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 (is_string_field(field)) {
 375                 flags |= HIST_FIELD_FL_STRING;
 376
 377                 if (field->filter_type == FILTER_STATIC_STRING)
 378                         hist_field->fn = hist_field_string;
 379                 else if (field->filter_type == FILTER_DYN_STRING)
 380                         hist_field->fn = hist_field_dynstring;
 381                 else
 382                         hist_field->fn = hist_field_pstring;
 383         } else {
 384                 hist_field->fn = select_value_fn(field->size,
 385                                                  field->is_signed);
 386                 if (!hist_field->fn) {
 387                         destroy_hist_field(hist_field);
 388                         return NULL;
 389                 }
 390         }
 391  out:
 392         hist_field->field = field;
 393         hist_field->flags = flags;
 394
 395         return hist_field;
 396 }
 397
 398 static void destroy_hist_fields(struct hist_trigger_data *hist_data)
 399 {
 400         unsigned int i;
 401
 402         for (i = 0; i < TRACING_MAP_FIELDS_MAX; i++) {
 403                 if (hist_data->fields[i]) {
 404                         destroy_hist_field(hist_data->fields[i]);
 405                         hist_data->fields[i] = NULL;
 406                 }
 407         }
 408 }
 409
 410 static int create_hitcount_val(struct hist_trigger_data *hist_data)
 411 {
 412         hist_data->fields[HITCOUNT_IDX] =
 413                 create_hist_field(NULL, HIST_FIELD_FL_HITCOUNT);
 414         if (!hist_data->fields[HITCOUNT_IDX])
 415                 return -ENOMEM;
 416
 417         hist_data->n_vals++;
 418
 419         if (WARN_ON(hist_data->n_vals > TRACING_MAP_VALS_MAX))
 420                 return -EINVAL;
 421
 422         return 0;
 423 }
 424
 425 static int create_val_field(struct hist_trigger_data *hist_data,
 426                             unsigned int val_idx,
 427                             struct trace_event_file *file,
 428                             char *field_str)
 429 {
 430         struct ftrace_event_field *field = NULL;
 431         unsigned long flags = 0;
 432         char *field_name;
 433         int ret = 0;
 434
 435         if (WARN_ON(val_idx >= TRACING_MAP_VALS_MAX))
 436                 return -EINVAL;
 437
 438         field_name = strsep(&field_str, ".");
 439         if (field_str) {
 440                 if (strcmp(field_str, "hex") == 0)
 441                         flags |= HIST_FIELD_FL_HEX;
 442                 else {
 443                         ret = -EINVAL;
 444                         goto out;
 445                 }
 446         }
 447
 448         field = trace_find_event_field(file->event_call, field_name);
 449         if (!field) {
 450                 ret = -EINVAL;
 451                 goto out;
 452         }
 453
 454         hist_data->fields[val_idx] = create_hist_field(field, flags);
 455         if (!hist_data->fields[val_idx]) {
 456                 ret = -ENOMEM;
 457                 goto out;
 458         }
 459
 460         ++hist_data->n_vals;
 461
 462         if (WARN_ON(hist_data->n_vals > TRACING_MAP_VALS_MAX))
 463                 ret = -EINVAL;
 464  out:
 465         return ret;
 466 }
 467
 468 static int create_val_fields(struct hist_trigger_data *hist_data,
 469                              struct trace_event_file *file)
 470 {
 471         char *fields_str, *field_str;
 472         unsigned int i, j;
 473         int ret;
 474
 475         ret = create_hitcount_val(hist_data);
 476         if (ret)
 477                 goto out;
 478
 479         fields_str = hist_data->attrs->vals_str;
 480         if (!fields_str)
 481                 goto out;
 482
 483         strsep(&fields_str, "=");
 484         if (!fields_str)
 485                 goto out;
 486
 487         for (i = 0, j = 1; i < TRACING_MAP_VALS_MAX &&
 488                      j < TRACING_MAP_VALS_MAX; i++) {
 489                 field_str = strsep(&fields_str, ",");
 490                 if (!field_str)
 491                         break;
 492                 if (strcmp(field_str, "hitcount") == 0)
 493                         continue;
 494                 ret = create_val_field(hist_data, j++, file, field_str);
 495                 if (ret)
 496                         goto out;
 497         }
 498         if (fields_str && (strcmp(fields_str, "hitcount") != 0))
 499                 ret = -EINVAL;
 500  out:
 501         return ret;
 502 }
 503
 504 static int create_key_field(struct hist_trigger_data *hist_data,
 505                             unsigned int key_idx,
 506                             unsigned int key_offset,
 507                             struct trace_event_file *file,
 508                             char *field_str)
 509 {
 510         struct ftrace_event_field *field = NULL;
 511         unsigned long flags = 0;
 512         unsigned int key_size;
 513         int ret = 0;
 514
 515         if (WARN_ON(key_idx >= TRACING_MAP_FIELDS_MAX))
 516                 return -EINVAL;
 517
 518         flags |= HIST_FIELD_FL_KEY;
 519
 520         if (strcmp(field_str, "stacktrace") == 0) {
 521                 flags |= HIST_FIELD_FL_STACKTRACE;
 522                 key_size = sizeof(unsigned long) * HIST_STACKTRACE_DEPTH;
 523         } else {
 524                 char *field_name = strsep(&field_str, ".");
 525
 526                 if (field_str) {
 527                         if (strcmp(field_str, "hex") == 0)
 528                                 flags |= HIST_FIELD_FL_HEX;
 529                         else if (strcmp(field_str, "sym") == 0)
 530                                 flags |= HIST_FIELD_FL_SYM;
 531                         else if (strcmp(field_str, "sym-offset") == 0)
 532                                 flags |= HIST_FIELD_FL_SYM_OFFSET;
 533                         else if ((strcmp(field_str, "execname") == 0) &&
 534                                  (strcmp(field_name, "common_pid") == 0))
 535                                 flags |= HIST_FIELD_FL_EXECNAME;
 536                         else if (strcmp(field_str, "syscall") == 0)
 537                                 flags |= HIST_FIELD_FL_SYSCALL;
 538                         else if (strcmp(field_str, "log2") == 0)
 539                                 flags |= HIST_FIELD_FL_LOG2;
 540                         else {
 541                                 ret = -EINVAL;
 542                                 goto out;
 543                         }
 544                 }
 545
