liblttng-ust/lttng-filter.c

   1 /*
   2  * lttng-filter.c
   3  *
   4  * LTTng UST filter code.
   5  *
   6  * Copyright (C) 2010-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
   7  *
   8  * This library is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU Lesser General Public
  10  * License as published by the Free Software Foundation; only
  11  * version 2.1 of the License.
  12  *
  13  * This library is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  16  * Lesser General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU Lesser General Public
  19  * License along with this library; if not, write to the Free Software
  20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  21  */
  22
  23 #include <urcu/rculist.h>
  24 #include "lttng-filter.h"
  25
  26 static const char *opnames[] = {
  27         [ FILTER_OP_UNKNOWN ] = "UNKNOWN",
  28
  29         [ FILTER_OP_RETURN ] = "RETURN",
  30
  31         /* binary */
  32         [ FILTER_OP_MUL ] = "MUL",
  33         [ FILTER_OP_DIV ] = "DIV",
  34         [ FILTER_OP_MOD ] = "MOD",
  35         [ FILTER_OP_PLUS ] = "PLUS",
  36         [ FILTER_OP_MINUS ] = "MINUS",
  37         [ FILTER_OP_RSHIFT ] = "RSHIFT",
  38         [ FILTER_OP_LSHIFT ] = "LSHIFT",
  39         [ FILTER_OP_BIN_AND ] = "BIN_AND",
  40         [ FILTER_OP_BIN_OR ] = "BIN_OR",
  41         [ FILTER_OP_BIN_XOR ] = "BIN_XOR",
  42
  43         /* binary comparators */
  44         [ FILTER_OP_EQ ] = "EQ",
  45         [ FILTER_OP_NE ] = "NE",
  46         [ FILTER_OP_GT ] = "GT",
  47         [ FILTER_OP_LT ] = "LT",
  48         [ FILTER_OP_GE ] = "GE",
  49         [ FILTER_OP_LE ] = "LE",
  50
  51         /* string binary comparators */
  52         [ FILTER_OP_EQ_STRING ] = "EQ_STRING",
  53         [ FILTER_OP_NE_STRING ] = "NE_STRING",
  54         [ FILTER_OP_GT_STRING ] = "GT_STRING",
  55         [ FILTER_OP_LT_STRING ] = "LT_STRING",
  56         [ FILTER_OP_GE_STRING ] = "GE_STRING",
  57         [ FILTER_OP_LE_STRING ] = "LE_STRING",
  58
  59         /* s64 binary comparators */
  60         [ FILTER_OP_EQ_S64 ] = "EQ_S64",
  61         [ FILTER_OP_NE_S64 ] = "NE_S64",
  62         [ FILTER_OP_GT_S64 ] = "GT_S64",
  63         [ FILTER_OP_LT_S64 ] = "LT_S64",
  64         [ FILTER_OP_GE_S64 ] = "GE_S64",
  65         [ FILTER_OP_LE_S64 ] = "LE_S64",
  66
  67         /* double binary comparators */
  68         [ FILTER_OP_EQ_DOUBLE ] = "EQ_DOUBLE",
  69         [ FILTER_OP_NE_DOUBLE ] = "NE_DOUBLE",
  70         [ FILTER_OP_GT_DOUBLE ] = "GT_DOUBLE",
  71         [ FILTER_OP_LT_DOUBLE ] = "LT_DOUBLE",
  72         [ FILTER_OP_GE_DOUBLE ] = "GE_DOUBLE",
  73         [ FILTER_OP_LE_DOUBLE ] = "LE_DOUBLE",
  74
  75         /* Mixed S64-double binary comparators */
  76         [ FILTER_OP_EQ_DOUBLE_S64 ] = "EQ_DOUBLE_S64",
  77         [ FILTER_OP_NE_DOUBLE_S64 ] = "NE_DOUBLE_S64",
  78         [ FILTER_OP_GT_DOUBLE_S64 ] = "GT_DOUBLE_S64",
  79         [ FILTER_OP_LT_DOUBLE_S64 ] = "LT_DOUBLE_S64",
  80         [ FILTER_OP_GE_DOUBLE_S64 ] = "GE_DOUBLE_S64",
  81         [ FILTER_OP_LE_DOUBLE_S64 ] = "LE_DOUBLE_S64",
  82
  83         [ FILTER_OP_EQ_S64_DOUBLE ] = "EQ_S64_DOUBLE",
  84         [ FILTER_OP_NE_S64_DOUBLE ] = "NE_S64_DOUBLE",
  85         [ FILTER_OP_GT_S64_DOUBLE ] = "GT_S64_DOUBLE",
  86         [ FILTER_OP_LT_S64_DOUBLE ] = "LT_S64_DOUBLE",
  87         [ FILTER_OP_GE_S64_DOUBLE ] = "GE_S64_DOUBLE",
