kernel/trace/trace_events_hist.c

   1 /*
   2  * trace_events_hist - trace event hist triggers
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation; either version 2 of the License, or
   7  * (at your option) any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * Copyright (C) 2015 Tom Zanussi <tom.zanussi@linux.intel.com>
  15  */
  16
  17 #include <linux/module.h>
  18 #include <linux/kallsyms.h>
  19 #include <linux/mutex.h>
  20 #include <linux/slab.h>
  21 #include <linux/stacktrace.h>
  22
  23 #include "tracing_map.h"
  24 #include "trace.h"
  25
  26 struct hist_field;
  27
  28 typedef u64 (*hist_field_fn_t) (struct hist_field *field, void *event);
  29
  30 struct hist_field {
  31         struct ftrace_event_field       *field;
  32         unsigned long                   flags;
  33         hist_field_fn_t                 fn;
  34         unsigned int                    size;
  35         unsigned int                    offset;
  36 };
  37
  38 static u64 hist_field_none(struct hist_field *field, void *event)
  39 {
  40         return 0;
  41 }
  42
  43 static u64 hist_field_counter(struct hist_field *field, void *event)
  44 {
  45         return 1;
  46 }
  47
  48 static u64 hist_field_string(struct hist_field *hist_field, void *event)
  49 {
  50         char *addr = (char *)(event + hist_field->field->offset);
  51
  52         return (u64)(unsigned long)addr;
  53 }
  54
  55 static u64 hist_field_dynstring(struct hist_field *hist_field, void *event)
  56 {
  57         u32 str_item = *(u32 *)(event + hist_field->field->offset);
  58         int str_loc = str_item & 0xffff;
  59         char *addr = (char *)(event + str_loc);
  60
  61         return (u64)(unsigned long)addr;
  62 }
  63
  64 static u64 hist_field_pstring(struct hist_field *hist_field, void *event)
  65 {
  66         char **addr = (char **)(event + hist_field->field->offset);
  67
  68         return (u64)(unsigned long)*addr;
  69 }
  70
  71 static u64 hist_field_log2(struct hist_field *hist_field, void *event)
  72 {
  73         u64 val = *(u64 *)(event + hist_field->field->offset);
  74
  75         return (u64) ilog2(roundup_pow_of_two(val));
  76 }
  77
  78 #define DEFINE_HIST_FIELD_FN(type)                                      \
  79 static u64 hist_field_##type(struct hist_field *hist_field, void *event)\
  80 {                                                                       \
  81         type *addr = (type *)(event + hist_field->field->offset);       \
  82                                                                         \
  83         return (u64)(unsigned long)*addr;                               \
  84 }
  85
  86 DEFINE_HIST_FIELD_FN(s64);
  87 DEFINE_HIST_FIELD_FN(u64);
  88 DEFINE_HIST_FIELD_FN(s32);
  89 DEFINE_HIST_FIELD_FN(u32);
  90 DEFINE_HIST_FIELD_FN(s16);
  91 DEFINE_HIST_FIELD_FN(u16);
  92 DEFINE_HIST_FIELD_FN(s8);
  93 DEFINE_HIST_FIELD_FN(u8);
  94
  95 #define for_each_hist_field(i, hist_data)       \
  96         for ((i) = 0; (i) < (hist_data)->n_fields; (i)++)
  97
  98 #define for_each_hist_val_field(i, hist_data)   \
  99         for ((i) = 0; (i) < (hist_data)->n_vals; (i)++)
 100
 101 #define for_each_hist_key_field(i, hist_data)   \
 102         for ((i) = (hist_data)->n_vals; (i) < (hist_data)->n_fields; (i)++)
 103
 104 #define HIST_STACKTRACE_DEPTH   16
 105 #define HIST_STACKTRACE_SIZE    (HIST_STACKTRACE_DEPTH * sizeof(unsigned long))
 106 #define HIST_STACKTRACE_SKIP    5
 107
 108 #define HITCOUNT_IDX            0
 109 #define HIST_KEY_SIZE_MAX       (MAX_FILTER_STR_VAL + HIST_STACKTRACE_SIZE)
 110
 111 enum hist_field_flags {
 112         HIST_FIELD_FL_HITCOUNT          = 1,
 113         HIST_FIELD_FL_KEY               = 2,
 114         HIST_FIELD_FL_STRING            = 4,
 115         HIST_FIELD_FL_HEX               = 8,
 116         HIST_FIELD_FL_SYM               = 16,
 117         HIST_FIELD_FL_SYM_OFFSET        = 32,
 118         HIST_FIELD_FL_EXECNAME          = 64,
 119         HIST_FIELD_FL_SYSCALL           = 128,
 120         HIST_FIELD_FL_STACKTRACE        = 256,
 121         HIST_FIELD_FL_LOG2              = 512,
 122 };
 123
 124 struct hist_trigger_attrs {
 125         char            *keys_str;
 126         char            *vals_str;
 127         char            *sort_key_str;
 128         char            *name;
 129         bool            pause;
 130         bool            cont;
 131         bool            clear;
 132         unsigned int    map_bits;
 133 };
 134
 135 struct hist_trigger_data {
 136         struct hist_field               *fields[TRACING_MAP_FIELDS_MAX];
 137         unsigned int                    n_vals;
 138         unsigned int                    n_keys;
 139         unsigned int                    n_fields;
 140         unsigned int                    key_size;
 141         struct tracing_map_sort_key     sort_keys[TRACING_MAP_SORT_KEYS_MAX];
 142         unsigned int                    n_sort_keys;
 143         struct trace_event_file         *event_file;
 144         struct hist_trigger_attrs       *attrs;
 145         struct tracing_map              *map;
 146 };
 147
 148 static hist_field_fn_t select_value_fn(int field_size, int field_is_signed)
 149 {
 150         hist_field_fn_t fn = NULL;
 151
 152         switch (field_size) {
 153         case 8:
 154                 if (field_is_signed)
 155                         fn = hist_field_s64;
 156                 else
 157                         fn = hist_field_u64;
 158                 break;
 159         case 4:
 160                 if (field_is_signed)
 161                         fn = hist_field_s32;
 162                 else
 163                         fn = hist_field_u32;
 164                 break;
 165         case 2:
 166                 if (field_is_signed)
 167                         fn = hist_field_s16;
 168                 else
 169                         fn = hist_field_u16;
 170                 break;
 171         case 1:
 172                 if (field_is_signed)
 173                         fn = hist_field_s8;
 174                 else
 175                         fn = hist_field_u8;
 176                 break;
 177         }
 178
 179         return fn;
 180 }
 181
 182 static int parse_map_size(char *str)
 183 {
 184         unsigned long size, map_bits;
 185         int ret;
 186
 187         strsep(&str, "=");
 188         if (!str) {
 189                 ret = -EINVAL;
 190                 goto out;
 191         }
 192
 193         ret = kstrtoul(str, 0, &size);
 194         if (ret)
 195                 goto out;
 196
 197         map_bits = ilog2(roundup_pow_of_two(size));
 198         if (map_bits < TRACING_MAP_BITS_MIN ||
 199             map_bits > TRACING_MAP_BITS_MAX)
 200                 ret = -EINVAL;
 201         else
 202                 ret = map_bits;
 203  out:
 204         return ret;
 205 }
 206
 207 static void destroy_hist_trigger_attrs(struct hist_trigger_attrs *attrs)
 208 {
 209         if (!attrs)
 210                 return;
 211
 212         kfree(attrs->name);
 213         kfree(attrs->sort_key_str);
 214         kfree(attrs->keys_str);
 215         kfree(attrs->vals_str);
 216         kfree(attrs);
 217 }
 218
 219 static struct hist_trigger_attrs *parse_hist_trigger_attrs(char *trigger_str)
 220 {
 221         struct hist_trigger_attrs *attrs;
 222         int ret = 0;
 223
 224         attrs = kzalloc(sizeof(*attrs), GFP_KERNEL);
 225         if (!attrs)
 226                 return ERR_PTR(-ENOMEM);
 227
 228         while (trigger_str) {
 229                 char *str = strsep(&trigger_str, ":");
 230
 231                 if ((strncmp(str, "key=", strlen("key=")) == 0) ||
 232                     (strncmp(str, "keys=", strlen("keys=")) == 0))
 233                         attrs->keys_str = kstrdup(str, GFP_KERNEL);
 234                 else if ((strncmp(str, "val=", strlen("val=")) == 0) ||
 235                          (strncmp(str, "vals=", strlen("vals=")) == 0) ||
 236                          (strncmp(str, "values=", strlen("values=")) == 0))
 237                         attrs->vals_str = kstrdup(str, GFP_KERNEL);
 238                 else if (strncmp(str, "sort=", strlen("sort=")) == 0)
 239                         attrs->sort_key_str = kstrdup(str, GFP_KERNEL);
 240                 else if (strncmp(str, "name=", strlen("name=")) == 0)
 241                         attrs->name = kstrdup(str, GFP_KERNEL);
