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, const 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, first = 1;
 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 (!first && delim)
 314                         trace_seq_puts(p, delim);
 315                 else
 316                         first = 0;
 317                 trace_seq_puts(p, str);
 318         }
 319
 320         /* check for left over flags */
 321         if (flags) {
 322                 if (!first && delim)
 323                         trace_seq_puts(p, delim);
 324                 trace_seq_printf(p, "0x%lx", flags);
 325         }
 326
 327         trace_seq_putc(p, 0);
 328
 329         return ret;
 330 }
 331 EXPORT_SYMBOL(ftrace_print_flags_seq);
 332
 333 const char *
 334 ftrace_print_symbols_seq(struct trace_seq *p, unsigned long val,
 335                          const struct trace_print_flags *symbol_array)
 336 {
 337         int i;
 338         const char *ret = p->buffer + p->len;
 339
 340         for (i = 0;  symbol_array[i].name; i++) {
 341
 342                 if (val != symbol_array[i].mask)
 343                         continue;
 344
 345                 trace_seq_puts(p, symbol_array[i].name);
 346                 break;
 347         }
 348
 349         if (ret == (const char *)(p->buffer + p->len))
 350                 trace_seq_printf(p, "0x%lx", val);
 351
 352         trace_seq_putc(p, 0);
 353
 354         return ret;
 355 }
 356 EXPORT_SYMBOL(ftrace_print_symbols_seq);
 357
 358 #if BITS_PER_LONG == 32
 359 const char *
 360 ftrace_print_symbols_seq_u64(struct trace_seq *p, unsigned long long val,
 361                          const struct trace_print_flags_u64 *symbol_array)
 362 {
 363         int i;
 364         const char *ret = p->buffer + p->len;
 365
 366         for (i = 0;  symbol_array[i].name; i++) {
 367
 368                 if (val != symbol_array[i].mask)
 369                         continue;
 370
 371                 trace_seq_puts(p, symbol_array[i].name);
 372                 break;
 373         }
 374
 375         if (ret == (const char *)(p->buffer + p->len))
 376                 trace_seq_printf(p, "0x%llx", val);
 377
 378         trace_seq_putc(p, 0);
 379
 380         return ret;
 381 }
 382 EXPORT_SYMBOL(ftrace_print_symbols_seq_u64);
 383 #endif
 384
 385 const char *
 386 ftrace_print_hex_seq(struct trace_seq *p, const unsigned char *buf, int buf_len)
 387 {
 388         int i;
 389         const char *ret = p->buffer + p->len;
 390
 391         for (i = 0; i < buf_len; i++)
 392                 trace_seq_printf(p, "%s%2.2x", i == 0 ? "" : " ", buf[i]);
 393
 394         trace_seq_putc(p, 0);
 395
 396         return ret;
 397 }
 398 EXPORT_SYMBOL(ftrace_print_hex_seq);
 399
 400 #ifdef CONFIG_KRETPROBES
 401 static inline const char *kretprobed(const char *name)
 402 {
 403         static const char tramp_name[] = "kretprobe_trampoline";
 404         int size = sizeof(tramp_name);
 405
 406         if (strncmp(tramp_name, name, size) == 0)
 407                 return "[unknown/kretprobe'd]";
 408         return name;
 409 }
 410 #else
 411 static inline const char *kretprobed(const char *name)
 412 {
 413         return name;
 414 }
 415 #endif /* CONFIG_KRETPROBES */
 416
 417 static int
 418 seq_print_sym_short(struct trace_seq *s, const char *fmt, unsigned long address)
 419 {
 420 #ifdef CONFIG_KALLSYMS
 421         char str[KSYM_SYMBOL_LEN];
 422         const char *name;
 423
 424         kallsyms_lookup(address, NULL, NULL, NULL, str);
 425
 426         name = kretprobed(str);
 427
 428         return trace_seq_printf(s, fmt, name);
 429 #endif
 430         return 1;
 431 }
 432
 433 static int
 434 seq_print_sym_offset(struct trace_seq *s, const char *fmt,
 435                      unsigned long address)
 436 {
 437 #ifdef CONFIG_KALLSYMS
 438         char str[KSYM_SYMBOL_LEN];
 439         const char *name;
 440
 441         sprint_symbol(str, address);
 442         name = kretprobed(str);
 443
