kernel/trace/trace_events.c

   1 /*
   2  * event tracer
   3  *
   4  * Copyright (C) 2008 Red Hat Inc, Steven Rostedt <srostedt@redhat.com>
   5  *
   6  *  - Added format output of fields of the trace point.
   7  *    This was based off of work by Tom Zanussi <tzanussi@gmail.com>.
   8  *
   9  */
  10
  11 #include <linux/workqueue.h>
  12 #include <linux/spinlock.h>
  13 #include <linux/kthread.h>
  14 #include <linux/debugfs.h>
  15 #include <linux/uaccess.h>
  16 #include <linux/module.h>
  17 #include <linux/ctype.h>
  18 #include <linux/slab.h>
  19 #include <linux/delay.h>
  20
  21 #include <asm/setup.h>
  22
  23 #include "trace_output.h"
  24
  25 #undef TRACE_SYSTEM
  26 #define TRACE_SYSTEM "TRACE_SYSTEM"
  27
  28 DEFINE_MUTEX(event_mutex);
  29
  30 LIST_HEAD(ftrace_events);
  31 LIST_HEAD(ftrace_common_fields);
  32
  33 struct list_head *
  34 trace_get_fields(struct ftrace_event_call *event_call)
  35 {
  36         if (!event_call->class->get_fields)
  37                 return &event_call->class->fields;
  38         return event_call->class->get_fields(event_call);
  39 }
  40
  41 static int __trace_define_field(struct list_head *head, const char *type,
  42                                 const char *name, int offset, int size,
  43                                 int is_signed, int filter_type)
  44 {
  45         struct ftrace_event_field *field;
  46
  47         field = kzalloc(sizeof(*field), GFP_KERNEL);
  48         if (!field)
  49                 goto err;
  50
  51         field->name = kstrdup(name, GFP_KERNEL);
  52         if (!field->name)
  53                 goto err;
  54
  55         field->type = kstrdup(type, GFP_KERNEL);
  56         if (!field->type)
  57                 goto err;
  58
  59         if (filter_type == FILTER_OTHER)
  60                 field->filter_type = filter_assign_type(type);
  61         else
  62                 field->filter_type = filter_type;
  63
  64         field->offset = offset;
  65         field->size = size;
  66         field->is_signed = is_signed;
  67
  68         list_add(&field->link, head);
  69
  70         return 0;
  71
  72 err:
  73         if (field)
  74                 kfree(field->name);
  75         kfree(field);
  76
  77         return -ENOMEM;
  78 }
  79
  80 int trace_define_field(struct ftrace_event_call *call, const char *type,
  81                        const char *name, int offset, int size, int is_signed,
  82                        int filter_type)
  83 {
  84         struct list_head *head;
  85
  86         if (WARN_ON(!call->class))
  87                 return 0;
  88
  89         head = trace_get_fields(call);
  90         return __trace_define_field(head, type, name, offset, size,
  91                                     is_signed, filter_type);
  92 }
  93 EXPORT_SYMBOL_GPL(trace_define_field);
  94
  95 #define __common_field(type, item)                                      \
  96         ret = __trace_define_field(&ftrace_common_fields, #type,        \
  97                                    "common_" #item,                     \
  98                                    offsetof(typeof(ent), item),         \
  99                                    sizeof(ent.item),                    \
 100                                    is_signed_type(type), FILTER_OTHER); \
 101         if (ret)                                                        \
 102                 return ret;
 103
 104 static int trace_define_common_fields(void)
 105 {
 106         int ret;
 107         struct trace_entry ent;
 108
 109         __common_field(unsigned short, type);
 110         __common_field(unsigned char, flags);
 111         __common_field(unsigned char, preempt_count);
 112         __common_field(int, pid);
 113         __common_field(int, lock_depth);
 114
 115         return ret;
 116 }
 117
 118 void trace_destroy_fields(struct ftrace_event_call *call)
 119 {
 120         struct ftrace_event_field *field, *next;
 121         struct list_head *head;
 122
 123         head = trace_get_fields(call);
 124         list_for_each_entry_safe(field, next, head, link) {
 125                 list_del(&field->link);
 126                 kfree(field->type);
 127                 kfree(field->name);
 128                 kfree(field);
 129         }
 130 }
 131
 132 int trace_event_raw_init(struct ftrace_event_call *call)
 133 {
 134         int id;
 135
 136         id = register_ftrace_event(&call->event);
 137         if (!id)
 138                 return -ENODEV;
 139
 140         return 0;
 141 }
 142 EXPORT_SYMBOL_GPL(trace_event_raw_init);
 143
 144 int ftrace_event_reg(struct ftrace_event_call *call, enum trace_reg type)
 145 {
 146         switch (type) {
 147         case TRACE_REG_REGISTER:
 148                 return tracepoint_probe_register(call->name,
 149                                                  call->class->probe,
 150                                                  call);
 151         case TRACE_REG_UNREGISTER:
 152                 tracepoint_probe_unregister(call->name,
 153                                             call->class->probe,
 154                                             call);
 155                 return 0;
 156
 157 #ifdef CONFIG_PERF_EVENTS
 158         case TRACE_REG_PERF_REGISTER:
 159                 return tracepoint_probe_register(call->name,
 160                                                  call->class->perf_probe,
 161                                                  call);
 162         case TRACE_REG_PERF_UNREGISTER:
 163                 tracepoint_probe_unregister(call->name,
 164                                             call->class->perf_probe,
 165                                             call);
 166                 return 0;
 167 #endif
 168         }
 169         return 0;
 170 }
 171 EXPORT_SYMBOL_GPL(ftrace_event_reg);
 172
 173 void trace_event_enable_cmd_record(bool enable)
 174 {
 175         struct ftrace_event_call *call;
 176
 177         mutex_lock(&event_mutex);
 178         list_for_each_entry(call, &ftrace_events, list) {
 179                 if (!(call->flags & TRACE_EVENT_FL_ENABLED))
 180                         continue;
 181
 182                 if (enable) {
 183                         tracing_start_cmdline_record();
 184                         call->flags |= TRACE_EVENT_FL_RECORDED_CMD;
 185                 } else {
 186                         tracing_stop_cmdline_record();
 187                         call->flags &= ~TRACE_EVENT_FL_RECORDED_CMD;
 188                 }
 189         }
 190         mutex_unlock(&event_mutex);
 191 }
 192
 193 static int ftrace_event_enable_disable(struct ftrace_event_call *call,
 194                                         int enable)
 195 {
 196         int ret = 0;
 197
 198         switch (enable) {
 199         case 0:
 200                 if (call->flags & TRACE_EVENT_FL_ENABLED) {
 201                         call->flags &= ~TRACE_EVENT_FL_ENABLED;
 202                         if (call->flags & TRACE_EVENT_FL_RECORDED_CMD) {
 203                                 tracing_stop_cmdline_record();
 204                                 call->flags &= ~TRACE_EVENT_FL_RECORDED_CMD;
 205                         }
 206                         call->class->reg(call, TRACE_REG_UNREGISTER);
 207                 }
 208                 break;
 209         case 1:
 210                 if (!(call->flags & TRACE_EVENT_FL_ENABLED)) {
 211                         if (trace_flags & TRACE_ITER_RECORD_CMD) {
 212                                 tracing_start_cmdline_record();
 213                                 call->flags |= TRACE_EVENT_FL_RECORDED_CMD;
 214                         }
 215                         ret = call->class->reg(call, TRACE_REG_REGISTER);
 216                         if (ret) {
 217                                 tracing_stop_cmdline_record();
 218                                 pr_info("event trace: Could not enable event "
 219                                         "%s\n", call->name);
 220                                 break;
 221                         }
 222                         call->flags |= TRACE_EVENT_FL_ENABLED;
 223                 }
 224                 break;
 225         }
 226
 227         return ret;
 228 }
 229
 230 static void ftrace_clear_events(void)
 231 {
 232         struct ftrace_event_call *call;
 233
 234         mutex_lock(&event_mutex);
 235         list_for_each_entry(call, &ftrace_events, list) {
 236                 ftrace_event_enable_disable(call, 0);
 237         }
 238         mutex_unlock(&event_mutex);
 239 }
 240
 241 /*
 242  * __ftrace_set_clr_event(NULL, NULL, NULL, set) will set/unset all events.
