Pileus Git - ~andy/linux/blob - 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 int ftrace_raw_output_prep(struct trace_iterator *iter,
 401                            struct trace_event *trace_event)
 402 {
 403         struct ftrace_event_call *event;
 404         struct trace_seq *s = &iter->seq;
 405         struct trace_seq *p = &iter->tmp_seq;
 406         struct trace_entry *entry;
 407         int ret;
 408
 409         event = container_of(trace_event, struct ftrace_event_call, event);
 410         entry = iter->ent;
 411
 412         if (entry->type != event->event.type) {
 413                 WARN_ON_ONCE(1);
 414                 return TRACE_TYPE_UNHANDLED;
 415         }
 416
 417         trace_seq_init(p);
 418         ret = trace_seq_printf(s, "%s: ", event->name);
 419         if (!ret)
 420                 return TRACE_TYPE_PARTIAL_LINE;
 421
 422         return 0;
 423 }
 424 EXPORT_SYMBOL(ftrace_raw_output_prep);
 425
 426 #ifdef CONFIG_KRETPROBES
 427 static inline const char *kretprobed(const char *name)
 428 {
 429         static const char tramp_name[] = "kretprobe_trampoline";
 430         int size = sizeof(tramp_name);
 431
 432         if (strncmp(tramp_name, name, size) == 0)
 433                 return "[unknown/kretprobe'd]";
 434         return name;
 435 }
 436 #else
 437 static inline const char *kretprobed(const char *name)
 438 {
 439         return name;
 440 }
 441 #endif /* CONFIG_KRETPROBES */
 442
 443 static int
 444 seq_print_sym_short(struct trace_seq *s, const char *fmt, unsigned long address)
 445 {
 446 #ifdef CONFIG_KALLSYMS
 447         char str[KSYM_SYMBOL_LEN];
 448         const char *name;
 449
 450         kallsyms_lookup(address, NULL, NULL, NULL, str);
 451
 452         name = kretprobed(str);
 453
 454         return trace_seq_printf(s, fmt, name);
 455 #endif
 456         return 1;
 457 }
 458
 459 static int
 460 seq_print_sym_offset(struct trace_seq *s, const char *fmt,
 461                      unsigned long address)
 462 {
 463 #ifdef CONFIG_KALLSYMS
 464         char str[KSYM_SYMBOL_LEN];
 465         const char *name;
 466
 467         sprint_symbol(str, address);
 468         name = kretprobed(str);
 469
 470         return trace_seq_printf(s, fmt, name);
 471 #endif
 472         return 1;
 473 }
 474
 475 #ifndef CONFIG_64BIT
 476 # define IP_FMT "%08lx"
 477 #else
 478 # define IP_FMT "%016lx"
 479 #endif
 480
 481 int seq_print_user_ip(struct trace_seq *s, struct mm_struct *mm,
 482                       unsigned long ip, unsigned long sym_flags)
 483 {
 484         struct file *file = NULL;
 485         unsigned long vmstart = 0;
 486         int ret = 1;
 487
 488         if (s->full)
 489                 return 0;
 490
 491         if (mm) {
 492                 const struct vm_area_struct *vma;
 493
 494                 down_read(&mm->mmap_sem);
 495                 vma = find_vma(mm, ip);
 496                 if (vma) {
 497                         file = vma->vm_file;
 498                         vmstart = vma->vm_start;
 499                 }
 500                 if (file) {
 501                         ret = trace_seq_path(s, &file->f_path);
 502                         if (ret)
 503                                 ret = trace_seq_printf(s, "[+0x%lx]",
 504                                                        ip - vmstart);
 505                 }
 506                 up_read(&mm->mmap_sem);
 507         }
 508         if (ret && ((sym_flags & TRACE_ITER_SYM_ADDR) || !file))
 509                 ret = trace_seq_printf(s, " <" IP_FMT ">", ip);
 510         return ret;
 511 }
 512
 513 int
 514 seq_print_userip_objs(const struct userstack_entry *entry, struct trace_seq *s,
 515                       unsigned long sym_flags)
 516 {
 517         struct mm_struct *mm = NULL;
 518         int ret = 1;
 519         unsigned int i;
 520
 521         if (trace_flags & TRACE_ITER_SYM_USEROBJ) {
 522                 struct task_struct *task;
 523                 /*
 524                  * we do the lookup on the thread group leader,
 525                  * since individual threads might have already quit!
