| 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 "lttng-filter.h" |
| 24 | |
| 25 | static const char *opnames[] = { |
| 26 | [ FILTER_OP_UNKNOWN ] = "UNKNOWN", |
| 27 | |
| 28 | [ FILTER_OP_RETURN ] = "RETURN", |
| 29 | |
| 30 | /* binary */ |
| 31 | [ FILTER_OP_MUL ] = "MUL", |
| 32 | [ FILTER_OP_DIV ] = "DIV", |
| 33 | [ FILTER_OP_MOD ] = "MOD", |
| 34 | [ FILTER_OP_PLUS ] = "PLUS", |
| 35 | [ FILTER_OP_MINUS ] = "MINUS", |
| 36 | [ FILTER_OP_RSHIFT ] = "RSHIFT", |
| 37 | [ FILTER_OP_LSHIFT ] = "LSHIFT", |
| 38 | [ FILTER_OP_BIN_AND ] = "BIN_AND", |
| 39 | [ FILTER_OP_BIN_OR ] = "BIN_OR", |
| 40 | [ FILTER_OP_BIN_XOR ] = "BIN_XOR", |
| 41 | |
| 42 | /* binary comparators */ |
| 43 | [ FILTER_OP_EQ ] = "EQ", |
| 44 | [ FILTER_OP_NE ] = "NE", |
| 45 | [ FILTER_OP_GT ] = "GT", |
| 46 | [ FILTER_OP_LT ] = "LT", |
| 47 | [ FILTER_OP_GE ] = "GE", |
| 48 | [ FILTER_OP_LE ] = "LE", |
| 49 | |
| 50 | /* string binary comparators */ |
| 51 | [ FILTER_OP_EQ_STRING ] = "EQ_STRING", |
| 52 | [ FILTER_OP_NE_STRING ] = "NE_STRING", |
| 53 | [ FILTER_OP_GT_STRING ] = "GT_STRING", |
| 54 | [ FILTER_OP_LT_STRING ] = "LT_STRING", |
| 55 | [ FILTER_OP_GE_STRING ] = "GE_STRING", |
| 56 | [ FILTER_OP_LE_STRING ] = "LE_STRING", |
| 57 | |
| 58 | /* s64 binary comparators */ |
| 59 | [ FILTER_OP_EQ_S64 ] = "EQ_S64", |
| 60 | [ FILTER_OP_NE_S64 ] = "NE_S64", |
| 61 | [ FILTER_OP_GT_S64 ] = "GT_S64", |
| 62 | [ FILTER_OP_LT_S64 ] = "LT_S64", |
| 63 | [ FILTER_OP_GE_S64 ] = "GE_S64", |
| 64 | [ FILTER_OP_LE_S64 ] = "LE_S64", |
| 65 | |
| 66 | /* double binary comparators */ |
| 67 | [ FILTER_OP_EQ_DOUBLE ] = "EQ_DOUBLE", |
| 68 | [ FILTER_OP_NE_DOUBLE ] = "NE_DOUBLE", |
| 69 | [ FILTER_OP_GT_DOUBLE ] = "GT_DOUBLE", |
| 70 | [ FILTER_OP_LT_DOUBLE ] = "LT_DOUBLE", |
| 71 | [ FILTER_OP_GE_DOUBLE ] = "GE_DOUBLE", |
| 72 | [ FILTER_OP_LE_DOUBLE ] = "LE_DOUBLE", |
| 73 | |
| 74 | /* Mixed S64-double binary comparators */ |
| 75 | [ FILTER_OP_EQ_DOUBLE_S64 ] = "EQ_DOUBLE_S64", |
| 76 | [ FILTER_OP_NE_DOUBLE_S64 ] = "NE_DOUBLE_S64", |
| 77 | [ FILTER_OP_GT_DOUBLE_S64 ] = "GT_DOUBLE_S64", |
| 78 | [ FILTER_OP_LT_DOUBLE_S64 ] = "LT_DOUBLE_S64", |
| 79 | [ FILTER_OP_GE_DOUBLE_S64 ] = "GE_DOUBLE_S64", |
| 80 | [ FILTER_OP_LE_DOUBLE_S64 ] = "LE_DOUBLE_S64", |
| 81 | |
| 82 | [ FILTER_OP_EQ_S64_DOUBLE ] = "EQ_S64_DOUBLE", |
| 83 | [ FILTER_OP_NE_S64_DOUBLE ] = "NE_S64_DOUBLE", |
| 84 | [ FILTER_OP_GT_S64_DOUBLE ] = "GT_S64_DOUBLE", |
| 85 | [ FILTER_OP_LT_S64_DOUBLE ] = "LT_S64_DOUBLE", |
| 86 | [ FILTER_OP_GE_S64_DOUBLE ] = "GE_S64_DOUBLE", |
| 87 | [ FILTER_OP_LE_S64_DOUBLE ] = "LE_S64_DOUBLE", |
| 88 | |
| 89 | /* unary */ |
| 90 | [ FILTER_OP_UNARY_PLUS ] = "UNARY_PLUS", |
| 91 | [ FILTER_OP_UNARY_MINUS ] = "UNARY_MINUS", |
| 92 | [ FILTER_OP_UNARY_NOT ] = "UNARY_NOT", |
| 93 | [ FILTER_OP_UNARY_PLUS_S64 ] = "UNARY_PLUS_S64", |
| 94 | [ FILTER_OP_UNARY_MINUS_S64 ] = "UNARY_MINUS_S64", |
| 95 | [ FILTER_OP_UNARY_NOT_S64 ] = "UNARY_NOT_S64", |
