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_sem);
  18
  19 static struct hlist_head event_hash[EVENT_HASHSIZE] __read_mostly;
  20
  21 static int next_event_type = __TRACE_LAST_TYPE + 1;
  22
  23 enum print_line_t trace_print_bputs_msg_only(struct trace_iterator *iter)
  24 {
  25         struct trace_seq *s = &iter->seq;
  26         struct trace_entry *entry = iter->ent;
  27         struct bputs_entry *field;
  28
  29         trace_assign_type(field, entry);
  30
  31         trace_seq_puts(s, field->str);
  32
  33         return trace_handle_return(s);
  34 }
  35
  36 enum print_line_t trace_print_bprintk_msg_only(struct trace_iterator *iter)
  37 {
  38         struct trace_seq *s = &iter->seq;
  39         struct trace_entry *entry = iter->ent;
  40         struct bprint_entry *field;
  41
  42         trace_assign_type(field, entry);
  43
  44         trace_seq_bprintf(s, field->fmt, field->buf);
  45
  46         return trace_handle_return(s);
  47 }
  48
  49 enum print_line_t trace_print_printk_msg_only(struct trace_iterator *iter)
  50 {
  51         struct trace_seq *s = &iter->seq;
  52         struct trace_entry *entry = iter->ent;
  53         struct print_entry *field;
  54
  55         trace_assign_type(field, entry);
  56
  57         trace_seq_puts(s, field->buf);
  58
  59         return trace_handle_return(s);
  60 }
  61
  62 const char *
  63 trace_print_flags_seq(struct trace_seq *p, const char *delim,
  64                       unsigned long flags,
  65                       const struct trace_print_flags *flag_array)
  66 {
  67         unsigned long mask;
  68         const char *str;
  69         const char *ret = trace_seq_buffer_ptr(p);
  70         int i, first = 1;
  71
  72         for (i = 0;  flag_array[i].name && flags; i++) {
  73
  74                 mask = flag_array[i].mask;
  75                 if ((flags & mask) != mask)
  76                         continue;
  77
  78                 str = flag_array[i].name;
  79                 flags &= ~mask;
  80                 if (!first && delim)
  81                         trace_seq_puts(p, delim);
  82                 else
  83                         first = 0;
  84                 trace_seq_puts(p, str);
  85         }
  86
  87         /* check for left over flags */
  88         if (flags) {
  89                 if (!first && delim)
  90                         trace_seq_puts(p, delim);
  91                 trace_seq_printf(p, "0x%lx", flags);
  92         }
  93
  94         trace_seq_putc(p, 0);
  95
  96         return ret;
  97 }
  98 EXPORT_SYMBOL(trace_print_flags_seq);
  99
 100 const char *
 101 trace_print_symbols_seq(struct trace_seq *p, unsigned long val,
 102                         const struct trace_print_flags *symbol_array)
 103 {
 104         int i;
 105         const char *ret = trace_seq_buffer_ptr(p);
 106
 107         for (i = 0;  symbol_array[i].name; i++) {
 108
 109                 if (val != symbol_array[i].mask)
 110                         continue;
 111
 112                 trace_seq_puts(p, symbol_array[i].name);
 113                 break;
 114         }
 115
 116         if (ret == (const char *)(trace_seq_buffer_ptr(p)))
 117                 trace_seq_printf(p, "0x%lx", val);
 118
 119         trace_seq_putc(p, 0);
 120
 121         return ret;
 122 }
 123 EXPORT_SYMBOL(trace_print_symbols_seq);
 124
 125 #if BITS_PER_LONG == 32
 126 const char *
 127 trace_print_symbols_seq_u64(struct trace_seq *p, unsigned long long val,
 128                          const struct trace_print_flags_u64 *symbol_array)
 129 {
 130         int i;
 131         const char *ret = trace_seq_buffer_ptr(p);
 132
 133         for (i = 0;  symbol_array[i].name; i++) {
 134
 135                 if (val != symbol_array[i].mask)
 136                         continue;
 137
 138                 trace_seq_puts(p, symbol_array[i].name);
 139                 break;
 140         }
 141
 142         if (ret == (const char *)(trace_seq_buffer_ptr(p)))
 143                 trace_seq_printf(p, "0x%llx", val);
 144
 145         trace_seq_putc(p, 0);
 146
 147         return ret;
 148 }
 149 EXPORT_SYMBOL(trace_print_symbols_seq_u64);
 150 #endif
 151
 152 const char *
 153 trace_print_bitmask_seq(struct trace_seq *p, void *bitmask_ptr,
 154                         unsigned int bitmask_size)
 155 {
 156         const char *ret = trace_seq_buffer_ptr(p);
 157
 158         trace_seq_bitmask(p, bitmask_ptr, bitmask_size * 8);
 159         trace_seq_putc(p, 0);
 160
 161         return ret;
 162 }
 163 EXPORT_SYMBOL_GPL(trace_print_bitmask_seq);
 164
 165 const char *
 166 trace_print_hex_seq(struct trace_seq *p, const unsigned char *buf, int buf_len)
 167 {
 168         int i;
 169         const char *ret = trace_seq_buffer_ptr(p);
 170
 171         for (i = 0; i < buf_len; i++)
