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 irqs_off;
 390         int hardirq;
 391         int softirq;
 392         int nmi;
 393
 394         nmi = entry->flags & TRACE_FLAG_NMI;
 395         hardirq = entry->flags & TRACE_FLAG_HARDIRQ;
 396         softirq = entry->flags & TRACE_FLAG_SOFTIRQ;
 397
 398         irqs_off =
 399                 (entry->flags & TRACE_FLAG_IRQS_OFF) ? 'd' :
 400                 (entry->flags & TRACE_FLAG_IRQS_NOSUPPORT) ? 'X' :
 401                 '.';
 402
 403         switch (entry->flags & (TRACE_FLAG_NEED_RESCHED |
 404                                 TRACE_FLAG_PREEMPT_RESCHED)) {
 405         case TRACE_FLAG_NEED_RESCHED | TRACE_FLAG_PREEMPT_RESCHED:
 406                 need_resched = 'N';
 407                 break;
 408         case TRACE_FLAG_NEED_RESCHED:
 409                 need_resched = 'n';
 410                 break;
 411         case TRACE_FLAG_PREEMPT_RESCHED:
 412                 need_resched = 'p';
 413                 break;
 414         default:
 415                 need_resched = '.';
 416                 break;
 417         }
 418
 419         hardsoft_irq =
 420                 (nmi && hardirq)     ? 'Z' :
 421                 nmi                  ? 'z' :
 422                 (hardirq && softirq) ? 'H' :
 423                 hardirq              ? 'h' :
 424                 softirq              ? 's' :
 425                                        '.' ;
 426
 427         trace_seq_printf(s, "%c%c%c",
 428                          irqs_off, need_resched, 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         return !trace_seq_has_overflowed(s);
 436 }
 437
 438 static int
 439 lat_print_generic(struct trace_seq *s, struct trace_entry *entry, int cpu)
 440 {
 441         char comm[TASK_COMM_LEN];
 442
 443         trace_find_cmdline(entry->pid, comm);
 444
 445         trace_seq_printf(s, "%8.8s-%-5d %3d",
 446                          comm, entry->pid, cpu);
 447
 448         return trace_print_lat_fmt(s, entry);
 449 }
 450
 451 #undef MARK
 452 #define MARK(v, s) {.val = v, .sym = s}
 453 /* trace overhead mark */
 454 static const struct trace_mark {
 455         unsigned long long      val; /* unit: nsec */
 456         char                    sym;
 457 } mark[] = {
 458         MARK(1000000000ULL      , '$'), /* 1 sec */
 459         MARK(100000000ULL       , '@'), /* 100 msec */
 460         MARK(10000000ULL        , '*'), /* 10 msec */
 461         MARK(1000000ULL         , '#'), /* 1000 usecs */
 462         MARK(100000ULL          , '!'), /* 100 usecs */
 463         MARK(10000ULL           , '+'), /* 10 usecs */
 464 };
 465 #undef MARK
 466
 467 char trace_find_mark(unsigned long long d)
 468 {
 469         int i;
 470         int size = ARRAY_SIZE(mark);
 471
 472         for (i = 0; i < size; i++) {
 473                 if (d > mark[i].val)
 474                         break;
 475         }
 476
 477         return (i == size) ? ' ' : mark[i].sym;
 478 }
 479
 480 static int
 481 lat_print_timestamp(struct trace_iterator *iter, u64 next_ts)
 482 {
 483         struct trace_array *tr = iter->tr;
 484         unsigned long verbose = tr->trace_flags & TRACE_ITER_VERBOSE;
 485         unsigned long in_ns = iter->iter_flags & TRACE_FILE_TIME_IN_NS;
 486         unsigned long long abs_ts = iter->ts - iter->trace_buffer->time_start;
 487         unsigned long long rel_ts = next_ts - iter->ts;
 488         struct trace_seq *s = &iter->seq;
 489
 490         if (in_ns) {
 491                 abs_ts = ns2usecs(abs_ts);
 492                 rel_ts = ns2usecs(rel_ts);
 493         }
 494
 495         if (verbose && in_ns) {
 496                 unsigned long abs_usec = do_div(abs_ts, USEC_PER_MSEC);
 497                 unsigned long abs_msec = (unsigned long)abs_ts;
 498                 unsigned long rel_usec = do_div(rel_ts, USEC_PER_MSEC);
