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 #define pr_fmt(fmt) fmt
  12
  13 #include <linux/workqueue.h>
  14 #include <linux/spinlock.h>
  15 #include <linux/kthread.h>
  16 #include <linux/debugfs.h>
  17 #include <linux/uaccess.h>
  18 #include <linux/module.h>
  19 #include <linux/ctype.h>
  20 #include <linux/slab.h>
  21 #include <linux/delay.h>
  22
  23 #include <asm/setup.h>
  24
  25 #include "trace_output.h"
  26
  27 #undef TRACE_SYSTEM
  28 #define TRACE_SYSTEM "TRACE_SYSTEM"
  29
  30 DEFINE_MUTEX(event_mutex);
  31
  32 LIST_HEAD(ftrace_events);
  33 static LIST_HEAD(ftrace_common_fields);
  34
  35 #define GFP_TRACE (GFP_KERNEL | __GFP_ZERO)
  36
  37 static struct kmem_cache *field_cachep;
  38 static struct kmem_cache *file_cachep;
  39
  40 #define SYSTEM_FL_FREE_NAME             (1 << 31)
  41
  42 static inline int system_refcount(struct event_subsystem *system)
  43 {
  44         return system->ref_count & ~SYSTEM_FL_FREE_NAME;
  45 }
  46
  47 static int system_refcount_inc(struct event_subsystem *system)
  48 {
  49         return (system->ref_count++) & ~SYSTEM_FL_FREE_NAME;
  50 }
  51
  52 static int system_refcount_dec(struct event_subsystem *system)
  53 {
  54         return (--system->ref_count) & ~SYSTEM_FL_FREE_NAME;
  55 }
  56
  57 /* Double loops, do not use break, only goto's work */
  58 #define do_for_each_event_file(tr, file)                        \
  59         list_for_each_entry(tr, &ftrace_trace_arrays, list) {   \
  60                 list_for_each_entry(file, &tr->events, list)
  61
  62 #define do_for_each_event_file_safe(tr, file)                   \
  63         list_for_each_entry(tr, &ftrace_trace_arrays, list) {   \
  64                 struct ftrace_event_file *___n;                         \
  65                 list_for_each_entry_safe(file, ___n, &tr->events, list)
  66
  67 #define while_for_each_event_file()             \
  68         }
  69
  70 static struct list_head *
  71 trace_get_fields(struct ftrace_event_call *event_call)
  72 {
  73         if (!event_call->class->get_fields)
  74                 return &event_call->class->fields;
  75         return event_call->class->get_fields(event_call);
  76 }
  77
  78 static struct ftrace_event_field *
  79 __find_event_field(struct list_head *head, char *name)
  80 {
  81         struct ftrace_event_field *field;
  82
  83         list_for_each_entry(field, head, link) {
  84                 if (!strcmp(field->name, name))
  85                         return field;
  86         }
  87
  88         return NULL;
  89 }
  90
  91 struct ftrace_event_field *
  92 trace_find_event_field(struct ftrace_event_call *call, char *name)
  93 {
  94         struct ftrace_event_field *field;
  95         struct list_head *head;
  96
  97         field = __find_event_field(&ftrace_common_fields, name);
  98         if (field)
  99                 return field;
 100
 101         head = trace_get_fields(call);
 102         return __find_event_field(head, name);
 103 }
 104
 105 static int __trace_define_field(struct list_head *head, const char *type,
 106                                 const char *name, int offset, int size,
 107                                 int is_signed, int filter_type)
 108 {
 109         struct ftrace_event_field *field;
 110
 111         field = kmem_cache_alloc(field_cachep, GFP_TRACE);
 112         if (!field)
 113                 return -ENOMEM;
 114
 115         field->name = name;
 116         field->type = type;
 117
 118         if (filter_type == FILTER_OTHER)
 119                 field->filter_type = filter_assign_type(type);
 120         else
 121                 field->filter_type = filter_type;
 122
 123         field->offset = offset;
 124         field->size = size;
 125         field->is_signed = is_signed;
 126
 127         list_add(&field->link, head);
 128
 129         return 0;
 130 }
 131
 132 int trace_define_field(struct ftrace_event_call *call, const char *type,
 133                        const char *name, int offset, int size, int is_signed,
 134                        int filter_type)
 135 {
 136         struct list_head *head;
 137
 138         if (WARN_ON(!call->class))
 139                 return 0;
 140
 141         head = trace_get_fields(call);
 142         return __trace_define_field(head, type, name, offset, size,
 143                                     is_signed, filter_type);
 144 }
 145 EXPORT_SYMBOL_GPL(trace_define_field);
 146
 147 #define __common_field(type, item)                                      \
 148         ret = __trace_define_field(&ftrace_common_fields, #type,        \
 149                                    "common_" #item,                     \
 150                                    offsetof(typeof(ent), item),         \
 151                                    sizeof(ent.item),                    \
 152                                    is_signed_type(type), FILTER_OTHER); \
 153         if (ret)                                                        \
 154                 return ret;
 155
 156 static int trace_define_common_fields(void)
 157 {
 158         int ret;
 159         struct trace_entry ent;
 160
 161         __common_field(unsigned short, type);
 162         __common_field(unsigned char, flags);
 163         __common_field(unsigned char, preempt_count);
 164         __common_field(int, pid);
 165
 166         return ret;
 167 }
 168
 169 static void trace_destroy_fields(struct ftrace_event_call *call)
 170 {
 171         struct ftrace_event_field *field, *next;
 172         struct list_head *head;
 173
 174         head = trace_get_fields(call);
 175         list_for_each_entry_safe(field, next, head, link) {
 176                 list_del(&field->link);
 177                 kmem_cache_free(field_cachep, field);
 178         }
 179 }
 180
 181 int trace_event_raw_init(struct ftrace_event_call *call)
 182 {
 183         int id;
 184
 185         id = register_ftrace_event(&call->event);
 186         if (!id)
 187                 return -ENODEV;
 188
 189         return 0;
 190 }
 191 EXPORT_SYMBOL_GPL(trace_event_raw_init);
 192
 193 void *ftrace_event_buffer_reserve(struct ftrace_event_buffer *fbuffer,
 194                                   struct ftrace_event_file *ftrace_file,
 195                                   unsigned long len)
 196 {
 197         struct ftrace_event_call *event_call = ftrace_file->event_call;
 198
 199         local_save_flags(fbuffer->flags);
 200         fbuffer->pc = preempt_count();
 201         fbuffer->ftrace_file = ftrace_file;
 202
 203         fbuffer->event =
 204                 trace_event_buffer_lock_reserve(&fbuffer->buffer, ftrace_file,
 205                                                 event_call->event.type, len,
 206                                                 fbuffer->flags, fbuffer->pc);
 207         if (!fbuffer->event)
 208                 return NULL;
 209
 210         fbuffer->entry = ring_buffer_event_data(fbuffer->event);
 211         return fbuffer->entry;
 212 }
 213 EXPORT_SYMBOL_GPL(ftrace_event_buffer_reserve);
 214
 215 void ftrace_event_buffer_commit(struct ftrace_event_buffer *fbuffer)
 216 {
 217         event_trigger_unlock_commit(fbuffer->ftrace_file, fbuffer->buffer,
 218                                     fbuffer->event, fbuffer->entry,
 219                                     fbuffer->flags, fbuffer->pc);
 220 }
 221 EXPORT_SYMBOL_GPL(ftrace_event_buffer_commit);
 222
 223 int ftrace_event_reg(struct ftrace_event_call *call,
 224                      enum trace_reg type, void *data)
 225 {
 226         struct ftrace_event_file *file = data;
 227
 228         WARN_ON(!(call->flags & TRACE_EVENT_FL_TRACEPOINT));
 229         switch (type) {
 230         case TRACE_REG_REGISTER:
 231                 return tracepoint_probe_register(call->tp,
 232                                                  call->class->probe,
 233                                                  file);
 234         case TRACE_REG_UNREGISTER:
 235                 tracepoint_probe_unregister(call->tp,
 236                                             call->class->probe,
 237                                             file);
 238                 return 0;
 239
 240 #ifdef CONFIG_PERF_EVENTS
 241         case TRACE_REG_PERF_REGISTER:
 242                 return tracepoint_probe_register(call->tp,
 243                                                  call->class->perf_probe,
 244                                                  call);
 245         case TRACE_REG_PERF_UNREGISTER:
 246                 tracepoint_probe_unregister(call->tp,
 247                                             call->class->perf_probe,
 248                                             call);
 249                 return 0;
 250         case TRACE_REG_PERF_OPEN:
 251         case TRACE_REG_PERF_CLOSE:
 252         case TRACE_REG_PERF_ADD:
 253         case TRACE_REG_PERF_DEL:
 254                 return 0;
 255 #endif
 256         }
 257         return 0;
 258 }
 259 EXPORT_SYMBOL_GPL(ftrace_event_reg);
 260
 261 void trace_event_enable_cmd_record(bool enable)
 262 {
 263         struct ftrace_event_file *file;
 264         struct trace_array *tr;
 265
 266         mutex_lock(&event_mutex);
 267         do_for_each_event_file(tr, file) {
 268
 269                 if (!(file->flags & FTRACE_EVENT_FL_ENABLED))
 270                         continue;
 271
 272                 if (enable) {
 273                         tracing_start_cmdline_record();
 274                         set_bit(FTRACE_EVENT_FL_RECORDED_CMD_BIT, &file->flags);
 275                 } else {
 276                         tracing_stop_cmdline_record();
 277                         clear_bit(FTRACE_EVENT_FL_RECORDED_CMD_BIT, &file->flags);
 278                 }
 279         } while_for_each_event_file();
 280         mutex_unlock(&event_mutex);
 281 }
 282
 283 static int __ftrace_event_enable_disable(struct ftrace_event_file *file,
 284                                          int enable, int soft_disable)
 285 {
 286         struct ftrace_event_call *call = file->event_call;
 287         int ret = 0;
 288         int disable;
 289
 290         switch (enable) {
 291         case 0:
 292                 /*
 293                  * When soft_disable is set and enable is cleared, the sm_ref
 294                  * reference counter is decremented. If it reaches 0, we want
 295                  * to clear the SOFT_DISABLED flag but leave the event in the
 296                  * state that it was. That is, if the event was enabled and
 297                  * SOFT_DISABLED isn't set, then do nothing. But if SOFT_DISABLED
 298                  * is set we do not want the event to be enabled before we
 299                  * clear the bit.
 300                  *
 301                  * When soft_disable is not set but the SOFT_MODE flag is,
 302                  * we do nothing. Do not disable the tracepoint, otherwise
 303                  * "soft enable"s (clearing the SOFT_DISABLED bit) wont work.