 526                  */
 527                 rcu_read_lock();
 528                 task = find_task_by_vpid(entry->tgid);
 529                 if (task)
 530                         mm = get_task_mm(task);
 531                 rcu_read_unlock();
 532         }
 533
 534         for (i = 0; i < FTRACE_STACK_ENTRIES; i++) {
 535                 unsigned long ip = entry->caller[i];
 536
 537                 if (ip == ULONG_MAX || !ret)
 538                         break;
 539                 if (ret)
 540                         ret = trace_seq_puts(s, " => ");
 541                 if (!ip) {
 542                         if (ret)
 543                                 ret = trace_seq_puts(s, "??");
 544                         if (ret)
 545                                 ret = trace_seq_puts(s, "\n");
 546                         continue;
 547                 }
 548                 if (!ret)
 549                         break;
 550                 if (ret)
 551                         ret = seq_print_user_ip(s, mm, ip, sym_flags);
 552                 ret = trace_seq_puts(s, "\n");
 553         }
 554
 555         if (mm)
 556                 mmput(mm);
 557         return ret;
 558 }
 559
 560 int
 561 seq_print_ip_sym(struct trace_seq *s, unsigned long ip, unsigned long sym_flags)
 562 {
 563         int ret;
 564
 565         if (!ip)
 566                 return trace_seq_printf(s, "0");
 567
 568         if (sym_flags & TRACE_ITER_SYM_OFFSET)
 569                 ret = seq_print_sym_offset(s, "%s", ip);
 570         else
 571                 ret = seq_print_sym_short(s, "%s", ip);
 572
 573         if (!ret)
 574                 return 0;
 575
 576         if (sym_flags & TRACE_ITER_SYM_ADDR)
 577                 ret = trace_seq_printf(s, " <" IP_FMT ">", ip);
 578         return ret;
 579 }
 580
 581 /**
 582  * trace_print_lat_fmt - print the irq, preempt and lockdep fields
 583  * @s: trace seq struct to write to
 584  * @entry: The trace entry field from the ring buffer
 585  *
 586  * Prints the generic fields of irqs off, in hard or softirq, preempt
 587  * count.
 588  */
 589 int trace_print_lat_fmt(struct trace_seq *s, struct trace_entry *entry)
 590 {
 591         char hardsoft_irq;
 592         char need_resched;
 593         char irqs_off;
 594         int hardirq;
 595         int softirq;
 596         int ret;
 597
 598         hardirq = entry->flags & TRACE_FLAG_HARDIRQ;
 599         softirq = entry->flags & TRACE_FLAG_SOFTIRQ;
 600
 601         irqs_off =
 602                 (entry->flags & TRACE_FLAG_IRQS_OFF) ? 'd' :
 603                 (entry->flags & TRACE_FLAG_IRQS_NOSUPPORT) ? 'X' :
 604                 '.';
 605         need_resched =
 606                 (entry->flags & TRACE_FLAG_NEED_RESCHED) ? 'N' : '.';
 607         hardsoft_irq =
 608                 (hardirq && softirq) ? 'H' :
 609                 hardirq ? 'h' :
 610                 softirq ? 's' :
 611                 '.';
 612
 613         if (!trace_seq_printf(s, "%c%c%c",
 614                               irqs_off, need_resched, hardsoft_irq))
 615                 return 0;
 616
 617         if (entry->preempt_count)
 618                 ret = trace_seq_printf(s, "%x", entry->preempt_count);
 619         else
 620                 ret = trace_seq_putc(s, '.');
 621
 622         return ret;
 623 }
 624
 625 static int
 626 lat_print_generic(struct trace_seq *s, struct trace_entry *entry, int cpu)
 627 {
 628         char comm[TASK_COMM_LEN];
 629
 630         trace_find_cmdline(entry->pid, comm);
 631
 632         if (!trace_seq_printf(s, "%8.8s-%-5d %3d",
 633                               comm, entry->pid, cpu))
 634                 return 0;
 635
 636         return trace_print_lat_fmt(s, entry);
 637 }
 638
 639 static unsigned long preempt_mark_thresh_us = 100;
 640
 641 static int
 642 lat_print_timestamp(struct trace_iterator *iter, u64 next_ts)
 643 {
 644         unsigned long verbose = trace_flags & TRACE_ITER_VERBOSE;
 645         unsigned long in_ns = iter->iter_flags & TRACE_FILE_TIME_IN_NS;
 646         unsigned long long abs_ts = iter->ts - iter->tr->time_start;
 647         unsigned long long rel_ts = next_ts - iter->ts;
 648         struct trace_seq *s = &iter->seq;
 649
 650         if (in_ns) {
 651                 abs_ts = ns2usecs(abs_ts);
 652                 rel_ts = ns2usecs(rel_ts);