 499                 unsigned long rel_msec = (unsigned long)rel_ts;
 500
 501                 trace_seq_printf(
 502                         s, "[%08llx] %ld.%03ldms (+%ld.%03ldms): ",
 503                         ns2usecs(iter->ts),
 504                         abs_msec, abs_usec,
 505                         rel_msec, rel_usec);
 506
 507         } else if (verbose && !in_ns) {
 508                 trace_seq_printf(
 509                         s, "[%016llx] %lld (+%lld): ",
 510                         iter->ts, abs_ts, rel_ts);
 511
 512         } else if (!verbose && in_ns) {
 513                 trace_seq_printf(
 514                         s, " %4lldus%c: ",
 515                         abs_ts,
 516                         trace_find_mark(rel_ts * NSEC_PER_USEC));
 517
 518         } else { /* !verbose && !in_ns */
 519                 trace_seq_printf(s, " %4lld: ", abs_ts);
 520         }
 521
 522         return !trace_seq_has_overflowed(s);
 523 }
 524
 525 int trace_print_context(struct trace_iterator *iter)
 526 {
 527         struct trace_array *tr = iter->tr;
 528         struct trace_seq *s = &iter->seq;
 529         struct trace_entry *entry = iter->ent;
 530         unsigned long long t;
 531         unsigned long secs, usec_rem;
 532         char comm[TASK_COMM_LEN];
 533
 534         trace_find_cmdline(entry->pid, comm);
 535
 536         trace_seq_printf(s, "%16s-%-5d [%03d] ",
 537                                comm, entry->pid, iter->cpu);
 538
 539         if (tr->trace_flags & TRACE_ITER_IRQ_INFO)
 540                 trace_print_lat_fmt(s, entry);
 541
 542         if (iter->iter_flags & TRACE_FILE_TIME_IN_NS) {
 543                 t = ns2usecs(iter->ts);
 544                 usec_rem = do_div(t, USEC_PER_SEC);
 545                 secs = (unsigned long)t;
 546                 trace_seq_printf(s, " %5lu.%06lu: ", secs, usec_rem);
 547         } else
 548                 trace_seq_printf(s, " %12llu: ", iter->ts);
 549
 550         return !trace_seq_has_overflowed(s);
 551 }
 552
 553 int trace_print_lat_context(struct trace_iterator *iter)
 554 {
 555         struct trace_array *tr = iter->tr;
 556         /* trace_find_next_entry will reset ent_size */
 557         int ent_size = iter->ent_size;
 558         struct trace_seq *s = &iter->seq;
 559         u64 next_ts;
 560         struct trace_entry *entry = iter->ent,
 561                            *next_entry = trace_find_next_entry(iter, NULL,
 562                                                                &next_ts);
 563         unsigned long verbose = (tr->trace_flags & TRACE_ITER_VERBOSE);
 564
 565         /* Restore the original ent_size */
 566         iter->ent_size = ent_size;
 567
 568         if (!next_entry)
 569                 next_ts = iter->ts;
 570
 571         if (verbose) {
 572                 char comm[TASK_COMM_LEN];
 573
 574                 trace_find_cmdline(entry->pid, comm);
 575
 576                 trace_seq_printf(
 577                         s, "%16s %5d %3d %d %08x %08lx ",
 578                         comm, entry->pid, iter->cpu, entry->flags,
 579                         entry->preempt_count, iter->idx);
 580         } else {
 581                 lat_print_generic(s, entry, iter->cpu);
 582         }
 583
 584         lat_print_timestamp(iter, next_ts);
 585
 586         return !trace_seq_has_overflowed(s);
 587 }
 588
 589 static const char state_to_char[] = TASK_STATE_TO_CHAR_STR;
 590
 591 static int task_state_char(unsigned long state)
 592 {
 593         int bit = state ? __ffs(state) + 1 : 0;
 594
 595         return bit < sizeof(state_to_char) - 1 ? state_to_char[bit] : '?';
 596 }
 597
 598 /**
 599  * ftrace_find_event - find a registered event
 600  * @type: the type of event to look for
 601  *
 602  * Returns an event of type @type otherwise NULL
 603  * Called with trace_event_read_lock() held.
