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 static int ftrace_output_raw(struct trace_iterator *iter, char *name,
 443                              char *fmt, va_list ap)
 444 {
 445         struct trace_seq *s = &iter->seq;
 446         int ret;
 447
 448         ret = trace_seq_printf(s, "%s: ", name);
 449         if (!ret)
 450                 return TRACE_TYPE_PARTIAL_LINE;
 451
 452         ret = trace_seq_vprintf(s, fmt, ap);
 453
 454         if (!ret)
 455                 return TRACE_TYPE_PARTIAL_LINE;
 456
 457         return TRACE_TYPE_HANDLED;
 458 }
 459
 460 int ftrace_output_call(struct trace_iterator *iter, char *name, char *fmt, ...)
 461 {
 462         va_list ap;
 463         int ret;
 464
 465         va_start(ap, fmt);
 466         ret = ftrace_output_raw(iter, name, fmt, ap);
 467         va_end(ap);
 468
 469         return ret;
 470 }
 471 EXPORT_SYMBOL_GPL(ftrace_output_call);
 472
 473 #ifdef CONFIG_KRETPROBES
 474 static inline const char *kretprobed(const char *name)
 475 {
 476         static const char tramp_name[] = "kretprobe_trampoline";
 477         int size = sizeof(tramp_name);
 478
 479         if (strncmp(tramp_name, name, size) == 0)
 480                 return "[unknown/kretprobe'd]";
 481         return name;
 482 }
 483 #else
 484 static inline const char *kretprobed(const char *name)
 485 {
 486         return name;
 487 }
 488 #endif /* CONFIG_KRETPROBES */
 489
 490 static int
 491 seq_print_sym_short(struct trace_seq *s, const char *fmt, unsigned long address)
 492 {
 493 #ifdef CONFIG_KALLSYMS
 494         char str[KSYM_SYMBOL_LEN];
 495         const char *name;
 496
 497         kallsyms_lookup(address, NULL, NULL, NULL, str);
 498
 499         name = kretprobed(str);
 500
 501         return trace_seq_printf(s, fmt, name);
 502 #endif
 503         return 1;
 504 }
 505
 506 static int
 507 seq_print_sym_offset(struct trace_seq *s, const char *fmt,
 508                      unsigned long address)
 509 {
 510 #ifdef CONFIG_KALLSYMS
 511         char str[KSYM_SYMBOL_LEN];
 512         const char *name;
 513
 514         sprint_symbol(str, address);
 515         name = kretprobed(str);
 516
 517         return trace_seq_printf(s, fmt, name);
 518 #endif
 519         return 1;
 520 }
 521
 522 #ifndef CONFIG_64BIT
 523 # define IP_FMT "%08lx"
 524 #else
 525 # define IP_FMT "%016lx"
 526 #endif
 527
 528 int seq_print_user_ip(struct trace_seq *s, struct mm_struct *mm,
 529                       unsigned long ip, unsigned long sym_flags)
 530 {
 531         struct file *file = NULL;
 532         unsigned long vmstart = 0;
 533         int ret = 1;
 534
 535         if (s->full)
 536                 return 0;
 537
 538         if (mm) {
 539                 const struct vm_area_struct *vma;
 540
 541                 down_read(&mm->mmap_sem);
 542                 vma = find_vma(mm, ip);
 543                 if (vma) {
 544                         file = vma->vm_file;
 545                         vmstart = vma->vm_start;
 546                 }
 547                 if (file) {
 548                         ret = trace_seq_path(s, &file->f_path);
 549                         if (ret)
 550                                 ret = trace_seq_printf(s, "[+0x%lx]",
 551                                                        ip - vmstart);
 552                 }
 553                 up_read(&mm->mmap_sem);
 554         }
 555         if (ret && ((sym_flags & TRACE_ITER_SYM_ADDR) || !file))
 556                 ret = trace_seq_printf(s, " <" IP_FMT ">", ip);
 557         return ret;
 558 }
 559
 560 int
 561 seq_print_userip_objs(const struct userstack_entry *entry, struct trace_seq *s,
 562                       unsigned long sym_flags)
 563 {
 564         struct mm_struct *mm = NULL;
 565         int ret = 1;
 566         unsigned int i;
 567
 568         if (trace_flags & TRACE_ITER_SYM_USEROBJ) {
 569                 struct task_struct *task;
 570                 /*
 571                  * we do the lookup on the thread group leader,
 572                  * since individual threads might have already quit!