  88         [ FILTER_OP_LE_S64_DOUBLE ] = "LE_S64_DOUBLE",
  89
  90         /* unary */
  91         [ FILTER_OP_UNARY_PLUS ] = "UNARY_PLUS",
  92         [ FILTER_OP_UNARY_MINUS ] = "UNARY_MINUS",
  93         [ FILTER_OP_UNARY_NOT ] = "UNARY_NOT",
  94         [ FILTER_OP_UNARY_PLUS_S64 ] = "UNARY_PLUS_S64",
  95         [ FILTER_OP_UNARY_MINUS_S64 ] = "UNARY_MINUS_S64",
  96         [ FILTER_OP_UNARY_NOT_S64 ] = "UNARY_NOT_S64",
  97         [ FILTER_OP_UNARY_PLUS_DOUBLE ] = "UNARY_PLUS_DOUBLE",
  98         [ FILTER_OP_UNARY_MINUS_DOUBLE ] = "UNARY_MINUS_DOUBLE",
  99         [ FILTER_OP_UNARY_NOT_DOUBLE ] = "UNARY_NOT_DOUBLE",
 100
 101         /* logical */
 102         [ FILTER_OP_AND ] = "AND",
 103         [ FILTER_OP_OR ] = "OR",
 104
 105         /* load field ref */
 106         [ FILTER_OP_LOAD_FIELD_REF ] = "LOAD_FIELD_REF",
 107         [ FILTER_OP_LOAD_FIELD_REF_STRING ] = "LOAD_FIELD_REF_STRING",
 108         [ FILTER_OP_LOAD_FIELD_REF_SEQUENCE ] = "LOAD_FIELD_REF_SEQUENCE",
 109         [ FILTER_OP_LOAD_FIELD_REF_S64 ] = "LOAD_FIELD_REF_S64",
 110         [ FILTER_OP_LOAD_FIELD_REF_DOUBLE ] = "LOAD_FIELD_REF_DOUBLE",
 111
 112         /* load from immediate operand */
 113         [ FILTER_OP_LOAD_STRING ] = "LOAD_STRING",
 114         [ FILTER_OP_LOAD_S64 ] = "LOAD_S64",
 115         [ FILTER_OP_LOAD_DOUBLE ] = "LOAD_DOUBLE",
 116
 117         /* cast */
 118         [ FILTER_OP_CAST_TO_S64 ] = "CAST_TO_S64",
 119         [ FILTER_OP_CAST_DOUBLE_TO_S64 ] = "CAST_DOUBLE_TO_S64",
 120         [ FILTER_OP_CAST_NOP ] = "CAST_NOP",
 121
 122         /* get context ref */
 123         [ FILTER_OP_GET_CONTEXT_REF ] = "GET_CONTEXT_REF",
 124         [ FILTER_OP_GET_CONTEXT_REF_STRING ] = "GET_CONTEXT_REF_STRING",
 125         [ FILTER_OP_GET_CONTEXT_REF_S64 ] = "GET_CONTEXT_REF_S64",
 126         [ FILTER_OP_GET_CONTEXT_REF_DOUBLE ] = "GET_CONTEXT_REF_DOUBLE",
 127 };
 128
 129 const char *print_op(enum filter_op op)
 130 {
 131         if (op >= NR_FILTER_OPS)
 132                 return "UNKNOWN";
 133         else
 134                 return opnames[op];
 135 }
 136
 137 static
 138 int apply_field_reloc(struct lttng_event *event,
 139                 struct bytecode_runtime *runtime,
 140                 uint32_t runtime_len,
 141                 uint32_t reloc_offset,
 142                 const char *field_name)
 143 {
 144         const struct lttng_event_desc *desc;
 145         const struct lttng_event_field *fields, *field = NULL;
 146         unsigned int nr_fields, i;
 147         struct field_ref *field_ref;
 148         struct load_op *op;
 149         uint32_t field_offset = 0;
 150
 151         dbg_printf("Apply field reloc: %u %s\n", reloc_offset, field_name);
 152
 153         /* Lookup event by name */
 154         desc = event->desc;
 155         if (!desc)
 156                 return -EINVAL;
 157         fields = desc->fields;
 158         if (!fields)
 159                 return -EINVAL;
 160         nr_fields = desc->nr_fields;
 161         for (i = 0; i < nr_fields; i++) {
 162                 if (!strcmp(fields[i].name, field_name)) {
 163                         field = &fields[i];
 164                         break;
 165                 }
 166                 /* compute field offset */
 167                 switch (fields[i].type.atype) {
 168                 case atype_integer:
 169                 case atype_enum:
