kernel/trace/trace_output.c

   1 /*
   2  * trace_output.c
   3  *
   4  * Copyright (C) 2008 Red Hat Inc, Steven Rostedt <srostedt@redhat.com>
   5  *
   6  */
   7 #include <linux/module.h>
   8 #include <linux/mutex.h>
   9 #include <linux/ftrace.h>
  10 #include <linux/sched/clock.h>
  11 #include <linux/sched/mm.h>
  12
  13 #include "trace_output.h"
  14
  15 /* must be a power of 2 */
  16 #define EVENT_HASHSIZE  128
  17
  18 DECLARE_RWSEM(trace_event_sem);
  19
  20 static struct hlist_head event_hash[EVENT_HASHSIZE] __read_mostly;
  21
  22 static int next_event_type = __TRACE_LAST_TYPE + 1;
  23
  24 enum print_line_t trace_print_bputs_msg_only(struct trace_iterator *iter)
  25 {
  26         struct trace_seq *s = &iter->seq;
  27         struct trace_entry *entry = iter->ent;
  28         struct bputs_entry *field;
  29
  30         trace_assign_type(field, entry);
  31
  32         trace_seq_puts(s, field->str);
  33
  34         return trace_handle_return(s);
  35 }
  36
  37 enum print_line_t trace_print_bprintk_msg_only(struct trace_iterator *iter)
  38 {
  39         struct trace_seq *s = &iter->seq;
  40         struct trace_entry *entry = iter->ent;
  41         struct bprint_entry *field;
  42
  43         trace_assign_type(field, entry);
  44
  45         trace_seq_bprintf(s, field->fmt, field->buf);
  46
  47         return trace_handle_return(s);
  48 }
  49
  50 enum print_line_t trace_print_printk_msg_only(struct trace_iterator *iter)
  51 {
  52         struct trace_seq *s = &iter->seq;
  53         struct trace_entry *entry = iter->ent;
  54         struct print_entry *field;
  55
  56         trace_assign_type(field, entry);
  57
  58         trace_seq_puts(s, field->buf);
  59
  60         return trace_handle_return(s);
  61 }
  62
  63 const char *
  64 trace_print_flags_seq(struct trace_seq *p, const char *delim,
  65                       unsigned long flags,
  66                       const struct trace_print_flags *flag_array)
  67 {
  68         unsigned long mask;
  69         const char *str;
  70         const char *ret = trace_seq_buffer_ptr(p);
  71         int i, first = 1;
  72
  73         for (i = 0;  flag_array[i].name && flags; i++) {
  74
  75                 mask = flag_array[i].mask;
  76                 if ((flags & mask) != mask)
  77                         continue;
  78
  79                 str = flag_array[i].name;
  80                 flags &= ~mask;
  81                 if (!first && delim)
  82                         trace_seq_puts(p, delim);
  83                 else
  84                         first = 0;
  85                 trace_seq_puts(p, str);
  86         }
  87
  88         /* check for left over flags */
  89         if (flags) {
  90                 if (!first && delim)
  91                         trace_seq_puts(p, delim);
  92                 trace_seq_printf(p, "0x%lx", flags);
  93         }
  94
  95         trace_seq_putc(p, 0);
  96
  97         return ret;
  98 }
  99 EXPORT_SYMBOL(trace_print_flags_seq);
 100
 101 const char *
 102 trace_print_symbols_seq(struct trace_seq *p, unsigned long val,
 103                         const struct trace_print_flags *symbol_array)
 104 {
 105         int i;
 106         const char *ret = trace_seq_buffer_ptr(p);
 107
 108         for (i = 0;  symbol_array[i].name; i++) {
 109
 110                 if (val != symbol_array[i].mask)
 111                         continue;
 112
 113                 trace_seq_puts(p, symbol_array[i].name);
 114                 break;
 115         }
 116
 117         if (ret == (const char *)(trace_seq_buffer_ptr(p)))
 118                 trace_seq_printf(p, "0x%lx", val);
 119
 120         trace_seq_putc(p, 0);
 121
 122         return ret;
 123 }
 124 EXPORT_SYMBOL(trace_print_symbols_seq);
 125
 126 #if BITS_PER_LONG == 32
 127 const char *
 128 trace_print_flags_seq_u64(struct trace_seq *p, const char *delim,
 129                       unsigned long long flags,
 130                       const struct trace_print_flags_u64 *flag_array)
 131 {
 132         unsigned long long mask;
 133         const char *str;
 134         const char *ret = trace_seq_buffer_ptr(p);
 135         int i, first = 1;
 136
 137         for (i = 0;  flag_array[i].name && flags; i++) {
 138
 139                 mask = flag_array[i].mask;
 140                 if ((flags & mask) != mask)
 141                         continue;
 142
 143                 str = flag_array[i].name;
 144                 flags &= ~mask;
 145                 if (!first && delim)
 146                         trace_seq_puts(p, delim);
 147                 else
 148                         first = 0;
 149                 trace_seq_puts(p, str);
 150         }
 151
 152         /* check for left over flags */
 153         if (flags) {
 154                 if (!first && delim)
 155                         trace_seq_puts(p, delim);
 156                 trace_seq_printf(p, "0x%llx", flags);
 157         }
 158
 159         trace_seq_putc(p, 0);
 160
 161         return ret;
 162 }
 163 EXPORT_SYMBOL(trace_print_flags_seq_u64);
 164
 165 const char *
 166 trace_print_symbols_seq_u64(struct trace_seq *p, unsigned long long val,
 167                          const struct trace_print_flags_u64 *symbol_array)
 168 {
 169         int i;
 170         const char *ret = trace_seq_buffer_ptr(p);
 171
 172         for (i = 0;  symbol_array[i].name; i++) {
 173
 174                 if (val != symbol_array[i].mask)
 175                         continue;
 176
 177                 trace_seq_puts(p, symbol_array[i].name);
 178                 break;
 179         }
 180
 181         if (ret == (const char *)(trace_seq_buffer_ptr(p)))
 182                 trace_seq_printf(p, "0x%llx", val);
 183
 184         trace_seq_putc(p, 0);
 185
 186         return ret;
 187 }
 188 EXPORT_SYMBOL(trace_print_symbols_seq_u64);
 189 #endif
 190
 191 const char *
 192 trace_print_bitmask_seq(struct trace_seq *p, void *bitmask_ptr,
 193                         unsigned int bitmask_size)
 194 {
 195         const char *ret = trace_seq_buffer_ptr(p);
 196
 197         trace_seq_bitmask(p, bitmask_ptr, bitmask_size * 8);
 198         trace_seq_putc(p, 0);
 199
 200         return ret;
 201 }
 202 EXPORT_SYMBOL_GPL(trace_print_bitmask_seq);
 203
 204 /**
 205  * trace_print_hex_seq - print buffer as hex sequence
 206  * @p: trace seq struct to write to
 207  * @buf: The buffer to print
 208  * @buf_len: Length of @buf in bytes
 209  * @concatenate: Print @buf as single hex string or with spacing
 210  *
 211  * Prints the passed buffer as a hex sequence either as a whole,
 212  * single hex string if @concatenate is true or with spacing after
 213  * each byte in case @concatenate is false.
