| 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 <errno.h> |
| 24 | #include <stdio.h> |
| 25 | #include <helper.h> |
| 26 | #include <lttng/ust-events.h> |
| 27 | #include <stdint.h> |
| 28 | #include <errno.h> |
| 29 | #include <string.h> |
| 30 | #include <inttypes.h> |
| 31 | #include <limits.h> |
| 32 | #include "filter-bytecode.h" |
| 33 | |
| 34 | #define NR_REG 2 |
| 35 | |
| 36 | #ifndef min_t |
| 37 | #define min_t(type, a, b) \ |
| 38 | ((type) (a) < (type) (b) ? (type) (a) : (type) (b)) |
| 39 | #endif |
| 40 | |
| 41 | #ifndef likely |
| 42 | #define likely(x) __builtin_expect(!!(x), 1) |
| 43 | #endif |
| 44 | |
| 45 | #ifndef unlikely |
| 46 | #define unlikely(x) __builtin_expect(!!(x), 0) |
| 47 | #endif |
| 48 | |
| 49 | #ifdef DEBUG |
| 50 | #define dbg_printf(fmt, args...) printf("[debug bytecode] " fmt, ## args) |
| 51 | #else |
| 52 | #define dbg_printf(fmt, args...) \ |
| 53 | do { \ |
| 54 | /* do nothing but check printf format */ \ |
| 55 | if (0) \ |
| 56 | printf("[debug bytecode] " fmt, ## args); \ |
| 57 | } while (0) |
| 58 | #endif |
| 59 | |
| 60 | /* Linked bytecode */ |
| 61 | struct bytecode_runtime { |
| 62 | uint16_t len; |
| 63 | char data[0]; |
| 64 | }; |
| 65 | |
| 66 | struct reg { |
| 67 | enum { |
| 68 | REG_S64, |
| 69 | REG_STRING, /* NULL-terminated string */ |
| 70 | REG_SEQUENCE, /* non-null terminated */ |
| 71 | } type; |
| 72 | int64_t v; |
| 73 | |
| 74 | const char *str; |
| 75 | size_t seq_len; |
| 76 | int literal; /* is string literal ? */ |
| 77 | }; |
| 78 | |
| 79 | static const char *opnames[] = { |
| 80 | [ FILTER_OP_UNKNOWN ] = "UNKNOWN", |
| 81 | |
| 82 | [ FILTER_OP_RETURN ] = "RETURN", |
| 83 | |
| 84 | /* binary */ |
| 85 | [ FILTER_OP_MUL ] = "MUL", |
| 86 | [ FILTER_OP_DIV ] = "DIV", |
| 87 | [ FILTER_OP_MOD ] = "MOD", |
| 88 | [ FILTER_OP_PLUS ] = "PLUS", |
| 89 | [ FILTER_OP_MINUS ] = "MINUS", |
| 90 | [ FILTER_OP_RSHIFT ] = "RSHIFT", |
| 91 | [ FILTER_OP_LSHIFT ] = "LSHIFT", |
| 92 | [ FILTER_OP_BIN_AND ] = "BIN_AND", |
| 93 | [ FILTER_OP_BIN_OR ] = "BIN_OR", |
| 94 | [ FILTER_OP_BIN_XOR ] = "BIN_XOR", |
| 95 | [ FILTER_OP_EQ ] = "EQ", |
| 96 | [ FILTER_OP_NE ] = "NE", |
| 97 | [ FILTER_OP_GT ] = "GT", |
| 98 | [ FILTER_OP_LT ] = "LT", |
| 99 | [ FILTER_OP_GE ] = "GE", |
| 100 | [ FILTER_OP_LE ] = "LE", |
| 101 | |
| 102 | /* unary */ |
| 103 | [ FILTER_OP_UNARY_PLUS ] = "UNARY_PLUS", |
| 104 | [ FILTER_OP_UNARY_MINUS ] = "UNARY_MINUS", |
| 105 | [ FILTER_OP_UNARY_NOT ] = "UNARY_NOT", |
| 106 | |
| 107 | /* logical */ |
| 108 | [ FILTER_OP_AND ] = "AND", |
| 109 | [ FILTER_OP_OR ] = "OR", |
| 110 | |
| 111 | /* load */ |
| 112 | [ FILTER_OP_LOAD_FIELD_REF ] = "LOAD_FIELD_REF", |
| 113 | [ FILTER_OP_LOAD_STRING ] = "LOAD_STRING", |
| 114 | [ FILTER_OP_LOAD_S64 ] = "LOAD_S64", |
| 115 | }; |
| 116 | |
| 117 | static |
| 118 | const char *print_op(enum filter_op op) |
| 119 | { |
| 120 | if (op >= NR_FILTER_OPS) |
| 121 | return "UNKNOWN"; |
| 122 | else |
| 123 | return opnames[op]; |
| 124 | } |
| 125 | |
| 126 | /* |
| 127 | * -1: wildcard found. |
| 128 | * -2: unknown escape char. |
| 129 | * 0: normal char. |
| 130 | */ |
| 131 | |
| 132 | static |
| 133 | int parse_char(const char **p) |
| 134 | { |
| 135 | switch (**p) { |
| 136 | case '\\': |
| 137 | (*p)++; |
| 138 | switch (**p) { |
| 139 | case '\\': |
