1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Common code for probe-based Dynamic events. 4 * 5 * This code was copied from kernel/trace/trace_kprobe.c written by 6 * Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> 7 * 8 * Updates to make this generic: 9 * Copyright (C) IBM Corporation, 2010-2011 10 * Author: Srikar Dronamraju 11 */ 12 #define pr_fmt(fmt) "trace_probe: " fmt 13 14 #include "trace_probe.h" 15 16 #undef C 17 #define C(a, b) b 18 19 static const char *trace_probe_err_text[] = { ERRORS }; 20 21 static const char *reserved_field_names[] = { 22 "common_type", 23 "common_flags", 24 "common_preempt_count", 25 "common_pid", 26 "common_tgid", 27 FIELD_STRING_IP, 28 FIELD_STRING_RETIP, 29 FIELD_STRING_FUNC, 30 }; 31 32 /* Printing in basic type function template */ 33 #define DEFINE_BASIC_PRINT_TYPE_FUNC(tname, type, fmt) \ 34 int PRINT_TYPE_FUNC_NAME(tname)(struct trace_seq *s, void *data, void *ent)\ 35 { \ 36 trace_seq_printf(s, fmt, *(type *)data); \ 37 return !trace_seq_has_overflowed(s); \ 38 } \ 39 const char PRINT_TYPE_FMT_NAME(tname)[] = fmt; 40 41 DEFINE_BASIC_PRINT_TYPE_FUNC(u8, u8, "%u") 42 DEFINE_BASIC_PRINT_TYPE_FUNC(u16, u16, "%u") 43 DEFINE_BASIC_PRINT_TYPE_FUNC(u32, u32, "%u") 44 DEFINE_BASIC_PRINT_TYPE_FUNC(u64, u64, "%Lu") 45 DEFINE_BASIC_PRINT_TYPE_FUNC(s8, s8, "%d") 46 DEFINE_BASIC_PRINT_TYPE_FUNC(s16, s16, "%d") 47 DEFINE_BASIC_PRINT_TYPE_FUNC(s32, s32, "%d") 48 DEFINE_BASIC_PRINT_TYPE_FUNC(s64, s64, "%Ld") 49 DEFINE_BASIC_PRINT_TYPE_FUNC(x8, u8, "0x%x") 50 DEFINE_BASIC_PRINT_TYPE_FUNC(x16, u16, "0x%x") 51 DEFINE_BASIC_PRINT_TYPE_FUNC(x32, u32, "0x%x") 52 DEFINE_BASIC_PRINT_TYPE_FUNC(x64, u64, "0x%Lx") 53 54 int PRINT_TYPE_FUNC_NAME(symbol)(struct trace_seq *s, void *data, void *ent) 55 { 56 trace_seq_printf(s, "%pS", (void *)*(unsigned long *)data); 57 return !trace_seq_has_overflowed(s); 58 } 59 const char PRINT_TYPE_FMT_NAME(symbol)[] = "%pS"; 60 61 /* Print type function for string type */ 62 int PRINT_TYPE_FUNC_NAME(string)(struct trace_seq *s, void *data, void *ent) 63 { 64 int len = *(u32 *)data >> 16; 65 66 if (!len) 67 trace_seq_puts(s, "(fault)"); 68 else 69 trace_seq_printf(s, "\"%s\"", 70 (const char *)get_loc_data(data, ent)); 71 return !trace_seq_has_overflowed(s); 72 } 73 74 const char PRINT_TYPE_FMT_NAME(string)[] = "\\\"%s\\\""; 75 76 /* Fetch type information table */ 77 static const struct fetch_type probe_fetch_types[] = { 78 /* Special types */ 79 __ASSIGN_FETCH_TYPE("string", string, string, sizeof(u32), 1, 80 "__data_loc char[]"), 81 __ASSIGN_FETCH_TYPE("ustring", string, string, sizeof(u32), 1, 82 "__data_loc char[]"), 83 /* Basic types */ 84 ASSIGN_FETCH_TYPE(u8, u8, 0), 85 ASSIGN_FETCH_TYPE(u16, u16, 0), 86 ASSIGN_FETCH_TYPE(u32, u32, 0), 87 ASSIGN_FETCH_TYPE(u64, u64, 0), 88 ASSIGN_FETCH_TYPE(s8, u8, 1), 89 ASSIGN_FETCH_TYPE(s16, u16, 1), 90 ASSIGN_FETCH_TYPE(s32, u32, 1), 91 ASSIGN_FETCH_TYPE(s64, u64, 1), 92 ASSIGN_FETCH_TYPE_ALIAS(x8, u8, u8, 0), 93 ASSIGN_FETCH_TYPE_ALIAS(x16, u16, u16, 0), 94 ASSIGN_FETCH_TYPE_ALIAS(x32, u32, u32, 0), 95 ASSIGN_FETCH_TYPE_ALIAS(x64, u64, u64, 0), 96 ASSIGN_FETCH_TYPE_ALIAS(symbol, ADDR_FETCH_TYPE, ADDR_FETCH_TYPE, 0), 97 98 ASSIGN_FETCH_TYPE_END 99 }; 100 101 static const struct fetch_type *find_fetch_type(const char *type) 102 { 103 int i; 104 105 if (!type) 106 type = DEFAULT_FETCH_TYPE_STR; 107 108 /* Special case: bitfield */ 109 if (*type == 'b') { 110 unsigned long bs; 111 112 type = strchr(type, '/'); 113 if (!type) 114 goto fail; 115 116 type++; 117 if (kstrtoul(type, 0, &bs)) 118 goto fail; 119 120 switch (bs) { 121 case 8: 122 return find_fetch_type("u8"); 123 case 16: 124 return find_fetch_type("u16"); 125 case 