 172                 trace_seq_printf(p, "%s%2.2x", i == 0 ? "" : " ", buf[i]);
 173
 174         trace_seq_putc(p, 0);
 175
 176         return ret;
 177 }
 178 EXPORT_SYMBOL(trace_print_hex_seq);
 179
 180 const char *
 181 trace_print_array_seq(struct trace_seq *p, const void *buf, int count,
 182                       size_t el_size)
 183 {
 184         const char *ret = trace_seq_buffer_ptr(p);
 185         const char *prefix = "";
 186         void *ptr = (void *)buf;
 187         size_t buf_len = count * el_size;
 188
 189         trace_seq_putc(p, '{');
 190
 191         while (ptr < buf + buf_len) {
 192                 switch (el_size) {
 193                 case 1:
 194                         trace_seq_printf(p, "%s0x%x", prefix,
 195                                          *(u8 *)ptr);
 196                         break;
 197                 case 2:
 198                         trace_seq_printf(p, "%s0x%x", prefix,
 199                                          *(u16 *)ptr);
 200                         break;
 201                 case 4:
 202                         trace_seq_printf(p, "%s0x%x", prefix,
 203                                          *(u32 *)ptr);
 204                         break;
 205                 case 8:
 206                         trace_seq_printf(p, "%s0x%llx", prefix,
 207                                          *(u64 *)ptr);
 208                         break;
 209                 default:
 210                         trace_seq_printf(p, "BAD SIZE:%zu 0x%x", el_size,
 211                                          *(u8 *)ptr);
 212                         el_size = 1;
 213                 }
 214                 prefix = ",";
 215                 ptr += el_size;
 216         }
 217
 218         trace_seq_putc(p, '}');
 219         trace_seq_putc(p, 0);
 220
 221         return ret;
 222 }
 223 EXPORT_SYMBOL(trace_print_array_seq);
 224
 225 int trace_raw_output_prep(struct trace_iterator *iter,
 226                           struct trace_event *trace_event)
 227 {
 228         struct trace_event_call *event;
 229         struct trace_seq *s = &iter->seq;
 230         struct trace_seq *p = &iter->tmp_seq;
 231         struct trace_entry *entry;
 232
 233         event = container_of(trace_event, struct trace_event_call, event);
 234         entry = iter->ent;
 235
 236         if (entry->type != event->event.type) {
 237                 WARN_ON_ONCE(1);
 238                 return TRACE_TYPE_UNHANDLED;
 239         }
 240
 241         trace_seq_init(p);
 242         trace_seq_printf(s, "%s: ", trace_event_name(event));
 243
 244         return trace_handle_return(s);
 245 }
 246 EXPORT_SYMBOL(trace_raw_output_prep);
 247
 248 static int trace_output_raw(struct trace_iterator *iter, char *name,
 249                             char *fmt, va_list ap)
 250 {
 251         struct trace_seq *s = &iter->seq;
 252
 253         trace_seq_printf(s, "%s: ", name);
 254         trace_seq_vprintf(s, fmt, ap);
 255
 256         return trace_handle_return(s);
 257 }
 258
 259 int trace_output_call(struct trace_iterator *iter, char *name, char *fmt, ...)
 260 {
 261         va_list ap;
 262         int ret;
 263
 264         va_start(ap, fmt);
 265         ret = trace_output_raw(iter, name, fmt, ap);
 266         va_end(ap);
 267
 268         return ret;
 269 }
 270 EXPORT_SYMBOL_GPL(trace_output_call);
 271
 272 #ifdef CONFIG_KRETPROBES
 273 static inline const char *kretprobed(const char *name)
 274 {
 275         static const char tramp_name[] = "kretprobe_trampoline";
 276         int size = sizeof(tramp_name);
 277
 278         if (strncmp(tramp_name, name, size) == 0)
 279                 return "[unknown/kretprobe'd]";
 280         return name;
 281 }
 282 #else
 283 static inline const char *kretprobed(const char *name)
 284 {
 285         return name;
 286 }
 287 #endif /* CONFIG_KRETPROBES */
 288
 289 static void
 290 seq_print_sym_short(struct trace_seq *s, const char *fmt, unsigned long address)
 291 {
 292 #ifdef CONFIG_KALLSYMS
 293         char str[KSYM_SYMBOL_LEN];
 294         const char *name;
 295
 296         kallsyms_lookup(address, NULL, NULL, NULL, str);
 297
 298         name = kretprobed(str);
 299
 300         trace_seq_printf(s, fmt, name);
 301 #endif
 302 }
 303
 304 static void
 305 seq_print_sym_offset(struct trace_seq *s, const char *fmt,
 306                      unsigned long address)
 307 {
 308 #ifdef CONFIG_KALLSYMS
 309         char str[KSYM_SYMBOL_LEN];
 310         const char *name;
 311
 312         sprint_symbol(str, address);
 313         name = kretprobed(str);
 314
 315         trace_seq_printf(s, fmt, name);
 316 #endif
 317 }
 318
 319 #ifndef CONFIG_64BIT
 320 # define IP_FMT "%08lx"
 321 #else
 322 # define IP_FMT "%016lx"
 323 #endif
 324
 325 static int seq_print_user_ip(struct trace_seq *s, struct mm_struct *mm,
 326                              unsigned long ip, unsigned long sym_flags)
