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 DEFINE_MUTEX(event_storage_mutex);
  31 EXPORT_SYMBOL_GPL(event_storage_mutex);
  32
  33 char event_storage[EVENT_STORAGE_SIZE];
  34 EXPORT_SYMBOL_GPL(event_storage);
  35
  36 LIST_HEAD(ftrace_events);
  37 LIST_HEAD(ftrace_common_fields);
  38
  39 struct list_head *
  40 trace_get_fields(struct ftrace_event_call *event_call)
  41 {
  42         if (!event_call->class->get_fields)
  43                 return &event_call->class->fields;
  44         return event_call->class->get_fields(event_call);
  45 }
  46
  47 static int __trace_define_field(struct list_head *head, const char *type,
  48                                 const char *name, int offset, int size,
  49                                 int is_signed, int filter_type)
  50 {
  51         struct ftrace_event_field *field;
  52
  53         field = kzalloc(sizeof(*field), GFP_KERNEL);
  54         if (!field)
  55                 goto err;
  56
  57         field->name = kstrdup(name, GFP_KERNEL);
  58         if (!field->name)
  59                 goto err;
  60
  61         field->type = kstrdup(type, GFP_KERNEL);
  62         if (!field->type)
  63                 goto err;
  64
  65         if (filter_type == FILTER_OTHER)
  66                 field->filter_type = filter_assign_type(type);
  67         else
  68                 field->filter_type = filter_type;
  69
  70         field->offset = offset;
  71         field->size = size;
  72         field->is_signed = is_signed;
  73
  74         list_add(&field->link, head);
  75
  76         return 0;
  77
  78 err:
  79         if (field)
  80                 kfree(field->name);
  81         kfree(field);
  82
  83         return -ENOMEM;
  84 }
  85
  86 int trace_define_field(struct ftrace_event_call *call, const char *type,
  87                        const char *name, int offset, int size, int is_signed,
  88                        int filter_type)
  89 {
  90         struct list_head *head;
  91
  92         if (WARN_ON(!call->class))
  93                 return 0;
  94
  95         head = trace_get_fields(call);
  96         return __trace_define_field(head, type, name, offset, size,
  97                                     is_signed, filter_type);
  98 }
  99 EXPORT_SYMBOL_GPL(trace_define_field);
 100
 101 #define __common_field(type, item)                                      \
 102         ret = __trace_define_field(&ftrace_common_fields, #type,        \
 103                                    "common_" #item,                     \
 104                                    offsetof(typeof(ent), item),         \
 105                                    sizeof(ent.item),                    \
 106                                    is_signed_type(type), FILTER_OTHER); \
 107         if (ret)                                                        \
 108                 return ret;
 109
 110 static int trace_define_common_fields(void)
 111 {
 112         int ret;
 113         struct trace_entry ent;
 114
 115         __common_field(unsigned short, type);
 116         __common_field(unsigned char, flags);
 117         __common_field(unsigned char, preempt_count);
 118         __common_field(int, pid);
 119         __common_field(int, padding);
 120
 121         return ret;
 122 }
 123
 124 void trace_destroy_fields(struct ftrace_event_call *call)
 125 {
 126         struct ftrace_event_field *field, *next;
 127         struct list_head *head;
 128
 129         head = trace_get_fields(call);
 130         list_for_each_entry_safe(field, next, head, link) {
 131                 list_del(&field->link);
 132                 kfree(field->type);
 133                 kfree(field->name);
 134                 kfree(field);
 135         }
 136 }
 137
 138 int trace_event_raw_init(struct ftrace_event_call *call)
 139 {
 140         int id;
 141
 142         id = register_ftrace_event(&call->event);
 143         if (!id)
 144                 return -ENODEV;
 145
 146         return 0;
 147 }
 148 EXPORT_SYMBOL_GPL(trace_event_raw_init);
 149
 150 int ftrace_event_reg(struct ftrace_event_call *call, enum trace_reg type)
 151 {
 152         switch (type) {
 153         case TRACE_REG_REGISTER:
 154                 return tracepoint_probe_register(call->name,
 155                                                  call->class->probe,
 156                                                  call);
 157         case TRACE_REG_UNREGISTER:
 158                 tracepoint_probe_unregister(call->name,
 159                                             call->class->probe,
 160                                             call);
 161                 return 0;
 162
 163 #ifdef CONFIG_PERF_EVENTS
 164         case TRACE_REG_PERF_REGISTER:
 165                 return tracepoint_probe_register(call->name,
 166                                                  call->class->perf_probe,
 167                                                  call);
 168         case TRACE_REG_PERF_UNREGISTER:
 169                 tracepoint_probe_unregister(call->name,
 170                                             call->class->perf_probe,
 171                                             call);
 172                 return 0;
 173 #endif
 174         }
 175         return 0;
 176 }
 177 EXPORT_SYMBOL_GPL(ftrace_event_reg);
 178
 179 void trace_event_enable_cmd_record(bool enable)
 180 {
 181         struct ftrace_event_call *call;
 182
 183         mutex_lock(&event_mutex);
 184         list_for_each_entry(call, &ftrace_events, list) {
 185                 if (!(call->flags & TRACE_EVENT_FL_ENABLED))
 186                         continue;
 187
 188                 if (enable) {
 189                         tracing_start_cmdline_record();
 190                         call->flags |= TRACE_EVENT_FL_RECORDED_CMD;
 191                 } else {
 192                         tracing_stop_cmdline_record();
 193                         call->flags &= ~TRACE_EVENT_FL_RECORDED_CMD;
 194                 }
 195         }
 196         mutex_unlock(&event_mutex);
 197 }
 198
 199 static int ftrace_event_enable_disable(struct ftrace_event_call *call,
 200                                         int enable)
 201 {
 202         int ret = 0;
 203
 204         switch (enable) {
 205         case 0:
 206                 if (call->flags & TRACE_EVENT_FL_ENABLED) {
 207                         call->flags &= ~TRACE_EVENT_FL_ENABLED;
 208                         if (call->flags & TRACE_EVENT_FL_RECORDED_CMD) {
 209                                 tracing_stop_cmdline_record();
 210                                 call->flags &= ~TRACE_EVENT_FL_RECORDED_CMD;
 211                         }
 212                         call->class->reg(call, TRACE_REG_UNREGISTER);
 213                 }
 214                 break;
 215         case 1:
 216                 if (!(call->flags & TRACE_EVENT_FL_ENABLED)) {
 217                         if (trace_flags & TRACE_ITER_RECORD_CMD) {
 218                                 tracing_start_cmdline_record();
 219                                 call->flags |= TRACE_EVENT_FL_RECORDED_CMD;
 220                         }
 221                         ret = call->class->reg(call, TRACE_REG_REGISTER);
 222                         if (ret) {
 223                                 tracing_stop_cmdline_record();
 224                                 pr_info("event trace: Could not enable event "
 225                                         "%s\n", call->name);
 226                                 break;
 227                         }
 228                         call->flags |= TRACE_EVENT_FL_ENABLED;
 229                 }
 230                 break;
 231         }
 232
 233         return ret;
 234 }
 235
 236 static void ftrace_clear_events(void)
 237 {
 238         struct ftrace_event_call *call;
 239
 240         mutex_lock(&event_mutex);
 241         list_for_each_entry(call, &ftrace_events, list) {
 242                 ftrace_event_enable_disable(call, 0);
 243         }
 244         mutex_unlock(&event_mutex);
 245 }
 246
 247 static void __put_system(struct event_subsystem *system)
 248 {
 249         struct event_filter *filter = system->filter;
 250
 251         WARN_ON_ONCE(system->ref_count == 0);
 252         if (--system->ref_count)
 253                 return;
 254
 255         if (filter) {
 256                 kfree(filter->filter_string);
 257                 kfree(filter);
 258         }
 259         kfree(system->name);
 260         kfree(system);
 261 }
 262
 263 static void __get_system(struct event_subsystem *system)
 264 {
 265         WARN_ON_ONCE(system->ref_count == 0);
 266         system->ref_count++;
 267 }
 268
 269 static void put_system(struct event_subsystem *system)
 270 {
 271         mutex_lock(&event_mutex);
 272         __put_system(system);
 273         mutex_unlock(&event_mutex);
 274 }
 275
 276 /*
 277  * __ftrace_set_clr_event(NULL, NULL, NULL, set) will set/unset all events.
