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 int trace_print_seq(struct seq_file *m, struct trace_seq *s)
  24 {
  25         int len = s->len >= PAGE_SIZE ? PAGE_SIZE - 1 : s->len;
  26         int ret;
  27
  28         ret = seq_write(m, s->buffer, len);
  29
  30         /*
  31          * Only reset this buffer if we successfully wrote to the
  32          * seq_file buffer.
  33          */
  34         if (!ret)
  35                 trace_seq_init(s);
  36
  37         return ret;
  38 }
  39
  40 enum print_line_t trace_print_bputs_msg_only(struct trace_iterator *iter)
  41 {
  42         struct trace_seq *s = &iter->seq;
  43         struct trace_entry *entry = iter->ent;
  44         struct bputs_entry *field;
  45         int ret;
  46
  47         trace_assign_type(field, entry);
  48
  49         ret = trace_seq_puts(s, field->str);
  50         if (!ret)
  51                 return TRACE_TYPE_PARTIAL_LINE;
  52
  53         return TRACE_TYPE_HANDLED;
  54 }
  55
  56 enum print_line_t trace_print_bprintk_msg_only(struct trace_iterator *iter)
  57 {
  58         struct trace_seq *s = &iter->seq;
  59         struct trace_entry *entry = iter->ent;
  60         struct bprint_entry *field;
  61         int ret;
  62
  63         trace_assign_type(field, entry);
  64
  65         ret = trace_seq_bprintf(s, field->fmt, field->buf);
  66         if (!ret)
  67                 return TRACE_TYPE_PARTIAL_LINE;
  68
  69         return TRACE_TYPE_HANDLED;
  70 }
  71
  72 enum print_line_t trace_print_printk_msg_only(struct trace_iterator *iter)
  73 {
  74         struct trace_seq *s = &iter->seq;
  75         struct trace_entry *entry = iter->ent;
  76         struct print_entry *field;
  77         int ret;
  78
  79         trace_assign_type(field, entry);
  80
  81         ret = trace_seq_puts(s, field->buf);
  82         if (!ret)
  83                 return TRACE_TYPE_PARTIAL_LINE;
  84
  85         return TRACE_TYPE_HANDLED;
  86 }
  87
  88 /**
  89  * trace_seq_printf - sequence printing of trace information
  90  * @s: trace sequence descriptor
  91  * @fmt: printf format string
  92  *
  93  * It returns 0 if the trace oversizes the buffer's free
  94  * space, 1 otherwise.
  95  *
  96  * The tracer may use either sequence operations or its own
  97  * copy to user routines. To simplify formating of a trace
  98  * trace_seq_printf is used to store strings into a special
  99  * buffer (@s). Then the output may be either used by
 100  * the sequencer or pulled into another buffer.
 101  */
 102 int
 103 trace_seq_printf(struct trace_seq *s, const char *fmt, ...)
 104 {
 105         int len = (PAGE_SIZE - 1) - s->len;
 106         va_list ap;
 107         int ret;
 108
 109         if (s->full || !len)
 110                 return 0;
 111
 112         va_start(ap, fmt);
 113         ret = vsnprintf(s->buffer + s->len, len, fmt, ap);
 114         va_end(ap);
 115
 116         /* If we can't write it all, don't bother writing anything */
 117         if (ret >= len) {
 118                 s->full = 1;
 119                 return 0;
 120         }
 121
 122         s->len += ret;
 123
 124         return 1;
 125 }
 126 EXPORT_SYMBOL_GPL(trace_seq_printf);
 127
 128 /**
 129  * trace_seq_vprintf - sequence printing of trace information
 130  * @s: trace sequence descriptor
 131  * @fmt: printf format string
 132  *
 133  * The tracer may use either sequence operations or its own
 134  * copy to user routines. To simplify formating of a trace
 135  * trace_seq_printf is used to store strings into a special
 136  * buffer (@s). Then the output may be either used by
 137  * the sequencer or pulled into another buffer.
 138  */
 139 int
 140 trace_seq_vprintf(struct trace_seq *s, const char *fmt, va_list args)
 141 {
 142         int len = (PAGE_SIZE - 1) - s->len;
 143         int ret;
 144
 145         if (s->full || !len)
 146                 return 0;
 147
 148         ret = vsnprintf(s->buffer + s->len, len, fmt, args);
 149
 150         /* If we can't write it all, don't bother writing anything */
 151         if (ret >= len) {
 152                 s->full = 1;
 153                 return 0;
 154         }
 155
 156         s->len += ret;
 157
 158         return len;
 159 }
 160 EXPORT_SYMBOL_GPL(trace_seq_vprintf);
 161
 162 int trace_seq_bprintf(struct trace_seq *s, const char *fmt, const u32 *binary)
 163 {
 164         int len = (PAGE_SIZE - 1) - s->len;
 165         int ret;
 166
 167         if (s->full || !len)
 168                 return 0;
 169
 170         ret = bstr_printf(s->buffer + s->len, len, fmt, binary);
 171
 172         /* If we can't write it all, don't bother writing anything */
 173         if (ret >= len) {
 174                 s->full = 1;
 175                 return 0;
 176         }
 177
 178         s->len += ret;
 179
 180         return len;
 181 }
 182
 183 /**
 184  * trace_seq_puts - trace sequence printing of simple string
 185  * @s: trace sequence descriptor
 186  * @str: simple string to record
 187  *
 188  * The tracer may use either the sequence operations or its own
 189  * copy to user routines. This function records a simple string
 190  * into a special buffer (@s) for later retrieval by a sequencer
 191  * or other mechanism.
