kernel/trace/trace_events.c

   1 /*
   2  * event tracer
   3  *
   4  * Copyright (C) 2008 Red Hat Inc, Steven Rostedt <srostedt@redhat.com>
   5  *
   6  *  - Added format output of fields of the trace point.
   7  *    This was based off of work by Tom Zanussi <tzanussi@gmail.com>.
   8  *
   9  */
  10
  11 #include <linux/workqueue.h>
  12 #include <linux/spinlock.h>
  13 #include <linux/kthread.h>
  14 #include <linux/debugfs.h>
  15 #include <linux/uaccess.h>
  16 #include <linux/module.h>
  17 #include <linux/ctype.h>
  18 #include <linux/slab.h>
  19 #include <linux/delay.h>
  20
  21 #include <asm/setup.h>
  22
  23 #include "trace_output.h"
  24
  25 #undef TRACE_SYSTEM
  26 #define TRACE_SYSTEM "TRACE_SYSTEM"
  27
  28 DEFINE_MUTEX(event_mutex);
  29
  30 DEFINE_MUTEX(event_storage_mutex);
  31 EXPORT_SYMBOL_GPL(event_storage_mutex);
  32
  33 char event_storage[EVENT_STORAGE_SIZE];
  34 EXPORT_SYMBOL_GPL(event_storage);
  35
  36 LIST_HEAD(ftrace_events);
  37 LIST_HEAD(ftrace_common_fields);
  38
  39 struct list_head *
  40 trace_get_fields(struct ftrace_event_call *event_call)
  41 {
  42         if (!event_call->class->get_fields)
  43                 return &event_call->class->fields;
  44         return event_call->class->get_fields(event_call);
  45 }
  46
  47 static int __trace_define_field(struct list_head *head, const char *type,
  48                                 const char *name, int offset, int size,
  49                                 int is_signed, int filter_type)
  50 {
  51         struct ftrace_event_field *field;
  52
  53         field = kzalloc(sizeof(*field), GFP_KERNEL);
  54         if (!field)
  55                 goto err;
  56
  57         field->name = kstrdup(name, GFP_KERNEL);
  58         if (!field->name)
  59                 goto err;
  60
  61         field->type = kstrdup(type, GFP_KERNEL);
  62         if (!field->type)
  63                 goto err;
  64
  65         if (filter_type == FILTER_OTHER)
  66                 field->filter_type = filter_assign_type(type);
  67         else
  68                 field->filter_type = filter_type;
  69
  70         field->offset = offset;
  71         field->size = size;
  72         field->is_signed = is_signed;
  73
  74         list_add(&field->link, head);
  75
  76         return 0;
  77
  78 err:
  79         if (field)
  80                 kfree(field->name);
  81         kfree(field);
  82
  83         return -ENOMEM;
  84 }
  85
  86 int trace_define_field(struct ftrace_event_call *call, const char *type,
  87                        const char *name, int offset, int size, int is_signed,
  88                        int filter_type)
  89 {
  90         struct list_head *head;
  91
  92         if (WARN_ON(!call->class))
  93                 return 0;
  94
  95         head = trace_get_fields(call);
  96         return __trace_define_field(head, type, name, offset, size,
  97                                     is_signed, filter_type);
  98 }
  99 EXPORT_SYMBOL_GPL(trace_define_field);
 100
 101 #define __common_field(type, item)                                      \
 102         ret = __trace_define_field(&ftrace_common_fields, #type,        \
 103                                    "common_" #item,                     \
 104                                    offsetof(typeof(ent), item),         \
 105                                    sizeof(ent.item),                    \
 106                                    is_signed_type(type), FILTER_OTHER); \
 107         if (ret)                                                        \
 108                 return ret;
 109
 110 static int trace_define_common_fields(void)
 111 {
 112         int ret;
 113         struct trace_entry ent;
 114
 115         __common_field(unsigned short, type);
 116         __common_field(unsigned char, flags);
 117         __common_field(unsigned char, preempt_count);
 118         __common_field(int, pid);
 119         __common_field(int, padding);
 120
 121         return ret;
 122 }
 123
 124 void trace_destroy_fields(struct ftrace_event_call *call)
 125 {
 126         struct ftrace_event_field *field, *next;
 127         struct list_head *head;
 128
 129         head = trace_get_fields(call);
 130         list_for_each_entry_safe(field, next, head, link) {
 131                 list_del(&field->link);
 132                 kfree(field->type);
 133                 kfree(field->name);
 134                 kfree(field);
 135         }
 136 }
 137
 138 int trace_event_raw_init(struct ftrace_event_call *call)
 139 {
 140         int id;
 141
 142         id = register_ftrace_event(&call->event);
 143         if (!id)
 144                 return -ENODEV;
 145
 146         return 0;
 147 }
 148 EXPORT_SYMBOL_GPL(trace_event_raw_init);
 149
 150 int ftrace_event_reg(struct ftrace_event_call *call, enum trace_reg type)
 151 {
 152         switch (type) {
 153         case TRACE_REG_REGISTER:
 154                 return tracepoint_probe_register(call->name,
 155                                                  call->class->probe,
 156                                                  call);
 157         case TRACE_REG_UNREGISTER:
 158                 tracepoint_probe_unregister(call->name,
 159                                             call->class->probe,
 160                                             call);
 161                 return 0;
 162
 163 #ifdef CONFIG_PERF_EVENTS
 164         case TRACE_REG_PERF_REGISTER:
 165                 return tracepoint_probe_register(call->name,
 166                                                  call->class->perf_probe,
 167                                                  call);
 168         case TRACE_REG_PERF_UNREGISTER:
 169                 tracepoint_probe_unregister(call->name,
 170                                             call->class->perf_probe,
 171                                             call);
 172                 return 0;
 173 #endif
 174         }
 175         return 0;
 176 }
 177 EXPORT_SYMBOL_GPL(ftrace_event_reg);
 178
 179 void trace_event_enable_cmd_record(bool enable)
 180 {
 181         struct ftrace_event_call *call;
 182
 183         mutex_lock(&event_mutex);
 184         list_for_each_entry(call, &ftrace_events, list) {
 185                 if (!(call->flags & TRACE_EVENT_FL_ENABLED))
 186                         continue;
 187
 188                 if (enable) {
 189                         tracing_start_cmdline_record();
 190                         call->flags |= TRACE_EVENT_FL_RECORDED_CMD;
 191                 } else {
 192                         tracing_stop_cmdline_record();
 193                         call->flags &= ~TRACE_EVENT_FL_RECORDED_CMD;
 194                 }
 195         }
 196         mutex_unlock(&event_mutex);
 197 }
 198
 199 static int ftrace_event_enable_disable(struct ftrace_event_call *call,
 200                                         int enable)
 201 {
 202         int ret = 0;
 203
 204         switch (enable) {
 205         case 0:
 206                 if (call->flags & TRACE_EVENT_FL_ENABLED) {
 207                         call->flags &= ~TRACE_EVENT_FL_ENABLED;
 208                         if (call->flags & TRACE_EVENT_FL_RECORDED_CMD) {
 209                                 tracing_stop_cmdline_record();
 210                                 call->flags &= ~TRACE_EVENT_FL_RECORDED_CMD;
 211                         }
 212                         call->class->reg(call, TRACE_REG_UNREGISTER);
 213                 }
 214                 break;
 215         case 1:
 216                 if (!(call->flags & TRACE_EVENT_FL_ENABLED)) {
 217                         if (trace_flags & TRACE_ITER_RECORD_CMD) {
 218                                 tracing_start_cmdline_record();
 219                                 call->flags |= TRACE_EVENT_FL_RECORDED_CMD;
 220                         }
 221                         ret = call->class->reg(call, TRACE_REG_REGISTER);
 222                         if (ret) {
 223                                 tracing_stop_cmdline_record();
 224                                 pr_info("event trace: Could not enable event "
 225                                         "%s\n", call->name);
 226                                 break;
 227                         }
 228                         call->flags |= TRACE_EVENT_FL_ENABLED;
 229                 }
 230                 break;
 231         }
 232
 233         return ret;
 234 }
 235
 236 static void ftrace_clear_events(void)
 237 {
 238         struct ftrace_event_call *call;
 239
 240         mutex_lock(&event_mutex);
 241         list_for_each_entry(call, &ftrace_events, list) {
 242                 ftrace_event_enable_disable(call, 0);
 243         }
 244         mutex_unlock(&event_mutex);
 245 }
 246
 247 /*
 248  * __ftrace_set_clr_event(NULL, NULL, NULL, set) will set/unset all events.
