kernel/trace/trace_output.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * trace_output.c
   4  *
   5  * Copyright (C) 2008 Red Hat Inc, Steven Rostedt <srostedt@redhat.com>
   6  *
   7  */
   8 #include <linux/module.h>
   9 #include <linux/mutex.h>
  10 #include <linux/ftrace.h>
  11 #include <linux/sched/clock.h>
  12 #include <linux/sched/mm.h>
  13
  14 #include "trace_output.h"
  15
  16 /* must be a power of 2 */
  17 #define EVENT_HASHSIZE  128
  18
  19 DECLARE_RWSEM(trace_event_sem);
  20
  21 static struct hlist_head event_hash[EVENT_HASHSIZE] __read_mostly;
  22
  23 static int next_event_type = __TRACE_LAST_TYPE;
  24
  25 enum print_line_t trace_print_bputs_msg_only(struct trace_iterator *iter)
  26 {
  27         struct trace_seq *s = &iter->seq;
  28         struct trace_entry *entry = iter->ent;
  29         struct bputs_entry *field;
  30
  31         trace_assign_type(field, entry);
  32
  33         trace_seq_puts(s, field->str);
  34
  35         return trace_handle_return(s);
  36 }
  37
  38 enum print_line_t trace_print_bprintk_msg_only(struct trace_iterator *iter)
  39 {
  40         struct trace_seq *s = &iter->seq;
  41         struct trace_entry *entry = iter->ent;
  42         struct bprint_entry *field;
  43
  44         trace_assign_type(field, entry);
  45
  46         trace_seq_bprintf(s, field->fmt, field->buf);
  47
  48         return trace_handle_return(s);
  49 }
  50
  51 enum print_line_t trace_print_printk_msg_only(struct trace_iterator *iter)
  52 {
  53         struct trace_seq *s = &iter->seq;
  54         struct trace_entry *entry = iter->ent;
  55         struct print_entry *field;
  56
  57         trace_assign_type(field, entry);
  58
  59         trace_seq_puts(s, field->buf);
  60
  61         return trace_handle_return(s);
  62 }
  63
  64 const char *
  65 trace_print_flags_seq(struct trace_seq *p, const char *delim,
  66                       unsigned long flags,
  67                       const struct trace_print_flags *flag_array)
  68 {
  69         unsigned long mask;
  70         const char *str;
  71         const char *ret = trace_seq_buffer_ptr(p);
  72         int i, first = 1;
  73
  74         for (i = 0;  flag_array[i].name && flags; i++) {
  75
  76                 mask = flag_array[i].mask;
  77                 if ((flags & mask) != mask)
  78                         continue;
  79
  80                 str = flag_array[i].name;
  81                 flags &= ~mask;
  82                 if (!first && delim)
  83                         trace_seq_puts(p, delim);
  84                 else
  85                         first = 0;
  86                 trace_seq_puts(p, str);
  87         }
  88
  89         /* check for left over flags */
  90         if (flags) {
  91                 if (!first && delim)
  92                         trace_seq_puts(p, delim);
  93                 trace_seq_printf(p, "0x%lx", flags);
  94         }
  95
  96         trace_seq_putc(p, 0);
  97
  98         return ret;
  99 }
 100 EXPORT_SYMBOL(trace_print_flags_seq);
 101
 102 const char *
 103 trace_print_symbols_seq(struct trace_seq *p, unsigned long val,
 104                         const struct trace_print_flags *symbol_array)
 105 {
 106         int i;
 107         const char *ret = trace_seq_buffer_ptr(p);
 108
 109         for (i = 0;  symbol_array[i].name; i++) {
 110
 111                 if (val != symbol_array[i].mask)
 112                         continue;
 113
 114                 trace_seq_puts(p, symbol_array[i].name);
 115                 break;
 116         }
 117
 118         if (ret == (const char *)(trace_seq_buffer_ptr(p)))
 119                 trace_seq_printf(p, "0x%lx", val);
 120
 121         trace_seq_putc(p, 0);
 122
 123         return ret;
 124 }
 125 EXPORT_SYMBOL(trace_print_symbols_seq);
 126
 127 #if BITS_PER_LONG == 32
 128 const char *
 129 trace_print_flags_seq_u64(struct trace_seq *p, const char *delim,
 130                       unsigned long long flags,
 131                       const struct trace_print_flags_u64 *flag_array)
 132 {
 133         unsigned long long mask;
 134         const char *str;
 135         const char *ret = trace_seq_buffer_ptr(p);
 136         int i, first = 1;
 137
 138         for (i = 0;  flag_array[i].name && flags; i++) {
 139
 140                 mask = flag_array[i].mask;
 141                 if ((flags & mask) != mask)
 142                         continue;
 143
 144                 str = flag_array[i].name;
 145                 flags &= ~mask;
 146                 if (!first && delim)
 147                         trace_seq_puts(p, delim);
 148                 else
 149                         first = 0;
 150                 trace_seq_puts(p, str);
 151         }
 152
 153         /* check for left over flags */
 154         if (flags) {
 155                 if (!first && delim)
 156                         trace_seq_puts(p, delim);
 157                 trace_seq_printf(p, "0x%llx", flags);
 158         }
 159
 160         trace_seq_putc(p, 0);
 161
 162         return ret;
 163 }
 164 EXPORT_SYMBOL(trace_print_flags_seq_u64);
 165
 166 const char *
 167 trace_print_symbols_seq_u64(struct trace_seq *p, unsigned long long val,
 168                          const struct trace_print_flags_u64 *symbol_array)
 169 {
 170         int i;
 171         const char *ret = trace_seq_buffer_ptr(p);
 172
 173         for (i = 0;  symbol_array[i].name; i++) {
 174
 175                 if (val != symbol_array[i].mask)
 176                         continue;
 177
 178                 trace_seq_puts(p, symbol_array[i].name);
 179                 break;
 180         }
 181
 182         if (ret == (const char *)(trace_seq_buffer_ptr(p)))
 183                 trace_seq_printf(p, "0x%llx", val);
 184
 185         trace_seq_putc(p, 0);
 186
 187         return ret;
 188 }
 189 EXPORT_SYMBOL(trace_print_symbols_seq_u64);
 190 #endif
 191
 192 const char *
 193 trace_print_bitmask_seq(struct trace_seq *p, void *bitmask_ptr,
 194                         unsigned int bitmask_size)
 195 {
 196         const char *ret = trace_seq_buffer_ptr(p);
 197
 198         trace_seq_bitmask(p, bitmask_ptr, bitmask_size * 8);
 199         trace_seq_putc(p, 0);
 200
 201         return ret;
 202 }
 203 EXPORT_SYMBOL_GPL(trace_print_bitmask_seq);
 204
 205 /**
 206  * trace_print_hex_seq - print buffer as hex sequence
 207  * @p: trace seq struct to write to
 208  * @buf: The buffer to print
 209  * @buf_len: Length of @buf in bytes
 210  * @concatenate: Print @buf as single hex string or with spacing
 211  *
 212  * Prints the passed buffer as a hex sequence either as a whole,
 213  * single hex string if @concatenate is true or with spacing after
 214  * each byte in case @concatenate is false.
