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 */
 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         [ FILTER_OP_LOAD_STRING ] = "LOAD_STRING",
 113         [ FILTER_OP_LOAD_S64 ] = "LOAD_S64",
 114         [ FILTER_OP_LOAD_DOUBLE ] = "LOAD_DOUBLE",
 115
 116         /* cast */
 117         [ FILTER_OP_CAST_TO_S64 ] = "CAST_TO_S64",
 118         [ FILTER_OP_CAST_DOUBLE_TO_S64 ] = "CAST_DOUBLE_TO_S64",
 119         [ FILTER_OP_CAST_NOP ] = "CAST_NOP",
 120 };
 121
 122 const char *print_op(enum filter_op op)
 123 {
 124         if (op >= NR_FILTER_OPS)
 125                 return "UNKNOWN";
 126         else
 127                 return opnames[op];
 128 }
 129
 130 static
 131 int apply_field_reloc(struct ltt_event *event,
 132                 struct bytecode_runtime *runtime,
 133                 uint32_t runtime_len,
 134                 uint32_t reloc_offset,
 135                 const char *field_name)
 136 {
 137         const struct lttng_event_desc *desc;
 138         const struct lttng_event_field *fields, *field = NULL;
 139         unsigned int nr_fields, i;
 140         struct field_ref *field_ref;
 141         struct load_op *op;
 142         uint32_t field_offset = 0;
 143
 144         dbg_printf("Apply reloc: %u %s\n", reloc_offset, field_name);
 145
 146         /* Ensure that the reloc is within the code */
 147         if (runtime_len - reloc_offset < sizeof(uint16_t))
 148                 return -EINVAL;
 149
 150         /* Lookup event by name */
 151         desc = event->desc;
 152         if (!desc)
 153                 return -EINVAL;
 154         fields = desc->fields;
 155         if (!fields)
 156                 return -EINVAL;
 157         nr_fields = desc->nr_fields;
 158         for (i = 0; i < nr_fields; i++) {
 159                 if (!strcmp(fields[i].name, field_name)) {
 160                         field = &fields[i];
 161                         break;
 162                 }
 163                 /* compute field offset */
 164                 switch (fields[i].type.atype) {
 165                 case atype_integer:
 166                 case atype_enum:
 167                         field_offset += sizeof(int64_t);
 168                         break;
 169                 case atype_array:
 170                 case atype_sequence:
 171                         field_offset += sizeof(unsigned long);
 172                         field_offset += sizeof(void *);
 173                         break;
 174                 case atype_string:
 175                         field_offset += sizeof(void *);
 176                         break;
 177                 case atype_float:
 178                         field_offset += sizeof(double);
 179                         break;
 180                 default:
 181                         return -EINVAL;
 182                 }
 183         }
 184         if (!field)
 185                 return -EINVAL;
 186
 187         /* Check if field offset is too large for 16-bit offset */
 188         if (field_offset > FILTER_BYTECODE_MAX_LEN - 1)
 189                 return -EINVAL;
 190
 191         /* set type */
 192         op = (struct load_op *) &runtime->data[reloc_offset];
 193         field_ref = (struct field_ref *) op->data;
 194         switch (field->type.atype) {
 195         case atype_integer:
 196         case atype_enum:
 197                 op->op = FILTER_OP_LOAD_FIELD_REF_S64;
 198                 break;
 199         case atype_array:
 200         case atype_sequence:
 201                 op->op = FILTER_OP_LOAD_FIELD_REF_SEQUENCE;
 202                 break;
 203         case atype_string:
 204                 op->op = FILTER_OP_LOAD_FIELD_REF_STRING;
 205                 break;
 206         case atype_float:
 207                 op->op = FILTER_OP_LOAD_FIELD_REF_DOUBLE;
 208                 break;
 209         default:
 210                 return -EINVAL;
 211         }
 212         /* set offset */
 213         field_ref->offset = (uint16_t) field_offset;
 214         return 0;
 215 }
 216
 217 static
 218 int bytecode_is_linked(struct lttng_ust_filter_bytecode_node *filter_bytecode,
 219                 struct ltt_event *event)
 220 {
 221         struct lttng_bytecode_runtime *bc_runtime;
 222
 223         cds_list_for_each_entry(bc_runtime, &event->bytecode_runtime, node) {
 224                 if (bc_runtime->bc == filter_bytecode)
 225                         return 1;
 226         }
 227         return 0;
 228 }
 229
 230 /*
 231  * Take a bytecode with reloc table and link it to an event to create a
 232  * bytecode runtime.
 233  */
 234 static
 235 int _lttng_filter_event_link_bytecode(struct ltt_event *event,
 236                 struct lttng_ust_filter_bytecode_node *filter_bytecode)
 237 {
 238         int ret, offset, next_offset;
 239         struct bytecode_runtime *runtime = NULL;
 240         size_t runtime_alloc_len;
 241
 242         if (!filter_bytecode)
 243                 return 0;
 244         /* Event is not connected to any description */
 245         if (!event->desc)
 246                 return 0;
 247         /* Bytecode already linked */
 248         if (bytecode_is_linked(filter_bytecode, event))
 249                 return 0;
 250
 251         dbg_printf("Linking...\n");
 252
 253         /* We don't need the reloc table in the runtime */
 254         runtime_alloc_len = sizeof(*runtime) + filter_bytecode->bc.reloc_offset;
 255         runtime = zmalloc(runtime_alloc_len);
 256         if (!runtime) {
 257                 ret = -ENOMEM;
 258                 goto link_error;
 259         }
 260         runtime->p.bc = filter_bytecode;
 261         runtime->len = filter_bytecode->bc.reloc_offset;
 262         /* copy original bytecode */
 263         memcpy(runtime->data, filter_bytecode->bc.data, runtime->len);
 264         /*
 265          * apply relocs. Those are a uint16_t (offset in bytecode)
 266          * followed by a string (field name).
