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         .llseek = default_llseek,
 936 };
 937
 938 static const struct file_operations ftrace_event_format_fops = {
 939         .open = trace_format_open,
 940         .read = seq_read,
 941         .llseek = seq_lseek,
 942         .release = seq_release,
 943 };
 944
 945 static const struct file_operations ftrace_event_id_fops = {
 946         .open = tracing_open_generic,
 947         .read = event_id_read,
 948         .llseek = default_llseek,
 949 };
 950
 951 static const struct file_operations ftrace_event_filter_fops = {
 952         .open = tracing_open_generic,
 953         .read = event_filter_read,
 954         .write = event_filter_write,
 955         .llseek = default_llseek,
 956 };
 957
 958 static const struct file_operations ftrace_subsystem_filter_fops = {
 959         .open = tracing_open_generic,
 960         .read = subsystem_filter_read,
 961         .write = subsystem_filter_write,
 962         .llseek = default_llseek,
 963 };
 964
 965 static const struct file_operations ftrace_system_enable_fops = {
 966         .open = tracing_open_generic,
 967         .read = system_enable_read,
 968         .write = system_enable_write,
 969         .llseek = default_llseek,
 970 };
 971
 972 static const struct file_operations ftrace_show_header_fops = {
 973         .open = tracing_open_generic,
 974         .read = show_header,
 975         .llseek = default_llseek,
 976 };
 977
 978 static struct dentry *event_trace_events_dir(void)
 979 {
 980         static struct dentry *d_tracer;
 981         static struct dentry *d_events;
 982
 983         if (d_events)
 984                 return d_events;
 985
 986         d_tracer = tracing_init_dentry();
 987         if (!d_tracer)
 988                 return NULL;
 989
 990         d_events = debugfs_create_dir("events", d_tracer);
 991         if (!d_events)
 992                 pr_warning("Could not create debugfs "
 993                            "'events' directory\n");
 994
 995         return d_events;
 996 }
 997
 998 static LIST_HEAD(event_subsystems);
 999
1000 static struct dentry *
1001 event_subsystem_dir(const char *name, struct dentry *d_events)
1002 {
1003         struct event_subsystem *system;
1004         struct dentry *entry;
1005
1006         /* First see if we did not already create this dir */
1007         list_for_each_entry(system, &event_subsystems, list) {
1008                 if (strcmp(system->name, name) == 0) {
1009                         system->nr_events++;
1010                         return system->entry;
1011                 }
1012         }
1013
1014         /* need to create new entry */
1015         system = kmalloc(sizeof(*system), GFP_KERNEL);
1016         if (!system) {
1017                 pr_warning("No memory to create event subsystem %s\n",
1018                            name);
1019                 return d_events;
1020         }
1021
1022         system->entry = debugfs_create_dir(name, d_events);
1023         if (!system->entry) {
1024                 pr_warning("Could not create event subsystem %s\n",
1025                            name);
1026                 kfree(system);
1027                 return d_events;
1028         }
1029
1030         system->nr_events = 1;
1031         system->name = kstrdup(name, GFP_KERNEL);
1032         if (!system->name) {
1033                 debugfs_remove(system->entry);
1034                 kfree(system);
1035                 return d_events;
1036         }
1037
1038         list_add(&system->list, &event_subsystems);
1039
1040         system->filter = NULL;
1041
1042         system->filter = kzalloc(sizeof(struct event_filter), GFP_KERNEL);
1043         if (!system->filter) {
1044                 pr_warning("Could not allocate filter for subsystem "
1045                            "'%s'\n", name);
1046                 return system->entry;
1047         }
1048
1049         entry = debugfs_create_file("filter", 0644, system->entry, system,
1050                                     &ftrace_subsystem_filter_fops);
1051         if (!entry) {
1052                 kfree(system->filter);
1053                 system->filter = NULL;
1054                 pr_warning("Could not create debugfs "
1055                            "'%s/filter' entry\n", name);
1056         }
1057
1058         trace_create_file("enable", 0644, system->entry,
1059                           (void *)system->name,
1060                           &ftrace_system_enable_fops);
1061
1062         return system->entry;
1063 }
1064
1065 static int
1066 event_create_dir(struct ftrace_event_call *call, struct dentry *d_events,
1067                  const struct file_operations *id,
1068                  const struct file_operations *enable,
1069                  const struct file_operations *filter,
1070                  const struct file_operations *format)
1071 {
1072         struct list_head *head;
1073         int ret;
1074
1075         /*
1076          * If the trace point header did not define TRACE_SYSTEM
1077          * then the system would be called "TRACE_SYSTEM".
