liblttng-ust/lttng-filter.c

   1 /*
   2  * lttng-filter.c
   3  *
   4  * LTTng UST filter code.
   5  *
   6  * Copyright (C) 2010-2016 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
   7  *
   8  * Permission is hereby granted, free of charge, to any person obtaining a copy
   9  * of this software and associated documentation files (the "Software"), to deal
  10  * in the Software without restriction, including without limitation the rights
  11  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  12  * copies of the Software, and to permit persons to whom the Software is
  13  * furnished to do so, subject to the following conditions:
  14  *
  15  * The above copyright notice and this permission notice shall be included in
  16  * all copies or substantial portions of the Software.
  17  *
  18  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  19  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  20  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  21  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  22  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  23  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  24  * SOFTWARE.
  25  */
  26
  27 #define _LGPL_SOURCE
  28 #include <urcu/rculist.h>
  29 #include "lttng-filter.h"
  30
  31 static const char *opnames[] = {
  32         [ FILTER_OP_UNKNOWN ] = "UNKNOWN",
  33
  34         [ FILTER_OP_RETURN ] = "RETURN",
  35
  36         /* binary */
  37         [ FILTER_OP_MUL ] = "MUL",
  38         [ FILTER_OP_DIV ] = "DIV",
  39         [ FILTER_OP_MOD ] = "MOD",
  40         [ FILTER_OP_PLUS ] = "PLUS",
  41         [ FILTER_OP_MINUS ] = "MINUS",
  42         [ FILTER_OP_BIT_RSHIFT ] = "BIT_RSHIFT",
  43         [ FILTER_OP_BIT_LSHIFT ] = "BIT_LSHIFT",
  44         [ FILTER_OP_BIT_AND ] = "BIT_AND",
  45         [ FILTER_OP_BIT_OR ] = "BIT_OR",
  46         [ FILTER_OP_BIT_XOR ] = "BIT_XOR",
  47
  48         /* binary comparators */
  49         [ FILTER_OP_EQ ] = "EQ",
  50         [ FILTER_OP_NE ] = "NE",
  51         [ FILTER_OP_GT ] = "GT",
  52         [ FILTER_OP_LT ] = "LT",
  53         [ FILTER_OP_GE ] = "GE",
  54         [ FILTER_OP_LE ] = "LE",
  55
  56         /* string binary comparators */
  57         [ FILTER_OP_EQ_STRING ] = "EQ_STRING",
  58         [ FILTER_OP_NE_STRING ] = "NE_STRING",
  59         [ FILTER_OP_GT_STRING ] = "GT_STRING",
  60         [ FILTER_OP_LT_STRING ] = "LT_STRING",
  61         [ FILTER_OP_GE_STRING ] = "GE_STRING",
  62         [ FILTER_OP_LE_STRING ] = "LE_STRING",
  63
  64         /* s64 binary comparators */
  65         [ FILTER_OP_EQ_S64 ] = "EQ_S64",
  66         [ FILTER_OP_NE_S64 ] = "NE_S64",
  67         [ FILTER_OP_GT_S64 ] = "GT_S64",
  68         [ FILTER_OP_LT_S64 ] = "LT_S64",
  69         [ FILTER_OP_GE_S64 ] = "GE_S64",
  70         [ FILTER_OP_LE_S64 ] = "LE_S64",
  71
  72         /* double binary comparators */
  73         [ FILTER_OP_EQ_DOUBLE ] = "EQ_DOUBLE",
  74         [ FILTER_OP_NE_DOUBLE ] = "NE_DOUBLE",
  75         [ FILTER_OP_GT_DOUBLE ] = "GT_DOUBLE",
