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 /**
 166  * trace_print_hex_seq - print buffer as hex sequence
 167  * @p: trace seq struct to write to
 168  * @buf: The buffer to print
 169  * @buf_len: Length of @buf in bytes
 170  * @concatenate: Print @buf as single hex string or with spacing
 171  *
 172  * Prints the passed buffer as a hex sequence either as a whole,
 173  * single hex string if @concatenate is true or with spacing after
 174  * each byte in case @concatenate is false.
 175  */
 176 const char *
 177 trace_print_hex_seq(struct trace_seq *p, const unsigned char *buf, int buf_len,
 178                     bool concatenate)
 179 {
 180         int i;
 181         const char *ret = trace_seq_buffer_ptr(p);
 182
 183         for (i = 0; i < buf_len; i++)
 184                 trace_seq_printf(p, "%s%2.2x", concatenate || i == 0 ? "" : " ",
 185                                  buf[i]);
 186         trace_seq_putc(p, 0);
 187
 188         return ret;
 189 }
 190 EXPORT_SYMBOL(trace_print_hex_seq);
 191
 192 const char *
 193 trace_print_array_seq(struct trace_seq *p, const void *buf, int count,
 194                       size_t el_size)
 195 {
 196         const char *ret = trace_seq_buffer_ptr(p);
 197         const char *prefix = "";
 198         void *ptr = (void *)buf;
 199         size_t buf_len = count * el_size;
 200
 201         trace_seq_putc(p, '{');
 202
 203         while (ptr < buf + buf_len) {
 204                 switch (el_size) {
 205                 case 1:
 206                         trace_seq_printf(p, "%s0x%x", prefix,
 207                                          *(u8 *)ptr);
 208                         break;
 209                 case 2:
 210                         trace_seq_printf(p, "%s0x%x", prefix,
 211                                          *(u16 *)ptr);
 212                         break;
 213                 case 4:
 214                         trace_seq_printf(p, "%s0x%x", prefix,
 215                                          *(u32 *)ptr);
 216                         break;
 217                 case 8:
 218                         trace_seq_printf(p, "%s0x%llx", prefix,
 219                                          *(u64 *)ptr);
 220                         break;
 221                 default:
 222                         trace_seq_printf(p, "BAD SIZE:%zu 0x%x", el_size,
 223                                          *(u8 *)ptr);
 224                         el_size = 1;
 225                 }
 226                 prefix = ",";
 227                 ptr += el_size;
 228         }
 229
 230         trace_seq_putc(p, '}');
 231         trace_seq_putc(p, 0);
 232
 233         return ret;
 234 }
 235 EXPORT_SYMBOL(trace_print_array_seq);
 236
 237 int trace_raw_output_prep(struct trace_iterator *iter,
 238                           struct trace_event *trace_event)
 239 {
 240         struct trace_event_call *event;
 241         struct trace_seq *s = &iter->seq;
 242         struct trace_seq *p = &iter->tmp_seq;
 243         struct trace_entry *entry;
 244
 245         event = container_of(trace_event, struct trace_event_call, event);
 246         entry = iter->ent;
 247
 248         if (entry->type != event->event.type) {
 249                 WARN_ON_ONCE(1);
 250                 return TRACE_TYPE_UNHANDLED;
 251         }
 252
 253         trace_seq_init(p);
 254         trace_seq_printf(s, "%s: ", trace_event_name(event));
 255
 256         return trace_handle_return(s);
 257 }
 258 EXPORT_SYMBOL(trace_raw_output_prep);
 259
 260 static int trace_output_raw(struct trace_iterator *iter, char *name,
 261                             char *fmt, va_list ap)
 262 {
 263         struct trace_seq *s = &iter->seq;
 264
 265         trace_seq_printf(s, "%s: ", name);
 266         trace_seq_vprintf(s, fmt, ap);
 267
 268         return trace_handle_return(s);
 269 }
 270
 271 int trace_output_call(struct trace_iterator *iter, char *name, char *fmt, ...)
