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 ftrace_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(ftrace_print_flags_seq);
  99
 100 const char *
 101 ftrace_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(ftrace_print_symbols_seq);
 124
 125 #if BITS_PER_LONG == 32
 126 const char *
 127 ftrace_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(ftrace_print_symbols_seq_u64);
 150 #endif
 151
 152 const char *
 153 ftrace_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(ftrace_print_bitmask_seq);
 164
 165 const char *
 166 ftrace_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(ftrace_print_hex_seq);
 179
 180 const char *
 181 ftrace_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(ftrace_print_array_seq);
 224
 225 int ftrace_raw_output_prep(struct trace_iterator *iter,
 226                            struct trace_event *trace_event)
 227 {
 228         struct ftrace_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 ftrace_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: ", ftrace_event_name(event));
 243
 244         return trace_handle_return(s);
 245 }
 246 EXPORT_SYMBOL(ftrace_raw_output_prep);
 247
 248 static int ftrace_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 ftrace_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 = ftrace_output_raw(iter, name, fmt, ap);
 266         va_end(ap);
 267
 268         return ret;
 269 }
 270 EXPORT_SYMBOL_GPL(ftrace_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 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_userip_objs(const struct userstack_entry *entry, struct trace_seq *s,
 359                       unsigned long sym_flags)
 360 {
 361         struct mm_struct *mm = NULL;
 362         unsigned int i;
 363
 364         if (trace_flags & TRACE_ITER_SYM_USEROBJ) {
 365                 struct task_struct *task;
 366                 /*
 367                  * we do the lookup on the thread group leader,
 368                  * since individual threads might have already quit!
 369                  */
 370                 rcu_read_lock();
 371                 task = find_task_by_vpid(entry->tgid);
 372                 if (task)
 373                         mm = get_task_mm(task);
 374                 rcu_read_unlock();
 375         }
 376
 377         for (i = 0; i < FTRACE_STACK_ENTRIES; i++) {
 378                 unsigned long ip = entry->caller[i];
 379
 380                 if (ip == ULONG_MAX || trace_seq_has_overflowed(s))
 381                         break;
 382
 383                 trace_seq_puts(s, " => ");
 384
 385                 if (!ip) {
 386                         trace_seq_puts(s, "??");
 387                         trace_seq_putc(s, '\n');
 388                         continue;
 389                 }
 390
 391                 seq_print_user_ip(s, mm, ip, sym_flags);
 392                 trace_seq_putc(s, '\n');
 393         }
 394
 395         if (mm)
 396                 mmput(mm);
 397
 398         return !trace_seq_has_overflowed(s);
 399 }
 400
 401 int
 402 seq_print_ip_sym(struct trace_seq *s, unsigned long ip, unsigned long sym_flags)
 403 {
 404         if (!ip) {
 405                 trace_seq_putc(s, '0');
 406                 goto out;
 407         }
 408
 409         if (sym_flags & TRACE_ITER_SYM_OFFSET)
 410                 seq_print_sym_offset(s, "%s", ip);
 411         else
 412                 seq_print_sym_short(s, "%s", ip);
 413
 414         if (sym_flags & TRACE_ITER_SYM_ADDR)
 415                 trace_seq_printf(s, " <" IP_FMT ">", ip);
 416
 417  out:
 418         return !trace_seq_has_overflowed(s);
 419 }
 420
 421 /**
 422  * trace_print_lat_fmt - print the irq, preempt and lockdep fields
 423  * @s: trace seq struct to write to
 424  * @entry: The trace entry field from the ring buffer
 425  *
 426  * Prints the generic fields of irqs off, in hard or softirq, preempt
 427  * count.