 242                 else if (strcmp(str, "pause") == 0)
 243                         attrs->pause = true;
 244                 else if ((strcmp(str, "cont") == 0) ||
 245                          (strcmp(str, "continue") == 0))
 246                         attrs->cont = true;
 247                 else if (strcmp(str, "clear") == 0)
 248                         attrs->clear = true;
 249                 else if (strncmp(str, "size=", strlen("size=")) == 0) {
 250                         int map_bits = parse_map_size(str);
 251
 252                         if (map_bits < 0) {
 253                                 ret = map_bits;
 254                                 goto free;
 255                         }
 256                         attrs->map_bits = map_bits;
 257                 } else {
 258                         ret = -EINVAL;
 259                         goto free;
 260                 }
 261         }
 262
 263         if (!attrs->keys_str) {
 264                 ret = -EINVAL;
 265                 goto free;
 266         }
 267
 268         return attrs;
 269  free:
 270         destroy_hist_trigger_attrs(attrs);
 271
 272         return ERR_PTR(ret);
 273 }
 274
 275 static inline void save_comm(char *comm, struct task_struct *task)
 276 {
 277         if (!task->pid) {
 278                 strcpy(comm, "<idle>");
 279                 return;
 280         }
 281
 282         if (WARN_ON_ONCE(task->pid < 0)) {
 283                 strcpy(comm, "<XXX>");
 284                 return;
 285         }
 286
 287         memcpy(comm, task->comm, TASK_COMM_LEN);
 288 }
 289
 290 static void hist_trigger_elt_comm_free(struct tracing_map_elt *elt)
 291 {
 292         kfree((char *)elt->private_data);
 293 }
 294
 295 static int hist_trigger_elt_comm_alloc(struct tracing_map_elt *elt)
 296 {
 297         struct hist_trigger_data *hist_data = elt->map->private_data;
 298         struct hist_field *key_field;
 299         unsigned int i;
 300
 301         for_each_hist_key_field(i, hist_data) {
 302                 key_field = hist_data->fields[i];
 303
 304                 if (key_field->flags & HIST_FIELD_FL_EXECNAME) {
 305                         unsigned int size = TASK_COMM_LEN + 1;
 306
 307                         elt->private_data = kzalloc(size, GFP_KERNEL);
 308                         if (!elt->private_data)
 309                                 return -ENOMEM;
 310                         break;
 311                 }
 312         }
 313
 314         return 0;
 315 }
 316
 317 static void hist_trigger_elt_comm_copy(struct tracing_map_elt *to,
 318                                        struct tracing_map_elt *from)
 319 {
 320         char *comm_from = from->private_data;
 321         char *comm_to = to->private_data;
 322
 323         if (comm_from)
 324                 memcpy(comm_to, comm_from, TASK_COMM_LEN + 1);
 325 }
 326
 327 static void hist_trigger_elt_comm_init(struct tracing_map_elt *elt)
 328 {
 329         char *comm = elt->private_data;
 330
 331         if (comm)
 332                 save_comm(comm, current);
 333 }
 334
 335 static const struct tracing_map_ops hist_trigger_elt_comm_ops = {
 336         .elt_alloc      = hist_trigger_elt_comm_alloc,
 337         .elt_copy       = hist_trigger_elt_comm_copy,
 338         .elt_free       = hist_trigger_elt_comm_free,
 339         .elt_init       = hist_trigger_elt_comm_init,
 340 };
 341
 342 static void destroy_hist_field(struct hist_field *hist_field)
 343 {
 344         kfree(hist_field);
 345 }
 346
 347 static struct hist_field *create_hist_field(struct ftrace_event_field *field,
 348                                             unsigned long flags)
 349 {
 350         struct hist_field *hist_field;
 351
 352         if (field && is_function_field(field))
 353                 return NULL;
 354
 355         hist_field = kzalloc(sizeof(struct hist_field), GFP_KERNEL);
 356         if (!hist_field)
 357                 return NULL;
 358
 359         if (flags & HIST_FIELD_FL_HITCOUNT) {
 360                 hist_field->fn = hist_field_counter;
 361                 goto out;
 362         }
 363
 364         if (flags & HIST_FIELD_FL_STACKTRACE) {
 365                 hist_field->fn = hist_field_none;
 366                 goto out;
 367         }
 368
 369         if (flags & HIST_FIELD_FL_LOG2) {
 370                 hist_field->fn = hist_field_log2;
 371                 goto out;
 372         }
 373
 374         if (WARN_ON_ONCE(!field))
 375                 goto out;
 376
 377         /* Pointers to strings are just pointers and dangerous to dereference */
 378         if (is_string_field(field) &&
 379             (field->filter_type != FILTER_PTR_STRING)) {
 380                 flags |= HIST_FIELD_FL_STRING;
 381
 382                 if (field->filter_type == FILTER_STATIC_STRING)
 383                         hist_field->fn = hist_field_string;
 384                 else if (field->filter_type == FILTER_DYN_STRING)
 385                         hist_field->fn = hist_field_dynstring;
 386                 else
 387                         hist_field->fn = hist_field_pstring;
 388         } else {
 389                 hist_field->fn = select_value_fn(field->size,
 390                                                  field->is_signed);
 391                 if (!hist_field->fn) {
 392                         destroy_hist_field(hist_field);
 393                         return NULL;
 394                 }
 395         }
 396  out:
 397         hist_field->field = field;
 398         hist_field->flags = flags;
 399
 400         return hist_field;
 401 }
 402
 403 static void destroy_hist_fields(struct hist_trigger_data *hist_data)
 404 {
 405         unsigned int i;
 406
 407         for (i = 0; i < TRACING_MAP_FIELDS_MAX; i++) {
 408                 if (hist_data->fields[i]) {
 409                         destroy_hist_field(hist_data->fields[i]);
 410                         hist_data->fields[i] = NULL;
 411                 }
 412         }
 413 }
 414
 415 static int create_hitcount_val(struct hist_trigger_data *hist_data)
 416 {
 417         hist_data->fields[HITCOUNT_IDX] =
 418                 create_hist_field(NULL, HIST_FIELD_FL_HITCOUNT);
 419         if (!hist_data->fields[HITCOUNT_IDX])
 420                 return -ENOMEM;
 421
 422         hist_data->n_vals++;
 423
 424         if (WARN_ON(hist_data->n_vals > TRACING_MAP_VALS_MAX))
 425                 return -EINVAL;
 426
 427         return 0;
 428 }
 429
 430 static int create_val_field(struct hist_trigger_data *hist_data,
 431                             unsigned int val_idx,
 432                             struct trace_event_file *file,
 433                             char *field_str)
 434 {
 435         struct ftrace_event_field *field = NULL;
 436         unsigned long flags = 0;
 437         char *field_name;
 438         int ret = 0;
 439
 440         if (WARN_ON(val_idx >= TRACING_MAP_VALS_MAX))
 441                 return -EINVAL;
 442
 443         field_name = strsep(&field_str, ".");
 444         if (field_str) {
 445                 if (strcmp(field_str, "hex") == 0)
 446                         flags |= HIST_FIELD_FL_HEX;
 447                 else {
 448                         ret = -EINVAL;
 449                         goto out;
 450                 }
 451         }
 452
 453         field = trace_find_event_field(file->event_call, field_name);
 454         if (!field || !field->size) {
 455                 ret = -EINVAL;
 456                 goto out;
 457         }
 458
 459         hist_data->fields[val_idx] = create_hist_field(field, flags);
 460         if (!hist_data->fields[val_idx]) {
 461                 ret = -ENOMEM;
 462                 goto out;
 463         }
 464
 465         ++hist_data->n_vals;
 466
 467         if (WARN_ON(hist_data->n_vals > TRACING_MAP_VALS_MAX))
 468                 ret = -EINVAL;
 469  out:
 470         return ret;
 471 }
 472
 473 static int create_val_fields(struct hist_trigger_data *hist_data,
 474                              struct trace_event_file *file)
 475 {
 476         char *fields_str, *field_str;
 477         unsigned int i, j;
 478         int ret;
 479
 480         ret = create_hitcount_val(hist_data);
 481         if (ret)
 482                 goto out;
 483
 484         fields_str = hist_data->attrs->vals_str;
 485         if (!fields_str)
 486                 goto out;
 487
 488         strsep(&fields_str, "=");