 192  */
 193 int trace_seq_puts(struct trace_seq *s, const char *str)
 194 {
 195         int len = strlen(str);
 196
 197         if (s->full)
 198                 return 0;
 199
 200         if (len > ((PAGE_SIZE - 1) - s->len)) {
 201                 s->full = 1;
 202                 return 0;
 203         }
 204
 205         memcpy(s->buffer + s->len, str, len);
 206         s->len += len;
 207
 208         return len;
 209 }
 210
 211 int trace_seq_putc(struct trace_seq *s, unsigned char c)
 212 {
 213         if (s->full)
 214                 return 0;
 215
 216         if (s->len >= (PAGE_SIZE - 1)) {
 217                 s->full = 1;
 218                 return 0;
 219         }
 220
 221         s->buffer[s->len++] = c;
 222
 223         return 1;
 224 }
 225 EXPORT_SYMBOL(trace_seq_putc);
 226
 227 int trace_seq_putmem(struct trace_seq *s, const void *mem, size_t len)
 228 {
 229         if (s->full)
 230                 return 0;
 231
 232         if (len > ((PAGE_SIZE - 1) - s->len)) {
 233                 s->full = 1;
 234                 return 0;
 235         }
 236
 237         memcpy(s->buffer + s->len, mem, len);
 238         s->len += len;
 239
 240         return len;
 241 }
 242
 243 int trace_seq_putmem_hex(struct trace_seq *s, const void *mem, size_t len)
 244 {
 245         unsigned char hex[HEX_CHARS];
 246         const unsigned char *data = mem;
 247         int i, j;
 248
 249         if (s->full)
 250                 return 0;
 251
 252 #ifdef __BIG_ENDIAN
 253         for (i = 0, j = 0; i < len; i++) {
 254 #else
 255         for (i = len-1, j = 0; i >= 0; i--) {
 256 #endif
 257                 hex[j++] = hex_asc_hi(data[i]);
 258                 hex[j++] = hex_asc_lo(data[i]);
 259         }
 260         hex[j++] = ' ';
 261
 262         return trace_seq_putmem(s, hex, j);
 263 }
 264
 265 void *trace_seq_reserve(struct trace_seq *s, size_t len)
 266 {
 267         void *ret;
 268
 269         if (s->full)
 270                 return NULL;
 271
 272         if (len > ((PAGE_SIZE - 1) - s->len)) {
 273                 s->full = 1;
 274                 return NULL;
 275         }
 276
 277         ret = s->buffer + s->len;
 278         s->len += len;
 279
 280         return ret;
 281 }
 282
 283 int trace_seq_path(struct trace_seq *s, const struct path *path)
 284 {
 285         unsigned char *p;
 286
 287         if (s->full)
 288                 return 0;
 289
 290         if (s->len >= (PAGE_SIZE - 1)) {
 291                 s->full = 1;
 292                 return 0;
 293         }
 294
 295         p = d_path(path, s->buffer + s->len, PAGE_SIZE - s->len);
 296         if (!IS_ERR(p)) {
 297                 p = mangle_path(s->buffer + s->len, p, "\n");
 298                 if (p) {
 299                         s->len = p - s->buffer;
 300                         return 1;
 301                 }
 302         } else {
 303                 s->buffer[s->len++] = '?';
 304                 return 1;
 305         }
 306
 307         s->full = 1;
 308         return 0;
 309 }
 310
 311 const char *
 312 ftrace_print_flags_seq(struct trace_seq *p, const char *delim,
 313                        unsigned long flags,
 314                        const struct trace_print_flags *flag_array)
 315 {
 316         unsigned long mask;
 317         const char *str;
 318         const char *ret = p->buffer + p->len;
 319         int i, first = 1;
 320
 321         for (i = 0;  flag_array[i].name && flags; i++) {
 322
 323                 mask = flag_array[i].mask;
 324                 if ((flags & mask) != mask)
 325                         continue;
 326
 327                 str = flag_array[i].name;
 328                 flags &= ~mask;
 329                 if (!first && delim)
 330                         trace_seq_puts(p, delim);
 331                 else
 332                         first = 0;
 333                 trace_seq_puts(p, str);
 334         }
 335
 336         /* check for left over flags */
 337         if (flags) {
 338                 if (!first && delim)
 339                         trace_seq_puts(p, delim);
 340                 trace_seq_printf(p, "0x%lx", flags);
 341         }
 342
 343         trace_seq_putc(p, 0);
 344
 345         return ret;
 346 }
 347 EXPORT_SYMBOL(ftrace_print_flags_seq);
 348
 349 const char *
 350 ftrace_print_symbols_seq(struct trace_seq *p, unsigned long val,
 351                          const struct trace_print_flags *symbol_array)
 352 {
 353         int i;
 354         const char *ret = p->buffer + p->len;
 355
 356         for (i = 0;  symbol_array[i].name; i++) {
 357
 358                 if (val != symbol_array[i].mask)
 359                         continue;
 360
 361                 trace_seq_puts(p, symbol_array[i].name);
 362                 break;
 363         }
 364
 365         if (ret == (const char *)(p->buffer + p->len))
 366                 trace_seq_printf(p, "0x%lx", val);
 367
 368         trace_seq_putc(p, 0);
 369
 370         return ret;
 371 }
 372 EXPORT_SYMBOL(ftrace_print_symbols_seq);
 373
 374 #if BITS_PER_LONG == 32
 375 const char *
 376 ftrace_print_symbols_seq_u64(struct trace_seq *p, unsigned long long val,
 377                          const struct trace_print_flags_u64 *symbol_array)
 378 {
 379         int i;
 380         const char *ret = p->buffer + p->len;
 381
 382         for (i = 0;  symbol_array[i].name; i++) {
 383
 384                 if (val != symbol_array[i].mask)
 385                         continue;
 386
 387                 trace_seq_puts(p, symbol_array[i].name);
 388                 break;
 389         }
 390
 391         if (ret == (const char *)(p->buffer + p->len))
 392                 trace_seq_printf(p, "0x%llx", val);
 393
 394         trace_seq_putc(p, 0);
 395
 396         return ret;
 397 }
 398 EXPORT_SYMBOL(ftrace_print_symbols_seq_u64);
 399 #endif
 400
 401 const char *
 402 ftrace_print_hex_seq(struct trace_seq *p, const unsigned char *buf, int buf_len)
 403 {
 404         int i;
 405         const char *ret = p->buffer + p->len;
 406
 407         for (i = 0; i < buf_len; i++)
 408                 trace_seq_printf(p, "%s%2.2x", i == 0 ? "" : " ", buf[i]);
 409
 410         trace_seq_putc(p, 0);
 411