 428  */
 429 int trace_print_lat_fmt(struct trace_seq *s, struct trace_entry *entry)
 430 {
 431         char hardsoft_irq;
 432         char need_resched;
 433         char irqs_off;
 434         int hardirq;
 435         int softirq;
 436
 437         hardirq = entry->flags & TRACE_FLAG_HARDIRQ;
 438         softirq = entry->flags & TRACE_FLAG_SOFTIRQ;
 439
 440         irqs_off =
 441                 (entry->flags & TRACE_FLAG_IRQS_OFF) ? 'd' :
 442                 (entry->flags & TRACE_FLAG_IRQS_NOSUPPORT) ? 'X' :
 443                 '.';
 444
 445         switch (entry->flags & (TRACE_FLAG_NEED_RESCHED |
 446                                 TRACE_FLAG_PREEMPT_RESCHED)) {
 447         case TRACE_FLAG_NEED_RESCHED | TRACE_FLAG_PREEMPT_RESCHED:
 448                 need_resched = 'N';
 449                 break;
 450         case TRACE_FLAG_NEED_RESCHED:
 451                 need_resched = 'n';
 452                 break;
 453         case TRACE_FLAG_PREEMPT_RESCHED:
 454                 need_resched = 'p';
 455                 break;
 456         default:
 457                 need_resched = '.';
 458                 break;
 459         }
 460
 461         hardsoft_irq =
 462                 (hardirq && softirq) ? 'H' :
 463                 hardirq ? 'h' :
 464                 softirq ? 's' :
 465                 '.';
 466
 467         trace_seq_printf(s, "%c%c%c",
 468                          irqs_off, need_resched, hardsoft_irq);
 469
 470         if (entry->preempt_count)
 471                 trace_seq_printf(s, "%x", entry->preempt_count);
 472         else
 473                 trace_seq_putc(s, '.');
 474
 475         return !trace_seq_has_overflowed(s);
 476 }
 477
 478 static int
 479 lat_print_generic(struct trace_seq *s, struct trace_entry *entry, int cpu)
 480 {
 481         char comm[TASK_COMM_LEN];
 482
 483         trace_find_cmdline(entry->pid, comm);
 484
 485         trace_seq_printf(s, "%8.8s-%-5d %3d",
 486                          comm, entry->pid, cpu);
 487
 488         return trace_print_lat_fmt(s, entry);
 489 }
 490
 491 #undef MARK
 492 #define MARK(v, s) {.val = v, .sym = s}
 493 /* trace overhead mark */
 494 static const struct trace_mark {
 495         unsigned long long      val; /* unit: nsec */
 496         char                    sym;
 497 } mark[] = {
 498         MARK(1000000000ULL      , '$'), /* 1 sec */
 499         MARK(1000000ULL         , '#'), /* 1000 usecs */
 500         MARK(100000ULL          , '!'), /* 100 usecs */
 501         MARK(10000ULL           , '+'), /* 10 usecs */
 502 };
 503 #undef MARK
 504
 505 char trace_find_mark(unsigned long long d)
 506 {
 507         int i;
 508         int size = ARRAY_SIZE(mark);
 509
 510         for (i = 0; i < size; i++) {
 511                 if (d >= mark[i].val)
 512                         break;
 513         }
 514
 515         return (i == size) ? ' ' : mark[i].sym;
 516 }
 517
 518 static int
 519 lat_print_timestamp(struct trace_iterator *iter, u64 next_ts)
 520 {
 521         unsigned long verbose = trace_flags & TRACE_ITER_VERBOSE;
 522         unsigned long in_ns = iter->iter_flags & TRACE_FILE_TIME_IN_NS;
 523         unsigned long long abs_ts = iter->ts - iter->trace_buffer->time_start;
 524         unsigned long long rel_ts = next_ts - iter->ts;
 525         struct trace_seq *s = &iter->seq;
 526
 527         if (in_ns) {
 528                 abs_ts = ns2usecs(abs_ts);
 529                 rel_ts = ns2usecs(rel_ts);
 530         }
 531
 532         if (verbose && in_ns) {
 533                 unsigned long abs_usec = do_div(abs_ts, USEC_PER_MSEC);
 534                 unsigned long abs_msec = (unsigned long)abs_ts;
 535                 unsigned long rel_usec = do_div(rel_ts, USEC_PER_MSEC);
