kernel/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_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 need_resched_lazy;
 390         char irqs_off;
 391         int hardirq;
 392         int softirq;
 393
 394         hardirq = entry->flags & TRACE_FLAG_HARDIRQ;
 395         softirq = entry->flags & TRACE_FLAG_SOFTIRQ;
 396
 397         irqs_off =
 398                 (entry->flags & TRACE_FLAG_IRQS_OFF) ? 'd' :
 399                 (entry->flags & TRACE_FLAG_IRQS_NOSUPPORT) ? 'X' :
 400                 '.';
 401
 402         switch (entry->flags & (TRACE_FLAG_NEED_RESCHED |
 403                                 TRACE_FLAG_PREEMPT_RESCHED)) {
 404         case TRACE_FLAG_NEED_RESCHED | TRACE_FLAG_PREEMPT_RESCHED:
 405                 need_resched = 'N';
 406                 break;
 407         case TRACE_FLAG_NEED_RESCHED:
 408                 need_resched = 'n';
 409                 break;
 410         case TRACE_FLAG_PREEMPT_RESCHED:
 411                 need_resched = 'p';
 412                 break;
 413         default:
 414                 need_resched = '.';
 415                 break;
 416         }
 417         need_resched_lazy =
 418                 (entry->flags & TRACE_FLAG_NEED_RESCHED_LAZY) ? 'L' : '.';
 419
 420         hardsoft_irq =
 421                 (hardirq && softirq) ? 'H' :
 422                 hardirq ? 'h' :
 423                 softirq ? 's' :
 424                 '.';
 425
 426         trace_seq_printf(s, "%c%c%c%c",
 427                          irqs_off, need_resched, need_resched_lazy,
 428                          hardsoft_irq);
 429
 430         if (entry->preempt_count)
 431                 trace_seq_printf(s, "%x", entry->preempt_count);
 432         else
 433                 trace_seq_putc(s, '.');
 434
 435         if (entry->preempt_lazy_count)
 436                 trace_seq_printf(s, "%x", entry->preempt_lazy_count);
 437         else
 438                 trace_seq_putc(s, '.');
 439
 440         if (entry->migrate_disable)
 441                 trace_seq_printf(s, "%x", entry->migrate_disable);
 442         else
 443                 trace_seq_putc(s, '.');
 444
 445         return !trace_seq_has_overflowed(s);
 446 }
 447
 448 static int
 449 lat_print_generic(struct trace_seq *s, struct trace_entry *entry, int cpu)
 450 {
 451         char comm[TASK_COMM_LEN];
 452
 453         trace_find_cmdline(entry->pid, comm);
 454
 455         trace_seq_printf(s, "%8.8s-%-5d %3d",
 456                          comm, entry->pid, cpu);
 457
 458         return trace_print_lat_fmt(s, entry);
 459 }
 460
 461 #undef MARK
 462 #define MARK(v, s) {.val = v, .sym = s}
 463 /* trace overhead mark */
 464 static const struct trace_mark {
 465         unsigned long long      val; /* unit: nsec */
 466         char                    sym;
 467 } mark[] = {
 468         MARK(1000000000ULL      , '$'), /* 1 sec */
 469         MARK(100000000ULL       , '@'), /* 100 msec */
 470         MARK(10000000ULL        , '*'), /* 10 msec */
 471         MARK(1000000ULL         , '#'), /* 1000 usecs */
 472         MARK(100000ULL          , '!'), /* 100 usecs */
 473         MARK(10000ULL           , '+'), /* 10 usecs */
 474 };
 475 #undef MARK
 476
 477 char trace_find_mark(unsigned long long d)
 478 {
 479         int i;
 480         int size = ARRAY_SIZE(mark);
 481
 482         for (i = 0; i < size; i++) {
 483                 if (d > mark[i].val)
 484                         break;
