Pileus Git - ~andy/linux/blob - 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 ssize_t
 495 event_enable_read(struct file *filp, char __user *ubuf, size_t cnt,
 496                   loff_t *ppos)
 497 {
 498         struct ftrace_event_call *call = filp->private_data;
 499         char *buf;
 500
 501         if (call->flags & TRACE_EVENT_FL_ENABLED)
 502                 buf = "1\n";
 503         else
 504                 buf = "0\n";
 505
 506         return simple_read_from_buffer(ubuf, cnt, ppos, buf, 2);
 507 }
 508
 509 static ssize_t
 510 event_enable_write(struct file *filp, const char __user *ubuf, size_t cnt,
 511                    loff_t *ppos)
 512 {
 513         struct ftrace_event_call *call = filp->private_data;
 514         unsigned long val;
 515         int ret;
 516
 517         ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
 518         if (ret)
 519                 return ret;
 520
 521         ret = tracing_update_buffers();
 522         if (ret < 0)
 523                 return ret;
 524
 525         switch (val) {
 526         case 0:
 527         case 1:
 528                 mutex_lock(&event_mutex);
 529                 ret = ftrace_event_enable_disable(call, val);
 530                 mutex_unlock(&event_mutex);
 531                 break;
 532
 533         default:
 534                 return -EINVAL;
 535         }
 536
 537         *ppos += cnt;
 538
 539         return ret ? ret : cnt;
 540 }
 541
 542 static ssize_t
 543 system_enable_read(struct file *filp, char __user *ubuf, size_t cnt,
 544                    loff_t *ppos)
 545 {
 546         const char set_to_char[4] = { '?', '0', '1', 'X' };
 547         struct event_subsystem *system = filp->private_data;
 548         struct ftrace_event_call *call;
 549         char buf[2];
 550         int set = 0;
 551         int ret;
 552
 553         mutex_lock(&event_mutex);
 554         list_for_each_entry(call, &ftrace_events, list) {
 555                 if (!call->name || !call->class || !call->class->reg)
 556                         continue;
 557
 558                 if (system && strcmp(call->class->system, system->name) != 0)
 559                         continue;
 560
 561                 /*
 562                  * We need to find out if all the events are set
 563                  * or if all events or cleared, or if we have
 564                  * a mixture.
 565                  */
 566                 set |= (1 << !!(call->flags & TRACE_EVENT_FL_ENABLED));
 567
 568                 /*
 569                  * If we have a mixture, no need to look further.
 570                  */
 571                 if (set == 3)
 572                         break;
 573         }
 574         mutex_unlock(&event_mutex);
 575
 576         buf[0] = set_to_char[set];
 577         buf[1] = '\n';
 578
 579         ret = simple_read_from_buffer(ubuf, cnt, ppos, buf, 2);
 580
 581         return ret;
 582 }
 583
 584 static ssize_t
 585 system_enable_write(struct file *filp, const char __user *ubuf, size_t cnt,
 586                     loff_t *ppos)
 587 {
 588         struct event_subsystem *system = filp->private_data;
 589         const char *name = NULL;
 590         unsigned long val;
 591         ssize_t ret;
 592
 593         ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
 594         if (ret)
 595                 return ret;
 596
 597         ret = tracing_update_buffers();
 598         if (ret < 0)
 599                 return ret;
 600
 601         if (val != 0 && val != 1)
 602                 return -EINVAL;
 603
 604         /*
 605          * Opening of "enable" adds a ref count to system,
 606          * so the name is safe to use.
 607          */
 608         if (system)
 609                 name = system->name;
 610
 611         ret = __ftrace_set_clr_event(NULL, name, NULL, val);
 612         if (ret)
 613                 goto out;
 614
 615         ret = cnt;
 616
 617 out:
 618         *ppos += cnt;
 619
 620         return ret;
 621 }
 622
 623 enum {
 624         FORMAT_HEADER           = 1,
 625         FORMAT_FIELD_SEPERATOR  = 2,
 626         FORMAT_PRINTFMT         = 3,
 627 };
 628
 629 static void *f_next(struct seq_file *m, void *v, loff_t *pos)
 630 {
 631         struct ftrace_event_call *call = m->private;
 632         struct ftrace_event_field *field;
 633         struct list_head *common_head = &ftrace_common_fields;
 634         struct list_head *head = trace_get_fields(call);
 635
 636         (*pos)++;
 637
 638         switch ((unsigned long)v) {
 639         case FORMAT_HEADER:
 640                 if (unlikely(list_empty(common_head)))
 641                         return NULL;
 642
 643                 field = list_entry(common_head->prev,
 644                                    struct ftrace_event_field, link);
 645                 return field;
 646
 647         case FORMAT_FIELD_SEPERATOR:
 648                 if (unlikely(list_empty(head)))
 649                         return NULL;
 650
 651                 field = list_entry(head->prev, struct ftrace_event_field, link);
 652                 return field;
 653
 654         case FORMAT_PRINTFMT:
 655                 /* all done */
 656                 return NULL;
 657         }
 658
 659         field = v;
 660         if (field->link.prev == common_head)
 661                 return (void *)FORMAT_FIELD_SEPERATOR;
 662         else if (field->link.prev == head)
 663                 return (void *)FORMAT_PRINTFMT;
 664
 665         field = list_entry(field->link.prev, struct ftrace_event_field, link);
 666
 667         return field;
 668 }
 669
 670 static void *f_start(struct seq_file *m, loff_t *pos)
 671 {
 672         loff_t l = 0;
 673         void *p;
 674
 675         /* Start by showing the header */
 676         if (!*pos)
 677                 return (void *)FORMAT_HEADER;
 678
 679         p = (void *)FORMAT_HEADER;
 680         do {
 681                 p = f_next(m, p, &l);
 682         } while (p && l < *pos);
 683
 684         return p;
 685 }
 686
 687 static int f_show(struct seq_file *m, void *v)
 688 {
 689         struct ftrace_event_call *call = m->private;
 690         struct ftrace_event_field *field;
 691         const char *array_descriptor;
 692
 693         switch ((unsigned long)v) {
 694         case FORMAT_HEADER:
 695                 seq_printf(m, "name: %s\n", call->name);
 696                 seq_printf(m, "ID: %d\n", call->event.type);
 697                 seq_printf(m, "format:\n");
 698                 return 0;
 699
 700         case FORMAT_FIELD_SEPERATOR:
 701                 seq_putc(m, '\n');
 702                 return 0;
 703
 704         case FORMAT_PRINTFMT:
 705                 seq_printf(m, "\nprint fmt: %s\n",
 706                            call->print_fmt);
 707                 return 0;
 708         }
 709
 710         field = v;
 711
 712         /*
 713          * Smartly shows the array type(except dynamic array).