| 140 | case '*': |
| 141 | return 0; |
| 142 | default: |
| 143 | return -2; |
| 144 | } |
| 145 | case '*': |
| 146 | return -1; |
| 147 | default: |
| 148 | return 0; |
| 149 | } |
| 150 | } |
| 151 | |
| 152 | static |
| 153 | int reg_strcmp(struct reg reg[NR_REG], const char *cmp_type) |
| 154 | { |
| 155 | const char *p = reg[REG_R0].str, *q = reg[REG_R1].str; |
| 156 | int ret; |
| 157 | int diff; |
| 158 | |
| 159 | for (;;) { |
| 160 | int escaped_r0 = 0; |
| 161 | |
| 162 | if (unlikely(p - reg[REG_R0].str > reg[REG_R0].seq_len || *p == '\0')) { |
| 163 | if (q - reg[REG_R1].str > reg[REG_R1].seq_len || *q == '\0') |
| 164 | diff = 0; |
| 165 | else |
| 166 | diff = -1; |
| 167 | break; |
| 168 | } |
| 169 | if (unlikely(q - reg[REG_R1].str > reg[REG_R1].seq_len || *q == '\0')) { |
| 170 | if (p - reg[REG_R0].str > reg[REG_R0].seq_len || *p == '\0') |
| 171 | diff = 0; |
| 172 | else |
| 173 | diff = 1; |
| 174 | break; |
| 175 | } |
| 176 | if (reg[REG_R0].literal) { |
| 177 | ret = parse_char(&p); |
| 178 | if (ret == -1) { |
| 179 | return 0; |
| 180 | } else if (ret == -2) { |
| 181 | escaped_r0 = 1; |
| 182 | } |
| 183 | /* else compare both char */ |
| 184 | } |
| 185 | if (reg[REG_R1].literal) { |
| 186 | ret = parse_char(&q); |
| 187 | if (ret == -1) { |
| 188 | return 0; |
| 189 | } else if (ret == -2) { |
| 190 | if (!escaped_r0) |
| 191 | return -1; |
| 192 | } else { |
| 193 | if (escaped_r0) |
| 194 | return 1; |
| 195 | } |
| 196 | } else { |
| 197 | if (escaped_r0) |
| 198 | return 1; |
| 199 | } |
| 200 | diff = *p - *q; |
| 201 | if (diff != 0) |
| 202 | break; |
| 203 | p++; |
| 204 | q++; |
| 205 | } |
| 206 | return diff; |
| 207 | } |
| 208 | |
| 209 | static |
| 210 | int lttng_filter_false(void *filter_data, |
| 211 | const char *filter_stack_data) |
| 212 | { |
| 213 | return 0; |
| 214 | } |
| 215 | |
| 216 | static |
| 217 | int lttng_filter_interpret_bytecode(void *filter_data, |
| 218 | const char *filter_stack_data) |
| 219 | { |
| 220 | struct bytecode_runtime *bytecode = filter_data; |
| 221 | void *pc, *next_pc, *start_pc; |
| 222 | int ret = -EINVAL; |
| 223 | int retval = 0; |
| 224 | struct reg reg[NR_REG]; |
| 225 | int i; |
| 226 | |
| 227 | for (i = 0; i < NR_REG; i++) { |
| 228 | reg[i].type = REG_S64; |
| 229 | reg[i].v = 0; |
| 230 | reg[i].str = NULL; |
| 231 | reg[i].seq_len = 0; |
| 232 | reg[i].literal = 0; |
| 233 | } |
| 234 | |
| 235 | start_pc = &bytecode->data[0]; |
| 236 | for (pc = next_pc = start_pc; pc - start_pc < bytecode->len; |
| 237 | pc = next_pc) { |
| 238 | if (unlikely(pc >= start_pc + bytecode->len)) { |
| 239 | fprintf(stderr, "[error] filter bytecode overflow\n"); |
| 240 | ret = -EINVAL; |
| 241 | goto end; |
| 242 | } |
| 243 | dbg_printf("Executing op %s (%u)\n", |
| 244 | print_op((unsigned int) *(filter_opcode_t *) pc), |
| 245 | (unsigned int) *(filter_opcode_t *) pc); |
| 246 | switch (*(filter_opcode_t *) pc) { |
| 247 | case FILTER_OP_UNKNOWN: |
| 248 | default: |
| 249 | fprintf(stderr, "[error] unknown bytecode op %u\n", |
| 250 | (unsigned int) *(filter_opcode_t *) pc); |
| 251 | ret = -EINVAL; |
| 252 | goto end; |
| 253 | |
| 254 | case FILTER_OP_RETURN: |
| 255 | retval = !!reg[0].v; |
| 256 | ret = 0; |
| 257 | goto end; |
| 258 | |
| 259 | /* binary */ |
| 260 | case FILTER_OP_MUL: |