 536                 unsigned long rel_msec = (unsigned long)rel_ts;
 537
 538                 trace_seq_printf(
 539                         s, "[%08llx] %ld.%03ldms (+%ld.%03ldms): ",
 540                         ns2usecs(iter->ts),
 541                         abs_msec, abs_usec,
 542                         rel_msec, rel_usec);
 543
 544         } else if (verbose && !in_ns) {
 545                 trace_seq_printf(
 546                         s, "[%016llx] %lld (+%lld): ",
 547                         iter->ts, abs_ts, rel_ts);
 548
 549         } else if (!verbose && in_ns) {
 550                 trace_seq_printf(
 551                         s, " %4lldus%c: ",
 552                         abs_ts,
 553                         trace_find_mark(rel_ts * NSEC_PER_USEC));
 554
 555         } else { /* !verbose && !in_ns */
 556                 trace_seq_printf(s, " %4lld: ", abs_ts);
 557         }
 558
 559         return !trace_seq_has_overflowed(s);
 560 }
 561
 562 int trace_print_context(struct trace_iterator *iter)
 563 {
 564         struct trace_seq *s = &iter->seq;
 565         struct trace_entry *entry = iter->ent;
 566         unsigned long long t;
 567         unsigned long secs, usec_rem;
 568         char comm[TASK_COMM_LEN];
 569
 570         trace_find_cmdline(entry->pid, comm);
 571
 572         trace_seq_printf(s, "%16s-%-5d [%03d] ",
 573                                comm, entry->pid, iter->cpu);
 574
 575         if (trace_flags & TRACE_ITER_IRQ_INFO)
 576                 trace_print_lat_fmt(s, entry);
 577
 578         if (iter->iter_flags & TRACE_FILE_TIME_IN_NS) {
 579                 t = ns2usecs(iter->ts);
 580                 usec_rem = do_div(t, USEC_PER_SEC);
 581                 secs = (unsigned long)t;
 582                 trace_seq_printf(s, " %5lu.%06lu: ", secs, usec_rem);
 583         } else
 584                 trace_seq_printf(s, " %12llu: ", iter->ts);
 585
 586         return !trace_seq_has_overflowed(s);
 587 }
 588
 589 int trace_print_lat_context(struct trace_iterator *iter)
 590 {
 591         u64 next_ts;
 592         /* trace_find_next_entry will reset ent_size */
 593         int ent_size = iter->ent_size;
 594         struct trace_seq *s = &iter->seq;
 595         struct trace_entry *entry = iter->ent,
 596                            *next_entry = trace_find_next_entry(iter, NULL,
 597                                                                &next_ts);
 598         unsigned long verbose = (trace_flags & TRACE_ITER_VERBOSE);
 599
 600         /* Restore the original ent_size */
 601         iter->ent_size = ent_size;
 602
 603         if (!next_entry)
 604                 next_ts = iter->ts;
 605
 606         if (verbose) {
 607                 char comm[TASK_COMM_LEN];
 608
 609                 trace_find_cmdline(entry->pid, comm);
 610
 611                 trace_seq_printf(
 612                         s, "%16s %5d %3d %d %08x %08lx ",
 613                         comm, entry->pid, iter->cpu, entry->flags,
 614                         entry->preempt_count, iter->idx);
 615         } else {
 616                 lat_print_generic(s, entry, iter->cpu);
 617         }
 618
 619         lat_print_timestamp(iter, next_ts);
 620
 621         return !trace_seq_has_overflowed(s);
 622 }
 623
 624 static const char state_to_char[] = TASK_STATE_TO_CHAR_STR;
 625
 626 static int task_state_char(unsigned long state)
 627 {
 628         int bit = state ? __ffs(state) + 1 : 0;
 629
 630         return bit < sizeof(state_to_char) - 1 ? state_to_char[bit] : '?';
 631 }
 632
 633 /**
 634  * ftrace_find_event - find a registered event
 635  * @type: the type of event to look for
 636  *
 637  * Returns an event of type @type otherwise NULL
 638  * Called with trace_event_read_lock() held.