 304                  */
 305                 if (soft_disable) {
 306                         if (atomic_dec_return(&file->sm_ref) > 0)
 307                                 break;
 308                         disable = file->flags & FTRACE_EVENT_FL_SOFT_DISABLED;
 309                         clear_bit(FTRACE_EVENT_FL_SOFT_MODE_BIT, &file->flags);
 310                 } else
 311                         disable = !(file->flags & FTRACE_EVENT_FL_SOFT_MODE);
 312
 313                 if (disable && (file->flags & FTRACE_EVENT_FL_ENABLED)) {
 314                         clear_bit(FTRACE_EVENT_FL_ENABLED_BIT, &file->flags);
 315                         if (file->flags & FTRACE_EVENT_FL_RECORDED_CMD) {
 316                                 tracing_stop_cmdline_record();
 317                                 clear_bit(FTRACE_EVENT_FL_RECORDED_CMD_BIT, &file->flags);
 318                         }
 319                         call->class->reg(call, TRACE_REG_UNREGISTER, file);
 320                 }
 321                 /* If in SOFT_MODE, just set the SOFT_DISABLE_BIT, else clear it */
 322                 if (file->flags & FTRACE_EVENT_FL_SOFT_MODE)
 323                         set_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &file->flags);
 324                 else
 325                         clear_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &file->flags);
 326                 break;
 327         case 1:
 328                 /*
 329                  * When soft_disable is set and enable is set, we want to
 330                  * register the tracepoint for the event, but leave the event
 331                  * as is. That means, if the event was already enabled, we do
 332                  * nothing (but set SOFT_MODE). If the event is disabled, we
 333                  * set SOFT_DISABLED before enabling the event tracepoint, so
 334                  * it still seems to be disabled.
 335                  */
 336                 if (!soft_disable)
 337                         clear_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &file->flags);
 338                 else {
 339                         if (atomic_inc_return(&file->sm_ref) > 1)
 340                                 break;
 341                         set_bit(FTRACE_EVENT_FL_SOFT_MODE_BIT, &file->flags);
 342                 }
 343
 344                 if (!(file->flags & FTRACE_EVENT_FL_ENABLED)) {
 345
 346                         /* Keep the event disabled, when going to SOFT_MODE. */
 347                         if (soft_disable)
 348                                 set_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &file->flags);
 349
 350                         if (trace_flags & TRACE_ITER_RECORD_CMD) {
 351                                 tracing_start_cmdline_record();
 352                                 set_bit(FTRACE_EVENT_FL_RECORDED_CMD_BIT, &file->flags);
 353                         }
 354                         ret = call->class->reg(call, TRACE_REG_REGISTER, file);
 355                         if (ret) {
 356                                 tracing_stop_cmdline_record();
 357                                 pr_info("event trace: Could not enable event "
 358                                         "%s\n", ftrace_event_name(call));
 359                                 break;
 360                         }
 361                         set_bit(FTRACE_EVENT_FL_ENABLED_BIT, &file->flags);
 362
 363                         /* WAS_ENABLED gets set but never cleared. */
 364                         call->flags |= TRACE_EVENT_FL_WAS_ENABLED;
 365                 }
 366                 break;
 367         }
 368
 369         return ret;
 370 }
 371
 372 int trace_event_enable_disable(struct ftrace_event_file *file,
 373                                int enable, int soft_disable)
 374 {
 375         return __ftrace_event_enable_disable(file, enable, soft_disable);
 376 }
 377
 378 static int ftrace_event_enable_disable(struct ftrace_event_file *file,
 379                                        int enable)
 380 {
 381         return __ftrace_event_enable_disable(file, enable, 0);
 382 }
 383
 384 static void ftrace_clear_events(struct trace_array *tr)
 385 {
 386         struct ftrace_event_file *file;
 387
 388         mutex_lock(&event_mutex);
 389         list_for_each_entry(file, &tr->events, list) {
 390                 ftrace_event_enable_disable(file, 0);
 391         }
 392         mutex_unlock(&event_mutex);
 393 }
 394
 395 static void __put_system(struct event_subsystem *system)
 396 {
 397         struct event_filter *filter = system->filter;
 398
 399         WARN_ON_ONCE(system_refcount(system) == 0);
 400         if (system_refcount_dec(system))
 401                 return;
 402
 403         list_del(&system->list);
 404
 405         if (filter) {
 406                 kfree(filter->filter_string);
 407                 kfree(filter);
 408         }
 409         if (system->ref_count & SYSTEM_FL_FREE_NAME)
 410                 kfree(system->name);
 411         kfree(system);
 412 }
 413
 414 static void __get_system(struct event_subsystem *system)
 415 {
 416         WARN_ON_ONCE(system_refcount(system) == 0);
 417         system_refcount_inc(system);
 418 }
 419
 420 static void __get_system_dir(struct ftrace_subsystem_dir *dir)
 421 {
 422         WARN_ON_ONCE(dir->ref_count == 0);
 423         dir->ref_count++;
 424         __get_system(dir->subsystem);
 425 }
 426
 427 static void __put_system_dir(struct ftrace_subsystem_dir *dir)
 428 {
 429         WARN_ON_ONCE(dir->ref_count == 0);
 430         /* If the subsystem is about to be freed, the dir must be too */
 431         WARN_ON_ONCE(system_refcount(dir->subsystem) == 1 && dir->ref_count != 1);
 432
 433         __put_system(dir->subsystem);
 434         if (!--dir->ref_count)
 435                 kfree(dir);
 436 }
 437
 438 static void put_system(struct ftrace_subsystem_dir *dir)
 439 {
 440         mutex_lock(&event_mutex);
 441         __put_system_dir(dir);
 442         mutex_unlock(&event_mutex);
 443 }
 444
 445 static void remove_subsystem(struct ftrace_subsystem_dir *dir)
 446 {
 447         if (!dir)
 448                 return;
 449
 450         if (!--dir->nr_events) {
 451                 debugfs_remove_recursive(dir->entry);
 452                 list_del(&dir->list);
 453                 __put_system_dir(dir);
 454         }
 455 }
 456
 457 static void remove_event_file_dir(struct ftrace_event_file *file)
 458 {
 459         struct dentry *dir = file->dir;
 460         struct dentry *child;
 461
 462         if (dir) {
 463                 spin_lock(&dir->d_lock);        /* probably unneeded */
 464                 list_for_each_entry(child, &dir->d_subdirs, d_u.d_child) {
 465                         if (child->d_inode)     /* probably unneeded */
 466                                 child->d_inode->i_private = NULL;
 467                 }
 468                 spin_unlock(&dir->d_lock);
 469
 470                 debugfs_remove_recursive(dir);
 471         }
 472
 473         list_del(&file->list);
 474         remove_subsystem(file->system);
 475         free_event_filter(file->filter);
 476         kmem_cache_free(file_cachep, file);
 477 }
 478
 479 /*
 480  * __ftrace_set_clr_event(NULL, NULL, NULL, set) will set/unset all events.
 481  */
 482 static int
 483 __ftrace_set_clr_event_nolock(struct trace_array *tr, const char *match,
 484                               const char *sub, const char *event, int set)
 485 {
 486         struct ftrace_event_file *file;
 487         struct ftrace_event_call *call;
 488         const char *name;
 489         int ret = -EINVAL;
 490
 491         list_for_each_entry(file, &tr->events, list) {
 492
 493                 call = file->event_call;
 494                 name = ftrace_event_name(call);
 495
 496                 if (!name || !call->class || !call->class->reg)
 497                         continue;
 498
 499                 if (call->flags & TRACE_EVENT_FL_IGNORE_ENABLE)
 500                         continue;
 501
 502                 if (match &&
 503                     strcmp(match, name) != 0 &&
 504                     strcmp(match, call->class->system) != 0)
 505                         continue;
 506
 507                 if (sub && strcmp(sub, call->class->system) != 0)
 508                         continue;
 509
 510                 if (event && strcmp(event, name) != 0)
 511                         continue;
 512
 513                 ftrace_event_enable_disable(file, set);
 514
 515                 ret = 0;
 516         }
 517
 518         return ret;
 519 }
 520
 521 static int __ftrace_set_clr_event(struct trace_array *tr, const char *match,
 522                                   const char *sub, const char *event, int set)
 523 {
 524         int ret;
 525
 526         mutex_lock(&event_mutex);
 527         ret = __ftrace_set_clr_event_nolock(tr, match, sub, event, set);
 528         mutex_unlock(&event_mutex);
 529
 530         return ret;
 531 }
 532
 533 static int ftrace_set_clr_event(struct trace_array *tr, char *buf, int set)
 534 {
 535         char *event = NULL, *sub = NULL, *match;
 536
 537         /*
 538          * The buf format can be <subsystem>:<event-name>
 539          *  *:<event-name> means any event by that name.
 540          *  :<event-name> is the same.
 541          *
 542          *  <subsystem>:* means all events in that subsystem
 543          *  <subsystem>: means the same.
 544          *
 545          *  <name> (no ':') means all events in a subsystem with
 546          *  the name <name> or any event that matches <name>
 547          */
 548
 549         match = strsep(&buf, ":");
 550         if (buf) {
 551                 sub = match;
 552                 event = buf;
 553                 match = NULL;
 554
 555                 if (!strlen(sub) || strcmp(sub, "*") == 0)
 556                         sub = NULL;
 557                 if (!strlen(event) || strcmp(event, "*") == 0)
 558                         event = NULL;
 559         }
 560
 561         return __ftrace_set_clr_event(tr, match, sub, event, set);
 562 }
 563
 564 /**
 565  * trace_set_clr_event - enable or disable an event
 566  * @system: system name to match (NULL for any system)
 567  * @event: event name to match (NULL for all events, within system)
 568  * @set: 1 to enable, 0 to disable
 569  *
 570  * This is a way for other parts of the kernel to enable or disable
 571  * event recording.
 572  *
 573  * Returns 0 on success, -EINVAL if the parameters do not match any
 574  * registered events.
 575  */
 576 int trace_set_clr_event(const char *system, const char *event, int set)
 577 {
 578         struct trace_array *tr = top_trace_array();
 579
 580         if (!tr)
 581                 return -ENODEV;
 582
 583         return __ftrace_set_clr_event(tr, NULL, system, event, set);
 584 }
 585 EXPORT_SYMBOL_GPL(trace_set_clr_event);
 586
 587 /* 128 should be much more than enough */
 588 #define EVENT_BUF_SIZE          127
 589
 590 static ssize_t
 591 ftrace_event_write(struct file *file, const char __user *ubuf,
 592                    size_t cnt, loff_t *ppos)
 593 {
 594         struct trace_parser parser;
 595         struct seq_file *m = file->private_data;
 596         struct trace_array *tr = m->private;
 597         ssize_t read, ret;
 598
 599         if (!cnt)
 600                 return 0;
 601
 602         ret = tracing_update_buffers();
 603         if (ret < 0)
 604                 return ret;
 605
 606         if (trace_parser_get_init(&parser, EVENT_BUF_SIZE + 1))
 607                 return -ENOMEM;
 608
 609         read = trace_get_user(&parser, ubuf, cnt, ppos);
 610
 611         if (read >= 0 && trace_parser_loaded((&parser))) {
 612                 int set = 1;
 613
 614                 if (*parser.buffer == '!')