| 96 | [ FILTER_OP_UNARY_PLUS_DOUBLE ] = "UNARY_PLUS_DOUBLE", |
| 97 | [ FILTER_OP_UNARY_MINUS_DOUBLE ] = "UNARY_MINUS_DOUBLE", |
| 98 | [ FILTER_OP_UNARY_NOT_DOUBLE ] = "UNARY_NOT_DOUBLE", |
| 99 | |
| 100 | /* logical */ |
| 101 | [ FILTER_OP_AND ] = "AND", |
| 102 | [ FILTER_OP_OR ] = "OR", |
| 103 | |
| 104 | /* load */ |
| 105 | [ FILTER_OP_LOAD_FIELD_REF ] = "LOAD_FIELD_REF", |
| 106 | [ FILTER_OP_LOAD_FIELD_REF_STRING ] = "LOAD_FIELD_REF_STRING", |
| 107 | [ FILTER_OP_LOAD_FIELD_REF_SEQUENCE ] = "LOAD_FIELD_REF_SEQUENCE", |
| 108 | [ FILTER_OP_LOAD_FIELD_REF_S64 ] = "LOAD_FIELD_REF_S64", |
| 109 | [ FILTER_OP_LOAD_FIELD_REF_DOUBLE ] = "LOAD_FIELD_REF_DOUBLE", |
| 110 | |
| 111 | [ FILTER_OP_LOAD_STRING ] = "LOAD_STRING", |
| 112 | [ FILTER_OP_LOAD_S64 ] = "LOAD_S64", |
| 113 | [ FILTER_OP_LOAD_DOUBLE ] = "LOAD_DOUBLE", |
| 114 | |
| 115 | /* cast */ |
| 116 | [ FILTER_OP_CAST_TO_S64 ] = "CAST_TO_S64", |
| 117 | [ FILTER_OP_CAST_DOUBLE_TO_S64 ] = "CAST_DOUBLE_TO_S64", |
| 118 | [ FILTER_OP_CAST_NOP ] = "CAST_NOP", |
| 119 | }; |
| 120 | |
| 121 | const char *print_op(enum filter_op op) |
| 122 | { |
| 123 | if (op >= NR_FILTER_OPS) |
| 124 | return "UNKNOWN"; |
| 125 | else |
| 126 | return opnames[op]; |
| 127 | } |
| 128 | |
| 129 | static |
| 130 | int apply_field_reloc(struct ltt_event *event, |
| 131 | struct bytecode_runtime *runtime, |
| 132 | uint32_t runtime_len, |
| 133 | uint32_t reloc_offset, |
| 134 | const char *field_name) |
| 135 | { |
| 136 | const struct lttng_event_desc *desc; |
| 137 | const struct lttng_event_field *fields, *field = NULL; |
| 138 | unsigned int nr_fields, i; |
| 139 | struct field_ref *field_ref; |
| 140 | struct load_op *op; |
| 141 | uint32_t field_offset = 0; |
| 142 | |
| 143 | dbg_printf("Apply reloc: %u %s\n", reloc_offset, field_name); |
| 144 | |
| 145 | /* Ensure that the reloc is within the code */ |
| 146 | if (runtime_len - reloc_offset < sizeof(uint16_t)) |
| 147 | return -EINVAL; |
| 148 | |
| 149 | /* Lookup event by name */ |
| 150 | desc = event->desc; |
| 151 | if (!desc) |
| 152 | return -EINVAL; |
| 153 | fields = desc->fields; |
| 154 | if (!fields) |
| 155 | return -EINVAL; |
| 156 | nr_fields = desc->nr_fields; |
| 157 | for (i = 0; i < nr_fields; i++) { |
| 158 | if (!strcmp(fields[i].name, field_name)) { |
| 159 | field = &fields[i]; |
| 160 | break; |
| 161 | } |
| 162 | /* compute field offset */ |
| 163 | switch (fields[i].type.atype) { |
| 164 | case atype_integer: |
| 165 | case atype_enum: |
| 166 | field_offset += sizeof(int64_t); |
| 167 | break; |
| 168 | case atype_array: |
| 169 | case atype_sequence: |
| 170 | field_offset += sizeof(unsigned long); |
| 171 | field_offset += sizeof(void *); |
| 172 | break; |
| 173 | case atype_string: |
| 174 | field_offset += sizeof(void *); |
| 175 | break; |
| 176 | case atype_float: |
| 177 | field_offset += sizeof(double); |
| 178 | break; |
| 179 | default: |
| 180 | return -EINVAL; |
| 181 | } |
| 182 | } |
