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 /* Recalculate 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 * appears 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 slash = strchr(event, '.'); 238 239 if (slash) { 240 if (slash == event) { 241 trace_probe_log_err(offset, NO_GROUP_NAME); 242 return -EINVAL; 243 } 244 if (slash - event + 1 > MAX_EVENT_NAME_LEN) { 245 trace_probe_log_err(offset, GROUP_TOO_LONG); 246 return -EINVAL; 247 } 248 strlcpy(buf, event, slash - event + 1); 249 if (!is_good_name(buf)) { 250 trace_probe_log_err(offset, BAD_GROUP_NAME); 251 return -EINVAL; 252 } 253 *pgroup = buf; 254 *pevent = slash + 1; 255 offset += slash - event + 1; 256 event = *pevent; 257 } 258 len = strlen(event); 259 if (len == 0) { 260 if (slash) { 261 *pevent = NULL; 262 return 0; 263 } 264 trace_probe_log_err(offset, NO_EVENT_NAME); 265 return -EINVAL; 266 } else if (len > MAX_EVENT_NAME_LEN) { 267 trace_probe_log_err(offset, EVENT_TOO_LONG); 268 return -EINVAL; 269 } 270 if (!is_good_name(event)) { 271 trace_probe_log_err(offset, BAD_EVENT_NAME); 272 return -EINVAL; 273 } 274 return 0; 275 } 276 277 #define PARAM_MAX_STACK (THREAD_SIZE / sizeof(unsigned long)) 278 279 static int parse_probe_vars(char *arg, const struct fetch_type *t, 280 struct fetch_insn *code, unsigned int flags, int offs) 281 { 282 unsigned long param; 283 int ret = 0; 284 int len; 285 286 if (strcmp(arg, "retval") == 0) { 287 if (flags & TPARG_FL_RETURN) { 288 code->op = FETCH_OP_RETVAL; 289 } else { 290 trace_probe_log_err(offs, RETVAL_ON_PROBE); 291 ret = -EINVAL; 292 } 293 } else if ((len = str_has_prefix(arg, "stack"))) { 294 if (arg[len] == '\0') { 295 code->op = FETCH_OP_STACKP; 296 } else if (isdigit(arg[len])) { 297 ret = kstrtoul(arg + len, 10, ¶m); 298 if (ret) { 299 goto inval_var; 300 } else if ((flags & TPARG_FL_KERNEL) && 301 param > PARAM_MAX_STACK) { 302 trace_probe_log_err(offs, BAD_STACK_NUM); 303 ret = -EINVAL; 304 } else { 305 code->op = FETCH_OP_STACK; 306 code->param = (unsigned int)param; 307 } 308 } else 309 goto inval_var; 310 } else if (strcmp(arg, "comm") == 0) { 311 code->op = FETCH_OP_COMM; 312 #ifdef CONFIG_HAVE_FUNCTION_ARG_ACCESS_API 313 } else if (((flags & TPARG_FL_MASK) == 314 (TPARG_FL_KERNEL | TPARG_FL_FENTRY)) && 315 (len = str_has_prefix(arg, "arg"))) { 316 ret = kstrtoul(arg + len, 10, ¶m); 317 if (ret) { 318 goto inval_var; 319 } else if (!param || param > PARAM_MAX_STACK) { 320 trace_probe_log_err(offs, BAD_ARG_NUM); 321 return -EINVAL; 322 } 323 code->op = FETCH_OP_ARG; 324 code->param = (unsigned int)param - 1; 325 #endif 326 } else if (flags & TPARG_FL_TPOINT) { 327 if (code->data) 328 return -EFAULT; 329 code->data = kstrdup(arg, GFP_KERNEL); 330 if (!code->data) 331 return -ENOMEM; 332 code->op = FETCH_OP_TP_ARG; 333 } else 334 goto inval_var; 335 336 return ret; 337 338 inval_var: 339 trace_probe_log_err(offs, BAD_VAR); 340 return -EINVAL; 341 } 342 343 static int str_to_immediate(char *str, unsigned long *imm) 344 { 345 if (isdigit(str[0])) 