 215  */
 216 const char *
 217 trace_print_hex_seq(struct trace_seq *p, const unsigned char *buf, int buf_len,
 218                     bool concatenate)
 219 {
 220         int i;
 221         const char *ret = trace_seq_buffer_ptr(p);
 222         const char *fmt = concatenate ? "%*phN" : "%*ph";
 223
 224         for (i = 0; i < buf_len; i += 16)
 225                 trace_seq_printf(p, fmt, min(buf_len - i, 16), &buf[i]);
 226         trace_seq_putc(p, 0);
 227
 228         return ret;
 229 }
 230 EXPORT_SYMBOL(trace_print_hex_seq);
 231
 232 const char *
 233 trace_print_array_seq(struct trace_seq *p, const void *buf, int count,
 234                       size_t el_size)
 235 {
 236         const char *ret = trace_seq_buffer_ptr(p);
 237         const char *prefix = "";
 238         void *ptr = (void *)buf;
 239         size_t buf_len = count * el_size;
 240
 241         trace_seq_putc(p, '{');
 242
 243         while (ptr < buf + buf_len) {
 244                 switch (el_size) {
 245                 case 1:
 246                         trace_seq_printf(p, "%s0x%x", prefix,
 247                                          *(u8 *)ptr);
 248                         break;
 249                 case 2:
 250                         trace_seq_printf(p, "%s0x%x", prefix,
 251                                          *(u16 *)ptr);
 252                         break;
 253                 case 4:
 254                         trace_seq_printf(p, "%s0x%x", prefix,
 255                                          *(u32 *)ptr);
 256                         break;
 257                 case 8:
 258                         trace_seq_printf(p, "%s0x%llx", prefix,
 259                                          *(u64 *)ptr);
 260                         break;
 261                 default:
 262                         trace_seq_printf(p, "BAD SIZE:%zu 0x%x", el_size,
 263                                          *(u8 *)ptr);
 264                         el_size = 1;
 265                 }
 266                 prefix = ",";
 267                 ptr += el_size;
 268         }
 269
 270         trace_seq_putc(p, '}');
 271         trace_seq_putc(p, 0);
 272
 273         return ret;
 274 }
 275 EXPORT_SYMBOL(trace_print_array_seq);
 276
 277 const char *
 278 trace_print_hex_dump_seq(struct trace_seq *p, const char *prefix_str,
 279                          int prefix_type, int rowsize, int groupsize,
 280                          const void *buf, size_t len, bool ascii)
 281 {
 282         const char *ret = trace_seq_buffer_ptr(p);
 283
 284         trace_seq_putc(p, '\n');
 285         trace_seq_hex_dump(p, prefix_str, prefix_type,
 286                            rowsize, groupsize, buf, len, ascii);
 287         trace_seq_putc(p, 0);
 288         return ret;
 289 }
 290 EXPORT_SYMBOL(trace_print_hex_dump_seq);
 291
 292 int trace_raw_output_prep(struct trace_iterator *iter,
 293                           struct trace_event *trace_event)
 294 {
 295         struct trace_event_call *event;
 296         struct trace_seq *s = &iter->seq;
 297         struct trace_seq *p = &iter->tmp_seq;
 298         struct trace_entry *entry;
 299
 300         event = container_of(trace_event, struct trace_event_call, event);
 301         entry = iter->ent;
 302
 303         if (entry->type != event->event.type) {
 304                 WARN_ON_ONCE(1);
 305                 return TRACE_TYPE_UNHANDLED;
 306         }
 307
 308         trace_seq_init(p);
 309         trace_seq_printf(s, "%s: ", trace_event_name(event));
 310
 311         return trace_handle_return(s);
 312 }
 313 EXPORT_SYMBOL(trace_raw_output_prep);
 314
 315 void trace_event_printf(struct trace_iterator *iter, const char *fmt, ...)
 316 {
 317         va_list ap;
 318
 319         va_start(ap, fmt);
 320         trace_seq_vprintf(&iter->seq, trace_event_format(iter, fmt), ap);
 321         va_end(ap);
 322 }
 323 EXPORT_SYMBOL(trace_event_printf);
 324
 325 static int trace_output_raw(struct trace_iterator *iter, char *name,
 326                             char *fmt, va_list ap)
 327 {
 328         struct trace_seq *s = &iter->seq;
 329
 330         trace_seq_printf(s, "%s: ", name);
 331         trace_seq_vprintf(s, trace_event_format(iter, fmt), ap);
 332
 333         return trace_handle_return(s);
 334 }
 335
 336 int trace_output_call(struct trace_iterator *iter, char *name, char *fmt, ...)
