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
 120         return ret;
 121 }
 122
 123 void trace_destroy_fields(struct ftrace_event_call *call)
 124 {
 125         struct ftrace_event_field *field, *next;
 126         struct list_head *head;
 127
 128         head = trace_get_fields(call);
 129         list_for_each_entry_safe(field, next, head, link) {
 130                 list_del(&field->link);
 131                 kfree(field->type);
 132                 kfree(field->name);
 133                 kfree(field);
 134         }
 135 }
 136
 137 int trace_event_raw_init(struct ftrace_event_call *call)
 138 {
 139         int id;
 140
 141         id = register_ftrace_event(&call->event);
 142         if (!id)
 143                 return -ENODEV;
 144
 145         return 0;
 146 }
 147 EXPORT_SYMBOL_GPL(trace_event_raw_init);
 148
 149 int ftrace_event_reg(struct ftrace_event_call *call,
 150                      enum trace_reg type, void *data)
 151 {
 152         switch (type) {
 153         case TRACE_REG_REGISTER:
 154                 return tracepoint_probe_register(call->name,
 155                                                  call->class->probe,
 156                                                  call);
 157         case TRACE_REG_UNREGISTER:
 158                 tracepoint_probe_unregister(call->name,
 159                                             call->class->probe,
 160                                             call);
 161                 return 0;
 162
 163 #ifdef CONFIG_PERF_EVENTS
 164         case TRACE_REG_PERF_REGISTER:
 165                 return tracepoint_probe_register(call->name,
 166                                                  call->class->perf_probe,
 167                                                  call);
 168         case TRACE_REG_PERF_UNREGISTER:
 169                 tracepoint_probe_unregister(call->name,
 170                                             call->class->perf_probe,
 171                                             call);
 172                 return 0;
 173         case TRACE_REG_PERF_OPEN:
 174         case TRACE_REG_PERF_CLOSE:
 175         case TRACE_REG_PERF_ADD:
 176         case TRACE_REG_PERF_DEL:
 177                 return 0;
 178 #endif
 179         }
 180         return 0;
 181 }
 182 EXPORT_SYMBOL_GPL(ftrace_event_reg);
 183
 184 void trace_event_enable_cmd_record(bool enable)
 185 {
 186         struct ftrace_event_call *call;
 187
 188         mutex_lock(&event_mutex);
 189         list_for_each_entry(call, &ftrace_events, list) {
 190                 if (!(call->flags & TRACE_EVENT_FL_ENABLED))
 191                         continue;
 192
 193                 if (enable) {
 194                         tracing_start_cmdline_record();
 195                         call->flags |= TRACE_EVENT_FL_RECORDED_CMD;
 196                 } else {
 197                         tracing_stop_cmdline_record();
 198                         call->flags &= ~TRACE_EVENT_FL_RECORDED_CMD;
 199                 }
 200         }
 201         mutex_unlock(&event_mutex);
 202 }
 203
 204 static int ftrace_event_enable_disable(struct ftrace_event_call *call,
 205                                         int enable)
 206 {
 207         int ret = 0;
 208
 209         switch (enable) {
 210         case 0:
 211                 if (call->flags & TRACE_EVENT_FL_ENABLED) {
 212                         call->flags &= ~TRACE_EVENT_FL_ENABLED;
 213                         if (call->flags & TRACE_EVENT_FL_RECORDED_CMD) {
 214                                 tracing_stop_cmdline_record();
 215                                 call->flags &= ~TRACE_EVENT_FL_RECORDED_CMD;
 216                         }
 217                         call->class->reg(call, TRACE_REG_UNREGISTER, NULL);
 218                 }
 219                 break;
 220         case 1:
 221                 if (!(call->flags & TRACE_EVENT_FL_ENABLED)) {
 222                         if (trace_flags & TRACE_ITER_RECORD_CMD) {
 223                                 tracing_start_cmdline_record();
 224                                 call->flags |= TRACE_EVENT_FL_RECORDED_CMD;
 225                         }
 226                         ret = call->class->reg(call, TRACE_REG_REGISTER, NULL);
 227                         if (ret) {
 228                                 tracing_stop_cmdline_record();
 229                                 pr_info("event trace: Could not enable event "
 230                                         "%s\n", call->name);
 231                                 break;
 232                         }
 233                         call->flags |= TRACE_EVENT_FL_ENABLED;
 234                 }
 235                 break;
 236         }
 237
 238         return ret;
 239 }
 240
 241 static void ftrace_clear_events(void)
 242 {
 243         struct ftrace_event_call *call;
 244
 245         mutex_lock(&event_mutex);
 246         list_for_each_entry(call, &ftrace_events, list) {
 247                 ftrace_event_enable_disable(call, 0);
 248         }
 249         mutex_unlock(&event_mutex);
 250 }
 251
 252 static void __put_system(struct event_subsystem *system)
 253 {
 254         struct event_filter *filter = system->filter;
 255
 256         WARN_ON_ONCE(system->ref_count == 0);
 257         if (--system->ref_count)
 258                 return;
 259
 260         if (filter) {
 261                 kfree(filter->filter_string);
 262                 kfree(filter);
 263         }
 264         kfree(system->name);
 265         kfree(system);
 266 }
 267
 268 static void __get_system(struct event_subsystem *system)
 269 {
 270         WARN_ON_ONCE(system->ref_count == 0);
 271         system->ref_count++;
 272 }
 273
 274 static void put_system(struct event_subsystem *system)
 275 {
 276         mutex_lock(&event_mutex);
 277         __put_system(system);
 278         mutex_unlock(&event_mutex);
 279 }
 280
 281 /*
 282  * __ftrace_set_clr_event(NULL, NULL, NULL, set) will set/unset all events.
 283  */
 284 static int __ftrace_set_clr_event(const char *match, const char *sub,
 285                                   const char *event, int set)
 286 {
 287         struct ftrace_event_call *call;
 288         int ret = -EINVAL;
 289
 290         mutex_lock(&event_mutex);
 291         list_for_each_entry(call, &ftrace_events, list) {
 292
 293                 if (!call->name || !call->class || !call->class->reg)
 294                         continue;
 295
 296                 if (call->flags & TRACE_EVENT_FL_IGNORE_ENABLE)
 297                         continue;
 298
 299                 if (match &&
 300                     strcmp(match, call->name) != 0 &&
 301                     strcmp(match, call->class->system) != 0)
 302                         continue;
 303
 304                 if (sub && strcmp(sub, call->class->system) != 0)
 305                         continue;
 306
 307                 if (event && strcmp(event, call->name) != 0)
 308                         continue;
 309
 310                 ftrace_event_enable_disable(call, set);
 311
 312                 ret = 0;
 313         }
 314         mutex_unlock(&event_mutex);
 315
 316         return ret;
 317 }
 318
 319 static int ftrace_set_clr_event(char *buf, int set)
 320 {
 321         char *event = NULL, *sub = NULL, *match;
 322
 323         /*
 324          * The buf format can be <subsystem>:<event-name>
 325          *  *:<event-name> means any event by that name.