 489         if (!fields_str)
 490                 goto out;
 491
 492         for (i = 0, j = 1; i < TRACING_MAP_VALS_MAX &&
 493                      j < TRACING_MAP_VALS_MAX; i++) {
 494                 field_str = strsep(&fields_str, ",");
 495                 if (!field_str)
 496                         break;
 497                 if (strcmp(field_str, "hitcount") == 0)
 498                         continue;
 499                 ret = create_val_field(hist_data, j++, file, field_str);
 500                 if (ret)
 501                         goto out;
 502         }
 503         if (fields_str && (strcmp(fields_str, "hitcount") != 0))
 504                 ret = -EINVAL;
 505  out:
 506         return ret;
 507 }
 508
 509 static int create_key_field(struct hist_trigger_data *hist_data,
 510                             unsigned int key_idx,
 511                             unsigned int key_offset,
 512                             struct trace_event_file *file,
 513                             char *field_str)
 514 {
 515         struct ftrace_event_field *field = NULL;
 516         unsigned long flags = 0;
 517         unsigned int key_size;
 518         int ret = 0;
 519
 520         if (WARN_ON(key_idx >= TRACING_MAP_FIELDS_MAX))
 521                 return -EINVAL;
 522
 523         flags |= HIST_FIELD_FL_KEY;
 524
 525         if (strcmp(field_str, "stacktrace") == 0) {
 526                 flags |= HIST_FIELD_FL_STACKTRACE;
 527                 key_size = sizeof(unsigned long) * HIST_STACKTRACE_DEPTH;
 528         } else {
 529                 char *field_name = strsep(&field_str, ".");
 530
 531                 if (field_str) {
 532                         if (strcmp(field_str, "hex") == 0)
 533                                 flags |= HIST_FIELD_FL_HEX;
 534                         else if (strcmp(field_str, "sym") == 0)
 535                                 flags |= HIST_FIELD_FL_SYM;
 536                         else if (strcmp(field_str, "sym-offset") == 0)
 537                                 flags |= HIST_FIELD_FL_SYM_OFFSET;
 538                         else if ((strcmp(field_str, "execname") == 0) &&
 539                                  (strcmp(field_name, "common_pid") == 0))
 540                                 flags |= HIST_FIELD_FL_EXECNAME;
 541                         else if (strcmp(field_str, "syscall") == 0)
 542                                 flags |= HIST_FIELD_FL_SYSCALL;
 543                         else if (strcmp(field_str, "log2") == 0)
 544                                 flags |= HIST_FIELD_FL_LOG2;
 545                         else {
 546                                 ret = -EINVAL;
 547                                 goto out;
 548                         }
 549                 }
 550
 551                 field = trace_find_event_field(file->event_call, field_name);
 552                 if (!field || !field->size) {
 553                         ret = -EINVAL;
 554                         goto out;
 555                 }
 556
 557                 if (is_string_field(field))
 558                         key_size = MAX_FILTER_STR_VAL;
 559                 else
 560                         key_size = field->size;
 561         }
 562
 563         hist_data->fields[key_idx] = create_hist_field(field, flags);
 564         if (!hist_data->fields[key_idx]) {
 565                 ret = -ENOMEM;
 566                 goto out;
 567         }
 568
 569         key_size = ALIGN(key_size, sizeof(u64));
 570         hist_data->fields[key_idx]->size = key_size;
 571         hist_data->fields[key_idx]->offset = key_offset;
 572         hist_data->key_size += key_size;
 573         if (hist_data->key_size > HIST_KEY_SIZE_MAX) {
 574                 ret = -EINVAL;
 575                 goto out;
 576         }
 577
 578         hist_data->n_keys++;
 579
 580         if (WARN_ON(hist_data->n_keys > TRACING_MAP_KEYS_MAX))
 581                 return -EINVAL;
 582
 583         ret = key_size;
 584  out:
 585         return ret;
 586 }
 587
 588 static int create_key_fields(struct hist_trigger_data *hist_data,
 589                              struct trace_event_file *file)
 590 {
 591         unsigned int i, key_offset = 0, n_vals = hist_data->n_vals;
 592         char *fields_str, *field_str;
 593         int ret = -EINVAL;
 594
 595         fields_str = hist_data->attrs->keys_str;
 596         if (!fields_str)
 597                 goto out;
 598
 599         strsep(&fields_str, "=");
 600         if (!fields_str)
 601                 goto out;
 602
 603         for (i = n_vals; i < n_vals + TRACING_MAP_KEYS_MAX; i++) {
 604                 field_str = strsep(&fields_str, ",");
 605                 if (!field_str)
 606                         break;
 607                 ret = create_key_field(hist_data, i, key_offset,
 608                                        file, field_str);
 609                 if (ret < 0)
 610                         goto out;
 611                 key_offset += ret;
 612         }
 613         if (fields_str) {
 614                 ret = -EINVAL;
 615                 goto out;
 616         }
 617         ret = 0;
 618  out:
 619         return ret;
 620 }
 621
 622 static int create_hist_fields(struct hist_trigger_data *hist_data,
 623                               struct trace_event_file *file)
 624 {
 625         int ret;
 626
 627         ret = create_val_fields(hist_data, file);
 628         if (ret)
 629                 goto out;
 630
 631         ret = create_key_fields(hist_data, file);
 632         if (ret)
 633                 goto out;
 634
 635         hist_data->n_fields = hist_data->n_vals + hist_data->n_keys;
 636  out:
 637         return ret;
 638 }
 639
 640 static int is_descending(const char *str)
 641 {
 642         if (!str)
 643                 return 0;
 644
 645         if (strcmp(str, "descending") == 0)
 646                 return 1;
 647
 648         if (strcmp(str, "ascending") == 0)
 649                 return 0;
 650
 651         return -EINVAL;
 652 }
 653
 654 static int create_sort_keys(struct hist_trigger_data *hist_data)
 655 {
 656         char *fields_str = hist_data->attrs->sort_key_str;
 657         struct ftrace_event_field *field = NULL;
 658         struct tracing_map_sort_key *sort_key;
 659         int descending, ret = 0;
 660         unsigned int i, j;
 661
 662         hist_data->n_sort_keys = 1; /* we always have at least one, hitcount */
 663
 664         if (!fields_str)
 665                 goto out;
 666
 667         strsep(&fields_str, "=");
 668         if (!fields_str) {
 669                 ret = -EINVAL;
 670                 goto out;
 671         }
 672
 673         for (i = 0; i < TRACING_MAP_SORT_KEYS_MAX; i++) {
 674                 char *field_str, *field_name;
 675
 676                 sort_key = &hist_data->sort_keys[i];
 677
 678                 field_str = strsep(&fields_str, ",");
 679                 if (!field_str) {
 680                         if (i == 0)
 681                                 ret = -EINVAL;
 682                         break;
 683                 }
 684
 685                 if ((i == TRACING_MAP_SORT_KEYS_MAX - 1) && fields_str) {
 686                         ret = -EINVAL;
 687                         break;
 688                 }
 689
 690                 field_name = strsep(&field_str, ".");
 691                 if (!field_name) {
 692                         ret = -EINVAL;
 693                         break;
 694                 }
 695
 696                 if (strcmp(field_name, "hitcount") == 0) {
 697                         descending = is_descending(field_str);
 698                         if (descending < 0) {
 699                                 ret = descending;
 700                                 break;
 701                         }
 702                         sort_key->descending = descending;
 703                         continue;
 704                 }
 705
 706                 for (j = 1; j < hist_data->n_fields; j++) {
 707                         field = hist_data->fields[j]->field;
 708                         if (field && (strcmp(field_name, field->name) == 0)) {
 709                                 sort_key->field_idx = j;
 710                                 descending = is_descending(field_str);
 711                                 if (descending < 0) {
 712                                         ret = descending;
 713                                         goto out;
