kernel/trace/trace_output.c

   1 /*
   2  * trace_output.c
   3  *
   4  * Copyright (C) 2008 Red Hat Inc, Steven Rostedt <[email protected]>
   5  *
   6  */
   7
   8 #include <linux/module.h>
   9 #include <linux/mutex.h>
  10 #include <linux/ftrace.h>
  11
  12 #include "trace_output.h"
  13
  14 /* must be a power of 2 */
  15 #define EVENT_HASHSIZE  128
  16
  17 DECLARE_RWSEM(trace_event_sem);
  18
  19 static struct hlist_head event_hash[EVENT_HASHSIZE] __read_mostly;
  20
  21 static int next_event_type = __TRACE_LAST_TYPE + 1;
  22
  23 enum print_line_t trace_print_bputs_msg_only(struct trace_iterator *iter)
  24 {
  25         struct trace_seq *s = &iter->seq;
  26         struct trace_entry *entry = iter->ent;
  27         struct bputs_entry *field;
  28
  29         trace_assign_type(field, entry);
  30
  31         trace_seq_puts(s, field->str);
  32
  33         return trace_handle_return(s);
  34 }
  35
  36 enum print_line_t trace_print_bprintk_msg_only(struct trace_iterator *iter)
  37 {
  38         struct trace_seq *s = &iter->seq;
  39         struct trace_entry *entry = iter->ent;
  40         struct bprint_entry *field;
  41
  42         trace_assign_type(field, entry);
  43
  44         trace_seq_bprintf(s, field->fmt, field->buf);
  45
  46         return trace_handle_return(s);
  47 }
  48
  49 enum print_line_t trace_print_printk_msg_only(struct trace_iterator *iter)
  50 {
  51         struct trace_seq *s = &iter->seq;
  52         struct trace_entry *entry = iter->ent;
  53         struct print_entry *field;
  54
  55         trace_assign_type(field, entry);
  56
  57         trace_seq_puts(s, field->buf);
  58
  59         return trace_handle_return(s);
  60 }
  61
  62 const char *
  63 trace_print_flags_seq(struct trace_seq *p, const char *delim,
  64                       unsigned long flags,
  65                       const struct trace_print_flags *flag_array)
  66 {
  67         unsigned long mask;
  68         const char *str;
  69         const char *ret = trace_seq_buffer_ptr(p);
  70         int i, first = 1;
  71
  72         for (i = 0;  flag_array[i].name && flags; i++) {
  73
  74                 mask = flag_array[i].mask;
  75                 if ((flags & mask) != mask)
  76                         continue;
  77
  78                 str = flag_array[i].name;
  79                 flags &= ~mask;
  80                 if (!first && delim)
  81                         trace_seq_puts(p, delim);
  82                 else
  83                         first = 0;
  84                 trace_seq_puts(p, str);
  85         }
  86
  87         /* check for left over flags */
  88         if (flags) {
  89                 if (!first && delim)
  90                         trace_seq_puts(p, delim);
  91                 trace_seq_printf(p, "0x%lx", flags);
  92         }
  93
  94         trace_seq_putc(p, 0);
  95
  96         return ret;
  97 }
  98 EXPORT_SYMBOL(trace_print_flags_seq);
  99
 100 const char *
 101 trace_print_symbols_seq(struct trace_seq *p, unsigned long val,
 102                         const struct trace_print_flags *symbol_array)
 103 {
 104         int i;
 105         const char *ret = trace_seq_buffer_ptr(p);
 106
 107         for (i = 0;  symbol_array[i].name; i++) {
 108
 109                 if (val != symbol_array[i].mask)
 110                         continue;
 111
 112                 trace_seq_puts(p, symbol_array[i].name);
 113                 break;
 114         }
 115
 116         if (ret == (const char *)(trace_seq_buffer_ptr(p)))
 117                 trace_seq_printf(p, "0x%lx", val);
 118
 119         trace_seq_putc(p, 0);
 120
 121         return ret;
 122 }
 123 EXPORT_SYMBOL(trace_print_symbols_seq);
 124
 125 #if BITS_PER_LONG == 32
 126 const char *
 127 trace_print_symbols_seq_u64(struct trace_seq *p, unsigned long long val,
 128                          const struct trace_print_flags_u64 *symbol_array)
 129 {
 130         int i;
 131         const char *ret = trace_seq_buffer_ptr(p);
 132
 133         for (i = 0;  symbol_array[i].name; i++) {
 134
 135                 if (val != symbol_array[i].mask)
 136                         continue;
 137
 138                 trace_seq_puts(p, symbol_array[i].name);
 139                 break;
 140         }
 141
 142         if (ret == (const char *)(trace_seq_buffer_ptr(p)))
 143                 trace_seq_printf(p, "0x%llx", val);
 144
 145         trace_seq_putc(p, 0);
 146
 147         return ret;
 148 }
 149 EXPORT_SYMBOL(trace_print_symbols_seq_u64);
 150 #endif
 151
 152 const char *
 153 trace_print_bitmask_seq(struct trace_seq *p, void *bitmask_ptr,
 154                         unsigned int bitmask_size)
 155 {
 156         const char *ret = trace_seq_buffer_ptr(p);
 157
 158         trace_seq_bitmask(p, bitmask_ptr, bitmask_size * 8);
 159         trace_seq_putc(p, 0);
 160
 161         return ret;
 162 }
 163 EXPORT_SYMBOL_GPL(trace_print_bitmask_seq);
 164
 165 const char *
 166 trace_print_hex_seq(struct trace_seq *p, const unsigned char *buf, int buf_len,
 167                     bool spacing)
 168 {
 169         int i;
 170         const char *ret = trace_seq_buffer_ptr(p);
 171
 172         for (i = 0; i < buf_len; i++)
 173                 trace_seq_printf(p, "%s%2.2x", !spacing || i == 0 ? "" : " ",
 174                                  buf[i]);
 175         trace_seq_putc(p, 0);
 176
 177         return ret;
 178 }
 179 EXPORT_SYMBOL(trace_print_hex_seq);
 180
 181 const char *
 182 trace_print_array_seq(struct trace_seq *p, const void *buf, int count,
 183                       size_t el_size)
 184 {
 185         const char *ret = trace_seq_buffer_ptr(p);
 186         const char *prefix = "";
 187         void *ptr = (void *)buf;
 188         size_t buf_len = count * el_size;
 189
 190         trace_seq_putc(p, '{');
 191
 192         while (ptr < buf + buf_len) {
 193                 switch (el_size) {
 194                 case 1:
 195                         trace_seq_printf(p, "%s0x%x", prefix,
 196                                          *(u8 *)ptr);
