struct ctx_switch_entry *field;
1017         struct trace_seq *s = &iter->seq;
1018
1019         trace_assign_type(field, iter->ent);
1020
1021         SEQ_PUT_FIELD_RET(s, field->prev_pid);
1022         SEQ_PUT_FIELD_RET(s, field->prev_prio);
1023         SEQ_PUT_FIELD_RET(s, field->prev_state);
1024         SEQ_PUT_FIELD_RET(s, field->next_pid);
1025         SEQ_PUT_FIELD_RET(s, field->next_prio);
1026         SEQ_PUT_FIELD_RET(s, field->next_state);
1027
1028         return TRACE_TYPE_HANDLED;
1029 }
1030
1031 static struct trace_event trace_ctx_event = {
1032         .type           = TRACE_CTX,
1033         .trace          = trace_ctx_print,
1034         .raw            = trace_ctx_raw,
1035         .hex            = trace_ctx_hex,
1036         .binary         = trace_ctxwake_bin,
1037 };
1038
1039 static struct trace_event trace_wake_event = {
1040         .type           = TRACE_WAKE,
1041         .trace          = trace_wake_print,
1042         .raw            = trace_wake_raw,
1043         .hex            = trace_wake_hex,
1044         .binary         = trace_ctxwake_bin,
1045 };
1046
1047 /* TRACE_SPECIAL */
1048 static enum print_line_t trace_special_print(struct trace_iterator *iter,
1049                                              int flags)
1050 {
1051         struct special_entry *field;
1052
1053         trace_assign_type(field, iter->ent);
1054
1055         if (!trace_seq_printf(&iter->seq, "# %ld %ld %ld\n",
1056                               field->arg1,
1057                               field->arg2,
1058                               field->arg3))
1059                 return TRACE_TYPE_PARTIAL_LINE;
1060
1061         return TRACE_TYPE_HANDLED;
1062 }
1063
1064 static enum print_line_t trace_special_hex(struct trace_iterator *iter,
1065                                            int flags)
1066 {
1067         struct special_entry *field;
1068         struct trace_seq *s = &iter->seq;
1069
1070         trace_assign_type(field, iter->ent);
1071
1072         SEQ_PUT_HEX_FIELD_RET(s, field->arg1);
1073         SEQ_PUT_HEX_FIELD_RET(s, field->arg2);
1074         SEQ_PUT_HEX_FIELD_RET(s, field->arg3);
1075
1076         return TRACE_TYPE_HANDLED;
1077 }
1078
1079 static enum print_line_t trace_special_bin(struct trace_iterator *iter,
1080                                            int flags)
1081 {
1082         struct special_entry *field;
1083         struct trace_seq *s = &iter->seq;
1084
1085         trace_assign_type(field, iter->ent);
1086
1087         SEQ_PUT_FIELD_RET(s, field->arg1);
1088         SEQ_PUT_FIELD_RET(s, field->arg2);
1089         SEQ_PUT_FIELD_RET(s, field->arg3);
1090
1091         return TRACE_TYPE_HANDLED;
1092 }
1093
1094 static struct trace_event trace_special_event = {
1095         .type           = TRACE_SPECIAL,
1096         .trace          = trace_special_print,
1097         .raw            = trace_special_print,
1098         .hex            = trace_special_hex,
1099         .binary         = trace_special_bin,
1100 };
1101
1102 /* TRACE_STACK */
1103
1104 static enum print_line_t trace_stack_print(struct trace_iterator *iter,
1105                                            int flags)
1106 {
1107         struct stack_entry *field;
1108         struct trace_seq *s = &iter->seq;
1109         int i;
1110
1111         trace_assign_type(field, iter->ent);
1112
1113         if (!trace_seq_puts(s, "<stack trace>\n"))
1114                 goto partial;
1115         for (i = 0; i < FTRACE_STACK_ENTRIES; i++) {
1116                 if (!field->caller[i] || (field->caller[i] == ULONG_MAX))
1117                         break;
1118                 if (!trace_seq_puts(s, " => "))
1119                         goto partial;
1120
1121                 if (!seq_print_ip_sym(s, field->caller[i], flags))
1122                         goto partial;
1123                 if (!trace_seq_puts(s, "\n"))
1124                         goto partial;
1125         }
1126
1127         return TRACE_TYPE_HANDLED;
1128
1129  partial:
1130         return TRACE_TYPE_PARTIAL_LINE;
1131 }
1132
1133 static struct trace_event trace_stack_event = {
1134         .type           = TRACE_STACK,
1135         .trace          = trace_stack_print,
1136         .raw            = trace_special_print,
1137         .hex            = trace_special_hex,
1138         .binary         = trace_special_bin,
1139 };
1140
1141 /* TRACE_USER_STACK */
1142 static enum print_line_t trace_user_stack_print(struct trace_iterator *iter,
1143                                                 int flags)