 714          * Normal:
 715          *      field:TYPE VAR
 716          * If TYPE := TYPE[LEN], it is shown:
 717          *      field:TYPE VAR[LEN]
 718          */
 719         array_descriptor = strchr(field->type, '[');
 720
 721         if (!strncmp(field->type, "__data_loc", 10))
 722                 array_descriptor = NULL;
 723
 724         if (!array_descriptor)
 725                 seq_printf(m, "\tfield:%s %s;\toffset:%u;\tsize:%u;\tsigned:%d;\n",
 726                            field->type, field->name, field->offset,
 727                            field->size, !!field->is_signed);
 728         else
 729                 seq_printf(m, "\tfield:%.*s %s%s;\toffset:%u;\tsize:%u;\tsigned:%d;\n",
 730                            (int)(array_descriptor - field->type),
 731                            field->type, field->name,
 732                            array_descriptor, field->offset,
 733                            field->size, !!field->is_signed);
 734
 735         return 0;
 736 }
 737
 738 static void f_stop(struct seq_file *m, void *p)
 739 {
 740 }
 741
 742 static const struct seq_operations trace_format_seq_ops = {
 743         .start          = f_start,
 744         .next           = f_next,
 745         .stop           = f_stop,
 746         .show           = f_show,
 747 };
 748
 749 static int trace_format_open(struct inode *inode, struct file *file)
 750 {
 751         struct ftrace_event_call *call = inode->i_private;
 752         struct seq_file *m;
 753         int ret;
 754
 755         ret = seq_open(file, &trace_format_seq_ops);
 756         if (ret < 0)
 757                 return ret;
 758
 759         m = file->private_data;
 760         m->private = call;
 761
 762         return 0;
 763 }
 764
 765 static ssize_t
 766 event_id_read(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos)
 767 {
 768         struct ftrace_event_call *call = filp->private_data;
 769         struct trace_seq *s;
 770         int r;
 771
 772         if (*ppos)
 773                 return 0;
 774
 775         s = kmalloc(sizeof(*s), GFP_KERNEL);
 776         if (!s)
 777                 return -ENOMEM;
 778
 779         trace_seq_init(s);
 780         trace_seq_printf(s, "%d\n", call->event.type);
 781
 782         r = simple_read_from_buffer(ubuf, cnt, ppos,
 783                                     s->buffer, s->len);
 784         kfree(s);
 785         return r;
 786 }
 787
 788 static ssize_t
 789 event_filter_read(struct file *filp, char __user *ubuf, size_t cnt,
 790                   loff_t *ppos)
 791 {
 792         struct ftrace_event_call *call = filp->private_data;
 793         struct trace_seq *s;
 794         int r;
 795
 796         if (*ppos)
 797                 return 0;
 798
 799         s = kmalloc(sizeof(*s), GFP_KERNEL);
 800         if (!s)
 801                 return -ENOMEM;
 802
 803         trace_seq_init(s);
 804
 805         print_event_filter(call, s);
 806         r = simple_read_from_buffer(ubuf, cnt, ppos, s->buffer, s->len);
 807
 808         kfree(s);
 809
 810         return r;
 811 }
 812
 813 static ssize_t
 814 event_filter_write(struct file *filp, const char __user *ubuf, size_t cnt,
 815                    loff_t *ppos)
 816 {
 817         struct ftrace_event_call *call = filp->private_data;
 818         char *buf;
 819         int err;
 820
 821         if (cnt >= PAGE_SIZE)
 822                 return -EINVAL;
 823
 824         buf = (char *)__get_free_page(GFP_TEMPORARY);
 825         if (!buf)
 826                 return -ENOMEM;
 827
 828         if (copy_from_user(buf, ubuf, cnt)) {
 829                 free_page((unsigned long) buf);
 830                 return -EFAULT;
 831         }
 832         buf[cnt] = '\0';
 833
 834         err = apply_event_filter(call, buf);
 835         free_page((unsigned long) buf);
 836         if (err < 0)
 837                 return err;
 838
 839         *ppos += cnt;
 840
 841         return cnt;
 842 }
 843
 844 static LIST_HEAD(event_subsystems);
 845
 846 static int subsystem_open(struct inode *inode, struct file *filp)
 847 {
 848         struct event_subsystem *system = NULL;
 849         int ret;
 850
 851         if (!inode->i_private)
 852                 goto skip_search;
 853
 854         /* Make sure the system still exists */
 855         mutex_lock(&event_mutex);
 856         list_for_each_entry(system, &event_subsystems, list) {
 857                 if (system == inode->i_private) {
 858                         /* Don't open systems with no events */
 859                         if (!system->nr_events) {
 860                                 system = NULL;
 861                                 break;
 862                         }
 863                         __get_system(system);
 864                         break;
 865                 }
 866         }
