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 #include <linux/sched/clock.h>
  12 #include <linux/sched/mm.h>
  13
  14 #include "trace_output.h"
  15
  16 /* must be a power of 2 */
  17 #define EVENT_HASHSIZE  128
  18
  19 DECLARE_RWSEM(trace_event_sem);
  20
  21 static struct hlist_head event_hash[EVENT_HASHSIZE] __read_mostly;
  22
  23 static int next_event_type = __TRACE_LAST_TYPE + 1;
  24
  25 enum print_line_t trace_print_bputs_msg_only(struct trace_iterator *iter)
  26 {
  27         struct trace_seq *s = &iter->seq;
  28         struct trace_entry *entry = iter->ent;
  29         struct bputs_entry *field;
  30
  31         trace_assign_type(field, entry);
  32
  33         trace_seq_puts(s, field->str);
  34
  35         return trace_handle_return(s);
  36 }
  37
  38 enum print_line_t trace_print_bprintk_msg_only(struct trace_iterator *iter)
  39 {
  40         struct trace_seq *s = &iter->seq;
  41         struct trace_entry *entry = iter->ent;
  42         struct bprint_entry *field;
  43
  44         trace_assign_type(field, entry);
  45
  46         trace_seq_bprintf(s, field->fmt, field->buf);
  47
  48         return trace_handle_return(s);
  49 }
  50
  51 enum print_line_t trace_print_printk_msg_only(struct trace_iterator *iter)
  52 {
  53         struct trace_seq *s = &iter->seq;
  54         struct trace_entry *entry = iter->ent;
  55         struct print_entry *field;
  56
  57         trace_assign_type(field, entry);
  58
  59         trace_seq_puts(s, field->buf);
  60
  61         return trace_handle_return(s);
  62 }
  63
  64 const char *
  65 trace_print_flags_seq(struct trace_seq *p, const char *delim,
  66                       unsigned long flags,
  67                       const struct trace_print_flags *flag_array)
  68 {
  69         unsigned long mask;
  70         const char *str;
  71         const char *ret = trace_seq_buffer_ptr(p);
  72         int i, first = 1;
  73
  74         for (i = 0;  flag_array[i].name && flags; i++) {
  75
  76                 mask = flag_array[i].mask;
  77                 if ((flags & mask) != mask)
  78                         continue;
  79
  80                 str = flag_array[i].name;
  81                 flags &= ~mask;
  82                 if (!first && delim)
  83                         trace_seq_puts(p, delim);
  84                 else
  85                         first = 0;
  86                 trace_seq_puts(p, str);
  87         }
  88
  89         /* check for left over flags */
  90         if (flags) {
  91                 if (!first && delim)
  92                         trace_seq_puts(p, delim);
  93                 trace_seq_printf(p, "0x%lx", flags);
  94         }
  95
  96         trace_seq_putc(p, 0);
  97
  98         return ret;
  99 }
 100 EXPORT_SYMBOL(trace_print_flags_seq);
 101
 102 const char *
 103 trace_print_symbols_seq(struct trace_seq *p, unsigned long val,
 104                         const struct trace_print_flags *symbol_array)
 105 {
 106         int i;
 107         const char *ret = trace_seq_buffer_ptr(p);
 108
 109         for (i = 0;  symbol_array[i].name; i++) {
 110
 111                 if (val != symbol_array[i].mask)
 112                         continue;
 113
 114                 trace_seq_puts(p, symbol_array[i].name);
 115                 break;
 116         }
 117
 118         if (ret == (const char *)(trace_seq_buffer_ptr(p)))
 119                 trace_seq_printf(p, "0x%lx", val);
 120
 121         trace_seq_putc(p, 0);
 122
 123         return ret;
 124 }
 125 EXPORT_SYMBOL(trace_print_symbols_seq);
 126
 127 #if BITS_PER_LONG == 32
 128 const char *
 129 trace_print_flags_seq_u64(struct trace_seq *p, const char *delim,
 130                       unsigned long long flags,
 131                       const struct trace_print_flags_u64 *flag_array)
 132 {
 133         unsigned long long mask;
 134         const char *str;
 135         const char *ret = trace_seq_buffer_ptr(p);
 136         int i, first = 1;
 137
 138         for (i = 0;  flag_array[i].name && flags; i++) {
 139
 140                 mask = flag_array[i].mask;
 141                 if ((flags & mask) != mask)
 142                         continue;
 143
 144                 str = flag_array[i].name;
 145                 flags &= ~mask;
 146                 if (!first && delim)
 147                         trace_seq_puts(p, delim);
 148                 else
 149                         first = 0;
 150                 trace_seq_puts(p, str);
 151         }
 152
 153         /* check for left over flags */
 154         if (flags) {
 155                 if (!first && delim)
 156                         trace_seq_puts(p, delim);
 157                 trace_seq_printf(p, "0x%llx", flags);
 158         }
 159
 160         trace_seq_putc(p, 0);
 161
 162         return ret;
 163 }
 164 EXPORT_SYMBOL(trace_print_flags_seq_u64);
 165
 166 const char *
 167 trace_print_symbols_seq_u64(struct trace_seq *p, unsigned long long val,
 168                          const struct trace_print_flags_u64 *symbol_array)
 169 {
 170         int i;
 171         const char *ret = trace_seq_buffer_ptr(p);
 172
 173         for (i = 0;  symbol_array[i].name; i++) {
 174
 175                 if (val != symbol_array[i].mask)
 176                         continue;
 177
 178                 trace_seq_puts(p, symbol_array[i].name);
 179                 break;
 180         }
 181
 182         if (ret == (const char *)(trace_seq_buffer_ptr(p)))
 183                 trace_seq_printf(p, "0x%llx", val);
 184
 185         trace_seq_putc(p, 0);
 186
 187         return ret;
 188 }
 189 EXPORT_SYMBOL(trace_print_symbols_seq_u64);
 190 #endif
 191
 192 const char *
 193 trace_print_bitmask_seq(struct trace_seq *p, void *bitmask_ptr,
 194                         unsigned int bitmask_size)
 195 {
 196         const char *ret = trace_seq_buffer_ptr(p);
 197
 198         trace_seq_bitmask(p, bitmask_ptr, bitmask_size * 8);
 199         trace_seq_putc(p, 0);
 200
 201         return ret;
 202 }
 203 EXPORT_SYMBOL_GPL(trace_print_bitmask_seq);
 204
 205 /**
 206  * trace_print_hex_seq - print buffer as hex sequence
 207  * @p: trace seq struct to write to
 208  * @buf: The buffer to print
 209  * @buf_len: Length of @buf in bytes
 210  * @concatenate: Print @buf as single hex string or with spacing
 211  *
 212  * Prints the passed buffer as a hex sequence either as a whole,
 213  * single hex string if @concatenate is true or with spacing after
 214  * each byte in case @concatenate is false.