 243  */
 244 static int __ftrace_set_clr_event(const char *match, const char *sub,
 245                                   const char *event, int set)
 246 {
 247         struct ftrace_event_call *call;
 248         int ret = -EINVAL;
 249
 250         mutex_lock(&event_mutex);
 251         list_for_each_entry(call, &ftrace_events, list) {
 252
 253                 if (!call->name || !call->class || !call->class->reg)
 254                         continue;
 255
 256                 if (match &&
 257                     strcmp(match, call->name) != 0 &&
 258                     strcmp(match, call->class->system) != 0)
 259                         continue;
 260
 261                 if (sub && strcmp(sub, call->class->system) != 0)
 262                         continue;
 263
 264                 if (event && strcmp(event, call->name) != 0)
 265                         continue;
 266
 267                 ftrace_event_enable_disable(call, set);
 268
 269                 ret = 0;
 270         }
 271         mutex_unlock(&event_mutex);
 272
 273         return ret;
 274 }
 275
 276 static int ftrace_set_clr_event(char *buf, int set)
 277 {
 278         char *event = NULL, *sub = NULL, *match;
 279
 280         /*
 281          * The buf format can be <subsystem>:<event-name>
 282          *  *:<event-name> means any event by that name.
 283          *  :<event-name> is the same.
 284          *
 285          *  <subsystem>:* means all events in that subsystem
 286          *  <subsystem>: means the same.
 287          *
 288          *  <name> (no ':') means all events in a subsystem with
 289          *  the name <name> or any event that matches <name>
 290          */
 291
 292         match = strsep(&buf, ":");
 293         if (buf) {
 294                 sub = match;
 295                 event = buf;
 296                 match = NULL;
 297
 298                 if (!strlen(sub) || strcmp(sub, "*") == 0)
 299                         sub = NULL;
 300                 if (!strlen(event) || strcmp(event, "*") == 0)
 301                         event = NULL;
 302         }
 303
 304         return __ftrace_set_clr_event(match, sub, event, set);
 305 }
 306
 307 /**
 308  * trace_set_clr_event - enable or disable an event
 309  * @system: system name to match (NULL for any system)
 310  * @event: event name to match (NULL for all events, within system)
 311  * @set: 1 to enable, 0 to disable
 312  *
 313  * This is a way for other parts of the kernel to enable or disable
 314  * event recording.
 315  *
 316  * Returns 0 on success, -EINVAL if the parameters do not match any
 317  * registered events.
 318  */
 319 int trace_set_clr_event(const char *system, const char *event, int set)
 320 {
 321         return __ftrace_set_clr_event(NULL, system, event, set);
 322 }
 323
 324 /* 128 should be much more than enough */
 325 #define EVENT_BUF_SIZE          127
 326
 327 static ssize_t
 328 ftrace_event_write(struct file *file, const char __user *ubuf,
 329                    size_t cnt, loff_t *ppos)
 330 {
 331         struct trace_parser parser;
 332         ssize_t read, ret;
 333
 334         if (!cnt)
 335                 return 0;
 336
 337         ret = tracing_update_buffers();
 338         if (ret < 0)
 339                 return ret;
 340
 341         if (trace_parser_get_init(&parser, EVENT_BUF_SIZE + 1))
 342                 return -ENOMEM;
 343
 344         read = trace_get_user(&parser, ubuf, cnt, ppos);
 345
 346         if (read >= 0 && trace_parser_loaded((&parser))) {
 347                 int set = 1;
 348
 349                 if (*parser.buffer == '!')
 350                         set = 0;
 351
 352                 parser.buffer[parser.idx] = 0;
 353
 354                 ret = ftrace_set_clr_event(parser.buffer + !set, set);
 355                 if (ret)
 356                         goto out_put;
 357         }
 358
 359         ret = read;
 360
 361  out_put:
 362         trace_parser_put(&parser);
 363
 364         return ret;
 365 }
 366
 367 static void *
 368 t_next(struct seq_file *m, void *v, loff_t *pos)
 369 {
 370         struct ftrace_event_call *call = v;
 371
 372         (*pos)++;
 373
 374         list_for_each_entry_continue(call, &ftrace_events, list) {
 375                 /*
 376                  * The ftrace subsystem is for showing formats only.
 377                  * They can not be enabled or disabled via the event files.