 327 {
 328         struct file *file = NULL;
 329         unsigned long vmstart = 0;
 330         int ret = 1;
 331
 332         if (s->full)
 333                 return 0;
 334
 335         if (mm) {
 336                 const struct vm_area_struct *vma;
 337
 338                 down_read(&mm->mmap_sem);
 339                 vma = find_vma(mm, ip);
 340                 if (vma) {
 341                         file = vma->vm_file;
 342                         vmstart = vma->vm_start;
 343                 }
 344                 if (file) {
 345                         ret = trace_seq_path(s, &file->f_path);
 346                         if (ret)
 347                                 trace_seq_printf(s, "[+0x%lx]",
 348                                                  ip - vmstart);
 349                 }
 350                 up_read(&mm->mmap_sem);
 351         }
 352         if (ret && ((sym_flags & TRACE_ITER_SYM_ADDR) || !file))
 353                 trace_seq_printf(s, " <" IP_FMT ">", ip);
 354         return !trace_seq_has_overflowed(s);
 355 }
 356
 357 int
 358 seq_print_ip_sym(struct trace_seq *s, unsigned long ip, unsigned long sym_flags)
 359 {
 360         if (!ip) {
 361                 trace_seq_putc(s, '0');
 362                 goto out;
 363         }
 364
 365         if (sym_flags & TRACE_ITER_SYM_OFFSET)
 366                 seq_print_sym_offset(s, "%s", ip);
 367         else
 368                 seq_print_sym_short(s, "%s", ip);
 369
 370         if (sym_flags & TRACE_ITER_SYM_ADDR)
 371                 trace_seq_printf(s, " <" IP_FMT ">", ip);
 372
 373  out:
 374         return !trace_seq_has_overflowed(s);
 375 }
 376
 377 /**
 378  * trace_print_lat_fmt - print the irq, preempt and lockdep fields
 379  * @s: trace seq struct to write to
 380  * @entry: The trace entry field from the ring buffer
 381  *
 382  * Prints the generic fields of irqs off, in hard or softirq, preempt
 383  * count.
 384  */
 385 int trace_print_lat_fmt(struct trace_seq *s, struct trace_entry *entry)
 386 {
 387         char hardsoft_irq;
 388         char need_resched;
 389         char irqs_off;
 390         int hardirq;
 391         int softirq;
 392
 393         hardirq = entry->flags & TRACE_FLAG_HARDIRQ;
 394         softirq = entry->flags & TRACE_FLAG_SOFTIRQ;
 395
 396         irqs_off =
 397                 (entry->flags & TRACE_FLAG_IRQS_OFF) ? 'd' :
 398                 (entry->flags & TRACE_FLAG_IRQS_NOSUPPORT) ? 'X' :
 399                 '.';
 400
 401         switch (entry->flags & (TRACE_FLAG_NEED_RESCHED |
 402                                 TRACE_FLAG_PREEMPT_RESCHED)) {
 403         case TRACE_FLAG_NEED_RESCHED | TRACE_FLAG_PREEMPT_RESCHED:
 404                 need_resched = 'N';
 405                 break;
 406         case TRACE_FLAG_NEED_RESCHED:
 407                 need_resched = 'n';
 408                 break;
 409         case TRACE_FLAG_PREEMPT_RESCHED:
 410                 need_resched = 'p';
 411                 break;
 412         default:
 413                 need_resched = '.';
 414                 break;
 415         }
 416
 417         hardsoft_irq =
 418                 (hardirq && softirq) ? 'H' :
 419                 hardirq ? 'h' :
 420                 softirq ? 's' :
 421                 '.';
 422
 423         trace_seq_printf(s, "%c%c%c",
 424                          irqs_off, need_resched, hardsoft_irq);
 425
 426         if (entry->preempt_count)
 427                 trace_seq_printf(s, "%x", entry->preempt_count);
 428         else
 429                 trace_seq_putc(s, '.');
 430
 431         return !trace_seq_has_overflowed(s);
 432 }
 433
 434 static int
 435 lat_print_generic(struct trace_seq *s, struct trace_entry *entry, int cpu)
 436 {
 437         char comm[TASK_COMM_LEN];
 438
 439         trace_find_cmdline(entry->pid, comm);
 440
 441         trace_seq_printf(s, "%8.8s-%-5d %3d",
 442                          comm, entry->pid, cpu);
 443
 444         return trace_print_lat_fmt(s, entry);
 445 }
 446
 447 #undef MARK
 448 #define MARK(v, s) {.val = v, .sym = s}
 449 /* trace overhead mark */
 450 static const struct trace_mark {
 451         unsigned long long      val; /* unit: nsec */
 452         char                    sym;
 453 } mark[] = {
 454         MARK(1000000000ULL      , '$'), /* 1 sec */
 455         MARK(100000000ULL       , '@'), /* 100 msec */
 456         MARK(10000000ULL        , '*'), /* 10 msec */
 457         MARK(1000000ULL         , '#'), /* 1000 usecs */
 458         MARK(100000ULL          , '!'), /* 100 usecs */
 459         MARK(10000ULL           , '+'), /* 10 usecs */
 460 };
 461 #undef MARK
 462
 463 char trace_find_mark(unsigned long long d)
 464 {
 465         int i;
 466         int size = ARRAY_SIZE(mark);
 467
 468         for (i = 0; i < size; i++) {
 469                 if (d > mark[i].val)