| 261 | case FILTER_OP_DIV: |
| 262 | case FILTER_OP_MOD: |
| 263 | case FILTER_OP_PLUS: |
| 264 | case FILTER_OP_MINUS: |
| 265 | case FILTER_OP_RSHIFT: |
| 266 | case FILTER_OP_LSHIFT: |
| 267 | case FILTER_OP_BIN_AND: |
| 268 | case FILTER_OP_BIN_OR: |
| 269 | case FILTER_OP_BIN_XOR: |
| 270 | fprintf(stderr, "[error] unsupported bytecode op %u\n", |
| 271 | (unsigned int) *(filter_opcode_t *) pc); |
| 272 | ret = -EINVAL; |
| 273 | goto end; |
| 274 | |
| 275 | case FILTER_OP_EQ: |
| 276 | { |
| 277 | if (unlikely((reg[REG_R0].type == REG_S64 && reg[REG_R1].type != REG_S64) |
| 278 | || (reg[REG_R0].type != REG_S64 && reg[REG_R1].type == REG_S64))) { |
| 279 | fprintf(stderr, "[error] type mismatch for '==' binary operator\n"); |
| 280 | ret = -EINVAL; |
| 281 | goto end; |
| 282 | } |
| 283 | switch (reg[REG_R0].type) { |
| 284 | default: |
| 285 | fprintf(stderr, "[error] unknown register type\n"); |
| 286 | ret = -EINVAL; |
| 287 | goto end; |
| 288 | |
| 289 | case REG_STRING: |
| 290 | case REG_SEQUENCE: |
| 291 | reg[REG_R0].v = (reg_strcmp(reg, "==") == 0); |
| 292 | break; |
| 293 | case REG_S64: |
| 294 | reg[REG_R0].v = (reg[REG_R0].v == reg[REG_R1].v); |
| 295 | break; |
| 296 | } |
| 297 | reg[REG_R0].type = REG_S64; |
| 298 | next_pc += sizeof(struct binary_op); |
| 299 | break; |
| 300 | } |
| 301 | case FILTER_OP_NE: |
| 302 | { |
| 303 | if (unlikely((reg[REG_R0].type == REG_S64 && reg[REG_R1].type != REG_S64) |
| 304 | || (reg[REG_R0].type != REG_S64 && reg[REG_R1].type == REG_S64))) { |
| 305 | fprintf(stderr, "[error] type mismatch for '!=' binary operator\n"); |
| 306 | ret = -EINVAL; |
| 307 | goto end; |
| 308 | } |
| 309 | switch (reg[REG_R0].type) { |
| 310 | default: |
| 311 | fprintf(stderr, "[error] unknown register type\n"); |
| 312 | ret = -EINVAL; |
| 313 | goto end; |
| 314 | |
| 315 | case REG_STRING: |
| 316 | case REG_SEQUENCE: |
| 317 | reg[REG_R0].v = (reg_strcmp(reg, "!=") != 0); |
| 318 | break; |
| 319 | case REG_S64: |
| 320 | reg[REG_R0].v = (reg[REG_R0].v != reg[REG_R1].v); |
| 321 | break; |
| 322 | } |
| 323 | reg[REG_R0].type = REG_S64; |
| 324 | next_pc += sizeof(struct binary_op); |
| 325 | break; |
| 326 | } |
| 327 | case FILTER_OP_GT: |
| 328 | { |
| 329 | if (unlikely((reg[REG_R0].type == REG_S64 && reg[REG_R1].type != REG_S64) |
| 330 | || (reg[REG_R0].type != REG_S64 && reg[REG_R1].type == REG_S64))) { |
| 331 | fprintf(stderr, "[error] type mismatch for '>' binary operator\n"); |
| 332 | ret = -EINVAL; |
| 333 | goto end; |
| 334 | } |
| 335 | switch (reg[REG_R0].type) { |
| 336 | default: |
| 337 | fprintf(stderr, "[error] unknown register type\n"); |
| 338 | ret = -EINVAL; |
| 339 | goto end; |
| 340 | |
| 341 | case REG_STRING: |
| 342 | case REG_SEQUENCE: |
| 343 | reg[REG_R0].v = (reg_strcmp(reg, ">") > 0); |
| 344 | break; |
| 345 | case REG_S64: |
| 346 | reg[REG_R0].v = (reg[REG_R0].v > reg[REG_R1].v); |
| 347 | break; |
| 348 | } |
| 349 | reg[REG_R0].type = REG_S64; |
| 350 | next_pc += sizeof(struct binary_op); |
| 351 | break; |
| 352 | } |
| 353 | case FILTER_OP_LT: |
| 354 | { |
| 355 | if (unlikely((reg[REG_R0].type == REG_S64 && reg[REG_R1].type != REG_S64) |
| 356 | || (reg[REG_R0].type != REG_S64 && reg[REG_R1].type == REG_S64))) { |
| 357 | fprintf(stderr, "[error] type mismatch for '<' binary operator\n"); |
