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 <stddef.h>
  29 #include <stdint.h>
  30
  31 #include <urcu/rculist.h>
  32
  33 #include "lttng-filter.h"
  34 #include "ust-events-internal.h"
  35
  36 static const char *opnames[] = {
  37         [ FILTER_OP_UNKNOWN ] = "UNKNOWN",
  38
  39         [ FILTER_OP_RETURN ] = "RETURN",
  40
  41         /* binary */
  42         [ FILTER_OP_MUL ] = "MUL",
  43         [ FILTER_OP_DIV ] = "DIV",
  44         [ FILTER_OP_MOD ] = "MOD",
  45         [ FILTER_OP_PLUS ] = "PLUS",
  46         [ FILTER_OP_MINUS ] = "MINUS",
  47         [ FILTER_OP_BIT_RSHIFT ] = "BIT_RSHIFT",
  48         [ FILTER_OP_BIT_LSHIFT ] = "BIT_LSHIFT",
  49         [ FILTER_OP_BIT_AND ] = "BIT_AND",
  50         [ FILTER_OP_BIT_OR ] = "BIT_OR",
  51         [ FILTER_OP_BIT_XOR ] = "BIT_XOR",
  52
  53         /* binary comparators */
  54         [ FILTER_OP_EQ ] = "EQ",
  55         [ FILTER_OP_NE ] = "NE",
  56         [ FILTER_OP_GT ] = "GT",
  57         [ FILTER_OP_LT ] = "LT",
  58         [ FILTER_OP_GE ] = "GE",
  59         [ FILTER_OP_LE ] = "LE",
  60
  61         /* string binary comparators */
  62         [ FILTER_OP_EQ_STRING ] = "EQ_STRING",
  63         [ FILTER_OP_NE_STRING ] = "NE_STRING",
  64         [ FILTER_OP_GT_STRING ] = "GT_STRING",
  65         [ FILTER_OP_LT_STRING ] = "LT_STRING",
  66         [ FILTER_OP_GE_STRING ] = "GE_STRING",
  67         [ FILTER_OP_LE_STRING ] = "LE_STRING",
  68
  69         /* s64 binary comparators */
  70         [ FILTER_OP_EQ_S64 ] = "EQ_S64",
  71         [ FILTER_OP_NE_S64 ] = "NE_S64",
  72         [ FILTER_OP_GT_S64 ] = "GT_S64",
  73         [ FILTER_OP_LT_S64 ] = "LT_S64",
  74         [ FILTER_OP_GE_S64 ] = "GE_S64",
  75         [ FILTER_OP_LE_S64 ] = "LE_S64",
  76
  77         /* double binary comparators */
  78         [ FILTER_OP_EQ_DOUBLE ] = "EQ_DOUBLE",
  79         [ FILTER_OP_NE_DOUBLE ] = "NE_DOUBLE",
  80         [ FILTER_OP_GT_DOUBLE ] = "GT_DOUBLE",
  81         [ FILTER_OP_LT_DOUBLE ] = "LT_DOUBLE",
  82         [ FILTER_OP_GE_DOUBLE ] = "GE_DOUBLE",
  83         [ FILTER_OP_LE_DOUBLE ] = "LE_DOUBLE",
  84
  85         /* Mixed S64-double binary comparators */
  86         [ FILTER_OP_EQ_DOUBLE_S64 ] = "EQ_DOUBLE_S64",
  87         [ FILTER_OP_NE_DOUBLE_S64 ] = "NE_DOUBLE_S64",
  88         [ FILTER_OP_GT_DOUBLE_S64 ] = "GT_DOUBLE_S64",
  89         [ FILTER_OP_LT_DOUBLE_S64 ] = "LT_DOUBLE_S64",
  90         [ FILTER_OP_GE_DOUBLE_S64 ] = "GE_DOUBLE_S64",
  91         [ FILTER_OP_LE_DOUBLE_S64 ] = "LE_DOUBLE_S64",
  92
  93         [ FILTER_OP_EQ_S64_DOUBLE ] = "EQ_S64_DOUBLE",
  94         [ FILTER_OP_NE_S64_DOUBLE ] = "NE_S64_DOUBLE",
  95         [ FILTER_OP_GT_S64_DOUBLE ] = "GT_S64_DOUBLE",