 326          *  :<event-name> is the same.
 327          *
 328          *  <subsystem>:* means all events in that subsystem
 329          *  <subsystem>: means the same.
 330          *
 331          *  <name> (no ':') means all events in a subsystem with
 332          *  the name <name> or any event that matches <name>
 333          */
 334
 335         match = strsep(&buf, ":");
 336         if (buf) {
 337                 sub = match;
 338                 event = buf;
 339                 match = NULL;
 340
 341                 if (!strlen(sub) || strcmp(sub, "*") == 0)
 342                         sub = NULL;
 343                 if (!strlen(event) || strcmp(event, "*") == 0)
 344                         event = NULL;
 345         }
 346
 347         return __ftrace_set_clr_event(match, sub, event, set);
 348 }
 349
 350 /**
 351  * trace_set_clr_event - enable or disable an event
 352  * @system: system name to match (NULL for any system)
 353  * @event: event name to match (NULL for all events, within system)
 354  * @set: 1 to enable, 0 to disable
 355  *
 356  * This is a way for other parts of the kernel to enable or disable
 357  * event recording.
 358  *
 359  * Returns 0 on success, -EINVAL if the parameters do not match any
 360  * registered events.
 361  */
 362 int trace_set_clr_event(const char *system, const char *event, int set)
 363 {
 364         return __ftrace_set_clr_event(NULL, system, event, set);
 365 }
 366 EXPORT_SYMBOL_GPL(trace_set_clr_event);
 367
 368 /* 128 should be much more than enough */
 369 #define EVENT_BUF_SIZE          127
 370
 371 static ssize_t
 372 ftrace_event_write(struct file *file, const char __user *ubuf,
 373                    size_t cnt, loff_t *ppos)
 374 {
 375         struct trace_parser parser;
 376         ssize_t read, ret;
 377
 378         if (!cnt)
 379                 return 0;
 380
 381         ret = tracing_update_buffers();
 382         if (ret < 0)
 383                 return ret;
 384
 385         if (trace_parser_get_init(&parser, EVENT_BUF_SIZE + 1))
 386                 return -ENOMEM;
 387
 388         read = trace_get_user(&parser, ubuf, cnt, ppos);
 389
 390         if (read >= 0 && trace_parser_loaded((&parser))) {
 391                 int set = 1;
 392
 393                 if (*parser.buffer == '!')
 394                         set = 0;
 395
 396                 parser.buffer[parser.idx] = 0;
 397
 398                 ret = ftrace_set_clr_event(parser.buffer + !set, set);
 399                 if (ret)
 400                         goto out_put;
 401         }
 402
 403         ret = read;
 404
 405  out_put:
 406         trace_parser_put(&parser);
 407
 408         return ret;
 409 }
 410
 411 static void *
 412 t_next(struct seq_file *m, void *v, loff_t *pos)
 413 {
 414         struct ftrace_event_call *call = v;
 415
 416         (*pos)++;
 417
 418         list_for_each_entry_continue(call, &ftrace_events, list) {
 419                 /*
 420                  * The ftrace subsystem is for showing formats only.
 421                  * They can not be enabled or disabled via the event files.
 422                  */
 423                 if (call->class && call->class->reg)
 424                         return call;
 425         }
 426
 427         return NULL;
 428 }
 429
 430 static void *t_start(struct seq_file *m, loff_t *pos)
 431 {
 432         struct ftrace_event_call *call;
 433         loff_t l;
 434
 435         mutex_lock(&event_mutex);
 436
 437         call = list_entry(&ftrace_events, struct ftrace_event_call, list);
 438         for (l = 0; l <= *pos; ) {
 439                 call = t_next(m, call, &l);
 440                 if (!call)
 441                         break;
 442         }
 443         return call;
 444 }
 445
 446 static void *
 447 s_next(struct seq_file *m, void *v, loff_t *pos)
 448 {
 449         struct ftrace_event_call *call = v;
 450
 451         (*pos)++;
 452
 453         list_for_each_entry_continue(call, &ftrace_events, list) {
 454                 if (call->flags & TRACE_EVENT_FL_ENABLED)
 455                         return call;
 456         }
 457
 458         return NULL;
 459 }
 460
 461 static void *s_start(struct seq_file *m, loff_t *pos)
 462 {
 463         struct ftrace_event_call *call;
 464         loff_t l;
 465
 466         mutex_lock(&event_mutex);
 467
 468         call = list_entry(&ftrace_events, struct ftrace_event_call, list);
 469         for (l = 0; l <= *pos; ) {
 470                 call = s_next(m, call, &l);
 471                 if (!call)
 472                         break;
 473         }
 474         return call;
 475 }
 476
 477 static int t_show(struct seq_file *m, void *v)
 478 {
 479         struct ftrace_event_call *call = v;
 480
 481         if (strcmp(call->class->system, TRACE_SYSTEM) != 0)
 482                 seq_printf(m, "%s:", call->class->system);
 483         seq_printf(m, "%s\n", call->name);
 484
 485         return 0;
 486 }
 487
 488 static void t_stop(struct seq_file *m, void *p)
 489 {
 490         mutex_unlock(&event_mutex);
 491 }
 492
 493 static ssize_t
 494 event_enable_read(struct file *filp, char __user *ubuf, size_t cnt,
 495                   loff_t *ppos)
 496 {
 497         struct ftrace_event_call *call = filp->private_data;
 498         char *buf;
 499
 500         if (call->flags & TRACE_EVENT_FL_ENABLED)
 501                 buf = "1\n";
 502         else
 503                 buf = "0\n";
 504
 505         return simple_read_from_buffer(ubuf, cnt, ppos, buf, 2);
 506 }
 507
 508 static ssize_t
 509 event_enable_write(struct file *filp, const char __user *ubuf, size_t cnt,
 510                    loff_t *ppos)
 511 {
 512         struct ftrace_event_call *call = filp->private_data;
 513         unsigned long val;
 514         int ret;
 515
 516         ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
 517         if (ret)
 518                 return ret;
 519
 520         ret = tracing_update_buffers();
 521         if (ret < 0)
 522                 return ret;
 523
 524         switch (val) {
 525         case 0:
 526         case 1:
 527                 mutex_lock(&event_mutex);
 528                 ret = ftrace_event_enable_disable(call, val);
 529                 mutex_unlock(&event_mutex);
 530                 break;
 531
 532         default:
 533                 return -EINVAL;
 534         }
 535
 536         *ppos += cnt;
 537
 538         return ret ? ret : cnt;
 539 }
 540
 541 static ssize_t
 542 system_enable_read(struct file *filp, char __user *ubuf, size_t cnt,
 543                    loff_t *ppos)
 544 {
 545         const char set_to_char[4] = { '?', '0', '1', 'X' };
 546         struct event_subsystem *system = filp->private_data;
 547         struct ftrace_event_call *call;
 548         char buf[2];
 549         int set = 0;
 550         int ret;
 551
 552         mutex_lock(&event_mutex);
 553         list_for_each_entry(call, &ftrace_events, list) {
 554                 if (!call->name || !call->class || !call->class->reg)
 555                         continue;
 556
 557                 if (system && strcmp(call->class->system, system->name) != 0)
 558                         continue;
 559
 560                 /*
 561                  * We need to find out if all the events are set
 562                  * or if all events or cleared, or if we have
 563                  * a mixture.
