kernel/trace/trace_events.c

   1 /*
   2  * event tracer
   3  *
   4  * Copyright (C) 2008 Red Hat Inc, Steven Rostedt <srostedt@redhat.com>
   5  *
   6  *  - Added format output of fields of the trace point.
   7  *    This was based off of work by Tom Zanussi <tzanussi@gmail.com>.
   8  *
   9  */
  10
  11 #include <linux/workqueue.h>
  12 #include <linux/spinlock.h>
  13 #include <linux/kthread.h>
  14 #include <linux/debugfs.h>
  15 #include <linux/uaccess.h>
  16 #include <linux/module.h>
  17 #include <linux/ctype.h>
  18 #include <linux/slab.h>
  19 #include <linux/delay.h>
  20
  21 #include <asm/setup.h>
  22
  23 #include "trace_output.h"
  24
  25 #undef TRACE_SYSTEM
  26 #define TRACE_SYSTEM "TRACE_SYSTEM"
  27
  28 DEFINE_MUTEX(event_mutex);
  29
  30 LIST_HEAD(ftrace_events);
  31 LIST_HEAD(ftrace_common_fields);
  32
  33 struct list_head *
  34 trace_get_fields(struct ftrace_event_call *event_call)
  35 {
  36         if (!event_call->class->get_fields)
  37                 return &event_call->class->fields;
  38         return event_call->class->get_fields(event_call);
  39 }
  40
  41 static int __trace_define_field(struct list_head *head, const char *type,
  42                                 const char *name, int offset, int size,
  43                                 int is_signed, int filter_type)
  44 {
  45         struct ftrace_event_field *field;
  46
  47         field = kzalloc(sizeof(*field), GFP_KERNEL);
  48         if (!field)
  49                 goto err;
  50
  51         field->name = kstrdup(name, GFP_KERNEL);
  52         if (!field->name)
  53                 goto err;
  54
  55         field->type = kstrdup(type, GFP_KERNEL);
  56         if (!field->type)
  57                 goto err;
  58
  59         if (filter_type == FILTER_OTHER)
  60                 field->filter_type = filter_assign_type(type);
  61         else
  62                 field->filter_type = filter_type;
  63
  64         field->offset = offset;
  65         field->size = size;
  66         field->is_signed = is_signed;
  67
  68         list_add(&field->link, head);
  69
  70         return 0;
  71
  72 err:
  73         if (field)
  74                 kfree(field->name);
  75         kfree(field);
  76
  77         return -ENOMEM;
  78 }
  79
  80 int trace_define_field(struct ftrace_event_call *call, const char *type,
  81                        const char *name, int offset, int size, int is_signed,
  82                        int filter_type)
  83 {
  84         struct list_head *head;
  85
  86         if (WARN_ON(!call->class))
  87                 return 0;
  88
  89         head = trace_get_fields(call);
  90         return __trace_define_field(head, type, name, offset, size,
  91                                     is_signed, filter_type);
  92 }
  93 EXPORT_SYMBOL_GPL(trace_define_field);
  94
  95 #define __common_field(type, item)                                      \
  96         ret = __trace_define_field(&ftrace_common_fields, #type,        \
  97                                    "common_" #item,                     \
  98                                    offsetof(typeof(ent), item),         \
  99                                    sizeof(ent.item),                    \
 100                                    is_signed_type(type), FILTER_OTHER); \
 101         if (ret)                                                        \
 102                 return ret;
 103
 104 static int trace_define_common_fields(void)
 105 {
 106         int ret;
 107         struct trace_entry ent;
 108
 109         __common_field(unsigned short, type);
 110         __common_field(unsigned char, flags);
 111         __common_field(unsigned char, preempt_count);
 112         __common_field(int, pid);
 113         __common_field(int, lock_depth);
 114
 115         return ret;
 116 }
 117
 118 void trace_destroy_fields(struct ftrace_event_call *call)
 119 {
 120         struct ftrace_event_field *field, *next;
 121         struct list_head *head;
 122
 123         head = trace_get_fields(call);
 124         list_for_each_entry_safe(field, next, head, link) {
 125                 list_del(&field->link);
 126                 kfree(field->type);
 127                 kfree(field->name);
 128                 kfree(field);
 129         }
 130 }
 131
 132 int trace_event_raw_init(struct ftrace_event_call *call)
 133 {
 134         int id;
 135
 136         id = register_ftrace_event(&call->event);
 137         if (!id)
 138                 return -ENODEV;
 139
 140         return 0;
 141 }
 142 EXPORT_SYMBOL_GPL(trace_event_raw_init);
 143
 144 static int ftrace_event_enable_disable(struct ftrace_event_call *call,
 145                                         int enable)
 146 {
 147         int ret = 0;
 148
 149         switch (enable) {
 150         case 0:
 151                 if (call->flags & TRACE_EVENT_FL_ENABLED) {
 152                         call->flags &= ~TRACE_EVENT_FL_ENABLED;
 153                         tracing_stop_cmdline_record();
 154                         if (call->class->reg)
 155                                 call->class->reg(call, TRACE_REG_UNREGISTER);
 156                         else
 157                                 tracepoint_probe_unregister(call->name,
 158                                                             call->class->probe,
 159                                                             call);
 160                 }
 161                 break;
 162         case 1:
 163                 if (!(call->flags & TRACE_EVENT_FL_ENABLED)) {
 164                         tracing_start_cmdline_record();
 165                         if (call->class->reg)
 166                                 ret = call->class->reg(call, TRACE_REG_REGISTER);
 167                         else
 168                                 ret = tracepoint_probe_register(call->name,
 169                                                                 call->class->probe,
 170                                                                 call);
 171                         if (ret) {
 172                                 tracing_stop_cmdline_record();
 173                                 pr_info("event trace: Could not enable event "
 174                                         "%s\n", call->name);
 175                                 break;
 176                         }
 177                         call->flags |= TRACE_EVENT_FL_ENABLED;
 178                 }
 179                 break;
 180         }
 181
 182         return ret;
 183 }
 184
 185 static void ftrace_clear_events(void)
 186 {
 187         struct ftrace_event_call *call;
 188
 189         mutex_lock(&event_mutex);
 190         list_for_each_entry(call, &ftrace_events, list) {
 191                 ftrace_event_enable_disable(call, 0);
 192         }
 193         mutex_unlock(&event_mutex);
 194 }
 195
 196 /*
 197  * __ftrace_set_clr_event(NULL, NULL, NULL, set) will set/unset all events.