 214  */
 215 const char *
 216 trace_print_hex_seq(struct trace_seq *p, const unsigned char *buf, int buf_len,
 217                     bool concatenate)
 218 {
 219         int i;
 220         const char *ret = trace_seq_buffer_ptr(p);
 221
 222         for (i = 0; i < buf_len; i++)
 223                 trace_seq_printf(p, "%s%2.2x", concatenate || i == 0 ? "" : " ",
 224                                  buf[i]);
 225         trace_seq_putc(p, 0);
 226
 227         return ret;
 228 }
 229 EXPORT_SYMBOL(trace_print_hex_seq);
 230
 231 const char *
 232 trace_print_array_seq(struct trace_seq *p, const void *buf, int count,
 233                       size_t el_size)
 234 {
 235         const char *ret = trace_seq_buffer_ptr(p);
 236         const char *prefix = "";
 237         void *ptr = (void *)buf;
 238         size_t buf_len = count * el_size;
 239
 240         trace_seq_putc(p, '{');
 241
 242         while (ptr < buf + buf_len) {
 243                 switch (el_size) {
 244                 case 1:
 245                         trace_seq_printf(p, "%s0x%x", prefix,
 246                                          *(u8 *)ptr);
 247                         break;
 248                 case 2:
 249                         trace_seq_printf(p, "%s0x%x", prefix,
 250                                          *(u16 *)ptr);
 251                         break;
 252                 case 4:
 253                         trace_seq_printf(p, "%s0x%x", prefix,
 254                                          *(u32 *)ptr);
 255                         break;
 256                 case 8:
 257                         trace_seq_printf(p, "%s0x%llx", prefix,
 258                                          *(u64 *)ptr);
 259                         break;
 260                 default:
 261                         trace_seq_printf(p, "BAD SIZE:%zu 0x%x", el_size,
 262                                          *(u8 *)ptr);
 263                         el_size = 1;
 264                 }
 265                 prefix = ",";
 266                 ptr += el_size;
 267         }
 268
 269         trace_seq_putc(p, '}');
 270         trace_seq_putc(p, 0);
 271
 272         return ret;
 273 }
 274 EXPORT_SYMBOL(trace_print_array_seq);
 275
 276 int trace_raw_output_prep(struct trace_iterator *iter,
 277                           struct trace_event *trace_event)
 278 {
 279         struct trace_event_call *event;
 280         struct trace_seq *s = &iter->seq;
 281         struct trace_seq *p = &iter->tmp_seq;
 282         struct trace_entry *entry;
 283
 284         event = container_of(trace_event, struct trace_event_call, event);
 285         entry = iter->ent;
 286
 287         if (entry->type != event->event.type) {
 288                 WARN_ON_ONCE(1);
 289                 return TRACE_TYPE_UNHANDLED;
 290         }
 291
 292         trace_seq_init(p);
 293         trace_seq_printf(s, "%s: ", trace_event_name(event));
 294
 295         return trace_handle_return(s);
 296 }
 297 EXPORT_SYMBOL(trace_raw_output_prep);
 298
 299 static int trace_output_raw(struct trace_iterator *iter, char *name,
 300                             char *fmt, va_list ap)
 301 {
 302         struct trace_seq *s = &iter->seq;
 303
 304         trace_seq_printf(s, "%s: ", name);
 305         trace_seq_vprintf(s, fmt, ap);
 306
 307         return trace_handle_return(s);
 308 }
 309
 310 int trace_output_call(struct trace_iterator *iter, char *name, char *fmt, ...)