 604  */
 605 struct trace_event *ftrace_find_event(int type)
 606 {
 607         struct trace_event *event;
 608         unsigned key;
 609
 610         key = type & (EVENT_HASHSIZE - 1);
 611
 612         hlist_for_each_entry(event, &event_hash[key], node) {
 613                 if (event->type == type)
 614                         return event;
 615         }
 616
 617         return NULL;
 618 }
 619
 620 static LIST_HEAD(ftrace_event_list);
 621
 622 static int trace_search_list(struct list_head **list)
 623 {
 624         struct trace_event *e;
 625         int last = __TRACE_LAST_TYPE;
 626
 627         if (list_empty(&ftrace_event_list)) {
 628                 *list = &ftrace_event_list;
 629                 return last + 1;
 630         }
 631
 632         /*
 633          * We used up all possible max events,
 634          * lets see if somebody freed one.
 635          */
 636         list_for_each_entry(e, &ftrace_event_list, list) {
 637                 if (e->type != last + 1)
 638                         break;
 639                 last++;
 640         }
 641
 642         /* Did we used up all 65 thousand events??? */
 643         if ((last + 1) > TRACE_EVENT_TYPE_MAX)
 644                 return 0;
 645
 646         *list = &e->list;
 647         return last + 1;
 648 }
 649
 650 void trace_event_read_lock(void)
 651 {
 652         down_read(&trace_event_sem);
 653 }
 654
 655 void trace_event_read_unlock(void)
 656 {
 657         up_read(&trace_event_sem);
 658 }
 659
 660 /**
 661  * register_trace_event - register output for an event type
 662  * @event: the event type to register
 663  *
 664  * Event types are stored in a hash and this hash is used to
 665  * find a way to print an event. If the @event->type is set
 666  * then it will use that type, otherwise it will assign a
 667  * type to use.
 668  *
 669  * If you assign your own type, please make sure it is added
 670  * to the trace_type enum in trace.h, to avoid collisions
 671  * with the dynamic types.
 672  *
 673  * Returns the event type number or zero on error.
 674  */
 675 int register_trace_event(struct trace_event *event)
 676 {
 677         unsigned key;
 678         int ret = 0;
 679
 680         down_write(&trace_event_sem);
 681
 682         if (WARN_ON(!event))
 683                 goto out;
 684
 685         if (WARN_ON(!event->funcs))
 686                 goto out;
 687
 688         INIT_LIST_HEAD(&event->list);
 689
 690         if (!event->type) {
 691                 struct list_head *list = NULL;
 692
 693                 if (next_event_type > TRACE_EVENT_TYPE_MAX) {
 694
 695                         event->type = trace_search_list(&list);
 696                         if (!event->type)
 697                                 goto out;
 698
 699                 } else {
 700
 701                         event->type = next_event_type++;
 702                         list = &ftrace_event_list;
 703                 }
 704
 705                 if (WARN_ON(ftrace_find_event(event->type)))
 706                         goto out;
 707
 708                 list_add_tail(&event->list, list);
 709
 710         } else if (event->type > __TRACE_LAST_TYPE) {
 711                 printk(KERN_WARNING "Need to add type to trace.h\n");
 712                 WARN_ON(1);
 713                 goto out;
 714         } else {
 715                 /* Is this event already used */
 716                 if (ftrace_find_event(event->type))
 717                         goto out;
 718         }
 719
 720         if (event->funcs->trace == NULL)
 721                 event->funcs->trace = trace_nop_print;
 722         if (event->funcs->raw == NULL)
 723                 event->funcs->raw = trace_nop_print;
 724         if (event->funcs->hex == NULL)
 725                 event->funcs->hex = trace_nop_print;
 726         if (event->funcs->binary == NULL)
 727                 event->funcs->binary = trace_nop_print;
 728
 729         key = event->type & (EVENT_HASHSIZE - 1);
 730
 731         hlist_add_head(&event->node, &event_hash[key]);
 732
 733         ret = event->type;
 734  out:
 735         up_write(&trace_event_sem);
 736
 737         return ret;
 738 }
 739 EXPORT_SYMBOL_GPL(register_trace_event);
 740
 741 /*
 742  * Used by module code with the trace_event_sem held for write.
