kernel/trace/trace_output.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * trace_output.c
   4  *
   5  * Copyright (C) 2008 Red Hat Inc, Steven Rostedt <srostedt@redhat.com>
   6  *
   7  */
   8 #include <linux/module.h>
   9 #include <linux/mutex.h>
  10 #include <linux/ftrace.h>
  11 #include <linux/sched/clock.h>
  12 #include <linux/sched/mm.h>
  13
  14 #include "trace_output.h"
  15
  16 /* must be a power of 2 */
  17 #define EVENT_HASHSIZE  128
  18
  19 DECLARE_RWSEM(trace_event_sem);
  20
  21 static struct hlist_head event_hash[EVENT_HASHSIZE] __read_mostly;
  22
  23 static int next_event_type = __TRACE_LAST_TYPE;
  24
  25 enum print_line_t trace_print_bputs_msg_only(struct trace_iterator *iter)
  26 {
  27         struct trace_seq *s = &iter->seq;
  28         struct trace_entry *entry = iter->ent;
  29         struct bputs_entry *field;
  30
  31         trace_assign_type(field, entry);
  32
  33         trace_seq_puts(s, field->str);
  34
  35         return trace_handle_return(s);
  36 }
  37
  38 enum print_line_t trace_print_bprintk_msg_only(struct trace_iterator *iter)
  39 {
  40         struct trace_seq *s = &iter->seq;
  41         struct trace_entry *entry = iter->ent;
  42         struct bprint_entry *field;
  43
  44         trace_assign_type(field, entry);
  45
  46         trace_seq_bprintf(s, field->fmt, field->buf);
  47
  48         return trace_handle_return(s);
  49 }
  50
  51 enum print_line_t trace_print_printk_msg_only(struct trace_iterator *iter)
  52 {
  53         struct trace_seq *s = &iter->seq;
  54         struct trace_entry *entry = iter->ent;
  55         struct print_entry *field;
  56
  57         trace_assign_type(field, entry);
  58
  59         trace_seq_puts(s, field->buf);
  60
  61         return trace_handle_return(s);
  62 }
  63
  64 const char *
  65 trace_print_flags_seq(struct trace_seq *p, const char *delim,
  66                       unsigned long flags,
  67                       const struct trace_print_flags *flag_array)
  68 {
  69         unsigned long mask;
  70         const char *str;
  71         const char *ret = trace_seq_buffer_ptr(p);
  72         int i, first = 1;
  73
  74         for (i = 0;  flag_array[i].name && flags; i++) {
  75
  76                 mask = flag_array[i].mask;
  77                 if ((flags & mask) != mask)
  78                         continue;
  79
  80                 str = flag_array[i].name;
  81                 flags &= ~mask;
  82                 if (!first && delim)
  83                         trace_seq_puts(p, delim);
  84                 else
  85                         first = 0;
  86                 trace_seq_puts(p, str);
  87         }
  88
  89         /* check for left over flags */
  90         if (flags) {
  91                 if (!first && delim)
  92                         trace_seq_puts(p, delim);
  93                 trace_seq_printf(p, "0x%lx", flags);
  94         }
  95
  96         trace_seq_putc(p, 0);
  97
  98         return ret;
  99 }
 100 EXPORT_SYMBOL(trace_print_flags_seq);
 101
 102 const char *
 103 trace_print_symbols_seq(struct trace_seq *p, unsigned long val,
 104                         const struct trace_print_flags *symbol_array)
 105 {
 106         int i;
 107         const char *ret = trace_seq_buffer_ptr(p);
 108
 109         for (i = 0;  symbol_array[i].name; i++) {
 110
 111                 if (val != symbol_array[i].mask)
 112                         continue;
 113
 114                 trace_seq_puts(p, symbol_array[i].name);
 115                 break;
 116         }
 117
 118         if (ret == (const char *)(trace_seq_buffer_ptr(p)))
 119                 trace_seq_printf(p, "0x%lx", val);
 120
 121         trace_seq_putc(p, 0);
 122
 123         return ret;
 124 }
 125 EXPORT_SYMBOL(trace_print_symbols_seq);
 126
 127 #if BITS_PER_LONG == 32
 128 const char *
 129 trace_print_flags_seq_u64(struct trace_seq *p, const char *delim,
 130                       unsigned long long flags,
 131                       const struct trace_print_flags_u64 *flag_array)
 132 {
 133         unsigned long long mask;
 134         const char *str;
 135         const char *ret = trace_seq_buffer_ptr(p);
 136         int i, first = 1;
 137
 138         for (i = 0;  flag_array[i].name && flags; i++) {
 139
 140                 mask = flag_array[i].mask;
 141                 if ((flags & mask) != mask)
 142                         continue;
 143
 144                 str = flag_array[i].name;
 145                 flags &= ~mask;
 146                 if (!first && delim)
 147                         trace_seq_puts(p, delim);
 148                 else
