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,
 151                      enum trace_reg type, void *data)
 152 {
 153         switch (type) {
 154         case TRACE_REG_REGISTER:
 155                 return tracepoint_probe_register(call->name,
 156                                                  call->class->probe,
 157                                                  call);
 158         case TRACE_REG_UNREGISTER:
 159                 tracepoint_probe_unregister(call->name,
 160                                             call->class->probe,
 161                                             call);
 162                 return 0;
 163
 164 #ifdef CONFIG_PERF_EVENTS
 165         case TRACE_REG_PERF_REGISTER:
 166                 return tracepoint_probe_register(call->name,
 167                                                  call->class->perf_probe,
 168                                                  call);
 169         case TRACE_REG_PERF_UNREGISTER:
 170                 tracepoint_probe_unregister(call->name,
 171                                             call->class->perf_probe,
 172                                             call);
 173                 return 0;
 174         case TRACE_REG_PERF_OPEN:
 175         case TRACE_REG_PERF_CLOSE:
 176         case TRACE_REG_PERF_ADD:
 177         case TRACE_REG_PERF_DEL:
 178                 return 0;
 179 #endif
 180         }
 181         return 0;
 182 }
 183 EXPORT_SYMBOL_GPL(ftrace_event_reg);
 184
 185 void trace_event_enable_cmd_record(bool enable)
 186 {
 187         struct ftrace_event_call *call;
 188
 189         mutex_lock(&event_mutex);
 190         list_for_each_entry(call, &ftrace_events, list) {
 191                 if (!(call->flags & TRACE_EVENT_FL_ENABLED))
 192                         continue;
 193
 194                 if (enable) {
 195                         tracing_start_cmdline_record();
 196                         call->flags |= TRACE_EVENT_FL_RECORDED_CMD;
 197                 } else {
 198                         tracing_stop_cmdline_record();
 199                         call->flags &= ~TRACE_EVENT_FL_RECORDED_CMD;
 200                 }
 201         }
 202         mutex_unlock(&event_mutex);
 203 }
 204
 205 static int ftrace_event_enable_disable(struct ftrace_event_call *call,
 206                                         int enable)
 207 {
 208         int ret = 0;
 209
 210         switch (enable) {
 211         case 0:
 212                 if (call->flags & TRACE_EVENT_FL_ENABLED) {
 213                         call->flags &= ~TRACE_EVENT_FL_ENABLED;
 214                         if (call->flags & TRACE_EVENT_FL_RECORDED_CMD) {
 215                                 tracing_stop_cmdline_record();
 216                                 call->flags &= ~TRACE_EVENT_FL_RECORDED_CMD;
 217                         }
 218                         call->class->reg(call, TRACE_REG_UNREGISTER, NULL);
 219                 }
 220                 break;
 221         case 1:
 222                 if (!(call->flags & TRACE_EVENT_FL_ENABLED)) {
 223                         if (trace_flags & TRACE_ITER_RECORD_CMD) {
 224                                 tracing_start_cmdline_record();
 225                                 call->flags |= TRACE_EVENT_FL_RECORDED_CMD;
 226                         }
 227                         ret = call->class->reg(call, TRACE_REG_REGISTER, NULL);
 228                         if (ret) {
 229                                 tracing_stop_cmdline_record();
 230                                 pr_info("event trace: Could not enable event "
 231                                         "%s\n", call->name);
 232                                 break;
 233                         }
 234                         call->flags |= TRACE_EVENT_FL_ENABLED;
 235                 }
 236                 break;
 237         }
 238
 239         return ret;
 240 }
 241
 242 static void ftrace_clear_events(void)
 243 {
 244         struct ftrace_event_call *call;
 245
 246         mutex_lock(&event_mutex);
 247         list_for_each_entry(call, &ftrace_events, list) {
 248                 ftrace_event_enable_disable(call, 0);
 249         }
 250         mutex_unlock(&event_mutex);
 251 }
 252
 253 static void __put_system(struct event_subsystem *system)
 254 {
 255         struct event_filter *filter = system->filter;
 256
 257         WARN_ON_ONCE(system->ref_count == 0);
 258         if (--system->ref_count)
 259                 return;
 260
 261         if (filter) {
 262                 kfree(filter->filter_string);
 263                 kfree(filter);
 264         }
 265         kfree(system->name);
 266         kfree(system);
 267 }
 268
 269 static void __get_system(struct event_subsystem *system)
 270 {
 271         WARN_ON_ONCE(system->ref_count == 0);
 272         system->ref_count++;
 273 }
 274
 275 static void put_system(struct event_subsystem *system)
 276 {
 277         mutex_lock(&event_mutex);
 278         __put_system(system);
 279         mutex_unlock(&event_mutex);
 280 }
 281
 282 /*
 283  * __ftrace_set_clr_event(NULL, NULL, NULL, set) will set/unset all events.
 284  */
 285 static int __ftrace_set_clr_event(const char *match, const char *sub,
 286                                   const char *event, int set)
 287 {
 288         struct ftrace_event_call *call;
 289         int ret = -EINVAL;
 290
 291         mutex_lock(&event_mutex);
 292         list_for_each_entry(call, &ftrace_events, list) {
 293
 294                 if (!call->name || !call->class || !call->class->reg)
 295                         continue;
 296
 297                 if (call->flags & TRACE_EVENT_FL_IGNORE_ENABLE)
 298                         continue;
 299
 300                 if (match &&
 301                     strcmp(match, call->name) != 0 &&
 302                     strcmp(match, call->class->system) != 0)
 303                         continue;
 304
 305                 if (sub && strcmp(sub, call->class->system) != 0)
 306                         continue;
 307
 308                 if (event && strcmp(event, call->name) != 0)
 309                         continue;
 310
 311                 ftrace_event_enable_disable(call, set);
 312
 313                 ret = 0;
 314         }
 315         mutex_unlock(&event_mutex);
 316
 317         return ret;
 318 }
 319
 320 static int ftrace_set_clr_event(char *buf, int set)
 321 {
 322         char *event = NULL, *sub = NULL, *match;
 323
 324         /*
 325          * The buf format can be <subsystem>:<event-name>
 326          *  *:<event-name> means any event by that name.
 327          *  :<event-name> is the same.
 328          *
 329          *  <subsystem>:* means all events in that subsystem
 330          *  <subsystem>: means the same.