 198  */
 199 static int __ftrace_set_clr_event(const char *match, const char *sub,
 200                                   const char *event, int set)
 201 {
 202         struct ftrace_event_call *call;
 203         int ret = -EINVAL;
 204
 205         mutex_lock(&event_mutex);
 206         list_for_each_entry(call, &ftrace_events, list) {
 207
 208                 if (!call->name || !call->class ||
 209                     (!call->class->probe && !call->class->reg))
 210                         continue;
 211
 212                 if (match &&
 213                     strcmp(match, call->name) != 0 &&
 214                     strcmp(match, call->class->system) != 0)
 215                         continue;
 216
 217                 if (sub && strcmp(sub, call->class->system) != 0)
 218                         continue;
 219
 220                 if (event && strcmp(event, call->name) != 0)
 221                         continue;
 222
 223                 ftrace_event_enable_disable(call, set);
 224
 225                 ret = 0;
 226         }
 227         mutex_unlock(&event_mutex);
 228
 229         return ret;
 230 }
 231
 232 static int ftrace_set_clr_event(char *buf, int set)
 233 {
 234         char *event = NULL, *sub = NULL, *match;
 235
 236         /*
 237          * The buf format can be <subsystem>:<event-name>
 238          *  *:<event-name> means any event by that name.
 239          *  :<event-name> is the same.
 240          *
 241          *  <subsystem>:* means all events in that subsystem
 242          *  <subsystem>: means the same.
 243          *
 244          *  <name> (no ':') means all events in a subsystem with
 245          *  the name <name> or any event that matches <name>
 246          */
 247
 248         match = strsep(&buf, ":");
 249         if (buf) {
 250                 sub = match;
 251                 event = buf;
 252                 match = NULL;
 253
 254                 if (!strlen(sub) || strcmp(sub, "*") == 0)
 255                         sub = NULL;
 256                 if (!strlen(event) || strcmp(event, "*") == 0)
 257                         event = NULL;
 258         }
 259
 260         return __ftrace_set_clr_event(match, sub, event, set);
 261 }
 262
 263 /**
 264  * trace_set_clr_event - enable or disable an event
 265  * @system: system name to match (NULL for any system)
 266  * @event: event name to match (NULL for all events, within system)
 267  * @set: 1 to enable, 0 to disable
 268  *
 269  * This is a way for other parts of the kernel to enable or disable
 270  * event recording.
 271  *
 272  * Returns 0 on success, -EINVAL if the parameters do not match any
 273  * registered events.
 274  */
 275 int trace_set_clr_event(const char *system, const char *event, int set)
 276 {
 277         return __ftrace_set_clr_event(NULL, system, event, set);
 278 }
 279
 280 /* 128 should be much more than enough */
 281 #define EVENT_BUF_SIZE          127
 282
 283 static ssize_t
 284 ftrace_event_write(struct file *file, const char __user *ubuf,
 285                    size_t cnt, loff_t *ppos)
 286 {
 287         struct trace_parser parser;
 288         ssize_t read, ret;
 289
 290         if (!cnt)
 291                 return 0;
 292
 293         ret = tracing_update_buffers();
 294         if (ret < 0)
 295                 return ret;
 296
 297         if (trace_parser_get_init(&parser, EVENT_BUF_SIZE + 1))
 298                 return -ENOMEM;
 299
 300         read = trace_get_user(&parser, ubuf, cnt, ppos);
 301
 302         if (read >= 0 && trace_parser_loaded((&parser))) {
 303                 int set = 1;
 304
 305                 if (*parser.buffer == '!')
 306                         set = 0;
 307
 308                 parser.buffer[parser.idx] = 0;
 309
 310                 ret = ftrace_set_clr_event(parser.buffer + !set, set);
 311                 if (ret)
 312                         goto out_put;
 313         }
 314
 315         ret = read;
 316
 317  out_put:
 318         trace_parser_put(&parser);
 319
 320         return ret;
 321 }
 322
 323 static void *
 324 t_next(struct seq_file *m, void *v, loff_t *pos)
 325 {
 326         struct ftrace_event_call *call = v;
 327
 328         (*pos)++;
 329
 330         list_for_each_entry_continue(call, &ftrace_events, list) {
 331                 /*
 332                  * The ftrace subsystem is for showing formats only.
 333                  * They can not be enabled or disabled via the event files.
 334                  */
 335                 if (call->class && (call->class->probe || call->class->reg))
 336                         return call;
 337         }
 338
 339         return NULL;
 340 }
 341
 342 static void *t_start(struct seq_file *m, loff_t *pos)
 343 {
 344         struct ftrace_event_call *call;
 345         loff_t l;
 346
 347         mutex_lock(&event_mutex);
 348
 349         call = list_entry(&ftrace_events, struct ftrace_event_call, list);
 350         for (l = 0; l <= *pos; ) {
 351                 call = t_next(m, call, &l);
 352                 if (!call)
 353                         break;
 354         }
 355         return call;
 356 }
 357
 358 static void *
 359 s_next(struct seq_file *m, void *v, loff_t *pos)
 360 {
 361         struct ftrace_event_call *call = v;
 362
 363         (*pos)++;
 364
 365         list_for_each_entry_continue(call, &ftrace_events, list) {
 366                 if (call->flags & TRACE_EVENT_FL_ENABLED)
 367                         return call;
 368         }
 369
 370         return NULL;
 371 }
 372
 373 static void *s_start(struct seq_file *m, loff_t *pos)
 374 {
 375         struct ftrace_event_call *call;
 376         loff_t l;
 377
 378         mutex_lock(&event_mutex);
 379
 380         call = list_entry(&ftrace_events, struct ftrace_event_call, list);
 381         for (l = 0; l <= *pos; ) {
 382                 call = s_next(m, call, &l);
 383                 if (!call)
 384                         break;
 385         }
 386         return call;
 387 }
 388
 389 static int t_show(struct seq_file *m, void *v)
 390 {
 391         struct ftrace_event_call *call = v;
 392
 393         if (strcmp(call->class->system, TRACE_SYSTEM) != 0)
 394                 seq_printf(m, "%s:", call->class->system);
 395         seq_printf(m, "%s\n", call->name);
 396
 397         return 0;
 398 }
 399
 400 static void t_stop(struct seq_file *m, void *p)
 401 {
 402         mutex_unlock(&event_mutex);
 403 }
 404
 405 static int
 406 ftrace_event_seq_open(struct inode *inode, struct file *file)
 407 {
 408         const struct seq_operations *seq_ops;
 409
 410         if ((file->f_mode & FMODE_WRITE) &&
 411             (file->f_flags & O_TRUNC))
 412                 ftrace_clear_events();
 413
 414         seq_ops = inode->i_private;
 415         return seq_open(file, seq_ops);
 416 }
 417
 418 static ssize_t