 444         return trace_seq_printf(s, fmt, name);
 445 #endif
 446         return 1;
 447 }
 448
 449 #ifndef CONFIG_64BIT
 450 # define IP_FMT "%08lx"
 451 #else
 452 # define IP_FMT "%016lx"
 453 #endif
 454
 455 int seq_print_user_ip(struct trace_seq *s, struct mm_struct *mm,
 456                       unsigned long ip, unsigned long sym_flags)
 457 {
 458         struct file *file = NULL;
 459         unsigned long vmstart = 0;
 460         int ret = 1;
 461
 462         if (s->full)
 463                 return 0;
 464
 465         if (mm) {
 466                 const struct vm_area_struct *vma;
 467
 468                 down_read(&mm->mmap_sem);
 469                 vma = find_vma(mm, ip);
 470                 if (vma) {
 471                         file = vma->vm_file;
 472                         vmstart = vma->vm_start;
 473                 }
 474                 if (file) {
 475                         ret = trace_seq_path(s, &file->f_path);
 476                         if (ret)
 477                                 ret = trace_seq_printf(s, "[+0x%lx]",
 478                                                        ip - vmstart);
 479                 }
 480                 up_read(&mm->mmap_sem);
 481         }
 482         if (ret && ((sym_flags & TRACE_ITER_SYM_ADDR) || !file))
 483                 ret = trace_seq_printf(s, " <" IP_FMT ">", ip);
 484         return ret;
 485 }
 486
 487 int
 488 seq_print_userip_objs(const struct userstack_entry *entry, struct trace_seq *s,
 489                       unsigned long sym_flags)
 490 {
 491         struct mm_struct *mm = NULL;
 492         int ret = 1;
 493         unsigned int i;
 494
 495         if (trace_flags & TRACE_ITER_SYM_USEROBJ) {
 496                 struct task_struct *task;
 497                 /*
 498                  * we do the lookup on the thread group leader,
 499                  * since individual threads might have already quit!
 500                  */
 501                 rcu_read_lock();
 502                 task = find_task_by_vpid(entry->tgid);
 503                 if (task)
 504                         mm = get_task_mm(task);
 505                 rcu_read_unlock();
 506         }
 507
 508         for (i = 0; i < FTRACE_STACK_ENTRIES; i++) {
 509                 unsigned long ip = entry->caller[i];
 510
 511                 if (ip == ULONG_MAX || !ret)
 512                         break;
 513                 if (ret)
 514                         ret = trace_seq_puts(s, " => ");
 515                 if (!ip) {
 516                         if (ret)
 517                                 ret = trace_seq_puts(s, "??");
 518                         if (ret)
 519                                 ret = trace_seq_puts(s, "\n");
 520                         continue;
 521                 }
 522                 if (!ret)
 523                         break;
 524                 if (ret)
 525                         ret = seq_print_user_ip(s, mm, ip, sym_flags);
 526                 ret = trace_seq_puts(s, "\n");
 527         }
 528
 529         if (mm)
 530                 mmput(mm);
 531         return ret;
 532 }
 533
 534 int
 535 seq_print_ip_sym(struct trace_seq *s, unsigned long ip, unsigned long sym_flags)
 536 {
 537         int ret;
 538
 539         if (!ip)
 540                 return trace_seq_printf(s, "0");
 541
 542         if (sym_flags & TRACE_ITER_SYM_OFFSET)
 543                 ret = seq_print_sym_offset(s, "%s", ip);
 544         else
 545                 ret = seq_print_sym_short(s, "%s", ip);
 546
 547         if (!ret)
 548                 return 0;
 549
 550         if (sym_flags & TRACE_ITER_SYM_ADDR)
 551                 ret = trace_seq_printf(s, " <" IP_FMT ">", ip);
 552         return ret;
 553 }
 554
 555 /**
 556  * trace_print_lat_fmt - print the irq, preempt and lockdep fields
 557  * @s: trace seq struct to write to
 558  * @entry: The trace entry field from the ring buffer
 559  *
 560  * Prints the generic fields of irqs off, in hard or softirq, preempt
 561  * count.