 215  */
 216 const char *
 217 trace_print_hex_seq(struct trace_seq *p, const unsigned char *buf, int buf_len,
 218                     bool concatenate)
 219 {
 220         int i;
 221         const char *ret = trace_seq_buffer_ptr(p);
 222
 223         for (i = 0; i < buf_len; i++)
 224                 trace_seq_printf(p, "%s%2.2x", concatenate || i == 0 ? "" : " ",
 225                                  buf[i]);
 226         trace_seq_putc(p, 0);
 227
 228         return ret;
 229 }
 230 EXPORT_SYMBOL(trace_print_hex_seq);
 231
 232 const char *
 233 trace_print_array_seq(struct trace_seq *p, const void *buf, int count,
 234                       size_t el_size)
 235 {
 236         const char *ret = trace_seq_buffer_ptr(p);
 237         const char *prefix = "";
 238         void *ptr = (void *)buf;
 239         size_t buf_len = count * el_size;
 240
 241         trace_seq_putc(p, '{');
 242
 243         while (ptr < buf + buf_len) {
 244                 switch (el_size) {
 245                 case 1:
 246                         trace_seq_printf(p, "%s0x%x", prefix,
 247                                          *(u8 *)ptr);
 248                         break;
 249                 case 2:
 250                         trace_seq_printf(p, "%s0x%x", prefix,
 251                                          *(u16 *)ptr);
 252                         break;
 253                 case 4:
 254                         trace_seq_printf(p, "%s0x%x", prefix,
 255                                          *(u32 *)ptr);
 256                         break;
 257                 case 8:
 258                         trace_seq_printf(p, "%s0x%llx", prefix,
 259                                          *(u64 *)ptr);
 260                         break;
 261                 default:
 262                         trace_seq_printf(p, "BAD SIZE:%zu 0x%x", el_size,
 263                                          *(u8 *)ptr);
 264                         el_size = 1;
 265                 }
 266                 prefix = ",";
 267                 ptr += el_size;
 268         }
 269
 270         trace_seq_putc(p, '}');
 271         trace_seq_putc(p, 0);
 272
 273         return ret;
 274 }
 275 EXPORT_SYMBOL(trace_print_array_seq);
 276
 277 int trace_raw_output_prep(struct trace_iterator *iter,
 278                           struct trace_event *trace_event)
 279 {
 280         struct trace_event_call *event;
 281         struct trace_seq *s = &iter->seq;
 282         struct trace_seq *p = &iter->tmp_seq;
 283         struct trace_entry *entry;
 284
 285         event = container_of(trace_event, struct trace_event_call, event);
 286         entry = iter->ent;
 287
 288         if (entry->type != event->event.type) {
 289                 WARN_ON_ONCE(1);
 290                 return TRACE_TYPE_UNHANDLED;
 291         }
 292
 293         trace_seq_init(p);
 294         trace_seq_printf(s, "%s: ", trace_event_name(event));
 295
 296         return trace_handle_return(s);
 297 }
 298 EXPORT_SYMBOL(trace_raw_output_prep);
 299
 300 static int trace_output_raw(struct trace_iterator *iter, char *name,
 301                             char *fmt, va_list ap)
 302 {
 303         struct trace_seq *s = &iter->seq;
 304
 305         trace_seq_printf(s, "%s: ", name);
 306         trace_seq_vprintf(s, fmt, ap);
 307
 308         return trace_handle_return(s);
 309 }
 310
 311 int trace_output_call(struct trace_iterator *iter, char *name, char *fmt, ...)
 312 {
 313         va_list ap;
 314         int ret;
 315
 316         va_start(ap, fmt);
 317         ret = trace_output_raw(iter, name, fmt, ap);
 318         va_end(ap);
 319
 320         return ret;
 321 }
 322 EXPORT_SYMBOL_GPL(trace_output_call);
 323
 324 #ifdef CONFIG_KRETPROBES
 325 static inline const char *kretprobed(const char *name)
 326 {
 327         static const char tramp_name[] = "kretprobe_trampoline";
 328         int size = sizeof(tramp_name);
 329
 330         if (strncmp(tramp_name, name, size) == 0)
 331                 return "[unknown/kretprobe'd]";
 332         return name;
 333 }
 334 #else
 335 static inline const char *kretprobed(const char *name)
 336 {
 337         return name;
 338 }
 339 #endif /* CONFIG_KRETPROBES */
 340
 341 static void
 342 seq_print_sym_short(struct trace_seq *s, const char *fmt, unsigned long address)
 343 {
 344 #ifdef CONFIG_KALLSYMS
 345         char str[KSYM_SYMBOL_LEN];
 346         const char *name;
 347
 348         kallsyms_lookup(address, NULL, NULL, NULL, str);
 349
 350         name = kretprobed(str);
 351
 352         trace_seq_printf(s, fmt, name);
 353 #endif
 354 }
 355
 356 static void
 357 seq_print_sym_offset(struct trace_seq *s, const char *fmt,
 358                      unsigned long address)
 359 {
 360 #ifdef CONFIG_KALLSYMS
 361         char str[KSYM_SYMBOL_LEN];
 362         const char *name;
 363
 364         sprint_symbol(str, address);
 365         name = kretprobed(str);
 366
 367         trace_seq_printf(s, fmt, name);
 368 #endif
 369 }
 370
 371 #ifndef CONFIG_64BIT
 372 # define IP_FMT "%08lx"
 373 #else
 374 # define IP_FMT "%016lx"
 375 #endif
 376
 377 static int seq_print_user_ip(struct trace_seq *s, struct mm_struct *mm,
 378                              unsigned long ip, unsigned long sym_flags)
 379 {
 380         struct file *file = NULL;
 381         unsigned long vmstart = 0;
 382         int ret = 1;