 714                                 }
 715                                 sort_key->descending = descending;
 716                                 break;
 717                         }
 718                 }
 719                 if (j == hist_data->n_fields) {
 720                         ret = -EINVAL;
 721                         break;
 722                 }
 723         }
 724         hist_data->n_sort_keys = i;
 725  out:
 726         return ret;
 727 }
 728
 729 static void destroy_hist_data(struct hist_trigger_data *hist_data)
 730 {
 731         destroy_hist_trigger_attrs(hist_data->attrs);
 732         destroy_hist_fields(hist_data);
 733         tracing_map_destroy(hist_data->map);
 734         kfree(hist_data);
 735 }
 736
 737 static int create_tracing_map_fields(struct hist_trigger_data *hist_data)
 738 {
 739         struct tracing_map *map = hist_data->map;
 740         struct ftrace_event_field *field;
 741         struct hist_field *hist_field;
 742         int i, idx;
 743
 744         for_each_hist_field(i, hist_data) {
 745                 hist_field = hist_data->fields[i];
 746                 if (hist_field->flags & HIST_FIELD_FL_KEY) {
 747                         tracing_map_cmp_fn_t cmp_fn;
 748
 749                         field = hist_field->field;
 750
 751                         if (hist_field->flags & HIST_FIELD_FL_STACKTRACE)
 752                                 cmp_fn = tracing_map_cmp_none;
 753                         else if (is_string_field(field))
 754                                 cmp_fn = tracing_map_cmp_string;
 755                         else
 756                                 cmp_fn = tracing_map_cmp_num(field->size,
 757                                                              field->is_signed);
 758                         idx = tracing_map_add_key_field(map,
 759                                                         hist_field->offset,
 760                                                         cmp_fn);
 761
 762                 } else
 763                         idx = tracing_map_add_sum_field(map);
 764
 765                 if (idx < 0)
 766                         return idx;
 767         }
 768
 769         return 0;
 770 }
 771
 772 static bool need_tracing_map_ops(struct hist_trigger_data *hist_data)
 773 {
 774         struct hist_field *key_field;
 775         unsigned int i;
 776
 777         for_each_hist_key_field(i, hist_data) {
 778                 key_field = hist_data->fields[i];
 779
 780                 if (key_field->flags & HIST_FIELD_FL_EXECNAME)
 781                         return true;
 782         }
 783
 784         return false;
 785 }
 786
 787 static struct hist_trigger_data *
 788 create_hist_data(unsigned int map_bits,
 789                  struct hist_trigger_attrs *attrs,
 790                  struct trace_event_file *file)
 791 {
 792         const struct tracing_map_ops *map_ops = NULL;
 793         struct hist_trigger_data *hist_data;
 794         int ret = 0;
 795
 796         hist_data = kzalloc(sizeof(*hist_data), GFP_KERNEL);
 797         if (!hist_data)
 798                 return ERR_PTR(-ENOMEM);
 799
 800         hist_data->attrs = attrs;
 801
 802         ret = create_hist_fields(hist_data, file);
 803         if (ret)
 804                 goto free;
 805
 806         ret = create_sort_keys(hist_data);
 807         if (ret)
 808                 goto free;
 809
 810         if (need_tracing_map_ops(hist_data))
 811                 map_ops = &hist_trigger_elt_comm_ops;
 812
 813         hist_data->map = tracing_map_create(map_bits, hist_data->key_size,
 814                                             map_ops, hist_data);
 815         if (IS_ERR(hist_data->map)) {
 816                 ret = PTR_ERR(hist_data->map);
 817                 hist_data->map = NULL;
 818                 goto free;
 819         }
 820
 821         ret = create_tracing_map_fields(hist_data);
 822         if (ret)
 823                 goto free;
 824
 825         ret = tracing_map_init(hist_data->map);
 826         if (ret)
 827                 goto free;
 828
 829         hist_data->event_file = file;
 830  out:
 831         return hist_data;
 832  free:
 833         hist_data->attrs = NULL;
 834
 835         destroy_hist_data(hist_data);
 836
 837         hist_data = ERR_PTR(ret);
 838
 839         goto out;
 840 }
 841
 842 static void hist_trigger_elt_update(struct hist_trigger_data *hist_data,
 843                                     struct tracing_map_elt *elt,
 844                                     void *rec)
 845 {
 846         struct hist_field *hist_field;
 847         unsigned int i;
 848         u64 hist_val;
 849
 850         for_each_hist_val_field(i, hist_data) {
 851                 hist_field = hist_data->fields[i];
 852                 hist_val = hist_field->fn(hist_field, rec);
 853                 tracing_map_update_sum(elt, i, hist_val);
 854         }
 855 }
 856
 857 static inline void add_to_key(char *compound_key, void *key,
 858                               struct hist_field *key_field, void *rec)
 859 {
 860         size_t size = key_field->size;
 861
 862         if (key_field->flags & HIST_FIELD_FL_STRING) {
 863                 struct ftrace_event_field *field;
 864
 865                 field = key_field->field;
 866                 if (field->filter_type == FILTER_DYN_STRING)
 867                         size = *(u32 *)(rec + field->offset) >> 16;
 868                 else if (field->filter_type == FILTER_STATIC_STRING)
 869                         size = field->size;
 870
 871                 /* ensure NULL-termination */
 872                 if (size > key_field->size - 1)
 873                         size = key_field->size - 1;
 874
 875                 strncpy(compound_key + key_field->offset, (char *)key, size);
 876         } else
 877                 memcpy(compound_key + key_field->offset, key, size);
 878 }
 879
 880 static void event_hist_trigger(struct event_trigger_data *data, void *rec)
 881 {
 882         struct hist_trigger_data *hist_data = data->private_data;
 883         bool use_compound_key = (hist_data->n_keys > 1);
 884         unsigned long entries[HIST_STACKTRACE_DEPTH];
 885         char compound_key[HIST_KEY_SIZE_MAX];
 886         struct stack_trace stacktrace;
 887         struct hist_field *key_field;
 888         struct tracing_map_elt *elt;
 889         u64 field_contents;
 890         void *key = NULL;
 891         unsigned int i;
 892
 893         memset(compound_key, 0, hist_data->key_size);
 894
 895         for_each_hist_key_field(i, hist_data) {
 896                 key_field = hist_data->fields[i];
 897
 898                 if (key_field->flags & HIST_FIELD_FL_STACKTRACE) {
 899                         stacktrace.max_entries = HIST_STACKTRACE_DEPTH;
 900                         stacktrace.entries = entries;
 901                         stacktrace.nr_entries = 0;
 902                         stacktrace.skip = HIST_STACKTRACE_SKIP;
 903
 904                         memset(stacktrace.entries, 0, HIST_STACKTRACE_SIZE);
 905                         save_stack_trace(&stacktrace);
 906
 907                         key = entries;
 908                 } else {
 909                         field_contents = key_field->fn(key_field, rec);
 910                         if (key_field->flags & HIST_FIELD_FL_STRING) {
 911                                 key = (void *)(unsigned long)field_contents;
 912                                 use_compound_key = true;
 913                         } else
 914                                 key = (void *)&field_contents;
 915                 }
 916
 917                 if (use_compound_key)
 918                         add_to_key(compound_key, key, key_field, rec);
 919         }
 920
 921         if (use_compound_key)
 922                 key = compound_key;
 923
 924         elt = tracing_map_insert(hist_data->map, key);
 925         if (elt)
 926                 hist_trigger_elt_update(hist_data, elt, rec);
 927 }
 928
 929 static void hist_trigger_stacktrace_print(struct seq_file *m,
 930                                           unsigned long *stacktrace_entries,
 931                                           unsigned int max_entries)
 932 {
 933         char str[KSYM_SYMBOL_LEN];
 934         unsigned int spaces = 8;
 935         unsigned int i;
 936
 937         for (i = 0; i < max_entries; i++) {
 938                 if (stacktrace_entries[i] == ULONG_MAX)