 546                 field = trace_find_event_field(file->event_call, field_name);
 547                 if (!field) {
 548                         ret = -EINVAL;
 549                         goto out;
 550                 }
 551
 552                 if (is_string_field(field))
 553                         key_size = MAX_FILTER_STR_VAL;
 554                 else
 555                         key_size = field->size;
 556         }
 557
 558         hist_data->fields[key_idx] = create_hist_field(field, flags);
 559         if (!hist_data->fields[key_idx]) {
 560                 ret = -ENOMEM;
 561                 goto out;
 562         }
 563
 564         key_size = ALIGN(key_size, sizeof(u64));
 565         hist_data->fields[key_idx]->size = key_size;
 566         hist_data->fields[key_idx]->offset = key_offset;
 567         hist_data->key_size += key_size;
 568         if (hist_data->key_size > HIST_KEY_SIZE_MAX) {
 569                 ret = -EINVAL;
 570                 goto out;
 571         }
 572
 573         hist_data->n_keys++;
 574
 575         if (WARN_ON(hist_data->n_keys > TRACING_MAP_KEYS_MAX))
 576                 return -EINVAL;
 577
 578         ret = key_size;
 579  out:
 580         return ret;
 581 }
 582
 583 static int create_key_fields(struct hist_trigger_data *hist_data,
 584                              struct trace_event_file *file)
 585 {
 586         unsigned int i, key_offset = 0, n_vals = hist_data->n_vals;
 587         char *fields_str, *field_str;
 588         int ret = -EINVAL;
 589
 590         fields_str = hist_data->attrs->keys_str;
 591         if (!fields_str)
 592                 goto out;
 593
 594         strsep(&fields_str, "=");
 595         if (!fields_str)
 596                 goto out;
 597
 598         for (i = n_vals; i < n_vals + TRACING_MAP_KEYS_MAX; i++) {
 599                 field_str = strsep(&fields_str, ",");
 600                 if (!field_str)
 601                         break;
 602                 ret = create_key_field(hist_data, i, key_offset,
 603                                        file, field_str);
 604                 if (ret < 0)
 605                         goto out;
 606                 key_offset += ret;
 607         }
 608         if (fields_str) {
 609                 ret = -EINVAL;
 610                 goto out;
 611         }
 612         ret = 0;
 613  out:
 614         return ret;
 615 }
 616
 617 static int create_hist_fields(struct hist_trigger_data *hist_data,
 618                               struct trace_event_file *file)
 619 {
 620         int ret;
 621
 622         ret = create_val_fields(hist_data, file);
 623         if (ret)
 624                 goto out;
 625
 626         ret = create_key_fields(hist_data, file);
 627         if (ret)
 628                 goto out;
 629
 630         hist_data->n_fields = hist_data->n_vals + hist_data->n_keys;
 631  out:
 632         return ret;
 633 }
 634
 635 static int is_descending(const char *str)
 636 {
 637         if (!str)
 638                 return 0;
 639
 640         if (strcmp(str, "descending") == 0)
 641                 return 1;
 642
 643         if (strcmp(str, "ascending") == 0)
 644                 return 0;
 645
 646         return -EINVAL;
 647 }
 648
 649 static int create_sort_keys(struct hist_trigger_data *hist_data)
 650 {
 651         char *fields_str = hist_data->attrs->sort_key_str;
 652         struct ftrace_event_field *field = NULL;
 653         struct tracing_map_sort_key *sort_key;
 654         int descending, ret = 0;
 655         unsigned int i, j;
 656
 657         hist_data->n_sort_keys = 1; /* we always have at least one, hitcount */
 658
 659         if (!fields_str)
 660                 goto out;
 661
 662         strsep(&fields_str, "=");
 663         if (!fields_str) {
 664                 ret = -EINVAL;
 665                 goto out;
 666         }
 667
 668         for (i = 0; i < TRACING_MAP_SORT_KEYS_MAX; i++) {
 669                 char *field_str, *field_name;
 670
 671                 sort_key = &hist_data->sort_keys[i];
 672
 673                 field_str = strsep(&fields_str, ",");
 674                 if (!field_str) {
 675                         if (i == 0)
 676                                 ret = -EINVAL;
 677                         break;
 678                 }
 679
 680                 if ((i == TRACING_MAP_SORT_KEYS_MAX - 1) && fields_str) {
 681                         ret = -EINVAL;
 682                         break;
 683                 }
 684
 685                 field_name = strsep(&field_str, ".");
 686                 if (!field_name) {
 687                         ret = -EINVAL;
 688                         break;
 689                 }
 690
 691                 if (strcmp(field_name, "hitcount") == 0) {
 692                         descending = is_descending(field_str);
 693                         if (descending < 0) {
 694                                 ret = descending;
 695                                 break;
 696                         }
 697                         sort_key->descending = descending;
 698                         continue;
 699                 }
 700
 701                 for (j = 1; j < hist_data->n_fields; j++) {
 702                         field = hist_data->fields[j]->field;
 703                         if (field && (strcmp(field_name, field->name) == 0)) {
 704                                 sort_key->field_idx = j;
 705                                 descending = is_descending(field_str);
 706                                 if (descending < 0) {
 707                                         ret = descending;
 708                                         goto out;
 709                                 }
 710                                 sort_key->descending = descending;
 711                                 break;
 712                         }
 713                 }
 714                 if (j == hist_data->n_fields) {
 715                         ret = -EINVAL;
 716                         break;
 717                 }
 718         }
 719         hist_data->n_sort_keys = i;
 720  out:
 721         return ret;
 722 }
 723
 724 static void destroy_hist_data(struct hist_trigger_data *hist_data)
 725 {
 726         destroy_hist_trigger_attrs(hist_data->attrs);
 727         destroy_hist_fields(hist_data);
 728         tracing_map_destroy(hist_data->map);
 729         kfree(hist_data);
 730 }
 731
 732 static int create_tracing_map_fields(struct hist_trigger_data *hist_data)
 733 {
 734         struct tracing_map *map = hist_data->map;
 735         struct ftrace_event_field *field;
