src/lttng-bytecode.c

   1 /* SPDX-License-Identifier: MIT
   2  *
   3  * lttng-bytecode.c
   4  *
   5  * LTTng modules bytecode code.
   6  *
   7  * Copyright (C) 2010-2016 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
   8  */
   9
  10 #include <linux/list.h>
  11 #include <linux/slab.h>
  12
  13 #include <lttng/lttng-bytecode.h>
  14
  15 static const char *opnames[] = {
  16         [ BYTECODE_OP_UNKNOWN ] = "UNKNOWN",
  17
  18         [ BYTECODE_OP_RETURN ] = "RETURN",
  19
  20         /* binary */
  21         [ BYTECODE_OP_MUL ] = "MUL",
  22         [ BYTECODE_OP_DIV ] = "DIV",
  23         [ BYTECODE_OP_MOD ] = "MOD",
  24         [ BYTECODE_OP_PLUS ] = "PLUS",
  25         [ BYTECODE_OP_MINUS ] = "MINUS",
  26         [ BYTECODE_OP_BIT_RSHIFT ] = "BIT_RSHIFT",
  27         [ BYTECODE_OP_BIT_LSHIFT ] = "BIT_LSHIFT",
  28         [ BYTECODE_OP_BIT_AND ] = "BIT_AND",
  29         [ BYTECODE_OP_BIT_OR ] = "BIT_OR",
  30         [ BYTECODE_OP_BIT_XOR ] = "BIT_XOR",
  31
  32         /* binary comparators */
  33         [ BYTECODE_OP_EQ ] = "EQ",
  34         [ BYTECODE_OP_NE ] = "NE",
  35         [ BYTECODE_OP_GT ] = "GT",
  36         [ BYTECODE_OP_LT ] = "LT",
  37         [ BYTECODE_OP_GE ] = "GE",
  38         [ BYTECODE_OP_LE ] = "LE",
  39
  40         /* string binary comparators */
  41         [ BYTECODE_OP_EQ_STRING ] = "EQ_STRING",
  42         [ BYTECODE_OP_NE_STRING ] = "NE_STRING",
  43         [ BYTECODE_OP_GT_STRING ] = "GT_STRING",
  44         [ BYTECODE_OP_LT_STRING ] = "LT_STRING",
  45         [ BYTECODE_OP_GE_STRING ] = "GE_STRING",
  46         [ BYTECODE_OP_LE_STRING ] = "LE_STRING",
  47
  48         /* s64 binary comparators */
  49         [ BYTECODE_OP_EQ_S64 ] = "EQ_S64",
  50         [ BYTECODE_OP_NE_S64 ] = "NE_S64",
  51         [ BYTECODE_OP_GT_S64 ] = "GT_S64",
  52         [ BYTECODE_OP_LT_S64 ] = "LT_S64",
  53         [ BYTECODE_OP_GE_S64 ] = "GE_S64",
  54         [ BYTECODE_OP_LE_S64 ] = "LE_S64",
  55
  56         /* double binary comparators */
  57         [ BYTECODE_OP_EQ_DOUBLE ] = "EQ_DOUBLE",
  58         [ BYTECODE_OP_NE_DOUBLE ] = "NE_DOUBLE",
  59         [ BYTECODE_OP_GT_DOUBLE ] = "GT_DOUBLE",
  60         [ BYTECODE_OP_LT_DOUBLE ] = "LT_DOUBLE",
  61         [ BYTECODE_OP_GE_DOUBLE ] = "GE_DOUBLE",
  62         [ BYTECODE_OP_LE_DOUBLE ] = "LE_DOUBLE",
  63
  64         /* Mixed S64-double binary comparators */
  65         [ BYTECODE_OP_EQ_DOUBLE_S64 ] = "EQ_DOUBLE_S64",
  66         [ BYTECODE_OP_NE_DOUBLE_S64 ] = "NE_DOUBLE_S64",
  67         [ BYTECODE_OP_GT_DOUBLE_S64 ] = "GT_DOUBLE_S64",
  68         [ BYTECODE_OP_LT_DOUBLE_S64 ] = "LT_DOUBLE_S64",
  69         [ BYTECODE_OP_GE_DOUBLE_S64 ] = "GE_DOUBLE_S64",