 197                         break;
 198                 case 2:
 199                         trace_seq_printf(p, "%s0x%x", prefix,
 200                                          *(u16 *)ptr);
 201                         break;
 202                 case 4:
 203                         trace_seq_printf(p, "%s0x%x", prefix,
 204                                          *(u32 *)ptr);
 205                         break;
 206                 case 8:
 207                         trace_seq_printf(p, "%s0x%llx", prefix,
 208                                          *(u64 *)ptr);
 209                         break;
 210                 default:
 211                         trace_seq_printf(p, "BAD SIZE:%zu 0x%x", el_size,
 212                                          *(u8 *)ptr);
 213                         el_size = 1;
 214                 }
 215                 prefix = ",";
 216                 ptr += el_size;
 217         }
 218
 219         trace_seq_putc(p, '}');
 220         trace_seq_putc(p, 0);
 221
 222         return ret;
 223 }
 224 EXPORT_SYMBOL(trace_print_array_seq);
 225
 226 int trace_raw_output_prep(struct trace_iterator *iter,
 227                           struct trace_event *trace_event)
 228 {
 229         struct trace_event_call *event;
 230         struct trace_seq *s = &iter->seq;
 231         struct trace_seq *p = &iter->tmp_seq;
 232         struct trace_entry *entry;
 233
 234         event = container_of(trace_event, struct trace_event_call, event);
 235         entry = iter->ent;
 236
 237         if (entry->type != event->event.type) {
 238                 WARN_ON_ONCE(1);
 239                 return TRACE_TYPE_UNHANDLED;
 240         }
 241
 242         trace_seq_init(p);
 243         trace_seq_printf(s, "%s: ", trace_event_name(event));
 244
 245         return trace_handle_return(s);
 246 }
 247 EXPORT_SYMBOL(trace_raw_output_prep);
 248
 249 static int trace_output_raw(struct trace_iterator *iter, char *name,
 250                             char *fmt, va_list ap)
 251 {
 252         struct trace_seq *s = &iter->seq;
 253
 254         trace_seq_printf(s, "%s: ", name);
 255         trace_seq_vprintf(s, fmt, ap);
 256
 257         return trace_handle_return(s);
 258 }
 259
 260 int trace_output_call(struct trace_iterator *iter, char *name, char *fmt, ...)
 261 {
 262         va_list ap;
 263         int ret;
 264
 265         va_start(ap, fmt);
 266         ret = trace_output_raw(iter, name, fmt, ap);
 267         va_end(ap);
 268
 269         return ret;
 270 }
 271 EXPORT_SYMBOL_GPL(trace_output_call);
 272
 273 #ifdef CONFIG_KRETPROBES
 274 static inline const char *kretprobed(const char *name)
 275 {
 276         static const char tramp_name[] = "kretprobe_trampoline";
 277         int size = sizeof(tramp_name);
 278
 279         if (strncmp(tramp_name, name, size) == 0)
 280                 return "[unknown/kretprobe'd]";
 281         return name;
 282 }
 283 #else
 284 static inline const char *kretprobed(const char *name)
 285 {
 286         return name;
 287 }
 288 #endif /* CONFIG_KRETPROBES */
 289
 290 static void
 291 seq_print_sym_short(struct trace_seq *s, const char *fmt, unsigned long address)
 292 {
 293 #ifdef CONFIG_KALLSYMS
 294         char str[KSYM_SYMBOL_LEN];
 295         const char *name;
 296
 297         kallsyms_lookup(address, NULL, NULL, NULL, str);
 298
 299         name = kretprobed(str);
 300
 301         trace_seq_printf(s, fmt, name);
 302 #endif
 303 }
 304
 305 static void
 306 seq_print_sym_offset(struct trace_seq *s, const char *fmt,
 307                      unsigned long address)
 308 {
 309 #ifdef CONFIG_KALLSYMS
 310         char str[KSYM_SYMBOL_LEN];
 311         const char *name;
 312
 313         sprint_symbol(str, address);
 314         name = kretprobed(str);
 315
 316         trace_seq_printf(s, fmt, name);
 317 #endif
 318 }
 319
 320 #ifndef CONFIG_64BIT
 321 # define IP_FMT "%08lx"
 322 #else
 323 # define IP_FMT "%016lx"
 324 #endif
 325
 326 static int seq_print_user_ip(struct trace_seq *s, struct mm_struct *mm,
 327                              unsigned long ip, unsigned long sym_flags)
 328 {
 329         struct file *file = NULL;
 330         unsigned long vmstart = 0;
 331         int ret = 1;
 332
 333         if (s->full)
 334                 return 0;
 335
 336         if (mm) {
 337                 const struct vm_area_struct *vma;
 338
 339                 down_read(&mm->mmap_sem);
 340                 vma = find_vma(mm, ip);
 341                 if (vma) {
 342                         file = vma->vm_file;
 343                         vmstart = vma->vm_start;
 344                 }
 345                 if (file) {
 346                         ret = trace_seq_path(s, &file->f_path);
 347                         if (ret)
 348                                 trace_seq_printf(s, "[+0x%lx]",
 349                                                  ip - vmstart);
 350                 }
 351                 up_read(&mm->mmap_sem);
 352         }
 353         if (ret && ((sym_flags & TRACE_ITER_SYM_ADDR) || !file))
 354                 trace_seq_printf(s, " <" IP_FMT ">", ip);
 355         return !trace_seq_has_overflowed(s);
 356 }
 357
 358 int
 359 seq_print_ip_sym(struct trace_seq *s, unsigned long ip, unsigned long sym_flags)
 360 {
 361         if (!ip) {
 362                 trace_seq_putc(s, '0');
 363                 goto out;
 364         }
 365
 366         if (sym_flags & TRACE_ITER_SYM_OFFSET)
 367                 seq_print_sym_offset(s, "%s", ip);
 368         else
 369                 seq_print_sym_short(s, "%s", ip);
 370
 371         if (sym_flags & TRACE_ITER_SYM_ADDR)
 372                 trace_seq_printf(s, " <" IP_FMT ">", ip);
 373
 374  out:
 375         return !trace_seq_has_overflowed(s);
 376 }
 377
 378 /**
 379  * trace_print_lat_fmt - print the irq, preempt and lockdep fields
 380  * @s: trace seq struct to write to
 381  * @entry: The trace entry field from the ring buffer
 382  *
 383  * Prints the generic fields of irqs off, in hard or softirq, preempt
 384  * count.