 311 {
 312         va_list ap;
 313         int ret;
 314
 315         va_start(ap, fmt);
 316         ret = trace_output_raw(iter, name, fmt, ap);
 317         va_end(ap);
 318
 319         return ret;
 320 }
 321 EXPORT_SYMBOL_GPL(trace_output_call);
 322
 323 #ifdef CONFIG_KRETPROBES
 324 static inline const char *kretprobed(const char *name)
 325 {
 326         static const char tramp_name[] = "kretprobe_trampoline";
 327         int size = sizeof(tramp_name);
 328
 329         if (strncmp(tramp_name, name, size) == 0)
 330                 return "[unknown/kretprobe'd]";
 331         return name;
 332 }
 333 #else
 334 static inline const char *kretprobed(const char *name)
 335 {
 336         return name;
 337 }
 338 #endif /* CONFIG_KRETPROBES */
 339
 340 static void
 341 seq_print_sym_short(struct trace_seq *s, const char *fmt, unsigned long address)
 342 {
 343         char str[KSYM_SYMBOL_LEN];
 344 #ifdef CONFIG_KALLSYMS
 345         const char *name;
 346
 347         kallsyms_lookup(address, NULL, NULL, NULL, str);
 348
 349         name = kretprobed(str);
 350
 351         if (name && strlen(name)) {
 352                 trace_seq_printf(s, fmt, name);
 353                 return;
 354         }
 355 #endif
 356         snprintf(str, KSYM_SYMBOL_LEN, "0x%08lx", address);
 357         trace_seq_printf(s, fmt, str);
 358 }
 359
 360 static void
 361 seq_print_sym_offset(struct trace_seq *s, const char *fmt,
 362                      unsigned long address)
 363 {
 364         char str[KSYM_SYMBOL_LEN];
 365 #ifdef CONFIG_KALLSYMS
 366         const char *name;
 367
 368         sprint_symbol(str, address);
 369         name = kretprobed(str);
 370
 371         if (name && strlen(name)) {
 372                 trace_seq_printf(s, fmt, name);
 373                 return;
 374         }
 375 #endif
 376         snprintf(str, KSYM_SYMBOL_LEN, "0x%08lx", address);
 377         trace_seq_printf(s, fmt, str);
 378 }
 379
 380 #ifndef CONFIG_64BIT
 381 # define IP_FMT "%08lx"
 382 #else
 383 # define IP_FMT "%016lx"
 384 #endif
 385
 386 static int seq_print_user_ip(struct trace_seq *s, struct mm_struct *mm,
 387                              unsigned long ip, unsigned long sym_flags)
 388 {
 389         struct file *file = NULL;
 390         unsigned long vmstart = 0;
 391         int ret = 1;
 392
 393         if (s->full)
 394                 return 0;
 395
 396         if (mm) {
 397                 const struct vm_area_struct *vma;
 398
 399                 down_read(&mm->mmap_sem);
 400                 vma = find_vma(mm, ip);
 401                 if (vma) {
 402                         file = vma->vm_file;
 403                         vmstart = vma->vm_start;
 404                 }
 405                 if (file) {
 406                         ret = trace_seq_path(s, &file->f_path);
 407                         if (ret)
 408                                 trace_seq_printf(s, "[+0x%lx]",
 409                                                  ip - vmstart);
 410                 }
 411                 up_read(&mm->mmap_sem);
 412         }
 413         if (ret && ((sym_flags & TRACE_ITER_SYM_ADDR) || !file))
 414                 trace_seq_printf(s, " <" IP_FMT ">", ip);
 415         return !trace_seq_has_overflowed(s);
 416 }
 417
 418 int
 419 seq_print_ip_sym(struct trace_seq *s, unsigned long ip, unsigned long sym_flags)
 420 {
 421         if (!ip) {
 422                 trace_seq_putc(s, '0');
 423                 goto out;
 424         }
 425
 426         if (sym_flags & TRACE_ITER_SYM_OFFSET)
 427                 seq_print_sym_offset(s, "%s", ip);
 428         else
 429                 seq_print_sym_short(s, "%s", ip);
 430
 431         if (sym_flags & TRACE_ITER_SYM_ADDR)
 432                 trace_seq_printf(s, " <" IP_FMT ">", ip);
 433
 434  out:
 435         return !trace_seq_has_overflowed(s);
 436 }
 437
 438 /**
 439  * trace_print_lat_fmt - print the irq, preempt and lockdep fields
 440  * @s: trace seq struct to write to
 441  * @entry: The trace entry field from the ring buffer
 442  *
 443  * Prints the generic fields of irqs off, in hard or softirq, preempt
 444  * count.
 445  */
 446 int trace_print_lat_fmt(struct trace_seq *s, struct trace_entry *entry)
 447 {
 448         char hardsoft_irq;
 449         char need_resched;
 450         char irqs_off;
 451         int hardirq;
 452         int softirq;
 453         int nmi;
 454
 455         nmi = entry->flags & TRACE_FLAG_NMI;
 456         hardirq = entry->flags & TRACE_FLAG_HARDIRQ;
 457         softirq = entry->flags & TRACE_FLAG_SOFTIRQ;
 458
 459         irqs_off =
 460                 (entry->flags & TRACE_FLAG_IRQS_OFF) ? 'd' :
 461                 (entry->flags & TRACE_FLAG_IRQS_NOSUPPORT) ? 'X' :
 462                 '.';
 463
 464         switch (entry->flags & (TRACE_FLAG_NEED_RESCHED |
 465                                 TRACE_FLAG_PREEMPT_RESCHED)) {
 466         case TRACE_FLAG_NEED_RESCHED | TRACE_FLAG_PREEMPT_RESCHED:
 467                 need_resched = 'N';
 468                 break;
 469         case TRACE_FLAG_NEED_RESCHED:
 470                 need_resched = 'n';
 471                 break;
 472         case TRACE_FLAG_PREEMPT_RESCHED:
 473                 need_resched = 'p';
 474                 break;
 475         default:
 476                 need_resched = '.';
 477                 break;
 478         }
 479
 480         hardsoft_irq =
 481                 (nmi && hardirq)     ? 'Z' :
 482                 nmi                  ? 'z' :
 483                 (hardirq && softirq) ? 'H' :
 484                 hardirq              ? 'h' :
 485                 softirq              ? 's' :
 486                                        '.' ;
 487
 488         trace_seq_printf(s, "%c%c%c",
 489                          irqs_off, need_resched, hardsoft_irq);
 490
 491         if (entry->preempt_count)
 492                 trace_seq_printf(s, "%x", entry->preempt_count);
 493         else
 494                 trace_seq_putc(s, '.');
 495
 496         return !trace_seq_has_overflowed(s);
 497 }
 498
 499 static int
 500 lat_print_generic(struct trace_seq *s, struct trace_entry *entry, int cpu)
 501 {
 502         char comm[TASK_COMM_LEN];
 503
 504         trace_find_cmdline(entry->pid, comm);
 505
 506         trace_seq_printf(s, "%8.8s-%-5d %3d",
 507                          comm, entry->pid, cpu);
 508
 509         return trace_print_lat_fmt(s, entry);
 510 }
 511
 512 #undef MARK
 513 #define MARK(v, s) {.val = v, .sym = s}
 514 /* trace overhead mark */