 653         }
 654
 655         if (verbose && in_ns) {
 656                 unsigned long abs_usec = do_div(abs_ts, USEC_PER_MSEC);
 657                 unsigned long abs_msec = (unsigned long)abs_ts;
 658                 unsigned long rel_usec = do_div(rel_ts, USEC_PER_MSEC);
 659                 unsigned long rel_msec = (unsigned long)rel_ts;
 660
 661                 return trace_seq_printf(
 662                                 s, "[%08llx] %ld.%03ldms (+%ld.%03ldms): ",
 663                                 ns2usecs(iter->ts),
 664                                 abs_msec, abs_usec,
 665                                 rel_msec, rel_usec);
 666         } else if (verbose && !in_ns) {
 667                 return trace_seq_printf(
 668                                 s, "[%016llx] %lld (+%lld): ",
 669                                 iter->ts, abs_ts, rel_ts);
 670         } else if (!verbose && in_ns) {
 671                 return trace_seq_printf(
 672                                 s, " %4lldus%c: ",
 673                                 abs_ts,
 674                                 rel_ts > preempt_mark_thresh_us ? '!' :
 675                                   rel_ts > 1 ? '+' : ' ');
 676         } else { /* !verbose && !in_ns */
 677                 return trace_seq_printf(s, " %4lld: ", abs_ts);
 678         }
 679 }
 680
 681 int trace_print_context(struct trace_iterator *iter)
 682 {
 683         struct trace_seq *s = &iter->seq;
 684         struct trace_entry *entry = iter->ent;
 685         unsigned long long t;
 686         unsigned long secs, usec_rem;
 687         char comm[TASK_COMM_LEN];
 688         int ret;
 689
 690         trace_find_cmdline(entry->pid, comm);
 691
 692         ret = trace_seq_printf(s, "%16s-%-5d [%03d] ",
 693                                comm, entry->pid, iter->cpu);
 694         if (!ret)
 695                 return 0;
 696
 697         if (trace_flags & TRACE_ITER_IRQ_INFO) {
 698                 ret = trace_print_lat_fmt(s, entry);
 699                 if (!ret)
 700                         return 0;
 701         }
 702
 703         if (iter->iter_flags & TRACE_FILE_TIME_IN_NS) {
 704                 t = ns2usecs(iter->ts);
 705                 usec_rem = do_div(t, USEC_PER_SEC);
 706                 secs = (unsigned long)t;
 707                 return trace_seq_printf(s, " %5lu.%06lu: ", secs, usec_rem);
 708         } else
 709                 return trace_seq_printf(s, " %12llu: ", iter->ts);
 710 }
 711
 712 int trace_print_lat_context(struct trace_iterator *iter)
 713 {
 714         u64 next_ts;
 715         int ret;
 716         /* trace_find_next_entry will reset ent_size */
 717         int ent_size = iter->ent_size;
 718         struct trace_seq *s = &iter->seq;
 719         struct trace_entry *entry = iter->ent,
 720                            *next_entry = trace_find_next_entry(iter, NULL,
 721                                                                &next_ts);
 722         unsigned long verbose = (trace_flags & TRACE_ITER_VERBOSE);
 723
 724         /* Restore the original ent_size */
 725         iter->ent_size = ent_size;
 726
 727         if (!next_entry)
 728                 next_ts = iter->ts;
 729
 730         if (verbose) {
 731                 char comm[TASK_COMM_LEN];
 732
 733                 trace_find_cmdline(entry->pid, comm);
 734
 735                 ret = trace_seq_printf(
 736                                 s, "%16s %5d %3d %d %08x %08lx ",
 737                                 comm, entry->pid, iter->cpu, entry->flags,
 738                                 entry->preempt_count, iter->idx);
 739         } else {
 740                 ret = lat_print_generic(s, entry, iter->cpu);
 741         }
 742
 743         if (ret)
 744                 ret = lat_print_timestamp(iter, next_ts);
 745
 746         return ret;
 747 }
 748
 749 static const char state_to_char[] = TASK_STATE_TO_CHAR_STR;
 750
 751 static int task_state_char(unsigned long state)
 752 {
 753         int bit = state ? __ffs(state) + 1 : 0;
 754
 755         return bit < sizeof(state_to_char) - 1 ? state_to_char[bit] : '?';
 756 }
 757
 758 /**
 759  * ftrace_find_event - find a registered event
 760  * @type: the type of event to look for
 761  *
 762  * Returns an event of type @type otherwise NULL
 763  * Called with trace_event_read_lock() held.