 331          *
 332          *  <name> (no ':') means all events in a subsystem with
 333          *  the name <name> or any event that matches <name>
 334          */
 335
 336         match = strsep(&buf, ":");
 337         if (buf) {
 338                 sub = match;
 339                 event = buf;
 340                 match = NULL;
 341
 342                 if (!strlen(sub) || strcmp(sub, "*") == 0)
 343                         sub = NULL;
 344                 if (!strlen(event) || strcmp(event, "*") == 0)
 345                         event = NULL;
 346         }
 347
 348         return __ftrace_set_clr_event(match, sub, event, set);
 349 }
 350
 351 /**
 352  * trace_set_clr_event - enable or disable an event
 353  * @system: system name to match (NULL for any system)
 354  * @event: event name to match (NULL for all events, within system)
 355  * @set: 1 to enable, 0 to disable
 356  *
 357  * This is a way for other parts of the kernel to enable or disable
 358  * event recording.
 359  *
 360  * Returns 0 on success, -EINVAL if the parameters do not match any
 361  * registered events.
 362  */
 363 int trace_set_clr_event(const char *system, const char *event, int set)
 364 {
 365         return __ftrace_set_clr_event(NULL, system, event, set);
 366 }
 367 EXPORT_SYMBOL_GPL(trace_set_clr_event);
 368
 369 /* 128 should be much more than enough */
 370 #define EVENT_BUF_SIZE          127
 371
 372 static ssize_t
 373 ftrace_event_write(struct file *file, const char __user *ubuf,
 374                    size_t cnt, loff_t *ppos)
 375 {
 376         struct trace_parser parser;
 377         ssize_t read, ret;
 378
 379         if (!cnt)
 380                 return 0;
 381
 382         ret = tracing_update_buffers();
 383         if (ret < 0)
 384                 return ret;
 385
 386         if (trace_parser_get_init(&parser, EVENT_BUF_SIZE + 1))
 387                 return -ENOMEM;
 388
 389         read = trace_get_user(&parser, ubuf, cnt, ppos);
 390
 391         if (read >= 0 && trace_parser_loaded((&parser))) {
 392                 int set = 1;
 393
 394                 if (*parser.buffer == '!')
 395                         set = 0;
 396
 397                 parser.buffer[parser.idx] = 0;
 398
 399                 ret = ftrace_set_clr_event(parser.buffer + !set, set);
 400                 if (ret)
 401                         goto out_put;
 402         }
 403
 404         ret = read;
 405
 406  out_put:
 407         trace_parser_put(&parser);
 408
 409         return ret;
 410 }
 411
 412 static void *
 413 t_next(struct seq_file *m, void *v, loff_t *pos)
 414 {
 415         struct ftrace_event_call *call = v;
 416
 417         (*pos)++;
 418
 419         list_for_each_entry_continue(call, &ftrace_events, list) {
 420                 /*
 421                  * The ftrace subsystem is for showing formats only.
 422                  * They can not be enabled or disabled via the event files.
 423                  */
 424                 if (call->class && call->class->reg)
 425                         return call;
 426         }
 427
 428         return NULL;
 429 }
 430
 431 static void *t_start(struct seq_file *m, loff_t *pos)
 432 {
 433         struct ftrace_event_call *call;
 434         loff_t l;
 435
 436         mutex_lock(&event_mutex);
 437
 438         call = list_entry(&ftrace_events, struct ftrace_event_call, list);
 439         for (l = 0; l <= *pos; ) {
 440                 call = t_next(m, call, &l);
 441                 if (!call)
 442                         break;
 443         }
 444         return call;
 445 }
 446
 447 static void *
 448 s_next(struct seq_file *m, void *v, loff_t *pos)
 449 {
 450         struct ftrace_event_call *call = v;
 451
 452         (*pos)++;
 453
 454         list_for_each_entry_continue(call, &ftrace_events, list) {
 455                 if (call->flags & TRACE_EVENT_FL_ENABLED)
 456                         return call;
 457         }
 458
 459         return NULL;
 460 }
 461
 462 static void *s_start(struct seq_file *m, loff_t *pos)
 463 {
 464         struct ftrace_event_call *call;
 465         loff_t l;
 466
 467         mutex_lock(&event_mutex);
 468
 469         call = list_entry(&ftrace_events, struct ftrace_event_call, list);
 470         for (l = 0; l <= *pos; ) {
 471                 call = s_next(m, call, &l);
 472                 if (!call)
 473                         break;
 474         }
 475         return call;
 476 }
 477
 478 static int t_show(struct seq_file *m, void *v)
 479 {
 480         struct ftrace_event_call *call = v;
 481
 482         if (strcmp(call->class->system, TRACE_SYSTEM) != 0)
 483                 seq_printf(m, "%s:", call->class->system);
 484         seq_printf(m, "%s\n", call->name);
 485
 486         return 0;
 487 }
 488
 489 static void t_stop(struct seq_file *m, void *p)
 490 {
 491         mutex_unlock(&event_mutex);
 492 }
 493
 494 static int
 495 ftrace_event_seq_open(struct inode *inode, struct file *file)
 496 {
 497         const struct seq_operations *seq_ops;
 498
 499         if ((file->f_mode & FMODE_WRITE) &&
 500             (file->f_flags & O_TRUNC))
 501                 ftrace_clear_events();
 502
 503         seq_ops = inode->i_private;
 504         return seq_open(file, seq_ops);
 505 }
 506
 507 static ssize_t
 508 event_enable_read(struct file *filp, char __user *ubuf, size_t cnt,
 509                   loff_t *ppos)
 510 {
 511         struct ftrace_event_call *call = filp->private_data;
 512         char *buf;
 513
 514         if (call->flags & TRACE_EVENT_FL_ENABLED)
 515                 buf = "1\n";
 516         else
 517                 buf = "0\n";
 518
 519         return simple_read_from_buffer(ubuf, cnt, ppos, buf, 2);
 520 }
 521
 522 static ssize_t
 523 event_enable_write(struct file *filp, const char __user *ubuf, size_t cnt,
 524                    loff_t *ppos)
 525 {
 526         struct ftrace_event_call *call = filp->private_data;
 527         unsigned long val;
 528         int ret;
 529
 530         ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
 531         if (ret)
 532                 return ret;
 533
 534         ret = tracing_update_buffers();
 535         if (ret < 0)
 536                 return ret;
 537
 538         switch (val) {
 539         case 0:
 540         case 1:
 541                 mutex_lock(&event_mutex);
 542                 ret = ftrace_event_enable_disable(call, val);
 543                 mutex_unlock(&event_mutex);
 544                 break;
 545
 546         default:
 547                 return -EINVAL;
 548         }
 549
 550         *ppos += cnt;
 551
 552         return ret ? ret : cnt;
 553 }
 554
 555 static ssize_t
 556 system_enable_read(struct file *filp, char __user *ubuf, size_t cnt,
 557                    loff_t *ppos)
 558 {
 559         const char set_to_char[4] = { '?', '0', '1', 'X' };
 560         struct event_subsystem *system = filp->private_data;
 561         struct ftrace_event_call *call;
 562         char buf[2];
 563         int set = 0;
 564         int ret;
 565
 566         mutex_lock(&event_mutex);
 567         list_for_each_entry(call, &ftrace_events, list) {
 568                 if (!call->name || !call->class || !call->class->reg)
 569                         continue;
 570
 571                 if (system && strcmp(call->class->system, system->name) != 0)
 572                         continue;
 573
 574                 /*
 575                  * We need to find out if all the events are set
 576                  * or if all events or cleared, or if we have
 577                  * a mixture.