 278  */
 279 static int __ftrace_set_clr_event(const char *match, const char *sub,
 280                                   const char *event, int set)
 281 {
 282         struct ftrace_event_call *call;
 283         int ret = -EINVAL;
 284
 285         mutex_lock(&event_mutex);
 286         list_for_each_entry(call, &ftrace_events, list) {
 287
 288                 if (!call->name || !call->class || !call->class->reg)
 289                         continue;
 290
 291                 if (match &&
 292                     strcmp(match, call->name) != 0 &&
 293                     strcmp(match, call->class->system) != 0)
 294                         continue;
 295
 296                 if (sub && strcmp(sub, call->class->system) != 0)
 297                         continue;
 298
 299                 if (event && strcmp(event, call->name) != 0)
 300                         continue;
 301
 302                 ftrace_event_enable_disable(call, set);
 303
 304                 ret = 0;
 305         }
 306         mutex_unlock(&event_mutex);
 307
 308         return ret;
 309 }
 310
 311 static int ftrace_set_clr_event(char *buf, int set)
 312 {
 313         char *event = NULL, *sub = NULL, *match;
 314
 315         /*
 316          * The buf format can be <subsystem>:<event-name>
 317          *  *:<event-name> means any event by that name.
 318          *  :<event-name> is the same.
 319          *
 320          *  <subsystem>:* means all events in that subsystem
 321          *  <subsystem>: means the same.
 322          *
 323          *  <name> (no ':') means all events in a subsystem with
 324          *  the name <name> or any event that matches <name>
 325          */
 326
 327         match = strsep(&buf, ":");
 328         if (buf) {
 329                 sub = match;
 330                 event = buf;
 331                 match = NULL;
 332
 333                 if (!strlen(sub) || strcmp(sub, "*") == 0)
 334                         sub = NULL;
 335                 if (!strlen(event) || strcmp(event, "*") == 0)
 336                         event = NULL;
 337         }
 338
 339         return __ftrace_set_clr_event(match, sub, event, set);
 340 }
 341
 342 /**
 343  * trace_set_clr_event - enable or disable an event
 344  * @system: system name to match (NULL for any system)
 345  * @event: event name to match (NULL for all events, within system)
 346  * @set: 1 to enable, 0 to disable
 347  *
 348  * This is a way for other parts of the kernel to enable or disable
 349  * event recording.
 350  *
 351  * Returns 0 on success, -EINVAL if the parameters do not match any
 352  * registered events.
 353  */
 354 int trace_set_clr_event(const char *system, const char *event, int set)
 355 {
 356         return __ftrace_set_clr_event(NULL, system, event, set);
 357 }
 358 EXPORT_SYMBOL_GPL(trace_set_clr_event);
 359
 360 /* 128 should be much more than enough */
 361 #define EVENT_BUF_SIZE          127
 362
 363 static ssize_t
 364 ftrace_event_write(struct file *file, const char __user *ubuf,
 365                    size_t cnt, loff_t *ppos)
 366 {
 367         struct trace_parser parser;
 368         ssize_t read, ret;
 369
 370         if (!cnt)
 371                 return 0;
 372
 373         ret = tracing_update_buffers();
 374         if (ret < 0)
 375                 return ret;
 376
 377         if (trace_parser_get_init(&parser, EVENT_BUF_SIZE + 1))
 378                 return -ENOMEM;
 379
 380         read = trace_get_user(&parser, ubuf, cnt, ppos);
 381
 382         if (read >= 0 && trace_parser_loaded((&parser))) {
 383                 int set = 1;
 384
 385                 if (*parser.buffer == '!')
 386                         set = 0;
 387
 388                 parser.buffer[parser.idx] = 0;
 389
 390                 ret = ftrace_set_clr_event(parser.buffer + !set, set);
 391                 if (ret)
 392                         goto out_put;
 393         }
 394
 395         ret = read;
 396
 397  out_put:
 398         trace_parser_put(&parser);
 399
 400         return ret;
 401 }
 402
 403 static void *
 404 t_next(struct seq_file *m, void *v, loff_t *pos)
 405 {
 406         struct ftrace_event_call *call = v;
 407
 408         (*pos)++;
 409
 410         list_for_each_entry_continue(call, &ftrace_events, list) {
 411                 /*
 412                  * The ftrace subsystem is for showing formats only.
 413                  * They can not be enabled or disabled via the event files.