  76         [ FILTER_OP_LT_DOUBLE ] = "LT_DOUBLE",
  77         [ FILTER_OP_GE_DOUBLE ] = "GE_DOUBLE",
  78         [ FILTER_OP_LE_DOUBLE ] = "LE_DOUBLE",
  79
  80         /* Mixed S64-double binary comparators */
  81         [ FILTER_OP_EQ_DOUBLE_S64 ] = "EQ_DOUBLE_S64",
  82         [ FILTER_OP_NE_DOUBLE_S64 ] = "NE_DOUBLE_S64",
  83         [ FILTER_OP_GT_DOUBLE_S64 ] = "GT_DOUBLE_S64",
  84         [ FILTER_OP_LT_DOUBLE_S64 ] = "LT_DOUBLE_S64",
  85         [ FILTER_OP_GE_DOUBLE_S64 ] = "GE_DOUBLE_S64",
  86         [ FILTER_OP_LE_DOUBLE_S64 ] = "LE_DOUBLE_S64",
  87
  88         [ FILTER_OP_EQ_S64_DOUBLE ] = "EQ_S64_DOUBLE",
  89         [ FILTER_OP_NE_S64_DOUBLE ] = "NE_S64_DOUBLE",
  90         [ FILTER_OP_GT_S64_DOUBLE ] = "GT_S64_DOUBLE",
  91         [ FILTER_OP_LT_S64_DOUBLE ] = "LT_S64_DOUBLE",
  92         [ FILTER_OP_GE_S64_DOUBLE ] = "GE_S64_DOUBLE",
  93         [ FILTER_OP_LE_S64_DOUBLE ] = "LE_S64_DOUBLE",
  94
  95         /* unary */
  96         [ FILTER_OP_UNARY_PLUS ] = "UNARY_PLUS",
  97         [ FILTER_OP_UNARY_MINUS ] = "UNARY_MINUS",
  98         [ FILTER_OP_UNARY_NOT ] = "UNARY_NOT",
  99         [ FILTER_OP_UNARY_PLUS_S64 ] = "UNARY_PLUS_S64",
 100         [ FILTER_OP_UNARY_MINUS_S64 ] = "UNARY_MINUS_S64",
 101         [ FILTER_OP_UNARY_NOT_S64 ] = "UNARY_NOT_S64",
 102         [ FILTER_OP_UNARY_PLUS_DOUBLE ] = "UNARY_PLUS_DOUBLE",
 103         [ FILTER_OP_UNARY_MINUS_DOUBLE ] = "UNARY_MINUS_DOUBLE",
 104         [ FILTER_OP_UNARY_NOT_DOUBLE ] = "UNARY_NOT_DOUBLE",
 105
 106         /* logical */
 107         [ FILTER_OP_AND ] = "AND",
 108         [ FILTER_OP_OR ] = "OR",
 109
 110         /* load field ref */
 111         [ FILTER_OP_LOAD_FIELD_REF ] = "LOAD_FIELD_REF",
 112         [ FILTER_OP_LOAD_FIELD_REF_STRING ] = "LOAD_FIELD_REF_STRING",
 113         [ FILTER_OP_LOAD_FIELD_REF_SEQUENCE ] = "LOAD_FIELD_REF_SEQUENCE",
 114         [ FILTER_OP_LOAD_FIELD_REF_S64 ] = "LOAD_FIELD_REF_S64",
 115         [ FILTER_OP_LOAD_FIELD_REF_DOUBLE ] = "LOAD_FIELD_REF_DOUBLE",
 116
 117         /* load from immediate operand */
 118         [ FILTER_OP_LOAD_STRING ] = "LOAD_STRING",
 119         [ FILTER_OP_LOAD_S64 ] = "LOAD_S64",
 120         [ FILTER_OP_LOAD_DOUBLE ] = "LOAD_DOUBLE",
 121
 122         /* cast */
 123         [ FILTER_OP_CAST_TO_S64 ] = "CAST_TO_S64",
 124         [ FILTER_OP_CAST_DOUBLE_TO_S64 ] = "CAST_DOUBLE_TO_S64",
 125         [ FILTER_OP_CAST_NOP ] = "CAST_NOP",
 126
 127         /* get context ref */
 128         [ FILTER_OP_GET_CONTEXT_REF ] = "GET_CONTEXT_REF",
 129         [ FILTER_OP_GET_CONTEXT_REF_STRING ] = "GET_CONTEXT_REF_STRING",
 130         [ FILTER_OP_GET_CONTEXT_REF_S64 ] = "GET_CONTEXT_REF_S64",
 131         [ FILTER_OP_GET_CONTEXT_REF_DOUBLE ] = "GET_CONTEXT_REF_DOUBLE",
 132
 133         /* load userspace field ref */
 134         [ FILTER_OP_LOAD_FIELD_REF_USER_STRING ] = "LOAD_FIELD_REF_USER_STRING",
 135         [ FILTER_OP_LOAD_FIELD_REF_USER_SEQUENCE ] = "LOAD_FIELD_REF_USER_SEQUENCE",
 136
 137         /*
 138          * load immediate star globbing pattern (literal string)
 139          * from immediate.
