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 #ifdef CONFIG_KRETPROBES
 359 static inline const char *kretprobed(const char *name)
 360 {
 361         static const char tramp_name[] = "kretprobe_trampoline";
 362         int size = sizeof(tramp_name);
 363
 364         if (strncmp(tramp_name, name, size) == 0)
 365                 return "[unknown/kretprobe'd]";
 366         return name;
 367 }
 368 #else
 369 static inline const char *kretprobed(const char *name)
 370 {
 371         return name;
 372 }
 373 #endif /* CONFIG_KRETPROBES */
 374
 375 static int
 376 seq_print_sym_short(struct trace_seq *s, const char *fmt, unsigned long address)
 377 {
 378 #ifdef CONFIG_KALLSYMS
 379         char str[KSYM_SYMBOL_LEN];
 380         const char *name;
 381
 382         kallsyms_lookup(address, NULL, NULL, NULL, str);
 383
 384         name = kretprobed(str);
 385
 386         return trace_seq_printf(s, fmt, name);
 387 #endif
 388         return 1;
 389 }
 390
 391 static int
 392 seq_print_sym_offset(struct trace_seq *s, const char *fmt,
 393                      unsigned long address)
 394 {
 395 #ifdef CONFIG_KALLSYMS
 396         char str[KSYM_SYMBOL_LEN];
 397         const char *name;
 398
 399         sprint_symbol(str, address);
 400         name = kretprobed(str);
 401
 402         return trace_seq_printf(s, fmt, name);
 403 #endif
 404         return 1;
 405 }
 406
 407 #ifndef CONFIG_64BIT
 408 # define IP_FMT "%08lx"
 409 #else
 410 # define IP_FMT "%016lx"
 411 #endif
 412
 413 int seq_print_user_ip(struct trace_seq *s, struct mm_struct *mm,
 414                       unsigned long ip, unsigned long sym_flags)
 415 {
 416         struct file *file = NULL;
 417         unsigned long vmstart = 0;
 418         int ret = 1;
 419
 420         if (s->full)
 421                 return 0;
 422
 423         if (mm) {
 424                 const struct vm_area_struct *vma;
 425
 426                 down_read(&mm->mmap_sem);
 427                 vma = find_vma(mm, ip);
 428                 if (vma) {
 429                         file = vma->vm_file;
 430                         vmstart = vma->vm_start;
 431                 }
 432                 if (file) {
 433                         ret = trace_seq_path(s, &file->f_path);
 434                         if (ret)
 435                                 ret = trace_seq_printf(s, "[+0x%lx]",
 436                                                        ip - vmstart);
 437                 }
 438                 up_read(&mm->mmap_sem);
 439         }
 440         if (ret && ((sym_flags & TRACE_ITER_SYM_ADDR) || !file))
 441                 ret = trace_seq_printf(s, " <" IP_FMT ">", ip);
 442         return ret;
 443 }
 444
 445 int
 446 seq_print_userip_objs(const struct userstack_entry *entry, struct trace_seq *s,
 447                       unsigned long sym_flags)
 448 {
 449         struct mm_struct *mm = NULL;
 450         int ret = 1;
 451         unsigned int i;
 452
 453         if (trace_flags & TRACE_ITER_SYM_USEROBJ) {
 454                 struct task_struct *task;
 455                 /*
 456                  * we do the lookup on the thread group leader,
 457                  * since individual threads might have already quit!