 337 {
 338         va_list ap;
 339         int ret;
 340
 341         va_start(ap, fmt);
 342         ret = trace_output_raw(iter, name, fmt, ap);
 343         va_end(ap);
 344
 345         return ret;
 346 }
 347 EXPORT_SYMBOL_GPL(trace_output_call);
 348
 349 #ifdef CONFIG_KRETPROBES
 350 static inline const char *kretprobed(const char *name)
 351 {
 352         static const char tramp_name[] = "kretprobe_trampoline";
 353         int size = sizeof(tramp_name);
 354
 355         if (strncmp(tramp_name, name, size) == 0)
 356                 return "[unknown/kretprobe'd]";
 357         return name;
 358 }
 359 #else
 360 static inline const char *kretprobed(const char *name)
 361 {
 362         return name;
 363 }
 364 #endif /* CONFIG_KRETPROBES */
 365
 366 static void
 367 seq_print_sym(struct trace_seq *s, unsigned long address, bool offset)
 368 {
 369 #ifdef CONFIG_KALLSYMS
 370         char str[KSYM_SYMBOL_LEN];
 371         const char *name;
 372
 373         if (offset)
 374                 sprint_symbol(str, address);
 375         else
 376                 kallsyms_lookup(address, NULL, NULL, NULL, str);
 377         name = kretprobed(str);
 378
 379         if (name && strlen(name)) {
 380                 trace_seq_puts(s, name);
 381                 return;
 382         }
 383 #endif
 384         trace_seq_printf(s, "0x%08lx", address);
 385 }
 386
 387 #ifndef CONFIG_64BIT
 388 # define IP_FMT "%08lx"
 389 #else
 390 # define IP_FMT "%016lx"
 391 #endif
 392
 393 static int seq_print_user_ip(struct trace_seq *s, struct mm_struct *mm,
 394                              unsigned long ip, unsigned long sym_flags)
 395 {
 396         struct file *file = NULL;
 397         unsigned long vmstart = 0;
 398         int ret = 1;
 399
 400         if (s->full)
 401                 return 0;
 402
 403         if (mm) {
 404                 const struct vm_area_struct *vma;
 405
 406                 mmap_read_lock(mm);
 407                 vma = find_vma(mm, ip);
 408                 if (vma) {
 409                         file = vma->vm_file;
 410                         vmstart = vma->vm_start;
 411                 }
 412                 if (file) {
 413                         ret = trace_seq_path(s, &file->f_path);
 414                         if (ret)
 415                                 trace_seq_printf(s, "[+0x%lx]",
 416                                                  ip - vmstart);
 417                 }
 418                 mmap_read_unlock(mm);
 419         }
 420         if (ret && ((sym_flags & TRACE_ITER_SYM_ADDR) || !file))
 421                 trace_seq_printf(s, " <" IP_FMT ">", ip);
 422         return !trace_seq_has_overflowed(s);
 423 }
 424
 425 int
 426 seq_print_ip_sym(struct trace_seq *s, unsigned long ip, unsigned long sym_flags)
 427 {
 428         if (!ip) {
 429                 trace_seq_putc(s, '0');
 430                 goto out;
 431         }
 432
 433         seq_print_sym(s, ip, sym_flags & TRACE_ITER_SYM_OFFSET);
 434
 435         if (sym_flags & TRACE_ITER_SYM_ADDR)
 436                 trace_seq_printf(s, " <" IP_FMT ">", ip);
 437
 438  out:
 439         return !trace_seq_has_overflowed(s);
 440 }
 441
 442 /**
 443  * trace_print_lat_fmt - print the irq, preempt and lockdep fields
 444  * @s: trace seq struct to write to
 445  * @entry: The trace entry field from the ring buffer
 446  *
 447  * Prints the generic fields of irqs off, in hard or softirq, preempt
 448  * count.
 449  */
 450 int trace_print_lat_fmt(struct trace_seq *s, struct trace_entry *entry)
 451 {
 452         char hardsoft_irq;
 453         char need_resched;
 454         char irqs_off;
 455         int hardirq;
 456         int softirq;
 457         int nmi;
 458
 459         nmi = entry->flags & TRACE_FLAG_NMI;
 460         hardirq = entry->flags & TRACE_FLAG_HARDIRQ;
 461         softirq = entry->flags & TRACE_FLAG_SOFTIRQ;
 462
 463         irqs_off =
 464                 (entry->flags & TRACE_FLAG_IRQS_OFF) ? 'd' :
 465                 (entry->flags & TRACE_FLAG_IRQS_NOSUPPORT) ? 'X' :
 466                 '.';
 467
 468         switch (entry->flags & (TRACE_FLAG_NEED_RESCHED |
 469                                 TRACE_FLAG_PREEMPT_RESCHED)) {
 470         case TRACE_FLAG_NEED_RESCHED | TRACE_FLAG_PREEMPT_RESCHED:
 471                 need_resched = 'N';
 472                 break;
 473         case TRACE_FLAG_NEED_RESCHED:
 474                 need_resched = 'n';
 475                 break;
 476         case TRACE_FLAG_PREEMPT_RESCHED:
 477                 need_resched = 'p';
 478                 break;
 479         default:
 480                 need_resched = '.';
 481                 break;
 482         }
 483
 484         hardsoft_irq =
 485                 (nmi && hardirq)     ? 'Z' :
 486                 nmi                  ? 'z' :
 487                 (hardirq && softirq) ? 'H' :
 488                 hardirq              ? 'h' :
 489                 softirq              ? 's' :
 490                                        '.' ;
 491
 492         trace_seq_printf(s, "%c%c%c",
 493                          irqs_off, need_resched, hardsoft_irq);
 494
 495         if (entry->preempt_count)
 496                 trace_seq_printf(s, "%x", entry->preempt_count);
 497         else
 498                 trace_seq_putc(s, '.');
 499
 500         return !trace_seq_has_overflowed(s);
 501 }
 502
 503 static int
 504 lat_print_generic(struct trace_seq *s, struct trace_entry *entry, int cpu)
 505 {
 506         char comm[TASK_COMM_LEN];
 507
 508         trace_find_cmdline(entry->pid, comm);
 509
 510         trace_seq_printf(s, "%8.8s-%-7d %3d",
 511                          comm, entry->pid, cpu);
 512
 513         return trace_print_lat_fmt(s, entry);
 514 }
 515
 516 #undef MARK
 517 #define MARK(v, s) {.val = v, .sym = s}
 518 /* trace overhead mark */
 519 static const struct trace_mark {
 520         unsigned long long      val; /* unit: nsec */
 521         char                    sym;
 522 } mark[] = {
 523         MARK(1000000000ULL      , '$'), /* 1 sec */
 524         MARK(100000000ULL       , '@'), /* 100 msec */