 419 event_enable_read(struct file *filp, char __user *ubuf, size_t cnt,
 420                   loff_t *ppos)
 421 {
 422         struct ftrace_event_call *call = filp->private_data;
 423         char *buf;
 424
 425         if (call->flags & TRACE_EVENT_FL_ENABLED)
 426                 buf = "1\n";
 427         else
 428                 buf = "0\n";
 429
 430         return simple_read_from_buffer(ubuf, cnt, ppos, buf, 2);
 431 }
 432
 433 static ssize_t
 434 event_enable_write(struct file *filp, const char __user *ubuf, size_t cnt,
 435                    loff_t *ppos)
 436 {
 437         struct ftrace_event_call *call = filp->private_data;
 438         char buf[64];
 439         unsigned long val;
 440         int ret;
 441
 442         if (cnt >= sizeof(buf))
 443                 return -EINVAL;
 444
 445         if (copy_from_user(&buf, ubuf, cnt))
 446                 return -EFAULT;
 447
 448         buf[cnt] = 0;
 449
 450         ret = strict_strtoul(buf, 10, &val);
 451         if (ret < 0)
 452                 return ret;
 453
 454         ret = tracing_update_buffers();
 455         if (ret < 0)
 456                 return ret;
 457
 458         switch (val) {
 459         case 0:
 460         case 1:
 461                 mutex_lock(&event_mutex);
 462                 ret = ftrace_event_enable_disable(call, val);
 463                 mutex_unlock(&event_mutex);
 464                 break;
 465
 466         default:
 467                 return -EINVAL;
 468         }
 469
 470         *ppos += cnt;
 471
 472         return ret ? ret : cnt;
 473 }
 474
 475 static ssize_t
 476 system_enable_read(struct file *filp, char __user *ubuf, size_t cnt,
 477                    loff_t *ppos)
 478 {
 479         const char set_to_char[4] = { '?', '0', '1', 'X' };
 480         const char *system = filp->private_data;
 481         struct ftrace_event_call *call;
 482         char buf[2];
 483         int set = 0;
 484         int ret;
 485
 486         mutex_lock(&event_mutex);
 487         list_for_each_entry(call, &ftrace_events, list) {
 488                 if (!call->name || !call->class ||
 489                     (!call->class->probe && !call->class->reg))
 490                         continue;
 491
 492                 if (system && strcmp(call->class->system, system) != 0)
 493                         continue;
 494
 495                 /*
 496                  * We need to find out if all the events are set
 497                  * or if all events or cleared, or if we have
 498                  * a mixture.
 499                  */
 500                 set |= (1 << !!(call->flags & TRACE_EVENT_FL_ENABLED));
 501
 502                 /*
 503                  * If we have a mixture, no need to look further.
 504                  */
 505                 if (set == 3)
 506                         break;
 507         }
 508         mutex_unlock(&event_mutex);
 509
 510         buf[0] = set_to_char[set];
 511         buf[1] = '\n';
 512
 513         ret = simple_read_from_buffer(ubuf, cnt, ppos, buf, 2);
 514
 515         return ret;
 516 }
 517
 518 static ssize_t
 519 system_enable_write(struct file *filp, const char __user *ubuf, size_t cnt,
 520                     loff_t *ppos)
 521 {
 522         const char *system = filp->private_data;
 523         unsigned long val;
 524         char buf[64];
 525         ssize_t ret;
 526
 527         if (cnt >= sizeof(buf))
 528                 return -EINVAL;
 529
 530         if (copy_from_user(&buf, ubuf, cnt))
 531                 return -EFAULT;
 532
 533         buf[cnt] = 0;
 534
 535         ret = strict_strtoul(buf, 10, &val);
 536         if (ret < 0)
 537                 return ret;
 538
 539         ret = tracing_update_buffers();
 540         if (ret < 0)
 541                 return ret;
 542
 543         if (val != 0 && val != 1)
 544                 return -EINVAL;
 545
 546         ret = __ftrace_set_clr_event(NULL, system, NULL, val);
 547         if (ret)
 548                 goto out;
 549
 550         ret = cnt;
 551
 552 out:
 553         *ppos += cnt;
 554
 555         return ret;
 556 }
 557
 558 static void print_event_fields(struct trace_seq *s, struct list_head *head)
 559 {
 560         struct ftrace_event_field *field;
 561
 562         list_for_each_entry_reverse(field, head, link) {
 563                 /*
 564                  * Smartly shows the array type(except dynamic array).
 565                  * Normal:
 566                  *      field:TYPE VAR
 567                  * If TYPE := TYPE[LEN], it is shown:
 568                  *      field:TYPE VAR[LEN]
 569                  */
 570                 const char *array_descriptor = strchr(field->type, '[');
 571
 572                 if (!strncmp(field->type, "__data_loc", 10))
 573                         array_descriptor = NULL;
 574
 575                 if (!array_descriptor) {
 576                         trace_seq_printf(s, "\tfield:%s %s;\toffset:%u;"
 577                                         "\tsize:%u;\tsigned:%d;\n",
 578                                         field->type, field->name, field->offset,
 579                                         field->size, !!field->is_signed);
 580                 } else {
 581                         trace_seq_printf(s, "\tfield:%.*s %s%s;\toffset:%u;"
 582                                         "\tsize:%u;\tsigned:%d;\n",
 583                                         (int)(array_descriptor - field->type),
 584                                         field->type, field->name,
 585                                         array_descriptor, field->offset,
 586                                         field->size, !!field->is_signed);
 587                 }
 588         }
 589 }
 590
 591 static ssize_t
 592 event_format_read(struct file *filp, char __user *ubuf, size_t cnt,
 593                   loff_t *ppos)
 594 {
 595         struct ftrace_event_call *call = filp->private_data;
 596         struct list_head *head;
 597         struct trace_seq *s;
 598         char *buf;
 599         int r;
 600
 601         if (*ppos)
 602                 return 0;
 603
 604         s = kmalloc(sizeof(*s), GFP_KERNEL);
 605         if (!s)
 606                 return -ENOMEM;
 607
 608         trace_seq_init(s);
 609
 610         trace_seq_printf(s, "name: %s\n", call->name);
 611         trace_seq_printf(s, "ID: %d\n", call->event.type);
 612         trace_seq_printf(s, "format:\n");
 613
 614         /* print common fields */
 615         print_event_fields(s, &ftrace_common_fields);
 616
 617         trace_seq_putc(s, '\n');
 618
 619         /* print event specific fields */
 620         head = trace_get_fields(call);
 621         print_event_fields(s, head);
 622
 623         r = trace_seq_printf(s, "\nprint fmt: %s\n", call->print_fmt);
 624
 625         if (!r) {
 626                 /*
 627                  * ug!  The format output is bigger than a PAGE!!