 615                         set = 0;
 616
 617                 parser.buffer[parser.idx] = 0;
 618
 619                 ret = ftrace_set_clr_event(tr, parser.buffer + !set, set);
 620                 if (ret)
 621                         goto out_put;
 622         }
 623
 624         ret = read;
 625
 626  out_put:
 627         trace_parser_put(&parser);
 628
 629         return ret;
 630 }
 631
 632 static void *
 633 t_next(struct seq_file *m, void *v, loff_t *pos)
 634 {
 635         struct ftrace_event_file *file = v;
 636         struct ftrace_event_call *call;
 637         struct trace_array *tr = m->private;
 638
 639         (*pos)++;
 640
 641         list_for_each_entry_continue(file, &tr->events, list) {
 642                 call = file->event_call;
 643                 /*
 644                  * The ftrace subsystem is for showing formats only.
 645                  * They can not be enabled or disabled via the event files.
 646                  */
 647                 if (call->class && call->class->reg)
 648                         return file;
 649         }
 650
 651         return NULL;
 652 }
 653
 654 static void *t_start(struct seq_file *m, loff_t *pos)
 655 {
 656         struct ftrace_event_file *file;
 657         struct trace_array *tr = m->private;
 658         loff_t l;
 659
 660         mutex_lock(&event_mutex);
 661
 662         file = list_entry(&tr->events, struct ftrace_event_file, list);
 663         for (l = 0; l <= *pos; ) {
 664                 file = t_next(m, file, &l);
 665                 if (!file)
 666                         break;
 667         }
 668         return file;
 669 }
 670
 671 static void *
 672 s_next(struct seq_file *m, void *v, loff_t *pos)
 673 {
 674         struct ftrace_event_file *file = v;
 675         struct trace_array *tr = m->private;
 676
 677         (*pos)++;
 678
 679         list_for_each_entry_continue(file, &tr->events, list) {
 680                 if (file->flags & FTRACE_EVENT_FL_ENABLED)
 681                         return file;
 682         }
 683
 684         return NULL;
 685 }
 686
 687 static void *s_start(struct seq_file *m, loff_t *pos)
 688 {
 689         struct ftrace_event_file *file;
 690         struct trace_array *tr = m->private;
 691         loff_t l;
 692
 693         mutex_lock(&event_mutex);
 694
 695         file = list_entry(&tr->events, struct ftrace_event_file, list);
 696         for (l = 0; l <= *pos; ) {
 697                 file = s_next(m, file, &l);
 698                 if (!file)
 699                         break;
 700         }
 701         return file;
 702 }
 703
 704 static int t_show(struct seq_file *m, void *v)
 705 {
 706         struct ftrace_event_file *file = v;
 707         struct ftrace_event_call *call = file->event_call;
 708
 709         if (strcmp(call->class->system, TRACE_SYSTEM) != 0)
 710                 seq_printf(m, "%s:", call->class->system);
 711         seq_printf(m, "%s\n", ftrace_event_name(call));
 712
 713         return 0;
 714 }
 715
 716 static void t_stop(struct seq_file *m, void *p)
 717 {
 718         mutex_unlock(&event_mutex);
 719 }
 720
 721 static ssize_t
 722 event_enable_read(struct file *filp, char __user *ubuf, size_t cnt,
 723                   loff_t *ppos)
 724 {
 725         struct ftrace_event_file *file;
 726         unsigned long flags;
 727         char buf[4] = "0";
 728
 729         mutex_lock(&event_mutex);
 730         file = event_file_data(filp);
 731         if (likely(file))
 732                 flags = file->flags;
 733         mutex_unlock(&event_mutex);
 734
 735         if (!file)
 736                 return -ENODEV;
 737
 738         if (flags & FTRACE_EVENT_FL_ENABLED &&
 739             !(flags & FTRACE_EVENT_FL_SOFT_DISABLED))
 740                 strcpy(buf, "1");
 741
 742         if (flags & FTRACE_EVENT_FL_SOFT_DISABLED ||
 743             flags & FTRACE_EVENT_FL_SOFT_MODE)
 744                 strcat(buf, "*");
 745
 746         strcat(buf, "\n");
 747
 748         return simple_read_from_buffer(ubuf, cnt, ppos, buf, strlen(buf));
 749 }
 750
 751 static ssize_t
 752 event_enable_write(struct file *filp, const char __user *ubuf, size_t cnt,
 753                    loff_t *ppos)
 754 {
 755         struct ftrace_event_file *file;
 756         unsigned long val;
 757         int ret;
 758
 759         ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
 760         if (ret)
 761                 return ret;
 762
 763         ret = tracing_update_buffers();
 764         if (ret < 0)
 765                 return ret;
 766
 767         switch (val) {
 768         case 0:
 769         case 1:
 770                 ret = -ENODEV;
 771                 mutex_lock(&event_mutex);
 772                 file = event_file_data(filp);
 773                 if (likely(file))
 774                         ret = ftrace_event_enable_disable(file, val);
 775                 mutex_unlock(&event_mutex);
 776                 break;
 777
 778         default:
 779                 return -EINVAL;
 780         }
 781
 782         *ppos += cnt;
 783
 784         return ret ? ret : cnt;
 785 }
 786
 787 static ssize_t
 788 system_enable_read(struct file *filp, char __user *ubuf, size_t cnt,
 789                    loff_t *ppos)
 790 {
 791         const char set_to_char[4] = { '?', '0', '1', 'X' };
 792         struct ftrace_subsystem_dir *dir = filp->private_data;
 793         struct event_subsystem *system = dir->subsystem;
 794         struct ftrace_event_call *call;
 795         struct ftrace_event_file *file;
 796         struct trace_array *tr = dir->tr;
 797         char buf[2];
 798         int set = 0;
 799         int ret;
 800
 801         mutex_lock(&event_mutex);
 802         list_for_each_entry(file, &tr->events, list) {
 803                 call = file->event_call;
 804                 if (!ftrace_event_name(call) || !call->class || !call->class->reg)
 805                         continue;
 806
 807                 if (system && strcmp(call->class->system, system->name) != 0)
 808                         continue;
 809
 810                 /*
 811                  * We need to find out if all the events are set
 812                  * or if all events or cleared, or if we have
 813                  * a mixture.
 814                  */
 815                 set |= (1 << !!(file->flags & FTRACE_EVENT_FL_ENABLED));
 816
 817                 /*
 818                  * If we have a mixture, no need to look further.
 819                  */
 820                 if (set == 3)
 821                         break;
 822         }
 823         mutex_unlock(&event_mutex);
 824
 825         buf[0] = set_to_char[set];
 826         buf[1] = '\n';
 827
 828         ret = simple_read_from_buffer(ubuf, cnt, ppos, buf, 2);
 829
 830         return ret;
 831 }
 832
 833 static ssize_t
 834 system_enable_write(struct file *filp, const char __user *ubuf, size_t cnt,
 835                     loff_t *ppos)
 836 {
 837         struct ftrace_subsystem_dir *dir = filp->private_data;
 838         struct event_subsystem *system = dir->subsystem;
 839         const char *name = NULL;
 840         unsigned long val;
 841         ssize_t ret;
 842
 843         ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
 844         if (ret)
 845                 return ret;
 846
 847         ret = tracing_update_buffers();
 848         if (ret < 0)
 849                 return ret;
 850
 851         if (val != 0 && val != 1)
 852                 return -EINVAL;
 853
 854         /*
 855          * Opening of "enable" adds a ref count to system,
 856          * so the name is safe to use.
 857          */
 858         if (system)
 859                 name = system->name;
 860
 861         ret = __ftrace_set_clr_event(dir->tr, NULL, name, NULL, val);
 862         if (ret)
 863                 goto out;
 864
 865         ret = cnt;
 866
 867 out:
 868         *ppos += cnt;
 869
 870         return ret;
 871 }
 872
 873 enum {
 874         FORMAT_HEADER           = 1,
 875         FORMAT_FIELD_SEPERATOR  = 2,
 876         FORMAT_PRINTFMT         = 3,
 877 };
 878
 879 static void *f_next(struct seq_file *m, void *v, loff_t *pos)
 880 {
 881         struct ftrace_event_call *call = event_file_data(m->private);
 882         struct list_head *common_head = &ftrace_common_fields;
 883         struct list_head *head = trace_get_fields(call);
 884         struct list_head *node = v;
 885
 886         (*pos)++;
 887
 888         switch ((unsigned long)v) {
 889         case FORMAT_HEADER:
 890                 node = common_head;
 891                 break;
 892
 893         case FORMAT_FIELD_SEPERATOR:
 894                 node = head;
 895                 break;
 896
 897         case FORMAT_PRINTFMT:
 898                 /* all done */
 899                 return NULL;
 900         }
 901
 902         node = node->prev;
 903         if (node == common_head)
 904                 return (void *)FORMAT_FIELD_SEPERATOR;
 905         else if (node == head)
 906                 return (void *)FORMAT_PRINTFMT;
 907         else
 908                 return node;
 909 }
 910
 911 static int f_show(struct seq_file *m, void *v)
 912 {
 913         struct ftrace_event_call *call = event_file_data(m->private);
 914         struct ftrace_event_field *field;
 915         const char *array_descriptor;
 916
 917         switch ((unsigned long)v) {
 918         case FORMAT_HEADER:
 919                 seq_printf(m, "name: %s\n", ftrace_event_name(call));
 920                 seq_printf(m, "ID: %d\n", call->event.type);
 921                 seq_puts(m, "format:\n");
 922                 return 0;
 923
 924         case FORMAT_FIELD_SEPERATOR:
 925                 seq_putc(m, '\n');
 926                 return 0;
 927
 928         case FORMAT_PRINTFMT:
 929                 seq_printf(m, "\nprint fmt: %s\n",
 930                            call->print_fmt);
 931                 return 0;
 932         }
 933
 934         field = list_entry(v, struct ftrace_event_field, link);
 935         /*
 936          * Smartly shows the array type(except dynamic array).