 272 {
 273         va_list ap;
 274         int ret;
 275
 276         va_start(ap, fmt);
 277         ret = trace_output_raw(iter, name, fmt, ap);
 278         va_end(ap);
 279
 280         return ret;
 281 }
 282 EXPORT_SYMBOL_GPL(trace_output_call);
 283
 284 #ifdef CONFIG_KRETPROBES
 285 static inline const char *kretprobed(const char *name)
 286 {
 287         static const char tramp_name[] = "kretprobe_trampoline";
 288         int size = sizeof(tramp_name);
 289
 290         if (strncmp(tramp_name, name, size) == 0)
 291                 return "[unknown/kretprobe'd]";
 292         return name;
 293 }
 294 #else
 295 static inline const char *kretprobed(const char *name)
 296 {
 297         return name;
 298 }
 299 #endif /* CONFIG_KRETPROBES */
 300
 301 static void
 302 seq_print_sym_short(struct trace_seq *s, const char *fmt, unsigned long address)
 303 {
 304 #ifdef CONFIG_KALLSYMS
 305         char str[KSYM_SYMBOL_LEN];
 306         const char *name;
 307
 308         kallsyms_lookup(address, NULL, NULL, NULL, str);
 309
 310         name = kretprobed(str);
 311
 312         trace_seq_printf(s, fmt, name);
 313 #endif
 314 }
 315
 316 static void
 317 seq_print_sym_offset(struct trace_seq *s, const char *fmt,
 318                      unsigned long address)
 319 {
 320 #ifdef CONFIG_KALLSYMS
 321         char str[KSYM_SYMBOL_LEN];
 322         const char *name;
 323
 324         sprint_symbol(str, address);
 325         name = kretprobed(str);
 326
 327         trace_seq_printf(s, fmt, name);
 328 #endif
 329 }
 330
 331 #ifndef CONFIG_64BIT
 332 # define IP_FMT "%08lx"
 333 #else
 334 # define IP_FMT "%016lx"
 335 #endif
 336
 337 static int seq_print_user_ip(struct trace_seq *s, struct mm_struct *mm,
 338                              unsigned long ip, unsigned long sym_flags)
 339 {
 340         struct file *file = NULL;
 341         unsigned long vmstart = 0;
 342         int ret = 1;
 343
 344         if (s->full)
 345                 return 0;
 346
 347         if (mm) {
 348                 const struct vm_area_struct *vma;
 349
 350                 down_read(&mm->mmap_sem);
 351                 vma = find_vma(mm, ip);
 352                 if (vma) {
 353                         file = vma->vm_file;
 354                         vmstart = vma->vm_start;
 355                 }
 356                 if (file) {
 357                         ret = trace_seq_path(s, &file->f_path);
 358                         if (ret)
 359                                 trace_seq_printf(s, "[+0x%lx]",
 360                                                  ip - vmstart);
 361                 }
 362                 up_read(&mm->mmap_sem);
 363         }
 364         if (ret && ((sym_flags & TRACE_ITER_SYM_ADDR) || !file))
 365                 trace_seq_printf(s, " <" IP_FMT ">", ip);
 366         return !trace_seq_has_overflowed(s);
 367 }
 368
 369 int
 370 seq_print_ip_sym(struct trace_seq *s, unsigned long ip, unsigned long sym_flags)
 371 {
 372         if (!ip) {
 373                 trace_seq_putc(s, '0');
 374                 goto out;
 375         }
 376
 377         if (sym_flags & TRACE_ITER_SYM_OFFSET)
 378                 seq_print_sym_offset(s, "%s", ip);
 379         else
 380                 seq_print_sym_short(s, "%s", ip);
 381
 382         if (sym_flags & TRACE_ITER_SYM_ADDR)
 383                 trace_seq_printf(s, " <" IP_FMT ">", ip);
 384
 385  out:
 386         return !trace_seq_has_overflowed(s);
 387 }
 388
 389 /**
 390  * trace_print_lat_fmt - print the irq, preempt and lockdep fields
 391  * @s: trace seq struct to write to
 392  * @entry: The trace entry field from the ring buffer
 393  *
 394  * Prints the generic fields of irqs off, in hard or softirq, preempt
 395  * count.
 396  */
 397 int trace_print_lat_fmt(struct trace_seq *s, struct trace_entry *entry)
 398 {
 399         char hardsoft_irq;
 400         char need_resched;
 401         char irqs_off;
 402         int hardirq;
 403         int softirq;
 404         int nmi;
 405
 406         nmi = entry->flags & TRACE_FLAG_NMI;
 407         hardirq = entry->flags & TRACE_FLAG_HARDIRQ;
 408         softirq = entry->flags & TRACE_FLAG_SOFTIRQ;
 409
 410         irqs_off =
 411                 (entry->flags & TRACE_FLAG_IRQS_OFF) ? 'd' :
 412                 (entry->flags & TRACE_FLAG_IRQS_NOSUPPORT) ? 'X' :
 413                 '.';
 414
 415         switch (entry->flags & (TRACE_FLAG_NEED_RESCHED |
 416                                 TRACE_FLAG_PREEMPT_RESCHED)) {
 417         case TRACE_FLAG_NEED_RESCHED | TRACE_FLAG_PREEMPT_RESCHED:
 418                 need_resched = 'N';
 419                 break;
 420         case TRACE_FLAG_NEED_RESCHED:
 421                 need_resched = 'n';
 422                 break;
 423         case TRACE_FLAG_PREEMPT_RESCHED:
 424                 need_resched = 'p';
 425                 break;
 426         default:
 427                 need_resched = '.';
 428                 break;
 429         }
 430
 431         hardsoft_irq =
 432                 (nmi && hardirq)     ? 'Z' :
 433                 nmi                  ? 'z' :
 434                 (hardirq && softirq) ? 'H' :
 435                 hardirq              ? 'h' :
 436                 softirq              ? 's' :
 437                                        '.' ;
 438
 439         trace_seq_printf(s, "%c%c%c",
 440                          irqs_off, need_resched, hardsoft_irq);
 441
 442         if (entry->preempt_count)
 443                 trace_seq_printf(s, "%x", entry->preempt_count);
 444         else
 445                 trace_seq_putc(s, '.');
 446
 447         return !trace_seq_has_overflowed(s);
 448 }
 449
 450 static int
 451 lat_print_generic(struct trace_seq *s, struct trace_entry *entry, int cpu)
 452 {
 453         char comm[TASK_COMM_LEN];
 454
 455         trace_find_cmdline(entry->pid, comm);
 456