 383
 384         if (s->full)
 385                 return 0;
 386
 387         if (mm) {
 388                 const struct vm_area_struct *vma;
 389
 390                 down_read(&mm->mmap_sem);
 391                 vma = find_vma(mm, ip);
 392                 if (vma) {
 393                         file = vma->vm_file;
 394                         vmstart = vma->vm_start;
 395                 }
 396                 if (file) {
 397                         ret = trace_seq_path(s, &file->f_path);
 398                         if (ret)
 399                                 trace_seq_printf(s, "[+0x%lx]",
 400                                                  ip - vmstart);
 401                 }
 402                 up_read(&mm->mmap_sem);
 403         }
 404         if (ret && ((sym_flags & TRACE_ITER_SYM_ADDR) || !file))
 405                 trace_seq_printf(s, " <" IP_FMT ">", ip);
 406         return !trace_seq_has_overflowed(s);
 407 }
 408
 409 int
 410 seq_print_ip_sym(struct trace_seq *s, unsigned long ip, unsigned long sym_flags)
 411 {
 412         if (!ip) {
 413                 trace_seq_putc(s, '0');
 414                 goto out;
 415         }
 416
 417         if (sym_flags & TRACE_ITER_SYM_OFFSET)
 418                 seq_print_sym_offset(s, "%s", ip);
 419         else
 420                 seq_print_sym_short(s, "%s", ip);
 421
 422         if (sym_flags & TRACE_ITER_SYM_ADDR)
 423                 trace_seq_printf(s, " <" IP_FMT ">", ip);
 424
 425  out:
 426         return !trace_seq_has_overflowed(s);
 427 }
 428
 429 /**
 430  * trace_print_lat_fmt - print the irq, preempt and lockdep fields
 431  * @s: trace seq struct to write to
 432  * @entry: The trace entry field from the ring buffer
 433  *
 434  * Prints the generic fields of irqs off, in hard or softirq, preempt
 435  * count.
 436  */
 437 int trace_print_lat_fmt(struct trace_seq *s, struct trace_entry *entry)
 438 {
 439         char hardsoft_irq;
 440         char need_resched;
 441         char irqs_off;
 442         int hardirq;
 443         int softirq;
 444         int nmi;
 445
 446         nmi = entry->flags & TRACE_FLAG_NMI;
 447         hardirq = entry->flags & TRACE_FLAG_HARDIRQ;
 448         softirq = entry->flags & TRACE_FLAG_SOFTIRQ;
 449
 450         irqs_off =
 451                 (entry->flags & TRACE_FLAG_IRQS_OFF) ? 'd' :
 452                 (entry->flags & TRACE_FLAG_IRQS_NOSUPPORT) ? 'X' :
 453                 '.';
 454
 455         switch (entry->flags & (TRACE_FLAG_NEED_RESCHED |
 456                                 TRACE_FLAG_PREEMPT_RESCHED)) {
 457         case TRACE_FLAG_NEED_RESCHED | TRACE_FLAG_PREEMPT_RESCHED:
 458                 need_resched = 'N';
 459                 break;
 460         case TRACE_FLAG_NEED_RESCHED:
 461                 need_resched = 'n';
 462                 break;
 463         case TRACE_FLAG_PREEMPT_RESCHED:
 464                 need_resched = 'p';
 465                 break;
 466         default:
 467                 need_resched = '.';
 468                 break;
 469         }
 470
 471         hardsoft_irq =
 472                 (nmi && hardirq)     ? 'Z' :
 473                 nmi                  ? 'z' :
 474                 (hardirq && softirq) ? 'H' :
 475                 hardirq              ? 'h' :
 476                 softirq              ? 's' :
 477                                        '.' ;
 478
 479         trace_seq_printf(s, "%c%c%c",
 480                          irqs_off, need_resched, hardsoft_irq);
 481
 482         if (entry->preempt_count)
 483                 trace_seq_printf(s, "%x", entry->preempt_count);
 484         else
 485                 trace_seq_putc(s, '.');
 486
 487         return !trace_seq_has_overflowed(s);
 488 }
 489
 490 static int
 491 lat_print_generic(struct trace_seq *s, struct trace_entry *entry, int cpu)
 492 {
 493         char comm[TASK_COMM_LEN];
 494
 495         trace_find_cmdline(entry->pid, comm);
 496
 497         trace_seq_printf(s, "%8.8s-%-5d %3d",
 498                          comm, entry->pid, cpu);
 499
 500         return trace_print_lat_fmt(s, entry);
 501 }
 502
 503 #undef MARK
 504 #define MARK(v, s) {.val = v, .sym = s}
 505 /* trace overhead mark */
 506 static const struct trace_mark {
 507         unsigned long long      val; /* unit: nsec */
 508         char                    sym;
 509 } mark[] = {
 510         MARK(1000000000ULL      , '$'), /* 1 sec */
 511         MARK(100000000ULL       , '@'), /* 100 msec */
 512         MARK(10000000ULL        , '*'), /* 10 msec */
 513         MARK(1000000ULL         , '#'), /* 1000 usecs */
 514         MARK(100000ULL          , '!'), /* 100 usecs */
 515         MARK(10000ULL           , '+'), /* 10 usecs */
 516 };
 517 #undef MARK
 518
 519 char trace_find_mark(unsigned long long d)
 520 {
 521         int i;
 522         int size = ARRAY_SIZE(mark);
 523
 524         for (i = 0; i < size; i++) {
 525                 if (d > mark[i].val)
 526                         break;
 527         }
 528
 529         return (i == size) ? ' ' : mark[i].sym;
 530 }
 531
 532 static int
 533 lat_print_timestamp(struct trace_iterator *iter, u64 next_ts)
 534 {
 535         struct trace_array *tr = iter->tr;
 536         unsigned long verbose = tr->trace_flags & TRACE_ITER_VERBOSE;
 537         unsigned long in_ns = iter->iter_flags & TRACE_FILE_TIME_IN_NS;