 573                  */
 574                 rcu_read_lock();
 575                 task = find_task_by_vpid(entry->tgid);
 576                 if (task)
 577                         mm = get_task_mm(task);
 578                 rcu_read_unlock();
 579         }
 580
 581         for (i = 0; i < FTRACE_STACK_ENTRIES; i++) {
 582                 unsigned long ip = entry->caller[i];
 583
 584                 if (ip == ULONG_MAX || !ret)
 585                         break;
 586                 if (ret)
 587                         ret = trace_seq_puts(s, " => ");
 588                 if (!ip) {
 589                         if (ret)
 590                                 ret = trace_seq_puts(s, "??");
 591                         if (ret)
 592                                 ret = trace_seq_putc(s, '\n');
 593                         continue;
 594                 }
 595                 if (!ret)
 596                         break;
 597                 if (ret)
 598                         ret = seq_print_user_ip(s, mm, ip, sym_flags);
 599                 ret = trace_seq_putc(s, '\n');
 600         }
 601
 602         if (mm)
 603                 mmput(mm);
 604         return ret;
 605 }
 606
 607 int
 608 seq_print_ip_sym(struct trace_seq *s, unsigned long ip, unsigned long sym_flags)
 609 {
 610         int ret;
 611
 612         if (!ip)
 613                 return trace_seq_putc(s, '0');
 614
 615         if (sym_flags & TRACE_ITER_SYM_OFFSET)
 616                 ret = seq_print_sym_offset(s, "%s", ip);
 617         else
 618                 ret = seq_print_sym_short(s, "%s", ip);
 619
 620         if (!ret)
 621                 return 0;
 622
 623         if (sym_flags & TRACE_ITER_SYM_ADDR)
 624                 ret = trace_seq_printf(s, " <" IP_FMT ">", ip);
 625         return ret;
 626 }
 627
 628 /**
 629  * trace_print_lat_fmt - print the irq, preempt and lockdep fields
 630  * @s: trace seq struct to write to
 631  * @entry: The trace entry field from the ring buffer
 632  *
 633  * Prints the generic fields of irqs off, in hard or softirq, preempt
 634  * count.
 635  */
 636 int trace_print_lat_fmt(struct trace_seq *s, struct trace_entry *entry)
 637 {
 638         char hardsoft_irq;
 639         char need_resched;
 640         char irqs_off;
 641         int hardirq;
 642         int softirq;
 643         int ret;
 644
 645         hardirq = entry->flags & TRACE_FLAG_HARDIRQ;
 646         softirq = entry->flags & TRACE_FLAG_SOFTIRQ;
 647
 648         irqs_off =
 649                 (entry->flags & TRACE_FLAG_IRQS_OFF) ? 'd' :
 650                 (entry->flags & TRACE_FLAG_IRQS_NOSUPPORT) ? 'X' :
 651                 '.';
 652
 653         switch (entry->flags & (TRACE_FLAG_NEED_RESCHED |
 654                                 TRACE_FLAG_PREEMPT_RESCHED)) {
 655         case TRACE_FLAG_NEED_RESCHED | TRACE_FLAG_PREEMPT_RESCHED:
 656                 need_resched = 'N';
 657                 break;
 658         case TRACE_FLAG_NEED_RESCHED:
 659                 need_resched = 'n';
 660                 break;
 661         case TRACE_FLAG_PREEMPT_RESCHED:
 662                 need_resched = 'p';
 663                 break;
 664         default:
 665                 need_resched = '.';
 666                 break;
 667         }
 668
 669         hardsoft_irq =
 670                 (hardirq && softirq) ? 'H' :
 671                 hardirq ? 'h' :
 672                 softirq ? 's' :
 673                 '.';
 674
 675         if (!trace_seq_printf(s, "%c%c%c",
 676                               irqs_off, need_resched, hardsoft_irq))
 677                 return 0;
 678
 679         if (entry->preempt_count)
 680                 ret = trace_seq_printf(s, "%x", entry->preempt_count);
 681         else
 682                 ret = trace_seq_putc(s, '.');
 683
 684         return ret;
 685 }
 686
 687 static int
 688 lat_print_generic(struct trace_seq *s, struct trace_entry *entry, int cpu)
 689 {
 690         char comm[TASK_COMM_LEN];
 691
 692         trace_find_cmdline(entry->pid, comm);
 693
 694         if (!trace_seq_printf(s, "%8.8s-%-5d %3d",
 695                               comm, entry->pid, cpu))
 696                 return 0;
 697
 698         return trace_print_lat_fmt(s, entry);
 699 }
 700
 701 static unsigned long preempt_mark_thresh_us = 100;
 702
 703 static int
 704 lat_print_timestamp(struct trace_iterator *iter, u64 next_ts)
 705 {
 706         unsigned long verbose = trace_flags & TRACE_ITER_VERBOSE;
 707         unsigned long in_ns = iter->iter_flags & TRACE_FILE_TIME_IN_NS;
 708         unsigned long long abs_ts = iter->ts - iter->trace_buffer->time_start;