 457         trace_seq_printf(s, "%8.8s-%-5d %3d",
 458                          comm, entry->pid, cpu);
 459
 460         return trace_print_lat_fmt(s, entry);
 461 }
 462
 463 #undef MARK
 464 #define MARK(v, s) {.val = v, .sym = s}
 465 /* trace overhead mark */
 466 static const struct trace_mark {
 467         unsigned long long      val; /* unit: nsec */
 468         char                    sym;
 469 } mark[] = {
 470         MARK(1000000000ULL      , '$'), /* 1 sec */
 471         MARK(100000000ULL       , '@'), /* 100 msec */
 472         MARK(10000000ULL        , '*'), /* 10 msec */
 473         MARK(1000000ULL         , '#'), /* 1000 usecs */
 474         MARK(100000ULL          , '!'), /* 100 usecs */
 475         MARK(10000ULL           , '+'), /* 10 usecs */
 476 };
 477 #undef MARK
 478
 479 char trace_find_mark(unsigned long long d)
 480 {
 481         int i;
 482         int size = ARRAY_SIZE(mark);
 483
 484         for (i = 0; i < size; i++) {
 485                 if (d > mark[i].val)
 486                         break;
 487         }
 488
 489         return (i == size) ? ' ' : mark[i].sym;
 490 }
 491
 492 static int
 493 lat_print_timestamp(struct trace_iterator *iter, u64 next_ts)
 494 {
 495         struct trace_array *tr = iter->tr;
 496         unsigned long verbose = tr->trace_flags & TRACE_ITER_VERBOSE;
 497         unsigned long in_ns = iter->iter_flags & TRACE_FILE_TIME_IN_NS;
 498         unsigned long long abs_ts = iter->ts - iter->trace_buffer->time_start;
 499         unsigned long long rel_ts = next_ts - iter->ts;
 500         struct trace_seq *s = &iter->seq;
 501
 502         if (in_ns) {
 503                 abs_ts = ns2usecs(abs_ts);
 504                 rel_ts = ns2usecs(rel_ts);
 505         }
 506
 507         if (verbose && in_ns) {
 508                 unsigned long abs_usec = do_div(abs_ts, USEC_PER_MSEC);
 509                 unsigned long abs_msec = (unsigned long)abs_ts;
 510                 unsigned long rel_usec = do_div(rel_ts, USEC_PER_MSEC);
 511                 unsigned long rel_msec = (unsigned long)rel_ts;
 512
 513                 trace_seq_printf(
 514                         s, "[%08llx] %ld.%03ldms (+%ld.%03ldms): ",
 515                         ns2usecs(iter->ts),
 516                         abs_msec, abs_usec,
 517                         rel_msec, rel_usec);
 518
 519         } else if (verbose && !in_ns) {
 520                 trace_seq_printf(
 521                         s, "[%016llx] %lld (+%lld): ",
 522                         iter->ts, abs_ts, rel_ts);
 523
 524         } else if (!verbose && in_ns) {
 525                 trace_seq_printf(
 526                         s, " %4lldus%c: ",
 527                         abs_ts,
 528                         trace_find_mark(rel_ts * NSEC_PER_USEC));
 529
 530         } else { /* !verbose && !in_ns */
 531                 trace_seq_printf(s, " %4lld: ", abs_ts);
 532         }
 533
 534         return !trace_seq_has_overflowed(s);
 535 }
 536
 537 int trace_print_context(struct trace_iterator *iter)
 538 {
 539         struct trace_array *tr = iter->tr;
 540         struct trace_seq *s = &iter->seq;
 541         struct trace_entry *entry = iter->ent;
 542         unsigned long long t;
 543         unsigned long secs, usec_rem;
 544         char comm[TASK_COMM_LEN];
 545
 546         trace_find_cmdline(entry->pid, comm);
 547
 548         trace_seq_printf(s, "%16s-%-5d [%03d] ",
 549                                comm, entry->pid, iter->cpu);
 550
 551         if (tr->trace_flags & TRACE_ITER_IRQ_INFO)
 552                 trace_print_lat_fmt(s, entry);
 553
 554         if (iter->iter_flags & TRACE_FILE_TIME_IN_NS) {
 555                 t = ns2usecs(iter->ts);
 556                 usec_rem = do_div(t, USEC_PER_SEC);
 557                 secs = (unsigned long)t;
 558                 trace_seq_printf(s, " %5lu.%06lu: ", secs, usec_rem);
 559         } else
 560                 trace_seq_printf(s, " %12llu: ", iter->ts);
 561
 562         return !trace_seq_has_overflowed(s);
 563 }
 564
 565 int trace_print_lat_context(struct trace_iterator *iter)
 566 {
 567         struct trace_array *tr = iter->tr;
 568         /* trace_find_next_entry will reset ent_size */
 569         int ent_size = iter->ent_size;
 570         struct trace_seq *s = &iter->seq;
 571         u64 next_ts;
 572         struct trace_entry *entry = iter->ent,
 573                            *next_entry = trace_find_next_entry(iter, NULL,
 574                                                                &next_ts);
 575         unsigned long verbose = (tr->trace_flags & TRACE_ITER_VERBOSE);
 576
 577         /* Restore the original ent_size */
 578         iter->ent_size = ent_size;
 579
 580         if (!next_entry)
 581                 next_ts = iter->ts;
 582
 583         if (verbose) {
 584                 char comm[TASK_COMM_LEN];
 585
 586                 trace_find_cmdline(entry->pid, comm);
 587
 588                 trace_seq_printf(
 589                         s, "%16s %5d %3d %d %08x %08lx ",
 590                         comm, entry->pid, iter->cpu, entry->flags,
 591                         entry->preempt_count, iter->idx);
 592         } else {
 593                 lat_print_generic(s, entry, iter->cpu);
 594         }
 595
 596         lat_print_timestamp(iter, next_ts);
 597
 598         return !trace_seq_has_overflowed(s);
 599 }
 600
 601 static const char state_to_char[] = TASK_STATE_TO_CHAR_STR;
 602
 603 static int task_state_char(unsigned long state)
 604 {
 605         int bit = state ? __ffs(state) + 1 : 0;
 606
 607         return bit < sizeof(state_to_char) - 1 ? state_to_char[bit] : '?';
 608 }
 609
 610 /**
 611  * ftrace_find_event - find a registered event
 612  * @type: the type of event to look for
 613  *
 614  * Returns an event of type @type otherwise NULL
 615  * Called with trace_event_read_lock() held.