346 return kstrtoul(str, 0, imm); 347 else if (str[0] == '-') 348 return kstrtol(str, 0, (long *)imm); 349 else if (str[0] == '+') 350 return kstrtol(str + 1, 0, (long *)imm); 351 return -EINVAL; 352 } 353 354 static int __parse_imm_string(char *str, char **pbuf, int offs) 355 { 356 size_t len = strlen(str); 357 358 if (str[len - 1] != '"') { 359 trace_probe_log_err(offs + len, IMMSTR_NO_CLOSE); 360 return -EINVAL; 361 } 362 *pbuf = kstrndup(str, len - 1, GFP_KERNEL); 363 if (!*pbuf) 364 return -ENOMEM; 365 return 0; 366 } 367 368 /* Recursive argument parser */ 369 static int 370 parse_probe_arg(char *arg, const struct fetch_type *type, 371 struct fetch_insn **pcode, struct fetch_insn *end, 372 unsigned int flags, int offs) 373 { 374 struct fetch_insn *code = *pcode; 375 unsigned long param; 376 int deref = FETCH_OP_DEREF; 377 long offset = 0; 378 char *tmp; 379 int ret = 0; 380 381 switch (arg[0]) { 382 case '$': 383 ret = parse_probe_vars(arg + 1, type, code, flags, offs); 384 break; 385 386 case '%': /* named register */ 387 ret = regs_query_register_offset(arg + 1); 388 if (ret >= 0) { 389 code->op = FETCH_OP_REG; 390 code->param = (unsigned int)ret; 391 ret = 0; 392 } else 393 trace_probe_log_err(offs, BAD_REG_NAME); 394 break; 395 396 case '@': /* memory, file-offset or symbol */ 397 if (isdigit(arg[1])) { 398 ret = kstrtoul(arg + 1, 0, ¶m); 399 if (ret) { 400 trace_probe_log_err(offs, BAD_MEM_ADDR); 401 break; 402 } 403 /* load address */ 404 code->op = FETCH_OP_IMM; 405 code->immediate = param; 406 } else if (arg[1] == '+') { 407 /* kprobes don't support file offsets */ 408 if (flags & TPARG_FL_KERNEL) { 409 trace_probe_log_err(offs, FILE_ON_KPROBE); 410 return -EINVAL; 411 } 412 ret = kstrtol(arg + 2, 0, &offset); 413 if (ret) { 414 trace_probe_log_err(offs, BAD_FILE_OFFS); 415 break; 416 } 417 418 code->op = FETCH_OP_FOFFS; 419 code->immediate = (unsigned long)offset; // imm64? 420 } else { 421 /* uprobes don't support symbols */ 422 if (!(flags & TPARG_FL_KERNEL)) { 423 trace_probe_log_err(offs, SYM_ON_UPROBE); 424 return -EINVAL; 425 } 426 /* Preserve symbol for updating */ 427 code->op = FETCH_NOP_SYMBOL; 428 code->data = kstrdup(arg + 1, GFP_KERNEL); 429 if (!code->data) 430 return -ENOMEM; 431 if (++code == end) { 432 trace_probe_log_err(offs, TOO_MANY_OPS); 433 return -EINVAL; 434 } 435 code->op = FETCH_OP_IMM; 436 code->immediate = 0; 437 } 438 /* These are fetching from memory */ 439 if (++code == end) { 440 trace_probe_log_err(offs, TOO_MANY_OPS); 441 return -EINVAL; 442 } 443 *pcode = code; 444 code->op = FETCH_OP_DEREF; 445 code->offset = offset; 446 break; 447 448 case '+': /* deref memory */ 449 case '-': 450 if (arg[1] == 'u') { 451 deref = FETCH_OP_UDEREF; 452 arg[1] = arg[0]; 453 arg++; 454 } 455 if (arg[0] == '+') 456 arg++; /* Skip '+', because kstrtol() rejects it. */ 457 tmp = strchr(arg, '('); 458 if (!tmp) { 459 trace_probe_log_err(offs, DEREF_NEED_BRACE); 460 return -EINVAL; 461 } 462 *tmp = '\0'; 463 ret = kstrtol(arg, 0, &offset); 464 if (ret) { 465 trace_probe_log_err(offs, BAD_DEREF_OFFS); 466 break; 467 } 468 offs += (tmp + 1 - arg) + (arg[0] != '-' ? 