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 #include <linux/module.h>
   8 #include <linux/mutex.h>
   9 #include <linux/ftrace.h>
  10 #include <linux/sched/clock.h>
  11 #include <linux/sched/mm.h>
  12
  13 #include "trace_output.h"
  14
  15 /* must be a power of 2 */
  16 #define EVENT_HASHSIZE  128
  17
  18 DECLARE_RWSEM(trace_event_sem);
  19
  20 static struct hlist_head event_hash[EVENT_HASHSIZE] __read_mostly;
  21
  22 static int next_event_type = __TRACE_LAST_TYPE + 1;
  23
  24 enum print_line_t trace_print_bputs_msg_only(struct trace_iterator *iter)
  25 {
  26         struct trace_seq *s = &iter->seq;
  27         struct trace_entry *entry = iter->ent;
  28         struct bputs_entry *field;
  29
  30         trace_assign_type(field, entry);
  31
  32         trace_seq_puts(s, field->str);
  33
  34         return trace_handle_return(s);
  35 }
  36
  37 enum print_line_t trace_print_bprintk_msg_only(struct trace_iterator *iter)
  38 {
  39         struct trace_seq *s = &iter->seq;
  40         struct trace_entry *entry = iter->ent;
  41         struct bprint_entry *field;
  42
  43         trace_assign_type(field, entry);
  44
  45         trace_seq_bprintf(s, field->fmt, field->buf);
  46
  47         return trace_handle_return(s);
  48 }
  49
  50 enum print_line_t trace_print_printk_msg_only(struct trace_iterator *iter)
  51 {
  52         struct trace_seq *s = &iter->seq;
  53         struct trace_entry *entry = iter->ent;
  54         struct print_entry *field;
  55
  56         trace_assign_type(field, entry);
  57
  58         trace_seq_puts(s, field->buf);
  59
  60         return trace_handle_return(s);
  61 }
  62
  63 const char *
  64 trace_print_flags_seq(struct trace_seq *p, const char *delim,
  65                       unsigned long flags,
  66                       const struct trace_print_flags *flag_array)
  67 {
  68         unsigned long mask;
  69         const char *str;
  70         const char *ret = trace_seq_buffer_ptr(p);
  71         int i, first = 1;
  72
  73         for (i = 0;  flag_array[i].name && flags; i++) {
  74
  75                 mask = flag_array[i].mask;
  76                 if ((flags & mask) != mask)
  77                         continue;
  78
  79                 str = flag_array[i].name;
  80                 flags &= ~mask;
  81                 if (!first && delim)
  82                         trace_seq_puts(p, delim);
  83                 else
  84                         first = 0;
  85                 trace_seq_puts(p, str);
  86         }
  87
  88         /* check for left over flags */
  89         if (flags) {
  90                 if (!first && delim)
  91                         trace_seq_puts(p, delim);
  92                 trace_seq_printf(p, "0x%lx", flags);
  93         }
  94
  95         trace_seq_putc(p, 0);
  96
  97         return ret;
  98 }
  99 EXPORT_SYMBOL(trace_print_flags_seq);
 100
 101 const char *
 102 trace_print_symbols_seq(struct trace_seq *p, unsigned long val,
 103                         const struct trace_print_flags *symbol_array)
 104 {
 105         int i;
 106         const char *ret = trace_seq_buffer_ptr(p);
 107
 108         for (i = 0;  symbol_array[i].name; i++) {
 109
 110                 if (val != symbol_array[i].mask)
 111                         continue;
 112
 113                 trace_seq_puts(p, symbol_array[i].name);
 114                 break;
 115         }
 116
 117         if (ret == (const char *)(trace_seq_buffer_ptr(p)))
 118                 trace_seq_printf(p, "0x%lx", val);
 119
 120         trace_seq_putc(p, 0);
 121
 122         return ret;
 123 }
 124 EXPORT_SYMBOL(trace_print_symbols_seq);
 125
 126 #if BITS_PER_LONG == 32
 127 const char *
 128 trace_print_flags_seq_u64(struct trace_seq *p, const char *delim,
 129                       unsigned long long flags,
 130                       const struct trace_print_flags_u64 *flag_array)
 131 {
 132         unsigned long long mask;
 133         const char *str;
 134         const char *ret = trace_seq_buffer_ptr(p);
 135         int i, first = 1;
 136
 137         for (i = 0;  flag_array[i].name && flags; i++) {
 138
 139                 mask = flag_array[i].mask;
 140                 if ((flags & mask) != mask)
 141                         continue;
 142
 143                 str = flag_array[i].name;
 144                 flags &= ~mask;
 145                 if (!first && delim)
 146                         trace_seq_puts(p, delim);
 147                 else
 148                         first = 0;
 149                 trace_seq_puts(p, str);
 150         }
 151
 152         /* check for left over flags */
 153         if (flags) {
 154                 if (!first && delim)
 155                         trace_seq_puts(p, delim);
 156                 trace_seq_printf(p, "0x%llx", flags);
 157         }
 158
 159         trace_seq_putc(p, 0);
 160
 161         return ret;
 162 }
 163 EXPORT_SYMBOL(trace_print_flags_seq_u64);
 164
 165 const char *
 166 trace_print_symbols_seq_u64(struct trace_seq *p, unsigned long long val,
 167                          const struct trace_print_flags_u64 *symbol_array)
 168 {
 169         int i;
 170         const char *ret = trace_seq_buffer_ptr(p);
 171
 172         for (i = 0;  symbol_array[i].name; i++) {
 173
 174                 if (val != symbol_array[i].mask)
 175                         continue;
 176
 177                 trace_seq_puts(p, symbol_array[i].name);
 178                 break;
 179         }
 180
 181         if (ret == (const char *)(trace_seq_buffer_ptr(p)))
 182                 trace_seq_printf(p, "0x%llx", val);
 183
 184         trace_seq_putc(p, 0);
 185
 186         return ret;
 187 }
 188 EXPORT_SYMBOL(trace_print_symbols_seq_u64);
 189 #endif
 190
 191 const char *
 192 trace_print_bitmask_seq(struct trace_seq *p, void *bitmask_ptr,
 193                         unsigned int bitmask_size)
 194 {
 195         const char *ret = trace_seq_buffer_ptr(p);
 196
 197         trace_seq_bitmask(p, bitmask_ptr, bitmask_size * 8);
 198         trace_seq_putc(p, 0);
 199
 200         return ret;
 201 }
 202 EXPORT_SYMBOL_GPL(trace_print_bitmask_seq);
 203
 204 /**
 205  * trace_print_hex_seq - print buffer as hex sequence
 206  * @p: trace seq struct to write to
 207  * @buf: The buffer to print
 208  * @buf_len: Length of @buf in bytes
 209  * @concatenate: Print @buf as single hex string or with spacing
 210  *
 211  * Prints the passed buffer as a hex sequence either as a whole,
 212  * single hex string if @concatenate is true or with spacing after
 213  * each byte in case @concatenate is false.