 578                  */
 579                 set |= (1 << !!(call->flags & TRACE_EVENT_FL_ENABLED));
 580
 581                 /*
 582                  * If we have a mixture, no need to look further.
 583                  */
 584                 if (set == 3)
 585                         break;
 586         }
 587         mutex_unlock(&event_mutex);
 588
 589         buf[0] = set_to_char[set];
 590         buf[1] = '\n';
 591
 592         ret = simple_read_from_buffer(ubuf, cnt, ppos, buf, 2);
 593
 594         return ret;
 595 }
 596
 597 static ssize_t
 598 system_enable_write(struct file *filp, const char __user *ubuf, size_t cnt,
 599                     loff_t *ppos)
 600 {
 601         struct event_subsystem *system = filp->private_data;
 602         const char *name = NULL;
 603         unsigned long val;
 604         ssize_t ret;
 605
 606         ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
 607         if (ret)
 608                 return ret;
 609
 610         ret = tracing_update_buffers();
 611         if (ret < 0)
 612                 return ret;
 613
 614         if (val != 0 && val != 1)
 615                 return -EINVAL;
 616
 617         /*
 618          * Opening of "enable" adds a ref count to system,
 619          * so the name is safe to use.
 620          */
 621         if (system)
 622                 name = system->name;
 623
 624         ret = __ftrace_set_clr_event(NULL, name, NULL, val);
 625         if (ret)
 626                 goto out;
 627
 628         ret = cnt;
 629
 630 out:
 631         *ppos += cnt;
 632
 633         return ret;
 634 }
 635
 636 enum {
 637         FORMAT_HEADER           = 1,
 638         FORMAT_FIELD_SEPERATOR  = 2,
 639         FORMAT_PRINTFMT         = 3,
 640 };
 641
 642 static void *f_next(struct seq_file *m, void *v, loff_t *pos)
 643 {
 644         struct ftrace_event_call *call = m->private;
 645         struct ftrace_event_field *field;
 646         struct list_head *common_head = &ftrace_common_fields;
 647         struct list_head *head = trace_get_fields(call);
 648
 649         (*pos)++;
 650
 651         switch ((unsigned long)v) {
 652         case FORMAT_HEADER:
 653                 if (unlikely(list_empty(common_head)))
 654                         return NULL;
 655
 656                 field = list_entry(common_head->prev,
 657                                    struct ftrace_event_field, link);
 658                 return field;
 659
 660         case FORMAT_FIELD_SEPERATOR:
 661                 if (unlikely(list_empty(head)))
 662                         return NULL;
 663
 664                 field = list_entry(head->prev, struct ftrace_event_field, link);
 665                 return field;
 666
 667         case FORMAT_PRINTFMT:
 668                 /* all done */
 669                 return NULL;
 670         }
 671
 672         field = v;
 673         if (field->link.prev == common_head)
 674                 return (void *)FORMAT_FIELD_SEPERATOR;
 675         else if (field->link.prev == head)
 676                 return (void *)FORMAT_PRINTFMT;
 677
 678         field = list_entry(field->link.prev, struct ftrace_event_field, link);
 679
 680         return field;
 681 }
 682
 683 static void *f_start(struct seq_file *m, loff_t *pos)
 684 {
 685         loff_t l = 0;
 686         void *p;
 687
 688         /* Start by showing the header */
 689         if (!*pos)
 690                 return (void *)FORMAT_HEADER;
 691
 692         p = (void *)FORMAT_HEADER;
 693         do {
 694                 p = f_next(m, p, &l);
 695         } while (p && l < *pos);
 696
 697         return p;
 698 }
 699
 700 static int f_show(struct seq_file *m, void *v)
 701 {
 702         struct ftrace_event_call *call = m->private;
 703         struct ftrace_event_field *field;
 704         const char *array_descriptor;
 705
 706         switch ((unsigned long)v) {
 707         case FORMAT_HEADER:
 708                 seq_printf(m, "name: %s\n", call->name);
 709                 seq_printf(m, "ID: %d\n", call->event.type);
 710                 seq_printf(m, "format:\n");
 711                 return 0;
 712
 713         case FORMAT_FIELD_SEPERATOR:
 714                 seq_putc(m, '\n');
 715                 return 0;
 716
 717         case FORMAT_PRINTFMT:
 718                 seq_printf(m, "\nprint fmt: %s\n",
 719                            call->print_fmt);
 720                 return 0;
 721         }
 722
 723         field = v;
 724
 725         /*
 726          * Smartly shows the array type(except dynamic array).