 867         mutex_unlock(&event_mutex);
 868
 869         if (system != inode->i_private)
 870                 return -ENODEV;
 871
 872  skip_search:
 873         ret = tracing_open_generic(inode, filp);
 874         if (ret < 0 && system)
 875                 put_system(system);
 876
 877         return ret;
 878 }
 879
 880 static int subsystem_release(struct inode *inode, struct file *file)
 881 {
 882         struct event_subsystem *system = inode->i_private;
 883
 884         if (system)
 885                 put_system(system);
 886
 887         return 0;
 888 }
 889
 890 static ssize_t
 891 subsystem_filter_read(struct file *filp, char __user *ubuf, size_t cnt,
 892                       loff_t *ppos)
 893 {
 894         struct event_subsystem *system = filp->private_data;
 895         struct trace_seq *s;
 896         int r;
 897
 898         if (*ppos)
 899                 return 0;
 900
 901         s = kmalloc(sizeof(*s), GFP_KERNEL);
 902         if (!s)
 903                 return -ENOMEM;
 904
 905         trace_seq_init(s);
 906
 907         print_subsystem_event_filter(system, s);
 908         r = simple_read_from_buffer(ubuf, cnt, ppos, s->buffer, s->len);
 909
 910         kfree(s);
 911
 912         return r;
 913 }
 914
 915 static ssize_t
 916 subsystem_filter_write(struct file *filp, const char __user *ubuf, size_t cnt,
 917                        loff_t *ppos)
 918 {
 919         struct event_subsystem *system = filp->private_data;
 920         char *buf;
 921         int err;
 922
 923         if (cnt >= PAGE_SIZE)
 924                 return -EINVAL;
 925
 926         buf = (char *)__get_free_page(GFP_TEMPORARY);
 927         if (!buf)
 928                 return -ENOMEM;
 929
 930         if (copy_from_user(buf, ubuf, cnt)) {
 931                 free_page((unsigned long) buf);
 932                 return -EFAULT;
 933         }
 934         buf[cnt] = '\0';
 935
 936         err = apply_subsystem_event_filter(system, buf);
 937         free_page((unsigned long) buf);
 938         if (err < 0)
 939                 return err;
 940
 941         *ppos += cnt;
 942
 943         return cnt;
 944 }
 945
 946 static ssize_t
 947 show_header(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos)
 948 {
 949         int (*func)(struct trace_seq *s) = filp->private_data;
 950         struct trace_seq *s;
 951         int r;
 952
 953         if (*ppos)
 954                 return 0;
 955
 956         s = kmalloc(sizeof(*s), GFP_KERNEL);
 957         if (!s)
 958                 return -ENOMEM;
 959
 960         trace_seq_init(s);
 961
 962         func(s);
 963         r = simple_read_from_buffer(ubuf, cnt, ppos, s->buffer, s->len);
 964
 965         kfree(s);
 966
 967         return r;
 968 }
 969
 970 static int ftrace_event_avail_open(struct inode *inode, struct file *file);
 971 static int ftrace_event_set_open(struct inode *inode, struct file *file);
 972
 973 static const struct seq_operations show_event_seq_ops = {
 974         .start = t_start,
 975         .next = t_next,
 976         .show = t_show,
 977         .stop = t_stop,
 978 };
 979
 980 static const struct seq_operations show_set_event_seq_ops = {
 981         .start = s_start,
 982         .next = s_next,
 983         .show = t_show,
 984         .stop = t_stop,
 985 };
 986
 987 static const struct file_operations ftrace_avail_fops = {
 988         .open = ftrace_event_avail_open,
 989         .read = seq_read,
 990         .llseek = seq_lseek,
 991         .release = seq_release,
 992 };
 993
 994 static const struct file_operations ftrace_set_event_fops = {
 995         .open = ftrace_event_set_open,
 996         .read = seq_read,
 997         .write = ftrace_event_write,
 998         .llseek = seq_lseek,
 999         .release = seq_release,
1000 };
1001
1002 static const struct file_operations ftrace_enable_fops = {
1003         .open = tracing_open_generic,
1004         .read = event_enable_read,
1005         .write = event_enable_write,
1006         .llseek = default_llseek,
1007 };
1008
1009 static const struct file_operations ftrace_event_format_fops = {
1010         .open = trace_format_open,
1011         .read = seq_read,
1012         .llseek = seq_lseek,
1013         .release = seq_release,
1014 };
1015
1016 static const struct file_operations ftrace_event_id_fops = {
1017         .open = tracing_open_generic,
1018         .read = event_id_read,
1019         .llseek = default_llseek,
1020 };
1021
1022 static const struct file_operations ftrace_event_filter_fops = {
1023         .open = tracing_open_generic,
1024         .read = event_filter_read,
1025         .write = event_filter_write,
1026         .llseek = default_llseek,
1027 };
1028
1029 static const struct file_operations ftrace_subsystem_filter_fops = {
1030         .open = subsystem_open,
