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
 134 const char *print_op(enum filter_op op)
 135 {
 136         if (op >= NR_FILTER_OPS)
 137                 return "UNKNOWN";
 138         else
 139                 return opnames[op];
 140 }
 141
 142 static
 143 int apply_field_reloc(struct lttng_event *event,
 144                 struct bytecode_runtime *runtime,
 145                 uint32_t runtime_len,
 146                 uint32_t reloc_offset,
 147                 const char *field_name)
 148 {
 149         const struct lttng_event_desc *desc;
 150         const struct lttng_event_field *fields, *field = NULL;
 151         unsigned int nr_fields, i;
 152         struct field_ref *field_ref;
 153         struct load_op *op;
 154         uint32_t field_offset = 0;
 155
 156         dbg_printf("Apply field reloc: %u %s\n", reloc_offset, field_name);
 157
 158         /* Lookup event by name */
 159         desc = event->desc;
 160         if (!desc)
 161                 return -EINVAL;
 162         fields = desc->fields;
 163         if (!fields)
 164                 return -EINVAL;
 165         nr_fields = desc->nr_fields;
 166         for (i = 0; i < nr_fields; i++) {
 167                 if (!strcmp(fields[i].name, field_name)) {
 168                         field = &fields[i];
 169                         break;
 170                 }
 171                 /* compute field offset */
 172                 switch (fields[i].type.atype) {
 173                 case atype_integer:
 174                 case atype_enum:
 175                         field_offset += sizeof(int64_t);
 176                         break;
 177                 case atype_array:
 178                 case atype_sequence:
 179                         field_offset += sizeof(unsigned long);
 180                         field_offset += sizeof(void *);
 181                         break;
 182                 case atype_string:
 183                         field_offset += sizeof(void *);
 184                         break;
 185                 case atype_float:
 186                         field_offset += sizeof(double);
 187                         break;
 188                 default:
 189                         return -EINVAL;
 190                 }
 191         }
 192         if (!field)
 193                 return -EINVAL;
 194
 195         /* Check if field offset is too large for 16-bit offset */
 196         if (field_offset > FILTER_BYTECODE_MAX_LEN - 1)
 197                 return -EINVAL;
 198
 199         /* set type */
 200         op = (struct load_op *) &runtime->data[reloc_offset];
 201         field_ref = (struct field_ref *) op->data;
 202         switch (field->type.atype) {
 203         case atype_integer:
 204         case atype_enum:
 205                 op->op = FILTER_OP_LOAD_FIELD_REF_S64;
 206                 break;
 207         case atype_array:
 208         case atype_sequence:
 209                 op->op = FILTER_OP_LOAD_FIELD_REF_SEQUENCE;
 210                 break;
 211         case atype_string:
 212                 op->op = FILTER_OP_LOAD_FIELD_REF_STRING;
 213                 break;
 214         case atype_float:
 215                 op->op = FILTER_OP_LOAD_FIELD_REF_DOUBLE;
 216                 break;
 217         default:
 218                 return -EINVAL;
 219         }
 220         /* set offset */
 221         field_ref->offset = (uint16_t) field_offset;
 222         return 0;
 223 }
 224
 225 static
 226 int apply_context_reloc(struct lttng_event *event,
 227                 struct bytecode_runtime *runtime,
 228                 uint32_t runtime_len,
 229                 uint32_t reloc_offset,
 230                 const char *context_name)
 231 {
 232         struct field_ref *field_ref;
 233         struct load_op *op;
 234         struct lttng_ctx_field *ctx_field;
 235         int idx;
 236         struct lttng_session *session = runtime->p.session;
 237
 238         dbg_printf("Apply context reloc: %u %s\n", reloc_offset, context_name);
 239
 240         /* Get context index */
 241         idx = lttng_get_context_index(session->ctx, context_name);
 242         if (idx < 0) {
 243                 if (lttng_context_is_app(context_name)) {
 244                         int ret;
 245
 246                         ret = lttng_ust_add_app_context_to_ctx_rcu(context_name,
 247                                         &session->ctx);
 248                         if (ret)
 249                                 return ret;
 250                         idx = lttng_get_context_index(session->ctx,
 251                                 context_name);