 214  */
 215 const char *
 216 trace_print_hex_seq(struct trace_seq *p, const unsigned char *buf, int buf_len,
 217                     bool concatenate)
 218 {
 219         int i;
 220         const char *ret = trace_seq_buffer_ptr(p);
 221
 222         for (i = 0; i < buf_len; i++)
 223                 trace_seq_printf(p, "%s%2.2x", concatenate || i == 0 ? "" : " ",
 224                                  buf[i]);
 225         trace_seq_putc(p, 0);
 226
 227         return ret;
 228 }
 229 EXPORT_SYMBOL(trace_print_hex_seq);
 230
 231 const char *
 232 trace_print_array_seq(struct trace_seq *p, const void *buf, int count,
 233                       size_t el_size)
 234 {
 235         const char *ret = trace_seq_buffer_ptr(p);
 236         const char *prefix = "";
 237         void *ptr = (void *)buf;
 238         size_t buf_len = count * el_size;
 239
 240         trace_seq_putc(p, '{');
 241
 242         while (ptr < buf + buf_len) {
 243                 switch (el_size) {
 244                 case 1:
 245                         trace_seq_printf(p, "%s0x%x", prefix,
 246                                          *(u8 *)ptr);
 247                         break;
 248                 case 2:
 249                         trace_seq_printf(p, "%s0x%x", prefix,
 250                                          *(u16 *)ptr);
 251                         break;
 252                 case 4:
 253                         trace_seq_printf(p, "%s0x%x", prefix,
 254                                          *(u32 *)ptr);
 255                         break;
 256                 case 8:
 257                         trace_seq_printf(p, "%s0x%llx", prefix,
 258                                          *(u64 *)ptr);
 259                         break;
 260                 default:
 261                         trace_seq_printf(p, "BAD SIZE:%zu 0x%x", el_size,
 262                                          *(u8 *)ptr);
 263                         el_size = 1;
 264                 }
 265                 prefix = ",";
 266                 ptr += el_size;
 267         }
 268
 269         trace_seq_putc(p, '}');
 270         trace_seq_putc(p, 0);
 271
 272         return ret;
 273 }
 274 EXPORT_SYMBOL(trace_print_array_seq);
 275
 276 int trace_raw_output_prep(struct trace_iterator *iter,
 277                           struct trace_event *trace_event)
 278 {
 279         struct trace_event_call *event;
 280         struct trace_seq *s = &iter->seq;
 281         struct trace_seq *p = &iter->tmp_seq;
 282         struct trace_entry *entry;
 283
 284         event = container_of(trace_event, struct trace_event_call, event);
 285         entry = iter->ent;
 286
 287         if (entry->type != event->event.type) {
 288                 WARN_ON_ONCE(1);
 289                 return TRACE_TYPE_UNHANDLED;
 290         }
 291
 292         trace_seq_init(p);
 293         trace_seq_printf(s, "%s: ", trace_event_name(event));
 294
 295         return trace_handle_return(s);
 296 }
 297 EXPORT_SYMBOL(trace_raw_output_prep);
 298
 299 static int trace_output_raw(struct trace_iterator *iter, char *name,
 300                             char *fmt, va_list ap)
 301 {
 302         struct trace_seq *s = &iter->seq;
 303
 304         trace_seq_printf(s, "%s: ", name);
 305         trace_seq_vprintf(s, fmt, ap);
 306
 307         return trace_handle_return(s);
 308 }
 309
 310 int trace_output_call(struct trace_iterator *iter, char *name, char *fmt, ...)
 311 {
 312         va_list ap;
 313         int ret;
 314
 315         va_start(ap, fmt);
 316         ret = trace_output_raw(iter, name, fmt, ap);
 317         va_end(ap);
 318
 319         return ret;
 320 }
 321 EXPORT_SYMBOL_GPL(trace_output_call);
 322
 323 #ifdef CONFIG_KRETPROBES
 324 static inline const char *kretprobed(const char *name)
 325 {
 326         static const char tramp_name[] = "kretprobe_trampoline";
 327         int size = sizeof(tramp_name);
 328
 329         if (strncmp(tramp_name, name, size) == 0)
 330                 return "[unknown/kretprobe'd]";
 331         return name;
 332 }
 333 #else
 334 static inline const char *kretprobed(const char *name)
 335 {
 336         return name;
 337 }
 338 #endif /* CONFIG_KRETPROBES */
 339
 340 static void
 341 seq_print_sym_short(struct trace_seq *s, const char *fmt, unsigned long address)
 342 {
 343         char str[KSYM_SYMBOL_LEN];
 344 #ifdef CONFIG_KALLSYMS
 345         const char *name;
 346
 347         kallsyms_lookup(address, NULL, NULL, NULL, str);
 348
 349         name = kretprobed(str);
 350
 351         if (name && strlen(name)) {
 352                 trace_seq_printf(s, fmt, name);
 353                 return;
 354         }
 355 #endif
 356         snprintf(str, KSYM_SYMBOL_LEN, "0x%08lx", address);
 357         trace_seq_printf(s, fmt, str);
 358 }
 359
 360 static void
 361 seq_print_sym_offset(struct trace_seq *s, const char *fmt,
 362                      unsigned long address)
 363 {
 364         char str[KSYM_SYMBOL_LEN];
 365 #ifdef CONFIG_KALLSYMS
 366         const char *name;
 367
 368         sprint_symbol(str, address);
 369         name = kretprobed(str);
 370
 371         if (name && strlen(name)) {
 372                 trace_seq_printf(s, fmt, name);
 373                 return;
 374         }
 375 #endif
 376         snprintf(str, KSYM_SYMBOL_LEN, "0x%08lx", address);
 377         trace_seq_printf(s, fmt, str);
 378 }
 379
 380 #ifndef CONFIG_64BIT
 381 # define IP_FMT "%08lx"
 382 #else
 383 # define IP_FMT "%016lx"
 384 #endif
 385