1 : 0); 469 arg = tmp + 1; 470 tmp = strrchr(arg, ')'); 471 if (!tmp) { 472 trace_probe_log_err(offs + strlen(arg), 473 DEREF_OPEN_BRACE); 474 return -EINVAL; 475 } else { 476 const struct fetch_type *t2 = find_fetch_type(NULL); 477 478 *tmp = '\0'; 479 ret = parse_probe_arg(arg, t2, &code, end, flags, offs); 480 if (ret) 481 break; 482 if (code->op == FETCH_OP_COMM || 483 code->op == FETCH_OP_DATA) { 484 trace_probe_log_err(offs, COMM_CANT_DEREF); 485 return -EINVAL; 486 } 487 if (++code == end) { 488 trace_probe_log_err(offs, TOO_MANY_OPS); 489 return -EINVAL; 490 } 491 *pcode = code; 492 493 code->op = deref; 494 code->offset = offset; 495 } 496 break; 497 case '\\': /* Immediate value */ 498 if (arg[1] == '"') { /* Immediate string */ 499 ret = __parse_imm_string(arg + 2, &tmp, offs + 2); 500 if (ret) 501 break; 502 code->op = FETCH_OP_DATA; 503 code->data = tmp; 504 } else { 505 ret = str_to_immediate(arg + 1, &code->immediate); 506 if (ret) 507 trace_probe_log_err(offs + 1, BAD_IMM); 508 else 509 code->op = FETCH_OP_IMM; 510 } 511 break; 512 } 513 if (!ret && code->op == FETCH_OP_NOP) { 514 /* Parsed, but do not find fetch method */ 515 trace_probe_log_err(offs, BAD_FETCH_ARG); 516 ret = -EINVAL; 517 } 518 return ret; 519 } 520 521 #define BYTES_TO_BITS(nb) ((BITS_PER_LONG * (nb)) / sizeof(long)) 522 523 /* Bitfield type needs to be parsed into a fetch function */ 524 static int __parse_bitfield_probe_arg(const char *bf, 525 const struct fetch_type *t, 526 struct fetch_insn **pcode) 527 { 528 struct fetch_insn *code = *pcode; 529 unsigned long bw, bo; 530 char *tail; 531 532 if (*bf != 'b') 533 return 0; 534 535 bw = simple_strtoul(bf + 1, &tail, 0); /* Use simple one */ 536 537 if (bw == 0 || *tail != '@') 538 return -EINVAL; 539 540 bf = tail + 1; 541 bo = simple_strtoul(bf, &tail, 0); 542 543 if (tail == bf || *tail != '/') 544 return -EINVAL; 545 code++; 546 if (code->op != FETCH_OP_NOP) 547 return -EINVAL; 548 *pcode = code; 549 550 code->op = FETCH_OP_MOD_BF; 551 code->lshift = BYTES_TO_BITS(t->size) - (bw + bo); 552 code->rshift = BYTES_TO_BITS(t->size) - bw; 553 code->basesize = t->size; 554 555 return (BYTES_TO_BITS(t->size) < (bw + bo)) ? -EINVAL : 0; 556 } 557 558 /* String length checking wrapper */ 559 static int traceprobe_parse_probe_arg_body(const char *argv, ssize_t *size, 560 struct probe_arg *parg, unsigned int flags, int offset) 561 { 562 struct fetch_insn *code, *scode, *tmp = NULL; 563 char *t, *t2, *t3; 564 char *arg; 565 int ret, len; 566 567 arg = kstrdup(argv, GFP_KERNEL); 568 if (!arg) 569 return -ENOMEM; 570 571 ret = -EINVAL; 572 len = strlen(arg); 573 if (len > MAX_ARGSTR_LEN) { 574 trace_probe_log_err(offset, ARG_TOO_LONG); 575 goto out; 576 } else if (len == 0) { 577 trace_probe_log_err(offset, NO_ARG_BODY); 578 goto out; 579 } 580 581 ret = -ENOMEM; 582 parg->comm = kstrdup(arg, GFP_KERNEL); 583 if (!parg->comm) 584 