 414                  */
 415                 if (call->class && call->class->reg)
 416                         return call;
 417         }
 418
 419         return NULL;
 420 }
 421
 422 static void *t_start(struct seq_file *m, loff_t *pos)
 423 {
 424         struct ftrace_event_call *call;
 425         loff_t l;
 426
 427         mutex_lock(&event_mutex);
 428
 429         call = list_entry(&ftrace_events, struct ftrace_event_call, list);
 430         for (l = 0; l <= *pos; ) {
 431                 call = t_next(m, call, &l);
 432                 if (!call)
 433                         break;
 434         }
 435         return call;
 436 }
 437
 438 static void *
 439 s_next(struct seq_file *m, void *v, loff_t *pos)
 440 {
 441         struct ftrace_event_call *call = v;
 442
 443         (*pos)++;
 444
 445         list_for_each_entry_continue(call, &ftrace_events, list) {
 446                 if (call->flags & TRACE_EVENT_FL_ENABLED)
 447                         return call;
 448         }
 449
 450         return NULL;
 451 }
 452
 453 static void *s_start(struct seq_file *m, loff_t *pos)
 454 {
 455         struct ftrace_event_call *call;
 456         loff_t l;
 457
 458         mutex_lock(&event_mutex);
 459
 460         call = list_entry(&ftrace_events, struct ftrace_event_call, list);
 461         for (l = 0; l <= *pos; ) {
 462                 call = s_next(m, call, &l);
 463                 if (!call)
 464                         break;
 465         }
 466         return call;
 467 }
 468
 469 static int t_show(struct seq_file *m, void *v)
 470 {
 471         struct ftrace_event_call *call = v;
 472
 473         if (strcmp(call->class->system, TRACE_SYSTEM) != 0)
 474                 seq_printf(m, "%s:", call->class->system);
 475         seq_printf(m, "%s\n", call->name);
 476
 477         return 0;
 478 }
 479
 480 static void t_stop(struct seq_file *m, void *p)
 481 {
 482         mutex_unlock(&event_mutex);
 483 }
 484
 485 static int
 486 ftrace_event_seq_open(struct inode *inode, struct file *file)
 487 {
 488         const struct seq_operations *seq_ops;
 489
 490         if ((file->f_mode & FMODE_WRITE) &&
 491             (file->f_flags & O_TRUNC))
 492                 ftrace_clear_events();
 493
 494         seq_ops = inode->i_private;
 495         return seq_open(file, seq_ops);
 496 }
 497
 498 static ssize_t
 499 event_enable_read(struct file *filp, char __user *ubuf, size_t cnt,
 500                   loff_t *ppos)
 501 {
 502         struct ftrace_event_call *call = filp->private_data;
 503         char *buf;
 504
 505         if (call->flags & TRACE_EVENT_FL_ENABLED)
 506                 buf = "1\n";
 507         else
 508                 buf = "0\n";
 509
 510         return simple_read_from_buffer(ubuf, cnt, ppos, buf, 2);
 511 }
 512
 513 static ssize_t
 514 event_enable_write(struct file *filp, const char __user *ubuf, size_t cnt,
 515                    loff_t *ppos)
 516 {
 517         struct ftrace_event_call *call = filp->private_data;
 518         unsigned long val;
 519         int ret;
 520
 521         ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
 522         if (ret)
 523                 return ret;
 524
 525         ret = tracing_update_buffers();
 526         if (ret < 0)
 527                 return ret;
 528
 529         switch (val) {
 530         case 0:
 531         case 1:
 532                 mutex_lock(&event_mutex);
 533                 ret = ftrace_event_enable_disable(call, val);
 534                 mutex_unlock(&event_mutex);
 535                 break;
 536
 537         default:
 538                 return -EINVAL;
 539         }
 540
 541         *ppos += cnt;
 542
 543         return ret ? ret : cnt;
 544 }
 545
 546 static ssize_t
 547 system_enable_read(struct file *filp, char __user *ubuf, size_t cnt,
 548                    loff_t *ppos)
 549 {
 550         const char set_to_char[4] = { '?', '0', '1', 'X' };
 551         struct event_subsystem *system = filp->private_data;
 552         struct ftrace_event_call *call;
 553         char buf[2];
 554         int set = 0;
 555         int ret;
 556
 557         mutex_lock(&event_mutex);
 558         list_for_each_entry(call, &ftrace_events, list) {
 559                 if (!call->name || !call->class || !call->class->reg)
 560                         continue;
 561
 562                 if (system && strcmp(call->class->system, system->name) != 0)
 563                         continue;
 564
 565                 /*
 566                  * We need to find out if all the events are set
 567                  * or if all events or cleared, or if we have
 568                  * a mixture.
 569                  */
 570                 set |= (1 << !!(call->flags & TRACE_EVENT_FL_ENABLED));
 571
 572                 /*
 573                  * If we have a mixture, no need to look further.
 574                  */
 575                 if (set == 3)
 576                         break;
 577         }
 578         mutex_unlock(&event_mutex);
 579
 580         buf[0] = set_to_char[set];
 581         buf[1] = '\n';
 582
 583         ret = simple_read_from_buffer(ubuf, cnt, ppos, buf, 2);
 584
 585         return ret;
 586 }
 587
 588 static ssize_t
 589 system_enable_write(struct file *filp, const char __user *ubuf, size_t cnt,
 590                     loff_t *ppos)
 591 {
 592         struct event_subsystem *system = filp->private_data;
 593         const char *name = NULL;
 594         unsigned long val;
 595         ssize_t ret;
 596
 597         ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
 598         if (ret)
 599                 return ret;
 600
 601         ret = tracing_update_buffers();
 602         if (ret < 0)
 603                 return ret;
 604
 605         if (val != 0 && val != 1)
 606                 return -EINVAL;
 607
 608         /*
 609          * Opening of "enable" adds a ref count to system,
 610          * so the name is safe to use.
 611          */
 612         if (system)
 613                 name = system->name;
 614
 615         ret = __ftrace_set_clr_event(NULL, name, NULL, val);
 616         if (ret)
 617                 goto out;
 618
 619         ret = cnt;
 620
 621 out:
 622         *ppos += cnt;
 623
 624         return ret;
 625 }
 626
 627 enum {
 628         FORMAT_HEADER           = 1,
 629         FORMAT_FIELD_SEPERATOR  = 2,
 630         FORMAT_PRINTFMT         = 3,
 631 };
 632
 633 static void *f_next(struct seq_file *m, void *v, loff_t *pos)
 634 {
 635         struct ftrace_event_call *call = m->private;
 636         struct ftrace_event_field *field;
 637         struct list_head *common_head = &ftrace_common_fields;
 638         struct list_head *head = trace_get_fields(call);
 639
 640         (*pos)++;
 641
 642         switch ((unsigned long)v) {
 643         case FORMAT_HEADER:
 644                 if (unlikely(list_empty(common_head)))
 645                         return NULL;
 646
 647                 field = list_entry(common_head->prev,
 648                                    struct ftrace_event_field, link);
 649                 return field;
 650
 651         case FORMAT_FIELD_SEPERATOR:
 652                 if (unlikely(list_empty(head)))
 653                         return NULL;
 654
 655                 field = list_entry(head->prev, struct ftrace_event_field, link);
 656                 return field;
 657
 658         case FORMAT_PRINTFMT:
 659                 /* all done */
 660                 return NULL;
 661         }
 662
 663         field = v;
 664         if (field->link.prev == common_head)
 665                 return (void *)FORMAT_FIELD_SEPERATOR;
 666         else if (field->link.prev == head)
 667                 return (void *)FORMAT_PRINTFMT;
 668
 669         field = list_entry(field->link.prev, struct ftrace_event_field, link);
 670
 671         return field;
 672 }
 673
 674 static void *f_start(struct seq_file *m, loff_t *pos)
 675 {
 676         loff_t l = 0;
 677         void *p;
 678
 679         /* Start by showing the header */
 680         if (!*pos)
 681                 return (void *)FORMAT_HEADER;
 682
 683         p = (void *)FORMAT_HEADER;
 684         do {
 685                 p = f_next(m, p, &l);
 686         } while (p && l < *pos);
 687
 688         return p;
 689 }
 690
 691 static int f_show(struct seq_file *m, void *v)
 692 {
 693         struct ftrace_event_call *call = m->private;
 694         struct ftrace_event_field *field;
 695         const char *array_descriptor;
 696
 697         switch ((unsigned long)v) {
 698         case FORMAT_HEADER:
 699                 seq_printf(m, "name: %s\n", call->name);
 700                 seq_printf(m, "ID: %d\n", call->event.type);
 701                 seq_printf(m, "format:\n");
 702                 return 0;
 703
 704         case FORMAT_FIELD_SEPERATOR:
 705                 seq_putc(m, '\n');
 706                 return 0;
 707
 708         case FORMAT_PRINTFMT:
 709                 seq_printf(m, "\nprint fmt: %s\n",
 710                            call->print_fmt);
 711                 return 0;
 712         }
 713
 714         field = v;
 715
 716         /*
 717          * Smartly shows the array type(except dynamic array).