 249  */
 250 static int __ftrace_set_clr_event(const char *match, const char *sub,
 251                                   const char *event, int set)
 252 {
 253         struct ftrace_event_call *call;
 254         int ret = -EINVAL;
 255
 256         mutex_lock(&event_mutex);
 257         list_for_each_entry(call, &ftrace_events, list) {
 258
 259                 if (!call->name || !call->class || !call->class->reg)
 260                         continue;
 261
 262                 if (match &&
 263                     strcmp(match, call->name) != 0 &&
 264                     strcmp(match, call->class->system) != 0)
 265                         continue;
 266
 267                 if (sub && strcmp(sub, call->class->system) != 0)
 268                         continue;
 269
 270                 if (event && strcmp(event, call->name) != 0)
 271                         continue;
 272
 273                 ftrace_event_enable_disable(call, set);
 274
 275                 ret = 0;
 276         }
 277         mutex_unlock(&event_mutex);
 278
 279         return ret;
 280 }
 281
 282 static int ftrace_set_clr_event(char *buf, int set)
 283 {
 284         char *event = NULL, *sub = NULL, *match;
 285
 286         /*
 287          * The buf format can be <subsystem>:<event-name>
 288          *  *:<event-name> means any event by that name.
 289          *  :<event-name> is the same.
 290          *
 291          *  <subsystem>:* means all events in that subsystem
 292          *  <subsystem>: means the same.
 293          *
 294          *  <name> (no ':') means all events in a subsystem with
 295          *  the name <name> or any event that matches <name>
 296          */
 297
 298         match = strsep(&buf, ":");
 299         if (buf) {
 300                 sub = match;
 301                 event = buf;
 302                 match = NULL;
 303
 304                 if (!strlen(sub) || strcmp(sub, "*") == 0)
 305                         sub = NULL;
 306                 if (!strlen(event) || strcmp(event, "*") == 0)
 307                         event = NULL;
 308         }
 309
 310         return __ftrace_set_clr_event(match, sub, event, set);
 311 }
 312
 313 /**
 314  * trace_set_clr_event - enable or disable an event
 315  * @system: system name to match (NULL for any system)
 316  * @event: event name to match (NULL for all events, within system)
 317  * @set: 1 to enable, 0 to disable
 318  *
 319  * This is a way for other parts of the kernel to enable or disable
 320  * event recording.
 321  *
 322  * Returns 0 on success, -EINVAL if the parameters do not match any
 323  * registered events.
 324  */
 325 int trace_set_clr_event(const char *system, const char *event, int set)
 326 {
 327         return __ftrace_set_clr_event(NULL, system, event, set);
 328 }
 329 EXPORT_SYMBOL_GPL(trace_set_clr_event);
 330
 331 /* 128 should be much more than enough */
 332 #define EVENT_BUF_SIZE          127
 333
 334 static ssize_t
 335 ftrace_event_write(struct file *file, const char __user *ubuf,
 336                    size_t cnt, loff_t *ppos)
 337 {
 338         struct trace_parser parser;
 339         ssize_t read, ret;
 340
 341         if (!cnt)
 342                 return 0;
 343
 344         ret = tracing_update_buffers();
 345         if (ret < 0)
 346                 return ret;
 347
 348         if (trace_parser_get_init(&parser, EVENT_BUF_SIZE + 1))
 349                 return -ENOMEM;
 350
 351         read = trace_get_user(&parser, ubuf, cnt, ppos);
 352
 353         if (read >= 0 && trace_parser_loaded((&parser))) {
 354                 int set = 1;
 355
 356                 if (*parser.buffer == '!')
 357                         set = 0;
 358
 359                 parser.buffer[parser.idx] = 0;
 360
 361                 ret = ftrace_set_clr_event(parser.buffer + !set, set);
 362                 if (ret)
 363                         goto out_put;
 364         }
 365
 366         ret = read;
 367
 368  out_put:
 369         trace_parser_put(&parser);
 370
 371         return ret;
 372 }
 373
 374 static void *
 375 t_next(struct seq_file *m, void *v, loff_t *pos)
 376 {
 377         struct ftrace_event_call *call = v;
 378
 379         (*pos)++;
 380
 381         list_for_each_entry_continue(call, &ftrace_events, list) {
 382                 /*
 383                  * The ftrace subsystem is for showing formats only.
 384                  * They can not be enabled or disabled via the event files.
