kernel/trace/trace_output.c

   1 /*
   2  * trace_output.c
   3  *
   4  * Copyright (C) 2008 Red Hat Inc, Steven Rostedt <srostedt@redhat.com>
   5  *
   6  */
   7
   8 #include <linux/module.h>
   9 #include <linux/mutex.h>
  10 #include <linux/ftrace.h>
  11 #include <linux/sched/clock.h>
  12
  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 #ifdef CONFIG_KALLSYMS
 344         char str[KSYM_SYMBOL_LEN];
 345         const char *name;
 346
 347         kallsyms_lookup(address, NULL, NULL, NULL, str);
 348
 349         name = kretprobed(str);
 350
 351         trace_seq_printf(s, fmt, name);
 352 #endif
 353 }
 354
 355 static void
 356 seq_print_sym_offset(struct trace_seq *s, const char *fmt,
 357                      unsigned long address)
 358 {
 359 #ifdef CONFIG_KALLSYMS
 360         char str[KSYM_SYMBOL_LEN];
 361         const char *name;
 362
 363         sprint_symbol(str, address);
 364         name = kretprobed(str);
 365
 366         trace_seq_printf(s, fmt, name);
 367 #endif
 368 }
 369
 370 #ifndef CONFIG_64BIT
 371 # define IP_FMT "%08lx"
 372 #else
 373 # define IP_FMT "%016lx"
 374 #endif
 375
 376 static int seq_print_user_ip(struct trace_seq *s, struct mm_struct *mm,
 377                              unsigned long ip, unsigned long sym_flags)
 378 {
 379         struct file *file = NULL;
 380         unsigned long vmstart = 0;
 381         int ret = 1;
 382
 383         if (s->full)
 384                 return 0;
 385
 386         if (mm) {
 387                 const struct vm_area_struct *vma;
 388
 389                 down_read(&mm->mmap_sem);
 390                 vma = find_vma(mm, ip);
 391                 if (vma) {
 392                         file = vma->vm_file;
 393                         vmstart = vma->vm_start;
 394                 }
 395                 if (file) {
 396                         ret = trace_seq_path(s, &file->f_path);
 397                         if (ret)
 398                                 trace_seq_printf(s, "[+0x%lx]",
 399                                                  ip - vmstart);
 400                 }
 401                 up_read(&mm->mmap_sem);
 402         }
 403         if (ret && ((sym_flags & TRACE_ITER_SYM_ADDR) || !file))
 404                 trace_seq_printf(s, " <" IP_FMT ">", ip);
 405         return !trace_seq_has_overflowed(s);
 406 }
 407
 408 int
 409 seq_print_ip_sym(struct trace_seq *s, unsigned long ip, unsigned long sym_flags)
 410 {
 411         if (!ip) {
 412                 trace_seq_putc(s, '0');
 413                 goto out;
 414         }
 415
 416         if (sym_flags & TRACE_ITER_SYM_OFFSET)
 417                 seq_print_sym_offset(s, "%s", ip);
 418         else
 419                 seq_print_sym_short(s, "%s", ip);
 420
 421         if (sym_flags & TRACE_ITER_SYM_ADDR)
 422                 trace_seq_printf(s, " <" IP_FMT ">", ip);
 423
 424  out:
 425         return !trace_seq_has_overflowed(s);
 426 }
 427
 428 /**
 429  * trace_print_lat_fmt - print the irq, preempt and lockdep fields
 430  * @s: trace seq struct to write to
 431  * @entry: The trace entry field from the ring buffer
 432  *
 433  * Prints the generic fields of irqs off, in hard or softirq, preempt
 434  * count.