 458                  */
 459                 rcu_read_lock();
 460                 task = find_task_by_vpid(entry->tgid);
 461                 if (task)
 462                         mm = get_task_mm(task);
 463                 rcu_read_unlock();
 464         }
 465
 466         for (i = 0; i < FTRACE_STACK_ENTRIES; i++) {
 467                 unsigned long ip = entry->caller[i];
 468
 469                 if (ip == ULONG_MAX || !ret)
 470                         break;
 471                 if (ret)
 472                         ret = trace_seq_puts(s, " => ");
 473                 if (!ip) {
 474                         if (ret)
 475                                 ret = trace_seq_puts(s, "??");
 476                         if (ret)
 477                                 ret = trace_seq_puts(s, "\n");
 478                         continue;
 479                 }
 480                 if (!ret)
 481                         break;
 482                 if (ret)
 483                         ret = seq_print_user_ip(s, mm, ip, sym_flags);
 484                 ret = trace_seq_puts(s, "\n");
 485         }
 486
 487         if (mm)
 488                 mmput(mm);
 489         return ret;
 490 }
 491
 492 int
 493 seq_print_ip_sym(struct trace_seq *s, unsigned long ip, unsigned long sym_flags)
 494 {
 495         int ret;
 496
 497         if (!ip)
 498                 return trace_seq_printf(s, "0");
 499
 500         if (sym_flags & TRACE_ITER_SYM_OFFSET)
 501                 ret = seq_print_sym_offset(s, "%s", ip);
 502         else
 503                 ret = seq_print_sym_short(s, "%s", ip);
 504
 505         if (!ret)
 506                 return 0;
 507
 508         if (sym_flags & TRACE_ITER_SYM_ADDR)
 509                 ret = trace_seq_printf(s, " <" IP_FMT ">", ip);
 510         return ret;
 511 }
 512
 513 /**
 514  * trace_print_lat_fmt - print the irq, preempt and lockdep fields
 515  * @s: trace seq struct to write to
 516  * @entry: The trace entry field from the ring buffer
 517  *
 518  * Prints the generic fields of irqs off, in hard or softirq, preempt
 519  * count and lock depth.
 520  */
 521 int trace_print_lat_fmt(struct trace_seq *s, struct trace_entry *entry)
 522 {
 523         int hardirq, softirq;
 524         int ret;
 525
 526         hardirq = entry->flags & TRACE_FLAG_HARDIRQ;
 527         softirq = entry->flags & TRACE_FLAG_SOFTIRQ;
 528
 529         if (!trace_seq_printf(s, "%c%c%c",
 530                               (entry->flags & TRACE_FLAG_IRQS_OFF) ? 'd' :
 531                                 (entry->flags & TRACE_FLAG_IRQS_NOSUPPORT) ?
 532                                   'X' : '.',
 533                               (entry->flags & TRACE_FLAG_NEED_RESCHED) ?
 534                                 'N' : '.',
 535                               (hardirq && softirq) ? 'H' :
 536                                 hardirq ? 'h' : softirq ? 's' : '.'))
 537                 return 0;
 538
 539         if (entry->preempt_count)
 540                 ret = trace_seq_printf(s, "%x", entry->preempt_count);
 541         else
 542                 ret = trace_seq_putc(s, '.');
 543
 544         if (!ret)
 545                 return 0;
 546
 547         if (entry->lock_depth < 0)
 548                 return trace_seq_putc(s, '.');
 549
 550         return trace_seq_printf(s, "%d", entry->lock_depth);
 551 }
 552
 553 static int
 554 lat_print_generic(struct trace_seq *s, struct trace_entry *entry, int cpu)
 555 {
 556         char comm[TASK_COMM_LEN];
 557
 558         trace_find_cmdline(entry->pid, comm);
 559
 560         if (!trace_seq_printf(s, "%8.8s-%-5d %3d",
 561                               comm, entry->pid, cpu))
 562                 return 0;
 563
 564         return trace_print_lat_fmt(s, entry);
 565 }
 566
 567 static unsigned long preempt_mark_thresh = 100;
 568
 569 static int
 570 lat_print_timestamp(struct trace_seq *s, u64 abs_usecs,
 571                     unsigned long rel_usecs)
 572 {