 170                         field_offset += sizeof(int64_t);
 171                         break;
 172                 case atype_array:
 173                 case atype_sequence:
 174                         field_offset += sizeof(unsigned long);
 175                         field_offset += sizeof(void *);
 176                         break;
 177                 case atype_string:
 178                         field_offset += sizeof(void *);
 179                         break;
 180                 case atype_float:
 181                         field_offset += sizeof(double);
 182                         break;
 183                 default:
 184                         return -EINVAL;
 185                 }
 186         }
 187         if (!field)
 188                 return -EINVAL;
 189
 190         /* Check if field offset is too large for 16-bit offset */
 191         if (field_offset > FILTER_BYTECODE_MAX_LEN - 1)
 192                 return -EINVAL;
 193
 194         /* set type */
 195         op = (struct load_op *) &runtime->data[reloc_offset];
 196         field_ref = (struct field_ref *) op->data;
 197         switch (field->type.atype) {
 198         case atype_integer:
 199         case atype_enum:
 200                 op->op = FILTER_OP_LOAD_FIELD_REF_S64;
 201                 break;
 202         case atype_array:
 203         case atype_sequence:
 204                 op->op = FILTER_OP_LOAD_FIELD_REF_SEQUENCE;
 205                 break;
 206         case atype_string:
 207                 op->op = FILTER_OP_LOAD_FIELD_REF_STRING;
 208                 break;
 209         case atype_float:
 210                 op->op = FILTER_OP_LOAD_FIELD_REF_DOUBLE;
 211                 break;
 212         default:
 213                 return -EINVAL;
 214         }
 215         /* set offset */
 216         field_ref->offset = (uint16_t) field_offset;
 217         return 0;
 218 }
 219
 220 static
 221 int apply_context_reloc(struct lttng_event *event,
 222                 struct bytecode_runtime *runtime,
 223                 uint32_t runtime_len,
 224                 uint32_t reloc_offset,
 225                 const char *context_name)
 226 {
 227         struct field_ref *field_ref;
 228         struct load_op *op;
 229         struct lttng_ctx_field *ctx_field;
 230         int idx;
 231
 232         dbg_printf("Apply context reloc: %u %s\n", reloc_offset, context_name);
 233
 234         /* Get context index */
 235         idx = lttng_get_context_index(lttng_static_ctx, context_name);
 236         if (idx < 0)
 237                 return -ENOENT;
 238
 239         /* Check if idx is too large for 16-bit offset */
 240         if (idx > FILTER_BYTECODE_MAX_LEN - 1)
 241                 return -EINVAL;
 242
 243         /* Get context return type */
 244         ctx_field = &lttng_static_ctx->fields[idx];
 245         op = (struct load_op *) &runtime->data[reloc_offset];
 246         field_ref = (struct field_ref *) op->data;
 247         switch (ctx_field->event_field.type.atype) {
 248         case atype_integer:
 249         case atype_enum:
 250                 op->op = FILTER_OP_GET_CONTEXT_REF_S64;
 251                 break;
 252                 /* Sequence and array supported as string */
 253         case atype_string:
 254         case atype_array:
 255         case atype_sequence:
 256                 op->op = FILTER_OP_GET_CONTEXT_REF_STRING;