| 358 | ret = -EINVAL; |
| 359 | goto end; |
| 360 | } |
| 361 | switch (reg[REG_R0].type) { |
| 362 | default: |
| 363 | fprintf(stderr, "[error] unknown register type\n"); |
| 364 | ret = -EINVAL; |
| 365 | goto end; |
| 366 | |
| 367 | case REG_STRING: |
| 368 | case REG_SEQUENCE: |
| 369 | reg[REG_R0].v = (reg_strcmp(reg, "<") < 0); |
| 370 | break; |
| 371 | case REG_S64: |
| 372 | reg[REG_R0].v = (reg[REG_R0].v < reg[REG_R1].v); |
| 373 | break; |
| 374 | } |
| 375 | reg[REG_R0].type = REG_S64; |
| 376 | next_pc += sizeof(struct binary_op); |
| 377 | break; |
| 378 | } |
| 379 | case FILTER_OP_GE: |
| 380 | { |
| 381 | if (unlikely((reg[REG_R0].type == REG_S64 && reg[REG_R1].type != REG_S64) |
| 382 | || (reg[REG_R0].type != REG_S64 && reg[REG_R1].type == REG_S64))) { |
| 383 | fprintf(stderr, "[error] type mismatch for '>=' binary operator\n"); |
| 384 | ret = -EINVAL; |
| 385 | goto end; |
| 386 | } |
| 387 | switch (reg[REG_R0].type) { |
| 388 | default: |
| 389 | fprintf(stderr, "[error] unknown register type\n"); |
| 390 | ret = -EINVAL; |
| 391 | goto end; |
| 392 | |
| 393 | case REG_STRING: |
| 394 | case REG_SEQUENCE: |
| 395 | reg[REG_R0].v = (reg_strcmp(reg, ">=") >= 0); |
| 396 | break; |
| 397 | case REG_S64: |
| 398 | reg[REG_R0].v = (reg[REG_R0].v >= reg[REG_R1].v); |
| 399 | break; |
| 400 | } |
| 401 | reg[REG_R0].type = REG_S64; |
| 402 | next_pc += sizeof(struct binary_op); |
| 403 | break; |
| 404 | } |
| 405 | case FILTER_OP_LE: |
| 406 | { |
| 407 | if (unlikely((reg[REG_R0].type == REG_S64 && reg[REG_R1].type != REG_S64) |
| 408 | || (reg[REG_R0].type != REG_S64 && reg[REG_R1].type == REG_S64))) { |
| 409 | fprintf(stderr, "[error] type mismatch for '<=' binary operator\n"); |
| 410 | ret = -EINVAL; |
| 411 | goto end; |
| 412 | } |
| 413 | switch (reg[REG_R0].type) { |
| 414 | default: |
| 415 | fprintf(stderr, "[error] unknown register type\n"); |
| 416 | ret = -EINVAL; |
| 417 | goto end; |
| 418 | |
| 419 | case REG_STRING: |
| 420 | case REG_SEQUENCE: |
| 421 | reg[REG_R0].v = (reg_strcmp(reg, "<=") <= 0); |
| 422 | break; |
| 423 | case REG_S64: |
| 424 | reg[REG_R0].v = (reg[REG_R0].v <= reg[REG_R1].v); |
| 425 | break; |
| 426 | } |
| 427 | reg[REG_R0].type = REG_S64; |
| 428 | next_pc += sizeof(struct binary_op); |
| 429 | break; |
| 430 | } |
| 431 | |
| 432 | /* unary */ |
| 433 | case FILTER_OP_UNARY_PLUS: |
| 434 | { |
| 435 | struct unary_op *insn = (struct unary_op *) pc; |
| 436 | |
| 437 | if (unlikely(insn->reg >= REG_ERROR)) { |
| 438 | fprintf(stderr, "[error] invalid register %u\n", |
| 439 | (unsigned int) insn->reg); |
| 440 | ret = -EINVAL; |
| 441 | goto end; |
| 442 | } |
| 443 | if (unlikely(reg[insn->reg].type != REG_S64)) { |
| 444 | fprintf(stderr, "[error] Unary plus can only be applied to numeric register\n"); |
| 445 | ret = -EINVAL; |
| 446 | goto end; |
| 447 | } |
| 448 | next_pc += sizeof(struct unary_op); |
| 449 | break; |
| 450 | } |
| 451 | case FILTER_OP_UNARY_MINUS: |
| 452 | { |
| 453 | struct unary_op *insn = (struct unary_op *) pc; |
| 454 | |
| 455 | if (unlikely(insn->reg >= REG_ERROR)) { |
| 456 | fprintf(stderr, "[error] invalid register %u\n", |
| 457 | (unsigned int) insn->reg); |
| 458 | ret = -EINVAL; |
| 459 | goto end; |
| 460 | } |
| 461 | if (unlikely(reg[insn->reg].type != REG_S64)) { |
