kernel/trace/trace_output.c

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