 764  */
 765 struct trace_event *ftrace_find_event(int type)
 766 {
 767         struct trace_event *event;
 768         struct hlist_node *n;
 769         unsigned key;
 770
 771         key = type & (EVENT_HASHSIZE - 1);
 772
 773         hlist_for_each_entry(event, n, &event_hash[key], node) {
 774                 if (event->type == type)
 775                         return event;
 776         }
 777
 778         return NULL;
 779 }
 780
 781 static LIST_HEAD(ftrace_event_list);
 782
 783 static int trace_search_list(struct list_head **list)
 784 {
 785         struct trace_event *e;
 786         int last = __TRACE_LAST_TYPE;
 787
 788         if (list_empty(&ftrace_event_list)) {
 789                 *list = &ftrace_event_list;
 790                 return last + 1;
 791         }
 792
 793         /*
 794          * We used up all possible max events,
 795          * lets see if somebody freed one.
 796          */
 797         list_for_each_entry(e, &ftrace_event_list, list) {
 798                 if (e->type != last + 1)
 799                         break;
 800                 last++;
 801         }
 802
 803         /* Did we used up all 65 thousand events??? */
 804         if ((last + 1) > FTRACE_MAX_EVENT)
 805                 return 0;
 806
 807         *list = &e->list;
 808         return last + 1;
 809 }
 810
 811 void trace_event_read_lock(void)
 812 {
 813         down_read(&trace_event_mutex);
 814 }
 815
 816 void trace_event_read_unlock(void)
 817 {
 818         up_read(&trace_event_mutex);
 819 }
 820
 821 /**
 822  * register_ftrace_event - register output for an event type
 823  * @event: the event type to register
 824  *
 825  * Event types are stored in a hash and this hash is used to
 826  * find a way to print an event. If the @event->type is set
 827  * then it will use that type, otherwise it will assign a
 828  * type to use.
 829  *
 830  * If you assign your own type, please make sure it is added
 831  * to the trace_type enum in trace.h, to avoid collisions
 832  * with the dynamic types.
 833  *
 834  * Returns the event type number or zero on error.
 835  */
 836 int register_ftrace_event(struct trace_event *event)
 837 {
 838         unsigned key;
 839         int ret = 0;
 840
 841         down_write(&trace_event_mutex);
 842
 843         if (WARN_ON(!event))
 844                 goto out;
 845
 846         if (WARN_ON(!event->funcs))
 847                 goto out;
 848
 849         INIT_LIST_HEAD(&event->list);
 850
 851         if (!event->type) {
 852                 struct list_head *list = NULL;
 853
 854                 if (next_event_type > FTRACE_MAX_EVENT) {
 855
 856                         event->type = trace_search_list(&list);
 857                         if (!event->type)
 858                                 goto out;
 859
 860                 } else {
 861
 862                         event->type = next_event_type++;
 863                         list = &ftrace_event_list;
 864                 }
 865
 866                 if (WARN_ON(ftrace_find_event(event->type)))
 867                         goto out;
 868
 869                 list_add_tail(&event->list, list);
 870
 871         } else if (event->type > __TRACE_LAST_TYPE) {
 872                 printk(KERN_WARNING "Need to add type to trace.h\n");
 873                 WARN_ON(1);
 874                 goto out;
 875         } else {
 876                 /* Is this event already used */
 877                 if (ftrace_find_event(event->type))
 878                         goto out;
 879         }
 880
 881         if (event->funcs->trace == NULL)
 882                 event->funcs->trace = trace_nop_print;
 883         if (event->funcs->raw == NULL)
 884                 event->funcs->raw = trace_nop_print;
 885         if (event->funcs->hex == NULL)
 886                 event->funcs->hex = trace_nop_print;
 887         if (event->funcs->binary == NULL)
 888                 event->funcs->binary = trace_nop_print;
 889
 890         key = event->type & (EVENT_HASHSIZE - 1);
 891
 892         hlist_add_head(&event->node, &event_hash[key]);
 893
 894         ret = event->type;
 895  out:
 896         up_write(&trace_event_mutex);
 897
 898         return ret;
 899 }
 900 EXPORT_SYMBOL_GPL(register_ftrace_event);
 901
 902 /*
 903  * Used by module code with the trace_event_mutex held for write.