1078          */
1079         if (strcmp(call->class->system, TRACE_SYSTEM) != 0)
1080                 d_events = event_subsystem_dir(call->class->system, d_events);
1081
1082         call->dir = debugfs_create_dir(call->name, d_events);
1083         if (!call->dir) {
1084                 pr_warning("Could not create debugfs "
1085                            "'%s' directory\n", call->name);
1086                 return -1;
1087         }
1088
1089         if (call->class->reg)
1090                 trace_create_file("enable", 0644, call->dir, call,
1091                                   enable);
1092
1093 #ifdef CONFIG_PERF_EVENTS
1094         if (call->event.type && call->class->reg)
1095                 trace_create_file("id", 0444, call->dir, call,
1096                                   id);
1097 #endif
1098
1099         /*
1100          * Other events may have the same class. Only update
1101          * the fields if they are not already defined.
1102          */
1103         head = trace_get_fields(call);
1104         if (list_empty(head)) {
1105                 ret = call->class->define_fields(call);
1106                 if (ret < 0) {
1107                         pr_warning("Could not initialize trace point"
1108                                    " events/%s\n", call->name);
1109                         return ret;
1110                 }
1111         }
1112         trace_create_file("filter", 0644, call->dir, call,
1113                           filter);
1114
1115         trace_create_file("format", 0444, call->dir, call,
1116                           format);
1117
1118         return 0;
1119 }
1120
1121 static int
1122 __trace_add_event_call(struct ftrace_event_call *call, struct module *mod,
1123                        const struct file_operations *id,
1124                        const struct file_operations *enable,
1125                        const struct file_operations *filter,
1126                        const struct file_operations *format)
1127 {
1128         struct dentry *d_events;
1129         int ret;
1130
1131         /* The linker may leave blanks */
1132         if (!call->name)
1133                 return -EINVAL;
1134
1135         if (call->class->raw_init) {
1136                 ret = call->class->raw_init(call);
1137                 if (ret < 0) {
1138                         if (ret != -ENOSYS)
1139                                 pr_warning("Could not initialize trace events/%s\n",
1140                                            call->name);
1141                         return ret;
1142                 }
1143         }
1144
1145         d_events = event_trace_events_dir();
1146         if (!d_events)
1147                 return -ENOENT;
1148
1149         ret = event_create_dir(call, d_events, id, enable, filter, format);
1150         if (!ret)
1151                 list_add(&call->list, &ftrace_events);
1152         call->mod = mod;
1153
1154         return ret;
1155 }
1156
1157 /* Add an additional event_call dynamically */
1158 int trace_add_event_call(struct ftrace_event_call *call)
1159 {
1160         int ret;
1161         mutex_lock(&event_mutex);
1162         ret = __trace_add_event_call(call, NULL, &ftrace_event_id_fops,
1163                                      &ftrace_enable_fops,
1164                                      &ftrace_event_filter_fops,
1165                                      &ftrace_event_format_fops);
1166         mutex_unlock(&event_mutex);
1167         return ret;
1168 }
1169
1170 static void remove_subsystem_dir(const char *name)
1171 {
1172         struct event_subsystem *system;
1173
1174         if (strcmp(name, TRACE_SYSTEM) == 0)
1175                 return;
1176
1177         list_for_each_entry(system, &event_subsystems, list) {
1178                 if (strcmp(system->name, name) == 0) {
1179                         if (!--system->nr_events) {
1180                                 struct event_filter *filter = system->filter;
1181
1182                                 debugfs_remove_recursive(system->entry);
1183                                 list_del(&system->list);
1184                                 if (filter) {
1185                                         kfree(filter->filter_string);
1186                                         kfree(filter);
1187                                 }
1188                                 kfree(system->name);
1189                                 kfree(system);
1190                         }
1191                         break;
1192                 }
1193         }
1194 }
1195
1196 /*
1197  * Must be called under locking both of event_mutex and trace_event_mutex.