 743  */
 744 int __unregister_trace_event(struct trace_event *event)
 745 {
 746         hlist_del(&event->node);
 747         list_del(&event->list);
 748         return 0;
 749 }
 750
 751 /**
 752  * unregister_trace_event - remove a no longer used event
 753  * @event: the event to remove
 754  */
 755 int unregister_trace_event(struct trace_event *event)
 756 {
 757         down_write(&trace_event_sem);
 758         __unregister_trace_event(event);
 759         up_write(&trace_event_sem);
 760
 761         return 0;
 762 }
 763 EXPORT_SYMBOL_GPL(unregister_trace_event);
 764
 765 /*
 766  * Standard events
 767  */
 768
 769 enum print_line_t trace_nop_print(struct trace_iterator *iter, int flags,
 770                                   struct trace_event *event)
 771 {
 772         trace_seq_printf(&iter->seq, "type: %d\n", iter->ent->type);
 773
 774         return trace_handle_return(&iter->seq);
 775 }
 776
 777 /* TRACE_FN */
 778 static enum print_line_t trace_fn_trace(struct trace_iterator *iter, int flags,
 779                                         struct trace_event *event)
 780 {
 781         struct ftrace_entry *field;
 782         struct trace_seq *s = &iter->seq;
 783
 784         trace_assign_type(field, iter->ent);
 785
 786         seq_print_ip_sym(s, field->ip, flags);
 787
 788         if ((flags & TRACE_ITER_PRINT_PARENT) && field->parent_ip) {
 789                 trace_seq_puts(s, " <-");
 790                 seq_print_ip_sym(s, field->parent_ip, flags);
 791         }
 792
 793         trace_seq_putc(s, '\n');
 794
 795         return trace_handle_return(s);
 796 }
 797
 798 static enum print_line_t trace_fn_raw(struct trace_iterator *iter, int flags,
 799                                       struct trace_event *event)
 800 {
 801         struct ftrace_entry *field;
 802
 803         trace_assign_type(field, iter->ent);
 804
 805         trace_seq_printf(&iter->seq, "%lx %lx\n",
 806                          field->ip,
 807                          field->parent_ip);
 808
 809         return trace_handle_return(&iter->seq);
 810 }
 811
 812 static enum print_line_t trace_fn_hex(struct trace_iterator *iter, int flags,
 813                                       struct trace_event *event)
 814 {
 815         struct ftrace_entry *field;
 816         struct trace_seq *s = &iter->seq;
 817
 818         trace_assign_type(field, iter->ent);
 819
 820         SEQ_PUT_HEX_FIELD(s, field->ip);
 821         SEQ_PUT_HEX_FIELD(s, field->parent_ip);
 822
 823         return trace_handle_return(s);
 824 }
 825
 826 static enum print_line_t trace_fn_bin(struct trace_iterator *iter, int flags,
 827                                       struct trace_event *event)
 828 {
 829         struct ftrace_entry *field;
 830         struct trace_seq *s = &iter->seq;
 831
 832         trace_assign_type(field, iter->ent);
 833
 834         SEQ_PUT_FIELD(s, field->ip);
 835         SEQ_PUT_FIELD(s, field->parent_ip);
 836
 837         return trace_handle_return(s);
 838 }
 839
 840 static struct trace_event_functions trace_fn_funcs = {
 841         .trace          = trace_fn_trace,
 842         .raw            = trace_fn_raw,
 843         .hex            = trace_fn_hex,
 844         .binary         = trace_fn_bin,
 845 };
 846
 847 static struct trace_event trace_fn_event = {
 848         .type           = TRACE_FN,
 849         .funcs          = &trace_fn_funcs,
 850 };
 851
 852 /* TRACE_CTX an TRACE_WAKE */
 853 static enum print_line_t trace_ctxwake_print(struct trace_iterator *iter,
 854                                              char *delim)
 855 {
 856         struct ctx_switch_entry *field;