 385                  */
 386                 if (call->class && call->class->reg)
 387                         return call;
 388         }
 389
 390         return NULL;
 391 }
 392
 393 static void *t_start(struct seq_file *m, loff_t *pos)
 394 {
 395         struct ftrace_event_call *call;
 396         loff_t l;
 397
 398         mutex_lock(&event_mutex);
 399
 400         call = list_entry(&ftrace_events, struct ftrace_event_call, list);
 401         for (l = 0; l <= *pos; ) {
 402                 call = t_next(m, call, &l);
 403                 if (!call)
 404                         break;
 405         }
 406         return call;
 407 }
 408
 409 static void *
 410 s_next(struct seq_file *m, void *v, loff_t *pos)
 411 {
 412         struct ftrace_event_call *call = v;
 413
 414         (*pos)++;
 415
 416         list_for_each_entry_continue(call, &ftrace_events, list) {
 417                 if (call->flags & TRACE_EVENT_FL_ENABLED)
 418                         return call;
 419         }
 420
 421         return NULL;
 422 }
 423
 424 static void *s_start(struct seq_file *m, loff_t *pos)
 425 {
 426         struct ftrace_event_call *call;
 427         loff_t l;
 428
 429         mutex_lock(&event_mutex);
 430
 431         call = list_entry(&ftrace_events, struct ftrace_event_call, list);
 432         for (l = 0; l <= *pos; ) {
 433                 call = s_next(m, call, &l);
 434                 if (!call)
 435                         break;
 436         }
 437         return call;
 438 }
 439
 440 static int t_show(struct seq_file *m, void *v)
 441 {
 442         struct ftrace_event_call *call = v;
 443
 444         if (strcmp(call->class->system, TRACE_SYSTEM) != 0)
 445                 seq_printf(m, "%s:", call->class->system);
 446         seq_printf(m, "%s\n", call->name);
 447
 448         return 0;
 449 }
 450
 451 static void t_stop(struct seq_file *m, void *p)
 452 {
 453         mutex_unlock(&event_mutex);
 454 }
 455
 456 static int
 457 ftrace_event_seq_open(struct inode *inode, struct file *file)
 458 {
 459         const struct seq_operations *seq_ops;
 460
 461         if ((file->f_mode & FMODE_WRITE) &&
 462             (file->f_flags & O_TRUNC))
 463                 ftrace_clear_events();
 464
 465         seq_ops = inode->i_private;
 466         return seq_open(file, seq_ops);
 467 }
 468
 469 static ssize_t
 470 event_enable_read(struct file *filp, char __user *ubuf, size_t cnt,
 471                   loff_t *ppos)
 472 {
 473         struct ftrace_event_call *call = filp->private_data;
 474         char *buf;
 475
 476         if (call->flags & TRACE_EVENT_FL_ENABLED)
 477                 buf = "1\n";
 478         else
 479                 buf = "0\n";
 480
 481         return simple_read_from_buffer(ubuf, cnt, ppos, buf, 2);
 482 }
 483
 484 static ssize_t
 485 event_enable_write(struct file *filp, const char __user *ubuf, size_t cnt,
 486                    loff_t *ppos)
 487 {
 488         struct ftrace_event_call *call = filp->private_data;
 489         char buf[64];
 490         unsigned long val;
 491         int ret;
 492
 493         if (cnt >= sizeof(buf))
 494                 return -EINVAL;
 495
 496         if (copy_from_user(&buf, ubuf, cnt))
 497                 return -EFAULT;
 498
 499         buf[cnt] = 0;
 500
 501         ret = strict_strtoul(buf, 10, &val);
 502         if (ret < 0)
 503                 return ret;
 504
 505         ret = tracing_update_buffers();
 506         if (ret < 0)
 507                 return ret;
 508
 509         switch (val) {
 510         case 0:
 511         case 1:
 512                 mutex_lock(&event_mutex);
 513                 ret = ftrace_event_enable_disable(call, val);
 514                 mutex_unlock(&event_mutex);
 515                 break;
 516
 517         default:
 518                 return -EINVAL;
 519         }
 520
 521         *ppos += cnt;
 522
 523         return ret ? ret : cnt;
 524 }
 525
 526 static ssize_t
 527 system_enable_read(struct file *filp, char __user *ubuf, size_t cnt,
 528                    loff_t *ppos)
 529 {
 530         const char set_to_char[4] = { '?', '0', '1', 'X' };
 531         const char *system = filp->private_data;
 532         struct ftrace_event_call *call;
 533         char buf[2];
 534         int set = 0;
 535         int ret;
 536
 537         mutex_lock(&event_mutex);
 538         list_for_each_entry(call, &ftrace_events, list) {
 539                 if (!call->name || !call->class || !call->class->reg)
 540                         continue;
 541
 542                 if (system && strcmp(call->class->system, system) != 0)
 543                         continue;
 544
 545                 /*
 546                  * We need to find out if all the events are set
 547                  * or if all events or cleared, or if we have
 548                  * a mixture.
 549                  */
 550                 set |= (1 << !!(call->flags & TRACE_EVENT_FL_ENABLED));
 551
 552                 /*
 553                  * If we have a mixture, no need to look further.
 554                  */
 555                 if (set == 3)
 556                         break;
 557         }
 558         mutex_unlock(&event_mutex);
 559
 560         buf[0] = set_to_char[set];
 561         buf[1] = '\n';
 562
 563         ret = simple_read_from_buffer(ubuf, cnt, ppos, buf, 2);
 564
 565         return ret;
 566 }
 567
 568 static ssize_t
 569 system_enable_write(struct file *filp, const char __user *ubuf, size_t cnt,
 570                     loff_t *ppos)
 571 {
 572         const char *system = filp->private_data;
 573         unsigned long val;
 574         char buf[64];
 575         ssize_t ret;
 576
 577         if (cnt >= sizeof(buf))
 578                 return -EINVAL;
 579
 580         if (copy_from_user(&buf, ubuf, cnt))
 581                 return -EFAULT;
 582
 583         buf[cnt] = 0;
 584
 585         ret = strict_strtoul(buf, 10, &val);
 586         if (ret < 0)
 587                 return ret;
 588
 589         ret = tracing_update_buffers();
 590         if (ret < 0)
 591                 return ret;
 592
 593         if (val != 0 && val != 1)
 594                 return -EINVAL;
 595
 596         ret = __ftrace_set_clr_event(NULL, system, NULL, val);
 597         if (ret)
 598                 goto out;
 599
 600         ret = cnt;
 601
 602 out:
 603         *ppos += cnt;
 604
 605         return ret;
 606 }
 607
 608 enum {
 609         FORMAT_HEADER           = 1,
 610         FORMAT_FIELD_SEPERATOR  = 2,
 611         FORMAT_PRINTFMT         = 3,
 612 };
 613
 614 static void *f_next(struct seq_file *m, void *v, loff_t *pos)
 615 {
 616         struct ftrace_event_call *call = m->private;
 617         struct ftrace_event_field *field;
 618         struct list_head *common_head = &ftrace_common_fields;
 619         struct list_head *head = trace_get_fields(call);
 620
 621         (*pos)++;
 622
 623         switch ((unsigned long)v) {
 624         case FORMAT_HEADER:
 625                 if (unlikely(list_empty(common_head)))
 626                         return NULL;
 627
 628                 field = list_entry(common_head->prev,
 629                                    struct ftrace_event_field, link);