 412         return ret;
 413 }
 414 EXPORT_SYMBOL(ftrace_print_hex_seq);
 415
 416 int ftrace_raw_output_prep(struct trace_iterator *iter,
 417                            struct trace_event *trace_event)
 418 {
 419         struct ftrace_event_call *event;
 420         struct trace_seq *s = &iter->seq;
 421         struct trace_seq *p = &iter->tmp_seq;
 422         struct trace_entry *entry;
 423         int ret;
 424
 425         event = container_of(trace_event, struct ftrace_event_call, event);
 426         entry = iter->ent;
 427
 428         if (entry->type != event->event.type) {
 429                 WARN_ON_ONCE(1);
 430                 return TRACE_TYPE_UNHANDLED;
 431         }
 432
 433         trace_seq_init(p);
 434         ret = trace_seq_printf(s, "%s: ", event->name);
 435         if (!ret)
 436                 return TRACE_TYPE_PARTIAL_LINE;
 437
 438         return 0;
 439 }
 440 EXPORT_SYMBOL(ftrace_raw_output_prep);
 441
 442 #ifdef CONFIG_KRETPROBES
 443 static inline const char *kretprobed(const char *name)
 444 {
 445         static const char tramp_name[] = "kretprobe_trampoline";
 446         int size = sizeof(tramp_name);
 447
 448         if (strncmp(tramp_name, name, size) == 0)
 449                 return "[unknown/kretprobe'd]";
 450         return name;
 451 }
 452 #else
 453 static inline const char *kretprobed(const char *name)
 454 {
 455         return name;
 456 }
 457 #endif /* CONFIG_KRETPROBES */
 458
 459 static int
 460 seq_print_sym_short(struct trace_seq *s, const char *fmt, unsigned long address)
 461 {
 462 #ifdef CONFIG_KALLSYMS
 463         char str[KSYM_SYMBOL_LEN];
 464         const char *name;
 465
 466         kallsyms_lookup(address, NULL, NULL, NULL, str);
 467
 468         name = kretprobed(str);
 469
 470         return trace_seq_printf(s, fmt, name);
 471 #endif
 472         return 1;
 473 }
 474
 475 static int
 476 seq_print_sym_offset(struct trace_seq *s, const char *fmt,
 477                      unsigned long address)
 478 {
 479 #ifdef CONFIG_KALLSYMS
 480         char str[KSYM_SYMBOL_LEN];
 481         const char *name;
 482
 483         sprint_symbol(str, address);
 484         name = kretprobed(str);
 485
 486         return trace_seq_printf(s, fmt, name);
 487 #endif
 488         return 1;
 489 }
 490
 491 #ifndef CONFIG_64BIT
 492 # define IP_FMT "%08lx"
 493 #else
 494 # define IP_FMT "%016lx"
 495 #endif
 496
 497 int seq_print_user_ip(struct trace_seq *s, struct mm_struct *mm,
 498                       unsigned long ip, unsigned long sym_flags)
 499 {
 500         struct file *file = NULL;
 501         unsigned long vmstart = 0;
 502         int ret = 1;
 503
 504         if (s->full)
 505                 return 0;
 506
 507         if (mm) {
 508                 const struct vm_area_struct *vma;
 509
 510                 down_read(&mm->mmap_sem);
 511                 vma = find_vma(mm, ip);
 512                 if (vma) {
 513                         file = vma->vm_file;
 514                         vmstart = vma->vm_start;
 515                 }
 516                 if (file) {
 517                         ret = trace_seq_path(s, &file->f_path);
 518                         if (ret)
 519                                 ret = trace_seq_printf(s, "[+0x%lx]",
 520                                                        ip - vmstart);
 521                 }
 522                 up_read(&mm->mmap_sem);
 523         }
 524         if (ret && ((sym_flags & TRACE_ITER_SYM_ADDR) || !file))
 525                 ret = trace_seq_printf(s, " <" IP_FMT ">", ip);
 526         return ret;
 527 }
 528
 529 int
 530 seq_print_userip_objs(const struct userstack_entry *entry, struct trace_seq *s,
 531                       unsigned long sym_flags)
 532 {
 533         struct mm_struct *mm = NULL;
 534         int ret = 1;
 535         unsigned int i;
 536
 537         if (trace_flags & TRACE_ITER_SYM_USEROBJ) {
 538                 struct task_struct *task;
 539                 /*
 540                  * we do the lookup on the thread group leader,
 541                  * since individual threads might have already quit!
 542                  */
 543                 rcu_read_lock();
 544                 task = find_task_by_vpid(entry->tgid);
 545                 if (task)
 546                         mm = get_task_mm(task);
 547                 rcu_read_unlock();
 548         }
 549
 550         for (i = 0; i < FTRACE_STACK_ENTRIES; i++) {
 551                 unsigned long ip = entry->caller[i];
 552
 553                 if (ip == ULONG_MAX || !ret)
 554                         break;
 555                 if (ret)
 556                         ret = trace_seq_puts(s, " => ");
 557                 if (!ip) {
 558                         if (ret)
 559                                 ret = trace_seq_puts(s, "??");
 560                         if (ret)
 561                                 ret = trace_seq_putc(s, '\n');
 562                         continue;
 563                 }
 564                 if (!ret)
 565                         break;
 566                 if (ret)
 567                         ret = seq_print_user_ip(s, mm, ip, sym_flags);
 568                 ret = trace_seq_putc(s, '\n');
 569         }
 570
 571         if (mm)
 572                 mmput(mm);
 573         return ret;
 574 }
 575
 576 int
 577 seq_print_ip_sym(struct trace_seq *s, unsigned long ip, unsigned long sym_flags)
 578 {
 579         int ret;
 580
 581         if (!ip)
 582                 return trace_seq_putc(s, '0');
 583
 584         if (sym_flags & TRACE_ITER_SYM_OFFSET)
 585                 ret = seq_print_sym_offset(s, "%s", ip);
 586         else
 587                 ret = seq_print_sym_short(s, "%s", ip);
 588
 589         if (!ret)
 590                 return 0;
 591
 592         if (sym_flags & TRACE_ITER_SYM_ADDR)
 593                 ret = trace_seq_printf(s, " <" IP_FMT ">", ip);
 594         return ret;
 595 }
 596
 597 /**
 598  * trace_print_lat_fmt - print the irq, preempt and lockdep fields
 599  * @s: trace seq struct to write to
 600  * @entry: The trace entry field from the ring buffer
 601  *
 602  * Prints the generic fields of irqs off, in hard or softirq, preempt
 603  * count.