 435  */
 436 int trace_print_lat_fmt(struct trace_seq *s, struct trace_entry *entry)
 437 {
 438         char hardsoft_irq;
 439         char need_resched;
 440         char irqs_off;
 441         int hardirq;
 442         int softirq;
 443         int nmi;
 444
 445         nmi = entry->flags & TRACE_FLAG_NMI;
 446         hardirq = entry->flags & TRACE_FLAG_HARDIRQ;
 447         softirq = entry->flags & TRACE_FLAG_SOFTIRQ;
 448
 449         irqs_off =
 450                 (entry->flags & TRACE_FLAG_IRQS_OFF) ? 'd' :
 451                 (entry->flags & TRACE_FLAG_IRQS_NOSUPPORT) ? 'X' :
 452                 '.';
 453
 454         switch (entry->flags & (TRACE_FLAG_NEED_RESCHED |
 455                                 TRACE_FLAG_PREEMPT_RESCHED)) {
 456         case TRACE_FLAG_NEED_RESCHED | TRACE_FLAG_PREEMPT_RESCHED:
 457                 need_resched = 'N';
 458                 break;
 459         case TRACE_FLAG_NEED_RESCHED:
 460                 need_resched = 'n';
 461                 break;
 462         case TRACE_FLAG_PREEMPT_RESCHED:
 463                 need_resched = 'p';
 464                 break;
 465         default:
 466                 need_resched = '.';
 467                 break;
 468         }
 469
 470         hardsoft_irq =
 471                 (nmi && hardirq)     ? 'Z' :
 472                 nmi                  ? 'z' :
 473                 (hardirq && softirq) ? 'H' :
 474                 hardirq              ? 'h' :
 475                 softirq              ? 's' :
 476                                        '.' ;
 477
 478         trace_seq_printf(s, "%c%c%c",
 479                          irqs_off, need_resched, hardsoft_irq);
 480
 481         if (entry->preempt_count)
 482                 trace_seq_printf(s, "%x", entry->preempt_count);
 483         else
 484                 trace_seq_putc(s, '.');
 485
 486         return !trace_seq_has_overflowed(s);
 487 }
 488
 489 static int
 490 lat_print_generic(struct trace_seq *s, struct trace_entry *entry, int cpu)
 491 {
 492         char comm[TASK_COMM_LEN];
 493
 494         trace_find_cmdline(entry->pid, comm);
 495
 496         trace_seq_printf(s, "%8.8s-%-5d %3d",
 497                          comm, entry->pid, cpu);
 498
 499         return trace_print_lat_fmt(s, entry);
 500 }
 501
 502 #undef MARK
 503 #define MARK(v, s) {.val = v, .sym = s}
 504 /* trace overhead mark */
 505 static const struct trace_mark {
 506         unsigned long long      val; /* unit: nsec */
 507         char                    sym;
 508 } mark[] = {
 509         MARK(1000000000ULL      , '$'), /* 1 sec */
 510         MARK(100000000ULL       , '@'), /* 100 msec */
 511         MARK(10000000ULL        , '*'), /* 10 msec */
 512         MARK(1000000ULL         , '#'), /* 1000 usecs */
 513         MARK(100000ULL          , '!'), /* 100 usecs */
 514         MARK(10000ULL           , '+'), /* 10 usecs */
 515 };
 516 #undef MARK
 517
 518 char trace_find_mark(unsigned long long d)
 519 {
 520         int i;
 521         int size = ARRAY_SIZE(mark);
 522
 523         for (i = 0; i < size; i++) {
 524                 if (d > mark[i].val)
 525                         break;
 526         }
 527
 528         return (i == size) ? ' ' : mark[i].sym;
 529 }
 530
 531 static int
 532 lat_print_timestamp(struct trace_iterator *iter, u64 next_ts)
 533 {
 534         struct trace_array *tr = iter->tr;
 535         unsigned long verbose = tr->trace_flags & TRACE_ITER_VERBOSE;
 536         unsigned long in_ns = iter->iter_flags & TRACE_FILE_TIME_IN_NS;
 537         unsigned long long abs_ts = iter->ts - iter->trace_buffer->time_start;
 538         unsigned long long rel_ts = next_ts - iter->ts;
 539         struct trace_seq *s = &iter->seq;
 540
 541         if (in_ns) {
 542                 abs_ts = ns2usecs(abs_ts);
 543                 rel_ts = ns2usecs(rel_ts);
 544         }
 545
 546         if (verbose && in_ns) {
 547                 unsigned long abs_usec = do_div(abs_ts, USEC_PER_MSEC);
 548                 unsigned long abs_msec = (unsigned long)abs_ts;
 549                 unsigned long rel_usec = do_div(rel_ts, USEC_PER_MSEC);
 550                 unsigned long rel_msec = (unsigned long)rel_ts;
 551
 552                 trace_seq_printf(
 553                         s, "[%08llx] %ld.%03ldms (+%ld.%03ldms): ",
 554                         ns2usecs(iter->ts),
 555                         abs_msec, abs_usec,
 556                         rel_msec, rel_usec);
 557
 558         } else if (verbose && !in_ns) {
 559                 trace_seq_printf(
 560                         s, "[%016llx] %lld (+%lld): ",
 561                         iter->ts, abs_ts, rel_ts);
 562
 563         } else if (!verbose && in_ns) {
 564                 trace_seq_printf(
 565                         s, " %4lldus%c: ",
 566                         abs_ts,
 567                         trace_find_mark(rel_ts * NSEC_PER_USEC));
 568