 386 static int seq_print_user_ip(struct trace_seq *s, struct mm_struct *mm,
 387                              unsigned long ip, unsigned long sym_flags)
 388 {
 389         struct file *file = NULL;
 390         unsigned long vmstart = 0;
 391         int ret = 1;
 392
 393         if (s->full)
 394                 return 0;
 395
 396         if (mm) {
 397                 const struct vm_area_struct *vma;
 398
 399                 down_read(&mm->mmap_sem);
 400                 vma = find_vma(mm, ip);
 401                 if (vma) {
 402                         file = vma->vm_file;
 403                         vmstart = vma->vm_start;
 404                 }
 405                 if (file) {
 406                         ret = trace_seq_path(s, &file->f_path);
 407                         if (ret)
 408                                 trace_seq_printf(s, "[+0x%lx]",
 409                                                  ip - vmstart);
 410                 }
 411                 up_read(&mm->mmap_sem);
 412         }
 413         if (ret && ((sym_flags & TRACE_ITER_SYM_ADDR) || !file))
 414                 trace_seq_printf(s, " <" IP_FMT ">", ip);
 415         return !trace_seq_has_overflowed(s);
 416 }
 417
 418 int
 419 seq_print_ip_sym(struct trace_seq *s, unsigned long ip, unsigned long sym_flags)
 420 {
 421         if (!ip) {
 422                 trace_seq_putc(s, '0');
 423                 goto out;
 424         }
 425
 426         if (sym_flags & TRACE_ITER_SYM_OFFSET)
 427                 seq_print_sym_offset(s, "%s", ip);
 428         else
 429                 seq_print_sym_short(s, "%s", ip);
 430
 431         if (sym_flags & TRACE_ITER_SYM_ADDR)
 432                 trace_seq_printf(s, " <" IP_FMT ">", ip);
 433
 434  out:
 435         return !trace_seq_has_overflowed(s);
 436 }
 437
 438 /**
 439  * trace_print_lat_fmt - print the irq, preempt and lockdep fields
 440  * @s: trace seq struct to write to
 441  * @entry: The trace entry field from the ring buffer
 442  *
 443  * Prints the generic fields of irqs off, in hard or softirq, preempt
 444  * count.
 445  */
 446 int trace_print_lat_fmt(struct trace_seq *s, struct trace_entry *entry)
 447 {
 448         char hardsoft_irq;
 449         char need_resched;
 450         char irqs_off;
 451         int hardirq;
 452         int softirq;
 453         int nmi;
 454
 455         nmi = entry->flags & TRACE_FLAG_NMI;
 456         hardirq = entry->flags & TRACE_FLAG_HARDIRQ;
 457         softirq = entry->flags & TRACE_FLAG_SOFTIRQ;
 458
 459         irqs_off =
 460                 (entry->flags & TRACE_FLAG_IRQS_OFF) ? 'd' :
 461                 (entry->flags & TRACE_FLAG_IRQS_NOSUPPORT) ? 'X' :
 462                 '.';
 463
 464         switch (entry->flags & (TRACE_FLAG_NEED_RESCHED |
 465                                 TRACE_FLAG_PREEMPT_RESCHED)) {
 466         case TRACE_FLAG_NEED_RESCHED | TRACE_FLAG_PREEMPT_RESCHED:
 467                 need_resched = 'N';
 468                 break;
 469         case TRACE_FLAG_NEED_RESCHED:
 470                 need_resched = 'n';
 471                 break;
 472         case TRACE_FLAG_PREEMPT_RESCHED:
 473                 need_resched = 'p';
 474                 break;
 475         default:
 476                 need_resched = '.';
 477                 break;
 478         }
 479
 480         hardsoft_irq =
 481                 (nmi && hardirq)     ? 'Z' :
 482                 nmi                  ? 'z' :
 483                 (hardirq && softirq) ? 'H' :
 484                 hardirq              ? 'h' :
 485                 softirq              ? 's' :
 486                                        '.' ;
 487
 488         trace_seq_printf(s, "%c%c%c",
 489                          irqs_off, need_resched, hardsoft_irq);
 490
 491         if (entry->preempt_count)
 492                 trace_seq_printf(s, "%x", entry->preempt_count);
 493         else
 494                 trace_seq_putc(s, '.');
 495
 496         return !trace_seq_has_overflowed(s);
 497 }
 498
 499 static int
 500 lat_print_generic(struct trace_seq *s, struct trace_entry *entry, int cpu)
 501 {
 502         char comm[TASK_COMM_LEN];
 503
 504         trace_find_cmdline(entry->pid, comm);
 505
 506         trace_seq_printf(s, "%8.8s-%-5d %3d",
 507                          comm, entry->pid, cpu);
 508
 509         return trace_print_lat_fmt(s, entry);
 510 }
 511
 512 #undef MARK
 513 #define MARK(v, s) {.val = v, .sym = s}
 514 /* trace overhead mark */
 515 static const struct trace_mark {
 516         unsigned long long      val; /* unit: nsec */
 517         char                    sym;
 518 } mark[] = {
 519         MARK(1000000000ULL      , '$'), /* 1 sec */
 520         MARK(100000000ULL       , '@'), /* 100 msec */
 521         MARK(10000000ULL        , '*'), /* 10 msec */
 522         MARK(1000000ULL         , '#'), /* 1000 usecs */
 523         MARK(100000ULL          , '!'), /* 100 usecs */
 524         MARK(10000ULL           , '+'), /* 10 usecs */
 525 };
 526 #undef MARK
 527
 528 char trace_find_mark(unsigned long long d)
 529 {
 530         int i;
 531         int size = ARRAY_SIZE(mark);
 532
 533         for (i = 0; i < size; i++) {
 534                 if (d > mark[i].val)
 535                         break;
 536         }
 537
 538         return (i == size) ? ' ' : mark[i].sym;
 539 }
 540
 541 static int
 542 lat_print_timestamp(struct trace_iterator *iter, u64 next_ts)
 543 {
 544         struct trace_array *tr = iter->tr;
 545         unsigned long verbose = tr->trace_flags & TRACE_ITER_VERBOSE;