| 462 | fprintf(stderr, "[error] Unary minus can only be applied to numeric register\n"); |
| 463 | ret = -EINVAL; |
| 464 | goto end; |
| 465 | } |
| 466 | reg[insn->reg].v = -reg[insn->reg].v; |
| 467 | next_pc += sizeof(struct unary_op); |
| 468 | break; |
| 469 | } |
| 470 | case FILTER_OP_UNARY_NOT: |
| 471 | { |
| 472 | struct unary_op *insn = (struct unary_op *) pc; |
| 473 | |
| 474 | if (unlikely(insn->reg >= REG_ERROR)) { |
| 475 | fprintf(stderr, "[error] invalid register %u\n", |
| 476 | (unsigned int) insn->reg); |
| 477 | ret = -EINVAL; |
| 478 | goto end; |
| 479 | } |
| 480 | if (unlikely(reg[insn->reg].type != REG_S64)) { |
| 481 | fprintf(stderr, "[error] Unary not can only be applied to numeric register\n"); |
| 482 | ret = -EINVAL; |
| 483 | goto end; |
| 484 | } |
| 485 | reg[insn->reg].v = !reg[insn->reg].v; |
| 486 | next_pc += sizeof(struct unary_op); |
| 487 | break; |
| 488 | } |
| 489 | /* logical */ |
| 490 | case FILTER_OP_AND: |
| 491 | { |
| 492 | struct logical_op *insn = (struct logical_op *) pc; |
| 493 | |
| 494 | if (unlikely(reg[REG_R0].type != REG_S64)) { |
| 495 | fprintf(stderr, "[error] Logical operator 'and' can only be applied to numeric register\n"); |
| 496 | ret = -EINVAL; |
| 497 | goto end; |
| 498 | } |
| 499 | |
| 500 | /* If REG_R0 is 0, skip and evaluate to 0 */ |
| 501 | if (reg[REG_R0].v == 0) { |
| 502 | dbg_printf("Jumping to bytecode offset %u\n", |
| 503 | (unsigned int) insn->skip_offset); |
| 504 | next_pc = start_pc + insn->skip_offset; |
| 505 | if (unlikely(next_pc <= pc)) { |
| 506 | fprintf(stderr, "[error] Loops are not allowed in bytecode\n"); |
| 507 | ret = -EINVAL; |
| 508 | goto end; |
| 509 | } |
| 510 | } else { |
| 511 | next_pc += sizeof(struct logical_op); |
| 512 | } |
| 513 | break; |
| 514 | } |
| 515 | case FILTER_OP_OR: |
| 516 | { |
| 517 | struct logical_op *insn = (struct logical_op *) pc; |
| 518 | |
| 519 | if (unlikely(reg[REG_R0].type != REG_S64)) { |
| 520 | fprintf(stderr, "[error] Logical operator 'and' can only be applied to numeric register\n"); |
| 521 | ret = -EINVAL; |
| 522 | goto end; |
| 523 | } |
| 524 | |
| 525 | /* If REG_R0 is nonzero, skip and evaluate to 1 */ |
| 526 | if (reg[REG_R0].v != 0) { |
| 527 | reg[REG_R0].v = 1; |
| 528 | dbg_printf("Jumping to bytecode offset %u\n", |
| 529 | (unsigned int) insn->skip_offset); |
| 530 | next_pc = start_pc + insn->skip_offset; |
| 531 | if (unlikely(next_pc <= pc)) { |
| 532 | fprintf(stderr, "[error] Loops are not allowed in bytecode\n"); |
| 533 | ret = -EINVAL; |
| 534 | goto end; |
| 535 | } |
| 536 | } else { |
| 537 | next_pc += sizeof(struct logical_op); |
| 538 | } |
| 539 | break; |
| 540 | } |
| 541 | |
| 542 | /* load */ |
| 543 | case FILTER_OP_LOAD_FIELD_REF: |
| 544 | { |
| 545 | struct load_op *insn = (struct load_op *) pc; |
| 546 | struct field_ref *ref = (struct field_ref *) insn->data; |
| 547 | |
| 548 | if (unlikely(insn->reg >= REG_ERROR)) { |
| 549 | fprintf(stderr, "[error] invalid register %u\n", |
| 550 | (unsigned int) insn->reg); |
| 551 | ret = -EINVAL; |
| 552 | goto end; |
| 553 | } |
| 554 | dbg_printf("load field ref offset %u type %u\n", |
| 555 | ref->offset, ref->type); |
| 556 | switch (ref->type) { |
| 557 | case FIELD_REF_UNKNOWN: |
| 558 | default: |
| 559 | fprintf(stderr, "[error] unknown field ref type\n"); |