32: 126 return find_fetch_type("u32"); 127 case 64: 128 return find_fetch_type("u64"); 129 default: 130 goto fail; 131 } 132 } 133 134 for (i = 0; probe_fetch_types[i].name; i++) { 135 if (strcmp(type, probe_fetch_types[i].name) == 0) 136 return &probe_fetch_types[i]; 137 } 138 139 fail: 140 return NULL; 141 } 142 143 static struct trace_probe_log trace_probe_log; 144 145 void trace_probe_log_init(const char *subsystem, int argc, const char **argv) 146 { 147 trace_probe_log.subsystem = subsystem; 148 trace_probe_log.argc = argc; 149 trace_probe_log.argv = argv; 150 trace_probe_log.index = 0; 151 } 152 153 void trace_probe_log_clear(void) 154 { 155 memset(&trace_probe_log, 0, sizeof(trace_probe_log)); 156 } 157 158 void trace_probe_log_set_index(int index) 159 { 160 trace_probe_log.index = index; 161 } 162 163 void __trace_probe_log_err(int offset, int err_type) 164 { 165 char *command, *p; 166 int i, len = 0, pos = 0; 167 168 if (!trace_probe_log.argv) 169 return; 170 171 /* Recalcurate the length and allocate buffer */ 172 for (i = 0; i < trace_probe_log.argc; i++) { 173 if (i == trace_probe_log.index) 174 pos = len; 175 len += strlen(trace_probe_log.argv[i]) + 1; 176 } 177 command = kzalloc(len, GFP_KERNEL); 178 if (!command) 179 return; 180 181 if (trace_probe_log.index >= trace_probe_log.argc) { 182 /** 183 * Set the error position is next to the last arg + space. 184 * Note that len includes the terminal null and the cursor 185 * appaers at pos + 1. 186 */ 187 pos = len; 188 offset = 0; 189 } 190 191 /* And make a command string from argv array */ 192 p = command; 193 for (i = 0; i < trace_probe_log.argc; i++) { 194 len = strlen(trace_probe_log.argv[i]); 195 strcpy(p, trace_probe_log.argv[i]); 196 p[len] = ' '; 197 p += len + 1; 198 } 199 *(p - 1) = '\0'; 200 201 tracing_log_err(NULL, trace_probe_log.subsystem, command, 202 trace_probe_err_text, err_type, pos + offset); 203 204 kfree(command); 205 } 206 207 /* Split symbol and offset. */ 208 int traceprobe_split_symbol_offset(char *symbol, long *offset) 209 { 210 char *tmp; 211 int ret; 212 213 if (!offset) 214 return -EINVAL; 215 216 tmp = strpbrk(symbol, "+-"); 217 if (tmp) { 218 ret = kstrtol(tmp, 0, offset); 219 if (ret) 220 return ret; 221 *tmp = '\0'; 222 } else 223 *offset = 0; 224 225 return 0; 226 } 227 228 /* @buf must has MAX_EVENT_NAME_LEN size */ 229 int traceprobe_parse_event_name(const char **pevent, const char **pgroup, 230 char *buf, int offset) 231 { 232 const char *slash, *event = *pevent; 233 int len; 234 235 slash = strchr(event, '/'); 236 if (slash) { 237 if (slash == event) { 238 trace_probe_log_err(offset, NO_GROUP_NAME); 239 return -EINVAL; 240 } 241 if (slash - event + 1 > MAX_EVENT_NAME_LEN) { 242 trace_probe_log_err(offset, GROUP_TOO_LONG); 243 return -EINVAL; 244 } 245 strlcpy(buf, event, slash - event + 1); 246 if (!is_good_name(buf)) { 247 trace_probe_log_err(offset, BAD_GROUP_NAME); 248 return -EINVAL; 249 } 250 *pgroup = buf; 251 *pevent = slash + 1; 252 offset += slash - event + 1; 253 event = *pevent; 254 } 255 len = strlen(event); 256 if (len == 0) { 257 trace_probe_log_err(offset, NO_EVENT_NAME); 258 return -EINVAL; 259 } else if (len > MAX_EVENT_NAME_LEN) { 260 trace_probe_log_err(offset, EVENT_TOO_LONG); 261 return -EINVAL; 262 } 263 if (!is_good_name(event)) { 264 trace_probe_log_err(offset, BAD_EVENT_NAME); 265 return -EINVAL; 266 } 267 return 0; 268 } 269 270 #define PARAM_MAX_STACK (THREAD_SIZE / sizeof(unsigned long)) 271 272 static int parse_probe_vars(char *arg, const struct fetch_type *t, 273 struct fetch_insn *code, unsigned int flags, int offs) 274 { 275 unsigned long param; 276 int ret = 0; 277 int len; 278 279 if (strcmp(arg, "retval") == 0) { 280 if (flags & TPARG_FL_RETURN) { 281 code->op = FETCH_OP_RETVAL; 282 } else { 283 trace_probe_log_err(offs, RETVAL_ON_PROBE); 284 ret = -EINVAL; 285 } 286 } else if ((len = str_has_prefix(arg, "stack"))) { 287 if (arg[len] == '\0') { 288 code->op = FETCH_OP_STACKP; 289 } else if (isdigit(arg[len])) { 290 ret = kstrtoul(arg + len, 10, ¶m); 291 if (ret) { 292 goto inval_var; 293 } else if ((flags & TPARG_FL_KERNEL) && 294 param > PARAM_MAX_STACK) { 295 trace_probe_log_err(offs, BAD_STACK_NUM); 296 ret = -EINVAL; 297 } else { 298 code->op = FETCH_OP_STACK; 299 code->param = (unsigned int)param; 300 } 301 } else 302 goto inval_var; 303 } else if (strcmp(arg, "comm") == 0) { 304 code->op = FETCH_OP_COMM; 305 #ifdef CONFIG_HAVE_FUNCTION_ARG_ACCESS_API 306 } else if (((flags & TPARG_FL_MASK) == 307 (TPARG_FL_KERNEL | TPARG_FL_FENTRY)) && 308 (len = str_has_prefix(arg, "arg"))) { 309 ret = kstrtoul(arg + len, 10, ¶m); 310 if (ret) { 311 goto inval_var; 312 } else if (!param || param > PARAM_MAX_STACK) { 313 trace_probe_log_err(offs, BAD_ARG_NUM); 314 return -EINVAL; 315 } 316 code->op = FETCH_OP_ARG; 317 code->param = (unsigned int)param - 1; 318 #endif 319 } else 320 goto inval_var; 321 322 return ret; 323 324 inval_var: 325 trace_probe_log_err(offs, BAD_VAR); 326 return -EINVAL; 327 } 328 329 static int str_to_immediate(char *str, unsigned long *imm) 330 { 331 if (isdigit(str[0])) 332 return kstrtoul(str, 0, imm); 333 else if (str[0] == '-') 334 return kstrtol(str, 0, (long *)imm); 335 else if (str[0] == '+') 336 return kstrtol(str + 1, 0, (long *)imm); 337 return -EINVAL; 338 } 339 340 static int __parse_imm_string(char *str, char **pbuf, int offs) 341 { 342 size_t len = strlen(str); 343 344 if (str[len - 1] != '"') { 345 trace_probe_log_err(offs + len, IMMSTR_NO_CLOSE); 346 return -EINVAL; 347 } 348 *pbuf = kstrndup(str, len - 1, GFP_KERNEL); 349 return 0; 350 } 351 352 /* Recursive argument parser */ 353 static int 354 parse_probe_arg(char *arg, const struct fetch_type *type, 355 struct fetch_insn **pcode, struct fetch_insn *end, 356 unsigned int flags, int offs) 357 { 358 struct fetch_insn *code = *pcode; 359 unsigned long param; 360 int deref = FETCH_OP_DEREF; 361 long offset = 0; 362 char *tmp; 363 int ret = 0; 364 365 switch (arg[0]) { 366 case '$': 367 ret = parse_probe_vars(arg + 1, type, code, flags, offs); 368 break; 369 370 case '%': /* named register */ 371 ret = regs_query_register_offset(arg + 1); 372 if (ret >= 0) { 373 code->op = FETCH_OP_REG; 374 code->param = (unsigned int)ret; 375 ret = 0; 376 } else 377 trace_probe_log_err(offs, BAD_REG_NAME); 378 break; 379 380 case '@': /* memory, file-offset or symbol */ 381 if (isdigit(arg[1])) { 382 ret = kstrtoul(arg + 1, 0, ¶m); 383 if (ret) { 384 trace_probe_log_err(offs, BAD_MEM_ADDR); 385 break; 386 } 387 /* load address */ 388 code->op = FETCH_OP_IMM; 389 code->immediate = param; 390 } else if (arg[1] == '+') { 391 /* kprobes don't support file offsets */ 392 if (flags & TPARG_FL_KERNEL) { 393 trace_probe_log_err(offs, FILE_ON_KPROBE); 394 return -EINVAL; 395 } 396 ret = kstrtol(arg + 2, 0, &offset); 397 if (ret) { 398 trace_probe_log_err(offs, BAD_FILE_OFFS); 399 break; 400 } 401 402 code->op = FETCH_OP_FOFFS; 403 code->immediate = (unsigned long)offset; // imm64? 404 } else { 405 /* uprobes don't support symbols */ 406 if (!