 546         unsigned long in_ns = iter->iter_flags & TRACE_FILE_TIME_IN_NS;
 547         unsigned long long abs_ts = iter->ts - iter->trace_buffer->time_start;
 548         unsigned long long rel_ts = next_ts - iter->ts;
 549         struct trace_seq *s = &iter->seq;
 550
 551         if (in_ns) {
 552                 abs_ts = ns2usecs(abs_ts);
 553                 rel_ts = ns2usecs(rel_ts);
 554         }
 555
 556         if (verbose && in_ns) {
 557                 unsigned long abs_usec = do_div(abs_ts, USEC_PER_MSEC);
 558                 unsigned long abs_msec = (unsigned long)abs_ts;
 559                 unsigned long rel_usec = do_div(rel_ts, USEC_PER_MSEC);
 560                 unsigned long rel_msec = (unsigned long)rel_ts;
 561
 562                 trace_seq_printf(
 563                         s, "[%08llx] %ld.%03ldms (+%ld.%03ldms): ",
 564                         ns2usecs(iter->ts),
 565                         abs_msec, abs_usec,
 566                         rel_msec, rel_usec);
 567
 568         } else if (verbose && !in_ns) {
 569                 trace_seq_printf(
 570                         s, "[%016llx] %lld (+%lld): ",
 571                         iter->ts, abs_ts, rel_ts);
 572
 573         } else if (!verbose && in_ns) {
 574                 trace_seq_printf(
 575                         s, " %4lldus%c: ",
 576                         abs_ts,
 577                         trace_find_mark(rel_ts * NSEC_PER_USEC));
 578
 579         } else { /* !verbose && !in_ns */
 580                 trace_seq_printf(s, " %4lld: ", abs_ts);
 581         }
 582
 583         return !trace_seq_has_overflowed(s);
 584 }
 585
 586 int trace_print_context(struct trace_iterator *iter)
 587 {
 588         struct trace_array *tr = iter->tr;
 589         struct trace_seq *s = &iter->seq;
 590         struct trace_entry *entry = iter->ent;
 591         unsigned long long t;
 592         unsigned long secs, usec_rem;
 593         char comm[TASK_COMM_LEN];
 594
 595         trace_find_cmdline(entry->pid, comm);
 596
 597         trace_seq_printf(s, "%16s-%-5d ", comm, entry->pid);
 598
 599         if (tr->trace_flags & TRACE_ITER_RECORD_TGID) {
 600                 unsigned int tgid = trace_find_tgid(entry->pid);
 601
 602                 if (!tgid)
 603                         trace_seq_printf(s, "(-----) ");
 604                 else
 605                         trace_seq_printf(s, "(%5d) ", tgid);
 606         }
 607
 608         trace_seq_printf(s, "[%03d] ", iter->cpu);
 609
 610         if (tr->trace_flags & TRACE_ITER_IRQ_INFO)
 611                 trace_print_lat_fmt(s, entry);
 612
 613         if (iter->iter_flags & TRACE_FILE_TIME_IN_NS) {
 614                 t = ns2usecs(iter->ts);
 615                 usec_rem = do_div(t, USEC_PER_SEC);
 616                 secs = (unsigned long)t;
 617                 trace_seq_printf(s, " %5lu.%06lu: ", secs, usec_rem);
 618         } else
 619                 trace_seq_printf(s, " %12llu: ", iter->ts);
 620
 621         return !trace_seq_has_overflowed(s);
 622 }
 623
 624 int trace_print_lat_context(struct trace_iterator *iter)
 625 {
 626         struct trace_array *tr = iter->tr;
 627         /* trace_find_next_entry will reset ent_size */
 628         int ent_size = iter->ent_size;
 629         struct trace_seq *s = &iter->seq;
 630         u64 next_ts;
 631         struct trace_entry *entry = iter->ent,
 632                            *next_entry = trace_find_next_entry(iter, NULL,
 633                                                                &next_ts);
 634         unsigned long verbose = (tr->trace_flags & TRACE_ITER_VERBOSE);
 635
 636         /* Restore the original ent_size */
 637         iter->ent_size = ent_size;
 638
 639         if (!next_entry)
 640                 next_ts = iter->ts;
 641
 642         if (verbose) {
 643                 char comm[TASK_COMM_LEN];
 644
 645                 trace_find_cmdline(entry->pid, comm);
 646
 647                 trace_seq_printf(
 648                         s, "%16s %5d %3d %d %08x %08lx ",
 649                         comm, entry->pid, iter->cpu, entry->flags,
 650                         entry->preempt_count, iter->idx);
 651         } else {
 652                 lat_print_generic(s, entry, iter->cpu);
 653         }
 654
 655         lat_print_timestamp(iter, next_ts);
 656
 657         return !trace_seq_has_overflowed(s);
 658 }
 659
 660 /**
 661  * ftrace_find_event - find a registered event
 662  * @type: the type of event to look for
 663  *
 664  * Returns an event of type @type otherwise NULL
 665  * Called with trace_event_read_lock() held.
 666  */
 667 struct trace_event *ftrace_find_event(int type)
 668 {
 669         struct trace_event *event;
 670         unsigned key;
 671
 672         key = type & (EVENT_HASHSIZE - 1);
 673
 674         hlist_for_each_entry(event, &event_hash[key], node) {
 675                 if (event->type == type)
 676                         return event;
 677         }
 678
 679         return NULL;
 680 }
 681
 682 static LIST_HEAD(ftrace_event_list);
 683
 684 static int trace_search_list(struct list_head **list)
 685 {
 686         struct trace_event *e;
 687         int last = __TRACE_LAST_TYPE;
 688
 689         if (list_empty(&ftrace_event_list)) {
 690                 *list = &ftrace_event_list;
 691                 return last + 1;
 692         }
 693
 694         /*
 695          * We used up all possible max events,
 696          * lets see if somebody freed one.