 538         unsigned long long abs_ts = iter->ts - iter->trace_buffer->time_start;
 539         unsigned long long rel_ts = next_ts - iter->ts;
 540         struct trace_seq *s = &iter->seq;
 541
 542         if (in_ns) {
 543                 abs_ts = ns2usecs(abs_ts);
 544                 rel_ts = ns2usecs(rel_ts);
 545         }
 546
 547         if (verbose && in_ns) {
 548                 unsigned long abs_usec = do_div(abs_ts, USEC_PER_MSEC);
 549                 unsigned long abs_msec = (unsigned long)abs_ts;
 550                 unsigned long rel_usec = do_div(rel_ts, USEC_PER_MSEC);
 551                 unsigned long rel_msec = (unsigned long)rel_ts;
 552
 553                 trace_seq_printf(
 554                         s, "[%08llx] %ld.%03ldms (+%ld.%03ldms): ",
 555                         ns2usecs(iter->ts),
 556                         abs_msec, abs_usec,
 557                         rel_msec, rel_usec);
 558
 559         } else if (verbose && !in_ns) {
 560                 trace_seq_printf(
 561                         s, "[%016llx] %lld (+%lld): ",
 562                         iter->ts, abs_ts, rel_ts);
 563
 564         } else if (!verbose && in_ns) {
 565                 trace_seq_printf(
 566                         s, " %4lldus%c: ",
 567                         abs_ts,
 568                         trace_find_mark(rel_ts * NSEC_PER_USEC));
 569
 570         } else { /* !verbose && !in_ns */
 571                 trace_seq_printf(s, " %4lld: ", abs_ts);
 572         }
 573
 574         return !trace_seq_has_overflowed(s);
 575 }
 576
 577 int trace_print_context(struct trace_iterator *iter)
 578 {
 579         struct trace_array *tr = iter->tr;
 580         struct trace_seq *s = &iter->seq;
 581         struct trace_entry *entry = iter->ent;
 582         unsigned long long t;
 583         unsigned long secs, usec_rem;
 584         char comm[TASK_COMM_LEN];
 585
 586         trace_find_cmdline(entry->pid, comm);
 587
 588         trace_seq_printf(s, "%16s-%-5d [%03d] ",
 589                                comm, entry->pid, iter->cpu);
 590
 591         if (tr->trace_flags & TRACE_ITER_IRQ_INFO)
 592                 trace_print_lat_fmt(s, entry);
 593
 594         if (iter->iter_flags & TRACE_FILE_TIME_IN_NS) {
 595                 t = ns2usecs(iter->ts);
 596                 usec_rem = do_div(t, USEC_PER_SEC);
 597                 secs = (unsigned long)t;
 598                 trace_seq_printf(s, " %5lu.%06lu: ", secs, usec_rem);
 599         } else
 600                 trace_seq_printf(s, " %12llu: ", iter->ts);
 601
 602         return !trace_seq_has_overflowed(s);
 603 }
 604
 605 int trace_print_lat_context(struct trace_iterator *iter)
 606 {
 607         struct trace_array *tr = iter->tr;
 608         /* trace_find_next_entry will reset ent_size */
 609         int ent_size = iter->ent_size;
 610         struct trace_seq *s = &iter->seq;
 611         u64 next_ts;
 612         struct trace_entry *entry = iter->ent,
 613                            *next_entry = trace_find_next_entry(iter, NULL,
 614                                                                &next_ts);
 615         unsigned long verbose = (tr->trace_flags & TRACE_ITER_VERBOSE);
 616
 617         /* Restore the original ent_size */
 618         iter->ent_size = ent_size;
 619
 620         if (!next_entry)
 621                 next_ts = iter->ts;
 622
 623         if (verbose) {
 624                 char comm[TASK_COMM_LEN];
 625
 626                 trace_find_cmdline(entry->pid, comm);
 627
 628                 trace_seq_printf(
 629                         s, "%16s %5d %3d %d %08x %08lx ",
 630                         comm, entry->pid, iter->cpu, entry->flags,
 631                         entry->preempt_count, iter->idx);
 632         } else {
 633                 lat_print_generic(s, entry, iter->cpu);
 634         }
 635
 636         lat_print_timestamp(iter, next_ts);
 637
 638         return !trace_seq_has_overflowed(s);
 639 }
 640
 641 static const char state_to_char[] = TASK_STATE_TO_CHAR_STR;
 642
 643 static int task_state_char(unsigned long state)
 644 {
 645         int bit = state ? __ffs(state) + 1 : 0;
 646
 647         return bit < sizeof(state_to_char) - 1 ? state_to_char[bit] : '?';
 648 }
 649
 650 /**
 651  * ftrace_find_event - find a registered event
 652  * @type: the type of event to look for
 653  *
 654  * Returns an event of type @type otherwise NULL
 655  * Called with trace_event_read_lock() held.
 656  */
 657 struct trace_event *ftrace_find_event(int type)
 658 {
 659         struct trace_event *event;
 660         unsigned key;
 661
 662         key = type & (EVENT_HASHSIZE - 1);
 663
 664         hlist_for_each_entry(event, &event_hash[key], node) {
 665                 if (event->type == type)
 666                         return event;
 667         }
 668
 669         return NULL;
 670 }
 671
 672 static LIST_HEAD(ftrace_event_list);
 673
 674 static int trace_search_list(struct list_head **list)
 675 {
 676         struct trace_event *e;
 677         int last = __TRACE_LAST_TYPE;
 678
 679         if (list_empty(&ftrace_event_list)) {
 680                 *list = &ftrace_event_list;
 681                 return last + 1;
 682         }
 683
 684         /*
 685          * We used up all possible max events,
 686          * lets see if somebody freed one.