  96         [ FILTER_OP_LT_S64_DOUBLE ] = "LT_S64_DOUBLE",
  97         [ FILTER_OP_GE_S64_DOUBLE ] = "GE_S64_DOUBLE",
  98         [ FILTER_OP_LE_S64_DOUBLE ] = "LE_S64_DOUBLE",
  99
 100         /* unary */
 101         [ FILTER_OP_UNARY_PLUS ] = "UNARY_PLUS",
 102         [ FILTER_OP_UNARY_MINUS ] = "UNARY_MINUS",
 103         [ FILTER_OP_UNARY_NOT ] = "UNARY_NOT",
 104         [ FILTER_OP_UNARY_PLUS_S64 ] = "UNARY_PLUS_S64",
 105         [ FILTER_OP_UNARY_MINUS_S64 ] = "UNARY_MINUS_S64",
 106         [ FILTER_OP_UNARY_NOT_S64 ] = "UNARY_NOT_S64",
 107         [ FILTER_OP_UNARY_PLUS_DOUBLE ] = "UNARY_PLUS_DOUBLE",
 108         [ FILTER_OP_UNARY_MINUS_DOUBLE ] = "UNARY_MINUS_DOUBLE",
 109         [ FILTER_OP_UNARY_NOT_DOUBLE ] = "UNARY_NOT_DOUBLE",
 110
 111         /* logical */
 112         [ FILTER_OP_AND ] = "AND",
 113         [ FILTER_OP_OR ] = "OR",
 114
 115         /* load field ref */
 116         [ FILTER_OP_LOAD_FIELD_REF ] = "LOAD_FIELD_REF",
 117         [ FILTER_OP_LOAD_FIELD_REF_STRING ] = "LOAD_FIELD_REF_STRING",
 118         [ FILTER_OP_LOAD_FIELD_REF_SEQUENCE ] = "LOAD_FIELD_REF_SEQUENCE",
 119         [ FILTER_OP_LOAD_FIELD_REF_S64 ] = "LOAD_FIELD_REF_S64",
 120         [ FILTER_OP_LOAD_FIELD_REF_DOUBLE ] = "LOAD_FIELD_REF_DOUBLE",
 121
 122         /* load from immediate operand */
 123         [ FILTER_OP_LOAD_STRING ] = "LOAD_STRING",
 124         [ FILTER_OP_LOAD_S64 ] = "LOAD_S64",
 125         [ FILTER_OP_LOAD_DOUBLE ] = "LOAD_DOUBLE",
 126
 127         /* cast */
 128         [ FILTER_OP_CAST_TO_S64 ] = "CAST_TO_S64",
 129         [ FILTER_OP_CAST_DOUBLE_TO_S64 ] = "CAST_DOUBLE_TO_S64",
 130         [ FILTER_OP_CAST_NOP ] = "CAST_NOP",
 131
 132         /* get context ref */
 133         [ FILTER_OP_GET_CONTEXT_REF ] = "GET_CONTEXT_REF",
 134         [ FILTER_OP_GET_CONTEXT_REF_STRING ] = "GET_CONTEXT_REF_STRING",
 135         [ FILTER_OP_GET_CONTEXT_REF_S64 ] = "GET_CONTEXT_REF_S64",
 136         [ FILTER_OP_GET_CONTEXT_REF_DOUBLE ] = "GET_CONTEXT_REF_DOUBLE",
 137
 138         /* load userspace field ref */
 139         [ FILTER_OP_LOAD_FIELD_REF_USER_STRING ] = "LOAD_FIELD_REF_USER_STRING",
 140         [ FILTER_OP_LOAD_FIELD_REF_USER_SEQUENCE ] = "LOAD_FIELD_REF_USER_SEQUENCE",
 141
 142         /*
 143          * load immediate star globbing pattern (literal string)
 144          * from immediate.
 145          */
 146         [ FILTER_OP_LOAD_STAR_GLOB_STRING ] = "LOAD_STAR_GLOB_STRING",
 147
 148         /* globbing pattern binary operator: apply to */
 149         [ FILTER_OP_EQ_STAR_GLOB_STRING ] = "EQ_STAR_GLOB_STRING",
 150         [ FILTER_OP_NE_STAR_GLOB_STRING ] = "NE_STAR_GLOB_STRING",
 151
 152         /*
 153          * Instructions for recursive traversal through composed types.