 939                         return;
 940
 941                 seq_printf(m, "%*c", 1 + spaces, ' ');
 942                 sprint_symbol(str, stacktrace_entries[i]);
 943                 seq_printf(m, "%s\n", str);
 944         }
 945 }
 946
 947 static void
 948 hist_trigger_entry_print(struct seq_file *m,
 949                          struct hist_trigger_data *hist_data, void *key,
 950                          struct tracing_map_elt *elt)
 951 {
 952         struct hist_field *key_field;
 953         char str[KSYM_SYMBOL_LEN];
 954         bool multiline = false;
 955         unsigned int i;
 956         u64 uval;
 957
 958         seq_puts(m, "{ ");
 959
 960         for_each_hist_key_field(i, hist_data) {
 961                 key_field = hist_data->fields[i];
 962
 963                 if (i > hist_data->n_vals)
 964                         seq_puts(m, ", ");
 965
 966                 if (key_field->flags & HIST_FIELD_FL_HEX) {
 967                         uval = *(u64 *)(key + key_field->offset);
 968                         seq_printf(m, "%s: %llx",
 969                                    key_field->field->name, uval);
 970                 } else if (key_field->flags & HIST_FIELD_FL_SYM) {
 971                         uval = *(u64 *)(key + key_field->offset);
 972                         sprint_symbol_no_offset(str, uval);
 973                         seq_printf(m, "%s: [%llx] %-45s",
 974                                    key_field->field->name, uval, str);
 975                 } else if (key_field->flags & HIST_FIELD_FL_SYM_OFFSET) {
 976                         uval = *(u64 *)(key + key_field->offset);
 977                         sprint_symbol(str, uval);
 978                         seq_printf(m, "%s: [%llx] %-55s",
 979                                    key_field->field->name, uval, str);
 980                 } else if (key_field->flags & HIST_FIELD_FL_EXECNAME) {
 981                         char *comm = elt->private_data;
 982
 983                         uval = *(u64 *)(key + key_field->offset);
 984                         seq_printf(m, "%s: %-16s[%10llu]",
 985                                    key_field->field->name, comm, uval);
 986                 } else if (key_field->flags & HIST_FIELD_FL_SYSCALL) {
 987                         const char *syscall_name;
 988
 989                         uval = *(u64 *)(key + key_field->offset);
 990                         syscall_name = get_syscall_name(uval);
 991                         if (!syscall_name)
 992                                 syscall_name = "unknown_syscall";
 993
 994                         seq_printf(m, "%s: %-30s[%3llu]",
 995                                    key_field->field->name, syscall_name, uval);
 996                 } else if (key_field->flags & HIST_FIELD_FL_STACKTRACE) {
 997                         seq_puts(m, "stacktrace:\n");
 998                         hist_trigger_stacktrace_print(m,
 999                                                       key + key_field->offset,
1000                                                       HIST_STACKTRACE_DEPTH);
1001                         multiline = true;
1002                 } else if (key_field->flags & HIST_FIELD_FL_LOG2) {
1003                         seq_printf(m, "%s: ~ 2^%-2llu", key_field->field->name,
1004                                    *(u64 *)(key + key_field->offset));
1005                 } else if (key_field->flags & HIST_FIELD_FL_STRING) {
1006                         seq_printf(m, "%s: %-50s", key_field->field->name,
1007                                    (char *)(key + key_field->offset));
1008                 } else {
1009                         uval = *(u64 *)(key + key_field->offset);
1010                         seq_printf(m, "%s: %10llu", key_field->field->name,
1011                                    uval);
1012                 }
1013         }
1014
1015         if (!multiline)
1016                 seq_puts(m, " ");
1017
1018         seq_puts(m, "}");
1019
1020         seq_printf(m, " hitcount: %10llu",
1021                    tracing_map_read_sum(elt, HITCOUNT_IDX));
1022
1023         for (i = 1; i < hist_data->n_vals; i++) {
1024                 if (hist_data->fields[i]->flags & HIST_FIELD_FL_HEX) {
1025                         seq_printf(m, "  %s: %10llx",
1026                                    hist_data->fields[i]->field->name,
1027                                    tracing_map_read_sum(elt, i));
1028                 } else {
1029                         seq_printf(m, "  %s: %10llu",
1030                                    hist_data->fields[i]->field->name,
1031                                    tracing_map_read_sum(elt, i));
1032                 }
1033         }
1034
1035         seq_puts(m, "\n");
1036 }
1037
1038 static int print_entries(struct seq_file *m,
1039                          struct hist_trigger_data *hist_data)
1040 {
1041         struct tracing_map_sort_entry **sort_entries = NULL;
1042         struct tracing_map *map = hist_data->map;
1043         int i, n_entries;
1044
1045         n_entries = tracing_map_sort_entries(map, hist_data->sort_keys,
1046                                              hist_data->n_sort_keys,
1047                                              &sort_entries);
1048         if (n_entries < 0)
1049                 return n_entries;
1050
1051         for (i = 0; i < n_entries; i++)
1052                 hist_trigger_entry_print(m, hist_data,
1053                                          sort_entries[i]->key,
1054                                          sort_entries[i]->elt);
1055
1056         tracing_map_destroy_sort_entries(sort_entries, n_entries);
1057
1058         return n_entries;
1059 }
1060
1061 static void hist_trigger_show(struct seq_file *m,
1062                               struct event_trigger_data *data, int n)
1063 {
1064         struct hist_trigger_data *hist_data;
1065         int n_entries, ret = 0;
1066
1067         if (n > 0)
1068                 seq_puts(m, "\n\n");
1069
1070         seq_puts(m, "# event histogram\n#\n# trigger info: ");
1071         data->ops->print(m, data->ops, data);
1072         seq_puts(m, "#\n\n");
1073
1074         hist_data = data->private_data;
1075         n_entries = print_entries(m, hist_data);
1076         if (n_entries < 0) {
1077                 ret = n_entries;
1078                 n_entries = 0;
1079         }
1080
1081         seq_printf(m, "\nTotals:\n    Hits: %llu\n    Entries: %u\n    Dropped: %llu\n",
1082                    (u64)atomic64_read(&hist_data->map->hits),
1083                    n_entries, (u64)atomic64_read(&hist_data->map->drops));
1084 }
1085
1086 static int hist_show(struct seq_file *m, void *v)
1087 {
1088         struct event_trigger_data *data;
1089         struct trace_event_file *event_file;
1090         int n = 0, ret = 0;
1091
1092         mutex_lock(&event_mutex);
1093
1094         event_file = event_file_data(m->private);
1095         if (unlikely(!event_file)) {
1096                 ret = -ENODEV;
1097                 goto out_unlock;
1098         }
1099
1100         list_for_each_entry_rcu(data, &event_file->triggers, list) {
1101                 if (data->cmd_ops->trigger_type == ETT_EVENT_HIST)
1102                         hist_trigger_show(m, data, n++);
1103         }
1104
1105  out_unlock:
1106         mutex_unlock(&event_mutex);
1107
1108         return ret;
1109 }
1110
1111 static int event_hist_open(struct inode *inode, struct file *file)
1112 {
1113         return single_open(file, hist_show, file);
1114 }
1115
1116 const struct file_operations event_hist_fops = {
1117         .open = event_hist_open,
1118         .read = seq_read,
1119         .llseek = seq_lseek,
1120         .release = single_release,
1121 };
1122
1123 static const char *get_hist_field_flags(struct hist_field *hist_field)
1124 {
1125         const char *flags_str = NULL;
1126
1127         if (hist_field->flags & HIST_FIELD_FL_HEX)
1128                 flags_str = "hex";
1129         else if (hist_field->flags & HIST_FIELD_FL_SYM)
1130                 flags_str = "sym";
1131         else if (hist_field->flags & HIST_FIELD_FL_SYM_OFFSET)
1132                 flags_str = "sym-offset";
1133         else if (hist_field->flags & HIST_FIELD_FL_EXECNAME)
1134                 flags_str = "execname";
1135         else if (hist_field->flags & HIST_FIELD_FL_SYSCALL)
1136                 flags_str = "syscall";