 470                         break;
 471         }
 472
 473         return (i == size) ? ' ' : mark[i].sym;
 474 }
 475
 476 static int
 477 lat_print_timestamp(struct trace_iterator *iter, u64 next_ts)
 478 {
 479         struct trace_array *tr = iter->tr;
 480         unsigned long verbose = tr->trace_flags & TRACE_ITER_VERBOSE;
 481         unsigned long in_ns = iter->iter_flags & TRACE_FILE_TIME_IN_NS;
 482         unsigned long long abs_ts = iter->ts - iter->trace_buffer->time_start;
 483         unsigned long long rel_ts = next_ts - iter->ts;
 484         struct trace_seq *s = &iter->seq;
 485
 486         if (in_ns) {
 487                 abs_ts = ns2usecs(abs_ts);
 488                 rel_ts = ns2usecs(rel_ts);
 489         }
 490
 491         if (verbose && in_ns) {
 492                 unsigned long abs_usec = do_div(abs_ts, USEC_PER_MSEC);
 493                 unsigned long abs_msec = (unsigned long)abs_ts;
 494                 unsigned long rel_usec = do_div(rel_ts, USEC_PER_MSEC);
 495                 unsigned long rel_msec = (unsigned long)rel_ts;
 496
 497                 trace_seq_printf(
 498                         s, "[%08llx] %ld.%03ldms (+%ld.%03ldms): ",
 499                         ns2usecs(iter->ts),
 500                         abs_msec, abs_usec,
 501                         rel_msec, rel_usec);
 502
 503         } else if (verbose && !in_ns) {
 504                 trace_seq_printf(
 505                         s, "[%016llx] %lld (+%lld): ",
 506                         iter->ts, abs_ts, rel_ts);
 507
 508         } else if (!verbose && in_ns) {
 509                 trace_seq_printf(
 510                         s, " %4lldus%c: ",
 511                         abs_ts,
 512                         trace_find_mark(rel_ts * NSEC_PER_USEC));
 513
 514         } else { /* !verbose && !in_ns */
 515                 trace_seq_printf(s, " %4lld: ", abs_ts);
 516         }
 517
 518         return !trace_seq_has_overflowed(s);
 519 }
 520
 521 int trace_print_context(struct trace_iterator *iter)
 522 {
 523         struct trace_array *tr = iter->tr;
 524         struct trace_seq *s = &iter->seq;
 525         struct trace_entry *entry = iter->ent;
 526         unsigned long long t;
 527         unsigned long secs, usec_rem;
 528         char comm[TASK_COMM_LEN];
 529
 530         trace_find_cmdline(entry->pid, comm);
 531
 532         trace_seq_printf(s, "%16s-%-5d [%03d] ",
 533                                comm, entry->pid, iter->cpu);
 534
 535         if (tr->trace_flags & TRACE_ITER_IRQ_INFO)
 536                 trace_print_lat_fmt(s, entry);
 537
 538         if (iter->iter_flags & TRACE_FILE_TIME_IN_NS) {
 539                 t = ns2usecs(iter->ts);
 540                 usec_rem = do_div(t, USEC_PER_SEC);
 541                 secs = (unsigned long)t;
 542                 trace_seq_printf(s, " %5lu.%06lu: ", secs, usec_rem);
 543         } else
 544                 trace_seq_printf(s, " %12llu: ", iter->ts);
 545
 546         return !trace_seq_has_overflowed(s);
 547 }
 548
 549 int trace_print_lat_context(struct trace_iterator *iter)
 550 {
 551         struct trace_array *tr = iter->tr;
 552         /* trace_find_next_entry will reset ent_size */
 553         int ent_size = iter->ent_size;
 554         struct trace_seq *s = &iter->seq;
 555         u64 next_ts;
 556         struct trace_entry *entry = iter->ent,
 557                            *next_entry = trace_find_next_entry(iter, NULL,
 558                                                                &next_ts);
 559         unsigned long verbose = (tr->trace_flags & TRACE_ITER_VERBOSE);
 560
 561         /* Restore the original ent_size */
 562         iter->ent_size = ent_size;
 563
 564         if (!next_entry)
 565                 next_ts = iter->ts;
 566
 567         if (verbose) {
 568                 char comm[TASK_COMM_LEN];
 569
 570                 trace_find_cmdline(entry->pid, comm);
 571
 572                 trace_seq_printf(
 573                         s, "%16s %5d %3d %d %08x %08lx ",
 574                         comm, entry->pid, iter->cpu, entry->flags,
 575                         entry->preempt_count, iter->idx);
 576         } else {
 577                 lat_print_generic(s, entry, iter->cpu);
 578         }
 579
 580         lat_print_timestamp(iter, next_ts);
 581
 582         return !trace_seq_has_overflowed(s);
 583 }
 584
 585 static const char state_to_char[] = TASK_STATE_TO_CHAR_STR;
 586
 587 static int task_state_char(unsigned long state)
 588 {
 589         int bit = state ? __ffs(state) + 1 : 0;
 590
 591         return bit < sizeof(state_to_char) - 1 ? state_to_char[bit] : '?';
 592 }
 593
 594 /**
 595  * ftrace_find_event - find a registered event
 596  * @type: the type of event to look for
 597  *
 598  * Returns an event of type @type otherwise NULL
 599  * Called with trace_event_read_lock() held.
