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 [%03d] ",
 598                                comm, entry->pid, iter->cpu);
 599
 600         if (tr->trace_flags & TRACE_ITER_RECORD_TGID) {
 601                 unsigned int tgid = trace_find_tgid(entry->pid);
 602
 603                 if (!tgid)
 604                         trace_seq_printf(s, "(-----) ");
 605                 else
 606                         trace_seq_printf(s, "(%5d) ", tgid);
 607         }
 608
 609         if (tr->trace_flags & TRACE_ITER_IRQ_INFO)
 610                 trace_print_lat_fmt(s, entry);
 611
 612         if (iter->iter_flags & TRACE_FILE_TIME_IN_NS) {
 613                 t = ns2usecs(iter->ts);
 614                 usec_rem = do_div(t, USEC_PER_SEC);
 615                 secs = (unsigned long)t;
 616                 trace_seq_printf(s, " %5lu.%06lu: ", secs, usec_rem);
 617         } else
 618                 trace_seq_printf(s, " %12llu: ", iter->ts);
 619
 620         return !trace_seq_has_overflowed(s);
 621 }
 622
 623 int trace_print_lat_context(struct trace_iterator *iter)
 624 {
 625         struct trace_array *tr = iter->tr;
 626         /* trace_find_next_entry will reset ent_size */
 627         int ent_size = iter->ent_size;
 628         struct trace_seq *s = &iter->seq;
 629         u64 next_ts;
 630         struct trace_entry *entry = iter->ent,
 631                            *next_entry = trace_find_next_entry(iter, NULL,
 632                                                                &next_ts);
 633         unsigned long verbose = (tr->trace_flags & TRACE_ITER_VERBOSE);
 634
 635         /* Restore the original ent_size */
 636         iter->ent_size = ent_size;
 637
 638         if (!next_entry)
 639                 next_ts = iter->ts;
 640
 641         if (verbose) {
 642                 char comm[TASK_COMM_LEN];
 643
 644                 trace_find_cmdline(entry->pid, comm);
 645
 646                 trace_seq_printf(
 647                         s, "%16s %5d %3d %d %08x %08lx ",
 648                         comm, entry->pid, iter->cpu, entry->flags,
 649                         entry->preempt_count, iter->idx);
 650         } else {
 651                 lat_print_generic(s, entry, iter->cpu);
 652         }
 653
 654         lat_print_timestamp(iter, next_ts);
 655
 656         return !trace_seq_has_overflowed(s);
 657 }
 658
 659 static const char state_to_char[] = TASK_STATE_TO_CHAR_STR;
 660
 661 static int task_state_char(unsigned long state)
 662 {
 663         int bit = state ? __ffs(state) + 1 : 0;
 664
 665         return bit < sizeof(state_to_char) - 1 ? state_to_char[bit] : '?';
 666 }
 667
 668 /**
 669  * ftrace_find_event - find a registered event
 670  * @type: the type of event to look for
 671  *
 672  * Returns an event of type @type otherwise NULL
 673  * Called with trace_event_read_lock() held.
 674  */
 675 struct trace_event *ftrace_find_event(int type)
 676 {
 677         struct trace_event *event;
 678         unsigned key;
 679
 680         key = type & (EVENT_HASHSIZE - 1);
 681
 682         hlist_for_each_entry(event, &event_hash[key], node) {
 683                 if (event->type == type)
 684                         return event;
 685         }
 686
 687         return NULL;
 688 }
 689
 690 static LIST_HEAD(ftrace_event_list);
 691
 692 static int trace_search_list(struct list_head **list)
 693 {
 694         struct trace_event *e;
 695         int last = __TRACE_LAST_TYPE;
 696
 697         if (list_empty(&ftrace_event_list)) {
 698                 *list = &ftrace_event_list;
 699                 return last + 1;
 700         }
 701
 702         /*
 703          * We used up all possible max events,
 704          * lets see if somebody freed one.
