liblttng-ust/lttng-bytecode.c

   1 /*
   2  * SPDX-License-Identifier: MIT
   3  *
   4  * Copyright (C) 2010-2016 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
   5  *
   6  * LTTng UST bytecode code.
   7  */
   8
   9 #define _LGPL_SOURCE
  10 #include <stddef.h>
  11 #include <stdint.h>
  12
  13 #include <urcu/rculist.h>
  14
  15 #include "lttng-bytecode.h"
  16 #include "ust-events-internal.h"
  17
  18 static const char *opnames[] = {
  19         [ BYTECODE_OP_UNKNOWN ] = "UNKNOWN",
  20
  21         [ BYTECODE_OP_RETURN ] = "RETURN",
  22
  23         /* binary */
  24         [ BYTECODE_OP_MUL ] = "MUL",
  25         [ BYTECODE_OP_DIV ] = "DIV",
  26         [ BYTECODE_OP_MOD ] = "MOD",
  27         [ BYTECODE_OP_PLUS ] = "PLUS",
  28         [ BYTECODE_OP_MINUS ] = "MINUS",
  29         [ BYTECODE_OP_BIT_RSHIFT ] = "BIT_RSHIFT",
  30         [ BYTECODE_OP_BIT_LSHIFT ] = "BIT_LSHIFT",
  31         [ BYTECODE_OP_BIT_AND ] = "BIT_AND",
  32         [ BYTECODE_OP_BIT_OR ] = "BIT_OR",
  33         [ BYTECODE_OP_BIT_XOR ] = "BIT_XOR",
  34
  35         /* binary comparators */
  36         [ BYTECODE_OP_EQ ] = "EQ",
  37         [ BYTECODE_OP_NE ] = "NE",
  38         [ BYTECODE_OP_GT ] = "GT",
  39         [ BYTECODE_OP_LT ] = "LT",
  40         [ BYTECODE_OP_GE ] = "GE",
  41         [ BYTECODE_OP_LE ] = "LE",
  42
  43         /* string binary comparators */
  44         [ BYTECODE_OP_EQ_STRING ] = "EQ_STRING",
  45         [ BYTECODE_OP_NE_STRING ] = "NE_STRING",
  46         [ BYTECODE_OP_GT_STRING ] = "GT_STRING",
  47         [ BYTECODE_OP_LT_STRING ] = "LT_STRING",
  48         [ BYTECODE_OP_GE_STRING ] = "GE_STRING",
  49         [ BYTECODE_OP_LE_STRING ] = "LE_STRING",
  50
  51         /* s64 binary comparators */
  52         [ BYTECODE_OP_EQ_S64 ] = "EQ_S64",
  53         [ BYTECODE_OP_NE_S64 ] = "NE_S64",
  54         [ BYTECODE_OP_GT_S64 ] = "GT_S64",
  55         [ BYTECODE_OP_LT_S64 ] = "LT_S64",
  56         [ BYTECODE_OP_GE_S64 ] = "GE_S64",
  57         [ BYTECODE_OP_LE_S64 ] = "LE_S64",
  58
  59         /* double binary comparators */
  60         [ BYTECODE_OP_EQ_DOUBLE ] = "EQ_DOUBLE",
  61         [ BYTECODE_OP_NE_DOUBLE ] = "NE_DOUBLE",
  62         [ BYTECODE_OP_GT_DOUBLE ] = "GT_DOUBLE",
  63         [ BYTECODE_OP_LT_DOUBLE ] = "LT_DOUBLE",
  64         [ BYTECODE_OP_GE_DOUBLE ] = "GE_DOUBLE",
  65         [ BYTECODE_OP_LE_DOUBLE ] = "LE_DOUBLE",
  66
  67         /* Mixed S64-double binary comparators */
  68         [ BYTECODE_OP_EQ_DOUBLE_S64 ] = "EQ_DOUBLE_S64",
  69         [ BYTECODE_OP_NE_DOUBLE_S64 ] = "NE_DOUBLE_S64",
  70         [ BYTECODE_OP_GT_DOUBLE_S64 ] = "GT_DOUBLE_S64",
  71         [ BYTECODE_OP_LT_DOUBLE_S64 ] = "LT_DOUBLE_S64",