 149                         first = 0;
 150                 trace_seq_puts(p, str);
 151         }
 152
 153         /* check for left over flags */
 154         if (flags) {
 155                 if (!first && delim)
 156                         trace_seq_puts(p, delim);
 157                 trace_seq_printf(p, "0x%llx", flags);
 158         }
 159
 160         trace_seq_putc(p, 0);
 161
 162         return ret;
 163 }
 164 EXPORT_SYMBOL(trace_print_flags_seq_u64);
 165
 166 const char *
 167 trace_print_symbols_seq_u64(struct trace_seq *p, unsigned long long val,
 168                          const struct trace_print_flags_u64 *symbol_array)
 169 {
 170         int i;
 171         const char *ret = trace_seq_buffer_ptr(p);
 172
 173         for (i = 0;  symbol_array[i].name; i++) {
 174
 175                 if (val != symbol_array[i].mask)
 176                         continue;
 177
 178                 trace_seq_puts(p, symbol_array[i].name);
 179                 break;
 180         }
 181
 182         if (ret == (const char *)(trace_seq_buffer_ptr(p)))
 183                 trace_seq_printf(p, "0x%llx", val);
 184
 185         trace_seq_putc(p, 0);
 186
 187         return ret;
 188 }
 189 EXPORT_SYMBOL(trace_print_symbols_seq_u64);
 190 #endif
 191
 192 const char *
 193 trace_print_bitmask_seq(struct trace_seq *p, void *bitmask_ptr,
 194                         unsigned int bitmask_size)
 195 {
 196         const char *ret = trace_seq_buffer_ptr(p);
 197
 198         trace_seq_bitmask(p, bitmask_ptr, bitmask_size * 8);
 199         trace_seq_putc(p, 0);
 200
 201         return ret;
 202 }
 203 EXPORT_SYMBOL_GPL(trace_print_bitmask_seq);
 204
 205 /**
 206  * trace_print_hex_seq - print buffer as hex sequence
 207  * @p: trace seq struct to write to
 208  * @buf: The buffer to print
 209  * @buf_len: Length of @buf in bytes
 210  * @concatenate: Print @buf as single hex string or with spacing
 211  *
 212  * Prints the passed buffer as a hex sequence either as a whole,
 213  * single hex string if @concatenate is true or with spacing after
 214  * each byte in case @concatenate is false.
 215  */
 216 const char *
 217 trace_print_hex_seq(struct trace_seq *p, const unsigned char *buf, int buf_len,
 218                     bool concatenate)
 219 {
 220         int i;
 221         const char *ret = trace_seq_buffer_ptr(p);
 222         const char *fmt = concatenate ? "%*phN" : "%*ph";
 223
 224         for (i = 0; i < buf_len; i += 16)
 225                 trace_seq_printf(p, fmt, min(buf_len - i, 16), &buf[i]);
 226         trace_seq_putc(p, 0);
 227
 228         return ret;
 229 }
 230 EXPORT_SYMBOL(trace_print_hex_seq);
 231
 232 const char *
 233 trace_print_array_seq(struct trace_seq *p, const void *buf, int count,
 234                       size_t el_size)
 235 {
 236         const char *ret = trace_seq_buffer_ptr(p);
 237         const char *prefix = "";
 238         void *ptr = (void *)buf;
 239         size_t buf_len = count * el_size;
 240
 241         trace_seq_putc(p, '{');
 242
 243         while (ptr < buf + buf_len) {
 244                 switch (el_size) {
 245                 case 1:
 246                         trace_seq_printf(p, "%s0x%x", prefix,
 247                                          *(u8 *)ptr);
 248                         break;
 249                 case 2:
 250                         trace_seq_printf(p, "%s0x%x", prefix,
 251                                          *(u16 *)ptr);
 252                         break;
 253                 case 4:
 254                         trace_seq_printf(p, "%s0x%x", prefix,
 255                                          *(u32 *)ptr);
 256                         break;
 257                 case 8:
 258                         trace_seq_printf(p, "%s0x%llx", prefix,
 259                                          *(u64 *)ptr);
 260                         break;
 261                 default:
 262                         trace_seq_printf(p, "BAD SIZE:%zu 0x%x", el_size,
 263                                          *(u8 *)ptr);
 264                         el_size = 1;
 265                 }
 266                 prefix = ",";
 267                 ptr += el_size;
 268         }
 269
 270         trace_seq_putc(p, '}');
 271         trace_seq_putc(p, 0);
 272
 273         return ret;
 274 }
 275 EXPORT_SYMBOL(trace_print_array_seq);
 276
 277 const char *
 278 trace_print_hex_dump_seq(struct trace_seq *p, const char *prefix_str,
 279                          int prefix_type, int rowsize, int groupsize,
 280                          const void *buf, size_t len, bool ascii)
 281 {
 282         const char *ret = trace_seq_buffer_ptr(p);