 378                  */
 379                 if (call->class && call->class->reg)
 380                         return call;
 381         }
 382
 383         return NULL;
 384 }
 385
 386 static void *t_start(struct seq_file *m, loff_t *pos)
 387 {
 388         struct ftrace_event_call *call;
 389         loff_t l;
 390
 391         mutex_lock(&event_mutex);
 392
 393         call = list_entry(&ftrace_events, struct ftrace_event_call, list);
 394         for (l = 0; l <= *pos; ) {
 395                 call = t_next(m, call, &l);
 396                 if (!call)
 397                         break;
 398         }
 399         return call;
 400 }
 401
 402 static void *
 403 s_next(struct seq_file *m, void *v, loff_t *pos)
 404 {
 405         struct ftrace_event_call *call = v;
 406
 407         (*pos)++;
 408
 409         list_for_each_entry_continue(call, &ftrace_events, list) {
 410                 if (call->flags & TRACE_EVENT_FL_ENABLED)
 411                         return call;
 412         }
 413
 414         return NULL;
 415 }
 416
 417 static void *s_start(struct seq_file *m, loff_t *pos)
 418 {
 419         struct ftrace_event_call *call;
 420         loff_t l;
 421
 422         mutex_lock(&event_mutex);
 423
 424         call = list_entry(&ftrace_events, struct ftrace_event_call, list);
 425         for (l = 0; l <= *pos; ) {
 426                 call = s_next(m, call, &l);
 427                 if (!call)
 428                         break;
 429         }
 430         return call;
 431 }
 432
 433 static int t_show(struct seq_file *m, void *v)
 434 {
 435         struct ftrace_event_call *call = v;
 436
 437         if (strcmp(call->class->system, TRACE_SYSTEM) != 0)
 438                 seq_printf(m, "%s:", call->class->system);
 439         seq_printf(m, "%s\n", call->name);
 440
 441         return 0;
 442 }
 443
 444 static void t_stop(struct seq_file *m, void *p)
 445 {
 446         mutex_unlock(&event_mutex);
 447 }
 448
 449 static int
 450 ftrace_event_seq_open(struct inode *inode, struct file *file)
 451 {
 452         const struct seq_operations *seq_ops;
 453
 454         if ((file->f_mode & FMODE_WRITE) &&
 455             (file->f_flags & O_TRUNC))
 456                 ftrace_clear_events();
 457
 458         seq_ops = inode->i_private;
 459         return seq_open(file, seq_ops);
 460 }
 461
 462 static ssize_t
 463 event_enable_read(struct file *filp, char __user *ubuf, size_t cnt,
 464                   loff_t *ppos)
 465 {
 466         struct ftrace_event_call *call = filp->private_data;
 467         char *buf;
 468
 469         if (call->flags & TRACE_EVENT_FL_ENABLED)
 470                 buf = "1\n";
 471         else
 472                 buf = "0\n";
 473
 474         return simple_read_from_buffer(ubuf, cnt, ppos, buf, 2);
 475 }
 476
 477 static ssize_t
 478 event_enable_write(struct file *filp, const char __user *ubuf, size_t cnt,
 479                    loff_t *ppos)
 480 {
 481         struct ftrace_event_call *call = filp->private_data;
 482         char buf[64];
 483         unsigned long val;
 484         int ret;
 485
 486         if (cnt >= sizeof(buf))
 487                 return -EINVAL;
 488
 489         if (copy_from_user(&buf, ubuf, cnt))
 490                 return -EFAULT;
 491
 492         buf[cnt] = 0;
 493
 494         ret = strict_strtoul(buf, 10, &val);
 495         if (ret < 0)
 496                 return ret;
 497
 498         ret = tracing_update_buffers();
 499         if (ret < 0)
 500                 return ret;
 501
 502         switch (val) {
 503         case 0:
 504         case 1:
 505                 mutex_lock(&event_mutex);
 506                 ret = ftrace_event_enable_disable(call, val);
 507                 mutex_unlock(&event_mutex);
 508                 break;
 509
 510         default:
 511                 return -EINVAL;
 512         }
 513
 514         *ppos += cnt;
 515
 516         return ret ? ret : cnt;
 517 }
 518
 519 static ssize_t
 520 system_enable_read(struct file *filp, char __user *ubuf, size_t cnt,
 521                    loff_t *ppos)
 522 {
 523         const char set_to_char[4] = { '?', '0', '1', 'X' };
 524         const char *system = filp->private_data;
 525         struct ftrace_event_call *call;
 526         char buf[2];
 527         int set = 0;
 528         int ret;
 529
 530         mutex_lock(&event_mutex);
 531         list_for_each_entry(call, &ftrace_events, list) {
 532                 if (!call->name || !call->class || !call->class->reg)
 533                         continue;
 534
 535                 if (system && strcmp(call->class->system, system) != 0)
 536                         continue;
 537
 538                 /*
 539                  * We need to find out if all the events are set
 540                  * or if all events or cleared, or if we have
 541                  * a mixture.
 542                  */
 543                 set |= (1 << !!(call->flags & TRACE_EVENT_FL_ENABLED));
 544
 545                 /*
 546                  * If we have a mixture, no need to look further.
 547                  */
 548                 if (set == 3)
 549                         break;
 550         }
 551         mutex_unlock(&event_mutex);
 552
 553         buf[0] = set_to_char[set];
 554         buf[1] = '\n';
 555
 556         ret = simple_read_from_buffer(ubuf, cnt, ppos, buf, 2);
 557
 558         return ret;
 559 }
 560
 561 static ssize_t
 562 system_enable_write(struct file *filp, const char __user *ubuf, size_t cnt,
 563                     loff_t *ppos)
 564 {
 565         const char *system = filp->private_data;
 566         unsigned long val;
 567         char buf[64];
 568         ssize_t ret;
 569
 570         if (cnt >= sizeof(buf))
 571                 return -EINVAL;
 572
 573         if (copy_from_user(&buf, ubuf, cnt))
 574                 return -EFAULT;
 575
 576         buf[cnt] = 0;
 577
 578         ret = strict_strtoul(buf, 10, &val);
 579         if (ret < 0)
 580                 return ret;
 581
 582         ret = tracing_update_buffers();
 583         if (ret < 0)
 584                 return ret;
 585
 586         if (val != 0 && val != 1)
 587                 return -EINVAL;
 588
 589         ret = __ftrace_set_clr_event(NULL, system, NULL, val);
 590         if (ret)
 591                 goto out;
 592
 593         ret = cnt;
 594
 595 out:
 596         *ppos += cnt;
 597
 598         return ret;
 599 }
 600
 601 enum {
 602         FORMAT_HEADER           = 1,
 603         FORMAT_FIELD_SEPERATOR  = 2,
 604         FORMAT_PRINTFMT         = 3,
 605 };
 606
 607 static void *f_next(struct seq_file *m, void *v, loff_t *pos)
 608 {
 609         struct ftrace_event_call *call = m->private;
 610         struct ftrace_event_field *field;
 611         struct list_head *common_head = &ftrace_common_fields;
 612         struct list_head *head = trace_get_fields(call);
 613
 614         (*pos)++;
 615
 616         switch ((unsigned long)v) {
 617         case FORMAT_HEADER:
 618                 if (unlikely(list_empty(common_head)))
 619                         return NULL;
 620
 621                 field = list_entry(common_head->prev,