 937          * Normal:
 938          *      field:TYPE VAR
 939          * If TYPE := TYPE[LEN], it is shown:
 940          *      field:TYPE VAR[LEN]
 941          */
 942         array_descriptor = strchr(field->type, '[');
 943
 944         if (!strncmp(field->type, "__data_loc", 10))
 945                 array_descriptor = NULL;
 946
 947         if (!array_descriptor)
 948                 seq_printf(m, "\tfield:%s %s;\toffset:%u;\tsize:%u;\tsigned:%d;\n",
 949                            field->type, field->name, field->offset,
 950                            field->size, !!field->is_signed);
 951         else
 952                 seq_printf(m, "\tfield:%.*s %s%s;\toffset:%u;\tsize:%u;\tsigned:%d;\n",
 953                            (int)(array_descriptor - field->type),
 954                            field->type, field->name,
 955                            array_descriptor, field->offset,
 956                            field->size, !!field->is_signed);
 957
 958         return 0;
 959 }
 960
 961 static void *f_start(struct seq_file *m, loff_t *pos)
 962 {
 963         void *p = (void *)FORMAT_HEADER;
 964         loff_t l = 0;
 965
 966         /* ->stop() is called even if ->start() fails */
 967         mutex_lock(&event_mutex);
 968         if (!event_file_data(m->private))
 969                 return ERR_PTR(-ENODEV);
 970
 971         while (l < *pos && p)
 972                 p = f_next(m, p, &l);
 973
 974         return p;
 975 }
 976
 977 static void f_stop(struct seq_file *m, void *p)
 978 {
 979         mutex_unlock(&event_mutex);
 980 }
 981
 982 static const struct seq_operations trace_format_seq_ops = {
 983         .start          = f_start,
 984         .next           = f_next,
 985         .stop           = f_stop,
 986         .show           = f_show,
 987 };
 988
 989 static int trace_format_open(struct inode *inode, struct file *file)
 990 {
 991         struct seq_file *m;
 992         int ret;
 993
 994         ret = seq_open(file, &trace_format_seq_ops);
 995         if (ret < 0)
 996                 return ret;
 997
 998         m = file->private_data;
 999         m->private = file;
1000
1001         return 0;
1002 }
1003
1004 static ssize_t
1005 event_id_read(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos)
1006 {
1007         int id = (long)event_file_data(filp);
1008         char buf[32];
1009         int len;
1010
1011         if (*ppos)
1012                 return 0;
1013
1014         if (unlikely(!id))
1015                 return -ENODEV;
1016
1017         len = sprintf(buf, "%d\n", id);
1018
1019         return simple_read_from_buffer(ubuf, cnt, ppos, buf, len);
1020 }
1021
1022 static ssize_t
1023 event_filter_read(struct file *filp, char __user *ubuf, size_t cnt,
1024                   loff_t *ppos)
1025 {
1026         struct ftrace_event_file *file;
1027         struct trace_seq *s;
1028         int r = -ENODEV;
1029
1030         if (*ppos)
1031                 return 0;
1032
1033         s = kmalloc(sizeof(*s), GFP_KERNEL);
1034
1035         if (!s)
1036                 return -ENOMEM;
1037
1038         trace_seq_init(s);
1039
1040         mutex_lock(&event_mutex);
1041         file = event_file_data(filp);
1042         if (file)
1043                 print_event_filter(file, s);
1044         mutex_unlock(&event_mutex);
1045
1046         if (file)
1047                 r = simple_read_from_buffer(ubuf, cnt, ppos, s->buffer, s->len);
1048
1049         kfree(s);
1050
1051         return r;
1052 }
1053
1054 static ssize_t
1055 event_filter_write(struct file *filp, const char __user *ubuf, size_t cnt,
1056                    loff_t *ppos)
1057 {
1058         struct ftrace_event_file *file;
1059         char *buf;
1060         int err = -ENODEV;
1061
1062         if (cnt >= PAGE_SIZE)
1063                 return -EINVAL;
1064
1065         buf = (char *)__get_free_page(GFP_TEMPORARY);
1066         if (!buf)
1067                 return -ENOMEM;
1068
1069         if (copy_from_user(buf, ubuf, cnt)) {
1070                 free_page((unsigned long) buf);
1071                 return -EFAULT;
1072         }
1073         buf[cnt] = '\0';
1074
1075         mutex_lock(&event_mutex);
1076         file = event_file_data(filp);
1077         if (file)
1078                 err = apply_event_filter(file, buf);
1079         mutex_unlock(&event_mutex);
1080
1081         free_page((unsigned long) buf);
1082         if (err < 0)
1083                 return err;
1084
1085         *ppos += cnt;
1086
1087         return cnt;
1088 }
1089
1090 static LIST_HEAD(event_subsystems);
1091
1092 static int subsystem_open(struct inode *inode, struct file *filp)
1093 {
1094         struct event_subsystem *system = NULL;
1095         struct ftrace_subsystem_dir *dir = NULL; /* Initialize for gcc */
1096         struct trace_array *tr;
1097         int ret;
1098
1099         if (tracing_is_disabled())
1100                 return -ENODEV;
1101
1102         /* Make sure the system still exists */
1103         mutex_lock(&trace_types_lock);
1104         mutex_lock(&event_mutex);
1105         list_for_each_entry(tr, &ftrace_trace_arrays, list) {
1106                 list_for_each_entry(dir, &tr->systems, list) {
1107                         if (dir == inode->i_private) {
1108                                 /* Don't open systems with no events */
1109                                 if (dir->nr_events) {
1110                                         __get_system_dir(dir);
1111                                         system = dir->subsystem;
1112                                 }
1113                                 goto exit_loop;
1114                         }
1115                 }
1116         }
1117  exit_loop:
1118         mutex_unlock(&event_mutex);
1119         mutex_unlock(&trace_types_lock);
1120
1121         if (!system)
1122                 return -ENODEV;
1123
1124         /* Some versions of gcc think dir can be uninitialized here */
1125         WARN_ON(!dir);
1126
1127         /* Still need to increment the ref count of the system */
1128         if (trace_array_get(tr) < 0) {
1129                 put_system(dir);
1130                 return -ENODEV;
1131         }
1132
1133         ret = tracing_open_generic(inode, filp);
1134         if (ret < 0) {
1135                 trace_array_put(tr);
1136                 put_system(dir);
1137         }
1138
1139         return ret;
1140 }
1141
1142 static int system_tr_open(struct inode *inode, struct file *filp)
1143 {
1144         struct ftrace_subsystem_dir *dir;
1145         struct trace_array *tr = inode->i_private;
1146         int ret;
1147
1148         if (tracing_is_disabled())
1149                 return -ENODEV;
1150
1151         if (trace_array_get(tr) < 0)
1152                 return -ENODEV;
1153
1154         /* Make a temporary dir that has no system but points to tr */
1155         dir = kzalloc(sizeof(*dir), GFP_KERNEL);
1156         if (!dir) {
1157                 trace_array_put(tr);
1158                 return -ENOMEM;
1159         }
1160
1161         dir->tr = tr;
1162
1163         ret = tracing_open_generic(inode, filp);
1164         if (ret < 0) {
1165                 trace_array_put(tr);
1166                 kfree(dir);
1167                 return ret;
1168         }
1169
1170         filp->private_data = dir;
1171
1172         return 0;
1173 }
1174
1175 static int subsystem_release(struct inode *inode, struct file *file)
1176 {
1177         struct ftrace_subsystem_dir *dir = file->private_data;
1178
1179         trace_array_put(dir->tr);
1180
1181         /*
1182          * If dir->subsystem is NULL, then this is a temporary
1183          * descriptor that was made for a trace_array to enable
1184          * all subsystems.
1185          */
1186         if (dir->subsystem)
1187                 put_system(dir);
1188         else
1189                 kfree(dir);
1190
1191         return 0;
1192 }
1193
1194 static ssize_t
1195 subsystem_filter_read(struct file *filp, char __user *ubuf, size_t cnt,
1196                       loff_t *ppos)
1197 {
1198         struct ftrace_subsystem_dir *dir = filp->private_data;
1199         struct event_subsystem *system = dir->subsystem;
1200         struct trace_seq *s;
1201         int r;
1202
1203         if (*ppos)
1204                 return 0;
1205
1206         s = kmalloc(sizeof(*s), GFP_KERNEL);
1207         if (!s)
1208                 return -ENOMEM;
1209
1210         trace_seq_init(s);
1211
1212         print_subsystem_event_filter(system, s);
1213         r = simple_read_from_buffer(ubuf, cnt, ppos, s->buffer, s->len);
1214
1215         kfree(s);
1216
1217         return r;
1218 }
1219
1220 static ssize_t
1221 subsystem_filter_write(struct file *filp, const char __user *ubuf, size_t cnt,
1222                        loff_t *ppos)
1223 {
1224         struct ftrace_subsystem_dir *dir = filp->private_data;
1225         char *buf;
1226         int err;
1227
1228         if (cnt >= PAGE_SIZE)
1229                 return -EINVAL;
1230
1231         buf = (char *)__get_free_page(GFP_TEMPORARY);
1232         if (!buf)
1233                 return -ENOMEM;
1234
1235         if (copy_from_user(buf, ubuf, cnt)) {
1236                 free_page((unsigned long) buf);
1237                 return -EFAULT;
1238         }
1239         buf[cnt] = '\0';
1240
1241         err = apply_subsystem_event_filter(dir, buf);
1242         free_page((unsigned long) buf);
1243         if (err < 0)
1244                 return err;
1245
1246         *ppos += cnt;
1247
1248         return cnt;
1249 }
1250
1251 static ssize_t
1252 show_header(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos)
1253 {
1254         int (*func)(struct trace_seq *s) = filp->private_data;
1255         struct trace_seq *s;
1256         int r;
1257
1258         if (*ppos)
1259                 return 0;
1260
1261         s = kmalloc(sizeof(*s), GFP_KERNEL);
1262         if (!s)
1263                 return -ENOMEM;
1264
1265         trace_seq_init(s);
1266
1267         func(s);
1268         r = simple_read_from_buffer(ubuf, cnt, ppos, s->buffer, s->len);
1269
1270         kfree(s);
1271
1272         return r;
1273 }
1274
1275 static int ftrace_event_avail_open(struct inode *inode, struct file *file);
1276 static int ftrace_event_set_open(struct inode *inode, struct file *file);
1277 static int ftrace_event_release(struct inode *inode, struct file *file);
1278
1279 static const struct seq_operations show_event_seq_ops = {
1280         .start = t_start,
1281         .next = t_next,
1282         .show = t_show,
1283         .stop = t_stop,
1284 };
1285
1286 static const struct seq_operations show_set_event_seq_ops = {
1287         .start = s_start,
1288         .next = s_next,
1289         .show = t_show,
1290         .stop = t_stop,
1291 };
1292
1293 static const struct file_operations ftrace_avail_fops = {
1294         .open = ftrace_event_avail_open,
1295         .read = seq_read,
1296         .llseek = seq_lseek,
1297         .release = seq_release,
1298 };
1299
1300 static const struct file_operations ftrace_set_event_fops = {
1301         .open = ftrace_event_set_open,
1302         .read = seq_read,
1303         .write = ftrace_event_write,
1304         .llseek = seq_lseek,
1305         .release = ftrace_event_release,
1306 };
1307
1308 static const struct file_operations ftrace_enable_fops = {
1309         .open = tracing_open_generic,
1310         .read = event_enable_read,
1311         .write = event_enable_write,
1312         .llseek = default_llseek,
1313 };
1314
1315 static const struct file_operations ftrace_event_format_fops = {
1316         .open = trace_format_open,
1317         .read = seq_read,
1318         .llseek = seq_lseek,
1319         .release = seq_release,
1320 };
1321
1322 static const struct file_operations ftrace_event_id_fops = {
1323         .read = event_id_read,
1324         .llseek = default_llseek,
1325 };
1326
1327 static const struct file_operations ftrace_event_filter_fops = {
1328         .open = tracing_open_generic,
1329         .read = event_filter_read,
1330         .write = event_filter_write,
1331         .llseek = default_llseek,
1332 };
1333
1334 static const struct file_operations ftrace_subsystem_filter_fops = {
1335         .open = subsystem_open,
1336         .read = subsystem_filter_read,
1337         .write = subsystem_filter_write,
1338         .llseek = default_llseek,
1339         .release = subsystem_release,
1340 };
1341
1342 static const struct file_operations ftrace_system_enable_fops = {
1343         .open = subsystem_open,