 600  */
 601 struct trace_event *ftrace_find_event(int type)
 602 {
 603         struct trace_event *event;
 604         unsigned key;
 605
 606         key = type & (EVENT_HASHSIZE - 1);
 607
 608         hlist_for_each_entry(event, &event_hash[key], node) {
 609                 if (event->type == type)
 610                         return event;
 611         }
 612
 613         return NULL;
 614 }
 615
 616 static LIST_HEAD(ftrace_event_list);
 617
 618 static int trace_search_list(struct list_head **list)
 619 {
 620         struct trace_event *e;
 621         int last = __TRACE_LAST_TYPE;
 622
 623         if (list_empty(&ftrace_event_list)) {
 624                 *list = &ftrace_event_list;
 625                 return last + 1;
 626         }
 627
 628         /*
 629          * We used up all possible max events,
 630          * lets see if somebody freed one.
 631          */
 632         list_for_each_entry(e, &ftrace_event_list, list) {
 633                 if (e->type != last + 1)
 634                         break;
 635                 last++;
 636         }
 637
 638         /* Did we used up all 65 thousand events??? */
 639         if ((last + 1) > TRACE_EVENT_TYPE_MAX)
 640                 return 0;
 641
 642         *list = &e->list;
 643         return last + 1;
 644 }
 645
 646 void trace_event_read_lock(void)
 647 {
 648         down_read(&trace_event_sem);
 649 }
 650
 651 void trace_event_read_unlock(void)
 652 {
 653         up_read(&trace_event_sem);
 654 }
 655
 656 /**
 657  * register_trace_event - register output for an event type
 658  * @event: the event type to register
 659  *
 660  * Event types are stored in a hash and this hash is used to
 661  * find a way to print an event. If the @event->type is set
 662  * then it will use that type, otherwise it will assign a
 663  * type to use.
 664  *
 665  * If you assign your own type, please make sure it is added
 666  * to the trace_type enum in trace.h, to avoid collisions
 667  * with the dynamic types.
 668  *
 669  * Returns the event type number or zero on error.
 670  */
 671 int register_trace_event(struct trace_event *event)
 672 {
 673         unsigned key;
 674         int ret = 0;
 675
 676         down_write(&trace_event_sem);
 677
 678         if (WARN_ON(!event))
 679                 goto out;
 680
 681         if (WARN_ON(!event->funcs))
 682                 goto out;
 683
 684         INIT_LIST_HEAD(&event->list);
 685
 686         if (!event->type) {
 687                 struct list_head *list = NULL;
 688
 689                 if (next_event_type > TRACE_EVENT_TYPE_MAX) {
 690
 691                         event->type = trace_search_list(&list);
 692                         if (!event->type)
 693                                 goto out;
 694
 695                 } else {
 696
 697                         event->type = next_event_type++;
 698                         list = &ftrace_event_list;
 699                 }
 700
 701                 if (WARN_ON(ftrace_find_event(event->type)))
 702                         goto out;
 703
 704                 list_add_tail(&event->list, list);
 705
 706         } else if (event->type > __TRACE_LAST_TYPE) {
 707                 printk(KERN_WARNING "Need to add type to trace.h\n");
 708                 WARN_ON(1);
 709                 goto out;
 710         } else {
 711                 /* Is this event already used */
 712                 if (ftrace_find_event(event->type))
 713                         goto out;
 714         }
 715
 716         if (event->funcs->trace == NULL)
 717                 event->funcs->trace = trace_nop_print;
 718         if (event->funcs->raw == NULL)
 719                 event->funcs->raw = trace_nop_print;
 720         if (event->funcs->hex == NULL)
 721                 event->funcs->hex = trace_nop_print;
 722         if (event->funcs->binary == NULL)
 723                 event->funcs->binary = trace_nop_print;
 724
 725         key = event->type & (EVENT_HASHSIZE - 1);
 726
 727         hlist_add_head(&event->node, &event_hash[key]);
 728
 729         ret = event->type;
 730  out:
 731         up_write(&trace_event_sem);
 732
 733         return ret;
 734 }
 735 EXPORT_SYMBOL_GPL(register_trace_event);
 736
 737 /*
 738  * Used by module code with the trace_event_sem held for write.