  72         [ BYTECODE_OP_GE_DOUBLE_S64 ] = "GE_DOUBLE_S64",
  73         [ BYTECODE_OP_LE_DOUBLE_S64 ] = "LE_DOUBLE_S64",
  74
  75         [ BYTECODE_OP_EQ_S64_DOUBLE ] = "EQ_S64_DOUBLE",
  76         [ BYTECODE_OP_NE_S64_DOUBLE ] = "NE_S64_DOUBLE",
  77         [ BYTECODE_OP_GT_S64_DOUBLE ] = "GT_S64_DOUBLE",
  78         [ BYTECODE_OP_LT_S64_DOUBLE ] = "LT_S64_DOUBLE",
  79         [ BYTECODE_OP_GE_S64_DOUBLE ] = "GE_S64_DOUBLE",
  80         [ BYTECODE_OP_LE_S64_DOUBLE ] = "LE_S64_DOUBLE",
  81
  82         /* unary */
  83         [ BYTECODE_OP_UNARY_PLUS ] = "UNARY_PLUS",
  84         [ BYTECODE_OP_UNARY_MINUS ] = "UNARY_MINUS",
  85         [ BYTECODE_OP_UNARY_NOT ] = "UNARY_NOT",
  86         [ BYTECODE_OP_UNARY_PLUS_S64 ] = "UNARY_PLUS_S64",
  87         [ BYTECODE_OP_UNARY_MINUS_S64 ] = "UNARY_MINUS_S64",
  88         [ BYTECODE_OP_UNARY_NOT_S64 ] = "UNARY_NOT_S64",
  89         [ BYTECODE_OP_UNARY_PLUS_DOUBLE ] = "UNARY_PLUS_DOUBLE",
  90         [ BYTECODE_OP_UNARY_MINUS_DOUBLE ] = "UNARY_MINUS_DOUBLE",
  91         [ BYTECODE_OP_UNARY_NOT_DOUBLE ] = "UNARY_NOT_DOUBLE",
  92
  93         /* logical */
  94         [ BYTECODE_OP_AND ] = "AND",
  95         [ BYTECODE_OP_OR ] = "OR",
  96
  97         /* load field ref */
  98         [ BYTECODE_OP_LOAD_FIELD_REF ] = "LOAD_FIELD_REF",
  99         [ BYTECODE_OP_LOAD_FIELD_REF_STRING ] = "LOAD_FIELD_REF_STRING",
 100         [ BYTECODE_OP_LOAD_FIELD_REF_SEQUENCE ] = "LOAD_FIELD_REF_SEQUENCE",
 101         [ BYTECODE_OP_LOAD_FIELD_REF_S64 ] = "LOAD_FIELD_REF_S64",
 102         [ BYTECODE_OP_LOAD_FIELD_REF_DOUBLE ] = "LOAD_FIELD_REF_DOUBLE",
 103
 104         /* load from immediate operand */
 105         [ BYTECODE_OP_LOAD_STRING ] = "LOAD_STRING",
 106         [ BYTECODE_OP_LOAD_S64 ] = "LOAD_S64",
 107         [ BYTECODE_OP_LOAD_DOUBLE ] = "LOAD_DOUBLE",
 108
 109         /* cast */
 110         [ BYTECODE_OP_CAST_TO_S64 ] = "CAST_TO_S64",
 111         [ BYTECODE_OP_CAST_DOUBLE_TO_S64 ] = "CAST_DOUBLE_TO_S64",
 112         [ BYTECODE_OP_CAST_NOP ] = "CAST_NOP",
 113
 114         /* get context ref */
 115         [ BYTECODE_OP_GET_CONTEXT_REF ] = "GET_CONTEXT_REF",
 116         [ BYTECODE_OP_GET_CONTEXT_REF_STRING ] = "GET_CONTEXT_REF_STRING",
 117         [ BYTECODE_OP_GET_CONTEXT_REF_S64 ] = "GET_CONTEXT_REF_S64",
 118         [ BYTECODE_OP_GET_CONTEXT_REF_DOUBLE ] = "GET_CONTEXT_REF_DOUBLE",
 119
 120         /* load userspace field ref */
 121         [ BYTECODE_OP_LOAD_FIELD_REF_USER_STRING ] = "LOAD_FIELD_REF_USER_STRING",
 122         [ BYTECODE_OP_LOAD_FIELD_REF_USER_SEQUENCE ] = "LOAD_FIELD_REF_USER_SEQUENCE",
 123
 124         /*
 125          * load immediate star globbing pattern (literal string)
 126          * from immediate.