 573         return trace_seq_printf(s, " %4lldus%c: ", abs_usecs,
 574                                 rel_usecs > preempt_mark_thresh ? '!' :
 575                                   rel_usecs > 1 ? '+' : ' ');
 576 }
 577
 578 int trace_print_context(struct trace_iterator *iter)
 579 {
 580         struct trace_seq *s = &iter->seq;
 581         struct trace_entry *entry = iter->ent;
 582         unsigned long long t = ns2usecs(iter->ts);
 583         unsigned long usec_rem = do_div(t, USEC_PER_SEC);
 584         unsigned long secs = (unsigned long)t;
 585         char comm[TASK_COMM_LEN];
 586
 587         trace_find_cmdline(entry->pid, comm);
 588
 589         return trace_seq_printf(s, "%16s-%-5d [%03d] %5lu.%06lu: ",
 590                                 comm, entry->pid, iter->cpu, secs, usec_rem);
 591 }
 592
 593 int trace_print_lat_context(struct trace_iterator *iter)
 594 {
 595         u64 next_ts;
 596         int ret;
 597         struct trace_seq *s = &iter->seq;
 598         struct trace_entry *entry = iter->ent,
 599                            *next_entry = trace_find_next_entry(iter, NULL,
 600                                                                &next_ts);
 601         unsigned long verbose = (trace_flags & TRACE_ITER_VERBOSE);
 602         unsigned long abs_usecs = ns2usecs(iter->ts - iter->tr->time_start);
 603         unsigned long rel_usecs;
 604
 605         if (!next_entry)
 606                 next_ts = iter->ts;
 607         rel_usecs = ns2usecs(next_ts - iter->ts);
 608
 609         if (verbose) {
 610                 char comm[TASK_COMM_LEN];
 611
 612                 trace_find_cmdline(entry->pid, comm);
 613
 614                 ret = trace_seq_printf(s, "%16s %5d %3d %d %08x %08lx [%08llx]"
 615                                        " %ld.%03ldms (+%ld.%03ldms): ", comm,
 616                                        entry->pid, iter->cpu, entry->flags,
 617                                        entry->preempt_count, iter->idx,
 618                                        ns2usecs(iter->ts),
 619                                        abs_usecs / USEC_PER_MSEC,
 620                                        abs_usecs % USEC_PER_MSEC,
 621                                        rel_usecs / USEC_PER_MSEC,
 622                                        rel_usecs % USEC_PER_MSEC);
 623         } else {
 624                 ret = lat_print_generic(s, entry, iter->cpu);
 625                 if (ret)
 626                         ret = lat_print_timestamp(s, abs_usecs, rel_usecs);
 627         }
 628
 629         return ret;
 630 }
 631
 632 static const char state_to_char[] = TASK_STATE_TO_CHAR_STR;
 633
 634 static int task_state_char(unsigned long state)
 635 {
 636         int bit = state ? __ffs(state) + 1 : 0;
 637
 638         return bit < sizeof(state_to_char) - 1 ? state_to_char[bit] : '?';
 639 }
 640
 641 /**
 642  * ftrace_find_event - find a registered event
 643  * @type: the type of event to look for
 644  *
 645  * Returns an event of type @type otherwise NULL
 646  * Called with trace_event_read_lock() held.
 647  */
 648 struct trace_event *ftrace_find_event(int type)
 649 {
 650         struct trace_event *event;
 651         struct hlist_node *n;
 652         unsigned key;
 653
 654         key = type & (EVENT_HASHSIZE - 1);
 655
 656         hlist_for_each_entry(event, n, &event_hash[key], node) {
 657                 if (event->type == type)
 658                         return event;
 659         }
 660
 661         return NULL;
 662 }
 663
 664 static LIST_HEAD(ftrace_event_list);
 665
 666 static int trace_search_list(struct list_head **list)
 667 {
 668         struct trace_event *e;
 669         int last = __TRACE_LAST_TYPE;
 670
 671         if (list_empty(&ftrace_event_list)) {
 672                 *list = &ftrace_event_list;
 673                 return last + 1;
 674         }
 675
 676         /*
 677          * We used up all possible max events,
 678          * lets see if somebody freed one.
