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 + 1;
  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 static int trace_output_raw(struct trace_iterator *iter, char *name,
 316                             char *fmt, va_list ap)
 317 {
 318         struct trace_seq *s = &iter->seq;
 319
 320         trace_seq_printf(s, "%s: ", name);
 321         trace_seq_vprintf(s, fmt, ap);
 322
 323         return trace_handle_return(s);
 324 }
 325
 326 int trace_output_call(struct trace_iterator *iter, char *name, char *fmt, ...)
 327 {
 328         va_list ap;
 329         int ret;
 330
 331         va_start(ap, fmt);
 332         ret = trace_output_raw(iter, name, fmt, ap);
 333         va_end(ap);
 334
 335         return ret;
 336 }
 337 EXPORT_SYMBOL_GPL(trace_output_call);
 338
 339 #ifdef CONFIG_KRETPROBES
 340 static inline const char *kretprobed(const char *name)
 341 {
 342         static const char tramp_name[] = "kretprobe_trampoline";
 343         int size = sizeof(tramp_name);
 344
 345         if (strncmp(tramp_name, name, size) == 0)
 346                 return "[unknown/kretprobe'd]";
 347         return name;
 348 }
 349 #else
 350 static inline const char *kretprobed(const char *name)
 351 {
 352         return name;
 353 }
 354 #endif /* CONFIG_KRETPROBES */
 355
 356 static void
 357 seq_print_sym(struct trace_seq *s, unsigned long address, bool offset)
 358 {
 359 #ifdef CONFIG_KALLSYMS
 360         char str[KSYM_SYMBOL_LEN];
 361         const char *name;
 362
 363         if (offset)
 364                 sprint_symbol(str, address);
 365         else
 366                 kallsyms_lookup(address, NULL, NULL, NULL, str);
 367         name = kretprobed(str);
 368
 369         if (name && strlen(name)) {
 370                 trace_seq_puts(s, name);
 371                 return;
 372         }
 373 #endif
 374         trace_seq_printf(s, "0x%08lx", address);
 375 }
 376
 377 #ifndef CONFIG_64BIT
 378 # define IP_FMT "%08lx"
 379 #else
 380 # define IP_FMT "%016lx"
 381 #endif
 382
 383 static int seq_print_user_ip(struct trace_seq *s, struct mm_struct *mm,
 384                              unsigned long ip, unsigned long sym_flags)
 385 {
 386         struct file *file = NULL;
 387         unsigned long vmstart = 0;
 388         int ret = 1;
 389
 390         if (s->full)
 391                 return 0;
 392
 393         if (mm) {
 394                 const struct vm_area_struct *vma;
 395
 396                 down_read(&mm->mmap_sem);
 397                 vma = find_vma(mm, ip);
 398                 if (vma) {
 399                         file = vma->vm_file;
 400                         vmstart = vma->vm_start;
 401                 }
 402                 if (file) {
 403                         ret = trace_seq_path(s, &file->f_path);
 404                         if (ret)
 405                                 trace_seq_printf(s, "[+0x%lx]",
 406                                                  ip - vmstart);
 407                 }
 408                 up_read(&mm->mmap_sem);
 409         }
 410         if (ret && ((sym_flags & TRACE_ITER_SYM_ADDR) || !file))
 411                 trace_seq_printf(s, " <" IP_FMT ">", ip);
 412         return !trace_seq_has_overflowed(s);
 413 }
 414
 415 int
 416 seq_print_ip_sym(struct trace_seq *s, unsigned long ip, unsigned long sym_flags)
 417 {
 418         if (!ip) {
 419                 trace_seq_putc(s, '0');
 420                 goto out;
 421         }
 422
 423         seq_print_sym(s, ip, sym_flags & TRACE_ITER_SYM_OFFSET);
 424
 425         if (sym_flags & TRACE_ITER_SYM_ADDR)
 426                 trace_seq_printf(s, " <" IP_FMT ">", ip);
 427
 428  out:
 429         return !trace_seq_has_overflowed(s);
 430 }
 431
 432 /**
 433  * trace_print_lat_fmt - print the irq, preempt and lockdep fields
 434  * @s: trace seq struct to write to
 435  * @entry: The trace entry field from the ring buffer
 436  *
 437  * Prints the generic fields of irqs off, in hard or softirq, preempt
 438  * count.