  70         [ BYTECODE_OP_LE_DOUBLE_S64 ] = "LE_DOUBLE_S64",
  71
  72         [ BYTECODE_OP_EQ_S64_DOUBLE ] = "EQ_S64_DOUBLE",
  73         [ BYTECODE_OP_NE_S64_DOUBLE ] = "NE_S64_DOUBLE",
  74         [ BYTECODE_OP_GT_S64_DOUBLE ] = "GT_S64_DOUBLE",
  75         [ BYTECODE_OP_LT_S64_DOUBLE ] = "LT_S64_DOUBLE",
  76         [ BYTECODE_OP_GE_S64_DOUBLE ] = "GE_S64_DOUBLE",
  77         [ BYTECODE_OP_LE_S64_DOUBLE ] = "LE_S64_DOUBLE",
  78
  79         /* unary */
  80         [ BYTECODE_OP_UNARY_PLUS ] = "UNARY_PLUS",
  81         [ BYTECODE_OP_UNARY_MINUS ] = "UNARY_MINUS",
  82         [ BYTECODE_OP_UNARY_NOT ] = "UNARY_NOT",
  83         [ BYTECODE_OP_UNARY_PLUS_S64 ] = "UNARY_PLUS_S64",
  84         [ BYTECODE_OP_UNARY_MINUS_S64 ] = "UNARY_MINUS_S64",
  85         [ BYTECODE_OP_UNARY_NOT_S64 ] = "UNARY_NOT_S64",
  86         [ BYTECODE_OP_UNARY_PLUS_DOUBLE ] = "UNARY_PLUS_DOUBLE",
  87         [ BYTECODE_OP_UNARY_MINUS_DOUBLE ] = "UNARY_MINUS_DOUBLE",
  88         [ BYTECODE_OP_UNARY_NOT_DOUBLE ] = "UNARY_NOT_DOUBLE",
  89
  90         /* logical */
  91         [ BYTECODE_OP_AND ] = "AND",
  92         [ BYTECODE_OP_OR ] = "OR",
  93
  94         /* load field ref */
  95         [ BYTECODE_OP_LOAD_FIELD_REF ] = "LOAD_FIELD_REF",
  96         [ BYTECODE_OP_LOAD_FIELD_REF_STRING ] = "LOAD_FIELD_REF_STRING",
  97         [ BYTECODE_OP_LOAD_FIELD_REF_SEQUENCE ] = "LOAD_FIELD_REF_SEQUENCE",
  98         [ BYTECODE_OP_LOAD_FIELD_REF_S64 ] = "LOAD_FIELD_REF_S64",
  99         [ BYTECODE_OP_LOAD_FIELD_REF_DOUBLE ] = "LOAD_FIELD_REF_DOUBLE",
 100
 101         /* load from immediate operand */
 102         [ BYTECODE_OP_LOAD_STRING ] = "LOAD_STRING",
 103         [ BYTECODE_OP_LOAD_S64 ] = "LOAD_S64",
 104         [ BYTECODE_OP_LOAD_DOUBLE ] = "LOAD_DOUBLE",
 105
 106         /* cast */
 107         [ BYTECODE_OP_CAST_TO_S64 ] = "CAST_TO_S64",
 108         [ BYTECODE_OP_CAST_DOUBLE_TO_S64 ] = "CAST_DOUBLE_TO_S64",
 109         [ BYTECODE_OP_CAST_NOP ] = "CAST_NOP",
 110
 111         /* get context ref */
 112         [ BYTECODE_OP_GET_CONTEXT_REF ] = "GET_CONTEXT_REF",
 113         [ BYTECODE_OP_GET_CONTEXT_REF_STRING ] = "GET_CONTEXT_REF_STRING",
 114         [ BYTECODE_OP_GET_CONTEXT_REF_S64 ] = "GET_CONTEXT_REF_S64",
 115         [ BYTECODE_OP_GET_CONTEXT_REF_DOUBLE ] = "GET_CONTEXT_REF_DOUBLE",
 116
 117         /* load userspace field ref */
 118         [ BYTECODE_OP_LOAD_FIELD_REF_USER_STRING ] = "LOAD_FIELD_REF_USER_STRING",
 119         [ BYTECODE_OP_LOAD_FIELD_REF_USER_SEQUENCE ] = "LOAD_FIELD_REF_USER_SEQUENCE",
 120
 121         /*
 122          * load immediate star globbing pattern (literal string)
 123          * from immediate.