| 560 | ret = -EINVAL; |
| 561 | goto end; |
| 562 | |
| 563 | case FIELD_REF_STRING: |
| 564 | reg[insn->reg].str = |
| 565 | *(const char * const *) &filter_stack_data[ref->offset]; |
| 566 | reg[insn->reg].type = REG_STRING; |
| 567 | reg[insn->reg].seq_len = UINT_MAX; |
| 568 | reg[insn->reg].literal = 0; |
| 569 | dbg_printf("ref load string %s\n", reg[insn->reg].str); |
| 570 | break; |
| 571 | case FIELD_REF_SEQUENCE: |
| 572 | reg[insn->reg].seq_len = |
| 573 | *(unsigned long *) &filter_stack_data[ref->offset]; |
| 574 | reg[insn->reg].str = |
| 575 | *(const char **) (&filter_stack_data[ref->offset |
| 576 | + sizeof(unsigned long)]); |
| 577 | reg[insn->reg].type = REG_SEQUENCE; |
| 578 | reg[insn->reg].literal = 0; |
| 579 | break; |
| 580 | case FIELD_REF_S64: |
| 581 | memcpy(®[insn->reg].v, &filter_stack_data[ref->offset], |
| 582 | sizeof(struct literal_numeric)); |
| 583 | reg[insn->reg].type = REG_S64; |
| 584 | reg[insn->reg].literal = 0; |
| 585 | dbg_printf("ref load s64 %" PRIi64 "\n", reg[insn->reg].v); |
| 586 | break; |
| 587 | } |
| 588 | |
| 589 | next_pc += sizeof(struct load_op) + sizeof(struct field_ref); |
| 590 | break; |
| 591 | } |
| 592 | |
| 593 | case FILTER_OP_LOAD_STRING: |
| 594 | { |
| 595 | struct load_op *insn = (struct load_op *) pc; |
| 596 | |
| 597 | if (unlikely(insn->reg >= REG_ERROR)) { |
| 598 | fprintf(stderr, "[error] invalid register %u\n", |
| 599 | (unsigned int) insn->reg); |
| 600 | ret = -EINVAL; |
| 601 | goto end; |
| 602 | } |
| 603 | dbg_printf("load string %s\n", insn->data); |
| 604 | reg[insn->reg].str = insn->data; |
| 605 | reg[insn->reg].type = REG_STRING; |
| 606 | reg[insn->reg].seq_len = UINT_MAX; |
| 607 | reg[insn->reg].literal = 1; |
| 608 | next_pc += sizeof(struct load_op) + strlen(insn->data) + 1; |
| 609 | break; |
| 610 | } |
| 611 | |
| 612 | case FILTER_OP_LOAD_S64: |
| 613 | { |
| 614 | struct load_op *insn = (struct load_op *) pc; |
| 615 | |
| 616 | if (unlikely(insn->reg >= REG_ERROR)) { |
| 617 | fprintf(stderr, "[error] invalid register %u\n", |
| 618 | (unsigned int) insn->reg); |
| 619 | ret = -EINVAL; |
| 620 | goto end; |
| 621 | } |
| 622 | memcpy(®[insn->reg].v, insn->data, |
| 623 | sizeof(struct literal_numeric)); |
| 624 | dbg_printf("load s64 %" PRIi64 "\n", reg[insn->reg].v); |
| 625 | reg[insn->reg].type = REG_S64; |
| 626 | next_pc += sizeof(struct load_op) |
| 627 | + sizeof(struct literal_numeric); |
| 628 | break; |
| 629 | } |
| 630 | } |
| 631 | } |
| 632 | end: |
| 633 | /* return 0 (discard) on error */ |
| 634 | if (ret) |
| 635 | return 0; |
| 636 | return retval; |
| 637 | } |
| 638 | |
| 639 | static |
| 640 | int apply_field_reloc(struct ltt_event *event, |
| 641 | struct bytecode_runtime *runtime, |
| 642 | uint32_t runtime_len, |
| 643 | uint32_t reloc_offset, |
| 644 | const char *field_name) |
| 645 | { |
| 646 | const struct lttng_event_desc *desc; |
| 647 | const struct lttng_event_field *fields, *field = NULL; |
| 648 | unsigned int nr_fields, i; |
| 649 | struct field_ref *field_ref; |
| 650 | uint32_t field_offset = 0; |
| 651 | |
| 652 | fprintf(stderr, "Apply reloc: %u %s\n", reloc_offset, field_name); |
| 653 | |
| 654 | /* Ensure that the reloc is within the code */ |
| 655 | if (runtime_len - reloc_offset < sizeof(uint16_t)) |