 485         }
 486
 487         return (i == size) ? ' ' : mark[i].sym;
 488 }
 489
 490 static int
 491 lat_print_timestamp(struct trace_iterator *iter, u64 next_ts)
 492 {
 493         struct trace_array *tr = iter->tr;
 494         unsigned long verbose = tr->trace_flags & TRACE_ITER_VERBOSE;
 495         unsigned long in_ns = iter->iter_flags & TRACE_FILE_TIME_IN_NS;
 496         unsigned long long abs_ts = iter->ts - iter->trace_buffer->time_start;
 497         unsigned long long rel_ts = next_ts - iter->ts;
 498         struct trace_seq *s = &iter->seq;
 499
 500         if (in_ns) {
 501                 abs_ts = ns2usecs(abs_ts);
 502                 rel_ts = ns2usecs(rel_ts);
 503         }
 504
 505         if (verbose && in_ns) {
 506                 unsigned long abs_usec = do_div(abs_ts, USEC_PER_MSEC);
 507                 unsigned long abs_msec = (unsigned long)abs_ts;
 508                 unsigned long rel_usec = do_div(rel_ts, USEC_PER_MSEC);
 509                 unsigned long rel_msec = (unsigned long)rel_ts;
 510
 511                 trace_seq_printf(
 512                         s, "[%08llx] %ld.%03ldms (+%ld.%03ldms): ",
 513                         ns2usecs(iter->ts),
 514                         abs_msec, abs_usec,
 515                         rel_msec, rel_usec);
 516
 517         } else if (verbose && !in_ns) {
 518                 trace_seq_printf(
 519                         s, "[%016llx] %lld (+%lld): ",
 520                         iter->ts, abs_ts, rel_ts);
 521
 522         } else if (!verbose && in_ns) {
 523                 trace_seq_printf(
 524                         s, " %4lldus%c: ",
 525                         abs_ts,
 526                         trace_find_mark(rel_ts * NSEC_PER_USEC));
 527
 528         } else { /* !verbose && !in_ns */
 529                 trace_seq_printf(s, " %4lld: ", abs_ts);
 530         }
 531
 532         return !trace_seq_has_overflowed(s);
 533 }
 534
 535 int trace_print_context(struct trace_iterator *iter)
 536 {
 537         struct trace_array *tr = iter->tr;
 538         struct trace_seq *s = &iter->seq;
 539         struct trace_entry *entry = iter->ent;
 540         unsigned long long t;
 541         unsigned long secs, usec_rem;
 542         char comm[TASK_COMM_LEN];
 543
 544         trace_find_cmdline(entry->pid, comm);
 545
 546         trace_seq_printf(s, "%16s-%-5d [%03d] ",
 547                                comm, entry->pid, iter->cpu);
 548
 549         if (tr->trace_flags & TRACE_ITER_IRQ_INFO)
 550                 trace_print_lat_fmt(s, entry);
 551
 552         if (iter->iter_flags & TRACE_FILE_TIME_IN_NS) {
 553                 t = ns2usecs(iter->ts);
 554                 usec_rem = do_div(t, USEC_PER_SEC);
 555                 secs = (unsigned long)t;
 556                 trace_seq_printf(s, " %5lu.%06lu: ", secs, usec_rem);
 557         } else
 558                 trace_seq_printf(s, " %12llu: ", iter->ts);
 559
 560         return !trace_seq_has_overflowed(s);
 561 }
 562
 563 int trace_print_lat_context(struct trace_iterator *iter)
 564 {
 565         struct trace_array *tr = iter->tr;
 566         /* trace_find_next_entry will reset ent_size */
 567         int ent_size = iter->ent_size;
 568         struct trace_seq *s = &iter->seq;
 569         u64 next_ts;
 570         struct trace_entry *entry = iter->ent,
 571                            *next_entry = trace_find_next_entry(iter, NULL,