 124          */
 125         [ BYTECODE_OP_LOAD_STAR_GLOB_STRING ] = "LOAD_STAR_GLOB_STRING",
 126
 127         /* globbing pattern binary operator: apply to */
 128         [ BYTECODE_OP_EQ_STAR_GLOB_STRING ] = "EQ_STAR_GLOB_STRING",
 129         [ BYTECODE_OP_NE_STAR_GLOB_STRING ] = "NE_STAR_GLOB_STRING",
 130
 131         /*
 132          * Instructions for recursive traversal through composed types.
 133          */
 134         [ BYTECODE_OP_GET_CONTEXT_ROOT ] = "GET_CONTEXT_ROOT",
 135         [ BYTECODE_OP_GET_APP_CONTEXT_ROOT ] = "GET_APP_CONTEXT_ROOT",
 136         [ BYTECODE_OP_GET_PAYLOAD_ROOT ] = "GET_PAYLOAD_ROOT",
 137
 138         [ BYTECODE_OP_GET_SYMBOL ] = "GET_SYMBOL",
 139         [ BYTECODE_OP_GET_SYMBOL_FIELD ] = "GET_SYMBOL_FIELD",
 140         [ BYTECODE_OP_GET_INDEX_U16 ] = "GET_INDEX_U16",
 141         [ BYTECODE_OP_GET_INDEX_U64 ] = "GET_INDEX_U64",
 142
 143         [ BYTECODE_OP_LOAD_FIELD ] = "LOAD_FIELD",
 144         [ BYTECODE_OP_LOAD_FIELD_S8 ] = "LOAD_FIELD_S8",
 145         [ BYTECODE_OP_LOAD_FIELD_S16 ] = "LOAD_FIELD_S16",
 146         [ BYTECODE_OP_LOAD_FIELD_S32 ] = "LOAD_FIELD_S32",
 147         [ BYTECODE_OP_LOAD_FIELD_S64 ] = "LOAD_FIELD_S64",
 148         [ BYTECODE_OP_LOAD_FIELD_U8 ] = "LOAD_FIELD_U8",
 149         [ BYTECODE_OP_LOAD_FIELD_U16 ] = "LOAD_FIELD_U16",
 150         [ BYTECODE_OP_LOAD_FIELD_U32 ] = "LOAD_FIELD_U32",
 151         [ BYTECODE_OP_LOAD_FIELD_U64 ] = "LOAD_FIELD_U64",
 152         [ BYTECODE_OP_LOAD_FIELD_STRING ] = "LOAD_FIELD_STRING",
 153         [ BYTECODE_OP_LOAD_FIELD_SEQUENCE ] = "LOAD_FIELD_SEQUENCE",
 154         [ BYTECODE_OP_LOAD_FIELD_DOUBLE ] = "LOAD_FIELD_DOUBLE",
 155
 156         [ BYTECODE_OP_UNARY_BIT_NOT ] = "UNARY_BIT_NOT",
 157
 158         [ BYTECODE_OP_RETURN_S64 ] = "RETURN_S64",
 159 };
 160
 161 const char *lttng_bytecode_print_op(enum bytecode_op op)
 162 {
 163         if (op >= NR_BYTECODE_OPS)
 164                 return "UNKNOWN";
 165         else
 166                 return opnames[op];
 167 }
 168
 169 static
 170 int apply_field_reloc(const struct lttng_event_desc *event_desc,
 171                 struct bytecode_runtime *runtime,
 172                 uint32_t runtime_len,
 173                 uint32_t reloc_offset,
 174                 const char *field_name,
 175                 enum bytecode_op bytecode_op)
 176 {
 177         const struct lttng_event_field *fields, *field = NULL;
 178         unsigned int nr_fields, i;
 179         struct load_op *op;
 180         uint32_t field_offset = 0;
 181
 182         dbg_printk("Apply field reloc: %u %s\n", reloc_offset, field_name);
 183
 184         /* Lookup event by name */
 185         if (!event_desc)
 186                 return -EINVAL;
 187         fields = event_desc->fields;
 188         if (!fields)
 189                 return -EINVAL;
 190         nr_fields = event_desc->nr_fields;
 191         for (i = 0; i < nr_fields; i++) {
 192                 if (fields[i].nofilter)
 193                         continue;
 194                 if (!strcmp(fields[i].name, field_name)) {
 195                         field = &fields[i];
 196                         break;
 197                 }
 198                 /* compute field offset */
 199                 switch (fields[i].type.type) {
 200                 case lttng_kernel_type_integer:
 201                 case lttng_kernel_type_enum_nestable:
 202                         field_offset += sizeof(int64_t);
 203                         break;
 204                 case lttng_kernel_type_array_nestable:
 205                         if (!lttng_is_bytewise_integer(fields[i].type.u.array_nestable.elem_type))
 206                                 return -EINVAL;