1344         .read = system_enable_read,
1345         .write = system_enable_write,
1346         .llseek = default_llseek,
1347         .release = subsystem_release,
1348 };
1349
1350 static const struct file_operations ftrace_tr_enable_fops = {
1351         .open = system_tr_open,
1352         .read = system_enable_read,
1353         .write = system_enable_write,
1354         .llseek = default_llseek,
1355         .release = subsystem_release,
1356 };
1357
1358 static const struct file_operations ftrace_show_header_fops = {
1359         .open = tracing_open_generic,
1360         .read = show_header,
1361         .llseek = default_llseek,
1362 };
1363
1364 static int
1365 ftrace_event_open(struct inode *inode, struct file *file,
1366                   const struct seq_operations *seq_ops)
1367 {
1368         struct seq_file *m;
1369         int ret;
1370
1371         ret = seq_open(file, seq_ops);
1372         if (ret < 0)
1373                 return ret;
1374         m = file->private_data;
1375         /* copy tr over to seq ops */
1376         m->private = inode->i_private;
1377
1378         return ret;
1379 }
1380
1381 static int ftrace_event_release(struct inode *inode, struct file *file)
1382 {
1383         struct trace_array *tr = inode->i_private;
1384
1385         trace_array_put(tr);
1386
1387         return seq_release(inode, file);
1388 }
1389
1390 static int
1391 ftrace_event_avail_open(struct inode *inode, struct file *file)
1392 {
1393         const struct seq_operations *seq_ops = &show_event_seq_ops;
1394
1395         return ftrace_event_open(inode, file, seq_ops);
1396 }
1397
1398 static int
1399 ftrace_event_set_open(struct inode *inode, struct file *file)
1400 {
1401         const struct seq_operations *seq_ops = &show_set_event_seq_ops;
1402         struct trace_array *tr = inode->i_private;
1403         int ret;
1404
1405         if (trace_array_get(tr) < 0)
1406                 return -ENODEV;
1407
1408         if ((file->f_mode & FMODE_WRITE) &&
1409             (file->f_flags & O_TRUNC))
1410                 ftrace_clear_events(tr);
1411
1412         ret = ftrace_event_open(inode, file, seq_ops);
1413         if (ret < 0)
1414                 trace_array_put(tr);
1415         return ret;
1416 }
1417
1418 static struct event_subsystem *
1419 create_new_subsystem(const char *name)
1420 {
1421         struct event_subsystem *system;
1422
1423         /* need to create new entry */
1424         system = kmalloc(sizeof(*system), GFP_KERNEL);
1425         if (!system)
1426                 return NULL;
1427
1428         system->ref_count = 1;
1429
1430         /* Only allocate if dynamic (kprobes and modules) */
1431         if (!core_kernel_data((unsigned long)name)) {
1432                 system->ref_count |= SYSTEM_FL_FREE_NAME;
1433                 system->name = kstrdup(name, GFP_KERNEL);
1434                 if (!system->name)
1435                         goto out_free;
1436         } else
1437                 system->name = name;
1438
1439         system->filter = NULL;
1440
1441         system->filter = kzalloc(sizeof(struct event_filter), GFP_KERNEL);
1442         if (!system->filter)
1443                 goto out_free;
1444
1445         list_add(&system->list, &event_subsystems);
1446
1447         return system;
1448
1449  out_free:
1450         if (system->ref_count & SYSTEM_FL_FREE_NAME)
1451                 kfree(system->name);
1452         kfree(system);
1453         return NULL;
1454 }
1455
1456 static struct dentry *
1457 event_subsystem_dir(struct trace_array *tr, const char *name,
1458                     struct ftrace_event_file *file, struct dentry *parent)
1459 {
1460         struct ftrace_subsystem_dir *dir;
1461         struct event_subsystem *system;
1462         struct dentry *entry;
1463
1464         /* First see if we did not already create this dir */
1465         list_for_each_entry(dir, &tr->systems, list) {
1466                 system = dir->subsystem;
1467                 if (strcmp(system->name, name) == 0) {
1468                         dir->nr_events++;
1469                         file->system = dir;
1470                         return dir->entry;
1471                 }
1472         }
1473
1474         /* Now see if the system itself exists. */
1475         list_for_each_entry(system, &event_subsystems, list) {
1476                 if (strcmp(system->name, name) == 0)
1477                         break;
1478         }
1479         /* Reset system variable when not found */
1480         if (&system->list == &event_subsystems)
1481                 system = NULL;
1482
1483         dir = kmalloc(sizeof(*dir), GFP_KERNEL);
1484         if (!dir)
1485                 goto out_fail;
1486
1487         if (!system) {
1488                 system = create_new_subsystem(name);
1489                 if (!system)
1490                         goto out_free;
1491         } else
1492                 __get_system(system);
1493
1494         dir->entry = debugfs_create_dir(name, parent);
1495         if (!dir->entry) {
1496                 pr_warn("Failed to create system directory %s\n", name);
1497                 __put_system(system);
1498                 goto out_free;
1499         }
1500
1501         dir->tr = tr;
1502         dir->ref_count = 1;
1503         dir->nr_events = 1;
1504         dir->subsystem = system;
1505         file->system = dir;
1506
1507         entry = debugfs_create_file("filter", 0644, dir->entry, dir,
1508                                     &ftrace_subsystem_filter_fops);
1509         if (!entry) {
1510                 kfree(system->filter);
1511                 system->filter = NULL;
1512                 pr_warn("Could not create debugfs '%s/filter' entry\n", name);
1513         }
1514
1515         trace_create_file("enable", 0644, dir->entry, dir,
1516                           &ftrace_system_enable_fops);
1517
1518         list_add(&dir->list, &tr->systems);
1519
1520         return dir->entry;
1521
1522  out_free:
1523         kfree(dir);
1524  out_fail:
1525         /* Only print this message if failed on memory allocation */
1526         if (!dir || !system)
1527                 pr_warn("No memory to create event subsystem %s\n", name);
1528         return NULL;
1529 }
1530
1531 static int
1532 event_create_dir(struct dentry *parent, struct ftrace_event_file *file)
1533 {
1534         struct ftrace_event_call *call = file->event_call;
1535         struct trace_array *tr = file->tr;
1536         struct list_head *head;
1537         struct dentry *d_events;
1538         const char *name;
1539         int ret;
1540
1541         /*
1542          * If the trace point header did not define TRACE_SYSTEM
1543          * then the system would be called "TRACE_SYSTEM".
1544          */
1545         if (strcmp(call->class->system, TRACE_SYSTEM) != 0) {
1546                 d_events = event_subsystem_dir(tr, call->class->system, file, parent);
1547                 if (!d_events)
1548                         return -ENOMEM;
1549         } else
1550                 d_events = parent;
1551
1552         name = ftrace_event_name(call);
1553         file->dir = debugfs_create_dir(name, d_events);
1554         if (!file->dir) {
1555                 pr_warn("Could not create debugfs '%s' directory\n", name);
1556                 return -1;
1557         }
1558
1559         if (call->class->reg && !(call->flags & TRACE_EVENT_FL_IGNORE_ENABLE))
1560                 trace_create_file("enable", 0644, file->dir, file,
1561                                   &ftrace_enable_fops);
1562
1563 #ifdef CONFIG_PERF_EVENTS
1564         if (call->event.type && call->class->reg)
1565                 trace_create_file("id", 0444, file->dir,
1566                                   (void *)(long)call->event.type,
1567                                   &ftrace_event_id_fops);
1568 #endif
1569
1570         /*
1571          * Other events may have the same class. Only update
1572          * the fields if they are not already defined.
1573          */
1574         head = trace_get_fields(call);
1575         if (list_empty(head)) {
1576                 ret = call->class->define_fields(call);
1577                 if (ret < 0) {
1578                         pr_warn("Could not initialize trace point events/%s\n",
1579                                 name);
1580                         return -1;
1581                 }
1582         }
1583         trace_create_file("filter", 0644, file->dir, file,
1584                           &ftrace_event_filter_fops);
1585
1586         trace_create_file("trigger", 0644, file->dir, file,
1587                           &event_trigger_fops);
1588
1589         trace_create_file("format", 0444, file->dir, call,
1590                           &ftrace_event_format_fops);
1591
1592         return 0;
1593 }
1594
1595 static void remove_event_from_tracers(struct ftrace_event_call *call)
1596 {
1597         struct ftrace_event_file *file;
1598         struct trace_array *tr;
1599
1600         do_for_each_event_file_safe(tr, file) {
1601                 if (file->event_call != call)
1602                         continue;
1603
1604                 remove_event_file_dir(file);
1605                 /*
1606                  * The do_for_each_event_file_safe() is
1607                  * a double loop. After finding the call for this
1608                  * trace_array, we use break to jump to the next
1609                  * trace_array.
1610                  */
1611                 break;
1612         } while_for_each_event_file();
1613 }
1614
1615 static void event_remove(struct ftrace_event_call *call)
1616 {
1617         struct trace_array *tr;
1618         struct ftrace_event_file *file;
1619
1620         do_for_each_event_file(tr, file) {
1621                 if (file->event_call != call)
1622                         continue;
1623                 ftrace_event_enable_disable(file, 0);
1624                 /*
1625                  * The do_for_each_event_file() is
1626                  * a double loop. After finding the call for this
1627                  * trace_array, we use break to jump to the next
1628                  * trace_array.
1629                  */
1630                 break;
1631         } while_for_each_event_file();
1632
1633         if (call->event.funcs)
1634                 __unregister_ftrace_event(&call->event);
1635         remove_event_from_tracers(call);
1636         list_del(&call->list);
1637 }
1638
1639 static int event_init(struct ftrace_event_call *call)
1640 {
1641         int ret = 0;
1642         const char *name;
1643
1644         name = ftrace_event_name(call);
1645         if (WARN_ON(!name))
1646                 return -EINVAL;
1647
1648         if (call->class->raw_init) {
1649                 ret = call->class->raw_init(call);
1650                 if (ret < 0 && ret != -ENOSYS)
1651                         pr_warn("Could not initialize trace events/%s\n", name);
1652         }
1653
1654         return ret;
1655 }
1656
1657 static int
1658 __register_event(struct ftrace_event_call *call, struct module *mod)
1659 {
1660         int ret;
1661
1662         ret = event_init(call);
1663         if (ret < 0)
1664                 return ret;
1665
1666         list_add(&call->list, &ftrace_events);
1667         call->mod = mod;
1668
1669         return 0;
1670 }
1671
1672 static struct ftrace_event_file *
1673 trace_create_new_event(struct ftrace_event_call *call,
1674                        struct trace_array *tr)
1675 {
1676         struct ftrace_event_file *file;
1677
1678         file = kmem_cache_alloc(file_cachep, GFP_TRACE);
1679         if (!file)
1680                 return NULL;
1681
1682         file->event_call = call;
1683         file->tr = tr;
1684         atomic_set(&file->sm_ref, 0);
1685         atomic_set(&file->tm_ref, 0);
1686         INIT_LIST_HEAD(&file->triggers);
1687         list_add(&file->list, &tr->events);
1688
1689         return file;
1690 }
1691
1692 /* Add an event to a trace directory */
1693 static int
1694 __trace_add_new_event(struct ftrace_event_call *call, struct trace_array *tr)
1695 {
1696         struct ftrace_event_file *file;
1697
1698         file = trace_create_new_event(call, tr);
1699         if (!file)
1700                 return -ENOMEM;
1701
1702         return event_create_dir(tr->event_dir, file);
1703 }
1704
1705 /*
1706  * Just create a decriptor for early init. A descriptor is required
1707  * for enabling events at boot. We want to enable events before
1708  * the filesystem is initialized.