 525         MARK(10000000ULL        , '*'), /* 10 msec */
 526         MARK(1000000ULL         , '#'), /* 1000 usecs */
 527         MARK(100000ULL          , '!'), /* 100 usecs */
 528         MARK(10000ULL           , '+'), /* 10 usecs */
 529 };
 530 #undef MARK
 531
 532 char trace_find_mark(unsigned long long d)
 533 {
 534         int i;
 535         int size = ARRAY_SIZE(mark);
 536
 537         for (i = 0; i < size; i++) {
 538                 if (d > mark[i].val)
 539                         break;
 540         }
 541
 542         return (i == size) ? ' ' : mark[i].sym;
 543 }
 544
 545 static int
 546 lat_print_timestamp(struct trace_iterator *iter, u64 next_ts)
 547 {
 548         struct trace_array *tr = iter->tr;
 549         unsigned long verbose = tr->trace_flags & TRACE_ITER_VERBOSE;
 550         unsigned long in_ns = iter->iter_flags & TRACE_FILE_TIME_IN_NS;
 551         unsigned long long abs_ts = iter->ts - iter->array_buffer->time_start;
 552         unsigned long long rel_ts = next_ts - iter->ts;
 553         struct trace_seq *s = &iter->seq;
 554
 555         if (in_ns) {
 556                 abs_ts = ns2usecs(abs_ts);
 557                 rel_ts = ns2usecs(rel_ts);
 558         }
 559
 560         if (verbose && in_ns) {
 561                 unsigned long abs_usec = do_div(abs_ts, USEC_PER_MSEC);
 562                 unsigned long abs_msec = (unsigned long)abs_ts;
 563                 unsigned long rel_usec = do_div(rel_ts, USEC_PER_MSEC);
 564                 unsigned long rel_msec = (unsigned long)rel_ts;
 565
 566                 trace_seq_printf(
 567                         s, "[%08llx] %ld.%03ldms (+%ld.%03ldms): ",
 568                         ns2usecs(iter->ts),
 569                         abs_msec, abs_usec,
 570                         rel_msec, rel_usec);
 571
 572         } else if (verbose && !in_ns) {
 573                 trace_seq_printf(
 574                         s, "[%016llx] %lld (+%lld): ",
 575                         iter->ts, abs_ts, rel_ts);
 576
 577         } else if (!verbose && in_ns) {
 578                 trace_seq_printf(
 579                         s, " %4lldus%c: ",
 580                         abs_ts,
 581                         trace_find_mark(rel_ts * NSEC_PER_USEC));
 582
 583         } else { /* !verbose && !in_ns */
 584                 trace_seq_printf(s, " %4lld: ", abs_ts);
 585         }
 586
 587         return !trace_seq_has_overflowed(s);
 588 }
 589
 590 int trace_print_context(struct trace_iterator *iter)
 591 {
 592         struct trace_array *tr = iter->tr;
 593         struct trace_seq *s = &iter->seq;
 594         struct trace_entry *entry = iter->ent;
 595         unsigned long long t;
 596         unsigned long secs, usec_rem;
 597         char comm[TASK_COMM_LEN];
 598
 599         trace_find_cmdline(entry->pid, comm);
 600
 601         trace_seq_printf(s, "%16s-%-7d ", comm, entry->pid);
 602
 603         if (tr->trace_flags & TRACE_ITER_RECORD_TGID) {
 604                 unsigned int tgid = trace_find_tgid(entry->pid);
 605
 606                 if (!tgid)
 607                         trace_seq_printf(s, "(-------) ");
 608                 else
 609                         trace_seq_printf(s, "(%7d) ", tgid);
 610         }
 611
 612         trace_seq_printf(s, "[%03d] ", iter->cpu);
 613
 614         if (tr->trace_flags & TRACE_ITER_IRQ_INFO)
 615                 trace_print_lat_fmt(s, entry);
 616
 617         if (iter->iter_flags & TRACE_FILE_TIME_IN_NS) {
 618                 t = ns2usecs(iter->ts);
 619                 usec_rem = do_div(t, USEC_PER_SEC);
 620                 secs = (unsigned long)t;
 621                 trace_seq_printf(s, " %5lu.%06lu: ", secs, usec_rem);
 622         } else
 623                 trace_seq_printf(s, " %12llu: ", iter->ts);
 624
 625         return !trace_seq_has_overflowed(s);
 626 }
 627
 628 int trace_print_lat_context(struct trace_iterator *iter)
 629 {
 630         struct trace_entry *entry, *next_entry;
 631         struct trace_array *tr = iter->tr;
 632         struct trace_seq *s = &iter->seq;
 633         unsigned long verbose = (tr->trace_flags & TRACE_ITER_VERBOSE);
 634         u64 next_ts;
 635
 636         next_entry = trace_find_next_entry(iter, NULL, &next_ts);
 637         if (!next_entry)
 638                 next_ts = iter->ts;
 639
 640         /* trace_find_next_entry() may change iter->ent */
 641         entry = iter->ent;
 642
 643         if (verbose) {
 644                 char comm[TASK_COMM_LEN];
 645
 646                 trace_find_cmdline(entry->pid, comm);
 647
 648                 trace_seq_printf(
 649                         s, "%16s %7d %3d %d %08x %08lx ",
 650                         comm, entry->pid, iter->cpu, entry->flags,
 651                         entry->preempt_count, iter->idx);
 652         } else {
 653                 lat_print_generic(s, entry, iter->cpu);
 654         }
 655
 656         lat_print_timestamp(iter, next_ts);
 657
 658         return !trace_seq_has_overflowed(s);
 659 }
 660
 661 /**
 662  * ftrace_find_event - find a registered event
 663  * @type: the type of event to look for
 664  *
 665  * Returns an event of type @type otherwise NULL
 666  * Called with trace_event_read_lock() held.
 667  */
 668 struct trace_event *ftrace_find_event(int type)
 669 {
 670         struct trace_event *event;
 671         unsigned key;
 672
 673         key = type & (EVENT_HASHSIZE - 1);
 674
 675         hlist_for_each_entry(event, &event_hash[key], node) {
 676                 if (event->type == type)
 677                         return event;
 678         }
 679
 680         return NULL;
 681 }
 682
 683 static LIST_HEAD(ftrace_event_list);
 684
 685 static int trace_search_list(struct list_head **list)
 686 {
 687         struct trace_event *e;
 688         int next = __TRACE_LAST_TYPE;
 689
 690         if (list_empty(&ftrace_event_list)) {
 691                 *list = &ftrace_event_list;
 692                 return next;
 693         }
 694
 695         /*
 696          * We used up all possible max events,
 697          * lets see if somebody freed one.