 572                                                                &next_ts);
 573         unsigned long verbose = (tr->trace_flags & TRACE_ITER_VERBOSE);
 574
 575         /* Restore the original ent_size */
 576         iter->ent_size = ent_size;
 577
 578         if (!next_entry)
 579                 next_ts = iter->ts;
 580
 581         if (verbose) {
 582                 char comm[TASK_COMM_LEN];
 583
 584                 trace_find_cmdline(entry->pid, comm);
 585
 586                 trace_seq_printf(
 587                         s, "%16s %5d %3d %d %08x %08lx ",
 588                         comm, entry->pid, iter->cpu, entry->flags,
 589                         entry->preempt_count, iter->idx);
 590         } else {
 591                 lat_print_generic(s, entry, iter->cpu);
 592         }
 593
 594         lat_print_timestamp(iter, next_ts);
 595
 596         return !trace_seq_has_overflowed(s);
 597 }
 598
 599 static const char state_to_char[] = TASK_STATE_TO_CHAR_STR;
 600
 601 static int task_state_char(unsigned long state)
 602 {
 603         int bit = state ? __ffs(state) + 1 : 0;
 604
 605         return bit < sizeof(state_to_char) - 1 ? state_to_char[bit] : '?';
 606 }
 607
 608 /**
 609  * ftrace_find_event - find a registered event
 610  * @type: the type of event to look for
 611  *
 612  * Returns an event of type @type otherwise NULL
 613  * Called with trace_event_read_lock() held.
 614  */
 615 struct trace_event *ftrace_find_event(int type)
 616 {
 617         struct trace_event *event;
 618         unsigned key;
 619
 620         key = type & (EVENT_HASHSIZE - 1);
 621
 622         hlist_for_each_entry(event, &event_hash[key], node) {
 623                 if (event->type == type)
 624                         return event;
 625         }
 626
 627         return NULL;
 628 }
 629
 630 static LIST_HEAD(ftrace_event_list);
 631
 632 static int trace_search_list(struct list_head **list)
 633 {
 634         struct trace_event *e;
 635         int last = __TRACE_LAST_TYPE;
 636
 637         if (list_empty(&ftrace_event_list)) {
 638                 *list = &ftrace_event_list;
 639                 return last + 1;
 640         }
 641
 642         /*
 643          * We used up all possible max events,
 644          * lets see if somebody freed one.
 645          */
 646         list_for_each_entry(e, &ftrace_event_list, list) {
 647                 if (e->type != last + 1)
 648                         break;
 649                 last++;
 650         }
 651
 652         /* Did we used up all 65 thousand events??? */
 653         if ((last + 1) > TRACE_EVENT_TYPE_MAX)
 654                 return 0;
 655
 656         *list = &e->list;
 657         return last + 1;
 658 }
 659
 660 void trace_event_read_lock(void)
 661 {
 662         down_read(&trace_event_sem);
 663 }
 664
 665 void trace_event_read_unlock(void)
 666 {
 667         up_read(&trace_event_sem);
 668 }
 669
 670 /**
 671  * register_trace_event - register output for an event type
 672  * @event: the event type to register
 673  *
 674  * Event types are stored in a hash and this hash is used to
 675  * find a way to print an event. If the @event->type is set
 676  * then it will use that type, otherwise it will assign a
 677  * type to use.
 678  *
 679  * If you assign your own type, please make sure it is added
 680  * to the trace_type enum in trace.h, to avoid collisions
 681  * with the dynamic types.
 682  *
 683  * Returns the event type number or zero on error.