| 183 | if (!field) |
| 184 | return -EINVAL; |
| 185 | |
| 186 | /* Check if field offset is too large for 16-bit offset */ |
| 187 | if (field_offset > FILTER_BYTECODE_MAX_LEN - 1) |
| 188 | return -EINVAL; |
| 189 | |
| 190 | /* set type */ |
| 191 | op = (struct load_op *) &runtime->data[reloc_offset]; |
| 192 | field_ref = (struct field_ref *) op->data; |
| 193 | switch (field->type.atype) { |
| 194 | case atype_integer: |
| 195 | case atype_enum: |
| 196 | op->op = FILTER_OP_LOAD_FIELD_REF_S64; |
| 197 | break; |
| 198 | case atype_array: |
| 199 | case atype_sequence: |
| 200 | op->op = FILTER_OP_LOAD_FIELD_REF_SEQUENCE; |
| 201 | break; |
| 202 | case atype_string: |
| 203 | op->op = FILTER_OP_LOAD_FIELD_REF_STRING; |
| 204 | break; |
| 205 | case atype_float: |
| 206 | op->op = FILTER_OP_LOAD_FIELD_REF_DOUBLE; |
| 207 | break; |
| 208 | default: |
| 209 | return -EINVAL; |
| 210 | } |
| 211 | /* set offset */ |
| 212 | field_ref->offset = (uint16_t) field_offset; |
| 213 | return 0; |
| 214 | } |
| 215 | |
| 216 | /* |
| 217 | * Take a bytecode with reloc table and link it to an event to create a |
| 218 | * bytecode runtime. |
| 219 | */ |
| 220 | static |
| 221 | int _lttng_filter_event_link_bytecode(struct ltt_event *event, |
| 222 | struct lttng_ust_filter_bytecode *filter_bytecode) |
| 223 | { |
| 224 | int ret, offset, next_offset; |
| 225 | struct bytecode_runtime *runtime = NULL; |
| 226 | size_t runtime_alloc_len; |
| 227 | |
| 228 | if (!filter_bytecode) |
| 229 | return 0; |
| 230 | /* Even is not connected to any description */ |
| 231 | if (!event->desc) |
| 232 | return 0; |
| 233 | /* Bytecode already linked */ |
| 234 | if (event->filter || event->filter_data) |
| 235 | return 0; |
| 236 | |
| 237 | dbg_printf("Linking\n"); |
| 238 | |
| 239 | /* We don't need the reloc table in the runtime */ |
| 240 | runtime_alloc_len = sizeof(*runtime) + filter_bytecode->reloc_offset; |
| 241 | runtime = zmalloc(runtime_alloc_len); |
| 242 | if (!runtime) { |
| 243 | ret = -ENOMEM; |
| 244 | goto link_error; |
| 245 | } |
| 246 | runtime->len = filter_bytecode->reloc_offset; |
| 247 | /* copy original bytecode */ |
| 248 | memcpy(runtime->data, filter_bytecode->data, runtime->len); |
| 249 | /* |
| 250 | * apply relocs. Those are a uint16_t (offset in bytecode) |
| 251 | * followed by a string (field name). |
| 252 | */ |
| 253 | for (offset = filter_bytecode->reloc_offset; |
| 254 | offset < filter_bytecode->len; |
| 255 | offset = next_offset) { |
| 256 | uint16_t reloc_offset = |
| 257 | *(uint16_t *) &filter_bytecode->data[offset]; |
| 258 | const char *field_name = |
| 259 | (const char *) &filter_bytecode->data[offset + sizeof(uint16_t)]; |
| 260 | |
| 261 | ret = apply_field_reloc(event, runtime, runtime->len, reloc_offset, field_name); |
| 262 | if (ret) { |
| 263 | goto link_error; |
| 264 | } |
| 265 | next_offset = offset + sizeof(uint16_t) + strlen(field_name) + 1; |
| 266 | } |