1137         else if (hist_field->flags & HIST_FIELD_FL_LOG2)
1138                 flags_str = "log2";
1139
1140         return flags_str;
1141 }
1142
1143 static void hist_field_print(struct seq_file *m, struct hist_field *hist_field)
1144 {
1145         seq_printf(m, "%s", hist_field->field->name);
1146         if (hist_field->flags) {
1147                 const char *flags_str = get_hist_field_flags(hist_field);
1148
1149                 if (flags_str)
1150                         seq_printf(m, ".%s", flags_str);
1151         }
1152 }
1153
1154 static int event_hist_trigger_print(struct seq_file *m,
1155                                     struct event_trigger_ops *ops,
1156                                     struct event_trigger_data *data)
1157 {
1158         struct hist_trigger_data *hist_data = data->private_data;
1159         struct hist_field *key_field;
1160         unsigned int i;
1161
1162         seq_puts(m, "hist:");
1163
1164         if (data->name)
1165                 seq_printf(m, "%s:", data->name);
1166
1167         seq_puts(m, "keys=");
1168
1169         for_each_hist_key_field(i, hist_data) {
1170                 key_field = hist_data->fields[i];
1171
1172                 if (i > hist_data->n_vals)
1173                         seq_puts(m, ",");
1174
1175                 if (key_field->flags & HIST_FIELD_FL_STACKTRACE)
1176                         seq_puts(m, "stacktrace");
1177                 else
1178                         hist_field_print(m, key_field);
1179         }
1180
1181         seq_puts(m, ":vals=");
1182
1183         for_each_hist_val_field(i, hist_data) {
1184                 if (i == HITCOUNT_IDX)
1185                         seq_puts(m, "hitcount");
1186                 else {
1187                         seq_puts(m, ",");
1188                         hist_field_print(m, hist_data->fields[i]);
1189                 }
1190         }
1191
1192         seq_puts(m, ":sort=");
1193
1194         for (i = 0; i < hist_data->n_sort_keys; i++) {
1195                 struct tracing_map_sort_key *sort_key;
1196
1197                 sort_key = &hist_data->sort_keys[i];
1198
1199                 if (i > 0)
1200                         seq_puts(m, ",");
1201
1202                 if (sort_key->field_idx == HITCOUNT_IDX)
1203                         seq_puts(m, "hitcount");
1204                 else {
1205                         unsigned int idx = sort_key->field_idx;
1206
1207                         if (WARN_ON(idx >= TRACING_MAP_FIELDS_MAX))
1208                                 return -EINVAL;
1209
1210                         hist_field_print(m, hist_data->fields[idx]);
1211                 }
1212
1213                 if (sort_key->descending)
1214                         seq_puts(m, ".descending");
1215         }
1216
1217         seq_printf(m, ":size=%u", (1 << hist_data->map->map_bits));
1218
1219         if (data->filter_str)
1220                 seq_printf(m, " if %s", data->filter_str);
1221
1222         if (data->paused)
1223                 seq_puts(m, " [paused]");
1224         else
1225                 seq_puts(m, " [active]");
1226
1227         seq_putc(m, '\n');
1228
1229         return 0;
1230 }
1231
1232 static int event_hist_trigger_init(struct event_trigger_ops *ops,
1233                                    struct event_trigger_data *data)
1234 {
1235         struct hist_trigger_data *hist_data = data->private_data;
1236
1237         if (!data->ref && hist_data->attrs->name)
1238                 save_named_trigger(hist_data->attrs->name, data);
1239
1240         data->ref++;
1241
1242         return 0;
1243 }
1244
1245 static void event_hist_trigger_free(struct event_trigger_ops *ops,
1246                                     struct event_trigger_data *data)
1247 {
1248         struct hist_trigger_data *hist_data = data->private_data;
1249
1250         if (WARN_ON_ONCE(data->ref <= 0))
1251                 return;
1252
1253         data->ref--;
1254         if (!data->ref) {
1255                 if (data->name)
1256                         del_named_trigger(data);
1257                 trigger_data_free(data);
1258                 destroy_hist_data(hist_data);
1259         }
1260 }
1261
1262 static struct event_trigger_ops event_hist_trigger_ops = {
1263         .func                   = event_hist_trigger,
1264         .print                  = event_hist_trigger_print,
1265         .init                   = event_hist_trigger_init,
1266         .free                   = event_hist_trigger_free,
1267 };
1268
1269 static int event_hist_trigger_named_init(struct event_trigger_ops *ops,
1270                                          struct event_trigger_data *data)
1271 {
1272         data->ref++;
1273
1274         save_named_trigger(data->named_data->name, data);
1275
1276         event_hist_trigger_init(ops, data->named_data);
1277
1278         return 0;
1279 }
1280
1281 static void event_hist_trigger_named_free(struct event_trigger_ops *ops,
1282                                           struct event_trigger_data *data)
1283 {
1284         if (WARN_ON_ONCE(data->ref <= 0))
1285                 return;
1286
1287         event_hist_trigger_free(ops, data->named_data);
1288
1289         data->ref--;
1290         if (!data->ref) {
1291                 del_named_trigger(data);
1292                 trigger_data_free(data);
1293         }
1294 }
1295
1296 static struct event_trigger_ops event_hist_trigger_named_ops = {
1297         .func                   = event_hist_trigger,
1298         .print                  = event_hist_trigger_print,
1299         .init                   = event_hist_trigger_named_init,
1300         .free                   = event_hist_trigger_named_free,
1301 };
1302
1303 static struct event_trigger_ops *event_hist_get_trigger_ops(char *cmd,
1304                                                             char *param)
1305 {
1306         return &event_hist_trigger_ops;
1307 }
1308
1309 static void hist_clear(struct event_trigger_data *data)
1310 {
1311         struct hist_trigger_data *hist_data = data->private_data;
1312
1313         if (data->name)
1314                 pause_named_trigger(data);
1315
1316         synchronize_sched();
1317
1318         tracing_map_clear(hist_data->map);
1319
1320         if (data->name)
1321                 unpause_named_trigger(data);
1322 }
1323
1324 static bool compatible_field(struct ftrace_event_field *field,
1325                              struct ftrace_event_field *test_field)
1326 {
1327         if (field == test_field)
1328                 return true;
1329         if (field == NULL || test_field == NULL)
1330                 return false;
1331         if (strcmp(field->name, test_field->name) != 0)
1332                 return false;
1333         if (strcmp(field->type, test_field->type) != 0)
1334                 return false;
1335         if (field->size != test_field->size)
1336                 return false;
1337         if (field->is_signed != test_field->is_signed)
1338                 return false;
1339
1340         return true;
1341 }
1342
1343 static bool hist_trigger_match(struct event_trigger_data *data,
1344                                struct event_trigger_data *data_test,
1345                                struct event_trigger_data *named_data,
1346                                bool ignore_filter)
1347 {
1348         struct tracing_map_sort_key *sort_key, *sort_key_test;
1349         struct hist_trigger_data *hist_data, *hist_data_test;
1350         struct hist_field *key_field, *key_field_test;
1351         unsigned int i;
1352
1353         if (named_data && (named_data != data_test) &&
1354             (named_data != data_test->named_data))
1355                 return false;
1356
1357         if (!named_data && is_named_trigger(data_test))
1358                 return false;
1359
1360         hist_data = data->private_data;
1361         hist_data_test = data_test->private_data;
1362
1363         if (hist_data->n_vals != hist_data_test->n_vals ||
1364             hist_data->n_fields != hist_data_test->n_fields ||
1365             hist_data->n_sort_keys != hist_data_test->n_sort_keys)
1366                 return false;
1367
1368         if (!ignore_filter) {
1369                 if ((data->filter_str && !data_test->filter_str) ||
1370                    (!data->filter_str && data_test->filter_str))
1371                         return false;
1372         }
1373
1374         for_each_hist_field(i, hist_data) {