 616  */
 617 struct trace_event *ftrace_find_event(int type)
 618 {
 619         struct trace_event *event;
 620         unsigned key;
 621
 622         key = type & (EVENT_HASHSIZE - 1);
 623
 624         hlist_for_each_entry(event, &event_hash[key], node) {
 625                 if (event->type == type)
 626                         return event;
 627         }
 628
 629         return NULL;
 630 }
 631
 632 static LIST_HEAD(ftrace_event_list);
 633
 634 static int trace_search_list(struct list_head **list)
 635 {
 636         struct trace_event *e;
 637         int last = __TRACE_LAST_TYPE;
 638
 639         if (list_empty(&ftrace_event_list)) {
 640                 *list = &ftrace_event_list;
 641                 return last + 1;
 642         }
 643
 644         /*
 645          * We used up all possible max events,
 646          * lets see if somebody freed one.
 647          */
 648         list_for_each_entry(e, &ftrace_event_list, list) {
 649                 if (e->type != last + 1)
 650                         break;
 651                 last++;
 652         }
 653
 654         /* Did we used up all 65 thousand events??? */
 655         if ((last + 1) > TRACE_EVENT_TYPE_MAX)
 656                 return 0;
 657
 658         *list = &e->list;
 659         return last + 1;
 660 }
 661
 662 void trace_event_read_lock(void)
 663 {
 664         down_read(&trace_event_sem);
 665 }
 666
 667 void trace_event_read_unlock(void)
 668 {
 669         up_read(&trace_event_sem);
 670 }
 671
 672 /**
 673  * register_trace_event - register output for an event type
 674  * @event: the event type to register
 675  *
 676  * Event types are stored in a hash and this hash is used to
 677  * find a way to print an event. If the @event->type is set
 678  * then it will use that type, otherwise it will assign a
 679  * type to use.
 680  *
 681  * If you assign your own type, please make sure it is added
 682  * to the trace_type enum in trace.h, to avoid collisions
 683  * with the dynamic types.
 684  *
 685  * Returns the event type number or zero on error.
 686  */
 687 int register_trace_event(struct trace_event *event)
 688 {
 689         unsigned key;
 690         int ret = 0;
 691
 692         down_write(&trace_event_sem);
 693
 694         if (WARN_ON(!event))
 695                 goto out;
 696
 697         if (WARN_ON(!event->funcs))
 698                 goto out;
 699
 700         INIT_LIST_HEAD(&event->list);
 701
 702         if (!event->type) {
 703                 struct list_head *list = NULL;
 704
 705                 if (next_event_type > TRACE_EVENT_TYPE_MAX) {
 706
 707                         event->type = trace_search_list(&list);
 708                         if (!event->type)
 709                                 goto out;
 710
 711                 } else {
 712
 713                         event->type = next_event_type++;
 714                         list = &ftrace_event_list;
 715                 }
 716
 717                 if (WARN_ON(ftrace_find_event(event->type)))
 718                         goto out;
 719
 720                 list_add_tail(&event->list, list);
 721
 722         } else if (event->type > __TRACE_LAST_TYPE) {
 723                 printk(KERN_WARNING "Need to add type to trace.h\n");
 724                 WARN_ON(1);
 725                 goto out;
 726         } else {
 727                 /* Is this event already used */
 728                 if (ftrace_find_event(event->type))
 729                         goto out;
 730         }
 731
 732         if (event->funcs->trace == NULL)
 733                 event->funcs->trace = trace_nop_print;
 734         if (event->funcs->raw == NULL)
 735                 event->funcs->raw = trace_nop_print;
 736         if (event->funcs->hex == NULL)
 737                 event->funcs->hex = trace_nop_print;
 738         if (event->funcs->binary == NULL)
 739                 event->funcs->binary = trace_nop_print;
 740
 741         key = event->type & (EVENT_HASHSIZE - 1);
 742
 743         hlist_add_head(&event->node, &event_hash[key]);
 744
 745         ret = event->type;
 746  out:
 747         up_write(&trace_event_sem);
 748
 749         return ret;
 750 }
 751 EXPORT_SYMBOL_GPL(register_trace_event);
 752
 753 /*
 754  * Used by module code with the trace_event_sem held for write.