 140          */
 141         [ FILTER_OP_LOAD_STAR_GLOB_STRING ] = "LOAD_STAR_GLOB_STRING",
 142
 143         /* globbing pattern binary operator: apply to */
 144         [ FILTER_OP_EQ_STAR_GLOB_STRING ] = "EQ_STAR_GLOB_STRING",
 145         [ FILTER_OP_NE_STAR_GLOB_STRING ] = "NE_STAR_GLOB_STRING",
 146
 147         /*
 148          * Instructions for recursive traversal through composed types.
 149          */
 150         [ FILTER_OP_GET_CONTEXT_ROOT ] = "GET_CONTEXT_ROOT",
 151         [ FILTER_OP_GET_APP_CONTEXT_ROOT ] = "GET_APP_CONTEXT_ROOT",
 152         [ FILTER_OP_GET_PAYLOAD_ROOT ] = "GET_PAYLOAD_ROOT",
 153
 154         [ FILTER_OP_GET_SYMBOL ] = "GET_SYMBOL",
 155         [ FILTER_OP_GET_SYMBOL_FIELD ] = "GET_SYMBOL_FIELD",
 156         [ FILTER_OP_GET_INDEX_U16 ] = "GET_INDEX_U16",
 157         [ FILTER_OP_GET_INDEX_U64 ] = "GET_INDEX_U64",
 158
 159         [ FILTER_OP_LOAD_FIELD ] = "LOAD_FIELD",
 160         [ FILTER_OP_LOAD_FIELD_S8 ] = "LOAD_FIELD_S8",
 161         [ FILTER_OP_LOAD_FIELD_S16 ] = "LOAD_FIELD_S16",
 162         [ FILTER_OP_LOAD_FIELD_S32 ] = "LOAD_FIELD_S32",
 163         [ FILTER_OP_LOAD_FIELD_S64 ] = "LOAD_FIELD_S64",
 164         [ FILTER_OP_LOAD_FIELD_U8 ] = "LOAD_FIELD_U8",
 165         [ FILTER_OP_LOAD_FIELD_U16 ] = "LOAD_FIELD_U16",
 166         [ FILTER_OP_LOAD_FIELD_U32 ] = "LOAD_FIELD_U32",
 167         [ FILTER_OP_LOAD_FIELD_U64 ] = "LOAD_FIELD_U64",
 168         [ FILTER_OP_LOAD_FIELD_STRING ] = "LOAD_FIELD_STRING",
 169         [ FILTER_OP_LOAD_FIELD_SEQUENCE ] = "LOAD_FIELD_SEQUENCE",
 170         [ FILTER_OP_LOAD_FIELD_DOUBLE ] = "LOAD_FIELD_DOUBLE",
 171
 172         [ FILTER_OP_UNARY_BIT_NOT ] = "UNARY_BIT_NOT",
 173 };
 174
 175 const char *print_op(enum filter_op op)
 176 {
 177         if (op >= NR_FILTER_OPS)
 178                 return "UNKNOWN";
 179         else
 180                 return opnames[op];
 181 }
 182
 183 static
 184 int apply_field_reloc(struct lttng_event *event,
 185                 struct bytecode_runtime *runtime,
 186                 uint32_t runtime_len,
 187                 uint32_t reloc_offset,
 188                 const char *field_name,
 189                 enum filter_op filter_op)
 190 {
 191         const struct lttng_event_desc *desc;
 192         const struct lttng_event_field *fields, *field = NULL;
 193         unsigned int nr_fields, i;
 194         struct load_op *op;
 195         uint32_t field_offset = 0;
 196
 197         dbg_printf("Apply field reloc: %u %s\n", reloc_offset, field_name);
 198
 199         /* Lookup event by name */
 200         desc = event->desc;
 201         if (!desc)
 202                 return -EINVAL;
 203         fields = desc->fields;
 204         if (!fields)
 205                 return -EINVAL;
 206         nr_fields = desc->nr_fields;
 207         for (i = 0; i < nr_fields; i++) {
 208                 if (!strcmp(fields[i].name, field_name)) {
 209                         field = &fields[i];
 210                         break;
 211                 }
 212                 /* compute field offset */
 213                 switch (fields[i].type.atype) {
 214                 case atype_integer:
 215                 case atype_enum:
 216                         field_offset += sizeof(int64_t);
 217                         break;
 218                 case atype_array:
 219                 case atype_sequence:
 220                         field_offset += sizeof(unsigned long);
 221                         field_offset += sizeof(void *);
 222                         break;
 223                 case atype_string:
 224                         field_offset += sizeof(void *);
 225                         break;
 226                 case atype_float:
 227                         field_offset += sizeof(double);
 228                         break;
 229                 default:
 230                         return -EINVAL;
 231                 }
 232         }
 233         if (!field)
 234                 return -EINVAL;
 235
 236         /* Check if field offset is too large for 16-bit offset */