 709         unsigned long long rel_ts = next_ts - iter->ts;
 710         struct trace_seq *s = &iter->seq;
 711
 712         if (in_ns) {
 713                 abs_ts = ns2usecs(abs_ts);
 714                 rel_ts = ns2usecs(rel_ts);
 715         }
 716
 717         if (verbose && in_ns) {
 718                 unsigned long abs_usec = do_div(abs_ts, USEC_PER_MSEC);
 719                 unsigned long abs_msec = (unsigned long)abs_ts;
 720                 unsigned long rel_usec = do_div(rel_ts, USEC_PER_MSEC);
 721                 unsigned long rel_msec = (unsigned long)rel_ts;
 722
 723                 return trace_seq_printf(
 724                                 s, "[%08llx] %ld.%03ldms (+%ld.%03ldms): ",
 725                                 ns2usecs(iter->ts),
 726                                 abs_msec, abs_usec,
 727                                 rel_msec, rel_usec);
 728         } else if (verbose && !in_ns) {
 729                 return trace_seq_printf(
 730                                 s, "[%016llx] %lld (+%lld): ",
 731                                 iter->ts, abs_ts, rel_ts);
 732         } else if (!verbose && in_ns) {
 733                 return trace_seq_printf(
 734                                 s, " %4lldus%c: ",
 735                                 abs_ts,
 736                                 rel_ts > preempt_mark_thresh_us ? '!' :
 737                                   rel_ts > 1 ? '+' : ' ');
 738         } else { /* !verbose && !in_ns */
 739                 return trace_seq_printf(s, " %4lld: ", abs_ts);
 740         }
 741 }
 742
 743 int trace_print_context(struct trace_iterator *iter)
 744 {
 745         struct trace_seq *s = &iter->seq;
 746         struct trace_entry *entry = iter->ent;
 747         unsigned long long t;
 748         unsigned long secs, usec_rem;
 749         char comm[TASK_COMM_LEN];
 750         int ret;
 751
 752         trace_find_cmdline(entry->pid, comm);
 753
 754         ret = trace_seq_printf(s, "%16s-%-5d [%03d] ",
 755                                comm, entry->pid, iter->cpu);
 756         if (!ret)
 757                 return 0;
 758
 759         if (trace_flags & TRACE_ITER_IRQ_INFO) {
 760                 ret = trace_print_lat_fmt(s, entry);
 761                 if (!ret)
 762                         return 0;
 763         }
 764
 765         if (iter->iter_flags & TRACE_FILE_TIME_IN_NS) {
 766                 t = ns2usecs(iter->ts);
 767                 usec_rem = do_div(t, USEC_PER_SEC);
 768                 secs = (unsigned long)t;
 769                 return trace_seq_printf(s, " %5lu.%06lu: ", secs, usec_rem);
 770         } else
 771                 return trace_seq_printf(s, " %12llu: ", iter->ts);
 772 }
 773
 774 int trace_print_lat_context(struct trace_iterator *iter)
 775 {
 776         u64 next_ts;
 777         int ret;
 778         /* trace_find_next_entry will reset ent_size */
 779         int ent_size = iter->ent_size;
 780         struct trace_seq *s = &iter->seq;
 781         struct trace_entry *entry = iter->ent,
 782                            *next_entry = trace_find_next_entry(iter, NULL,
 783                                                                &next_ts);
 784         unsigned long verbose = (trace_flags & TRACE_ITER_VERBOSE);
 785
 786         /* Restore the original ent_size */
 787         iter->ent_size = ent_size;
 788
 789         if (!next_entry)
 790                 next_ts = iter->ts;
 791
 792         if (verbose) {
 793                 char comm[TASK_COMM_LEN];
 794
 795                 trace_find_cmdline(entry->pid, comm);
 796
 797                 ret = trace_seq_printf(
 798                                 s, "%16s %5d %3d %d %08x %08lx ",
 799                                 comm, entry->pid, iter->cpu, entry->flags,
 800                                 entry->preempt_count, iter->idx);
 801         } else {
 802                 ret = lat_print_generic(s, entry, iter->cpu);
 803         }
 804
 805         if (ret)
 806                 ret = lat_print_timestamp(iter, next_ts);
 807
 808         return ret;
 809 }
 810
 811 static const char state_to_char[] = TASK_STATE_TO_CHAR_STR;
 812
 813 static int task_state_char(unsigned long state)
 814 {
 815         int bit = state ? __ffs(state) + 1 : 0;
 816
 817         return bit < sizeof(state_to_char) - 1 ? state_to_char[bit] : '?';
 818 }
 819
 820 /**
 821  * ftrace_find_event - find a registered event
 822  * @type: the type of event to look for
 823  *
 824  * Returns an event of type @type otherwise NULL
 825  * Called with trace_event_read_lock() held.