 604  */
 605 int trace_print_lat_fmt(struct trace_seq *s, struct trace_entry *entry)
 606 {
 607         char hardsoft_irq;
 608         char need_resched;
 609         char irqs_off;
 610         int hardirq;
 611         int softirq;
 612         int ret;
 613
 614         hardirq = entry->flags & TRACE_FLAG_HARDIRQ;
 615         softirq = entry->flags & TRACE_FLAG_SOFTIRQ;
 616
 617         irqs_off =
 618                 (entry->flags & TRACE_FLAG_IRQS_OFF) ? 'd' :
 619                 (entry->flags & TRACE_FLAG_IRQS_NOSUPPORT) ? 'X' :
 620                 '.';
 621
 622         switch (entry->flags & (TRACE_FLAG_NEED_RESCHED |
 623                                 TRACE_FLAG_PREEMPT_RESCHED)) {
 624         case TRACE_FLAG_NEED_RESCHED | TRACE_FLAG_PREEMPT_RESCHED:
 625                 need_resched = 'N';
 626                 break;
 627         case TRACE_FLAG_NEED_RESCHED:
 628                 need_resched = 'n';
 629                 break;
 630         case TRACE_FLAG_PREEMPT_RESCHED:
 631                 need_resched = 'p';
 632                 break;
 633         default:
 634                 need_resched = '.';
 635                 break;
 636         }
 637
 638         hardsoft_irq =
 639                 (hardirq && softirq) ? 'H' :
 640                 hardirq ? 'h' :
 641                 softirq ? 's' :
 642                 '.';
 643
 644         if (!trace_seq_printf(s, "%c%c%c",
 645                               irqs_off, need_resched, hardsoft_irq))
 646                 return 0;
 647
 648         if (entry->preempt_count)
 649                 ret = trace_seq_printf(s, "%x", entry->preempt_count);
 650         else
 651                 ret = trace_seq_putc(s, '.');
 652
 653         return ret;
 654 }
 655
 656 static int
 657 lat_print_generic(struct trace_seq *s, struct trace_entry *entry, int cpu)
 658 {
 659         char comm[TASK_COMM_LEN];
 660
 661         trace_find_cmdline(entry->pid, comm);
 662
 663         if (!trace_seq_printf(s, "%8.8s-%-5d %3d",
 664                               comm, entry->pid, cpu))
 665                 return 0;
 666
 667         return trace_print_lat_fmt(s, entry);
 668 }
 669
 670 static unsigned long preempt_mark_thresh_us = 100;
 671
 672 static int
 673 lat_print_timestamp(struct trace_iterator *iter, u64 next_ts)
 674 {
 675         unsigned long verbose = trace_flags & TRACE_ITER_VERBOSE;
 676         unsigned long in_ns = iter->iter_flags & TRACE_FILE_TIME_IN_NS;
 677         unsigned long long abs_ts = iter->ts - iter->trace_buffer->time_start;
 678         unsigned long long rel_ts = next_ts - iter->ts;
 679         struct trace_seq *s = &iter->seq;
 680
 681         if (in_ns) {
 682                 abs_ts = ns2usecs(abs_ts);
 683                 rel_ts = ns2usecs(rel_ts);
 684         }
 685
 686         if (verbose && in_ns) {
 687                 unsigned long abs_usec = do_div(abs_ts, USEC_PER_MSEC);
 688                 unsigned long abs_msec = (unsigned long)abs_ts;
 689                 unsigned long rel_usec = do_div(rel_ts, USEC_PER_MSEC);
 690                 unsigned long rel_msec = (unsigned long)rel_ts;
 691
 692                 return trace_seq_printf(
 693                                 s, "[%08llx] %ld.%03ldms (+%ld.%03ldms): ",
 694                                 ns2usecs(iter->ts),
 695                                 abs_msec, abs_usec,
 696                                 rel_msec, rel_usec);
 697         } else if (verbose && !in_ns) {
 698                 return trace_seq_printf(
 699                                 s, "[%016llx] %lld (+%lld): ",
 700                                 iter->ts, abs_ts, rel_ts);
 701         } else if (!verbose && in_ns) {
 702                 return trace_seq_printf(
 703                                 s, " %4lldus%c: ",
 704                                 abs_ts,
 705                                 rel_ts > preempt_mark_thresh_us ? '!' :
 706                                   rel_ts > 1 ? '+' : ' ');
 707         } else { /* !verbose && !in_ns */
 708                 return trace_seq_printf(s, " %4lld: ", abs_ts);
 709         }
 710 }
 711
 712 int trace_print_context(struct trace_iterator *iter)
 713 {
 714         struct trace_seq *s = &iter->seq;
 715         struct trace_entry *entry = iter->ent;
 716         unsigned long long t;
 717         unsigned long secs, usec_rem;
 718         char comm[TASK_COMM_LEN];
 719         int ret;
 720
 721         trace_find_cmdline(entry->pid, comm);
 722
 723         ret = trace_seq_printf(s, "%16s-%-5d [%03d] ",
 724                                comm, entry->pid, iter->cpu);
 725         if (!ret)
 726                 return 0;
 727
 728         if (trace_flags & TRACE_ITER_IRQ_INFO) {
 729                 ret = trace_print_lat_fmt(s, entry);
 730                 if (!ret)
 731                         return 0;
 732         }
 733
 734         if (iter->iter_flags & TRACE_FILE_TIME_IN_NS) {
 735                 t = ns2usecs(iter->ts);
 736                 usec_rem = do_div(t, USEC_PER_SEC);
 737                 secs = (unsigned long)t;
 738                 return trace_seq_printf(s, " %5lu.%06lu: ", secs, usec_rem);
 739         } else
 740                 return trace_seq_printf(s, " %12llu: ", iter->ts);
 741 }
 742
 743 int trace_print_lat_context(struct trace_iterator *iter)
 744 {
 745         u64 next_ts;
 746         int ret;
 747         /* trace_find_next_entry will reset ent_size */
 748         int ent_size = iter->ent_size;
 749         struct trace_seq *s = &iter->seq;
 750         struct trace_entry *entry = iter->ent,
 751                            *next_entry = trace_find_next_entry(iter, NULL,
 752                                                                &next_ts);
 753         unsigned long verbose = (trace_flags & TRACE_ITER_VERBOSE);
 754
 755         /* Restore the original ent_size */
 756         iter->ent_size = ent_size;
 757
 758         if (!next_entry)
 759                 next_ts = iter->ts;
 760
 761         if (verbose) {
 762                 char comm[TASK_COMM_LEN];
 763
 764                 trace_find_cmdline(entry->pid, comm);
 765
 766                 ret = trace_seq_printf(
 767                                 s, "%16s %5d %3d %d %08x %08lx ",
 768                                 comm, entry->pid, iter->cpu, entry->flags,
 769                                 entry->preempt_count, iter->idx);
 770         } else {
 771                 ret = lat_print_generic(s, entry, iter->cpu);
 772         }
 773
 774         if (ret)
 775                 ret = lat_print_timestamp(iter, next_ts);
 776
 777         return ret;
 778 }
 779
 780 static const char state_to_char[] = TASK_STATE_TO_CHAR_STR;
 781
 782 static int task_state_char(unsigned long state)
 783 {
 784         int bit = state ? __ffs(state) + 1 : 0;
 785
 786         return bit < sizeof(state_to_char) - 1 ? state_to_char[bit] : '?';
 787 }
 788
 789 /**
 790  * ftrace_find_event - find a registered event
 791  * @type: the type of event to look for
 792  *
 793  * Returns an event of type @type otherwise NULL
 794  * Called with trace_event_read_lock() held.