 630                 return field;
 631
 632         case FORMAT_FIELD_SEPERATOR:
 633                 if (unlikely(list_empty(head)))
 634                         return NULL;
 635
 636                 field = list_entry(head->prev, struct ftrace_event_field, link);
 637                 return field;
 638
 639         case FORMAT_PRINTFMT:
 640                 /* all done */
 641                 return NULL;
 642         }
 643
 644         field = v;
 645         if (field->link.prev == common_head)
 646                 return (void *)FORMAT_FIELD_SEPERATOR;
 647         else if (field->link.prev == head)
 648                 return (void *)FORMAT_PRINTFMT;
 649
 650         field = list_entry(field->link.prev, struct ftrace_event_field, link);
 651
 652         return field;
 653 }
 654
 655 static void *f_start(struct seq_file *m, loff_t *pos)
 656 {
 657         loff_t l = 0;
 658         void *p;
 659
 660         /* Start by showing the header */
 661         if (!*pos)
 662                 return (void *)FORMAT_HEADER;
 663
 664         p = (void *)FORMAT_HEADER;
 665         do {
 666                 p = f_next(m, p, &l);
 667         } while (p && l < *pos);
 668
 669         return p;
 670 }
 671
 672 static int f_show(struct seq_file *m, void *v)
 673 {
 674         struct ftrace_event_call *call = m->private;
 675         struct ftrace_event_field *field;
 676         const char *array_descriptor;
 677
 678         switch ((unsigned long)v) {
 679         case FORMAT_HEADER:
 680                 seq_printf(m, "name: %s\n", call->name);
 681                 seq_printf(m, "ID: %d\n", call->event.type);
 682                 seq_printf(m, "format:\n");
 683                 return 0;
 684
 685         case FORMAT_FIELD_SEPERATOR:
 686                 seq_putc(m, '\n');
 687                 return 0;
 688
 689         case FORMAT_PRINTFMT:
 690                 seq_printf(m, "\nprint fmt: %s\n",
 691                            call->print_fmt);
 692                 return 0;
 693         }
 694
 695         field = v;
 696
 697         /*
 698          * Smartly shows the array type(except dynamic array).
 699          * Normal:
 700          *      field:TYPE VAR
 701          * If TYPE := TYPE[LEN], it is shown:
 702          *      field:TYPE VAR[LEN]
 703          */
 704         array_descriptor = strchr(field->type, '[');
 705
 706         if (!strncmp(field->type, "__data_loc", 10))
 707                 array_descriptor = NULL;
 708
 709         if (!array_descriptor)
 710                 seq_printf(m, "\tfield:%s %s;\toffset:%u;\tsize:%u;\tsigned:%d;\n",
 711                            field->type, field->name, field->offset,
 712                            field->size, !!field->is_signed);
 713         else
 714                 seq_printf(m, "\tfield:%.*s %s%s;\toffset:%u;\tsize:%u;\tsigned:%d;\n",
 715                            (int)(array_descriptor - field->type),
 716                            field->type, field->name,
 717                            array_descriptor, field->offset,
 718                            field->size, !!field->is_signed);
 719
 720         return 0;
 721 }
 722
 723 static void f_stop(struct seq_file *m, void *p)
 724 {
 725 }
 726
 727 static const struct seq_operations trace_format_seq_ops = {
 728         .start          = f_start,
 729         .next           = f_next,
 730         .stop           = f_stop,
 731         .show           = f_show,
 732 };
 733
 734 static int trace_format_open(struct inode *inode, struct file *file)
 735 {
 736         struct ftrace_event_call *call = inode->i_private;
 737         struct seq_file *m;
 738         int ret;
 739
 740         ret = seq_open(file, &trace_format_seq_ops);
 741         if (ret < 0)
 742                 return ret;
 743
 744         m = file->private_data;
 745         m->private = call;
 746
 747         return 0;
 748 }
 749
 750 static ssize_t
 751 event_id_read(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos)
 752 {
 753         struct ftrace_event_call *call = filp->private_data;
 754         struct trace_seq *s;
 755         int r;
 756
 757         if (*ppos)
 758                 return 0;
 759
 760         s = kmalloc(sizeof(*s), GFP_KERNEL);
 761         if (!s)
 762                 return -ENOMEM;
 763
 764         trace_seq_init(s);
 765         trace_seq_printf(s, "%d\n", call->event.type);
 766
 767         r = simple_read_from_buffer(ubuf, cnt, ppos,
 768                                     s->buffer, s->len);
 769         kfree(s);
 770         return r;
 771 }
 772
 773 static ssize_t
 774 event_filter_read(struct file *filp, char __user *ubuf, size_t cnt,
 775                   loff_t *ppos)
 776 {
 777         struct ftrace_event_call *call = filp->private_data;
 778         struct trace_seq *s;
 779         int r;
 780
 781         if (*ppos)
 782                 return 0;
 783
 784         s = kmalloc(sizeof(*s), GFP_KERNEL);
 785         if (!s)
 786                 return -ENOMEM;
 787
 788         trace_seq_init(s);
 789
 790         print_event_filter(call, s);
 791         r = simple_read_from_buffer(ubuf, cnt, ppos, s->buffer, s->len);
 792
 793         kfree(s);
 794
 795         return r;
 796 }
 797
 798 static ssize_t
 799 event_filter_write(struct file *filp, const char __user *ubuf, size_t cnt,
 800                    loff_t *ppos)
 801 {
 802         struct ftrace_event_call *call = filp->private_data;
 803         char *buf;
 804         int err;
 805
 806         if (cnt >= PAGE_SIZE)
 807                 return -EINVAL;
 808
 809         buf = (char *)__get_free_page(GFP_TEMPORARY);
 810         if (!buf)
 811                 return -ENOMEM;
 812
 813         if (copy_from_user(buf, ubuf, cnt)) {
 814                 free_page((unsigned long) buf);
 815                 return -EFAULT;
 816         }
 817         buf[cnt] = '\0';
 818
 819         err = apply_event_filter(call, buf);
 820         free_page((unsigned long) buf);
 821         if (err < 0)
 822                 return err;
 823
 824         *ppos += cnt;
 825
 826         return cnt;
 827 }
 828
 829 static ssize_t
 830 subsystem_filter_read(struct file *filp, char __user *ubuf, size_t cnt,
 831                       loff_t *ppos)
 832 {
 833         struct event_subsystem *system = filp->private_data;
 834         struct trace_seq *s;
 835         int r;
 836
 837         if (*ppos)
 838                 return 0;
 839
 840         s = kmalloc(sizeof(*s), GFP_KERNEL);
 841         if (!s)
 842                 return -ENOMEM;
 843
 844         trace_seq_init(s);
 845
 846         print_subsystem_event_filter(system, s);
 847         r = simple_read_from_buffer(ubuf, cnt, ppos, s->buffer, s->len);
 848
 849         kfree(s);
 850
 851         return r;
 852 }
 853
 854 static ssize_t
 855 subsystem_filter_write(struct file *filp, const char __user *ubuf, size_t cnt,
 856                        loff_t *ppos)
 857 {
 858         struct event_subsystem *system = filp->private_data;
 859         char *buf;
 860         int err;
 861
 862         if (cnt >= PAGE_SIZE)
 863                 return -EINVAL;
 864
 865         buf = (char *)__get_free_page(GFP_TEMPORARY);