| 267 | /* Validate bytecode */ |
| 268 | ret = lttng_filter_validate_bytecode(runtime); |
| 269 | if (ret) { |
| 270 | goto link_error; |
| 271 | } |
| 272 | /* Specialize bytecode */ |
| 273 | ret = lttng_filter_specialize_bytecode(runtime); |
| 274 | if (ret) { |
| 275 | goto link_error; |
| 276 | } |
| 277 | event->filter_data = runtime; |
| 278 | event->filter = lttng_filter_interpret_bytecode; |
| 279 | return 0; |
| 280 | |
| 281 | link_error: |
| 282 | event->filter = lttng_filter_false; |
| 283 | free(runtime); |
| 284 | return ret; |
| 285 | } |
| 286 | |
| 287 | void lttng_filter_event_link_bytecode(struct ltt_event *event, |
| 288 | struct lttng_ust_filter_bytecode *filter_bytecode) |
| 289 | { |
| 290 | int ret; |
| 291 | |
| 292 | ret = _lttng_filter_event_link_bytecode(event, filter_bytecode); |
| 293 | if (ret) { |
| 294 | dbg_printf("[lttng filter] warning: cannot link event bytecode\n"); |
| 295 | } |
| 296 | } |
| 297 | |
| 298 | /* |
| 299 | * Link bytecode to all events for a wildcard. Skips events that already |
| 300 | * have a bytecode linked. |
| 301 | * We do not set each event's filter_bytecode field, because they do not |
| 302 | * own the filter_bytecode: the wildcard owns it. |
| 303 | */ |
| 304 | void lttng_filter_wildcard_link_bytecode(struct session_wildcard *wildcard) |
| 305 | { |
| 306 | struct ltt_event *event; |
| 307 | int ret; |
| 308 | |
| 309 | if (!wildcard->filter_bytecode) |
| 310 | return; |
| 311 | |
| 312 | cds_list_for_each_entry(event, &wildcard->events, wildcard_list) { |
| 313 | if (event->filter) |
| 314 | continue; |
| 315 | ret = _lttng_filter_event_link_bytecode(event, |
| 316 | wildcard->filter_bytecode); |
| 317 | if (ret) { |
| 318 | fprintf(stderr, "[lttng filter] error linking wildcard bytecode\n"); |
| 319 | } |
| 320 | |
| 321 | } |
| 322 | return; |
| 323 | } |
| 324 | |
| 325 | /* |
| 326 | * Need to attach filter to an event before starting tracing for the |
| 327 | * session. We own the filter_bytecode if we return success. |
| 328 | */ |
| 329 | int lttng_filter_event_attach_bytecode(struct ltt_event *event, |
| 330 | struct lttng_ust_filter_bytecode *filter_bytecode) |
| 331 | { |
| 332 | if (event->chan->session->been_active) |
| 333 | return -EPERM; |
| 334 | if (event->filter_bytecode) |
| 335 | return -EEXIST; |
| 336 | event->filter_bytecode = filter_bytecode; |
| 337 | return 0; |
| 338 | } |
| 339 | |
| 340 | /* |
| 341 | * Need to attach filter to a wildcard before starting tracing for the |
| 342 | * session. We own the filter_bytecode if we return success. |
| 343 | */ |
| 344 | int lttng_filter_wildcard_attach_bytecode(struct session_wildcard *wildcard, |
| 345 | struct lttng_ust_filter_bytecode *filter_bytecode) |
| 346 | { |
| 347 | if (wildcard->chan->session->been_active) |
| 348 | return -EPERM; |
| 349 | if (wildcard->filter_bytecode) |
| 350 | return -EEXIST; |
| 351 | wildcard->filter_bytecode = filter_bytecode; |
| 352 | return 0; |
| 353 | } |