 127          */
 128         [ BYTECODE_OP_LOAD_STAR_GLOB_STRING ] = "LOAD_STAR_GLOB_STRING",
 129
 130         /* globbing pattern binary operator: apply to */
 131         [ BYTECODE_OP_EQ_STAR_GLOB_STRING ] = "EQ_STAR_GLOB_STRING",
 132         [ BYTECODE_OP_NE_STAR_GLOB_STRING ] = "NE_STAR_GLOB_STRING",
 133
 134         /*
 135          * Instructions for recursive traversal through composed types.
 136          */
 137         [ BYTECODE_OP_GET_CONTEXT_ROOT ] = "GET_CONTEXT_ROOT",
 138         [ BYTECODE_OP_GET_APP_CONTEXT_ROOT ] = "GET_APP_CONTEXT_ROOT",
 139         [ BYTECODE_OP_GET_PAYLOAD_ROOT ] = "GET_PAYLOAD_ROOT",
 140
 141         [ BYTECODE_OP_GET_SYMBOL ] = "GET_SYMBOL",
 142         [ BYTECODE_OP_GET_SYMBOL_FIELD ] = "GET_SYMBOL_FIELD",
 143         [ BYTECODE_OP_GET_INDEX_U16 ] = "GET_INDEX_U16",
 144         [ BYTECODE_OP_GET_INDEX_U64 ] = "GET_INDEX_U64",
 145
 146         [ BYTECODE_OP_LOAD_FIELD ] = "LOAD_FIELD",
 147         [ BYTECODE_OP_LOAD_FIELD_S8 ] = "LOAD_FIELD_S8",
 148         [ BYTECODE_OP_LOAD_FIELD_S16 ] = "LOAD_FIELD_S16",
 149         [ BYTECODE_OP_LOAD_FIELD_S32 ] = "LOAD_FIELD_S32",
 150         [ BYTECODE_OP_LOAD_FIELD_S64 ] = "LOAD_FIELD_S64",
 151         [ BYTECODE_OP_LOAD_FIELD_U8 ] = "LOAD_FIELD_U8",
 152         [ BYTECODE_OP_LOAD_FIELD_U16 ] = "LOAD_FIELD_U16",
 153         [ BYTECODE_OP_LOAD_FIELD_U32 ] = "LOAD_FIELD_U32",
 154         [ BYTECODE_OP_LOAD_FIELD_U64 ] = "LOAD_FIELD_U64",
 155         [ BYTECODE_OP_LOAD_FIELD_STRING ] = "LOAD_FIELD_STRING",
 156         [ BYTECODE_OP_LOAD_FIELD_SEQUENCE ] = "LOAD_FIELD_SEQUENCE",
 157         [ BYTECODE_OP_LOAD_FIELD_DOUBLE ] = "LOAD_FIELD_DOUBLE",
 158
 159         [ BYTECODE_OP_UNARY_BIT_NOT ] = "UNARY_BIT_NOT",
 160
 161         [ BYTECODE_OP_RETURN_S64 ] = "RETURN_S64",
 162 };
 163
 164 const char *print_op(enum bytecode_op op)
 165 {
 166         if (op >= NR_BYTECODE_OPS)
 167                 return "UNKNOWN";
 168         else
 169                 return opnames[op];
 170 }
 171
 172 static
 173 int apply_field_reloc(const struct lttng_event_desc *event_desc,
 174                 struct bytecode_runtime *runtime,
 175                 uint32_t runtime_len,
 176                 uint32_t reloc_offset,
 177                 const char *field_name,
 178                 enum bytecode_op bytecode_op)
 179 {
 180         const struct lttng_event_field *fields, *field = NULL;
 181         unsigned int nr_fields, i;
 182         struct load_op *op;
 183         uint32_t field_offset = 0;
 184
 185         dbg_printf("Apply field reloc: %u %s\n", reloc_offset, field_name);
 186
 187         /* Lookup event by name */
 188         if (!event_desc)
 189                 return -EINVAL;
 190         fields = event_desc->fields;
 191         if (!fields)
 192                 return -EINVAL;
 193         nr_fields = event_desc->nr_fields;
 194         for (i = 0; i < nr_fields; i++) {
 195                 if (fields[i].u.ext.nofilter) {
 196                         continue;
 197                 }
 198                 if (!strcmp(fields[i].name, field_name)) {
 199                         field = &fields[i];
 200                         break;
 201                 }
 202                 /* compute field offset */
 203                 switch (fields[i].type.atype) {
 204                 case atype_integer:
 205                 case atype_enum:
 206                 case atype_enum_nestable:
 207                         field_offset += sizeof(int64_t);
 208                         break;
 209                 case atype_array:
 210                 case atype_array_nestable:
 211                 case atype_sequence:
 212                 case atype_sequence_nestable:
 213                         field_offset += sizeof(unsigned long);
 214                         field_offset += sizeof(void *);
 215                         break;
 216                 case atype_string:
 217                         field_offset += sizeof(void *);
 218                         break;
 219                 case atype_float:
 220                         field_offset += sizeof(double);
 221                         break;
 222                 default:
 223                         return -EINVAL;
 224                 }
 225         }
 226         if (!field)
 227                 return -EINVAL;
 228
 229         /* Check if field offset is too large for 16-bit offset */
 230         if (field_offset > FILTER_BYTECODE_MAX_LEN - 1)
 231                 return -EINVAL;
 232
 233         /* set type */
 234         op = (struct load_op *) &runtime->code[reloc_offset];
 235
 236         switch (bytecode_op) {
 237         case BYTECODE_OP_LOAD_FIELD_REF:
 238         {
 239                 struct field_ref *field_ref;
 240
 241                 field_ref = (struct field_ref *) op->data;
 242                 switch (field->type.atype) {
 243                 case atype_integer:
 244                 case atype_enum:
 245                 case atype_enum_nestable:
 246                         op->op = BYTECODE_OP_LOAD_FIELD_REF_S64;
 247                         break;
 248                 case atype_array:
 249                 case atype_array_nestable:
 250                 case atype_sequence:
 251                 case atype_sequence_nestable:
 252                         op->op = BYTECODE_OP_LOAD_FIELD_REF_SEQUENCE;
 253                         break;
 254                 case atype_string:
 255                         op->op = BYTECODE_OP_LOAD_FIELD_REF_STRING;
 256                         break;
 257                 case atype_float:
 258                         op->op = BYTECODE_OP_LOAD_FIELD_REF_DOUBLE;
 259                         break;
 260                 default:
 261                         return -EINVAL;
 262                 }
 263                 /* set offset */
 264                 field_ref->offset = (uint16_t) field_offset;
 265                 break;
 266         }
 267         default:
 268                 return -EINVAL;
 269         }
 270         return 0;
 271 }
 272
 273 static
 274 int apply_context_reloc(struct bytecode_runtime *runtime,
 275                 uint32_t runtime_len,
 276                 uint32_t reloc_offset,
 277                 const char *context_name,
 278                 enum bytecode_op bytecode_op)
 279 {
 280         struct load_op *op;
 281         struct lttng_ctx_field *ctx_field;
 282         int idx;
 283         struct lttng_ctx **pctx = runtime->p.pctx;
 284
 285         dbg_printf("Apply context reloc: %u %s\n", reloc_offset, context_name);
 286
 287         /* Get context index */
 288         idx = lttng_get_context_index(*pctx, context_name);
 289         if (idx < 0) {
 290                 if (lttng_context_is_app(context_name)) {
 291                         int ret;
 292
 293                         ret = lttng_ust_add_app_context_to_ctx_rcu(context_name,
 294                                         pctx);
 295                         if (ret)
 296                                 return ret;
 297                         idx = lttng_get_context_index(*pctx, context_name);
 298                         if (idx < 0)
 299                                 return -ENOENT;
 300                 } else {
 301                         return -ENOENT;
 302                 }
 303         }
 304         /* Check if idx is too large for 16-bit offset */
 305         if (idx > FILTER_BYTECODE_MAX_LEN - 1)
 306                 return -EINVAL;
 307
 308         /* Get context return type */