 639  */
 640 struct trace_event *ftrace_find_event(int type)
 641 {
 642         struct trace_event *event;
 643         unsigned key;
 644
 645         key = type & (EVENT_HASHSIZE - 1);
 646
 647         hlist_for_each_entry(event, &event_hash[key], node) {
 648                 if (event->type == type)
 649                         return event;
 650         }
 651
 652         return NULL;
 653 }
 654
 655 static LIST_HEAD(ftrace_event_list);
 656
 657 static int trace_search_list(struct list_head **list)
 658 {
 659         struct trace_event *e;
 660         int last = __TRACE_LAST_TYPE;
 661
 662         if (list_empty(&ftrace_event_list)) {
 663                 *list = &ftrace_event_list;
 664                 return last + 1;
 665         }
 666
 667         /*
 668          * We used up all possible max events,
 669          * lets see if somebody freed one.
 670          */
 671         list_for_each_entry(e, &ftrace_event_list, list) {
 672                 if (e->type != last + 1)
 673                         break;
 674                 last++;
 675         }
 676
 677         /* Did we used up all 65 thousand events??? */
 678         if ((last + 1) > FTRACE_MAX_EVENT)
 679                 return 0;
 680
 681         *list = &e->list;
 682         return last + 1;
 683 }
 684
 685 void trace_event_read_lock(void)
 686 {
 687         down_read(&trace_event_sem);
 688 }
 689
 690 void trace_event_read_unlock(void)
 691 {
 692         up_read(&trace_event_sem);
 693 }
 694
 695 /**
 696  * register_ftrace_event - register output for an event type
 697  * @event: the event type to register
 698  *
 699  * Event types are stored in a hash and this hash is used to
 700  * find a way to print an event. If the @event->type is set
 701  * then it will use that type, otherwise it will assign a
 702  * type to use.
 703  *
 704  * If you assign your own type, please make sure it is added
 705  * to the trace_type enum in trace.h, to avoid collisions
 706  * with the dynamic types.
 707  *
 708  * Returns the event type number or zero on error.
 709  */
 710 int register_ftrace_event(struct trace_event *event)
 711 {
 712         unsigned key;
 713         int ret = 0;
 714
 715         down_write(&trace_event_sem);
 716
 717         if (WARN_ON(!event))
 718                 goto out;
 719
 720         if (WARN_ON(!event->funcs))
 721                 goto out;
 722
 723         INIT_LIST_HEAD(&event->list);
 724
 725         if (!event->type) {
 726                 struct list_head *list = NULL;
 727
 728                 if (next_event_type > FTRACE_MAX_EVENT) {
 729
 730                         event->type = trace_search_list(&list);
 731                         if (!event->type)
 732                                 goto out;
 733
 734                 } else {
 735
 736                         event->type = next_event_type++;
 737                         list = &ftrace_event_list;
 738                 }
 739
 740                 if (WARN_ON(ftrace_find_event(event->type)))
 741                         goto out;
 742
 743                 list_add_tail(&event->list, list);
 744
 745         } else if (event->type > __TRACE_LAST_TYPE) {
 746                 printk(KERN_WARNING "Need to add type to trace.h\n");
 747                 WARN_ON(1);
 748                 goto out;
 749         } else {
 750                 /* Is this event already used */
 751                 if (ftrace_find_event(event->type))
 752                         goto out;
 753         }
 754
 755         if (event->funcs->trace == NULL)
 756                 event->funcs->trace = trace_nop_print;
 757         if (event->funcs->raw == NULL)
 758                 event->funcs->raw = trace_nop_print;
 759         if (event->funcs->hex == NULL)
 760                 event->funcs->hex = trace_nop_print;
 761         if (event->funcs->binary == NULL)
 762                 event->funcs->binary = trace_nop_print;
 763
 764         key = event->type & (EVENT_HASHSIZE - 1);
 765
 766         hlist_add_head(&event->node, &event_hash[key]);
 767
 768         ret = event->type;
 769  out:
 770         up_write(&trace_event_sem);
 771
 772         return ret;
 773 }
 774 EXPORT_SYMBOL_GPL(register_ftrace_event);
 775
 776 /*
 777  * Used by module code with the trace_event_sem held for write.