 628                  */
 629                 buf = "FORMAT TOO BIG\n";
 630                 r = simple_read_from_buffer(ubuf, cnt, ppos,
 631                                               buf, strlen(buf));
 632                 goto out;
 633         }
 634
 635         r = simple_read_from_buffer(ubuf, cnt, ppos,
 636                                     s->buffer, s->len);
 637  out:
 638         kfree(s);
 639         return r;
 640 }
 641
 642 static ssize_t
 643 event_id_read(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos)
 644 {
 645         struct ftrace_event_call *call = filp->private_data;
 646         struct trace_seq *s;
 647         int r;
 648
 649         if (*ppos)
 650                 return 0;
 651
 652         s = kmalloc(sizeof(*s), GFP_KERNEL);
 653         if (!s)
 654                 return -ENOMEM;
 655
 656         trace_seq_init(s);
 657         trace_seq_printf(s, "%d\n", call->event.type);
 658
 659         r = simple_read_from_buffer(ubuf, cnt, ppos,
 660                                     s->buffer, s->len);
 661         kfree(s);
 662         return r;
 663 }
 664
 665 static ssize_t
 666 event_filter_read(struct file *filp, char __user *ubuf, size_t cnt,
 667                   loff_t *ppos)
 668 {
 669         struct ftrace_event_call *call = filp->private_data;
 670         struct trace_seq *s;
 671         int r;
 672
 673         if (*ppos)
 674                 return 0;
 675
 676         s = kmalloc(sizeof(*s), GFP_KERNEL);
 677         if (!s)
 678                 return -ENOMEM;
 679
 680         trace_seq_init(s);
 681
 682         print_event_filter(call, s);
 683         r = simple_read_from_buffer(ubuf, cnt, ppos, s->buffer, s->len);
 684
 685         kfree(s);
 686
 687         return r;
 688 }
 689
 690 static ssize_t
 691 event_filter_write(struct file *filp, const char __user *ubuf, size_t cnt,
 692                    loff_t *ppos)
 693 {
 694         struct ftrace_event_call *call = filp->private_data;
 695         char *buf;
 696         int err;
 697
 698         if (cnt >= PAGE_SIZE)
 699                 return -EINVAL;
 700
 701         buf = (char *)__get_free_page(GFP_TEMPORARY);
 702         if (!buf)
 703                 return -ENOMEM;
 704
 705         if (copy_from_user(buf, ubuf, cnt)) {
 706                 free_page((unsigned long) buf);
 707                 return -EFAULT;
 708         }
 709         buf[cnt] = '\0';
 710
 711         err = apply_event_filter(call, buf);
 712         free_page((unsigned long) buf);
 713         if (err < 0)
 714                 return err;
 715
 716         *ppos += cnt;
 717
 718         return cnt;
 719 }
 720
 721 static ssize_t
 722 subsystem_filter_read(struct file *filp, char __user *ubuf, size_t cnt,
 723                       loff_t *ppos)
 724 {
 725         struct event_subsystem *system = filp->private_data;
 726         struct trace_seq *s;
 727         int r;
 728
 729         if (*ppos)
 730                 return 0;
 731
 732         s = kmalloc(sizeof(*s), GFP_KERNEL);
 733         if (!s)
 734                 return -ENOMEM;
 735
 736         trace_seq_init(s);
 737
 738         print_subsystem_event_filter(system, s);
 739         r = simple_read_from_buffer(ubuf, cnt, ppos, s->buffer, s->len);
 740
 741         kfree(s);
 742
 743         return r;
 744 }
 745
 746 static ssize_t
 747 subsystem_filter_write(struct file *filp, const char __user *ubuf, size_t cnt,
 748                        loff_t *ppos)
 749 {
 750         struct event_subsystem *system = filp->private_data;
 751         char *buf;
 752         int err;
 753
 754         if (cnt >= PAGE_SIZE)
 755                 return -EINVAL;
 756
 757         buf = (char *)__get_free_page(GFP_TEMPORARY);
 758         if (!buf)
 759                 return -ENOMEM;
 760
 761         if (copy_from_user(buf, ubuf, cnt)) {
 762                 free_page((unsigned long) buf);
 763                 return -EFAULT;
 764         }
 765         buf[cnt] = '\0';
 766
 767         err = apply_subsystem_event_filter(system, buf);
 768         free_page((unsigned long) buf);
 769         if (err < 0)
 770                 return err;
 771
 772         *ppos += cnt;
 773
 774         return cnt;
 775 }
 776
 777 static ssize_t
 778 show_header(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos)
 779 {
 780         int (*func)(struct trace_seq *s) = filp->private_data;
 781         struct trace_seq *s;
 782         int r;
 783
 784         if (*ppos)
 785                 return 0;
 786
 787         s = kmalloc(sizeof(*s), GFP_KERNEL);
 788         if (!s)
 789                 return -ENOMEM;
 790
 791         trace_seq_init(s);
 792
 793         func(s);
 794         r = simple_read_from_buffer(ubuf, cnt, ppos, s->buffer, s->len);
 795
 796         kfree(s);
 797
 798         return r;
 799 }
 800
 801 static const struct seq_operations show_event_seq_ops = {
 802         .start = t_start,
 803         .next = t_next,
 804         .show = t_show,
 805         .stop = t_stop,
 806 };
 807
 808 static const struct seq_operations show_set_event_seq_ops = {
 809         .start = s_start,
 810         .next = s_next,
 811         .show = t_show,
 812         .stop = t_stop,
 813 };
 814
 815 static const struct file_operations ftrace_avail_fops = {
 816         .open = ftrace_event_seq_open,
 817         .read = seq_read,
 818         .llseek = seq_lseek,
 819         .release = seq_release,
 820 };
 821
 822 static const struct file_operations ftrace_set_event_fops = {
 823         .open = ftrace_event_seq_open,
 824         .read = seq_read,
 825         .write = ftrace_event_write,
 826         .llseek = seq_lseek,
 827         .release = seq_release,
 828 };
 829
 830 static const struct file_operations ftrace_enable_fops = {
 831         .open = tracing_open_generic,