 826  */
 827 struct trace_event *ftrace_find_event(int type)
 828 {
 829         struct trace_event *event;
 830         unsigned key;
 831
 832         key = type & (EVENT_HASHSIZE - 1);
 833
 834         hlist_for_each_entry(event, &event_hash[key], node) {
 835                 if (event->type == type)
 836                         return event;
 837         }
 838
 839         return NULL;
 840 }
 841
 842 static LIST_HEAD(ftrace_event_list);
 843
 844 static int trace_search_list(struct list_head **list)
 845 {
 846         struct trace_event *e;
 847         int last = __TRACE_LAST_TYPE;
 848
 849         if (list_empty(&ftrace_event_list)) {
 850                 *list = &ftrace_event_list;
 851                 return last + 1;
 852         }
 853
 854         /*
 855          * We used up all possible max events,
 856          * lets see if somebody freed one.
 857          */
 858         list_for_each_entry(e, &ftrace_event_list, list) {
 859                 if (e->type != last + 1)
 860                         break;
 861                 last++;
 862         }
 863
 864         /* Did we used up all 65 thousand events??? */
 865         if ((last + 1) > FTRACE_MAX_EVENT)
 866                 return 0;
 867
 868         *list = &e->list;
 869         return last + 1;
 870 }
 871
 872 void trace_event_read_lock(void)
 873 {
 874         down_read(&trace_event_sem);
 875 }
 876
 877 void trace_event_read_unlock(void)
 878 {
 879         up_read(&trace_event_sem);
 880 }
 881
 882 /**
 883  * register_ftrace_event - register output for an event type
 884  * @event: the event type to register
 885  *
 886  * Event types are stored in a hash and this hash is used to
 887  * find a way to print an event. If the @event->type is set
 888  * then it will use that type, otherwise it will assign a
 889  * type to use.
 890  *
 891  * If you assign your own type, please make sure it is added
 892  * to the trace_type enum in trace.h, to avoid collisions
 893  * with the dynamic types.
 894  *
 895  * Returns the event type number or zero on error.
 896  */
 897 int register_ftrace_event(struct trace_event *event)
 898 {
 899         unsigned key;
 900         int ret = 0;
 901
 902         down_write(&trace_event_sem);
 903
 904         if (WARN_ON(!event))
 905                 goto out;
 906
 907         if (WARN_ON(!event->funcs))
 908                 goto out;
 909
 910         INIT_LIST_HEAD(&event->list);
 911
 912         if (!event->type) {
 913                 struct list_head *list = NULL;
 914
 915                 if (next_event_type > FTRACE_MAX_EVENT) {
 916
 917                         event->type = trace_search_list(&list);
 918                         if (!event->type)
 919                                 goto out;
 920
 921                 } else {
 922
 923                         event->type = next_event_type++;
 924                         list = &ftrace_event_list;
 925                 }
 926
 927                 if (WARN_ON(ftrace_find_event(event->type)))
 928                         goto out;
 929
 930                 list_add_tail(&event->list, list);
 931
 932         } else if (event->type > __TRACE_LAST_TYPE) {
 933                 printk(KERN_WARNING "Need to add type to trace.h\n");
 934                 WARN_ON(1);
 935                 goto out;
 936         } else {
 937                 /* Is this event already used */
 938                 if (ftrace_find_event(event->type))
 939                         goto out;
 940         }
 941
 942         if (event->funcs->trace == NULL)
 943                 event->funcs->trace = trace_nop_print;
 944         if (event->funcs->raw == NULL)
 945                 event->funcs->raw = trace_nop_print;
 946         if (event->funcs->hex == NULL)
 947                 event->funcs->hex = trace_nop_print;
 948         if (event->funcs->binary == NULL)
 949                 event->funcs->binary = trace_nop_print;
 950
 951         key = event->type & (EVENT_HASHSIZE - 1);
 952
 953         hlist_add_head(&event->node, &event_hash[key]);
 954
 955         ret = event->type;
 956  out:
 957         up_write(&trace_event_sem);
 958
 959         return ret;
 960 }
 961 EXPORT_SYMBOL_GPL(register_ftrace_event);
 962
 963 /*
 964  * Used by module code with the trace_event_sem held for write.