 207                         field_offset += sizeof(unsigned long);
 208                         field_offset += sizeof(void *);
 209                         break;
 210                 case lttng_kernel_type_sequence_nestable:
 211                         if (!lttng_is_bytewise_integer(fields[i].type.u.sequence_nestable.elem_type))
 212                                 return -EINVAL;
 213                         field_offset += sizeof(unsigned long);
 214                         field_offset += sizeof(void *);
 215                         break;
 216                 case lttng_kernel_type_string:
 217                         field_offset += sizeof(void *);
 218                         break;
 219                 case lttng_kernel_type_struct_nestable: /* Unsupported. */
 220                 case lttng_kernel_type_variant_nestable:        /* Unsupported. */
 221                 default:
 222                         return -EINVAL;
 223                 }
 224         }
 225         if (!field)
 226                 return -EINVAL;
 227
 228         /* Check if field offset is too large for 16-bit offset */
 229         if (field_offset > LTTNG_KERNEL_FILTER_BYTECODE_MAX_LEN - 1)
 230                 return -EINVAL;
 231
 232         /* set type */
 233         op = (struct load_op *) &runtime->code[reloc_offset];
 234
 235         switch (bytecode_op) {
 236         case BYTECODE_OP_LOAD_FIELD_REF:
 237         {
 238                 struct field_ref *field_ref;
 239
 240                 field_ref = (struct field_ref *) op->data;
 241                 switch (field->type.type) {
 242                 case lttng_kernel_type_integer:
 243                 case lttng_kernel_type_enum_nestable:
 244                         op->op = BYTECODE_OP_LOAD_FIELD_REF_S64;
 245                         break;
 246                 case lttng_kernel_type_array_nestable:
 247                 {
 248                         const struct lttng_type *elem_type = field->type.u.array_nestable.elem_type;
 249
 250                         if (!lttng_is_bytewise_integer(elem_type) || elem_type->u.integer.encoding == lttng_kernel_string_encoding_none)
 251                                 return -EINVAL;
 252                         if (field->user)
 253                                 op->op = BYTECODE_OP_LOAD_FIELD_REF_USER_SEQUENCE;
 254                         else
 255                                 op->op = BYTECODE_OP_LOAD_FIELD_REF_SEQUENCE;
 256                         break;
 257                 }
 258                 case lttng_kernel_type_sequence_nestable:
 259                 {
 260                         const struct lttng_type *elem_type = field->type.u.sequence_nestable.elem_type;
 261
 262                         if (!lttng_is_bytewise_integer(elem_type) || elem_type->u.integer.encoding == lttng_kernel_string_encoding_none)
 263                                 return -EINVAL;
 264                         if (field->user)
 265                                 op->op = BYTECODE_OP_LOAD_FIELD_REF_USER_SEQUENCE;
 266                         else
 267                                 op->op = BYTECODE_OP_LOAD_FIELD_REF_SEQUENCE;
 268                         break;
 269                 }
 270                 case lttng_kernel_type_string:
 271                         if (field->user)
 272                                 op->op = BYTECODE_OP_LOAD_FIELD_REF_USER_STRING;
 273                         else
 274                                 op->op = BYTECODE_OP_LOAD_FIELD_REF_STRING;
 275                         break;
 276                 case lttng_kernel_type_struct_nestable: /* Unsupported. */