 562  */
 563 int trace_print_lat_fmt(struct trace_seq *s, struct trace_entry *entry)
 564 {
 565         char hardsoft_irq;
 566         char need_resched;
 567         char irqs_off;
 568         int hardirq;
 569         int softirq;
 570         int ret;
 571
 572         hardirq = entry->flags & TRACE_FLAG_HARDIRQ;
 573         softirq = entry->flags & TRACE_FLAG_SOFTIRQ;
 574
 575         irqs_off =
 576                 (entry->flags & TRACE_FLAG_IRQS_OFF) ? 'd' :
 577                 (entry->flags & TRACE_FLAG_IRQS_NOSUPPORT) ? 'X' :
 578                 '.';
 579         need_resched =
 580                 (entry->flags & TRACE_FLAG_NEED_RESCHED) ? 'N' : '.';
 581         hardsoft_irq =
 582                 (hardirq && softirq) ? 'H' :
 583                 hardirq ? 'h' :
 584                 softirq ? 's' :
 585                 '.';
 586
 587         if (!trace_seq_printf(s, "%c%c%c",
 588                               irqs_off, need_resched, hardsoft_irq))
 589                 return 0;
 590
 591         if (entry->preempt_count)
 592                 ret = trace_seq_printf(s, "%x", entry->preempt_count);
 593         else
 594                 ret = trace_seq_putc(s, '.');
 595
 596         return ret;
 597 }
 598
 599 static int
 600 lat_print_generic(struct trace_seq *s, struct trace_entry *entry, int cpu)
 601 {
 602         char comm[TASK_COMM_LEN];
 603
 604         trace_find_cmdline(entry->pid, comm);
 605
 606         if (!trace_seq_printf(s, "%8.8s-%-5d %3d",
 607                               comm, entry->pid, cpu))
 608                 return 0;
 609
 610         return trace_print_lat_fmt(s, entry);
 611 }
 612
 613 static unsigned long preempt_mark_thresh = 100;
 614
 615 static int
 616 lat_print_timestamp(struct trace_seq *s, u64 abs_usecs,
 617                     unsigned long rel_usecs)
 618 {
 619         return trace_seq_printf(s, " %4lldus%c: ", abs_usecs,
 620                                 rel_usecs > preempt_mark_thresh ? '!' :
 621                                   rel_usecs > 1 ? '+' : ' ');
 622 }
 623
 624 int trace_print_context(struct trace_iterator *iter)
 625 {
 626         struct trace_seq *s = &iter->seq;
 627         struct trace_entry *entry = iter->ent;
 628         unsigned long long t = ns2usecs(iter->ts);
 629         unsigned long usec_rem = do_div(t, USEC_PER_SEC);
 630         unsigned long secs = (unsigned long)t;
 631         char comm[TASK_COMM_LEN];
 632         int ret;
 633
 634         trace_find_cmdline(entry->pid, comm);
 635
 636         ret = trace_seq_printf(s, "%16s-%-5d [%03d] ",
 637                                comm, entry->pid, iter->cpu);
 638         if (!ret)
 639                 return 0;
 640
 641         if (trace_flags & TRACE_ITER_IRQ_INFO) {
 642                 ret = trace_print_lat_fmt(s, entry);
 643                 if (!ret)
 644                         return 0;
 645         }
 646
 647         return trace_seq_printf(s, " %5lu.%06lu: ",
 648                                 secs, usec_rem);
 649 }
 650
 651 int trace_print_lat_context(struct trace_iterator *iter)
 652 {
 653         u64 next_ts;
 654         int ret;
 655         /* trace_find_next_entry will reset ent_size */
 656         int ent_size = iter->ent_size;
 657         struct trace_seq *s = &iter->seq;
 658         struct trace_entry *entry = iter->ent,
 659                            *next_entry = trace_find_next_entry(iter, NULL,
 660                                                                &next_ts);
 661         unsigned long verbose = (trace_flags & TRACE_ITER_VERBOSE);
 662         unsigned long abs_usecs = ns2usecs(iter->ts - iter->tr->time_start);
 663         unsigned long rel_usecs;
 664
 665         /* Restore the original ent_size */
 666         iter->ent_size = ent_size;
 667
 668         if (!next_entry)
 669                 next_ts = iter->ts;
 670         rel_usecs = ns2usecs(next_ts - iter->ts);
 671
 672         if (verbose) {
 673                 char comm[TASK_COMM_LEN];
 674
 675                 trace_find_cmdline(entry->pid, comm);
 676
 677                 ret = trace_seq_printf(s, "%16s %5d %3d %d %08x %08lx [%08llx]"
 678                                        " %ld.%03ldms (+%ld.%03ldms): ", comm,
 679                                        entry->pid, iter->cpu, entry->flags,
 680                                        entry->preempt_count, iter->idx,
 681                                        ns2usecs(iter->ts),
 682                                        abs_usecs / USEC_PER_MSEC,
 683                                        abs_usecs % USEC_PER_MSEC,
 684                                        rel_usecs / USEC_PER_MSEC,
 685                                        rel_usecs % USEC_PER_MSEC);
 686         } else {
 687                 ret = lat_print_generic(s, entry, iter->cpu);
 688                 if (ret)
 689                         ret = lat_print_timestamp(s, abs_usecs, rel_usecs);
 690         }
 691
 692         return ret;
 693 }
 694
 695 static const char state_to_char[] = TASK_STATE_TO_CHAR_STR;
 696
 697 static int task_state_char(unsigned long state)
 698 {
 699         int bit = state ? __ffs(state) + 1 : 0;
 700
 701         return bit < sizeof(state_to_char) - 1 ? state_to_char[bit] : '?';
 702 }
 703
 704 /**
 705  * ftrace_find_event - find a registered event
 706  * @type: the type of event to look for
 707  *
 708  * Returns an event of type @type otherwise NULL
 709  * Called with trace_event_read_lock() held.