 687          */
 688         list_for_each_entry(e, &ftrace_event_list, list) {
 689                 if (e->type != last + 1)
 690                         break;
 691                 last++;
 692         }
 693
 694         /* Did we used up all 65 thousand events??? */
 695         if ((last + 1) > TRACE_EVENT_TYPE_MAX)
 696                 return 0;
 697
 698         *list = &e->list;
 699         return last + 1;
 700 }
 701
 702 void trace_event_read_lock(void)
 703 {
 704         down_read(&trace_event_sem);
 705 }
 706
 707 void trace_event_read_unlock(void)
 708 {
 709         up_read(&trace_event_sem);
 710 }
 711
 712 /**
 713  * register_trace_event - register output for an event type
 714  * @event: the event type to register
 715  *
 716  * Event types are stored in a hash and this hash is used to
 717  * find a way to print an event. If the @event->type is set
 718  * then it will use that type, otherwise it will assign a
 719  * type to use.
 720  *
 721  * If you assign your own type, please make sure it is added
 722  * to the trace_type enum in trace.h, to avoid collisions
 723  * with the dynamic types.
 724  *
 725  * Returns the event type number or zero on error.
 726  */
 727 int register_trace_event(struct trace_event *event)
 728 {
 729         unsigned key;
 730         int ret = 0;
 731
 732         down_write(&trace_event_sem);
 733
 734         if (WARN_ON(!event))
 735                 goto out;
 736
 737         if (WARN_ON(!event->funcs))
 738                 goto out;
 739
 740         INIT_LIST_HEAD(&event->list);
 741
 742         if (!event->type) {
 743                 struct list_head *list = NULL;
 744
 745                 if (next_event_type > TRACE_EVENT_TYPE_MAX) {
 746
 747                         event->type = trace_search_list(&list);
 748                         if (!event->type)
 749                                 goto out;
 750
 751                 } else {
 752
 753                         event->type = next_event_type++;
 754                         list = &ftrace_event_list;
 755                 }
 756
 757                 if (WARN_ON(ftrace_find_event(event->type)))
 758                         goto out;
 759
 760                 list_add_tail(&event->list, list);
 761
 762         } else if (event->type > __TRACE_LAST_TYPE) {
 763                 printk(KERN_WARNING "Need to add type to trace.h\n");
 764                 WARN_ON(1);
 765                 goto out;
 766         } else {
 767                 /* Is this event already used */
 768                 if (ftrace_find_event(event->type))
 769                         goto out;
 770         }
 771
 772         if (event->funcs->trace == NULL)
 773                 event->funcs->trace = trace_nop_print;
 774         if (event->funcs->raw == NULL)
 775                 event->funcs->raw = trace_nop_print;
 776         if (event->funcs->hex == NULL)
 777                 event->funcs->hex = trace_nop_print;
 778         if (event->funcs->binary == NULL)
 779                 event->funcs->binary = trace_nop_print;
 780
 781         key = event->type & (EVENT_HASHSIZE - 1);
 782
 783         hlist_add_head(&event->node, &event_hash[key]);
 784
 785         ret = event->type;
 786  out:
 787         up_write(&trace_event_sem);
 788
 789         return ret;
 790 }
 791 EXPORT_SYMBOL_GPL(register_trace_event);
 792
 793 /*
 794  * Used by module code with the trace_event_sem held for write.
 795  */
 796 int __unregister_trace_event(struct trace_event *event)
 797 {
 798         hlist_del(&event->node);
 799         list_del(&event->list);
 800         return 0;
 801 }
 802
 803 /**
 804  * unregister_trace_event - remove a no longer used event
 805  * @event: the event to remove
 806  */
 807 int unregister_trace_event(struct trace_event *event)
 808 {
 809         down_write(&trace_event_sem);
 810         __unregister_trace_event(event);
 811         up_write(&trace_event_sem);
 812
 813         return 0;
 814 }
 815 EXPORT_SYMBOL_GPL(unregister_trace_event);
 816
 817 /*
 818  * Standard events
 819  */
 820
 821 enum print_line_t trace_nop_print(struct trace_iterator *iter, int flags,
 822                                   struct trace_event *event)
 823 {
 824         trace_seq_printf(&iter->seq, "type: %d\n", iter->ent->type);
 825
 826         return trace_handle_return(&iter->seq);
 827 }
 828
 829 /* TRACE_FN */
 830 static enum print_line_t trace_fn_trace(struct trace_iterator *iter, int flags,
 831                                         struct trace_event *event)
 832 {
 833         struct ftrace_entry *field;
 834         struct trace_seq *s = &iter->seq;
 835
 836         trace_assign_type(field, iter->ent);
 837
 838         seq_print_ip_sym(s, field->ip, flags);
 839
 840         if ((flags & TRACE_ITER_PRINT_PARENT) && field->parent_ip) {
 841                 trace_seq_puts(s, " <-");
 842                 seq_print_ip_sym(s, field->parent_ip, flags);
 843         }
 844
 845         trace_seq_putc(s, '\n');
 846
 847         return trace_handle_return(s);
 848 }
 849
 850 static enum print_line_t trace_fn_raw(struct trace_iterator *iter, int flags,
 851                                       struct trace_event *event)
 852 {
 853         struct ftrace_entry *field;
 854
 855         trace_assign_type(field, iter->ent);
 856
 857         trace_seq_printf(&iter->seq, "%lx %lx\n",
 858                          field->ip,
 859                          field->parent_ip);
 860
 861         return trace_handle_return(&iter->seq);
 862 }
 863