 698          */
 699         list_for_each_entry(e, &ftrace_event_list, list) {
 700                 if (e->type != next)
 701                         break;
 702                 next++;
 703         }
 704
 705         /* Did we used up all 65 thousand events??? */
 706         if (next > TRACE_EVENT_TYPE_MAX)
 707                 return 0;
 708
 709         *list = &e->list;
 710         return next;
 711 }
 712
 713 void trace_event_read_lock(void)
 714 {
 715         down_read(&trace_event_sem);
 716 }
 717
 718 void trace_event_read_unlock(void)
 719 {
 720         up_read(&trace_event_sem);
 721 }
 722
 723 /**
 724  * register_trace_event - register output for an event type
 725  * @event: the event type to register
 726  *
 727  * Event types are stored in a hash and this hash is used to
 728  * find a way to print an event. If the @event->type is set
 729  * then it will use that type, otherwise it will assign a
 730  * type to use.
 731  *
 732  * If you assign your own type, please make sure it is added
 733  * to the trace_type enum in trace.h, to avoid collisions
 734  * with the dynamic types.
 735  *
 736  * Returns the event type number or zero on error.
 737  */
 738 int register_trace_event(struct trace_event *event)
 739 {
 740         unsigned key;
 741         int ret = 0;
 742
 743         down_write(&trace_event_sem);
 744
 745         if (WARN_ON(!event))
 746                 goto out;
 747
 748         if (WARN_ON(!event->funcs))
 749                 goto out;
 750
 751         INIT_LIST_HEAD(&event->list);
 752
 753         if (!event->type) {
 754                 struct list_head *list = NULL;
 755
 756                 if (next_event_type > TRACE_EVENT_TYPE_MAX) {
 757
 758                         event->type = trace_search_list(&list);
 759                         if (!event->type)
 760                                 goto out;
 761
 762                 } else {
 763
 764                         event->type = next_event_type++;
 765                         list = &ftrace_event_list;
 766                 }
 767
 768                 if (WARN_ON(ftrace_find_event(event->type)))
 769                         goto out;
 770
 771                 list_add_tail(&event->list, list);
 772
 773         } else if (event->type > __TRACE_LAST_TYPE) {
 774                 printk(KERN_WARNING "Need to add type to trace.h\n");
 775                 WARN_ON(1);
 776                 goto out;
 777         } else {
 778                 /* Is this event already used */
 779                 if (ftrace_find_event(event->type))
 780                         goto out;
 781         }
 782
 783         if (event->funcs->trace == NULL)
 784                 event->funcs->trace = trace_nop_print;
 785         if (event->funcs->raw == NULL)
 786                 event->funcs->raw = trace_nop_print;
 787         if (event->funcs->hex == NULL)
 788                 event->funcs->hex = trace_nop_print;
 789         if (event->funcs->binary == NULL)
 790                 event->funcs->binary = trace_nop_print;
 791
 792         key = event->type & (EVENT_HASHSIZE - 1);
 793
 794         hlist_add_head(&event->node, &event_hash[key]);
 795
 796         ret = event->type;
 797  out:
 798         up_write(&trace_event_sem);
 799
 800         return ret;
 801 }
 802 EXPORT_SYMBOL_GPL(register_trace_event);
 803
 804 /*
 805  * Used by module code with the trace_event_sem held for write.
 806  */
 807 int __unregister_trace_event(struct trace_event *event)
 808 {
 809         hlist_del(&event->node);
 810         list_del(&event->list);
 811         return 0;
 812 }
 813
 814 /**
 815  * unregister_trace_event - remove a no longer used event
 816  * @event: the event to remove
 817  */
 818 int unregister_trace_event(struct trace_event *event)
 819 {
 820         down_write(&trace_event_sem);
 821         __unregister_trace_event(event);
 822         up_write(&trace_event_sem);
 823
 824         return 0;
 825 }
 826 EXPORT_SYMBOL_GPL(unregister_trace_event);
 827
 828 /*
 829  * Standard events
 830  */
 831
 832 enum print_line_t trace_nop_print(struct trace_iterator *iter, int flags,
 833                                   struct trace_event *event)
 834 {
 835         trace_seq_printf(&iter->seq, "type: %d\n", iter->ent->type);
 836
 837         return trace_handle_return(&iter->seq);
 838 }
 839
 840 /* TRACE_FN */
 841 static enum print_line_t trace_fn_trace(struct trace_iterator *iter, int flags,
 842                                         struct trace_event *event)
 843 {
 844         struct ftrace_entry *field;
 845         struct trace_seq *s = &iter->seq;
 846
 847         trace_assign_type(field, iter->ent);
 848
 849         seq_print_ip_sym(s, field->ip, flags);
 850
 851         if ((flags & TRACE_ITER_PRINT_PARENT) && field->parent_ip) {
 852                 trace_seq_puts(s, " <-");
 853                 seq_print_ip_sym(s, field->parent_ip, flags);
 854         }
 855
 856         trace_seq_putc(s, '\n');
 857
 858         return trace_handle_return(s);
 859 }
 860
 861 static enum print_line_t trace_fn_raw(struct trace_iterator *iter, int flags,
 862                                       struct trace_event *event)
 863 {
 864         struct ftrace_entry *field;
 865
 866         trace_assign_type(field, iter->ent);
 867
 868         trace_seq_printf(&iter->seq, "%lx %lx\n",
 869                          field->ip,
 870                          field->parent_ip);
 871
