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