 832         .read = event_enable_read,
 833         .write = event_enable_write,
 834 };
 835
 836 static const struct file_operations ftrace_event_format_fops = {
 837         .open = tracing_open_generic,
 838         .read = event_format_read,
 839 };
 840
 841 static const struct file_operations ftrace_event_id_fops = {
 842         .open = tracing_open_generic,
 843         .read = event_id_read,
 844 };
 845
 846 static const struct file_operations ftrace_event_filter_fops = {
 847         .open = tracing_open_generic,
 848         .read = event_filter_read,
 849         .write = event_filter_write,
 850 };
 851
 852 static const struct file_operations ftrace_subsystem_filter_fops = {
 853         .open = tracing_open_generic,
 854         .read = subsystem_filter_read,
 855         .write = subsystem_filter_write,
 856 };
 857
 858 static const struct file_operations ftrace_system_enable_fops = {
 859         .open = tracing_open_generic,
 860         .read = system_enable_read,
 861         .write = system_enable_write,
 862 };
 863
 864 static const struct file_operations ftrace_show_header_fops = {
 865         .open = tracing_open_generic,
 866         .read = show_header,
 867 };
 868
 869 static struct dentry *event_trace_events_dir(void)
 870 {
 871         static struct dentry *d_tracer;
 872         static struct dentry *d_events;
 873
 874         if (d_events)
 875                 return d_events;
 876
 877         d_tracer = tracing_init_dentry();
 878         if (!d_tracer)
 879                 return NULL;
 880
 881         d_events = debugfs_create_dir("events", d_tracer);
 882         if (!d_events)
 883                 pr_warning("Could not create debugfs "
 884                            "'events' directory\n");
 885
 886         return d_events;
 887 }
 888
 889 static LIST_HEAD(event_subsystems);
 890
 891 static struct dentry *
 892 event_subsystem_dir(const char *name, struct dentry *d_events)
 893 {
 894         struct event_subsystem *system;
 895         struct dentry *entry;
 896
 897         /* First see if we did not already create this dir */
 898         list_for_each_entry(system, &event_subsystems, list) {
 899                 if (strcmp(system->name, name) == 0) {
 900                         system->nr_events++;
 901                         return system->entry;
 902                 }
 903         }
 904
 905         /* need to create new entry */
 906         system = kmalloc(sizeof(*system), GFP_KERNEL);
 907         if (!system) {
 908                 pr_warning("No memory to create event subsystem %s\n",
 909                            name);
 910                 return d_events;
 911         }
 912
 913         system->entry = debugfs_create_dir(name, d_events);
 914         if (!system->entry) {
 915                 pr_warning("Could not create event subsystem %s\n",
 916                            name);
 917                 kfree(system);
 918                 return d_events;
 919         }
 920
 921         system->nr_events = 1;
 922         system->name = kstrdup(name, GFP_KERNEL);
 923         if (!system->name) {
 924                 debugfs_remove(system->entry);
 925                 kfree(system);
 926                 return d_events;
 927         }
 928
 929         list_add(&system->list, &event_subsystems);
 930
 931         system->filter = NULL;
 932
 933         system->filter = kzalloc(sizeof(struct event_filter), GFP_KERNEL);
 934         if (!system->filter) {
 935                 pr_warning("Could not allocate filter for subsystem "
 936                            "'%s'\n", name);
 937                 return system->entry;
 938         }
 939
 940         entry = debugfs_create_file("filter", 0644, system->entry, system,
 941                                     &ftrace_subsystem_filter_fops);
 942         if (!entry) {
 943                 kfree(system->filter);
 944                 system->filter = NULL;
 945                 pr_warning("Could not create debugfs "
 946                            "'%s/filter' entry\n", name);
 947         }
 948
 949         trace_create_file("enable", 0644, system->entry,
 950                           (void *)system->name,
 951                           &ftrace_system_enable_fops);
 952
 953         return system->entry;
 954 }
 955
 956 static int
 957 event_create_dir(struct ftrace_event_call *call, struct dentry *d_events,
 958                  const struct file_operations *id,
 959                  const struct file_operations *enable,
 960                  const struct file_operations *filter,
 961                  const struct file_operations *format)
 962 {
 963         struct list_head *head;
 964         int ret;
 965
 966         /*
 967          * If the trace point header did not define TRACE_SYSTEM
 968          * then the system would be called "TRACE_SYSTEM".
 969          */
 970         if (strcmp(call->class->system, TRACE_SYSTEM) != 0)
 971                 d_events = event_subsystem_dir(call->class->system, d_events);
 972
 973         call->dir = debugfs_create_dir(call->name, d_events);
 974         if (!call->dir) {
 975                 pr_warning("Could not create debugfs "
 976                            "'%s' directory\n", call->name);
 977                 return -1;
 978         }
 979
 980         if (call->class->probe || call->class->reg)
 981                 trace_create_file("enable", 0644, call->dir, call,
 982                                   enable);
 983
 984 #ifdef CONFIG_PERF_EVENTS
 985         if (call->event.type && (call->class->perf_probe || call->class->reg))
 986                 trace_create_file("id", 0444, call->dir, call,
 987                                   id);
 988 #endif
 989
 990         /*
 991          * Other events may have the same class. Only update
 992          * the fields if they are not already defined.