 684  */
 685 int register_trace_event(struct trace_event *event)
 686 {
 687         unsigned key;
 688         int ret = 0;
 689
 690         down_write(&trace_event_sem);
 691
 692         if (WARN_ON(!event))
 693                 goto out;
 694
 695         if (WARN_ON(!event->funcs))
 696                 goto out;
 697
 698         INIT_LIST_HEAD(&event->list);
 699
 700         if (!event->type) {
 701                 struct list_head *list = NULL;
 702
 703                 if (next_event_type > TRACE_EVENT_TYPE_MAX) {
 704
 705                         event->type = trace_search_list(&list);
 706                         if (!event->type)
 707                                 goto out;
 708
 709                 } else {
 710
 711                         event->type = next_event_type++;
 712                         list = &ftrace_event_list;
 713                 }
 714
 715                 if (WARN_ON(ftrace_find_event(event->type)))
 716                         goto out;
 717
 718                 list_add_tail(&event->list, list);
 719
 720         } else if (event->type > __TRACE_LAST_TYPE) {
 721                 printk(KERN_WARNING "Need to add type to trace.h\n");
 722                 WARN_ON(1);
 723                 goto out;
 724         } else {
 725                 /* Is this event already used */
 726                 if (ftrace_find_event(event->type))
 727                         goto out;
 728         }
 729
 730         if (event->funcs->trace == NULL)
 731                 event->funcs->trace = trace_nop_print;
 732         if (event->funcs->raw == NULL)
 733                 event->funcs->raw = trace_nop_print;
 734         if (event->funcs->hex == NULL)
 735                 event->funcs->hex = trace_nop_print;
 736         if (event->funcs->binary == NULL)
 737                 event->funcs->binary = trace_nop_print;
 738
 739         key = event->type & (EVENT_HASHSIZE - 1);
 740
 741         hlist_add_head(&event->node, &event_hash[key]);
 742
 743         ret = event->type;
 744  out:
 745         up_write(&trace_event_sem);
 746
 747         return ret;
 748 }
 749 EXPORT_SYMBOL_GPL(register_trace_event);
 750
 751 /*
 752  * Used by module code with the trace_event_sem held for write.
 753  */
 754 int __unregister_trace_event(struct trace_event *event)
 755 {
 756         hlist_del(&event->node);
 757         list_del(&event->list);
 758         return 0;
 759 }
 760
 761 /**
 762  * unregister_trace_event - remove a no longer used event
 763  * @event: the event to remove
 764  */
 765 int unregister_trace_event(struct trace_event *event)
 766 {
 767         down_write(&trace_event_sem);
 768         __unregister_trace_event(event);
 769         up_write(&trace_event_sem);
 770
 771         return 0;
 772 }
 773 EXPORT_SYMBOL_GPL(unregister_trace_event);
 774
 775 /*
 776  * Standard events
 777  */
 778
 779 enum print_line_t trace_nop_print(struct trace_iterator *iter, int flags,
 780                                   struct trace_event *event)
 781 {
 782         trace_seq_printf(&iter->seq, "type: %d\n", iter->ent->type);
 783
 784         return trace_handle_return(&iter->seq);
 785 }
 786
 787 /* TRACE_FN */
 788 static enum print_line_t trace_fn_trace(struct trace_iterator *iter, int flags,
 789                                         struct trace_event *event)
 790 {
 791         struct ftrace_entry *field;
 792         struct trace_seq *s = &iter->seq;
 793
 794         trace_assign_type(field, iter->ent);
 795
 796         seq_print_ip_sym(s, field->ip, flags);
 797
 798         if ((flags & TRACE_ITER_PRINT_PARENT) && field->parent_ip) {
 799                 trace_seq_puts(s, " <-");
 800                 seq_print_ip_sym(s, field->parent_ip, flags);
 801         }
 802
 803         trace_seq_putc(s, '\n');
 804
 805         return trace_handle_return(s);