 710  */
 711 struct trace_event *ftrace_find_event(int type)
 712 {
 713         struct trace_event *event;
 714         struct hlist_node *n;
 715         unsigned key;
 716
 717         key = type & (EVENT_HASHSIZE - 1);
 718
 719         hlist_for_each_entry(event, n, &event_hash[key], node) {
 720                 if (event->type == type)
 721                         return event;
 722         }
 723
 724         return NULL;
 725 }
 726
 727 static LIST_HEAD(ftrace_event_list);
 728
 729 static int trace_search_list(struct list_head **list)
 730 {
 731         struct trace_event *e;
 732         int last = __TRACE_LAST_TYPE;
 733
 734         if (list_empty(&ftrace_event_list)) {
 735                 *list = &ftrace_event_list;
 736                 return last + 1;
 737         }
 738
 739         /*
 740          * We used up all possible max events,
 741          * lets see if somebody freed one.
 742          */
 743         list_for_each_entry(e, &ftrace_event_list, list) {
 744                 if (e->type != last + 1)
 745                         break;
 746                 last++;
 747         }
 748
 749         /* Did we used up all 65 thousand events??? */
 750         if ((last + 1) > FTRACE_MAX_EVENT)
 751                 return 0;
 752
 753         *list = &e->list;
 754         return last + 1;
 755 }
 756
 757 void trace_event_read_lock(void)
 758 {
 759         down_read(&trace_event_mutex);
 760 }
 761
 762 void trace_event_read_unlock(void)
 763 {
 764         up_read(&trace_event_mutex);
 765 }
 766
 767 /**
 768  * register_ftrace_event - register output for an event type
 769  * @event: the event type to register
 770  *
 771  * Event types are stored in a hash and this hash is used to
 772  * find a way to print an event. If the @event->type is set
 773  * then it will use that type, otherwise it will assign a
 774  * type to use.
 775  *
 776  * If you assign your own type, please make sure it is added
 777  * to the trace_type enum in trace.h, to avoid collisions
 778  * with the dynamic types.
 779  *
 780  * Returns the event type number or zero on error.
 781  */
 782 int register_ftrace_event(struct trace_event *event)
 783 {
 784         unsigned key;
 785         int ret = 0;
 786
 787         down_write(&trace_event_mutex);
 788
 789         if (WARN_ON(!event))
 790                 goto out;
 791
 792         if (WARN_ON(!event->funcs))
 793                 goto out;
 794
 795         INIT_LIST_HEAD(&event->list);
 796
 797         if (!event->type) {
 798                 struct list_head *list = NULL;
 799
 800                 if (next_event_type > FTRACE_MAX_EVENT) {
 801
 802                         event->type = trace_search_list(&list);
 803                         if (!event->type)
 804                                 goto out;
 805
 806                 } else {
 807
 808                         event->type = next_event_type++;
 809                         list = &ftrace_event_list;
 810                 }
 811
 812                 if (WARN_ON(ftrace_find_event(event->type)))
 813                         goto out;
 814
 815                 list_add_tail(&event->list, list);
 816
 817         } else if (event->type > __TRACE_LAST_TYPE) {
 818                 printk(KERN_WARNING "Need to add type to trace.h\n");
 819                 WARN_ON(1);
 820                 goto out;
 821         } else {
 822                 /* Is this event already used */
 823                 if (ftrace_find_event(event->type))
 824                         goto out;
 825         }
 826
 827         if (event->funcs->trace == NULL)
 828                 event->funcs->trace = trace_nop_print;
 829         if (event->funcs->raw == NULL)
 830                 event->funcs->raw = trace_nop_print;
 831         if (event->funcs->hex == NULL)
 832                 event->funcs->hex = trace_nop_print;
 833         if (event->funcs->binary == NULL)
 834                 event->funcs->binary = trace_nop_print;
 835
 836         key = event->type & (EVENT_HASHSIZE - 1);
 837
 838         hlist_add_head(&event->node, &event_hash[key]);
 839
 840         ret = event->type;
 841  out:
 842         up_write(&trace_event_mutex);
 843
 844         return ret;
 845 }
 846 EXPORT_SYMBOL_GPL(register_ftrace_event);
 847
 848 /*
 849  * Used by module code with the trace_event_mutex held for write.