goto out; 585 586 ret = -EINVAL; 587 t = strchr(arg, ':'); 588 if (t) { 589 *t = '\0'; 590 t2 = strchr(++t, '['); 591 if (t2) { 592 *t2++ = '\0'; 593 t3 = strchr(t2, ']'); 594 if (!t3) { 595 offset += t2 + strlen(t2) - arg; 596 trace_probe_log_err(offset, 597 ARRAY_NO_CLOSE); 598 goto out; 599 } else if (t3[1] != '\0') { 600 trace_probe_log_err(offset + t3 + 1 - arg, 601 BAD_ARRAY_SUFFIX); 602 goto out; 603 } 604 *t3 = '\0'; 605 if (kstrtouint(t2, 0, &parg->count) || !parg->count) { 606 trace_probe_log_err(offset + t2 - arg, 607 BAD_ARRAY_NUM); 608 goto out; 609 } 610 if (parg->count > MAX_ARRAY_LEN) { 611 trace_probe_log_err(offset + t2 - arg, 612 ARRAY_TOO_BIG); 613 goto out; 614 } 615 } 616 } 617 618 /* 619 * Since $comm and immediate string can not be dereferenced, 620 * we can find those by strcmp. 621 */ 622 if (strcmp(arg, "$comm") == 0 || strncmp(arg, "\\\"", 2) == 0) { 623 /* The type of $comm must be "string", and not an array. */ 624 if (parg->count || (t && strcmp(t, "string"))) 625 goto out; 626 parg->type = find_fetch_type("string"); 627 } else 628 parg->type = find_fetch_type(t); 629 if (!parg->type) { 630 trace_probe_log_err(offset + (t ? (t - arg) : 0), BAD_TYPE); 631 goto out; 632 } 633 parg->offset = *size; 634 *size += parg->type->size * (parg->count ?: 1); 635 636 ret = -ENOMEM; 637 if (parg->count) { 638 len = strlen(parg->type->fmttype) + 6; 639 parg->fmt = kmalloc(len, GFP_KERNEL); 640 if (!parg->fmt) 641 goto out; 642 snprintf(parg->fmt, len, "%s[%d]", parg->type->fmttype, 643 parg->count); 644 } 645 646 code = tmp = kcalloc(FETCH_INSN_MAX, sizeof(*code), GFP_KERNEL); 647 if (!code) 648 goto out; 649 code[FETCH_INSN_MAX - 1].op = FETCH_OP_END; 650 651 ret = parse_probe_arg(arg, parg->type, &code, &code[FETCH_INSN_MAX - 1], 652 flags, offset); 653 if (ret) 654 goto fail; 655 656 ret = -EINVAL; 657 /* Store operation */ 658 if (!strcmp(parg->type->name, "string") || 659 !strcmp(parg->type->name, "ustring")) { 660 if (code->op != FETCH_OP_DEREF && code->op != FETCH_OP_UDEREF && 661 code->op != FETCH_OP_IMM && code->op != FETCH_OP_COMM && 662 code->op != FETCH_OP_DATA && code->op != FETCH_OP_TP_ARG) { 663 trace_probe_log_err(offset + (t ? (t - arg) : 0), 664 BAD_STRING); 665 goto fail; 666 } 667 if ((code->op == FETCH_OP_IMM || code->op == FETCH_OP_COMM || 668 code->op == FETCH_OP_DATA) || code->op == FETCH_OP_TP_ARG || 669 parg->count) { 670 /* 671 * IMM, DATA and COMM is pointing actual address, those 672 * must be kept, and if parg->count != 0, this is an 673 * array of string pointers instead of string address 674 * itself. 