 727          * Normal:
 728          *      field:TYPE VAR
 729          * If TYPE := TYPE[LEN], it is shown:
 730          *      field:TYPE VAR[LEN]
 731          */
 732         array_descriptor = strchr(field->type, '[');
 733
 734         if (!strncmp(field->type, "__data_loc", 10))
 735                 array_descriptor = NULL;
 736
 737         if (!array_descriptor)
 738                 seq_printf(m, "\tfield:%s %s;\toffset:%u;\tsize:%u;\tsigned:%d;\n",
 739                            field->type, field->name, field->offset,
 740                            field->size, !!field->is_signed);
 741         else
 742                 seq_printf(m, "\tfield:%.*s %s%s;\toffset:%u;\tsize:%u;\tsigned:%d;\n",
 743                            (int)(array_descriptor - field->type),
 744                            field->type, field->name,
 745                            array_descriptor, field->offset,
 746                            field->size, !!field->is_signed);
 747
 748         return 0;
 749 }
 750
 751 static void f_stop(struct seq_file *m, void *p)
 752 {
 753 }
 754
 755 static const struct seq_operations trace_format_seq_ops = {
 756         .start          = f_start,
 757         .next           = f_next,
 758         .stop           = f_stop,
 759         .show           = f_show,
 760 };
 761
 762 static int trace_format_open(struct inode *inode, struct file *file)
 763 {
 764         struct ftrace_event_call *call = inode->i_private;
 765         struct seq_file *m;
 766         int ret;
 767
 768         ret = seq_open(file, &trace_format_seq_ops);
 769         if (ret < 0)
 770                 return ret;
 771
 772         m = file->private_data;
 773         m->private = call;
 774
 775         return 0;
 776 }
 777
 778 static ssize_t
 779 event_id_read(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos)
 780 {
 781         struct ftrace_event_call *call = filp->private_data;
 782         struct trace_seq *s;
 783         int r;
 784
 785         if (*ppos)
 786                 return 0;
 787
 788         s = kmalloc(sizeof(*s), GFP_KERNEL);
 789         if (!s)
 790                 return -ENOMEM;
 791
 792         trace_seq_init(s);
 793         trace_seq_printf(s, "%d\n", call->event.type);
 794
 795         r = simple_read_from_buffer(ubuf, cnt, ppos,
 796                                     s->buffer, s->len);
 797         kfree(s);
 798         return r;
 799 }
 800
 801 static ssize_t
 802 event_filter_read(struct file *filp, char __user *ubuf, size_t cnt,
 803                   loff_t *ppos)
 804 {
 805         struct ftrace_event_call *call = filp->private_data;
 806         struct trace_seq *s;
 807         int r;
 808
 809         if (*ppos)
 810                 return 0;
 811
 812         s = kmalloc(sizeof(*s), GFP_KERNEL);
 813         if (!s)
 814                 return -ENOMEM;
 815
 816         trace_seq_init(s);
 817
 818         print_event_filter(call, s);
 819         r = simple_read_from_buffer(ubuf, cnt, ppos, s->buffer, s->len);
 820
 821         kfree(s);
 822
 823         return r;
 824 }
 825
 826 static ssize_t
 827 event_filter_write(struct file *filp, const char __user *ubuf, size_t cnt,
 828                    loff_t *ppos)
 829 {
 830         struct ftrace_event_call *call = filp->private_data;
 831         char *buf;
 832         int err;
 833
 834         if (cnt >= PAGE_SIZE)
 835                 return -EINVAL;
 836
 837         buf = (char *)__get_free_page(GFP_TEMPORARY);
 838         if (!buf)
 839                 return -ENOMEM;
 840
 841         if (copy_from_user(buf, ubuf, cnt)) {
 842                 free_page((unsigned long) buf);
 843                 return -EFAULT;
 844         }
 845         buf[cnt] = '\0';
 846
 847         err = apply_event_filter(call, buf);
 848         free_page((unsigned long) buf);
 849         if (err < 0)
 850                 return err;
 851
 852         *ppos += cnt;
 853
 854         return cnt;
 855 }
 856
 857 static LIST_HEAD(event_subsystems);
 858
 859 static int subsystem_open(struct inode *inode, struct file *filp)
 860 {
 861         struct event_subsystem *system = NULL;
 862         int ret;
 863
 864         if (!inode->i_private)
 865                 goto skip_search;
 866
 867         /* Make sure the system still exists */
 868         mutex_lock(&event_mutex);
 869         list_for_each_entry(system, &event_subsystems, list) {
 870                 if (system == inode->i_private) {
 871                         /* Don't open systems with no events */
 872                         if (!system->nr_events) {
 873                                 system = NULL;
 874                                 break;
 875                         }
 876                         __get_system(system);
 877                         break;
 878                 }
 879         }
 880         mutex_unlock(&event_mutex);
 881
 882         if (system != inode->i_private)
 883                 return -ENODEV;
 884
 885  skip_search:
 886         ret = tracing_open_generic(inode, filp);
 887         if (ret < 0 && system)
 888                 put_system(system);
 889
 890         return ret;
 891 }
 892
 893 static int subsystem_release(struct inode *inode, struct file *file)
 894 {
 895         struct event_subsystem *system = inode->i_private;
 896
 897         if (system)
 898                 put_system(system);
 899
 900         return 0;
 901 }
 902
 903 static ssize_t
 904 subsystem_filter_read(struct file *filp, char __user *ubuf, size_t cnt,
 905                       loff_t *ppos)
 906 {
 907         struct event_subsystem *system = filp->private_data;
 908         struct trace_seq *s;
 909         int r;
 910
 911         if (*ppos)
 912                 return 0;
 913
 914         s = kmalloc(sizeof(*s), GFP_KERNEL);
 915         if (!s)
 916                 return -ENOMEM;
 917
 918         trace_seq_init(s);
 919
 920         print_subsystem_event_filter(system, s);
 921         r = simple_read_from_buffer(ubuf, cnt, ppos, s->buffer, s->len);
 922
 923         kfree(s);
 924
 925         return r;
 926 }
 927
 928 static ssize_t
 929 subsystem_filter_write(struct file *filp, const char __user *ubuf, size_t cnt,
 930                        loff_t *ppos)
 931 {
 932         struct event_subsystem *system = filp->private_data;
 933         char *buf;
 934         int err;
 935
 936         if (cnt >= PAGE_SIZE)
 937                 return -EINVAL;
 938
 939         buf = (char *)__get_free_page(GFP_TEMPORARY);
 940         if (!buf)
 941                 return -ENOMEM;
 942
 943         if (copy_from_user(buf, ubuf, cnt)) {
 944                 free_page((unsigned long) buf);
 945                 return -EFAULT;
 946         }
 947         buf[cnt] = '\0';
 948
 949         err = apply_subsystem_event_filter(system, buf);
 950         free_page((unsigned long) buf);
 951         if (err < 0)
 952                 return err;
 953
 954         *ppos += cnt;
 955
 956         return cnt;
 957 }
 958
 959 static ssize_t
 960 show_header(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos)
 961 {
 962         int (*func)(struct trace_seq *s) = filp->private_data;
 963         struct trace_seq *s;
 964         int r;
 965
 966         if (*ppos)
 967                 return 0;
 968
 969         s = kmalloc(sizeof(*s), GFP_KERNEL);
 970         if (!s)
 971                 return -ENOMEM;