 679          */
 680         list_for_each_entry(e, &ftrace_event_list, list) {
 681                 if (e->type != last + 1)
 682                         break;
 683                 last++;
 684         }
 685
 686         /* Did we used up all 65 thousand events??? */
 687         if ((last + 1) > FTRACE_MAX_EVENT)
 688                 return 0;
 689
 690         *list = &e->list;
 691         return last + 1;
 692 }
 693
 694 void trace_event_read_lock(void)
 695 {
 696         down_read(&trace_event_mutex);
 697 }
 698
 699 void trace_event_read_unlock(void)
 700 {
 701         up_read(&trace_event_mutex);
 702 }
 703
 704 /**
 705  * register_ftrace_event - register output for an event type
 706  * @event: the event type to register
 707  *
 708  * Event types are stored in a hash and this hash is used to
 709  * find a way to print an event. If the @event->type is set
 710  * then it will use that type, otherwise it will assign a
 711  * type to use.
 712  *
 713  * If you assign your own type, please make sure it is added
 714  * to the trace_type enum in trace.h, to avoid collisions
 715  * with the dynamic types.
 716  *
 717  * Returns the event type number or zero on error.
 718  */
 719 int register_ftrace_event(struct trace_event *event)
 720 {
 721         unsigned key;
 722         int ret = 0;
 723
 724         down_write(&trace_event_mutex);
 725
 726         if (WARN_ON(!event))
 727                 goto out;
 728
 729         INIT_LIST_HEAD(&event->list);
 730
 731         if (!event->type) {
 732                 struct list_head *list = NULL;
 733
 734                 if (next_event_type > FTRACE_MAX_EVENT) {
 735
 736                         event->type = trace_search_list(&list);
 737                         if (!event->type)
 738                                 goto out;
 739
 740                 } else {
 741
 742                         event->type = next_event_type++;
 743                         list = &ftrace_event_list;
 744                 }
 745
 746                 if (WARN_ON(ftrace_find_event(event->type)))
 747                         goto out;
 748
 749                 list_add_tail(&event->list, list);
 750
 751         } else if (event->type > __TRACE_LAST_TYPE) {
 752                 printk(KERN_WARNING "Need to add type to trace.h\n");
 753                 WARN_ON(1);
 754                 goto out;
 755         } else {
 756                 /* Is this event already used */
 757                 if (ftrace_find_event(event->type))
 758                         goto out;
 759         }
 760
 761         if (event->trace == NULL)
 762                 event->trace = trace_nop_print;
 763         if (event->raw == NULL)
 764                 event->raw = trace_nop_print;
 765         if (event->hex == NULL)
 766                 event->hex = trace_nop_print;
 767         if (event->binary == NULL)
 768                 event->binary = trace_nop_print;
 769
 770         key = event->type & (EVENT_HASHSIZE - 1);
 771
 772         hlist_add_head(&event->node, &event_hash[key]);
 773
 774         ret = event->type;
 775  out:
 776         up_write(&trace_event_mutex);
 777
 778         return ret;
 779 }
 780 EXPORT_SYMBOL_GPL(register_ftrace_event);
 781
 782 /*
 783  * Used by module code with the trace_event_mutex held for write.