 439  */
 440 int trace_print_lat_fmt(struct trace_seq *s, struct trace_entry *entry)
 441 {
 442         char hardsoft_irq;
 443         char need_resched;
 444         char irqs_off;
 445         int hardirq;
 446         int softirq;
 447         int nmi;
 448
 449         nmi = entry->flags & TRACE_FLAG_NMI;
 450         hardirq = entry->flags & TRACE_FLAG_HARDIRQ;
 451         softirq = entry->flags & TRACE_FLAG_SOFTIRQ;
 452
 453         irqs_off =
 454                 (entry->flags & TRACE_FLAG_IRQS_OFF) ? 'd' :
 455                 (entry->flags & TRACE_FLAG_IRQS_NOSUPPORT) ? 'X' :
 456                 '.';
 457
 458         switch (entry->flags & (TRACE_FLAG_NEED_RESCHED |
 459                                 TRACE_FLAG_PREEMPT_RESCHED)) {
 460         case TRACE_FLAG_NEED_RESCHED | TRACE_FLAG_PREEMPT_RESCHED:
 461                 need_resched = 'N';
 462                 break;
 463         case TRACE_FLAG_NEED_RESCHED:
 464                 need_resched = 'n';
 465                 break;
 466         case TRACE_FLAG_PREEMPT_RESCHED:
 467                 need_resched = 'p';
 468                 break;
 469         default:
 470                 need_resched = '.';
 471                 break;
 472         }
 473
 474         hardsoft_irq =
 475                 (nmi && hardirq)     ? 'Z' :
 476                 nmi                  ? 'z' :
 477                 (hardirq && softirq) ? 'H' :
 478                 hardirq              ? 'h' :
 479                 softirq              ? 's' :
 480                                        '.' ;
 481
 482         trace_seq_printf(s, "%c%c%c",
 483                          irqs_off, need_resched, hardsoft_irq);
 484
 485         if (entry->preempt_count)
 486                 trace_seq_printf(s, "%x", entry->preempt_count);
 487         else
 488                 trace_seq_putc(s, '.');
 489
 490         return !trace_seq_has_overflowed(s);
 491 }
 492
 493 static int
 494 lat_print_generic(struct trace_seq *s, struct trace_entry *entry, int cpu)
 495 {
 496         char comm[TASK_COMM_LEN];
 497
 498         trace_find_cmdline(entry->pid, comm);
 499
 500         trace_seq_printf(s, "%8.8s-%-5d %3d",
 501                          comm, entry->pid, cpu);
 502
 503         return trace_print_lat_fmt(s, entry);
 504 }
 505
 506 #undef MARK
 507 #define MARK(v, s) {.val = v, .sym = s}
 508 /* trace overhead mark */
 509 static const struct trace_mark {
 510         unsigned long long      val; /* unit: nsec */
 511         char                    sym;
 512 } mark[] = {
 513         MARK(1000000000ULL      , '$'), /* 1 sec */
 514         MARK(100000000ULL       , '@'), /* 100 msec */
 515         MARK(10000000ULL        , '*'), /* 10 msec */
 516         MARK(1000000ULL         , '#'), /* 1000 usecs */
 517         MARK(100000ULL          , '!'), /* 100 usecs */
 518         MARK(10000ULL           , '+'), /* 10 usecs */
 519 };
 520 #undef MARK
 521
 522 char trace_find_mark(unsigned long long d)
 523 {
 524         int i;
 525         int size = ARRAY_SIZE(mark);
 526
 527         for (i = 0; i < size; i++) {
 528                 if (d > mark[i].val)
 529                         break;
 530         }
 531
 532         return (i == size) ? ' ' : mark[i].sym;
 533 }
 534
 535 static int
 536 lat_print_timestamp(struct trace_iterator *iter, u64 next_ts)
 537 {
 538         struct trace_array *tr = iter->tr;
 539         unsigned long verbose = tr->trace_flags & TRACE_ITER_VERBOSE;
 540         unsigned long in_ns = iter->iter_flags & TRACE_FILE_TIME_IN_NS;
 541         unsigned long long abs_ts = iter->ts - iter->array_buffer->time_start;
 542         unsigned long long rel_ts = next_ts - iter->ts;
 543         struct trace_seq *s = &iter->seq;
 544
 545         if (in_ns) {
 546                 abs_ts = ns2usecs(abs_ts);
 547                 rel_ts = ns2usecs(rel_ts);
 548         }
 549
 550         if (verbose && in_ns) {
 551                 unsigned long abs_usec = do_div(abs_ts, USEC_PER_MSEC);
 552                 unsigned long abs_msec = (unsigned long)abs_ts;
 553                 unsigned long rel_usec = do_div(rel_ts, USEC_PER_MSEC);
 554                 unsigned long rel_msec = (unsigned long)rel_ts;
 555
 556                 trace_seq_printf(
 557                         s, "[%08llx] %ld.%03ldms (+%ld.%03ldms): ",
 558                         ns2usecs(iter->ts),
 559                         abs_msec, abs_usec,
 560                         rel_msec, rel_usec);
 561