 257                 break;
 258         case atype_float:
 259                 op->op = FILTER_OP_GET_CONTEXT_REF_DOUBLE;
 260                 break;
 261         default:
 262                 return -EINVAL;
 263         }
 264         /* set offset to context index within channel contexts */
 265         field_ref->offset = (uint16_t) idx;
 266         return 0;
 267 }
 268
 269 static
 270 int apply_reloc(struct lttng_event *event,
 271                 struct bytecode_runtime *runtime,
 272                 uint32_t runtime_len,
 273                 uint32_t reloc_offset,
 274                 const char *name)
 275 {
 276         struct load_op *op;
 277
 278         dbg_printf("Apply reloc: %u %s\n", reloc_offset, name);
 279
 280         /* Ensure that the reloc is within the code */
 281         if (runtime_len - reloc_offset < sizeof(uint16_t))
 282                 return -EINVAL;
 283
 284         op = (struct load_op *) &runtime->data[reloc_offset];
 285         switch (op->op) {
 286         case FILTER_OP_LOAD_FIELD_REF:
 287                 return apply_field_reloc(event, runtime, runtime_len,
 288                         reloc_offset, name);
 289         case FILTER_OP_GET_CONTEXT_REF:
 290                 return apply_context_reloc(event, runtime, runtime_len,
 291                         reloc_offset, name);
 292         default:
 293                 ERR("Unknown reloc op type %u\n", op->op);
 294                 return -EINVAL;
 295         }
 296         return 0;
 297 }
 298
 299 static
 300 int bytecode_is_linked(struct lttng_ust_filter_bytecode_node *filter_bytecode,
 301                 struct lttng_event *event)
 302 {
 303         struct lttng_bytecode_runtime *bc_runtime;
 304
 305         cds_list_for_each_entry(bc_runtime,
 306                         &event->bytecode_runtime_head, node) {
 307                 if (bc_runtime->bc == filter_bytecode)
 308                         return 1;
 309         }
 310         return 0;
 311 }
 312
 313 /*
 314  * Take a bytecode with reloc table and link it to an event to create a
 315  * bytecode runtime.
 316  */
 317 static
 318 int _lttng_filter_event_link_bytecode(struct lttng_event *event,
 319                 struct lttng_ust_filter_bytecode_node *filter_bytecode,
 320                 struct cds_list_head *insert_loc)
 321 {
 322         int ret, offset, next_offset;
 323         struct bytecode_runtime *runtime = NULL;
 324         size_t runtime_alloc_len;
 325
 326         if (!filter_bytecode)
 327                 return 0;
 328         /* Bytecode already linked */
 329         if (bytecode_is_linked(filter_bytecode, event))
 330                 return 0;
 331
 332         dbg_printf("Linking...\n");
 333
 334         /* We don't need the reloc table in the runtime */
 335         runtime_alloc_len = sizeof(*runtime) + filter_bytecode->bc.reloc_offset;
 336         runtime = zmalloc(runtime_alloc_len);
 337         if (!runtime) {
 338                 ret = -ENOMEM;
 339                 goto alloc_error;
 340         }
 341         runtime->p.bc = filter_bytecode;
 342         runtime->len = filter_bytecode->bc.reloc_offset;
 343         /* copy original bytecode */
 344         memcpy(runtime->data, filter_bytecode->bc.data, runtime->len);
 345         /*
 346          * apply relocs. Those are a uint16_t (offset in bytecode)
 347          * followed by a string (field name).