 784  */
 785 int __unregister_ftrace_event(struct trace_event *event)
 786 {
 787         hlist_del(&event->node);
 788         list_del(&event->list);
 789         return 0;
 790 }
 791
 792 /**
 793  * unregister_ftrace_event - remove a no longer used event
 794  * @event: the event to remove
 795  */
 796 int unregister_ftrace_event(struct trace_event *event)
 797 {
 798         down_write(&trace_event_mutex);
 799         __unregister_ftrace_event(event);
 800         up_write(&trace_event_mutex);
 801
 802         return 0;
 803 }
 804 EXPORT_SYMBOL_GPL(unregister_ftrace_event);
 805
 806 /*
 807  * Standard events
 808  */
 809
 810 enum print_line_t trace_nop_print(struct trace_iterator *iter, int flags)
 811 {
 812         return TRACE_TYPE_HANDLED;
 813 }
 814
 815 /* TRACE_FN */
 816 static enum print_line_t trace_fn_trace(struct trace_iterator *iter, int flags)
 817 {
 818         struct ftrace_entry *field;
 819         struct trace_seq *s = &iter->seq;
 820
 821         trace_assign_type(field, iter->ent);
 822
 823         if (!seq_print_ip_sym(s, field->ip, flags))
 824                 goto partial;
 825
 826         if ((flags & TRACE_ITER_PRINT_PARENT) && field->parent_ip) {
 827                 if (!trace_seq_printf(s, " <-"))
 828                         goto partial;
 829                 if (!seq_print_ip_sym(s,
 830                                       field->parent_ip,
 831                                       flags))
 832                         goto partial;
 833         }
 834         if (!trace_seq_printf(s, "\n"))
 835                 goto partial;
 836
 837         return TRACE_TYPE_HANDLED;
 838
 839  partial:
 840         return TRACE_TYPE_PARTIAL_LINE;
 841 }
 842
 843 static enum print_line_t trace_fn_raw(struct trace_iterator *iter, int flags)
 844 {
 845         struct ftrace_entry *field;
 846
 847         trace_assign_type(field, iter->ent);
 848
 849         if (!trace_seq_printf(&iter->seq, "%lx %lx\n",
 850                               field->ip,
 851                               field->parent_ip))
 852                 return TRACE_TYPE_PARTIAL_LINE;
 853
 854         return TRACE_TYPE_HANDLED;
 855 }
 856
 857 static enum print_line_t trace_fn_hex(struct trace_iterator *iter, int flags)
 858 {
 859         struct ftrace_entry *field;
 860         struct trace_seq *s = &iter->seq;
 861
 862         trace_assign_type(field, iter->ent);
 863
 864         SEQ_PUT_HEX_FIELD_RET(s, field->ip);
 865         SEQ_PUT_HEX_FIELD_RET(s, field->parent_ip);
 866
 867         return TRACE_TYPE_HANDLED;
 868 }
 869
 870 static enum print_line_t trace_fn_bin(struct trace_iterator *iter, int flags)
 871 {
 872         struct ftrace_entry *field;
 873         struct trace_seq *s = &iter->seq;
 874
 875         trace_assign_type(field, iter->ent);
 876
 877         SEQ_PUT_FIELD_RET(s, field->ip);
 878         SEQ_PUT_FIELD_RET(s, field->parent_ip);
 879
 880         return TRACE_TYPE_HANDLED;
 881 }
 882
 883 static struct trace_event trace_fn_event = {
 884         .type           = TRACE_FN,
 885         .trace          = trace_fn_trace,
 886         .raw            = trace_fn_raw,
 887         .hex            = trace_fn_hex,
 888         .binary         = trace_fn_bin,
 889 };
 890
 891 /* TRACE_CTX an TRACE_WAKE */
 892 static enum print_line_t trace_ctxwake_print(struct trace_iterator *iter,
 893                                              char *delim)
 894 {
 895         struct ctx_switch_entry *field;
 896         char comm[TASK_COMM_LEN];
 897         int S, T;
 898
 899
 900         trace_assign_type(field, iter->ent);
 901
 902         T = task_state_char(field->next_state);
 903         S = task_state_char(field->prev_state);
 904         trace_find_cmdline(field->next_pid, comm);
 905         if (!trace_seq_printf(&iter->seq,
 906                               " %5d:%3d:%c %s [%03d] %5d:%3d:%c %s\n",
 907                               field->prev_pid,
 908                               field->prev_prio,