 806 }
 807
 808 static enum print_line_t trace_fn_raw(struct trace_iterator *iter, int flags,
 809                                       struct trace_event *event)
 810 {
 811         struct ftrace_entry *field;
 812
 813         trace_assign_type(field, iter->ent);
 814
 815         trace_seq_printf(&iter->seq, "%lx %lx\n",
 816                          field->ip,
 817                          field->parent_ip);
 818
 819         return trace_handle_return(&iter->seq);
 820 }
 821
 822 static enum print_line_t trace_fn_hex(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_HEX_FIELD(s, field->ip);
 831         SEQ_PUT_HEX_FIELD(s, field->parent_ip);
 832
 833         return trace_handle_return(s);
 834 }
 835
 836 static enum print_line_t trace_fn_bin(struct trace_iterator *iter, int flags,
 837                                       struct trace_event *event)
 838 {
 839         struct ftrace_entry *field;
 840         struct trace_seq *s = &iter->seq;
 841
 842         trace_assign_type(field, iter->ent);
 843
 844         SEQ_PUT_FIELD(s, field->ip);
 845         SEQ_PUT_FIELD(s, field->parent_ip);
 846
 847         return trace_handle_return(s);
 848 }
 849
 850 static struct trace_event_functions trace_fn_funcs = {
 851         .trace          = trace_fn_trace,
 852         .raw            = trace_fn_raw,
 853         .hex            = trace_fn_hex,
 854         .binary         = trace_fn_bin,
 855 };
 856
 857 static struct trace_event trace_fn_event = {
 858         .type           = TRACE_FN,
 859         .funcs          = &trace_fn_funcs,
 860 };
 861
 862 /* TRACE_CTX an TRACE_WAKE */
 863 static enum print_line_t trace_ctxwake_print(struct trace_iterator *iter,
 864                                              char *delim)
 865 {
 866         struct ctx_switch_entry *field;
 867         char comm[TASK_COMM_LEN];
 868         int S, T;
 869
 870
 871         trace_assign_type(field, iter->ent);
 872
 873         T = task_state_char(field->next_state);
 874         S = task_state_char(field->prev_state);
 875         trace_find_cmdline(field->next_pid, comm);
 876         trace_seq_printf(&iter->seq,
 877                          " %5d:%3d:%c %s [%03d] %5d:%3d:%c %s\n",
 878                          field->prev_pid,
 879                          field->prev_prio,
 880                          S, delim,
 881                          field->next_cpu,
 882                          field->next_pid,
 883                          field->next_prio,
 884                          T, comm);
 885
 886         return trace_handle_return(&iter->seq);
 887 }
 888
 889 static enum print_line_t trace_ctx_print(struct trace_iterator *iter, int flags,
 890                                          struct trace_event *event)
 891 {
 892         return trace_ctxwake_print(iter, "==>");
 893 }
 894
 895 static enum print_line_t trace_wake_print(struct trace_iterator *iter,
 896                                           int flags, struct trace_event *event)
 897 {
 898         return trace_ctxwake_print(iter, "  +");
 899 }
 900
 901 static int trace_ctxwake_raw(struct trace_iterator *iter, char S)
 902 {
 903         struct ctx_switch_entry *field;
 904         int T;
 905
 906         trace_assign_type(field, iter->ent);
 907
 908         if (!S)
 909                 S = task_state_char(field->prev_state);
 910         T = task_state_char(field->next_state);
 911         trace_seq_printf(&iter->seq, "%d %d %c %d %d %d %c\n",
 912                          field->prev_pid,
 913                          field->prev_prio,
 914                          S,
 915                          field->next_cpu,
 916                          field->next_pid,
 917                          field->next_prio,
 918                          T);
 919
 920         return trace_handle_return(&iter->seq);
 921 }