 795  */
 796 struct trace_event *ftrace_find_event(int type)
 797 {
 798         struct trace_event *event;
 799         unsigned key;
 800
 801         key = type & (EVENT_HASHSIZE - 1);
 802
 803         hlist_for_each_entry(event, &event_hash[key], node) {
 804                 if (event->type == type)
 805                         return event;
 806         }
 807
 808         return NULL;
 809 }
 810
 811 static LIST_HEAD(ftrace_event_list);
 812
 813 static int trace_search_list(struct list_head **list)
 814 {
 815         struct trace_event *e;
 816         int last = __TRACE_LAST_TYPE;
 817
 818         if (list_empty(&ftrace_event_list)) {
 819                 *list = &ftrace_event_list;
 820                 return last + 1;
 821         }
 822
 823         /*
 824          * We used up all possible max events,
 825          * lets see if somebody freed one.
 826          */
 827         list_for_each_entry(e, &ftrace_event_list, list) {
 828                 if (e->type != last + 1)
 829                         break;
 830                 last++;
 831         }
 832
 833         /* Did we used up all 65 thousand events??? */
 834         if ((last + 1) > FTRACE_MAX_EVENT)
 835                 return 0;
 836
 837         *list = &e->list;
 838         return last + 1;
 839 }
 840
 841 void trace_event_read_lock(void)
 842 {
 843         down_read(&trace_event_sem);
 844 }
 845
 846 void trace_event_read_unlock(void)
 847 {
 848         up_read(&trace_event_sem);
 849 }
 850
 851 /**
 852  * register_ftrace_event - register output for an event type
 853  * @event: the event type to register
 854  *
 855  * Event types are stored in a hash and this hash is used to
 856  * find a way to print an event. If the @event->type is set
 857  * then it will use that type, otherwise it will assign a
 858  * type to use.
 859  *
 860  * If you assign your own type, please make sure it is added
 861  * to the trace_type enum in trace.h, to avoid collisions
 862  * with the dynamic types.
 863  *
 864  * Returns the event type number or zero on error.
 865  */
 866 int register_ftrace_event(struct trace_event *event)
 867 {
 868         unsigned key;
 869         int ret = 0;
 870
 871         down_write(&trace_event_sem);
 872
 873         if (WARN_ON(!event))
 874                 goto out;
 875
 876         if (WARN_ON(!event->funcs))
 877                 goto out;
 878
 879         INIT_LIST_HEAD(&event->list);
 880
 881         if (!event->type) {
 882                 struct list_head *list = NULL;
 883
 884                 if (next_event_type > FTRACE_MAX_EVENT) {
 885
 886                         event->type = trace_search_list(&list);
 887                         if (!event->type)
 888                                 goto out;
 889
 890                 } else {
 891
 892                         event->type = next_event_type++;
 893                         list = &ftrace_event_list;
 894                 }
 895
 896                 if (WARN_ON(ftrace_find_event(event->type)))
 897                         goto out;
 898
 899                 list_add_tail(&event->list, list);
 900
 901         } else if (event->type > __TRACE_LAST_TYPE) {
 902                 printk(KERN_WARNING "Need to add type to trace.h\n");
 903                 WARN_ON(1);
 904                 goto out;
 905         } else {
 906                 /* Is this event already used */
 907                 if (ftrace_find_event(event->type))
 908                         goto out;
 909         }
 910
 911         if (event->funcs->trace == NULL)
 912                 event->funcs->trace = trace_nop_print;
 913         if (event->funcs->raw == NULL)
 914                 event->funcs->raw = trace_nop_print;
 915         if (event->funcs->hex == NULL)
 916                 event->funcs->hex = trace_nop_print;
 917         if (event->funcs->binary == NULL)
 918                 event->funcs->binary = trace_nop_print;
 919
 920         key = event->type & (EVENT_HASHSIZE - 1);
 921
 922         hlist_add_head(&event->node, &event_hash[key]);
 923
 924         ret = event->type;
 925  out:
 926         up_write(&trace_event_sem);
 927
 928         return ret;
 929 }
 930 EXPORT_SYMBOL_GPL(register_ftrace_event);
 931
 932 /*
 933  * Used by module code with the trace_event_sem held for write.