 277                 case lttng_kernel_type_variant_nestable:        /* Unsupported. */
 278                 default:
 279                         return -EINVAL;
 280                 }
 281                 /* set offset */
 282                 field_ref->offset = (uint16_t) field_offset;
 283                 break;
 284         }
 285         default:
 286                 return -EINVAL;
 287         }
 288         return 0;
 289 }
 290
 291 static
 292 int apply_context_reloc(struct bytecode_runtime *runtime,
 293                 uint32_t runtime_len,
 294                 uint32_t reloc_offset,
 295                 const char *context_name,
 296                 enum bytecode_op bytecode_op)
 297 {
 298         struct load_op *op;
 299         struct lttng_ctx_field *ctx_field;
 300         int idx;
 301
 302         dbg_printk("Apply context reloc: %u %s\n", reloc_offset, context_name);
 303
 304         /* Get context index */
 305         idx = lttng_get_context_index(lttng_static_ctx, context_name);
 306         if (idx < 0)
 307                 return -ENOENT;
 308
 309         /* Check if idx is too large for 16-bit offset */
 310         if (idx > LTTNG_KERNEL_FILTER_BYTECODE_MAX_LEN - 1)
 311                 return -EINVAL;
 312
 313         /* Get context return type */
 314         ctx_field = &lttng_static_ctx->fields[idx];
 315         op = (struct load_op *) &runtime->code[reloc_offset];
 316
 317         switch (bytecode_op) {
 318         case BYTECODE_OP_GET_CONTEXT_REF:
 319         {
 320                 struct field_ref *field_ref;
 321
 322                 field_ref = (struct field_ref *) op->data;
 323                 switch (ctx_field->event_field.type.type) {
 324                 case lttng_kernel_type_integer:
 325                 case lttng_kernel_type_enum_nestable:
 326                         op->op = BYTECODE_OP_GET_CONTEXT_REF_S64;
 327                         break;
 328                         /* Sequence and array supported as string */
 329                 case lttng_kernel_type_string:
 330                         BUG_ON(ctx_field->event_field.user);
 331                         op->op = BYTECODE_OP_GET_CONTEXT_REF_STRING;
 332                         break;
 333                 case lttng_kernel_type_array_nestable:
 334                 {
 335                         const struct lttng_type *elem_type = ctx_field->event_field.type.u.array_nestable.elem_type;
 336
 337                         if (!lttng_is_bytewise_integer(elem_type) || elem_type->u.integer.encoding == lttng_kernel_string_encoding_none)
 338                                 return -EINVAL;
 339                         BUG_ON(ctx_field->event_field.user);
 340                         op->op = BYTECODE_OP_GET_CONTEXT_REF_STRING;
 341                         break;
 342                 }
 343                 case lttng_kernel_type_sequence_nestable:
 344                 {
 345                         const struct lttng_type *elem_type = ctx_field->event_field.type.u.sequence_nestable.elem_type;
 346
 347                         if (!lttng_is_bytewise_integer(elem_type) || elem_type->u.integer.encoding == lttng_kernel_string_encoding_none)
 348                                 return -EINVAL;
 349                         BUG_ON(ctx_field->event_field.user);
 350                         op->op = BYTECODE_OP_GET_CONTEXT_REF_STRING;
 351                         break;
 352                 }
 353                 case lttng_kernel_type_struct_nestable: /* Unsupported. */
 354                 case lttng_kernel_type_variant_nestable:        /* Unsupported. */
 355                 default:
 356                         return -EINVAL;
 357                 }