 857         char comm[TASK_COMM_LEN];
 858         int S, T;
 859
 860
 861         trace_assign_type(field, iter->ent);
 862
 863         T = task_state_char(field->next_state);
 864         S = task_state_char(field->prev_state);
 865         trace_find_cmdline(field->next_pid, comm);
 866         trace_seq_printf(&iter->seq,
 867                          " %5d:%3d:%c %s [%03d] %5d:%3d:%c %s\n",
 868                          field->prev_pid,
 869                          field->prev_prio,
 870                          S, delim,
 871                          field->next_cpu,
 872                          field->next_pid,
 873                          field->next_prio,
 874                          T, comm);
 875
 876         return trace_handle_return(&iter->seq);
 877 }
 878
 879 static enum print_line_t trace_ctx_print(struct trace_iterator *iter, int flags,
 880                                          struct trace_event *event)
 881 {
 882         return trace_ctxwake_print(iter, "==>");
 883 }
 884
 885 static enum print_line_t trace_wake_print(struct trace_iterator *iter,
 886                                           int flags, struct trace_event *event)
 887 {
 888         return trace_ctxwake_print(iter, "  +");
 889 }
 890
 891 static int trace_ctxwake_raw(struct trace_iterator *iter, char S)
 892 {
 893         struct ctx_switch_entry *field;
 894         int T;
 895
 896         trace_assign_type(field, iter->ent);
 897
 898         if (!S)
 899                 S = task_state_char(field->prev_state);
 900         T = task_state_char(field->next_state);
 901         trace_seq_printf(&iter->seq, "%d %d %c %d %d %d %c\n",
 902                          field->prev_pid,
 903                          field->prev_prio,
 904                          S,
 905                          field->next_cpu,
 906                          field->next_pid,
 907                          field->next_prio,
 908                          T);
 909
 910         return trace_handle_return(&iter->seq);
 911 }
 912
 913 static enum print_line_t trace_ctx_raw(struct trace_iterator *iter, int flags,
 914                                        struct trace_event *event)
 915 {
 916         return trace_ctxwake_raw(iter, 0);
 917 }
 918
 919 static enum print_line_t trace_wake_raw(struct trace_iterator *iter, int flags,
 920                                         struct trace_event *event)
 921 {
 922         return trace_ctxwake_raw(iter, '+');
 923 }
 924
 925
 926 static int trace_ctxwake_hex(struct trace_iterator *iter, char S)
 927 {
 928         struct ctx_switch_entry *field;
 929         struct trace_seq *s = &iter->seq;
 930         int T;
 931
 932         trace_assign_type(field, iter->ent);
 933
 934         if (!S)
 935                 S = task_state_char(field->prev_state);
 936         T = task_state_char(field->next_state);
 937
 938         SEQ_PUT_HEX_FIELD(s, field->prev_pid);
 939         SEQ_PUT_HEX_FIELD(s, field->prev_prio);
 940         SEQ_PUT_HEX_FIELD(s, S);
 941         SEQ_PUT_HEX_FIELD(s, field->next_cpu);
 942         SEQ_PUT_HEX_FIELD(s, field->next_pid);
 943         SEQ_PUT_HEX_FIELD(s, field->next_prio);
 944         SEQ_PUT_HEX_FIELD(s, T);
 945
 946         return trace_handle_return(s);
 947 }
 948
 949 static enum print_line_t trace_ctx_hex(struct trace_iterator *iter, int flags,
 950                                        struct trace_event *event)
 951 {
 952         return trace_ctxwake_hex(iter, 0);
 953 }
 954
 955 static enum print_line_t trace_wake_hex(struct trace_iterator *iter, int flags,
 956                                         struct trace_event *event)
 957 {