 972
 973         trace_seq_init(s);
 974
 975         func(s);
 976         r = simple_read_from_buffer(ubuf, cnt, ppos, s->buffer, s->len);
 977
 978         kfree(s);
 979
 980         return r;
 981 }
 982
 983 static const struct seq_operations show_event_seq_ops = {
 984         .start = t_start,
 985         .next = t_next,
 986         .show = t_show,
 987         .stop = t_stop,
 988 };
 989
 990 static const struct seq_operations show_set_event_seq_ops = {
 991         .start = s_start,
 992         .next = s_next,
 993         .show = t_show,
 994         .stop = t_stop,
 995 };
 996
 997 static const struct file_operations ftrace_avail_fops = {
 998         .open = ftrace_event_seq_open,
 999         .read = seq_read,
1000         .llseek = seq_lseek,
1001         .release = seq_release,
1002 };
1003
1004 static const struct file_operations ftrace_set_event_fops = {
1005         .open = ftrace_event_seq_open,
1006         .read = seq_read,
1007         .write = ftrace_event_write,
1008         .llseek = seq_lseek,
1009         .release = seq_release,
1010 };
1011
1012 static const struct file_operations ftrace_enable_fops = {
1013         .open = tracing_open_generic,
1014         .read = event_enable_read,
1015         .write = event_enable_write,
1016         .llseek = default_llseek,
1017 };
1018
1019 static const struct file_operations ftrace_event_format_fops = {
1020         .open = trace_format_open,
1021         .read = seq_read,
1022         .llseek = seq_lseek,
1023         .release = seq_release,
1024 };
1025
1026 static const struct file_operations ftrace_event_id_fops = {
1027         .open = tracing_open_generic,
1028         .read = event_id_read,
1029         .llseek = default_llseek,
1030 };
1031
1032 static const struct file_operations ftrace_event_filter_fops = {
1033         .open = tracing_open_generic,
1034         .read = event_filter_read,
1035         .write = event_filter_write,
1036         .llseek = default_llseek,
1037 };
1038
1039 static const struct file_operations ftrace_subsystem_filter_fops = {
1040         .open = subsystem_open,
1041         .read = subsystem_filter_read,
1042         .write = subsystem_filter_write,
1043         .llseek = default_llseek,
1044         .release = subsystem_release,
1045 };
1046
1047 static const struct file_operations ftrace_system_enable_fops = {
1048         .open = subsystem_open,
1049         .read = system_enable_read,
1050         .write = system_enable_write,
1051         .llseek = default_llseek,
1052         .release = subsystem_release,
1053 };
1054
1055 static const struct file_operations ftrace_show_header_fops = {
1056         .open = tracing_open_generic,
1057         .read = show_header,
1058         .llseek = default_llseek,
1059 };
1060
1061 static struct dentry *event_trace_events_dir(void)
1062 {
1063         static struct dentry *d_tracer;
1064         static struct dentry *d_events;
1065
1066         if (d_events)
1067                 return d_events;
1068
1069         d_tracer = tracing_init_dentry();
1070         if (!d_tracer)
1071                 return NULL;
1072
1073         d_events = debugfs_create_dir("events", d_tracer);
1074         if (!d_events)
1075                 pr_warning("Could not create debugfs "
1076                            "'events' directory\n");
1077
1078         return d_events;
1079 }
1080
1081 static struct dentry *
1082 event_subsystem_dir(const char *name, struct dentry *d_events)
1083 {
1084         struct event_subsystem *system;
1085         struct dentry *entry;
1086
1087         /* First see if we did not already create this dir */
1088         list_for_each_entry(system, &event_subsystems, list) {
1089                 if (strcmp(system->name, name) == 0) {
1090                         system->nr_events++;
1091                         return system->entry;
1092                 }
1093         }
1094
1095         /* need to create new entry */
1096         system = kmalloc(sizeof(*system), GFP_KERNEL);
1097         if (!system) {
1098                 pr_warning("No memory to create event subsystem %s\n",
1099                            name);
1100                 return d_events;
1101         }
1102
1103         system->entry = debugfs_create_dir(name, d_events);
1104         if (!system->entry) {
1105                 pr_warning("Could not create event subsystem %s\n",
1106                            name);
1107                 kfree(system);
1108                 return d_events;
1109         }
1110
1111         system->nr_events = 1;
1112         system->ref_count = 1;
1113         system->name = kstrdup(name, GFP_KERNEL);
1114         if (!system->name) {
1115                 debugfs_remove(system->entry);
1116                 kfree(system);
1117                 return d_events;
1118         }
1119
1120         list_add(&system->list, &event_subsystems);
1121
1122         system->filter = NULL;
1123
1124         system->filter = kzalloc(sizeof(struct event_filter), GFP_KERNEL);
1125         if (!system->filter) {
1126                 pr_warning("Could not allocate filter for subsystem "
1127                            "'%s'\n", name);
1128                 return system->entry;
1129         }
1130
1131         entry = debugfs_create_file("filter", 0644, system->entry, system,
1132                                     &ftrace_subsystem_filter_fops);
1133         if (!entry) {
1134                 kfree(system->filter);
1135                 system->filter = NULL;
1136                 pr_warning("Could not create debugfs "
1137                            "'%s/filter' entry\n", name);
1138         }
1139
1140         trace_create_file("enable", 0644, system->entry, system,
1141                           &ftrace_system_enable_fops);
1142
1143         return system->entry;
1144 }
1145
1146 static int
1147 event_create_dir(struct ftrace_event_call *call, struct dentry *d_events,
1148                  const struct file_operations *id,
1149                  const struct file_operations *enable,
1150                  const struct file_operations *filter,
1151                  const struct file_operations *format)
1152 {
1153         struct list_head *head;
1154         int ret;
1155
1156         /*
1157          * If the trace point header did not define TRACE_SYSTEM
1158          * then the system would be called "TRACE_SYSTEM".
1159          */
1160         if (strcmp(call->class->system, TRACE_SYSTEM) != 0)
1161                 d_events = event_subsystem_dir(call->class->system, d_events);
1162
1163         call->dir = debugfs_create_dir(call->name, d_events);
1164         if (!call->dir) {
1165                 pr_warning("Could not create debugfs "
1166                            "'%s' directory\n", call->name);
1167                 return -1;
1168         }
1169
1170         if (call->class->reg && !(call->flags & TRACE_EVENT_FL_IGNORE_ENABLE))
1171                 trace_create_file("enable", 0644, call->dir, call,
1172                                   enable);
1173
1174 #ifdef CONFIG_PERF_EVENTS
1175         if (call->event.type && call->class->reg)
1176                 trace_create_file("id", 0444, call->dir, call,
1177                                   id);
1178 #endif
1179
1180         /*
1181          * Other events may have the same class. Only update
1182          * the fields if they are not already defined.