 705          */
 706         list_for_each_entry(e, &ftrace_event_list, list) {
 707                 if (e->type != last + 1)
 708                         break;
 709                 last++;
 710         }
 711
 712         /* Did we used up all 65 thousand events??? */
 713         if ((last + 1) > TRACE_EVENT_TYPE_MAX)
 714                 return 0;
 715
 716         *list = &e->list;
 717         return last + 1;
 718 }
 719
 720 void trace_event_read_lock(void)
 721 {
 722         down_read(&trace_event_sem);
 723 }
 724
 725 void trace_event_read_unlock(void)
 726 {
 727         up_read(&trace_event_sem);
 728 }
 729
 730 /**
 731  * register_trace_event - register output for an event type
 732  * @event: the event type to register
 733  *
 734  * Event types are stored in a hash and this hash is used to
 735  * find a way to print an event. If the @event->type is set
 736  * then it will use that type, otherwise it will assign a
 737  * type to use.
 738  *
 739  * If you assign your own type, please make sure it is added
 740  * to the trace_type enum in trace.h, to avoid collisions
 741  * with the dynamic types.
 742  *
 743  * Returns the event type number or zero on error.
 744  */
 745 int register_trace_event(struct trace_event *event)
 746 {
 747         unsigned key;
 748         int ret = 0;
 749
 750         down_write(&trace_event_sem);
 751
 752         if (WARN_ON(!event))
 753                 goto out;
 754
 755         if (WARN_ON(!event->funcs))
 756                 goto out;
 757
 758         INIT_LIST_HEAD(&event->list);
 759
 760         if (!event->type) {
 761                 struct list_head *list = NULL;
 762
 763                 if (next_event_type > TRACE_EVENT_TYPE_MAX) {
 764
 765                         event->type = trace_search_list(&list);
 766                         if (!event->type)
 767                                 goto out;
 768
 769                 } else {
 770
 771                         event->type = next_event_type++;
 772                         list = &ftrace_event_list;
 773                 }
 774
 775                 if (WARN_ON(ftrace_find_event(event->type)))
 776                         goto out;
 777
 778                 list_add_tail(&event->list, list);
 779
 780         } else if (event->type > __TRACE_LAST_TYPE) {
 781                 printk(KERN_WARNING "Need to add type to trace.h\n");
 782                 WARN_ON(1);
 783                 goto out;
 784         } else {
 785                 /* Is this event already used */
 786                 if (ftrace_find_event(event->type))
 787                         goto out;
 788         }
 789
 790         if (event->funcs->trace == NULL)
 791                 event->funcs->trace = trace_nop_print;
 792         if (event->funcs->raw == NULL)
 793                 event->funcs->raw = trace_nop_print;
 794         if (event->funcs->hex == NULL)
 795                 event->funcs->hex = trace_nop_print;
 796         if (event->funcs->binary == NULL)
 797                 event->funcs->binary = trace_nop_print;
 798
 799         key = event->type & (EVENT_HASHSIZE - 1);
 800
 801         hlist_add_head(&event->node, &event_hash[key]);
 802
 803         ret = event->type;
 804  out:
 805         up_write(&trace_event_sem);
 806
 807         return ret;
 808 }
 809 EXPORT_SYMBOL_GPL(register_trace_event);
 810
 811 /*
 812  * Used by module code with the trace_event_sem held for write.