 739  */
 740 int __unregister_trace_event(struct trace_event *event)
 741 {
 742         hlist_del(&event->node);
 743         list_del(&event->list);
 744         return 0;
 745 }
 746
 747 /**
 748  * unregister_trace_event - remove a no longer used event
 749  * @event: the event to remove
 750  */
 751 int unregister_trace_event(struct trace_event *event)
 752 {
 753         down_write(&trace_event_sem);
 754         __unregister_trace_event(event);
 755         up_write(&trace_event_sem);
 756
 757         return 0;
 758 }
 759 EXPORT_SYMBOL_GPL(unregister_trace_event);
 760
 761 /*
 762  * Standard events
 763  */
 764
 765 enum print_line_t trace_nop_print(struct trace_iterator *iter, int flags,
 766                                   struct trace_event *event)
 767 {
 768         trace_seq_printf(&iter->seq, "type: %d\n", iter->ent->type);
 769
 770         return trace_handle_return(&iter->seq);
 771 }
 772
 773 /* TRACE_FN */
 774 static enum print_line_t trace_fn_trace(struct trace_iterator *iter, int flags,
 775                                         struct trace_event *event)
 776 {
 777         struct ftrace_entry *field;
 778         struct trace_seq *s = &iter->seq;
 779
 780         trace_assign_type(field, iter->ent);
 781
 782         seq_print_ip_sym(s, field->ip, flags);
 783
 784         if ((flags & TRACE_ITER_PRINT_PARENT) && field->parent_ip) {
 785                 trace_seq_puts(s, " <-");
 786                 seq_print_ip_sym(s, field->parent_ip, flags);
 787         }
 788
 789         trace_seq_putc(s, '\n');
 790
 791         return trace_handle_return(s);
 792 }
 793
 794 static enum print_line_t trace_fn_raw(struct trace_iterator *iter, int flags,
 795                                       struct trace_event *event)
 796 {
 797         struct ftrace_entry *field;
 798
 799         trace_assign_type(field, iter->ent);
 800
 801         trace_seq_printf(&iter->seq, "%lx %lx\n",
 802                          field->ip,
 803                          field->parent_ip);
 804
 805         return trace_handle_return(&iter->seq);
 806 }
 807
 808 static enum print_line_t trace_fn_hex(struct trace_iterator *iter, int flags,
 809                                       struct trace_event *event)
 810 {
 811         struct ftrace_entry *field;
 812         struct trace_seq *s = &iter->seq;
 813
 814         trace_assign_type(field, iter->ent);
 815
 816         SEQ_PUT_HEX_FIELD(s, field->ip);
 817         SEQ_PUT_HEX_FIELD(s, field->parent_ip);
 818
 819         return trace_handle_return(s);
 820 }
 821
 822 static enum print_line_t trace_fn_bin(struct trace_iterator *iter, int flags,
 823                                       struct trace_event *event)
 824 {
 825         struct ftrace_entry *field;
 826         struct trace_seq *s = &iter->seq;
 827
 828         trace_assign_type(field, iter->ent);
 829
 830         SEQ_PUT_FIELD(s, field->ip);
 831         SEQ_PUT_FIELD(s, field->parent_ip);
 832
 833         return trace_handle_return(s);
 834 }
 835
 836 static struct trace_event_functions trace_fn_funcs = {
 837         .trace          = trace_fn_trace,
 838         .raw            = trace_fn_raw,
 839         .hex            = trace_fn_hex,
 840         .binary         = trace_fn_bin,
 841 };
 842
 843 static struct trace_event trace_fn_event = {
 844         .type           = TRACE_FN,
 845         .funcs          = &trace_fn_funcs,
 846 };
 847
 848 /* TRACE_CTX an TRACE_WAKE */
 849 static enum print_line_t trace_ctxwake_print(struct trace_iterator *iter,
 850                                              char *delim)
 851 {
 852         struct ctx_switch_entry *field;
 853         char comm[TASK_COMM_LEN];
 854         int S, T;
 855
 856
 857         trace_assign_type(field, iter->ent);
 858
 859         T = task_state_char(field->next_state);
 860         S = task_state_char(field->prev_state);
 861         trace_find_cmdline(field->next_pid, comm);
 862         trace_seq_printf(&iter->seq,
 863                          " %5d:%3d:%c %s [%03d] %5d:%3d:%c %s\n",
 864                          field->prev_pid,
 865                          field->prev_prio,
 866                          S, delim,
 867                          field->next_cpu,
 868                          field->next_pid,
 869                          field->next_prio,
 870                          T, comm);
 871
 872         return trace_handle_return(&iter->seq);
 873 }
 874
 875 static enum print_line_t trace_ctx_print(struct trace_iterator *iter, int flags,
 876                                          struct trace_event *event)
 877 {
 878         return trace_ctxwake_print(iter, "==>");
 879 }
 880
 881 static enum print_line_t trace_wake_print(struct trace_iterator *iter,
 882                                           int flags, struct trace_event *event)
 883 {
 884         return trace_ctxwake_print(iter, "  +");
 885 }
 886
 887 static int trace_ctxwake_raw(struct trace_iterator *iter, char S)
 888 {
 889         struct ctx_switch_entry *field;
 890         int T;
 891
 892         trace_assign_type(field, iter->ent);
 893
 894         if (!S)
 895                 S = task_state_char(field->prev_state);
 896         T = task_state_char(field->next_state);
 897         trace_seq_printf(&iter->seq, "%d %d %c %d %d %d %c\n",
 898                          field->prev_pid,
 899                          field->prev_prio,
 900                          S,
 901                          field->next_cpu,