 904  */
 905 int __unregister_ftrace_event(struct trace_event *event)
 906 {
 907         hlist_del(&event->node);
 908         list_del(&event->list);
 909         return 0;
 910 }
 911
 912 /**
 913  * unregister_ftrace_event - remove a no longer used event
 914  * @event: the event to remove
 915  */
 916 int unregister_ftrace_event(struct trace_event *event)
 917 {
 918         down_write(&trace_event_mutex);
 919         __unregister_ftrace_event(event);
 920         up_write(&trace_event_mutex);
 921
 922         return 0;
 923 }
 924 EXPORT_SYMBOL_GPL(unregister_ftrace_event);
 925
 926 /*
 927  * Standard events
 928  */
 929
 930 enum print_line_t trace_nop_print(struct trace_iterator *iter, int flags,
 931                                   struct trace_event *event)
 932 {
 933         if (!trace_seq_printf(&iter->seq, "type: %d\n", iter->ent->type))
 934                 return TRACE_TYPE_PARTIAL_LINE;
 935
 936         return TRACE_TYPE_HANDLED;
 937 }
 938
 939 /* TRACE_FN */
 940 static enum print_line_t trace_fn_trace(struct trace_iterator *iter, int flags,
 941                                         struct trace_event *event)
 942 {
 943         struct ftrace_entry *field;
 944         struct trace_seq *s = &iter->seq;
 945
 946         trace_assign_type(field, iter->ent);
 947
 948         if (!seq_print_ip_sym(s, field->ip, flags))
 949                 goto partial;
 950
 951         if ((flags & TRACE_ITER_PRINT_PARENT) && field->parent_ip) {
 952                 if (!trace_seq_printf(s, " <-"))
 953                         goto partial;
 954                 if (!seq_print_ip_sym(s,
 955                                       field->parent_ip,
 956                                       flags))
 957                         goto partial;
 958         }
 959         if (!trace_seq_printf(s, "\n"))
 960                 goto partial;
 961
 962         return TRACE_TYPE_HANDLED;
 963
 964  partial:
 965         return TRACE_TYPE_PARTIAL_LINE;
 966 }
 967
 968 static enum print_line_t trace_fn_raw(struct trace_iterator *iter, int flags,
 969                                       struct trace_event *event)
 970 {
 971         struct ftrace_entry *field;
 972
 973         trace_assign_type(field, iter->ent);
 974
 975         if (!trace_seq_printf(&iter->seq, "%lx %lx\n",
 976                               field->ip,
 977                               field->parent_ip))
 978                 return TRACE_TYPE_PARTIAL_LINE;
 979
 980         return TRACE_TYPE_HANDLED;
 981 }
 982
 983 static enum print_line_t trace_fn_hex(struct trace_iterator *iter, int flags,
 984                                       struct trace_event *event)
 985 {
 986         struct ftrace_entry *field;
 987         struct trace_seq *s = &iter->seq;
 988
 989         trace_assign_type(field, iter->ent);
 990
 991         SEQ_PUT_HEX_FIELD_RET(s, field->ip);
 992         SEQ_PUT_HEX_FIELD_RET(s, field->parent_ip);
 993
 994         return TRACE_TYPE_HANDLED;
 995 }
 996
 997 static enum print_line_t trace_fn_bin(struct trace_iterator *iter, int flags,
 998                                       struct trace_event *event)
 999 {
1000         struct ftrace_entry *field;
1001         struct trace_seq *s = &iter->seq;
1002
1003         trace_assign_type(field, iter->ent);
1004
1005         SEQ_PUT_FIELD_RET(s, field->ip);
1006         SEQ_PUT_FIELD_RET(s, field->parent_ip);
1007
1008         return TRACE_TYPE_HANDLED;
1009 }
1010
1011 static struct trace_event_functions trace_fn_funcs = {
1012         .trace          = trace_fn_trace,
1013         .raw            = trace_fn_raw,
1014         .hex            = trace_fn_hex,
1015         .binary         = trace_fn_bin,
1016 };
1017
1018 static struct trace_event trace_fn_event = {
1019         .type           = TRACE_FN,
1020         .funcs          = &trace_fn_funcs,
1021 };
1022
1023 /* TRACE_CTX an TRACE_WAKE */
1024 static enum print_line_t trace_ctxwake_print(struct trace_iterator *iter,