 564                  */
 565                 set |= (1 << !!(call->flags & TRACE_EVENT_FL_ENABLED));
 566
 567                 /*
 568                  * If we have a mixture, no need to look further.
 569                  */
 570                 if (set == 3)
 571                         break;
 572         }
 573         mutex_unlock(&event_mutex);
 574
 575         buf[0] = set_to_char[set];
 576         buf[1] = '\n';
 577
 578         ret = simple_read_from_buffer(ubuf, cnt, ppos, buf, 2);
 579
 580         return ret;
 581 }
 582
 583 static ssize_t
 584 system_enable_write(struct file *filp, const char __user *ubuf, size_t cnt,
 585                     loff_t *ppos)
 586 {
 587         struct event_subsystem *system = filp->private_data;
 588         const char *name = NULL;
 589         unsigned long val;
 590         ssize_t ret;
 591
 592         ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
 593         if (ret)
 594                 return ret;
 595
 596         ret = tracing_update_buffers();
 597         if (ret < 0)
 598                 return ret;
 599
 600         if (val != 0 && val != 1)
 601                 return -EINVAL;
 602
 603         /*
 604          * Opening of "enable" adds a ref count to system,
 605          * so the name is safe to use.
 606          */
 607         if (system)
 608                 name = system->name;
 609
 610         ret = __ftrace_set_clr_event(NULL, name, NULL, val);
 611         if (ret)
 612                 goto out;
 613
 614         ret = cnt;
 615
 616 out:
 617         *ppos += cnt;
 618
 619         return ret;
 620 }
 621
 622 enum {
 623         FORMAT_HEADER           = 1,
 624         FORMAT_FIELD_SEPERATOR  = 2,
 625         FORMAT_PRINTFMT         = 3,
 626 };
 627
 628 static void *f_next(struct seq_file *m, void *v, loff_t *pos)
 629 {
 630         struct ftrace_event_call *call = m->private;
 631         struct ftrace_event_field *field;
 632         struct list_head *common_head = &ftrace_common_fields;
 633         struct list_head *head = trace_get_fields(call);
 634
 635         (*pos)++;
 636
 637         switch ((unsigned long)v) {
 638         case FORMAT_HEADER:
 639                 if (unlikely(list_empty(common_head)))
 640                         return NULL;
 641
 642                 field = list_entry(common_head->prev,
 643                                    struct ftrace_event_field, link);
 644                 return field;
 645
 646         case FORMAT_FIELD_SEPERATOR:
 647                 if (unlikely(list_empty(head)))
 648                         return NULL;
 649
 650                 field = list_entry(head->prev, struct ftrace_event_field, link);
 651                 return field;
 652
 653         case FORMAT_PRINTFMT:
 654                 /* all done */
 655                 return NULL;
 656         }
 657
 658         field = v;
 659         if (field->link.prev == common_head)
 660                 return (void *)FORMAT_FIELD_SEPERATOR;
 661         else if (field->link.prev == head)
 662                 return (void *)FORMAT_PRINTFMT;
 663
 664         field = list_entry(field->link.prev, struct ftrace_event_field, link);
 665
 666         return field;
 667 }
 668
 669 static void *f_start(struct seq_file *m, loff_t *pos)
 670 {
 671         loff_t l = 0;
 672         void *p;
 673
 674         /* Start by showing the header */
 675         if (!*pos)
 676                 return (void *)FORMAT_HEADER;
 677
 678         p = (void *)FORMAT_HEADER;
 679         do {
 680                 p = f_next(m, p, &l);
 681         } while (p && l < *pos);
 682
 683         return p;
 684 }
 685
 686 static int f_show(struct seq_file *m, void *v)
 687 {
 688         struct ftrace_event_call *call = m->private;
 689         struct ftrace_event_field *field;
 690         const char *array_descriptor;
 691
 692         switch ((unsigned long)v) {
 693         case FORMAT_HEADER:
 694                 seq_printf(m, "name: %s\n", call->name);
 695                 seq_printf(m, "ID: %d\n", call->event.type);
 696                 seq_printf(m, "format:\n");
 697                 return 0;
 698
 699         case FORMAT_FIELD_SEPERATOR:
 700                 seq_putc(m, '\n');
 701                 return 0;
 702
 703         case FORMAT_PRINTFMT:
 704                 seq_printf(m, "\nprint fmt: %s\n",
 705                            call->print_fmt);
 706                 return 0;
 707         }
 708
 709         field = v;
 710
 711         /*
 712          * Smartly shows the array type(except dynamic array).