1031         .read = subsystem_filter_read,
1032         .write = subsystem_filter_write,
1033         .llseek = default_llseek,
1034         .release = subsystem_release,
1035 };
1036
1037 static const struct file_operations ftrace_system_enable_fops = {
1038         .open = subsystem_open,
1039         .read = system_enable_read,
1040         .write = system_enable_write,
1041         .llseek = default_llseek,
1042         .release = subsystem_release,
1043 };
1044
1045 static const struct file_operations ftrace_show_header_fops = {
1046         .open = tracing_open_generic,
1047         .read = show_header,
1048         .llseek = default_llseek,
1049 };
1050
1051 static struct dentry *event_trace_events_dir(void)
1052 {
1053         static struct dentry *d_tracer;
1054         static struct dentry *d_events;
1055
1056         if (d_events)
1057                 return d_events;
1058
1059         d_tracer = tracing_init_dentry();
1060         if (!d_tracer)
1061                 return NULL;
1062
1063         d_events = debugfs_create_dir("events", d_tracer);
1064         if (!d_events)
1065                 pr_warning("Could not create debugfs "
1066                            "'events' directory\n");
1067
1068         return d_events;
1069 }
1070
1071 static int
1072 ftrace_event_avail_open(struct inode *inode, struct file *file)
1073 {
1074         const struct seq_operations *seq_ops = &show_event_seq_ops;
1075
1076         return seq_open(file, seq_ops);
1077 }
1078
1079 static int
1080 ftrace_event_set_open(struct inode *inode, struct file *file)
1081 {
1082         const struct seq_operations *seq_ops = &show_set_event_seq_ops;
1083
1084         if ((file->f_mode & FMODE_WRITE) &&
1085             (file->f_flags & O_TRUNC))
1086                 ftrace_clear_events();
1087
1088         return seq_open(file, seq_ops);
1089 }
1090
1091 static struct dentry *
1092 event_subsystem_dir(const char *name, struct dentry *d_events)
1093 {
1094         struct event_subsystem *system;
1095         struct dentry *entry;
1096
1097         /* First see if we did not already create this dir */
1098         list_for_each_entry(system, &event_subsystems, list) {
1099                 if (strcmp(system->name, name) == 0) {
1100                         system->nr_events++;
1101                         return system->entry;
1102                 }
1103         }
1104
1105         /* need to create new entry */
1106         system = kmalloc(sizeof(*system), GFP_KERNEL);
1107         if (!system) {
1108                 pr_warning("No memory to create event subsystem %s\n",
1109                            name);
1110                 return d_events;
1111         }
1112
1113         system->entry = debugfs_create_dir(name, d_events);
1114         if (!system->entry) {
1115                 pr_warning("Could not create event subsystem %s\n",
1116                            name);
1117                 kfree(system);
1118                 return d_events;
1119         }
1120
1121         system->nr_events = 1;
1122         system->ref_count = 1;
1123         system->name = kstrdup(name, GFP_KERNEL);
1124         if (!system->name) {
1125                 debugfs_remove(system->entry);
1126                 kfree(system);
1127                 return d_events;
1128         }
1129
1130         list_add(&system->list, &event_subsystems);
1131
1132         system->filter = NULL;
1133
1134         system->filter = kzalloc(sizeof(struct event_filter), GFP_KERNEL);
1135         if (!system->filter) {
1136                 pr_warning("Could not allocate filter for subsystem "
1137                            "'%s'\n", name);
1138                 return system->entry;
1139         }
1140
1141         entry = debugfs_create_file("filter", 0644, system->entry, system,
1142                                     &ftrace_subsystem_filter_fops);
1143         if (!entry) {
1144                 kfree(system->filter);
1145                 system->filter = NULL;
1146                 pr_warning("Could not create debugfs "
1147                            "'%s/filter' entry\n", name);
1148         }
1149
1150         trace_create_file("enable", 0644, system->entry, system,
1151                           &ftrace_system_enable_fops);
1152
1153         return system->entry;
1154 }
1155
1156 static int
1157 event_create_dir(struct ftrace_event_call *call, struct dentry *d_events,
1158                  const struct file_operations *id,
1159                  const struct file_operations *enable,
1160                  const struct file_operations *filter,
1161                  const struct file_operations *format)
1162 {
1163         struct list_head *head;
1164         int ret;
1165
1166         /*
1167          * If the trace point header did not define TRACE_SYSTEM
1168          * then the system would be called "TRACE_SYSTEM".