675 */ 676 code++; 677 if (code->op != FETCH_OP_NOP) { 678 trace_probe_log_err(offset, TOO_MANY_OPS); 679 goto fail; 680 } 681 } 682 /* If op == DEREF, replace it with STRING */ 683 if (!strcmp(parg->type->name, "ustring") || 684 code->op == FETCH_OP_UDEREF) 685 code->op = FETCH_OP_ST_USTRING; 686 else 687 code->op = FETCH_OP_ST_STRING; 688 code->size = parg->type->size; 689 parg->dynamic = true; 690 } else if (code->op == FETCH_OP_DEREF) { 691 code->op = FETCH_OP_ST_MEM; 692 code->size = parg->type->size; 693 } else if (code->op == FETCH_OP_UDEREF) { 694 code->op = FETCH_OP_ST_UMEM; 695 code->size = parg->type->size; 696 } else { 697 code++; 698 if (code->op != FETCH_OP_NOP) { 699 trace_probe_log_err(offset, TOO_MANY_OPS); 700 goto fail; 701 } 702 code->op = FETCH_OP_ST_RAW; 703 code->size = parg->type->size; 704 } 705 scode = code; 706 /* Modify operation */ 707 if (t != NULL) { 708 ret = __parse_bitfield_probe_arg(t, parg->type, &code); 709 if (ret) { 710 trace_probe_log_err(offset + t - arg, BAD_BITFIELD); 711 goto fail; 712 } 713 } 714 ret = -EINVAL; 715 /* Loop(Array) operation */ 716 if (parg->count) { 717 if (scode->op != FETCH_OP_ST_MEM && 718 scode->op != FETCH_OP_ST_STRING && 719 scode->op != FETCH_OP_ST_USTRING) { 720 trace_probe_log_err(offset + (t ? (t - arg) : 0), 721 BAD_STRING); 722 goto fail; 723 } 724 code++; 725 if (code->op != FETCH_OP_NOP) { 726 trace_probe_log_err(offset, TOO_MANY_OPS); 727 goto fail; 728 } 729 code->op = FETCH_OP_LP_ARRAY; 730 code->param = parg->count; 731 } 732 code++; 733 code->op = FETCH_OP_END; 734 735 ret = 0; 736 /* Shrink down the code buffer */ 737 parg->code = kcalloc(code - tmp + 1, sizeof(*code), GFP_KERNEL); 738 if (!parg->code) 739 ret = -ENOMEM; 740 else 741 memcpy(parg->code, tmp, sizeof(*code) * (code - tmp + 1)); 742 743 fail: 744 if (ret) { 745 for (code = tmp; code < tmp + FETCH_INSN_MAX; code++) 746 if (code->op == FETCH_NOP_SYMBOL || 747 code->op == FETCH_OP_DATA) 748 kfree(code->data); 749 } 750 kfree(tmp); 751 out: 752 kfree(arg); 753 754 return ret; 755 } 756 757 /* Return 1 if name is reserved or already used by another argument */ 758 static int traceprobe_conflict_field_name(const char *name, 759 struct probe_arg *args, int narg) 760 { 761 int i; 762 763 for (i = 0; i < ARRAY_SIZE(reserved_field_names); i++) 764 if (strcmp(reserved_field_names[i], name) == 0) 765 return 1; 766 767 for (i = 0; i < narg; i++) 768 if (strcmp(args[i].name, name) == 0) 769 return 1; 770 771 return 0; 772 } 773 774 int traceprobe_parse_probe_arg(struct trace_probe *tp, int i, const char *arg, 775 unsigned int flags) 776 { 777 struct probe_arg *parg = &tp->args[i]; 778 const char *body; 779 780 /* Increment count for freeing args in error case */ 781 tp->nr_args++; 782 783 body = strchr(arg, '='); 784 if (body) { 785 if (body - arg > MAX_ARG_NAME_LEN) { 786 trace_probe_log_err(0, ARG_NAME_TOO_LONG); 787 return -EINVAL; 788 } else if (body == arg) { 789 trace_probe_log_err(0, NO_ARG_NAME); 790 return -EINVAL; 791 } 792 parg->name = kmemdup_nul(arg, body - arg, GFP_KERNEL); 793 body++; 794 } else { 795 /* If argument name is omitted, set "argN" */ 796 parg->name = kasprintf(GFP_KERNEL, "arg%d", i + 1); 797 body = arg; 798 } 799 if (!parg->name) 800 return -ENOMEM; 801 802 if (!is_good_name(parg->name)) { 803 trace_probe_log_err(0, BAD_ARG_NAME); 804 return -EINVAL; 805 } 806 if (traceprobe_conflict_field_name(parg->name, tp->args, i)) { 807 