 934  */
 935 int __unregister_ftrace_event(struct trace_event *event)
 936 {
 937         hlist_del(&event->node);
 938         list_del(&event->list);
 939         return 0;
 940 }
 941
 942 /**
 943  * unregister_ftrace_event - remove a no longer used event
 944  * @event: the event to remove
 945  */
 946 int unregister_ftrace_event(struct trace_event *event)
 947 {
 948         down_write(&trace_event_sem);
 949         __unregister_ftrace_event(event);
 950         up_write(&trace_event_sem);
 951
 952         return 0;
 953 }
 954 EXPORT_SYMBOL_GPL(unregister_ftrace_event);
 955
 956 /*
 957  * Standard events
 958  */
 959
 960 enum print_line_t trace_nop_print(struct trace_iterator *iter, int flags,
 961                                   struct trace_event *event)
 962 {
 963         if (!trace_seq_printf(&iter->seq, "type: %d\n", iter->ent->type))
 964                 return TRACE_TYPE_PARTIAL_LINE;
 965
 966         return TRACE_TYPE_HANDLED;
 967 }
 968
 969 /* TRACE_FN */
 970 static enum print_line_t trace_fn_trace(struct trace_iterator *iter, int flags,
 971                                         struct trace_event *event)
 972 {
 973         struct ftrace_entry *field;
 974         struct trace_seq *s = &iter->seq;
 975
 976         trace_assign_type(field, iter->ent);
 977
 978         if (!seq_print_ip_sym(s, field->ip, flags))
 979                 goto partial;
 980
 981         if ((flags & TRACE_ITER_PRINT_PARENT) && field->parent_ip) {
 982                 if (!trace_seq_puts(s, " <-"))
 983                         goto partial;
 984                 if (!seq_print_ip_sym(s,
 985                                       field->parent_ip,
 986                                       flags))
 987                         goto partial;
 988         }
 989         if (!trace_seq_putc(s, '\n'))
 990                 goto partial;
 991
 992         return TRACE_TYPE_HANDLED;
 993
 994  partial:
 995         return TRACE_TYPE_PARTIAL_LINE;
 996 }
 997
 998 static enum print_line_t trace_fn_raw(struct trace_iterator *iter, int flags,
 999                                       struct trace_event *event)
1000 {
1001         struct ftrace_entry *field;
1002
1003         trace_assign_type(field, iter->ent);
1004
1005         if (!trace_seq_printf(&iter->seq, "%lx %lx\n",
1006                               field->ip,
1007                               field->parent_ip))
1008                 return TRACE_TYPE_PARTIAL_LINE;
1009
1010         return TRACE_TYPE_HANDLED;
1011 }
1012
1013 static enum print_line_t trace_fn_hex(struct trace_iterator *iter, int flags,
1014                                       struct trace_event *event)
1015 {
1016         struct ftrace_entry *field;
1017         struct trace_seq *s = &iter->seq;
1018
1019         trace_assign_type(field, iter->ent);
1020
1021         SEQ_PUT_HEX_FIELD_RET(s, field->ip);
1022         SEQ_PUT_HEX_FIELD_RET(s, field->parent_ip);
1023
1024         return TRACE_TYPE_HANDLED;
1025 }
1026
1027 static enum print_line_t trace_fn_bin(struct trace_iterator *iter, int flags,
1028                                       struct trace_event *event)
1029 {
1030         struct ftrace_entry *field;
1031         struct trace_seq *s = &iter->seq;
1032
1033         trace_assign_type(field, iter->ent);
1034
1035         SEQ_PUT_FIELD_RET(s, field->ip);
1036         SEQ_PUT_FIELD_RET(s, field->parent_ip);
1037
1038         return TRACE_TYPE_HANDLED;
1039 }
1040
1041 static struct trace_event_functions trace_fn_funcs = {
1042         .trace          = trace_fn_trace,
1043         .raw            = trace_fn_raw,
1044         .hex            = trace_fn_hex,
1045         .binary         = trace_fn_bin,
1046 };
1047
1048 static struct trace_event trace_fn_event = {
1049         .type           = TRACE_FN,
1050         .funcs          = &trace_fn_funcs,
1051 };
1052
1053 /* TRACE_CTX an TRACE_WAKE */
1054 static enum print_line_t trace_ctxwake_print(struct trace_iterator *iter,
1055                                              char *delim)
1056 {
1057         struct ctx_switch_entry *field;
1058         char comm[TASK_COMM_LEN];
1059         int S, T;
1060
1061
1062         trace_assign_type(field, iter->ent);
1063
1064         T = task_state_char(field->next_state);
1065         S = task_state_char(field->prev_state);
1066         trace_find_cmdline(field->next_pid, comm);
1067         if (!trace_seq_printf(&iter->seq,
1068                               " %5d:%3d:%c %s [%03d] %5d:%3d:%c %s\n",
1069                               field->prev_pid,
1070                               field->prev_prio,
1071                               S, delim,
1072                               field->next_cpu,
1073                               field->next_pid,
1074                               field->next_prio,
1075                               T, comm))
1076                 return TRACE_TYPE_PARTIAL_LINE;
1077
1078         return TRACE_TYPE_HANDLED;
1079 }
1080
1081 static enum print_line_t trace_ctx_print(struct trace_iterator *iter, int flags,
1082                                          struct trace_event *event)
1083 {
1084         return trace_ctxwake_print(iter, "==>");
1085 }
1086
1087 static enum print_line_t trace_wake_print(struct trace_iterator *iter,
1088                                           int flags, struct trace_event *event)
1089 {
1090         return trace_ctxwake_print(iter, "  +");
1091 }
1092
1093 static int trace_ctxwake_raw(struct trace_iterator *iter, char S)
1094 {
1095         struct ctx_switch_entry *field;
1096         int T;
1097
1098         trace_assign_type(field, iter->ent);
1099
1100         if (!S)
1101                 S = task_state_char(field->prev_state);
1102         T = task_state_char(field->next_state);
1103         if (!trace_seq_printf(&iter->seq, "%d %d %c %d %d %d %c\n",
1104                               field->prev_pid,