 154          */
 155         [ FILTER_OP_GET_CONTEXT_ROOT ] = "GET_CONTEXT_ROOT",
 156         [ FILTER_OP_GET_APP_CONTEXT_ROOT ] = "GET_APP_CONTEXT_ROOT",
 157         [ FILTER_OP_GET_PAYLOAD_ROOT ] = "GET_PAYLOAD_ROOT",
 158
 159         [ FILTER_OP_GET_SYMBOL ] = "GET_SYMBOL",
 160         [ FILTER_OP_GET_SYMBOL_FIELD ] = "GET_SYMBOL_FIELD",
 161         [ FILTER_OP_GET_INDEX_U16 ] = "GET_INDEX_U16",
 162         [ FILTER_OP_GET_INDEX_U64 ] = "GET_INDEX_U64",
 163
 164         [ FILTER_OP_LOAD_FIELD ] = "LOAD_FIELD",
 165         [ FILTER_OP_LOAD_FIELD_S8 ] = "LOAD_FIELD_S8",
 166         [ FILTER_OP_LOAD_FIELD_S16 ] = "LOAD_FIELD_S16",
 167         [ FILTER_OP_LOAD_FIELD_S32 ] = "LOAD_FIELD_S32",
 168         [ FILTER_OP_LOAD_FIELD_S64 ] = "LOAD_FIELD_S64",
 169         [ FILTER_OP_LOAD_FIELD_U8 ] = "LOAD_FIELD_U8",
 170         [ FILTER_OP_LOAD_FIELD_U16 ] = "LOAD_FIELD_U16",
 171         [ FILTER_OP_LOAD_FIELD_U32 ] = "LOAD_FIELD_U32",
 172         [ FILTER_OP_LOAD_FIELD_U64 ] = "LOAD_FIELD_U64",
 173         [ FILTER_OP_LOAD_FIELD_STRING ] = "LOAD_FIELD_STRING",
 174         [ FILTER_OP_LOAD_FIELD_SEQUENCE ] = "LOAD_FIELD_SEQUENCE",
 175         [ FILTER_OP_LOAD_FIELD_DOUBLE ] = "LOAD_FIELD_DOUBLE",
 176
 177         [ FILTER_OP_UNARY_BIT_NOT ] = "UNARY_BIT_NOT",
 178
 179         [ FILTER_OP_RETURN_S64 ] = "RETURN_S64",
 180 };
 181
 182 const char *print_op(enum filter_op op)
 183 {
 184         if (op >= NR_FILTER_OPS)
 185                 return "UNKNOWN";
 186         else
 187                 return opnames[op];
 188 }
 189
 190 static
 191 int apply_field_reloc(const struct lttng_event_desc *event_desc,
 192                 struct bytecode_runtime *runtime,
 193                 uint32_t runtime_len,
 194                 uint32_t reloc_offset,
 195                 const char *field_name,
 196                 enum filter_op filter_op)
 197 {
 198         const struct lttng_event_field *fields, *field = NULL;
 199         unsigned int nr_fields, i;
 200         struct load_op *op;
 201         uint32_t field_offset = 0;
 202
 203         dbg_printf("Apply field reloc: %u %s\n", reloc_offset, field_name);
 204
 205         /* Lookup event by name */
 206         if (!event_desc)
 207                 return -EINVAL;
 208         fields = event_desc->fields;
 209         if (!fields)
 210                 return -EINVAL;
 211         nr_fields = event_desc->nr_fields;
 212         for (i = 0; i < nr_fields; i++) {
 213                 if (!strcmp(fields[i].name, field_name)) {
 214                         field = &fields[i];
 215                         break;
 216                 }
 217                 /* compute field offset */
 218                 switch (fields[i].type.atype) {
 219                 case atype_integer:
 220                 case atype_enum:
 221                         field_offset += sizeof(int64_t);
 222                         break;
 223                 case atype_array:
 224                 case atype_sequence:
 225                         field_offset += sizeof(unsigned long);
 226                         field_offset += sizeof(void *);
 227                         break;
 228                 case atype_string:
 229                         field_offset += sizeof(void *);
 230                         break;
 231                 case atype_float:
 232                         field_offset += sizeof(double);
 233                         break;
 234                 default:
 235                         return -EINVAL;
 236                 }
 237         }
 238         if (!field)
 239                 return -EINVAL;
 240
 241         /* Check if field offset is too large for 16-bit offset */
 242         if (field_offset > FILTER_BYTECODE_MAX_LEN - 1)
 243                 return -EINVAL;
 244
 245         /* set type */
 246         op = (struct load_op *) &runtime->code[reloc_offset];
 247
 248         switch (filter_op) {
 249         case FILTER_OP_LOAD_FIELD_REF:
 250         {
 251                 struct field_ref *field_ref;
 252
 253                 field_ref = (struct field_ref *) op->data;
 254                 switch (field->type.atype) {
 255                 case atype_integer:
 256                 case atype_enum:
 257                         op->op = FILTER_OP_LOAD_FIELD_REF_S64;
 258                         break;
 259                 case atype_array:
 260                 case atype_sequence:
 261                         op->op = FILTER_OP_LOAD_FIELD_REF_SEQUENCE;
 262                         break;
 263                 case atype_string:
 264                         op->op = FILTER_OP_LOAD_FIELD_REF_STRING;
 265                         break;
 266                 case atype_float:
 267                         op->op = FILTER_OP_LOAD_FIELD_REF_DOUBLE;
 268                         break;
 269                 default:
 270                         return -EINVAL;
 271                 }
 272                 /* set offset */
 273                 field_ref->offset = (uint16_t) field_offset;
 274                 break;
 275         }
 276         default:
 277                 return -EINVAL;
 278         }
 279         return 0;
 280 }
 281
 282 static
 283 int apply_context_reloc(struct bytecode_runtime *runtime,
 284                 uint32_t runtime_len,
 285                 uint32_t reloc_offset,
 286                 const char *context_name,
 287                 enum filter_op filter_op)
 288 {
 289         struct load_op *op;
 290         struct lttng_ctx_field *ctx_field;
 291         int idx;
 292         struct lttng_ctx *ctx = *runtime->p.ctx;
 293
 294         dbg_printf("Apply context reloc: %u %s\n", reloc_offset, context_name);
 295
 296         /* Get context index */
 297         idx = lttng_get_context_index(ctx, context_name);
 298         if (idx < 0) {
 299                 if (lttng_context_is_app(context_name)) {
 300                         int ret;
 301
 302                         ret = lttng_ust_add_app_context_to_ctx_rcu(context_name,
 303                                         &ctx);
 304                         if (ret)
 305                                 return ret;
 306                         idx = lttng_get_context_index(ctx, context_name);
 307                         if (idx < 0)
 308                                 return -ENOENT;
 309                 } else {
 310                         return -ENOENT;
 311                 }
 312         }
 313         /* Check if idx is too large for 16-bit offset */
 314         if (idx > FILTER_BYTECODE_MAX_LEN - 1)
 315                 return -EINVAL;
 316
 317         /* Get context return type */
 318         ctx_field = &ctx->fields[idx];
 319         op = (struct load_op *) &runtime->code[reloc_offset];
 320
 321         switch (filter_op) {
 322         case FILTER_OP_GET_CONTEXT_REF:
 323         {
 324                 struct field_ref *field_ref;
 325
 326                 field_ref = (struct field_ref *) op->data;
 327                 switch (ctx_field->event_field.type.atype) {
 328                 case atype_integer:
 329                 case atype_enum:
 330                         op->op = FILTER_OP_GET_CONTEXT_REF_S64;
 331                         break;
 332                         /* Sequence and array supported as string */
 333                 case atype_string:
 334                 case atype_array:
 335                 case atype_sequence:
 336                         op->op = FILTER_OP_GET_CONTEXT_REF_STRING;
 337                         break;
 338                 case atype_float:
 339                         op->op = FILTER_OP_GET_CONTEXT_REF_DOUBLE;
 340                         break;
 341                 case atype_dynamic:
 342                         op->op = FILTER_OP_GET_CONTEXT_REF;
 343                         break;
 344                 default:
 345                         return -EINVAL;
 346                 }
 347                 /* set offset to context index within channel contexts */
 348                 field_ref->offset = (uint16_t) idx;
 349                 break;
 350         }
 351         default:
 352                 return -EINVAL;
 353         }
 354         return 0;
 355 }
 356
 357 static
 358 int apply_reloc(const struct lttng_event_desc *event_desc,
 359                 struct bytecode_runtime *runtime,
 360                 uint32_t runtime_len,
 361                 uint32_t reloc_offset,
 362                 const char *name)
 363 {
 364         struct load_op *op;
 365
 366         dbg_printf("Apply reloc: %u %s\n", reloc_offset, name);
 367
 368         /* Ensure that the reloc is within the code */
 369         if (runtime_len - reloc_offset < sizeof(uint16_t))
 370                 return -EINVAL;
 371
 372         op = (struct load_op *) &runtime->code[reloc_offset];
 373         switch (op->op) {
 374         case FILTER_OP_LOAD_FIELD_REF:
 375                 return apply_field_reloc(event_desc, runtime, runtime_len,
 376                         reloc_offset, name, op->op);
 377         case FILTER_OP_GET_CONTEXT_REF:
 378                 return apply_context_reloc(runtime, runtime_len,
 379                         reloc_offset, name, op->op);
 380         case FILTER_OP_GET_SYMBOL:
 381         case FILTER_OP_GET_SYMBOL_FIELD:
 382                 /*
 383                  * Will be handled by load specialize phase or
 384                  * dynamically by interpreter.
