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_RSHIFT ] = "RSHIFT",
  43         [ FILTER_OP_LSHIFT ] = "LSHIFT",
  44         [ FILTER_OP_BIN_AND ] = "BIN_AND",
  45         [ FILTER_OP_BIN_OR ] = "BIN_OR",
  46         [ FILTER_OP_BIN_XOR ] = "BIN_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 const char *print_op(enum filter_op op)
 149 {
 150         if (op >= NR_FILTER_OPS)
 151                 return "UNKNOWN";
 152         else
 153                 return opnames[op];
 154 }
 155
 156 static
 157 int apply_field_reloc(struct lttng_event *event,
 158                 struct bytecode_runtime *runtime,
 159                 uint32_t runtime_len,
 160                 uint32_t reloc_offset,
 161                 const char *field_name)
 162 {
 163         const struct lttng_event_desc *desc;
 164         const struct lttng_event_field *fields, *field = NULL;
 165         unsigned int nr_fields, i;
 166         struct field_ref *field_ref;
 167         struct load_op *op;
 168         uint32_t field_offset = 0;
 169
 170         dbg_printf("Apply field reloc: %u %s\n", reloc_offset, field_name);
 171
 172         /* Lookup event by name */
 173         desc = event->desc;
 174         if (!desc)
 175                 return -EINVAL;
 176         fields = desc->fields;
 177         if (!fields)
 178                 return -EINVAL;
 179         nr_fields = desc->nr_fields;
 180         for (i = 0; i < nr_fields; i++) {
 181                 if (!strcmp(fields[i].name, field_name)) {
 182                         field = &fields[i];
 183                         break;
 184                 }
 185                 /* compute field offset */
 186                 switch (fields[i].type.atype) {
 187                 case atype_integer:
 188                 case atype_enum:
 189                         field_offset += sizeof(int64_t);
 190                         break;
 191                 case atype_array:
 192                 case atype_sequence:
 193                         field_offset += sizeof(unsigned long);
 194                         field_offset += sizeof(void *);
 195                         break;
 196                 case atype_string:
 197                         field_offset += sizeof(void *);
 198                         break;
 199                 case atype_float:
 200                         field_offset += sizeof(double);
 201                         break;
 202                 default:
 203                         return -EINVAL;
 204                 }
 205         }
 206         if (!field)
 207                 return -EINVAL;
 208
 209         /* Check if field offset is too large for 16-bit offset */
 210         if (field_offset > FILTER_BYTECODE_MAX_LEN - 1)
 211                 return -EINVAL;
 212
 213         /* set type */
 214         op = (struct load_op *) &runtime->data[reloc_offset];
 215         field_ref = (struct field_ref *) op->data;
 216         switch (field->type.atype) {
 217         case atype_integer:
 218         case atype_enum:
 219                 op->op = FILTER_OP_LOAD_FIELD_REF_S64;
 220                 break;
 221         case atype_array:
 222         case atype_sequence:
 223                 op->op = FILTER_OP_LOAD_FIELD_REF_SEQUENCE;
 224                 break;
 225         case atype_string:
 226                 op->op = FILTER_OP_LOAD_FIELD_REF_STRING;
 227                 break;
 228         case atype_float:
 229                 op->op = FILTER_OP_LOAD_FIELD_REF_DOUBLE;
 230                 break;
 231         default:
 232                 return -EINVAL;
 233         }
 234         /* set offset */
 235         field_ref->offset = (uint16_t) field_offset;
 236         return 0;
 237 }
 238
 239 static
 240 int apply_context_reloc(struct lttng_event *event,
 241                 struct bytecode_runtime *runtime,
 242                 uint32_t runtime_len,
 243                 uint32_t reloc_offset,
 244                 const char *context_name)
 245 {
 246         struct field_ref *field_ref;
 247         struct load_op *op;
 248         struct lttng_ctx_field *ctx_field;
 249         int idx;
 250         struct lttng_session *session = runtime->p.session;
 251
 252         dbg_printf("Apply context reloc: %u %s\n", reloc_offset, context_name);
 253
 254         /* Get context index */
 255         idx = lttng_get_context_index(session->ctx, context_name);
 256         if (idx < 0) {
 257                 if (lttng_context_is_app(context_name)) {
 258                         int ret;
 259
 260                         ret = lttng_ust_add_app_context_to_ctx_rcu(context_name,
 261                                         &session->ctx);
 262                         if (ret)
 263                                 return ret;