 348          */
 349         for (offset = filter_bytecode->bc.reloc_offset;
 350                         offset < filter_bytecode->bc.len;
 351                         offset = next_offset) {
 352                 uint16_t reloc_offset =
 353                         *(uint16_t *) &filter_bytecode->bc.data[offset];
 354                 const char *name =
 355                         (const char *) &filter_bytecode->bc.data[offset + sizeof(uint16_t)];
 356
 357                 ret = apply_reloc(event, runtime, runtime->len, reloc_offset, name);
 358                 if (ret) {
 359                         goto link_error;
 360                 }
 361                 next_offset = offset + sizeof(uint16_t) + strlen(name) + 1;
 362         }
 363         /* Validate bytecode */
 364         ret = lttng_filter_validate_bytecode(runtime);
 365         if (ret) {
 366                 goto link_error;
 367         }
 368         /* Specialize bytecode */
 369         ret = lttng_filter_specialize_bytecode(runtime);
 370         if (ret) {
 371                 goto link_error;
 372         }
 373         runtime->p.filter = lttng_filter_interpret_bytecode;
 374         runtime->p.link_failed = 0;
 375         cds_list_add_rcu(&runtime->p.node, insert_loc);
 376         dbg_printf("Linking successful.\n");
 377         return 0;
 378
 379 link_error:
 380         runtime->p.filter = lttng_filter_false;
 381         runtime->p.link_failed = 1;
 382         cds_list_add_rcu(&runtime->p.node, insert_loc);
 383 alloc_error:
 384         dbg_printf("Linking failed.\n");
 385         return ret;
 386 }
 387
 388 void lttng_filter_sync_state(struct lttng_bytecode_runtime *runtime)
 389 {
 390         struct lttng_ust_filter_bytecode_node *bc = runtime->bc;
 391
 392         if (!bc->enabler->enabled || runtime->link_failed)
 393                 runtime->filter = lttng_filter_false;
 394         else
 395                 runtime->filter = lttng_filter_interpret_bytecode;
 396 }
 397
 398 /*
 399  * Link bytecode for all enablers referenced by an event.
 400  */
 401 void lttng_enabler_event_link_bytecode(struct lttng_event *event,
 402                 struct lttng_enabler *enabler)
 403 {
 404         struct lttng_ust_filter_bytecode_node *bc;
 405         struct lttng_bytecode_runtime *runtime;
 406
 407         /* Can only be called for events with desc attached */
 408         assert(event->desc);
 409
 410         /* Link each bytecode. */
 411         cds_list_for_each_entry(bc, &enabler->filter_bytecode_head, node) {
 412                 int found = 0, ret;
 413                 struct cds_list_head *insert_loc;
 414
 415                 cds_list_for_each_entry(runtime,
 416                                 &event->bytecode_runtime_head, node) {
 417                         if (runtime->bc == bc) {
 418                                 found = 1;
 419                                 break;
 420                         }
 421                 }
 422                 /* Skip bytecode already linked */
 423                 if (found)
 424                         continue;
 425
 426                 /*
 427                  * Insert at specified priority (seqnum) in increasing
 428                  * order.
 429                  */
 430                 cds_list_for_each_entry_reverse(runtime,
 431                                 &event->bytecode_runtime_head, node) {
 432                         if (runtime->bc->bc.seqnum < bc->bc.seqnum) {
 433                                 /* insert here */
 434                                 insert_loc = &runtime->node;
 435                                 goto add_within;
 436                         }
 437                 }
 438                 /* Add to head to list */
 439                 insert_loc = &event->bytecode_runtime_head;
 440         add_within:
 441                 dbg_printf("linking bytecode\n");
 442                 ret = _lttng_filter_event_link_bytecode(event, bc,
 443                                 insert_loc);
 444                 if (ret) {
 445                         dbg_printf("[lttng filter] warning: cannot link event bytecode\n");
 446                 }
 447         }
 448 }
 449
 450 /*
 451  * We own the filter_bytecode if we return success.
 452  */
 453 int lttng_filter_enabler_attach_bytecode(struct lttng_enabler *enabler,
 454                 struct lttng_ust_filter_bytecode_node *filter_bytecode)
 455 {
 456         cds_list_add(&filter_bytecode->node, &enabler->filter_bytecode_head);
 457         return 0;
 458 }
 459
 460 void lttng_free_enabler_filter_bytecode(struct lttng_enabler *enabler)
 461 {
 462         struct lttng_ust_filter_bytecode_node *filter_bytecode, *tmp;
 463
 464         cds_list_for_each_entry_safe(filter_bytecode, tmp,
 465                         &enabler->filter_bytecode_head, node) {
 466                 free(filter_bytecode);
 467         }
 468 }
 469
 470 void lttng_free_event_filter_runtime(struct lttng_event *event)
 471 {
 472         struct bytecode_runtime *runtime, *tmp;
 473
 474         cds_list_for_each_entry_safe(runtime, tmp,
 475                         &event->bytecode_runtime_head, p.node) {
 476                 free(runtime);
 477         }
 478 }