 569         } else { /* !verbose && !in_ns */
 570                 trace_seq_printf(s, " %4lld: ", abs_ts);
 571         }
 572
 573         return !trace_seq_has_overflowed(s);
 574 }
 575
 576 int trace_print_context(struct trace_iterator *iter)
 577 {
 578         struct trace_array *tr = iter->tr;
 579         struct trace_seq *s = &iter->seq;
 580         struct trace_entry *entry = iter->ent;
 581         unsigned long long t;
 582         unsigned long secs, usec_rem;
 583         char comm[TASK_COMM_LEN];
 584
 585         trace_find_cmdline(entry->pid, comm);
 586
 587         trace_seq_printf(s, "%16s-%-5d [%03d] ",
 588                                comm, entry->pid, iter->cpu);
 589
 590         if (tr->trace_flags & TRACE_ITER_IRQ_INFO)
 591                 trace_print_lat_fmt(s, entry);
 592
 593         if (iter->iter_flags & TRACE_FILE_TIME_IN_NS) {
 594                 t = ns2usecs(iter->ts);
 595                 usec_rem = do_div(t, USEC_PER_SEC);
 596                 secs = (unsigned long)t;
 597                 trace_seq_printf(s, " %5lu.%06lu: ", secs, usec_rem);
 598         } else
 599                 trace_seq_printf(s, " %12llu: ", iter->ts);
 600
 601         return !trace_seq_has_overflowed(s);
 602 }
 603
 604 int trace_print_lat_context(struct trace_iterator *iter)
 605 {
 606         struct trace_array *tr = iter->tr;
 607         /* trace_find_next_entry will reset ent_size */
 608         int ent_size = iter->ent_size;
 609         struct trace_seq *s = &iter->seq;
 610         u64 next_ts;
 611         struct trace_entry *entry = iter->ent,
 612                            *next_entry = trace_find_next_entry(iter, NULL,
 613                                                                &next_ts);
 614         unsigned long verbose = (tr->trace_flags & TRACE_ITER_VERBOSE);
 615
 616         /* Restore the original ent_size */
 617         iter->ent_size = ent_size;
 618
 619         if (!next_entry)
 620                 next_ts = iter->ts;
 621
 622         if (verbose) {
 623                 char comm[TASK_COMM_LEN];
 624
 625                 trace_find_cmdline(entry->pid, comm);
 626
 627                 trace_seq_printf(
 628                         s, "%16s %5d %3d %d %08x %08lx ",
 629                         comm, entry->pid, iter->cpu, entry->flags,
 630                         entry->preempt_count, iter->idx);
 631         } else {
 632                 lat_print_generic(s, entry, iter->cpu);
 633         }
 634
 635         lat_print_timestamp(iter, next_ts);
 636
 637         return !trace_seq_has_overflowed(s);
 638 }
 639
 640 static const char state_to_char[] = TASK_STATE_TO_CHAR_STR;
 641
 642 static int task_state_char(unsigned long state)
 643 {
 644         int bit = state ? __ffs(state) + 1 : 0;
 645
 646         return bit < sizeof(state_to_char) - 1 ? state_to_char[bit] : '?';
 647 }
 648
 649 /**
 650  * ftrace_find_event - find a registered event
 651  * @type: the type of event to look for
 652  *
 653  * Returns an event of type @type otherwise NULL
 654  * Called with trace_event_read_lock() held.
 655  */
 656 struct trace_event *ftrace_find_event(int type)
 657 {
 658         struct trace_event *event;
 659         unsigned key;
 660
 661         key = type & (EVENT_HASHSIZE - 1);
 662
 663         hlist_for_each_entry(event, &event_hash[key], node) {
 664                 if (event->type == type)
 665                         return event;
 666         }
 667
 668         return NULL;
 669 }
 670
 671 static LIST_HEAD(ftrace_event_list);
 672
 673 static int trace_search_list(struct list_head **list)
 674 {
 675         struct trace_event *e;
 676         int last = __TRACE_LAST_TYPE;
 677
 678         if (list_empty(&ftrace_event_list)) {
 679                 *list = &ftrace_event_list;
 680                 return last + 1;
 681         }
 682
 683         /*
 684          * We used up all possible max events,
 685          * lets see if somebody freed one.
 686          */
 687         list_for_each_entry(e, &ftrace_event_list, list) {
 688                 if (e->type != last + 1)
 689                         break;
 690                 last++;
 691         }
 692
 693         /* Did we used up all 65 thousand events??? */
 694         if ((last + 1) > TRACE_EVENT_TYPE_MAX)
 695                 return 0;
 696
 697         *list = &e->list;
 698         return last + 1;
 699 }
 700
 701 void trace_event_read_lock(void)
 702 {
 703         down_read(&trace_event_sem);
 704 }
 705
 706 void trace_event_read_unlock(void)
 707 {
 708         up_read(&trace_event_sem);
 709 }
 710
 711 /**
 712  * register_trace_event - register output for an event type
 713  * @event: the event type to register
 714  *
 715  * Event types are stored in a hash and this hash is used to
 716  * find a way to print an event. If the @event->type is set
 717  * then it will use that type, otherwise it will assign a
 718  * type to use.