 866         if (!buf)
 867                 return -ENOMEM;
 868
 869         if (copy_from_user(buf, ubuf, cnt)) {
 870                 free_page((unsigned long) buf);
 871                 return -EFAULT;
 872         }
 873         buf[cnt] = '\0';
 874
 875         err = apply_subsystem_event_filter(system, buf);
 876         free_page((unsigned long) buf);
 877         if (err < 0)
 878                 return err;
 879
 880         *ppos += cnt;
 881
 882         return cnt;
 883 }
 884
 885 static ssize_t
 886 show_header(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos)
 887 {
 888         int (*func)(struct trace_seq *s) = filp->private_data;
 889         struct trace_seq *s;
 890         int r;
 891
 892         if (*ppos)
 893                 return 0;
 894
 895         s = kmalloc(sizeof(*s), GFP_KERNEL);
 896         if (!s)
 897                 return -ENOMEM;
 898
 899         trace_seq_init(s);
 900
 901         func(s);
 902         r = simple_read_from_buffer(ubuf, cnt, ppos, s->buffer, s->len);
 903
 904         kfree(s);
 905
 906         return r;
 907 }
 908
 909 static const struct seq_operations show_event_seq_ops = {
 910         .start = t_start,
 911         .next = t_next,
 912         .show = t_show,
 913         .stop = t_stop,
 914 };
 915
 916 static const struct seq_operations show_set_event_seq_ops = {
 917         .start = s_start,
 918         .next = s_next,
 919         .show = t_show,
 920         .stop = t_stop,
 921 };
 922
 923 static const struct file_operations ftrace_avail_fops = {
 924         .open = ftrace_event_seq_open,
 925         .read = seq_read,
 926         .llseek = seq_lseek,
 927         .release = seq_release,
 928 };
 929
 930 static const struct file_operations ftrace_set_event_fops = {
 931         .open = ftrace_event_seq_open,
 932         .read = seq_read,
 933         .write = ftrace_event_write,
 934         .llseek = seq_lseek,
 935         .release = seq_release,
 936 };
 937
 938 static const struct file_operations ftrace_enable_fops = {
 939         .open = tracing_open_generic,
 940         .read = event_enable_read,
 941         .write = event_enable_write,
 942         .llseek = default_llseek,
 943 };
 944
 945 static const struct file_operations ftrace_event_format_fops = {
 946         .open = trace_format_open,
 947         .read = seq_read,
 948         .llseek = seq_lseek,
 949         .release = seq_release,
 950 };
 951
 952 static const struct file_operations ftrace_event_id_fops = {
 953         .open = tracing_open_generic,
 954         .read = event_id_read,
 955         .llseek = default_llseek,
 956 };
 957
 958 static const struct file_operations ftrace_event_filter_fops = {
 959         .open = tracing_open_generic,
 960         .read = event_filter_read,
 961         .write = event_filter_write,
 962         .llseek = default_llseek,
 963 };
 964
 965 static const struct file_operations ftrace_subsystem_filter_fops = {
 966         .open = tracing_open_generic,
 967         .read = subsystem_filter_read,
 968         .write = subsystem_filter_write,
 969         .llseek = default_llseek,
 970 };
 971
 972 static const struct file_operations ftrace_system_enable_fops = {
 973         .open = tracing_open_generic,
 974         .read = system_enable_read,
 975         .write = system_enable_write,
 976         .llseek = default_llseek,
 977 };
 978
 979 static const struct file_operations ftrace_show_header_fops = {
 980         .open = tracing_open_generic,
 981         .read = show_header,
 982         .llseek = default_llseek,
 983 };
 984
 985 static struct dentry *event_trace_events_dir(void)
 986 {
 987         static struct dentry *d_tracer;
 988         static struct dentry *d_events;
 989
 990         if (d_events)
 991                 return d_events;
 992
 993         d_tracer = tracing_init_dentry();
 994         if (!d_tracer)
 995                 return NULL;
 996
 997         d_events = debugfs_create_dir("events", d_tracer);
 998         if (!d_events)
 999                 pr_warning("Could not create debugfs "
1000                            "'events' directory\n");
1001
1002         return d_events;
1003 }
1004
1005 static LIST_HEAD(event_subsystems);
1006
1007 static struct dentry *
1008 event_subsystem_dir(const char *name, struct dentry *d_events)
1009 {
1010         struct event_subsystem *system;
1011         struct dentry *entry;
1012
1013         /* First see if we did not already create this dir */
1014         list_for_each_entry(system, &event_subsystems, list) {
1015                 if (strcmp(system->name, name) == 0) {
1016                         system->nr_events++;
1017                         return system->entry;
1018                 }
1019         }
1020
1021         /* need to create new entry */
1022         system = kmalloc(sizeof(*system), GFP_KERNEL);
1023         if (!system) {
1024                 pr_warning("No memory to create event subsystem %s\n",
1025                            name);
1026                 return d_events;
1027         }
1028
1029         system->entry = debugfs_create_dir(name, d_events);
1030         if (!system->entry) {
1031                 pr_warning("Could not create event subsystem %s\n",
1032                            name);
1033                 kfree(system);
1034                 return d_events;
1035         }
1036
1037         system->nr_events = 1;
1038         system->name = kstrdup(name, GFP_KERNEL);
1039         if (!system->name) {
1040                 debugfs_remove(system->entry);
1041                 kfree(system);
1042                 return d_events;
1043         }
1044
1045         list_add(&system->list, &event_subsystems);
1046
1047         system->filter = NULL;
1048
1049         system->filter = kzalloc(sizeof(struct event_filter), GFP_KERNEL);
1050         if (!system->filter) {
1051                 pr_warning("Could not allocate filter for subsystem "
1052                            "'%s'\n", name);
1053                 return system->entry;
1054         }
1055
1056         entry = debugfs_create_file("filter", 0644, system->entry, system,
1057                                     &ftrace_subsystem_filter_fops);
1058         if (!entry) {
1059                 kfree(system->filter);
1060                 system->filter = NULL;
1061                 pr_warning("Could not create debugfs "
1062                            "'%s/filter' entry\n", name);
1063         }
1064
1065         trace_create_file("enable", 0644, system->entry,
1066                           (void *)system->name,
1067                           &ftrace_system_enable_fops);
1068
1069         return system->entry;
1070 }
1071
1072 static int
1073 event_create_dir(struct ftrace_event_call *call, struct dentry *d_events,
1074                  const struct file_operations *id,
1075                  const struct file_operations *enable,
1076                  const struct file_operations *filter,
1077                  const struct file_operations *format)
1078 {
1079         struct list_head *head;
1080         int ret;
1081
1082         /*
1083          * If the trace point header did not define TRACE_SYSTEM
1084          * then the system would be called "TRACE_SYSTEM".