 778  */
 779 int __unregister_ftrace_event(struct trace_event *event)
 780 {
 781         hlist_del(&event->node);
 782         list_del(&event->list);
 783         return 0;
 784 }
 785
 786 /**
 787  * unregister_ftrace_event - remove a no longer used event
 788  * @event: the event to remove
 789  */
 790 int unregister_ftrace_event(struct trace_event *event)
 791 {
 792         down_write(&trace_event_sem);
 793         __unregister_ftrace_event(event);
 794         up_write(&trace_event_sem);
 795
 796         return 0;
 797 }
 798 EXPORT_SYMBOL_GPL(unregister_ftrace_event);
 799
 800 /*
 801  * Standard events
 802  */
 803
 804 enum print_line_t trace_nop_print(struct trace_iterator *iter, int flags,
 805                                   struct trace_event *event)
 806 {
 807         trace_seq_printf(&iter->seq, "type: %d\n", iter->ent->type);
 808
 809         return trace_handle_return(&iter->seq);
 810 }
 811
 812 /* TRACE_FN */
 813 static enum print_line_t trace_fn_trace(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_print_ip_sym(s, field->ip, flags);
 822
 823         if ((flags & TRACE_ITER_PRINT_PARENT) && field->parent_ip) {
 824                 trace_seq_puts(s, " <-");
 825                 seq_print_ip_sym(s, field->parent_ip, flags);
 826         }
 827
 828         trace_seq_putc(s, '\n');
 829
 830         return trace_handle_return(s);
 831 }
 832
 833 static enum print_line_t trace_fn_raw(struct trace_iterator *iter, int flags,
 834                                       struct trace_event *event)
 835 {
 836         struct ftrace_entry *field;
 837
 838         trace_assign_type(field, iter->ent);
 839
 840         trace_seq_printf(&iter->seq, "%lx %lx\n",
 841                          field->ip,
 842                          field->parent_ip);
 843
 844         return trace_handle_return(&iter->seq);
 845 }
 846
 847 static enum print_line_t trace_fn_hex(struct trace_iterator *iter, int flags,
 848                                       struct trace_event *event)
 849 {
 850         struct ftrace_entry *field;
 851         struct trace_seq *s = &iter->seq;
 852
 853         trace_assign_type(field, iter->ent);
 854
 855         SEQ_PUT_HEX_FIELD(s, field->ip);
 856         SEQ_PUT_HEX_FIELD(s, field->parent_ip);
 857
 858         return trace_handle_return(s);
 859 }
 860
 861 static enum print_line_t trace_fn_bin(struct trace_iterator *iter, int flags,
 862                                       struct trace_event *event)
 863 {
 864         struct ftrace_entry *field;
 865         struct trace_seq *s = &iter->seq;
 866
 867         trace_assign_type(field, iter->ent);
 868
 869         SEQ_PUT_FIELD(s, field->ip);
 870         SEQ_PUT_FIELD(s, field->parent_ip);
 871
 872         return trace_handle_return(s);
 873 }
 874
 875 static struct trace_event_functions trace_fn_funcs = {
 876         .trace          = trace_fn_trace,
 877         .raw            = trace_fn_raw,
 878         .hex            = trace_fn_hex,
 879         .binary         = trace_fn_bin,
 880 };
 881
 882 static struct trace_event trace_fn_event = {
 883         .type           = TRACE_FN,
 884         .funcs          = &trace_fn_funcs,
 885 };
 886
 887 /* TRACE_CTX an TRACE_WAKE */
 888 static enum print_line_t trace_ctxwake_print(struct trace_iterator *iter,
 889                                              char *delim)
 890 {
 891         struct ctx_switch_entry *field;
 892         char comm[TASK_COMM_LEN];
 893         int S, T;
 894
 895
 896         trace_assign_type(field, iter->ent);
 897
 898         T = task_state_char(field->next_state);
 899         S = task_state_char(field->prev_state);
 900         trace_find_cmdline(field->next_pid, comm);
 901         trace_seq_printf(&iter->seq,
 902                          " %5d:%3d:%c %s [%03d] %5d:%3d:%c %s\n",
 903                          field->prev_pid,
 904                          field->prev_prio,