 719  *
 720  * If you assign your own type, please make sure it is added
 721  * to the trace_type enum in trace.h, to avoid collisions
 722  * with the dynamic types.
 723  *
 724  * Returns the event type number or zero on error.
 725  */
 726 int register_trace_event(struct trace_event *event)
 727 {
 728         unsigned key;
 729         int ret = 0;
 730
 731         down_write(&trace_event_sem);
 732
 733         if (WARN_ON(!event))
 734                 goto out;
 735
 736         if (WARN_ON(!event->funcs))
 737                 goto out;
 738
 739         INIT_LIST_HEAD(&event->list);
 740
 741         if (!event->type) {
 742                 struct list_head *list = NULL;
 743
 744                 if (next_event_type > TRACE_EVENT_TYPE_MAX) {
 745
 746                         event->type = trace_search_list(&list);
 747                         if (!event->type)
 748                                 goto out;
 749
 750                 } else {
 751
 752                         event->type = next_event_type++;
 753                         list = &ftrace_event_list;
 754                 }
 755
 756                 if (WARN_ON(ftrace_find_event(event->type)))
 757                         goto out;
 758
 759                 list_add_tail(&event->list, list);
 760
 761         } else if (event->type > __TRACE_LAST_TYPE) {
 762                 printk(KERN_WARNING "Need to add type to trace.h\n");
 763                 WARN_ON(1);
 764                 goto out;
 765         } else {
 766                 /* Is this event already used */
 767                 if (ftrace_find_event(event->type))
 768                         goto out;
 769         }
 770
 771         if (event->funcs->trace == NULL)
 772                 event->funcs->trace = trace_nop_print;
 773         if (event->funcs->raw == NULL)
 774                 event->funcs->raw = trace_nop_print;
 775         if (event->funcs->hex == NULL)
 776                 event->funcs->hex = trace_nop_print;
 777         if (event->funcs->binary == NULL)
 778                 event->funcs->binary = trace_nop_print;
 779
 780         key = event->type & (EVENT_HASHSIZE - 1);
 781
 782         hlist_add_head(&event->node, &event_hash[key]);
 783
 784         ret = event->type;
 785  out:
 786         up_write(&trace_event_sem);
 787
 788         return ret;
 789 }
 790 EXPORT_SYMBOL_GPL(register_trace_event);
 791
 792 /*
 793  * Used by module code with the trace_event_sem held for write.
 794  */
 795 int __unregister_trace_event(struct trace_event *event)
 796 {
 797         hlist_del(&event->node);
 798         list_del(&event->list);
 799         return 0;
 800 }
 801
 802 /**
 803  * unregister_trace_event - remove a no longer used event
 804  * @event: the event to remove
 805  */
 806 int unregister_trace_event(struct trace_event *event)
 807 {
 808         down_write(&trace_event_sem);
 809         __unregister_trace_event(event);
 810         up_write(&trace_event_sem);
 811
 812         return 0;
 813 }
 814 EXPORT_SYMBOL_GPL(unregister_trace_event);
 815
 816 /*
 817  * Standard events
 818  */
 819
 820 enum print_line_t trace_nop_print(struct trace_iterator *iter, int flags,
 821                                   struct trace_event *event)
 822 {
 823         trace_seq_printf(&iter->seq, "type: %d\n", iter->ent->type);
 824
 825         return trace_handle_return(&iter->seq);
 826 }
 827
 828 /* TRACE_FN */
 829 static enum print_line_t trace_fn_trace(struct trace_iterator *iter, int flags,
 830                                         struct trace_event *event)
 831 {
 832         struct ftrace_entry *field;
 833         struct trace_seq *s = &iter->seq;
 834
 835         trace_assign_type(field, iter->ent);
 836
 837         seq_print_ip_sym(s, field->ip, flags);
 838
 839         if ((flags & TRACE_ITER_PRINT_PARENT) && field->parent_ip) {
 840                 trace_seq_puts(s, " <-");
 841                 seq_print_ip_sym(s, field->parent_ip, flags);
 842         }
 843
 844         trace_seq_putc(s, '\n');
 845
 846         return trace_handle_return(s);
 847 }
 848
 849 static enum print_line_t trace_fn_raw(struct trace_iterator *iter, int flags,
 850                                       struct trace_event *event)
 851 {
 852         struct ftrace_entry *field;
 853
 854         trace_assign_type(field, iter->ent);
 855
 856         trace_seq_printf(&iter->seq, "%lx %lx\n",
 857                          field->ip,
 858                          field->parent_ip);