 993          */
 994         head = trace_get_fields(call);
 995         if (list_empty(head)) {
 996                 ret = call->class->define_fields(call);
 997                 if (ret < 0) {
 998                         pr_warning("Could not initialize trace point"
 999                                    " events/%s\n", call->name);
1000                         return ret;
1001                 }
1002         }
1003         trace_create_file("filter", 0644, call->dir, call,
1004                           filter);
1005
1006         trace_create_file("format", 0444, call->dir, call,
1007                           format);
1008
1009         return 0;
1010 }
1011
1012 static int __trace_add_event_call(struct ftrace_event_call *call)
1013 {
1014         struct dentry *d_events;
1015         int ret;
1016
1017         if (!call->name)
1018                 return -EINVAL;
1019
1020         if (call->class->raw_init) {
1021                 ret = call->class->raw_init(call);
1022                 if (ret < 0) {
1023                         if (ret != -ENOSYS)
1024                                 pr_warning("Could not initialize trace "
1025                                 "events/%s\n", call->name);
1026                         return ret;
1027                 }
1028         }
1029
1030         d_events = event_trace_events_dir();
1031         if (!d_events)
1032                 return -ENOENT;
1033
1034         ret = event_create_dir(call, d_events, &ftrace_event_id_fops,
1035                                 &ftrace_enable_fops, &ftrace_event_filter_fops,
1036                                 &ftrace_event_format_fops);
1037         if (!ret)
1038                 list_add(&call->list, &ftrace_events);
1039
1040         return ret;
1041 }
1042
1043 /* Add an additional event_call dynamically */
1044 int trace_add_event_call(struct ftrace_event_call *call)
1045 {
1046         int ret;
1047         mutex_lock(&event_mutex);
1048         ret = __trace_add_event_call(call);
1049         mutex_unlock(&event_mutex);
1050         return ret;
1051 }
1052
1053 static void remove_subsystem_dir(const char *name)
1054 {
1055         struct event_subsystem *system;
1056
1057         if (strcmp(name, TRACE_SYSTEM) == 0)
1058                 return;
1059
1060         list_for_each_entry(system, &event_subsystems, list) {
1061                 if (strcmp(system->name, name) == 0) {
1062                         if (!--system->nr_events) {
1063                                 struct event_filter *filter = system->filter;
1064
1065                                 debugfs_remove_recursive(system->entry);
1066                                 list_del(&system->list);
1067                                 if (filter) {
1068                                         kfree(filter->filter_string);
1069                                         kfree(filter);
1070                                 }
1071                                 kfree(system->name);
1072                                 kfree(system);
1073                         }
1074                         break;
1075                 }
1076         }
1077 }
1078
1079 /*
1080  * Must be called under locking both of event_mutex and trace_event_mutex.
1081  */
1082 static void __trace_remove_event_call(struct ftrace_event_call *call)
1083 {
1084         ftrace_event_enable_disable(call, 0);
1085         if (call->event.funcs)
1086                 __unregister_ftrace_event(&call->event);
1087         debugfs_remove_recursive(call->dir);
1088         list_del(&call->list);
1089         trace_destroy_fields(call);
1090         destroy_preds(call);
1091         remove_subsystem_dir(call->class->system);
1092 }
1093
1094 /* Remove an event_call */
1095 void trace_remove_event_call(struct ftrace_event_call *call)
1096 {
1097         mutex_lock(&event_mutex);
1098         down_write(&trace_event_mutex);
1099         __trace_remove_event_call(call);
1100         up_write(&trace_event_mutex);
1101         mutex_unlock(&event_mutex);
1102 }
1103
1104 #define for_each_event(event, start, end)                       \
1105         for (event = start;                                     \
1106              (unsigned long)event < (unsigned long)end;         \
1107              event++)
1108
1109 #ifdef CONFIG_MODULES
1110
1111 static LIST_HEAD(ftrace_module_file_list);
1112
1113 /*
1114  * Modules must own their file_operations to keep up with
1115  * reference counting.
1116  */
1117 struct ftrace_module_file_ops {
1118         struct list_head                list;
1119         struct module                   *mod;
1120         struct file_operations          id;
1121         struct file_operations          enable;
1122         struct file_operations          format;
1123         struct file_operations          filter;
1124 };
1125
1126 static struct ftrace_module_file_ops *
1127 trace_create_file_ops(struct module *mod)
1128 {
1129         struct ftrace_module_file_ops *file_ops;
1130
1131         /*
1132          * This is a bit of a PITA. To allow for correct reference
1133          * counting, modules must "own" their file_operations.
1134          * To do this, we allocate the file operations that will be
1135          * used in the event directory.
1136          */
1137
1138         file_ops = kmalloc(sizeof(*file_ops), GFP_KERNEL);
1139         if (!file_ops)
1140                 return NULL;
1141
1142         file_ops->mod = mod;
1143
1144         file_ops->id = ftrace_event_id_fops;
1145         file_ops->id.owner = mod;
1146
1147         file_ops->enable = ftrace_enable_fops;
1148         file_ops->enable.owner = mod;
1149
1150         file_ops->filter = ftrace_event_filter_fops;
1151         file_ops->filter.owner = mod;
1152
1153         file_ops->format = ftrace_event_format_fops;
1154         file_ops->format.owner = mod;
1155
1156         list_add(&file_ops->list, &ftrace_module_file_list);
1157
1158         return file_ops;
1159 }
1160
1161 static void trace_module_add_events(struct module *mod)
1162 {
1163         struct ftrace_module_file_ops *file_ops = NULL;
1164         struct ftrace_event_call *call, *start, *end;
1165         struct dentry *d_events;
1166         int ret;
1167
1168         start = mod->trace_events;
1169         end = mod->trace_events + mod->num_trace_events;
1170
1171         if (start == end)
1172                 return;
1173
1174         d_events = event_trace_events_dir();
1175         if (!d_events)
1176                 return;
1177
1178         for_each_event(call, start, end) {
1179                 /* The linker may leave blanks */
1180                 if (!call->name)
1181                         continue;
1182                 if (call->class->raw_init) {
1183                         ret = call->class->raw_init(call);
1184                         if (ret < 0) {
1185                                 if (ret != -ENOSYS)
1186                                         pr_warning("Could not initialize trace "
1187                                         "point events/%s\n", call->name);
1188                                 continue;
1189                         }
1190                 }
1191                 /*
1192                  * This module has events, create file ops for this module
1193                  * if not already done.