 713          * Normal:
 714          *      field:TYPE VAR
 715          * If TYPE := TYPE[LEN], it is shown:
 716          *      field:TYPE VAR[LEN]
 717          */
 718         array_descriptor = strchr(field->type, '[');
 719
 720         if (!strncmp(field->type, "__data_loc", 10))
 721                 array_descriptor = NULL;
 722
 723         if (!array_descriptor)
 724                 seq_printf(m, "\tfield:%s %s;\toffset:%u;\tsize:%u;\tsigned:%d;\n",
 725                            field->type, field->name, field->offset,
 726                            field->size, !!field->is_signed);
 727         else
 728                 seq_printf(m, "\tfield:%.*s %s%s;\toffset:%u;\tsize:%u;\tsigned:%d;\n",
 729                            (int)(array_descriptor - field->type),
 730                            field->type, field->name,
 731                            array_descriptor, field->offset,
 732                            field->size, !!field->is_signed);
 733
 734         return 0;
 735 }
 736
 737 static void f_stop(struct seq_file *m, void *p)
 738 {
 739 }
 740
 741 static const struct seq_operations trace_format_seq_ops = {
 742         .start          = f_start,
 743         .next           = f_next,
 744         .stop           = f_stop,
 745         .show           = f_show,
 746 };
 747
 748 static int trace_format_open(struct inode *inode, struct file *file)
 749 {
 750         struct ftrace_event_call *call = inode->i_private;
 751         struct seq_file *m;
 752         int ret;
 753
 754         ret = seq_open(file, &trace_format_seq_ops);
 755         if (ret < 0)
 756                 return ret;
 757
 758         m = file->private_data;
 759         m->private = call;
 760
 761         return 0;
 762 }
 763
 764 static ssize_t
 765 event_id_read(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos)
 766 {
 767         struct ftrace_event_call *call = filp->private_data;
 768         struct trace_seq *s;
 769         int r;
 770
 771         if (*ppos)
 772                 return 0;
 773
 774         s = kmalloc(sizeof(*s), GFP_KERNEL);
 775         if (!s)
 776                 return -ENOMEM;
 777
 778         trace_seq_init(s);
 779         trace_seq_printf(s, "%d\n", call->event.type);
 780
 781         r = simple_read_from_buffer(ubuf, cnt, ppos,
 782                                     s->buffer, s->len);
 783         kfree(s);
 784         return r;
 785 }
 786
 787 static ssize_t
 788 event_filter_read(struct file *filp, char __user *ubuf, size_t cnt,
 789                   loff_t *ppos)
 790 {
 791         struct ftrace_event_call *call = filp->private_data;
 792         struct trace_seq *s;
 793         int r;
 794
 795         if (*ppos)
 796                 return 0;
 797
 798         s = kmalloc(sizeof(*s), GFP_KERNEL);
 799         if (!s)
 800                 return -ENOMEM;
 801
 802         trace_seq_init(s);
 803
 804         print_event_filter(call, s);
 805         r = simple_read_from_buffer(ubuf, cnt, ppos, s->buffer, s->len);
 806
 807         kfree(s);
 808
 809         return r;
 810 }
 811
 812 static ssize_t
 813 event_filter_write(struct file *filp, const char __user *ubuf, size_t cnt,
 814                    loff_t *ppos)
 815 {
 816         struct ftrace_event_call *call = filp->private_data;
 817         char *buf;
 818         int err;
 819
 820         if (cnt >= PAGE_SIZE)
 821                 return -EINVAL;
 822
 823         buf = (char *)__get_free_page(GFP_TEMPORARY);
 824         if (!buf)
 825                 return -ENOMEM;
 826
 827         if (copy_from_user(buf, ubuf, cnt)) {
 828                 free_page((unsigned long) buf);
 829                 return -EFAULT;
 830         }
 831         buf[cnt] = '\0';
 832
 833         err = apply_event_filter(call, buf);
 834         free_page((unsigned long) buf);
 835         if (err < 0)
 836                 return err;
 837
 838         *ppos += cnt;
 839
 840         return cnt;
 841 }
 842
 843 static LIST_HEAD(event_subsystems);
 844
 845 static int subsystem_open(struct inode *inode, struct file *filp)
 846 {
 847         struct event_subsystem *system = NULL;
 848         int ret;
 849
 850         if (!inode->i_private)
 851                 goto skip_search;
 852
 853         /* Make sure the system still exists */
 854         mutex_lock(&event_mutex);
 855         list_for_each_entry(system, &event_subsystems, list) {
 856                 if (system == inode->i_private) {
 857                         /* Don't open systems with no events */
 858                         if (!system->nr_events) {
 859                                 system = NULL;
 860                                 break;
 861                         }
 862                         __get_system(system);
 863                         break;
 864                 }
 865         }
 866         mutex_unlock(&event_mutex);
 867
 868         if (system != inode->i_private)
 869                 return -ENODEV;
 870
 871  skip_search:
 872         ret = tracing_open_generic(inode, filp);
 873         if (ret < 0 && system)
 874                 put_system(system);
 875
 876         return ret;
 877 }
 878
 879 static int subsystem_release(struct inode *inode, struct file *file)
 880 {
 881         struct event_subsystem *system = inode->i_private;
 882
 883         if (system)
 884                 put_system(system);
 885
 886         return 0;
 887 }
 888
 889 static ssize_t
 890 subsystem_filter_read(struct file *filp, char __user *ubuf, size_t cnt,
 891                       loff_t *ppos)
 892 {
 893         struct event_subsystem *system = filp->private_data;
 894         struct trace_seq *s;
 895         int r;
 896
 897         if (*ppos)
 898                 return 0;
 899
 900         s = kmalloc(sizeof(*s), GFP_KERNEL);
 901         if (!s)
 902                 return -ENOMEM;
 903
 904         trace_seq_init(s);
 905
 906         print_subsystem_event_filter(system, s);
 907         r = simple_read_from_buffer(ubuf, cnt, ppos, s->buffer, s->len);
 908
 909         kfree(s);
 910
 911         return r;
 912 }
 913
 914 static ssize_t
 915 subsystem_filter_write(struct file *filp, const char __user *ubuf, size_t cnt,
 916                        loff_t *ppos)
 917 {
 918         struct event_subsystem *system = filp->private_data;
 919         char *buf;
 920         int err;
 921
 922         if (cnt >= PAGE_SIZE)
 923                 return -EINVAL;
 924
 925         buf = (char *)__get_free_page(GFP_TEMPORARY);
 926         if (!buf)
 927                 return -ENOMEM;
 928
 929         if (copy_from_user(buf, ubuf, cnt)) {
 930                 free_page((unsigned long) buf);
 931                 return -EFAULT;
 932         }
 933         buf[cnt] = '\0';
 934
 935         err = apply_subsystem_event_filter(system, buf);
 936         free_page((unsigned long) buf);
 937         if (err < 0)
 938                 return err;
 939
 940         *ppos += cnt;
 941
 942         return cnt;
 943 }
 944
 945 static ssize_t
 946 show_header(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos)
 947 {
 948         int (*func)(struct trace_seq *s) = filp->private_data;
 949         struct trace_seq *s;
 950         int r;
 951
 952         if (*ppos)
 953                 return 0;
 954
 955         s = kmalloc(sizeof(*s), GFP_KERNEL);
 956         if (!s)
 957                 return -ENOMEM;
 958
 959         trace_seq_init(s);
 960
 961         func(s);
 962         r = simple_read_from_buffer(ubuf, cnt, ppos, s->buffer, s->len);
 963
 964         kfree(s);
 965
 966         return r;
 967 }
 968
 969 static int ftrace_event_avail_open(struct inode *inode, struct file *file);
 970 static int ftrace_event_set_open(struct inode *inode, struct file *file);