 697          */
 698         list_for_each_entry(e, &ftrace_event_list, list) {
 699                 if (e->type != last + 1)
 700                         break;
 701                 last++;
 702         }
 703
 704         /* Did we used up all 65 thousand events??? */
 705         if ((last + 1) > TRACE_EVENT_TYPE_MAX)
 706                 return 0;
 707
 708         *list = &e->list;
 709         return last + 1;
 710 }
 711
 712 void trace_event_read_lock(void)
 713 {
 714         down_read(&trace_event_sem);
 715 }
 716
 717 void trace_event_read_unlock(void)
 718 {
 719         up_read(&trace_event_sem);
 720 }
 721
 722 /**
 723  * register_trace_event - register output for an event type
 724  * @event: the event type to register
 725  *
 726  * Event types are stored in a hash and this hash is used to
 727  * find a way to print an event. If the @event->type is set
 728  * then it will use that type, otherwise it will assign a
 729  * type to use.
 730  *
 731  * If you assign your own type, please make sure it is added
 732  * to the trace_type enum in trace.h, to avoid collisions
 733  * with the dynamic types.
 734  *
 735  * Returns the event type number or zero on error.
 736  */
 737 int register_trace_event(struct trace_event *event)
 738 {
 739         unsigned key;
 740         int ret = 0;
 741
 742         down_write(&trace_event_sem);
 743
 744         if (WARN_ON(!event))
 745                 goto out;
 746
 747         if (WARN_ON(!event->funcs))
 748                 goto out;
 749
 750         INIT_LIST_HEAD(&event->list);
 751
 752         if (!event->type) {
 753                 struct list_head *list = NULL;
 754
 755                 if (next_event_type > TRACE_EVENT_TYPE_MAX) {
 756
 757                         event->type = trace_search_list(&list);
 758                         if (!event->type)
 759                                 goto out;
 760
 761                 } else {
 762
 763                         event->type = next_event_type++;
 764                         list = &ftrace_event_list;
 765                 }
 766
 767                 if (WARN_ON(ftrace_find_event(event->type)))
 768                         goto out;
 769
 770                 list_add_tail(&event->list, list);
 771
 772         } else if (event->type > __TRACE_LAST_TYPE) {
 773                 printk(KERN_WARNING "Need to add type to trace.h\n");
 774                 WARN_ON(1);
 775                 goto out;
 776         } else {
 777                 /* Is this event already used */
 778                 if (ftrace_find_event(event->type))
 779                         goto out;
 780         }
 781
 782         if (event->funcs->trace == NULL)
 783                 event->funcs->trace = trace_nop_print;
 784         if (event->funcs->raw == NULL)
 785                 event->funcs->raw = trace_nop_print;
 786         if (event->funcs->hex == NULL)
 787                 event->funcs->hex = trace_nop_print;
 788         if (event->funcs->binary == NULL)
 789                 event->funcs->binary = trace_nop_print;
 790
 791         key = event->type & (EVENT_HASHSIZE - 1);
 792
 793         hlist_add_head(&event->node, &event_hash[key]);
 794
 795         ret = event->type;
 796  out:
 797         up_write(&trace_event_sem);
 798
 799         return ret;
 800 }
 801 EXPORT_SYMBOL_GPL(register_trace_event);
 802
 803 /*
 804  * Used by module code with the trace_event_sem held for write.
 805  */
 806 int __unregister_trace_event(struct trace_event *event)
 807 {
 808         hlist_del(&event->node);
 809         list_del(&event->list);
 810         return 0;
 811 }
 812
 813 /**
 814  * unregister_trace_event - remove a no longer used event
 815  * @event: the event to remove
 816  */
 817 int unregister_trace_event(struct trace_event *event)
 818 {
 819         down_write(&trace_event_sem);
 820         __unregister_trace_event(event);
 821         up_write(&trace_event_sem);
 822
 823         return 0;
 824 }
 825 EXPORT_SYMBOL_GPL(unregister_trace_event);
 826
 827 /*
 828  * Standard events
 829  */
 830
 831 enum print_line_t trace_nop_print(struct trace_iterator *iter, int flags,
 832                                   struct trace_event *event)
 833 {
 834         trace_seq_printf(&iter->seq, "type: %d\n", iter->ent->type);
 835
 836         return trace_handle_return(&iter->seq);
 837 }
 838
 839 /* TRACE_FN */
 840 static enum print_line_t trace_fn_trace(struct trace_iterator *iter, int flags,
 841                                         struct trace_event *event)
 842 {
 843         struct ftrace_entry *field;
 844         struct trace_seq *s = &iter->seq;
 845
 846         trace_assign_type(field, iter->ent);
 847
 848         seq_print_ip_sym(s, field->ip, flags);
 849
 850         if ((flags & TRACE_ITER_PRINT_PARENT) && field->parent_ip) {
 851                 trace_seq_puts(s, " <-");
 852                 seq_print_ip_sym(s, field->parent_ip, flags);
 853         }
 854
 855         trace_seq_putc(s, '\n');
 856
 857         return trace_handle_return(s);
 858 }
 859
 860 static enum print_line_t trace_fn_raw(struct trace_iterator *iter, int flags,
 861                                       struct trace_event *event)
 862 {
 863         struct ftrace_entry *field;
 864
 865         trace_assign_type(field, iter->ent);
 866
 867         trace_seq_printf(&iter->seq, "%lx %lx\n",
 868                          field->ip,
 869                          field->parent_ip);
 870
 871         return trace_handle_return(&iter->seq);
 872 }
 873