1194                  */
1195                 if (!file_ops) {
1196                         file_ops = trace_create_file_ops(mod);
1197                         if (!file_ops)
1198                                 return;
1199                 }
1200                 call->mod = mod;
1201                 ret = event_create_dir(call, d_events,
1202                                        &file_ops->id, &file_ops->enable,
1203                                        &file_ops->filter, &file_ops->format);
1204                 if (!ret)
1205                         list_add(&call->list, &ftrace_events);
1206         }
1207 }
1208
1209 static void trace_module_remove_events(struct module *mod)
1210 {
1211         struct ftrace_module_file_ops *file_ops;
1212         struct ftrace_event_call *call, *p;
1213         bool found = false;
1214
1215         down_write(&trace_event_mutex);
1216         list_for_each_entry_safe(call, p, &ftrace_events, list) {
1217                 if (call->mod == mod) {
1218                         found = true;
1219                         __trace_remove_event_call(call);
1220                 }
1221         }
1222
1223         /* Now free the file_operations */
1224         list_for_each_entry(file_ops, &ftrace_module_file_list, list) {
1225                 if (file_ops->mod == mod)
1226                         break;
1227         }
1228         if (&file_ops->list != &ftrace_module_file_list) {
1229                 list_del(&file_ops->list);
1230                 kfree(file_ops);
1231         }
1232
1233         /*
1234          * It is safest to reset the ring buffer if the module being unloaded
1235          * registered any events.
1236          */
1237         if (found)
1238                 tracing_reset_current_online_cpus();
1239         up_write(&trace_event_mutex);
1240 }
1241
1242 static int trace_module_notify(struct notifier_block *self,
1243                                unsigned long val, void *data)
1244 {
1245         struct module *mod = data;
1246
1247         mutex_lock(&event_mutex);
1248         switch (val) {
1249         case MODULE_STATE_COMING:
1250                 trace_module_add_events(mod);
1251                 break;
1252         case MODULE_STATE_GOING:
1253                 trace_module_remove_events(mod);
1254                 break;
1255         }
1256         mutex_unlock(&event_mutex);
1257
1258         return 0;
1259 }
1260 #else
1261 static int trace_module_notify(struct notifier_block *self,
1262                                unsigned long val, void *data)
1263 {
1264         return 0;
1265 }
1266 #endif /* CONFIG_MODULES */
1267
1268 static struct notifier_block trace_module_nb = {
1269         .notifier_call = trace_module_notify,
1270         .priority = 0,
1271 };
1272
1273 extern struct ftrace_event_call __start_ftrace_events[];
1274 extern struct ftrace_event_call __stop_ftrace_events[];
1275
1276 static char bootup_event_buf[COMMAND_LINE_SIZE] __initdata;
1277
1278 static __init int setup_trace_event(char *str)
1279 {
1280         strlcpy(bootup_event_buf, str, COMMAND_LINE_SIZE);
1281         ring_buffer_expanded = 1;
1282         tracing_selftest_disabled = 1;
1283
1284         return 1;
1285 }
1286 __setup("trace_event=", setup_trace_event);
1287
1288 static __init int event_trace_init(void)
1289 {
1290         struct ftrace_event_call *call;
1291         struct dentry *d_tracer;
1292         struct dentry *entry;
1293         struct dentry *d_events;
1294         int ret;
1295         char *buf = bootup_event_buf;
1296         char *token;
1297
1298         d_tracer = tracing_init_dentry();
1299         if (!d_tracer)
1300                 return 0;
1301
1302         entry = debugfs_create_file("available_events", 0444, d_tracer,
1303                                     (void *)&show_event_seq_ops,
1304                                     &ftrace_avail_fops);
1305         if (!entry)
1306                 pr_warning("Could not create debugfs "
1307                            "'available_events' entry\n");
1308
1309         entry = debugfs_create_file("set_event", 0644, d_tracer,
1310                                     (void *)&show_set_event_seq_ops,
1311                                     &ftrace_set_event_fops);
1312         if (!entry)
1313                 pr_warning("Could not create debugfs "
1314                            "'set_event' entry\n");
1315
1316         d_events = event_trace_events_dir();
1317         if (!d_events)
1318                 return 0;
1319
1320         /* ring buffer internal formats */
1321         trace_create_file("header_page", 0444, d_events,
1322                           ring_buffer_print_page_header,
1323                           &ftrace_show_header_fops);
1324
1325         trace_create_file("header_event", 0444, d_events,
1326                           ring_buffer_print_entry_header,
1327                           &ftrace_show_header_fops);
1328
1329         trace_create_file("enable", 0644, d_events,
1330                           NULL, &ftrace_system_enable_fops);
1331
1332         if (trace_define_common_fields())
1333                 pr_warning("tracing: Failed to allocate common fields");
1334
1335         for_each_event(call, __start_ftrace_events, __stop_ftrace_events) {
1336                 /* The linker may leave blanks */
1337                 if (!call->name)
1338                         continue;
1339                 if (call->class->raw_init) {
1340                         ret = call->class->raw_init(call);
1341                         if (ret < 0) {
1342                                 if (ret != -ENOSYS)
1343                                         pr_warning("Could not initialize trace "
1344                                         "point events/%s\n", call->name);
1345                                 continue;
1346                         }
1347                 }
1348                 ret = event_create_dir(call, d_events, &ftrace_event_id_fops,
1349                                        &ftrace_enable_fops,
1350                                        &ftrace_event_filter_fops,
1351                                        &ftrace_event_format_fops);
1352                 if (!ret)
1353                         list_add(&call->list, &ftrace_events);
1354         }
1355
1356         while (true) {
1357                 token = strsep(&buf, ",");
1358
1359                 if (!token)
1360                         break;
1361                 if (!*token)
1362                         continue;
1363
1364                 ret = ftrace_set_clr_event(token, 1);
1365                 if (ret)
1366                         pr_warning("Failed to enable trace event: %s\n", token);
1367         }
1368
1369         ret = register_module_notifier(&trace_module_nb);
1370         if (ret)
1371                 pr_warning("Failed to register trace events module notifier\n");
1372
1373         return 0;
1374 }
1375 fs_initcall(event_trace_init);
1376
1377 #ifdef CONFIG_FTRACE_STARTUP_TEST
1378
1379 static DEFINE_SPINLOCK(test_spinlock);
1380 static DEFINE_SPINLOCK(test_spinlock_irq);
1381 static DEFINE_MUTEX(test_mutex);
1382
1383 static __init void test_work(struct work_struct *dummy)
1384 {
1385         spin_lock(&test_spinlock);
1386         spin_lock_irq(&test_spinlock_irq);
1387         udelay(1);
1388         spin_unlock_irq(&test_spinlock_irq);
1389         spin_unlock(&test_spinlock);
1390
1391         mutex_lock(&test_mutex);
1392         msleep(1);
1393         mutex_unlock(&test_mutex);
1394 }
1395
1396 static __init int event_test_thread(void *unused)
1397 {
1398         void *test_malloc;
1399
1400         test_malloc = kmalloc(1234, GFP_KERNEL);
1401         if (!test_malloc)
1402                 pr_info("failed to kmalloc\n");
1403
1404         schedule_on_each_cpu(test_work);
1405
1406         kfree(test_malloc);
1407
1408         set_current_state(TASK_INTERRUPTIBLE);
1409         while (!kthread_should_stop())
1410                 schedule();
1411
1412         return 0;
1413 }
1414
1415 /*
1416  * Do various things that may trigger events.