 909                               S, delim,
 910                               field->next_cpu,
 911                               field->next_pid,
 912                               field->next_prio,
 913                               T, comm))
 914                 return TRACE_TYPE_PARTIAL_LINE;
 915
 916         return TRACE_TYPE_HANDLED;
 917 }
 918
 919 static enum print_line_t trace_ctx_print(struct trace_iterator *iter, int flags)
 920 {
 921         return trace_ctxwake_print(iter, "==>");
 922 }
 923
 924 static enum print_line_t trace_wake_print(struct trace_iterator *iter,
 925                                           int flags)
 926 {
 927         return trace_ctxwake_print(iter, "  +");
 928 }
 929
 930 static int trace_ctxwake_raw(struct trace_iterator *iter, char S)
 931 {
 932         struct ctx_switch_entry *field;
 933         int T;
 934
 935         trace_assign_type(field, iter->ent);
 936
 937         if (!S)
 938                 S = task_state_char(field->prev_state);
 939         T = task_state_char(field->next_state);
 940         if (!trace_seq_printf(&iter->seq, "%d %d %c %d %d %d %c\n",
 941                               field->prev_pid,
 942                               field->prev_prio,
 943                               S,
 944                               field->next_cpu,
 945                               field->next_pid,
 946                               field->next_prio,
 947                               T))
 948                 return TRACE_TYPE_PARTIAL_LINE;
 949
 950         return TRACE_TYPE_HANDLED;
 951 }
 952
 953 static enum print_line_t trace_ctx_raw(struct trace_iterator *iter, int flags)
 954 {
 955         return trace_ctxwake_raw(iter, 0);
 956 }
 957
 958 static enum print_line_t trace_wake_raw(struct trace_iterator *iter, int flags)
 959 {
 960         return trace_ctxwake_raw(iter, '+');
 961 }
 962
 963
 964 static int trace_ctxwake_hex(struct trace_iterator *iter, char S)
 965 {
 966         struct ctx_switch_entry *field;
 967         struct trace_seq *s = &iter->seq;
 968         int T;
 969
 970         trace_assign_type(field, iter->ent);
 971
 972         if (!S)
 973                 S = task_state_char(field->prev_state);
 974         T = task_state_char(field->next_state);
 975
 976         SEQ_PUT_HEX_FIELD_RET(s, field->prev_pid);
 977         SEQ_PUT_HEX_FIELD_RET(s, field->prev_prio);
 978         SEQ_PUT_HEX_FIELD_RET(s, S);
 979         SEQ_PUT_HEX_FIELD_RET(s, field->next_cpu);
 980         SEQ_PUT_HEX_FIELD_RET(s, field->next_pid);
 981         SEQ_PUT_HEX_FIELD_RET(s, field->next_prio);
 982         SEQ_PUT_HEX_FIELD_RET(s, T);
 983
 984         return TRACE_TYPE_HANDLED;
 985 }
 986
 987 static enum print_line_t trace_ctx_hex(struct trace_iterator *iter, int flags)
 988 {
 989         return trace_ctxwake_hex(iter, 0);
 990 }
 991
 992 static enum print_line_t trace_wake_hex(struct trace_iterator *iter, int flags)
 993 {
 994         return trace_ctxwake_hex(iter, '+');
 995 }
 996
 997 static enum print_line_t trace_ctxwake_bin(struct trace_iterator *iter,
 998                                            int flags)
 999 {
1000         struct ctx_switch_entry *field;
1001         struct trace_seq *s = &iter->seq;
1002
1003         trace_assign_type(field, iter->ent);
1004
1005         SEQ_PUT_FIELD_RET(s, field->prev_pid);
1006         SEQ_PUT_FIELD_RET(s, field->prev_prio);
1007         SEQ_PUT_FIELD_RET(s, field->prev_state);
1008         SEQ_PUT_FIELD_RET(s, field->next_pid);
1009         SEQ_PUT_FIELD_RET(s, field->next_prio);
1010         SEQ_PUT_FIELD_RET(s, field->next_state);
1011
1012         return TRACE_TYPE_HANDLED;
1013 }
1014
1015 static struct trace_event trace_ctx_event = {
1016         .type           = TRACE_CTX,
1017         .trace          = trace_ctx_print,
1018         .raw            = trace_ctx_raw,
1019         .hex            = trace_ctx_hex,
1020         .binary         = trace_ctxwake_bin,
1021 };
1022
1023 static struct trace_event trace_wake_event = {