 622                                    struct ftrace_event_field, link);
 623                 return field;
 624
 625         case FORMAT_FIELD_SEPERATOR:
 626                 if (unlikely(list_empty(head)))
 627                         return NULL;
 628
 629                 field = list_entry(head->prev, struct ftrace_event_field, link);
 630                 return field;
 631
 632         case FORMAT_PRINTFMT:
 633                 /* all done */
 634                 return NULL;
 635         }
 636
 637         field = v;
 638         if (field->link.prev == common_head)
 639                 return (void *)FORMAT_FIELD_SEPERATOR;
 640         else if (field->link.prev == head)
 641                 return (void *)FORMAT_PRINTFMT;
 642
 643         field = list_entry(field->link.prev, struct ftrace_event_field, link);
 644
 645         return field;
 646 }
 647
 648 static void *f_start(struct seq_file *m, loff_t *pos)
 649 {
 650         loff_t l = 0;
 651         void *p;
 652
 653         /* Start by showing the header */
 654         if (!*pos)
 655                 return (void *)FORMAT_HEADER;
 656
 657         p = (void *)FORMAT_HEADER;
 658         do {
 659                 p = f_next(m, p, &l);
 660         } while (p && l < *pos);
 661
 662         return p;
 663 }
 664
 665 static int f_show(struct seq_file *m, void *v)
 666 {
 667         struct ftrace_event_call *call = m->private;
 668         struct ftrace_event_field *field;
 669         const char *array_descriptor;
 670
 671         switch ((unsigned long)v) {
 672         case FORMAT_HEADER:
 673                 seq_printf(m, "name: %s\n", call->name);
 674                 seq_printf(m, "ID: %d\n", call->event.type);
 675                 seq_printf(m, "format:\n");
 676                 return 0;
 677
 678         case FORMAT_FIELD_SEPERATOR:
 679                 seq_putc(m, '\n');
 680                 return 0;
 681
 682         case FORMAT_PRINTFMT:
 683                 seq_printf(m, "\nprint fmt: %s\n",
 684                            call->print_fmt);
 685                 return 0;
 686         }
 687
 688         field = v;
 689
 690         /*
 691          * Smartly shows the array type(except dynamic array).
 692          * Normal:
 693          *      field:TYPE VAR
 694          * If TYPE := TYPE[LEN], it is shown:
 695          *      field:TYPE VAR[LEN]
 696          */
 697         array_descriptor = strchr(field->type, '[');
 698
 699         if (!strncmp(field->type, "__data_loc", 10))
 700                 array_descriptor = NULL;
 701
 702         if (!array_descriptor)
 703                 seq_printf(m, "\tfield:%s %s;\toffset:%u;\tsize:%u;\tsigned:%d;\n",
 704                            field->type, field->name, field->offset,
 705                            field->size, !!field->is_signed);
 706         else
 707                 seq_printf(m, "\tfield:%.*s %s%s;\toffset:%u;\tsize:%u;\tsigned:%d;\n",
 708                            (int)(array_descriptor - field->type),
 709                            field->type, field->name,
 710                            array_descriptor, field->offset,
 711                            field->size, !!field->is_signed);
 712
 713         return 0;
 714 }
 715
 716 static void f_stop(struct seq_file *m, void *p)
 717 {
 718 }
 719
 720 static const struct seq_operations trace_format_seq_ops = {
 721         .start          = f_start,
 722         .next           = f_next,
 723         .stop           = f_stop,
 724         .show           = f_show,
 725 };
 726
 727 static int trace_format_open(struct inode *inode, struct file *file)
 728 {
 729         struct ftrace_event_call *call = inode->i_private;
 730         struct seq_file *m;
 731         int ret;
 732
 733         ret = seq_open(file, &trace_format_seq_ops);
 734         if (ret < 0)
 735                 return ret;
 736
 737         m = file->private_data;
 738         m->private = call;
 739
 740         return 0;
 741 }
 742
 743 static ssize_t
 744 event_id_read(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos)
 745 {
 746         struct ftrace_event_call *call = filp->private_data;
 747         struct trace_seq *s;
 748         int r;
 749
 750         if (*ppos)
 751                 return 0;
 752
 753         s = kmalloc(sizeof(*s), GFP_KERNEL);
 754         if (!s)
 755                 return -ENOMEM;
 756
 757         trace_seq_init(s);
 758         trace_seq_printf(s, "%d\n", call->event.type);
 759
 760         r = simple_read_from_buffer(ubuf, cnt, ppos,
 761                                     s->buffer, s->len);
 762         kfree(s);
 763         return r;
 764 }
 765
 766 static ssize_t
 767 event_filter_read(struct file *filp, char __user *ubuf, size_t cnt,
 768                   loff_t *ppos)
 769 {
 770         struct ftrace_event_call *call = filp->private_data;
 771         struct trace_seq *s;
 772         int r;
 773
 774         if (*ppos)
 775                 return 0;
 776
 777         s = kmalloc(sizeof(*s), GFP_KERNEL);
 778         if (!s)
 779                 return -ENOMEM;
 780
 781         trace_seq_init(s);
 782
 783         print_event_filter(call, s);
 784         r = simple_read_from_buffer(ubuf, cnt, ppos, s->buffer, s->len);
 785
 786         kfree(s);
 787
 788         return r;
 789 }
 790
 791 static ssize_t
 792 event_filter_write(struct file *filp, const char __user *ubuf, size_t cnt,
 793                    loff_t *ppos)
 794 {
 795         struct ftrace_event_call *call = filp->private_data;
 796         char *buf;
 797         int err;
 798
 799         if (cnt >= PAGE_SIZE)
 800                 return -EINVAL;
 801
 802         buf = (char *)__get_free_page(GFP_TEMPORARY);
 803         if (!buf)
 804                 return -ENOMEM;
 805
 806         if (copy_from_user(buf, ubuf, cnt)) {
 807                 free_page((unsigned long) buf);
 808                 return -EFAULT;
 809         }
 810         buf[cnt] = '\0';
 811
 812         err = apply_event_filter(call, buf);
 813         free_page((unsigned long) buf);
 814         if (err < 0)
 815                 return err;
 816
 817         *ppos += cnt;
 818
 819         return cnt;
 820 }
 821
 822 static ssize_t
 823 subsystem_filter_read(struct file *filp, char __user *ubuf, size_t cnt,
 824                       loff_t *ppos)
 825 {
 826         struct event_subsystem *system = filp->private_data;
 827         struct trace_seq *s;
 828         int r;
 829
 830         if (*ppos)
 831                 return 0;
 832
 833         s = kmalloc(sizeof(*s), GFP_KERNEL);
 834         if (!s)
 835                 return -ENOMEM;
 836
 837         trace_seq_init(s);
 838
 839         print_subsystem_event_filter(system, s);
 840         r = simple_read_from_buffer(ubuf, cnt, ppos, s->buffer, s->len);
 841
 842         kfree(s);
 843
 844         return r;
 845 }
 846
 847 static ssize_t
 848 subsystem_filter_write(struct file *filp, const char __user *ubuf, size_t cnt,
 849                        loff_t *ppos)
 850 {
 851         struct event_subsystem *system = filp->private_data;
 852         char *buf;
 853         int err;