 562         } else if (verbose && !in_ns) {
 563                 trace_seq_printf(
 564                         s, "[%016llx] %lld (+%lld): ",
 565                         iter->ts, abs_ts, rel_ts);
 566
 567         } else if (!verbose && in_ns) {
 568                 trace_seq_printf(
 569                         s, " %4lldus%c: ",
 570                         abs_ts,
 571                         trace_find_mark(rel_ts * NSEC_PER_USEC));
 572
 573         } else { /* !verbose && !in_ns */
 574                 trace_seq_printf(s, " %4lld: ", abs_ts);
 575         }
 576
 577         return !trace_seq_has_overflowed(s);
 578 }
 579
 580 int trace_print_context(struct trace_iterator *iter)
 581 {
 582         struct trace_array *tr = iter->tr;
 583         struct trace_seq *s = &iter->seq;
 584         struct trace_entry *entry = iter->ent;
 585         unsigned long long t;
 586         unsigned long secs, usec_rem;
 587         char comm[TASK_COMM_LEN];
 588
 589         trace_find_cmdline(entry->pid, comm);
 590
 591         trace_seq_printf(s, "%16s-%-5d ", comm, entry->pid);
 592
 593         if (tr->trace_flags & TRACE_ITER_RECORD_TGID) {
 594                 unsigned int tgid = trace_find_tgid(entry->pid);
 595
 596                 if (!tgid)
 597                         trace_seq_printf(s, "(-----) ");
 598                 else
 599                         trace_seq_printf(s, "(%5d) ", tgid);
 600         }
 601
 602         trace_seq_printf(s, "[%03d] ", iter->cpu);
 603
 604         if (tr->trace_flags & TRACE_ITER_IRQ_INFO)
 605                 trace_print_lat_fmt(s, entry);
 606
 607         if (iter->iter_flags & TRACE_FILE_TIME_IN_NS) {
 608                 t = ns2usecs(iter->ts);
 609                 usec_rem = do_div(t, USEC_PER_SEC);
 610                 secs = (unsigned long)t;
 611                 trace_seq_printf(s, " %5lu.%06lu: ", secs, usec_rem);
 612         } else
 613                 trace_seq_printf(s, " %12llu: ", iter->ts);
 614
 615         return !trace_seq_has_overflowed(s);
 616 }
 617
 618 int trace_print_lat_context(struct trace_iterator *iter)
 619 {
 620         struct trace_array *tr = iter->tr;
 621         /* trace_find_next_entry will reset ent_size */
 622         int ent_size = iter->ent_size;
 623         struct trace_seq *s = &iter->seq;
 624         u64 next_ts;
 625         struct trace_entry *entry = iter->ent,
 626                            *next_entry = trace_find_next_entry(iter, NULL,
 627                                                                &next_ts);
 628         unsigned long verbose = (tr->trace_flags & TRACE_ITER_VERBOSE);
 629
 630         /* Restore the original ent_size */
 631         iter->ent_size = ent_size;
 632
 633         if (!next_entry)
 634                 next_ts = iter->ts;
 635
 636         if (verbose) {
 637                 char comm[TASK_COMM_LEN];
 638
 639                 trace_find_cmdline(entry->pid, comm);
 640
 641                 trace_seq_printf(
 642                         s, "%16s %5d %3d %d %08x %08lx ",
 643                         comm, entry->pid, iter->cpu, entry->flags,
 644                         entry->preempt_count, iter->idx);
 645         } else {
 646                 lat_print_generic(s, entry, iter->cpu);
 647         }
 648
 649         lat_print_timestamp(iter, next_ts);
 650
 651         return !trace_seq_has_overflowed(s);
 652 }
 653
 654 /**
 655  * ftrace_find_event - find a registered event
 656  * @type: the type of event to look for
 657  *
 658  * Returns an event of type @type otherwise NULL
 659  * Called with trace_event_read_lock() held.
 660  */
 661 struct trace_event *ftrace_find_event(int type)
 662 {
 663         struct trace_event *event;
 664         unsigned key;
 665
 666         key = type & (EVENT_HASHSIZE - 1);
 667
 668         hlist_for_each_entry(event, &event_hash[key], node) {
 669                 if (event->type == type)
 670                         return event;
 671         }
 672
 673         return NULL;
 674 }
 675
 676 static LIST_HEAD(ftrace_event_list);
 677
 678 static int trace_search_list(struct list_head **list)
 679 {
 680         struct trace_event *e;
 681         int last = __TRACE_LAST_TYPE;
 682
 683         if (list_empty(&ftrace_event_list)) {
 684                 *list = &ftrace_event_list;
 685                 return last + 1;
 686         }
 687
 688         /*
 689          * We used up all possible max events,
 690          * lets see if somebody freed one.