1024         .type           = TRACE_WAKE,
1025         .trace          = trace_wake_print,
1026         .raw            = trace_wake_raw,
1027         .hex            = trace_wake_hex,
1028         .binary         = trace_ctxwake_bin,
1029 };
1030
1031 /* TRACE_SPECIAL */
1032 static enum print_line_t trace_special_print(struct trace_iterator *iter,
1033                                              int flags)
1034 {
1035         struct special_entry *field;
1036
1037         trace_assign_type(field, iter->ent);
1038
1039         if (!trace_seq_printf(&iter->seq, "# %ld %ld %ld\n",
1040                               field->arg1,
1041                               field->arg2,
1042                               field->arg3))
1043                 return TRACE_TYPE_PARTIAL_LINE;
1044
1045         return TRACE_TYPE_HANDLED;
1046 }
1047
1048 static enum print_line_t trace_special_hex(struct trace_iterator *iter,
1049                                            int flags)
1050 {
1051         struct special_entry *field;
1052         struct trace_seq *s = &iter->seq;
1053
1054         trace_assign_type(field, iter->ent);
1055
1056         SEQ_PUT_HEX_FIELD_RET(s, field->arg1);
1057         SEQ_PUT_HEX_FIELD_RET(s, field->arg2);
1058         SEQ_PUT_HEX_FIELD_RET(s, field->arg3);
1059
1060         return TRACE_TYPE_HANDLED;
1061 }
1062
1063 static enum print_line_t trace_special_bin(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_FIELD_RET(s, field->arg1);
1072         SEQ_PUT_FIELD_RET(s, field->arg2);
1073         SEQ_PUT_FIELD_RET(s, field->arg3);
1074
1075         return TRACE_TYPE_HANDLED;
1076 }
1077
1078 static struct trace_event trace_special_event = {
1079         .type           = TRACE_SPECIAL,
1080         .trace          = trace_special_print,
1081         .raw            = trace_special_print,
1082         .hex            = trace_special_hex,
1083         .binary         = trace_special_bin,
1084 };
1085
1086 /* TRACE_STACK */
1087
1088 static enum print_line_t trace_stack_print(struct trace_iterator *iter,
1089                                            int flags)
1090 {
1091         struct stack_entry *field;
1092         struct trace_seq *s = &iter->seq;
1093         int i;
1094
1095         trace_assign_type(field, iter->ent);
1096
1097         if (!trace_seq_puts(s, "<stack trace>\n"))
1098                 goto partial;
1099         for (i = 0; i < FTRACE_STACK_ENTRIES; i++) {
1100                 if (!field->caller[i] || (field->caller[i] == ULONG_MAX))
1101                         break;
1102                 if (!trace_seq_puts(s, " => "))
1103                         goto partial;
1104
1105                 if (!seq_print_ip_sym(s, field->caller[i], flags))
1106                         goto partial;
1107                 if (!trace_seq_puts(s, "\n"))
1108                         goto partial;
1109         }
1110
1111         return TRACE_TYPE_HANDLED;
1112
1113  partial:
1114         return TRACE_TYPE_PARTIAL_LINE;
1115 }
1116
1117 static struct trace_event trace_stack_event = {
1118         .type           = TRACE_STACK,
1119         .trace          = trace_stack_print,
1120         .raw            = trace_special_print,
1121         .hex            = trace_special_hex,
1122         .binary         = trace_special_bin,
1123 };
1124
1125 /* TRACE_USER_STACK */
1126 static enum print_line_t trace_user_stack_print(struct trace_iterator *iter,
1127                                                 int flags)
1128 {
1129         struct userstack_entry *field;
1130         struct trace_seq *s = &iter->seq;
1131
1132         trace_assign_type(field, iter->ent);
1133
1134         if (!trace_seq_puts(s, "<user stack trace>\n"))
1135                 goto partial;
1136
1137         if (!seq_print_userip_objs(field, s, flags))
1138                 goto partial;
1139
1140         return TRACE_TYPE_HANDLED;
1141
1142  partial:
1143         return TRACE_TYPE_PARTIAL_LINE;
1144 }
1145
1146 static struct trace_event trace_user_stack_event = {