 859
 860         return trace_handle_return(&iter->seq);
 861 }
 862
 863 static enum print_line_t trace_fn_hex(struct trace_iterator *iter, int flags,
 864                                       struct trace_event *event)
 865 {
 866         struct ftrace_entry *field;
 867         struct trace_seq *s = &iter->seq;
 868
 869         trace_assign_type(field, iter->ent);
 870
 871         SEQ_PUT_HEX_FIELD(s, field->ip);
 872         SEQ_PUT_HEX_FIELD(s, field->parent_ip);
 873
 874         return trace_handle_return(s);
 875 }
 876
 877 static enum print_line_t trace_fn_bin(struct trace_iterator *iter, int flags,
 878                                       struct trace_event *event)
 879 {
 880         struct ftrace_entry *field;
 881         struct trace_seq *s = &iter->seq;
 882
 883         trace_assign_type(field, iter->ent);
 884
 885         SEQ_PUT_FIELD(s, field->ip);
 886         SEQ_PUT_FIELD(s, field->parent_ip);
 887
 888         return trace_handle_return(s);
 889 }
 890
 891 static struct trace_event_functions trace_fn_funcs = {
 892         .trace          = trace_fn_trace,
 893         .raw            = trace_fn_raw,
 894         .hex            = trace_fn_hex,
 895         .binary         = trace_fn_bin,
 896 };
 897
 898 static struct trace_event trace_fn_event = {
 899         .type           = TRACE_FN,
 900         .funcs          = &trace_fn_funcs,
 901 };
 902
 903 /* TRACE_CTX an TRACE_WAKE */
 904 static enum print_line_t trace_ctxwake_print(struct trace_iterator *iter,
 905                                              char *delim)
 906 {
 907         struct ctx_switch_entry *field;
 908         char comm[TASK_COMM_LEN];
 909         int S, T;
 910
 911
 912         trace_assign_type(field, iter->ent);
 913
 914         T = task_state_char(field->next_state);
 915         S = task_state_char(field->prev_state);
 916         trace_find_cmdline(field->next_pid, comm);
 917         trace_seq_printf(&iter->seq,
 918                          " %5d:%3d:%c %s [%03d] %5d:%3d:%c %s\n",
 919                          field->prev_pid,
 920                          field->prev_prio,
 921                          S, delim,
 922                          field->next_cpu,
 923                          field->next_pid,
 924                          field->next_prio,
 925                          T, comm);
 926
 927         return trace_handle_return(&iter->seq);
 928 }
 929
 930 static enum print_line_t trace_ctx_print(struct trace_iterator *iter, int flags,
 931                                          struct trace_event *event)
 932 {
 933         return trace_ctxwake_print(iter, "==>");
 934 }
 935
 936 static enum print_line_t trace_wake_print(struct trace_iterator *iter,
 937                                           int flags, struct trace_event *event)
 938 {
 939         return trace_ctxwake_print(iter, "  +");
 940 }
 941
 942 static int trace_ctxwake_raw(struct trace_iterator *iter, char S)
 943 {
 944         struct ctx_switch_entry *field;
 945         int T;
 946
 947         trace_assign_type(field, iter->ent);
 948
 949         if (!S)
 950                 S = task_state_char(field->prev_state);
 951         T = task_state_char(field->next_state);
 952         trace_seq_printf(&iter->seq, "%d %d %c %d %d %d %c\n",
 953                          field->prev_pid,
 954                          field->prev_prio,
 955                          S,
 956                          field->next_cpu,
 957                          field->next_pid,
 958                          field->next_prio,
 959                          T);
 960
 961         return trace_handle_return(&iter->seq);
 962 }
 963
 964 static enum print_line_t trace_ctx_raw(struct trace_iterator *iter, int flags,
 965                                        struct trace_event *event)
 966 {
 967         return trace_ctxwake_raw(iter, 0);
 968 }
 969
 970 static enum print_line_t trace_wake_raw(struct trace_iterator *iter, int flags,
 971                                         struct trace_event *event)
 972 {
 973         return trace_ctxwake_raw(iter, '+');
 974 }
 975
 976
 977 static int trace_ctxwake_hex(struct trace_iterator *iter, char S)
 978 {
 979         struct ctx_switch_entry *field;
 980         struct trace_seq *s = &iter->seq;
 981         int T;
 982
 983         trace_assign_type(field, iter->ent);
 984
 985         if (!S)
 986                 S = task_state_char(field->prev_state);