 691          */
 692         list_for_each_entry(e, &ftrace_event_list, list) {
 693                 if (e->type != last + 1)
 694                         break;
 695                 last++;
 696         }
 697
 698         /* Did we used up all 65 thousand events??? */
 699         if ((last + 1) > TRACE_EVENT_TYPE_MAX)
 700                 return 0;
 701
 702         *list = &e->list;
 703         return last + 1;
 704 }
 705
 706 void trace_event_read_lock(void)
 707 {
 708         down_read(&trace_event_sem);
 709 }
 710
 711 void trace_event_read_unlock(void)
 712 {
 713         up_read(&trace_event_sem);
 714 }
 715
 716 /**
 717  * register_trace_event - register output for an event type
 718  * @event: the event type to register
 719  *
 720  * Event types are stored in a hash and this hash is used to
 721  * find a way to print an event. If the @event->type is set
 722  * then it will use that type, otherwise it will assign a
 723  * type to use.
 724  *
 725  * If you assign your own type, please make sure it is added
 726  * to the trace_type enum in trace.h, to avoid collisions
 727  * with the dynamic types.
 728  *
 729  * Returns the event type number or zero on error.
 730  */
 731 int register_trace_event(struct trace_event *event)
 732 {
 733         unsigned key;
 734         int ret = 0;
 735
 736         down_write(&trace_event_sem);
 737
 738         if (WARN_ON(!event))
 739                 goto out;
 740
 741         if (WARN_ON(!event->funcs))
 742                 goto out;
 743
 744         INIT_LIST_HEAD(&event->list);
 745
 746         if (!event->type) {
 747                 struct list_head *list = NULL;
 748
 749                 if (next_event_type > TRACE_EVENT_TYPE_MAX) {
 750
 751                         event->type = trace_search_list(&list);
 752                         if (!event->type)
 753                                 goto out;
 754
 755                 } else {
 756
 757                         event->type = next_event_type++;
 758                         list = &ftrace_event_list;
 759                 }
 760
 761                 if (WARN_ON(ftrace_find_event(event->type)))
 762                         goto out;
 763
 764                 list_add_tail(&event->list, list);
 765
 766         } else if (event->type > __TRACE_LAST_TYPE) {
 767                 printk(KERN_WARNING "Need to add type to trace.h\n");
 768                 WARN_ON(1);
 769                 goto out;
 770         } else {
 771                 /* Is this event already used */
 772                 if (ftrace_find_event(event->type))
 773                         goto out;
 774         }
 775
 776         if (event->funcs->trace == NULL)
 777                 event->funcs->trace = trace_nop_print;
 778         if (event->funcs->raw == NULL)
 779                 event->funcs->raw = trace_nop_print;
 780         if (event->funcs->hex == NULL)
 781                 event->funcs->hex = trace_nop_print;
 782         if (event->funcs->binary == NULL)
 783                 event->funcs->binary = trace_nop_print;
 784
 785         key = event->type & (EVENT_HASHSIZE - 1);
 786
 787         hlist_add_head(&event->node, &event_hash[key]);
 788
 789         ret = event->type;
 790  out:
 791         up_write(&trace_event_sem);
 792
 793         return ret;
 794 }
 795 EXPORT_SYMBOL_GPL(register_trace_event);
 796
 797 /*
 798  * Used by module code with the trace_event_sem held for write.
 799  */
 800 int __unregister_trace_event(struct trace_event *event)
 801 {
 802         hlist_del(&event->node);
 803         list_del(&event->list);
 804         return 0;
 805 }
 806
 807 /**
 808  * unregister_trace_event - remove a no longer used event
 809  * @event: the event to remove
 810  */
 811 int unregister_trace_event(struct trace_event *event)
 812 {
 813         down_write(&trace_event_sem);
 814         __unregister_trace_event(event);
 815         up_write(&trace_event_sem);
 816
 817         return 0;
 818 }
 819 EXPORT_SYMBOL_GPL(unregister_trace_event);
 820
 821 /*
 822  * Standard events
 823  */
 824
 825 enum print_line_t trace_nop_print(struct trace_iterator *iter, int flags,
 826                                   struct trace_event *event)
 827 {
 828         trace_seq_printf(&iter->seq, "type: %d\n", iter->ent->type);
 829
 830         return trace_handle_return(&iter->seq);
 831 }
 832
 833 /* TRACE_FN */
 834 static enum print_line_t trace_fn_trace(struct trace_iterator *iter, int flags,
 835                                         struct trace_event *event)
 836 {
 837         struct ftrace_entry *field;
 838         struct trace_seq *s = &iter->seq;
 839
 840         trace_assign_type(field, iter->ent);
 841
 842         seq_print_ip_sym(s, field->ip, flags);
 843
 844         if ((flags & TRACE_ITER_PRINT_PARENT) && field->parent_ip) {