 755  */
 756 int __unregister_trace_event(struct trace_event *event)
 757 {
 758         hlist_del(&event->node);
 759         list_del(&event->list);
 760         return 0;
 761 }
 762
 763 /**
 764  * unregister_trace_event - remove a no longer used event
 765  * @event: the event to remove
 766  */
 767 int unregister_trace_event(struct trace_event *event)
 768 {
 769         down_write(&trace_event_sem);
 770         __unregister_trace_event(event);
 771         up_write(&trace_event_sem);
 772
 773         return 0;
 774 }
 775 EXPORT_SYMBOL_GPL(unregister_trace_event);
 776
 777 /*
 778  * Standard events
 779  */
 780
 781 enum print_line_t trace_nop_print(struct trace_iterator *iter, int flags,
 782                                   struct trace_event *event)
 783 {
 784         trace_seq_printf(&iter->seq, "type: %d\n", iter->ent->type);
 785
 786         return trace_handle_return(&iter->seq);
 787 }
 788
 789 /* TRACE_FN */
 790 static enum print_line_t trace_fn_trace(struct trace_iterator *iter, int flags,
 791                                         struct trace_event *event)
 792 {
 793         struct ftrace_entry *field;
 794         struct trace_seq *s = &iter->seq;
 795
 796         trace_assign_type(field, iter->ent);
 797
 798         seq_print_ip_sym(s, field->ip, flags);
 799
 800         if ((flags & TRACE_ITER_PRINT_PARENT) && field->parent_ip) {
 801                 trace_seq_puts(s, " <-");
 802                 seq_print_ip_sym(s, field->parent_ip, flags);
 803         }
 804
 805         trace_seq_putc(s, '\n');
 806
 807         return trace_handle_return(s);
 808 }
 809
 810 static enum print_line_t trace_fn_raw(struct trace_iterator *iter, int flags,
 811                                       struct trace_event *event)
 812 {
 813         struct ftrace_entry *field;
 814
 815         trace_assign_type(field, iter->ent);
 816
 817         trace_seq_printf(&iter->seq, "%lx %lx\n",
 818                          field->ip,
 819                          field->parent_ip);
 820
 821         return trace_handle_return(&iter->seq);
 822 }
 823
 824 static enum print_line_t trace_fn_hex(struct trace_iterator *iter, int flags,
 825                                       struct trace_event *event)
 826 {
 827         struct ftrace_entry *field;
 828         struct trace_seq *s = &iter->seq;
 829
 830         trace_assign_type(field, iter->ent);
 831
 832         SEQ_PUT_HEX_FIELD(s, field->ip);
 833         SEQ_PUT_HEX_FIELD(s, field->parent_ip);
 834
 835         return trace_handle_return(s);
 836 }
 837
 838 static enum print_line_t trace_fn_bin(struct trace_iterator *iter, int flags,
 839                                       struct trace_event *event)
 840 {
 841         struct ftrace_entry *field;
 842         struct trace_seq *s = &iter->seq;
 843
 844         trace_assign_type(field, iter->ent);
 845
 846         SEQ_PUT_FIELD(s, field->ip);
 847         SEQ_PUT_FIELD(s, field->parent_ip);
 848
 849         return trace_handle_return(s);
 850 }
 851
 852 static struct trace_event_functions trace_fn_funcs = {
 853         .trace          = trace_fn_trace,
 854         .raw            = trace_fn_raw,
 855         .hex            = trace_fn_hex,
 856         .binary         = trace_fn_bin,
 857 };
 858
 859 static struct trace_event trace_fn_event = {
 860         .type           = TRACE_FN,
 861         .funcs          = &trace_fn_funcs,
 862 };
 863
 864 /* TRACE_CTX an TRACE_WAKE */
 865 static enum print_line_t trace_ctxwake_print(struct trace_iterator *iter,
 866                                              char *delim)
 867 {
 868         struct ctx_switch_entry *field;
 869         char comm[TASK_COMM_LEN];
 870         int S, T;
 871
 872
 873         trace_assign_type(field, iter->ent);
 874
 875         T = task_state_char(field->next_state);
 876         S = task_state_char(field->prev_state);
 877         trace_find_cmdline(field->next_pid, comm);
 878         trace_seq_printf(&iter->seq,
 879                          " %5d:%3d:%c %s [%03d] %5d:%3d:%c %s\n",
 880                          field->prev_pid,
 881                          field->prev_prio,
 882                          S, delim,
 883                          field->next_cpu,
 884                          field->next_pid,
 885                          field->next_prio,
 886                          T, comm);
 887
 888         return trace_handle_return(&iter->seq);
 889 }
 890
 891 static enum print_line_t trace_ctx_print(struct trace_iterator *iter, int flags,
 892                                          struct trace_event *event)
 893 {
 894         return trace_ctxwake_print(iter, "==>");
 895 }
 896
 897 static enum print_line_t trace_wake_print(struct trace_iterator *iter,
 898                                           int flags, struct trace_event *event)
 899 {
 900         return trace_ctxwake_print(iter, "  +");
 901 }
 902
 903 static int trace_ctxwake_raw(struct trace_iterator *iter, char S)
 904 {
 905         struct ctx_switch_entry *field;
 906         int T;
 907
 908         trace_assign_type(field, iter->ent);
 909
 910         if (!S)
 911                 S = task_state_char(field->prev_state);
 912         T = task_state_char(field->next_state);
 913         trace_seq_printf(&iter->seq, "%d %d %c %d %d %d %c\n",
 914                          field->prev_pid,
 915                          field->prev_prio,
 916                          S,
 917                          field->next_cpu,