 813  */
 814 int __unregister_trace_event(struct trace_event *event)
 815 {
 816         hlist_del(&event->node);
 817         list_del(&event->list);
 818         return 0;
 819 }
 820
 821 /**
 822  * unregister_trace_event - remove a no longer used event
 823  * @event: the event to remove
 824  */
 825 int unregister_trace_event(struct trace_event *event)
 826 {
 827         down_write(&trace_event_sem);
 828         __unregister_trace_event(event);
 829         up_write(&trace_event_sem);
 830
 831         return 0;
 832 }
 833 EXPORT_SYMBOL_GPL(unregister_trace_event);
 834
 835 /*
 836  * Standard events
 837  */
 838
 839 enum print_line_t trace_nop_print(struct trace_iterator *iter, int flags,
 840                                   struct trace_event *event)
 841 {
 842         trace_seq_printf(&iter->seq, "type: %d\n", iter->ent->type);
 843
 844         return trace_handle_return(&iter->seq);
 845 }
 846
 847 /* TRACE_FN */
 848 static enum print_line_t trace_fn_trace(struct trace_iterator *iter, int flags,
 849                                         struct trace_event *event)
 850 {
 851         struct ftrace_entry *field;
 852         struct trace_seq *s = &iter->seq;
 853
 854         trace_assign_type(field, iter->ent);
 855
 856         seq_print_ip_sym(s, field->ip, flags);
 857
 858         if ((flags & TRACE_ITER_PRINT_PARENT) && field->parent_ip) {
 859                 trace_seq_puts(s, " <-");
 860                 seq_print_ip_sym(s, field->parent_ip, flags);
 861         }
 862
 863         trace_seq_putc(s, '\n');
 864
 865         return trace_handle_return(s);
 866 }
 867
 868 static enum print_line_t trace_fn_raw(struct trace_iterator *iter, int flags,
 869                                       struct trace_event *event)
 870 {
 871         struct ftrace_entry *field;
 872
 873         trace_assign_type(field, iter->ent);
 874
 875         trace_seq_printf(&iter->seq, "%lx %lx\n",
 876                          field->ip,
 877                          field->parent_ip);
 878
 879         return trace_handle_return(&iter->seq);
 880 }
 881
 882 static enum print_line_t trace_fn_hex(struct trace_iterator *iter, int flags,
 883                                       struct trace_event *event)
 884 {
 885         struct ftrace_entry *field;
 886         struct trace_seq *s = &iter->seq;
 887
 888         trace_assign_type(field, iter->ent);
 889
 890         SEQ_PUT_HEX_FIELD(s, field->ip);
 891         SEQ_PUT_HEX_FIELD(s, field->parent_ip);
 892
 893         return trace_handle_return(s);
 894 }
 895
 896 static enum print_line_t trace_fn_bin(struct trace_iterator *iter, int flags,
 897                                       struct trace_event *event)
 898 {
 899         struct ftrace_entry *field;
 900         struct trace_seq *s = &iter->seq;
 901
 902         trace_assign_type(field, iter->ent);
 903
 904         SEQ_PUT_FIELD(s, field->ip);
 905         SEQ_PUT_FIELD(s, field->parent_ip);
 906
 907         return trace_handle_return(s);
 908 }
 909
 910 static struct trace_event_functions trace_fn_funcs = {
 911         .trace          = trace_fn_trace,
 912         .raw            = trace_fn_raw,
 913         .hex            = trace_fn_hex,
 914         .binary         = trace_fn_bin,
 915 };
 916
 917 static struct trace_event trace_fn_event = {
 918         .type           = TRACE_FN,
 919         .funcs          = &trace_fn_funcs,
 920 };
 921
 922 /* TRACE_CTX an TRACE_WAKE */
 923 static enum print_line_t trace_ctxwake_print(struct trace_iterator *iter,
 924                                              char *delim)
 925 {
 926         struct ctx_switch_entry *field;
 927         char comm[TASK_COMM_LEN];
 928         int S, T;
 929
 930
 931         trace_assign_type(field, iter->ent);
 932
 933         T = task_state_char(field->next_state);
 934         S = task_state_char(field->prev_state);
 935         trace_find_cmdline(field->next_pid, comm);
 936         trace_seq_printf(&iter->seq,
 937                          " %5d:%3d:%c %s [%03d] %5d:%3d:%c %s\n",
 938                          field->prev_pid,
 939                          field->prev_prio,
 940                          S, delim,
 941                          field->next_cpu,
 942                          field->next_pid,
 943                          field->next_prio,
 944                          T, comm);
 945