 736         struct hist_field *hist_field;
 737         unsigned int i, idx;
 738
 739         for_each_hist_field(i, hist_data) {
 740                 hist_field = hist_data->fields[i];
 741                 if (hist_field->flags & HIST_FIELD_FL_KEY) {
 742                         tracing_map_cmp_fn_t cmp_fn;
 743
 744                         field = hist_field->field;
 745
 746                         if (hist_field->flags & HIST_FIELD_FL_STACKTRACE)
 747                                 cmp_fn = tracing_map_cmp_none;
 748                         else if (is_string_field(field))
 749                                 cmp_fn = tracing_map_cmp_string;
 750                         else
 751                                 cmp_fn = tracing_map_cmp_num(field->size,
 752                                                              field->is_signed);
 753                         idx = tracing_map_add_key_field(map,
 754                                                         hist_field->offset,
 755                                                         cmp_fn);
 756
 757                 } else
 758                         idx = tracing_map_add_sum_field(map);
 759
 760                 if (idx < 0)
 761                         return idx;
 762         }
 763
 764         return 0;
 765 }
 766
 767 static bool need_tracing_map_ops(struct hist_trigger_data *hist_data)
 768 {
 769         struct hist_field *key_field;
 770         unsigned int i;
 771
 772         for_each_hist_key_field(i, hist_data) {
 773                 key_field = hist_data->fields[i];
 774
 775                 if (key_field->flags & HIST_FIELD_FL_EXECNAME)
 776                         return true;
 777         }
 778
 779         return false;
 780 }
 781
 782 static struct hist_trigger_data *
 783 create_hist_data(unsigned int map_bits,
 784                  struct hist_trigger_attrs *attrs,
 785                  struct trace_event_file *file)
 786 {
 787         const struct tracing_map_ops *map_ops = NULL;
 788         struct hist_trigger_data *hist_data;
 789         int ret = 0;
 790
 791         hist_data = kzalloc(sizeof(*hist_data), GFP_KERNEL);
 792         if (!hist_data)
 793                 return ERR_PTR(-ENOMEM);
 794
 795         hist_data->attrs = attrs;
 796
 797         ret = create_hist_fields(hist_data, file);
 798         if (ret)
 799                 goto free;
 800
 801         ret = create_sort_keys(hist_data);
 802         if (ret)
 803                 goto free;
 804
 805         if (need_tracing_map_ops(hist_data))
 806                 map_ops = &hist_trigger_elt_comm_ops;
 807
 808         hist_data->map = tracing_map_create(map_bits, hist_data->key_size,
 809                                             map_ops, hist_data);
 810         if (IS_ERR(hist_data->map)) {
 811                 ret = PTR_ERR(hist_data->map);
 812                 hist_data->map = NULL;
 813                 goto free;
 814         }
 815
 816         ret = create_tracing_map_fields(hist_data);
 817         if (ret)
 818                 goto free;
 819
 820         ret = tracing_map_init(hist_data->map);
 821         if (ret)
 822                 goto free;
 823
 824         hist_data->event_file = file;
 825  out:
 826         return hist_data;
 827  free:
 828         hist_data->attrs = NULL;
 829
 830         destroy_hist_data(hist_data);
 831
 832         hist_data = ERR_PTR(ret);
 833
 834         goto out;
 835 }
 836
 837 static void hist_trigger_elt_update(struct hist_trigger_data *hist_data,
 838                                     struct tracing_map_elt *elt,
 839                                     void *rec)
 840 {
 841         struct hist_field *hist_field;
 842         unsigned int i;
 843         u64 hist_val;
 844
 845         for_each_hist_val_field(i, hist_data) {
 846                 hist_field = hist_data->fields[i];
 847                 hist_val = hist_field->fn(hist_field, rec);
 848                 tracing_map_update_sum(elt, i, hist_val);
 849         }
 850 }
 851
 852 static inline void add_to_key(char *compound_key, void *key,
 853                               struct hist_field *key_field, void *rec)
 854 {
 855         size_t size = key_field->size;
 856
 857         if (key_field->flags & HIST_FIELD_FL_STRING) {
 858                 struct ftrace_event_field *field;
 859
 860                 field = key_field->field;
 861                 if (field->filter_type == FILTER_DYN_STRING)
 862                         size = *(u32 *)(rec + field->offset) >> 16;
 863                 else if (field->filter_type == FILTER_PTR_STRING)
 864                         size = strlen(key);
 865                 else if (field->filter_type == FILTER_STATIC_STRING)
 866                         size = field->size;
 867
 868                 /* ensure NULL-termination */
 869                 if (size > key_field->size - 1)
 870                         size = key_field->size - 1;
 871         }
 872
 873         memcpy(compound_key + key_field->offset, key, size);
 874 }
 875
 876 static void event_hist_trigger(struct event_trigger_data *data, void *rec)
 877 {
 878         struct hist_trigger_data *hist_data = data->private_data;
 879         bool use_compound_key = (hist_data->n_keys > 1);
 880         unsigned long entries[HIST_STACKTRACE_DEPTH];
 881         char compound_key[HIST_KEY_SIZE_MAX];
 882         struct stack_trace stacktrace;
 883         struct hist_field *key_field;
 884         struct tracing_map_elt *elt;
 885         u64 field_contents;
 886         void *key = NULL;
 887         unsigned int i;
 888
 889         memset(compound_key, 0, hist_data->key_size);
 890
 891         for_each_hist_key_field(i, hist_data) {
 892                 key_field = hist_data->fields[i];
 893
 894                 if (key_field->flags & HIST_FIELD_FL_STACKTRACE) {
 895                         stacktrace.max_entries = HIST_STACKTRACE_DEPTH;
 896                         stacktrace.entries = entries;
 897                         stacktrace.nr_entries = 0;
 898                         stacktrace.skip = HIST_STACKTRACE_SKIP;
 899
 900                         memset(stacktrace.entries, 0, HIST_STACKTRACE_SIZE);
 901                         save_stack_trace(&stacktrace);
 902
 903                         key = entries;
 904                 } else {
 905                         field_contents = key_field->fn(key_field, rec);
 906                         if (key_field->flags & HIST_FIELD_FL_STRING) {
 907                                 key = (void *)(unsigned long)field_contents;