1105                               field->prev_prio,
1106                               S,
1107                               field->next_cpu,
1108                               field->next_pid,
1109                               field->next_prio,
1110                               T))
1111                 return TRACE_TYPE_PARTIAL_LINE;
1112
1113         return TRACE_TYPE_HANDLED;
1114 }
1115
1116 static enum print_line_t trace_ctx_raw(struct trace_iterator *iter, int flags,
1117                                        struct trace_event *event)
1118 {
1119         return trace_ctxwake_raw(iter, 0);
1120 }
1121
1122 static enum print_line_t trace_wake_raw(struct trace_iterator *iter, int flags,
1123                                         struct trace_event *event)
1124 {
1125         return trace_ctxwake_raw(iter, '+');
1126 }
1127
1128
1129 static int trace_ctxwake_hex(struct trace_iterator *iter, char S)
1130 {
1131         struct ctx_switch_entry *field;
1132         struct trace_seq *s = &iter->seq;
1133         int T;
1134
1135         trace_assign_type(field, iter->ent);
1136
1137         if (!S)
1138                 S = task_state_char(field->prev_state);
1139         T = task_state_char(field->next_state);
1140
1141         SEQ_PUT_HEX_FIELD_RET(s, field->prev_pid);
1142         SEQ_PUT_HEX_FIELD_RET(s, field->prev_prio);
1143         SEQ_PUT_HEX_FIELD_RET(s, S);
1144         SEQ_PUT_HEX_FIELD_RET(s, field->next_cpu);
1145         SEQ_PUT_HEX_FIELD_RET(s, field->next_pid);
1146         SEQ_PUT_HEX_FIELD_RET(s, field->next_prio);
1147         SEQ_PUT_HEX_FIELD_RET(s, T);
1148
1149         return TRACE_TYPE_HANDLED;
1150 }
1151
1152 static enum print_line_t trace_ctx_hex(struct trace_iterator *iter, int flags,
1153                                        struct trace_event *event)
1154 {
1155         return trace_ctxwake_hex(iter, 0);
1156 }
1157
1158 static enum print_line_t trace_wake_hex(struct trace_iterator *iter, int flags,
1159                                         struct trace_event *event)
1160 {
1161         return trace_ctxwake_hex(iter, '+');
1162 }
1163
1164 static enum print_line_t trace_ctxwake_bin(struct trace_iterator *iter,
1165                                            int flags, struct trace_event *event)
1166 {
1167         struct ctx_switch_entry *field;
1168         struct trace_seq *s = &iter->seq;
1169
1170         trace_assign_type(field, iter->ent);
1171
1172         SEQ_PUT_FIELD_RET(s, field->prev_pid);
1173         SEQ_PUT_FIELD_RET(s, field->prev_prio);
1174         SEQ_PUT_FIELD_RET(s, field->prev_state);
1175         SEQ_PUT_FIELD_RET(s, field->next_pid);
1176         SEQ_PUT_FIELD_RET(s, field->next_prio);
1177         SEQ_PUT_FIELD_RET(s, field->next_state);
1178
1179         return TRACE_TYPE_HANDLED;
1180 }
1181
1182 static struct trace_event_functions trace_ctx_funcs = {
1183         .trace          = trace_ctx_print,
1184         .raw            = trace_ctx_raw,
1185         .hex            = trace_ctx_hex,
1186         .binary         = trace_ctxwake_bin,
1187 };
1188
1189 static struct trace_event trace_ctx_event = {
1190         .type           = TRACE_CTX,
1191         .funcs          = &trace_ctx_funcs,
1192 };
1193
1194 static struct trace_event_functions trace_wake_funcs = {
1195         .trace          = trace_wake_print,
1196         .raw            = trace_wake_raw,
1197         .hex            = trace_wake_hex,
1198         .binary         = trace_ctxwake_bin,
1199 };
1200
1201 static struct trace_event trace_wake_event = {
1202         .type           = TRACE_WAKE,
1203         .funcs          = &trace_wake_funcs,
1204 };
1205
1206 /* TRACE_STACK */
1207
1208 static enum print_line_t trace_stack_print(struct trace_iterator *iter,
1209                                            int flags, struct trace_event *event)
1210 {
1211         struct stack_entry *field;
1212         struct trace_seq *s = &iter->seq;
1213         unsigned long *p;
1214         unsigned long *end;
1215
1216         trace_assign_type(field, iter->ent);
1217         end = (unsigned long *)((long)iter->ent + iter->ent_size);
1218
1219         if (!trace_seq_puts(s, "<stack trace>\n"))
1220                 goto partial;
1221
1222         for (p = field->caller; p && *p != ULONG_MAX && p < end; p++) {
1223                 if (!trace_seq_puts(s, " => "))
1224                         goto partial;
1225
1226                 if (!seq_print_ip_sym(s, *p, flags))
1227                         goto partial;
1228                 if (!trace_seq_putc(s, '\n'))
1229                         goto partial;
1230         }
1231
1232         return TRACE_TYPE_HANDLED;
1233
1234  partial:
1235         return TRACE_TYPE_PARTIAL_LINE;
1236 }
1237
1238 static struct trace_event_functions trace_stack_funcs = {
1239         .trace          = trace_stack_print,
1240 };
1241
1242 static struct trace_event trace_stack_event = {
1243         .type           = TRACE_STACK,
1244         .funcs          = &trace_stack_funcs,
1245 };
1246
1247 /* TRACE_USER_STACK */
1248 static enum print_line_t trace_user_stack_print(struct trace_iterator *iter,
1249                                                 int flags, struct trace_event *event)
1250 {
1251         struct userstack_entry *field;
1252         struct trace_seq *s = &iter->seq;
1253
1254         trace_assign_type(field, iter->ent);
1255
1256         if (!trace_seq_puts(s, "<user stack trace>\n"))
1257                 goto partial;
1258
1259         if (!seq_print_userip_objs(field, s, flags))
1260                 goto partial;
1261
1262         return TRACE_TYPE_HANDLED;
1263
1264  partial:
1265         return TRACE_TYPE_PARTIAL_LINE;
1266 }
1267
1268 static struct trace_event_functions trace_user_stack_funcs = {
1269         .trace          = trace_user_stack_print,
1270 };
1271
1272 static struct trace_event trace_user_stack_event = {
1273         .type           = TRACE_USER_STACK,