 946         return trace_handle_return(&iter->seq);
 947 }
 948
 949 static enum print_line_t trace_ctx_print(struct trace_iterator *iter, int flags,
 950                                          struct trace_event *event)
 951 {
 952         return trace_ctxwake_print(iter, "==>");
 953 }
 954
 955 static enum print_line_t trace_wake_print(struct trace_iterator *iter,
 956                                           int flags, struct trace_event *event)
 957 {
 958         return trace_ctxwake_print(iter, "  +");
 959 }
 960
 961 static int trace_ctxwake_raw(struct trace_iterator *iter, char S)
 962 {
 963         struct ctx_switch_entry *field;
 964         int T;
 965
 966         trace_assign_type(field, iter->ent);
 967
 968         if (!S)
 969                 S = task_state_char(field->prev_state);
 970         T = task_state_char(field->next_state);
 971         trace_seq_printf(&iter->seq, "%d %d %c %d %d %d %c\n",
 972                          field->prev_pid,
 973                          field->prev_prio,
 974                          S,
 975                          field->next_cpu,
 976                          field->next_pid,
 977                          field->next_prio,
 978                          T);
 979
 980         return trace_handle_return(&iter->seq);
 981 }
 982
 983 static enum print_line_t trace_ctx_raw(struct trace_iterator *iter, int flags,
 984                                        struct trace_event *event)
 985 {
 986         return trace_ctxwake_raw(iter, 0);
 987 }
 988
 989 static enum print_line_t trace_wake_raw(struct trace_iterator *iter, int flags,
 990                                         struct trace_event *event)
 991 {
 992         return trace_ctxwake_raw(iter, '+');
 993 }
 994
 995
 996 static int trace_ctxwake_hex(struct trace_iterator *iter, char S)
 997 {
 998         struct ctx_switch_entry *field;
 999         struct trace_seq *s = &iter->seq;
1000         int T;
1001
1002         trace_assign_type(field, iter->ent);
1003
1004         if (!S)
1005                 S = task_state_char(field->prev_state);
1006         T = task_state_char(field->next_state);
1007
1008         SEQ_PUT_HEX_FIELD(s, field->prev_pid);
1009         SEQ_PUT_HEX_FIELD(s, field->prev_prio);
1010         SEQ_PUT_HEX_FIELD(s, S);
1011         SEQ_PUT_HEX_FIELD(s, field->next_cpu);
1012         SEQ_PUT_HEX_FIELD(s, field->next_pid);
1013         SEQ_PUT_HEX_FIELD(s, field->next_prio);
1014         SEQ_PUT_HEX_FIELD(s, T);
1015
1016         return trace_handle_return(s);
1017 }
1018
1019 static enum print_line_t trace_ctx_hex(struct trace_iterator *iter, int flags,
1020                                        struct trace_event *event)
1021 {
1022         return trace_ctxwake_hex(iter, 0);
1023 }
1024
1025 static enum print_line_t trace_wake_hex(struct trace_iterator *iter, int flags,
1026                                         struct trace_event *event)
1027 {
1028         return trace_ctxwake_hex(iter, '+');
1029 }
1030
1031 static enum print_line_t trace_ctxwake_bin(struct trace_iterator *iter,
1032                                            int flags, struct trace_event *event)
1033 {
1034         struct ctx_switch_entry *field;
1035         struct trace_seq *s = &iter->seq;
1036
1037         trace_assign_type(field, iter->ent);
1038
1039         SEQ_PUT_FIELD(s, field->prev_pid);
1040         SEQ_PUT_FIELD(s, field->prev_prio);
1041         SEQ_PUT_FIELD(s, field->prev_state);
1042         SEQ_PUT_FIELD(s, field->next_cpu);
1043         SEQ_PUT_FIELD(s, field->next_pid);
1044         SEQ_PUT_FIELD(s, field->next_prio);
1045         SEQ_PUT_FIELD(s, field->next_state);
1046
1047         return trace_handle_return(s);
1048 }
1049
1050 static struct trace_event_functions trace_ctx_funcs = {
1051         .trace          = trace_ctx_print,
1052         .raw            = trace_ctx_raw,
1053         .hex            = trace_ctx_hex,
1054         .binary         = trace_ctxwake_bin,
1055 };
1056
1057 static struct trace_event trace_ctx_event = {
1058         .type           = TRACE_CTX,
1059         .funcs          = &trace_ctx_funcs,
1060 };
1061
1062 static struct trace_event_functions trace_wake_funcs = {
1063         .trace          = trace_wake_print,
1064         .raw            = trace_wake_raw,
1065         .hex            = trace_wake_hex,
1066         .binary         = trace_ctxwake_bin,
1067 };
1068