 385  */
 386 int trace_print_lat_fmt(struct trace_seq *s, struct trace_entry *entry)
 387 {
 388         char hardsoft_irq;
 389         char need_resched;
 390         char irqs_off;
 391         int hardirq;
 392         int softirq;
 393         int nmi;
 394
 395         nmi = entry->flags & TRACE_FLAG_NMI;
 396         hardirq = entry->flags & TRACE_FLAG_HARDIRQ;
 397         softirq = entry->flags & TRACE_FLAG_SOFTIRQ;
 398
 399         irqs_off =
 400                 (entry->flags & TRACE_FLAG_IRQS_OFF) ? 'd' :
 401                 (entry->flags & TRACE_FLAG_IRQS_NOSUPPORT) ? 'X' :
 402                 '.';
 403
 404         switch (entry->flags & (TRACE_FLAG_NEED_RESCHED |
 405                                 TRACE_FLAG_PREEMPT_RESCHED)) {
 406         case TRACE_FLAG_NEED_RESCHED | TRACE_FLAG_PREEMPT_RESCHED:
 407                 need_resched = 'N';
 408                 break;
 409         case TRACE_FLAG_NEED_RESCHED:
 410                 need_resched = 'n';
 411                 break;
 412         case TRACE_FLAG_PREEMPT_RESCHED:
 413                 need_resched = 'p';
 414                 break;
 415         default:
 416                 need_resched = '.';
 417                 break;
 418         }
 419
 420         hardsoft_irq =
 421                 (nmi && hardirq)     ? 'Z' :
 422                 nmi                  ? 'z' :
 423                 (hardirq && softirq) ? 'H' :
 424                 hardirq              ? 'h' :
 425                 softirq              ? 's' :
 426                                        '.' ;
 427
 428         trace_seq_printf(s, "%c%c%c",
 429                          irqs_off, need_resched, hardsoft_irq);
 430
 431         if (entry->preempt_count)
 432                 trace_seq_printf(s, "%x", entry->preempt_count);
 433         else
 434                 trace_seq_putc(s, '.');
 435
 436         return !trace_seq_has_overflowed(s);
 437 }
 438
 439 static int
 440 lat_print_generic(struct trace_seq *s, struct trace_entry *entry, int cpu)
 441 {
 442         char comm[TASK_COMM_LEN];
 443
 444         trace_find_cmdline(entry->pid, comm);
 445
 446         trace_seq_printf(s, "%8.8s-%-5d %3d",
 447                          comm, entry->pid, cpu);
 448
 449         return trace_print_lat_fmt(s, entry);
 450 }
 451
 452 #undef MARK
 453 #define MARK(v, s) {.val = v, .sym = s}
 454 /* trace overhead mark */
 455 static const struct trace_mark {
 456         unsigned long long      val; /* unit: nsec */
 457         char                    sym;
 458 } mark[] = {
 459         MARK(1000000000ULL      , '$'), /* 1 sec */
 460         MARK(100000000ULL       , '@'), /* 100 msec */
 461         MARK(10000000ULL        , '*'), /* 10 msec */
 462         MARK(1000000ULL         , '#'), /* 1000 usecs */
 463         MARK(100000ULL          , '!'), /* 100 usecs */
 464         MARK(10000ULL           , '+'), /* 10 usecs */
 465 };
 466 #undef MARK
 467
 468 char trace_find_mark(unsigned long long d)
 469 {
 470         int i;
 471         int size = ARRAY_SIZE(mark);
 472
 473         for (i = 0; i < size; i++) {
 474                 if (d > mark[i].val)
 475                         break;
 476         }
 477
 478         return (i == size) ? ' ' : mark[i].sym;
 479 }
 480
 481 static int
 482 lat_print_timestamp(struct trace_iterator *iter, u64 next_ts)
 483 {
 484         struct trace_array *tr = iter->tr;
 485         unsigned long verbose = tr->trace_flags & TRACE_ITER_VERBOSE;
 486         unsigned long in_ns = iter->iter_flags & TRACE_FILE_TIME_IN_NS;
 487         unsigned long long abs_ts = iter->ts - iter->trace_buffer->time_start;
 488         unsigned long long rel_ts = next_ts - iter->ts;
 489         struct trace_seq *s = &iter->seq;
 490
 491         if (in_ns) {
 492                 abs_ts = ns2usecs(abs_ts);
 493                 rel_ts = ns2usecs(rel_ts);
 494         }
 495
 496         if (verbose && in_ns) {
 497                 unsigned long abs_usec = do_div(abs_ts, USEC_PER_MSEC);
 498                 unsigned long abs_msec = (unsigned long)abs_ts;
 499                 unsigned long rel_usec = do_div(rel_ts, USEC_PER_MSEC);
 500                 unsigned long rel_msec = (unsigned long)rel_ts;
 501
 502                 trace_seq_printf(
 503                         s, "[%08llx] %ld.%03ldms (+%ld.%03ldms): ",
 504                         ns2usecs(iter->ts),
 505                         abs_msec, abs_usec,
 506                         rel_msec, rel_usec);
 507
 508         } else if (verbose && !in_ns) {
 509                 trace_seq_printf(
 510                         s, "[%016llx] %lld (+%lld): ",
 511                         iter->ts, abs_ts, rel_ts);
 512
 513         } else if (!verbose && in_ns) {
 514                 trace_seq_printf(
 515                         s, " %4lldus%c: ",
 516                         abs_ts,
 517                         trace_find_mark(rel_ts * NSEC_PER_USEC));
 518