 965  */
 966 int __unregister_ftrace_event(struct trace_event *event)
 967 {
 968         hlist_del(&event->node);
 969         list_del(&event->list);
 970         return 0;
 971 }
 972
 973 /**
 974  * unregister_ftrace_event - remove a no longer used event
 975  * @event: the event to remove
 976  */
 977 int unregister_ftrace_event(struct trace_event *event)
 978 {
 979         down_write(&trace_event_sem);
 980         __unregister_ftrace_event(event);
 981         up_write(&trace_event_sem);
 982
 983         return 0;
 984 }
 985 EXPORT_SYMBOL_GPL(unregister_ftrace_event);
 986
 987 /*
 988  * Standard events
 989  */
 990
 991 enum print_line_t trace_nop_print(struct trace_iterator *iter, int flags,
 992                                   struct trace_event *event)
 993 {
 994         if (!trace_seq_printf(&iter->seq, "type: %d\n", iter->ent->type))
 995                 return TRACE_TYPE_PARTIAL_LINE;
 996
 997         return TRACE_TYPE_HANDLED;
 998 }
 999
1000 /* TRACE_FN */
1001 static enum print_line_t trace_fn_trace(struct trace_iterator *iter, int flags,
1002                                         struct trace_event *event)
1003 {
1004         struct ftrace_entry *field;
1005         struct trace_seq *s = &iter->seq;
1006
1007         trace_assign_type(field, iter->ent);
1008
1009         if (!seq_print_ip_sym(s, field->ip, flags))
1010                 goto partial;
1011
1012         if ((flags & TRACE_ITER_PRINT_PARENT) && field->parent_ip) {
1013                 if (!trace_seq_puts(s, " <-"))
1014                         goto partial;
1015                 if (!seq_print_ip_sym(s,
1016                                       field->parent_ip,
1017                                       flags))
1018                         goto partial;
1019         }
1020         if (!trace_seq_putc(s, '\n'))
1021                 goto partial;
1022
1023         return TRACE_TYPE_HANDLED;
1024
1025  partial:
1026         return TRACE_TYPE_PARTIAL_LINE;
1027 }
1028
1029 static enum print_line_t trace_fn_raw(struct trace_iterator *iter, int flags,
1030                                       struct trace_event *event)
1031 {
1032         struct ftrace_entry *field;
1033
1034         trace_assign_type(field, iter->ent);
1035
1036         if (!trace_seq_printf(&iter->seq, "%lx %lx\n",
1037                               field->ip,
1038                               field->parent_ip))
1039                 return TRACE_TYPE_PARTIAL_LINE;
1040
1041         return TRACE_TYPE_HANDLED;
1042 }
1043
1044 static enum print_line_t trace_fn_hex(struct trace_iterator *iter, int flags,
1045                                       struct trace_event *event)
1046 {
1047         struct ftrace_entry *field;
1048         struct trace_seq *s = &iter->seq;
1049
1050         trace_assign_type(field, iter->ent);
1051
1052         SEQ_PUT_HEX_FIELD_RET(s, field->ip);
1053         SEQ_PUT_HEX_FIELD_RET(s, field->parent_ip);
1054
1055         return TRACE_TYPE_HANDLED;
1056 }
1057
1058 static enum print_line_t trace_fn_bin(struct trace_iterator *iter, int flags,
1059                                       struct trace_event *event)
1060 {
1061         struct ftrace_entry *field;
1062         struct trace_seq *s = &iter->seq;
1063
1064         trace_assign_type(field, iter->ent);
1065
1066         SEQ_PUT_FIELD_RET(s, field->ip);
1067         SEQ_PUT_FIELD_RET(s, field->parent_ip);
1068
1069         return TRACE_TYPE_HANDLED;
1070 }
1071
1072 static struct trace_event_functions trace_fn_funcs = {
1073         .trace          = trace_fn_trace,
1074         .raw            = trace_fn_raw,
1075         .hex            = trace_fn_hex,
1076         .binary         = trace_fn_bin,
1077 };
1078
1079 static struct trace_event trace_fn_event = {
1080         .type           = TRACE_FN,
1081         .funcs          = &trace_fn_funcs,
1082 };
1083
1084 /* TRACE_CTX an TRACE_WAKE */
1085 static enum print_line_t trace_ctxwake_print(struct trace_iterator *iter,
1086                                              char *delim)
1087 {
1088         struct ctx_switch_entry *field;
1089         char comm[TASK_COMM_LEN];
1090         int S, T;
1091
1092
1093         trace_assign_type(field, iter->ent);
1094
1095         T = task_state_char(field->next_state);
1096         S = task_state_char(field->prev_state);
1097         trace_find_cmdline(field->next_pid, comm);
1098         if (!trace_seq_printf(&iter->seq,