1169          */
1170         if (strcmp(call->class->system, TRACE_SYSTEM) != 0)
1171                 d_events = event_subsystem_dir(call->class->system, d_events);
1172
1173         call->dir = debugfs_create_dir(call->name, d_events);
1174         if (!call->dir) {
1175                 pr_warning("Could not create debugfs "
1176                            "'%s' directory\n", call->name);
1177                 return -1;
1178         }
1179
1180         if (call->class->reg && !(call->flags & TRACE_EVENT_FL_IGNORE_ENABLE))
1181                 trace_create_file("enable", 0644, call->dir, call,
1182                                   enable);
1183
1184 #ifdef CONFIG_PERF_EVENTS
1185         if (call->event.type && call->class->reg)
1186                 trace_create_file("id", 0444, call->dir, call,
1187                                   id);
1188 #endif
1189
1190         /*
1191          * Other events may have the same class. Only update
1192          * the fields if they are not already defined.
1193          */
1194         head = trace_get_fields(call);
1195         if (list_empty(head)) {
1196                 ret = call->class->define_fields(call);
1197                 if (ret < 0) {
1198                         pr_warning("Could not initialize trace point"
1199                                    " events/%s\n", call->name);
1200                         return ret;
1201                 }
1202         }
1203         trace_create_file("filter", 0644, call->dir, call,
1204                           filter);
1205
1206         trace_create_file("format", 0444, call->dir, call,
1207                           format);
1208
1209         return 0;
1210 }
1211
1212 static void event_remove(struct ftrace_event_call *call)
1213 {
1214         ftrace_event_enable_disable(call, 0);
1215         if (call->event.funcs)
1216                 __unregister_ftrace_event(&call->event);
1217         list_del(&call->list);
1218 }
1219
1220 static int event_init(struct ftrace_event_call *call)
1221 {
1222         int ret = 0;
1223
1224         if (WARN_ON(!call->name))
1225                 return -EINVAL;
1226
1227         if (call->class->raw_init) {
1228                 ret = call->class->raw_init(call);
1229                 if (ret < 0 && ret != -ENOSYS)
1230                         pr_warn("Could not initialize trace events/%s\n",
1231                                 call->name);
1232         }
1233
1234         return ret;
1235 }
1236
1237 static int
1238 __trace_add_event_call(struct ftrace_event_call *call, struct module *mod,
1239                        const struct file_operations *id,
1240                        const struct file_operations *enable,
1241                        const struct file_operations *filter,
1242                        const struct file_operations *format)
1243 {
1244         struct dentry *d_events;
1245         int ret;
1246
1247         ret = event_init(call);
1248         if (ret < 0)
1249                 return ret;
1250
1251         d_events = event_trace_events_dir();
1252         if (!d_events)
1253                 return -ENOENT;
1254
1255         ret = event_create_dir(call, d_events, id, enable, filter, format);
1256         if (!ret)
1257                 list_add(&call->list, &ftrace_events);
1258         call->mod = mod;
1259
1260         return ret;
1261 }
1262
1263 /* Add an additional event_call dynamically */
1264 int trace_add_event_call(struct ftrace_event_call *call)
1265 {
1266         int ret;
1267         mutex_lock(&event_mutex);
1268         ret = __trace_add_event_call(call, NULL, &ftrace_event_id_fops,
1269                                      &ftrace_enable_fops,
1270                                      &ftrace_event_filter_fops,
1271                                      &ftrace_event_format_fops);
1272         mutex_unlock(&event_mutex);
1273         return ret;
1274 }
1275
1276 static void remove_subsystem_dir(const char *name)
1277 {
1278         struct event_subsystem *system;
1279
1280         if (strcmp(name, TRACE_SYSTEM) == 0)
1281                 return;
1282
1283         list_for_each_entry(system, &event_subsystems, list) {
1284                 if (strcmp(system->name, name) == 0) {
1285                         if (!--system->nr_events) {
1286                                 debugfs_remove_recursive(system->entry);
1287                                 list_del(&system->list);
1288                                 __put_system(system);
1289                         }
1290                         break;
1291                 }
1292         }
1293 }
1294
1295 /*
1296  * Must be called under locking both of event_mutex and trace_event_mutex.
1297  */
1298 static void __trace_remove_event_call(struct ftrace_event_call *call)
1299 {
1300         event_remove(call);
1301         trace_destroy_fields(call);
1302         destroy_preds(call);
1303         debugfs_remove_recursive(call->dir);
1304         remove_subsystem_dir(call->class->system);
1305 }
1306
1307 /* Remove an event_call */
1308 void trace_remove_event_call(struct ftrace_event_call *call)
1309 {
1310         mutex_lock(&event_mutex);
1311         down_write(&trace_event_mutex);
1312         __trace_remove_event_call(call);
1313         up_write(&trace_event_mutex);
1314         mutex_unlock(&event_mutex);
1315 }
1316
1317 #define for_each_event(event, start, end)                       \
1318         for (event = start;                                     \
1319              (unsigned long)event < (unsigned long)end;         \
1320              event++)
1321
1322 #ifdef CONFIG_MODULES
1323
1324 static LIST_HEAD(ftrace_module_file_list);
1325
1326 /*
1327  * Modules must own their file_operations to keep up with
1328  * reference counting.