1144 {
1145         struct userstack_entry *field;
1146         struct trace_seq *s = &iter->seq;
1147
1148         trace_assign_type(field, iter->ent);
1149
1150         if (!trace_seq_puts(s, "<user stack trace>\n"))
1151                 goto partial;
1152
1153         if (!seq_print_userip_objs(field, s, flags))
1154                 goto partial;
1155
1156         return TRACE_TYPE_HANDLED;
1157
1158  partial:
1159         return TRACE_TYPE_PARTIAL_LINE;
1160 }
1161
1162 static struct trace_event trace_user_stack_event = {
1163         .type           = TRACE_USER_STACK,
1164         .trace          = trace_user_stack_print,
1165         .raw            = trace_special_print,
1166         .hex            = trace_special_hex,
1167         .binary         = trace_special_bin,
1168 };
1169
1170 /* TRACE_BPRINT */
1171 static enum print_line_t
1172 trace_bprint_print(struct trace_iterator *iter, int flags)
1173 {
1174         struct trace_entry *entry = iter->ent;
1175         struct trace_seq *s = &iter->seq;
1176         struct bprint_entry *field;
1177
1178         trace_assign_type(field, entry);
1179
1180         if (!seq_print_ip_sym(s, field->ip, flags))
1181                 goto partial;
1182
1183         if (!trace_seq_puts(s, ": "))
1184                 goto partial;
1185
1186         if (!trace_seq_bprintf(s, field->fmt, field->buf))
1187                 goto partial;
1188
1189         return TRACE_TYPE_HANDLED;
1190
1191  partial:
1192         return TRACE_TYPE_PARTIAL_LINE;
1193 }
1194
1195
1196 static enum print_line_t
1197 trace_bprint_raw(struct trace_iterator *iter, int flags)
1198 {
1199         struct bprint_entry *field;
1200         struct trace_seq *s = &iter->seq;
1201
1202         trace_assign_type(field, iter->ent);
1203
1204         if (!trace_seq_printf(s, ": %lx : ", field->ip))
1205                 goto partial;
1206
1207         if (!trace_seq_bprintf(s, field->fmt, field->buf))
1208                 goto partial;
1209
1210         return TRACE_TYPE_HANDLED;
1211
1212  partial:
1213         return TRACE_TYPE_PARTIAL_LINE;
1214 }
1215
1216
1217 static struct trace_event trace_bprint_event = {
1218         .type           = TRACE_BPRINT,
1219         .trace          = trace_bprint_print,
1220         .raw            = trace_bprint_raw,
1221 };
1222
1223 /* TRACE_PRINT */
1224 static enum print_line_t trace_print_print(struct trace_iterator *iter,
1225                                            int flags)
1226 {
1227         struct print_entry *field;
1228         struct trace_seq *s = &iter->seq;
1229
1230         trace_assign_type(field, iter->ent);
1231
1232         if (!seq_print_ip_sym(s, field->ip, flags))
1233                 goto partial;
1234
1235         if (!trace_seq_printf(s, ": %s", field->buf))
1236                 goto partial;
1237
1238         return TRACE_TYPE_HANDLED;
1239
1240  partial:
1241         return TRACE_TYPE_PARTIAL_LINE;
1242 }
1243
1244 static enum print_line_t trace_print_raw(struct trace_iterator *iter, int flags)
1245 {
1246         struct print_entry *field;
1247
1248         trace_assign_type(field, iter->ent);
1249
1250         if (!trace_seq_printf(&iter->seq, "# %lx %s", field->ip, field->buf))
1251                 goto partial;
1252
1253         return TRACE_TYPE_HANDLED;
1254
1255  partial:
1256         return TRACE_TYPE_PARTIAL_LINE;
1257 }
1258
1259 static struct trace_event trace_print_event = {
1260         .type           = TRACE_PRINT,
1261         .trace          = trace_print_print,
1262         .raw            = trace_print_raw,
1263 };
1264
1265
1266 static struct trace_event *events[] __initdata = {
1267         &trace_fn_event,
1268         &trace_ctx_event,
1269         &trace_wake_event,
1270         &trace_special_event,
1271         &trace_stack_event,
1272         &trace_user_stack_event,
1273         &trace_bprint_event,
1274         &trace_print_event,
1275         NULL
1276 };
1277
1278 __init static int init_events(void)
1279 {
1280         struct trace_event *event;
1281         int i, ret;
1282
1283         for (i = 0; events[i]; i++) {
1284                 event = events[i];
1285
1286                 ret = register_ftrace_event(event);
1287                 if (!ret) {
1288                         printk(KERN_WARNING "event %d failed to register\n",
1289                                event->type);
1290                         WARN_ON_ONCE(1);
1291                 }
1292         }
1293
1294         return 0;
1295 }
1296 device_initcall(init_events);