 519         } else { /* !verbose && !in_ns */
 520                 trace_seq_printf(s, " %4lld: ", abs_ts);
 521         }
 522
 523         return !trace_seq_has_overflowed(s);
 524 }
 525
 526 int trace_print_context(struct trace_iterator *iter)
 527 {
 528         struct trace_array *tr = iter->tr;
 529         struct trace_seq *s = &iter->seq;
 530         struct trace_entry *entry = iter->ent;
 531         unsigned long long t;
 532         unsigned long secs, usec_rem;
 533         char comm[TASK_COMM_LEN];
 534
 535         trace_find_cmdline(entry->pid, comm);
 536
 537         trace_seq_printf(s, "%16s-%-5d [%03d] ",
 538                                comm, entry->pid, iter->cpu);
 539
 540         if (tr->trace_flags & TRACE_ITER_IRQ_INFO)
 541                 trace_print_lat_fmt(s, entry);
 542
 543         if (iter->iter_flags & TRACE_FILE_TIME_IN_NS) {
 544                 t = ns2usecs(iter->ts);
 545                 usec_rem = do_div(t, USEC_PER_SEC);
 546                 secs = (unsigned long)t;
 547                 trace_seq_printf(s, " %5lu.%06lu: ", secs, usec_rem);
 548         } else
 549                 trace_seq_printf(s, " %12llu: ", iter->ts);
 550
 551         return !trace_seq_has_overflowed(s);
 552 }
 553
 554 int trace_print_lat_context(struct trace_iterator *iter)
 555 {
 556         struct trace_array *tr = iter->tr;
 557         /* trace_find_next_entry will reset ent_size */
 558         int ent_size = iter->ent_size;
 559         struct trace_seq *s = &iter->seq;
 560         u64 next_ts;
 561         struct trace_entry *entry = iter->ent,
 562                            *next_entry = trace_find_next_entry(iter, NULL,
 563                                                                &next_ts);
 564         unsigned long verbose = (tr->trace_flags & TRACE_ITER_VERBOSE);
 565
 566         /* Restore the original ent_size */
 567         iter->ent_size = ent_size;
 568
 569         if (!next_entry)
 570                 next_ts = iter->ts;
 571
 572         if (verbose) {
 573                 char comm[TASK_COMM_LEN];
 574
 575                 trace_find_cmdline(entry->pid, comm);
 576
 577                 trace_seq_printf(
 578                         s, "%16s %5d %3d %d %08x %08lx ",
 579                         comm, entry->pid, iter->cpu, entry->flags,
 580                         entry->preempt_count, iter->idx);
 581         } else {
 582                 lat_print_generic(s, entry, iter->cpu);
 583         }
 584
 585         lat_print_timestamp(iter, next_ts);
 586
 587         return !trace_seq_has_overflowed(s);
 588 }
 589
 590 static const char state_to_char[] = TASK_STATE_TO_CHAR_STR;
 591
 592 static int task_state_char(unsigned long state)
 593 {
 594         int bit = state ? __ffs(state) + 1 : 0;
 595
 596         return bit < sizeof(state_to_char) - 1 ? state_to_char[bit] : '?';
 597 }
 598
 599 /**
 600  * ftrace_find_event - find a registered event
 601  * @type: the type of event to look for
 602  *
 603  * Returns an event of type @type otherwise NULL
 604  * Called with trace_event_read_lock() held.
 605  */
 606 struct trace_event *ftrace_find_event(int type)
 607 {
 608         struct trace_event *event;
 609         unsigned key;
 610
 611         key = type & (EVENT_HASHSIZE - 1);
 612
 613         hlist_for_each_entry(event, &event_hash[key], node) {
 614                 if (event->type == type)
 615                         return event;
 616         }
 617
 618         return NULL;
 619 }
 620
 621 static LIST_HEAD(ftrace_event_list);
 622
 623 static int trace_search_list(struct list_head **list)
 624 {
 625         struct trace_event *e;
 626         int last = __TRACE_LAST_TYPE;
 627
 628         if (list_empty(&ftrace_event_list)) {
 629                 *list = &ftrace_event_list;
 630                 return last + 1;
 631         }
 632
 633         /*
 634          * We used up all possible max events,
 635          * lets see if somebody freed one.
 636          */
 637         list_for_each_entry(e, &ftrace_event_list, list) {
 638                 if (e->type != last + 1)
 639                         break;
 640                 last++;
 641         }
 642
 643         /* Did we used up all 65 thousand events??? */
 644         if ((last + 1) > TRACE_EVENT_TYPE_MAX)
 645                 return 0;
 646
 647         *list = &e->list;
 648         return last + 1;
 649 }
 650
 651 void trace_event_read_lock(void)
 652 {
 653         down_read(&trace_event_sem);
 654 }
 655
 656 void trace_event_read_unlock(void)
 657 {
 658         up_read(&trace_event_sem);
 659 }
 660
 661 /**
 662  * register_trace_event - register output for an event type
 663  * @event: the event type to register
 664  *
 665  * Event types are stored in a hash and this hash is used to
 666  * find a way to print an event. If the @event->type is set
 667  * then it will use that type, otherwise it will assign a
 668  * type to use.