1329  */
1330 struct ftrace_module_file_ops {
1331         struct list_head                list;
1332         struct module                   *mod;
1333         struct file_operations          id;
1334         struct file_operations          enable;
1335         struct file_operations          format;
1336         struct file_operations          filter;
1337 };
1338
1339 static struct ftrace_module_file_ops *
1340 trace_create_file_ops(struct module *mod)
1341 {
1342         struct ftrace_module_file_ops *file_ops;
1343
1344         /*
1345          * This is a bit of a PITA. To allow for correct reference
1346          * counting, modules must "own" their file_operations.
1347          * To do this, we allocate the file operations that will be
1348          * used in the event directory.
1349          */
1350
1351         file_ops = kmalloc(sizeof(*file_ops), GFP_KERNEL);
1352         if (!file_ops)
1353                 return NULL;
1354
1355         file_ops->mod = mod;
1356
1357         file_ops->id = ftrace_event_id_fops;
1358         file_ops->id.owner = mod;
1359
1360         file_ops->enable = ftrace_enable_fops;
1361         file_ops->enable.owner = mod;
1362
1363         file_ops->filter = ftrace_event_filter_fops;
1364         file_ops->filter.owner = mod;
1365
1366         file_ops->format = ftrace_event_format_fops;
1367         file_ops->format.owner = mod;
1368
1369         list_add(&file_ops->list, &ftrace_module_file_list);
1370
1371         return file_ops;
1372 }
1373
1374 static void trace_module_add_events(struct module *mod)
1375 {
1376         struct ftrace_module_file_ops *file_ops = NULL;
1377         struct ftrace_event_call **call, **start, **end;
1378
1379         start = mod->trace_events;
1380         end = mod->trace_events + mod->num_trace_events;
1381
1382         if (start == end)
1383                 return;
1384
1385         file_ops = trace_create_file_ops(mod);
1386         if (!file_ops)
1387                 return;
1388
1389         for_each_event(call, start, end) {
1390                 __trace_add_event_call(*call, mod,
1391                                        &file_ops->id, &file_ops->enable,
1392                                        &file_ops->filter, &file_ops->format);
1393         }
1394 }
1395
1396 static void trace_module_remove_events(struct module *mod)
1397 {
1398         struct ftrace_module_file_ops *file_ops;
1399         struct ftrace_event_call *call, *p;
1400         bool found = false;
1401
1402         down_write(&trace_event_mutex);
1403         list_for_each_entry_safe(call, p, &ftrace_events, list) {
1404                 if (call->mod == mod) {
1405                         found = true;
1406                         __trace_remove_event_call(call);
1407                 }
1408         }
1409
1410         /* Now free the file_operations */
1411         list_for_each_entry(file_ops, &ftrace_module_file_list, list) {
1412                 if (file_ops->mod == mod)
1413                         break;
1414         }
1415         if (&file_ops->list != &ftrace_module_file_list) {
1416                 list_del(&file_ops->list);
1417                 kfree(file_ops);
1418         }
1419
1420         /*
1421          * It is safest to reset the ring buffer if the module being unloaded
1422          * registered any events.
1423          */
1424         if (found)
1425                 tracing_reset_current_online_cpus();
1426         up_write(&trace_event_mutex);
1427 }
1428
1429 static int trace_module_notify(struct notifier_block *self,
1430                                unsigned long val, void *data)
1431 {
1432         struct module *mod = data;
1433
1434         mutex_lock(&event_mutex);
1435         switch (val) {
1436         case MODULE_STATE_COMING:
1437                 trace_module_add_events(mod);
1438                 break;
1439         case MODULE_STATE_GOING:
1440                 trace_module_remove_events(mod);
1441                 break;
1442         }
1443         mutex_unlock(&event_mutex);
1444
1445         return 0;
1446 }
1447 #else
1448 static int trace_module_notify(struct notifier_block *self,
1449                                unsigned long val, void *data)
1450 {
1451         return 0;
1452 }
1453 #endif /* CONFIG_MODULES */
1454
1455 static struct notifier_block trace_module_nb = {
1456         .notifier_call = trace_module_notify,
1457         .priority = 0,
1458 };
1459
1460 extern struct ftrace_event_call *__start_ftrace_events[];
1461 extern struct ftrace_event_call *__stop_ftrace_events[];
1462
1463 static char bootup_event_buf[COMMAND_LINE_SIZE] __initdata;
1464
1465 static __init int setup_trace_event(char *str)
1466 {
1467         strlcpy(bootup_event_buf, str, COMMAND_LINE_SIZE);
1468         ring_buffer_expanded = 1;
1469         tracing_selftest_disabled = 1;
1470
1471         return 1;
1472 }
1473 __setup("trace_event=", setup_trace_event);
1474
1475 static __init int event_trace_enable(void)
1476 {
1477         struct ftrace_event_call **iter, *call;
1478         char *buf = bootup_event_buf;
1479         char *token;
1480         int ret;
1481
1482         for_each_event(iter, __start_ftrace_events, __stop_ftrace_events) {
1483
1484                 call = *iter;
1485                 ret = event_init(call);
1486                 if (!ret)
1487                         list_add(&call->list, &ftrace_events);
1488         }
1489
