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