 918                          field->next_pid,
 919                          field->next_prio,
 920                          T);
 921
 922         return trace_handle_return(&iter->seq);
 923 }
 924
 925 static enum print_line_t trace_ctx_raw(struct trace_iterator *iter, int flags,
 926                                        struct trace_event *event)
 927 {
 928         return trace_ctxwake_raw(iter, 0);
 929 }
 930
 931 static enum print_line_t trace_wake_raw(struct trace_iterator *iter, int flags,
 932                                         struct trace_event *event)
 933 {
 934         return trace_ctxwake_raw(iter, '+');
 935 }
 936
 937
 938 static int trace_ctxwake_hex(struct trace_iterator *iter, char S)
 939 {
 940         struct ctx_switch_entry *field;
 941         struct trace_seq *s = &iter->seq;
 942         int T;
 943
 944         trace_assign_type(field, iter->ent);
 945
 946         if (!S)
 947                 S = task_state_char(field->prev_state);
 948         T = task_state_char(field->next_state);
 949
 950         SEQ_PUT_HEX_FIELD(s, field->prev_pid);
 951         SEQ_PUT_HEX_FIELD(s, field->prev_prio);
 952         SEQ_PUT_HEX_FIELD(s, S);
 953         SEQ_PUT_HEX_FIELD(s, field->next_cpu);
 954         SEQ_PUT_HEX_FIELD(s, field->next_pid);
 955         SEQ_PUT_HEX_FIELD(s, field->next_prio);
 956         SEQ_PUT_HEX_FIELD(s, T);
 957
 958         return trace_handle_return(s);
 959 }
 960
 961 static enum print_line_t trace_ctx_hex(struct trace_iterator *iter, int flags,
 962                                        struct trace_event *event)
 963 {
 964         return trace_ctxwake_hex(iter, 0);
 965 }
 966
 967 static enum print_line_t trace_wake_hex(struct trace_iterator *iter, int flags,
 968                                         struct trace_event *event)
 969 {
 970         return trace_ctxwake_hex(iter, '+');
 971 }
 972
 973 static enum print_line_t trace_ctxwake_bin(struct trace_iterator *iter,
 974                                            int flags, struct trace_event *event)
 975 {
 976         struct ctx_switch_entry *field;
 977         struct trace_seq *s = &iter->seq;
 978
 979         trace_assign_type(field, iter->ent);
 980
 981         SEQ_PUT_FIELD(s, field->prev_pid);
 982         SEQ_PUT_FIELD(s, field->prev_prio);
 983         SEQ_PUT_FIELD(s, field->prev_state);
 984         SEQ_PUT_FIELD(s, field->next_cpu);
 985         SEQ_PUT_FIELD(s, field->next_pid);
 986         SEQ_PUT_FIELD(s, field->next_prio);
 987         SEQ_PUT_FIELD(s, field->next_state);
 988
 989         return trace_handle_return(s);
 990 }
 991
 992 static struct trace_event_functions trace_ctx_funcs = {
 993         .trace          = trace_ctx_print,
 994         .raw            = trace_ctx_raw,
 995         .hex            = trace_ctx_hex,
 996         .binary         = trace_ctxwake_bin,
 997 };
 998
 999 static struct trace_event trace_ctx_event = {
1000         .type           = TRACE_CTX,
1001         .funcs          = &trace_ctx_funcs,
1002 };
1003
1004 static struct trace_event_functions trace_wake_funcs = {
1005         .trace          = trace_wake_print,
1006         .raw            = trace_wake_raw,
1007         .hex            = trace_wake_hex,
1008         .binary         = trace_ctxwake_bin,
1009 };
1010
1011 static struct trace_event trace_wake_event = {
1012         .type           = TRACE_WAKE,
1013         .funcs          = &trace_wake_funcs,
1014 };
1015
1016 /* TRACE_STACK */
1017
1018 static enum print_line_t trace_stack_print(struct trace_iterator *iter,
1019                                            int flags, struct trace_event *event)
1020 {
1021         struct stack_entry *field;
1022         struct trace_seq *s = &iter->seq;
1023         unsigned long *p;
1024         unsigned long *end;
1025
1026         trace_assign_type(field, iter->ent);
1027         end = (unsigned long *)((long)iter->ent + iter->ent_size);
1028
1029         trace_seq_puts(s, "<stack trace>\n");
1030
1031         for (p = field->caller; p && *p != ULONG_MAX && p < end; p++) {
1032
1033                 if (trace_seq_has_overflowed(s))
1034                         break;
1035
1036                 trace_seq_puts(s, " => ");
1037                 seq_print_ip_sym(s, *p, flags);
1038                 trace_seq_putc(s, '\n');
1039         }
1040
1041         return trace_handle_return(s);
1042 }
1043
1044 static struct trace_event_functions trace_stack_funcs = {
1045         .trace          = trace_stack_print,
1046 };
1047
1048 static struct trace_event trace_stack_event = {
1049         .type           = TRACE_STACK,
1050         .funcs          = &trace_stack_funcs,
1051 };
1052
1053 /* TRACE_USER_STACK */
1054 static enum print_line_t trace_user_stack_print(struct trace_iterator *iter,
1055                                                 int flags, struct trace_event *event)
1056 {
1057         struct trace_array *tr = iter->tr;
1058         struct userstack_entry *field;
1059         struct trace_seq *s = &iter->seq;
1060         struct mm_struct *mm = NULL;
1061         unsigned int i;
1062
1063         trace_assign_type(field, iter->ent);
1064
1065         trace_seq_puts(s, "<user stack trace>\n");
1066
1067         if (tr->trace_flags & TRACE_ITER_SYM_USEROBJ) {
1068                 struct task_struct *task;
1069                 /*
1070                  * we do the lookup on the thread group leader,
1071                  * since individual threads might have already quit!