1709  */
1710 static __init int
1711 __trace_early_add_new_event(struct ftrace_event_call *call,
1712                             struct trace_array *tr)
1713 {
1714         struct ftrace_event_file *file;
1715
1716         file = trace_create_new_event(call, tr);
1717         if (!file)
1718                 return -ENOMEM;
1719
1720         return 0;
1721 }
1722
1723 struct ftrace_module_file_ops;
1724 static void __add_event_to_tracers(struct ftrace_event_call *call);
1725
1726 /* Add an additional event_call dynamically */
1727 int trace_add_event_call(struct ftrace_event_call *call)
1728 {
1729         int ret;
1730         mutex_lock(&trace_types_lock);
1731         mutex_lock(&event_mutex);
1732
1733         ret = __register_event(call, NULL);
1734         if (ret >= 0)
1735                 __add_event_to_tracers(call);
1736
1737         mutex_unlock(&event_mutex);
1738         mutex_unlock(&trace_types_lock);
1739         return ret;
1740 }
1741
1742 /*
1743  * Must be called under locking of trace_types_lock, event_mutex and
1744  * trace_event_sem.
1745  */
1746 static void __trace_remove_event_call(struct ftrace_event_call *call)
1747 {
1748         event_remove(call);
1749         trace_destroy_fields(call);
1750         free_event_filter(call->filter);
1751         call->filter = NULL;
1752 }
1753
1754 static int probe_remove_event_call(struct ftrace_event_call *call)
1755 {
1756         struct trace_array *tr;
1757         struct ftrace_event_file *file;
1758
1759 #ifdef CONFIG_PERF_EVENTS
1760         if (call->perf_refcount)
1761                 return -EBUSY;
1762 #endif
1763         do_for_each_event_file(tr, file) {
1764                 if (file->event_call != call)
1765                         continue;
1766                 /*
1767                  * We can't rely on ftrace_event_enable_disable(enable => 0)
1768                  * we are going to do, FTRACE_EVENT_FL_SOFT_MODE can suppress
1769                  * TRACE_REG_UNREGISTER.
1770                  */
1771                 if (file->flags & FTRACE_EVENT_FL_ENABLED)
1772                         return -EBUSY;
1773                 /*
1774                  * The do_for_each_event_file_safe() is
1775                  * a double loop. After finding the call for this
1776                  * trace_array, we use break to jump to the next
1777                  * trace_array.
1778                  */
1779                 break;
1780         } while_for_each_event_file();
1781
1782         __trace_remove_event_call(call);
1783
1784         return 0;
1785 }
1786
1787 /* Remove an event_call */
1788 int trace_remove_event_call(struct ftrace_event_call *call)
1789 {
1790         int ret;
1791
1792         mutex_lock(&trace_types_lock);
1793         mutex_lock(&event_mutex);
1794         down_write(&trace_event_sem);
1795         ret = probe_remove_event_call(call);
1796         up_write(&trace_event_sem);
1797         mutex_unlock(&event_mutex);
1798         mutex_unlock(&trace_types_lock);
1799
1800         return ret;
1801 }
1802
1803 #define for_each_event(event, start, end)                       \
1804         for (event = start;                                     \
1805              (unsigned long)event < (unsigned long)end;         \
1806              event++)
1807
1808 #ifdef CONFIG_MODULES
1809
1810 static void trace_module_add_events(struct module *mod)
1811 {
1812         struct ftrace_event_call **call, **start, **end;
1813
1814         if (!mod->num_trace_events)
1815                 return;
1816
1817         /* Don't add infrastructure for mods without tracepoints */
1818         if (trace_module_has_bad_taint(mod)) {
1819                 pr_err("%s: module has bad taint, not creating trace events\n",
1820                        mod->name);
1821                 return;
1822         }
1823
1824         start = mod->trace_events;
1825         end = mod->trace_events + mod->num_trace_events;
1826
1827         for_each_event(call, start, end) {
1828                 __register_event(*call, mod);
1829                 __add_event_to_tracers(*call);
1830         }
1831 }
1832
1833 static void trace_module_remove_events(struct module *mod)
1834 {
1835         struct ftrace_event_call *call, *p;
1836         bool clear_trace = false;
1837
1838         down_write(&trace_event_sem);
1839         list_for_each_entry_safe(call, p, &ftrace_events, list) {
1840                 if (call->mod == mod) {
1841                         if (call->flags & TRACE_EVENT_FL_WAS_ENABLED)
1842                                 clear_trace = true;
1843                         __trace_remove_event_call(call);
1844                 }
1845         }
1846         up_write(&trace_event_sem);
1847
1848         /*
1849          * It is safest to reset the ring buffer if the module being unloaded
1850          * registered any events that were used. The only worry is if
1851          * a new module gets loaded, and takes on the same id as the events
1852          * of this module. When printing out the buffer, traced events left
1853          * over from this module may be passed to the new module events and
1854          * unexpected results may occur.
1855          */
1856         if (clear_trace)
1857                 tracing_reset_all_online_cpus();
1858 }
1859
1860 static int trace_module_notify(struct notifier_block *self,
1861                                unsigned long val, void *data)
1862 {
1863         struct module *mod = data;
1864
1865         mutex_lock(&trace_types_lock);
1866         mutex_lock(&event_mutex);
1867         switch (val) {
1868         case MODULE_STATE_COMING:
1869                 trace_module_add_events(mod);
1870                 break;
1871         case MODULE_STATE_GOING:
1872                 trace_module_remove_events(mod);
1873                 break;
1874         }
1875         mutex_unlock(&event_mutex);
1876         mutex_unlock(&trace_types_lock);
1877
1878         return 0;
1879 }
1880
1881 static struct notifier_block trace_module_nb = {
1882         .notifier_call = trace_module_notify,
1883         .priority = 0,
1884 };
1885 #endif /* CONFIG_MODULES */
1886
1887 /* Create a new event directory structure for a trace directory. */
1888 static void
1889 __trace_add_event_dirs(struct trace_array *tr)
1890 {
1891         struct ftrace_event_call *call;
1892         int ret;
1893
1894         list_for_each_entry(call, &ftrace_events, list) {
1895                 ret = __trace_add_new_event(call, tr);
1896                 if (ret < 0)
1897                         pr_warn("Could not create directory for event %s\n",
1898                                 ftrace_event_name(call));
1899         }
1900 }
1901
1902 struct ftrace_event_file *
1903 find_event_file(struct trace_array *tr, const char *system,  const char *event)
1904 {
1905         struct ftrace_event_file *file;
1906         struct ftrace_event_call *call;
1907         const char *name;
1908
1909         list_for_each_entry(file, &tr->events, list) {
1910
1911                 call = file->event_call;
1912                 name = ftrace_event_name(call);
1913
1914                 if (!name || !call->class || !call->class->reg)
1915                         continue;
1916
1917                 if (call->flags & TRACE_EVENT_FL_IGNORE_ENABLE)
1918                         continue;
1919
1920                 if (strcmp(event, name) == 0 &&
1921                     strcmp(system, call->class->system) == 0)
1922                         return file;
1923         }
1924         return NULL;
1925 }
1926
1927 #ifdef CONFIG_DYNAMIC_FTRACE
1928
1929 /* Avoid typos */
1930 #define ENABLE_EVENT_STR        "enable_event"
1931 #define DISABLE_EVENT_STR       "disable_event"
1932
1933 struct event_probe_data {
1934         struct ftrace_event_file        *file;
1935         unsigned long                   count;
1936         int                             ref;
1937         bool                            enable;
1938 };
1939
1940 static void
1941 event_enable_probe(unsigned long ip, unsigned long parent_ip, void **_data)
1942 {
1943         struct event_probe_data **pdata = (struct event_probe_data **)_data;
1944         struct event_probe_data *data = *pdata;
1945
1946         if (!data)
1947                 return;
1948
1949         if (data->enable)
1950                 clear_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &data->file->flags);
1951         else
1952                 set_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &data->file->flags);
1953 }
1954
1955 static void
1956 event_enable_count_probe(unsigned long ip, unsigned long parent_ip, void **_data)
1957 {
1958         struct event_probe_data **pdata = (struct event_probe_data **)_data;
1959         struct event_probe_data *data = *pdata;
1960
1961         if (!data)
1962                 return;
1963
1964         if (!data->count)
1965                 return;
1966
1967         /* Skip if the event is in a state we want to switch to */
1968         if (data->enable == !(data->file->flags & FTRACE_EVENT_FL_SOFT_DISABLED))
1969                 return;
1970
1971         if (data->count != -1)
1972                 (data->count)--;
1973
1974         event_enable_probe(ip, parent_ip, _data);
1975 }
1976
1977 static int
1978 event_enable_print(struct seq_file *m, unsigned long ip,
1979                       struct ftrace_probe_ops *ops, void *_data)
1980 {
1981         struct event_probe_data *data = _data;
1982
1983         seq_printf(m, "%ps:", (void *)ip);
1984
1985         seq_printf(m, "%s:%s:%s",
1986                    data->enable ? ENABLE_EVENT_STR : DISABLE_EVENT_STR,
1987                    data->file->event_call->class->system,
1988                    ftrace_event_name(data->file->event_call));
1989
1990         if (data->count == -1)
1991                 seq_puts(m, ":unlimited\n");
1992         else
1993                 seq_printf(m, ":count=%ld\n", data->count);
1994
1995         return 0;
1996 }
1997
1998 static int
1999 event_enable_init(struct ftrace_probe_ops *ops, unsigned long ip,
2000                   void **_data)
2001 {
2002         struct event_probe_data **pdata = (struct event_probe_data **)_data;
2003         struct event_probe_data *data = *pdata;
2004
2005         data->ref++;
2006         return 0;
2007 }
2008
2009 static void
2010 event_enable_free(struct ftrace_probe_ops *ops, unsigned long ip,
2011                   void **_data)
2012 {
2013         struct event_probe_data **pdata = (struct event_probe_data **)_data;
2014         struct event_probe_data *data = *pdata;
2015
2016         if (WARN_ON_ONCE(data->ref <= 0))
2017                 return;
2018
2019         data->ref--;
2020         if (!data->ref) {
2021                 /* Remove the SOFT_MODE flag */
2022                 __ftrace_event_enable_disable(data->file, 0, 1);
2023                 module_put(data->file->event_call->mod);
2024                 kfree(data);
2025         }
2026         *pdata = NULL;
2027 }
2028
2029 static struct ftrace_probe_ops event_enable_probe_ops = {
2030         .func                   = event_enable_probe,
2031         .print                  = event_enable_print,
2032         .init                   = event_enable_init,
2033         .free                   = event_enable_free,
2034 };
2035
2036 static struct ftrace_probe_ops event_enable_count_probe_ops = {
2037         .func                   = event_enable_count_probe,
2038         .print                  = event_enable_print,
2039         .init                   = event_enable_init,
2040         .free                   = event_enable_free,
2041 };
2042
2043 static struct ftrace_probe_ops event_disable_probe_ops = {
2044         .func                   = event_enable_probe,
2045         .print                  = event_enable_print,
2046         .init                   = event_enable_init,
2047         .free                   = event_enable_free,
2048 };
2049
2050 static struct ftrace_probe_ops event_disable_count_probe_ops = {
2051         .func                   = event_enable_count_probe,
2052         .print                  = event_enable_print,
2053         .init                   = event_enable_init,
2054         .free                   = event_enable_free,
2055 };
2056
2057 static int
2058 event_enable_func(struct ftrace_hash *hash,
2059                   char *glob, char *cmd, char *param, int enabled)
2060 {
2061         struct trace_array *tr = top_trace_array();
2062         struct ftrace_event_file *file;
2063         struct ftrace_probe_ops *ops;
2064         struct event_probe_data *data;
2065         const char *system;
2066         const char *event;
2067         char *number;
2068         bool enable;
2069         int ret;
2070
2071         if (!tr)
2072                 return -ENODEV;
2073
2074         /* hash funcs only work with set_ftrace_filter */
2075         if (!enabled || !param)
2076                 return -EINVAL;
2077
2078         system = strsep(&param, ":");
2079         if (!param)
2080                 return -EINVAL;
2081
2082         event = strsep(&param, ":");
2083
2084         mutex_lock(&event_mutex);
2085
2086         ret = -EINVAL;
2087         file = find_event_file(tr, system, event);
2088         if (!file)
2089                 goto out;
2090
2091         enable = strcmp(cmd, ENABLE_EVENT_STR) == 0;
2092
2093         if (enable)
2094                 ops = param ? &event_enable_count_probe_ops : &event_enable_probe_ops;
2095         else
2096                 ops = param ? &event_disable_count_probe_ops : &event_disable_probe_ops;
2097
2098         if (glob[0] == '!') {
2099                 unregister_ftrace_function_probe_func(glob+1, ops);
2100                 ret = 0;
2101                 goto out;
2102         }
2103
2104         ret = -ENOMEM;
2105         data = kzalloc(sizeof(*data), GFP_KERNEL);
2106         if (!data)
2107                 goto out;
2108
2109         data->enable = enable;
2110         data->count = -1;
2111         data->file = file;
2112
2113         if (!param)
2114                 goto out_reg;
2115
2116         number = strsep(&param, ":");
2117
2118         ret = -EINVAL;
2119         if (!strlen(number))
2120                 goto out_free;
2121
2122         /*
2123          * We use the callback data field (which is a pointer)
2124          * as our counter.