 669  *
 670  * If you assign your own type, please make sure it is added
 671  * to the trace_type enum in trace.h, to avoid collisions
 672  * with the dynamic types.
 673  *
 674  * Returns the event type number or zero on error.
 675  */
 676 int register_trace_event(struct trace_event *event)
 677 {
 678         unsigned key;
 679         int ret = 0;
 680
 681         down_write(&trace_event_sem);
 682
 683         if (WARN_ON(!event))
 684                 goto out;
 685
 686         if (WARN_ON(!event->funcs))
 687                 goto out;
 688
 689         INIT_LIST_HEAD(&event->list);
 690
 691         if (!event->type) {
 692                 struct list_head *list = NULL;
 693
 694                 if (next_event_type > TRACE_EVENT_TYPE_MAX) {
 695
 696                         event->type = trace_search_list(&list);
 697                         if (!event->type)
 698                                 goto out;
 699
 700                 } else {
 701
 702                         event->type = next_event_type++;
 703                         list = &ftrace_event_list;
 704                 }
 705
 706                 if (WARN_ON(ftrace_find_event(event->type)))
 707                         goto out;
 708
 709                 list_add_tail(&event->list, list);
 710
 711         } else if (event->type > __TRACE_LAST_TYPE) {
 712                 printk(KERN_WARNING "Need to add type to trace.h\n");
 713                 WARN_ON(1);
 714                 goto out;
 715         } else {
 716                 /* Is this event already used */
 717                 if (ftrace_find_event(event->type))
 718                         goto out;
 719         }
 720
 721         if (event->funcs->trace == NULL)
 722                 event->funcs->trace = trace_nop_print;
 723         if (event->funcs->raw == NULL)
 724                 event->funcs->raw = trace_nop_print;
 725         if (event->funcs->hex == NULL)
 726                 event->funcs->hex = trace_nop_print;
 727         if (event->funcs->binary == NULL)
 728                 event->funcs->binary = trace_nop_print;
 729
 730         key = event->type & (EVENT_HASHSIZE - 1);
 731
 732         hlist_add_head(&event->node, &event_hash[key]);
 733
 734         ret = event->type;
 735  out:
 736         up_write(&trace_event_sem);
 737
 738         return ret;
 739 }
 740 EXPORT_SYMBOL_GPL(register_trace_event);
 741
 742 /*
 743  * Used by module code with the trace_event_sem held for write.
 744  */
 745 int __unregister_trace_event(struct trace_event *event)
 746 {
 747         hlist_del(&event->node);
 748         list_del(&event->list);
 749         return 0;
 750 }
 751
 752 /**
 753  * unregister_trace_event - remove a no longer used event
 754  * @event: the event to remove
 755  */
 756 int unregister_trace_event(struct trace_event *event)
 757 {
 758         down_write(&trace_event_sem);
 759         __unregister_trace_event(event);
 760         up_write(&trace_event_sem);
 761
 762         return 0;
 763 }
 764 EXPORT_SYMBOL_GPL(unregister_trace_event);
 765
 766 /*
 767  * Standard events
 768  */
 769
 770 enum print_line_t trace_nop_print(struct trace_iterator *iter, int flags,
 771                                   struct trace_event *event)
 772 {
 773         trace_seq_printf(&iter->seq, "type: %d\n", iter->ent->type);
 774
 775         return trace_handle_return(&iter->seq);
 776 }
 777
 778 /* TRACE_FN */
 779 static enum print_line_t trace_fn_trace(struct trace_iterator *iter, int flags,
 780                                         struct trace_event *event)
 781 {
 782         struct ftrace_entry *field;
 783         struct trace_seq *s = &iter->seq;
 784
 785         trace_assign_type(field, iter->ent);
 786
 787         seq_print_ip_sym(s, field->ip, flags);
 788
 789         if ((flags & TRACE_ITER_PRINT_PARENT) && field->parent_ip) {
 790                 trace_seq_puts(s, " <-");
 791                 seq_print_ip_sym(s, field->parent_ip, flags);
 792         }
 793
 794         trace_seq_putc(s, '\n');
 795
 796         return trace_handle_return(s);
 797 }
 798
 799 static enum print_line_t trace_fn_raw(struct trace_iterator *iter, int flags,
 800                                       struct trace_event *event)
 801 {
 802         struct ftrace_entry *field;
 803
 804         trace_assign_type(field, iter->ent);
 805
 806         trace_seq_printf(&iter->seq, "%lx %lx\n",
 807                          field->ip,
 808                          field->parent_ip);
 809
 810         return trace_handle_return(&iter->seq);
 811 }
 812
 813 static enum print_line_t trace_fn_hex(struct trace_iterator *iter, int flags,
 814                                       struct trace_event *event)
 815 {
 816         struct ftrace_entry *field;
 817         struct trace_seq *s = &iter->seq;
 818
 819         trace_assign_type(field, iter->ent);
 820
 821         SEQ_PUT_HEX_FIELD(s, field->ip);
 822         SEQ_PUT_HEX_FIELD(s, field->parent_ip);
 823
 824         return trace_handle_return(s);
 825 }
 826
 827 static enum print_line_t trace_fn_bin(struct trace_iterator *iter, int flags,
 828                                       struct trace_event *event)
 829 {
 830         struct ftrace_entry *field;
 831         struct trace_seq *s = &iter->seq;
 832
 833         trace_assign_type(field, iter->ent);
 834
 835         SEQ_PUT_FIELD(s, field->ip);
 836         SEQ_PUT_FIELD(s, field->parent_ip);
 837
 838         return trace_handle_return(s);
 839 }
 840
 841 static struct trace_event_functions trace_fn_funcs = {
 842         .trace          = trace_fn_trace,
 843         .raw            = trace_fn_raw,
 844         .hex            = trace_fn_hex,
 845         .binary         = trace_fn_bin,
 846 };
 847
 848 static struct trace_event trace_fn_event = {