 874 static enum print_line_t trace_fn_hex(struct trace_iterator *iter, int flags,
 875                                       struct trace_event *event)
 876 {
 877         struct ftrace_entry *field;
 878         struct trace_seq *s = &iter->seq;
 879
 880         trace_assign_type(field, iter->ent);
 881
 882         SEQ_PUT_HEX_FIELD(s, field->ip);
 883         SEQ_PUT_HEX_FIELD(s, field->parent_ip);
 884
 885         return trace_handle_return(s);
 886 }
 887
 888 static enum print_line_t trace_fn_bin(struct trace_iterator *iter, int flags,
 889                                       struct trace_event *event)
 890 {
 891         struct ftrace_entry *field;
 892         struct trace_seq *s = &iter->seq;
 893
 894         trace_assign_type(field, iter->ent);
 895
 896         SEQ_PUT_FIELD(s, field->ip);
 897         SEQ_PUT_FIELD(s, field->parent_ip);
 898
 899         return trace_handle_return(s);
 900 }
 901
 902 static struct trace_event_functions trace_fn_funcs = {
 903         .trace          = trace_fn_trace,
 904         .raw            = trace_fn_raw,
 905         .hex            = trace_fn_hex,
 906         .binary         = trace_fn_bin,
 907 };
 908
 909 static struct trace_event trace_fn_event = {
 910         .type           = TRACE_FN,
 911         .funcs          = &trace_fn_funcs,
 912 };
 913
 914 /* TRACE_CTX an TRACE_WAKE */
 915 static enum print_line_t trace_ctxwake_print(struct trace_iterator *iter,
 916                                              char *delim)
 917 {
 918         struct ctx_switch_entry *field;
 919         char comm[TASK_COMM_LEN];
 920         int S, T;
 921
 922
 923         trace_assign_type(field, iter->ent);
 924
 925         T = task_index_to_char(field->next_state);
 926         S = task_index_to_char(field->prev_state);
 927         trace_find_cmdline(field->next_pid, comm);
 928         trace_seq_printf(&iter->seq,
 929                          " %5d:%3d:%c %s [%03d] %5d:%3d:%c %s\n",
 930                          field->prev_pid,
 931                          field->prev_prio,
 932                          S, delim,
 933                          field->next_cpu,
 934                          field->next_pid,
 935                          field->next_prio,
 936                          T, comm);
 937
 938         return trace_handle_return(&iter->seq);
 939 }
 940
 941 static enum print_line_t trace_ctx_print(struct trace_iterator *iter, int flags,
 942                                          struct trace_event *event)
 943 {
 944         return trace_ctxwake_print(iter, "==>");
 945 }
 946
 947 static enum print_line_t trace_wake_print(struct trace_iterator *iter,
 948                                           int flags, struct trace_event *event)
 949 {
 950         return trace_ctxwake_print(iter, "  +");
 951 }
 952
 953 static int trace_ctxwake_raw(struct trace_iterator *iter, char S)
 954 {
 955         struct ctx_switch_entry *field;
 956         int T;
 957
 958         trace_assign_type(field, iter->ent);
 959
 960         if (!S)
 961                 S = task_index_to_char(field->prev_state);
 962         T = task_index_to_char(field->next_state);
 963         trace_seq_printf(&iter->seq, "%d %d %c %d %d %d %c\n",
 964                          field->prev_pid,
 965                          field->prev_prio,
 966                          S,
 967                          field->next_cpu,
 968                          field->next_pid,
 969                          field->next_prio,
 970                          T);
 971
 972         return trace_handle_return(&iter->seq);
 973 }
 974
 975 static enum print_line_t trace_ctx_raw(struct trace_iterator *iter, int flags,
 976                                        struct trace_event *event)
 977 {
 978         return trace_ctxwake_raw(iter, 0);
 979 }
 980
 981 static enum print_line_t trace_wake_raw(struct trace_iterator *iter, int flags,
 982                                         struct trace_event *event)
 983 {
 984         return trace_ctxwake_raw(iter, '+');
 985 }
 986
 987
 988 static int trace_ctxwake_hex(struct trace_iterator *iter, char S)
 989 {
 990         struct ctx_switch_entry *field;
 991         struct trace_seq *s = &iter->seq;
 992         int T;
 993
 994         trace_assign_type(field, iter->ent);
 995
 996         if (!S)
 997                 S = task_index_to_char(field->prev_state);
 998         T = task_index_to_char(field->next_state);
 999
1000         SEQ_PUT_HEX_FIELD(s, field->prev_pid);
1001         SEQ_PUT_HEX_FIELD(s, field->prev_prio);
1002         SEQ_PUT_HEX_FIELD(s, S);
1003         SEQ_PUT_HEX_FIELD(s, field->next_cpu);
1004         SEQ_PUT_HEX_FIELD(s, field->next_pid);
1005         SEQ_PUT_HEX_FIELD(s, field->next_prio);
1006         SEQ_PUT_HEX_FIELD(s, T);
1007
1008         return trace_handle_return(s);
1009 }
1010
1011 static enum print_line_t trace_ctx_hex(struct trace_iterator *iter, int flags,
1012                                        struct trace_event *event)
1013 {
1014         return trace_ctxwake_hex(iter, 0);
1015 }
1016
1017 static enum print_line_t trace_wake_hex(struct trace_iterator *iter, int flags,
1018                                         struct trace_event *event)
1019 {
1020         return trace_ctxwake_hex(iter, '+');
1021 }
1022
1023 static enum print_line_t trace_ctxwake_bin(struct trace_iterator *iter,
1024                                            int flags, struct trace_event *event)
1025 {
1026         struct ctx_switch_entry *field;
1027         struct trace_seq *s = &iter->seq;
1028