 958         return trace_ctxwake_hex(iter, '+');
 959 }
 960
 961 static enum print_line_t trace_ctxwake_bin(struct trace_iterator *iter,
 962                                            int flags, struct trace_event *event)
 963 {
 964         struct ctx_switch_entry *field;
 965         struct trace_seq *s = &iter->seq;
 966
 967         trace_assign_type(field, iter->ent);
 968
 969         SEQ_PUT_FIELD(s, field->prev_pid);
 970         SEQ_PUT_FIELD(s, field->prev_prio);
 971         SEQ_PUT_FIELD(s, field->prev_state);
 972         SEQ_PUT_FIELD(s, field->next_cpu);
 973         SEQ_PUT_FIELD(s, field->next_pid);
 974         SEQ_PUT_FIELD(s, field->next_prio);
 975         SEQ_PUT_FIELD(s, field->next_state);
 976
 977         return trace_handle_return(s);
 978 }
 979
 980 static struct trace_event_functions trace_ctx_funcs = {
 981         .trace          = trace_ctx_print,
 982         .raw            = trace_ctx_raw,
 983         .hex            = trace_ctx_hex,
 984         .binary         = trace_ctxwake_bin,
 985 };
 986
 987 static struct trace_event trace_ctx_event = {
 988         .type           = TRACE_CTX,
 989         .funcs          = &trace_ctx_funcs,
 990 };
 991
 992 static struct trace_event_functions trace_wake_funcs = {
 993         .trace          = trace_wake_print,
 994         .raw            = trace_wake_raw,
 995         .hex            = trace_wake_hex,
 996         .binary         = trace_ctxwake_bin,
 997 };
 998
 999 static struct trace_event trace_wake_event = {
1000         .type           = TRACE_WAKE,
1001         .funcs          = &trace_wake_funcs,
1002 };
1003
1004 /* TRACE_STACK */
1005
1006 static enum print_line_t trace_stack_print(struct trace_iterator *iter,
1007                                            int flags, struct trace_event *event)
1008 {
1009         struct stack_entry *field;
1010         struct trace_seq *s = &iter->seq;
1011         unsigned long *p;
1012         unsigned long *end;
1013
1014         trace_assign_type(field, iter->ent);
1015         end = (unsigned long *)((long)iter->ent + iter->ent_size);
1016
1017         trace_seq_puts(s, "<stack trace>\n");
1018
1019         for (p = field->caller; p && *p != ULONG_MAX && p < end; p++) {
1020
1021                 if (trace_seq_has_overflowed(s))
1022                         break;
1023
1024                 trace_seq_puts(s, " => ");
1025                 seq_print_ip_sym(s, *p, flags);
1026                 trace_seq_putc(s, '\n');
1027         }
1028
1029         return trace_handle_return(s);
1030 }
1031
1032 static struct trace_event_functions trace_stack_funcs = {
1033         .trace          = trace_stack_print,
1034 };
1035
1036 static struct trace_event trace_stack_event = {
1037         .type           = TRACE_STACK,
1038         .funcs          = &trace_stack_funcs,
1039 };
1040
1041 /* TRACE_USER_STACK */
1042 static enum print_line_t trace_user_stack_print(struct trace_iterator *iter,
1043                                                 int flags, struct trace_event *event)
1044 {
1045         struct trace_array *tr = iter->tr;
1046         struct userstack_entry *field;
1047         struct trace_seq *s = &iter->seq;
1048         struct mm_struct *mm = NULL;
1049         unsigned int i;
1050
1051         trace_assign_type(field, iter->ent);
1052
1053         trace_seq_puts(s, "<user stack trace>\n");
1054
1055         if (tr->trace_flags & TRACE_ITER_SYM_USEROBJ) {
1056                 struct task_struct *task;
1057                 /*
1058                  * we do the lookup on the thread group leader,
1059                  * since individual threads might have already quit!