1198  */
1199 static void __trace_remove_event_call(struct ftrace_event_call *call)
1200 {
1201         ftrace_event_enable_disable(call, 0);
1202         if (call->event.funcs)
1203                 __unregister_ftrace_event(&call->event);
1204         debugfs_remove_recursive(call->dir);
1205         list_del(&call->list);
1206         trace_destroy_fields(call);
1207         destroy_preds(call);
1208         remove_subsystem_dir(call->class->system);
1209 }
1210
1211 /* Remove an event_call */
1212 void trace_remove_event_call(struct ftrace_event_call *call)
1213 {
1214         mutex_lock(&event_mutex);
1215         down_write(&trace_event_mutex);
1216         __trace_remove_event_call(call);
1217         up_write(&trace_event_mutex);
1218         mutex_unlock(&event_mutex);
1219 }
1220
1221 #define for_each_event(event, start, end)                       \
1222         for (event = start;                                     \
1223              (unsigned long)event < (unsigned long)end;         \
1224              event++)
1225
1226 #ifdef CONFIG_MODULES
1227
1228 static LIST_HEAD(ftrace_module_file_list);
1229
1230 /*
1231  * Modules must own their file_operations to keep up with
1232  * reference counting.
1233  */
1234 struct ftrace_module_file_ops {
1235         struct list_head                list;
1236         struct module                   *mod;
1237         struct file_operations          id;
1238         struct file_operations          enable;
1239         struct file_operations          format;
1240         struct file_operations          filter;
1241 };
1242
1243 static struct ftrace_module_file_ops *
1244 trace_create_file_ops(struct module *mod)
1245 {
1246         struct ftrace_module_file_ops *file_ops;
1247
1248         /*
1249          * This is a bit of a PITA. To allow for correct reference
1250          * counting, modules must "own" their file_operations.
1251          * To do this, we allocate the file operations that will be
1252          * used in the event directory.
1253          */
1254
1255         file_ops = kmalloc(sizeof(*file_ops), GFP_KERNEL);
1256         if (!file_ops)
1257                 return NULL;
1258
1259         file_ops->mod = mod;
1260
1261         file_ops->id = ftrace_event_id_fops;
1262         file_ops->id.owner = mod;
1263
1264         file_ops->enable = ftrace_enable_fops;
1265         file_ops->enable.owner = mod;
1266
1267         file_ops->filter = ftrace_event_filter_fops;
1268         file_ops->filter.owner = mod;
1269
1270         file_ops->format = ftrace_event_format_fops;
1271         file_ops->format.owner = mod;
1272
1273         list_add(&file_ops->list, &ftrace_module_file_list);
1274
1275         return file_ops;
1276 }
1277
1278 static void trace_module_add_events(struct module *mod)
1279 {
1280         struct ftrace_module_file_ops *file_ops = NULL;
1281         struct ftrace_event_call *call, *start, *end;
1282
1283         start = mod->trace_events;
1284         end = mod->trace_events + mod->num_trace_events;
1285
1286         if (start == end)
1287                 return;
1288
1289         file_ops = trace_create_file_ops(mod);
1290         if (!file_ops)
1291                 return;
1292
1293         for_each_event(call, start, end) {
1294                 __trace_add_event_call(call, mod,
1295                                        &file_ops->id, &file_ops->enable,
1296                                        &file_ops->filter, &file_ops->format);
1297         }
1298 }
1299
1300 static void trace_module_remove_events(struct module *mod)
1301 {
1302         struct ftrace_module_file_ops *file_ops;
1303         struct ftrace_event_call *call, *p;
1304         bool found = false;
1305
1306         down_write(&trace_event_mutex);
1307         list_for_each_entry_safe(call, p, &ftrace_events, list) {
1308                 if (call->mod == mod) {
1309                         found = true;
1310                         __trace_remove_event_call(call);
1311                 }
1312         }
1313
1314         /* Now free the file_operations */
1315         list_for_each_entry(file_ops, &ftrace_module_file_list, list) {
1316                 if (file_ops->mod == mod)
1317                         break;
1318         }
1319         if (&file_ops->list != &ftrace_module_file_list) {
1320                 list_del(&file_ops->list);
1321                 kfree(file_ops);
1322         }
1323
1324         /*
1325          * It is safest to reset the ring buffer if the module being unloaded
1326          * registered any events.