1417  */
1418 static __init void event_test_stuff(void)
1419 {
1420         struct task_struct *test_thread;
1421
1422         test_thread = kthread_run(event_test_thread, NULL, "test-events");
1423         msleep(1);
1424         kthread_stop(test_thread);
1425 }
1426
1427 /*
1428  * For every trace event defined, we will test each trace point separately,
1429  * and then by groups, and finally all trace points.
1430  */
1431 static __init void event_trace_self_tests(void)
1432 {
1433         struct ftrace_event_call *call;
1434         struct event_subsystem *system;
1435         int ret;
1436
1437         pr_info("Running tests on trace events:\n");
1438
1439         list_for_each_entry(call, &ftrace_events, list) {
1440
1441                 /* Only test those that have a probe */
1442                 if (!call->class || !call->class->probe)
1443                         continue;
1444
1445 /*
1446  * Testing syscall events here is pretty useless, but
1447  * we still do it if configured. But this is time consuming.
1448  * What we really need is a user thread to perform the
1449  * syscalls as we test.
1450  */
1451 #ifndef CONFIG_EVENT_TRACE_TEST_SYSCALLS
1452                 if (call->class->system &&
1453                     strcmp(call->class->system, "syscalls") == 0)
1454                         continue;
1455 #endif
1456
1457                 pr_info("Testing event %s: ", call->name);
1458
1459                 /*
1460                  * If an event is already enabled, someone is using
1461                  * it and the self test should not be on.
1462                  */
1463                 if (call->flags & TRACE_EVENT_FL_ENABLED) {
1464                         pr_warning("Enabled event during self test!\n");
1465                         WARN_ON_ONCE(1);
1466                         continue;
1467                 }
1468
1469                 ftrace_event_enable_disable(call, 1);
1470                 event_test_stuff();
1471                 ftrace_event_enable_disable(call, 0);
1472
1473                 pr_cont("OK\n");
1474         }
1475
1476         /* Now test at the sub system level */
1477
1478         pr_info("Running tests on trace event systems:\n");
1479
1480         list_for_each_entry(system, &event_subsystems, list) {
1481
1482                 /* the ftrace system is special, skip it */
1483                 if (strcmp(system->name, "ftrace") == 0)
1484                         continue;
1485
1486                 pr_info("Testing event system %s: ", system->name);
1487
1488                 ret = __ftrace_set_clr_event(NULL, system->name, NULL, 1);
1489                 if (WARN_ON_ONCE(ret)) {
1490                         pr_warning("error enabling system %s\n",
1491                                    system->name);
1492                         continue;
1493                 }
1494
1495                 event_test_stuff();
1496
1497                 ret = __ftrace_set_clr_event(NULL, system->name, NULL, 0);
1498                 if (WARN_ON_ONCE(ret))
1499                         pr_warning("error disabling system %s\n",
1500                                    system->name);
1501
1502                 pr_cont("OK\n");
1503         }
1504
1505         /* Test with all events enabled */
1506
1507         pr_info("Running tests on all trace events:\n");
1508         pr_info("Testing all events: ");
1509
1510         ret = __ftrace_set_clr_event(NULL, NULL, NULL, 1);
1511         if (WARN_ON_ONCE(ret)) {
1512                 pr_warning("error enabling all events\n");
1513                 return;
1514         }
1515
1516         event_test_stuff();
1517
1518         /* reset sysname */
1519         ret = __ftrace_set_clr_event(NULL, NULL, NULL, 0);
1520         if (WARN_ON_ONCE(ret)) {
1521                 pr_warning("error disabling all events\n");
1522                 return;
1523         }
1524
1525         pr_cont("OK\n");
1526 }
1527
1528 #ifdef CONFIG_FUNCTION_TRACER
1529
1530 static DEFINE_PER_CPU(atomic_t, ftrace_test_event_disable);
1531
1532 static void
1533 function_test_events_call(unsigned long ip, unsigned long parent_ip)
1534 {
1535         struct ring_buffer_event *event;
1536         struct ring_buffer *buffer;
1537         struct ftrace_entry *entry;
1538         unsigned long flags;
1539         long disabled;
1540         int cpu;
1541         int pc;
1542
1543         pc = preempt_count();
1544         preempt_disable_notrace();
1545         cpu = raw_smp_processor_id();
1546         disabled = atomic_inc_return(&per_cpu(ftrace_test_event_disable, cpu));
1547
1548         if (disabled != 1)
1549                 goto out;
1550
1551         local_save_flags(flags);
1552
1553         event = trace_current_buffer_lock_reserve(&buffer,
1554                                                   TRACE_FN, sizeof(*entry),
1555                                                   flags, pc);
1556         if (!event)
1557                 goto out;
1558         entry   = ring_buffer_event_data(event);
1559         entry->ip                       = ip;
1560         entry->parent_ip                = parent_ip;
1561
1562         trace_nowake_buffer_unlock_commit(buffer, event, flags, pc);
1563
1564  out:
1565         atomic_dec(&per_cpu(ftrace_test_event_disable, cpu));
1566         preempt_enable_notrace();
1567 }
1568
1569 static struct ftrace_ops trace_ops __initdata  =
1570 {
1571         .func = function_test_events_call,
1572 };
1573
1574 static __init void event_trace_self_test_with_function(void)
1575 {
1576         register_ftrace_function(&trace_ops);
1577         pr_info("Running tests again, along with the function tracer\n");
1578         event_trace_self_tests();
1579         unregister_ftrace_function(&trace_ops);
1580 }
1581 #else
1582 static __init void event_trace_self_test_with_function(void)
1583 {
1584 }
1585 #endif
1586
1587 static __init int event_trace_self_tests_init(void)
1588 {
1589         if (!tracing_selftest_disabled) {
1590                 event_trace_self_tests();
1591                 event_trace_self_test_with_function();
1592         }
1593
1594         return 0;
1595 }
1596
1597 late_initcall(event_trace_self_tests_init);
1598
1599 #endif