1029         trace_assign_type(field, iter->ent);
1030
1031         SEQ_PUT_FIELD(s, field->prev_pid);
1032         SEQ_PUT_FIELD(s, field->prev_prio);
1033         SEQ_PUT_FIELD(s, field->prev_state);
1034         SEQ_PUT_FIELD(s, field->next_cpu);
1035         SEQ_PUT_FIELD(s, field->next_pid);
1036         SEQ_PUT_FIELD(s, field->next_prio);
1037         SEQ_PUT_FIELD(s, field->next_state);
1038
1039         return trace_handle_return(s);
1040 }
1041
1042 static struct trace_event_functions trace_ctx_funcs = {
1043         .trace          = trace_ctx_print,
1044         .raw            = trace_ctx_raw,
1045         .hex            = trace_ctx_hex,
1046         .binary         = trace_ctxwake_bin,
1047 };
1048
1049 static struct trace_event trace_ctx_event = {
1050         .type           = TRACE_CTX,
1051         .funcs          = &trace_ctx_funcs,
1052 };
1053
1054 static struct trace_event_functions trace_wake_funcs = {
1055         .trace          = trace_wake_print,
1056         .raw            = trace_wake_raw,
1057         .hex            = trace_wake_hex,
1058         .binary         = trace_ctxwake_bin,
1059 };
1060
1061 static struct trace_event trace_wake_event = {
1062         .type           = TRACE_WAKE,
1063         .funcs          = &trace_wake_funcs,
1064 };
1065
1066 /* TRACE_STACK */
1067
1068 static enum print_line_t trace_stack_print(struct trace_iterator *iter,
1069                                            int flags, struct trace_event *event)
1070 {
1071         struct stack_entry *field;
1072         struct trace_seq *s = &iter->seq;
1073         unsigned long *p;
1074         unsigned long *end;
1075
1076         trace_assign_type(field, iter->ent);
1077         end = (unsigned long *)((long)iter->ent + iter->ent_size);
1078
1079         trace_seq_puts(s, "<stack trace>\n");
1080
1081         for (p = field->caller; p && *p != ULONG_MAX && p < end; p++) {
1082
1083                 if (trace_seq_has_overflowed(s))
1084                         break;
1085
1086                 trace_seq_puts(s, " => ");
1087                 seq_print_ip_sym(s, *p, flags);
1088                 trace_seq_putc(s, '\n');
1089         }
1090
1091         return trace_handle_return(s);
1092 }
1093
1094 static struct trace_event_functions trace_stack_funcs = {
1095         .trace          = trace_stack_print,
1096 };
1097
1098 static struct trace_event trace_stack_event = {
1099         .type           = TRACE_STACK,
1100         .funcs          = &trace_stack_funcs,
1101 };
1102
1103 /* TRACE_USER_STACK */
1104 static enum print_line_t trace_user_stack_print(struct trace_iterator *iter,
1105                                                 int flags, struct trace_event *event)
1106 {
1107         struct trace_array *tr = iter->tr;
1108         struct userstack_entry *field;
1109         struct trace_seq *s = &iter->seq;
1110         struct mm_struct *mm = NULL;
1111         unsigned int i;
1112
1113         trace_assign_type(field, iter->ent);
1114
1115         trace_seq_puts(s, "<user stack trace>\n");
1116
1117         if (tr->trace_flags & TRACE_ITER_SYM_USEROBJ) {
1118                 struct task_struct *task;
1119                 /*
1120                  * we do the lookup on the thread group leader,
1121                  * since individual threads might have already quit!
1122                  */
1123                 rcu_read_lock();
1124                 task = find_task_by_vpid(field->tgid);
1125                 if (task)
1126                         mm = get_task_mm(task);
1127                 rcu_read_unlock();
1128         }
1129
1130         for (i = 0; i < FTRACE_STACK_ENTRIES; i++) {
1131                 unsigned long ip = field->caller[i];
1132
1133                 if (ip == ULONG_MAX || trace_seq_has_overflowed(s))
1134                         break;
1135
1136                 trace_seq_puts(s, " => ");
1137
1138                 if (!ip) {
1139                         trace_seq_puts(s, "??");
1140                         trace_seq_putc(s, '\n');
1141                         continue;
1142                 }
1143
1144                 seq_print_user_ip(s, mm, ip, flags);
1145                 trace_seq_putc(s, '\n');
1146         }
1147
1148         if (mm)
1149                 mmput(mm);
1150
1151         return trace_handle_return(s);
1152 }
1153
1154 static struct trace_event_functions trace_user_stack_funcs = {
1155         .trace          = trace_user_stack_print,
1156 };
1157
1158 static struct trace_event trace_user_stack_event = {
1159         .type           = TRACE_USER_STACK,
1160         .funcs          = &trace_user_stack_funcs,
1161 };
1162
1163 /* TRACE_HWLAT */
1164 static enum print_line_t
1165 trace_hwlat_print(struct trace_iterator *iter, int flags,
1166                   struct trace_event *event)
1167 {
1168         struct trace_entry *entry = iter->ent;
1169         struct trace_seq *s = &iter->seq;
1170         struct hwlat_entry *field;
1171
1172         trace_assign_type(field, entry);
1173
1174         trace_seq_printf(s, "#%-5u inner/outer(us): %4llu/%-5llu ts:%lld.%09ld",
1175                          field->seqnum,
1176                          field->duration,
1177                          field->outer_duration,
1178                          (long long)field->timestamp.tv_sec,
1179                          field->timestamp.tv_nsec);
1180
1181         if (field->nmi_count) {
1182                 /*
1183                  * The generic sched_clock() is not NMI safe, thus
1184                  * we only record the count and not the time.