(flags & TPARG_FL_KERNEL)) { 407 trace_probe_log_err(offs, SYM_ON_UPROBE); 408 return -EINVAL; 409 } 410 /* Preserve symbol for updating */ 411 code->op = FETCH_NOP_SYMBOL; 412 code->data = kstrdup(arg + 1, GFP_KERNEL); 413 if (!code->data) 414 return -ENOMEM; 415 if (++code == end) { 416 trace_probe_log_err(offs, TOO_MANY_OPS); 417 return -EINVAL; 418 } 419 code->op = FETCH_OP_IMM; 420 code->immediate = 0; 421 } 422 /* These are fetching from memory */ 423 if (++code == end) { 424 trace_probe_log_err(offs, TOO_MANY_OPS); 425 return -EINVAL; 426 } 427 *pcode = code; 428 code->op = FETCH_OP_DEREF; 429 code->offset = offset; 430 break; 431 432 case '+': /* deref memory */ 433 case '-': 434 if (arg[1] == 'u') { 435 deref = FETCH_OP_UDEREF; 436 arg[1] = arg[0]; 437 arg++; 438 } 439 if (arg[0] == '+') 440 arg++; /* Skip '+', because kstrtol() rejects it. */ 441 tmp = strchr(arg, '('); 442 if (!tmp) { 443 trace_probe_log_err(offs, DEREF_NEED_BRACE); 444 return -EINVAL; 445 } 446 *tmp = '\0'; 447 ret = kstrtol(arg, 0, &offset); 448 if (ret) { 449 trace_probe_log_err(offs, BAD_DEREF_OFFS); 450 break; 451 } 452 offs += (tmp + 1 - arg) + (arg[0] != '-' ? 1 : 0); 453 arg = tmp + 1; 454 tmp = strrchr(arg, ')'); 455 if (!tmp) { 456 trace_probe_log_err(offs + strlen(arg), 457 DEREF_OPEN_BRACE); 458 return -EINVAL; 459 } else { 460 const struct fetch_type *t2 = find_fetch_type(NULL); 461 462 *tmp = '\0'; 463 ret = parse_probe_arg(arg, t2, &code, end, flags, offs); 464 if (ret) 465 break; 466 if (code->op == FETCH_OP_COMM || 467 code->op == FETCH_OP_DATA) { 468 trace_probe_log_err(offs, COMM_CANT_DEREF); 469 return -EINVAL; 470 } 471 if (++code == end) { 472 trace_probe_log_err(offs, TOO_MANY_OPS); 473 return -EINVAL; 474 } 475 *pcode = code; 476 477 code->op = deref; 478 code->offset = offset; 479 } 480 break; 481 case '\\': /* Immediate value */ 482 if (arg[1] == '"') { /* Immediate string */ 483 ret = __parse_imm_string(arg + 2, &tmp, offs + 2); 484 if (ret) 485 break; 486 code->op = FETCH_OP_DATA; 487 code->data = tmp; 488 } else { 489 ret = str_to_immediate(arg + 1, &code->immediate); 490 if (ret) 491 trace_probe_log_err(offs + 1, BAD_IMM); 492 else 493 code->op = FETCH_OP_IMM; 494 } 495 break; 496 } 497 if (!ret && code->op == FETCH_OP_NOP) { 498 /* Parsed, but do not find fetch method */ 499 trace_probe_log_err(offs, BAD_FETCH_ARG); 500 ret = -EINVAL; 501 } 502 return ret; 503 } 504 505 #define BYTES_TO_BITS(nb) ((BITS_PER_LONG * (nb)) / sizeof(long)) 506 507 /* Bitfield type needs to be parsed into a fetch function */ 508 static int __parse_bitfield_probe_arg(const char *bf, 509 const struct fetch_type *t, 510 struct fetch_insn **pcode) 511 { 512 struct fetch_insn *code = *pcode; 513 unsigned long bw, bo; 514 char *tail; 515 516 if (*bf != 'b') 517 return 0; 518 519 bw = simple_strtoul(bf + 1, &tail, 0); /* Use simple one */ 520 521 if (bw == 0 || *tail != '@') 522 return -EINVAL; 523 524 bf = tail + 1; 525 bo = simple_strtoul(bf, &tail, 0); 526 527 if (tail == bf || *tail != '/') 528 return -EINVAL; 529 code++; 530 if (code->op != FETCH_OP_NOP) 531 return -EINVAL; 532 *pcode = code; 533 534 code->op = FETCH_OP_MOD_BF; 535 code->lshift = BYTES_TO_BITS(t->size) - (bw + bo); 536 code->rshift = BYTES_TO_BITS(t->size) - bw; 537 code->basesize = t->size; 538 539 return (BYTES_TO_BITS(t->size) < (bw + bo)) ? -EINVAL : 0; 540 } 541 542 /* String length checking wrapper */ 543 static int traceprobe_parse_probe_arg_body(char *arg, ssize_t *size, 544 struct probe_arg *parg, unsigned int flags, int offset) 545 { 546 struct fetch_insn *code, *scode, *tmp = NULL; 547 char *t, *t2, *t3; 548 int ret, len; 549 550 len = strlen(arg); 551 if (len > MAX_ARGSTR_LEN) { 552 trace_probe_log_err(offset, ARG_TOO_LONG); 553 return -EINVAL; 554 } else if (len == 0) { 555 trace_probe_log_err(offset, NO_ARG_BODY); 556 return -EINVAL; 557 } 558 559 parg->comm = kstrdup(arg, GFP_KERNEL); 560 if (!parg->comm) 561 return -ENOMEM; 562 563 t = strchr(arg, ':'); 564 if (t) { 565 *t = '\0'; 566 