| 656 | return -EINVAL; |
| 657 | |
| 658 | /* Lookup event by name */ |
| 659 | desc = event->desc; |
| 660 | if (!desc) |
| 661 | return -EINVAL; |
| 662 | fields = desc->fields; |
| 663 | if (!fields) |
| 664 | return -EINVAL; |
| 665 | nr_fields = desc->nr_fields; |
| 666 | for (i = 0; i < nr_fields; i++) { |
| 667 | if (!strcmp(fields[i].name, field_name)) { |
| 668 | field = &fields[i]; |
| 669 | break; |
| 670 | } |
| 671 | /* compute field offset */ |
| 672 | switch (fields[i].type.atype) { |
| 673 | case atype_integer: |
| 674 | case atype_enum: |
| 675 | field_offset += sizeof(int64_t); |
| 676 | break; |
| 677 | case atype_array: |
| 678 | case atype_sequence: |
| 679 | field_offset += sizeof(unsigned long); |
| 680 | field_offset += sizeof(void *); |
| 681 | break; |
| 682 | case atype_string: |
| 683 | field_offset += sizeof(void *); |
| 684 | break; |
| 685 | case atype_float: |
| 686 | field_offset += sizeof(double); |
| 687 | default: |
| 688 | return -EINVAL; |
| 689 | } |
| 690 | } |
| 691 | if (!field) |
| 692 | return -EINVAL; |
| 693 | |
| 694 | /* Check if field offset is too large for 16-bit offset */ |
| 695 | if (field_offset > FILTER_BYTECODE_MAX_LEN) |
| 696 | return -EINVAL; |
| 697 | |
| 698 | /* set type */ |
| 699 | field_ref = (struct field_ref *) &runtime->data[reloc_offset]; |
| 700 | switch (field->type.atype) { |
| 701 | case atype_integer: |
| 702 | case atype_enum: |
| 703 | field_ref->type = FIELD_REF_S64; |
| 704 | field_ref->type = FIELD_REF_S64; |
| 705 | break; |
| 706 | case atype_array: |
| 707 | case atype_sequence: |
| 708 | field_ref->type = FIELD_REF_SEQUENCE; |
| 709 | break; |
| 710 | case atype_string: |
| 711 | field_ref->type = FIELD_REF_STRING; |
| 712 | break; |
| 713 | case atype_float: |
| 714 | return -EINVAL; |
| 715 | default: |
| 716 | return -EINVAL; |
| 717 | } |
| 718 | /* set offset */ |
| 719 | field_ref->offset = (uint16_t) field_offset; |
| 720 | return 0; |
| 721 | } |
| 722 | |
| 723 | /* |
| 724 | * Take a bytecode with reloc table and link it to an event to create a |
| 725 | * bytecode runtime. |
| 726 | */ |
| 727 | static |
| 728 | int _lttng_filter_event_link_bytecode(struct ltt_event *event, |
| 729 | struct lttng_ust_filter_bytecode *filter_bytecode) |
| 730 | { |
| 731 | int ret, offset, next_offset; |
| 732 | struct bytecode_runtime *runtime = NULL; |
| 733 | size_t runtime_alloc_len; |
| 734 | |
| 735 | if (!filter_bytecode) |
| 736 | return 0; |
| 737 | /* Even is not connected to any description */ |
| 738 | if (!event->desc) |
| 739 | return 0; |
| 740 | /* Bytecode already linked */ |
| 741 | if (event->filter || event->filter_data) |
| 742 | return 0; |
| 743 | |
| 744 | fprintf(stderr, "Linking\n"); |
| 745 | |
| 746 | /* We don't need the reloc table in the runtime */ |
| 747 | runtime_alloc_len = sizeof(*runtime) + filter_bytecode->reloc_offset; |
| 748 | runtime = zmalloc(runtime_alloc_len); |
| 749 | if (!runtime) { |
| 750 | ret = -ENOMEM; |
| 751 | goto link_error; |
| 752 | } |
| 753 | runtime->len = filter_bytecode->reloc_offset; |
| 754 | /* copy original bytecode */ |
| 755 | memcpy(runtime->data, filter_bytecode->data, runtime->len); |
| 756 | /* |
| 757 | * apply relocs. Those are a uint16_t (offset in bytecode) |
| 758 | * followed by a string (field name). |
| 759 | */ |