1099                               " %5d:%3d:%c %s [%03d] %5d:%3d:%c %s\n",
1100                               field->prev_pid,
1101                               field->prev_prio,
1102                               S, delim,
1103                               field->next_cpu,
1104                               field->next_pid,
1105                               field->next_prio,
1106                               T, comm))
1107                 return TRACE_TYPE_PARTIAL_LINE;
1108
1109         return TRACE_TYPE_HANDLED;
1110 }
1111
1112 static enum print_line_t trace_ctx_print(struct trace_iterator *iter, int flags,
1113                                          struct trace_event *event)
1114 {
1115         return trace_ctxwake_print(iter, "==>");
1116 }
1117
1118 static enum print_line_t trace_wake_print(struct trace_iterator *iter,
1119                                           int flags, struct trace_event *event)
1120 {
1121         return trace_ctxwake_print(iter, "  +");
1122 }
1123
1124 static int trace_ctxwake_raw(struct trace_iterator *iter, char S)
1125 {
1126         struct ctx_switch_entry *field;
1127         int T;
1128
1129         trace_assign_type(field, iter->ent);
1130
1131         if (!S)
1132                 S = task_state_char(field->prev_state);
1133         T = task_state_char(field->next_state);
1134         if (!trace_seq_printf(&iter->seq, "%d %d %c %d %d %d %c\n",
1135                               field->prev_pid,
1136                               field->prev_prio,
1137                               S,
1138                               field->next_cpu,
1139                               field->next_pid,
1140                               field->next_prio,
1141                               T))
1142                 return TRACE_TYPE_PARTIAL_LINE;
1143
1144         return TRACE_TYPE_HANDLED;
1145 }
1146
1147 static enum print_line_t trace_ctx_raw(struct trace_iterator *iter, int flags,
1148                                        struct trace_event *event)
1149 {
1150         return trace_ctxwake_raw(iter, 0);
1151 }
1152
1153 static enum print_line_t trace_wake_raw(struct trace_iterator *iter, int flags,
1154                                         struct trace_event *event)
1155 {
1156         return trace_ctxwake_raw(iter, '+');
1157 }
1158
1159
1160 static int trace_ctxwake_hex(struct trace_iterator *iter, char S)
1161 {
1162         struct ctx_switch_entry *field;
1163         struct trace_seq *s = &iter->seq;
1164         int T;
1165
1166         trace_assign_type(field, iter->ent);
1167
1168         if (!S)
1169                 S = task_state_char(field->prev_state);
1170         T = task_state_char(field->next_state);
1171
1172         SEQ_PUT_HEX_FIELD_RET(s, field->prev_pid);
1173         SEQ_PUT_HEX_FIELD_RET(s, field->prev_prio);
1174         SEQ_PUT_HEX_FIELD_RET(s, S);
1175         SEQ_PUT_HEX_FIELD_RET(s, field->next_cpu);
1176         SEQ_PUT_HEX_FIELD_RET(s, field->next_pid);
1177         SEQ_PUT_HEX_FIELD_RET(s, field->next_prio);
1178         SEQ_PUT_HEX_FIELD_RET(s, T);
1179
1180         return TRACE_TYPE_HANDLED;
1181 }
1182
1183 static enum print_line_t trace_ctx_hex(struct trace_iterator *iter, int flags,
1184                                        struct trace_event *event)
1185 {
1186         return trace_ctxwake_hex(iter, 0);
1187 }
1188
1189 static enum print_line_t trace_wake_hex(struct trace_iterator *iter, int flags,
1190                                         struct trace_event *event)
1191 {
1192         return trace_ctxwake_hex(iter, '+');
1193 }
1194
1195 static enum print_line_t trace_ctxwake_bin(struct trace_iterator *iter,
1196                                            int flags, struct trace_event *event)
1197 {
1198         struct ctx_switch_entry *field;
1199         struct trace_seq *s = &iter->seq;
1200
1201         trace_assign_type(field, iter->ent);
1202
1203         SEQ_PUT_FIELD_RET(s, field->prev_pid);
1204         SEQ_PUT_FIELD_RET(s, field->prev_prio);
1205         SEQ_PUT_FIELD_RET(s, field->prev_state);
1206         SEQ_PUT_FIELD_RET(s, field->next_pid);
1207         SEQ_PUT_FIELD_RET(s, field->next_prio);
1208         SEQ_PUT_FIELD_RET(s, field->next_state);
1209
1210         return TRACE_TYPE_HANDLED;
1211 }
1212
1213 static struct trace_event_functions trace_ctx_funcs = {
1214         .trace          = trace_ctx_print,
1215         .raw            = trace_ctx_raw,
1216         .hex            = trace_ctx_hex,