 902                          field->next_pid,
 903                          field->next_prio,
 904                          T);
 905
 906         return trace_handle_return(&iter->seq);
 907 }
 908
 909 static enum print_line_t trace_ctx_raw(struct trace_iterator *iter, int flags,
 910                                        struct trace_event *event)
 911 {
 912         return trace_ctxwake_raw(iter, 0);
 913 }
 914
 915 static enum print_line_t trace_wake_raw(struct trace_iterator *iter, int flags,
 916                                         struct trace_event *event)
 917 {
 918         return trace_ctxwake_raw(iter, '+');
 919 }
 920
 921
 922 static int trace_ctxwake_hex(struct trace_iterator *iter, char S)
 923 {
 924         struct ctx_switch_entry *field;
 925         struct trace_seq *s = &iter->seq;
 926         int T;
 927
 928         trace_assign_type(field, iter->ent);
 929
 930         if (!S)
 931                 S = task_state_char(field->prev_state);
 932         T = task_state_char(field->next_state);
 933
 934         SEQ_PUT_HEX_FIELD(s, field->prev_pid);
 935         SEQ_PUT_HEX_FIELD(s, field->prev_prio);
 936         SEQ_PUT_HEX_FIELD(s, S);
 937         SEQ_PUT_HEX_FIELD(s, field->next_cpu);
 938         SEQ_PUT_HEX_FIELD(s, field->next_pid);
 939         SEQ_PUT_HEX_FIELD(s, field->next_prio);
 940         SEQ_PUT_HEX_FIELD(s, T);
 941
 942         return trace_handle_return(s);
 943 }
 944
 945 static enum print_line_t trace_ctx_hex(struct trace_iterator *iter, int flags,
 946                                        struct trace_event *event)
 947 {
 948         return trace_ctxwake_hex(iter, 0);
 949 }
 950
 951 static enum print_line_t trace_wake_hex(struct trace_iterator *iter, int flags,
 952                                         struct trace_event *event)
 953 {
 954         return trace_ctxwake_hex(iter, '+');
 955 }
 956
 957 static enum print_line_t trace_ctxwake_bin(struct trace_iterator *iter,
 958                                            int flags, struct trace_event *event)
 959 {
 960         struct ctx_switch_entry *field;
 961         struct trace_seq *s = &iter->seq;
 962
 963         trace_assign_type(field, iter->ent);
 964
 965         SEQ_PUT_FIELD(s, field->prev_pid);
 966         SEQ_PUT_FIELD(s, field->prev_prio);
 967         SEQ_PUT_FIELD(s, field->prev_state);
 968         SEQ_PUT_FIELD(s, field->next_cpu);
 969         SEQ_PUT_FIELD(s, field->next_pid);
 970         SEQ_PUT_FIELD(s, field->next_prio);
 971         SEQ_PUT_FIELD(s, field->next_state);
 972
 973         return trace_handle_return(s);
 974 }
 975
 976 static struct trace_event_functions trace_ctx_funcs = {
 977         .trace          = trace_ctx_print,
 978         .raw            = trace_ctx_raw,
 979         .hex            = trace_ctx_hex,
 980         .binary         = trace_ctxwake_bin,
 981 };
 982
 983 static struct trace_event trace_ctx_event = {
 984         .type           = TRACE_CTX,
 985         .funcs          = &trace_ctx_funcs,
 986 };
 987
 988 static struct trace_event_functions trace_wake_funcs = {
 989         .trace          = trace_wake_print,
 990         .raw            = trace_wake_raw,
 991         .hex            = trace_wake_hex,
 992         .binary         = trace_ctxwake_bin,
 993 };
 994
 995 static struct trace_event trace_wake_event = {
 996         .type           = TRACE_WAKE,
 997         .funcs          = &trace_wake_funcs,
 998 };
 999
1000 /* TRACE_STACK */
1001
1002 static enum print_line_t trace_stack_print(struct trace_iterator *iter,
1003                                            int flags, struct trace_event *event)
1004 {
1005         struct stack_entry *field;
1006         struct trace_seq *s = &iter->seq;
1007         unsigned long *p;
1008         unsigned long *end;
1009
1010         trace_assign_type(field, iter->ent);
1011         end = (unsigned long *)((long)iter->ent + iter->ent_size);
1012
1013         trace_seq_puts(s, "<stack trace>\n");
1014
1015         for (p = field->caller; p && *p != ULONG_MAX && p < end; p++) {
1016
1017                 if (trace_seq_has_overflowed(s))
1018                         break;
1019
1020                 trace_seq_puts(s, " => ");
1021                 seq_print_ip_sym(s, *p, flags);
1022                 trace_seq_putc(s, '\n');
1023         }
1024
1025         return trace_handle_return(s);
1026 }
1027
1028 static struct trace_event_functions trace_stack_funcs = {
1029         .trace          = trace_stack_print,
1030 };
1031
1032 static struct trace_event trace_stack_event = {
1033         .type           = TRACE_STACK,
1034         .funcs          = &trace_stack_funcs,
1035 };
1036
1037 /* TRACE_USER_STACK */
1038 static enum print_line_t trace_user_stack_print(struct trace_iterator *iter,
1039                                                 int flags, struct trace_event *event)
1040 {
1041         struct trace_array *tr = iter->tr;
1042         struct userstack_entry *field;
1043         struct trace_seq *s = &iter->seq;
1044         struct mm_struct *mm = NULL;
1045         unsigned int i;
1046
1047         trace_assign_type(field, iter->ent);
1048
1049         trace_seq_puts(s, "<user stack trace>\n");
1050
1051         if (tr->trace_flags & TRACE_ITER_SYM_USEROBJ) {
1052                 struct task_struct *task;
1053                 /*
1054                  * we do the lookup on the thread group leader,
1055                  * since individual threads might have already quit!