 718          * Normal:
 719          *      field:TYPE VAR
 720          * If TYPE := TYPE[LEN], it is shown:
 721          *      field:TYPE VAR[LEN]
 722          */
 723         array_descriptor = strchr(field->type, '[');
 724
 725         if (!strncmp(field->type, "__data_loc", 10))
 726                 array_descriptor = NULL;
 727
 728         if (!array_descriptor)
 729                 seq_printf(m, "\tfield:%s %s;\toffset:%u;\tsize:%u;\tsigned:%d;\n",
 730                            field->type, field->name, field->offset,
 731                            field->size, !!field->is_signed);
 732         else
 733                 seq_printf(m, "\tfield:%.*s %s%s;\toffset:%u;\tsize:%u;\tsigned:%d;\n",
 734                            (int)(array_descriptor - field->type),
 735                            field->type, field->name,
 736                            array_descriptor, field->offset,
 737                            field->size, !!field->is_signed);
 738
 739         return 0;
 740 }
 741
 742 static void f_stop(struct seq_file *m, void *p)
 743 {
 744 }
 745
 746 static const struct seq_operations trace_format_seq_ops = {
 747         .start          = f_start,
 748         .next           = f_next,
 749         .stop           = f_stop,
 750         .show           = f_show,
 751 };
 752
 753 static int trace_format_open(struct inode *inode, struct file *file)
 754 {
 755         struct ftrace_event_call *call = inode->i_private;
 756         struct seq_file *m;
 757         int ret;
 758
 759         ret = seq_open(file, &trace_format_seq_ops);
 760         if (ret < 0)
 761                 return ret;
 762
 763         m = file->private_data;
 764         m->private = call;
 765
 766         return 0;
 767 }
 768
 769 static ssize_t
 770 event_id_read(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos)
 771 {
 772         struct ftrace_event_call *call = filp->private_data;
 773         struct trace_seq *s;
 774         int r;
 775
 776         if (*ppos)
 777                 return 0;
 778
 779         s = kmalloc(sizeof(*s), GFP_KERNEL);
 780         if (!s)
 781                 return -ENOMEM;
 782
 783         trace_seq_init(s);
 784         trace_seq_printf(s, "%d\n", call->event.type);
 785
 786         r = simple_read_from_buffer(ubuf, cnt, ppos,
 787                                     s->buffer, s->len);
 788         kfree(s);
 789         return r;
 790 }
 791
 792 static ssize_t
 793 event_filter_read(struct file *filp, char __user *ubuf, size_t cnt,
 794                   loff_t *ppos)
 795 {
 796         struct ftrace_event_call *call = filp->private_data;
 797         struct trace_seq *s;
 798         int r;
 799
 800         if (*ppos)
 801                 return 0;
 802
 803         s = kmalloc(sizeof(*s), GFP_KERNEL);
 804         if (!s)
 805                 return -ENOMEM;
 806
 807         trace_seq_init(s);
 808
 809         print_event_filter(call, s);
 810         r = simple_read_from_buffer(ubuf, cnt, ppos, s->buffer, s->len);
 811
 812         kfree(s);
 813
 814         return r;
 815 }
 816
 817 static ssize_t
 818 event_filter_write(struct file *filp, const char __user *ubuf, size_t cnt,
 819                    loff_t *ppos)
 820 {
 821         struct ftrace_event_call *call = filp->private_data;
 822         char *buf;
 823         int err;
 824
 825         if (cnt >= PAGE_SIZE)
 826                 return -EINVAL;
 827
 828         buf = (char *)__get_free_page(GFP_TEMPORARY);
 829         if (!buf)
 830                 return -ENOMEM;
 831
 832         if (copy_from_user(buf, ubuf, cnt)) {
 833                 free_page((unsigned long) buf);
 834                 return -EFAULT;
 835         }
 836         buf[cnt] = '\0';
 837
 838         err = apply_event_filter(call, buf);
 839         free_page((unsigned long) buf);
 840         if (err < 0)
 841                 return err;
 842
 843         *ppos += cnt;
 844
 845         return cnt;
 846 }
 847
 848 static LIST_HEAD(event_subsystems);
 849
 850 static int subsystem_open(struct inode *inode, struct file *filp)
 851 {
 852         struct event_subsystem *system = NULL;
 853         int ret;
 854
 855         if (!inode->i_private)
 856                 goto skip_search;
 857
 858         /* Make sure the system still exists */
 859         mutex_lock(&event_mutex);
 860         list_for_each_entry(system, &event_subsystems, list) {
 861                 if (system == inode->i_private) {
 862                         /* Don't open systems with no events */
 863                         if (!system->nr_events) {
 864                                 system = NULL;
 865                                 break;
 866                         }
 867                         __get_system(system);
 868                         break;
 869                 }
 870         }
 871         mutex_unlock(&event_mutex);
 872
 873         if (system != inode->i_private)
 874                 return -ENODEV;
 875
 876  skip_search:
 877         ret = tracing_open_generic(inode, filp);
 878         if (ret < 0 && system)
 879                 put_system(system);
 880
 881         return ret;
 882 }
 883
 884 static int subsystem_release(struct inode *inode, struct file *file)
 885 {
 886         struct event_subsystem *system = inode->i_private;
 887
 888         if (system)
 889                 put_system(system);
 890
 891         return 0;
 892 }
 893
 894 static ssize_t
 895 subsystem_filter_read(struct file *filp, char __user *ubuf, size_t cnt,
 896                       loff_t *ppos)
 897 {
 898         struct event_subsystem *system = filp->private_data;
 899         struct trace_seq *s;
 900         int r;
 901
 902         if (*ppos)
 903                 return 0;
 904
 905         s = kmalloc(sizeof(*s), GFP_KERNEL);
 906         if (!s)
 907                 return -ENOMEM;
 908
 909         trace_seq_init(s);
 910
 911         print_subsystem_event_filter(system, s);
 912         r = simple_read_from_buffer(ubuf, cnt, ppos, s->buffer, s->len);
 913
 914         kfree(s);
 915
 916         return r;
 917 }
 918
 919 static ssize_t
 920 subsystem_filter_write(struct file *filp, const char __user *ubuf, size_t cnt,
 921                        loff_t *ppos)
 922 {
 923         struct event_subsystem *system = filp->private_data;
 924         char *buf;
 925         int err;
 926
 927         if (cnt >= PAGE_SIZE)
 928                 return -EINVAL;
 929
 930         buf = (char *)__get_free_page(GFP_TEMPORARY);
 931         if (!buf)
 932                 return -ENOMEM;
 933
 934         if (copy_from_user(buf, ubuf, cnt)) {
 935                 free_page((unsigned long) buf);
 936                 return -EFAULT;
 937         }
 938         buf[cnt] = '\0';
 939
 940         err = apply_subsystem_event_filter(system, buf);
 941         free_page((unsigned long) buf);
 942         if (err < 0)