 845                 trace_seq_puts(s, " <-");
 846                 seq_print_ip_sym(s, field->parent_ip, flags);
 847         }
 848
 849         trace_seq_putc(s, '\n');
 850
 851         return trace_handle_return(s);
 852 }
 853
 854 static enum print_line_t trace_fn_raw(struct trace_iterator *iter, int flags,
 855                                       struct trace_event *event)
 856 {
 857         struct ftrace_entry *field;
 858
 859         trace_assign_type(field, iter->ent);
 860
 861         trace_seq_printf(&iter->seq, "%lx %lx\n",
 862                          field->ip,
 863                          field->parent_ip);
 864
 865         return trace_handle_return(&iter->seq);
 866 }
 867
 868 static enum print_line_t trace_fn_hex(struct trace_iterator *iter, int flags,
 869                                       struct trace_event *event)
 870 {
 871         struct ftrace_entry *field;
 872         struct trace_seq *s = &iter->seq;
 873
 874         trace_assign_type(field, iter->ent);
 875
 876         SEQ_PUT_HEX_FIELD(s, field->ip);
 877         SEQ_PUT_HEX_FIELD(s, field->parent_ip);
 878
 879         return trace_handle_return(s);
 880 }
 881
 882 static enum print_line_t trace_fn_bin(struct trace_iterator *iter, int flags,
 883                                       struct trace_event *event)
 884 {
 885         struct ftrace_entry *field;
 886         struct trace_seq *s = &iter->seq;
 887
 888         trace_assign_type(field, iter->ent);
 889
 890         SEQ_PUT_FIELD(s, field->ip);
 891         SEQ_PUT_FIELD(s, field->parent_ip);
 892
 893         return trace_handle_return(s);
 894 }
 895
 896 static struct trace_event_functions trace_fn_funcs = {
 897         .trace          = trace_fn_trace,
 898         .raw            = trace_fn_raw,
 899         .hex            = trace_fn_hex,
 900         .binary         = trace_fn_bin,
 901 };
 902
 903 static struct trace_event trace_fn_event = {
 904         .type           = TRACE_FN,
 905         .funcs          = &trace_fn_funcs,
 906 };
 907
 908 /* TRACE_CTX an TRACE_WAKE */
 909 static enum print_line_t trace_ctxwake_print(struct trace_iterator *iter,
 910                                              char *delim)
 911 {
 912         struct ctx_switch_entry *field;
 913         char comm[TASK_COMM_LEN];
 914         int S, T;
 915
 916
 917         trace_assign_type(field, iter->ent);
 918
 919         T = task_index_to_char(field->next_state);
 920         S = task_index_to_char(field->prev_state);
 921         trace_find_cmdline(field->next_pid, comm);
 922         trace_seq_printf(&iter->seq,
 923                          " %5d:%3d:%c %s [%03d] %5d:%3d:%c %s\n",
 924                          field->prev_pid,
 925                          field->prev_prio,
 926                          S, delim,
 927                          field->next_cpu,
 928                          field->next_pid,
 929                          field->next_prio,
 930                          T, comm);
 931
 932         return trace_handle_return(&iter->seq);
 933 }
 934
 935 static enum print_line_t trace_ctx_print(struct trace_iterator *iter, int flags,
 936                                          struct trace_event *event)
 937 {
 938         return trace_ctxwake_print(iter, "==>");
 939 }
 940
 941 static enum print_line_t trace_wake_print(struct trace_iterator *iter,
 942                                           int flags, struct trace_event *event)
 943 {
 944         return trace_ctxwake_print(iter, "  +");
 945 }
 946
 947 static int trace_ctxwake_raw(struct trace_iterator *iter, char S)
 948 {
 949         struct ctx_switch_entry *field;
 950         int T;
 951
 952         trace_assign_type(field, iter->ent);
 953
 954         if (!S)
 955                 S = task_index_to_char(field->prev_state);
 956         T = task_index_to_char(field->next_state);
 957         trace_seq_printf(&iter->seq, "%d %d %c %d %d %d %c\n",
 958                          field->prev_pid,
 959                          field->prev_prio,
 960                          S,
 961                          field->next_cpu,
 962                          field->next_pid,
 963                          field->next_prio,
 964                          T);
 965
 966         return trace_handle_return(&iter->seq);
 967 }
 968
 969 static enum print_line_t trace_ctx_raw(struct trace_iterator *iter, int flags,
 970                                        struct trace_event *event)
 971 {
 972         return trace_ctxwake_raw(iter, 0);
 973 }
 974
 975 static enum print_line_t trace_wake_raw(struct trace_iterator *iter, int flags,
 976                                         struct trace_event *event)
 977 {
 978         return trace_ctxwake_raw(iter, '+');
 979 }
 980
 981