1274         .funcs          = &trace_user_stack_funcs,
1275 };
1276
1277 /* TRACE_BPUTS */
1278 static enum print_line_t
1279 trace_bputs_print(struct trace_iterator *iter, int flags,
1280                    struct trace_event *event)
1281 {
1282         struct trace_entry *entry = iter->ent;
1283         struct trace_seq *s = &iter->seq;
1284         struct bputs_entry *field;
1285
1286         trace_assign_type(field, entry);
1287
1288         if (!seq_print_ip_sym(s, field->ip, flags))
1289                 goto partial;
1290
1291         if (!trace_seq_puts(s, ": "))
1292                 goto partial;
1293
1294         if (!trace_seq_puts(s, field->str))
1295                 goto partial;
1296
1297         return TRACE_TYPE_HANDLED;
1298
1299  partial:
1300         return TRACE_TYPE_PARTIAL_LINE;
1301 }
1302
1303
1304 static enum print_line_t
1305 trace_bputs_raw(struct trace_iterator *iter, int flags,
1306                 struct trace_event *event)
1307 {
1308         struct bputs_entry *field;
1309         struct trace_seq *s = &iter->seq;
1310
1311         trace_assign_type(field, iter->ent);
1312
1313         if (!trace_seq_printf(s, ": %lx : ", field->ip))
1314                 goto partial;
1315
1316         if (!trace_seq_puts(s, field->str))
1317                 goto partial;
1318
1319         return TRACE_TYPE_HANDLED;
1320
1321  partial:
1322         return TRACE_TYPE_PARTIAL_LINE;
1323 }
1324
1325 static struct trace_event_functions trace_bputs_funcs = {
1326         .trace          = trace_bputs_print,
1327         .raw            = trace_bputs_raw,
1328 };
1329
1330 static struct trace_event trace_bputs_event = {
1331         .type           = TRACE_BPUTS,
1332         .funcs          = &trace_bputs_funcs,
1333 };
1334
1335 /* TRACE_BPRINT */
1336 static enum print_line_t
1337 trace_bprint_print(struct trace_iterator *iter, int flags,
1338                    struct trace_event *event)
1339 {
1340         struct trace_entry *entry = iter->ent;
1341         struct trace_seq *s = &iter->seq;
1342         struct bprint_entry *field;
1343
1344         trace_assign_type(field, entry);
1345
1346         if (!seq_print_ip_sym(s, field->ip, flags))
1347                 goto partial;
1348
1349         if (!trace_seq_puts(s, ": "))
1350                 goto partial;
1351
1352         if (!trace_seq_bprintf(s, field->fmt, field->buf))
1353                 goto partial;
1354
1355         return TRACE_TYPE_HANDLED;
1356
1357  partial:
1358         return TRACE_TYPE_PARTIAL_LINE;
1359 }
1360
1361
1362 static enum print_line_t
1363 trace_bprint_raw(struct trace_iterator *iter, int flags,
1364                  struct trace_event *event)
1365 {
1366         struct bprint_entry *field;
1367         struct trace_seq *s = &iter->seq;
1368
1369         trace_assign_type(field, iter->ent);
1370
1371         if (!trace_seq_printf(s, ": %lx : ", field->ip))
1372                 goto partial;
1373
1374         if (!trace_seq_bprintf(s, field->fmt, field->buf))
1375                 goto partial;
1376
1377         return TRACE_TYPE_HANDLED;
1378
1379  partial:
1380         return TRACE_TYPE_PARTIAL_LINE;
1381 }
1382
1383 static struct trace_event_functions trace_bprint_funcs = {
1384         .trace          = trace_bprint_print,
1385         .raw            = trace_bprint_raw,
1386 };
1387
1388 static struct trace_event trace_bprint_event = {
1389         .type           = TRACE_BPRINT,
1390         .funcs          = &trace_bprint_funcs,
1391 };
1392
1393 /* TRACE_PRINT */
1394 static enum print_line_t trace_print_print(struct trace_iterator *iter,
1395                                            int flags, struct trace_event *event)
1396 {
1397         struct print_entry *field;
1398         struct trace_seq *s = &iter->seq;
1399
1400         trace_assign_type(field, iter->ent);
1401
1402         if (!seq_print_ip_sym(s, field->ip, flags))
1403                 goto partial;
1404
1405         if (!trace_seq_printf(s, ": %s", field->buf))
1406                 goto partial;
1407
1408         return TRACE_TYPE_HANDLED;
1409
1410  partial:
1411         return TRACE_TYPE_PARTIAL_LINE;
1412 }
1413
1414 static enum print_line_t trace_print_raw(struct trace_iterator *iter, int flags,
1415                                          struct trace_event *event)
1416 {
1417         struct print_entry *field;
1418
1419         trace_assign_type(field, iter->ent);
1420
1421         if (!trace_seq_printf(&iter->seq, "# %lx %s", field->ip, field->buf))
1422                 goto partial;
1423
1424         return TRACE_TYPE_HANDLED;
1425
1426  partial:
1427         return TRACE_TYPE_PARTIAL_LINE;
1428 }
1429
1430 static struct trace_event_functions trace_print_funcs = {
1431         .trace          = trace_print_print,
1432         .raw            = trace_print_raw,
1433 };
1434
1435 static struct trace_event trace_print_event = {
1436         .type           = TRACE_PRINT,
1437         .funcs          = &trace_print_funcs,
1438 };
1439
1440
1441 static struct trace_event *events[] __initdata = {
1442         &trace_fn_event,
1443         &trace_ctx_event,
1444         &trace_wake_event,
1445         &trace_stack_event,
1446         &trace_user_stack_event,
1447         &trace_bputs_event,
1448         &trace_bprint_event,
1449         &trace_print_event,
1450         NULL
1451 };
1452
1453 __init static int init_events(void)
1454 {
1455         struct trace_event *event;
1456         int i, ret;
1457
1458         for (i = 0; events[i]; i++) {
1459                 event = events[i];
1460
1461                 ret = register_ftrace_event(event);
1462                 if (!ret) {
1463                         printk(KERN_WARNING "event %d failed to register\n",
1464                                event->type);
1465                         WARN_ON_ONCE(1);
1466                 }
1467         }
1468
1469         return 0;
1470 }
1471 early_initcall(init_events);