 971
 972 static const struct seq_operations show_event_seq_ops = {
 973         .start = t_start,
 974         .next = t_next,
 975         .show = t_show,
 976         .stop = t_stop,
 977 };
 978
 979 static const struct seq_operations show_set_event_seq_ops = {
 980         .start = s_start,
 981         .next = s_next,
 982         .show = t_show,
 983         .stop = t_stop,
 984 };
 985
 986 static const struct file_operations ftrace_avail_fops = {
 987         .open = ftrace_event_avail_open,
 988         .read = seq_read,
 989         .llseek = seq_lseek,
 990         .release = seq_release,
 991 };
 992
 993 static const struct file_operations ftrace_set_event_fops = {
 994         .open = ftrace_event_set_open,
 995         .read = seq_read,
 996         .write = ftrace_event_write,
 997         .llseek = seq_lseek,
 998         .release = seq_release,
 999 };
1000
1001 static const struct file_operations ftrace_enable_fops = {
1002         .open = tracing_open_generic,
1003         .read = event_enable_read,
1004         .write = event_enable_write,
1005         .llseek = default_llseek,
1006 };
1007
1008 static const struct file_operations ftrace_event_format_fops = {
1009         .open = trace_format_open,
1010         .read = seq_read,
1011         .llseek = seq_lseek,
1012         .release = seq_release,
1013 };
1014
1015 static const struct file_operations ftrace_event_id_fops = {
1016         .open = tracing_open_generic,
1017         .read = event_id_read,
1018         .llseek = default_llseek,
1019 };
1020
1021 static const struct file_operations ftrace_event_filter_fops = {
1022         .open = tracing_open_generic,
1023         .read = event_filter_read,
1024         .write = event_filter_write,
1025         .llseek = default_llseek,
1026 };
1027
1028 static const struct file_operations ftrace_subsystem_filter_fops = {
1029         .open = subsystem_open,
1030         .read = subsystem_filter_read,
1031         .write = subsystem_filter_write,
1032         .llseek = default_llseek,
1033         .release = subsystem_release,
1034 };
1035
1036 static const struct file_operations ftrace_system_enable_fops = {
1037         .open = subsystem_open,
1038         .read = system_enable_read,
1039         .write = system_enable_write,
1040         .llseek = default_llseek,
1041         .release = subsystem_release,
1042 };
1043
1044 static const struct file_operations ftrace_show_header_fops = {
1045         .open = tracing_open_generic,
1046         .read = show_header,
1047         .llseek = default_llseek,
1048 };
1049
1050 static struct dentry *event_trace_events_dir(void)
1051 {
1052         static struct dentry *d_tracer;
1053         static struct dentry *d_events;
1054
1055         if (d_events)
1056                 return d_events;
1057
1058         d_tracer = tracing_init_dentry();
1059         if (!d_tracer)
1060                 return NULL;
1061
1062         d_events = debugfs_create_dir("events", d_tracer);
1063         if (!d_events)
1064                 pr_warning("Could not create debugfs "
1065                            "'events' directory\n");
1066
1067         return d_events;
1068 }
1069
1070 static int
1071 ftrace_event_avail_open(struct inode *inode, struct file *file)
1072 {
1073         const struct seq_operations *seq_ops = &show_event_seq_ops;
1074
1075         return seq_open(file, seq_ops);
1076 }
1077
1078 static int
1079 ftrace_event_set_open(struct inode *inode, struct file *file)
1080 {
1081         const struct seq_operations *seq_ops = &show_set_event_seq_ops;
1082
1083         if ((file->f_mode & FMODE_WRITE) &&
1084             (file->f_flags & O_TRUNC))
1085                 ftrace_clear_events();
1086
1087         return seq_open(file, seq_ops);
1088 }
1089
1090 static struct dentry *
1091 event_subsystem_dir(const char *name, struct dentry *d_events)
1092 {
1093         struct event_subsystem *system;
1094         struct dentry *entry;
1095
1096         /* First see if we did not already create this dir */
1097         list_for_each_entry(system, &event_subsystems, list) {
1098                 if (strcmp(system->name, name) == 0) {
1099                         system->nr_events++;
1100                         return system->entry;
1101                 }
1102         }
1103
1104         /* need to create new entry */
1105         system = kmalloc(sizeof(*system), GFP_KERNEL);
1106         if (!system) {
1107                 pr_warning("No memory to create event subsystem %s\n",
1108                            name);
1109                 return d_events;
1110         }
1111
1112         system->entry = debugfs_create_dir(name, d_events);
1113         if (!system->entry) {
1114                 pr_warning("Could not create event subsystem %s\n",
1115                            name);
1116                 kfree(system);
1117                 return d_events;
1118         }
1119
1120         system->nr_events = 1;
1121         system->ref_count = 1;
1122         system->name = kstrdup(name, GFP_KERNEL);
1123         if (!system->name) {
1124                 debugfs_remove(system->entry);
1125                 kfree(system);
1126                 return d_events;
1127         }
1128
1129         list_add(&system->list, &event_subsystems);
1130
1131         system->filter = NULL;
1132
1133         system->filter = kzalloc(sizeof(struct event_filter), GFP_KERNEL);
1134         if (!system->filter) {
1135                 pr_warning("Could not allocate filter for subsystem "
1136                            "'%s'\n", name);
1137                 return system->entry;
1138         }
1139
1140         entry = debugfs_create_file("filter", 0644, system->entry, system,
1141                                     &ftrace_subsystem_filter_fops);
1142         if (!entry) {
1143                 kfree(system->filter);
1144                 system->filter = NULL;
1145                 pr_warning("Could not create debugfs "
1146                            "'%s/filter' entry\n", name);
1147         }
1148
1149         trace_create_file("enable", 0644, system->entry, system,
1150                           &ftrace_system_enable_fops);
1151
1152         return system->entry;
1153 }
1154
1155 static int
1156 event_create_dir(struct ftrace_event_call *call, struct dentry *d_events,
1157                  const struct file_operations *id,
1158                  const struct file_operations *enable,
1159                  const struct file_operations *filter,
1160                  const struct file_operations *format)
1161 {
1162         struct list_head *head;
1163         int ret;
1164
1165         /*
1166          * If the trace point header did not define TRACE_SYSTEM
1167          * then the system would be called "TRACE_SYSTEM".
1168          */
1169         if (strcmp(call->class->system, TRACE_SYSTEM) != 0)
1170                 d_events = event_subsystem_dir(call->class->system, d_events);
1171
1172         call->dir = debugfs_create_dir(call->name, d_events);
1173         if (!call->dir) {
1174                 pr_warning("Could not create debugfs "
1175                            "'%s' directory\n", call->name);
1176                 return -1;
1177         }
1178
1179         if (call->class->reg && !(call->flags & TRACE_EVENT_FL_IGNORE_ENABLE))
1180                 trace_create_file("enable", 0644, call->dir, call,
1181                                   enable);
1182
1183 #ifdef CONFIG_PERF_EVENTS
1184         if (call->event.type && call->class->reg)
1185                 trace_create_file("id", 0444, call->dir, call,
1186                                   id);
1187 #endif
1188
1189         /*
1190          * Other events may have the same class. Only update
1191          * the fields if they are not already defined.