1217         .binary         = trace_ctxwake_bin,
1218 };
1219
1220 static struct trace_event trace_ctx_event = {
1221         .type           = TRACE_CTX,
1222         .funcs          = &trace_ctx_funcs,
1223 };
1224
1225 static struct trace_event_functions trace_wake_funcs = {
1226         .trace          = trace_wake_print,
1227         .raw            = trace_wake_raw,
1228         .hex            = trace_wake_hex,
1229         .binary         = trace_ctxwake_bin,
1230 };
1231
1232 static struct trace_event trace_wake_event = {
1233         .type           = TRACE_WAKE,
1234         .funcs          = &trace_wake_funcs,
1235 };
1236
1237 /* TRACE_STACK */
1238
1239 static enum print_line_t trace_stack_print(struct trace_iterator *iter,
1240                                            int flags, struct trace_event *event)
1241 {
1242         struct stack_entry *field;
1243         struct trace_seq *s = &iter->seq;
1244         unsigned long *p;
1245         unsigned long *end;
1246
1247         trace_assign_type(field, iter->ent);
1248         end = (unsigned long *)((long)iter->ent + iter->ent_size);
1249
1250         if (!trace_seq_puts(s, "<stack trace>\n"))
1251                 goto partial;
1252
1253         for (p = field->caller; p && *p != ULONG_MAX && p < end; p++) {
1254                 if (!trace_seq_puts(s, " => "))
1255                         goto partial;
1256
1257                 if (!seq_print_ip_sym(s, *p, flags))
1258                         goto partial;
1259                 if (!trace_seq_putc(s, '\n'))
1260                         goto partial;
1261         }
1262
1263         return TRACE_TYPE_HANDLED;
1264
1265  partial:
1266         return TRACE_TYPE_PARTIAL_LINE;
1267 }
1268
1269 static struct trace_event_functions trace_stack_funcs = {
1270         .trace          = trace_stack_print,
1271 };
1272
1273 static struct trace_event trace_stack_event = {
1274         .type           = TRACE_STACK,
1275         .funcs          = &trace_stack_funcs,
1276 };
1277
1278 /* TRACE_USER_STACK */
1279 static enum print_line_t trace_user_stack_print(struct trace_iterator *iter,
1280                                                 int flags, struct trace_event *event)
1281 {
1282         struct userstack_entry *field;
1283         struct trace_seq *s = &iter->seq;
1284
1285         trace_assign_type(field, iter->ent);
1286
1287         if (!trace_seq_puts(s, "<user stack trace>\n"))
1288                 goto partial;
1289
1290         if (!seq_print_userip_objs(field, s, flags))
1291                 goto partial;
1292
1293         return TRACE_TYPE_HANDLED;
1294
1295  partial:
1296         return TRACE_TYPE_PARTIAL_LINE;
1297 }
1298
1299 static struct trace_event_functions trace_user_stack_funcs = {
1300         .trace          = trace_user_stack_print,
1301 };
1302
1303 static struct trace_event trace_user_stack_event = {
1304         .type           = TRACE_USER_STACK,
1305         .funcs          = &trace_user_stack_funcs,
1306 };
1307
1308 /* TRACE_BPUTS */
1309 static enum print_line_t
1310 trace_bputs_print(struct trace_iterator *iter, int flags,
1311                    struct trace_event *event)
1312 {
1313         struct trace_entry *entry = iter->ent;
1314         struct trace_seq *s = &iter->seq;
1315         struct bputs_entry *field;
1316
1317         trace_assign_type(field, entry);
1318
1319         if (!seq_print_ip_sym(s, field->ip, flags))
1320                 goto partial;
1321
1322         if (!trace_seq_puts(s, ": "))
1323                 goto partial;
1324
1325         if (!trace_seq_puts(s, field->str))
1326                 goto partial;
1327
1328         return TRACE_TYPE_HANDLED;
1329
1330  partial:
1331         return TRACE_TYPE_PARTIAL_LINE;
1332 }
1333
1334
1335 static enum print_line_t
1336 trace_bputs_raw(struct trace_iterator *iter, int flags,
1337                 struct trace_event *event)
1338 {
1339         struct bputs_entry *field;
1340         struct trace_seq *s = &iter->seq;
1341
1342         trace_assign_type(field, iter->ent);
1343
1344         if (!trace_seq_printf(s, ": %lx : ", field->ip))
1345                 goto partial;
1346
1347         if (!trace_seq_puts(s, field->str))
1348                 goto partial;
1349
1350         return TRACE_TYPE_HANDLED;
1351
1352  partial:
1353         return TRACE_TYPE_PARTIAL_LINE;
1354 }
1355
1356 static struct trace_event_functions trace_bputs_funcs = {