 905                          S, delim,
 906                          field->next_cpu,
 907                          field->next_pid,
 908                          field->next_prio,
 909                          T, comm);
 910
 911         return trace_handle_return(&iter->seq);
 912 }
 913
 914 static enum print_line_t trace_ctx_print(struct trace_iterator *iter, int flags,
 915                                          struct trace_event *event)
 916 {
 917         return trace_ctxwake_print(iter, "==>");
 918 }
 919
 920 static enum print_line_t trace_wake_print(struct trace_iterator *iter,
 921                                           int flags, struct trace_event *event)
 922 {
 923         return trace_ctxwake_print(iter, "  +");
 924 }
 925
 926 static int trace_ctxwake_raw(struct trace_iterator *iter, char S)
 927 {
 928         struct ctx_switch_entry *field;
 929         int T;
 930
 931         trace_assign_type(field, iter->ent);
 932
 933         if (!S)
 934                 S = task_state_char(field->prev_state);
 935         T = task_state_char(field->next_state);
 936         trace_seq_printf(&iter->seq, "%d %d %c %d %d %d %c\n",
 937                          field->prev_pid,
 938                          field->prev_prio,
 939                          S,
 940                          field->next_cpu,
 941                          field->next_pid,
 942                          field->next_prio,
 943                          T);
 944
 945         return trace_handle_return(&iter->seq);
 946 }
 947
 948 static enum print_line_t trace_ctx_raw(struct trace_iterator *iter, int flags,
 949                                        struct trace_event *event)
 950 {
 951         return trace_ctxwake_raw(iter, 0);
 952 }
 953
 954 static enum print_line_t trace_wake_raw(struct trace_iterator *iter, int flags,
 955                                         struct trace_event *event)
 956 {
 957         return trace_ctxwake_raw(iter, '+');
 958 }
 959
 960
 961 static int trace_ctxwake_hex(struct trace_iterator *iter, char S)
 962 {
 963         struct ctx_switch_entry *field;
 964         struct trace_seq *s = &iter->seq;
 965         int T;
 966
 967         trace_assign_type(field, iter->ent);
 968
 969         if (!S)
 970                 S = task_state_char(field->prev_state);
 971         T = task_state_char(field->next_state);
 972
 973         SEQ_PUT_HEX_FIELD(s, field->prev_pid);
 974         SEQ_PUT_HEX_FIELD(s, field->prev_prio);
 975         SEQ_PUT_HEX_FIELD(s, S);
 976         SEQ_PUT_HEX_FIELD(s, field->next_cpu);
 977         SEQ_PUT_HEX_FIELD(s, field->next_pid);
 978         SEQ_PUT_HEX_FIELD(s, field->next_prio);
 979         SEQ_PUT_HEX_FIELD(s, T);
 980
 981         return trace_handle_return(s);
 982 }
 983
 984 static enum print_line_t trace_ctx_hex(struct trace_iterator *iter, int flags,
 985                                        struct trace_event *event)
 986 {
 987         return trace_ctxwake_hex(iter, 0);
 988 }
 989
 990 static enum print_line_t trace_wake_hex(struct trace_iterator *iter, int flags,
 991                                         struct trace_event *event)
 992 {
 993         return trace_ctxwake_hex(iter, '+');
 994 }
 995
 996 static enum print_line_t trace_ctxwake_bin(struct trace_iterator *iter,
 997                                            int flags, struct trace_event *event)
 998 {
 999         struct ctx_switch_entry *field;
1000         struct trace_seq *s = &iter->seq;
1001
1002         trace_assign_type(field, iter->ent);
1003
1004         SEQ_PUT_FIELD(s, field->prev_pid);
1005         SEQ_PUT_FIELD(s, field->prev_prio);
1006         SEQ_PUT_FIELD(s, field->prev_state);
1007         SEQ_PUT_FIELD(s, field->next_cpu);
1008         SEQ_PUT_FIELD(s, field->next_pid);
1009         SEQ_PUT_FIELD(s, field->next_prio);
1010         SEQ_PUT_FIELD(s, field->next_state);
1011
1012         return trace_handle_return(s);