1490         while (true) {
1491                 token = strsep(&buf, ",");
1492
1493                 if (!token)
1494                         break;
1495                 if (!*token)
1496                         continue;
1497
1498                 ret = ftrace_set_clr_event(token, 1);
1499                 if (ret)
1500                         pr_warn("Failed to enable trace event: %s\n", token);
1501         }
1502
1503         trace_printk_start_comm();
1504
1505         return 0;
1506 }
1507
1508 static __init int event_trace_init(void)
1509 {
1510         struct ftrace_event_call *call;
1511         struct dentry *d_tracer;
1512         struct dentry *entry;
1513         struct dentry *d_events;
1514         int ret;
1515
1516         d_tracer = tracing_init_dentry();
1517         if (!d_tracer)
1518                 return 0;
1519
1520         entry = debugfs_create_file("available_events", 0444, d_tracer,
1521                                     NULL, &ftrace_avail_fops);
1522         if (!entry)
1523                 pr_warning("Could not create debugfs "
1524                            "'available_events' entry\n");
1525
1526         entry = debugfs_create_file("set_event", 0644, d_tracer,
1527                                     NULL, &ftrace_set_event_fops);
1528         if (!entry)
1529                 pr_warning("Could not create debugfs "
1530                            "'set_event' entry\n");
1531
1532         d_events = event_trace_events_dir();
1533         if (!d_events)
1534                 return 0;
1535
1536         /* ring buffer internal formats */
1537         trace_create_file("header_page", 0444, d_events,
1538                           ring_buffer_print_page_header,
1539                           &ftrace_show_header_fops);
1540
1541         trace_create_file("header_event", 0444, d_events,
1542                           ring_buffer_print_entry_header,
1543                           &ftrace_show_header_fops);
1544
1545         trace_create_file("enable", 0644, d_events,
1546                           NULL, &ftrace_system_enable_fops);
1547
1548         if (trace_define_common_fields())
1549                 pr_warning("tracing: Failed to allocate common fields");
1550
1551         /*
1552          * Early initialization already enabled ftrace event.
1553          * Now it's only necessary to create the event directory.
1554          */
1555         list_for_each_entry(call, &ftrace_events, list) {
1556
1557                 ret = event_create_dir(call, d_events,
1558                                        &ftrace_event_id_fops,
1559                                        &ftrace_enable_fops,
1560                                        &ftrace_event_filter_fops,
1561                                        &ftrace_event_format_fops);
1562                 if (ret < 0)
1563                         event_remove(call);
1564         }
1565
1566         ret = register_module_notifier(&trace_module_nb);
1567         if (ret)
1568                 pr_warning("Failed to register trace events module notifier\n");
1569
1570         return 0;
1571 }
1572 core_initcall(event_trace_enable);
1573 fs_initcall(event_trace_init);
1574
1575 #ifdef CONFIG_FTRACE_STARTUP_TEST
1576
1577 static DEFINE_SPINLOCK(test_spinlock);
1578 static DEFINE_SPINLOCK(test_spinlock_irq);
1579 static DEFINE_MUTEX(test_mutex);
1580
1581 static __init void test_work(struct work_struct *dummy)
1582 {
1583         spin_lock(&test_spinlock);
1584         spin_lock_irq(&test_spinlock_irq);
1585         udelay(1);
1586         spin_unlock_irq(&test_spinlock_irq);
1587         spin_unlock(&test_spinlock);
1588
1589         mutex_lock(&test_mutex);
1590         msleep(1);
1591         mutex_unlock(&test_mutex);
1592 }
1593
1594 static __init int event_test_thread(void *unused)
1595 {
1596         void *test_malloc;
1597
1598         test_malloc = kmalloc(1234, GFP_KERNEL);
1599         if (!test_malloc)
1600                 pr_info("failed to kmalloc\n");
1601
1602         schedule_on_each_cpu(test_work);
1603
1604         kfree(test_malloc);
1605
1606         set_current_state(TASK_INTERRUPTIBLE);
1607         while (!kthread_should_stop())
1608                 schedule();
1609
1610         return 0;
1611 }
1612
1613 /*
1614  * Do various things that may trigger events.
1615  */
1616 static __init void event_test_stuff(void)
1617 {
1618         struct task_struct *test_thread;
1619
1620         test_thread = kthread_run(event_test_thread, NULL, "test-events");
1621         msleep(1);
1622         kthread_stop(test_thread);
1623 }
1624
1625 /*
1626  * For every trace event defined, we will test each trace point separately,
1627  * and then by groups, and finally all trace points.
1628  */
1629 static __init void event_trace_self_tests(void)
1630 {
1631         struct ftrace_event_call *call;
1632         struct event_subsystem *system;
1633         int ret;
1634
1635         pr_info("Running tests on trace events:\n");
1636
1637         list_for_each_entry(call, &ftrace_events, list) {
1638
1639                 /* Only test those that have a probe */
1640                 if (!call->class || !call->class->probe)
1641                         continue;
1642
1643 /*
1644  * Testing syscall events here is pretty useless, but
1645  * we still do it if configured. But this is time consuming.
1646  * What we really need is a user thread to perform the
1647  * syscalls as we test.