1183          */
1184         head = trace_get_fields(call);
1185         if (list_empty(head)) {
1186                 ret = call->class->define_fields(call);
1187                 if (ret < 0) {
1188                         pr_warning("Could not initialize trace point"
1189                                    " events/%s\n", call->name);
1190                         return ret;
1191                 }
1192         }
1193         trace_create_file("filter", 0644, call->dir, call,
1194                           filter);
1195
1196         trace_create_file("format", 0444, call->dir, call,
1197                           format);
1198
1199         return 0;
1200 }
1201
1202 static void event_remove(struct ftrace_event_call *call)
1203 {
1204         ftrace_event_enable_disable(call, 0);
1205         if (call->event.funcs)
1206                 __unregister_ftrace_event(&call->event);
1207         list_del(&call->list);
1208 }
1209
1210 static int event_init(struct ftrace_event_call *call)
1211 {
1212         int ret = 0;
1213
1214         if (WARN_ON(!call->name))
1215                 return -EINVAL;
1216
1217         if (call->class->raw_init) {
1218                 ret = call->class->raw_init(call);
1219                 if (ret < 0 && ret != -ENOSYS)
1220                         pr_warn("Could not initialize trace events/%s\n",
1221                                 call->name);
1222         }
1223
1224         return ret;
1225 }
1226
1227 static int
1228 __trace_add_event_call(struct ftrace_event_call *call, struct module *mod,
1229                        const struct file_operations *id,
1230                        const struct file_operations *enable,
1231                        const struct file_operations *filter,
1232                        const struct file_operations *format)
1233 {
1234         struct dentry *d_events;
1235         int ret;
1236
1237         ret = event_init(call);
1238         if (ret < 0)
1239                 return ret;
1240
1241         d_events = event_trace_events_dir();
1242         if (!d_events)
1243                 return -ENOENT;
1244
1245         ret = event_create_dir(call, d_events, id, enable, filter, format);
1246         if (!ret)
1247                 list_add(&call->list, &ftrace_events);
1248         call->mod = mod;
1249
1250         return ret;
1251 }
1252
1253 /* Add an additional event_call dynamically */
1254 int trace_add_event_call(struct ftrace_event_call *call)
1255 {
1256         int ret;
1257         mutex_lock(&event_mutex);
1258         ret = __trace_add_event_call(call, NULL, &ftrace_event_id_fops,
1259                                      &ftrace_enable_fops,
1260                                      &ftrace_event_filter_fops,
1261                                      &ftrace_event_format_fops);
1262         mutex_unlock(&event_mutex);
1263         return ret;
1264 }
1265
1266 static void remove_subsystem_dir(const char *name)
1267 {
1268         struct event_subsystem *system;
1269
1270         if (strcmp(name, TRACE_SYSTEM) == 0)
1271                 return;
1272
1273         list_for_each_entry(system, &event_subsystems, list) {
1274                 if (strcmp(system->name, name) == 0) {
1275                         if (!--system->nr_events) {
1276                                 debugfs_remove_recursive(system->entry);
1277                                 list_del(&system->list);
1278                                 __put_system(system);
1279                         }
1280                         break;
1281                 }
1282         }
1283 }
1284
1285 /*
1286  * Must be called under locking both of event_mutex and trace_event_mutex.
1287  */
1288 static void __trace_remove_event_call(struct ftrace_event_call *call)
1289 {
1290         event_remove(call);
1291         trace_destroy_fields(call);
1292         destroy_preds(call);
1293         debugfs_remove_recursive(call->dir);
1294         remove_subsystem_dir(call->class->system);
1295 }
1296
1297 /* Remove an event_call */
1298 void trace_remove_event_call(struct ftrace_event_call *call)
1299 {
1300         mutex_lock(&event_mutex);
1301         down_write(&trace_event_mutex);
1302         __trace_remove_event_call(call);
1303         up_write(&trace_event_mutex);
1304         mutex_unlock(&event_mutex);
1305 }
1306
1307 #define for_each_event(event, start, end)                       \
1308         for (event = start;                                     \
1309              (unsigned long)event < (unsigned long)end;         \
1310              event++)
1311
1312 #ifdef CONFIG_MODULES
1313
1314 static LIST_HEAD(ftrace_module_file_list);
1315
1316 /*
1317  * Modules must own their file_operations to keep up with
1318  * reference counting.
1319  */
1320 struct ftrace_module_file_ops {
1321         struct list_head                list;
1322         struct module                   *mod;
1323         struct file_operations          id;
1324         struct file_operations          enable;
1325         struct file_operations          format;
1326         struct file_operations          filter;
1327 };
1328
1329 static struct ftrace_module_file_ops *
1330 trace_create_file_ops(struct module *mod)
1331 {
1332         struct ftrace_module_file_ops *file_ops;
1333
1334         /*
1335          * This is a bit of a PITA. To allow for correct reference
1336          * counting, modules must "own" their file_operations.
1337          * To do this, we allocate the file operations that will be
1338          * used in the event directory.
1339          */
1340
1341         file_ops = kmalloc(sizeof(*file_ops), GFP_KERNEL);
1342         if (!file_ops)
1343                 return NULL;
1344
1345         file_ops->mod = mod;
1346
1347         file_ops->id = ftrace_event_id_fops;
1348         file_ops->id.owner = mod;
1349
1350         file_ops->enable = ftrace_enable_fops;
1351         file_ops->enable.owner = mod;
1352
1353         file_ops->filter = ftrace_event_filter_fops;
1354         file_ops->filter.owner = mod;
1355
1356         file_ops->format = ftrace_event_format_fops;
1357         file_ops->format.owner = mod;
1358
1359         list_add(&file_ops->list, &ftrace_module_file_list);
1360
1361         return file_ops;
1362 }
1363
1364 static void trace_module_add_events(struct module *mod)
1365 {
1366         struct ftrace_module_file_ops *file_ops = NULL;
1367         struct ftrace_event_call **call, **start, **end;
1368
1369         start = mod->trace_events;
1370         end = mod->trace_events + mod->num_trace_events;
1371
1372         if (start == end)
1373                 return;
1374
1375         file_ops = trace_create_file_ops(mod);
1376         if (!file_ops)
1377                 return;
1378
1379         for_each_event(call, start, end) {
1380                 __trace_add_event_call(*call, mod,
1381                                        &file_ops->id, &file_ops->enable,
1382                                        &file_ops->filter, &file_ops->format);
1383         }
1384 }
1385
1386 static void trace_module_remove_events(struct module *mod)
1387 {
1388         struct ftrace_module_file_ops *file_ops;
1389         struct ftrace_event_call *call, *p;
1390         bool found = false;
1391
1392         down_write(&trace_event_mutex);
1393         list_for_each_entry_safe(call, p, &ftrace_events, list) {
1394                 if (call->mod == mod) {
1395                         found = true;
1396                         __trace_remove_event_call(call);
1397                 }
1398         }
1399
1400         /* Now free the file_operations */
1401         list_for_each_entry(file_ops, &ftrace_module_file_list, list) {
1402                 if (file_ops->mod == mod)
1403                         break;
1404         }
1405         if (&file_ops->list != &ftrace_module_file_list) {
1406                 list_del(&file_ops->list);
1407                 kfree(file_ops);
1408         }
1409
1410         /*
1411          * It is safest to reset the ring buffer if the module being unloaded
1412          * registered any events.