1069 static struct trace_event trace_wake_event = {
1070         .type           = TRACE_WAKE,
1071         .funcs          = &trace_wake_funcs,
1072 };
1073
1074 /* TRACE_STACK */
1075
1076 static enum print_line_t trace_stack_print(struct trace_iterator *iter,
1077                                            int flags, struct trace_event *event)
1078 {
1079         struct stack_entry *field;
1080         struct trace_seq *s = &iter->seq;
1081         unsigned long *p;
1082         unsigned long *end;
1083
1084         trace_assign_type(field, iter->ent);
1085         end = (unsigned long *)((long)iter->ent + iter->ent_size);
1086
1087         trace_seq_puts(s, "<stack trace>\n");
1088
1089         for (p = field->caller; p && *p != ULONG_MAX && p < end; p++) {
1090
1091                 if (trace_seq_has_overflowed(s))
1092                         break;
1093
1094                 trace_seq_puts(s, " => ");
1095                 seq_print_ip_sym(s, *p, flags);
1096                 trace_seq_putc(s, '\n');
1097         }
1098
1099         return trace_handle_return(s);
1100 }
1101
1102 static struct trace_event_functions trace_stack_funcs = {
1103         .trace          = trace_stack_print,
1104 };
1105
1106 static struct trace_event trace_stack_event = {
1107         .type           = TRACE_STACK,
1108         .funcs          = &trace_stack_funcs,
1109 };
1110
1111 /* TRACE_USER_STACK */
1112 static enum print_line_t trace_user_stack_print(struct trace_iterator *iter,
1113                                                 int flags, struct trace_event *event)
1114 {
1115         struct trace_array *tr = iter->tr;
1116         struct userstack_entry *field;
1117         struct trace_seq *s = &iter->seq;
1118         struct mm_struct *mm = NULL;
1119         unsigned int i;
1120
1121         trace_assign_type(field, iter->ent);
1122
1123         trace_seq_puts(s, "<user stack trace>\n");
1124
1125         if (tr->trace_flags & TRACE_ITER_SYM_USEROBJ) {
1126                 struct task_struct *task;
1127                 /*
1128                  * we do the lookup on the thread group leader,
1129                  * since individual threads might have already quit!
1130                  */
1131                 rcu_read_lock();
1132                 task = find_task_by_vpid(field->tgid);
1133                 if (task)
1134                         mm = get_task_mm(task);
1135                 rcu_read_unlock();
1136         }
1137
1138         for (i = 0; i < FTRACE_STACK_ENTRIES; i++) {
1139                 unsigned long ip = field->caller[i];
1140
1141                 if (ip == ULONG_MAX || trace_seq_has_overflowed(s))
1142                         break;
1143
1144                 trace_seq_puts(s, " => ");
1145
1146                 if (!ip) {
1147                         trace_seq_puts(s, "??");
1148                         trace_seq_putc(s, '\n');
1149                         continue;
1150                 }
1151
1152                 seq_print_user_ip(s, mm, ip, flags);
1153                 trace_seq_putc(s, '\n');
1154         }
1155
1156         if (mm)
1157                 mmput(mm);
1158
1159         return trace_handle_return(s);
1160 }
1161
1162 static struct trace_event_functions trace_user_stack_funcs = {
1163         .trace          = trace_user_stack_print,
1164 };
1165
1166 static struct trace_event trace_user_stack_event = {
1167         .type           = TRACE_USER_STACK,
1168         .funcs          = &trace_user_stack_funcs,
1169 };
1170
1171 /* TRACE_HWLAT */
1172 static enum print_line_t
1173 trace_hwlat_print(struct trace_iterator *iter, int flags,
1174                   struct trace_event *event)
1175 {
1176         struct trace_entry *entry = iter->ent;
1177         struct trace_seq *s = &iter->seq;
1178         struct hwlat_entry *field;
1179
1180         trace_assign_type(field, entry);
1181
1182         trace_seq_printf(s, "#%-5u inner/outer(us): %4llu/%-5llu ts:%lld.%09ld",
1183                          field->seqnum,
1184                          field->duration,
1185                          field->outer_duration,
1186                          (long long)field->timestamp.tv_sec,
1187                          field->timestamp.tv_nsec);
1188
1189         if (field->nmi_count) {
1190                 /*
1191                  * The generic sched_clock() is not NMI safe, thus
1192                  * we only record the count and not the time.