 515 static const struct trace_mark {
 516         unsigned long long      val; /* unit: nsec */
 517         char                    sym;
 518 } mark[] = {
 519         MARK(1000000000ULL      , '$'), /* 1 sec */
 520         MARK(100000000ULL       , '@'), /* 100 msec */
 521         MARK(10000000ULL        , '*'), /* 10 msec */
 522         MARK(1000000ULL         , '#'), /* 1000 usecs */
 523         MARK(100000ULL          , '!'), /* 100 usecs */
 524         MARK(10000ULL           , '+'), /* 10 usecs */
 525 };
 526 #undef MARK
 527
 528 char trace_find_mark(unsigned long long d)
 529 {
 530         int i;
 531         int size = ARRAY_SIZE(mark);
 532
 533         for (i = 0; i < size; i++) {
 534                 if (d > mark[i].val)
 535                         break;
 536         }
 537
 538         return (i == size) ? ' ' : mark[i].sym;
 539 }
 540
 541 static int
 542 lat_print_timestamp(struct trace_iterator *iter, u64 next_ts)
 543 {
 544         struct trace_array *tr = iter->tr;
 545         unsigned long verbose = tr->trace_flags & TRACE_ITER_VERBOSE;
 546         unsigned long in_ns = iter->iter_flags & TRACE_FILE_TIME_IN_NS;
 547         unsigned long long abs_ts = iter->ts - iter->trace_buffer->time_start;
 548         unsigned long long rel_ts = next_ts - iter->ts;
 549         struct trace_seq *s = &iter->seq;
 550
 551         if (in_ns) {
 552                 abs_ts = ns2usecs(abs_ts);
 553                 rel_ts = ns2usecs(rel_ts);
 554         }
 555
 556         if (verbose && in_ns) {
 557                 unsigned long abs_usec = do_div(abs_ts, USEC_PER_MSEC);
 558                 unsigned long abs_msec = (unsigned long)abs_ts;
 559                 unsigned long rel_usec = do_div(rel_ts, USEC_PER_MSEC);
 560                 unsigned long rel_msec = (unsigned long)rel_ts;
 561
 562                 trace_seq_printf(
 563                         s, "[%08llx] %ld.%03ldms (+%ld.%03ldms): ",
 564                         ns2usecs(iter->ts),
 565                         abs_msec, abs_usec,
 566                         rel_msec, rel_usec);
 567
 568         } else if (verbose && !in_ns) {
 569                 trace_seq_printf(
 570                         s, "[%016llx] %lld (+%lld): ",
 571                         iter->ts, abs_ts, rel_ts);
 572
 573         } else if (!verbose && in_ns) {
 574                 trace_seq_printf(
 575                         s, " %4lldus%c: ",
 576                         abs_ts,
 577                         trace_find_mark(rel_ts * NSEC_PER_USEC));
 578
 579         } else { /* !verbose && !in_ns */
 580                 trace_seq_printf(s, " %4lld: ", abs_ts);
 581         }
 582
 583         return !trace_seq_has_overflowed(s);
 584 }
 585
 586 int trace_print_context(struct trace_iterator *iter)
 587 {
 588         struct trace_array *tr = iter->tr;
 589         struct trace_seq *s = &iter->seq;
 590         struct trace_entry *entry = iter->ent;
 591         unsigned long long t;
 592         unsigned long secs, usec_rem;
 593         char comm[TASK_COMM_LEN];
 594
 595         trace_find_cmdline(entry->pid, comm);
 596
 597         trace_seq_printf(s, "%16s-%-5d [%03d] ",
 598                                comm, entry->pid, iter->cpu);
 599
 600         if (tr->trace_flags & TRACE_ITER_RECORD_TGID) {
 601                 unsigned int tgid = trace_find_tgid(entry->pid);
 602
 603                 if (!tgid)
 604                         trace_seq_printf(s, "(-----) ");
 605                 else
 606                         trace_seq_printf(s, "(%5d) ", tgid);
 607         }
 608
 609         if (tr->trace_flags & TRACE_ITER_IRQ_INFO)
 610                 trace_print_lat_fmt(s, entry);
 611
 612         if (iter->iter_flags & TRACE_FILE_TIME_IN_NS) {
 613                 t = ns2usecs(iter->ts);
 614                 usec_rem = do_div(t, USEC_PER_SEC);
 615                 secs = (unsigned long)t;
 616                 trace_seq_printf(s, " %5lu.%06lu: ", secs, usec_rem);
 617         } else
 618                 trace_seq_printf(s, " %12llu: ", iter->ts);
 619
 620         return !trace_seq_has_overflowed(s);
 621 }
 622
 623 int trace_print_lat_context(struct trace_iterator *iter)
 624 {
 625         struct trace_array *tr = iter->tr;
 626         /* trace_find_next_entry will reset ent_size */
 627         int ent_size = iter->ent_size;
 628         struct trace_seq *s = &iter->seq;
 629         u64 next_ts;
 630         struct trace_entry *entry = iter->ent,
 631                            *next_entry = trace_find_next_entry(iter, NULL,
 632                                                                &next_ts);
 633         unsigned long verbose = (tr->trace_flags & TRACE_ITER_VERBOSE);
 634
 635         /* Restore the original ent_size */
 636         iter->ent_size = ent_size;
 637
 638         if (!next_entry)
 639                 next_ts = iter->ts;
 640
 641         if (verbose) {
 642                 char comm[TASK_COMM_LEN];
 643
 644                 trace_find_cmdline(entry->pid, comm);
 645
 646                 trace_seq_printf(
 647                         s, "%16s %5d %3d %d %08x %08lx ",
 648                         comm, entry->pid, iter->cpu, entry->flags,
 649                         entry->preempt_count, iter->idx);
 650         } else {
 651                 lat_print_generic(s, entry, iter->cpu);
 652         }
 653
 654         lat_print_timestamp(iter, next_ts);
 655
 656         return !trace_seq_has_overflowed(s);
 657 }
 658
 659 /**
 660  * ftrace_find_event - find a registered event
 661  * @type: the type of event to look for
 662  *
 663  * Returns an event of type @type otherwise NULL
 664  * Called with trace_event_read_lock() held.
 665  */
 666 struct trace_event *ftrace_find_event(int type)
 667 {
 668         struct trace_event *event;
 669         unsigned key;
 670
 671         key = type & (EVENT_HASHSIZE - 1);
 672
 673         hlist_for_each_entry(event, &event_hash[key], node) {
 674                 if (event->type == type)
 675                         return event;
 676         }
 677
 678         return NULL;
 679 }
 680
 681 static LIST_HEAD(ftrace_event_list);
 682
 683 static int trace_search_list(struct list_head **list)
 684 {
 685         struct trace_event *e;
 686         int last = __TRACE_LAST_TYPE;
 687
 688         if (list_empty(&ftrace_event_list)) {
 689                 *list = &ftrace_event_list;
 690                 return last + 1;
 691         }
 692
 693         /*
 694          * We used up all possible max events,
 695          * lets see if somebody freed one.