 358                 /* set offset to context index within channel contexts */
 359                 field_ref->offset = (uint16_t) idx;
 360                 break;
 361         }
 362         default:
 363                 return -EINVAL;
 364         }
 365         return 0;
 366 }
 367
 368 static
 369 int apply_reloc(const struct lttng_event_desc *event_desc,
 370                 struct bytecode_runtime *runtime,
 371                 uint32_t runtime_len,
 372                 uint32_t reloc_offset,
 373                 const char *name)
 374 {
 375         struct load_op *op;
 376
 377         dbg_printk("Apply reloc: %u %s\n", reloc_offset, name);
 378
 379         /* Ensure that the reloc is within the code */
 380         if (runtime_len - reloc_offset < sizeof(uint16_t))
 381                 return -EINVAL;
 382
 383         op = (struct load_op *) &runtime->code[reloc_offset];
 384         switch (op->op) {
 385         case BYTECODE_OP_LOAD_FIELD_REF:
 386                 return apply_field_reloc(event_desc, runtime, runtime_len,
 387                         reloc_offset, name, op->op);
 388         case BYTECODE_OP_GET_CONTEXT_REF:
 389                 return apply_context_reloc(runtime, runtime_len,
 390                         reloc_offset, name, op->op);
 391         case BYTECODE_OP_GET_SYMBOL:
 392         case BYTECODE_OP_GET_SYMBOL_FIELD:
 393                 /*
 394                  * Will be handled by load specialize phase or
 395                  * dynamically by interpreter.
 396                  */
 397                 return 0;
 398         default:
 399                 printk(KERN_WARNING "LTTng: filter: Unknown reloc op type %u\n", op->op);
 400                 return -EINVAL;
 401         }
 402         return 0;
 403 }
 404
 405 static
 406 int bytecode_is_linked(struct lttng_bytecode_node *bytecode,
 407                 struct list_head *bytecode_runtime_head)
 408 {
 409         struct lttng_bytecode_runtime *bc_runtime;
 410
 411         list_for_each_entry(bc_runtime, bytecode_runtime_head, node) {
 412                 if (bc_runtime->bc == bytecode)
 413                         return 1;
 414         }
 415         return 0;
 416 }
 417
 418 /*
 419  * Take a bytecode with reloc table and link it to an event to create a
 420  * bytecode runtime.
 421  */
 422 static
 423 int link_bytecode(const struct lttng_event_desc *event_desc,
 424                 struct lttng_ctx *ctx,
 425                 struct lttng_bytecode_node *bytecode,
 426                 struct list_head *bytecode_runtime_head,
 427                 struct list_head *insert_loc)
 428 {
 429         int ret, offset, next_offset;
 430         struct bytecode_runtime *runtime = NULL;
 431         size_t runtime_alloc_len;
 432
 433         if (!bytecode)
 434                 return 0;
 435         /* Bytecode already linked */
 436         if (bytecode_is_linked(bytecode, bytecode_runtime_head))
 437                 return 0;
 438
 439         dbg_printk("Linking...\n");
 440
 441         /* We don't need the reloc table in the runtime */
 442         runtime_alloc_len = sizeof(*runtime) + bytecode->bc.reloc_offset;
 443         runtime = kzalloc(runtime_alloc_len, GFP_KERNEL);
 444         if (!runtime) {
 445                 ret = -ENOMEM;
 446                 goto alloc_error;
 447         }
 448         runtime->p.bc = bytecode;
 449         runtime->p.ctx = ctx;
 450         runtime->len = bytecode->bc.reloc_offset;
 451         /* copy original bytecode */
 452         memcpy(runtime->code, bytecode->bc.data, runtime->len);
 453         /*
 454          * apply relocs. Those are a uint16_t (offset in bytecode)
 455          * followed by a string (field name).