1327          */
1328         if (found)
1329                 tracing_reset_current_online_cpus();
1330         up_write(&trace_event_mutex);
1331 }
1332
1333 static int trace_module_notify(struct notifier_block *self,
1334                                unsigned long val, void *data)
1335 {
1336         struct module *mod = data;
1337
1338         mutex_lock(&event_mutex);
1339         switch (val) {
1340         case MODULE_STATE_COMING:
1341                 trace_module_add_events(mod);
1342                 break;
1343         case MODULE_STATE_GOING:
1344                 trace_module_remove_events(mod);
1345                 break;
1346         }
1347         mutex_unlock(&event_mutex);
1348
1349         return 0;
1350 }
1351 #else
1352 static int trace_module_notify(struct notifier_block *self,
1353                                unsigned long val, void *data)
1354 {
1355         return 0;
1356 }
1357 #endif /* CONFIG_MODULES */
1358
1359 static struct notifier_block trace_module_nb = {
1360         .notifier_call = trace_module_notify,
1361         .priority = 0,
1362 };
1363
1364 extern struct ftrace_event_call __start_ftrace_events[];
1365 extern struct ftrace_event_call __stop_ftrace_events[];
1366
1367 static char bootup_event_buf[COMMAND_LINE_SIZE] __initdata;
1368
1369 static __init int setup_trace_event(char *str)
1370 {
1371         strlcpy(bootup_event_buf, str, COMMAND_LINE_SIZE);
1372         ring_buffer_expanded = 1;
1373         tracing_selftest_disabled = 1;
1374
1375         return 1;
1376 }
1377 __setup("trace_event=", setup_trace_event);
1378
1379 static __init int event_trace_init(void)
1380 {
1381         struct ftrace_event_call *call;
1382         struct dentry *d_tracer;
1383         struct dentry *entry;
1384         struct dentry *d_events;
1385         int ret;
1386         char *buf = bootup_event_buf;
1387         char *token;
1388
1389         d_tracer = tracing_init_dentry();
1390         if (!d_tracer)
1391                 return 0;
1392
1393         entry = debugfs_create_file("available_events", 0444, d_tracer,
1394                                     (void *)&show_event_seq_ops,
1395                                     &ftrace_avail_fops);
1396         if (!entry)
1397                 pr_warning("Could not create debugfs "
1398                            "'available_events' entry\n");
1399
1400         entry = debugfs_create_file("set_event", 0644, d_tracer,
1401                                     (void *)&show_set_event_seq_ops,
1402                                     &ftrace_set_event_fops);
1403         if (!entry)
1404                 pr_warning("Could not create debugfs "
1405                            "'set_event' entry\n");
1406
1407         d_events = event_trace_events_dir();
1408         if (!d_events)
1409                 return 0;
1410
1411         /* ring buffer internal formats */
1412         trace_create_file("header_page", 0444, d_events,
1413                           ring_buffer_print_page_header,
1414                           &ftrace_show_header_fops);
1415
1416         trace_create_file("header_event", 0444, d_events,
1417                           ring_buffer_print_entry_header,
1418                           &ftrace_show_header_fops);
1419
1420         trace_create_file("enable", 0644, d_events,
1421                           NULL, &ftrace_system_enable_fops);
1422
1423         if (trace_define_common_fields())
1424                 pr_warning("tracing: Failed to allocate common fields");
1425
1426         for_each_event(call, __start_ftrace_events, __stop_ftrace_events) {
1427                 __trace_add_event_call(call, NULL, &ftrace_event_id_fops,