 982 static int trace_ctxwake_hex(struct trace_iterator *iter, char S)
 983 {
 984         struct ctx_switch_entry *field;
 985         struct trace_seq *s = &iter->seq;
 986         int T;
 987
 988         trace_assign_type(field, iter->ent);
 989
 990         if (!S)
 991                 S = task_index_to_char(field->prev_state);
 992         T = task_index_to_char(field->next_state);
 993
 994         SEQ_PUT_HEX_FIELD(s, field->prev_pid);
 995         SEQ_PUT_HEX_FIELD(s, field->prev_prio);
 996         SEQ_PUT_HEX_FIELD(s, S);
 997         SEQ_PUT_HEX_FIELD(s, field->next_cpu);
 998         SEQ_PUT_HEX_FIELD(s, field->next_pid);
 999         SEQ_PUT_HEX_FIELD(s, field->next_prio);
1000         SEQ_PUT_HEX_FIELD(s, T);
1001
1002         return trace_handle_return(s);
1003 }
1004
1005 static enum print_line_t trace_ctx_hex(struct trace_iterator *iter, int flags,
1006                                        struct trace_event *event)
1007 {
1008         return trace_ctxwake_hex(iter, 0);
1009 }
1010
1011 static enum print_line_t trace_wake_hex(struct trace_iterator *iter, int flags,
1012                                         struct trace_event *event)
1013 {
1014         return trace_ctxwake_hex(iter, '+');
1015 }
1016
1017 static enum print_line_t trace_ctxwake_bin(struct trace_iterator *iter,
1018                                            int flags, struct trace_event *event)
1019 {
1020         struct ctx_switch_entry *field;
1021         struct trace_seq *s = &iter->seq;
1022
1023         trace_assign_type(field, iter->ent);
1024
1025         SEQ_PUT_FIELD(s, field->prev_pid);
1026         SEQ_PUT_FIELD(s, field->prev_prio);
1027         SEQ_PUT_FIELD(s, field->prev_state);
1028         SEQ_PUT_FIELD(s, field->next_cpu);
1029         SEQ_PUT_FIELD(s, field->next_pid);
1030         SEQ_PUT_FIELD(s, field->next_prio);
1031         SEQ_PUT_FIELD(s, field->next_state);
1032
1033         return trace_handle_return(s);
1034 }
1035
1036 static struct trace_event_functions trace_ctx_funcs = {
1037         .trace          = trace_ctx_print,
1038         .raw            = trace_ctx_raw,
1039         .hex            = trace_ctx_hex,
1040         .binary         = trace_ctxwake_bin,
1041 };
1042
1043 static struct trace_event trace_ctx_event = {
1044         .type           = TRACE_CTX,
1045         .funcs          = &trace_ctx_funcs,
1046 };
1047
1048 static struct trace_event_functions trace_wake_funcs = {
1049         .trace          = trace_wake_print,
1050         .raw            = trace_wake_raw,
1051         .hex            = trace_wake_hex,
1052         .binary         = trace_ctxwake_bin,
1053 };
1054
1055 static struct trace_event trace_wake_event = {
1056         .type           = TRACE_WAKE,
1057         .funcs          = &trace_wake_funcs,
1058 };
1059
1060 /* TRACE_STACK */
1061
1062 static enum print_line_t trace_stack_print(struct trace_iterator *iter,
1063                                            int flags, struct trace_event *event)
1064 {
1065         struct stack_entry *field;
1066         struct trace_seq *s = &iter->seq;
1067         unsigned long *p;
1068         unsigned long *end;
1069
1070         trace_assign_type(field, iter->ent);
1071         end = (unsigned long *)((long)iter->ent + iter->ent_size);
1072
1073         trace_seq_puts(s, "<stack trace>\n");
1074
1075         for (p = field->caller; p && p < end && *p != ULONG_MAX; p++) {
1076
1077                 if (trace_seq_has_overflowed(s))
1078                         break;
1079
1080                 trace_seq_puts(s, " => ");
1081                 seq_print_ip_sym(s, *p, flags);
1082                 trace_seq_putc(s, '\n');
1083         }
1084
1085         return trace_handle_return(s);
1086 }
1087
1088 static struct trace_event_functions trace_stack_funcs = {
1089         .trace          = trace_stack_print,
1090 };
1091
1092 static struct trace_event trace_stack_event = {
1093         .type           = TRACE_STACK,
1094         .funcs          = &trace_stack_funcs,
1095 };
1096
1097 /* TRACE_USER_STACK */
1098 static enum print_line_t trace_user_stack_print(struct trace_iterator *iter,
1099                                                 int flags, struct trace_event *event)
1100 {
1101         struct trace_array *tr = iter->tr;
1102         struct userstack_entry *field;
1103         struct trace_seq *s = &iter->seq;
1104         struct mm_struct *mm = NULL;
1105         unsigned int i;
1106
1107         trace_assign_type(field, iter->ent);
1108
1109         trace_seq_puts(s, "<user stack trace>\n");
1110
1111         if (tr->trace_flags & TRACE_ITER_SYM_USEROBJ) {
1112                 struct task_struct *task;
1113                 /*
1114                  * we do the lookup on the thread group leader,
1115                  * since individual threads might have already quit!