 385                  */
 386                 return 0;
 387         default:
 388                 ERR("Unknown reloc op type %u\n", op->op);
 389                 return -EINVAL;
 390         }
 391         return 0;
 392 }
 393
 394 static
 395 int bytecode_is_linked(struct lttng_ust_filter_bytecode_node *filter_bytecode,
 396                 struct cds_list_head *bytecode_runtime_head)
 397 {
 398         struct lttng_bytecode_runtime *bc_runtime;
 399
 400         cds_list_for_each_entry(bc_runtime, bytecode_runtime_head, node) {
 401                 if (bc_runtime->bc == filter_bytecode)
 402                         return 1;
 403         }
 404         return 0;
 405 }
 406
 407 /*
 408  * Take a bytecode with reloc table and link it to an event to create a
 409  * bytecode runtime.
 410  */
 411 static
 412 int _lttng_filter_link_bytecode(const struct lttng_event_desc *event_desc,
 413                 struct lttng_ctx **ctx,
 414                 struct lttng_ust_filter_bytecode_node *filter_bytecode,
 415                 struct cds_list_head *insert_loc)
 416 {
 417         int ret, offset, next_offset;
 418         struct bytecode_runtime *runtime = NULL;
 419         size_t runtime_alloc_len;
 420
 421         if (!filter_bytecode)
 422                 return 0;
 423         /* Bytecode already linked */
 424         if (bytecode_is_linked(filter_bytecode, insert_loc))
 425                 return 0;
 426
 427         dbg_printf("Linking...\n");
 428
 429         /* We don't need the reloc table in the runtime */
 430         runtime_alloc_len = sizeof(*runtime) + filter_bytecode->bc.reloc_offset;
 431         runtime = zmalloc(runtime_alloc_len);
 432         if (!runtime) {
 433                 ret = -ENOMEM;
 434                 goto alloc_error;
 435         }
 436         runtime->p.bc = filter_bytecode;
 437         runtime->p.ctx = ctx;
 438         runtime->len = filter_bytecode->bc.reloc_offset;
 439         /* copy original bytecode */
 440         memcpy(runtime->code, filter_bytecode->bc.data, runtime->len);
 441         /*
 442          * apply relocs. Those are a uint16_t (offset in bytecode)
 443          * followed by a string (field name).