2125          */
2126         ret = kstrtoul(number, 0, &data->count);
2127         if (ret)
2128                 goto out_free;
2129
2130  out_reg:
2131         /* Don't let event modules unload while probe registered */
2132         ret = try_module_get(file->event_call->mod);
2133         if (!ret) {
2134                 ret = -EBUSY;
2135                 goto out_free;
2136         }
2137
2138         ret = __ftrace_event_enable_disable(file, 1, 1);
2139         if (ret < 0)
2140                 goto out_put;
2141         ret = register_ftrace_function_probe(glob, ops, data);
2142         /*
2143          * The above returns on success the # of functions enabled,
2144          * but if it didn't find any functions it returns zero.
2145          * Consider no functions a failure too.
2146          */
2147         if (!ret) {
2148                 ret = -ENOENT;
2149                 goto out_disable;
2150         } else if (ret < 0)
2151                 goto out_disable;
2152         /* Just return zero, not the number of enabled functions */
2153         ret = 0;
2154  out:
2155         mutex_unlock(&event_mutex);
2156         return ret;
2157
2158  out_disable:
2159         __ftrace_event_enable_disable(file, 0, 1);
2160  out_put:
2161         module_put(file->event_call->mod);
2162  out_free:
2163         kfree(data);
2164         goto out;
2165 }
2166
2167 static struct ftrace_func_command event_enable_cmd = {
2168         .name                   = ENABLE_EVENT_STR,
2169         .func                   = event_enable_func,
2170 };
2171
2172 static struct ftrace_func_command event_disable_cmd = {
2173         .name                   = DISABLE_EVENT_STR,
2174         .func                   = event_enable_func,
2175 };
2176
2177 static __init int register_event_cmds(void)
2178 {
2179         int ret;
2180
2181         ret = register_ftrace_command(&event_enable_cmd);
2182         if (WARN_ON(ret < 0))
2183                 return ret;
2184         ret = register_ftrace_command(&event_disable_cmd);
2185         if (WARN_ON(ret < 0))
2186                 unregister_ftrace_command(&event_enable_cmd);
2187         return ret;
2188 }
2189 #else
2190 static inline int register_event_cmds(void) { return 0; }
2191 #endif /* CONFIG_DYNAMIC_FTRACE */
2192
2193 /*
2194  * The top level array has already had its ftrace_event_file
2195  * descriptors created in order to allow for early events to
2196  * be recorded. This function is called after the debugfs has been
2197  * initialized, and we now have to create the files associated
2198  * to the events.
2199  */
2200 static __init void
2201 __trace_early_add_event_dirs(struct trace_array *tr)
2202 {
2203         struct ftrace_event_file *file;
2204         int ret;
2205
2206
2207         list_for_each_entry(file, &tr->events, list) {
2208                 ret = event_create_dir(tr->event_dir, file);
2209                 if (ret < 0)
2210                         pr_warn("Could not create directory for event %s\n",
2211                                 ftrace_event_name(file->event_call));
2212         }
2213 }
2214
2215 /*
2216  * For early boot up, the top trace array requires to have
2217  * a list of events that can be enabled. This must be done before
2218  * the filesystem is set up in order to allow events to be traced
2219  * early.
2220  */
2221 static __init void
2222 __trace_early_add_events(struct trace_array *tr)
2223 {
2224         struct ftrace_event_call *call;
2225         int ret;
2226
2227         list_for_each_entry(call, &ftrace_events, list) {
2228                 /* Early boot up should not have any modules loaded */
2229                 if (WARN_ON_ONCE(call->mod))
2230                         continue;
2231
2232                 ret = __trace_early_add_new_event(call, tr);
2233                 if (ret < 0)
2234                         pr_warn("Could not create early event %s\n",
2235                                 ftrace_event_name(call));
2236         }
2237 }
2238
2239 /* Remove the event directory structure for a trace directory. */
2240 static void
2241 __trace_remove_event_dirs(struct trace_array *tr)
2242 {
2243         struct ftrace_event_file *file, *next;
2244
2245         list_for_each_entry_safe(file, next, &tr->events, list)
2246                 remove_event_file_dir(file);
2247 }
2248
2249 static void __add_event_to_tracers(struct ftrace_event_call *call)
2250 {
2251         struct trace_array *tr;
2252
2253         list_for_each_entry(tr, &ftrace_trace_arrays, list)
2254                 __trace_add_new_event(call, tr);
2255 }
2256
2257 extern struct ftrace_event_call *__start_ftrace_events[];
2258 extern struct ftrace_event_call *__stop_ftrace_events[];
2259
2260 static char bootup_event_buf[COMMAND_LINE_SIZE] __initdata;
2261
2262 static __init int setup_trace_event(char *str)
2263 {
2264         strlcpy(bootup_event_buf, str, COMMAND_LINE_SIZE);
2265         ring_buffer_expanded = true;
2266         tracing_selftest_disabled = true;
2267
2268         return 1;
2269 }
2270 __setup("trace_event=", setup_trace_event);
2271
2272 /* Expects to have event_mutex held when called */
2273 static int
2274 create_event_toplevel_files(struct dentry *parent, struct trace_array *tr)
2275 {
2276         struct dentry *d_events;
2277         struct dentry *entry;
2278
2279         entry = debugfs_create_file("set_event", 0644, parent,
2280                                     tr, &ftrace_set_event_fops);
2281         if (!entry) {
2282                 pr_warn("Could not create debugfs 'set_event' entry\n");
2283                 return -ENOMEM;
2284         }
2285
2286         d_events = debugfs_create_dir("events", parent);
2287         if (!d_events) {
2288                 pr_warn("Could not create debugfs 'events' directory\n");
2289                 return -ENOMEM;
2290         }
2291
2292         /* ring buffer internal formats */
2293         trace_create_file("header_page", 0444, d_events,
2294                           ring_buffer_print_page_header,
2295                           &ftrace_show_header_fops);
2296
2297         trace_create_file("header_event", 0444, d_events,
2298                           ring_buffer_print_entry_header,
2299                           &ftrace_show_header_fops);
2300
2301         trace_create_file("enable", 0644, d_events,
2302                           tr, &ftrace_tr_enable_fops);
2303
2304         tr->event_dir = d_events;
2305
2306         return 0;
2307 }
2308
2309 /**
2310  * event_trace_add_tracer - add a instance of a trace_array to events
2311  * @parent: The parent dentry to place the files/directories for events in
2312  * @tr: The trace array associated with these events
2313  *
2314  * When a new instance is created, it needs to set up its events
2315  * directory, as well as other files associated with events. It also
2316  * creates the event hierachry in the @parent/events directory.
2317  *
2318  * Returns 0 on success.
2319  */
2320 int event_trace_add_tracer(struct dentry *parent, struct trace_array *tr)
2321 {
2322         int ret;
2323
2324         mutex_lock(&event_mutex);
2325
2326         ret = create_event_toplevel_files(parent, tr);
2327         if (ret)
2328                 goto out_unlock;
2329
2330         down_write(&trace_event_sem);
2331         __trace_add_event_dirs(tr);
2332         up_write(&trace_event_sem);
2333
2334  out_unlock:
2335         mutex_unlock(&event_mutex);
2336
2337         return ret;
2338 }
2339
2340 /*
2341  * The top trace array already had its file descriptors created.
2342  * Now the files themselves need to be created.
2343  */
2344 static __init int
2345 early_event_add_tracer(struct dentry *parent, struct trace_array *tr)
2346 {
2347         int ret;
2348
2349         mutex_lock(&event_mutex);
2350
2351         ret = create_event_toplevel_files(parent, tr);
2352         if (ret)
2353                 goto out_unlock;
2354
2355         down_write(&trace_event_sem);
2356         __trace_early_add_event_dirs(tr);
2357         up_write(&trace_event_sem);
2358
2359  out_unlock:
2360         mutex_unlock(&event_mutex);
2361
2362         return ret;
2363 }
2364
2365 int event_trace_del_tracer(struct trace_array *tr)
2366 {
2367         mutex_lock(&event_mutex);
2368
2369         /* Disable any event triggers and associated soft-disabled events */
2370         clear_event_triggers(tr);
2371
2372         /* Disable any running events */
2373         __ftrace_set_clr_event_nolock(tr, NULL, NULL, NULL, 0);
2374
2375         /* Access to events are within rcu_read_lock_sched() */
2376         synchronize_sched();
2377
2378         down_write(&trace_event_sem);
2379         __trace_remove_event_dirs(tr);
2380         debugfs_remove_recursive(tr->event_dir);
2381         up_write(&trace_event_sem);
2382
2383         tr->event_dir = NULL;
2384
2385         mutex_unlock(&event_mutex);
2386
2387         return 0;
2388 }
2389
2390 static __init int event_trace_memsetup(void)
2391 {
2392         field_cachep = KMEM_CACHE(ftrace_event_field, SLAB_PANIC);
2393         file_cachep = KMEM_CACHE(ftrace_event_file, SLAB_PANIC);
2394         return 0;
2395 }
2396
2397 static __init int event_trace_enable(void)
2398 {
2399         struct trace_array *tr = top_trace_array();
2400         struct ftrace_event_call **iter, *call;
2401         char *buf = bootup_event_buf;
2402         char *token;
2403         int ret;
2404
2405         if (!tr)
2406                 return -ENODEV;
2407
2408         for_each_event(iter, __start_ftrace_events, __stop_ftrace_events) {
2409
2410                 call = *iter;
2411                 ret = event_init(call);
2412                 if (!ret)
2413                         list_add(&call->list, &ftrace_events);
2414         }
2415
2416         /*
2417          * We need the top trace array to have a working set of trace
2418          * points at early init, before the debug files and directories
2419          * are created. Create the file entries now, and attach them
2420          * to the actual file dentries later.