1085          */
1086         if (strcmp(call->class->system, TRACE_SYSTEM) != 0)
1087                 d_events = event_subsystem_dir(call->class->system, d_events);
1088
1089         call->dir = debugfs_create_dir(call->name, d_events);
1090         if (!call->dir) {
1091                 pr_warning("Could not create debugfs "
1092                            "'%s' directory\n", call->name);
1093                 return -1;
1094         }
1095
1096         if (call->class->reg)
1097                 trace_create_file("enable", 0644, call->dir, call,
1098                                   enable);
1099
1100 #ifdef CONFIG_PERF_EVENTS
1101         if (call->event.type && call->class->reg)
1102                 trace_create_file("id", 0444, call->dir, call,
1103                                   id);
1104 #endif
1105
1106         /*
1107          * Other events may have the same class. Only update
1108          * the fields if they are not already defined.
1109          */
1110         head = trace_get_fields(call);
1111         if (list_empty(head)) {
1112                 ret = call->class->define_fields(call);
1113                 if (ret < 0) {
1114                         pr_warning("Could not initialize trace point"
1115                                    " events/%s\n", call->name);
1116                         return ret;
1117                 }
1118         }
1119         trace_create_file("filter", 0644, call->dir, call,
1120                           filter);
1121
1122         trace_create_file("format", 0444, call->dir, call,
1123                           format);
1124
1125         return 0;
1126 }
1127
1128 static int
1129 __trace_add_event_call(struct ftrace_event_call *call, struct module *mod,
1130                        const struct file_operations *id,
1131                        const struct file_operations *enable,
1132                        const struct file_operations *filter,
1133                        const struct file_operations *format)
1134 {
1135         struct dentry *d_events;
1136         int ret;
1137
1138         /* The linker may leave blanks */
1139         if (!call->name)
1140                 return -EINVAL;
1141
1142         if (call->class->raw_init) {
1143                 ret = call->class->raw_init(call);
1144                 if (ret < 0) {
1145                         if (ret != -ENOSYS)
1146                                 pr_warning("Could not initialize trace events/%s\n",
1147                                            call->name);
1148                         return ret;
1149                 }
1150         }
1151
1152         d_events = event_trace_events_dir();
1153         if (!d_events)
1154                 return -ENOENT;
1155
1156         ret = event_create_dir(call, d_events, id, enable, filter, format);
1157         if (!ret)
1158                 list_add(&call->list, &ftrace_events);
1159         call->mod = mod;
1160
1161         return ret;
1162 }
1163
1164 /* Add an additional event_call dynamically */
1165 int trace_add_event_call(struct ftrace_event_call *call)
1166 {
1167         int ret;
1168         mutex_lock(&event_mutex);
1169         ret = __trace_add_event_call(call, NULL, &ftrace_event_id_fops,
1170                                      &ftrace_enable_fops,
1171                                      &ftrace_event_filter_fops,
1172                                      &ftrace_event_format_fops);
1173         mutex_unlock(&event_mutex);
1174         return ret;
1175 }
1176
1177 static void remove_subsystem_dir(const char *name)
1178 {
1179         struct event_subsystem *system;
1180
1181         if (strcmp(name, TRACE_SYSTEM) == 0)
1182                 return;
1183
1184         list_for_each_entry(system, &event_subsystems, list) {
1185                 if (strcmp(system->name, name) == 0) {
1186                         if (!--system->nr_events) {
1187                                 struct event_filter *filter = system->filter;
1188
1189                                 debugfs_remove_recursive(system->entry);
1190                                 list_del(&system->list);
1191                                 if (filter) {
1192                                         kfree(filter->filter_string);
1193                                         kfree(filter);
1194                                 }
1195                                 kfree(system->name);
1196                                 kfree(system);
1197                         }
1198                         break;
1199                 }
1200         }
1201 }
1202
1203 /*
1204  * Must be called under locking both of event_mutex and trace_event_mutex.
1205  */
1206 static void __trace_remove_event_call(struct ftrace_event_call *call)
1207 {
1208         ftrace_event_enable_disable(call, 0);
1209         if (call->event.funcs)
1210                 __unregister_ftrace_event(&call->event);
1211         debugfs_remove_recursive(call->dir);
1212         list_del(&call->list);
1213         trace_destroy_fields(call);
1214         destroy_preds(call);
1215         remove_subsystem_dir(call->class->system);
1216 }
1217
1218 /* Remove an event_call */
1219 void trace_remove_event_call(struct ftrace_event_call *call)
1220 {
1221         mutex_lock(&event_mutex);
1222         down_write(&trace_event_mutex);
1223         __trace_remove_event_call(call);
1224         up_write(&trace_event_mutex);
1225         mutex_unlock(&event_mutex);
1226 }
1227
1228 #define for_each_event(event, start, end)                       \
1229         for (event = start;                                     \
1230              (unsigned long)event < (unsigned long)end;         \
1231              event++)
1232
1233 #ifdef CONFIG_MODULES
1234
1235 static LIST_HEAD(ftrace_module_file_list);
1236
1237 /*
1238  * Modules must own their file_operations to keep up with
1239  * reference counting.
1240  */
1241 struct ftrace_module_file_ops {
1242         struct list_head                list;
1243         struct module                   *mod;
1244         struct file_operations          id;
1245         struct file_operations          enable;
1246         struct file_operations          format;
1247         struct file_operations          filter;
1248 };
1249
1250 static struct ftrace_module_file_ops *
1251 trace_create_file_ops(struct module *mod)
1252 {
1253         struct ftrace_module_file_ops *file_ops;
1254
1255         /*
1256          * This is a bit of a PITA. To allow for correct reference
1257          * counting, modules must "own" their file_operations.
1258          * To do this, we allocate the file operations that will be
1259          * used in the event directory.