 987         T = task_state_char(field->next_state);
 988
 989         SEQ_PUT_HEX_FIELD(s, field->prev_pid);
 990         SEQ_PUT_HEX_FIELD(s, field->prev_prio);
 991         SEQ_PUT_HEX_FIELD(s, S);
 992         SEQ_PUT_HEX_FIELD(s, field->next_cpu);
 993         SEQ_PUT_HEX_FIELD(s, field->next_pid);
 994         SEQ_PUT_HEX_FIELD(s, field->next_prio);
 995         SEQ_PUT_HEX_FIELD(s, T);
 996
 997         return trace_handle_return(s);
 998 }
 999
1000 static enum print_line_t trace_ctx_hex(struct trace_iterator *iter, int flags,
1001                                        struct trace_event *event)
1002 {
1003         return trace_ctxwake_hex(iter, 0);
1004 }
1005
1006 static enum print_line_t trace_wake_hex(struct trace_iterator *iter, int flags,
1007                                         struct trace_event *event)
1008 {
1009         return trace_ctxwake_hex(iter, '+');
1010 }
1011
1012 static enum print_line_t trace_ctxwake_bin(struct trace_iterator *iter,
1013                                            int flags, struct trace_event *event)
1014 {
1015         struct ctx_switch_entry *field;
1016         struct trace_seq *s = &iter->seq;
1017
1018         trace_assign_type(field, iter->ent);
1019
1020         SEQ_PUT_FIELD(s, field->prev_pid);
1021         SEQ_PUT_FIELD(s, field->prev_prio);
1022         SEQ_PUT_FIELD(s, field->prev_state);
1023         SEQ_PUT_FIELD(s, field->next_cpu);
1024         SEQ_PUT_FIELD(s, field->next_pid);
1025         SEQ_PUT_FIELD(s, field->next_prio);
1026         SEQ_PUT_FIELD(s, field->next_state);
1027
1028         return trace_handle_return(s);
1029 }
1030
1031 static struct trace_event_functions trace_ctx_funcs = {
1032         .trace          = trace_ctx_print,
1033         .raw            = trace_ctx_raw,
1034         .hex            = trace_ctx_hex,
1035         .binary         = trace_ctxwake_bin,
1036 };
1037
1038 static struct trace_event trace_ctx_event = {
1039         .type           = TRACE_CTX,
1040         .funcs          = &trace_ctx_funcs,
1041 };
1042
1043 static struct trace_event_functions trace_wake_funcs = {
1044         .trace          = trace_wake_print,
1045         .raw            = trace_wake_raw,
1046         .hex            = trace_wake_hex,
1047         .binary         = trace_ctxwake_bin,
1048 };
1049
1050 static struct trace_event trace_wake_event = {
1051         .type           = TRACE_WAKE,
1052         .funcs          = &trace_wake_funcs,
1053 };
1054
1055 /* TRACE_STACK */
1056
1057 static enum print_line_t trace_stack_print(struct trace_iterator *iter,
1058                                            int flags, struct trace_event *event)
1059 {
1060         struct stack_entry *field;
1061         struct trace_seq *s = &iter->seq;
1062         unsigned long *p;
1063         unsigned long *end;
1064
1065         trace_assign_type(field, iter->ent);
1066         end = (unsigned long *)((long)iter->ent + iter->ent_size);
1067
1068         trace_seq_puts(s, "<stack trace>\n");
1069
1070         for (p = field->caller; p && *p != ULONG_MAX && p < end; p++) {
1071
1072                 if (trace_seq_has_overflowed(s))
1073                         break;
1074
1075                 trace_seq_puts(s, " => ");
1076                 seq_print_ip_sym(s, *p, flags);
1077                 trace_seq_putc(s, '\n');
1078         }
1079
1080         return trace_handle_return(s);
1081 }
1082
1083 static struct trace_event_functions trace_stack_funcs = {
1084         .trace          = trace_stack_print,
1085 };
1086
1087 static struct trace_event trace_stack_event = {
1088         .type           = TRACE_STACK,
1089         .funcs          = &trace_stack_funcs,
1090 };
1091
1092 /* TRACE_USER_STACK */
1093 static enum print_line_t trace_user_stack_print(struct trace_iterator *iter,
1094                                                 int flags, struct trace_event *event)
1095 {
1096         struct trace_array *tr = iter->tr;
1097         struct userstack_entry *field;
1098         struct trace_seq *s = &iter->seq;
1099         struct mm_struct *mm = NULL;
1100         unsigned int i;
1101
1102         trace_assign_type(field, iter->ent);
1103
1104         trace_seq_puts(s, "<user stack trace>\n");
1105
1106         if (tr->trace_flags & TRACE_ITER_SYM_USEROBJ) {
1107                 struct task_struct *task;
1108                 /*
1109                  * we do the lookup on the thread group leader,
1110                  * since individual threads might have already quit!