 854
 855         if (cnt >= PAGE_SIZE)
 856                 return -EINVAL;
 857
 858         buf = (char *)__get_free_page(GFP_TEMPORARY);
 859         if (!buf)
 860                 return -ENOMEM;
 861
 862         if (copy_from_user(buf, ubuf, cnt)) {
 863                 free_page((unsigned long) buf);
 864                 return -EFAULT;
 865         }
 866         buf[cnt] = '\0';
 867
 868         err = apply_subsystem_event_filter(system, buf);
 869         free_page((unsigned long) buf);
 870         if (err < 0)
 871                 return err;
 872
 873         *ppos += cnt;
 874
 875         return cnt;
 876 }
 877
 878 static ssize_t
 879 show_header(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos)
 880 {
 881         int (*func)(struct trace_seq *s) = filp->private_data;
 882         struct trace_seq *s;
 883         int r;
 884
 885         if (*ppos)
 886                 return 0;
 887
 888         s = kmalloc(sizeof(*s), GFP_KERNEL);
 889         if (!s)
 890                 return -ENOMEM;
 891
 892         trace_seq_init(s);
 893
 894         func(s);
 895         r = simple_read_from_buffer(ubuf, cnt, ppos, s->buffer, s->len);
 896
 897         kfree(s);
 898
 899         return r;
 900 }
 901
 902 static const struct seq_operations show_event_seq_ops = {
 903         .start = t_start,
 904         .next = t_next,
 905         .show = t_show,
 906         .stop = t_stop,
 907 };
 908
 909 static const struct seq_operations show_set_event_seq_ops = {
 910         .start = s_start,
 911         .next = s_next,
 912         .show = t_show,
 913         .stop = t_stop,
 914 };
 915
 916 static const struct file_operations ftrace_avail_fops = {
 917         .open = ftrace_event_seq_open,
 918         .read = seq_read,
 919         .llseek = seq_lseek,
 920         .release = seq_release,
 921 };
 922
 923 static const struct file_operations ftrace_set_event_fops = {
 924         .open = ftrace_event_seq_open,
 925         .read = seq_read,
 926         .write = ftrace_event_write,
 927         .llseek = seq_lseek,
 928         .release = seq_release,
 929 };
 930
 931 static const struct file_operations ftrace_enable_fops = {
 932         .open = tracing_open_generic,
 933         .read = event_enable_read,
 934         .write = event_enable_write,
 935 };
 936
 937 static const struct file_operations ftrace_event_format_fops = {
 938         .open = trace_format_open,
 939         .read = seq_read,
 940         .llseek = seq_lseek,
 941         .release = seq_release,
 942 };
 943
 944 static const struct file_operations ftrace_event_id_fops = {
 945         .open = tracing_open_generic,
 946         .read = event_id_read,
 947 };
 948
 949 static const struct file_operations ftrace_event_filter_fops = {
 950         .open = tracing_open_generic,
 951         .read = event_filter_read,
 952         .write = event_filter_write,
 953 };
 954
 955 static const struct file_operations ftrace_subsystem_filter_fops = {
 956         .open = tracing_open_generic,
 957         .read = subsystem_filter_read,
 958         .write = subsystem_filter_write,
 959 };
 960
 961 static const struct file_operations ftrace_system_enable_fops = {
 962         .open = tracing_open_generic,
 963         .read = system_enable_read,
 964         .write = system_enable_write,
 965 };
 966
 967 static const struct file_operations ftrace_show_header_fops = {
 968         .open = tracing_open_generic,
 969         .read = show_header,
 970 };
 971
 972 static struct dentry *event_trace_events_dir(void)
 973 {
 974         static struct dentry *d_tracer;
 975         static struct dentry *d_events;
 976
 977         if (d_events)
 978                 return d_events;
 979
 980         d_tracer = tracing_init_dentry();
 981         if (!d_tracer)
 982                 return NULL;
 983
 984         d_events = debugfs_create_dir("events", d_tracer);
 985         if (!d_events)
 986                 pr_warning("Could not create debugfs "
 987                            "'events' directory\n");
 988
 989         return d_events;
 990 }
 991
 992 static LIST_HEAD(event_subsystems);
 993
 994 static struct dentry *
 995 event_subsystem_dir(const char *name, struct dentry *d_events)
 996 {
 997         struct event_subsystem *system;
 998         struct dentry *entry;
 999
1000         /* First see if we did not already create this dir */
1001         list_for_each_entry(system, &event_subsystems, list) {
1002                 if (strcmp(system->name, name) == 0) {
1003                         system->nr_events++;
1004                         return system->entry;
1005                 }
1006         }
1007
1008         /* need to create new entry */
1009         system = kmalloc(sizeof(*system), GFP_KERNEL);
1010         if (!system) {
1011                 pr_warning("No memory to create event subsystem %s\n",
1012                            name);
1013                 return d_events;
1014         }
1015
1016         system->entry = debugfs_create_dir(name, d_events);
1017         if (!system->entry) {
1018                 pr_warning("Could not create event subsystem %s\n",
1019                            name);
1020                 kfree(system);
1021                 return d_events;
1022         }
1023
1024         system->nr_events = 1;
1025         system->name = kstrdup(name, GFP_KERNEL);
1026         if (!system->name) {
1027                 debugfs_remove(system->entry);
1028                 kfree(system);
1029                 return d_events;
1030         }
1031
1032         list_add(&system->list, &event_subsystems);
1033
1034         system->filter = NULL;
1035
1036         system->filter = kzalloc(sizeof(struct event_filter), GFP_KERNEL);
1037         if (!system->filter) {
1038                 pr_warning("Could not allocate filter for subsystem "
1039                            "'%s'\n", name);
1040                 return system->entry;
1041         }
1042
1043         entry = debugfs_create_file("filter", 0644, system->entry, system,
1044                                     &ftrace_subsystem_filter_fops);
1045         if (!entry) {
1046                 kfree(system->filter);
1047                 system->filter = NULL;
1048                 pr_warning("Could not create debugfs "
1049                            "'%s/filter' entry\n", name);
1050         }
1051
1052         trace_create_file("enable", 0644, system->entry,
1053                           (void *)system->name,
1054                           &ftrace_system_enable_fops);
1055
1056         return system->entry;
1057 }
1058
1059 static int
1060 event_create_dir(struct ftrace_event_call *call, struct dentry *d_events,
1061                  const struct file_operations *id,
1062                  const struct file_operations *enable,
1063                  const struct file_operations *filter,
1064                  const struct file_operations *format)
1065 {
1066         struct list_head *head;
1067         int ret;
1068
1069         /*
1070          * If the trace point header did not define TRACE_SYSTEM
1071          * then the system would be called "TRACE_SYSTEM".