 309         ctx_field = &(*pctx)->fields[idx];
 310         op = (struct load_op *) &runtime->code[reloc_offset];
 311
 312         switch (bytecode_op) {
 313         case BYTECODE_OP_GET_CONTEXT_REF:
 314         {
 315                 struct field_ref *field_ref;
 316
 317                 field_ref = (struct field_ref *) op->data;
 318                 switch (ctx_field->event_field.type.atype) {
 319                 case atype_integer:
 320                 case atype_enum:
 321                 case atype_enum_nestable:
 322                         op->op = BYTECODE_OP_GET_CONTEXT_REF_S64;
 323                         break;
 324                         /* Sequence and array supported as string */
 325                 case atype_string:
 326                 case atype_array:
 327                 case atype_array_nestable:
 328                 case atype_sequence:
 329                 case atype_sequence_nestable:
 330                         op->op = BYTECODE_OP_GET_CONTEXT_REF_STRING;
 331                         break;
 332                 case atype_float:
 333                         op->op = BYTECODE_OP_GET_CONTEXT_REF_DOUBLE;
 334                         break;
 335                 case atype_dynamic:
 336                         op->op = BYTECODE_OP_GET_CONTEXT_REF;
 337                         break;
 338                 default:
 339                         return -EINVAL;
 340                 }
 341                 /* set offset to context index within channel contexts */
 342                 field_ref->offset = (uint16_t) idx;
 343                 break;
 344         }
 345         default:
 346                 return -EINVAL;
 347         }
 348         return 0;
 349 }
 350
 351 static
 352 int apply_reloc(const struct lttng_event_desc *event_desc,
 353                 struct bytecode_runtime *runtime,
 354                 uint32_t runtime_len,
 355                 uint32_t reloc_offset,
 356                 const char *name)
 357 {
 358         struct load_op *op;
 359
 360         dbg_printf("Apply reloc: %u %s\n", reloc_offset, name);
 361
 362         /* Ensure that the reloc is within the code */
 363         if (runtime_len - reloc_offset < sizeof(uint16_t))
 364                 return -EINVAL;
 365
 366         op = (struct load_op *) &runtime->code[reloc_offset];
 367         switch (op->op) {
 368         case BYTECODE_OP_LOAD_FIELD_REF:
 369                 return apply_field_reloc(event_desc, runtime, runtime_len,
 370                         reloc_offset, name, op->op);
 371         case BYTECODE_OP_GET_CONTEXT_REF:
 372                 return apply_context_reloc(runtime, runtime_len,
 373                         reloc_offset, name, op->op);
 374         case BYTECODE_OP_GET_SYMBOL:
 375         case BYTECODE_OP_GET_SYMBOL_FIELD:
 376                 /*
 377                  * Will be handled by load specialize phase or
 378                  * dynamically by interpreter.
 379                  */
 380                 return 0;
 381         default:
 382                 ERR("Unknown reloc op type %u\n", op->op);
 383                 return -EINVAL;
 384         }
 385         return 0;
 386 }
 387
 388 static
 389 int bytecode_is_linked(struct lttng_ust_bytecode_node *bytecode,
 390                 struct cds_list_head *bytecode_runtime_head)
 391 {
 392         struct lttng_bytecode_runtime *bc_runtime;
 393
 394         cds_list_for_each_entry(bc_runtime, bytecode_runtime_head, node) {
 395                 if (bc_runtime->bc == bytecode)
 396                         return 1;
 397         }
 398         return 0;
 399 }
 400
 401 /*
 402  * Take a bytecode with reloc table and link it to an event to create a
 403  * bytecode runtime.