 283
 284         trace_seq_putc(p, '\n');
 285         trace_seq_hex_dump(p, prefix_str, prefix_type,
 286                            rowsize, groupsize, buf, len, ascii);
 287         trace_seq_putc(p, 0);
 288         return ret;
 289 }
 290 EXPORT_SYMBOL(trace_print_hex_dump_seq);
 291
 292 int trace_raw_output_prep(struct trace_iterator *iter,
 293                           struct trace_event *trace_event)
 294 {
 295         struct trace_event_call *event;
 296         struct trace_seq *s = &iter->seq;
 297         struct trace_seq *p = &iter->tmp_seq;
 298         struct trace_entry *entry;
 299
 300         event = container_of(trace_event, struct trace_event_call, event);
 301         entry = iter->ent;
 302
 303         if (entry->type != event->event.type) {
 304                 WARN_ON_ONCE(1);
 305                 return TRACE_TYPE_UNHANDLED;
 306         }
 307
 308         trace_seq_init(p);
 309         trace_seq_printf(s, "%s: ", trace_event_name(event));
 310
 311         return trace_handle_return(s);
 312 }
 313 EXPORT_SYMBOL(trace_raw_output_prep);
 314
 315 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                 mmap_read_lock(mm);
 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                 mmap_read_unlock(mm);
 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-%-7d %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-%-7d ", 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, "(%7d) ", 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_entry *entry, *next_entry;
 621         struct trace_array *tr = iter->tr;
 622         struct trace_seq *s = &iter->seq;
 623         unsigned long verbose = (tr->trace_flags & TRACE_ITER_VERBOSE);
 624         u64 next_ts;
 625
 626         next_entry = trace_find_next_entry(iter, NULL, &next_ts);
 627         if (!next_entry)
 628                 next_ts = iter->ts;
 629
 630         /* trace_find_next_entry() may change iter->ent */
 631         entry = iter->ent;
 632
 633         if (verbose) {
 634                 char comm[TASK_COMM_LEN];
 635
 636                 trace_find_cmdline(entry->pid, comm);
 637
 638                 trace_seq_printf(
 639                         s, "%16s %7d %3d %d %08x %08lx ",
 640                         comm, entry->pid, iter->cpu, entry->flags,
 641                         entry->preempt_count, iter->idx);
 642         } else {
 643                 lat_print_generic(s, entry, iter->cpu);
 644         }
 645
 646         lat_print_timestamp(iter, next_ts);
 647
 648         return !trace_seq_has_overflowed(s);
 649 }
 650
 651 /**
 652  * ftrace_find_event - find a registered event
 653  * @type: the type of event to look for
 654  *
 655  * Returns an event of type @type otherwise NULL
 656  * Called with trace_event_read_lock() held.
 657  */
 658 struct trace_event *ftrace_find_event(int type)
 659 {
 660         struct trace_event *event;
 661         unsigned key;
 662
 663         key = type & (EVENT_HASHSIZE - 1);
 664
 665         hlist_for_each_entry(event, &event_hash[key], node) {
 666                 if (event->type == type)
 667                         return event;
 668         }
 669
 670         return NULL;
 671 }
 672
 673 static LIST_HEAD(ftrace_event_list);
 674
 675 static int trace_search_list(struct list_head **list)
 676 {
 677         struct trace_event *e;
 678         int next = __TRACE_LAST_TYPE;
 679
 680         if (list_empty(&ftrace_event_list)) {
 681                 *list = &ftrace_event_list;
 682                 return next;
 683         }
 684
 685         /*
 686          * We used up all possible max events,
 687          * lets see if somebody freed one.
 688          */
 689         list_for_each_entry(e, &ftrace_event_list, list) {
 690                 if (e->type != next)
 691                         break;
 692                 next++;
 693         }
 694
 695         /* Did we used up all 65 thousand events??? */
 696         if (next > TRACE_EVENT_TYPE_MAX)
 697                 return 0;
 698
 699         *list = &e->list;
 700         return next;
 701 }
 702
 703 void trace_event_read_lock(void)
 704 {
 705         down_read(&trace_event_sem);
 706 }
 707
 708 void trace_event_read_unlock(void)
 709 {
 710         up_read(&trace_event_sem);
 711 }
 712
 713 /**
 714  * register_trace_event - register output for an event type
 715  * @event: the event type to register
 716  *
 717  * Event types are stored in a hash and this hash is used to
 718  * find a way to print an event. If the @event->type is set
 719  * then it will use that type, otherwise it will assign a
 720  * type to use.