 849         .type           = TRACE_FN,
 850         .funcs          = &trace_fn_funcs,
 851 };
 852
 853 /* TRACE_CTX an TRACE_WAKE */
 854 static enum print_line_t trace_ctxwake_print(struct trace_iterator *iter,
 855                                              char *delim)
 856 {
 857         struct ctx_switch_entry *field;
 858         char comm[TASK_COMM_LEN];
 859         int S, T;
 860
 861
 862         trace_assign_type(field, iter->ent);
 863
 864         T = task_state_char(field->next_state);
 865         S = task_state_char(field->prev_state);
 866         trace_find_cmdline(field->next_pid, comm);
 867         trace_seq_printf(&iter->seq,
 868                          " %5d:%3d:%c %s [%03d] %5d:%3d:%c %s\n",
 869                          field->prev_pid,
 870                          field->prev_prio,
 871                          S, delim,
 872                          field->next_cpu,
 873                          field->next_pid,
 874                          field->next_prio,
 875                          T, comm);
 876
 877         return trace_handle_return(&iter->seq);
 878 }
 879
 880 static enum print_line_t trace_ctx_print(struct trace_iterator *iter, int flags,
 881                                          struct trace_event *event)
 882 {
 883         return trace_ctxwake_print(iter, "==>");
 884 }
 885
 886 static enum print_line_t trace_wake_print(struct trace_iterator *iter,
 887                                           int flags, struct trace_event *event)
 888 {
 889         return trace_ctxwake_print(iter, "  +");
 890 }
 891
 892 static int trace_ctxwake_raw(struct trace_iterator *iter, char S)
 893 {
 894         struct ctx_switch_entry *field;
 895         int T;
 896
 897         trace_assign_type(field, iter->ent);
 898
 899         if (!S)
 900                 S = task_state_char(field->prev_state);
 901         T = task_state_char(field->next_state);
 902         trace_seq_printf(&iter->seq, "%d %d %c %d %d %d %c\n",
 903                          field->prev_pid,
 904                          field->prev_prio,
 905                          S,
 906                          field->next_cpu,
 907                          field->next_pid,
 908                          field->next_prio,
 909                          T);
 910
 911         return trace_handle_return(&iter->seq);
 912 }
 913
 914 static enum print_line_t trace_ctx_raw(struct trace_iterator *iter, int flags,
 915                                        struct trace_event *event)
 916 {
 917         return trace_ctxwake_raw(iter, 0);
 918 }
 919
 920 static enum print_line_t trace_wake_raw(struct trace_iterator *iter, int flags,
 921                                         struct trace_event *event)
 922 {
 923         return trace_ctxwake_raw(iter, '+');
 924 }
 925
 926
 927 static int trace_ctxwake_hex(struct trace_iterator *iter, char S)
 928 {
 929         struct ctx_switch_entry *field;
 930         struct trace_seq *s = &iter->seq;
 931         int T;
 932
 933         trace_assign_type(field, iter->ent);
 934
 935         if (!S)
 936                 S = task_state_char(field->prev_state);
 937         T = task_state_char(field->next_state);
 938
 939         SEQ_PUT_HEX_FIELD(s, field->prev_pid);
 940         SEQ_PUT_HEX_FIELD(s, field->prev_prio);
 941         SEQ_PUT_HEX_FIELD(s, S);
 942         SEQ_PUT_HEX_FIELD(s, field->next_cpu);
 943         SEQ_PUT_HEX_FIELD(s, field->next_pid);
 944         SEQ_PUT_HEX_FIELD(s, field->next_prio);
 945         SEQ_PUT_HEX_FIELD(s, T);
 946
 947         return trace_handle_return(s);
 948 }
 949
 950 static enum print_line_t trace_ctx_hex(struct trace_iterator *iter, int flags,
 951                                        struct trace_event *event)
 952 {
 953         return trace_ctxwake_hex(iter, 0);
 954 }
 955
 956 static enum print_line_t trace_wake_hex(struct trace_iterator *iter, int flags,
 957                                         struct trace_event *event)
 958 {
 959         return trace_ctxwake_hex(iter, '+');
 960 }
 961
 962 static enum print_line_t trace_ctxwake_bin(struct trace_iterator *iter,
 963                                            int flags, struct trace_event *event)
 964 {
 965         struct ctx_switch_entry *field;
 966         struct trace_seq *s = &iter->seq;
 967
 968         trace_assign_type(field, iter->ent);
 969
 970         SEQ_PUT_FIELD(s, field->prev_pid);
 971         SEQ_PUT_FIELD(s, field->prev_prio);
 972         SEQ_PUT_FIELD(s, field->prev_state);
 973         SEQ_PUT_FIELD(s, field->next_cpu);
 974         SEQ_PUT_FIELD(s, field->next_pid);
 975         SEQ_PUT_FIELD(s, field->next_prio);
 976         SEQ_PUT_FIELD(s, field->next_state);
 977
 978         return trace_handle_return(s);
 979 }
 980
 981 static struct trace_event_functions trace_ctx_funcs = {
 982         .trace          = trace_ctx_print,
 983         .raw            = trace_ctx_raw,
 984         .hex            = trace_ctx_hex,
 985         .binary         = trace_ctxwake_bin,
 986 };
 987
 988 static struct trace_event trace_ctx_event = {
 989         .type           = TRACE_CTX,
 990         .funcs          = &trace_ctx_funcs,
 991 };
 992
 993 static struct trace_event_functions trace_wake_funcs = {
 994         .trace          = trace_wake_print,
 995         .raw            = trace_wake_raw,
 996         .hex            = trace_wake_hex,
 997         .binary         = trace_ctxwake_bin,
 998 };
 999
1000 static struct trace_event trace_wake_event = {
1001         .type           = TRACE_WAKE,
1002         .funcs          = &trace_wake_funcs,
1003 };
1004
1005 /* TRACE_STACK */
1006
1007 static enum print_line_t trace_stack_print(struct trace_iterator *iter,
1008                                            int flags, struct trace_event *event)