1428                                        &ftrace_enable_fops,
1429                                        &ftrace_event_filter_fops,
1430                                        &ftrace_event_format_fops);
1431         }
1432
1433         while (true) {
1434                 token = strsep(&buf, ",");
1435
1436                 if (!token)
1437                         break;
1438                 if (!*token)
1439                         continue;
1440
1441                 ret = ftrace_set_clr_event(token, 1);
1442                 if (ret)
1443                         pr_warning("Failed to enable trace event: %s\n", token);
1444         }
1445
1446         ret = register_module_notifier(&trace_module_nb);
1447         if (ret)
1448                 pr_warning("Failed to register trace events module notifier\n");
1449
1450         return 0;
1451 }
1452 fs_initcall(event_trace_init);
1453
1454 #ifdef CONFIG_FTRACE_STARTUP_TEST
1455
1456 static DEFINE_SPINLOCK(test_spinlock);
1457 static DEFINE_SPINLOCK(test_spinlock_irq);
1458 static DEFINE_MUTEX(test_mutex);
1459
1460 static __init void test_work(struct work_struct *dummy)
1461 {
1462         spin_lock(&test_spinlock);
1463         spin_lock_irq(&test_spinlock_irq);
1464         udelay(1);
1465         spin_unlock_irq(&test_spinlock_irq);
1466         spin_unlock(&test_spinlock);
1467
1468         mutex_lock(&test_mutex);
1469         msleep(1);
1470         mutex_unlock(&test_mutex);
1471 }
1472
1473 static __init int event_test_thread(void *unused)
1474 {
1475         void *test_malloc;
1476
1477         test_malloc = kmalloc(1234, GFP_KERNEL);
1478         if (!test_malloc)
1479                 pr_info("failed to kmalloc\n");
1480
1481         schedule_on_each_cpu(test_work);
1482
1483         kfree(test_malloc);
1484
1485         set_current_state(TASK_INTERRUPTIBLE);
1486         while (!kthread_should_stop())
1487                 schedule();
1488
1489         return 0;
1490 }
1491
1492 /*
1493  * Do various things that may trigger events.
1494  */
1495 static __init void event_test_stuff(void)
1496 {
1497         struct task_struct *test_thread;
1498
1499         test_thread = kthread_run(event_test_thread, NULL, "test-events");
1500         msleep(1);
1501         kthread_stop(test_thread);
1502 }
1503
1504 /*
1505  * For every trace event defined, we will test each trace point separately,
1506  * and then by groups, and finally all trace points.
1507  */
1508 static __init void event_trace_self_tests(void)
1509 {
1510         struct ftrace_event_call *call;
1511         struct event_subsystem *system;
1512         int ret;
1513
1514         pr_info("Running tests on trace events:\n");
1515
1516         list_for_each_entry(call, &ftrace_events, list) {
1517
1518                 /* Only test those that have a probe */
1519                 if (!call->class || !call->class->probe)
1520                         continue;
1521
1522 /*
1523  * Testing syscall events here is pretty useless, but
1524  * we still do it if configured. But this is time consuming.
1525  * What we really need is a user thread to perform the
1526  * syscalls as we test.
1527  */
1528 #ifndef CONFIG_EVENT_TRACE_TEST_SYSCALLS
1529                 if (call->class->system &&
1530                     strcmp(call->class->system, "syscalls") == 0)
1531                         continue;
1532 #endif
1533
1534                 pr_info("Testing event %s: ", call->name);
1535
1536                 /*
1537                  * If an event is already enabled, someone is using
1538                  * it and the self test should not be on.