 850  */
 851 int __unregister_ftrace_event(struct trace_event *event)
 852 {
 853         hlist_del(&event->node);
 854         list_del(&event->list);
 855         return 0;
 856 }
 857
 858 /**
 859  * unregister_ftrace_event - remove a no longer used event
 860  * @event: the event to remove
 861  */
 862 int unregister_ftrace_event(struct trace_event *event)
 863 {
 864         down_write(&trace_event_mutex);
 865         __unregister_ftrace_event(event);
 866         up_write(&trace_event_mutex);
 867
 868         return 0;
 869 }
 870 EXPORT_SYMBOL_GPL(unregister_ftrace_event);
 871
 872 /*
 873  * Standard events
 874  */
 875
 876 enum print_line_t trace_nop_print(struct trace_iterator *iter, int flags,
 877                                   struct trace_event *event)
 878 {
 879         if (!trace_seq_printf(&iter->seq, "type: %d\n", iter->ent->type))
 880                 return TRACE_TYPE_PARTIAL_LINE;
 881
 882         return TRACE_TYPE_HANDLED;
 883 }
 884
 885 /* TRACE_FN */
 886 static enum print_line_t trace_fn_trace(struct trace_iterator *iter, int flags,
 887                                         struct trace_event *event)
 888 {
 889         struct ftrace_entry *field;
 890         struct trace_seq *s = &iter->seq;
 891
 892         trace_assign_type(field, iter->ent);
 893
 894         if (!seq_print_ip_sym(s, field->ip, flags))
 895                 goto partial;
 896
 897         if ((flags & TRACE_ITER_PRINT_PARENT) && field->parent_ip) {
 898                 if (!trace_seq_printf(s, " <-"))
 899                         goto partial;
 900                 if (!seq_print_ip_sym(s,
 901                                       field->parent_ip,
 902                                       flags))
 903                         goto partial;
 904         }
 905         if (!trace_seq_printf(s, "\n"))
 906                 goto partial;
 907
 908         return TRACE_TYPE_HANDLED;
 909
 910  partial:
 911         return TRACE_TYPE_PARTIAL_LINE;
 912 }
 913
 914 static enum print_line_t trace_fn_raw(struct trace_iterator *iter, int flags,
 915                                       struct trace_event *event)
 916 {
 917         struct ftrace_entry *field;
 918
 919         trace_assign_type(field, iter->ent);
 920
 921         if (!trace_seq_printf(&iter->seq, "%lx %lx\n",
 922                               field->ip,
 923                               field->parent_ip))
 924                 return TRACE_TYPE_PARTIAL_LINE;
 925
 926         return TRACE_TYPE_HANDLED;
 927 }
 928
 929 static enum print_line_t trace_fn_hex(struct trace_iterator *iter, int flags,
 930                                       struct trace_event *event)
 931 {
 932         struct ftrace_entry *field;
 933         struct trace_seq *s = &iter->seq;
 934
 935         trace_assign_type(field, iter->ent);
 936
 937         SEQ_PUT_HEX_FIELD_RET(s, field->ip);
 938         SEQ_PUT_HEX_FIELD_RET(s, field->parent_ip);
 939
 940         return TRACE_TYPE_HANDLED;
 941 }
 942
 943 static enum print_line_t trace_fn_bin(struct trace_iterator *iter, int flags,
 944                                       struct trace_event *event)
 945 {
 946         struct ftrace_entry *field;
 947         struct trace_seq *s = &iter->seq;
 948
 949         trace_assign_type(field, iter->ent);
 950
 951         SEQ_PUT_FIELD_RET(s, field->ip);
 952         SEQ_PUT_FIELD_RET(s, field->parent_ip);
 953
 954         return TRACE_TYPE_HANDLED;
 955 }
 956
 957 static struct trace_event_functions trace_fn_funcs = {
 958         .trace          = trace_fn_trace,
 959         .raw            = trace_fn_raw,
 960         .hex            = trace_fn_hex,
 961         .binary         = trace_fn_bin,
 962 };
 963
 964 static struct trace_event trace_fn_event = {
 965         .type           = TRACE_FN,
 966         .funcs          = &trace_fn_funcs,
 967 };
 968
 969 /* TRACE_CTX an TRACE_WAKE */
 970 static enum print_line_t trace_ctxwake_print(struct trace_iterator *iter,