 872         return trace_handle_return(&iter->seq);
 873 }
 874
 875 static enum print_line_t trace_fn_hex(struct trace_iterator *iter, int flags,
 876                                       struct trace_event *event)
 877 {
 878         struct ftrace_entry *field;
 879         struct trace_seq *s = &iter->seq;
 880
 881         trace_assign_type(field, iter->ent);
 882
 883         SEQ_PUT_HEX_FIELD(s, field->ip);
 884         SEQ_PUT_HEX_FIELD(s, field->parent_ip);
 885
 886         return trace_handle_return(s);
 887 }
 888
 889 static enum print_line_t trace_fn_bin(struct trace_iterator *iter, int flags,
 890                                       struct trace_event *event)
 891 {
 892         struct ftrace_entry *field;
 893         struct trace_seq *s = &iter->seq;
 894
 895         trace_assign_type(field, iter->ent);
 896
 897         SEQ_PUT_FIELD(s, field->ip);
 898         SEQ_PUT_FIELD(s, field->parent_ip);
 899
 900         return trace_handle_return(s);
 901 }
 902
 903 static struct trace_event_functions trace_fn_funcs = {
 904         .trace          = trace_fn_trace,
 905         .raw            = trace_fn_raw,
 906         .hex            = trace_fn_hex,
 907         .binary         = trace_fn_bin,
 908 };
 909
 910 static struct trace_event trace_fn_event = {
 911         .type           = TRACE_FN,
 912         .funcs          = &trace_fn_funcs,
 913 };
 914
 915 /* TRACE_CTX an TRACE_WAKE */
 916 static enum print_line_t trace_ctxwake_print(struct trace_iterator *iter,
 917                                              char *delim)
 918 {
 919         struct ctx_switch_entry *field;
 920         char comm[TASK_COMM_LEN];
 921         int S, T;
 922
 923
 924         trace_assign_type(field, iter->ent);
 925
 926         T = task_index_to_char(field->next_state);
 927         S = task_index_to_char(field->prev_state);
 928         trace_find_cmdline(field->next_pid, comm);
 929         trace_seq_printf(&iter->seq,
 930                          " %7d:%3d:%c %s [%03d] %7d:%3d:%c %s\n",
 931                          field->prev_pid,
 932                          field->prev_prio,
 933                          S, delim,
 934                          field->next_cpu,
 935                          field->next_pid,
 936                          field->next_prio,
 937                          T, comm);
 938
 939         return trace_handle_return(&iter->seq);
 940 }
 941
 942 static enum print_line_t trace_ctx_print(struct trace_iterator *iter, int flags,
 943                                          struct trace_event *event)
 944 {
 945         return trace_ctxwake_print(iter, "==>");
 946 }
 947
 948 static enum print_line_t trace_wake_print(struct trace_iterator *iter,
 949                                           int flags, struct trace_event *event)
 950 {
 951         return trace_ctxwake_print(iter, "  +");
 952 }
 953
 954 static int trace_ctxwake_raw(struct trace_iterator *iter, char S)
 955 {
 956         struct ctx_switch_entry *field;
 957         int T;
 958
 959         trace_assign_type(field, iter->ent);
 960
 961         if (!S)
 962                 S = task_index_to_char(field->prev_state);
 963         T = task_index_to_char(field->next_state);
 964         trace_seq_printf(&iter->seq, "%d %d %c %d %d %d %c\n",
 965                          field->prev_pid,
 966                          field->prev_prio,
 967                          S,
 968                          field->next_cpu,
 969                          field->next_pid,
 970                          field->next_prio,
 971                          T);
 972
 973         return trace_handle_return(&iter->seq);
 974 }
 975
 976 static enum print_line_t trace_ctx_raw(struct trace_iterator *iter, int flags,
 977                                        struct trace_event *event)
 978 {
 979         return trace_ctxwake_raw(iter, 0);
 980 }
 981
 982 static enum print_line_t trace_wake_raw(struct trace_iterator *iter, int flags,
 983                                         struct trace_event *event)
 984 {
 985         return trace_ctxwake_raw(iter, '+');
 986 }
 987
 988
 989 static int trace_ctxwake_hex(struct trace_iterator *iter, char S)
 990 {
 991         struct ctx_switch_entry *field;
 992         struct trace_seq *s = &iter->seq;
 993         int T;
 994
 995         trace_assign_type(field, iter->ent);
 996
 997         if (!S)
 998                 S = task_index_to_char(field->prev_state);
 999         T = task_index_to_char(field->next_state);
1000
1001         SEQ_PUT_HEX_FIELD(s, field->prev_pid);
1002         SEQ_PUT_HEX_FIELD(s, field->prev_prio);
1003         SEQ_PUT_HEX_FIELD(s, S);
1004         SEQ_PUT_HEX_FIELD(s, field->next_cpu);
1005         SEQ_PUT_HEX_FIELD(s, field->next_pid);
1006         SEQ_PUT_HEX_FIELD(s, field->next_prio);
1007         SEQ_PUT_HEX_FIELD(s, T);
1008
1009         return trace_handle_return(s);
1010 }
1011
1012 static enum print_line_t trace_ctx_hex(struct trace_iterator *iter, int flags,
1013                                        struct trace_event *event)
1014 {
1015         return trace_ctxwake_hex(iter, 0);
1016 }
1017
1018 static enum print_line_t trace_wake_hex(struct trace_iterator *iter, int flags,
1019                                         struct trace_event *event)
1020 {
1021         return trace_ctxwake_hex(iter, '+');
1022 }
1023
1024 static enum print_line_t trace_ctxwake_bin(struct trace_iterator *iter,
1025                                            int flags, struct trace_event *event)