2421          */
2422         __trace_early_add_events(tr);
2423
2424         while (true) {
2425                 token = strsep(&buf, ",");
2426
2427                 if (!token)
2428                         break;
2429                 if (!*token)
2430                         continue;
2431
2432                 ret = ftrace_set_clr_event(tr, token, 1);
2433                 if (ret)
2434                         pr_warn("Failed to enable trace event: %s\n", token);
2435         }
2436
2437         trace_printk_start_comm();
2438
2439         register_event_cmds();
2440
2441         register_trigger_cmds();
2442
2443         return 0;
2444 }
2445
2446 static __init int event_trace_init(void)
2447 {
2448         struct trace_array *tr;
2449         struct dentry *d_tracer;
2450         struct dentry *entry;
2451         int ret;
2452
2453         tr = top_trace_array();
2454         if (!tr)
2455                 return -ENODEV;
2456
2457         d_tracer = tracing_init_dentry();
2458         if (!d_tracer)
2459                 return 0;
2460
2461         entry = debugfs_create_file("available_events", 0444, d_tracer,
2462                                     tr, &ftrace_avail_fops);
2463         if (!entry)
2464                 pr_warn("Could not create debugfs 'available_events' entry\n");
2465
2466         if (trace_define_common_fields())
2467                 pr_warn("tracing: Failed to allocate common fields");
2468
2469         ret = early_event_add_tracer(d_tracer, tr);
2470         if (ret)
2471                 return ret;
2472
2473 #ifdef CONFIG_MODULES
2474         ret = register_module_notifier(&trace_module_nb);
2475         if (ret)
2476                 pr_warn("Failed to register trace events module notifier\n");
2477 #endif
2478         return 0;
2479 }
2480
2481 void __init trace_event_init(void)
2482 {
2483         event_trace_memsetup();
2484         init_ftrace_syscalls();
2485         event_trace_enable();
2486 }
2487
2488 fs_initcall(event_trace_init);
2489
2490 #ifdef CONFIG_FTRACE_STARTUP_TEST
2491
2492 static DEFINE_SPINLOCK(test_spinlock);
2493 static DEFINE_SPINLOCK(test_spinlock_irq);
2494 static DEFINE_MUTEX(test_mutex);
2495
2496 static __init void test_work(struct work_struct *dummy)
2497 {
2498         spin_lock(&test_spinlock);
2499         spin_lock_irq(&test_spinlock_irq);
2500         udelay(1);
2501         spin_unlock_irq(&test_spinlock_irq);
2502         spin_unlock(&test_spinlock);
2503
2504         mutex_lock(&test_mutex);
2505         msleep(1);
2506         mutex_unlock(&test_mutex);
2507 }
2508
2509 static __init int event_test_thread(void *unused)
2510 {
2511         void *test_malloc;
2512
2513         test_malloc = kmalloc(1234, GFP_KERNEL);
2514         if (!test_malloc)
2515                 pr_info("failed to kmalloc\n");
2516
2517         schedule_on_each_cpu(test_work);
2518
2519         kfree(test_malloc);
2520
2521         set_current_state(TASK_INTERRUPTIBLE);
2522         while (!kthread_should_stop()) {
2523                 schedule();
2524                 set_current_state(TASK_INTERRUPTIBLE);
2525         }
2526         __set_current_state(TASK_RUNNING);
2527
2528         return 0;
2529 }
2530
2531 /*
2532  * Do various things that may trigger events.
2533  */
2534 static __init void event_test_stuff(void)
2535 {
2536         struct task_struct *test_thread;
2537
2538         test_thread = kthread_run(event_test_thread, NULL, "test-events");
2539         msleep(1);
2540         kthread_stop(test_thread);
2541 }
2542
2543 /*
2544  * For every trace event defined, we will test each trace point separately,
2545  * and then by groups, and finally all trace points.
2546  */
2547 static __init void event_trace_self_tests(void)
2548 {
2549         struct ftrace_subsystem_dir *dir;
2550         struct ftrace_event_file *file;
2551         struct ftrace_event_call *call;
2552         struct event_subsystem *system;
2553         struct trace_array *tr;
2554         int ret;
2555
2556         tr = top_trace_array();
2557         if (!tr)
2558                 return;
2559
2560         pr_info("Running tests on trace events:\n");
2561
2562         list_for_each_entry(file, &tr->events, list) {
2563
2564                 call = file->event_call;
2565
2566                 /* Only test those that have a probe */
2567                 if (!call->class || !call->class->probe)
2568                         continue;
2569
2570 /*
2571  * Testing syscall events here is pretty useless, but
2572  * we still do it if configured. But this is time consuming.
2573  * What we really need is a user thread to perform the
2574  * syscalls as we test.
2575  */
2576 #ifndef CONFIG_EVENT_TRACE_TEST_SYSCALLS
2577                 if (call->class->system &&
2578                     strcmp(call->class->system, "syscalls") == 0)
2579                         continue;
2580 #endif
2581
2582                 pr_info("Testing event %s: ", ftrace_event_name(call));
2583
2584                 /*
2585                  * If an event is already enabled, someone is using
2586                  * it and the self test should not be on.
2587                  */
2588                 if (file->flags & FTRACE_EVENT_FL_ENABLED) {
2589                         pr_warn("Enabled event during self test!\n");
2590                         WARN_ON_ONCE(1);
2591                         continue;
2592                 }
2593
2594                 ftrace_event_enable_disable(file, 1);
2595                 event_test_stuff();
2596                 ftrace_event_enable_disable(file, 0);
2597
2598                 pr_cont("OK\n");
2599         }
2600
2601         /* Now test at the sub system level */
2602
2603         pr_info("Running tests on trace event systems:\n");
2604
2605         list_for_each_entry(dir, &tr->systems, list) {
2606
2607                 system = dir->subsystem;
2608
2609                 /* the ftrace system is special, skip it */
2610                 if (strcmp(system->name, "ftrace") == 0)
2611                         continue;
2612
2613                 pr_info("Testing event system %s: ", system->name);
2614
2615                 ret = __ftrace_set_clr_event(tr, NULL, system->name, NULL, 1);
2616                 if (WARN_ON_ONCE(ret)) {
2617                         pr_warn("error enabling system %s\n",
2618                                 system->name);
2619                         continue;
2620                 }
2621
2622                 event_test_stuff();
2623
2624                 ret = __ftrace_set_clr_event(tr, NULL, system->name, NULL, 0);
2625                 if (WARN_ON_ONCE(ret)) {
2626                         pr_warn("error disabling system %s\n",
2627                                 system->name);
2628                         continue;
2629                 }
2630
2631                 pr_cont("OK\n");
2632         }
2633
2634         /* Test with all events enabled */
2635
2636         pr_info("Running tests on all trace events:\n");
2637         pr_info("Testing all events: ");
2638
2639         ret = __ftrace_set_clr_event(tr, NULL, NULL, NULL, 1);
2640         if (WARN_ON_ONCE(ret)) {
2641                 pr_warn("error enabling all events\n");
2642                 return;
2643         }
2644
2645         event_test_stuff();
2646
2647         /* reset sysname */
2648         ret = __ftrace_set_clr_event(tr, NULL, NULL, NULL, 0);
2649         if (WARN_ON_ONCE(ret)) {
2650                 pr_warn("error disabling all events\n");
2651                 return;
2652         }
2653
2654         pr_cont("OK\n");
2655 }
2656
2657 #ifdef CONFIG_FUNCTION_TRACER
2658
2659 static DEFINE_PER_CPU(atomic_t, ftrace_test_event_disable);
2660
2661 static void
2662 function_test_events_call(unsigned long ip, unsigned long parent_ip,
2663                           struct ftrace_ops *op, struct pt_regs *pt_regs)
2664 {
2665         struct ring_buffer_event *event;
2666         struct ring_buffer *buffer;
2667         struct ftrace_entry *entry;
2668         unsigned long flags;
2669         long disabled;
2670         int cpu;
2671         int pc;
2672
2673         pc = preempt_count();
2674         preempt_disable_notrace();
2675         cpu = raw_smp_processor_id();
2676         disabled = atomic_inc_return(&per_cpu(ftrace_test_event_disable, cpu));
2677
2678         if (disabled != 1)
2679                 goto out;
2680
2681         local_save_flags(flags);
2682
2683         event = trace_current_buffer_lock_reserve(&buffer,
2684                                                   TRACE_FN, sizeof(*entry),
2685                                                   flags, pc);
2686         if (!event)
2687                 goto out;
2688         entry   = ring_buffer_event_data(event);
2689         entry->ip                       = ip;
2690         entry->parent_ip                = parent_ip;
2691
2692         trace_buffer_unlock_commit(buffer, event, flags, pc);
2693
2694  out:
2695         atomic_dec(&per_cpu(ftrace_test_event_disable, cpu));
2696         preempt_enable_notrace();
2697 }
2698
2699 static struct ftrace_ops trace_ops __initdata  =
2700 {
2701         .func = function_test_events_call,
2702         .flags = FTRACE_OPS_FL_RECURSION_SAFE,
2703 };
2704
2705 static __init void event_trace_self_test_with_function(void)
2706 {
2707         int ret;
2708         ret = register_ftrace_function(&trace_ops);
2709         if (WARN_ON(ret < 0)) {
2710                 pr_info("Failed to enable function tracer for event tests\n");
2711                 return;
2712         }
2713         pr_info("Running tests again, along with the function tracer\n");
2714         event_trace_self_tests();
2715         unregister_ftrace_function(&trace_ops);
2716 }
2717 #else
2718 static __init void event_trace_self_test_with_function(void)
2719 {
2720 }
2721 #endif
2722
2723 static __init int event_trace_self_tests_init(void)
2724 {
2725         if (!tracing_selftest_disabled) {
2726                 event_trace_self_tests();
2727                 event_trace_self_test_with_function();
2728         }
2729
2730         return 0;
2731 }
2732
2733 late_initcall(event_trace_self_tests_init);
2734
2735 #endif