1260          */
1261
1262         file_ops = kmalloc(sizeof(*file_ops), GFP_KERNEL);
1263         if (!file_ops)
1264                 return NULL;
1265
1266         file_ops->mod = mod;
1267
1268         file_ops->id = ftrace_event_id_fops;
1269         file_ops->id.owner = mod;
1270
1271         file_ops->enable = ftrace_enable_fops;
1272         file_ops->enable.owner = mod;
1273
1274         file_ops->filter = ftrace_event_filter_fops;
1275         file_ops->filter.owner = mod;
1276
1277         file_ops->format = ftrace_event_format_fops;
1278         file_ops->format.owner = mod;
1279
1280         list_add(&file_ops->list, &ftrace_module_file_list);
1281
1282         return file_ops;
1283 }
1284
1285 static void trace_module_add_events(struct module *mod)
1286 {
1287         struct ftrace_module_file_ops *file_ops = NULL;
1288         struct ftrace_event_call **call, **start, **end;
1289
1290         start = mod->trace_events;
1291         end = mod->trace_events + mod->num_trace_events;
1292
1293         if (start == end)
1294                 return;
1295
1296         file_ops = trace_create_file_ops(mod);
1297         if (!file_ops)
1298                 return;
1299
1300         for_each_event(call, start, end) {
1301                 __trace_add_event_call(*call, mod,
1302                                        &file_ops->id, &file_ops->enable,
1303                                        &file_ops->filter, &file_ops->format);
1304         }
1305 }
1306
1307 static void trace_module_remove_events(struct module *mod)
1308 {
1309         struct ftrace_module_file_ops *file_ops;
1310         struct ftrace_event_call *call, *p;
1311         bool found = false;
1312
1313         down_write(&trace_event_mutex);
1314         list_for_each_entry_safe(call, p, &ftrace_events, list) {
1315                 if (call->mod == mod) {
1316                         found = true;
1317                         __trace_remove_event_call(call);
1318                 }
1319         }
1320
1321         /* Now free the file_operations */
1322         list_for_each_entry(file_ops, &ftrace_module_file_list, list) {
1323                 if (file_ops->mod == mod)
1324                         break;
1325         }
1326         if (&file_ops->list != &ftrace_module_file_list) {
1327                 list_del(&file_ops->list);
1328                 kfree(file_ops);
1329         }
1330
1331         /*
1332          * It is safest to reset the ring buffer if the module being unloaded
1333          * registered any events.
1334          */
1335         if (found)
1336                 tracing_reset_current_online_cpus();
1337         up_write(&trace_event_mutex);
1338 }
1339
1340 static int trace_module_notify(struct notifier_block *self,
1341                                unsigned long val, void *data)
1342 {
1343         struct module *mod = data;
1344
1345         mutex_lock(&event_mutex);
1346         switch (val) {
1347         case MODULE_STATE_COMING:
1348                 trace_module_add_events(mod);
1349                 break;
1350         case MODULE_STATE_GOING:
1351                 trace_module_remove_events(mod);
1352                 break;
1353         }
1354         mutex_unlock(&event_mutex);
1355
1356         return 0;
1357 }
1358 #else
1359 static int trace_module_notify(struct notifier_block *self,
1360                                unsigned long val, void *data)
1361 {
1362         return 0;
1363 }
1364 #endif /* CONFIG_MODULES */
1365
1366 static struct notifier_block trace_module_nb = {
1367         .notifier_call = trace_module_notify,
1368         .priority = 0,
1369 };
1370
1371 extern struct ftrace_event_call *__start_ftrace_events[];
1372 extern struct ftrace_event_call *__stop_ftrace_events[];
1373
1374 static char bootup_event_buf[COMMAND_LINE_SIZE] __initdata;
1375
1376 static __init int setup_trace_event(char *str)
1377 {
1378         strlcpy(bootup_event_buf, str, COMMAND_LINE_SIZE);
1379         ring_buffer_expanded = 1;
1380         tracing_selftest_disabled = 1;
1381
1382         return 1;
1383 }
1384 __setup("trace_event=", setup_trace_event);
1385
1386 static __init int event_trace_init(void)
1387 {
1388         struct ftrace_event_call **call;
1389         struct dentry *d_tracer;
1390         struct dentry *entry;
1391         struct dentry *d_events;
1392         int ret;
1393         char *buf = bootup_event_buf;
1394         char *token;
1395
1396         d_tracer = tracing_init_dentry();
1397         if (!d_tracer)
1398                 return 0;
1399
1400         entry = debugfs_create_file("available_events", 0444, d_tracer,
1401                                     (void *)&show_event_seq_ops,
1402                                     &ftrace_avail_fops);
1403         if (!entry)
1404                 pr_warning("Could not create debugfs "
1405                            "'available_events' entry\n");
1406
1407         entry = debugfs_create_file("set_event", 0644, d_tracer,
1408                                     (void *)&show_set_event_seq_ops,
1409                                     &ftrace_set_event_fops);
1410         if (!entry)
1411                 pr_warning("Could not create debugfs "
1412                            "'set_event' entry\n");
1413
1414         d_events = event_trace_events_dir();
1415         if (!d_events)
1416                 return 0;
1417
1418         /* ring buffer internal formats */
1419         trace_create_file("header_page", 0444, d_events,
1420                           ring_buffer_print_page_header,
1421                           &ftrace_show_header_fops);
1422
1423         trace_create_file("header_event", 0444, d_events,
1424                           ring_buffer_print_entry_header,
1425                           &ftrace_show_header_fops);
1426
1427         trace_create_file("enable", 0644, d_events,
1428                           NULL, &ftrace_system_enable_fops);
1429
1430         if (trace_define_common_fields())
1431                 pr_warning("tracing: Failed to allocate common fields");
1432
1433         for_each_event(call, __start_ftrace_events, __stop_ftrace_events) {
1434                 __trace_add_event_call(*call, NULL, &ftrace_event_id_fops,
1435                                        &ftrace_enable_fops,
1436                                        &ftrace_event_filter_fops,
1437                                        &ftrace_event_format_fops);
1438         }
1439
1440         while (true) {
1441                 token = strsep(&buf, ",");
1442
1443                 if (!token)
1444                         break;
1445                 if (!*token)
1446                         continue;
1447
1448                 ret = ftrace_set_clr_event(token, 1);
1449                 if (ret)
1450                         pr_warning("Failed to enable trace event: %s\n", token);
1451         }
1452
1453         ret = register_module_notifier(&trace_module_nb);
1454         if (ret)
1455                 pr_warning("Failed to register trace events module notifier\n");
1456
1457         return 0;
1458 }
1459 fs_initcall(event_trace_init);
1460
1461 #ifdef CONFIG_FTRACE_STARTUP_TEST
1462
1463 static DEFINE_SPINLOCK(test_spinlock);
1464 static DEFINE_SPINLOCK(test_spinlock_irq);
1465 static DEFINE_MUTEX(test_mutex);
1466
1467 static __init void test_work(struct work_struct *dummy)
1468 {
1469         spin_lock(&test_spinlock);
1470         spin_lock_irq(&test_spinlock_irq);
1471         udelay(1);
1472         spin_unlock_irq(&test_spinlock_irq);
1473         spin_unlock(&test_spinlock);
1474
1475         mutex_lock(&test_mutex);
1476         msleep(1);
1477         mutex_unlock(&test_mutex);
1478 }
1479
1480 static __init int event_test_thread(void *unused)
1481 {
1482         void *test_malloc;
1483
1484         test_malloc = kmalloc(1234, GFP_KERNEL);
1485         if (!test_malloc)
1486                 pr_info("failed to kmalloc\n");
1487
1488         schedule_on_each_cpu(test_work);
1489
1490         kfree(test_malloc);
1491
1492         set_current_state(TASK_INTERRUPTIBLE);
1493         while (!kthread_should_stop())
1494                 schedule();
1495
1496         return 0;
1497 }
1498
1499 /*
1500  * Do various things that may trigger events.