1185                  */
1186                 if (!IS_ENABLED(CONFIG_GENERIC_SCHED_CLOCK))
1187                         trace_seq_printf(s, " nmi-total:%llu",
1188                                          field->nmi_total_ts);
1189                 trace_seq_printf(s, " nmi-count:%u",
1190                                  field->nmi_count);
1191         }
1192
1193         trace_seq_putc(s, '\n');
1194
1195         return trace_handle_return(s);
1196 }
1197
1198
1199 static enum print_line_t
1200 trace_hwlat_raw(struct trace_iterator *iter, int flags,
1201                 struct trace_event *event)
1202 {
1203         struct hwlat_entry *field;
1204         struct trace_seq *s = &iter->seq;
1205
1206         trace_assign_type(field, iter->ent);
1207
1208         trace_seq_printf(s, "%llu %lld %lld %09ld %u\n",
1209                          field->duration,
1210                          field->outer_duration,
1211                          (long long)field->timestamp.tv_sec,
1212                          field->timestamp.tv_nsec,
1213                          field->seqnum);
1214
1215         return trace_handle_return(s);
1216 }
1217
1218 static struct trace_event_functions trace_hwlat_funcs = {
1219         .trace          = trace_hwlat_print,
1220         .raw            = trace_hwlat_raw,
1221 };
1222
1223 static struct trace_event trace_hwlat_event = {
1224         .type           = TRACE_HWLAT,
1225         .funcs          = &trace_hwlat_funcs,
1226 };
1227
1228 /* TRACE_BPUTS */
1229 static enum print_line_t
1230 trace_bputs_print(struct trace_iterator *iter, int flags,
1231                    struct trace_event *event)
1232 {
1233         struct trace_entry *entry = iter->ent;
1234         struct trace_seq *s = &iter->seq;
1235         struct bputs_entry *field;
1236
1237         trace_assign_type(field, entry);
1238
1239         seq_print_ip_sym(s, field->ip, flags);
1240         trace_seq_puts(s, ": ");
1241         trace_seq_puts(s, field->str);
1242
1243         return trace_handle_return(s);
1244 }
1245
1246
1247 static enum print_line_t
1248 trace_bputs_raw(struct trace_iterator *iter, int flags,
1249                 struct trace_event *event)
1250 {
1251         struct bputs_entry *field;
1252         struct trace_seq *s = &iter->seq;
1253
1254         trace_assign_type(field, iter->ent);
1255
1256         trace_seq_printf(s, ": %lx : ", field->ip);
1257         trace_seq_puts(s, field->str);
1258
1259         return trace_handle_return(s);
1260 }
1261
1262 static struct trace_event_functions trace_bputs_funcs = {
1263         .trace          = trace_bputs_print,
1264         .raw            = trace_bputs_raw,
1265 };
1266
1267 static struct trace_event trace_bputs_event = {
1268         .type           = TRACE_BPUTS,
1269         .funcs          = &trace_bputs_funcs,
1270 };
1271
1272 /* TRACE_BPRINT */
1273 static enum print_line_t
1274 trace_bprint_print(struct trace_iterator *iter, int flags,
1275                    struct trace_event *event)
1276 {
1277         struct trace_entry *entry = iter->ent;
1278         struct trace_seq *s = &iter->seq;
1279         struct bprint_entry *field;
1280
1281         trace_assign_type(field, entry);
1282
1283         seq_print_ip_sym(s, field->ip, flags);
1284         trace_seq_puts(s, ": ");
1285         trace_seq_bprintf(s, field->fmt, field->buf);
1286
1287         return trace_handle_return(s);
1288 }
1289
1290
1291 static enum print_line_t
1292 trace_bprint_raw(struct trace_iterator *iter, int flags,
1293                  struct trace_event *event)
1294 {
1295         struct bprint_entry *field;
1296         struct trace_seq *s = &iter->seq;
1297
1298         trace_assign_type(field, iter->ent);
1299
1300         trace_seq_printf(s, ": %lx : ", field->ip);
1301         trace_seq_bprintf(s, field->fmt, field->buf);
1302
1303         return trace_handle_return(s);
1304 }
1305
1306 static struct trace_event_functions trace_bprint_funcs = {
1307         .trace          = trace_bprint_print,
1308         .raw            = trace_bprint_raw,
1309 };
1310
1311 static struct trace_event trace_bprint_event = {
1312         .type           = TRACE_BPRINT,
1313         .funcs          = &trace_bprint_funcs,
1314 };
1315
1316 /* TRACE_PRINT */
1317 static enum print_line_t trace_print_print(struct trace_iterator *iter,
1318                                            int flags, struct trace_event *event)
1319 {
1320         struct print_entry *field;
1321         struct trace_seq *s = &iter->seq;
1322
1323         trace_assign_type(field, iter->ent);
1324
1325         seq_print_ip_sym(s, field->ip, flags);
1326         trace_seq_printf(s, ": %s", field->buf);
1327
1328         return trace_handle_return(s);
1329 }
1330
1331 static enum print_line_t trace_print_raw(struct trace_iterator *iter, int flags,
1332                                          struct trace_event *event)
1333 {
1334         struct print_entry *field;
1335
1336         trace_assign_type(field, iter->ent);
1337
1338         trace_seq_printf(&iter->seq, "# %lx %s", field->ip, field->buf);
1339
1340         return trace_handle_return(&iter->seq);
1341 }
1342
1343 static struct trace_event_functions trace_print_funcs = {
1344         .trace          = trace_print_print,
1345         .raw            = trace_print_raw,
1346 };
1347
1348 static struct trace_event trace_print_event = {
1349         .type           = TRACE_PRINT,
1350         .funcs          = &trace_print_funcs,
1351 };
1352
1353 static enum print_line_t trace_raw_data(struct trace_iterator *iter, int flags,
1354                                          struct trace_event *event)
1355 {
1356         struct raw_data_entry *field;
1357         int i;
1358
1359         trace_assign_type(field, iter->ent);
1360
1361         trace_seq_printf(&iter->seq, "# %x buf:", field->id);
1362
1363         for (i = 0; i < iter->ent_size - offsetof(struct raw_data_entry, buf); i++)
1364                 trace_seq_printf(&iter->seq, " %02x",
1365                                  (unsigned char)field->buf[i]);
1366
1367         trace_seq_putc(&iter->seq, '\n');
1368
1369         return trace_handle_return(&iter->seq);
1370 }
1371
1372 static struct trace_event_functions trace_raw_data_funcs = {
1373         .trace          = trace_raw_data,
1374         .raw            = trace_raw_data,
1375 };
1376
1377 static struct trace_event trace_raw_data_event = {
1378         .type           = TRACE_RAW_DATA,
1379         .funcs          = &trace_raw_data_funcs,
1380 };
1381
1382
1383 static struct trace_event *events[] __initdata = {
1384         &trace_fn_event,
1385         &trace_ctx_event,
1386         &trace_wake_event,
1387         &trace_stack_event,
1388         &trace_user_stack_event,
1389         &trace_bputs_event,
1390         &trace_bprint_event,
1391         &trace_print_event,
1392         &trace_hwlat_event,
1393         &trace_raw_data_event,
1394         NULL
1395 };
1396
1397 __init static int init_events(void)
1398 {
1399         struct trace_event *event;
1400         int i, ret;
1401
1402         for (i = 0; events[i]; i++) {
1403                 event = events[i];
1404
1405                 ret = register_trace_event(event);
1406                 if (!ret) {
1407                         printk(KERN_WARNING "event %d failed to register\n",
1408                                event->type);
1409                         WARN_ON_ONCE(1);
1410                 }
1411         }
1412
1413         return 0;
1414 }
1415 early_initcall(init_events);