1192          */
1193         head = trace_get_fields(call);
1194         if (list_empty(head)) {
1195                 ret = call->class->define_fields(call);
1196                 if (ret < 0) {
1197                         pr_warning("Could not initialize trace point"
1198                                    " events/%s\n", call->name);
1199                         return ret;
1200                 }
1201         }
1202         trace_create_file("filter", 0644, call->dir, call,
1203                           filter);
1204
1205         trace_create_file("format", 0444, call->dir, call,
1206                           format);
1207
1208         return 0;
1209 }
1210
1211 static void event_remove(struct ftrace_event_call *call)
1212 {
1213         ftrace_event_enable_disable(call, 0);
1214         if (call->event.funcs)
1215                 __unregister_ftrace_event(&call->event);
1216         list_del(&call->list);
1217 }
1218
1219 static int event_init(struct ftrace_event_call *call)
1220 {
1221         int ret = 0;
1222
1223         if (WARN_ON(!call->name))
1224                 return -EINVAL;
1225
1226         if (call->class->raw_init) {
1227                 ret = call->class->raw_init(call);
1228                 if (ret < 0 && ret != -ENOSYS)
1229                         pr_warn("Could not initialize trace events/%s\n",
1230                                 call->name);
1231         }
1232
1233         return ret;
1234 }
1235
1236 static int
1237 __trace_add_event_call(struct ftrace_event_call *call, struct module *mod,
1238                        const struct file_operations *id,
1239                        const struct file_operations *enable,
1240                        const struct file_operations *filter,
1241                        const struct file_operations *format)
1242 {
1243         struct dentry *d_events;
1244         int ret;
1245
1246         ret = event_init(call);
1247         if (ret < 0)
1248                 return ret;
1249
1250         d_events = event_trace_events_dir();
1251         if (!d_events)
1252                 return -ENOENT;
1253
1254         ret = event_create_dir(call, d_events, id, enable, filter, format);
1255         if (!ret)
1256                 list_add(&call->list, &ftrace_events);
1257         call->mod = mod;
1258
1259         return ret;
1260 }
1261
1262 /* Add an additional event_call dynamically */
1263 int trace_add_event_call(struct ftrace_event_call *call)
1264 {
1265         int ret;
1266         mutex_lock(&event_mutex);
1267         ret = __trace_add_event_call(call, NULL, &ftrace_event_id_fops,
1268                                      &ftrace_enable_fops,
1269                                      &ftrace_event_filter_fops,
1270                                      &ftrace_event_format_fops);
1271         mutex_unlock(&event_mutex);
1272         return ret;
1273 }
1274
1275 static void remove_subsystem_dir(const char *name)
1276 {
1277         struct event_subsystem *system;
1278
1279         if (strcmp(name, TRACE_SYSTEM) == 0)
1280                 return;
1281
1282         list_for_each_entry(system, &event_subsystems, list) {
1283                 if (strcmp(system->name, name) == 0) {
1284                         if (!--system->nr_events) {
1285                                 debugfs_remove_recursive(system->entry);
1286                                 list_del(&system->list);
1287                                 __put_system(system);
1288                         }
1289                         break;
1290                 }
1291         }
1292 }
1293
1294 /*
1295  * Must be called under locking both of event_mutex and trace_event_mutex.
1296  */
1297 static void __trace_remove_event_call(struct ftrace_event_call *call)
1298 {
1299         event_remove(call);
1300         trace_destroy_fields(call);
1301         destroy_preds(call);
1302         debugfs_remove_recursive(call->dir);
1303         remove_subsystem_dir(call->class->system);
1304 }
1305
1306 /* Remove an event_call */
1307 void trace_remove_event_call(struct ftrace_event_call *call)
1308 {
1309         mutex_lock(&event_mutex);
1310         down_write(&trace_event_mutex);
1311         __trace_remove_event_call(call);
1312         up_write(&trace_event_mutex);
1313         mutex_unlock(&event_mutex);
1314 }
1315
1316 #define for_each_event(event, start, end)                       \
1317         for (event = start;                                     \
1318              (unsigned long)event < (unsigned long)end;         \
1319              event++)
1320
1321 #ifdef CONFIG_MODULES
1322
1323 static LIST_HEAD(ftrace_module_file_list);
1324
1325 /*
1326  * Modules must own their file_operations to keep up with
1327  * reference counting.
1328  */
1329 struct ftrace_module_file_ops {
1330         struct list_head                list;
1331         struct module                   *mod;
1332         struct file_operations          id;
1333         struct file_operations          enable;
1334         struct file_operations          format;
1335         struct file_operations          filter;
1336 };
1337
1338 static struct ftrace_module_file_ops *
1339 trace_create_file_ops(struct module *mod)
1340 {
1341         struct ftrace_module_file_ops *file_ops;
1342
1343         /*
1344          * This is a bit of a PITA. To allow for correct reference
1345          * counting, modules must "own" their file_operations.
1346          * To do this, we allocate the file operations that will be
1347          * used in the event directory.
1348          */
1349
1350         file_ops = kmalloc(sizeof(*file_ops), GFP_KERNEL);
1351         if (!file_ops)
1352                 return NULL;
1353
1354         file_ops->mod = mod;
1355
1356         file_ops->id = ftrace_event_id_fops;
1357         file_ops->id.owner = mod;
1358
1359         file_ops->enable = ftrace_enable_fops;
1360         file_ops->enable.owner = mod;
1361
1362         file_ops->filter = ftrace_event_filter_fops;
1363         file_ops->filter.owner = mod;
1364
1365         file_ops->format = ftrace_event_format_fops;
1366         file_ops->format.owner = mod;
1367
1368         list_add(&file_ops->list, &ftrace_module_file_list);
1369
1370         return file_ops;
1371 }
1372
1373 static void trace_module_add_events(struct module *mod)
1374 {
1375         struct ftrace_module_file_ops *file_ops = NULL;
1376         struct ftrace_event_call **call, **start, **end;
1377
1378         start = mod->trace_events;
1379         end = mod->trace_events + mod->num_trace_events;
1380
1381         if (start == end)
1382                 return;
1383
1384         file_ops = trace_create_file_ops(mod);
1385         if (!file_ops)
1386                 return;
1387
1388         for_each_event(call, start, end) {
1389                 __trace_add_event_call(*call, mod,
1390                                        &file_ops->id, &file_ops->enable,
1391                                        &file_ops->filter, &file_ops->format);
1392         }
1393 }
1394
1395 static void trace_module_remove_events(struct module *mod)
1396 {
1397         struct ftrace_module_file_ops *file_ops;
1398         struct ftrace_event_call *call, *p;
1399         bool found = false;
1400
1401         down_write(&trace_event_mutex);
1402         list_for_each_entry_safe(call, p, &ftrace_events, list) {
1403                 if (call->mod == mod) {
1404                         found = true;
1405                         __trace_remove_event_call(call);
1406                 }
1407         }
1408
1409         /* Now free the file_operations */
1410         list_for_each_entry(file_ops, &ftrace_module_file_list, list) {
1411                 if (file_ops->mod == mod)
1412                         break;
1413         }
1414         if (&file_ops->list != &ftrace_module_file_list) {
1415                 list_del(&file_ops->list);
1416                 kfree(file_ops);
1417         }
1418
1419         /*
1420          * It is safest to reset the ring buffer if the module being unloaded
1421          * registered any events.