1072                  */
1073                 rcu_read_lock();
1074                 task = find_task_by_vpid(field->tgid);
1075                 if (task)
1076                         mm = get_task_mm(task);
1077                 rcu_read_unlock();
1078         }
1079
1080         for (i = 0; i < FTRACE_STACK_ENTRIES; i++) {
1081                 unsigned long ip = field->caller[i];
1082
1083                 if (ip == ULONG_MAX || trace_seq_has_overflowed(s))
1084                         break;
1085
1086                 trace_seq_puts(s, " => ");
1087
1088                 if (!ip) {
1089                         trace_seq_puts(s, "??");
1090                         trace_seq_putc(s, '\n');
1091                         continue;
1092                 }
1093
1094                 seq_print_user_ip(s, mm, ip, flags);
1095                 trace_seq_putc(s, '\n');
1096         }
1097
1098         if (mm)
1099                 mmput(mm);
1100
1101         return trace_handle_return(s);
1102 }
1103
1104 static struct trace_event_functions trace_user_stack_funcs = {
1105         .trace          = trace_user_stack_print,
1106 };
1107
1108 static struct trace_event trace_user_stack_event = {
1109         .type           = TRACE_USER_STACK,
1110         .funcs          = &trace_user_stack_funcs,
1111 };
1112
1113 /* TRACE_HWLAT */
1114 static enum print_line_t
1115 trace_hwlat_print(struct trace_iterator *iter, int flags,
1116                   struct trace_event *event)
1117 {
1118         struct trace_entry *entry = iter->ent;
1119         struct trace_seq *s = &iter->seq;
1120         struct hwlat_entry *field;
1121
1122         trace_assign_type(field, entry);
1123
1124         trace_seq_printf(s, "#%-5u inner/outer(us): %4llu/%-5llu ts:%ld.%09ld",
1125                          field->seqnum,
1126                          field->duration,
1127                          field->outer_duration,
1128                          field->timestamp.tv_sec,
1129                          field->timestamp.tv_nsec);
1130
1131         if (field->nmi_count) {
1132                 /*
1133                  * The generic sched_clock() is not NMI safe, thus
1134                  * we only record the count and not the time.
1135                  */
1136                 if (!IS_ENABLED(CONFIG_GENERIC_SCHED_CLOCK))
1137                         trace_seq_printf(s, " nmi-total:%llu",
1138                                          field->nmi_total_ts);
1139                 trace_seq_printf(s, " nmi-count:%u",
1140                                  field->nmi_count);
1141         }
1142
1143         trace_seq_putc(s, '\n');
1144
1145         return trace_handle_return(s);
1146 }
1147
1148
1149 static enum print_line_t
1150 trace_hwlat_raw(struct trace_iterator *iter, int flags,
1151                 struct trace_event *event)
1152 {
1153         struct hwlat_entry *field;
1154         struct trace_seq *s = &iter->seq;
1155
1156         trace_assign_type(field, iter->ent);
1157
1158         trace_seq_printf(s, "%llu %lld %ld %09ld %u\n",
1159                          field->duration,
1160                          field->outer_duration,
1161                          field->timestamp.tv_sec,
1162                          field->timestamp.tv_nsec,
1163                          field->seqnum);
1164
1165         return trace_handle_return(s);
1166 }
1167
1168 static struct trace_event_functions trace_hwlat_funcs = {
1169         .trace          = trace_hwlat_print,
1170         .raw            = trace_hwlat_raw,
1171 };
1172
1173 static struct trace_event trace_hwlat_event = {
1174         .type           = TRACE_HWLAT,
1175         .funcs          = &trace_hwlat_funcs,
1176 };
1177
1178 /* TRACE_BPUTS */
1179 static enum print_line_t
1180 trace_bputs_print(struct trace_iterator *iter, int flags,
1181                    struct trace_event *event)
1182 {
1183         struct trace_entry *entry = iter->ent;
1184         struct trace_seq *s = &iter->seq;
1185         struct bputs_entry *field;
1186
1187         trace_assign_type(field, entry);
1188
1189         seq_print_ip_sym(s, field->ip, flags);
1190         trace_seq_puts(s, ": ");
1191         trace_seq_puts(s, field->str);
1192
1193         return trace_handle_return(s);
1194 }
1195
1196
1197 static enum print_line_t
1198 trace_bputs_raw(struct trace_iterator *iter, int flags,
1199                 struct trace_event *event)
1200 {
1201         struct bputs_entry *field;
1202         struct trace_seq *s = &iter->seq;
1203
1204         trace_assign_type(field, iter->ent);
1205
1206         trace_seq_printf(s, ": %lx : ", field->ip);
1207         trace_seq_puts(s, field->str);
1208
1209         return trace_handle_return(s);
1210 }
1211
1212 static struct trace_event_functions trace_bputs_funcs = {
1213         .trace          = trace_bputs_print,
1214         .raw            = trace_bputs_raw,