 721  *
 722  * If you assign your own type, please make sure it is added
 723  * to the trace_type enum in trace.h, to avoid collisions
 724  * with the dynamic types.
 725  *
 726  * Returns the event type number or zero on error.
 727  */
 728 int register_trace_event(struct trace_event *event)
 729 {
 730         unsigned key;
 731         int ret = 0;
 732
 733         down_write(&trace_event_sem);
 734
 735         if (WARN_ON(!event))
 736                 goto out;
 737
 738         if (WARN_ON(!event->funcs))
 739                 goto out;
 740
 741         INIT_LIST_HEAD(&event->list);
 742
 743         if (!event->type) {
 744                 struct list_head *list = NULL;
 745
 746                 if (next_event_type > TRACE_EVENT_TYPE_MAX) {
 747
 748                         event->type = trace_search_list(&list);
 749                         if (!event->type)
 750                                 goto out;
 751
 752                 } else {
 753
 754                         event->type = next_event_type++;
 755                         list = &ftrace_event_list;
 756                 }
 757
 758                 if (WARN_ON(ftrace_find_event(event->type)))
 759                         goto out;
 760
 761                 list_add_tail(&event->list, list);
 762
 763         } else if (event->type > __TRACE_LAST_TYPE) {
 764                 printk(KERN_WARNING "Need to add type to trace.h\n");
 765                 WARN_ON(1);
 766                 goto out;
 767         } else {
 768                 /* Is this event already used */
 769                 if (ftrace_find_event(event->type))
 770                         goto out;
 771         }
 772
 773         if (event->funcs->trace == NULL)
 774                 event->funcs->trace = trace_nop_print;
 775         if (event->funcs->raw == NULL)
 776                 event->funcs->raw = trace_nop_print;
 777         if (event->funcs->hex == NULL)
 778                 event->funcs->hex = trace_nop_print;
 779         if (event->funcs->binary == NULL)
 780                 event->funcs->binary = trace_nop_print;
 781
 782         key = event->type & (EVENT_HASHSIZE - 1);
 783
 784         hlist_add_head(&event->node, &event_hash[key]);
 785
 786         ret = event->type;
 787  out:
 788         up_write(&trace_event_sem);
 789
 790         return ret;
 791 }
 792 EXPORT_SYMBOL_GPL(register_trace_event);
 793
 794 /*
 795  * Used by module code with the trace_event_sem held for write.
 796  */
 797 int __unregister_trace_event(struct trace_event *event)
 798 {
 799         hlist_del(&event->node);
 800         list_del(&event->list);
 801         return 0;
 802 }
 803
 804 /**
 805  * unregister_trace_event - remove a no longer used event
 806  * @event: the event to remove
 807  */
 808 int unregister_trace_event(struct trace_event *event)
 809 {
 810         down_write(&trace_event_sem);
 811         __unregister_trace_event(event);
 812         up_write(&trace_event_sem);
 813
 814         return 0;
 815 }
 816 EXPORT_SYMBOL_GPL(unregister_trace_event);
 817
 818 /*
 819  * Standard events
 820  */
 821
 822 enum print_line_t trace_nop_print(struct trace_iterator *iter, int flags,
 823                                   struct trace_event *event)
 824 {
 825         trace_seq_printf(&iter->seq, "type: %d\n", iter->ent->type);
 826
 827         return trace_handle_return(&iter->seq);
 828 }
 829
 830 /* TRACE_FN */
 831 static enum print_line_t trace_fn_trace(struct trace_iterator *iter, int flags,
 832                                         struct trace_event *event)
 833 {
 834         struct ftrace_entry *field;
 835         struct trace_seq *s = &iter->seq;
 836
 837         trace_assign_type(field, iter->ent);
 838
 839         seq_print_ip_sym(s, field->ip, flags);
 840
 841         if ((flags & TRACE_ITER_PRINT_PARENT) && field->parent_ip) {
 842                 trace_seq_puts(s, " <-");
 843                 seq_print_ip_sym(s, field->parent_ip, flags);
 844         }
 845
 846         trace_seq_putc(s, '\n');
 847
 848         return trace_handle_return(s);
 849 }
 850
 851 static enum print_line_t trace_fn_raw(struct trace_iterator *iter, int flags,
 852                                       struct trace_event *event)
 853 {
 854         struct ftrace_entry *field;
 855
 856         trace_assign_type(field, iter->ent);
 857
 858         trace_seq_printf(&iter->seq, "%lx %lx\n",
 859                          field->ip,
 860                          field->parent_ip);