t2 = strchr(++t, '['); 567 if (t2) { 568 *t2++ = '\0'; 569 t3 = strchr(t2, ']'); 570 if (!t3) { 571 offset += t2 + strlen(t2) - arg; 572 trace_probe_log_err(offset, 573 ARRAY_NO_CLOSE); 574 return -EINVAL; 575 } else if (t3[1] != '\0') { 576 trace_probe_log_err(offset + t3 + 1 - arg, 577 BAD_ARRAY_SUFFIX); 578 return -EINVAL; 579 } 580 *t3 = '\0'; 581 if (kstrtouint(t2, 0, &parg->count) || !parg->count) { 582 trace_probe_log_err(offset + t2 - arg, 583 BAD_ARRAY_NUM); 584 return -EINVAL; 585 } 586 if (parg->count > MAX_ARRAY_LEN) { 587 trace_probe_log_err(offset + t2 - arg, 588 ARRAY_TOO_BIG); 589 return -EINVAL; 590 } 591 } 592 } 593 594 /* 595 * Since $comm and immediate string can not be dereferred, 596 * we can find those by strcmp. 597 */ 598 if (strcmp(arg, "$comm") == 0 || strncmp(arg, "\\\"", 2) == 0) { 599 /* The type of $comm must be "string", and not an array. */ 600 if (parg->count || (t && strcmp(t, "string"))) 601 return -EINVAL; 602 parg->type = find_fetch_type("string"); 603 } else 604 parg->type = find_fetch_type(t); 605 if (!parg->type) { 606 trace_probe_log_err(offset + (t ? (t - arg) : 0), BAD_TYPE); 607 return -EINVAL; 608 } 609 parg->offset = *size; 610 *size += parg->type->size * (parg->count ?: 1); 611 612 if (parg->count) { 613 len = strlen(parg->type->fmttype) + 6; 614 parg->fmt = kmalloc(len, GFP_KERNEL); 615 if (!parg->fmt) 616 return -ENOMEM; 617 snprintf(parg->fmt, len, "%s[%d]", parg->type->fmttype, 618 parg->count); 619 } 620 621 code = tmp = kcalloc(FETCH_INSN_MAX, sizeof(*code), GFP_KERNEL); 622 if (!code) 623 return -ENOMEM; 624 code[FETCH_INSN_MAX - 1].op = FETCH_OP_END; 625 626 ret = parse_probe_arg(arg, parg->type, &code, &code[FETCH_INSN_MAX - 1], 627 flags, offset); 628 if (ret) 629 goto fail; 630 631 /* Store operation */ 632 if (!strcmp(parg->type->name, "string") || 633 !strcmp(parg->type->name, "ustring")) { 634 if (code->op != FETCH_OP_DEREF && code->op != FETCH_OP_UDEREF && 635 code->op != FETCH_OP_IMM && code->op != FETCH_OP_COMM && 636 code->op != FETCH_OP_DATA) { 637 trace_probe_log_err(offset + (t ? (t - arg) : 0), 638 BAD_STRING); 639 ret = -EINVAL; 640 goto fail; 641 } 642 if ((code->op == FETCH_OP_IMM || code->op == FETCH_OP_COMM) || 643 parg->count) { 644 /* 645 * IMM, DATA and COMM is pointing actual address, those 646 * must be kept, and if parg->count != 0, this is an 647 * array of string pointers instead of string address 648 * itself. 649 */ 650 code++; 651 if (code->op != FETCH_OP_NOP) { 652 trace_probe_log_err(offset, TOO_MANY_OPS); 653 ret = -EINVAL; 654 goto fail; 655 } 656 } 657 /* If op == DEREF, replace it with STRING */ 658 if (!strcmp(parg->type->name, "ustring") || 659 code->op == FETCH_OP_UDEREF) 660 code->op = FETCH_OP_ST_USTRING; 661 else 662 code->op = FETCH_OP_ST_STRING; 663 code->size = parg->type->size; 664 parg->dynamic = true; 665 } else if (code->op == FETCH_OP_DEREF) { 666 code->op = FETCH_OP_ST_MEM; 667 code->size = parg->type->size; 668 } else if (code->op == FETCH_OP_UDEREF) { 669 code->op = FETCH_OP_ST_UMEM; 670 code->size = parg->type->size; 671 } else { 672 code++; 673 if (code->op != FETCH_OP_NOP) { 674 trace_probe_log_err(offset, TOO_MANY_OPS); 675 ret = -EINVAL; 676 goto fail; 677 } 678 code->op = FETCH_OP_ST_RAW; 679 code->size = parg->type->size; 680 } 681 scode = code; 682 /* Modify operation */ 683 if (t != NULL) { 684 ret = __parse_bitfield_probe_arg(t, parg->type, &code); 685 if (ret) { 686 trace_probe_log_err(offset + t - arg, BAD_BITFIELD); 687 goto fail; 688 } 689 } 690 /* Loop(Array) operation */ 691 if (parg->count) { 692 if (scode->op != FETCH_OP_ST_MEM && 693 scode->op != FETCH_OP_ST_STRING && 694 scode->op != FETCH_OP_ST_USTRING) { 