1215 };
1216
1217 static struct trace_event trace_bputs_event = {
1218         .type           = TRACE_BPUTS,
1219         .funcs          = &trace_bputs_funcs,
1220 };
1221
1222 /* TRACE_BPRINT */
1223 static enum print_line_t
1224 trace_bprint_print(struct trace_iterator *iter, int flags,
1225                    struct trace_event *event)
1226 {
1227         struct trace_entry *entry = iter->ent;
1228         struct trace_seq *s = &iter->seq;
1229         struct bprint_entry *field;
1230
1231         trace_assign_type(field, entry);
1232
1233         seq_print_ip_sym(s, field->ip, flags);
1234         trace_seq_puts(s, ": ");
1235         trace_seq_bprintf(s, field->fmt, field->buf);
1236
1237         return trace_handle_return(s);
1238 }
1239
1240
1241 static enum print_line_t
1242 trace_bprint_raw(struct trace_iterator *iter, int flags,
1243                  struct trace_event *event)
1244 {
1245         struct bprint_entry *field;
1246         struct trace_seq *s = &iter->seq;
1247
1248         trace_assign_type(field, iter->ent);
1249
1250         trace_seq_printf(s, ": %lx : ", field->ip);
1251         trace_seq_bprintf(s, field->fmt, field->buf);
1252
1253         return trace_handle_return(s);
1254 }
1255
1256 static struct trace_event_functions trace_bprint_funcs = {
1257         .trace          = trace_bprint_print,
1258         .raw            = trace_bprint_raw,
1259 };
1260
1261 static struct trace_event trace_bprint_event = {
1262         .type           = TRACE_BPRINT,
1263         .funcs          = &trace_bprint_funcs,
1264 };
1265
1266 /* TRACE_PRINT */
1267 static enum print_line_t trace_print_print(struct trace_iterator *iter,
1268                                            int flags, struct trace_event *event)
1269 {
1270         struct print_entry *field;
1271         struct trace_seq *s = &iter->seq;
1272
1273         trace_assign_type(field, iter->ent);
1274
1275         seq_print_ip_sym(s, field->ip, flags);
1276         trace_seq_printf(s, ": %s", field->buf);
1277
1278         return trace_handle_return(s);
1279 }
1280
1281 static enum print_line_t trace_print_raw(struct trace_iterator *iter, int flags,
1282                                          struct trace_event *event)
1283 {
1284         struct print_entry *field;
1285
1286         trace_assign_type(field, iter->ent);
1287
1288         trace_seq_printf(&iter->seq, "# %lx %s", field->ip, field->buf);
1289
1290         return trace_handle_return(&iter->seq);
1291 }
1292
1293 static struct trace_event_functions trace_print_funcs = {
1294         .trace          = trace_print_print,
1295         .raw            = trace_print_raw,
1296 };
1297
1298 static struct trace_event trace_print_event = {
1299         .type           = TRACE_PRINT,
1300         .funcs          = &trace_print_funcs,
1301 };
1302
1303 static enum print_line_t trace_raw_data(struct trace_iterator *iter, int flags,
1304                                          struct trace_event *event)
1305 {
1306         struct raw_data_entry *field;
1307         int i;
1308
1309         trace_assign_type(field, iter->ent);
1310
1311         trace_seq_printf(&iter->seq, "# %x buf:", field->id);
1312
1313         for (i = 0; i < iter->ent_size - offsetof(struct raw_data_entry, buf); i++)
1314                 trace_seq_printf(&iter->seq, " %02x",
1315                                  (unsigned char)field->buf[i]);
1316
1317         trace_seq_putc(&iter->seq, '\n');
1318
1319         return trace_handle_return(&iter->seq);
1320 }
1321
1322 static struct trace_event_functions trace_raw_data_funcs = {
1323         .trace          = trace_raw_data,
1324         .raw            = trace_raw_data,
1325 };
1326
1327 static struct trace_event trace_raw_data_event = {
1328         .type           = TRACE_RAW_DATA,
1329         .funcs          = &trace_raw_data_funcs,
1330 };
1331
1332
1333 static struct trace_event *events[] __initdata = {
1334         &trace_fn_event,
1335         &trace_ctx_event,
1336         &trace_wake_event,
1337         &trace_stack_event,
1338         &trace_user_stack_event,
1339         &trace_bputs_event,
1340         &trace_bprint_event,
1341         &trace_print_event,
1342         &trace_hwlat_event,
1343         &trace_raw_data_event,
1344         NULL
1345 };
1346
1347 __init static int init_events(void)
1348 {
1349         struct trace_event *event;
1350         int i, ret;
1351
1352         for (i = 0; events[i]; i++) {
1353                 event = events[i];
1354
1355                 ret = register_trace_event(event);
1356                 if (!ret) {
1357                         printk(KERN_WARNING "event %d failed to register\n",
1358                                event->type);
1359                         WARN_ON_ONCE(1);
1360                 }
1361         }
1362
1363         return 0;
1364 }
1365 early_initcall(init_events);