 237         if (field_offset > FILTER_BYTECODE_MAX_LEN - 1)
 238                 return -EINVAL;
 239
 240         /* set type */
 241         op = (struct load_op *) &runtime->code[reloc_offset];
 242
 243         switch (filter_op) {
 244         case FILTER_OP_LOAD_FIELD_REF:
 245         {
 246                 struct field_ref *field_ref;
 247
 248                 field_ref = (struct field_ref *) op->data;
 249                 switch (field->type.atype) {
 250                 case atype_integer:
 251                 case atype_enum:
 252                         op->op = FILTER_OP_LOAD_FIELD_REF_S64;
 253                         break;
 254                 case atype_array:
 255                 case atype_sequence:
 256                         op->op = FILTER_OP_LOAD_FIELD_REF_SEQUENCE;
 257                         break;
 258                 case atype_string:
 259                         op->op = FILTER_OP_LOAD_FIELD_REF_STRING;
 260                         break;
 261                 case atype_float:
 262                         op->op = FILTER_OP_LOAD_FIELD_REF_DOUBLE;
 263                         break;
 264                 default:
 265                         return -EINVAL;
 266                 }
 267                 /* set offset */
 268                 field_ref->offset = (uint16_t) field_offset;
 269                 break;
 270         }
 271         default:
 272                 return -EINVAL;
 273         }
 274         return 0;
 275 }
 276
 277 static
 278 int apply_context_reloc(struct lttng_event *event,
 279                 struct bytecode_runtime *runtime,
 280                 uint32_t runtime_len,
 281                 uint32_t reloc_offset,
 282                 const char *context_name,
 283                 enum filter_op filter_op)
 284 {
 285         struct load_op *op;
 286         struct lttng_ctx_field *ctx_field;
 287         int idx;
 288         struct lttng_session *session = runtime->p.session;
 289
 290         dbg_printf("Apply context reloc: %u %s\n", reloc_offset, context_name);
 291
 292         /* Get context index */
 293         idx = lttng_get_context_index(session->ctx, context_name);
 294         if (idx < 0) {
 295                 if (lttng_context_is_app(context_name)) {
 296                         int ret;
 297
 298                         ret = lttng_ust_add_app_context_to_ctx_rcu(context_name,
 299                                         &session->ctx);
 300                         if (ret)
 301                                 return ret;
 302                         idx = lttng_get_context_index(session->ctx,
 303                                 context_name);
 304                         if (idx < 0)
 305                                 return -ENOENT;
 306                 } else {
 307                         return -ENOENT;
 308                 }
 309         }
 310         /* Check if idx is too large for 16-bit offset */
 311         if (idx > FILTER_BYTECODE_MAX_LEN - 1)
 312                 return -EINVAL;
 313
 314         /* Get context return type */
 315         ctx_field = &session->ctx->fields[idx];
 316         op = (struct load_op *) &runtime->code[reloc_offset];
 317
 318         switch (filter_op) {
 319         case FILTER_OP_GET_CONTEXT_REF:
 320         {
 321                 struct field_ref *field_ref;
 322
 323                 field_ref = (struct field_ref *) op->data;
 324                 switch (ctx_field->event_field.type.atype) {
 325                 case atype_integer:
 326                 case atype_enum:
 327                         op->op = FILTER_OP_GET_CONTEXT_REF_S64;
 328                         break;
 329                         /* Sequence and array supported as string */
 330                 case atype_string:
 331                 case atype_array:
 332                 case atype_sequence:
 333                         op->op = FILTER_OP_GET_CONTEXT_REF_STRING;
 334                         break;
 335                 case atype_float:
 336                         op->op = FILTER_OP_GET_CONTEXT_REF_DOUBLE;
 337                         break;
 338                 case atype_dynamic:
 339                         op->op = FILTER_OP_GET_CONTEXT_REF;
 340                         break;
 341                 default:
 342                         return -EINVAL;
 343                 }
 344                 /* set offset to context index within channel contexts */
 345                 field_ref->offset = (uint16_t) idx;
 346                 break;
 347         }
 348         default:
 349                 return -EINVAL;
 350         }
 351         return 0;
 352 }
 353
 354 static
 355 int apply_reloc(struct lttng_event *event,
 356                 struct bytecode_runtime *runtime,
 357                 uint32_t runtime_len,
 358                 uint32_t reloc_offset,
 359                 const char *name)
 360 {
 361         struct load_op *op;
 362
 363         dbg_printf("Apply reloc: %u %s\n", reloc_offset, name);
 364
 365         /* Ensure that the reloc is within the code */
 366         if (runtime_len - reloc_offset < sizeof(uint16_t))
 367                 return -EINVAL;
 368
 369         op = (struct load_op *) &runtime->code[reloc_offset];
 370         switch (op->op) {
 371         case FILTER_OP_LOAD_FIELD_REF:
 372                 return apply_field_reloc(event, runtime, runtime_len,
 373                         reloc_offset, name, op->op);
 374         case FILTER_OP_GET_CONTEXT_REF:
 375                 return apply_context_reloc(event, runtime, runtime_len,
 376                         reloc_offset, name, op->op);
 377         case FILTER_OP_GET_SYMBOL:
 378         case FILTER_OP_GET_SYMBOL_FIELD:
 379                 /*
 380                  * Will be handled by load specialize phase or
 381                  * dynamically by interpreter.
 382                  */
 383                 return 0;
 384         default:
 385                 ERR("Unknown reloc op type %u\n", op->op);
 386                 return -EINVAL;
 387         }
 388         return 0;
 389 }
 390
 391 static
 392 int bytecode_is_linked(struct lttng_ust_filter_bytecode_node *filter_bytecode,
 393                 struct lttng_event *event)
 394 {
 395         struct lttng_bytecode_runtime *bc_runtime;
 396
 397         cds_list_for_each_entry(bc_runtime,
 398                         &event->bytecode_runtime_head, node) {
 399                 if (bc_runtime->bc == filter_bytecode)
 400                         return 1;
 401         }
 402         return 0;
 403 }
 404
 405 /*
 406  * Take a bytecode with reloc table and link it to an event to create a
 407  * bytecode runtime.
 408  */
 409 static
 410 int _lttng_filter_event_link_bytecode(struct lttng_event *event,
 411                 struct lttng_ust_filter_bytecode_node *filter_bytecode,
 412                 struct cds_list_head *insert_loc)
 413 {
 414         int ret, offset, next_offset;
 415         struct bytecode_runtime *runtime = NULL;
 416         size_t runtime_alloc_len;
 417
 418         if (!filter_bytecode)
 419                 return 0;
 420         /* Bytecode already linked */
 421         if (bytecode_is_linked(filter_bytecode, event))
 422                 return 0;
 423
 424         dbg_printf("Linking...\n");
 425
 426         /* We don't need the reloc table in the runtime */
 427         runtime_alloc_len = sizeof(*runtime) + filter_bytecode->bc.reloc_offset;
 428         runtime = zmalloc(runtime_alloc_len);
 429         if (!runtime) {
 430                 ret = -ENOMEM;
 431                 goto alloc_error;
 432         }
 433         runtime->p.bc = filter_bytecode;
 434         runtime->p.session = event->chan->session;
 435         runtime->p.event = event;
 436         runtime->len = filter_bytecode->bc.reloc_offset;
 437         /* copy original bytecode */
 438         memcpy(runtime->code, filter_bytecode->bc.data, runtime->len);
 439         /*
 440          * apply relocs. Those are a uint16_t (offset in bytecode)
 441          * followed by a string (field name).