 943                 return err;
 944
 945         *ppos += cnt;
 946
 947         return cnt;
 948 }
 949
 950 static ssize_t
 951 show_header(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos)
 952 {
 953         int (*func)(struct trace_seq *s) = filp->private_data;
 954         struct trace_seq *s;
 955         int r;
 956
 957         if (*ppos)
 958                 return 0;
 959
 960         s = kmalloc(sizeof(*s), GFP_KERNEL);
 961         if (!s)
 962                 return -ENOMEM;
 963
 964         trace_seq_init(s);
 965
 966         func(s);
 967         r = simple_read_from_buffer(ubuf, cnt, ppos, s->buffer, s->len);
 968
 969         kfree(s);
 970
 971         return r;
 972 }
 973
 974 static const struct seq_operations show_event_seq_ops = {
 975         .start = t_start,
 976         .next = t_next,
 977         .show = t_show,
 978         .stop = t_stop,
 979 };
 980
 981 static const struct seq_operations show_set_event_seq_ops = {
 982         .start = s_start,
 983         .next = s_next,
 984         .show = t_show,
 985         .stop = t_stop,
 986 };
 987
 988 static const struct file_operations ftrace_avail_fops = {
 989         .open = ftrace_event_seq_open,
 990         .read = seq_read,
 991         .llseek = seq_lseek,
 992         .release = seq_release,
 993 };
 994
 995 static const struct file_operations ftrace_set_event_fops = {
 996         .open = ftrace_event_seq_open,
 997         .read = seq_read,
 998         .write = ftrace_event_write,
 999         .llseek = seq_lseek,
1000         .release = seq_release,
1001 };
1002
1003 static const struct file_operations ftrace_enable_fops = {
1004         .open = tracing_open_generic,
1005         .read = event_enable_read,
1006         .write = event_enable_write,
1007         .llseek = default_llseek,
1008 };
1009
1010 static const struct file_operations ftrace_event_format_fops = {
1011         .open = trace_format_open,
1012         .read = seq_read,
1013         .llseek = seq_lseek,
1014         .release = seq_release,
1015 };
1016
1017 static const struct file_operations ftrace_event_id_fops = {
1018         .open = tracing_open_generic,
1019         .read = event_id_read,
1020         .llseek = default_llseek,
1021 };
1022
1023 static const struct file_operations ftrace_event_filter_fops = {
1024         .open = tracing_open_generic,
1025         .read = event_filter_read,
1026         .write = event_filter_write,
1027         .llseek = default_llseek,
1028 };
1029
1030 static const struct file_operations ftrace_subsystem_filter_fops = {
1031         .open = subsystem_open,
1032         .read = subsystem_filter_read,
1033         .write = subsystem_filter_write,
1034         .llseek = default_llseek,
1035         .release = subsystem_release,
1036 };
1037
1038 static const struct file_operations ftrace_system_enable_fops = {
1039         .open = subsystem_open,
1040         .read = system_enable_read,
1041         .write = system_enable_write,
1042         .llseek = default_llseek,
1043         .release = subsystem_release,
1044 };
1045
1046 static const struct file_operations ftrace_show_header_fops = {
1047         .open = tracing_open_generic,
1048         .read = show_header,
1049         .llseek = default_llseek,
1050 };
1051
1052 static struct dentry *event_trace_events_dir(void)
1053 {
1054         static struct dentry *d_tracer;
1055         static struct dentry *d_events;
1056
1057         if (d_events)
1058                 return d_events;
1059
1060         d_tracer = tracing_init_dentry();
1061         if (!d_tracer)
1062                 return NULL;
1063
1064         d_events = debugfs_create_dir("events", d_tracer);
1065         if (!d_events)
1066                 pr_warning("Could not create debugfs "
1067                            "'events' directory\n");
1068
1069         return d_events;
1070 }
1071
1072 static struct dentry *
1073 event_subsystem_dir(const char *name, struct dentry *d_events)
1074 {
1075         struct event_subsystem *system;
1076         struct dentry *entry;
1077
1078         /* First see if we did not already create this dir */
1079         list_for_each_entry(system, &event_subsystems, list) {
1080                 if (strcmp(system->name, name) == 0) {
1081                         __get_system(system);
1082                         system->nr_events++;
1083                         return system->entry;
1084                 }
1085         }
1086
1087         /* need to create new entry */
1088         system = kmalloc(sizeof(*system), GFP_KERNEL);
1089         if (!system) {
1090                 pr_warning("No memory to create event subsystem %s\n",
1091                            name);
1092                 return d_events;
1093         }
1094
1095         system->entry = debugfs_create_dir(name, d_events);
1096         if (!system->entry) {
1097                 pr_warning("Could not create event subsystem %s\n",
1098                            name);
1099                 kfree(system);
1100                 return d_events;
1101         }
1102
1103         system->nr_events = 1;
1104         system->ref_count = 1;
1105         system->name = kstrdup(name, GFP_KERNEL);
1106         if (!system->name) {
1107                 debugfs_remove(system->entry);
1108                 kfree(system);
1109                 return d_events;
1110         }
1111
1112         list_add(&system->list, &event_subsystems);
1113
1114         system->filter = NULL;
1115
1116         system->filter = kzalloc(sizeof(struct event_filter), GFP_KERNEL);
1117         if (!system->filter) {
1118                 pr_warning("Could not allocate filter for subsystem "
1119                            "'%s'\n", name);
1120                 return system->entry;
1121         }
1122
1123         entry = debugfs_create_file("filter", 0644, system->entry, system,
1124                                     &ftrace_subsystem_filter_fops);
1125         if (!entry) {
1126                 kfree(system->filter);
1127                 system->filter = NULL;
1128                 pr_warning("Could not create debugfs "
1129                            "'%s/filter' entry\n", name);
1130         }
1131
1132         trace_create_file("enable", 0644, system->entry, system,
1133                           &ftrace_system_enable_fops);
1134
1135         return system->entry;
1136 }
1137
1138 static int
1139 event_create_dir(struct ftrace_event_call *call, struct dentry *d_events,
1140                  const struct file_operations *id,
1141                  const struct file_operations *enable,
1142                  const struct file_operations *filter,
1143                  const struct file_operations *format)
1144 {
1145         struct list_head *head;
1146         int ret;
1147
1148         /*
1149          * If the trace point header did not define TRACE_SYSTEM
1150          * then the system would be called "TRACE_SYSTEM".