1026 {
1027         struct ctx_switch_entry *field;
1028         struct trace_seq *s = &iter->seq;
1029
1030         trace_assign_type(field, iter->ent);
1031
1032         SEQ_PUT_FIELD(s, field->prev_pid);
1033         SEQ_PUT_FIELD(s, field->prev_prio);
1034         SEQ_PUT_FIELD(s, field->prev_state);
1035         SEQ_PUT_FIELD(s, field->next_cpu);
1036         SEQ_PUT_FIELD(s, field->next_pid);
1037         SEQ_PUT_FIELD(s, field->next_prio);
1038         SEQ_PUT_FIELD(s, field->next_state);
1039
1040         return trace_handle_return(s);
1041 }
1042
1043 static struct trace_event_functions trace_ctx_funcs = {
1044         .trace          = trace_ctx_print,
1045         .raw            = trace_ctx_raw,
1046         .hex            = trace_ctx_hex,
1047         .binary         = trace_ctxwake_bin,
1048 };
1049
1050 static struct trace_event trace_ctx_event = {
1051         .type           = TRACE_CTX,
1052         .funcs          = &trace_ctx_funcs,
1053 };
1054
1055 static struct trace_event_functions trace_wake_funcs = {
1056         .trace          = trace_wake_print,
1057         .raw            = trace_wake_raw,
1058         .hex            = trace_wake_hex,
1059         .binary         = trace_ctxwake_bin,
1060 };
1061
1062 static struct trace_event trace_wake_event = {
1063         .type           = TRACE_WAKE,
1064         .funcs          = &trace_wake_funcs,
1065 };
1066
1067 /* TRACE_STACK */
1068
1069 static enum print_line_t trace_stack_print(struct trace_iterator *iter,
1070                                            int flags, struct trace_event *event)
1071 {
1072         struct stack_entry *field;
1073         struct trace_seq *s = &iter->seq;
1074         unsigned long *p;
1075         unsigned long *end;
1076
1077         trace_assign_type(field, iter->ent);
1078         end = (unsigned long *)((long)iter->ent + iter->ent_size);
1079
1080         trace_seq_puts(s, "<stack trace>\n");
1081
1082         for (p = field->caller; p && p < end && *p != ULONG_MAX; p++) {
1083
1084                 if (trace_seq_has_overflowed(s))
1085                         break;
1086
1087                 trace_seq_puts(s, " => ");
1088                 seq_print_ip_sym(s, *p, flags);
1089                 trace_seq_putc(s, '\n');
1090         }
1091
1092         return trace_handle_return(s);
1093 }
1094
1095 static struct trace_event_functions trace_stack_funcs = {
1096         .trace          = trace_stack_print,
1097 };
1098
1099 static struct trace_event trace_stack_event = {
1100         .type           = TRACE_STACK,
1101         .funcs          = &trace_stack_funcs,
1102 };
1103
1104 /* TRACE_USER_STACK */
1105 static enum print_line_t trace_user_stack_print(struct trace_iterator *iter,
1106                                                 int flags, struct trace_event *event)
1107 {
1108         struct trace_array *tr = iter->tr;
1109         struct userstack_entry *field;
1110         struct trace_seq *s = &iter->seq;
1111         struct mm_struct *mm = NULL;
1112         unsigned int i;
1113
1114         trace_assign_type(field, iter->ent);
1115
1116         trace_seq_puts(s, "<user stack trace>\n");
1117
1118         if (tr->trace_flags & TRACE_ITER_SYM_USEROBJ) {
1119                 struct task_struct *task;
1120                 /*
1121                  * we do the lookup on the thread group leader,
1122                  * since individual threads might have already quit!
1123                  */
1124                 rcu_read_lock();
1125                 task = find_task_by_vpid(field->tgid);
1126                 if (task)
1127                         mm = get_task_mm(task);
1128                 rcu_read_unlock();
1129         }
1130
1131         for (i = 0; i < FTRACE_STACK_ENTRIES; i++) {
1132                 unsigned long ip = field->caller[i];
1133
1134                 if (!ip || trace_seq_has_overflowed(s))
1135                         break;
1136
1137                 trace_seq_puts(s, " => ");
1138                 seq_print_user_ip(s, mm, ip, flags);
1139                 trace_seq_putc(s, '\n');
1140         }
1141
1142         if (mm)
1143                 mmput(mm);
1144
1145         return trace_handle_return(s);
1146 }
1147
1148 static struct trace_event_functions trace_user_stack_funcs = {
1149         .trace          = trace_user_stack_print,
1150 };
1151
1152 static struct trace_event trace_user_stack_event = {
1153         .type           = TRACE_USER_STACK,
1154         .funcs          = &trace_user_stack_funcs,
1155 };
1156
1157 /* TRACE_HWLAT */
1158 static enum print_line_t
1159 trace_hwlat_print(struct trace_iterator *iter, int flags,
1160                   struct trace_event *event)
1161 {
1162         struct trace_entry *entry = iter->ent;
1163         struct trace_seq *s = &iter->seq;
1164         struct hwlat_entry *field;
1165
1166         trace_assign_type(field, entry);
1167
1168         trace_seq_printf(s, "#%-5u inner/outer(us): %4llu/%-5llu ts:%lld.%09ld count:%d",
1169                          field->seqnum,
1170                          field->duration,
1171                          field->outer_duration,
1172                          (long long)field->timestamp.tv_sec,
1173                          field->timestamp.tv_nsec, field->count);
1174
1175         if (field->nmi_count) {
1176                 /*
1177                  * The generic sched_clock() is not NMI safe, thus
1178                  * we only record the count and not the time.