 864 static enum print_line_t trace_fn_hex(struct trace_iterator *iter, int flags,
 865                                       struct trace_event *event)
 866 {
 867         struct ftrace_entry *field;
 868         struct trace_seq *s = &iter->seq;
 869
 870         trace_assign_type(field, iter->ent);
 871
 872         SEQ_PUT_HEX_FIELD(s, field->ip);
 873         SEQ_PUT_HEX_FIELD(s, field->parent_ip);
 874
 875         return trace_handle_return(s);
 876 }
 877
 878 static enum print_line_t trace_fn_bin(struct trace_iterator *iter, int flags,
 879                                       struct trace_event *event)
 880 {
 881         struct ftrace_entry *field;
 882         struct trace_seq *s = &iter->seq;
 883
 884         trace_assign_type(field, iter->ent);
 885
 886         SEQ_PUT_FIELD(s, field->ip);
 887         SEQ_PUT_FIELD(s, field->parent_ip);
 888
 889         return trace_handle_return(s);
 890 }
 891
 892 static struct trace_event_functions trace_fn_funcs = {
 893         .trace          = trace_fn_trace,
 894         .raw            = trace_fn_raw,
 895         .hex            = trace_fn_hex,
 896         .binary         = trace_fn_bin,
 897 };
 898
 899 static struct trace_event trace_fn_event = {
 900         .type           = TRACE_FN,
 901         .funcs          = &trace_fn_funcs,
 902 };
 903
 904 /* TRACE_CTX an TRACE_WAKE */
 905 static enum print_line_t trace_ctxwake_print(struct trace_iterator *iter,
 906                                              char *delim)
 907 {
 908         struct ctx_switch_entry *field;
 909         char comm[TASK_COMM_LEN];
 910         int S, T;
 911
 912
 913         trace_assign_type(field, iter->ent);
 914
 915         T = task_state_char(field->next_state);
 916         S = task_state_char(field->prev_state);
 917         trace_find_cmdline(field->next_pid, comm);
 918         trace_seq_printf(&iter->seq,
 919                          " %5d:%3d:%c %s [%03d] %5d:%3d:%c %s\n",
 920                          field->prev_pid,
 921                          field->prev_prio,
 922                          S, delim,
 923                          field->next_cpu,
 924                          field->next_pid,
 925                          field->next_prio,
 926                          T, comm);
 927
 928         return trace_handle_return(&iter->seq);
 929 }
 930
 931 static enum print_line_t trace_ctx_print(struct trace_iterator *iter, int flags,
 932                                          struct trace_event *event)
 933 {
 934         return trace_ctxwake_print(iter, "==>");
 935 }
 936
 937 static enum print_line_t trace_wake_print(struct trace_iterator *iter,
 938                                           int flags, struct trace_event *event)
 939 {
 940         return trace_ctxwake_print(iter, "  +");
 941 }
 942
 943 static int trace_ctxwake_raw(struct trace_iterator *iter, char S)
 944 {
 945         struct ctx_switch_entry *field;
 946         int T;
 947
 948         trace_assign_type(field, iter->ent);
 949
 950         if (!S)
 951                 S = task_state_char(field->prev_state);
 952         T = task_state_char(field->next_state);
 953         trace_seq_printf(&iter->seq, "%d %d %c %d %d %d %c\n",
 954                          field->prev_pid,
 955                          field->prev_prio,
 956                          S,
 957                          field->next_cpu,
 958                          field->next_pid,
 959                          field->next_prio,
 960                          T);
 961
 962         return trace_handle_return(&iter->seq);
 963 }
 964
 965 static enum print_line_t trace_ctx_raw(struct trace_iterator *iter, int flags,
 966                                        struct trace_event *event)
 967 {
 968         return trace_ctxwake_raw(iter, 0);
 969 }
 970
 971 static enum print_line_t trace_wake_raw(struct trace_iterator *iter, int flags,
 972                                         struct trace_event *event)
 973 {
 974         return trace_ctxwake_raw(iter, '+');
 975 }
 976
 977
 978 static int trace_ctxwake_hex(struct trace_iterator *iter, char S)
 979 {
 980         struct ctx_switch_entry *field;
 981         struct trace_seq *s = &iter->seq;
 982         int T;
 983
 984         trace_assign_type(field, iter->ent);
 985
 986         if (!S)
 987                 S = task_state_char(field->prev_state);
 988         T = task_state_char(field->next_state);
 989
 990         SEQ_PUT_HEX_FIELD(s, field->prev_pid);
 991         SEQ_PUT_HEX_FIELD(s, field->prev_prio);
 992         SEQ_PUT_HEX_FIELD(s, S);
 993         SEQ_PUT_HEX_FIELD(s, field->next_cpu);
 994         SEQ_PUT_HEX_FIELD(s, field->next_pid);
 995         SEQ_PUT_HEX_FIELD(s, field->next_prio);
 996         SEQ_PUT_HEX_FIELD(s, T);
 997
 998         return trace_handle_return(s);
 999 }
1000
1001 static enum print_line_t trace_ctx_hex(struct trace_iterator *iter, int flags,
1002                                        struct trace_event *event)
1003 {
1004         return trace_ctxwake_hex(iter, 0);
1005 }
1006
1007 static enum print_line_t trace_wake_hex(struct trace_iterator *iter, int flags,
1008                                         struct trace_event *event)
1009 {
1010         return trace_ctxwake_hex(iter, '+');
1011 }
1012
1013 static enum print_line_t trace_ctxwake_bin(struct trace_iterator *iter,
1014                                            int flags, struct trace_event *event)
1015 {
1016         struct ctx_switch_entry *field;
1017         struct trace_seq *s = &iter->seq;
1018