| 760 | fprintf(stderr, "iter for %d %d\n", filter_bytecode->reloc_offset, filter_bytecode->len); |
| 761 | for (offset = filter_bytecode->reloc_offset; |
| 762 | offset < filter_bytecode->len; |
| 763 | offset = next_offset) { |
| 764 | uint16_t reloc_offset = |
| 765 | *(uint16_t *) &filter_bytecode->data[offset]; |
| 766 | const char *field_name = |
| 767 | (const char *) &filter_bytecode->data[offset + sizeof(uint16_t)]; |
| 768 | |
| 769 | ret = apply_field_reloc(event, runtime, runtime->len, reloc_offset, field_name); |
| 770 | if (ret) { |
| 771 | goto link_error; |
| 772 | } |
| 773 | next_offset = offset + sizeof(uint16_t) + strlen(field_name) + 1; |
| 774 | } |
| 775 | event->filter_data = runtime; |
| 776 | event->filter = lttng_filter_interpret_bytecode; |
| 777 | return 0; |
| 778 | |
| 779 | link_error: |
| 780 | event->filter = lttng_filter_false; |
| 781 | free(runtime); |
| 782 | return ret; |
| 783 | } |
| 784 | |
| 785 | void lttng_filter_event_link_bytecode(struct ltt_event *event, |
| 786 | struct lttng_ust_filter_bytecode *filter_bytecode) |
| 787 | { |
| 788 | int ret; |
| 789 | |
| 790 | ret = _lttng_filter_event_link_bytecode(event, filter_bytecode); |
| 791 | if (ret) { |
| 792 | fprintf(stderr, "[lttng filter] error linking event bytecode\n"); |
| 793 | } |
| 794 | } |
| 795 | |
| 796 | /* |
| 797 | * Link bytecode to all events for a wildcard. Skips events that already |
| 798 | * have a bytecode linked. |
| 799 | * We do not set each event's filter_bytecode field, because they do not |
| 800 | * own the filter_bytecode: the wildcard owns it. |
| 801 | */ |
| 802 | void lttng_filter_wildcard_link_bytecode(struct session_wildcard *wildcard) |
| 803 | { |
| 804 | struct ltt_event *event; |
| 805 | int ret; |
| 806 | |
| 807 | if (!wildcard->filter_bytecode) |
| 808 | return; |
| 809 | |
| 810 | cds_list_for_each_entry(event, &wildcard->events, wildcard_list) { |
| 811 | if (event->filter) |
| 812 | continue; |
| 813 | ret = _lttng_filter_event_link_bytecode(event, |
| 814 | wildcard->filter_bytecode); |
| 815 | if (ret) { |
| 816 | fprintf(stderr, "[lttng filter] error linking wildcard bytecode\n"); |
| 817 | } |
| 818 | |
| 819 | } |
| 820 | return; |
| 821 | } |
| 822 | |
| 823 | /* |
| 824 | * Need to attach filter to an event before starting tracing for the |
| 825 | * session. We own the filter_bytecode if we return success. |
| 826 | */ |
| 827 | int lttng_filter_event_attach_bytecode(struct ltt_event *event, |
| 828 | struct lttng_ust_filter_bytecode *filter_bytecode) |
| 829 | { |
| 830 | if (event->chan->session->been_active) |
| 831 | return -EPERM; |
| 832 | if (event->filter_bytecode) |
| 833 | return -EEXIST; |
| 834 | event->filter_bytecode = filter_bytecode; |
| 835 | return 0; |
| 836 | } |
| 837 | |
| 838 | /* |
| 839 | * Need to attach filter to a wildcard before starting tracing for the |
| 840 | * session. We own the filter_bytecode if we return success. |
| 841 | */ |
| 842 | int lttng_filter_wildcard_attach_bytecode(struct session_wildcard *wildcard, |
| 843 | struct lttng_ust_filter_bytecode *filter_bytecode) |
| 844 | { |
| 845 | if (wildcard->chan->session->been_active) |
| 846 | return -EPERM; |
| 847 | if (wildcard->filter_bytecode) |
| 848 | return -EEXIST; |
| 849 | wildcard->filter_bytecode = filter_bytecode; |
| 850 | return 0; |
| 851 | } |