 908                                 use_compound_key = true;
 909                         } else
 910                                 key = (void *)&field_contents;
 911                 }
 912
 913                 if (use_compound_key)
 914                         add_to_key(compound_key, key, key_field, rec);
 915         }
 916
 917         if (use_compound_key)
 918                 key = compound_key;
 919
 920         elt = tracing_map_insert(hist_data->map, key);
 921         if (elt)
 922                 hist_trigger_elt_update(hist_data, elt, rec);
 923 }
 924
 925 static void hist_trigger_stacktrace_print(struct seq_file *m,
 926                                           unsigned long *stacktrace_entries,
 927                                           unsigned int max_entries)
 928 {
 929         char str[KSYM_SYMBOL_LEN];
 930         unsigned int spaces = 8;
 931         unsigned int i;
 932
 933         for (i = 0; i < max_entries; i++) {
 934                 if (stacktrace_entries[i] == ULONG_MAX)
 935                         return;
 936
 937                 seq_printf(m, "%*c", 1 + spaces, ' ');
 938                 sprint_symbol(str, stacktrace_entries[i]);
 939                 seq_printf(m, "%s\n", str);
 940         }
 941 }
 942
 943 static void
 944 hist_trigger_entry_print(struct seq_file *m,
 945                          struct hist_trigger_data *hist_data, void *key,
 946                          struct tracing_map_elt *elt)
 947 {
 948         struct hist_field *key_field;
 949         char str[KSYM_SYMBOL_LEN];
 950         bool multiline = false;
 951         unsigned int i;
 952         u64 uval;
 953
 954         seq_puts(m, "{ ");
 955
 956         for_each_hist_key_field(i, hist_data) {
 957                 key_field = hist_data->fields[i];
 958
 959                 if (i > hist_data->n_vals)
 960                         seq_puts(m, ", ");
 961
 962                 if (key_field->flags & HIST_FIELD_FL_HEX) {
 963                         uval = *(u64 *)(key + key_field->offset);
 964                         seq_printf(m, "%s: %llx",
 965                                    key_field->field->name, uval);
 966                 } else if (key_field->flags & HIST_FIELD_FL_SYM) {
 967                         uval = *(u64 *)(key + key_field->offset);
 968                         sprint_symbol_no_offset(str, uval);
 969                         seq_printf(m, "%s: [%llx] %-45s",
 970                                    key_field->field->name, uval, str);
 971                 } else if (key_field->flags & HIST_FIELD_FL_SYM_OFFSET) {
 972                         uval = *(u64 *)(key + key_field->offset);
 973                         sprint_symbol(str, uval);
 974                         seq_printf(m, "%s: [%llx] %-55s",
 975                                    key_field->field->name, uval, str);
 976                 } else if (key_field->flags & HIST_FIELD_FL_EXECNAME) {
 977                         char *comm = elt->private_data;
 978
 979                         uval = *(u64 *)(key + key_field->offset);
 980                         seq_printf(m, "%s: %-16s[%10llu]",
 981                                    key_field->field->name, comm, uval);
 982                 } else if (key_field->flags & HIST_FIELD_FL_SYSCALL) {
 983                         const char *syscall_name;
 984
 985                         uval = *(u64 *)(key + key_field->offset);
 986                         syscall_name = get_syscall_name(uval);
 987                         if (!syscall_name)
 988                                 syscall_name = "unknown_syscall";
 989
 990                         seq_printf(m, "%s: %-30s[%3llu]",
 991                                    key_field->field->name, syscall_name, uval);
 992                 } else if (key_field->flags & HIST_FIELD_FL_STACKTRACE) {
 993                         seq_puts(m, "stacktrace:\n");
 994                         hist_trigger_stacktrace_print(m,
 995                                                       key + key_field->offset,
 996                                                       HIST_STACKTRACE_DEPTH);
 997                         multiline = true;
 998                 } else if (key_field->flags & HIST_FIELD_FL_LOG2) {
 999                         seq_printf(m, "%s: ~ 2^%-2llu", key_field->field->name,
1000                                    *(u64 *)(key + key_field->offset));
1001                 } else if (key_field->flags & HIST_FIELD_FL_STRING) {
1002                         seq_printf(m, "%s: %-50s", key_field->field->name,
1003                                    (char *)(key + key_field->offset));
1004                 } else {
1005                         uval = *(u64 *)(key + key_field->offset);
1006                         seq_printf(m, "%s: %10llu", key_field->field->name,
1007                                    uval);
1008                 }
1009         }
1010
1011         if (!multiline)
1012                 seq_puts(m, " ");
1013
1014         seq_puts(m, "}");
1015
1016         seq_printf(m, " hitcount: %10llu",
1017                    tracing_map_read_sum(elt, HITCOUNT_IDX));
1018
1019         for (i = 1; i < hist_data->n_vals; i++) {
1020                 if (hist_data->fields[i]->flags & HIST_FIELD_FL_HEX) {
1021                         seq_printf(m, "  %s: %10llx",
1022                                    hist_data->fields[i]->field->name,
1023                                    tracing_map_read_sum(elt, i));
1024                 } else {
1025                         seq_printf(m, "  %s: %10llu",
1026                                    hist_data->fields[i]->field->name,
1027                                    tracing_map_read_sum(elt, i));
1028                 }
1029         }
1030
1031         seq_puts(m, "\n");
1032 }
1033
1034 static int print_entries(struct seq_file *m,
1035                          struct hist_trigger_data *hist_data)
1036 {
1037         struct tracing_map_sort_entry **sort_entries = NULL;
1038         struct tracing_map *map = hist_data->map;
1039         unsigned int i, n_entries;
1040
1041         n_entries = tracing_map_sort_entries(map, hist_data->sort_keys,
1042                                              hist_data->n_sort_keys,
1043                                              &sort_entries);
1044         if (n_entries < 0)
1045                 return n_entries;
1046
1047         for (i = 0; i < n_entries; i++)
1048                 hist_trigger_entry_print(m, hist_data,
1049                                          sort_entries[i]->key,
1050                                          sort_entries[i]->elt);
1051