 456          */
 457         for (offset = bytecode->bc.reloc_offset;
 458                         offset < bytecode->bc.len;
 459                         offset = next_offset) {
 460                 uint16_t reloc_offset =
 461                         *(uint16_t *) &bytecode->bc.data[offset];
 462                 const char *name =
 463                         (const char *) &bytecode->bc.data[offset + sizeof(uint16_t)];
 464
 465                 ret = apply_reloc(event_desc, runtime, runtime->len, reloc_offset, name);
 466                 if (ret) {
 467                         goto link_error;
 468                 }
 469                 next_offset = offset + sizeof(uint16_t) + strlen(name) + 1;
 470         }
 471         /* Validate bytecode */
 472         ret = lttng_bytecode_validate(runtime);
 473         if (ret) {
 474                 goto link_error;
 475         }
 476         /* Specialize bytecode */
 477         ret = lttng_bytecode_specialize(event_desc, runtime);
 478         if (ret) {
 479                 goto link_error;
 480         }
 481
 482         switch (bytecode->type) {
 483         case LTTNG_BYTECODE_NODE_TYPE_FILTER:
 484                 runtime->p.interpreter_funcs.filter = lttng_bytecode_filter_interpret;
 485                 break;
 486         case LTTNG_BYTECODE_NODE_TYPE_CAPTURE:
 487                 runtime->p.interpreter_funcs.capture = lttng_bytecode_capture_interpret_false;
 488                 break;
 489         default:
 490                 WARN_ON(1);
 491         }
 492
 493         runtime->p.link_failed = 0;
 494         list_add_rcu(&runtime->p.node, insert_loc);
 495         dbg_printk("Linking successful.\n");
 496         return 0;
 497
 498 link_error:
 499
 500         switch (bytecode->type) {
 501         case LTTNG_BYTECODE_NODE_TYPE_FILTER:
 502                 runtime->p.interpreter_funcs.filter = lttng_bytecode_filter_interpret_false;
 503                 break;
 504         case LTTNG_BYTECODE_NODE_TYPE_CAPTURE:
 505                 runtime->p.interpreter_funcs.capture = lttng_bytecode_capture_interpret_false;
 506                 break;
 507         default:
 508                 WARN_ON(1);
 509         }
 510         runtime->p.link_failed = 1;
 511         list_add_rcu(&runtime->p.node, insert_loc);
 512 alloc_error:
 513         dbg_printk("Linking failed.\n");
 514         return ret;
 515 }
 516
 517 void lttng_bytecode_filter_sync_state(struct lttng_bytecode_runtime *runtime)
 518 {
 519         struct lttng_bytecode_node *bc = runtime->bc;
 520
 521         if (!bc->enabler->enabled || runtime->link_failed)
 522                 runtime->interpreter_funcs.filter = lttng_bytecode_filter_interpret_false;
 523         else
 524                 runtime->interpreter_funcs.filter = lttng_bytecode_filter_interpret;
 525 }
 526
 527 void lttng_bytecode_capture_sync_state(struct lttng_bytecode_runtime *runtime)
 528 {
 529         struct lttng_bytecode_node *bc = runtime->bc;
 530
 531         if (!bc->enabler->enabled || runtime->link_failed)
 532                 runtime->interpreter_funcs.capture = lttng_bytecode_capture_interpret_false;
 533         else
 534                 runtime->interpreter_funcs.capture = lttng_bytecode_capture_interpret;
 535 }
 536
 537 /*
 538  * Given the lists of bytecode programs of an instance (event or event
 539  * notifier) and of a matching enabler, try to link all the enabler's bytecode
 540  * programs with the instance.