 696          */
 697         list_for_each_entry(e, &ftrace_event_list, list) {
 698                 if (e->type != last + 1)
 699                         break;
 700                 last++;
 701         }
 702
 703         /* Did we used up all 65 thousand events??? */
 704         if ((last + 1) > TRACE_EVENT_TYPE_MAX)
 705                 return 0;
 706
 707         *list = &e->list;
 708         return last + 1;
 709 }
 710
 711 void trace_event_read_lock(void)
 712 {
 713         down_read(&trace_event_sem);
 714 }
 715
 716 void trace_event_read_unlock(void)
 717 {
 718         up_read(&trace_event_sem);
 719 }
 720
 721 /**
 722  * register_trace_event - register output for an event type
 723  * @event: the event type to register
 724  *
 725  * Event types are stored in a hash and this hash is used to
 726  * find a way to print an event. If the @event->type is set
 727  * then it will use that type, otherwise it will assign a
 728  * type to use.
 729  *
 730  * If you assign your own type, please make sure it is added
 731  * to the trace_type enum in trace.h, to avoid collisions
 732  * with the dynamic types.
 733  *
 734  * Returns the event type number or zero on error.
 735  */
 736 int register_trace_event(struct trace_event *event)
 737 {
 738         unsigned key;
 739         int ret = 0;
 740
 741         down_write(&trace_event_sem);
 742
 743         if (WARN_ON(!event))
 744                 goto out;
 745
 746         if (WARN_ON(!event->funcs))
 747                 goto out;
 748
 749         INIT_LIST_HEAD(&event->list);
 750
 751         if (!event->type) {
 752                 struct list_head *list = NULL;
 753
 754                 if (next_event_type > TRACE_EVENT_TYPE_MAX) {
 755
 756                         event->type = trace_search_list(&list);
 757                         if (!event->type)
 758                                 goto out;
 759
 760                 } else {
 761
 762                         event->type = next_event_type++;
 763                         list = &ftrace_event_list;
 764                 }
 765
 766                 if (WARN_ON(ftrace_find_event(event->type)))
 767                         goto out;
 768
 769                 list_add_tail(&event->list, list);
 770
 771         } else if (event->type > __TRACE_LAST_TYPE) {
 772                 printk(KERN_WARNING "Need to add type to trace.h\n");
 773                 WARN_ON(1);
 774                 goto out;
 775         } else {
 776                 /* Is this event already used */
 777                 if (ftrace_find_event(event->type))
 778                         goto out;
 779         }
 780
 781         if (event->funcs->trace == NULL)
 782                 event->funcs->trace = trace_nop_print;
 783         if (event->funcs->raw == NULL)
 784                 event->funcs->raw = trace_nop_print;
 785         if (event->funcs->hex == NULL)
 786                 event->funcs->hex = trace_nop_print;
 787         if (event->funcs->binary == NULL)
 788                 event->funcs->binary = trace_nop_print;
 789
 790         key = event->type & (EVENT_HASHSIZE - 1);
 791
 792         hlist_add_head(&event->node, &event_hash[key]);
 793
 794         ret = event->type;
 795  out:
 796         up_write(&trace_event_sem);
 797
 798         return ret;
 799 }
 800 EXPORT_SYMBOL_GPL(register_trace_event);
 801
 802 /*
 803  * Used by module code with the trace_event_sem held for write.
 804  */
 805 int __unregister_trace_event(struct trace_event *event)
 806 {
 807         hlist_del(&event->node);
 808         list_del(&event->list);
 809         return 0;
 810 }
 811
 812 /**
 813  * unregister_trace_event - remove a no longer used event
 814  * @event: the event to remove
 815  */
 816 int unregister_trace_event(struct trace_event *event)
 817 {
 818         down_write(&trace_event_sem);
 819         __unregister_trace_event(event);
 820         up_write(&trace_event_sem);
 821
 822         return 0;
 823 }
 824 EXPORT_SYMBOL_GPL(unregister_trace_event);
 825
 826 /*
 827  * Standard events
 828  */
 829
 830 enum print_line_t trace_nop_print(struct trace_iterator *iter, int flags,
 831                                   struct trace_event *event)
 832 {
 833         trace_seq_printf(&iter->seq, "type: %d\n", iter->ent->type);
 834
 835         return trace_handle_return(&iter->seq);
 836 }
 837
 838 /* TRACE_FN */
 839 static enum print_line_t trace_fn_trace(struct trace_iterator *iter, int flags,
 840                                         struct trace_event *event)
 841 {
 842         struct ftrace_entry *field;
 843         struct trace_seq *s = &iter->seq;
 844
 845         trace_assign_type(field, iter->ent);
 846
 847         seq_print_ip_sym(s, field->ip, flags);
 848
 849         if ((flags & TRACE_ITER_PRINT_PARENT) && field->parent_ip) {
 850                 trace_seq_puts(s, " <-");
 851                 seq_print_ip_sym(s, field->parent_ip, flags);
 852         }
 853
 854         trace_seq_putc(s, '\n');
 855
 856         return trace_handle_return(s);
 857 }
 858
 859 static enum print_line_t trace_fn_raw(struct trace_iterator *iter, int flags,
 860                                       struct trace_event *event)
 861 {
 862         struct ftrace_entry *field;
 863
 864         trace_assign_type(field, iter->ent);
 865
 866         trace_seq_printf(&iter->seq, "%lx %lx\n",
 867                          field->ip,
 868                          field->parent_ip);
 869
 870         return trace_handle_return(&iter->seq);
 871 }
 872