 404  */
 405 static
 406 int link_bytecode(const struct lttng_event_desc *event_desc,
 407                 struct lttng_ctx **ctx,
 408                 struct lttng_ust_bytecode_node *bytecode,
 409                 struct cds_list_head *insert_loc)
 410 {
 411         int ret, offset, next_offset;
 412         struct bytecode_runtime *runtime = NULL;
 413         size_t runtime_alloc_len;
 414
 415         if (!bytecode)
 416                 return 0;
 417         /* Bytecode already linked */
 418         if (bytecode_is_linked(bytecode, insert_loc))
 419                 return 0;
 420
 421         dbg_printf("Linking...\n");
 422
 423         /* We don't need the reloc table in the runtime */
 424         runtime_alloc_len = sizeof(*runtime) + bytecode->bc.reloc_offset;
 425         runtime = zmalloc(runtime_alloc_len);
 426         if (!runtime) {
 427                 ret = -ENOMEM;
 428                 goto alloc_error;
 429         }
 430         runtime->p.bc = bytecode;
 431         runtime->p.pctx = ctx;
 432         runtime->len = bytecode->bc.reloc_offset;
 433         /* copy original bytecode */
 434         memcpy(runtime->code, bytecode->bc.data, runtime->len);
 435         /*
 436          * apply relocs. Those are a uint16_t (offset in bytecode)
 437          * followed by a string (field name).
 438          */
 439         for (offset = bytecode->bc.reloc_offset;
 440                         offset < bytecode->bc.len;
 441                         offset = next_offset) {
 442                 uint16_t reloc_offset =
 443                         *(uint16_t *) &bytecode->bc.data[offset];
 444                 const char *name =
 445                         (const char *) &bytecode->bc.data[offset + sizeof(uint16_t)];
 446
 447                 ret = apply_reloc(event_desc, runtime, runtime->len, reloc_offset, name);
 448                 if (ret) {
 449                         goto link_error;
 450                 }
 451                 next_offset = offset + sizeof(uint16_t) + strlen(name) + 1;
 452         }
 453         /* Validate bytecode */
 454         ret = lttng_bytecode_validate(runtime);
 455         if (ret) {
 456                 goto link_error;
 457         }
 458         /* Specialize bytecode */
 459         ret = lttng_bytecode_specialize(event_desc, runtime);
 460         if (ret) {
 461                 goto link_error;
 462         }
 463
 464         switch (bytecode->type) {
 465         case LTTNG_UST_BYTECODE_NODE_TYPE_FILTER:
 466                 runtime->p.interpreter_funcs.filter = lttng_bytecode_filter_interpret;
 467                 break;
 468         case LTTNG_UST_BYTECODE_NODE_TYPE_CAPTURE:
 469                 runtime->p.interpreter_funcs.capture = lttng_bytecode_capture_interpret;
 470                 break;
 471         default:
 472                 abort();
 473         }
 474
 475         runtime->p.link_failed = 0;
 476         cds_list_add_rcu(&runtime->p.node, insert_loc);
 477         dbg_printf("Linking successful.\n");
 478         return 0;
 479
 480 link_error:
 481         switch (bytecode->type) {
 482         case LTTNG_UST_BYTECODE_NODE_TYPE_FILTER:
 483                 runtime->p.interpreter_funcs.filter = lttng_bytecode_filter_interpret_false;
 484                 break;
 485         case LTTNG_UST_BYTECODE_NODE_TYPE_CAPTURE:
 486                 runtime->p.interpreter_funcs.capture = lttng_bytecode_capture_interpret_false;
 487                 break;
 488         default:
 489                 abort();
 490         }
 491
 492         runtime->p.link_failed = 1;
 493         cds_list_add_rcu(&runtime->p.node, insert_loc);
 494 alloc_error:
 495         dbg_printf("Linking failed.\n");
 496         return ret;
 497 }
 498
 499 void lttng_bytecode_filter_sync_state(struct lttng_bytecode_runtime *runtime)
 500 {
 501         struct lttng_ust_bytecode_node *bc = runtime->bc;
 502
 503         if (!bc->enabler->enabled || runtime->link_failed)
 504                 runtime->interpreter_funcs.filter = lttng_bytecode_filter_interpret_false;
 505         else
 506                 runtime->interpreter_funcs.filter = lttng_bytecode_filter_interpret;
 507 }
 508
 509 void lttng_bytecode_capture_sync_state(struct lttng_bytecode_runtime *runtime)
 510 {
 511         struct lttng_ust_bytecode_node *bc = runtime->bc;
 512
 513         if (!bc->enabler->enabled || runtime->link_failed)
 514                 runtime->interpreter_funcs.capture = lttng_bytecode_capture_interpret_false;
 515         else
 516                 runtime->interpreter_funcs.capture = lttng_bytecode_capture_interpret;
 517 }
 518
 519 /*
 520  * Given the lists of bytecode programs of an instance (trigger or event) and
 521  * of a matching enabler, try to link all the enabler's bytecode programs with
 522  * the instance.