1013 }
1014
1015 static struct trace_event_functions trace_ctx_funcs = {
1016         .trace          = trace_ctx_print,
1017         .raw            = trace_ctx_raw,
1018         .hex            = trace_ctx_hex,
1019         .binary         = trace_ctxwake_bin,
1020 };
1021
1022 static struct trace_event trace_ctx_event = {
1023         .type           = TRACE_CTX,
1024         .funcs          = &trace_ctx_funcs,
1025 };
1026
1027 static struct trace_event_functions trace_wake_funcs = {
1028         .trace          = trace_wake_print,
1029         .raw            = trace_wake_raw,
1030         .hex            = trace_wake_hex,
1031         .binary         = trace_ctxwake_bin,
1032 };
1033
1034 static struct trace_event trace_wake_event = {
1035         .type           = TRACE_WAKE,
1036         .funcs          = &trace_wake_funcs,
1037 };
1038
1039 /* TRACE_STACK */
1040
1041 static enum print_line_t trace_stack_print(struct trace_iterator *iter,
1042                                            int flags, struct trace_event *event)
1043 {
1044         struct stack_entry *field;
1045         struct trace_seq *s = &iter->seq;
1046         unsigned long *p;
1047         unsigned long *end;
1048
1049         trace_assign_type(field, iter->ent);
1050         end = (unsigned long *)((long)iter->ent + iter->ent_size);
1051
1052         trace_seq_puts(s, "<stack trace>\n");
1053
1054         for (p = field->caller; p && *p != ULONG_MAX && p < end; p++) {
1055
1056                 if (trace_seq_has_overflowed(s))
1057                         break;
1058
1059                 trace_seq_puts(s, " => ");
1060                 seq_print_ip_sym(s, *p, flags);
1061                 trace_seq_putc(s, '\n');
1062         }
1063
1064         return trace_handle_return(s);
1065 }
1066
1067 static struct trace_event_functions trace_stack_funcs = {
1068         .trace          = trace_stack_print,
1069 };
1070
1071 static struct trace_event trace_stack_event = {
1072         .type           = TRACE_STACK,
1073         .funcs          = &trace_stack_funcs,
1074 };
1075
1076 /* TRACE_USER_STACK */
1077 static enum print_line_t trace_user_stack_print(struct trace_iterator *iter,
1078                                                 int flags, struct trace_event *event)
1079 {
1080         struct userstack_entry *field;
1081         struct trace_seq *s = &iter->seq;
1082
1083         trace_assign_type(field, iter->ent);
1084
1085         trace_seq_puts(s, "<user stack trace>\n");
1086         seq_print_userip_objs(field, s, flags);
1087
1088         return trace_handle_return(s);
1089 }
1090
1091 static struct trace_event_functions trace_user_stack_funcs = {
1092         .trace          = trace_user_stack_print,
1093 };
1094
1095 static struct trace_event trace_user_stack_event = {
1096         .type           = TRACE_USER_STACK,
1097         .funcs          = &trace_user_stack_funcs,
1098 };
1099
1100 /* TRACE_BPUTS */
1101 static enum print_line_t
1102 trace_bputs_print(struct trace_iterator *iter, int flags,
1103                    struct trace_event *event)
1104 {
1105         struct trace_entry *entry = iter->ent;
1106         struct trace_seq *s = &iter->seq;
1107         struct bputs_entry *field;
1108
1109         trace_assign_type(field, entry);
1110
1111         seq_print_ip_sym(s, field->ip, flags);
1112         trace_seq_puts(s, ": ");
1113         trace_seq_puts(s, field->str);
1114
1115         return trace_handle_return(s);
1116 }
1117
1118
1119 static enum print_line_t
1120 trace_bputs_raw(struct trace_iterator *iter, int flags,
1121                 struct trace_event *event)
1122 {
1123         struct bputs_entry *field;
1124         struct trace_seq *s = &iter->seq;
1125
1126         trace_assign_type(field, iter->ent);
1127
1128         trace_seq_printf(s, ": %lx : ", field->ip);
1129         trace_seq_puts(s, field->str);
1130
1131         return trace_handle_return(s);