1179                  */
1180                 if (!IS_ENABLED(CONFIG_GENERIC_SCHED_CLOCK))
1181                         trace_seq_printf(s, " nmi-total:%llu",
1182                                          field->nmi_total_ts);
1183                 trace_seq_printf(s, " nmi-count:%u",
1184                                  field->nmi_count);
1185         }
1186
1187         trace_seq_putc(s, '\n');
1188
1189         return trace_handle_return(s);
1190 }
1191
1192
1193 static enum print_line_t
1194 trace_hwlat_raw(struct trace_iterator *iter, int flags,
1195                 struct trace_event *event)
1196 {
1197         struct hwlat_entry *field;
1198         struct trace_seq *s = &iter->seq;
1199
1200         trace_assign_type(field, iter->ent);
1201
1202         trace_seq_printf(s, "%llu %lld %lld %09ld %u\n",
1203                          field->duration,
1204                          field->outer_duration,
1205                          (long long)field->timestamp.tv_sec,
1206                          field->timestamp.tv_nsec,
1207                          field->seqnum);
1208
1209         return trace_handle_return(s);
1210 }
1211
1212 static struct trace_event_functions trace_hwlat_funcs = {
1213         .trace          = trace_hwlat_print,
1214         .raw            = trace_hwlat_raw,
1215 };
1216
1217 static struct trace_event trace_hwlat_event = {
1218         .type           = TRACE_HWLAT,
1219         .funcs          = &trace_hwlat_funcs,
1220 };
1221
1222 /* TRACE_BPUTS */
1223 static enum print_line_t
1224 trace_bputs_print(struct trace_iterator *iter, int flags,
1225                    struct trace_event *event)
1226 {
1227         struct trace_entry *entry = iter->ent;
1228         struct trace_seq *s = &iter->seq;
1229         struct bputs_entry *field;
1230
1231         trace_assign_type(field, entry);
1232
1233         seq_print_ip_sym(s, field->ip, flags);
1234         trace_seq_puts(s, ": ");
1235         trace_seq_puts(s, field->str);
1236
1237         return trace_handle_return(s);
1238 }
1239
1240
1241 static enum print_line_t
1242 trace_bputs_raw(struct trace_iterator *iter, int flags,
1243                 struct trace_event *event)
1244 {
1245         struct bputs_entry *field;
1246         struct trace_seq *s = &iter->seq;
1247
1248         trace_assign_type(field, iter->ent);
1249
1250         trace_seq_printf(s, ": %lx : ", field->ip);
1251         trace_seq_puts(s, field->str);
1252
1253         return trace_handle_return(s);
1254 }
1255
1256 static struct trace_event_functions trace_bputs_funcs = {
1257         .trace          = trace_bputs_print,
1258         .raw            = trace_bputs_raw,
1259 };
1260
1261 static struct trace_event trace_bputs_event = {
1262         .type           = TRACE_BPUTS,
1263         .funcs          = &trace_bputs_funcs,
1264 };
1265
1266 /* TRACE_BPRINT */
1267 static enum print_line_t
1268 trace_bprint_print(struct trace_iterator *iter, int flags,
1269                    struct trace_event *event)
1270 {
1271         struct trace_entry *entry = iter->ent;
1272         struct trace_seq *s = &iter->seq;
1273         struct bprint_entry *field;
1274
1275         trace_assign_type(field, entry);
1276
1277         seq_print_ip_sym(s, field->ip, flags);
1278         trace_seq_puts(s, ": ");
1279         trace_seq_bprintf(s, field->fmt, field->buf);
1280
1281         return trace_handle_return(s);
1282 }
1283
1284
1285 static enum print_line_t
1286 trace_bprint_raw(struct trace_iterator *iter, int flags,
1287                  struct trace_event *event)
1288 {
1289         struct bprint_entry *field;
1290         struct trace_seq *s = &iter->seq;
1291
1292         trace_assign_type(field, iter->ent);
1293
1294         trace_seq_printf(s, ": %lx : ", field->ip);
1295         trace_seq_bprintf(s, field->fmt, field->buf);
1296
1297         return trace_handle_return(s);
1298 }
1299
1300 static struct trace_event_functions trace_bprint_funcs = {
1301         .trace          = trace_bprint_print,
1302         .raw            = trace_bprint_raw,
1303 };
1304
1305 static struct trace_event trace_bprint_event = {
1306         .type           = TRACE_BPRINT,
1307         .funcs          = &trace_bprint_funcs,
1308 };
1309
1310 /* TRACE_PRINT */
1311 static enum print_line_t trace_print_print(struct trace_iterator *iter,
1312                                            int flags, struct trace_event *event)
1313 {
1314         struct print_entry *field;
1315         struct trace_seq *s = &iter->seq;
1316         int max = iter->ent_size - offsetof(struct print_entry, buf);
1317
1318         trace_assign_type(field, iter->ent);
1319
1320         seq_print_ip_sym(s, field->ip, flags);
1321         trace_seq_printf(s, ": %.*s", max, field->buf);
1322
1323         return trace_handle_return(s);
1324 }
1325
1326 static enum print_line_t trace_print_raw(struct trace_iterator *iter, int flags,
1327                                          struct trace_event *event)
1328 {
1329         struct print_entry *field;
1330         int max = iter->ent_size - offsetof(struct print_entry, buf);
1331
1332         trace_assign_type(field, iter->ent);
1333
1334         trace_seq_printf(&iter->seq, "# %lx %.*s", field->ip, max, field->buf);
1335
1336         return trace_handle_return(&iter->seq);
1337 }
1338
1339 static struct trace_event_functions trace_print_funcs = {
1340         .trace          = trace_print_print,
1341         .raw            = trace_print_raw,
1342 };
1343
1344 static struct trace_event trace_print_event = {
1345         .type           = TRACE_PRINT,
1346         .funcs          = &trace_print_funcs,
1347 };
1348
1349 static enum print_line_t trace_raw_data(struct trace_iterator *iter, int flags,
1350                                          struct trace_event *event)
1351 {
1352         struct raw_data_entry *field;
1353         int i;
1354
1355         trace_assign_type(field, iter->ent);
1356
1357         trace_seq_printf(&iter->seq, "# %x buf:", field->id);
1358
1359         for (i = 0; i < iter->ent_size - offsetof(struct raw_data_entry, buf); i++)
1360                 trace_seq_printf(&iter->seq, " %02x",
1361                                  (unsigned char)field->buf[i]);
1362
1363         trace_seq_putc(&iter->seq, '\n');
1364
1365         return trace_handle_return(&iter->seq);
1366 }
1367
1368 static struct trace_event_functions trace_raw_data_funcs = {
1369         .trace          = trace_raw_data,
1370         .raw            = trace_raw_data,
1371 };
1372
1373 static struct trace_event trace_raw_data_event = {
1374         .type           = TRACE_RAW_DATA,
1375         .funcs          = &trace_raw_data_funcs,
1376 };
1377
1378
1379 static struct trace_event *events[] __initdata = {
1380         &trace_fn_event,
1381         &trace_ctx_event,
1382         &trace_wake_event,
1383         &trace_stack_event,
1384         &trace_user_stack_event,
1385         &trace_bputs_event,
1386         &trace_bprint_event,
1387         &trace_print_event,
1388         &trace_hwlat_event,
1389         &trace_raw_data_event,
1390         NULL
1391 };
1392
1393 __init int init_events(void)
1394 {
1395         struct trace_event *event;
1396         int i, ret;
1397
1398         for (i = 0; events[i]; i++) {
1399                 event = events[i];
1400
1401                 ret = register_trace_event(event);
1402                 if (!ret) {
1403                         printk(KERN_WARNING "event %d failed to register\n",
1404                                event->type);
1405                         WARN_ON_ONCE(1);
1406                 }
1407         }
1408
1409         return 0;
1410 }