1151          */
1152         if (strcmp(call->class->system, TRACE_SYSTEM) != 0)
1153                 d_events = event_subsystem_dir(call->class->system, d_events);
1154
1155         call->dir = debugfs_create_dir(call->name, d_events);
1156         if (!call->dir) {
1157                 pr_warning("Could not create debugfs "
1158                            "'%s' directory\n", call->name);
1159                 return -1;
1160         }
1161
1162         if (call->class->reg)
1163                 trace_create_file("enable", 0644, call->dir, call,
1164                                   enable);
1165
1166 #ifdef CONFIG_PERF_EVENTS
1167         if (call->event.type && call->class->reg)
1168                 trace_create_file("id", 0444, call->dir, call,
1169                                   id);
1170 #endif
1171
1172         /*
1173          * Other events may have the same class. Only update
1174          * the fields if they are not already defined.
1175          */
1176         head = trace_get_fields(call);
1177         if (list_empty(head)) {
1178                 ret = call->class->define_fields(call);
1179                 if (ret < 0) {
1180                         pr_warning("Could not initialize trace point"
1181                                    " events/%s\n", call->name);
1182                         return ret;
1183                 }
1184         }
1185         trace_create_file("filter", 0644, call->dir, call,
1186                           filter);
1187
1188         trace_create_file("format", 0444, call->dir, call,
1189                           format);
1190
1191         return 0;
1192 }
1193
1194 static int
1195 __trace_add_event_call(struct ftrace_event_call *call, struct module *mod,
1196                        const struct file_operations *id,
1197                        const struct file_operations *enable,
1198                        const struct file_operations *filter,
1199                        const struct file_operations *format)
1200 {
1201         struct dentry *d_events;
1202         int ret;
1203
1204         /* The linker may leave blanks */
1205         if (!call->name)
1206                 return -EINVAL;
1207
1208         if (call->class->raw_init) {
1209                 ret = call->class->raw_init(call);
1210                 if (ret < 0) {
1211                         if (ret != -ENOSYS)
1212                                 pr_warning("Could not initialize trace events/%s\n",
1213                                            call->name);
1214                         return ret;
1215                 }
1216         }
1217
1218         d_events = event_trace_events_dir();
1219         if (!d_events)
1220                 return -ENOENT;
1221
1222         ret = event_create_dir(call, d_events, id, enable, filter, format);
1223         if (!ret)
1224                 list_add(&call->list, &ftrace_events);
1225         call->mod = mod;
1226
1227         return ret;
1228 }
1229
1230 /* Add an additional event_call dynamically */
1231 int trace_add_event_call(struct ftrace_event_call *call)
1232 {
1233         int ret;
1234         mutex_lock(&event_mutex);
1235         ret = __trace_add_event_call(call, NULL, &ftrace_event_id_fops,
1236                                      &ftrace_enable_fops,
1237                                      &ftrace_event_filter_fops,
1238                                      &ftrace_event_format_fops);
1239         mutex_unlock(&event_mutex);
1240         return ret;
1241 }
1242
1243 static void remove_subsystem_dir(const char *name)
1244 {
1245         struct event_subsystem *system;
1246
1247         if (strcmp(name, TRACE_SYSTEM) == 0)
1248                 return;
1249
1250         list_for_each_entry(system, &event_subsystems, list) {
1251                 if (strcmp(system->name, name) == 0) {
1252                         if (!--system->nr_events) {
1253                                 debugfs_remove_recursive(system->entry);
1254                                 list_del(&system->list);
1255                                 __put_system(system);
1256                         }
1257                         break;
1258                 }
1259         }
1260 }
1261
1262 /*
1263  * Must be called under locking both of event_mutex and trace_event_mutex.
1264  */
1265 static void __trace_remove_event_call(struct ftrace_event_call *call)
1266 {
1267         ftrace_event_enable_disable(call, 0);
1268         if (call->event.funcs)
1269                 __unregister_ftrace_event(&call->event);
1270         debugfs_remove_recursive(call->dir);
1271         list_del(&call->list);
1272         trace_destroy_fields(call);
1273         destroy_preds(call);
1274         remove_subsystem_dir(call->class->system);
1275 }
1276
1277 /* Remove an event_call */
1278 void trace_remove_event_call(struct ftrace_event_call *call)
1279 {
1280         mutex_lock(&event_mutex);
1281         down_write(&trace_event_mutex);
1282         __trace_remove_event_call(call);
1283         up_write(&trace_event_mutex);
1284         mutex_unlock(&event_mutex);
1285 }
1286
1287 #define for_each_event(event, start, end)                       \
1288         for (event = start;                                     \
1289              (unsigned long)event < (unsigned long)end;         \
1290              event++)
1291
1292 #ifdef CONFIG_MODULES
1293
1294 static LIST_HEAD(ftrace_module_file_list);
1295
1296 /*
1297  * Modules must own their file_operations to keep up with
1298  * reference counting.
1299  */
1300 struct ftrace_module_file_ops {
1301         struct list_head                list;
1302         struct module                   *mod;
1303         struct file_operations          id;
1304         struct file_operations          enable;
1305         struct file_operations          format;
1306         struct file_operations          filter;
1307 };
1308
1309 static struct ftrace_module_file_ops *
1310 trace_create_file_ops(struct module *mod)
1311 {
1312         struct ftrace_module_file_ops *file_ops;
1313
1314         /*
1315          * This is a bit of a PITA. To allow for correct reference
1316          * counting, modules must "own" their file_operations.
1317          * To do this, we allocate the file operations that will be
1318          * used in the event directory.