1539                  */
1540                 if (call->flags & TRACE_EVENT_FL_ENABLED) {
1541                         pr_warning("Enabled event during self test!\n");
1542                         WARN_ON_ONCE(1);
1543                         continue;
1544                 }
1545
1546                 ftrace_event_enable_disable(call, 1);
1547                 event_test_stuff();
1548                 ftrace_event_enable_disable(call, 0);
1549
1550                 pr_cont("OK\n");
1551         }
1552
1553         /* Now test at the sub system level */
1554
1555         pr_info("Running tests on trace event systems:\n");
1556
1557         list_for_each_entry(system, &event_subsystems, list) {
1558
1559                 /* the ftrace system is special, skip it */
1560                 if (strcmp(system->name, "ftrace") == 0)
1561                         continue;
1562
1563                 pr_info("Testing event system %s: ", system->name);
1564
1565                 ret = __ftrace_set_clr_event(NULL, system->name, NULL, 1);
1566                 if (WARN_ON_ONCE(ret)) {
1567                         pr_warning("error enabling system %s\n",
1568                                    system->name);
1569                         continue;
1570                 }
1571
1572                 event_test_stuff();
1573
1574                 ret = __ftrace_set_clr_event(NULL, system->name, NULL, 0);
1575                 if (WARN_ON_ONCE(ret))
1576                         pr_warning("error disabling system %s\n",
1577                                    system->name);
1578
1579                 pr_cont("OK\n");
1580         }
1581
1582         /* Test with all events enabled */
1583
1584         pr_info("Running tests on all trace events:\n");
1585         pr_info("Testing all events: ");
1586
1587         ret = __ftrace_set_clr_event(NULL, NULL, NULL, 1);
1588         if (WARN_ON_ONCE(ret)) {
1589                 pr_warning("error enabling all events\n");
1590                 return;
1591         }
1592
1593         event_test_stuff();
1594
1595         /* reset sysname */
1596         ret = __ftrace_set_clr_event(NULL, NULL, NULL, 0);
1597         if (WARN_ON_ONCE(ret)) {
1598                 pr_warning("error disabling all events\n");
1599                 return;
1600         }
1601
1602         pr_cont("OK\n");
1603 }
1604
1605 #ifdef CONFIG_FUNCTION_TRACER
1606
1607 static DEFINE_PER_CPU(atomic_t, ftrace_test_event_disable);
1608
1609 static void
1610 function_test_events_call(unsigned long ip, unsigned long parent_ip)
1611 {
1612         struct ring_buffer_event *event;
1613         struct ring_buffer *buffer;
1614         struct ftrace_entry *entry;
1615         unsigned long flags;
1616         long disabled;
1617         int cpu;
1618         int pc;
1619
1620         pc = preempt_count();
1621         preempt_disable_notrace();
1622         cpu = raw_smp_processor_id();
1623         disabled = atomic_inc_return(&per_cpu(ftrace_test_event_disable, cpu));
1624
1625         if (disabled != 1)
1626                 goto out;
1627
1628         local_save_flags(flags);
1629
1630         event = trace_current_buffer_lock_reserve(&buffer,
1631                                                   TRACE_FN, sizeof(*entry),
1632                                                   flags, pc);
1633         if (!event)
1634                 goto out;
1635         entry   = ring_buffer_event_data(event);
1636         entry->ip                       = ip;
1637         entry->parent_ip                = parent_ip;
1638
1639         trace_nowake_buffer_unlock_commit(buffer, event, flags, pc);
1640
1641  out:
1642         atomic_dec(&per_cpu(ftrace_test_event_disable, cpu));
1643         preempt_enable_notrace();
1644 }
1645
1646 static struct ftrace_ops trace_ops __initdata  =
1647 {
1648         .func = function_test_events_call,
1649 };
1650
1651 static __init void event_trace_self_test_with_function(void)
1652 {
1653         register_ftrace_function(&trace_ops);
1654         pr_info("Running tests again, along with the function tracer\n");
1655         event_trace_self_tests();
1656         unregister_ftrace_function(&trace_ops);
1657 }
1658 #else
1659 static __init void event_trace_self_test_with_function(void)
1660 {
1661 }
1662 #endif
1663
1664 static __init int event_trace_self_tests_init(void)
1665 {
1666         if (!tracing_selftest_disabled) {
1667                 event_trace_self_tests();
1668                 event_trace_self_test_with_function();
1669         }
1670
1671         return 0;
1672 }
1673
1674 late_initcall(event_trace_self_tests_init);
1675
1676 #endif