1111                  */
1112                 rcu_read_lock();
1113                 task = find_task_by_vpid(field->tgid);
1114                 if (task)
1115                         mm = get_task_mm(task);
1116                 rcu_read_unlock();
1117         }
1118
1119         for (i = 0; i < FTRACE_STACK_ENTRIES; i++) {
1120                 unsigned long ip = field->caller[i];
1121
1122                 if (ip == ULONG_MAX || trace_seq_has_overflowed(s))
1123                         break;
1124
1125                 trace_seq_puts(s, " => ");
1126
1127                 if (!ip) {
1128                         trace_seq_puts(s, "??");
1129                         trace_seq_putc(s, '\n');
1130                         continue;
1131                 }
1132
1133                 seq_print_user_ip(s, mm, ip, flags);
1134                 trace_seq_putc(s, '\n');
1135         }
1136
1137         if (mm)
1138                 mmput(mm);
1139
1140         return trace_handle_return(s);
1141 }
1142
1143 static struct trace_event_functions trace_user_stack_funcs = {
1144         .trace          = trace_user_stack_print,
1145 };
1146
1147 static struct trace_event trace_user_stack_event = {
1148         .type           = TRACE_USER_STACK,
1149         .funcs          = &trace_user_stack_funcs,
1150 };
1151
1152 /* TRACE_HWLAT */
1153 static enum print_line_t
1154 trace_hwlat_print(struct trace_iterator *iter, int flags,
1155                   struct trace_event *event)
1156 {
1157         struct trace_entry *entry = iter->ent;
1158         struct trace_seq *s = &iter->seq;
1159         struct hwlat_entry *field;
1160
1161         trace_assign_type(field, entry);
1162
1163         trace_seq_printf(s, "#%-5u inner/outer(us): %4llu/%-5llu ts:%ld.%09ld",
1164                          field->seqnum,
1165                          field->duration,
1166                          field->outer_duration,
1167                          field->timestamp.tv_sec,
1168                          field->timestamp.tv_nsec);
1169
1170         if (field->nmi_count) {
1171                 /*
1172                  * The generic sched_clock() is not NMI safe, thus
1173                  * we only record the count and not the time.
1174                  */
1175                 if (!IS_ENABLED(CONFIG_GENERIC_SCHED_CLOCK))
1176                         trace_seq_printf(s, " nmi-total:%llu",
1177                                          field->nmi_total_ts);
1178                 trace_seq_printf(s, " nmi-count:%u",
1179                                  field->nmi_count);
1180         }
1181
1182         trace_seq_putc(s, '\n');
1183
1184         return trace_handle_return(s);
1185 }
1186
1187
1188 static enum print_line_t
1189 trace_hwlat_raw(struct trace_iterator *iter, int flags,
1190                 struct trace_event *event)
1191 {
1192         struct hwlat_entry *field;
1193         struct trace_seq *s = &iter->seq;
1194
1195         trace_assign_type(field, iter->ent);
1196
1197         trace_seq_printf(s, "%llu %lld %ld %09ld %u\n",
1198                          field->duration,
1199                          field->outer_duration,
1200                          field->timestamp.tv_sec,
1201                          field->timestamp.tv_nsec,
1202                          field->seqnum);
1203
1204         return trace_handle_return(s);
1205 }
1206
1207 static struct trace_event_functions trace_hwlat_funcs = {
1208         .trace          = trace_hwlat_print,
1209         .raw            = trace_hwlat_raw,
1210 };
1211
1212 static struct trace_event trace_hwlat_event = {
1213         .type           = TRACE_HWLAT,
1214         .funcs          = &trace_hwlat_funcs,
1215 };
1216
1217 /* TRACE_BPUTS */
1218 static enum print_line_t
1219 trace_bputs_print(struct trace_iterator *iter, int flags,
1220                    struct trace_event *event)
1221 {
1222         struct trace_entry *entry = iter->ent;
1223         struct trace_seq *s = &iter->seq;
1224         struct bputs_entry *field;
1225
1226         trace_assign_type(field, entry);
1227
1228         seq_print_ip_sym(s, field->ip, flags);
1229         trace_seq_puts(s, ": ");
1230         trace_seq_puts(s, field->str);
1231
1232         return trace_handle_return(s);
1233 }
1234
1235
1236 static enum print_line_t
1237 trace_bputs_raw(struct trace_iterator *iter, int flags,
1238                 struct trace_event *event)
1239 {
1240         struct bputs_entry *field;
1241         struct trace_seq *s = &iter->seq;
1242
1243         trace_assign_type(field, iter->ent);
1244
1245         trace_seq_printf(s, ": %lx : ", field->ip);
1246         trace_seq_puts(s, field->str);
1247
1248         return trace_handle_return(s);
1249 }
1250
1251 static struct trace_event_functions trace_bputs_funcs = {
1252         .trace          = trace_bputs_print,
1253         .raw            = trace_bputs_raw,