1319          */
1320
1321         file_ops = kmalloc(sizeof(*file_ops), GFP_KERNEL);
1322         if (!file_ops)
1323                 return NULL;
1324
1325         file_ops->mod = mod;
1326
1327         file_ops->id = ftrace_event_id_fops;
1328         file_ops->id.owner = mod;
1329
1330         file_ops->enable = ftrace_enable_fops;
1331         file_ops->enable.owner = mod;
1332
1333         file_ops->filter = ftrace_event_filter_fops;
1334         file_ops->filter.owner = mod;
1335
1336         file_ops->format = ftrace_event_format_fops;
1337         file_ops->format.owner = mod;
1338
1339         list_add(&file_ops->list, &ftrace_module_file_list);
1340
1341         return file_ops;
1342 }
1343
1344 static void trace_module_add_events(struct module *mod)
1345 {
1346         struct ftrace_module_file_ops *file_ops = NULL;
1347         struct ftrace_event_call **call, **start, **end;
1348
1349         start = mod->trace_events;
1350         end = mod->trace_events + mod->num_trace_events;
1351
1352         if (start == end)
1353                 return;
1354
1355         file_ops = trace_create_file_ops(mod);
1356         if (!file_ops)
1357                 return;
1358
1359         for_each_event(call, start, end) {
1360                 __trace_add_event_call(*call, mod,
1361                                        &file_ops->id, &file_ops->enable,
1362                                        &file_ops->filter, &file_ops->format);
1363         }
1364 }
1365
1366 static void trace_module_remove_events(struct module *mod)
1367 {
1368         struct ftrace_module_file_ops *file_ops;
1369         struct ftrace_event_call *call, *p;
1370         bool found = false;
1371
1372         down_write(&trace_event_mutex);
1373         list_for_each_entry_safe(call, p, &ftrace_events, list) {
1374                 if (call->mod == mod) {
1375                         found = true;
1376                         __trace_remove_event_call(call);
1377                 }
1378         }
1379
1380         /* Now free the file_operations */
1381         list_for_each_entry(file_ops, &ftrace_module_file_list, list) {
1382                 if (file_ops->mod == mod)
1383                         break;
1384         }
1385         if (&file_ops->list != &ftrace_module_file_list) {
1386                 list_del(&file_ops->list);
1387                 kfree(file_ops);
1388         }
1389
1390         /*
1391          * It is safest to reset the ring buffer if the module being unloaded
1392          * registered any events.
1393          */
1394         if (found)
1395                 tracing_reset_current_online_cpus();
1396         up_write(&trace_event_mutex);
1397 }
1398
1399 static int trace_module_notify(struct notifier_block *self,
1400                                unsigned long val, void *data)
1401 {
1402         struct module *mod = data;
1403
1404         mutex_lock(&event_mutex);
1405         switch (val) {
1406         case MODULE_STATE_COMING:
1407                 trace_module_add_events(mod);
1408                 break;
1409         case MODULE_STATE_GOING:
1410                 trace_module_remove_events(mod);
1411                 break;
1412         }
1413         mutex_unlock(&event_mutex);
1414
1415         return 0;
1416 }
1417 #else
1418 static int trace_module_notify(struct notifier_block *self,
1419                                unsigned long val, void *data)
1420 {
1421         return 0;
1422 }
1423 #endif /* CONFIG_MODULES */
1424
1425 static struct notifier_block trace_module_nb = {
1426         .notifier_call = trace_module_notify,
1427         .priority = 0,
1428 };
1429
1430 extern struct ftrace_event_call *__start_ftrace_events[];
1431 extern struct ftrace_event_call *__stop_ftrace_events[];
1432
1433 static char bootup_event_buf[COMMAND_LINE_SIZE] __initdata;
1434
1435 static __init int setup_trace_event(char *str)
1436 {
1437         strlcpy(bootup_event_buf, str, COMMAND_LINE_SIZE);
1438         ring_buffer_expanded = 1;
1439         tracing_selftest_disabled = 1;
1440
1441         return 1;
1442 }
1443 __setup("trace_event=", setup_trace_event);
1444
1445 static __init int event_trace_init(void)
1446 {
1447         struct ftrace_event_call **call;
1448         struct dentry *d_tracer;
1449         struct dentry *entry;
1450         struct dentry *d_events;
1451         int ret;
1452         char *buf = bootup_event_buf;
1453         char *token;
1454
1455         d_tracer = tracing_init_dentry();
1456         if (!d_tracer)
1457                 return 0;
1458
1459         entry = debugfs_create_file("available_events", 0444, d_tracer,
1460                                     (void *)&show_event_seq_ops,
1461                                     &ftrace_avail_fops);
1462         if (!entry)
1463                 pr_warning("Could not create debugfs "
1464                            "'available_events' entry\n");
1465
1466         entry = debugfs_create_file("set_event", 0644, d_tracer,
1467                                     (void *)&show_set_event_seq_ops,
1468                                     &ftrace_set_event_fops);
1469         if (!entry)
1470                 pr_warning("Could not create debugfs "
1471                            "'set_event' entry\n");
1472
1473         d_events = event_trace_events_dir();
1474         if (!d_events)
1475                 return 0;
1476
1477         /* ring buffer internal formats */
1478         trace_create_file("header_page", 0444, d_events,
1479                           ring_buffer_print_page_header,
1480                           &ftrace_show_header_fops);
1481
1482         trace_create_file("header_event", 0444, d_events,
1483                           ring_buffer_print_entry_header,
1484                           &ftrace_show_header_fops);
1485
1486         trace_create_file("enable", 0644, d_events,
1487                           NULL, &ftrace_system_enable_fops);
1488
1489         if (trace_define_common_fields())
1490                 pr_warning("tracing: Failed to allocate common fields");
1491
1492         for_each_event(call, __start_ftrace_events, __stop_ftrace_events) {
1493                 __trace_add_event_call(*call, NULL, &ftrace_event_id_fops,
1494                                        &ftrace_enable_fops,
1495                                        &ftrace_event_filter_fops,
1496                                        &ftrace_event_format_fops);
1497         }
1498
1499         while (true) {
1500                 token = strsep(&buf, ",");
1501
1502                 if (!token)
1503                         break;
1504                 if (!*token)
1505                         continue;
1506
1507                 ret = ftrace_set_clr_event(token, 1);
1508                 if (ret)
1509                         pr_warning("Failed to enable trace event: %s\n", token);
1510         }
1511
1512         ret = register_module_notifier(&trace_module_nb);
1513         if (ret)
1514                 pr_warning("Failed to register trace events module notifier\n");
1515
1516         return 0;
1517 }
1518 fs_initcall(event_trace_init);
1519
1520 #ifdef CONFIG_FTRACE_STARTUP_TEST
1521
1522 static DEFINE_SPINLOCK(test_spinlock);
1523 static DEFINE_SPINLOCK(test_spinlock_irq);
1524 static DEFINE_MUTEX(test_mutex);
1525
1526 static __init void test_work(struct work_struct *dummy)
1527 {
1528         spin_lock(&test_spinlock);
1529         spin_lock_irq(&test_spinlock_irq);
1530         udelay(1);
1531         spin_unlock_irq(&test_spinlock_irq);
1532         spin_unlock(&test_spinlock);
1533
1534         mutex_lock(&test_mutex);
1535         msleep(1);
1536         mutex_unlock(&test_mutex);
1537 }
1538
1539 static __init int event_test_thread(void *unused)
1540 {
1541         void *test_malloc;
1542
1543         test_malloc = kmalloc(1234, GFP_KERNEL);
1544         if (!test_malloc)
1545                 pr_info("failed to kmalloc\n");
1546
1547         schedule_on_each_cpu(test_work);
1548
1549         kfree(test_malloc);
1550
1551         set_current_state(TASK_INTERRUPTIBLE);
1552         while (!kthread_should_stop())
1553                 schedule();
1554
1555         return 0;
1556 }
1557
1558 /*
1559  * Do various things that may trigger events.