1648  */
1649 #ifndef CONFIG_EVENT_TRACE_TEST_SYSCALLS
1650                 if (call->class->system &&
1651                     strcmp(call->class->system, "syscalls") == 0)
1652                         continue;
1653 #endif
1654
1655                 pr_info("Testing event %s: ", call->name);
1656
1657                 /*
1658                  * If an event is already enabled, someone is using
1659                  * it and the self test should not be on.
1660                  */
1661                 if (call->flags & TRACE_EVENT_FL_ENABLED) {
1662                         pr_warning("Enabled event during self test!\n");
1663                         WARN_ON_ONCE(1);
1664                         continue;
1665                 }
1666
1667                 ftrace_event_enable_disable(call, 1);
1668                 event_test_stuff();
1669                 ftrace_event_enable_disable(call, 0);
1670
1671                 pr_cont("OK\n");
1672         }
1673
1674         /* Now test at the sub system level */
1675
1676         pr_info("Running tests on trace event systems:\n");
1677
1678         list_for_each_entry(system, &event_subsystems, list) {
1679
1680                 /* the ftrace system is special, skip it */
1681                 if (strcmp(system->name, "ftrace") == 0)
1682                         continue;
1683
1684                 pr_info("Testing event system %s: ", system->name);
1685
1686                 ret = __ftrace_set_clr_event(NULL, system->name, NULL, 1);
1687                 if (WARN_ON_ONCE(ret)) {
1688                         pr_warning("error enabling system %s\n",
1689                                    system->name);
1690                         continue;
1691                 }
1692
1693                 event_test_stuff();
1694
1695                 ret = __ftrace_set_clr_event(NULL, system->name, NULL, 0);
1696                 if (WARN_ON_ONCE(ret)) {
1697                         pr_warning("error disabling system %s\n",
1698                                    system->name);
1699                         continue;
1700                 }
1701
1702                 pr_cont("OK\n");
1703         }
1704
1705         /* Test with all events enabled */
1706
1707         pr_info("Running tests on all trace events:\n");
1708         pr_info("Testing all events: ");
1709
1710         ret = __ftrace_set_clr_event(NULL, NULL, NULL, 1);
1711         if (WARN_ON_ONCE(ret)) {
1712                 pr_warning("error enabling all events\n");
1713                 return;
1714         }
1715
1716         event_test_stuff();
1717
1718         /* reset sysname */
1719         ret = __ftrace_set_clr_event(NULL, NULL, NULL, 0);
1720         if (WARN_ON_ONCE(ret)) {
1721                 pr_warning("error disabling all events\n");
1722                 return;
1723         }
1724
1725         pr_cont("OK\n");
1726 }
1727
1728 #ifdef CONFIG_FUNCTION_TRACER
1729
1730 static DEFINE_PER_CPU(atomic_t, ftrace_test_event_disable);
1731
1732 static void
1733 function_test_events_call(unsigned long ip, unsigned long parent_ip,
1734                           struct ftrace_ops *op, struct pt_regs *pt_regs)
1735 {
1736         struct ring_buffer_event *event;
1737         struct ring_buffer *buffer;
1738         struct ftrace_entry *entry;
1739         unsigned long flags;
1740         long disabled;
1741         int cpu;
1742         int pc;
1743
1744         pc = preempt_count();
1745         preempt_disable_notrace();
1746         cpu = raw_smp_processor_id();
1747         disabled = atomic_inc_return(&per_cpu(ftrace_test_event_disable, cpu));
1748
1749         if (disabled != 1)
1750                 goto out;
1751
1752         local_save_flags(flags);
1753
1754         event = trace_current_buffer_lock_reserve(&buffer,
1755                                                   TRACE_FN, sizeof(*entry),
1756                                                   flags, pc);
1757         if (!event)
1758                 goto out;
1759         entry   = ring_buffer_event_data(event);
1760         entry->ip                       = ip;
1761         entry->parent_ip                = parent_ip;
1762
1763         trace_buffer_unlock_commit(buffer, event, flags, pc);
1764
1765  out:
1766         atomic_dec(&per_cpu(ftrace_test_event_disable, cpu));
1767         preempt_enable_notrace();
1768 }
1769
1770 static struct ftrace_ops trace_ops __initdata  =
1771 {
1772         .func = function_test_events_call,
1773         .flags = FTRACE_OPS_FL_RECURSION_SAFE,
1774 };
1775
1776 static __init void event_trace_self_test_with_function(void)
1777 {
1778         int ret;
1779         ret = register_ftrace_function(&trace_ops);
1780         if (WARN_ON(ret < 0)) {
1781                 pr_info("Failed to enable function tracer for event tests\n");
1782                 return;
1783         }
1784         pr_info("Running tests again, along with the function tracer\n");
1785         event_trace_self_tests();
1786         unregister_ftrace_function(&trace_ops);
1787 }
1788 #else
1789 static __init void event_trace_self_test_with_function(void)
1790 {
1791 }
1792 #endif
1793
1794 static __init int event_trace_self_tests_init(void)
1795 {
1796         if (!tracing_selftest_disabled) {
1797                 event_trace_self_tests();
1798                 event_trace_self_test_with_function();
1799         }
1800
1801         return 0;
1802 }
1803
1804 late_initcall(event_trace_self_tests_init);
1805
1806 #endif