1072          */
1073         if (strcmp(call->class->system, TRACE_SYSTEM) != 0)
1074                 d_events = event_subsystem_dir(call->class->system, d_events);
1075
1076         call->dir = debugfs_create_dir(call->name, d_events);
1077         if (!call->dir) {
1078                 pr_warning("Could not create debugfs "
1079                            "'%s' directory\n", call->name);
1080                 return -1;
1081         }
1082
1083         if (call->class->reg)
1084                 trace_create_file("enable", 0644, call->dir, call,
1085                                   enable);
1086
1087 #ifdef CONFIG_PERF_EVENTS
1088         if (call->event.type && call->class->reg)
1089                 trace_create_file("id", 0444, call->dir, call,
1090                                   id);
1091 #endif
1092
1093         /*
1094          * Other events may have the same class. Only update
1095          * the fields if they are not already defined.
1096          */
1097         head = trace_get_fields(call);
1098         if (list_empty(head)) {
1099                 ret = call->class->define_fields(call);
1100                 if (ret < 0) {
1101                         pr_warning("Could not initialize trace point"
1102                                    " events/%s\n", call->name);
1103                         return ret;
1104                 }
1105         }
1106         trace_create_file("filter", 0644, call->dir, call,
1107                           filter);
1108
1109         trace_create_file("format", 0444, call->dir, call,
1110                           format);
1111
1112         return 0;
1113 }
1114
1115 static int
1116 __trace_add_event_call(struct ftrace_event_call *call, struct module *mod,
1117                        const struct file_operations *id,
1118                        const struct file_operations *enable,
1119                        const struct file_operations *filter,
1120                        const struct file_operations *format)
1121 {
1122         struct dentry *d_events;
1123         int ret;
1124
1125         /* The linker may leave blanks */
1126         if (!call->name)
1127                 return -EINVAL;
1128
1129         if (call->class->raw_init) {
1130                 ret = call->class->raw_init(call);
1131                 if (ret < 0) {
1132                         if (ret != -ENOSYS)
1133                                 pr_warning("Could not initialize trace events/%s\n",
1134                                            call->name);
1135                         return ret;
1136                 }
1137         }
1138
1139         d_events = event_trace_events_dir();
1140         if (!d_events)
1141                 return -ENOENT;
1142
1143         ret = event_create_dir(call, d_events, id, enable, filter, format);
1144         if (!ret)
1145                 list_add(&call->list, &ftrace_events);
1146         call->mod = mod;
1147
1148         return ret;
1149 }
1150
1151 /* Add an additional event_call dynamically */
1152 int trace_add_event_call(struct ftrace_event_call *call)
1153 {
1154         int ret;
1155         mutex_lock(&event_mutex);
1156         ret = __trace_add_event_call(call, NULL, &ftrace_event_id_fops,
1157                                      &ftrace_enable_fops,
1158                                      &ftrace_event_filter_fops,
1159                                      &ftrace_event_format_fops);
1160         mutex_unlock(&event_mutex);
1161         return ret;
1162 }
1163
1164 static void remove_subsystem_dir(const char *name)
1165 {
1166         struct event_subsystem *system;
1167
1168         if (strcmp(name, TRACE_SYSTEM) == 0)
1169                 return;
1170
1171         list_for_each_entry(system, &event_subsystems, list) {
1172                 if (strcmp(system->name, name) == 0) {
1173                         if (!--system->nr_events) {
1174                                 struct event_filter *filter = system->filter;
1175
1176                                 debugfs_remove_recursive(system->entry);
1177                                 list_del(&system->list);
1178                                 if (filter) {
1179                                         kfree(filter->filter_string);
1180                                         kfree(filter);
1181                                 }
1182                                 kfree(system->name);
1183                                 kfree(system);
1184                         }
1185                         break;
1186                 }
1187         }
1188 }
1189
1190 /*
1191  * Must be called under locking both of event_mutex and trace_event_mutex.
1192  */
1193 static void __trace_remove_event_call(struct ftrace_event_call *call)
1194 {
1195         ftrace_event_enable_disable(call, 0);
1196         if (call->event.funcs)
1197                 __unregister_ftrace_event(&call->event);
1198         debugfs_remove_recursive(call->dir);
1199         list_del(&call->list);
1200         trace_destroy_fields(call);
1201         destroy_preds(call);
1202         remove_subsystem_dir(call->class->system);
1203 }
1204
1205 /* Remove an event_call */
1206 void trace_remove_event_call(struct ftrace_event_call *call)
1207 {
1208         mutex_lock(&event_mutex);
1209         down_write(&trace_event_mutex);
1210         __trace_remove_event_call(call);
1211         up_write(&trace_event_mutex);
1212         mutex_unlock(&event_mutex);
1213 }
1214
1215 #define for_each_event(event, start, end)                       \
1216         for (event = start;                                     \
1217              (unsigned long)event < (unsigned long)end;         \
1218              event++)
1219
1220 #ifdef CONFIG_MODULES
1221
1222 static LIST_HEAD(ftrace_module_file_list);
1223
1224 /*
1225  * Modules must own their file_operations to keep up with
1226  * reference counting.
1227  */
1228 struct ftrace_module_file_ops {
1229         struct list_head                list;
1230         struct module                   *mod;
1231         struct file_operations          id;
1232         struct file_operations          enable;
1233         struct file_operations          format;
1234         struct file_operations          filter;
1235 };
1236
1237 static struct ftrace_module_file_ops *
1238 trace_create_file_ops(struct module *mod)
1239 {
1240         struct ftrace_module_file_ops *file_ops;
1241
1242         /*
1243          * This is a bit of a PITA. To allow for correct reference
1244          * counting, modules must "own" their file_operations.
1245          * To do this, we allocate the file operations that will be
1246          * used in the event directory.