1019         trace_assign_type(field, iter->ent);
1020
1021         SEQ_PUT_FIELD(s, field->prev_pid);
1022         SEQ_PUT_FIELD(s, field->prev_prio);
1023         SEQ_PUT_FIELD(s, field->prev_state);
1024         SEQ_PUT_FIELD(s, field->next_cpu);
1025         SEQ_PUT_FIELD(s, field->next_pid);
1026         SEQ_PUT_FIELD(s, field->next_prio);
1027         SEQ_PUT_FIELD(s, field->next_state);
1028
1029         return trace_handle_return(s);
1030 }
1031
1032 static struct trace_event_functions trace_ctx_funcs = {
1033         .trace          = trace_ctx_print,
1034         .raw            = trace_ctx_raw,
1035         .hex            = trace_ctx_hex,
1036         .binary         = trace_ctxwake_bin,
1037 };
1038
1039 static struct trace_event trace_ctx_event = {
1040         .type           = TRACE_CTX,
1041         .funcs          = &trace_ctx_funcs,
1042 };
1043
1044 static struct trace_event_functions trace_wake_funcs = {
1045         .trace          = trace_wake_print,
1046         .raw            = trace_wake_raw,
1047         .hex            = trace_wake_hex,
1048         .binary         = trace_ctxwake_bin,
1049 };
1050
1051 static struct trace_event trace_wake_event = {
1052         .type           = TRACE_WAKE,
1053         .funcs          = &trace_wake_funcs,
1054 };
1055
1056 /* TRACE_STACK */
1057
1058 static enum print_line_t trace_stack_print(struct trace_iterator *iter,
1059                                            int flags, struct trace_event *event)
1060 {
1061         struct stack_entry *field;
1062         struct trace_seq *s = &iter->seq;
1063         unsigned long *p;
1064         unsigned long *end;
1065
1066         trace_assign_type(field, iter->ent);
1067         end = (unsigned long *)((long)iter->ent + iter->ent_size);
1068
1069         trace_seq_puts(s, "<stack trace>\n");
1070
1071         for (p = field->caller; p && *p != ULONG_MAX && p < end; p++) {
1072
1073                 if (trace_seq_has_overflowed(s))
1074                         break;
1075
1076                 trace_seq_puts(s, " => ");
1077                 seq_print_ip_sym(s, *p, flags);
1078                 trace_seq_putc(s, '\n');
1079         }
1080
1081         return trace_handle_return(s);
1082 }
1083
1084 static struct trace_event_functions trace_stack_funcs = {
1085         .trace          = trace_stack_print,
1086 };
1087
1088 static struct trace_event trace_stack_event = {
1089         .type           = TRACE_STACK,
1090         .funcs          = &trace_stack_funcs,
1091 };
1092
1093 /* TRACE_USER_STACK */
1094 static enum print_line_t trace_user_stack_print(struct trace_iterator *iter,
1095                                                 int flags, struct trace_event *event)
1096 {
1097         struct trace_array *tr = iter->tr;
1098         struct userstack_entry *field;
1099         struct trace_seq *s = &iter->seq;
1100         struct mm_struct *mm = NULL;
1101         unsigned int i;
1102
1103         trace_assign_type(field, iter->ent);
1104
1105         trace_seq_puts(s, "<user stack trace>\n");
1106
1107         if (tr->trace_flags & TRACE_ITER_SYM_USEROBJ) {
1108                 struct task_struct *task;
1109                 /*
1110                  * we do the lookup on the thread group leader,
1111                  * since individual threads might have already quit!
1112                  */
1113                 rcu_read_lock();
1114                 task = find_task_by_vpid(field->tgid);
1115                 if (task)
1116                         mm = get_task_mm(task);
1117                 rcu_read_unlock();
1118         }
1119
1120         for (i = 0; i < FTRACE_STACK_ENTRIES; i++) {
1121                 unsigned long ip = field->caller[i];
1122
1123                 if (ip == ULONG_MAX || trace_seq_has_overflowed(s))
1124                         break;
1125
1126                 trace_seq_puts(s, " => ");
1127
1128                 if (!ip) {
1129                         trace_seq_puts(s, "??");
1130                         trace_seq_putc(s, '\n');
1131                         continue;
1132                 }
1133
1134                 seq_print_user_ip(s, mm, ip, flags);
1135                 trace_seq_putc(s, '\n');
1136         }
1137
1138         if (mm)
1139                 mmput(mm);
1140
1141         return trace_handle_return(s);
1142 }
1143
1144 static struct trace_event_functions trace_user_stack_funcs = {
1145         .trace          = trace_user_stack_print,
1146 };
1147
1148 static struct trace_event trace_user_stack_event = {
1149         .type           = TRACE_USER_STACK,
1150         .funcs          = &trace_user_stack_funcs,
1151 };
1152
1153 /* TRACE_HWLAT */
1154 static enum print_line_t
1155 trace_hwlat_print(struct trace_iterator *iter, int flags,
1156                   struct trace_event *event)
1157 {
1158         struct trace_entry *entry = iter->ent;
1159         struct trace_seq *s = &iter->seq;
1160         struct hwlat_entry *field;
1161
1162         trace_assign_type(field, entry);
1163
1164         trace_seq_printf(s, "#%-5u inner/outer(us): %4llu/%-5llu ts:%ld.%09ld",
1165                          field->seqnum,
1166                          field->duration,
1167                          field->outer_duration,
1168                          field->timestamp.tv_sec,
1169                          field->timestamp.tv_nsec);
1170
1171         if (field->nmi_count) {
1172                 /*
1173                  * The generic sched_clock() is not NMI safe, thus
1174                  * we only record the count and not the time.