695 trace_probe_log_err(offset + (t ? (t - arg) : 0), 696 BAD_STRING); 697 ret = -EINVAL; 698 goto fail; 699 } 700 code++; 701 if (code->op != FETCH_OP_NOP) { 702 trace_probe_log_err(offset, TOO_MANY_OPS); 703 ret = -EINVAL; 704 goto fail; 705 } 706 code->op = FETCH_OP_LP_ARRAY; 707 code->param = parg->count; 708 } 709 code++; 710 code->op = FETCH_OP_END; 711 712 /* Shrink down the code buffer */ 713 parg->code = kcalloc(code - tmp + 1, sizeof(*code), GFP_KERNEL); 714 if (!parg->code) 715 ret = -ENOMEM; 716 else 717 memcpy(parg->code, tmp, sizeof(*code) * (code - tmp + 1)); 718 719 fail: 720 if (ret) { 721 for (code = tmp; code < tmp + FETCH_INSN_MAX; code++) 722 if (code->op == FETCH_NOP_SYMBOL || 723 code->op == FETCH_OP_DATA) 724 kfree(code->data); 725 } 726 kfree(tmp); 727 728 return ret; 729 } 730 731 /* Return 1 if name is reserved or already used by another argument */ 732 static int traceprobe_conflict_field_name(const char *name, 733 struct probe_arg *args, int narg) 734 { 735 int i; 736 737 for (i = 0; i < ARRAY_SIZE(reserved_field_names); i++) 738 if (strcmp(reserved_field_names[i], name) == 0) 739 return 1; 740 741 for (i = 0; i < narg; i++) 742 if (strcmp(args[i].name, name) == 0) 743 return 1; 744 745 return 0; 746 } 747 748 int traceprobe_parse_probe_arg(struct trace_probe *tp, int i, char *arg, 749 unsigned int flags) 750 { 751 struct probe_arg *parg = &tp->args[i]; 752 char *body; 753 754 /* Increment count for freeing args in error case */ 755 tp->nr_args++; 756 757 body = strchr(arg, '='); 758 if (body) { 759 if (body - arg > MAX_ARG_NAME_LEN) { 760 trace_probe_log_err(0, ARG_NAME_TOO_LONG); 761 return -EINVAL; 762 } else if (body == arg) { 763 trace_probe_log_err(0, NO_ARG_NAME); 764 return -EINVAL; 765 } 766 parg->name = kmemdup_nul(arg, body - arg, GFP_KERNEL); 767 body++; 768 } else { 769 /* If argument name is omitted, set "argN" */ 770 parg->name = kasprintf(GFP_KERNEL, "arg%d", i + 1); 771 body = arg; 772 } 773 if (!parg->name) 774 return -ENOMEM; 775 776 if (!is_good_name(parg->name)) { 777 trace_probe_log_err(0, BAD_ARG_NAME); 778 return -EINVAL; 779 } 780 if (traceprobe_conflict_field_name(parg->name, tp->args, i)) { 781 trace_probe_log_err(0, USED_ARG_NAME); 782 return -EINVAL; 783 } 784 /* Parse fetch argument */ 785 return traceprobe_parse_probe_arg_body(body, &tp->size, parg, flags, 786 body - arg); 787 } 788 789 void traceprobe_free_probe_arg(struct probe_arg *arg) 790 { 791 struct fetch_insn *code = arg->code; 792 793 while (code && code->op != FETCH_OP_END) { 794 if (code->op == FETCH_NOP_SYMBOL || 795 code->op == FETCH_OP_DATA) 796 kfree(code->data); 797 code++; 798 } 799 kfree(arg->code); 800 kfree(arg->name); 801 kfree(arg->comm); 802 kfree(arg->fmt); 803 } 804 805 int traceprobe_update_arg(struct probe_arg *arg) 806 { 807 struct fetch_insn *code = arg->code; 808 long offset; 809 char *tmp; 810 char c; 811 int ret = 0; 812 813 while (code && code->op != FETCH_OP_END) { 814 if (code->op == FETCH_NOP_SYMBOL) { 815 if (code[1].op != FETCH_OP_IMM) 816 return -EINVAL; 817 818 tmp = strpbrk(code->data, "+-"); 819 if (tmp) 820 c = *tmp; 821 ret = traceprobe_split_symbol_offset(code->data, 822 &offset); 823 if (ret) 824 return ret; 825 826 code[1].immediate = 827 (unsigned long)kallsyms_lookup_name(code->data); 828 if (tmp) 829 *tmp = c; 830 if (!code[1].immediate) 831 return -ENOENT; 832 code[1].immediate += offset; 833 } 834 code++; 835 } 836 return 0; 837 } 838 839 /* When len=0, we just calculate the needed length */ 840 #define LEN_OR_ZERO (len ? len - pos : 0) 841 static int __set_print_fmt(struct trace_probe *tp, char *buf, int len, 842 bool is_return) 843 { 844 struct probe_arg *parg; 