 971                                              char *delim)
 972 {
 973         struct ctx_switch_entry *field;
 974         char comm[TASK_COMM_LEN];
 975         int S, T;
 976
 977
 978         trace_assign_type(field, iter->ent);
 979
 980         T = task_state_char(field->next_state);
 981         S = task_state_char(field->prev_state);
 982         trace_find_cmdline(field->next_pid, comm);
 983         if (!trace_seq_printf(&iter->seq,
 984                               " %5d:%3d:%c %s [%03d] %5d:%3d:%c %s\n",
 985                               field->prev_pid,
 986                               field->prev_prio,
 987                               S, delim,
 988                               field->next_cpu,
 989                               field->next_pid,
 990                               field->next_prio,
 991                               T, comm))
 992                 return TRACE_TYPE_PARTIAL_LINE;
 993
 994         return TRACE_TYPE_HANDLED;
 995 }
 996
 997 static enum print_line_t trace_ctx_print(struct trace_iterator *iter, int flags,
 998                                          struct trace_event *event)
 999 {
1000         return trace_ctxwake_print(iter, "==>");
1001 }
1002
1003 static enum print_line_t trace_wake_print(struct trace_iterator *iter,
1004                                           int flags, struct trace_event *event)
1005 {
1006         return trace_ctxwake_print(iter, "  +");
1007 }
1008
1009 static int trace_ctxwake_raw(struct trace_iterator *iter, char S)
1010 {
1011         struct ctx_switch_entry *field;
1012         int T;
1013
1014         trace_assign_type(field, iter->ent);
1015
1016         if (!S)
1017                 S = task_state_char(field->prev_state);
1018         T = task_state_char(field->next_state);
1019         if (!trace_seq_printf(&iter->seq, "%d %d %c %d %d %d %c\n",
1020                               field->prev_pid,
1021                               field->prev_prio,
1022                               S,
1023                               field->next_cpu,
1024                               field->next_pid,
1025                               field->next_prio,
1026                               T))
1027                 return TRACE_TYPE_PARTIAL_LINE;
1028
1029         return TRACE_TYPE_HANDLED;
1030 }
1031
1032 static enum print_line_t trace_ctx_raw(struct trace_iterator *iter, int flags,
1033                                        struct trace_event *event)
1034 {
1035         return trace_ctxwake_raw(iter, 0);
1036 }
1037
1038 static enum print_line_t trace_wake_raw(struct trace_iterator *iter, int flags,
1039                                         struct trace_event *event)
1040 {
1041         return trace_ctxwake_raw(iter, '+');
1042 }
1043
1044
1045 static int trace_ctxwake_hex(struct trace_iterator *iter, char S)
1046 {
1047         struct ctx_switch_entry *field;
1048         struct trace_seq *s = &iter->seq;
1049         int T;
1050
1051         trace_assign_type(field, iter->ent);
1052
1053         if (!S)
1054                 S = task_state_char(field->prev_state);
1055         T = task_state_char(field->next_state);
1056
1057         SEQ_PUT_HEX_FIELD_RET(s, field->prev_pid);
1058         SEQ_PUT_HEX_FIELD_RET(s, field->prev_prio);
1059         SEQ_PUT_HEX_FIELD_RET(s, S);
1060         SEQ_PUT_HEX_FIELD_RET(s, field->next_cpu);
1061         SEQ_PUT_HEX_FIELD_RET(s, field->next_pid);
1062         SEQ_PUT_HEX_FIELD_RET(s, field->next_prio);
1063         SEQ_PUT_HEX_FIELD_RET(s, T);
1064
1065         return TRACE_TYPE_HANDLED;
1066 }
1067
1068 static enum print_line_t trace_ctx_hex(struct trace_iterator *iter, int flags,
1069                                        struct trace_event *event)
1070 {
1071         return trace_ctxwake_hex(iter, 0);
1072 }
1073
1074 static enum print_line_t trace_wake_hex(struct trace_iterator *iter, int flags,
1075                                         struct trace_event *event)
1076 {
1077         return trace_ctxwake_hex(iter, '+');
1078 }
1079