 861
 862         return trace_handle_return(&iter->seq);
 863 }
 864
 865 static enum print_line_t trace_fn_hex(struct trace_iterator *iter, int flags,
 866                                       struct trace_event *event)
 867 {
 868         struct ftrace_entry *field;
 869         struct trace_seq *s = &iter->seq;
 870
 871         trace_assign_type(field, iter->ent);
 872
 873         SEQ_PUT_HEX_FIELD(s, field->ip);
 874         SEQ_PUT_HEX_FIELD(s, field->parent_ip);
 875
 876         return trace_handle_return(s);
 877 }
 878
 879 static enum print_line_t trace_fn_bin(struct trace_iterator *iter, int flags,
 880                                       struct trace_event *event)
 881 {
 882         struct ftrace_entry *field;
 883         struct trace_seq *s = &iter->seq;
 884
 885         trace_assign_type(field, iter->ent);
 886
 887         SEQ_PUT_FIELD(s, field->ip);
 888         SEQ_PUT_FIELD(s, field->parent_ip);
 889
 890         return trace_handle_return(s);
 891 }
 892
 893 static struct trace_event_functions trace_fn_funcs = {
 894         .trace          = trace_fn_trace,
 895         .raw            = trace_fn_raw,
 896         .hex            = trace_fn_hex,
 897         .binary         = trace_fn_bin,
 898 };
 899
 900 static struct trace_event trace_fn_event = {
 901         .type           = TRACE_FN,
 902         .funcs          = &trace_fn_funcs,
 903 };
 904
 905 /* TRACE_CTX an TRACE_WAKE */
 906 static enum print_line_t trace_ctxwake_print(struct trace_iterator *iter,
 907                                              char *delim)
 908 {
 909         struct ctx_switch_entry *field;
 910         char comm[TASK_COMM_LEN];
 911         int S, T;
 912
 913
 914         trace_assign_type(field, iter->ent);
 915
 916         T = task_index_to_char(field->next_state);
 917         S = task_index_to_char(field->prev_state);
 918         trace_find_cmdline(field->next_pid, comm);
 919         trace_seq_printf(&iter->seq,
 920                          " %7d:%3d:%c %s [%03d] %7d:%3d:%c %s\n",
 921                          field->prev_pid,
 922                          field->prev_prio,
 923                          S, delim,
 924                          field->next_cpu,
 925                          field->next_pid,
 926                          field->next_prio,
 927                          T, comm);
 928
 929         return trace_handle_return(&iter->seq);
 930 }
 931
 932 static enum print_line_t trace_ctx_print(struct trace_iterator *iter, int flags,
 933                                          struct trace_event *event)
 934 {
 935         return trace_ctxwake_print(iter, "==>");
 936 }
 937
 938 static enum print_line_t trace_wake_print(struct trace_iterator *iter,
 939                                           int flags, struct trace_event *event)
 940 {
 941         return trace_ctxwake_print(iter, "  +");
 942 }
 943
 944 static int trace_ctxwake_raw(struct trace_iterator *iter, char S)
 945 {
 946         struct ctx_switch_entry *field;
 947         int T;
 948
 949         trace_assign_type(field, iter->ent);
 950
 951         if (!S)
 952                 S = task_index_to_char(field->prev_state);
 953         T = task_index_to_char(field->next_state);
 954         trace_seq_printf(&iter->seq, "%d %d %c %d %d %d %c\n",
 955                          field->prev_pid,
 956                          field->prev_prio,
 957                          S,
 958                          field->next_cpu,
 959                          field->next_pid,
 960                          field->next_prio,
 961                          T);
 962
 963         return trace_handle_return(&iter->seq);
 964 }
 965
 966 static enum print_line_t trace_ctx_raw(struct trace_iterator *iter, int flags,
 967                                        struct trace_event *event)
 968 {
 969         return trace_ctxwake_raw(iter, 0);
 970 }
 971
 972 static enum print_line_t trace_wake_raw(struct trace_iterator *iter, int flags,
 973                                         struct trace_event *event)
 974 {
 975         return trace_ctxwake_raw(iter, '+');
 976 }
 977
 978
 979 static int trace_ctxwake_hex(struct trace_iterator *iter, char S)
 980 {
 981         struct ctx_switch_entry *field;
 982         struct trace_seq *s = &iter->seq;
 983         int T;
 984
 985         trace_assign_type(field, iter->ent);
 986
 987         if (!S)
 988                 S = task_index_to_char(field->prev_state);