 873 static enum print_line_t trace_fn_hex(struct trace_iterator *iter, int flags,
 874                                       struct trace_event *event)
 875 {
 876         struct ftrace_entry *field;
 877         struct trace_seq *s = &iter->seq;
 878
 879         trace_assign_type(field, iter->ent);
 880
 881         SEQ_PUT_HEX_FIELD(s, field->ip);
 882         SEQ_PUT_HEX_FIELD(s, field->parent_ip);
 883
 884         return trace_handle_return(s);
 885 }
 886
 887 static enum print_line_t trace_fn_bin(struct trace_iterator *iter, int flags,
 888                                       struct trace_event *event)
 889 {
 890         struct ftrace_entry *field;
 891         struct trace_seq *s = &iter->seq;
 892
 893         trace_assign_type(field, iter->ent);
 894
 895         SEQ_PUT_FIELD(s, field->ip);
 896         SEQ_PUT_FIELD(s, field->parent_ip);
 897
 898         return trace_handle_return(s);
 899 }
 900
 901 static struct trace_event_functions trace_fn_funcs = {
 902         .trace          = trace_fn_trace,
 903         .raw            = trace_fn_raw,
 904         .hex            = trace_fn_hex,
 905         .binary         = trace_fn_bin,
 906 };
 907
 908 static struct trace_event trace_fn_event = {
 909         .type           = TRACE_FN,
 910         .funcs          = &trace_fn_funcs,
 911 };
 912
 913 /* TRACE_CTX an TRACE_WAKE */
 914 static enum print_line_t trace_ctxwake_print(struct trace_iterator *iter,
 915                                              char *delim)
 916 {
 917         struct ctx_switch_entry *field;
 918         char comm[TASK_COMM_LEN];
 919         int S, T;
 920
 921
 922         trace_assign_type(field, iter->ent);
 923
 924         T = task_index_to_char(field->next_state);
 925         S = task_index_to_char(field->prev_state);
 926         trace_find_cmdline(field->next_pid, comm);
 927         trace_seq_printf(&iter->seq,
 928                          " %5d:%3d:%c %s [%03d] %5d:%3d:%c %s\n",
 929                          field->prev_pid,
 930                          field->prev_prio,
 931                          S, delim,
 932                          field->next_cpu,
 933                          field->next_pid,
 934                          field->next_prio,
 935                          T, comm);
 936
 937         return trace_handle_return(&iter->seq);
 938 }
 939
 940 static enum print_line_t trace_ctx_print(struct trace_iterator *iter, int flags,
 941                                          struct trace_event *event)
 942 {
 943         return trace_ctxwake_print(iter, "==>");
 944 }
 945
 946 static enum print_line_t trace_wake_print(struct trace_iterator *iter,
 947                                           int flags, struct trace_event *event)
 948 {
 949         return trace_ctxwake_print(iter, "  +");
 950 }
 951
 952 static int trace_ctxwake_raw(struct trace_iterator *iter, char S)
 953 {
 954         struct ctx_switch_entry *field;
 955         int T;
 956
 957         trace_assign_type(field, iter->ent);
 958
 959         if (!S)
 960                 S = task_index_to_char(field->prev_state);
 961         T = task_index_to_char(field->next_state);
 962         trace_seq_printf(&iter->seq, "%d %d %c %d %d %d %c\n",
 963                          field->prev_pid,
 964                          field->prev_prio,
 965                          S,
 966                          field->next_cpu,
 967                          field->next_pid,
 968                          field->next_prio,
 969                          T);
 970
 971         return trace_handle_return(&iter->seq);
 972 }
 973
 974 static enum print_line_t trace_ctx_raw(struct trace_iterator *iter, int flags,
 975                                        struct trace_event *event)
 976 {
 977         return trace_ctxwake_raw(iter, 0);
 978 }
 979
 980 static enum print_line_t trace_wake_raw(struct trace_iterator *iter, int flags,
 981                                         struct trace_event *event)
 982 {
 983         return trace_ctxwake_raw(iter, '+');
 984 }
 985
 986
 987 static int trace_ctxwake_hex(struct trace_iterator *iter, char S)
 988 {
 989         struct ctx_switch_entry *field;
 990         struct trace_seq *s = &iter->seq;
 991         int T;
 992
 993         trace_assign_type(field, iter->ent);
 994
 995         if (!S)
 996                 S = task_index_to_char(field->prev_state);
 997         T = task_index_to_char(field->next_state);
 998
 999         SEQ_PUT_HEX_FIELD(s, field->prev_pid);
1000         SEQ_PUT_HEX_FIELD(s, field->prev_prio);
1001         SEQ_PUT_HEX_FIELD(s, S);
1002         SEQ_PUT_HEX_FIELD(s, field->next_cpu);
1003         SEQ_PUT_HEX_FIELD(s, field->next_pid);
1004         SEQ_PUT_HEX_FIELD(s, field->next_prio);
1005         SEQ_PUT_HEX_FIELD(s, T);
1006
1007         return trace_handle_return(s);
1008 }
1009
1010 static enum print_line_t trace_ctx_hex(struct trace_iterator *iter, int flags,
1011                                        struct trace_event *event)
1012 {
1013         return trace_ctxwake_hex(iter, 0);
1014 }
1015
1016 static enum print_line_t trace_wake_hex(struct trace_iterator *iter, int flags,
1017                                         struct trace_event *event)
1018 {
1019         return trace_ctxwake_hex(iter, '+');
1020 }
1021
1022 static enum print_line_t trace_ctxwake_bin(struct trace_iterator *iter,
1023                                            int flags, struct trace_event *event)
1024 {
1025         struct ctx_switch_entry *field;
1026         struct trace_seq *s = &iter->seq;
1027