1025                                              char *delim)
1026 {
1027         struct ctx_switch_entry *field;
1028         char comm[TASK_COMM_LEN];
1029         int S, T;
1030
1031
1032         trace_assign_type(field, iter->ent);
1033
1034         T = task_state_char(field->next_state);
1035         S = task_state_char(field->prev_state);
1036         trace_find_cmdline(field->next_pid, comm);
1037         if (!trace_seq_printf(&iter->seq,
1038                               " %5d:%3d:%c %s [%03d] %5d:%3d:%c %s\n",
1039                               field->prev_pid,
1040                               field->prev_prio,
1041                               S, delim,
1042                               field->next_cpu,
1043                               field->next_pid,
1044                               field->next_prio,
1045                               T, comm))
1046                 return TRACE_TYPE_PARTIAL_LINE;
1047
1048         return TRACE_TYPE_HANDLED;
1049 }
1050
1051 static enum print_line_t trace_ctx_print(struct trace_iterator *iter, int flags,
1052                                          struct trace_event *event)
1053 {
1054         return trace_ctxwake_print(iter, "==>");
1055 }
1056
1057 static enum print_line_t trace_wake_print(struct trace_iterator *iter,
1058                                           int flags, struct trace_event *event)
1059 {
1060         return trace_ctxwake_print(iter, "  +");
1061 }
1062
1063 static int trace_ctxwake_raw(struct trace_iterator *iter, char S)
1064 {
1065         struct ctx_switch_entry *field;
1066         int T;
1067
1068         trace_assign_type(field, iter->ent);
1069
1070         if (!S)
1071                 S = task_state_char(field->prev_state);
1072         T = task_state_char(field->next_state);
1073         if (!trace_seq_printf(&iter->seq, "%d %d %c %d %d %d %c\n",
1074                               field->prev_pid,
1075                               field->prev_prio,
1076                               S,
1077                               field->next_cpu,
1078                               field->next_pid,
1079                               field->next_prio,
1080                               T))
1081                 return TRACE_TYPE_PARTIAL_LINE;
1082
1083         return TRACE_TYPE_HANDLED;
1084 }
1085
1086 static enum print_line_t trace_ctx_raw(struct trace_iterator *iter, int flags,
1087                                        struct trace_event *event)
1088 {
1089         return trace_ctxwake_raw(iter, 0);
1090 }
1091
1092 static enum print_line_t trace_wake_raw(struct trace_iterator *iter, int flags,
1093                                         struct trace_event *event)
1094 {
1095         return trace_ctxwake_raw(iter, '+');
1096 }
1097
1098
1099 static int trace_ctxwake_hex(struct trace_iterator *iter, char S)
1100 {
1101         struct ctx_switch_entry *field;
1102         struct trace_seq *s = &iter->seq;
1103         int T;
1104
1105         trace_assign_type(field, iter->ent);
1106
1107         if (!S)
1108                 S = task_state_char(field->prev_state);
1109         T = task_state_char(field->next_state);
1110
1111         SEQ_PUT_HEX_FIELD_RET(s, field->prev_pid);
1112         SEQ_PUT_HEX_FIELD_RET(s, field->prev_prio);
1113         SEQ_PUT_HEX_FIELD_RET(s, S);
1114         SEQ_PUT_HEX_FIELD_RET(s, field->next_cpu);
1115         SEQ_PUT_HEX_FIELD_RET(s, field->next_pid);
1116         SEQ_PUT_HEX_FIELD_RET(s, field->next_prio);
1117         SEQ_PUT_HEX_FIELD_RET(s, T);
1118
1119         return TRACE_TYPE_HANDLED;
1120 }
1121
1122 static enum print_line_t trace_ctx_hex(struct trace_iterator *iter, int flags,
1123                                        struct trace_event *event)
1124 {
1125         return trace_ctxwake_hex(iter, 0);
1126 }
1127
1128 static enum print_line_t trace_wake_hex(struct trace_iterator *iter, int flags,
1129                                         struct trace_event *event)