845 int i, j; 846 int pos = 0; 847 const char *fmt, *arg; 848 849 if (!is_return) { 850 fmt = "(%lx)"; 851 arg = "REC->" FIELD_STRING_IP; 852 } else { 853 fmt = "(%lx <- %lx)"; 854 arg = "REC->" FIELD_STRING_FUNC ", REC->" FIELD_STRING_RETIP; 855 } 856 857 pos += snprintf(buf + pos, LEN_OR_ZERO, "\"%s", fmt); 858 859 for (i = 0; i < tp->nr_args; i++) { 860 parg = tp->args + i; 861 pos += snprintf(buf + pos, LEN_OR_ZERO, " %s=", parg->name); 862 if (parg->count) { 863 pos += snprintf(buf + pos, LEN_OR_ZERO, "{%s", 864 parg->type->fmt); 865 for (j = 1; j < parg->count; j++) 866 pos += snprintf(buf + pos, LEN_OR_ZERO, ",%s", 867 parg->type->fmt); 868 pos += snprintf(buf + pos, LEN_OR_ZERO, "}"); 869 } else 870 pos += snprintf(buf + pos, LEN_OR_ZERO, "%s", 871 parg->type->fmt); 872 } 873 874 pos += snprintf(buf + pos, LEN_OR_ZERO, "\", %s", arg); 875 876 for (i = 0; i < tp->nr_args; i++) { 877 parg = tp->args + i; 878 if (parg->count) { 879 if ((strcmp(parg->type->name, "string") == 0) || 880 (strcmp(parg->type->name, "ustring") == 0)) 881 fmt = ", __get_str(%s[%d])"; 882 else 883 fmt = ", REC->%s[%d]"; 884 for (j = 0; j < parg->count; j++) 885 pos += snprintf(buf + pos, LEN_OR_ZERO, 886 fmt, parg->name, j); 887 } else { 888 if ((strcmp(parg->type->name, "string") == 0) || 889 (strcmp(parg->type->name, "ustring") == 0)) 890 fmt = ", __get_str(%s)"; 891 else 892 fmt = ", REC->%s"; 893 pos += snprintf(buf + pos, LEN_OR_ZERO, 894 fmt, parg->name); 895 } 896 } 897 898 /* return the length of print_fmt */ 899 return pos; 900 } 901 #undef LEN_OR_ZERO 902 903 int traceprobe_set_print_fmt(struct trace_probe *tp, bool is_return) 904 { 905 struct trace_event_call *call = trace_probe_event_call(tp); 906 int len; 907 char *print_fmt; 908 909 /* First: called with 0 length to calculate the needed length */ 910 len = __set_print_fmt(tp, NULL, 0, is_return); 911 print_fmt = kmalloc(len + 1, GFP_KERNEL); 912 if (!print_fmt) 913 return -ENOMEM; 914 915 /* Second: actually write the @print_fmt */ 916 __set_print_fmt(tp, print_fmt, len + 1, is_return); 917 call->print_fmt = print_fmt; 918 919 return 0; 920 } 921 922 int traceprobe_define_arg_fields(struct trace_event_call *event_call, 923 size_t offset, struct trace_probe *tp) 924 { 925 int ret, i; 926 927 /* Set argument names as fields */ 928 for (i = 0; i < tp->nr_args; i++) { 929 struct probe_arg *parg = &tp->args[i]; 930 const char *fmt = parg->type->fmttype; 931 int size = parg->type->size; 932 933 if (parg->fmt) 934 fmt = parg->fmt; 935 if (parg->count) 936 size *= parg->count; 937 ret = trace_define_field(event_call, fmt, parg->name, 938 offset + parg->offset, size, 939 parg->type->is_signed, 940 FILTER_OTHER); 941 if (ret) 942 return ret; 943 } 944 return 0; 945 } 946 947 static void trace_probe_event_free(struct trace_probe_event *tpe) 948 { 949 kfree(tpe->class.system); 950 kfree(tpe->call.name); 951 kfree(tpe->call.print_fmt); 952 kfree(tpe); 953 } 954 955 int trace_probe_append(struct trace_probe *tp, struct trace_probe *to) 956 { 957 if (trace_probe_has_sibling(tp)) 958 return -EBUSY; 959 960 list_del_init(&tp->list); 961 trace_probe_event_free(tp->event); 962 963 tp->event = to->event; 964 list_add_tail(&tp->list, trace_probe_probe_list(to)); 965 966 return 0; 967 } 968 969 void trace_probe_unlink(struct trace_probe *tp) 970 { 971 list_del_init(&tp->list); 972 if (list_empty(trace_probe_probe_list(tp))) 973 trace_probe_event_free(tp->event); 974 tp->event = NULL; 975 } 976 977 void trace_probe_cleanup(struct trace_probe *tp) 978 { 979 int i; 980 981 for (i = 0; i < tp->nr_args; i++) 982 traceprobe_free_probe_arg(&tp->args[i]); 983 984 if (tp->event) 985 trace_probe_unlink(tp); 986 } 987 