1254 };
1255
1256 static struct trace_event trace_bputs_event = {
1257         .type           = TRACE_BPUTS,
1258         .funcs          = &trace_bputs_funcs,
1259 };
1260
1261 /* TRACE_BPRINT */
1262 static enum print_line_t
1263 trace_bprint_print(struct trace_iterator *iter, int flags,
1264                    struct trace_event *event)
1265 {
1266         struct trace_entry *entry = iter->ent;
1267         struct trace_seq *s = &iter->seq;
1268         struct bprint_entry *field;
1269
1270         trace_assign_type(field, entry);
1271
1272         seq_print_ip_sym(s, field->ip, flags);
1273         trace_seq_puts(s, ": ");
1274         trace_seq_bprintf(s, field->fmt, field->buf);
1275
1276         return trace_handle_return(s);
1277 }
1278
1279
1280 static enum print_line_t
1281 trace_bprint_raw(struct trace_iterator *iter, int flags,
1282                  struct trace_event *event)
1283 {
1284         struct bprint_entry *field;
1285         struct trace_seq *s = &iter->seq;
1286
1287         trace_assign_type(field, iter->ent);
1288
1289         trace_seq_printf(s, ": %lx : ", field->ip);
1290         trace_seq_bprintf(s, field->fmt, field->buf);
1291
1292         return trace_handle_return(s);
1293 }
1294
1295 static struct trace_event_functions trace_bprint_funcs = {
1296         .trace          = trace_bprint_print,
1297         .raw            = trace_bprint_raw,
1298 };
1299
1300 static struct trace_event trace_bprint_event = {
1301         .type           = TRACE_BPRINT,
1302         .funcs          = &trace_bprint_funcs,
1303 };
1304
1305 /* TRACE_PRINT */
1306 static enum print_line_t trace_print_print(struct trace_iterator *iter,
1307                                            int flags, struct trace_event *event)
1308 {
1309         struct print_entry *field;
1310         struct trace_seq *s = &iter->seq;
1311
1312         trace_assign_type(field, iter->ent);
1313
1314         seq_print_ip_sym(s, field->ip, flags);
1315         trace_seq_printf(s, ": %s", field->buf);
1316
1317         return trace_handle_return(s);
1318 }
1319
1320 static enum print_line_t trace_print_raw(struct trace_iterator *iter, int flags,
1321                                          struct trace_event *event)
1322 {
1323         struct print_entry *field;
1324
1325         trace_assign_type(field, iter->ent);
1326
1327         trace_seq_printf(&iter->seq, "# %lx %s", field->ip, field->buf);
1328
1329         return trace_handle_return(&iter->seq);
1330 }
1331
1332 static struct trace_event_functions trace_print_funcs = {
1333         .trace          = trace_print_print,
1334         .raw            = trace_print_raw,
1335 };
1336
1337 static struct trace_event trace_print_event = {
1338         .type           = TRACE_PRINT,
1339         .funcs          = &trace_print_funcs,
1340 };
1341
1342 static enum print_line_t trace_raw_data(struct trace_iterator *iter, int flags,
1343                                          struct trace_event *event)
1344 {
1345         struct raw_data_entry *field;
1346         int i;
1347
1348         trace_assign_type(field, iter->ent);
1349
1350         trace_seq_printf(&iter->seq, "# %x buf:", field->id);
1351
1352         for (i = 0; i < iter->ent_size - offsetof(struct raw_data_entry, buf); i++)
1353                 trace_seq_printf(&iter->seq, " %02x",
1354                                  (unsigned char)field->buf[i]);
1355
1356         trace_seq_putc(&iter->seq, '\n');
1357
1358         return trace_handle_return(&iter->seq);
1359 }
1360
1361 static struct trace_event_functions trace_raw_data_funcs = {
1362         .trace          = trace_raw_data,
1363         .raw            = trace_raw_data,
1364 };
1365
1366 static struct trace_event trace_raw_data_event = {
1367         .type           = TRACE_RAW_DATA,
1368         .funcs          = &trace_raw_data_funcs,
1369 };
1370
1371
1372 static struct trace_event *events[] __initdata = {
1373         &trace_fn_event,
1374         &trace_ctx_event,
1375         &trace_wake_event,
1376         &trace_stack_event,
1377         &trace_user_stack_event,
1378         &trace_bputs_event,
1379         &trace_bprint_event,
1380         &trace_print_event,
1381         &trace_hwlat_event,
1382         &trace_raw_data_event,
1383         NULL
1384 };
1385
1386 __init static int init_events(void)
1387 {
1388         struct trace_event *event;
1389         int i, ret;
1390
1391         for (i = 0; events[i]; i++) {
1392                 event = events[i];
1393
1394                 ret = register_trace_event(event);
1395                 if (!ret) {
1396                         printk(KERN_WARNING "event %d failed to register\n",
1397                                event->type);
1398                         WARN_ON_ONCE(1);
1399                 }
1400         }
1401
1402         return 0;
1403 }
1404 early_initcall(init_events);