1052         tracing_map_destroy_sort_entries(sort_entries, n_entries);
1053
1054         return n_entries;
1055 }
1056
1057 static void hist_trigger_show(struct seq_file *m,
1058                               struct event_trigger_data *data, int n)
1059 {
1060         struct hist_trigger_data *hist_data;
1061         int n_entries, ret = 0;
1062
1063         if (n > 0)
1064                 seq_puts(m, "\n\n");
1065
1066         seq_puts(m, "# event histogram\n#\n# trigger info: ");
1067         data->ops->print(m, data->ops, data);
1068         seq_puts(m, "#\n\n");
1069
1070         hist_data = data->private_data;
1071         n_entries = print_entries(m, hist_data);
1072         if (n_entries < 0) {
1073                 ret = n_entries;
1074                 n_entries = 0;
1075         }
1076
1077         seq_printf(m, "\nTotals:\n    Hits: %llu\n    Entries: %u\n    Dropped: %llu\n",
1078                    (u64)atomic64_read(&hist_data->map->hits),
1079                    n_entries, (u64)atomic64_read(&hist_data->map->drops));
1080 }
1081
1082 static int hist_show(struct seq_file *m, void *v)
1083 {
1084         struct event_trigger_data *data;
1085         struct trace_event_file *event_file;
1086         int n = 0, ret = 0;
1087
1088         mutex_lock(&event_mutex);
1089
1090         event_file = event_file_data(m->private);
1091         if (unlikely(!event_file)) {
1092                 ret = -ENODEV;
1093                 goto out_unlock;
1094         }
1095
1096         list_for_each_entry_rcu(data, &event_file->triggers, list) {
1097                 if (data->cmd_ops->trigger_type == ETT_EVENT_HIST)
1098                         hist_trigger_show(m, data, n++);
1099         }
1100
1101  out_unlock:
1102         mutex_unlock(&event_mutex);
1103
1104         return ret;
1105 }
1106
1107 static int event_hist_open(struct inode *inode, struct file *file)
1108 {
1109         return single_open(file, hist_show, file);
1110 }
1111
1112 const struct file_operations event_hist_fops = {
1113         .open = event_hist_open,
1114         .read = seq_read,
1115         .llseek = seq_lseek,
1116         .release = single_release,
1117 };
1118
1119 static const char *get_hist_field_flags(struct hist_field *hist_field)
1120 {
1121         const char *flags_str = NULL;
1122
1123         if (hist_field->flags & HIST_FIELD_FL_HEX)
1124                 flags_str = "hex";
1125         else if (hist_field->flags & HIST_FIELD_FL_SYM)
1126                 flags_str = "sym";
1127         else if (hist_field->flags & HIST_FIELD_FL_SYM_OFFSET)
1128                 flags_str = "sym-offset";
1129         else if (hist_field->flags & HIST_FIELD_FL_EXECNAME)
1130                 flags_str = "execname";
1131         else if (hist_field->flags & HIST_FIELD_FL_SYSCALL)
1132                 flags_str = "syscall";
1133         else if (hist_field->flags & HIST_FIELD_FL_LOG2)
1134                 flags_str = "log2";
1135
1136         return flags_str;
1137 }
1138
1139 static void hist_field_print(struct seq_file *m, struct hist_field *hist_field)
1140 {
1141         seq_printf(m, "%s", hist_field->field->name);
1142         if (hist_field->flags) {
1143                 const char *flags_str = get_hist_field_flags(hist_field);
1144
1145                 if (flags_str)
1146                         seq_printf(m, ".%s", flags_str);
1147         }
1148 }
1149
1150 static int event_hist_trigger_print(struct seq_file *m,
1151                                     struct event_trigger_ops *ops,
1152                                     struct event_trigger_data *data)
1153 {
1154         struct hist_trigger_data *hist_data = data->private_data;
1155         struct hist_field *key_field;
1156         unsigned int i;
1157
1158         seq_puts(m, "hist:");
1159
1160         if (data->name)
1161                 seq_printf(m, "%s:", data->name);
1162
1163         seq_puts(m, "keys=");
1164
1165         for_each_hist_key_field(i, hist_data) {
1166                 key_field = hist_data->fields[i];
1167
1168                 if (i > hist_data->n_vals)
1169                         seq_puts(m, ",");
1170
1171                 if (key_field->flags & HIST_FIELD_FL_STACKTRACE)
1172                         seq_puts(m, "stacktrace");
1173                 else
1174                         hist_field_print(m, key_field);
1175         }
1176
1177         seq_puts(m, ":vals=");
1178
1179         for_each_hist_val_field(i, hist_data) {
1180                 if (i == HITCOUNT_IDX)
1181                         seq_puts(m, "hitcount");
1182                 else {
1183                         seq_puts(m, ",");
1184                         hist_field_print(m, hist_data->fields[i]);
1185                 }
1186         }
1187
1188         seq_puts(m, ":sort=");
1189
1190         for (i = 0; i < hist_data->n_sort_keys; i++) {
1191                 struct tracing_map_sort_key *sort_key;
1192
1193                 sort_key = &hist_data->sort_keys[i];
1194
1195                 if (i > 0)
1196                         seq_puts(m, ",");
1197
1198                 if (sort_key->field_idx == HITCOUNT_IDX)
1199                         seq_puts(m, "hitcount");
1200                 else {
1201                         unsigned int idx = sort_key->field_idx;
1202
1203                         if (WARN_ON(idx >= TRACING_MAP_FIELDS_MAX))
1204                                 return -EINVAL;
1205
1206                         hist_field_print(m, hist_data->fields[idx]);
1207                 }
1208
1209                 if (sort_key->descending)
1210                         seq_puts(m, ".descending");
1211         }
1212
1213         seq_printf(m, ":size=%u", (1 << hist_data->map->map_bits));
1214
1215         if (data->filter_str)
1216                 seq_printf(m, " if %s", data->filter_str);
1217
1218         if (data->paused)
1219                 seq_puts(m, " [paused]");
1220         else
1221                 seq_puts(m, " [active]");
1222
1223         seq_putc(m, '\n');
1224
1225         return 0;
1226 }
1227
1228 static int event_hist_trigger_init(struct event_trigger_ops *ops,
1229                                    struct event_trigger_data *data)
1230 {
1231         struct hist_trigger_data *hist_data = data->private_data;
1232
1233         if (!data->ref && hist_data->attrs->name)
1234                 save_named_trigger(hist_data->attrs->name, data);
1235
1236         data->ref++;
1237
1238         return 0;
1239 }
1240
1241 static void event_hist_trigger_free(struct event_trigger_ops *ops,
1242                                     struct event_trigger_data *data)