1080 static enum print_line_t trace_ctxwake_bin(struct trace_iterator *iter,
1081                                            int flags, struct trace_event *event)
1082 {
1083         struct ctx_switch_entry *field;
1084         struct trace_seq *s = &iter->seq;
1085
1086         trace_assign_type(field, iter->ent);
1087
1088         SEQ_PUT_FIELD_RET(s, field->prev_pid);
1089         SEQ_PUT_FIELD_RET(s, field->prev_prio);
1090         SEQ_PUT_FIELD_RET(s, field->prev_state);
1091         SEQ_PUT_FIELD_RET(s, field->next_pid);
1092         SEQ_PUT_FIELD_RET(s, field->next_prio);
1093         SEQ_PUT_FIELD_RET(s, field->next_state);
1094
1095         return TRACE_TYPE_HANDLED;
1096 }
1097
1098 static struct trace_event_functions trace_ctx_funcs = {
1099         .trace          = trace_ctx_print,
1100         .raw            = trace_ctx_raw,
1101         .hex            = trace_ctx_hex,
1102         .binary         = trace_ctxwake_bin,
1103 };
1104
1105 static struct trace_event trace_ctx_event = {
1106         .type           = TRACE_CTX,
1107         .funcs          = &trace_ctx_funcs,
1108 };
1109
1110 static struct trace_event_functions trace_wake_funcs = {
1111         .trace          = trace_wake_print,
1112         .raw            = trace_wake_raw,
1113         .hex            = trace_wake_hex,
1114         .binary         = trace_ctxwake_bin,
1115 };
1116
1117 static struct trace_event trace_wake_event = {
1118         .type           = TRACE_WAKE,
1119         .funcs          = &trace_wake_funcs,
1120 };
1121
1122 /* TRACE_STACK */
1123
1124 static enum print_line_t trace_stack_print(struct trace_iterator *iter,
1125                                            int flags, struct trace_event *event)
1126 {
1127         struct stack_entry *field;
1128         struct trace_seq *s = &iter->seq;
1129         unsigned long *p;
1130         unsigned long *end;
1131
1132         trace_assign_type(field, iter->ent);
1133         end = (unsigned long *)((long)iter->ent + iter->ent_size);
1134
1135         if (!trace_seq_puts(s, "<stack trace>\n"))
1136                 goto partial;
1137
1138         for (p = field->caller; p && *p != ULONG_MAX && p < end; p++) {
1139                 if (!trace_seq_puts(s, " => "))
1140                         goto partial;
1141
1142                 if (!seq_print_ip_sym(s, *p, flags))
1143                         goto partial;
1144                 if (!trace_seq_puts(s, "\n"))
1145                         goto partial;
1146         }
1147
1148         return TRACE_TYPE_HANDLED;
1149
1150  partial:
1151         return TRACE_TYPE_PARTIAL_LINE;
1152 }
1153
1154 static struct trace_event_functions trace_stack_funcs = {
1155         .trace          = trace_stack_print,
1156 };
1157
1158 static struct trace_event trace_stack_event = {
1159         .type           = TRACE_STACK,
1160         .funcs          = &trace_stack_funcs,
1161 };
1162
1163 /* TRACE_USER_STACK */
1164 static enum print_line_t trace_user_stack_print(struct trace_iterator *iter,
1165                                                 int flags, struct trace_event *event)
1166 {
1167         struct userstack_entry *field;
1168         struct trace_seq *s = &iter->seq;
1169
1170         trace_assign_type(field, iter->ent);
1171
1172         if (!trace_seq_puts(s, "<user stack trace>\n"))
1173                 goto partial;
1174
1175         if (!seq_print_userip_objs(field, s, flags))
1176                 goto partial;
1177
1178         return TRACE_TYPE_HANDLED;
1179
1180  partial:
1181         return TRACE_TYPE_PARTIAL_LINE;
1182 }
1183
1184 static struct trace_event_functions trace_user_stack_funcs = {
1185         .trace          = trace_user_stack_print,
1186 };
1187
1188 static struct trace_event trace_user_stack_event = {
1189         .type           = TRACE_USER_STACK,
1190         .funcs          = &trace_user_stack_funcs,
1191 };
1192
1193 /* TRACE_BPRINT */
1194 static enum print_line_t
1195 trace_bprint_print(struct trace_iterator *iter, int flags,