1413          */
1414         if (found)
1415                 tracing_reset_current_online_cpus();
1416         up_write(&trace_event_mutex);
1417 }
1418
1419 static int trace_module_notify(struct notifier_block *self,
1420                                unsigned long val, void *data)
1421 {
1422         struct module *mod = data;
1423
1424         mutex_lock(&event_mutex);
1425         switch (val) {
1426         case MODULE_STATE_COMING:
1427                 trace_module_add_events(mod);
1428                 break;
1429         case MODULE_STATE_GOING:
1430                 trace_module_remove_events(mod);
1431                 break;
1432         }
1433         mutex_unlock(&event_mutex);
1434
1435         return 0;
1436 }
1437 #else
1438 static int trace_module_notify(struct notifier_block *self,
1439                                unsigned long val, void *data)
1440 {
1441         return 0;
1442 }
1443 #endif /* CONFIG_MODULES */
1444
1445 static struct notifier_block trace_module_nb = {
1446         .notifier_call = trace_module_notify,
1447         .priority = 0,
1448 };
1449
1450 extern struct ftrace_event_call *__start_ftrace_events[];
1451 extern struct ftrace_event_call *__stop_ftrace_events[];
1452
1453 static char bootup_event_buf[COMMAND_LINE_SIZE] __initdata;
1454
1455 static __init int setup_trace_event(char *str)
1456 {
1457         strlcpy(bootup_event_buf, str, COMMAND_LINE_SIZE);
1458         ring_buffer_expanded = 1;
1459         tracing_selftest_disabled = 1;
1460
1461         return 1;
1462 }
1463 __setup("trace_event=", setup_trace_event);
1464
1465 static __init int event_trace_enable(void)
1466 {
1467         struct ftrace_event_call **iter, *call;
1468         char *buf = bootup_event_buf;
1469         char *token;
1470         int ret;
1471
1472         for_each_event(iter, __start_ftrace_events, __stop_ftrace_events) {
1473
1474                 call = *iter;
1475                 ret = event_init(call);
1476                 if (!ret)
1477                         list_add(&call->list, &ftrace_events);
1478         }
1479
1480         while (true) {
1481                 token = strsep(&buf, ",");
1482
1483                 if (!token)
1484                         break;
1485                 if (!*token)
1486                         continue;
1487
1488                 ret = ftrace_set_clr_event(token, 1);
1489                 if (ret)
1490                         pr_warn("Failed to enable trace event: %s\n", token);
1491         }
1492         return 0;
1493 }
1494
1495 static __init int event_trace_init(void)
1496 {
1497         struct ftrace_event_call *call;
1498         struct dentry *d_tracer;
1499         struct dentry *entry;
1500         struct dentry *d_events;
1501         int ret;
1502
1503         d_tracer = tracing_init_dentry();
1504         if (!d_tracer)
1505                 return 0;
1506
1507         entry = debugfs_create_file("available_events", 0444, d_tracer,
1508                                     (void *)&show_event_seq_ops,
1509                                     &ftrace_avail_fops);
1510         if (!entry)
1511                 pr_warning("Could not create debugfs "
1512                            "'available_events' entry\n");
1513
1514         entry = debugfs_create_file("set_event", 0644, d_tracer,
1515                                     (void *)&show_set_event_seq_ops,
1516                                     &ftrace_set_event_fops);
1517         if (!entry)
1518                 pr_warning("Could not create debugfs "
1519                            "'set_event' entry\n");
1520
1521         d_events = event_trace_events_dir();
1522         if (!d_events)
1523                 return 0;
1524
1525         /* ring buffer internal formats */
1526         trace_create_file("header_page", 0444, d_events,
1527                           ring_buffer_print_page_header,
1528                           &ftrace_show_header_fops);
1529
1530         trace_create_file("header_event", 0444, d_events,
1531                           ring_buffer_print_entry_header,
1532                           &ftrace_show_header_fops);
1533
1534         trace_create_file("enable", 0644, d_events,
1535                           NULL, &ftrace_system_enable_fops);
1536
1537         if (trace_define_common_fields())
1538                 pr_warning("tracing: Failed to allocate common fields");
1539
1540         /*
1541          * Early initialization already enabled ftrace event.
1542          * Now it's only necessary to create the event directory.
1543          */
1544         list_for_each_entry(call, &ftrace_events, list) {
1545
1546                 ret = event_create_dir(call, d_events,
1547                                        &ftrace_event_id_fops,
1548                                        &ftrace_enable_fops,
1549                                        &ftrace_event_filter_fops,
1550                                        &ftrace_event_format_fops);
1551                 if (ret < 0)
1552                         event_remove(call);
1553         }
1554
1555         ret = register_module_notifier(&trace_module_nb);
1556         if (ret)
1557                 pr_warning("Failed to register trace events module notifier\n");
1558
1559         return 0;
1560 }
1561 core_initcall(event_trace_enable);
1562 fs_initcall(event_trace_init);
1563
1564 #ifdef CONFIG_FTRACE_STARTUP_TEST
1565
1566 static DEFINE_SPINLOCK(test_spinlock);
1567 static DEFINE_SPINLOCK(test_spinlock_irq);
1568 static DEFINE_MUTEX(test_mutex);
1569
1570 static __init void test_work(struct work_struct *dummy)
1571 {
1572         spin_lock(&test_spinlock);
1573         spin_lock_irq(&test_spinlock_irq);
1574         udelay(1);
1575         spin_unlock_irq(&test_spinlock_irq);
1576         spin_unlock(&test_spinlock);
1577
1578         mutex_lock(&test_mutex);
1579         msleep(1);
1580         mutex_unlock(&test_mutex);
1581 }
1582
1583 static __init int event_test_thread(void *unused)
1584 {
1585         void *test_malloc;
1586
1587         test_malloc = kmalloc(1234, GFP_KERNEL);
1588         if (!test_malloc)
1589                 pr_info("failed to kmalloc\n");
1590
1591         schedule_on_each_cpu(test_work);
1592
1593         kfree(test_malloc);
1594
1595         set_current_state(TASK_INTERRUPTIBLE);
1596         while (!kthread_should_stop())
1597                 schedule();
1598
1599         return 0;
1600 }
1601
1602 /*
1603  * Do various things that may trigger events.