1243 {
1244         struct hist_trigger_data *hist_data = data->private_data;
1245
1246         if (WARN_ON_ONCE(data->ref <= 0))
1247                 return;
1248
1249         data->ref--;
1250         if (!data->ref) {
1251                 if (data->name)
1252                         del_named_trigger(data);
1253                 trigger_data_free(data);
1254                 destroy_hist_data(hist_data);
1255         }
1256 }
1257
1258 static struct event_trigger_ops event_hist_trigger_ops = {
1259         .func                   = event_hist_trigger,
1260         .print                  = event_hist_trigger_print,
1261         .init                   = event_hist_trigger_init,
1262         .free                   = event_hist_trigger_free,
1263 };
1264
1265 static int event_hist_trigger_named_init(struct event_trigger_ops *ops,
1266                                          struct event_trigger_data *data)
1267 {
1268         data->ref++;
1269
1270         save_named_trigger(data->named_data->name, data);
1271
1272         event_hist_trigger_init(ops, data->named_data);
1273
1274         return 0;
1275 }
1276
1277 static void event_hist_trigger_named_free(struct event_trigger_ops *ops,
1278                                           struct event_trigger_data *data)
1279 {
1280         if (WARN_ON_ONCE(data->ref <= 0))
1281                 return;
1282
1283         event_hist_trigger_free(ops, data->named_data);
1284
1285         data->ref--;
1286         if (!data->ref) {
1287                 del_named_trigger(data);
1288                 trigger_data_free(data);
1289         }
1290 }
1291
1292 static struct event_trigger_ops event_hist_trigger_named_ops = {
1293         .func                   = event_hist_trigger,
1294         .print                  = event_hist_trigger_print,
1295         .init                   = event_hist_trigger_named_init,
1296         .free                   = event_hist_trigger_named_free,
1297 };
1298
1299 static struct event_trigger_ops *event_hist_get_trigger_ops(char *cmd,
1300                                                             char *param)
1301 {
1302         return &event_hist_trigger_ops;
1303 }
1304
1305 static void hist_clear(struct event_trigger_data *data)
1306 {
1307         struct hist_trigger_data *hist_data = data->private_data;
1308
1309         if (data->name)
1310                 pause_named_trigger(data);
1311
1312         synchronize_sched();
1313
1314         tracing_map_clear(hist_data->map);
1315
1316         if (data->name)
1317                 unpause_named_trigger(data);
1318 }
1319
1320 static bool compatible_field(struct ftrace_event_field *field,
1321                              struct ftrace_event_field *test_field)
1322 {
1323         if (field == test_field)
1324                 return true;
1325         if (field == NULL || test_field == NULL)
1326                 return false;
1327         if (strcmp(field->name, test_field->name) != 0)
1328                 return false;
1329         if (strcmp(field->type, test_field->type) != 0)
1330                 return false;
1331         if (field->size != test_field->size)
1332                 return false;
1333         if (field->is_signed != test_field->is_signed)
1334                 return false;
1335
1336         return true;
1337 }
1338
1339 static bool hist_trigger_match(struct event_trigger_data *data,
1340                                struct event_trigger_data *data_test,
1341                                struct event_trigger_data *named_data,
1342                                bool ignore_filter)
1343 {
1344         struct tracing_map_sort_key *sort_key, *sort_key_test;
1345         struct hist_trigger_data *hist_data, *hist_data_test;
1346         struct hist_field *key_field, *key_field_test;
1347         unsigned int i;
1348
1349         if (named_data && (named_data != data_test) &&
1350             (named_data != data_test->named_data))
1351                 return false;
1352
1353         if (!named_data && is_named_trigger(data_test))
1354                 return false;
1355
1356         hist_data = data->private_data;
1357         hist_data_test = data_test->private_data;
1358
1359         if (hist_data->n_vals != hist_data_test->n_vals ||
1360             hist_data->n_fields != hist_data_test->n_fields ||
1361             hist_data->n_sort_keys != hist_data_test->n_sort_keys)
1362                 return false;
1363
1364         if (!ignore_filter) {
1365                 if ((data->filter_str && !data_test->filter_str) ||
1366                    (!data->filter_str && data_test->filter_str))
1367                         return false;
1368         }
1369
1370         for_each_hist_field(i, hist_data) {
1371                 key_field = hist_data->fields[i];
1372                 key_field_test = hist_data_test->fields[i];
1373
1374                 if (key_field->flags != key_field_test->flags)
1375                         return false;
1376                 if (!compatible_field(key_field->field, key_field_test->field))
1377                         return false;
1378                 if (key_field->offset != key_field_test->offset)
1379                         return false;
1380         }
1381
1382         for (i = 0; i < hist_data->n_sort_keys; i++) {
1383                 sort_key = &hist_data->sort_keys[i];
1384                 sort_key_test = &hist_data_test->sort_keys[i];
1385
1386                 if (sort_key->field_idx != sort_key_test->field_idx ||
1387                     sort_key->descending != sort_key_test->descending)
1388                         return false;
1389         }
1390
1391         if (!ignore_filter && data->filter_str &&
1392             (strcmp(data->filter_str, data_test->filter_str) != 0))
1393                 return false;
1394
1395         return true;
1396 }
1397
1398 static int hist_register_trigger(char *glob, struct event_trigger_ops *ops,
1399                                  struct event_trigger_data *data,
1400                                  struct trace_event_file *file)
1401 {
1402         struct hist_trigger_data *hist_data = data->private_data;
1403         struct event_trigger_data *test, *named_data = NULL;
1404         int ret = 0;
1405
1406         if (hist_data->attrs->name) {
1407                 named_data = find_named_trigger(hist_data->attrs->name);
1408                 if (named_data) {
1409                         if (!hist_trigger_match(data, named_data, named_data,
1410                                                 true)) {
1411                                 ret = -EINVAL;