 922
 923 static enum print_line_t trace_ctx_raw(struct trace_iterator *iter, int flags,
 924                                        struct trace_event *event)
 925 {
 926         return trace_ctxwake_raw(iter, 0);
 927 }
 928
 929 static enum print_line_t trace_wake_raw(struct trace_iterator *iter, int flags,
 930                                         struct trace_event *event)
 931 {
 932         return trace_ctxwake_raw(iter, '+');
 933 }
 934
 935
 936 static int trace_ctxwake_hex(struct trace_iterator *iter, char S)
 937 {
 938         struct ctx_switch_entry *field;
 939         struct trace_seq *s = &iter->seq;
 940         int T;
 941
 942         trace_assign_type(field, iter->ent);
 943
 944         if (!S)
 945                 S = task_state_char(field->prev_state);
 946         T = task_state_char(field->next_state);
 947
 948         SEQ_PUT_HEX_FIELD(s, field->prev_pid);
 949         SEQ_PUT_HEX_FIELD(s, field->prev_prio);
 950         SEQ_PUT_HEX_FIELD(s, S);
 951         SEQ_PUT_HEX_FIELD(s, field->next_cpu);
 952         SEQ_PUT_HEX_FIELD(s, field->next_pid);
 953         SEQ_PUT_HEX_FIELD(s, field->next_prio);
 954         SEQ_PUT_HEX_FIELD(s, T);
 955
 956         return trace_handle_return(s);
 957 }
 958
 959 static enum print_line_t trace_ctx_hex(struct trace_iterator *iter, int flags,
 960                                        struct trace_event *event)
 961 {
 962         return trace_ctxwake_hex(iter, 0);
 963 }
 964
 965 static enum print_line_t trace_wake_hex(struct trace_iterator *iter, int flags,
 966                                         struct trace_event *event)
 967 {
 968         return trace_ctxwake_hex(iter, '+');
 969 }
 970
 971 static enum print_line_t trace_ctxwake_bin(struct trace_iterator *iter,
 972                                            int flags, struct trace_event *event)
 973 {
 974         struct ctx_switch_entry *field;
 975         struct trace_seq *s = &iter->seq;
 976
 977         trace_assign_type(field, iter->ent);
 978
 979         SEQ_PUT_FIELD(s, field->prev_pid);
 980         SEQ_PUT_FIELD(s, field->prev_prio);
 981         SEQ_PUT_FIELD(s, field->prev_state);
 982         SEQ_PUT_FIELD(s, field->next_cpu);
 983         SEQ_PUT_FIELD(s, field->next_pid);
 984         SEQ_PUT_FIELD(s, field->next_prio);
 985         SEQ_PUT_FIELD(s, field->next_state);
 986
 987         return trace_handle_return(s);
 988 }
 989
 990 static struct trace_event_functions trace_ctx_funcs = {
 991         .trace          = trace_ctx_print,
 992         .raw            = trace_ctx_raw,
 993         .hex            = trace_ctx_hex,
 994         .binary         = trace_ctxwake_bin,
 995 };
 996
 997 static struct trace_event trace_ctx_event = {
 998         .type           = TRACE_CTX,
 999         .funcs          = &trace_ctx_funcs,
1000 };
1001
1002 static struct trace_event_functions trace_wake_funcs = {
1003         .trace          = trace_wake_print,
1004         .raw            = trace_wake_raw,
1005         .hex            = trace_wake_hex,
1006         .binary         = trace_ctxwake_bin,
1007 };
1008
1009 static struct trace_event trace_wake_event = {
1010         .type           = TRACE_WAKE,
1011         .funcs          = &trace_wake_funcs,
1012 };
1013
1014 /* TRACE_STACK */
1015
1016 static enum print_line_t trace_stack_print(struct trace_iterator *iter,
1017                                            int flags, struct trace_event *event)
1018 {
1019         struct stack_entry *field;
1020         struct trace_seq *s = &iter->seq;
1021         unsigned long *p;
1022         unsigned long *end;
1023
1024         trace_assign_type(field, iter->ent);
1025         end = (unsigned long *)((long)iter->ent + iter->ent_size);
1026
1027         trace_seq_puts(s, "<stack trace>\n");
1028
1029         for (p = field->caller; p && *p != ULONG_MAX && p < end; p++) {