1422          */
1423         if (found)
1424                 tracing_reset_current_online_cpus();
1425         up_write(&trace_event_mutex);
1426 }
1427
1428 static int trace_module_notify(struct notifier_block *self,
1429                                unsigned long val, void *data)
1430 {
1431         struct module *mod = data;
1432
1433         mutex_lock(&event_mutex);
1434         switch (val) {
1435         case MODULE_STATE_COMING:
1436                 trace_module_add_events(mod);
1437                 break;
1438         case MODULE_STATE_GOING:
1439                 trace_module_remove_events(mod);
1440                 break;
1441         }
1442         mutex_unlock(&event_mutex);
1443
1444         return 0;
1445 }
1446 #else
1447 static int trace_module_notify(struct notifier_block *self,
1448                                unsigned long val, void *data)
1449 {
1450         return 0;
1451 }
1452 #endif /* CONFIG_MODULES */
1453
1454 static struct notifier_block trace_module_nb = {
1455         .notifier_call = trace_module_notify,
1456         .priority = 0,
1457 };
1458
1459 extern struct ftrace_event_call *__start_ftrace_events[];
1460 extern struct ftrace_event_call *__stop_ftrace_events[];
1461
1462 static char bootup_event_buf[COMMAND_LINE_SIZE] __initdata;
1463
1464 static __init int setup_trace_event(char *str)
1465 {
1466         strlcpy(bootup_event_buf, str, COMMAND_LINE_SIZE);
1467         ring_buffer_expanded = 1;
1468         tracing_selftest_disabled = 1;
1469
1470         return 1;
1471 }
1472 __setup("trace_event=", setup_trace_event);
1473
1474 static __init int event_trace_enable(void)
1475 {
1476         struct ftrace_event_call **iter, *call;
1477         char *buf = bootup_event_buf;
1478         char *token;
1479         int ret;
1480
1481         for_each_event(iter, __start_ftrace_events, __stop_ftrace_events) {
1482
1483                 call = *iter;
1484                 ret = event_init(call);
1485                 if (!ret)
1486                         list_add(&call->list, &ftrace_events);
1487         }
1488
1489         while (true) {
1490                 token = strsep(&buf, ",");
1491
1492                 if (!token)
1493                         break;
1494                 if (!*token)
1495                         continue;
1496
1497                 ret = ftrace_set_clr_event(token, 1);
1498                 if (ret)
1499                         pr_warn("Failed to enable trace event: %s\n", token);
1500         }
1501
1502         trace_printk_start_comm();
1503
1504         return 0;
1505 }
1506
1507 static __init int event_trace_init(void)
1508 {
1509         struct ftrace_event_call *call;
1510         struct dentry *d_tracer;
1511         struct dentry *entry;
1512         struct dentry *d_events;
1513         int ret;
1514
1515         d_tracer = tracing_init_dentry();
1516         if (!d_tracer)
1517                 return 0;
1518
1519         entry = debugfs_create_file("available_events", 0444, d_tracer,
1520                                     NULL, &ftrace_avail_fops);
1521         if (!entry)
1522                 pr_warning("Could not create debugfs "
1523                            "'available_events' entry\n");
1524
1525         entry = debugfs_create_file("set_event", 0644, d_tracer,
1526                                     NULL, &ftrace_set_event_fops);
1527         if (!entry)
1528                 pr_warning("Could not create debugfs "
1529                            "'set_event' entry\n");
1530
1531         d_events = event_trace_events_dir();
1532         if (!d_events)
1533                 return 0;
1534
1535         /* ring buffer internal formats */
1536         trace_create_file("header_page", 0444, d_events,
1537                           ring_buffer_print_page_header,
1538                           &ftrace_show_header_fops);
1539
1540         trace_create_file("header_event", 0444, d_events,
1541                           ring_buffer_print_entry_header,
1542                           &ftrace_show_header_fops);
1543
1544         trace_create_file("enable", 0644, d_events,
1545                           NULL, &ftrace_system_enable_fops);
1546
1547         if (trace_define_common_fields())
1548                 pr_warning("tracing: Failed to allocate common fields");
1549
1550         /*
1551          * Early initialization already enabled ftrace event.
1552          * Now it's only necessary to create the event directory.
1553          */
1554         list_for_each_entry(call, &ftrace_events, list) {
1555
1556                 ret = event_create_dir(call, d_events,
1557                                        &ftrace_event_id_fops,
1558                                        &ftrace_enable_fops,
1559                                        &ftrace_event_filter_fops,
1560                                        &ftrace_event_format_fops);
1561                 if (ret < 0)
1562                         event_remove(call);
1563         }
1564
1565         ret = register_module_notifier(&trace_module_nb);
1566         if (ret)
1567                 pr_warning("Failed to register trace events module notifier\n");
1568
1569         return 0;
1570 }
1571 core_initcall(event_trace_enable);
1572 fs_initcall(event_trace_init);
1573
1574 #ifdef CONFIG_FTRACE_STARTUP_TEST
1575
1576 static DEFINE_SPINLOCK(test_spinlock);
1577 static DEFINE_SPINLOCK(test_spinlock_irq);
1578 static DEFINE_MUTEX(test_mutex);
1579
1580 static __init void test_work(struct work_struct *dummy)
1581 {
1582         spin_lock(&test_spinlock);
1583         spin_lock_irq(&test_spinlock_irq);
1584         udelay(1);
1585         spin_unlock_irq(&test_spinlock_irq);
1586         spin_unlock(&test_spinlock);
1587
1588         mutex_lock(&test_mutex);
1589         msleep(1);
1590         mutex_unlock(&test_mutex);
1591 }
1592
1593 static __init int event_test_thread(void *unused)
1594 {
1595         void *test_malloc;
1596
1597         test_malloc = kmalloc(1234, GFP_KERNEL);
1598         if (!test_malloc)
1599                 pr_info("failed to kmalloc\n");
1600
1601         schedule_on_each_cpu(test_work);
1602
1603         kfree(test_malloc);
1604
1605         set_current_state(TASK_INTERRUPTIBLE);
1606         while (!kthread_should_stop())
1607                 schedule();
1608
1609         return 0;
1610 }
1611
1612 /*
1613  * Do various things that may trigger events.