1412                                 goto out;
1413                         }
1414                 }
1415         }
1416
1417         if (hist_data->attrs->name && !named_data)
1418                 goto new;
1419
1420         list_for_each_entry_rcu(test, &file->triggers, list) {
1421                 if (test->cmd_ops->trigger_type == ETT_EVENT_HIST) {
1422                         if (!hist_trigger_match(data, test, named_data, false))
1423                                 continue;
1424                         if (hist_data->attrs->pause)
1425                                 test->paused = true;
1426                         else if (hist_data->attrs->cont)
1427                                 test->paused = false;
1428                         else if (hist_data->attrs->clear)
1429                                 hist_clear(test);
1430                         else
1431                                 ret = -EEXIST;
1432                         goto out;
1433                 }
1434         }
1435  new:
1436         if (hist_data->attrs->cont || hist_data->attrs->clear) {
1437                 ret = -ENOENT;
1438                 goto out;
1439         }
1440
1441         if (named_data) {
1442                 destroy_hist_data(data->private_data);
1443                 data->private_data = named_data->private_data;
1444                 set_named_trigger_data(data, named_data);
1445                 data->ops = &event_hist_trigger_named_ops;
1446         }
1447
1448         if (hist_data->attrs->pause)
1449                 data->paused = true;
1450
1451         if (data->ops->init) {
1452                 ret = data->ops->init(data->ops, data);
1453                 if (ret < 0)
1454                         goto out;
1455         }
1456
1457         list_add_rcu(&data->list, &file->triggers);
1458         ret++;
1459
1460         update_cond_flag(file);
1461
1462         if (trace_event_trigger_enable_disable(file, 1) < 0) {
1463                 list_del_rcu(&data->list);
1464                 update_cond_flag(file);
1465                 ret--;
1466         }
1467  out:
1468         return ret;
1469 }
1470
1471 static void hist_unregister_trigger(char *glob, struct event_trigger_ops *ops,
1472                                     struct event_trigger_data *data,
1473                                     struct trace_event_file *file)
1474 {
1475         struct hist_trigger_data *hist_data = data->private_data;
1476         struct event_trigger_data *test, *named_data = NULL;
1477         bool unregistered = false;
1478
1479         if (hist_data->attrs->name)
1480                 named_data = find_named_trigger(hist_data->attrs->name);
1481
1482         list_for_each_entry_rcu(test, &file->triggers, list) {
1483                 if (test->cmd_ops->trigger_type == ETT_EVENT_HIST) {
1484                         if (!hist_trigger_match(data, test, named_data, false))
1485                                 continue;
1486                         unregistered = true;
1487                         list_del_rcu(&test->list);
1488                         trace_event_trigger_enable_disable(file, 0);
1489                         update_cond_flag(file);
1490                         break;
1491                 }
1492         }
1493
1494         if (unregistered && test->ops->free)
1495                 test->ops->free(test->ops, test);
1496 }
1497
1498 static void hist_unreg_all(struct trace_event_file *file)
1499 {
1500         struct event_trigger_data *test;
1501
1502         list_for_each_entry_rcu(test, &file->triggers, list) {
1503                 if (test->cmd_ops->trigger_type == ETT_EVENT_HIST) {
1504                         list_del_rcu(&test->list);
1505                         trace_event_trigger_enable_disable(file, 0);
1506                         update_cond_flag(file);
1507                         if (test->ops->free)
1508                                 test->ops->free(test->ops, test);
1509                 }
1510         }
1511 }
1512
1513 static int event_hist_trigger_func(struct event_command *cmd_ops,
1514                                    struct trace_event_file *file,
1515                                    char *glob, char *cmd, char *param)
1516 {
1517         unsigned int hist_trigger_bits = TRACING_MAP_BITS_DEFAULT;
1518         struct event_trigger_data *trigger_data;
1519         struct hist_trigger_attrs *attrs;
1520         struct event_trigger_ops *trigger_ops;
1521         struct hist_trigger_data *hist_data;
1522         char *trigger;
1523         int ret = 0;
1524
1525         if (!param)
1526                 return -EINVAL;
1527
1528         /* separate the trigger from the filter (k:v [if filter]) */
1529         trigger = strsep(&param, " \t");
1530         if (!trigger)
1531                 return -EINVAL;
1532
1533         attrs = parse_hist_trigger_attrs(trigger);
1534         if (IS_ERR(attrs))
1535                 return PTR_ERR(attrs);
1536
1537         if (attrs->map_bits)
1538                 hist_trigger_bits = attrs->map_bits;
1539
1540         hist_data = create_hist_data(hist_trigger_bits, attrs, file);
1541         if (IS_ERR(hist_data)) {
1542                 destroy_hist_trigger_attrs(attrs);
1543                 return PTR_ERR(hist_data);
1544         }
1545
1546         trigger_ops = cmd_ops->get_trigger_ops(cmd, trigger);
1547
1548         ret = -ENOMEM;
1549         trigger_data = kzalloc(sizeof(*trigger_data), GFP_KERNEL);
1550         if (!trigger_data)
1551                 goto out_free;
1552
1553         trigger_data->count = -1;
1554         trigger_data->ops = trigger_ops;
1555         trigger_data->cmd_ops = cmd_ops;
1556
1557         INIT_LIST_HEAD(&trigger_data->list);
1558         RCU_INIT_POINTER(trigger_data->filter, NULL);
1559
1560         trigger_data->private_data = hist_data;
1561
1562         /* if param is non-empty, it's supposed to be a filter */
1563         if (param && cmd_ops->set_filter) {
1564                 ret = cmd_ops->set_filter(param, trigger_data, file);
1565                 if (ret < 0)
1566                         goto out_free;
1567         }
1568
1569         if (glob[0] == '!') {
1570                 cmd_ops->unreg(glob+1, trigger_ops, trigger_data, file);
1571                 ret = 0;
1572                 goto out_free;
1573         }
1574
1575         ret = cmd_ops->reg(glob, trigger_ops, trigger_data, file);
1576         /*
1577          * The above returns on success the # of triggers registered,
1578          * but if it didn't register any it returns zero.  Consider no
1579          * triggers registered a failure too.