1196                    struct trace_event *event)
1197 {
1198         struct trace_entry *entry = iter->ent;
1199         struct trace_seq *s = &iter->seq;
1200         struct bprint_entry *field;
1201
1202         trace_assign_type(field, entry);
1203
1204         if (!seq_print_ip_sym(s, field->ip, flags))
1205                 goto partial;
1206
1207         if (!trace_seq_puts(s, ": "))
1208                 goto partial;
1209
1210         if (!trace_seq_bprintf(s, field->fmt, field->buf))
1211                 goto partial;
1212
1213         return TRACE_TYPE_HANDLED;
1214
1215  partial:
1216         return TRACE_TYPE_PARTIAL_LINE;
1217 }
1218
1219
1220 static enum print_line_t
1221 trace_bprint_raw(struct trace_iterator *iter, int flags,
1222                  struct trace_event *event)
1223 {
1224         struct bprint_entry *field;
1225         struct trace_seq *s = &iter->seq;
1226
1227         trace_assign_type(field, iter->ent);
1228
1229         if (!trace_seq_printf(s, ": %lx : ", field->ip))
1230                 goto partial;
1231
1232         if (!trace_seq_bprintf(s, field->fmt, field->buf))
1233                 goto partial;
1234
1235         return TRACE_TYPE_HANDLED;
1236
1237  partial:
1238         return TRACE_TYPE_PARTIAL_LINE;
1239 }
1240
1241 static struct trace_event_functions trace_bprint_funcs = {
1242         .trace          = trace_bprint_print,
1243         .raw            = trace_bprint_raw,
1244 };
1245
1246 static struct trace_event trace_bprint_event = {
1247         .type           = TRACE_BPRINT,
1248         .funcs          = &trace_bprint_funcs,
1249 };
1250
1251 /* TRACE_PRINT */
1252 static enum print_line_t trace_print_print(struct trace_iterator *iter,
1253                                            int flags, struct trace_event *event)
1254 {
1255         struct print_entry *field;
1256         struct trace_seq *s = &iter->seq;
1257
1258         trace_assign_type(field, iter->ent);
1259
1260         if (!seq_print_ip_sym(s, field->ip, flags))
1261                 goto partial;
1262
1263         if (!trace_seq_printf(s, ": %s", field->buf))
1264                 goto partial;
1265
1266         return TRACE_TYPE_HANDLED;
1267
1268  partial:
1269         return TRACE_TYPE_PARTIAL_LINE;
1270 }
1271
1272 static enum print_line_t trace_print_raw(struct trace_iterator *iter, int flags,
1273                                          struct trace_event *event)
1274 {
1275         struct print_entry *field;
1276
1277         trace_assign_type(field, iter->ent);
1278
1279         if (!trace_seq_printf(&iter->seq, "# %lx %s", field->ip, field->buf))
1280                 goto partial;
1281
1282         return TRACE_TYPE_HANDLED;
1283
1284  partial:
1285         return TRACE_TYPE_PARTIAL_LINE;
1286 }
1287
1288 static struct trace_event_functions trace_print_funcs = {
1289         .trace          = trace_print_print,
1290         .raw            = trace_print_raw,
1291 };
1292
1293 static struct trace_event trace_print_event = {
1294         .type           = TRACE_PRINT,
1295         .funcs          = &trace_print_funcs,
1296 };
1297
1298
1299 static struct trace_event *events[] __initdata = {
1300         &trace_fn_event,
1301         &trace_ctx_event,
1302         &trace_wake_event,
1303         &trace_stack_event,
1304         &trace_user_stack_event,
1305         &trace_bprint_event,
1306         &trace_print_event,
1307         NULL
1308 };
1309
1310 __init static int init_events(void)
1311 {
1312         struct trace_event *event;
1313         int i, ret;
1314
1315         for (i = 0; events[i]; i++) {
1316                 event = events[i];
1317
1318                 ret = register_ftrace_event(event);
1319                 if (!ret) {
1320                         printk(KERN_WARNING "event %d failed to register\n",
1321                                event->type);
1322                         WARN_ON_ONCE(1);
1323                 }
1324         }
1325
1326         return 0;
1327 }
1328 early_initcall(init_events);