1357         .trace          = trace_bputs_print,
1358         .raw            = trace_bputs_raw,
1359 };
1360
1361 static struct trace_event trace_bputs_event = {
1362         .type           = TRACE_BPUTS,
1363         .funcs          = &trace_bputs_funcs,
1364 };
1365
1366 /* TRACE_BPRINT */
1367 static enum print_line_t
1368 trace_bprint_print(struct trace_iterator *iter, int flags,
1369                    struct trace_event *event)
1370 {
1371         struct trace_entry *entry = iter->ent;
1372         struct trace_seq *s = &iter->seq;
1373         struct bprint_entry *field;
1374
1375         trace_assign_type(field, entry);
1376
1377         if (!seq_print_ip_sym(s, field->ip, flags))
1378                 goto partial;
1379
1380         if (!trace_seq_puts(s, ": "))
1381                 goto partial;
1382
1383         if (!trace_seq_bprintf(s, field->fmt, field->buf))
1384                 goto partial;
1385
1386         return TRACE_TYPE_HANDLED;
1387
1388  partial:
1389         return TRACE_TYPE_PARTIAL_LINE;
1390 }
1391
1392
1393 static enum print_line_t
1394 trace_bprint_raw(struct trace_iterator *iter, int flags,
1395                  struct trace_event *event)
1396 {
1397         struct bprint_entry *field;
1398         struct trace_seq *s = &iter->seq;
1399
1400         trace_assign_type(field, iter->ent);
1401
1402         if (!trace_seq_printf(s, ": %lx : ", field->ip))
1403                 goto partial;
1404
1405         if (!trace_seq_bprintf(s, field->fmt, field->buf))
1406                 goto partial;
1407
1408         return TRACE_TYPE_HANDLED;
1409
1410  partial:
1411         return TRACE_TYPE_PARTIAL_LINE;
1412 }
1413
1414 static struct trace_event_functions trace_bprint_funcs = {
1415         .trace          = trace_bprint_print,
1416         .raw            = trace_bprint_raw,
1417 };
1418
1419 static struct trace_event trace_bprint_event = {
1420         .type           = TRACE_BPRINT,
1421         .funcs          = &trace_bprint_funcs,
1422 };
1423
1424 /* TRACE_PRINT */
1425 static enum print_line_t trace_print_print(struct trace_iterator *iter,
1426                                            int flags, struct trace_event *event)
1427 {
1428         struct print_entry *field;
1429         struct trace_seq *s = &iter->seq;
1430
1431         trace_assign_type(field, iter->ent);
1432
1433         if (!seq_print_ip_sym(s, field->ip, flags))
1434                 goto partial;
1435
1436         if (!trace_seq_printf(s, ": %s", field->buf))
1437                 goto partial;
1438
1439         return TRACE_TYPE_HANDLED;
1440
1441  partial:
1442         return TRACE_TYPE_PARTIAL_LINE;
1443 }
1444
1445 static enum print_line_t trace_print_raw(struct trace_iterator *iter, int flags,
1446                                          struct trace_event *event)
1447 {
1448         struct print_entry *field;
1449
1450         trace_assign_type(field, iter->ent);
1451
1452         if (!trace_seq_printf(&iter->seq, "# %lx %s", field->ip, field->buf))
1453                 goto partial;
1454
1455         return TRACE_TYPE_HANDLED;
1456
1457  partial:
1458         return TRACE_TYPE_PARTIAL_LINE;
1459 }
1460
1461 static struct trace_event_functions trace_print_funcs = {
1462         .trace          = trace_print_print,
1463         .raw            = trace_print_raw,
1464 };
1465
1466 static struct trace_event trace_print_event = {
1467         .type           = TRACE_PRINT,
1468         .funcs          = &trace_print_funcs,
1469 };
1470
1471
1472 static struct trace_event *events[] __initdata = {
1473         &trace_fn_event,
1474         &trace_ctx_event,
1475         &trace_wake_event,
1476         &trace_stack_event,
1477         &trace_user_stack_event,
1478         &trace_bputs_event,
1479         &trace_bprint_event,
1480         &trace_print_event,
1481         NULL
1482 };
1483
1484 __init static int init_events(void)
1485 {
1486         struct trace_event *event;
1487         int i, ret;
1488
1489         for (i = 0; events[i]; i++) {
1490                 event = events[i];
1491
1492                 ret = register_ftrace_event(event);
1493                 if (!ret) {
1494                         printk(KERN_WARNING "event %d failed to register\n",
1495                                event->type);
1496                         WARN_ON_ONCE(1);
1497                 }
1498         }
1499
1500         return 0;
1501 }
1502 early_initcall(init_events);