 264                         idx = lttng_get_context_index(session->ctx,
 265                                 context_name);
 266                         if (idx < 0)
 267                                 return -ENOENT;
 268                 } else {
 269                         return -ENOENT;
 270                 }
 271         }
 272         /* Check if idx is too large for 16-bit offset */
 273         if (idx > FILTER_BYTECODE_MAX_LEN - 1)
 274                 return -EINVAL;
 275
 276         /* Get context return type */
 277         ctx_field = &session->ctx->fields[idx];
 278         op = (struct load_op *) &runtime->data[reloc_offset];
 279         field_ref = (struct field_ref *) op->data;
 280         switch (ctx_field->event_field.type.atype) {
 281         case atype_integer:
 282         case atype_enum:
 283                 op->op = FILTER_OP_GET_CONTEXT_REF_S64;
 284                 break;
 285                 /* Sequence and array supported as string */
 286         case atype_string:
 287         case atype_array:
 288         case atype_sequence:
 289                 op->op = FILTER_OP_GET_CONTEXT_REF_STRING;
 290                 break;
 291         case atype_float:
 292                 op->op = FILTER_OP_GET_CONTEXT_REF_DOUBLE;
 293                 break;
 294         case atype_dynamic:
 295                 op->op = FILTER_OP_GET_CONTEXT_REF;
 296                 break;
 297         default:
 298                 return -EINVAL;
 299         }
 300         /* set offset to context index within channel contexts */
 301         field_ref->offset = (uint16_t) idx;
 302         return 0;
 303 }
 304
 305 static
 306 int apply_reloc(struct lttng_event *event,
 307                 struct bytecode_runtime *runtime,
 308                 uint32_t runtime_len,
 309                 uint32_t reloc_offset,
 310                 const char *name)
 311 {
 312         struct load_op *op;
 313
 314         dbg_printf("Apply reloc: %u %s\n", reloc_offset, name);
 315
 316         /* Ensure that the reloc is within the code */
 317         if (runtime_len - reloc_offset < sizeof(uint16_t))
 318                 return -EINVAL;
 319
 320         op = (struct load_op *) &runtime->data[reloc_offset];
 321         switch (op->op) {
 322         case FILTER_OP_LOAD_FIELD_REF:
 323                 return apply_field_reloc(event, runtime, runtime_len,
 324                         reloc_offset, name);
 325         case FILTER_OP_GET_CONTEXT_REF:
 326                 return apply_context_reloc(event, runtime, runtime_len,
 327                         reloc_offset, name);
 328         default:
 329                 ERR("Unknown reloc op type %u\n", op->op);
 330                 return -EINVAL;
 331         }
 332         return 0;
 333 }
 334
 335 static
 336 int bytecode_is_linked(struct lttng_ust_filter_bytecode_node *filter_bytecode,
 337                 struct lttng_event *event)
 338 {
 339         struct lttng_bytecode_runtime *bc_runtime;
 340
 341         cds_list_for_each_entry(bc_runtime,
 342                         &event->bytecode_runtime_head, node) {
 343                 if (bc_runtime->bc == filter_bytecode)
 344                         return 1;
 345         }
 346         return 0;
 347 }
 348
 349 /*
 350  * Take a bytecode with reloc table and link it to an event to create a
 351  * bytecode runtime.
 352  */
 353 static
 354 int _lttng_filter_event_link_bytecode(struct lttng_event *event,
 355                 struct lttng_ust_filter_bytecode_node *filter_bytecode,
 356                 struct cds_list_head *insert_loc)
 357 {
 358         int ret, offset, next_offset;
 359         struct bytecode_runtime *runtime = NULL;
 360         size_t runtime_alloc_len;
 361
 362         if (!filter_bytecode)
 363                 return 0;
 364         /* Bytecode already linked */
 365         if (bytecode_is_linked(filter_bytecode, event))
 366                 return 0;
 367
 368         dbg_printf("Linking...\n");
 369
 370         /* We don't need the reloc table in the runtime */
 371         runtime_alloc_len = sizeof(*runtime) + filter_bytecode->bc.reloc_offset;
 372         runtime = zmalloc(runtime_alloc_len);
 373         if (!runtime) {
 374                 ret = -ENOMEM;
 375                 goto alloc_error;
 376         }
 377         runtime->p.bc = filter_bytecode;
 378         runtime->p.session = event->chan->session;
 379         runtime->len = filter_bytecode->bc.reloc_offset;
 380         /* copy original bytecode */
 381         memcpy(runtime->data, filter_bytecode->bc.data, runtime->len);
 382         /*
 383          * apply relocs. Those are a uint16_t (offset in bytecode)
 384          * followed by a string (field name).