1009 {
1010         struct stack_entry *field;
1011         struct trace_seq *s = &iter->seq;
1012         unsigned long *p;
1013         unsigned long *end;
1014
1015         trace_assign_type(field, iter->ent);
1016         end = (unsigned long *)((long)iter->ent + iter->ent_size);
1017
1018         trace_seq_puts(s, "<stack trace>\n");
1019
1020         for (p = field->caller; p && *p != ULONG_MAX && p < end; p++) {
1021
1022                 if (trace_seq_has_overflowed(s))
1023                         break;
1024
1025                 trace_seq_puts(s, " => ");
1026                 seq_print_ip_sym(s, *p, flags);
1027                 trace_seq_putc(s, '\n');
1028         }
1029
1030         return trace_handle_return(s);
1031 }
1032
1033 static struct trace_event_functions trace_stack_funcs = {
1034         .trace          = trace_stack_print,
1035 };
1036
1037 static struct trace_event trace_stack_event = {
1038         .type           = TRACE_STACK,
1039         .funcs          = &trace_stack_funcs,
1040 };
1041
1042 /* TRACE_USER_STACK */
1043 static enum print_line_t trace_user_stack_print(struct trace_iterator *iter,
1044                                                 int flags, struct trace_event *event)
1045 {
1046         struct trace_array *tr = iter->tr;
1047         struct userstack_entry *field;
1048         struct trace_seq *s = &iter->seq;
1049         struct mm_struct *mm = NULL;
1050         unsigned int i;
1051
1052         trace_assign_type(field, iter->ent);
1053
1054         trace_seq_puts(s, "<user stack trace>\n");
1055
1056         if (tr->trace_flags & TRACE_ITER_SYM_USEROBJ) {
1057                 struct task_struct *task;
1058                 /*
1059                  * we do the lookup on the thread group leader,
1060                  * since individual threads might have already quit!
1061                  */
1062                 rcu_read_lock();
1063                 task = find_task_by_vpid(field->tgid);
1064                 if (task)
1065                         mm = get_task_mm(task);
1066                 rcu_read_unlock();
1067         }
1068
1069         for (i = 0; i < FTRACE_STACK_ENTRIES; i++) {
1070                 unsigned long ip = field->caller[i];
1071
1072                 if (ip == ULONG_MAX || trace_seq_has_overflowed(s))
1073                         break;
1074
1075                 trace_seq_puts(s, " => ");
1076
1077                 if (!ip) {
1078                         trace_seq_puts(s, "??");
1079                         trace_seq_putc(s, '\n');
1080                         continue;
1081                 }
1082
1083                 seq_print_user_ip(s, mm, ip, flags);
1084                 trace_seq_putc(s, '\n');
1085         }
1086
1087         if (mm)
1088                 mmput(mm);
1089
1090         return trace_handle_return(s);
1091 }
1092
1093 static struct trace_event_functions trace_user_stack_funcs = {
1094         .trace          = trace_user_stack_print,
1095 };
1096
1097 static struct trace_event trace_user_stack_event = {
1098         .type           = TRACE_USER_STACK,
1099         .funcs          = &trace_user_stack_funcs,
1100 };
1101
1102 /* TRACE_HWLAT */
1103 static enum print_line_t
1104 trace_hwlat_print(struct trace_iterator *iter, int flags,
1105                   struct trace_event *event)
1106 {
1107         struct trace_entry *entry = iter->ent;
1108         struct trace_seq *s = &iter->seq;
1109         struct hwlat_entry *field;
1110
1111         trace_assign_type(field, entry);
1112
1113         trace_seq_printf(s, "#%-5u inner/outer(us): %4llu/%-5llu ts:%ld.%09ld",
1114                          field->seqnum,
1115                          field->duration,
1116                          field->outer_duration,
1117                          field->timestamp.tv_sec,
1118                          field->timestamp.tv_nsec);
1119
1120         if (field->nmi_count) {
1121                 /*
1122                  * The generic sched_clock() is not NMI safe, thus
1123                  * we only record the count and not the time.
1124                  */
1125                 if (!IS_ENABLED(CONFIG_GENERIC_SCHED_CLOCK))
1126                         trace_seq_printf(s, " nmi-total:%llu",
1127                                          field->nmi_total_ts);
1128                 trace_seq_printf(s, " nmi-count:%u",
1129                                  field->nmi_count);
1130         }
1131
1132         trace_seq_putc(s, '\n');
1133
1134         return trace_handle_return(s);
1135 }
1136
1137
1138 static enum print_line_t
1139 trace_hwlat_raw(struct trace_iterator *iter, int flags,
1140                 struct trace_event *event)
1141 {
1142         struct hwlat_entry *field;
1143         struct trace_seq *s = &iter->seq;
1144
1145         trace_assign_type(field, iter->ent);
1146
1147         trace_seq_printf(s, "%llu %lld %ld %09ld %u\n",
1148                          field->duration,
1149                          field->outer_duration,
1150                          field->timestamp.tv_sec,
1151                          field->timestamp.tv_nsec,
1152                          field->seqnum);
1153
1154         return trace_handle_return(s);
1155 }
1156
1157 static struct trace_event_functions trace_hwlat_funcs = {
1158         .trace          = trace_hwlat_print,
1159         .raw            = trace_hwlat_raw,
1160 };
1161
1162 static struct trace_event trace_hwlat_event = {
1163         .type           = TRACE_HWLAT,
1164         .funcs          = &trace_hwlat_funcs,
1165 };
1166
1167 /* TRACE_BPUTS */
1168 static enum print_line_t
1169 trace_bputs_print(struct trace_iterator *iter, int flags,
1170                    struct trace_event *event)
1171 {
1172         struct trace_entry *entry = iter->ent;
1173         struct trace_seq *s = &iter->seq;