 989         T = task_index_to_char(field->next_state);
 990
 991         SEQ_PUT_HEX_FIELD(s, field->prev_pid);
 992         SEQ_PUT_HEX_FIELD(s, field->prev_prio);
 993         SEQ_PUT_HEX_FIELD(s, S);
 994         SEQ_PUT_HEX_FIELD(s, field->next_cpu);
 995         SEQ_PUT_HEX_FIELD(s, field->next_pid);
 996         SEQ_PUT_HEX_FIELD(s, field->next_prio);
 997         SEQ_PUT_HEX_FIELD(s, T);
 998
 999         return trace_handle_return(s);
1000 }
1001
1002 static enum print_line_t trace_ctx_hex(struct trace_iterator *iter, int flags,
1003                                        struct trace_event *event)
1004 {
1005         return trace_ctxwake_hex(iter, 0);
1006 }
1007
1008 static enum print_line_t trace_wake_hex(struct trace_iterator *iter, int flags,
1009                                         struct trace_event *event)
1010 {
1011         return trace_ctxwake_hex(iter, '+');
1012 }
1013
1014 static enum print_line_t trace_ctxwake_bin(struct trace_iterator *iter,
1015                                            int flags, struct trace_event *event)
1016 {
1017         struct ctx_switch_entry *field;
1018         struct trace_seq *s = &iter->seq;
1019
1020         trace_assign_type(field, iter->ent);
1021
1022         SEQ_PUT_FIELD(s, field->prev_pid);
1023         SEQ_PUT_FIELD(s, field->prev_prio);
1024         SEQ_PUT_FIELD(s, field->prev_state);
1025         SEQ_PUT_FIELD(s, field->next_cpu);
1026         SEQ_PUT_FIELD(s, field->next_pid);
1027         SEQ_PUT_FIELD(s, field->next_prio);
1028         SEQ_PUT_FIELD(s, field->next_state);
1029
1030         return trace_handle_return(s);
1031 }
1032
1033 static struct trace_event_functions trace_ctx_funcs = {
1034         .trace          = trace_ctx_print,
1035         .raw            = trace_ctx_raw,
1036         .hex            = trace_ctx_hex,
1037         .binary         = trace_ctxwake_bin,
1038 };
1039
1040 static struct trace_event trace_ctx_event = {
1041         .type           = TRACE_CTX,
1042         .funcs          = &trace_ctx_funcs,
1043 };
1044
1045 static struct trace_event_functions trace_wake_funcs = {
1046         .trace          = trace_wake_print,
1047         .raw            = trace_wake_raw,
1048         .hex            = trace_wake_hex,
1049         .binary         = trace_ctxwake_bin,
1050 };
1051
1052 static struct trace_event trace_wake_event = {
1053         .type           = TRACE_WAKE,
1054         .funcs          = &trace_wake_funcs,
1055 };
1056
1057 /* TRACE_STACK */
1058
1059 static enum print_line_t trace_stack_print(struct trace_iterator *iter,
1060                                            int flags, struct trace_event *event)
1061 {
1062         struct stack_entry *field;
1063         struct trace_seq *s = &iter->seq;
1064         unsigned long *p;
1065         unsigned long *end;
1066
1067         trace_assign_type(field, iter->ent);
1068         end = (unsigned long *)((long)iter->ent + iter->ent_size);
1069
1070         trace_seq_puts(s, "<stack trace>\n");
1071
1072         for (p = field->caller; p && p < end && *p != ULONG_MAX; p++) {
1073
1074                 if (trace_seq_has_overflowed(s))
1075                         break;
1076
1077                 trace_seq_puts(s, " => ");
1078                 seq_print_ip_sym(s, *p, flags);
1079                 trace_seq_putc(s, '\n');
1080         }
1081
1082         return trace_handle_return(s);
1083 }
1084
1085 static struct trace_event_functions trace_stack_funcs = {
1086         .trace          = trace_stack_print,
1087 };
1088
1089 static struct trace_event trace_stack_event = {
1090         .type           = TRACE_STACK,
1091         .funcs          = &trace_stack_funcs,
1092 };
1093
1094 /* TRACE_USER_STACK */
1095 static enum print_line_t trace_user_stack_print(struct trace_iterator *iter,
1096                                                 int flags, struct trace_event *event)
1097 {
1098         struct trace_array *tr = iter->tr;
1099         struct userstack_entry *field;
1100         struct trace_seq *s = &iter->seq;
1101         struct mm_struct *mm = NULL;
1102         unsigned int i;
1103
1104         trace_assign_type(field, iter->ent);
1105
1106         trace_seq_puts(s, "<user stack trace>\n");
1107
1108         if (tr->trace_flags & TRACE_ITER_SYM_USEROBJ) {
1109                 struct task_struct *task;
1110                 /*
1111                  * we do the lookup on the thread group leader,
1112                  * since individual threads might have already quit!