1193                  */
1194                 if (!IS_ENABLED(CONFIG_GENERIC_SCHED_CLOCK))
1195                         trace_seq_printf(s, " nmi-total:%llu",
1196                                          field->nmi_total_ts);
1197                 trace_seq_printf(s, " nmi-count:%u",
1198                                  field->nmi_count);
1199         }
1200
1201         trace_seq_putc(s, '\n');
1202
1203         return trace_handle_return(s);
1204 }
1205
1206
1207 static enum print_line_t
1208 trace_hwlat_raw(struct trace_iterator *iter, int flags,
1209                 struct trace_event *event)
1210 {
1211         struct hwlat_entry *field;
1212         struct trace_seq *s = &iter->seq;
1213
1214         trace_assign_type(field, iter->ent);
1215
1216         trace_seq_printf(s, "%llu %lld %lld %09ld %u\n",
1217                          field->duration,
1218                          field->outer_duration,
1219                          (long long)field->timestamp.tv_sec,
1220                          field->timestamp.tv_nsec,
1221                          field->seqnum);
1222
1223         return trace_handle_return(s);
1224 }
1225
1226 static struct trace_event_functions trace_hwlat_funcs = {
1227         .trace          = trace_hwlat_print,
1228         .raw            = trace_hwlat_raw,
1229 };
1230
1231 static struct trace_event trace_hwlat_event = {
1232         .type           = TRACE_HWLAT,
1233         .funcs          = &trace_hwlat_funcs,
1234 };
1235
1236 /* TRACE_BPUTS */
1237 static enum print_line_t
1238 trace_bputs_print(struct trace_iterator *iter, int flags,
1239                    struct trace_event *event)
1240 {
1241         struct trace_entry *entry = iter->ent;
1242         struct trace_seq *s = &iter->seq;
1243         struct bputs_entry *field;
1244
1245         trace_assign_type(field, entry);
1246
1247         seq_print_ip_sym(s, field->ip, flags);
1248         trace_seq_puts(s, ": ");
1249         trace_seq_puts(s, field->str);
1250
1251         return trace_handle_return(s);
1252 }
1253
1254
1255 static enum print_line_t
1256 trace_bputs_raw(struct trace_iterator *iter, int flags,
1257                 struct trace_event *event)
1258 {
1259         struct bputs_entry *field;
1260         struct trace_seq *s = &iter->seq;
1261
1262         trace_assign_type(field, iter->ent);
1263
1264         trace_seq_printf(s, ": %lx : ", field->ip);
1265         trace_seq_puts(s, field->str);
1266
1267         return trace_handle_return(s);
1268 }
1269
1270 static struct trace_event_functions trace_bputs_funcs = {
1271         .trace          = trace_bputs_print,
1272         .raw            = trace_bputs_raw,
1273 };
1274
1275 static struct trace_event trace_bputs_event = {
1276         .type           = TRACE_BPUTS,
1277         .funcs          = &trace_bputs_funcs,
1278 };
1279
1280 /* TRACE_BPRINT */
1281 static enum print_line_t
1282 trace_bprint_print(struct trace_iterator *iter, int flags,
1283                    struct trace_event *event)
1284 {
1285         struct trace_entry *entry = iter->ent;
1286         struct trace_seq *s = &iter->seq;
1287         struct bprint_entry *field;
1288
1289         trace_assign_type(field, entry);
1290
1291         seq_print_ip_sym(s, field->ip, flags);
1292         trace_seq_puts(s, ": ");
1293         trace_seq_bprintf(s, field->fmt, field->buf);
1294
1295         return trace_handle_return(s);
1296 }
1297
1298
1299 static enum print_line_t
1300 trace_bprint_raw(struct trace_iterator *iter, int flags,
1301                  struct trace_event *event)
1302 {
1303         struct bprint_entry *field;
1304         struct trace_seq *s = &iter->seq;
1305
1306         trace_assign_type(field, iter->ent);
1307
1308         trace_seq_printf(s, ": %lx : ", field->ip);