988 int trace_probe_init(struct trace_probe *tp, const char *event, 989 const char *group, bool alloc_filter) 990 { 991 struct trace_event_call *call; 992 size_t size = sizeof(struct trace_probe_event); 993 int ret = 0; 994 995 if (!event || !group) 996 return -EINVAL; 997 998 if (alloc_filter) 999 size += sizeof(struct trace_uprobe_filter); 1000 1001 tp->event = kzalloc(size, GFP_KERNEL); 1002 if (!tp->event) 1003 return -ENOMEM; 1004 1005 INIT_LIST_HEAD(&tp->event->files); 1006 INIT_LIST_HEAD(&tp->event->class.fields); 1007 INIT_LIST_HEAD(&tp->event->probes); 1008 INIT_LIST_HEAD(&tp->list); 1009 list_add(&tp->event->probes, &tp->list); 1010 1011 call = trace_probe_event_call(tp); 1012 call->class = &tp->event->class; 1013 call->name = kstrdup(event, GFP_KERNEL); 1014 if (!call->name) { 1015 ret = -ENOMEM; 1016 goto error; 1017 } 1018 1019 tp->event->class.system = kstrdup(group, GFP_KERNEL); 1020 if (!tp->event->class.system) { 1021 ret = -ENOMEM; 1022 goto error; 1023 } 1024 1025 return 0; 1026 1027 error: 1028 trace_probe_cleanup(tp); 1029 return ret; 1030 } 1031 1032 int trace_probe_register_event_call(struct trace_probe *tp) 1033 { 1034 struct trace_event_call *call = trace_probe_event_call(tp); 1035 int ret; 1036 1037 ret = register_trace_event(&call->event); 1038 if (!ret) 1039 return -ENODEV; 1040 1041 ret = trace_add_event_call(call); 1042 if (ret) 1043 unregister_trace_event(&call->event); 1044 1045 return ret; 1046 } 1047 1048 int trace_probe_add_file(struct trace_probe *tp, struct trace_event_file *file) 1049 { 1050 struct event_file_link *link; 1051 1052 link = kmalloc(sizeof(*link), GFP_KERNEL); 1053 if (!link) 1054 return -ENOMEM; 1055 1056 link->file = file; 1057 INIT_LIST_HEAD(&link->list); 1058 list_add_tail_rcu(&link->list, &tp->event->files); 1059 trace_probe_set_flag(tp, TP_FLAG_TRACE); 1060 return 0; 1061 } 1062 1063 struct event_file_link *trace_probe_get_file_link(struct trace_probe *tp, 1064 struct trace_event_file *file) 1065 { 1066 struct event_file_link *link; 1067 1068 trace_probe_for_each_link(link, tp) { 1069 if (link->file == file) 1070 return link; 1071 } 1072 1073 return NULL; 1074 } 1075 1076 int trace_probe_remove_file(struct trace_probe *tp, 1077 struct trace_event_file *file) 1078 { 1079 struct event_file_link *link; 1080 1081 link = trace_probe_get_file_link(tp, file); 1082 if (!link) 1083 return -ENOENT; 1084 1085 list_del_rcu(&link->list); 1086 synchronize_rcu(); 1087 kfree(link); 1088 1089 if (list_empty(&tp->event->files)) 1090 trace_probe_clear_flag(tp, TP_FLAG_TRACE); 1091 1092 return 0; 1093 } 1094 1095 /* 1096 * Return the smallest index of different type argument (start from 1). 1097 * If all argument types and name are same, return 0. 1098 */ 1099 int trace_probe_compare_arg_type(struct trace_probe *a, struct trace_probe *b) 1100 { 1101 int i; 1102 1103 /* In case of more arguments */ 1104 if (a->nr_args < b->nr_args) 1105 return a->nr_args + 1; 1106 if (a->nr_args > b->nr_args) 1107 return b->nr_args + 1; 1108 1109 for (i = 0; i < a->nr_args; i++) { 1110 if ((b->nr_args <= i) || 1111 ((a->args[i].type != b->args[i].type) || 1112 (a->args[i].count != b->args[i].count) || 1113 strcmp(a->args[i].name, b->args[i].name))) 1114 return i + 1; 1115 } 1116 1117 return 0; 1118 } 1119 1120 bool trace_probe_match_command_args(struct trace_probe *tp, 1121 int argc, const char **argv) 1122 { 1123 char buf[MAX_ARGSTR_LEN + 1]; 1124 int i; 1125 1126 if (tp->nr_args < argc) 1127 return false; 1128 1129 for (i = 0; i < argc; i++) { 1130 snprintf(buf, sizeof(buf), "%s=%s", 1131 tp->args[i].name, tp->args[i].comm); 1132 if (strcmp(buf, argv[i])) 1133 return false; 1134 } 1135 return true; 1136 } 1137