1604  */
1605 static __init void event_test_stuff(void)
1606 {
1607         struct task_struct *test_thread;
1608
1609         test_thread = kthread_run(event_test_thread, NULL, "test-events");
1610         msleep(1);
1611         kthread_stop(test_thread);
1612 }
1613
1614 /*
1615  * For every trace event defined, we will test each trace point separately,
1616  * and then by groups, and finally all trace points.
1617  */
1618 static __init void event_trace_self_tests(void)
1619 {
1620         struct ftrace_event_call *call;
1621         struct event_subsystem *system;
1622         int ret;
1623
1624         pr_info("Running tests on trace events:\n");
1625
1626         list_for_each_entry(call, &ftrace_events, list) {
1627
1628                 /* Only test those that have a probe */
1629                 if (!call->class || !call->class->probe)
1630                         continue;
1631
1632 /*
1633  * Testing syscall events here is pretty useless, but
1634  * we still do it if configured. But this is time consuming.
1635  * What we really need is a user thread to perform the
1636  * syscalls as we test.
1637  */
1638 #ifndef CONFIG_EVENT_TRACE_TEST_SYSCALLS
1639                 if (call->class->system &&
1640                     strcmp(call->class->system, "syscalls") == 0)
1641                         continue;
1642 #endif
1643
1644                 pr_info("Testing event %s: ", call->name);
1645
1646                 /*
1647                  * If an event is already enabled, someone is using
1648                  * it and the self test should not be on.
1649                  */
1650                 if (call->flags & TRACE_EVENT_FL_ENABLED) {
1651                         pr_warning("Enabled event during self test!\n");
1652                         WARN_ON_ONCE(1);
1653                         continue;
1654                 }
1655
1656                 ftrace_event_enable_disable(call, 1);
1657                 event_test_stuff();
1658                 ftrace_event_enable_disable(call, 0);
1659
1660                 pr_cont("OK\n");
1661         }
1662
1663         /* Now test at the sub system level */
1664
1665         pr_info("Running tests on trace event systems:\n");
1666
1667         list_for_each_entry(system, &event_subsystems, list) {
1668
1669                 /* the ftrace system is special, skip it */
1670                 if (strcmp(system->name, "ftrace") == 0)
1671                         continue;
1672
1673                 pr_info("Testing event system %s: ", system->name);
1674
1675                 ret = __ftrace_set_clr_event(NULL, system->name, NULL, 1);
1676                 if (WARN_ON_ONCE(ret)) {
1677                         pr_warning("error enabling system %s\n",
1678                                    system->name);
1679                         continue;
1680                 }
1681
1682                 event_test_stuff();
1683
1684                 ret = __ftrace_set_clr_event(NULL, system->name, NULL, 0);
1685                 if (WARN_ON_ONCE(ret)) {
1686                         pr_warning("error disabling system %s\n",
1687                                    system->name);
1688                         continue;
1689                 }
1690
1691                 pr_cont("OK\n");
1692         }
1693
1694         /* Test with all events enabled */
1695
1696         pr_info("Running tests on all trace events:\n");
1697         pr_info("Testing all events: ");
1698
1699         ret = __ftrace_set_clr_event(NULL, NULL, NULL, 1);
1700         if (WARN_ON_ONCE(ret)) {
1701                 pr_warning("error enabling all events\n");
1702                 return;
1703         }
1704
1705         event_test_stuff();
1706
1707         /* reset sysname */
1708         ret = __ftrace_set_clr_event(NULL, NULL, NULL, 0);
1709         if (WARN_ON_ONCE(ret)) {
1710                 pr_warning("error disabling all events\n");
1711                 return;
1712         }
1713
1714         pr_cont("OK\n");
1715 }
1716
1717 #ifdef CONFIG_FUNCTION_TRACER
1718
1719 static DEFINE_PER_CPU(atomic_t, ftrace_test_event_disable);
1720
1721 static void
1722 function_test_events_call(unsigned long ip, unsigned long parent_ip,
1723                           struct ftrace_ops *op, struct pt_regs *pt_regs)
1724 {
1725         struct ring_buffer_event *event;
1726         struct ring_buffer *buffer;
1727         struct ftrace_entry *entry;
1728         unsigned long flags;
1729         long disabled;
1730         int cpu;
1731         int pc;
1732
1733         pc = preempt_count();
1734         preempt_disable_notrace();
1735         cpu = raw_smp_processor_id();
1736         disabled = atomic_inc_return(&per_cpu(ftrace_test_event_disable, cpu));
1737
1738         if (disabled != 1)
1739                 goto out;
1740
1741         local_save_flags(flags);
1742
1743         event = trace_current_buffer_lock_reserve(&buffer,
1744                                                   TRACE_FN, sizeof(*entry),
1745                                                   flags, pc);
1746         if (!event)
1747                 goto out;
1748         entry   = ring_buffer_event_data(event);
1749         entry->ip                       = ip;
1750         entry->parent_ip                = parent_ip;
1751
1752         trace_nowake_buffer_unlock_commit(buffer, event, flags, pc);
1753
1754  out:
1755         atomic_dec(&per_cpu(ftrace_test_event_disable, cpu));
1756         preempt_enable_notrace();
1757 }
1758
1759 static struct ftrace_ops trace_ops __initdata  =
1760 {
1761         .func = function_test_events_call,
1762         .flags = FTRACE_OPS_FL_RECURSION_SAFE,
1763 };
1764
1765 static __init void event_trace_self_test_with_function(void)
1766 {
1767         int ret;
1768         ret = register_ftrace_function(&trace_ops);
1769         if (WARN_ON(ret < 0)) {
1770                 pr_info("Failed to enable function tracer for event tests\n");
1771                 return;
1772         }
1773         pr_info("Running tests again, along with the function tracer\n");
1774         event_trace_self_tests();
1775         unregister_ftrace_function(&trace_ops);
1776 }
1777 #else
1778 static __init void event_trace_self_test_with_function(void)
1779 {
1780 }
1781 #endif
1782
1783 static __init int event_trace_self_tests_init(void)
1784 {
1785         if (!tracing_selftest_disabled) {
1786                 event_trace_self_tests();
1787                 event_trace_self_test_with_function();
1788         }
1789
1790         return 0;
1791 }
1792
1793 late_initcall(event_trace_self_tests_init);
1794
1795 #endif