1130 {
1131         return trace_ctxwake_hex(iter, '+');
1132 }
1133
1134 static enum print_line_t trace_ctxwake_bin(struct trace_iterator *iter,
1135                                            int flags, struct trace_event *event)
1136 {
1137         struct ctx_switch_entry *field;
1138         struct trace_seq *s = &iter->seq;
1139
1140         trace_assign_type(field, iter->ent);
1141
1142         SEQ_PUT_FIELD_RET(s, field->prev_pid);
1143         SEQ_PUT_FIELD_RET(s, field->prev_prio);
1144         SEQ_PUT_FIELD_RET(s, field->prev_state);
1145         SEQ_PUT_FIELD_RET(s, field->next_pid);
1146         SEQ_PUT_FIELD_RET(s, field->next_prio);
1147         SEQ_PUT_FIELD_RET(s, field->next_state);
1148
1149         return TRACE_TYPE_HANDLED;
1150 }
1151
1152 static struct trace_event_functions trace_ctx_funcs = {
1153         .trace          = trace_ctx_print,
1154         .raw            = trace_ctx_raw,
1155         .hex            = trace_ctx_hex,
1156         .binary         = trace_ctxwake_bin,
1157 };
1158
1159 static struct trace_event trace_ctx_event = {
1160         .type           = TRACE_CTX,
1161         .funcs          = &trace_ctx_funcs,
1162 };
1163
1164 static struct trace_event_functions trace_wake_funcs = {
1165         .trace          = trace_wake_print,
1166         .raw            = trace_wake_raw,
1167         .hex            = trace_wake_hex,
1168         .binary         = trace_ctxwake_bin,
1169 };
1170
1171 static struct trace_event trace_wake_event = {
1172         .type           = TRACE_WAKE,
1173         .funcs          = &trace_wake_funcs,
1174 };
1175
1176 /* TRACE_STACK */
1177
1178 static enum print_line_t trace_stack_print(struct trace_iterator *iter,
1179                                            int flags, struct trace_event *event)
1180 {
1181         struct stack_entry *field;
1182         struct trace_seq *s = &iter->seq;
1183         unsigned long *p;
1184         unsigned long *end;
1185
1186         trace_assign_type(field, iter->ent);
1187         end = (unsigned long *)((long)iter->ent + iter->ent_size);
1188
1189         if (!trace_seq_puts(s, "<stack trace>\n"))
1190                 goto partial;
1191
1192         for (p = field->caller; p && *p != ULONG_MAX && p < end; p++) {
1193                 if (!trace_seq_puts(s, " => "))
1194                         goto partial;
1195
1196                 if (!seq_print_ip_sym(s, *p, flags))
1197                         goto partial;
1198                 if (!trace_seq_puts(s, "\n"))
1199                         goto partial;
1200         }
1201
1202         return TRACE_TYPE_HANDLED;
1203
1204  partial:
1205         return TRACE_TYPE_PARTIAL_LINE;
1206 }
1207
1208 static struct trace_event_functions trace_stack_funcs = {
1209         .trace          = trace_stack_print,
1210 };
1211
1212 static struct trace_event trace_stack_event = {
1213         .type           = TRACE_STACK,
1214         .funcs          = &trace_stack_funcs,
1215 };
1216
1217 /* TRACE_USER_STACK */
1218 static enum print_line_t trace_user_stack_print(struct trace_iterator *iter,
1219                                                 int flags, struct trace_event *event)
1220 {
1221         struct userstack_entry *field;
1222         struct trace_seq *s = &iter->seq;
1223
1224         trace_assign_type(field, iter->ent);
1225
1226         if (!trace_seq_puts(s, "<user stack trace>\n"))
1227                 goto partial;
1228
1229         if (!seq_print_userip_objs(field, s, flags))
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_user_stack_funcs = {
1239         .trace          = trace_user_stack_print,
1240 };
1241
1242 static struct trace_event trace_user_stack_event = {
1243         .type           = TRACE_USER_STACK,
1244         .funcs          = &trace_user_stack_funcs,
1245 };
1246
1247 /* TRACE_BPRINT */
1248 static enum print_line_t
1249 trace_bprint_print(struct trace_iterator *iter, int flags,
1250                    struct trace_event *event)