1375                 key_field = hist_data->fields[i];
1376                 key_field_test = hist_data_test->fields[i];
1377
1378                 if (key_field->flags != key_field_test->flags)
1379                         return false;
1380                 if (!compatible_field(key_field->field, key_field_test->field))
1381                         return false;
1382                 if (key_field->offset != key_field_test->offset)
1383                         return false;
1384         }
1385
1386         for (i = 0; i < hist_data->n_sort_keys; i++) {
1387                 sort_key = &hist_data->sort_keys[i];
1388                 sort_key_test = &hist_data_test->sort_keys[i];
1389
1390                 if (sort_key->field_idx != sort_key_test->field_idx ||
1391                     sort_key->descending != sort_key_test->descending)
1392                         return false;
1393         }
1394
1395         if (!ignore_filter && data->filter_str &&
1396             (strcmp(data->filter_str, data_test->filter_str) != 0))
1397                 return false;
1398
1399         return true;
1400 }
1401
1402 static int hist_register_trigger(char *glob, struct event_trigger_ops *ops,
1403                                  struct event_trigger_data *data,
1404                                  struct trace_event_file *file)
1405 {
1406         struct hist_trigger_data *hist_data = data->private_data;
1407         struct event_trigger_data *test, *named_data = NULL;
1408         int ret = 0;
1409
1410         if (hist_data->attrs->name) {
1411                 named_data = find_named_trigger(hist_data->attrs->name);
1412                 if (named_data) {
1413                         if (!hist_trigger_match(data, named_data, named_data,
1414                                                 true)) {
1415                                 ret = -EINVAL;
1416                                 goto out;
1417                         }
1418                 }
1419         }
1420
1421         if (hist_data->attrs->name && !named_data)
1422                 goto new;
1423
1424         list_for_each_entry_rcu(test, &file->triggers, list) {
1425                 if (test->cmd_ops->trigger_type == ETT_EVENT_HIST) {
1426                         if (!hist_trigger_match(data, test, named_data, false))
1427                                 continue;
1428                         if (hist_data->attrs->pause)
1429                                 test->paused = true;
1430                         else if (hist_data->attrs->cont)
1431                                 test->paused = false;
1432                         else if (hist_data->attrs->clear)
1433                                 hist_clear(test);
1434                         else
1435                                 ret = -EEXIST;
1436                         goto out;
1437                 }
1438         }
1439  new:
1440         if (hist_data->attrs->cont || hist_data->attrs->clear) {
1441                 ret = -ENOENT;
1442                 goto out;
1443         }
1444
1445         if (hist_data->attrs->pause)
1446                 data->paused = true;
1447
1448         if (named_data) {
1449                 destroy_hist_data(data->private_data);
1450                 data->private_data = named_data->private_data;
1451                 set_named_trigger_data(data, named_data);
1452                 data->ops = &event_hist_trigger_named_ops;
1453         }
1454
1455         if (data->ops->init) {
1456                 ret = data->ops->init(data->ops, data);
1457                 if (ret < 0)
1458                         goto out;
1459         }
1460
1461         list_add_rcu(&data->list, &file->triggers);
1462         ret++;
1463
1464         update_cond_flag(file);
1465
1466         if (trace_event_trigger_enable_disable(file, 1) < 0) {
1467                 list_del_rcu(&data->list);
1468                 update_cond_flag(file);
1469                 ret--;
1470         }
1471  out:
1472         return ret;
1473 }
1474
1475 static void hist_unregister_trigger(char *glob, struct event_trigger_ops *ops,
1476                                     struct event_trigger_data *data,
1477                                     struct trace_event_file *file)
1478 {
1479         struct hist_trigger_data *hist_data = data->private_data;
1480         struct event_trigger_data *test, *named_data = NULL;
1481         bool unregistered = false;
1482
1483         if (hist_data->attrs->name)
1484                 named_data = find_named_trigger(hist_data->attrs->name);
1485
1486         list_for_each_entry_rcu(test, &file->triggers, list) {
1487                 if (test->cmd_ops->trigger_type == ETT_EVENT_HIST) {
1488                         if (!hist_trigger_match(data, test, named_data, false))
1489                                 continue;
1490                         unregistered = true;
1491                         list_del_rcu(&test->list);
1492                         trace_event_trigger_enable_disable(file, 0);
1493                         update_cond_flag(file);
1494                         break;
1495                 }
1496         }
1497
1498         if (unregistered && test->ops->free)
1499                 test->ops->free(test->ops, test);
1500 }
1501
1502 static void hist_unreg_all(struct trace_event_file *file)
1503 {
1504         struct event_trigger_data *test, *n;
1505
1506         list_for_each_entry_safe(test, n, &file->triggers, list) {
1507                 if (test->cmd_ops->trigger_type == ETT_EVENT_HIST) {
1508                         list_del_rcu(&test->list);
1509                         trace_event_trigger_enable_disable(file, 0);
1510                         update_cond_flag(file);
1511                         if (test->ops->free)
1512                                 test->ops->free(test->ops, test);
1513                 }
1514         }
1515 }
1516
1517 static int event_hist_trigger_func(struct event_command *cmd_ops,
1518                                    struct trace_event_file *file,
1519                                    char *glob, char *cmd, char *param)
1520 {
1521         unsigned int hist_trigger_bits = TRACING_MAP_BITS_DEFAULT;
1522         struct event_trigger_data *trigger_data;
1523         struct hist_trigger_attrs *attrs;
1524         struct event_trigger_ops *trigger_ops;
1525         struct hist_trigger_data *hist_data;
1526         char *trigger;
1527         int ret = 0;
1528
1529         if (!param)
1530                 return -EINVAL;
1531
1532         /* separate the trigger from the filter (k:v [if filter]) */
1533         trigger = strsep(&param, " \t");
1534         if (!trigger)
1535                 return -EINVAL;
1536
1537         attrs = parse_hist_trigger_attrs(trigger);
1538         if (IS_ERR(attrs))
1539                 return PTR_ERR(attrs);
1540
1541         if (attrs->map_bits)
1542                 hist_trigger_bits = attrs->map_bits;
1543
1544         hist_data = create_hist_data(hist_trigger_bits, attrs, file);
1545         if (IS_ERR(hist_data)) {
1546                 destroy_hist_trigger_attrs(attrs);
1547                 return PTR_ERR(hist_data);
1548         }
1549
1550         trigger_ops = cmd_ops->get_trigger_ops(cmd, trigger);
1551
1552         ret = -ENOMEM;
1553         trigger_data = kzalloc(sizeof(*trigger_data), GFP_KERNEL);
1554         if (!trigger_data)
1555                 goto out_free;
1556
1557         trigger_data->count = -1;
1558         trigger_data->ops = trigger_ops;
1559         trigger_data->cmd_ops = cmd_ops;
1560
1561         INIT_LIST_HEAD(&trigger_data->list);
1562         RCU_INIT_POINTER(trigger_data->filter, NULL);
1563
1564         trigger_data->private_data = hist_data;
1565
1566         /* if param is non-empty, it's supposed to be a filter */
1567         if (param && cmd_ops->set_filter) {
1568                 ret = cmd_ops->set_filter(param, trigger_data, file);
1569                 if (ret < 0)
1570                         goto out_free;
1571         }
1572
1573         if (glob[0] == '!') {
1574                 cmd_ops->unreg(glob+1, trigger_ops, trigger_data, file);
1575                 ret = 0;
1576                 goto out_free;
1577         }
1578
1579         ret = cmd_ops->reg(glob, trigger_ops, trigger_data, file);
1580         /*
1581          * The above returns on success the # of triggers registered,
1582          * but if it didn't register any it returns zero.  Consider no
1583          * triggers registered a failure too.