1132 }
1133
1134 static struct trace_event_functions trace_bputs_funcs = {
1135         .trace          = trace_bputs_print,
1136         .raw            = trace_bputs_raw,
1137 };
1138
1139 static struct trace_event trace_bputs_event = {
1140         .type           = TRACE_BPUTS,
1141         .funcs          = &trace_bputs_funcs,
1142 };
1143
1144 /* TRACE_BPRINT */
1145 static enum print_line_t
1146 trace_bprint_print(struct trace_iterator *iter, int flags,
1147                    struct trace_event *event)
1148 {
1149         struct trace_entry *entry = iter->ent;
1150         struct trace_seq *s = &iter->seq;
1151         struct bprint_entry *field;
1152
1153         trace_assign_type(field, entry);
1154
1155         seq_print_ip_sym(s, field->ip, flags);
1156         trace_seq_puts(s, ": ");
1157         trace_seq_bprintf(s, field->fmt, field->buf);
1158
1159         return trace_handle_return(s);
1160 }
1161
1162
1163 static enum print_line_t
1164 trace_bprint_raw(struct trace_iterator *iter, int flags,
1165                  struct trace_event *event)
1166 {
1167         struct bprint_entry *field;
1168         struct trace_seq *s = &iter->seq;
1169
1170         trace_assign_type(field, iter->ent);
1171
1172         trace_seq_printf(s, ": %lx : ", field->ip);
1173         trace_seq_bprintf(s, field->fmt, field->buf);
1174
1175         return trace_handle_return(s);
1176 }
1177
1178 static struct trace_event_functions trace_bprint_funcs = {
1179         .trace          = trace_bprint_print,
1180         .raw            = trace_bprint_raw,
1181 };
1182
1183 static struct trace_event trace_bprint_event = {
1184         .type           = TRACE_BPRINT,
1185         .funcs          = &trace_bprint_funcs,
1186 };
1187
1188 /* TRACE_PRINT */
1189 static enum print_line_t trace_print_print(struct trace_iterator *iter,
1190                                            int flags, struct trace_event *event)
1191 {
1192         struct print_entry *field;
1193         struct trace_seq *s = &iter->seq;
1194
1195         trace_assign_type(field, iter->ent);
1196
1197         seq_print_ip_sym(s, field->ip, flags);
1198         trace_seq_printf(s, ": %s", field->buf);
1199
1200         return trace_handle_return(s);
1201 }
1202
1203 static enum print_line_t trace_print_raw(struct trace_iterator *iter, int flags,
1204                                          struct trace_event *event)
1205 {
1206         struct print_entry *field;
1207
1208         trace_assign_type(field, iter->ent);
1209
1210         trace_seq_printf(&iter->seq, "# %lx %s", field->ip, field->buf);
1211
1212         return trace_handle_return(&iter->seq);
1213 }
1214
1215 static struct trace_event_functions trace_print_funcs = {
1216         .trace          = trace_print_print,
1217         .raw            = trace_print_raw,
1218 };
1219
1220 static struct trace_event trace_print_event = {
1221         .type           = TRACE_PRINT,
1222         .funcs          = &trace_print_funcs,
1223 };
1224
1225
1226 static struct trace_event *events[] __initdata = {
1227         &trace_fn_event,
1228         &trace_ctx_event,
1229         &trace_wake_event,
1230         &trace_stack_event,
1231         &trace_user_stack_event,
1232         &trace_bputs_event,
1233         &trace_bprint_event,
1234         &trace_print_event,
1235         NULL
1236 };
1237
1238 __init static int init_events(void)
1239 {
1240         struct trace_event *event;
1241         int i, ret;
1242
1243         for (i = 0; events[i]; i++) {
1244                 event = events[i];
1245
1246                 ret = register_ftrace_event(event);
1247                 if (!ret) {
1248                         printk(KERN_WARNING "event %d failed to register\n",
1249                                event->type);
1250                         WARN_ON_ONCE(1);
1251                 }
1252         }
1253
1254         return 0;
1255 }
1256 early_initcall(init_events);