1614  */
1615 static __init void event_test_stuff(void)
1616 {
1617         struct task_struct *test_thread;
1618
1619         test_thread = kthread_run(event_test_thread, NULL, "test-events");
1620         msleep(1);
1621         kthread_stop(test_thread);
1622 }
1623
1624 /*
1625  * For every trace event defined, we will test each trace point separately,
1626  * and then by groups, and finally all trace points.
1627  */
1628 static __init void event_trace_self_tests(void)
1629 {
1630         struct ftrace_event_call *call;
1631         struct event_subsystem *system;
1632         int ret;
1633
1634         pr_info("Running tests on trace events:\n");
1635
1636         list_for_each_entry(call, &ftrace_events, list) {
1637
1638                 /* Only test those that have a probe */
1639                 if (!call->class || !call->class->probe)
1640                         continue;
1641
1642 /*
1643  * Testing syscall events here is pretty useless, but
1644  * we still do it if configured. But this is time consuming.
1645  * What we really need is a user thread to perform the
1646  * syscalls as we test.
1647  */
1648 #ifndef CONFIG_EVENT_TRACE_TEST_SYSCALLS
1649                 if (call->class->system &&
1650                     strcmp(call->class->system, "syscalls") == 0)
1651                         continue;
1652 #endif
1653
1654                 pr_info("Testing event %s: ", call->name);
1655
1656                 /*
1657                  * If an event is already enabled, someone is using
1658                  * it and the self test should not be on.
1659                  */
1660                 if (call->flags & TRACE_EVENT_FL_ENABLED) {
1661                         pr_warning("Enabled event during self test!\n");
1662                         WARN_ON_ONCE(1);
1663                         continue;
1664                 }
1665
1666                 ftrace_event_enable_disable(call, 1);
1667                 event_test_stuff();
1668                 ftrace_event_enable_disable(call, 0);
1669
1670                 pr_cont("OK\n");
1671         }
1672
1673         /* Now test at the sub system level */
1674
1675         pr_info("Running tests on trace event systems:\n");
1676
1677         list_for_each_entry(system, &event_subsystems, list) {
1678
1679                 /* the ftrace system is special, skip it */
1680                 if (strcmp(system->name, "ftrace") == 0)
1681                         continue;
1682
1683                 pr_info("Testing event system %s: ", system->name);
1684
1685                 ret = __ftrace_set_clr_event(NULL, system->name, NULL, 1);
1686                 if (WARN_ON_ONCE(ret)) {
1687                         pr_warning("error enabling system %s\n",
1688                                    system->name);
1689                         continue;
1690                 }
1691
1692                 event_test_stuff();
1693
1694                 ret = __ftrace_set_clr_event(NULL, system->name, NULL, 0);
1695                 if (WARN_ON_ONCE(ret)) {
1696                         pr_warning("error disabling system %s\n",
1697                                    system->name);
1698                         continue;
1699                 }
1700
1701                 pr_cont("OK\n");
1702         }
1703
1704         /* Test with all events enabled */
1705
1706         pr_info("Running tests on all trace events:\n");
1707         pr_info("Testing all events: ");
1708
1709         ret = __ftrace_set_clr_event(NULL, NULL, NULL, 1);
1710         if (WARN_ON_ONCE(ret)) {
1711                 pr_warning("error enabling all events\n");
1712                 return;
1713         }
1714
1715         event_test_stuff();
1716
1717         /* reset sysname */
1718         ret = __ftrace_set_clr_event(NULL, NULL, NULL, 0);
1719         if (WARN_ON_ONCE(ret)) {
1720                 pr_warning("error disabling all events\n");
1721                 return;
1722         }
1723
1724         pr_cont("OK\n");
1725 }
1726
1727 #ifdef CONFIG_FUNCTION_TRACER
1728
1729 static DEFINE_PER_CPU(atomic_t, ftrace_test_event_disable);
1730
1731 static void
1732 function_test_events_call(unsigned long ip, unsigned long parent_ip,
1733                           struct ftrace_ops *op, struct pt_regs *pt_regs)
1734 {
1735         struct ring_buffer_event *event;
1736         struct ring_buffer *buffer;
1737         struct ftrace_entry *entry;
1738         unsigned long flags;
1739         long disabled;
1740         int cpu;
1741         int pc;
1742
1743         pc = preempt_count();
1744         preempt_disable_notrace();
1745         cpu = raw_smp_processor_id();
1746         disabled = atomic_inc_return(&per_cpu(ftrace_test_event_disable, cpu));
1747
1748         if (disabled != 1)
1749                 goto out;
1750
1751         local_save_flags(flags);
1752
1753         event = trace_current_buffer_lock_reserve(&buffer,
1754                                                   TRACE_FN, sizeof(*entry),
1755                                                   flags, pc);
1756         if (!event)
1757                 goto out;
1758         entry   = ring_buffer_event_data(event);
1759         entry->ip                       = ip;
1760         entry->parent_ip                = parent_ip;
1761
1762         trace_buffer_unlock_commit(buffer, event, flags, pc);
1763
1764  out:
1765         atomic_dec(&per_cpu(ftrace_test_event_disable, cpu));
1766         preempt_enable_notrace();
1767 }
1768
1769 static struct ftrace_ops trace_ops __initdata  =
1770 {
1771         .func = function_test_events_call,
1772         .flags = FTRACE_OPS_FL_RECURSION_SAFE,
1773 };
1774
1775 static __init void event_trace_self_test_with_function(void)
1776 {
1777         int ret;
1778         ret = register_ftrace_function(&trace_ops);
1779         if (WARN_ON(ret < 0)) {
1780                 pr_info("Failed to enable function tracer for event tests\n");
1781                 return;
1782         }
1783         pr_info("Running tests again, along with the function tracer\n");
1784         event_trace_self_tests();
1785         unregister_ftrace_function(&trace_ops);
1786 }
1787 #else
1788 static __init void event_trace_self_test_with_function(void)
1789 {
1790 }
1791 #endif
1792
1793 static __init int event_trace_self_tests_init(void)
1794 {
1795         if (!tracing_selftest_disabled) {
1796                 event_trace_self_tests();
1797                 event_trace_self_test_with_function();
1798         }
1799
1800         return 0;
1801 }
1802
1803 late_initcall(event_trace_self_tests_init);
1804
1805 #endif