1584          */
1585         if (!ret) {
1586                 if (!(attrs->pause || attrs->cont || attrs->clear))
1587                         ret = -ENOENT;
1588                 goto out_free;
1589         } else if (ret < 0)
1590                 goto out_free;
1591         /* Just return zero, not the number of registered triggers */
1592         ret = 0;
1593  out:
1594         return ret;
1595  out_free:
1596         if (cmd_ops->set_filter)
1597                 cmd_ops->set_filter(NULL, trigger_data, NULL);
1598
1599         kfree(trigger_data);
1600
1601         destroy_hist_data(hist_data);
1602         goto out;
1603 }
1604
1605 static struct event_command trigger_hist_cmd = {
1606         .name                   = "hist",
1607         .trigger_type           = ETT_EVENT_HIST,
1608         .flags                  = EVENT_CMD_FL_NEEDS_REC,
1609         .func                   = event_hist_trigger_func,
1610         .reg                    = hist_register_trigger,
1611         .unreg                  = hist_unregister_trigger,
1612         .unreg_all              = hist_unreg_all,
1613         .get_trigger_ops        = event_hist_get_trigger_ops,
1614         .set_filter             = set_trigger_filter,
1615 };
1616
1617 __init int register_trigger_hist_cmd(void)
1618 {
1619         int ret;
1620
1621         ret = register_event_command(&trigger_hist_cmd);
1622         WARN_ON(ret < 0);
1623
1624         return ret;
1625 }
1626
1627 static void
1628 hist_enable_trigger(struct event_trigger_data *data, void *rec)
1629 {
1630         struct enable_trigger_data *enable_data = data->private_data;
1631         struct event_trigger_data *test;
1632
1633         list_for_each_entry_rcu(test, &enable_data->file->triggers, list) {
1634                 if (test->cmd_ops->trigger_type == ETT_EVENT_HIST) {
1635                         if (enable_data->enable)
1636                                 test->paused = false;
1637                         else
1638                                 test->paused = true;
1639                 }
1640         }
1641 }
1642
1643 static void
1644 hist_enable_count_trigger(struct event_trigger_data *data, void *rec)
1645 {
1646         if (!data->count)
1647                 return;
1648
1649         if (data->count != -1)
1650                 (data->count)--;
1651
1652         hist_enable_trigger(data, rec);
1653 }
1654
1655 static struct event_trigger_ops hist_enable_trigger_ops = {
1656         .func                   = hist_enable_trigger,
1657         .print                  = event_enable_trigger_print,
1658         .init                   = event_trigger_init,
1659         .free                   = event_enable_trigger_free,
1660 };
1661
1662 static struct event_trigger_ops hist_enable_count_trigger_ops = {
1663         .func                   = hist_enable_count_trigger,
1664         .print                  = event_enable_trigger_print,
1665         .init                   = event_trigger_init,
1666         .free                   = event_enable_trigger_free,
1667 };
1668
1669 static struct event_trigger_ops hist_disable_trigger_ops = {
1670         .func                   = hist_enable_trigger,
1671         .print                  = event_enable_trigger_print,
1672         .init                   = event_trigger_init,
1673         .free                   = event_enable_trigger_free,
1674 };
1675
1676 static struct event_trigger_ops hist_disable_count_trigger_ops = {
1677         .func                   = hist_enable_count_trigger,
1678         .print                  = event_enable_trigger_print,
1679         .init                   = event_trigger_init,
1680         .free                   = event_enable_trigger_free,
1681 };
1682
1683 static struct event_trigger_ops *
1684 hist_enable_get_trigger_ops(char *cmd, char *param)
1685 {
1686         struct event_trigger_ops *ops;
1687         bool enable;
1688
1689         enable = (strcmp(cmd, ENABLE_HIST_STR) == 0);
1690
1691         if (enable)
1692                 ops = param ? &hist_enable_count_trigger_ops :
1693                         &hist_enable_trigger_ops;
1694         else
1695                 ops = param ? &hist_disable_count_trigger_ops :
1696                         &hist_disable_trigger_ops;
1697
1698         return ops;
1699 }
1700
1701 static void hist_enable_unreg_all(struct trace_event_file *file)
1702 {
1703         struct event_trigger_data *test, *n;
1704
1705         list_for_each_entry_safe(test, n, &file->triggers, list) {
1706                 if (test->cmd_ops->trigger_type == ETT_HIST_ENABLE) {
1707                         list_del_rcu(&test->list);
1708                         update_cond_flag(file);
1709                         trace_event_trigger_enable_disable(file, 0);
1710                         if (test->ops->free)
1711                                 test->ops->free(test->ops, test);
1712                 }
1713         }
1714 }
1715
1716 static struct event_command trigger_hist_enable_cmd = {
1717         .name                   = ENABLE_HIST_STR,
1718         .trigger_type           = ETT_HIST_ENABLE,
1719         .func                   = event_enable_trigger_func,
1720         .reg                    = event_enable_register_trigger,
1721         .unreg                  = event_enable_unregister_trigger,
1722         .unreg_all              = hist_enable_unreg_all,
1723         .get_trigger_ops        = hist_enable_get_trigger_ops,
1724         .set_filter             = set_trigger_filter,
1725 };
1726
1727 static struct event_command trigger_hist_disable_cmd = {
1728         .name                   = DISABLE_HIST_STR,
1729         .trigger_type           = ETT_HIST_ENABLE,
1730         .func                   = event_enable_trigger_func,
1731         .reg                    = event_enable_register_trigger,
1732         .unreg                  = event_enable_unregister_trigger,
1733         .unreg_all              = hist_enable_unreg_all,
1734         .get_trigger_ops        = hist_enable_get_trigger_ops,
1735         .set_filter             = set_trigger_filter,
1736 };
1737
1738 static __init void unregister_trigger_hist_enable_disable_cmds(void)
1739 {
1740         unregister_event_command(&trigger_hist_enable_cmd);
1741         unregister_event_command(&trigger_hist_disable_cmd);
1742 }
1743
1744 __init int register_trigger_hist_enable_disable_cmds(void)
1745 {
1746         int ret;
1747
1748         ret = register_event_command(&trigger_hist_enable_cmd);
1749         if (WARN_ON(ret < 0))
1750                 return ret;
1751         ret = register_event_command(&trigger_hist_disable_cmd);
1752         if (WARN_ON(ret < 0))
1753                 unregister_trigger_hist_enable_disable_cmds();
1754
1755         return ret;
1756 }