1247          */
1248
1249         file_ops = kmalloc(sizeof(*file_ops), GFP_KERNEL);
1250         if (!file_ops)
1251                 return NULL;
1252
1253         file_ops->mod = mod;
1254
1255         file_ops->id = ftrace_event_id_fops;
1256         file_ops->id.owner = mod;
1257
1258         file_ops->enable = ftrace_enable_fops;
1259         file_ops->enable.owner = mod;
1260
1261         file_ops->filter = ftrace_event_filter_fops;
1262         file_ops->filter.owner = mod;
1263
1264         file_ops->format = ftrace_event_format_fops;
1265         file_ops->format.owner = mod;
1266
1267         list_add(&file_ops->list, &ftrace_module_file_list);
1268
1269         return file_ops;
1270 }
1271
1272 static void trace_module_add_events(struct module *mod)
1273 {
1274         struct ftrace_module_file_ops *file_ops = NULL;
1275         struct ftrace_event_call *call, *start, *end;
1276
1277         start = mod->trace_events;
1278         end = mod->trace_events + mod->num_trace_events;
1279
1280         if (start == end)
1281                 return;
1282
1283         file_ops = trace_create_file_ops(mod);
1284         if (!file_ops)
1285                 return;
1286
1287         for_each_event(call, start, end) {
1288                 __trace_add_event_call(call, mod,
1289                                        &file_ops->id, &file_ops->enable,
1290                                        &file_ops->filter, &file_ops->format);
1291         }
1292 }
1293
1294 static void trace_module_remove_events(struct module *mod)
1295 {
1296         struct ftrace_module_file_ops *file_ops;
1297         struct ftrace_event_call *call, *p;
1298         bool found = false;
1299
1300         down_write(&trace_event_mutex);
1301         list_for_each_entry_safe(call, p, &ftrace_events, list) {
1302                 if (call->mod == mod) {
1303                         found = true;
1304                         __trace_remove_event_call(call);
1305                 }
1306         }
1307
1308         /* Now free the file_operations */
1309         list_for_each_entry(file_ops, &ftrace_module_file_list, list) {
1310                 if (file_ops->mod == mod)
1311                         break;
1312         }
1313         if (&file_ops->list != &ftrace_module_file_list) {
1314                 list_del(&file_ops->list);
1315                 kfree(file_ops);
1316         }
1317
1318         /*
1319          * It is safest to reset the ring buffer if the module being unloaded
1320          * registered any events.
1321          */
1322         if (found)
1323                 tracing_reset_current_online_cpus();
1324         up_write(&trace_event_mutex);
1325 }
1326
1327 static int trace_module_notify(struct notifier_block *self,
1328                                unsigned long val, void *data)
1329 {
1330         struct module *mod = data;
1331
1332         mutex_lock(&event_mutex);
1333         switch (val) {
1334         case MODULE_STATE_COMING:
1335                 trace_module_add_events(mod);
1336                 break;
1337         case MODULE_STATE_GOING:
1338                 trace_module_remove_events(mod);
1339                 break;
1340         }
1341         mutex_unlock(&event_mutex);
1342
1343         return 0;
1344 }
1345 #else
1346 static int trace_module_notify(struct notifier_block *self,
1347                                unsigned long val, void *data)
1348 {
1349         return 0;
1350 }
1351 #endif /* CONFIG_MODULES */
1352
1353 static struct notifier_block trace_module_nb = {
1354         .notifier_call = trace_module_notify,
1355         .priority = 0,
1356 };
1357
1358 extern struct ftrace_event_call __start_ftrace_events[];
1359 extern struct ftrace_event_call __stop_ftrace_events[];
1360
1361 static char bootup_event_buf[COMMAND_LINE_SIZE] __initdata;
1362
1363 static __init int setup_trace_event(char *str)
1364 {
1365         strlcpy(bootup_event_buf, str, COMMAND_LINE_SIZE);
1366         ring_buffer_expanded = 1;
1367         tracing_selftest_disabled = 1;
1368
1369         return 1;
1370 }
1371 __setup("trace_event=", setup_trace_event);
1372
1373 static __init int event_trace_init(void)
1374 {
1375         struct ftrace_event_call *call;
1376         struct dentry *d_tracer;
1377         struct dentry *entry;
1378         struct dentry *d_events;
1379         int ret;
1380         char *buf = bootup_event_buf;
1381         char *token;
1382
1383         d_tracer = tracing_init_dentry();
1384         if (!d_tracer)
1385                 return 0;
1386
1387         entry = debugfs_create_file("available_events", 0444, d_tracer,
1388                                     (void *)&show_event_seq_ops,
1389                                     &ftrace_avail_fops);
1390         if (!entry)
1391                 pr_warning("Could not create debugfs "
1392                            "'available_events' entry\n");
1393
1394         entry = debugfs_create_file("set_event", 0644, d_tracer,
1395                                     (void *)&show_set_event_seq_ops,
1396                                     &ftrace_set_event_fops);
1397         if (!entry)
1398                 pr_warning("Could not create debugfs "
1399                            "'set_event' entry\n");
1400
1401         d_events = event_trace_events_dir();
1402         if (!d_events)
1403                 return 0;
1404
1405         /* ring buffer internal formats */
1406         trace_create_file("header_page", 0444, d_events,
1407                           ring_buffer_print_page_header,
1408                           &ftrace_show_header_fops);
1409
1410         trace_create_file("header_event", 0444, d_events,
1411                           ring_buffer_print_entry_header,
1412                           &ftrace_show_header_fops);
1413
1414         trace_create_file("enable", 0644, d_events,
1415                           NULL, &ftrace_system_enable_fops);
1416
1417         if (trace_define_common_fields())
1418                 pr_warning("tracing: Failed to allocate common fields");
1419
1420         for_each_event(call, __start_ftrace_events, __stop_ftrace_events) {
1421                 __trace_add_event_call(call, NULL, &ftrace_event_id_fops,
1422                                        &ftrace_enable_fops,
1423                                        &ftrace_event_filter_fops,
1424                                        &ftrace_event_format_fops);
1425         }
1426
1427         while (true) {
1428                 token = strsep(&buf, ",");
1429
1430                 if (!token)
1431                         break;
1432                 if (!*token)
1433                         continue;
1434
1435                 ret = ftrace_set_clr_event(token, 1);
1436                 if (ret)
1437                         pr_warning("Failed to enable trace event: %s\n", token);
1438         }
1439
1440         ret = register_module_notifier(&trace_module_nb);
1441         if (ret)
1442                 pr_warning("Failed to register trace events module notifier\n");
1443
1444         return 0;
1445 }
1446 fs_initcall(event_trace_init);
1447
1448 #ifdef CONFIG_FTRACE_STARTUP_TEST
1449
1450 static DEFINE_SPINLOCK(test_spinlock);
1451 static DEFINE_SPINLOCK(test_spinlock_irq);
1452 static DEFINE_MUTEX(test_mutex);
1453
1454 static __init void test_work(struct work_struct *dummy)
1455 {
1456         spin_lock(&test_spinlock);
1457         spin_lock_irq(&test_spinlock_irq);
1458         udelay(1);
1459         spin_unlock_irq(&test_spinlock_irq);
1460         spin_unlock(&test_spinlock);
1461
1462         mutex_lock(&test_mutex);
1463         msleep(1);
1464         mutex_unlock(&test_mutex);
1465 }
1466
1467 static __init int event_test_thread(void *unused)
1468 {
1469         void *test_malloc;
1470
1471         test_malloc = kmalloc(1234, GFP_KERNEL);
1472         if (!test_malloc)
1473                 pr_info("failed to kmalloc\n");
1474
1475         schedule_on_each_cpu(test_work);
1476
1477         kfree(test_malloc);
1478
1479         set_current_state(TASK_INTERRUPTIBLE);
1480         while (!kthread_should_stop())
1481                 schedule();
1482
1483         return 0;
1484 }
1485
1486 /*
1487  * Do various things that may trigger events.