 523  *
 524  * This function is called after we confirmed that name enabler and the
 525  * instance are name matching (or glob pattern matching).
 526  */
 527 void lttng_enabler_link_bytecode(const struct lttng_event_desc *event_desc,
 528                 struct lttng_ctx **ctx,
 529                 struct cds_list_head *instance_bytecode_head,
 530                 struct cds_list_head *enabler_bytecode_head)
 531 {
 532         struct lttng_ust_bytecode_node *enabler_bc;
 533         struct lttng_bytecode_runtime *runtime;
 534
 535         assert(event_desc);
 536
 537         /* Go over all the bytecode programs of the enabler. */
 538         cds_list_for_each_entry(enabler_bc, enabler_bytecode_head, node) {
 539                 int found = 0, ret;
 540                 struct cds_list_head *insert_loc;
 541
 542                 /*
 543                  * Check if the current enabler bytecode program is already
 544                  * linked with the instance.
 545                  */
 546                 cds_list_for_each_entry(runtime, instance_bytecode_head, node) {
 547                         if (runtime->bc == enabler_bc) {
 548                                 found = 1;
 549                                 break;
 550                         }
 551                 }
 552
 553                 /*
 554                  * Skip bytecode already linked, go to the next enabler
 555                  * bytecode program.
 556                  */
 557                 if (found)
 558                         continue;
 559
 560                 /*
 561                  * Insert at specified priority (seqnum) in increasing
 562                  * order. If there already is a bytecode of the same priority,
 563                  * insert the new bytecode right after it.
 564                  */
 565                 cds_list_for_each_entry_reverse(runtime,
 566                                 instance_bytecode_head, node) {
 567                         if (runtime->bc->bc.seqnum <= enabler_bc->bc.seqnum) {
 568                                 /* insert here */
 569                                 insert_loc = &runtime->node;
 570                                 goto add_within;
 571                         }
 572                 }
 573
 574                 /* Add to head to list */
 575                 insert_loc = instance_bytecode_head;
 576         add_within:
 577                 dbg_printf("linking bytecode\n");
 578                 ret = link_bytecode(event_desc, ctx, enabler_bc, insert_loc);
 579                 if (ret) {
 580                         dbg_printf("[lttng filter] warning: cannot link event bytecode\n");
 581                 }
 582         }
 583 }
 584
 585 /*
 586  * We own the bytecode if we return success.
 587  */
 588 int lttng_filter_enabler_attach_bytecode(struct lttng_enabler *enabler,
 589                 struct lttng_ust_bytecode_node *bytecode)
 590 {
 591         cds_list_add(&bytecode->node, &enabler->filter_bytecode_head);
 592         return 0;
 593 }
 594
 595 static
 596 void free_filter_runtime(struct cds_list_head *bytecode_runtime_head)
 597 {
 598         struct bytecode_runtime *runtime, *tmp;
 599
 600         cds_list_for_each_entry_safe(runtime, tmp, bytecode_runtime_head,
 601                         p.node) {
 602                 free(runtime->data);
 603                 free(runtime);
 604         }
 605 }
 606
 607 void lttng_free_event_filter_runtime(struct lttng_event *event)
 608 {
 609         free_filter_runtime(&event->filter_bytecode_runtime_head);
 610 }
 611
 612 void lttng_free_event_notifier_filter_runtime(
 613                 struct lttng_event_notifier *event_notifier)
 614 {
 615         free_filter_runtime(&event_notifier->filter_bytecode_runtime_head);
 616 }