1060                  */
1061                 rcu_read_lock();
1062                 task = find_task_by_vpid(field->tgid);
1063                 if (task)
1064                         mm = get_task_mm(task);
1065                 rcu_read_unlock();
1066         }
1067
1068         for (i = 0; i < FTRACE_STACK_ENTRIES; i++) {
1069                 unsigned long ip = field->caller[i];
1070
1071                 if (ip == ULONG_MAX || trace_seq_has_overflowed(s))
1072                         break;
1073
1074                 trace_seq_puts(s, " => ");
1075
1076                 if (!ip) {
1077                         trace_seq_puts(s, "??");
1078                         trace_seq_putc(s, '\n');
1079                         continue;
1080                 }
1081
1082                 seq_print_user_ip(s, mm, ip, flags);
1083                 trace_seq_putc(s, '\n');
1084         }
1085
1086         if (mm)
1087                 mmput(mm);
1088
1089         return trace_handle_return(s);
1090 }
1091
1092 static struct trace_event_functions trace_user_stack_funcs = {
1093         .trace          = trace_user_stack_print,
1094 };
1095
1096 static struct trace_event trace_user_stack_event = {
1097         .type           = TRACE_USER_STACK,
1098         .funcs          = &trace_user_stack_funcs,
1099 };
1100
1101 /* TRACE_HWLAT */
1102 static enum print_line_t
1103 trace_hwlat_print(struct trace_iterator *iter, int flags,
1104                   struct trace_event *event)
1105 {
1106         struct trace_entry *entry = iter->ent;
1107         struct trace_seq *s = &iter->seq;
1108         struct hwlat_entry *field;
1109
1110         trace_assign_type(field, entry);
1111
1112         trace_seq_printf(s, "#%-5u inner/outer(us): %4llu/%-5llu ts:%ld.%09ld\n",
1113                          field->seqnum,
1114                          field->duration,
1115                          field->outer_duration,
1116                          field->timestamp.tv_sec,
1117                          field->timestamp.tv_nsec);
1118
1119         return trace_handle_return(s);
1120 }
1121
1122
1123 static enum print_line_t
1124 trace_hwlat_raw(struct trace_iterator *iter, int flags,
1125                 struct trace_event *event)
1126 {
1127         struct hwlat_entry *field;
1128         struct trace_seq *s = &iter->seq;
1129
1130         trace_assign_type(field, iter->ent);
1131
1132         trace_seq_printf(s, "%llu %lld %ld %09ld %u\n",
1133                          field->duration,
1134                          field->outer_duration,
1135                          field->timestamp.tv_sec,
1136                          field->timestamp.tv_nsec,
1137                          field->seqnum);
1138
1139         return trace_handle_return(s);
1140 }
1141
1142 static struct trace_event_functions trace_hwlat_funcs = {
1143         .trace          = trace_hwlat_print,
1144         .raw            = trace_hwlat_raw,
1145 };
1146
1147 static struct trace_event trace_hwlat_event = {
1148         .type           = TRACE_HWLAT,
1149         .funcs          = &trace_hwlat_funcs,
1150 };
1151
1152 /* TRACE_BPUTS */
1153 static enum print_line_t
1154 trace_bputs_print(struct trace_iterator *iter, int flags,
1155                    struct trace_event *event)
1156 {
1157         struct trace_entry *entry = iter->ent;
1158         struct trace_seq *s = &iter->seq;
1159         struct bputs_entry *field;
1160
1161         trace_assign_type(field, entry);
1162
1163         seq_print_ip_sym(s, field->ip, flags);
1164         trace_seq_puts(s, ": ");
1165         trace_seq_puts(s, field->str);
1166
1167         return trace_handle_return(s);
1168 }
1169
1170
1171 static enum print_line_t
1172 trace_bputs_raw(struct trace_iterator *iter, int flags,
1173                 struct trace_event *event)
1174 {
1175         struct bputs_entry *field;
1176         struct trace_seq *s = &iter->seq;
1177
1178         trace_assign_type(field, iter->ent);
1179
1180         trace_seq_printf(s, ": %lx : ", field->ip);
1181         trace_seq_puts(s, field->str);