1113                  */
1114                 rcu_read_lock();
1115                 task = find_task_by_vpid(field->tgid);
1116                 if (task)
1117                         mm = get_task_mm(task);
1118                 rcu_read_unlock();
1119         }
1120
1121         for (i = 0; i < FTRACE_STACK_ENTRIES; i++) {
1122                 unsigned long ip = field->caller[i];
1123
1124                 if (!ip || trace_seq_has_overflowed(s))
1125                         break;
1126
1127                 trace_seq_puts(s, " => ");
1128                 seq_print_user_ip(s, mm, ip, flags);
1129                 trace_seq_putc(s, '\n');
1130         }
1131
1132         if (mm)
1133                 mmput(mm);
1134
1135         return trace_handle_return(s);
1136 }
1137
1138 static struct trace_event_functions trace_user_stack_funcs = {
1139         .trace          = trace_user_stack_print,
1140 };
1141
1142 static struct trace_event trace_user_stack_event = {
1143         .type           = TRACE_USER_STACK,
1144         .funcs          = &trace_user_stack_funcs,
1145 };
1146
1147 /* TRACE_HWLAT */
1148 static enum print_line_t
1149 trace_hwlat_print(struct trace_iterator *iter, int flags,
1150                   struct trace_event *event)
1151 {
1152         struct trace_entry *entry = iter->ent;
1153         struct trace_seq *s = &iter->seq;
1154         struct hwlat_entry *field;
1155
1156         trace_assign_type(field, entry);
1157
1158         trace_seq_printf(s, "#%-5u inner/outer(us): %4llu/%-5llu ts:%lld.%09ld count:%d",
1159                          field->seqnum,
1160                          field->duration,
1161                          field->outer_duration,
1162                          (long long)field->timestamp.tv_sec,
1163                          field->timestamp.tv_nsec, field->count);
1164
1165         if (field->nmi_count) {
1166                 /*
1167                  * The generic sched_clock() is not NMI safe, thus
1168                  * we only record the count and not the time.
1169                  */
1170                 if (!IS_ENABLED(CONFIG_GENERIC_SCHED_CLOCK))
1171                         trace_seq_printf(s, " nmi-total:%llu",
1172                                          field->nmi_total_ts);
1173                 trace_seq_printf(s, " nmi-count:%u",
1174                                  field->nmi_count);
1175         }
1176
1177         trace_seq_putc(s, '\n');
1178
1179         return trace_handle_return(s);
1180 }
1181
1182
1183 static enum print_line_t
1184 trace_hwlat_raw(struct trace_iterator *iter, int flags,
1185                 struct trace_event *event)
1186 {
1187         struct hwlat_entry *field;
1188         struct trace_seq *s = &iter->seq;
1189
1190         trace_assign_type(field, iter->ent);
1191
1192         trace_seq_printf(s, "%llu %lld %lld %09ld %u\n",
1193                          field->duration,
1194                          field->outer_duration,
1195                          (long long)field->timestamp.tv_sec,
1196                          field->timestamp.tv_nsec,
1197                          field->seqnum);
1198
1199         return trace_handle_return(s);
1200 }
1201
1202 static struct trace_event_functions trace_hwlat_funcs = {
1203         .trace          = trace_hwlat_print,
1204         .raw            = trace_hwlat_raw,
1205 };
1206
1207 static struct trace_event trace_hwlat_event = {
1208         .type           = TRACE_HWLAT,
1209         .funcs          = &trace_hwlat_funcs,
1210 };
1211
1212 /* TRACE_BPUTS */
1213 static enum print_line_t
1214 trace_bputs_print(struct trace_iterator *iter, int flags,
1215                    struct trace_event *event)
1216 {
1217         struct trace_entry *entry = iter->ent;
1218         struct trace_seq *s = &iter->seq;
1219         struct bputs_entry *field;
1220
1221         trace_assign_type(field, entry);
1222
1223         seq_print_ip_sym(s, field->ip, flags);
1224         trace_seq_puts(s, ": ");
1225         trace_seq_puts(s, field->str);
1226
1227         return trace_handle_return(s);
1228 }
1229
1230
1231 static enum print_line_t
1232 trace_bputs_raw(struct trace_iterator *iter, int flags,
1233                 struct trace_event *event)
1234 {
1235         struct bputs_entry *field;
1236         struct trace_seq *s = &iter->seq;
1237
1238         trace_assign_type(field, iter->ent);
1239
1240         trace_seq_printf(s, ": %lx : ", field->ip);
1241         trace_seq_puts(s, field->str);
1242
1243         return trace_handle_return(s);
1244 }
1245
1246 static struct trace_event_functions trace_bputs_funcs = {
1247         .trace          = trace_bputs_print,
1248         .raw            = trace_bputs_raw,
1249 };
1250
1251 static struct trace_event trace_bputs_event = {