1030
1031                 if (trace_seq_has_overflowed(s))
1032                         break;
1033
1034                 trace_seq_puts(s, " => ");
1035                 seq_print_ip_sym(s, *p, flags);
1036                 trace_seq_putc(s, '\n');
1037         }
1038
1039         return trace_handle_return(s);
1040 }
1041
1042 static struct trace_event_functions trace_stack_funcs = {
1043         .trace          = trace_stack_print,
1044 };
1045
1046 static struct trace_event trace_stack_event = {
1047         .type           = TRACE_STACK,
1048         .funcs          = &trace_stack_funcs,
1049 };
1050
1051 /* TRACE_USER_STACK */
1052 static enum print_line_t trace_user_stack_print(struct trace_iterator *iter,
1053                                                 int flags, struct trace_event *event)
1054 {
1055         struct trace_array *tr = iter->tr;
1056         struct userstack_entry *field;
1057         struct trace_seq *s = &iter->seq;
1058         struct mm_struct *mm = NULL;
1059         unsigned int i;
1060
1061         trace_assign_type(field, iter->ent);
1062
1063         trace_seq_puts(s, "<user stack trace>\n");
1064
1065         if (tr->trace_flags & TRACE_ITER_SYM_USEROBJ) {
1066                 struct task_struct *task;
1067                 /*
1068                  * we do the lookup on the thread group leader,
1069                  * since individual threads might have already quit!
1070                  */
1071                 rcu_read_lock();
1072                 task = find_task_by_vpid(field->tgid);
1073                 if (task)
1074                         mm = get_task_mm(task);
1075                 rcu_read_unlock();
1076         }
1077
1078         for (i = 0; i < FTRACE_STACK_ENTRIES; i++) {
1079                 unsigned long ip = field->caller[i];
1080
1081                 if (ip == ULONG_MAX || trace_seq_has_overflowed(s))
1082                         break;
1083
1084                 trace_seq_puts(s, " => ");
1085
1086                 if (!ip) {
1087                         trace_seq_puts(s, "??");
1088                         trace_seq_putc(s, '\n');
1089                         continue;
1090                 }
1091
1092                 seq_print_user_ip(s, mm, ip, flags);
1093                 trace_seq_putc(s, '\n');
1094         }
1095
1096         if (mm)
1097                 mmput(mm);
1098
1099         return trace_handle_return(s);
1100 }
1101
1102 static struct trace_event_functions trace_user_stack_funcs = {
1103         .trace          = trace_user_stack_print,
1104 };
1105
1106 static struct trace_event trace_user_stack_event = {
1107         .type           = TRACE_USER_STACK,
1108         .funcs          = &trace_user_stack_funcs,
1109 };
1110
1111 /* TRACE_BPUTS */
1112 static enum print_line_t
1113 trace_bputs_print(struct trace_iterator *iter, int flags,
1114                    struct trace_event *event)
1115 {
1116         struct trace_entry *entry = iter->ent;
1117         struct trace_seq *s = &iter->seq;
1118         struct bputs_entry *field;
1119
1120         trace_assign_type(field, entry);
1121
1122         seq_print_ip_sym(s, field->ip, flags);
1123         trace_seq_puts(s, ": ");
1124         trace_seq_puts(s, field->str);
1125
1126         return trace_handle_return(s);
1127 }
1128
1129
1130 static enum print_line_t
1131 trace_bputs_raw(struct trace_iterator *iter, int flags,
1132                 struct trace_event *event)
1133 {
1134         struct bputs_entry *field;
1135         struct trace_seq *s = &iter->seq;
1136
1137         trace_assign_type(field, iter->ent);
1138
1139         trace_seq_printf(s, ": %lx : ", field->ip);
1140         trace_seq_puts(s, field->str);
1141
1142         return trace_handle_return(s);
1143 }
1144
1145 static struct trace_event_functions trace_bputs_funcs = {