 541  *
 542  * This function is called after we confirmed that name enabler and the
 543  * instance are matching names (or glob pattern matching).
 544  */
 545 void lttng_enabler_link_bytecode(const struct lttng_event_desc *event_desc,
 546                 struct lttng_ctx *ctx,
 547                 struct list_head *instance_bytecode_head,
 548                 struct list_head *enabler_bytecode_head)
 549 {
 550         struct lttng_bytecode_node *enabler_bc;
 551         struct lttng_bytecode_runtime *runtime;
 552
 553         WARN_ON_ONCE(!event_desc);
 554
 555         /* Go over all the bytecode programs of the enabler.  */
 556         list_for_each_entry(enabler_bc, enabler_bytecode_head, node) {
 557                 int found = 0, ret;
 558                 struct list_head *insert_loc;
 559
 560                 /*
 561                  * Check if the current enabler bytecode program is already
 562                  * linked with the instance.
 563                  */
 564                 list_for_each_entry(runtime, instance_bytecode_head, node) {
 565                         if (runtime->bc == enabler_bc) {
 566                                 found = 1;
 567                                 break;
 568                         }
 569                 }
 570
 571                 /*
 572                  * Skip bytecode already linked, go to the next enabler
 573                  * bytecode program.
 574                  */
 575                 if (found)
 576                         continue;
 577
 578                 /*
 579                  * Insert at specified priority (seqnum) in increasing
 580                  * order. If there already is a bytecode of the same priority,
 581                  * insert the new bytecode right after it.
 582                  */
 583                 list_for_each_entry_reverse(runtime,
 584                                 instance_bytecode_head, node) {
 585                         if (runtime->bc->bc.seqnum <= enabler_bc->bc.seqnum) {
 586                                 /* insert here */
 587                                 insert_loc = &runtime->node;
 588                                 goto add_within;
 589                         }
 590                 }
 591                 /* Add to head to list */
 592                 insert_loc = instance_bytecode_head;
 593         add_within:
 594                 dbg_printk("linking bytecode\n");
 595                 ret = link_bytecode(event_desc, ctx, enabler_bc, instance_bytecode_head, insert_loc);
 596                 if (ret) {
 597                         dbg_printk("[lttng filter] warning: cannot link event bytecode\n");
 598                 }
 599         }
 600 }
 601
 602 /*
 603  * We own the filter_bytecode if we return success.
 604  */
 605 int lttng_filter_enabler_attach_bytecode(struct lttng_enabler *enabler,
 606                 struct lttng_bytecode_node *filter_bytecode)
 607 {
 608         list_add(&filter_bytecode->node, &enabler->filter_bytecode_head);
 609         return 0;
 610 }
 611
 612 void lttng_free_enabler_filter_bytecode(struct lttng_enabler *enabler)
 613 {
 614         struct lttng_bytecode_node *filter_bytecode, *tmp;
 615
 616         list_for_each_entry_safe(filter_bytecode, tmp,
 617                         &enabler->filter_bytecode_head, node) {
 618                 kfree(filter_bytecode);
 619         }
 620 }
 621
 622 void lttng_free_event_filter_runtime(struct lttng_event *event)
 623 {
 624         struct bytecode_runtime *runtime, *tmp;
 625
 626         list_for_each_entry_safe(runtime, tmp,
 627                         &event->filter_bytecode_runtime_head, p.node) {
 628                 kfree(runtime->data);
 629                 kfree(runtime);
 630         }
 631 }
 632
 633 void lttng_free_event_notifier_filter_runtime(struct lttng_event_notifier *event_notifier)
 634 {
 635         struct bytecode_runtime *runtime, *tmp;
 636
 637         list_for_each_entry_safe(runtime, tmp,
 638                         &event_notifier->filter_bytecode_runtime_head, p.node) {
 639                 kfree(runtime->data);
 640                 kfree(runtime);
 641         }
 642 }