1251 {
1252         struct trace_entry *entry = iter->ent;
1253         struct trace_seq *s = &iter->seq;
1254         struct bprint_entry *field;
1255
1256         trace_assign_type(field, entry);
1257
1258         if (!seq_print_ip_sym(s, field->ip, flags))
1259                 goto partial;
1260
1261         if (!trace_seq_puts(s, ": "))
1262                 goto partial;
1263
1264         if (!trace_seq_bprintf(s, field->fmt, field->buf))
1265                 goto partial;
1266
1267         return TRACE_TYPE_HANDLED;
1268
1269  partial:
1270         return TRACE_TYPE_PARTIAL_LINE;
1271 }
1272
1273
1274 static enum print_line_t
1275 trace_bprint_raw(struct trace_iterator *iter, int flags,
1276                  struct trace_event *event)
1277 {
1278         struct bprint_entry *field;
1279         struct trace_seq *s = &iter->seq;
1280
1281         trace_assign_type(field, iter->ent);
1282
1283         if (!trace_seq_printf(s, ": %lx : ", field->ip))
1284                 goto partial;
1285
1286         if (!trace_seq_bprintf(s, field->fmt, field->buf))
1287                 goto partial;
1288
1289         return TRACE_TYPE_HANDLED;
1290
1291  partial:
1292         return TRACE_TYPE_PARTIAL_LINE;
1293 }
1294
1295 static struct trace_event_functions trace_bprint_funcs = {
1296         .trace          = trace_bprint_print,
1297         .raw            = trace_bprint_raw,
1298 };
1299
1300 static struct trace_event trace_bprint_event = {
1301         .type           = TRACE_BPRINT,
1302         .funcs          = &trace_bprint_funcs,
1303 };
1304
1305 /* TRACE_PRINT */
1306 static enum print_line_t trace_print_print(struct trace_iterator *iter,
1307                                            int flags, struct trace_event *event)
1308 {
1309         struct print_entry *field;
1310         struct trace_seq *s = &iter->seq;
1311
1312         trace_assign_type(field, iter->ent);
1313
1314         if (!seq_print_ip_sym(s, field->ip, flags))
1315                 goto partial;
1316
1317         if (!trace_seq_printf(s, ": %s", field->buf))
1318                 goto partial;
1319
1320         return TRACE_TYPE_HANDLED;
1321
1322  partial:
1323         return TRACE_TYPE_PARTIAL_LINE;
1324 }
1325
1326 static enum print_line_t trace_print_raw(struct trace_iterator *iter, int flags,
1327                                          struct trace_event *event)
1328 {
1329         struct print_entry *field;
1330
1331         trace_assign_type(field, iter->ent);
1332
1333         if (!trace_seq_printf(&iter->seq, "# %lx %s", field->ip, field->buf))
1334                 goto partial;
1335
1336         return TRACE_TYPE_HANDLED;
1337
1338  partial:
1339         return TRACE_TYPE_PARTIAL_LINE;
1340 }
1341
1342 static struct trace_event_functions trace_print_funcs = {
1343         .trace          = trace_print_print,
1344         .raw            = trace_print_raw,
1345 };
1346
1347 static struct trace_event trace_print_event = {
1348         .type           = TRACE_PRINT,
1349         .funcs          = &trace_print_funcs,
1350 };
1351
1352
1353 static struct trace_event *events[] __initdata = {
1354         &trace_fn_event,
1355         &trace_ctx_event,
1356         &trace_wake_event,
1357         &trace_stack_event,
1358         &trace_user_stack_event,
1359         &trace_bprint_event,
1360         &trace_print_event,
1361         NULL
1362 };
1363
1364 __init static int init_events(void)
1365 {
1366         struct trace_event *event;
1367         int i, ret;
1368
1369         for (i = 0; events[i]; i++) {
1370                 event = events[i];
1371
1372                 ret = register_ftrace_event(event);
1373                 if (!ret) {
1374                         printk(KERN_WARNING "event %d failed to register\n",
1375                                event->type);
1376                         WARN_ON_ONCE(1);
1377                 }
1378         }
1379
1380         return 0;
1381 }
1382 early_initcall(init_events);