1252         .type           = TRACE_BPUTS,
1253         .funcs          = &trace_bputs_funcs,
1254 };
1255
1256 /* TRACE_BPRINT */
1257 static enum print_line_t
1258 trace_bprint_print(struct trace_iterator *iter, int flags,
1259                    struct trace_event *event)
1260 {
1261         struct trace_entry *entry = iter->ent;
1262         struct trace_seq *s = &iter->seq;
1263         struct bprint_entry *field;
1264
1265         trace_assign_type(field, entry);
1266
1267         seq_print_ip_sym(s, field->ip, flags);
1268         trace_seq_puts(s, ": ");
1269         trace_seq_bprintf(s, field->fmt, field->buf);
1270
1271         return trace_handle_return(s);
1272 }
1273
1274
1275 static enum print_line_t
1276 trace_bprint_raw(struct trace_iterator *iter, int flags,
1277                  struct trace_event *event)
1278 {
1279         struct bprint_entry *field;
1280         struct trace_seq *s = &iter->seq;
1281
1282         trace_assign_type(field, iter->ent);
1283
1284         trace_seq_printf(s, ": %lx : ", field->ip);
1285         trace_seq_bprintf(s, field->fmt, field->buf);
1286
1287         return trace_handle_return(s);
1288 }
1289
1290 static struct trace_event_functions trace_bprint_funcs = {
1291         .trace          = trace_bprint_print,
1292         .raw            = trace_bprint_raw,
1293 };
1294
1295 static struct trace_event trace_bprint_event = {
1296         .type           = TRACE_BPRINT,
1297         .funcs          = &trace_bprint_funcs,
1298 };
1299
1300 /* TRACE_PRINT */
1301 static enum print_line_t trace_print_print(struct trace_iterator *iter,
1302                                            int flags, struct trace_event *event)
1303 {
1304         struct print_entry *field;
1305         struct trace_seq *s = &iter->seq;
1306
1307         trace_assign_type(field, iter->ent);
1308
1309         seq_print_ip_sym(s, field->ip, flags);
1310         trace_seq_printf(s, ": %s", field->buf);
1311
1312         return trace_handle_return(s);
1313 }
1314
1315 static enum print_line_t trace_print_raw(struct trace_iterator *iter, int flags,
1316                                          struct trace_event *event)
1317 {
1318         struct print_entry *field;
1319
1320         trace_assign_type(field, iter->ent);
1321
1322         trace_seq_printf(&iter->seq, "# %lx %s", field->ip, field->buf);
1323
1324         return trace_handle_return(&iter->seq);
1325 }
1326
1327 static struct trace_event_functions trace_print_funcs = {
1328         .trace          = trace_print_print,
1329         .raw            = trace_print_raw,
1330 };
1331
1332 static struct trace_event trace_print_event = {
1333         .type           = TRACE_PRINT,
1334         .funcs          = &trace_print_funcs,
1335 };
1336
1337 static enum print_line_t trace_raw_data(struct trace_iterator *iter, int flags,
1338                                          struct trace_event *event)
1339 {
1340         struct raw_data_entry *field;
1341         int i;
1342
1343         trace_assign_type(field, iter->ent);
1344
1345         trace_seq_printf(&iter->seq, "# %x buf:", field->id);
1346
1347         for (i = 0; i < iter->ent_size - offsetof(struct raw_data_entry, buf); i++)
1348                 trace_seq_printf(&iter->seq, " %02x",
1349                                  (unsigned char)field->buf[i]);
1350
1351         trace_seq_putc(&iter->seq, '\n');
1352
1353         return trace_handle_return(&iter->seq);
1354 }
1355
1356 static struct trace_event_functions trace_raw_data_funcs = {
1357         .trace          = trace_raw_data,
1358         .raw            = trace_raw_data,
1359 };
1360
1361 static struct trace_event trace_raw_data_event = {
1362         .type           = TRACE_RAW_DATA,
1363         .funcs          = &trace_raw_data_funcs,
1364 };
1365
1366
1367 static struct trace_event *events[] __initdata = {
1368         &trace_fn_event,
1369         &trace_ctx_event,
1370         &trace_wake_event,
1371         &trace_stack_event,
1372         &trace_user_stack_event,
1373         &trace_bputs_event,
1374         &trace_bprint_event,
1375         &trace_print_event,
1376         &trace_hwlat_event,
1377         &trace_raw_data_event,
1378         NULL
1379 };
1380
1381 __init static int init_events(void)
1382 {
1383         struct trace_event *event;
1384         int i, ret;
1385
1386         for (i = 0; events[i]; i++) {
1387                 event = events[i];
1388
1389                 ret = register_trace_event(event);
1390                 if (!ret) {
1391                         printk(KERN_WARNING "event %d failed to register\n",
1392                                event->type);
1393                         WARN_ON_ONCE(1);
1394                 }
1395         }
1396
1397         return 0;
1398 }
1399 early_initcall(init_events);