1488  */
1489 static __init void event_test_stuff(void)
1490 {
1491         struct task_struct *test_thread;
1492
1493         test_thread = kthread_run(event_test_thread, NULL, "test-events");
1494         msleep(1);
1495         kthread_stop(test_thread);
1496 }
1497
1498 /*
1499  * For every trace event defined, we will test each trace point separately,
1500  * and then by groups, and finally all trace points.
1501  */
1502 static __init void event_trace_self_tests(void)
1503 {
1504         struct ftrace_event_call *call;
1505         struct event_subsystem *system;
1506         int ret;
1507
1508         pr_info("Running tests on trace events:\n");
1509
1510         list_for_each_entry(call, &ftrace_events, list) {
1511
1512                 /* Only test those that have a probe */
1513                 if (!call->class || !call->class->probe)
1514                         continue;
1515
1516 /*
1517  * Testing syscall events here is pretty useless, but
1518  * we still do it if configured. But this is time consuming.
1519  * What we really need is a user thread to perform the
1520  * syscalls as we test.
1521  */
1522 #ifndef CONFIG_EVENT_TRACE_TEST_SYSCALLS
1523                 if (call->class->system &&
1524                     strcmp(call->class->system, "syscalls") == 0)
1525                         continue;
1526 #endif
1527
1528                 pr_info("Testing event %s: ", call->name);
1529
1530                 /*
1531                  * If an event is already enabled, someone is using
1532                  * it and the self test should not be on.
1533                  */
1534                 if (call->flags & TRACE_EVENT_FL_ENABLED) {
1535                         pr_warning("Enabled event during self test!\n");
1536                         WARN_ON_ONCE(1);
1537                         continue;
1538                 }
1539
1540                 ftrace_event_enable_disable(call, 1);
1541                 event_test_stuff();
1542                 ftrace_event_enable_disable(call, 0);
1543
1544                 pr_cont("OK\n");
1545         }
1546
1547         /* Now test at the sub system level */
1548
1549         pr_info("Running tests on trace event systems:\n");
1550
1551         list_for_each_entry(system, &event_subsystems, list) {
1552
1553                 /* the ftrace system is special, skip it */
1554                 if (strcmp(system->name, "ftrace") == 0)
1555                         continue;
1556
1557                 pr_info("Testing event system %s: ", system->name);
1558
1559                 ret = __ftrace_set_clr_event(NULL, system->name, NULL, 1);
1560                 if (WARN_ON_ONCE(ret)) {
1561                         pr_warning("error enabling system %s\n",
1562                                    system->name);
1563                         continue;
1564                 }
1565
1566                 event_test_stuff();
1567
1568                 ret = __ftrace_set_clr_event(NULL, system->name, NULL, 0);
1569                 if (WARN_ON_ONCE(ret))
1570                         pr_warning("error disabling system %s\n",
1571                                    system->name);
1572
1573                 pr_cont("OK\n");
1574         }
1575
1576         /* Test with all events enabled */
1577
1578         pr_info("Running tests on all trace events:\n");
1579         pr_info("Testing all events: ");
1580
1581         ret = __ftrace_set_clr_event(NULL, NULL, NULL, 1);
1582         if (WARN_ON_ONCE(ret)) {
1583                 pr_warning("error enabling all events\n");
1584                 return;
1585         }
1586
1587         event_test_stuff();
1588
1589         /* reset sysname */
1590         ret = __ftrace_set_clr_event(NULL, NULL, NULL, 0);
1591         if (WARN_ON_ONCE(ret)) {
1592                 pr_warning("error disabling all events\n");
1593                 return;
1594         }
1595
1596         pr_cont("OK\n");
1597 }
1598
1599 #ifdef CONFIG_FUNCTION_TRACER
1600
1601 static DEFINE_PER_CPU(atomic_t, ftrace_test_event_disable);
1602
1603 static void
1604 function_test_events_call(unsigned long ip, unsigned long parent_ip)
1605 {
1606         struct ring_buffer_event *event;
1607         struct ring_buffer *buffer;
1608         struct ftrace_entry *entry;
1609         unsigned long flags;
1610         long disabled;
1611         int cpu;
1612         int pc;
1613
1614         pc = preempt_count();
1615         preempt_disable_notrace();
1616         cpu = raw_smp_processor_id();
1617         disabled = atomic_inc_return(&per_cpu(ftrace_test_event_disable, cpu));
1618
1619         if (disabled != 1)
1620                 goto out;
1621
1622         local_save_flags(flags);
1623
1624         event = trace_current_buffer_lock_reserve(&buffer,
1625                                                   TRACE_FN, sizeof(*entry),
1626                                                   flags, pc);
1627         if (!event)
1628                 goto out;
1629         entry   = ring_buffer_event_data(event);
1630         entry->ip                       = ip;
1631         entry->parent_ip                = parent_ip;
1632
1633         trace_nowake_buffer_unlock_commit(buffer, event, flags, pc);
1634
1635  out:
1636         atomic_dec(&per_cpu(ftrace_test_event_disable, cpu));
1637         preempt_enable_notrace();
1638 }
1639
1640 static struct ftrace_ops trace_ops __initdata  =
1641 {
1642         .func = function_test_events_call,
1643 };
1644
1645 static __init void event_trace_self_test_with_function(void)
1646 {
1647         register_ftrace_function(&trace_ops);
1648         pr_info("Running tests again, along with the function tracer\n");
1649         event_trace_self_tests();
1650         unregister_ftrace_function(&trace_ops);
1651 }
1652 #else
1653 static __init void event_trace_self_test_with_function(void)
1654 {
1655 }
1656 #endif
1657
1658 static __init int event_trace_self_tests_init(void)
1659 {
1660         if (!tracing_selftest_disabled) {
1661                 event_trace_self_tests();
1662                 event_trace_self_test_with_function();
1663         }
1664
1665         return 0;
1666 }
1667
1668 late_initcall(event_trace_self_tests_init);
1669
1670 #endif