1116                  */
1117                 rcu_read_lock();
1118                 task = find_task_by_vpid(field->tgid);
1119                 if (task)
1120                         mm = get_task_mm(task);
1121                 rcu_read_unlock();
1122         }
1123
1124         for (i = 0; i < FTRACE_STACK_ENTRIES; i++) {
1125                 unsigned long ip = field->caller[i];
1126
1127                 if (!ip || trace_seq_has_overflowed(s))
1128                         break;
1129
1130                 trace_seq_puts(s, " => ");
1131                 seq_print_user_ip(s, mm, ip, flags);
1132                 trace_seq_putc(s, '\n');
1133         }
1134
1135         if (mm)
1136                 mmput(mm);
1137
1138         return trace_handle_return(s);
1139 }
1140
1141 static struct trace_event_functions trace_user_stack_funcs = {
1142         .trace          = trace_user_stack_print,
1143 };
1144
1145 static struct trace_event trace_user_stack_event = {
1146         .type           = TRACE_USER_STACK,
1147         .funcs          = &trace_user_stack_funcs,
1148 };
1149
1150 /* TRACE_HWLAT */
1151 static enum print_line_t
1152 trace_hwlat_print(struct trace_iterator *iter, int flags,
1153                   struct trace_event *event)
1154 {
1155         struct trace_entry *entry = iter->ent;
1156         struct trace_seq *s = &iter->seq;
1157         struct hwlat_entry *field;
1158
1159         trace_assign_type(field, entry);
1160
1161         trace_seq_printf(s, "#%-5u inner/outer(us): %4llu/%-5llu ts:%lld.%09ld",
1162                          field->seqnum,
1163                          field->duration,
1164                          field->outer_duration,
1165                          (long long)field->timestamp.tv_sec,
1166                          field->timestamp.tv_nsec);
1167
1168         if (field->nmi_count) {
1169                 /*
1170                  * The generic sched_clock() is not NMI safe, thus
1171                  * we only record the count and not the time.
1172                  */
1173                 if (!IS_ENABLED(CONFIG_GENERIC_SCHED_CLOCK))
1174                         trace_seq_printf(s, " nmi-total:%llu",
1175                                          field->nmi_total_ts);
1176                 trace_seq_printf(s, " nmi-count:%u",
1177                                  field->nmi_count);
1178         }
1179
1180         trace_seq_putc(s, '\n');
1181
1182         return trace_handle_return(s);
1183 }
1184
1185
1186 static enum print_line_t
1187 trace_hwlat_raw(struct trace_iterator *iter, int flags,
1188                 struct trace_event *event)
1189 {
1190         struct hwlat_entry *field;
1191         struct trace_seq *s = &iter->seq;
1192
1193         trace_assign_type(field, iter->ent);
1194
1195         trace_seq_printf(s, "%llu %lld %lld %09ld %u\n",
1196                          field->duration,
1197                          field->outer_duration,
1198                          (long long)field->timestamp.tv_sec,
1199                          field->timestamp.tv_nsec,
1200                          field->seqnum);
1201
1202         return trace_handle_return(s);
1203 }
1204
1205 static struct trace_event_functions trace_hwlat_funcs = {
1206         .trace          = trace_hwlat_print,
1207         .raw            = trace_hwlat_raw,
1208 };
1209
1210 static struct trace_event trace_hwlat_event = {
1211         .type           = TRACE_HWLAT,
1212         .funcs          = &trace_hwlat_funcs,
1213 };
1214
1215 /* TRACE_BPUTS */
1216 static enum print_line_t
1217 trace_bputs_print(struct trace_iterator *iter, int flags,
1218                    struct trace_event *event)
1219 {
1220         struct trace_entry *entry = iter->ent;
1221         struct trace_seq *s = &iter->seq;
1222         struct bputs_entry *field;
1223
1224         trace_assign_type(field, entry);
1225
1226         seq_print_ip_sym(s, field->ip, flags);
1227         trace_seq_puts(s, ": ");
1228         trace_seq_puts(s, field->str);
1229
1230         return trace_handle_return(s);
1231 }
1232
1233
1234 static enum print_line_t
1235 trace_bputs_raw(struct trace_iterator *iter, int flags,
1236                 struct trace_event *event)
1237 {
1238         struct bputs_entry *field;
1239         struct trace_seq *s = &iter->seq;
1240
1241         trace_assign_type(field, iter->ent);
1242
1243         trace_seq_printf(s, ": %lx : ", field->ip);
1244         trace_seq_puts(s, field->str);
1245
1246         return trace_handle_return(s);
1247 }
1248
1249 static struct trace_event_functions trace_bputs_funcs = {
1250         .trace          = trace_bputs_print,
1251         .raw            = trace_bputs_raw,
1252 };
1253
1254 static struct trace_event trace_bputs_event = {
1255         .type           = TRACE_BPUTS,