1147         .type           = TRACE_USER_STACK,
1148         .trace          = trace_user_stack_print,
1149         .raw            = trace_special_print,
1150         .hex            = trace_special_hex,
1151         .binary         = trace_special_bin,
1152 };
1153
1154 /* TRACE_BPRINT */
1155 static enum print_line_t
1156 trace_bprint_print(struct trace_iterator *iter, int flags)
1157 {
1158         struct trace_entry *entry = iter->ent;
1159         struct trace_seq *s = &iter->seq;
1160         struct bprint_entry *field;
1161
1162         trace_assign_type(field, entry);
1163
1164         if (!seq_print_ip_sym(s, field->ip, flags))
1165                 goto partial;
1166
1167         if (!trace_seq_puts(s, ": "))
1168                 goto partial;
1169
1170         if (!trace_seq_bprintf(s, field->fmt, field->buf))
1171                 goto partial;
1172
1173         return TRACE_TYPE_HANDLED;
1174
1175  partial:
1176         return TRACE_TYPE_PARTIAL_LINE;
1177 }
1178
1179
1180 static enum print_line_t
1181 trace_bprint_raw(struct trace_iterator *iter, int flags)
1182 {
1183         struct bprint_entry *field;
1184         struct trace_seq *s = &iter->seq;
1185
1186         trace_assign_type(field, iter->ent);
1187
1188         if (!trace_seq_printf(s, ": %lx : ", field->ip))
1189                 goto partial;
1190
1191         if (!trace_seq_bprintf(s, field->fmt, field->buf))
1192                 goto partial;
1193
1194         return TRACE_TYPE_HANDLED;
1195
1196  partial:
1197         return TRACE_TYPE_PARTIAL_LINE;
1198 }
1199
1200
1201 static struct trace_event trace_bprint_event = {
1202         .type           = TRACE_BPRINT,
1203         .trace          = trace_bprint_print,
1204         .raw            = trace_bprint_raw,
1205 };
1206
1207 /* TRACE_PRINT */
1208 static enum print_line_t trace_print_print(struct trace_iterator *iter,
1209                                            int flags)
1210 {
1211         struct print_entry *field;
1212         struct trace_seq *s = &iter->seq;
1213
1214         trace_assign_type(field, iter->ent);
1215
1216         if (!seq_print_ip_sym(s, field->ip, flags))
1217                 goto partial;
1218
1219         if (!trace_seq_printf(s, ": %s", field->buf))
1220                 goto partial;
1221
1222         return TRACE_TYPE_HANDLED;
1223
1224  partial:
1225         return TRACE_TYPE_PARTIAL_LINE;
1226 }
1227
1228 static enum print_line_t trace_print_raw(struct trace_iterator *iter, int flags)
1229 {
1230         struct print_entry *field;
1231
1232         trace_assign_type(field, iter->ent);
1233
1234         if (!trace_seq_printf(&iter->seq, "# %lx %s", field->ip, field->buf))
1235                 goto partial;
1236
1237         return TRACE_TYPE_HANDLED;
1238
1239  partial:
1240         return TRACE_TYPE_PARTIAL_LINE;
1241 }
1242
1243 static struct trace_event trace_print_event = {
1244         .type           = TRACE_PRINT,
1245         .trace          = trace_print_print,
1246         .raw            = trace_print_raw,
1247 };
1248
1249
1250 static struct trace_event *events[] __initdata = {
1251         &trace_fn_event,
1252         &trace_ctx_event,
1253         &trace_wake_event,
1254         &trace_special_event,
1255         &trace_stack_event,
1256         &trace_user_stack_event,
1257         &trace_bprint_event,
1258         &trace_print_event,
1259         NULL
1260 };
1261
1262 __init static int init_events(void)
1263 {
1264         struct trace_event *event;
1265         int i, ret;
1266
1267         for (i = 0; events[i]; i++) {
1268                 event = events[i];
1269
1270                 ret = register_ftrace_event(event);
1271                 if (!ret) {
1272                         printk(KERN_WARNING "event %d failed to register\n",
1273                                event->type);
1274                         WARN_ON_ONCE(1);
1275                 }
1276         }
1277
1278         return 0;
1279 }
1280 device_initcall(init_events);