 267          */
 268         for (offset = filter_bytecode->bc.reloc_offset;
 269                         offset < filter_bytecode->bc.len;
 270                         offset = next_offset) {
 271                 uint16_t reloc_offset =
 272                         *(uint16_t *) &filter_bytecode->bc.data[offset];
 273                 const char *field_name =
 274                         (const char *) &filter_bytecode->bc.data[offset + sizeof(uint16_t)];
 275
 276                 ret = apply_field_reloc(event, runtime, runtime->len, reloc_offset, field_name);
 277                 if (ret) {
 278                         goto link_error;
 279                 }
 280                 next_offset = offset + sizeof(uint16_t) + strlen(field_name) + 1;
 281         }
 282         /* Validate bytecode */
 283         ret = lttng_filter_validate_bytecode(runtime);
 284         if (ret) {
 285                 goto link_error;
 286         }
 287         /* Specialize bytecode */
 288         ret = lttng_filter_specialize_bytecode(runtime);
 289         if (ret) {
 290                 goto link_error;
 291         }
 292         runtime->p.filter = lttng_filter_interpret_bytecode;
 293         /* TODO: add with prio */
 294         cds_list_add_rcu(&runtime->p.node, &event->bytecode_runtime);
 295         dbg_printf("Linking successful.\n");
 296         return 0;
 297
 298 link_error:
 299         runtime->p.filter = lttng_filter_false;
 300         /* TODO: add with prio */
 301         cds_list_add_rcu(&runtime->p.node, &event->bytecode_runtime);
 302         dbg_printf("Linking failed.\n");
 303         return ret;
 304 }
 305
 306 void lttng_filter_event_link_bytecode(struct ltt_event *event)
 307 {
 308         struct lttng_ust_filter_bytecode_node *filter_bytecode;
 309         int ret;
 310
 311         cds_list_for_each_entry(filter_bytecode, &event->filter_bytecode, node) {
 312                 dbg_printf("linking bytecode\n");
 313                 ret = _lttng_filter_event_link_bytecode(event, filter_bytecode);
 314                 if (ret) {
 315                         dbg_printf("[lttng filter] warning: cannot link event bytecode\n");
 316                 }
 317         }
 318 }
 319
 320 void lttng_filter_event_link_wildcard_bytecode(struct ltt_event *event,
 321                 struct session_wildcard *wildcard)
 322 {
 323         struct lttng_ust_filter_bytecode_node *filter_bytecode;
 324         int ret;
 325
 326         cds_list_for_each_entry(filter_bytecode, &wildcard->filter_bytecode, node) {
 327                 dbg_printf("linking bytecode\n");
 328                 ret = _lttng_filter_event_link_bytecode(event, filter_bytecode);
 329                 if (ret) {
 330                         dbg_printf("[lttng filter] error linking wildcard bytecode\n");
 331                 }
 332         }
 333 }
 334
 335 /*
 336  * Link bytecode to all events for a wildcard.
 337  * The "is_linked" check in _lttng_filter_event_link_bytecode() ensures
 338  * that we don't link the same bytecode to an event more than once.
 339  */
 340 void lttng_filter_wildcard_link_bytecode(struct session_wildcard *wildcard)
 341 {
 342         struct ltt_event *event;
 343
 344         if (cds_list_empty(&wildcard->filter_bytecode))
 345                 return;
 346         cds_list_for_each_entry(event, &wildcard->events, wildcard_list) {
 347                 dbg_printf("linking bytecode\n");
 348                 lttng_filter_event_link_wildcard_bytecode(event, wildcard);
 349         }
 350         return;
 351 }
 352
 353 /*
 354  * Need to attach filter to an event before starting tracing for the
 355  * session. We own the filter_bytecode if we return success.
 356  */
 357 int lttng_filter_event_attach_bytecode(struct ltt_event *event,
 358                 struct lttng_ust_filter_bytecode_node *filter_bytecode)
 359 {
 360         cds_list_add(&filter_bytecode->node, &event->filter_bytecode);
 361         return 0;
 362 }
 363
 364 /*
 365  * Need to attach filter to a wildcard before starting tracing for the
 366  * session. We own the filter_bytecode if we return success.
 367  */
 368 int lttng_filter_wildcard_attach_bytecode(struct session_wildcard *wildcard,
 369                 struct lttng_ust_filter_bytecode_node *filter_bytecode)
 370 {
 371         cds_list_add(&filter_bytecode->node, &wildcard->filter_bytecode);
 372         return 0;
 373 }
 374
 375 void lttng_free_event_filter_bytecode(struct ltt_event *event)
 376 {
 377         struct lttng_ust_filter_bytecode_node *filter_bytecode, *tmp;
 378
 379         cds_list_for_each_entry_safe(filter_bytecode, tmp,
 380                         &event->filter_bytecode, node) {
 381                 free(filter_bytecode);
 382         }
 383 }
 384
 385 void lttng_free_wildcard_filter_bytecode(struct session_wildcard *wildcard)
 386 {
 387         struct lttng_ust_filter_bytecode_node *filter_bytecode, *tmp;
 388
 389         cds_list_for_each_entry_safe(filter_bytecode, tmp,
 390                         &wildcard->filter_bytecode, node) {
 391                 free(filter_bytecode);
 392         }
 393 }
 394
 395 void lttng_free_event_filter_runtime(struct ltt_event *event)
 396 {
 397         struct bytecode_runtime *runtime, *tmp;
 398
 399         cds_list_for_each_entry_safe(runtime, tmp,
 400                         &event->bytecode_runtime, p.node) {
 401                 free(runtime);
 402         }
 403 }