1256         .funcs          = &trace_bputs_funcs,
1257 };
1258
1259 /* TRACE_BPRINT */
1260 static enum print_line_t
1261 trace_bprint_print(struct trace_iterator *iter, int flags,
1262                    struct trace_event *event)
1263 {
1264         struct trace_entry *entry = iter->ent;
1265         struct trace_seq *s = &iter->seq;
1266         struct bprint_entry *field;
1267
1268         trace_assign_type(field, entry);
1269
1270         seq_print_ip_sym(s, field->ip, flags);
1271         trace_seq_puts(s, ": ");
1272         trace_seq_bprintf(s, field->fmt, field->buf);
1273
1274         return trace_handle_return(s);
1275 }
1276
1277
1278 static enum print_line_t
1279 trace_bprint_raw(struct trace_iterator *iter, int flags,
1280                  struct trace_event *event)
1281 {
1282         struct bprint_entry *field;
1283         struct trace_seq *s = &iter->seq;
1284
1285         trace_assign_type(field, iter->ent);
1286
1287         trace_seq_printf(s, ": %lx : ", field->ip);
1288         trace_seq_bprintf(s, field->fmt, field->buf);
1289
1290         return trace_handle_return(s);
1291 }
1292
1293 static struct trace_event_functions trace_bprint_funcs = {
1294         .trace          = trace_bprint_print,
1295         .raw            = trace_bprint_raw,
1296 };
1297
1298 static struct trace_event trace_bprint_event = {
1299         .type           = TRACE_BPRINT,
1300         .funcs          = &trace_bprint_funcs,
1301 };
1302
1303 /* TRACE_PRINT */
1304 static enum print_line_t trace_print_print(struct trace_iterator *iter,
1305                                            int flags, struct trace_event *event)
1306 {
1307         struct print_entry *field;
1308         struct trace_seq *s = &iter->seq;
1309
1310         trace_assign_type(field, iter->ent);
1311
1312         seq_print_ip_sym(s, field->ip, flags);
1313         trace_seq_printf(s, ": %s", field->buf);
1314
1315         return trace_handle_return(s);
1316 }
1317
1318 static enum print_line_t trace_print_raw(struct trace_iterator *iter, int flags,
1319                                          struct trace_event *event)
1320 {
1321         struct print_entry *field;
1322
1323         trace_assign_type(field, iter->ent);
1324
1325         trace_seq_printf(&iter->seq, "# %lx %s", field->ip, field->buf);
1326
1327         return trace_handle_return(&iter->seq);
1328 }
1329
1330 static struct trace_event_functions trace_print_funcs = {
1331         .trace          = trace_print_print,
1332         .raw            = trace_print_raw,
1333 };
1334
1335 static struct trace_event trace_print_event = {
1336         .type           = TRACE_PRINT,
1337         .funcs          = &trace_print_funcs,
1338 };
1339
1340 static enum print_line_t trace_raw_data(struct trace_iterator *iter, int flags,
1341                                          struct trace_event *event)
1342 {
1343         struct raw_data_entry *field;
1344         int i;
1345
1346         trace_assign_type(field, iter->ent);
1347
1348         trace_seq_printf(&iter->seq, "# %x buf:", field->id);
1349
1350         for (i = 0; i < iter->ent_size - offsetof(struct raw_data_entry, buf); i++)
1351                 trace_seq_printf(&iter->seq, " %02x",
1352                                  (unsigned char)field->buf[i]);
1353
1354         trace_seq_putc(&iter->seq, '\n');
1355
1356         return trace_handle_return(&iter->seq);
1357 }
1358
1359 static struct trace_event_functions trace_raw_data_funcs = {
1360         .trace          = trace_raw_data,
1361         .raw            = trace_raw_data,
1362 };
1363
1364 static struct trace_event trace_raw_data_event = {
1365         .type           = TRACE_RAW_DATA,
1366         .funcs          = &trace_raw_data_funcs,
1367 };
1368
1369
1370 static struct trace_event *events[] __initdata = {
1371         &trace_fn_event,
1372         &trace_ctx_event,
1373         &trace_wake_event,
1374         &trace_stack_event,
1375         &trace_user_stack_event,
1376         &trace_bputs_event,
1377         &trace_bprint_event,
1378         &trace_print_event,
1379         &trace_hwlat_event,
1380         &trace_raw_data_event,
1381         NULL
1382 };
1383
1384 __init static int init_events(void)
1385 {
1386         struct trace_event *event;
1387         int i, ret;
1388
1389         for (i = 0; events[i]; i++) {
1390                 event = events[i];
1391
1392                 ret = register_trace_event(event);
1393                 if (!ret) {
1394                         printk(KERN_WARNING "event %d failed to register\n",
1395                                event->type);
1396                         WARN_ON_ONCE(1);
1397                 }
1398         }
1399
1400         return 0;
1401 }
1402 early_initcall(init_events);