 385          */
 386         for (offset = filter_bytecode->bc.reloc_offset;
 387                         offset < filter_bytecode->bc.len;
 388                         offset = next_offset) {
 389                 uint16_t reloc_offset =
 390                         *(uint16_t *) &filter_bytecode->bc.data[offset];
 391                 const char *name =
 392                         (const char *) &filter_bytecode->bc.data[offset + sizeof(uint16_t)];
 393
 394                 ret = apply_reloc(event, runtime, runtime->len, reloc_offset, name);
 395                 if (ret) {
 396                         goto link_error;
 397                 }
 398                 next_offset = offset + sizeof(uint16_t) + strlen(name) + 1;
 399         }
 400         /* Validate bytecode */
 401         ret = lttng_filter_validate_bytecode(runtime);
 402         if (ret) {
 403                 goto link_error;
 404         }
 405         /* Specialize bytecode */
 406         ret = lttng_filter_specialize_bytecode(runtime);
 407         if (ret) {
 408                 goto link_error;
 409         }
 410         runtime->p.filter = lttng_filter_interpret_bytecode;
 411         runtime->p.link_failed = 0;
 412         cds_list_add_rcu(&runtime->p.node, insert_loc);
 413         dbg_printf("Linking successful.\n");
 414         return 0;
 415
 416 link_error:
 417         runtime->p.filter = lttng_filter_false;
 418         runtime->p.link_failed = 1;
 419         cds_list_add_rcu(&runtime->p.node, insert_loc);
 420 alloc_error:
 421         dbg_printf("Linking failed.\n");
 422         return ret;
 423 }
 424
 425 void lttng_filter_sync_state(struct lttng_bytecode_runtime *runtime)
 426 {
 427         struct lttng_ust_filter_bytecode_node *bc = runtime->bc;
 428
 429         if (!bc->enabler->enabled || runtime->link_failed)
 430                 runtime->filter = lttng_filter_false;
 431         else
 432                 runtime->filter = lttng_filter_interpret_bytecode;
 433 }
 434
 435 /*
 436  * Link bytecode for all enablers referenced by an event.
 437  */
 438 void lttng_enabler_event_link_bytecode(struct lttng_event *event,
 439                 struct lttng_enabler *enabler)
 440 {
 441         struct lttng_ust_filter_bytecode_node *bc;
 442         struct lttng_bytecode_runtime *runtime;
 443
 444         /* Can only be called for events with desc attached */
 445         assert(event->desc);
 446
 447         /* Link each bytecode. */
 448         cds_list_for_each_entry(bc, &enabler->filter_bytecode_head, node) {
 449                 int found = 0, ret;
 450                 struct cds_list_head *insert_loc;
 451
 452                 cds_list_for_each_entry(runtime,
 453                                 &event->bytecode_runtime_head, node) {
 454                         if (runtime->bc == bc) {
 455                                 found = 1;
 456                                 break;
 457                         }
 458                 }
 459                 /* Skip bytecode already linked */
 460                 if (found)
 461                         continue;
 462
 463                 /*
 464                  * Insert at specified priority (seqnum) in increasing
 465                  * order.
 466                  */
 467                 cds_list_for_each_entry_reverse(runtime,
 468                                 &event->bytecode_runtime_head, node) {
 469                         if (runtime->bc->bc.seqnum < bc->bc.seqnum) {
 470                                 /* insert here */
 471                                 insert_loc = &runtime->node;
 472                                 goto add_within;
 473                         }
 474                 }
 475                 /* Add to head to list */
 476                 insert_loc = &event->bytecode_runtime_head;
 477         add_within:
 478                 dbg_printf("linking bytecode\n");
 479                 ret = _lttng_filter_event_link_bytecode(event, bc,
 480                                 insert_loc);
 481                 if (ret) {
 482                         dbg_printf("[lttng filter] warning: cannot link event bytecode\n");
 483                 }
 484         }
 485 }
 486
 487 /*
 488  * We own the filter_bytecode if we return success.
 489  */
 490 int lttng_filter_enabler_attach_bytecode(struct lttng_enabler *enabler,
 491                 struct lttng_ust_filter_bytecode_node *filter_bytecode)
 492 {
 493         cds_list_add(&filter_bytecode->node, &enabler->filter_bytecode_head);
 494         return 0;
 495 }
 496
 497 void lttng_free_enabler_filter_bytecode(struct lttng_enabler *enabler)
 498 {
 499         struct lttng_ust_filter_bytecode_node *filter_bytecode, *tmp;
 500
 501         cds_list_for_each_entry_safe(filter_bytecode, tmp,
 502                         &enabler->filter_bytecode_head, node) {
 503                 free(filter_bytecode);
 504         }
 505 }
 506
 507 void lttng_free_event_filter_runtime(struct lttng_event *event)
 508 {
 509         struct bytecode_runtime *runtime, *tmp;
 510
 511         cds_list_for_each_entry_safe(runtime, tmp,
 512                         &event->bytecode_runtime_head, p.node) {
 513                 free(runtime);
 514         }
 515 }