1028         trace_assign_type(field, iter->ent);
1029
1030         SEQ_PUT_FIELD(s, field->prev_pid);
1031         SEQ_PUT_FIELD(s, field->prev_prio);
1032         SEQ_PUT_FIELD(s, field->prev_state);
1033         SEQ_PUT_FIELD(s, field->next_cpu);
1034         SEQ_PUT_FIELD(s, field->next_pid);
1035         SEQ_PUT_FIELD(s, field->next_prio);
1036         SEQ_PUT_FIELD(s, field->next_state);
1037
1038         return trace_handle_return(s);
1039 }
1040
1041 static struct trace_event_functions trace_ctx_funcs = {
1042         .trace          = trace_ctx_print,
1043         .raw            = trace_ctx_raw,
1044         .hex            = trace_ctx_hex,
1045         .binary         = trace_ctxwake_bin,
1046 };
1047
1048 static struct trace_event trace_ctx_event = {
1049         .type           = TRACE_CTX,
1050         .funcs          = &trace_ctx_funcs,
1051 };
1052
1053 static struct trace_event_functions trace_wake_funcs = {
1054         .trace          = trace_wake_print,
1055         .raw            = trace_wake_raw,
1056         .hex            = trace_wake_hex,
1057         .binary         = trace_ctxwake_bin,
1058 };
1059
1060 static struct trace_event trace_wake_event = {
1061         .type           = TRACE_WAKE,
1062         .funcs          = &trace_wake_funcs,
1063 };
1064
1065 /* TRACE_STACK */
1066
1067 static enum print_line_t trace_stack_print(struct trace_iterator *iter,
1068                                            int flags, struct trace_event *event)
1069 {
1070         struct stack_entry *field;
1071         struct trace_seq *s = &iter->seq;
1072         unsigned long *p;
1073         unsigned long *end;
1074
1075         trace_assign_type(field, iter->ent);
1076         end = (unsigned long *)((long)iter->ent + iter->ent_size);
1077
1078         trace_seq_puts(s, "<stack trace>\n");
1079
1080         for (p = field->caller; p && *p != ULONG_MAX && p < end; p++) {
1081
1082                 if (trace_seq_has_overflowed(s))
1083                         break;
1084
1085                 trace_seq_puts(s, " => ");
1086                 seq_print_ip_sym(s, *p, flags);
1087                 trace_seq_putc(s, '\n');
1088         }
1089
1090         return trace_handle_return(s);
1091 }
1092
1093 static struct trace_event_functions trace_stack_funcs = {
1094         .trace          = trace_stack_print,
1095 };
1096
1097 static struct trace_event trace_stack_event = {
1098         .type           = TRACE_STACK,
1099         .funcs          = &trace_stack_funcs,
1100 };
1101
1102 /* TRACE_USER_STACK */
1103 static enum print_line_t trace_user_stack_print(struct trace_iterator *iter,
1104                                                 int flags, struct trace_event *event)
1105 {
1106         struct trace_array *tr = iter->tr;
1107         struct userstack_entry *field;
1108         struct trace_seq *s = &iter->seq;
1109         struct mm_struct *mm = NULL;
1110         unsigned int i;
1111
1112         trace_assign_type(field, iter->ent);
1113
1114         trace_seq_puts(s, "<user stack trace>\n");
1115
1116         if (tr->trace_flags & TRACE_ITER_SYM_USEROBJ) {
1117                 struct task_struct *task;
1118                 /*
1119                  * we do the lookup on the thread group leader,
1120                  * since individual threads might have already quit!
1121                  */
1122                 rcu_read_lock();
1123                 task = find_task_by_vpid(field->tgid);
1124                 if (task)
1125                         mm = get_task_mm(task);
1126                 rcu_read_unlock();
1127         }
1128
1129         for (i = 0; i < FTRACE_STACK_ENTRIES; i++) {
1130                 unsigned long ip = field->caller[i];
1131
1132                 if (ip == ULONG_MAX || trace_seq_has_overflowed(s))
1133                         break;
1134
1135                 trace_seq_puts(s, " => ");
1136
1137                 if (!ip) {
1138                         trace_seq_puts(s, "??");
1139                         trace_seq_putc(s, '\n');
1140                         continue;
1141                 }
1142
1143                 seq_print_user_ip(s, mm, ip, flags);
1144                 trace_seq_putc(s, '\n');
1145         }
1146
1147         if (mm)
1148                 mmput(mm);
1149
1150         return trace_handle_return(s);
1151 }
1152
1153 static struct trace_event_functions trace_user_stack_funcs = {
1154         .trace          = trace_user_stack_print,
1155 };
1156
1157 static struct trace_event trace_user_stack_event = {
1158         .type           = TRACE_USER_STACK,
1159         .funcs          = &trace_user_stack_funcs,
1160 };
1161
1162 /* TRACE_HWLAT */
1163 static enum print_line_t
1164 trace_hwlat_print(struct trace_iterator *iter, int flags,
1165                   struct trace_event *event)
1166 {
1167         struct trace_entry *entry = iter->ent;
1168         struct trace_seq *s = &iter->seq;
1169         struct hwlat_entry *field;
1170
1171         trace_assign_type(field, entry);
1172
1173         trace_seq_printf(s, "#%-5u inner/outer(us): %4llu/%-5llu ts:%lld.%09ld",
1174                          field->seqnum,
1175                          field->duration,
1176                          field->outer_duration,
1177                          (long long)field->timestamp.tv_sec,
1178                          field->timestamp.tv_nsec);
1179
1180         if (field->nmi_count) {
1181                 /*
1182                  * The generic sched_clock() is not NMI safe, thus
1183                  * we only record the count and not the time.