1175                  */
1176                 if (!IS_ENABLED(CONFIG_GENERIC_SCHED_CLOCK))
1177                         trace_seq_printf(s, " nmi-total:%llu",
1178                                          field->nmi_total_ts);
1179                 trace_seq_printf(s, " nmi-count:%u",
1180                                  field->nmi_count);
1181         }
1182
1183         trace_seq_putc(s, '\n');
1184
1185         return trace_handle_return(s);
1186 }
1187
1188
1189 static enum print_line_t
1190 trace_hwlat_raw(struct trace_iterator *iter, int flags,
1191                 struct trace_event *event)
1192 {
1193         struct hwlat_entry *field;
1194         struct trace_seq *s = &iter->seq;
1195
1196         trace_assign_type(field, iter->ent);
1197
1198         trace_seq_printf(s, "%llu %lld %ld %09ld %u\n",
1199                          field->duration,
1200                          field->outer_duration,
1201                          field->timestamp.tv_sec,
1202                          field->timestamp.tv_nsec,
1203                          field->seqnum);
1204
1205         return trace_handle_return(s);
1206 }
1207
1208 static struct trace_event_functions trace_hwlat_funcs = {
1209         .trace          = trace_hwlat_print,
1210         .raw            = trace_hwlat_raw,
1211 };
1212
1213 static struct trace_event trace_hwlat_event = {
1214         .type           = TRACE_HWLAT,
1215         .funcs          = &trace_hwlat_funcs,
1216 };
1217
1218 /* TRACE_BPUTS */
1219 static enum print_line_t
1220 trace_bputs_print(struct trace_iterator *iter, int flags,
1221                    struct trace_event *event)
1222 {
1223         struct trace_entry *entry = iter->ent;
1224         struct trace_seq *s = &iter->seq;
1225         struct bputs_entry *field;
1226
1227         trace_assign_type(field, entry);
1228
1229         seq_print_ip_sym(s, field->ip, flags);
1230         trace_seq_puts(s, ": ");
1231         trace_seq_puts(s, field->str);
1232
1233         return trace_handle_return(s);
1234 }
1235
1236
1237 static enum print_line_t
1238 trace_bputs_raw(struct trace_iterator *iter, int flags,
1239                 struct trace_event *event)
1240 {
1241         struct bputs_entry *field;
1242         struct trace_seq *s = &iter->seq;
1243
1244         trace_assign_type(field, iter->ent);
1245
1246         trace_seq_printf(s, ": %lx : ", field->ip);
1247         trace_seq_puts(s, field->str);
1248
1249         return trace_handle_return(s);
1250 }
1251
1252 static struct trace_event_functions trace_bputs_funcs = {
1253         .trace          = trace_bputs_print,
1254         .raw            = trace_bputs_raw,
1255 };
1256
1257 static struct trace_event trace_bputs_event = {
1258         .type           = TRACE_BPUTS,
1259         .funcs          = &trace_bputs_funcs,
1260 };
1261
1262 /* TRACE_BPRINT */
1263 static enum print_line_t
1264 trace_bprint_print(struct trace_iterator *iter, int flags,
1265                    struct trace_event *event)
1266 {
1267         struct trace_entry *entry = iter->ent;
1268         struct trace_seq *s = &iter->seq;
1269         struct bprint_entry *field;
1270
1271         trace_assign_type(field, entry);
1272
1273         seq_print_ip_sym(s, field->ip, flags);
1274         trace_seq_puts(s, ": ");
1275         trace_seq_bprintf(s, field->fmt, field->buf);
1276
1277         return trace_handle_return(s);
1278 }
1279
1280
1281 static enum print_line_t
1282 trace_bprint_raw(struct trace_iterator *iter, int flags,
1283                  struct trace_event *event)
1284 {
1285         struct bprint_entry *field;
1286         struct trace_seq *s = &iter->seq;
1287
1288         trace_assign_type(field, iter->ent);
1289
1290         trace_seq_printf(s, ": %lx : ", field->ip);
1291         trace_seq_bprintf(s, field->fmt, field->buf);
1292
1293         return trace_handle_return(s);
1294 }
1295
1296 static struct trace_event_functions trace_bprint_funcs = {
1297         .trace          = trace_bprint_print,
1298         .raw            = trace_bprint_raw,
1299 };
1300
1301 static struct trace_event trace_bprint_event = {
1302         .type           = TRACE_BPRINT,
1303         .funcs          = &trace_bprint_funcs,
1304 };
1305
1306 /* TRACE_PRINT */
1307 static enum print_line_t trace_print_print(struct trace_iterator *iter,
1308                                            int flags, struct trace_event *event)
1309 {
1310         struct print_entry *field;
1311         struct trace_seq *s = &iter->seq;
1312
1313         trace_assign_type(field, iter->ent);
1314
1315         seq_print_ip_sym(s, field->ip, flags);
1316         trace_seq_printf(s, ": %s", field->buf);
1317
1318         return trace_handle_return(s);
1319 }
1320
1321 static enum print_line_t trace_print_raw(struct trace_iterator *iter, int flags,
1322                                          struct trace_event *event)
1323 {
1324         struct print_entry *field;
1325
1326         trace_assign_type(field, iter->ent);
1327
1328         trace_seq_printf(&iter->seq, "# %lx %s", field->ip, field->buf);
1329
1330         return trace_handle_return(&iter->seq);
1331 }
1332
1333 static struct trace_event_functions trace_print_funcs = {
1334         .trace          = trace_print_print,
1335         .raw            = trace_print_raw,
1336 };
1337
1338 static struct trace_event trace_print_event = {
1339         .type           = TRACE_PRINT,
1340         .funcs          = &trace_print_funcs,
1341 };
1342
1343 static enum print_line_t trace_raw_data(struct trace_iterator *iter, int flags,
1344                                          struct trace_event *event)
1345 {
1346         struct raw_data_entry *field;
1347         int i;
1348
1349         trace_assign_type(field, iter->ent);
1350
1351         trace_seq_printf(&iter->seq, "# %x buf:", field->id);
1352
1353         for (i = 0; i < iter->ent_size - offsetof(struct raw_data_entry, buf); i++)
1354                 trace_seq_printf(&iter->seq, " %02x",
1355                                  (unsigned char)field->buf[i]);
1356
1357         trace_seq_putc(&iter->seq, '\n');
1358
1359         return trace_handle_return(&iter->seq);
1360 }
1361
1362 static struct trace_event_functions trace_raw_data_funcs = {
1363         .trace          = trace_raw_data,
1364         .raw            = trace_raw_data,
1365 };
1366
1367 static struct trace_event trace_raw_data_event = {
1368         .type           = TRACE_RAW_DATA,
1369         .funcs          = &trace_raw_data_funcs,
1370 };
1371
1372
1373 static struct trace_event *events[] __initdata = {
1374         &trace_fn_event,
1375         &trace_ctx_event,
1376         &trace_wake_event,
1377         &trace_stack_event,
1378         &trace_user_stack_event,
1379         &trace_bputs_event,
1380         &trace_bprint_event,
1381         &trace_print_event,
1382         &trace_hwlat_event,
1383         &trace_raw_data_event,
1384         NULL
1385 };
1386
1387 __init static int init_events(void)
1388 {
1389         struct trace_event *event;
1390         int i, ret;
1391
1392         for (i = 0; events[i]; i++) {
1393                 event = events[i];
1394
1395                 ret = register_trace_event(event);
1396                 if (!ret) {
1397                         printk(KERN_WARNING "event %d failed to register\n",
1398                                event->type);
1399                         WARN_ON_ONCE(1);
1400                 }
1401         }
1402
1403         return 0;
1404 }
1405 early_initcall(init_events);