 444          */
 445         for (offset = filter_bytecode->bc.reloc_offset;
 446                         offset < filter_bytecode->bc.len;
 447                         offset = next_offset) {
 448                 uint16_t reloc_offset =
 449                         *(uint16_t *) &filter_bytecode->bc.data[offset];
 450                 const char *name =
 451                         (const char *) &filter_bytecode->bc.data[offset + sizeof(uint16_t)];
 452
 453                 ret = apply_reloc(event_desc, runtime, runtime->len, reloc_offset, name);
 454                 if (ret) {
 455                         goto link_error;
 456                 }
 457                 next_offset = offset + sizeof(uint16_t) + strlen(name) + 1;
 458         }
 459         /* Validate bytecode */
 460         ret = lttng_filter_validate_bytecode(runtime);
 461         if (ret) {
 462                 goto link_error;
 463         }
 464         /* Specialize bytecode */
 465         ret = lttng_filter_specialize_bytecode(event_desc, runtime);
 466         if (ret) {
 467                 goto link_error;
 468         }
 469         runtime->p.filter = lttng_filter_interpret_bytecode;
 470         runtime->p.link_failed = 0;
 471         cds_list_add_rcu(&runtime->p.node, insert_loc);
 472         dbg_printf("Linking successful.\n");
 473         return 0;
 474
 475 link_error:
 476         runtime->p.filter = lttng_filter_false;
 477         runtime->p.link_failed = 1;
 478         cds_list_add_rcu(&runtime->p.node, insert_loc);
 479 alloc_error:
 480         dbg_printf("Linking failed.\n");
 481         return ret;
 482 }
 483
 484 void lttng_filter_sync_state(struct lttng_bytecode_runtime *runtime)
 485 {
 486         struct lttng_ust_filter_bytecode_node *bc = runtime->bc;
 487
 488         if (!bc->enabler->enabled || runtime->link_failed)
 489                 runtime->filter = lttng_filter_false;
 490         else
 491                 runtime->filter = lttng_filter_interpret_bytecode;
 492 }
 493
 494 /*
 495  * Link bytecode for all enablers referenced by an event.
 496  */
 497 void lttng_enabler_link_bytecode(const struct lttng_event_desc *event_desc,
 498                 struct lttng_ctx **ctx,
 499                 struct cds_list_head *bytecode_runtime_head,
 500                 struct lttng_enabler *enabler)
 501 {
 502         struct lttng_ust_filter_bytecode_node *bc;
 503         struct lttng_bytecode_runtime *runtime;
 504
 505         assert(event_desc);
 506
 507         /* Link each bytecode. */
 508         cds_list_for_each_entry(bc, &enabler->filter_bytecode_head, node) {
 509                 int found = 0, ret;
 510                 struct cds_list_head *insert_loc;
 511
 512                 cds_list_for_each_entry(runtime,
 513                                 bytecode_runtime_head, node) {
 514                         if (runtime->bc == bc) {
 515                                 found = 1;
 516                                 break;
 517                         }
 518                 }
 519                 /* Skip bytecode already linked */
 520                 if (found)
 521                         continue;
 522
 523                 /*
 524                  * Insert at specified priority (seqnum) in increasing
 525                  * order.
 526                  */
 527                 cds_list_for_each_entry_reverse(runtime,
 528                                 bytecode_runtime_head, node) {
 529                         if (runtime->bc->bc.seqnum < bc->bc.seqnum) {
 530                                 /* insert here */
 531                                 insert_loc = &runtime->node;
 532                                 goto add_within;
 533                         }
 534                 }
 535
 536                 /* Add to head to list */
 537                 insert_loc = bytecode_runtime_head;
 538         add_within:
 539                 dbg_printf("linking bytecode\n");
 540                 ret = _lttng_filter_link_bytecode(event_desc, ctx, bc,
 541                         insert_loc);
 542                 if (ret) {
 543                         dbg_printf("[lttng filter] warning: cannot link event bytecode\n");
 544                 }
 545         }
 546 }
 547
 548 /*
 549  * We own the filter_bytecode if we return success.
 550  */
 551 int lttng_filter_enabler_attach_bytecode(struct lttng_enabler *enabler,
 552                 struct lttng_ust_filter_bytecode_node *filter_bytecode)
 553 {
 554         cds_list_add(&filter_bytecode->node, &enabler->filter_bytecode_head);
 555         return 0;
 556 }
 557
 558 static
 559 void free_filter_runtime(struct cds_list_head *bytecode_runtime_head)
 560 {
 561         struct bytecode_runtime *runtime, *tmp;
 562
 563         cds_list_for_each_entry_safe(runtime, tmp, bytecode_runtime_head,
 564                         p.node) {
 565                 free(runtime->data);
 566                 free(runtime);
 567         }
 568 }
 569
 570 void lttng_free_event_filter_runtime(struct lttng_event *event)
 571 {
 572         free_filter_runtime(&event->bytecode_runtime_head);
 573 }
 574
 575 void lttng_free_trigger_filter_runtime(struct lttng_trigger *trigger)
 576 {
 577         free_filter_runtime(&trigger->bytecode_runtime_head);
 578 }