1309         trace_seq_bprintf(s, field->fmt, field->buf);
1310
1311         return trace_handle_return(s);
1312 }
1313
1314 static struct trace_event_functions trace_bprint_funcs = {
1315         .trace          = trace_bprint_print,
1316         .raw            = trace_bprint_raw,
1317 };
1318
1319 static struct trace_event trace_bprint_event = {
1320         .type           = TRACE_BPRINT,
1321         .funcs          = &trace_bprint_funcs,
1322 };
1323
1324 /* TRACE_PRINT */
1325 static enum print_line_t trace_print_print(struct trace_iterator *iter,
1326                                            int flags, struct trace_event *event)
1327 {
1328         struct print_entry *field;
1329         struct trace_seq *s = &iter->seq;
1330
1331         trace_assign_type(field, iter->ent);
1332
1333         seq_print_ip_sym(s, field->ip, flags);
1334         trace_seq_printf(s, ": %s", field->buf);
1335
1336         return trace_handle_return(s);
1337 }
1338
1339 static enum print_line_t trace_print_raw(struct trace_iterator *iter, int flags,
1340                                          struct trace_event *event)
1341 {
1342         struct print_entry *field;
1343
1344         trace_assign_type(field, iter->ent);
1345
1346         trace_seq_printf(&iter->seq, "# %lx %s", field->ip, field->buf);
1347
1348         return trace_handle_return(&iter->seq);
1349 }
1350
1351 static struct trace_event_functions trace_print_funcs = {
1352         .trace          = trace_print_print,
1353         .raw            = trace_print_raw,
1354 };
1355
1356 static struct trace_event trace_print_event = {
1357         .type           = TRACE_PRINT,
1358         .funcs          = &trace_print_funcs,
1359 };
1360
1361 static enum print_line_t trace_raw_data(struct trace_iterator *iter, int flags,
1362                                          struct trace_event *event)
1363 {
1364         struct raw_data_entry *field;
1365         int i;
1366
1367         trace_assign_type(field, iter->ent);
1368
1369         trace_seq_printf(&iter->seq, "# %x buf:", field->id);
1370
1371         for (i = 0; i < iter->ent_size - offsetof(struct raw_data_entry, buf); i++)
1372                 trace_seq_printf(&iter->seq, " %02x",
1373                                  (unsigned char)field->buf[i]);
1374
1375         trace_seq_putc(&iter->seq, '\n');
1376
1377         return trace_handle_return(&iter->seq);
1378 }
1379
1380 static struct trace_event_functions trace_raw_data_funcs = {
1381         .trace          = trace_raw_data,
1382         .raw            = trace_raw_data,
1383 };
1384
1385 static struct trace_event trace_raw_data_event = {
1386         .type           = TRACE_RAW_DATA,
1387         .funcs          = &trace_raw_data_funcs,
1388 };
1389
1390
1391 static struct trace_event *events[] __initdata = {
1392         &trace_fn_event,
1393         &trace_ctx_event,
1394         &trace_wake_event,
1395         &trace_stack_event,
1396         &trace_user_stack_event,
1397         &trace_bputs_event,
1398         &trace_bprint_event,
1399         &trace_print_event,
1400         &trace_hwlat_event,
1401         &trace_raw_data_event,
1402         NULL
1403 };
1404
1405 __init static int init_events(void)
1406 {
1407         struct trace_event *event;
1408         int i, ret;
1409
1410         for (i = 0; events[i]; i++) {
1411                 event = events[i];
1412
1413                 ret = register_trace_event(event);
1414                 if (!ret) {
1415                         printk(KERN_WARNING "event %d failed to register\n",
1416                                event->type);
1417                         WARN_ON_ONCE(1);
1418                 }
1419         }
1420
1421         return 0;
1422 }
1423 early_initcall(init_events);