1184                  */
1185                 if (!IS_ENABLED(CONFIG_GENERIC_SCHED_CLOCK))
1186                         trace_seq_printf(s, " nmi-total:%llu",
1187                                          field->nmi_total_ts);
1188                 trace_seq_printf(s, " nmi-count:%u",
1189                                  field->nmi_count);
1190         }
1191
1192         trace_seq_putc(s, '\n');
1193
1194         return trace_handle_return(s);
1195 }
1196
1197
1198 static enum print_line_t
1199 trace_hwlat_raw(struct trace_iterator *iter, int flags,
1200                 struct trace_event *event)
1201 {
1202         struct hwlat_entry *field;
1203         struct trace_seq *s = &iter->seq;
1204
1205         trace_assign_type(field, iter->ent);
1206
1207         trace_seq_printf(s, "%llu %lld %lld %09ld %u\n",
1208                          field->duration,
1209                          field->outer_duration,
1210                          (long long)field->timestamp.tv_sec,
1211                          field->timestamp.tv_nsec,
1212                          field->seqnum);
1213
1214         return trace_handle_return(s);
1215 }
1216
1217 static struct trace_event_functions trace_hwlat_funcs = {
1218         .trace          = trace_hwlat_print,
1219         .raw            = trace_hwlat_raw,
1220 };
1221
1222 static struct trace_event trace_hwlat_event = {
1223         .type           = TRACE_HWLAT,
1224         .funcs          = &trace_hwlat_funcs,
1225 };
1226
1227 /* TRACE_BPUTS */
1228 static enum print_line_t
1229 trace_bputs_print(struct trace_iterator *iter, int flags,
1230                    struct trace_event *event)
1231 {
1232         struct trace_entry *entry = iter->ent;
1233         struct trace_seq *s = &iter->seq;
1234         struct bputs_entry *field;
1235
1236         trace_assign_type(field, entry);
1237
1238         seq_print_ip_sym(s, field->ip, flags);
1239         trace_seq_puts(s, ": ");
1240         trace_seq_puts(s, field->str);
1241
1242         return trace_handle_return(s);
1243 }
1244
1245
1246 static enum print_line_t
1247 trace_bputs_raw(struct trace_iterator *iter, int flags,
1248                 struct trace_event *event)
1249 {
1250         struct bputs_entry *field;
1251         struct trace_seq *s = &iter->seq;
1252
1253         trace_assign_type(field, iter->ent);
1254
1255         trace_seq_printf(s, ": %lx : ", field->ip);
1256         trace_seq_puts(s, field->str);
1257
1258         return trace_handle_return(s);
1259 }
1260
1261 static struct trace_event_functions trace_bputs_funcs = {
1262         .trace          = trace_bputs_print,
1263         .raw            = trace_bputs_raw,
1264 };
1265
1266 static struct trace_event trace_bputs_event = {
1267         .type           = TRACE_BPUTS,
1268         .funcs          = &trace_bputs_funcs,
1269 };
1270
1271 /* TRACE_BPRINT */
1272 static enum print_line_t
1273 trace_bprint_print(struct trace_iterator *iter, int flags,
1274                    struct trace_event *event)
1275 {
1276         struct trace_entry *entry = iter->ent;
1277         struct trace_seq *s = &iter->seq;
1278         struct bprint_entry *field;
1279
1280         trace_assign_type(field, entry);
1281
1282         seq_print_ip_sym(s, field->ip, flags);
1283         trace_seq_puts(s, ": ");
1284         trace_seq_bprintf(s, field->fmt, field->buf);
1285
1286         return trace_handle_return(s);
1287 }
1288
1289
1290 static enum print_line_t
1291 trace_bprint_raw(struct trace_iterator *iter, int flags,
1292                  struct trace_event *event)
1293 {
1294         struct bprint_entry *field;
1295         struct trace_seq *s = &iter->seq;
1296
1297         trace_assign_type(field, iter->ent);
1298
1299         trace_seq_printf(s, ": %lx : ", field->ip);
1300         trace_seq_bprintf(s, field->fmt, field->buf);
1301
1302         return trace_handle_return(s);
1303 }
1304
1305 static struct trace_event_functions trace_bprint_funcs = {
1306         .trace          = trace_bprint_print,
1307         .raw            = trace_bprint_raw,
1308 };
1309
1310 static struct trace_event trace_bprint_event = {
1311         .type           = TRACE_BPRINT,
1312         .funcs          = &trace_bprint_funcs,
1313 };
1314
1315 /* TRACE_PRINT */
1316 static enum print_line_t trace_print_print(struct trace_iterator *iter,
1317                                            int flags, struct trace_event *event)
1318 {
1319         struct print_entry *field;
1320         struct trace_seq *s = &iter->seq;
1321
1322         trace_assign_type(field, iter->ent);
1323
1324         seq_print_ip_sym(s, field->ip, flags);
1325         trace_seq_printf(s, ": %s", field->buf);
1326
1327         return trace_handle_return(s);
1328 }
1329
1330 static enum print_line_t trace_print_raw(struct trace_iterator *iter, int flags,
1331                                          struct trace_event *event)
1332 {
1333         struct print_entry *field;
1334
1335         trace_assign_type(field, iter->ent);
1336
1337         trace_seq_printf(&iter->seq, "# %lx %s", field->ip, field->buf);
1338
1339         return trace_handle_return(&iter->seq);
1340 }
1341
1342 static struct trace_event_functions trace_print_funcs = {
1343         .trace          = trace_print_print,
1344         .raw            = trace_print_raw,
1345 };
1346
1347 static struct trace_event trace_print_event = {
1348         .type           = TRACE_PRINT,
1349         .funcs          = &trace_print_funcs,
1350 };
1351
1352 static enum print_line_t trace_raw_data(struct trace_iterator *iter, int flags,
1353                                          struct trace_event *event)
1354 {
1355         struct raw_data_entry *field;
1356         int i;
1357
1358         trace_assign_type(field, iter->ent);
1359
1360         trace_seq_printf(&iter->seq, "# %x buf:", field->id);
1361
1362         for (i = 0; i < iter->ent_size - offsetof(struct raw_data_entry, buf); i++)
1363                 trace_seq_printf(&iter->seq, " %02x",
1364                                  (unsigned char)field->buf[i]);
1365
1366         trace_seq_putc(&iter->seq, '\n');
1367
1368         return trace_handle_return(&iter->seq);
1369 }
1370
1371 static struct trace_event_functions trace_raw_data_funcs = {
1372         .trace          = trace_raw_data,
1373         .raw            = trace_raw_data,
1374 };
1375
1376 static struct trace_event trace_raw_data_event = {
1377         .type           = TRACE_RAW_DATA,
1378         .funcs          = &trace_raw_data_funcs,
1379 };
1380
1381
1382 static struct trace_event *events[] __initdata = {
1383         &trace_fn_event,
1384         &trace_ctx_event,
1385         &trace_wake_event,
1386         &trace_stack_event,
1387         &trace_user_stack_event,
1388         &trace_bputs_event,
1389         &trace_bprint_event,
1390         &trace_print_event,
1391         &trace_hwlat_event,
1392         &trace_raw_data_event,
1393         NULL
1394 };
1395
1396 __init static int init_events(void)
1397 {
1398         struct trace_event *event;
1399         int i, ret;
1400
1401         for (i = 0; events[i]; i++) {
1402                 event = events[i];
1403
1404                 ret = register_trace_event(event);
1405                 if (!ret) {
1406                         printk(KERN_WARNING "event %d failed to register\n",
1407                                event->type);
1408                         WARN_ON_ONCE(1);
1409                 }
1410         }
1411
1412         return 0;
1413 }
1414 early_initcall(init_events);