 252                         if (idx < 0)
 253                                 return -ENOENT;
 254                 } else {
 255                         return -ENOENT;
 256                 }
 257         }
 258         /* Check if idx is too large for 16-bit offset */
 259         if (idx > FILTER_BYTECODE_MAX_LEN - 1)
 260                 return -EINVAL;
 261
 262         /* Get context return type */
 263         ctx_field = &session->ctx->fields[idx];
 264         op = (struct load_op *) &runtime->data[reloc_offset];
 265         field_ref = (struct field_ref *) op->data;
 266         switch (ctx_field->event_field.type.atype) {
 267         case atype_integer:
 268         case atype_enum:
 269                 op->op = FILTER_OP_GET_CONTEXT_REF_S64;
 270                 break;
 271                 /* Sequence and array supported as string */
 272         case atype_string:
 273         case atype_array:
 274         case atype_sequence:
 275                 op->op = FILTER_OP_GET_CONTEXT_REF_STRING;
 276                 break;
 277         case atype_float:
 278                 op->op = FILTER_OP_GET_CONTEXT_REF_DOUBLE;
 279                 break;
 280         case atype_dynamic:
 281                 op->op = FILTER_OP_GET_CONTEXT_REF;
 282                 break;
 283         default:
 284                 return -EINVAL;
 285         }
 286         /* set offset to context index within channel contexts */
 287         field_ref->offset = (uint16_t) idx;
 288         return 0;
 289 }
 290
 291 static
 292 int apply_reloc(struct lttng_event *event,
 293                 struct bytecode_runtime *runtime,
 294                 uint32_t runtime_len,
 295                 uint32_t reloc_offset,
 296                 const char *name)
 297 {
 298         struct load_op *op;
 299
 300         dbg_printf("Apply reloc: %u %s\n", reloc_offset, name);
 301
 302         /* Ensure that the reloc is within the code */
 303         if (runtime_len - reloc_offset < sizeof(uint16_t))
 304                 return -EINVAL;
 305
 306         op = (struct load_op *) &runtime->data[reloc_offset];
 307         switch (op->op) {
 308         case FILTER_OP_LOAD_FIELD_REF:
 309                 return apply_field_reloc(event, runtime, runtime_len,
 310                         reloc_offset, name);
 311         case FILTER_OP_GET_CONTEXT_REF:
 312                 return apply_context_reloc(event, runtime, runtime_len,
 313                         reloc_offset, name);
 314         default:
 315                 ERR("Unknown reloc op type %u\n", op->op);
 316                 return -EINVAL;
 317         }
 318         return 0;
 319 }
 320
 321 static
 322 int bytecode_is_linked(struct lttng_ust_filter_bytecode_node *filter_bytecode,
 323                 struct lttng_event *event)
 324 {
 325         struct lttng_bytecode_runtime *bc_runtime;
 326
 327         cds_list_for_each_entry(bc_runtime,
 328                         &event->bytecode_runtime_head, node) {
 329                 if (bc_runtime->bc == filter_bytecode)
 330                         return 1;
 331         }
 332         return 0;
 333 }
 334
 335 /*
 336  * Take a bytecode with reloc table and link it to an event to create a
 337  * bytecode runtime.
 338  */
 339 static
 340 int _lttng_filter_event_link_bytecode(struct lttng_event *event,
 341                 struct lttng_ust_filter_bytecode_node *filter_bytecode,
 342                 struct cds_list_head *insert_loc)
 343 {
 344         int ret, offset, next_offset;
 345         struct bytecode_runtime *runtime = NULL;
 346         size_t runtime_alloc_len;
 347
 348         if (!filter_bytecode)
 349                 return 0;
 350         /* Bytecode already linked */
 351         if (bytecode_is_linked(filter_bytecode, event))
 352                 return 0;
 353
 354         dbg_printf("Linking...\n");
 355
 356         /* We don't need the reloc table in the runtime */
 357         runtime_alloc_len = sizeof(*runtime) + filter_bytecode->bc.reloc_offset;
 358         runtime = zmalloc(runtime_alloc_len);
 359         if (!runtime) {
 360                 ret = -ENOMEM;
 361                 goto alloc_error;
 362         }
 363         runtime->p.bc = filter_bytecode;
 364         runtime->p.session = event->chan->session;
 365         runtime->len = filter_bytecode->bc.reloc_offset;
 366         /* copy original bytecode */
 367         memcpy(runtime->data, filter_bytecode->bc.data, runtime->len);
 368         /*
 369          * apply relocs. Those are a uint16_t (offset in bytecode)
 370          * followed by a string (field name).