1174         struct bputs_entry *field;
1175
1176         trace_assign_type(field, entry);
1177
1178         seq_print_ip_sym(s, field->ip, flags);
1179         trace_seq_puts(s, ": ");
1180         trace_seq_puts(s, field->str);
1181
1182         return trace_handle_return(s);
1183 }
1184
1185
1186 static enum print_line_t
1187 trace_bputs_raw(struct trace_iterator *iter, int flags,
1188                 struct trace_event *event)
1189 {
1190         struct bputs_entry *field;
1191         struct trace_seq *s = &iter->seq;
1192
1193         trace_assign_type(field, iter->ent);
1194
1195         trace_seq_printf(s, ": %lx : ", field->ip);
1196         trace_seq_puts(s, field->str);
1197
1198         return trace_handle_return(s);
1199 }
1200
1201 static struct trace_event_functions trace_bputs_funcs = {
1202         .trace          = trace_bputs_print,
1203         .raw            = trace_bputs_raw,
1204 };
1205
1206 static struct trace_event trace_bputs_event = {
1207         .type           = TRACE_BPUTS,
1208         .funcs          = &trace_bputs_funcs,
1209 };
1210
1211 /* TRACE_BPRINT */
1212 static enum print_line_t
1213 trace_bprint_print(struct trace_iterator *iter, int flags,
1214                    struct trace_event *event)
1215 {
1216         struct trace_entry *entry = iter->ent;
1217         struct trace_seq *s = &iter->seq;
1218         struct bprint_entry *field;
1219
1220         trace_assign_type(field, entry);
1221
1222         seq_print_ip_sym(s, field->ip, flags);
1223         trace_seq_puts(s, ": ");
1224         trace_seq_bprintf(s, field->fmt, field->buf);
1225
1226         return trace_handle_return(s);
1227 }
1228
1229
1230 static enum print_line_t
1231 trace_bprint_raw(struct trace_iterator *iter, int flags,
1232                  struct trace_event *event)
1233 {
1234         struct bprint_entry *field;
1235         struct trace_seq *s = &iter->seq;
1236
1237         trace_assign_type(field, iter->ent);
1238
1239         trace_seq_printf(s, ": %lx : ", field->ip);
1240         trace_seq_bprintf(s, field->fmt, field->buf);
1241
1242         return trace_handle_return(s);
1243 }
1244
1245 static struct trace_event_functions trace_bprint_funcs = {
1246         .trace          = trace_bprint_print,
1247         .raw            = trace_bprint_raw,
1248 };
1249
1250 static struct trace_event trace_bprint_event = {
1251         .type           = TRACE_BPRINT,
1252         .funcs          = &trace_bprint_funcs,
1253 };
1254
1255 /* TRACE_PRINT */
1256 static enum print_line_t trace_print_print(struct trace_iterator *iter,
1257                                            int flags, struct trace_event *event)
1258 {
1259         struct print_entry *field;
1260         struct trace_seq *s = &iter->seq;
1261
1262         trace_assign_type(field, iter->ent);
1263
1264         seq_print_ip_sym(s, field->ip, flags);
1265         trace_seq_printf(s, ": %s", field->buf);
1266
1267         return trace_handle_return(s);
1268 }
1269
1270 static enum print_line_t trace_print_raw(struct trace_iterator *iter, int flags,
1271                                          struct trace_event *event)
1272 {
1273         struct print_entry *field;
1274
1275         trace_assign_type(field, iter->ent);
1276
1277         trace_seq_printf(&iter->seq, "# %lx %s", field->ip, field->buf);
1278
1279         return trace_handle_return(&iter->seq);
1280 }
1281
1282 static struct trace_event_functions trace_print_funcs = {
1283         .trace          = trace_print_print,
1284         .raw            = trace_print_raw,
1285 };
1286
1287 static struct trace_event trace_print_event = {
1288         .type           = TRACE_PRINT,
1289         .funcs          = &trace_print_funcs,
1290 };
1291
1292 static enum print_line_t trace_raw_data(struct trace_iterator *iter, int flags,
1293                                          struct trace_event *event)
1294 {
1295         struct raw_data_entry *field;
1296         int i;
1297
1298         trace_assign_type(field, iter->ent);
1299
1300         trace_seq_printf(&iter->seq, "# %x buf:", field->id);
1301
1302         for (i = 0; i < iter->ent_size - offsetof(struct raw_data_entry, buf); i++)
1303                 trace_seq_printf(&iter->seq, " %02x",
1304                                  (unsigned char)field->buf[i]);
1305
1306         trace_seq_putc(&iter->seq, '\n');
1307
1308         return trace_handle_return(&iter->seq);
1309 }
1310
1311 static struct trace_event_functions trace_raw_data_funcs = {
1312         .trace          = trace_raw_data,
1313         .raw            = trace_raw_data,
1314 };
1315
1316 static struct trace_event trace_raw_data_event = {
1317         .type           = TRACE_RAW_DATA,
1318         .funcs          = &trace_raw_data_funcs,
1319 };
1320
1321
1322 static struct trace_event *events[] __initdata = {
1323         &trace_fn_event,
1324         &trace_ctx_event,
1325         &trace_wake_event,
1326         &trace_stack_event,
1327         &trace_user_stack_event,
1328         &trace_bputs_event,
1329         &trace_bprint_event,
1330         &trace_print_event,
1331         &trace_hwlat_event,
1332         &trace_raw_data_event,
1333         NULL
1334 };
1335
1336 __init static int init_events(void)
1337 {
1338         struct trace_event *event;
1339         int i, ret;
1340
1341         for (i = 0; events[i]; i++) {
1342                 event = events[i];
1343
1344                 ret = register_trace_event(event);
1345                 if (!ret) {
1346                         printk(KERN_WARNING "event %d failed to register\n",
1347                                event->type);
1348                         WARN_ON_ONCE(1);
1349                 }
1350         }
1351
1352         return 0;
1353 }
1354 early_initcall(init_events);