1146         .trace          = trace_bputs_print,
1147         .raw            = trace_bputs_raw,
1148 };
1149
1150 static struct trace_event trace_bputs_event = {
1151         .type           = TRACE_BPUTS,
1152         .funcs          = &trace_bputs_funcs,
1153 };
1154
1155 /* TRACE_BPRINT */
1156 static enum print_line_t
1157 trace_bprint_print(struct trace_iterator *iter, int flags,
1158                    struct trace_event *event)
1159 {
1160         struct trace_entry *entry = iter->ent;
1161         struct trace_seq *s = &iter->seq;
1162         struct bprint_entry *field;
1163
1164         trace_assign_type(field, entry);
1165
1166         seq_print_ip_sym(s, field->ip, flags);
1167         trace_seq_puts(s, ": ");
1168         trace_seq_bprintf(s, field->fmt, field->buf);
1169
1170         return trace_handle_return(s);
1171 }
1172
1173
1174 static enum print_line_t
1175 trace_bprint_raw(struct trace_iterator *iter, int flags,
1176                  struct trace_event *event)
1177 {
1178         struct bprint_entry *field;
1179         struct trace_seq *s = &iter->seq;
1180
1181         trace_assign_type(field, iter->ent);
1182
1183         trace_seq_printf(s, ": %lx : ", field->ip);
1184         trace_seq_bprintf(s, field->fmt, field->buf);
1185
1186         return trace_handle_return(s);
1187 }
1188
1189 static struct trace_event_functions trace_bprint_funcs = {
1190         .trace          = trace_bprint_print,
1191         .raw            = trace_bprint_raw,
1192 };
1193
1194 static struct trace_event trace_bprint_event = {
1195         .type           = TRACE_BPRINT,
1196         .funcs          = &trace_bprint_funcs,
1197 };
1198
1199 /* TRACE_PRINT */
1200 static enum print_line_t trace_print_print(struct trace_iterator *iter,
1201                                            int flags, struct trace_event *event)
1202 {
1203         struct print_entry *field;
1204         struct trace_seq *s = &iter->seq;
1205
1206         trace_assign_type(field, iter->ent);
1207
1208         seq_print_ip_sym(s, field->ip, flags);
1209         trace_seq_printf(s, ": %s", field->buf);
1210
1211         return trace_handle_return(s);
1212 }
1213
1214 static enum print_line_t trace_print_raw(struct trace_iterator *iter, int flags,
1215                                          struct trace_event *event)
1216 {
1217         struct print_entry *field;
1218
1219         trace_assign_type(field, iter->ent);
1220
1221         trace_seq_printf(&iter->seq, "# %lx %s", field->ip, field->buf);
1222
1223         return trace_handle_return(&iter->seq);
1224 }
1225
1226 static struct trace_event_functions trace_print_funcs = {
1227         .trace          = trace_print_print,
1228         .raw            = trace_print_raw,
1229 };
1230
1231 static struct trace_event trace_print_event = {
1232         .type           = TRACE_PRINT,
1233         .funcs          = &trace_print_funcs,
1234 };
1235
1236
1237 static struct trace_event *events[] __initdata = {
1238         &trace_fn_event,
1239         &trace_ctx_event,
1240         &trace_wake_event,
1241         &trace_stack_event,
1242         &trace_user_stack_event,
1243         &trace_bputs_event,
1244         &trace_bprint_event,
1245         &trace_print_event,
1246         NULL
1247 };
1248
1249 __init static int init_events(void)
1250 {
1251         struct trace_event *event;
1252         int i, ret;
1253
1254         for (i = 0; events[i]; i++) {
1255                 event = events[i];
1256
1257                 ret = register_trace_event(event);
1258                 if (!ret) {
1259                         printk(KERN_WARNING "event %d failed to register\n",
1260                                event->type);
1261                         WARN_ON_ONCE(1);
1262                 }
1263         }
1264
1265         return 0;
1266 }
1267 early_initcall(init_events);