1501  */
1502 static __init void event_test_stuff(void)
1503 {
1504         struct task_struct *test_thread;
1505
1506         test_thread = kthread_run(event_test_thread, NULL, "test-events");
1507         msleep(1);
1508         kthread_stop(test_thread);
1509 }
1510
1511 /*
1512  * For every trace event defined, we will test each trace point separately,
1513  * and then by groups, and finally all trace points.
1514  */
1515 static __init void event_trace_self_tests(void)
1516 {
1517         struct ftrace_event_call *call;
1518         struct event_subsystem *system;
1519         int ret;
1520
1521         pr_info("Running tests on trace events:\n");
1522
1523         list_for_each_entry(call, &ftrace_events, list) {
1524
1525                 /* Only test those that have a probe */
1526                 if (!call->class || !call->class->probe)
1527                         continue;
1528
1529 /*
1530  * Testing syscall events here is pretty useless, but
1531  * we still do it if configured. But this is time consuming.
1532  * What we really need is a user thread to perform the
1533  * syscalls as we test.
1534  */
1535 #ifndef CONFIG_EVENT_TRACE_TEST_SYSCALLS
1536                 if (call->class->system &&
1537                     strcmp(call->class->system, "syscalls") == 0)
1538                         continue;
1539 #endif
1540
1541                 pr_info("Testing event %s: ", call->name);
1542
1543                 /*
1544                  * If an event is already enabled, someone is using
1545                  * it and the self test should not be on.
1546                  */
1547                 if (call->flags & TRACE_EVENT_FL_ENABLED) {
1548                         pr_warning("Enabled event during self test!\n");
1549                         WARN_ON_ONCE(1);
1550                         continue;
1551                 }
1552
1553                 ftrace_event_enable_disable(call, 1);
1554                 event_test_stuff();
1555                 ftrace_event_enable_disable(call, 0);
1556
1557                 pr_cont("OK\n");
1558         }
1559
1560         /* Now test at the sub system level */
1561
1562         pr_info("Running tests on trace event systems:\n");
1563
1564         list_for_each_entry(system, &event_subsystems, list) {
1565
1566                 /* the ftrace system is special, skip it */
1567                 if (strcmp(system->name, "ftrace") == 0)
1568                         continue;
1569
1570                 pr_info("Testing event system %s: ", system->name);
1571
1572                 ret = __ftrace_set_clr_event(NULL, system->name, NULL, 1);
1573                 if (WARN_ON_ONCE(ret)) {
1574                         pr_warning("error enabling system %s\n",
1575                                    system->name);
1576                         continue;
1577                 }
1578
1579                 event_test_stuff();
1580
1581                 ret = __ftrace_set_clr_event(NULL, system->name, NULL, 0);
1582                 if (WARN_ON_ONCE(ret))
1583                         pr_warning("error disabling system %s\n",
1584                                    system->name);
1585
1586                 pr_cont("OK\n");
1587         }
1588
1589         /* Test with all events enabled */
1590
1591         pr_info("Running tests on all trace events:\n");
1592         pr_info("Testing all events: ");
1593
1594         ret = __ftrace_set_clr_event(NULL, NULL, NULL, 1);
1595         if (WARN_ON_ONCE(ret)) {
1596                 pr_warning("error enabling all events\n");
1597                 return;
1598         }
1599
1600         event_test_stuff();
1601
1602         /* reset sysname */
1603         ret = __ftrace_set_clr_event(NULL, NULL, NULL, 0);
1604         if (WARN_ON_ONCE(ret)) {
1605                 pr_warning("error disabling all events\n");
1606                 return;
1607         }
1608
1609         pr_cont("OK\n");
1610 }
1611
1612 #ifdef CONFIG_FUNCTION_TRACER
1613
1614 static DEFINE_PER_CPU(atomic_t, ftrace_test_event_disable);
1615
1616 static void
1617 function_test_events_call(unsigned long ip, unsigned long parent_ip)
1618 {
1619         struct ring_buffer_event *event;
1620         struct ring_buffer *buffer;
1621         struct ftrace_entry *entry;
1622         unsigned long flags;
1623         long disabled;
1624         int cpu;
1625         int pc;
1626
1627         pc = preempt_count();
1628         preempt_disable_notrace();
1629         cpu = raw_smp_processor_id();
1630         disabled = atomic_inc_return(&per_cpu(ftrace_test_event_disable, cpu));
1631
1632         if (disabled != 1)
1633                 goto out;
1634
1635         local_save_flags(flags);
1636
1637         event = trace_current_buffer_lock_reserve(&buffer,
1638                                                   TRACE_FN, sizeof(*entry),
1639                                                   flags, pc);
1640         if (!event)
1641                 goto out;
1642         entry   = ring_buffer_event_data(event);
1643         entry->ip                       = ip;
1644         entry->parent_ip                = parent_ip;
1645
1646         trace_nowake_buffer_unlock_commit(buffer, event, flags, pc);
1647
1648  out:
1649         atomic_dec(&per_cpu(ftrace_test_event_disable, cpu));
1650         preempt_enable_notrace();
1651 }
1652
1653 static struct ftrace_ops trace_ops __initdata  =
1654 {
1655         .func = function_test_events_call,
1656 };
1657
1658 static __init void event_trace_self_test_with_function(void)
1659 {
1660         register_ftrace_function(&trace_ops);
1661         pr_info("Running tests again, along with the function tracer\n");
1662         event_trace_self_tests();
1663         unregister_ftrace_function(&trace_ops);
1664 }
1665 #else
1666 static __init void event_trace_self_test_with_function(void)
1667 {
1668 }
1669 #endif
1670
1671 static __init int event_trace_self_tests_init(void)
1672 {
1673         if (!tracing_selftest_disabled) {
1674                 event_trace_self_tests();
1675                 event_trace_self_test_with_function();
1676         }
1677
1678         return 0;
1679 }
1680
1681 late_initcall(event_trace_self_tests_init);
1682
1683 #endif