1056                  */
1057                 rcu_read_lock();
1058                 task = find_task_by_vpid(field->tgid);
1059                 if (task)
1060                         mm = get_task_mm(task);
1061                 rcu_read_unlock();
1062         }
1063
1064         for (i = 0; i < FTRACE_STACK_ENTRIES; i++) {
1065                 unsigned long ip = field->caller[i];
1066
1067                 if (ip == ULONG_MAX || trace_seq_has_overflowed(s))
1068                         break;
1069
1070                 trace_seq_puts(s, " => ");
1071
1072                 if (!ip) {
1073                         trace_seq_puts(s, "??");
1074                         trace_seq_putc(s, '\n');
1075                         continue;
1076                 }
1077
1078                 seq_print_user_ip(s, mm, ip, flags);
1079                 trace_seq_putc(s, '\n');
1080         }
1081
1082         if (mm)
1083                 mmput(mm);
1084
1085         return trace_handle_return(s);
1086 }
1087
1088 static struct trace_event_functions trace_user_stack_funcs = {
1089         .trace          = trace_user_stack_print,
1090 };
1091
1092 static struct trace_event trace_user_stack_event = {
1093         .type           = TRACE_USER_STACK,
1094         .funcs          = &trace_user_stack_funcs,
1095 };
1096
1097 /* TRACE_BPUTS */
1098 static enum print_line_t
1099 trace_bputs_print(struct trace_iterator *iter, int flags,
1100                    struct trace_event *event)
1101 {
1102         struct trace_entry *entry = iter->ent;
1103         struct trace_seq *s = &iter->seq;
1104         struct bputs_entry *field;
1105
1106         trace_assign_type(field, entry);
1107
1108         seq_print_ip_sym(s, field->ip, flags);
1109         trace_seq_puts(s, ": ");
1110         trace_seq_puts(s, field->str);
1111
1112         return trace_handle_return(s);
1113 }
1114
1115
1116 static enum print_line_t
1117 trace_bputs_raw(struct trace_iterator *iter, int flags,
1118                 struct trace_event *event)
1119 {
1120         struct bputs_entry *field;
1121         struct trace_seq *s = &iter->seq;
1122
1123         trace_assign_type(field, iter->ent);
1124
1125         trace_seq_printf(s, ": %lx : ", field->ip);
1126         trace_seq_puts(s, field->str);
1127
1128         return trace_handle_return(s);
1129 }
1130
1131 static struct trace_event_functions trace_bputs_funcs = {
1132         .trace          = trace_bputs_print,
1133         .raw            = trace_bputs_raw,
1134 };
1135
1136 static struct trace_event trace_bputs_event = {
1137         .type           = TRACE_BPUTS,
1138         .funcs          = &trace_bputs_funcs,
1139 };
1140
1141 /* TRACE_BPRINT */
1142 static enum print_line_t
1143 trace_bprint_print(struct trace_iterator *iter, int flags,
1144                    struct trace_event *event)
1145 {
1146         struct trace_entry *entry = iter->ent;
1147         struct trace_seq *s = &iter->seq;
1148         struct bprint_entry *field;
1149
1150         trace_assign_type(field, entry);
1151
1152         seq_print_ip_sym(s, field->ip, flags);
1153         trace_seq_puts(s, ": ");
1154         trace_seq_bprintf(s, field->fmt, field->buf);
1155
1156         return trace_handle_return(s);
1157 }
1158
1159
1160 static enum print_line_t
1161 trace_bprint_raw(struct trace_iterator *iter, int flags,
1162                  struct trace_event *event)
1163 {
1164         struct bprint_entry *field;
1165         struct trace_seq *s = &iter->seq;
1166
1167         trace_assign_type(field, iter->ent);
1168
1169         trace_seq_printf(s, ": %lx : ", field->ip);
1170         trace_seq_bprintf(s, field->fmt, field->buf);
1171
1172         return trace_handle_return(s);
1173 }
1174
1175 static struct trace_event_functions trace_bprint_funcs = {
1176         .trace          = trace_bprint_print,
1177         .raw            = trace_bprint_raw,
1178 };
1179
1180 static struct trace_event trace_bprint_event = {
1181         .type           = TRACE_BPRINT,
1182         .funcs          = &trace_bprint_funcs,
1183 };
1184
1185 /* TRACE_PRINT */
1186 static enum print_line_t trace_print_print(struct trace_iterator *iter,
1187                                            int flags, struct trace_event *event)
1188 {
1189         struct print_entry *field;
1190         struct trace_seq *s = &iter->seq;
1191
1192         trace_assign_type(field, iter->ent);
1193
1194         seq_print_ip_sym(s, field->ip, flags);
1195         trace_seq_printf(s, ": %s", field->buf);
1196
1197         return trace_handle_return(s);
1198 }
1199
1200 static enum print_line_t trace_print_raw(struct trace_iterator *iter, int flags,
1201                                          struct trace_event *event)
1202 {
1203         struct print_entry *field;
1204
1205         trace_assign_type(field, iter->ent);
1206
1207         trace_seq_printf(&iter->seq, "# %lx %s", field->ip, field->buf);
1208
1209         return trace_handle_return(&iter->seq);
1210 }
1211
1212 static struct trace_event_functions trace_print_funcs = {
1213         .trace          = trace_print_print,
1214         .raw            = trace_print_raw,
1215 };
1216
1217 static struct trace_event trace_print_event = {
1218         .type           = TRACE_PRINT,
1219         .funcs          = &trace_print_funcs,
1220 };
1221
1222
1223 static struct trace_event *events[] __initdata = {
1224         &trace_fn_event,
1225         &trace_ctx_event,
1226         &trace_wake_event,
1227         &trace_stack_event,
1228         &trace_user_stack_event,
1229         &trace_bputs_event,
1230         &trace_bprint_event,
1231         &trace_print_event,
1232         NULL
1233 };
1234
1235 __init static int init_events(void)
1236 {
1237         struct trace_event *event;
1238         int i, ret;
1239
1240         for (i = 0; events[i]; i++) {
1241                 event = events[i];
1242
1243                 ret = register_trace_event(event);
1244                 if (!ret) {
1245                         printk(KERN_WARNING "event %d failed to register\n",
1246                                event->type);
1247                         WARN_ON_ONCE(1);
1248                 }
1249         }
1250
1251         return 0;
1252 }
1253 early_initcall(init_events);