 371          */
 372         for (offset = filter_bytecode->bc.reloc_offset;
 373                         offset < filter_bytecode->bc.len;
 374                         offset = next_offset) {
 375                 uint16_t reloc_offset =
 376                         *(uint16_t *) &filter_bytecode->bc.data[offset];
 377                 const char *name =
 378                         (const char *) &filter_bytecode->bc.data[offset + sizeof(uint16_t)];
 379
 380                 ret = apply_reloc(event, runtime, runtime->len, reloc_offset, name);
 381                 if (ret) {
 382                         goto link_error;
 383                 }
 384                 next_offset = offset + sizeof(uint16_t) + strlen(name) + 1;
 385         }
 386         /* Validate bytecode */
 387         ret = lttng_filter_validate_bytecode(runtime);
 388         if (ret) {
 389                 goto link_error;
 390         }
 391         /* Specialize bytecode */
 392         ret = lttng_filter_specialize_bytecode(runtime);
 393         if (ret) {
 394                 goto link_error;
 395         }
 396         runtime->p.filter = lttng_filter_interpret_bytecode;
 397         runtime->p.link_failed = 0;
 398         cds_list_add_rcu(&runtime->p.node, insert_loc);
 399         dbg_printf("Linking successful.\n");
 400         return 0;
 401
 402 link_error:
 403         runtime->p.filter = lttng_filter_false;
 404         runtime->p.link_failed = 1;
 405         cds_list_add_rcu(&runtime->p.node, insert_loc);
 406 alloc_error:
 407         dbg_printf("Linking failed.\n");
 408         return ret;
 409 }
 410
 411 void lttng_filter_sync_state(struct lttng_bytecode_runtime *runtime)
 412 {
 413         struct lttng_ust_filter_bytecode_node *bc = runtime->bc;
 414
 415         if (!bc->enabler->enabled || runtime->link_failed)
 416                 runtime->filter = lttng_filter_false;
 417         else
 418                 runtime->filter = lttng_filter_interpret_bytecode;
 419 }
 420
 421 /*
 422  * Link bytecode for all enablers referenced by an event.
 423  */
 424 void lttng_enabler_event_link_bytecode(struct lttng_event *event,
 425                 struct lttng_enabler *enabler)
 426 {
 427         struct lttng_ust_filter_bytecode_node *bc;
 428         struct lttng_bytecode_runtime *runtime;
 429
 430         /* Can only be called for events with desc attached */
 431         assert(event->desc);
 432
 433         /* Link each bytecode. */
 434         cds_list_for_each_entry(bc, &enabler->filter_bytecode_head, node) {
 435                 int found = 0, ret;
 436                 struct cds_list_head *insert_loc;
 437
 438                 cds_list_for_each_entry(runtime,
 439                                 &event->bytecode_runtime_head, node) {
 440                         if (runtime->bc == bc) {
 441                                 found = 1;
 442                                 break;
 443                         }
 444                 }
 445                 /* Skip bytecode already linked */
 446                 if (found)
 447                         continue;
 448
 449                 /*
 450                  * Insert at specified priority (seqnum) in increasing
 451                  * order.
 452                  */
 453                 cds_list_for_each_entry_reverse(runtime,
 454                                 &event->bytecode_runtime_head, node) {
 455                         if (runtime->bc->bc.seqnum < bc->bc.seqnum) {
 456                                 /* insert here */
 457                                 insert_loc = &runtime->node;
 458                                 goto add_within;
 459                         }
 460                 }
 461                 /* Add to head to list */
 462                 insert_loc = &event->bytecode_runtime_head;
 463         add_within:
 464                 dbg_printf("linking bytecode\n");
 465                 ret = _lttng_filter_event_link_bytecode(event, bc,
 466                                 insert_loc);
 467                 if (ret) {
 468                         dbg_printf("[lttng filter] warning: cannot link event bytecode\n");
 469                 }
 470         }
 471 }
 472
 473 /*
 474  * We own the filter_bytecode if we return success.
 475  */
 476 int lttng_filter_enabler_attach_bytecode(struct lttng_enabler *enabler,
 477                 struct lttng_ust_filter_bytecode_node *filter_bytecode)
 478 {
 479         cds_list_add(&filter_bytecode->node, &enabler->filter_bytecode_head);
 480         return 0;
 481 }
 482
 483 void lttng_free_enabler_filter_bytecode(struct lttng_enabler *enabler)
 484 {
 485         struct lttng_ust_filter_bytecode_node *filter_bytecode, *tmp;
 486
 487         cds_list_for_each_entry_safe(filter_bytecode, tmp,
 488                         &enabler->filter_bytecode_head, node) {
 489                 free(filter_bytecode);
 490         }
 491 }
 492
 493 void lttng_free_event_filter_runtime(struct lttng_event *event)
 494 {
 495         struct bytecode_runtime *runtime, *tmp;
 496
 497         cds_list_for_each_entry_safe(runtime, tmp,
 498                         &event->bytecode_runtime_head, p.node) {
 499                 free(runtime);
 500         }
 501 }