1580          */
1581         if (!ret) {
1582                 if (!(attrs->pause || attrs->cont || attrs->clear))
1583                         ret = -ENOENT;
1584                 goto out_free;
1585         } else if (ret < 0)
1586                 goto out_free;
1587         /* Just return zero, not the number of registered triggers */
1588         ret = 0;
1589  out:
1590         return ret;
1591  out_free:
1592         if (cmd_ops->set_filter)
1593                 cmd_ops->set_filter(NULL, trigger_data, NULL);
1594
1595         kfree(trigger_data);
1596
1597         destroy_hist_data(hist_data);
1598         goto out;
1599 }
1600
1601 static struct event_command trigger_hist_cmd = {
1602         .name                   = "hist",
1603         .trigger_type           = ETT_EVENT_HIST,
1604         .flags                  = EVENT_CMD_FL_NEEDS_REC,
1605         .func                   = event_hist_trigger_func,
1606         .reg                    = hist_register_trigger,
1607         .unreg                  = hist_unregister_trigger,
1608         .unreg_all              = hist_unreg_all,
1609         .get_trigger_ops        = event_hist_get_trigger_ops,
1610         .set_filter             = set_trigger_filter,
1611 };
1612
1613 __init int register_trigger_hist_cmd(void)
1614 {
1615         int ret;
1616
1617         ret = register_event_command(&trigger_hist_cmd);
1618         WARN_ON(ret < 0);
1619
1620         return ret;
1621 }
1622
1623 static void
1624 hist_enable_trigger(struct event_trigger_data *data, void *rec)
1625 {
1626         struct enable_trigger_data *enable_data = data->private_data;
1627         struct event_trigger_data *test;
1628
1629         list_for_each_entry_rcu(test, &enable_data->file->triggers, list) {
1630                 if (test->cmd_ops->trigger_type == ETT_EVENT_HIST) {
1631                         if (enable_data->enable)
1632                                 test->paused = false;
1633                         else
1634                                 test->paused = true;
1635                 }
1636         }
1637 }
1638
1639 static void
1640 hist_enable_count_trigger(struct event_trigger_data *data, void *rec)
1641 {
1642         if (!data->count)
1643                 return;
1644
1645         if (data->count != -1)
1646                 (data->count)--;
1647
1648         hist_enable_trigger(data, rec);
1649 }
1650
1651 static struct event_trigger_ops hist_enable_trigger_ops = {
1652         .func                   = hist_enable_trigger,
1653         .print                  = event_enable_trigger_print,
1654         .init                   = event_trigger_init,
1655         .free                   = event_enable_trigger_free,
1656 };
1657
1658 static struct event_trigger_ops hist_enable_count_trigger_ops = {
1659         .func                   = hist_enable_count_trigger,
1660         .print                  = event_enable_trigger_print,
1661         .init                   = event_trigger_init,
1662         .free                   = event_enable_trigger_free,
1663 };
1664
1665 static struct event_trigger_ops hist_disable_trigger_ops = {
1666         .func                   = hist_enable_trigger,
1667         .print                  = event_enable_trigger_print,
1668         .init                   = event_trigger_init,
1669         .free                   = event_enable_trigger_free,
1670 };
1671
1672 static struct event_trigger_ops hist_disable_count_trigger_ops = {
1673         .func                   = hist_enable_count_trigger,
1674         .print                  = event_enable_trigger_print,
1675         .init                   = event_trigger_init,
1676         .free                   = event_enable_trigger_free,
1677 };
1678
1679 static struct event_trigger_ops *
1680 hist_enable_get_trigger_ops(char *cmd, char *param)
1681 {
1682         struct event_trigger_ops *ops;
1683         bool enable;
1684
1685         enable = (strcmp(cmd, ENABLE_HIST_STR) == 0);
1686
1687         if (enable)
1688                 ops = param ? &hist_enable_count_trigger_ops :
1689                         &hist_enable_trigger_ops;
1690         else
1691                 ops = param ? &hist_disable_count_trigger_ops :
1692                         &hist_disable_trigger_ops;
1693
1694         return ops;
1695 }
1696
1697 static void hist_enable_unreg_all(struct trace_event_file *file)
1698 {
1699         struct event_trigger_data *test;
1700
1701         list_for_each_entry_rcu(test, &file->triggers, list) {
1702                 if (test->cmd_ops->trigger_type == ETT_HIST_ENABLE) {
1703                         list_del_rcu(&test->list);
1704                         update_cond_flag(file);
1705                         trace_event_trigger_enable_disable(file, 0);
1706                         if (test->ops->free)
1707                                 test->ops->free(test->ops, test);
1708                 }
1709         }
1710 }
1711
1712 static struct event_command trigger_hist_enable_cmd = {
1713         .name                   = ENABLE_HIST_STR,
1714         .trigger_type           = ETT_HIST_ENABLE,
1715         .func                   = event_enable_trigger_func,
1716         .reg                    = event_enable_register_trigger,
1717         .unreg                  = event_enable_unregister_trigger,
1718         .unreg_all              = hist_enable_unreg_all,
1719         .get_trigger_ops        = hist_enable_get_trigger_ops,
1720         .set_filter             = set_trigger_filter,
1721 };
1722
1723 static struct event_command trigger_hist_disable_cmd = {
1724         .name                   = DISABLE_HIST_STR,
1725         .trigger_type           = ETT_HIST_ENABLE,
1726         .func                   = event_enable_trigger_func,
1727         .reg                    = event_enable_register_trigger,
1728         .unreg                  = event_enable_unregister_trigger,
1729         .unreg_all              = hist_enable_unreg_all,
1730         .get_trigger_ops        = hist_enable_get_trigger_ops,
1731         .set_filter             = set_trigger_filter,
1732 };
1733
1734 static __init void unregister_trigger_hist_enable_disable_cmds(void)
1735 {
1736         unregister_event_command(&trigger_hist_enable_cmd);
1737         unregister_event_command(&trigger_hist_disable_cmd);
1738 }
1739
1740 __init int register_trigger_hist_enable_disable_cmds(void)
1741 {
1742         int ret;
1743
1744         ret = register_event_command(&trigger_hist_enable_cmd);
1745         if (WARN_ON(ret < 0))
1746                 return ret;
1747         ret = register_event_command(&trigger_hist_disable_cmd);
1748         if (WARN_ON(ret < 0))
1749                 unregister_trigger_hist_enable_disable_cmds();
1750
1751         return ret;
1752 }