1560  */
1561 static __init void event_test_stuff(void)
1562 {
1563         struct task_struct *test_thread;
1564
1565         test_thread = kthread_run(event_test_thread, NULL, "test-events");
1566         msleep(1);
1567         kthread_stop(test_thread);
1568 }
1569
1570 /*
1571  * For every trace event defined, we will test each trace point separately,
1572  * and then by groups, and finally all trace points.
1573  */
1574 static __init void event_trace_self_tests(void)
1575 {
1576         struct ftrace_event_call *call;
1577         struct event_subsystem *system;
1578         int ret;
1579
1580         pr_info("Running tests on trace events:\n");
1581
1582         list_for_each_entry(call, &ftrace_events, list) {
1583
1584                 /* Only test those that have a probe */
1585                 if (!call->class || !call->class->probe)
1586                         continue;
1587
1588 /*
1589  * Testing syscall events here is pretty useless, but
1590  * we still do it if configured. But this is time consuming.
1591  * What we really need is a user thread to perform the
1592  * syscalls as we test.
1593  */
1594 #ifndef CONFIG_EVENT_TRACE_TEST_SYSCALLS
1595                 if (call->class->system &&
1596                     strcmp(call->class->system, "syscalls") == 0)
1597                         continue;
1598 #endif
1599
1600                 pr_info("Testing event %s: ", call->name);
1601
1602                 /*
1603                  * If an event is already enabled, someone is using
1604                  * it and the self test should not be on.
1605                  */
1606                 if (call->flags & TRACE_EVENT_FL_ENABLED) {
1607                         pr_warning("Enabled event during self test!\n");
1608                         WARN_ON_ONCE(1);
1609                         continue;
1610                 }
1611
1612                 ftrace_event_enable_disable(call, 1);
1613                 event_test_stuff();
1614                 ftrace_event_enable_disable(call, 0);
1615
1616                 pr_cont("OK\n");
1617         }
1618
1619         /* Now test at the sub system level */
1620
1621         pr_info("Running tests on trace event systems:\n");
1622
1623         list_for_each_entry(system, &event_subsystems, list) {
1624
1625                 /* the ftrace system is special, skip it */
1626                 if (strcmp(system->name, "ftrace") == 0)
1627                         continue;
1628
1629                 pr_info("Testing event system %s: ", system->name);
1630
1631                 ret = __ftrace_set_clr_event(NULL, system->name, NULL, 1);
1632                 if (WARN_ON_ONCE(ret)) {
1633                         pr_warning("error enabling system %s\n",
1634                                    system->name);
1635                         continue;
1636                 }
1637
1638                 event_test_stuff();
1639
1640                 ret = __ftrace_set_clr_event(NULL, system->name, NULL, 0);
1641                 if (WARN_ON_ONCE(ret))
1642                         pr_warning("error disabling system %s\n",
1643                                    system->name);
1644
1645                 pr_cont("OK\n");
1646         }
1647
1648         /* Test with all events enabled */
1649
1650         pr_info("Running tests on all trace events:\n");
1651         pr_info("Testing all events: ");
1652
1653         ret = __ftrace_set_clr_event(NULL, NULL, NULL, 1);
1654         if (WARN_ON_ONCE(ret)) {
1655                 pr_warning("error enabling all events\n");
1656                 return;
1657         }
1658
1659         event_test_stuff();
1660
1661         /* reset sysname */
1662         ret = __ftrace_set_clr_event(NULL, NULL, NULL, 0);
1663         if (WARN_ON_ONCE(ret)) {
1664                 pr_warning("error disabling all events\n");
1665                 return;
1666         }
1667
1668         pr_cont("OK\n");
1669 }
1670
1671 #ifdef CONFIG_FUNCTION_TRACER
1672
1673 static DEFINE_PER_CPU(atomic_t, ftrace_test_event_disable);
1674
1675 static void
1676 function_test_events_call(unsigned long ip, unsigned long parent_ip)
1677 {
1678         struct ring_buffer_event *event;
1679         struct ring_buffer *buffer;
1680         struct ftrace_entry *entry;
1681         unsigned long flags;
1682         long disabled;
1683         int cpu;
1684         int pc;
1685
1686         pc = preempt_count();
1687         preempt_disable_notrace();
1688         cpu = raw_smp_processor_id();
1689         disabled = atomic_inc_return(&per_cpu(ftrace_test_event_disable, cpu));
1690
1691         if (disabled != 1)
1692                 goto out;
1693
1694         local_save_flags(flags);
1695
1696         event = trace_current_buffer_lock_reserve(&buffer,
1697                                                   TRACE_FN, sizeof(*entry),
1698                                                   flags, pc);
1699         if (!event)
1700                 goto out;
1701         entry   = ring_buffer_event_data(event);
1702         entry->ip                       = ip;
1703         entry->parent_ip                = parent_ip;
1704
1705         trace_nowake_buffer_unlock_commit(buffer, event, flags, pc);
1706
1707  out:
1708         atomic_dec(&per_cpu(ftrace_test_event_disable, cpu));
1709         preempt_enable_notrace();
1710 }
1711
1712 static struct ftrace_ops trace_ops __initdata  =
1713 {
1714         .func = function_test_events_call,
1715 };
1716
1717 static __init void event_trace_self_test_with_function(void)
1718 {
1719         int ret;
1720         ret = register_ftrace_function(&trace_ops);
1721         if (WARN_ON(ret < 0)) {
1722                 pr_info("Failed to enable function tracer for event tests\n");
1723                 return;
1724         }
1725         pr_info("Running tests again, along with the function tracer\n");
1726         event_trace_self_tests();
1727         unregister_ftrace_function(&trace_ops);
1728 }
1729 #else
1730 static __init void event_trace_self_test_with_function(void)
1731 {
1732 }
1733 #endif
1734
1735 static __init int event_trace_self_tests_init(void)
1736 {
1737         if (!tracing_selftest_disabled) {
1738                 event_trace_self_tests();
1739                 event_trace_self_test_with_function();
1740         }
1741
1742         return 0;
1743 }
1744
1745 late_initcall(event_trace_self_tests_init);
1746
1747 #endif