 442          */
 443         for (offset = filter_bytecode->bc.reloc_offset;
 444                         offset < filter_bytecode->bc.len;
 445                         offset = next_offset) {
 446                 uint16_t reloc_offset =
 447                         *(uint16_t *) &filter_bytecode->bc.data[offset];
 448                 const char *name =
 449                         (const char *) &filter_bytecode->bc.data[offset + sizeof(uint16_t)];
 450
 451                 ret = apply_reloc(event, runtime, runtime->len, reloc_offset, name);
 452                 if (ret) {
 453                         goto link_error;
 454                 }
 455                 next_offset = offset + sizeof(uint16_t) + strlen(name) + 1;
 456         }
 457         /* Validate bytecode */
 458         ret = lttng_filter_validate_bytecode(runtime);
 459         if (ret) {
 460                 goto link_error;
 461         }
 462         /* Specialize bytecode */
 463         ret = lttng_filter_specialize_bytecode(event, runtime);
 464         if (ret) {
 465                 goto link_error;
 466         }
 467         runtime->p.filter = lttng_filter_interpret_bytecode;
 468         runtime->p.link_failed = 0;
 469         cds_list_add_rcu(&runtime->p.node, insert_loc);
 470         dbg_printf("Linking successful.\n");
 471         return 0;
 472
 473 link_error:
 474         runtime->p.filter = lttng_filter_false;
 475         runtime->p.link_failed = 1;
 476         cds_list_add_rcu(&runtime->p.node, insert_loc);
 477 alloc_error:
 478         dbg_printf("Linking failed.\n");
 479         return ret;
 480 }
 481
 482 void lttng_filter_sync_state(struct lttng_bytecode_runtime *runtime)
 483 {
 484         struct lttng_ust_filter_bytecode_node *bc = runtime->bc;
 485
 486         if (!bc->enabler->enabled || runtime->link_failed)
 487                 runtime->filter = lttng_filter_false;
 488         else
 489                 runtime->filter = lttng_filter_interpret_bytecode;
 490 }
 491
 492 /*
 493  * Link bytecode for all enablers referenced by an event.
 494  */
 495 void lttng_enabler_event_link_bytecode(struct lttng_event *event,
 496                 struct lttng_enabler *enabler)
 497 {
 498         struct lttng_ust_filter_bytecode_node *bc;
 499         struct lttng_bytecode_runtime *runtime;
 500
 501         /* Can only be called for events with desc attached */
 502         assert(event->desc);
 503
 504         /* Link each bytecode. */
 505         cds_list_for_each_entry(bc, &enabler->filter_bytecode_head, node) {
 506                 int found = 0, ret;
 507                 struct cds_list_head *insert_loc;
 508
 509                 cds_list_for_each_entry(runtime,
 510                                 &event->bytecode_runtime_head, node) {
 511                         if (runtime->bc == bc) {
 512                                 found = 1;
 513                                 break;
 514                         }
 515                 }
 516                 /* Skip bytecode already linked */
 517                 if (found)
 518                         continue;
 519
 520                 /*
 521                  * Insert at specified priority (seqnum) in increasing
 522                  * order.
 523                  */
 524                 cds_list_for_each_entry_reverse(runtime,
 525                                 &event->bytecode_runtime_head, node) {
 526                         if (runtime->bc->bc.seqnum < bc->bc.seqnum) {
 527                                 /* insert here */
 528                                 insert_loc = &runtime->node;
 529                                 goto add_within;
 530                         }
 531                 }
 532                 /* Add to head to list */
 533                 insert_loc = &event->bytecode_runtime_head;
 534         add_within:
 535                 dbg_printf("linking bytecode\n");
 536                 ret = _lttng_filter_event_link_bytecode(event, bc,
 537                                 insert_loc);
 538                 if (ret) {
 539                         dbg_printf("[lttng filter] warning: cannot link event bytecode\n");
 540                 }
 541         }
 542 }
 543
 544 /*
 545  * We own the filter_bytecode if we return success.
 546  */
 547 int lttng_filter_enabler_attach_bytecode(struct lttng_enabler *enabler,
 548                 struct lttng_ust_filter_bytecode_node *filter_bytecode)
 549 {
 550         cds_list_add(&filter_bytecode->node, &enabler->filter_bytecode_head);
 551         return 0;
 552 }
 553
 554 void lttng_free_enabler_filter_bytecode(struct lttng_enabler *enabler)
 555 {
 556         struct lttng_ust_filter_bytecode_node *filter_bytecode, *tmp;
 557
 558         cds_list_for_each_entry_safe(filter_bytecode, tmp,
 559                         &enabler->filter_bytecode_head, node) {
 560                 free(filter_bytecode);
 561         }
 562 }
 563
 564 void lttng_free_event_filter_runtime(struct lttng_event *event)
 565 {
 566         struct bytecode_runtime *runtime, *tmp;
 567
 568         cds_list_for_each_entry_safe(runtime, tmp,
 569                         &event->bytecode_runtime_head, p.node) {
 570                 free(runtime->data);
 571                 free(runtime);
 572         }
 573 }