1182
1183         return trace_handle_return(s);
1184 }
1185
1186 static struct trace_event_functions trace_bputs_funcs = {
1187         .trace          = trace_bputs_print,
1188         .raw            = trace_bputs_raw,
1189 };
1190
1191 static struct trace_event trace_bputs_event = {
1192         .type           = TRACE_BPUTS,
1193         .funcs          = &trace_bputs_funcs,
1194 };
1195
1196 /* TRACE_BPRINT */
1197 static enum print_line_t
1198 trace_bprint_print(struct trace_iterator *iter, int flags,
1199                    struct trace_event *event)
1200 {
1201         struct trace_entry *entry = iter->ent;
1202         struct trace_seq *s = &iter->seq;
1203         struct bprint_entry *field;
1204
1205         trace_assign_type(field, entry);
1206
1207         seq_print_ip_sym(s, field->ip, flags);
1208         trace_seq_puts(s, ": ");
1209         trace_seq_bprintf(s, field->fmt, field->buf);
1210
1211         return trace_handle_return(s);
1212 }
1213
1214
1215 static enum print_line_t
1216 trace_bprint_raw(struct trace_iterator *iter, int flags,
1217                  struct trace_event *event)
1218 {
1219         struct bprint_entry *field;
1220         struct trace_seq *s = &iter->seq;
1221
1222         trace_assign_type(field, iter->ent);
1223
1224         trace_seq_printf(s, ": %lx : ", field->ip);
1225         trace_seq_bprintf(s, field->fmt, field->buf);
1226
1227         return trace_handle_return(s);
1228 }
1229
1230 static struct trace_event_functions trace_bprint_funcs = {
1231         .trace          = trace_bprint_print,
1232         .raw            = trace_bprint_raw,
1233 };
1234
1235 static struct trace_event trace_bprint_event = {
1236         .type           = TRACE_BPRINT,
1237         .funcs          = &trace_bprint_funcs,
1238 };
1239
1240 /* TRACE_PRINT */
1241 static enum print_line_t trace_print_print(struct trace_iterator *iter,
1242                                            int flags, struct trace_event *event)
1243 {
1244         struct print_entry *field;
1245         struct trace_seq *s = &iter->seq;
1246
1247         trace_assign_type(field, iter->ent);
1248
1249         seq_print_ip_sym(s, field->ip, flags);
1250         trace_seq_printf(s, ": %s", field->buf);
1251
1252         return trace_handle_return(s);
1253 }
1254
1255 static enum print_line_t trace_print_raw(struct trace_iterator *iter, int flags,
1256                                          struct trace_event *event)
1257 {
1258         struct print_entry *field;
1259
1260         trace_assign_type(field, iter->ent);
1261
1262         trace_seq_printf(&iter->seq, "# %lx %s", field->ip, field->buf);
1263
1264         return trace_handle_return(&iter->seq);
1265 }
1266
1267 static struct trace_event_functions trace_print_funcs = {
1268         .trace          = trace_print_print,
1269         .raw            = trace_print_raw,
1270 };
1271
1272 static struct trace_event trace_print_event = {
1273         .type           = TRACE_PRINT,
1274         .funcs          = &trace_print_funcs,
1275 };
1276
1277
1278 static struct trace_event *events[] __initdata = {
1279         &trace_fn_event,
1280         &trace_ctx_event,
1281         &trace_wake_event,
1282         &trace_stack_event,
1283         &trace_user_stack_event,
1284         &trace_bputs_event,
1285         &trace_bprint_event,
1286         &trace_print_event,
1287         &trace_hwlat_event,
1288         NULL
1289 };
1290
1291 __init static int init_events(void)
1292 {
1293         struct trace_event *event;
1294         int i, ret;
1295
1296         for (i = 0; events[i]; i++) {
1297                 event = events[i];
1298
1299                 ret = register_trace_event(event);
1300                 if (!ret) {
1301                         printk(KERN_WARNING "event %d failed to register\n",
1302                                event->type);
1303                         WARN_ON_ONCE(1);
1304                 }
1305         }
1306
1307         return 0;
1308 }
1309 early_initcall(init_events);