trace_probe_log_err(0, USED_ARG_NAME); 808 return -EINVAL; 809 } 810 /* Parse fetch argument */ 811 return traceprobe_parse_probe_arg_body(body, &tp->size, parg, flags, 812 body - arg); 813 } 814 815 void traceprobe_free_probe_arg(struct probe_arg *arg) 816 { 817 struct fetch_insn *code = arg->code; 818 819 while (code && code->op != FETCH_OP_END) { 820 if (code->op == FETCH_NOP_SYMBOL || 821 code->op == FETCH_OP_DATA) 822 kfree(code->data); 823 code++; 824 } 825 kfree(arg->code); 826 kfree(arg->name); 827 kfree(arg->comm); 828 kfree(arg->fmt); 829 } 830 831 int traceprobe_update_arg(struct probe_arg *arg) 832 { 833 struct fetch_insn *code = arg->code; 834 long offset; 835 char *tmp; 836 char c; 837 int ret = 0; 838 839 while (code && code->op != FETCH_OP_END) { 840 if (code->op == FETCH_NOP_SYMBOL) { 841 if (code[1].op != FETCH_OP_IMM) 842 return -EINVAL; 843 844 tmp = strpbrk(code->data, "+-"); 845 if (tmp) 846 c = *tmp; 847 ret = traceprobe_split_symbol_offset(code->data, 848 &offset); 849 if (ret) 850 return ret; 851 852 code[1].immediate = 853 (unsigned long)kallsyms_lookup_name(code->data); 854 if (tmp) 855 *tmp = c; 856 if (!code[1].immediate) 857 return -ENOENT; 858 code[1].immediate += offset; 859 } 860 code++; 861 } 862 return 0; 863 } 864 865 /* When len=0, we just calculate the needed length */ 866 #define LEN_OR_ZERO (len ? len - pos : 0) 867 static int __set_print_fmt(struct trace_probe *tp, char *buf, int len, 868 enum probe_print_type ptype) 869 { 870 struct probe_arg *parg; 871 int i, j; 872 int pos = 0; 873 const char *fmt, *arg; 874 875 switch (ptype) { 876 case PROBE_PRINT_NORMAL: 877 fmt = "(%lx)"; 878 arg = ", REC->" FIELD_STRING_IP; 879 break; 880 case PROBE_PRINT_RETURN: 881 fmt = "(%lx <- %lx)"; 882 arg = ", REC->" FIELD_STRING_FUNC ", REC->" FIELD_STRING_RETIP; 883 break; 884 case PROBE_PRINT_EVENT: 885 fmt = ""; 886 arg = ""; 887 break; 888 default: 889 WARN_ON_ONCE(1); 890 return 0; 891 } 892 893 pos += snprintf(buf + pos, LEN_OR_ZERO, "\"%s", fmt); 894 895 for (i = 0; i < tp->nr_args; i++) { 896 parg = tp->args + i; 897 pos += snprintf(buf + pos, LEN_OR_ZERO, " %s=", parg->name); 898 if (parg->count) { 899 pos += snprintf(buf + pos, LEN_OR_ZERO, "{%s", 900 parg->type->fmt); 901 for (j = 1; j < parg->count; j++) 902 pos += snprintf(buf + pos, LEN_OR_ZERO, ",%s", 903 parg->type->fmt); 904 pos += snprintf(buf + pos, LEN_OR_ZERO, "}"); 905 } else 906 pos += snprintf(buf + pos, LEN_OR_ZERO, "%s", 907 parg->type->fmt); 908 } 909 910 pos += snprintf(buf + pos, LEN_OR_ZERO, "\"%s", arg); 911 912 for (i = 0; i < tp->nr_args; i++) { 913 parg = tp->args + i; 914 if (parg->count) { 915 if ((strcmp(parg->type->name, "string") == 0) || 916 (strcmp(parg->type->name, "ustring") == 0)) 917 fmt = ", __get_str(%s[%d])"; 918 else 919 fmt = ", REC->%s[%d]"; 920 for (j = 0; j < parg->count; j++) 921 pos += snprintf(buf + pos, LEN_OR_ZERO, 922 fmt, parg->name, j); 923 } else { 924 if ((strcmp(parg->type->name, "string") == 0) || 925 (strcmp(parg->type->name, "ustring") == 0)) 926 fmt = ", __get_str(%s)"; 927 else 928 fmt = ", REC->%s"; 929 pos += snprintf(buf + pos, LEN_OR_ZERO, 930 fmt, parg->name); 931 } 932 } 933 934 /* return the length of print_fmt */ 935 return pos; 936 } 937 #undef LEN_OR_ZERO 938 939 int traceprobe_set_print_fmt(struct trace_probe *tp, enum probe_print_type ptype) 940 { 941 struct trace_event_call *call = trace_probe_event_call(tp); 942 int len; 943 char *print_fmt; 944 945 /* First: called with 0 length to calculate the needed length */ 946 len = __set_print_fmt(tp, NULL, 0, ptype); 947 print_fmt = kmalloc(len + 1, GFP_KERNEL); 948 if (!print_fmt) 949 return -ENOMEM; 950 951 /* Second: actually write the @print_fmt */ 952 __set_print_fmt(tp, print_fmt, len + 1, ptype); 953 call->print_fmt = print_fmt; 954 955 return 0; 956 } 957 958 int traceprobe_define_arg_fields(struct trace_event_call *event_call, 959 size_t offset, struct trace_probe *tp) 960 { 961 int ret, i; 962 963 /* Set argument names as fields */ 964 for (i = 0; i < tp->nr_args; i++) { 965 struct probe_arg *parg = &tp->args[i]; 966 const char *fmt = parg->type->fmttype; 967 int size = parg->type->size; 968 969 if (parg->fmt) 970 fmt = parg->fmt; 971 if (parg->count) 972 size *= parg->count; 973 ret = trace_define_field(event_call, fmt, parg->name, 974 offset + parg->offset, size, 975 parg->type->is_signed, 976 FILTER_OTHER); 977 if (ret) 978 return ret; 979 } 980 return 0; 981 } 982 983 static void trace_probe_event_free(struct trace_probe_event *tpe) 984 { 985 kfree(tpe->class.system); 986 kfree(tpe->call.name); 987 kfree(tpe->call.print_fmt); 988 kfree(tpe); 989 } 990 991 int trace_probe_append(struct trace_probe *tp, struct trace_probe *to) 992 { 993 if (trace_probe_has_sibling(tp)) 994 return -EBUSY; 995 996 list_del_init(&tp->list); 997 trace_probe_event_free(tp->event); 998 999 tp->event = to->event; 1000 list_add_tail(&tp->list, trace_probe_probe_list(to)); 1001 1002 return 0; 1003 } 1004 1005 void trace_probe_unlink(struct trace_probe *tp) 1006 { 1007 list_del_init(&tp->list); 1008 if (list_empty(trace_probe_probe_list(tp))) 1009 trace_probe_event_free(tp->event); 1010 tp->event = NULL; 1011 } 1012 1013 void trace_probe_cleanup(struct trace_probe *tp) 1014 { 1015 int i; 1016 1017 for (i = 0; i < tp->nr_args; i++) 1018 traceprobe_free_probe_arg(&tp->args[i]); 1019 1020 if (tp->event) 1021 trace_probe_unlink(tp); 1022 } 1023 1024 int trace_probe_init(struct trace_probe *tp, const char *event, 1025 const char *group, bool alloc_filter) 1026 { 1027 struct trace_event_call *call; 1028 size_t size = sizeof(struct trace_probe_event); 1029 int ret = 0; 1030 1031 if (!event || !group) 1032 return -EINVAL; 1033 1034 if (alloc_filter) 1035 size += sizeof(struct trace_uprobe_filter); 1036 1037 tp->event = kzalloc(size, GFP_KERNEL); 1038 if (!tp->event) 1039 return -ENOMEM; 1040 1041 INIT_LIST_HEAD(&tp->event->files); 1042 INIT_LIST_HEAD(&tp->event->class.fields); 1043 INIT_LIST_HEAD(&tp->event->probes); 1044 INIT_LIST_HEAD(&tp->list); 1045 list_add(&tp->list, &tp->event->probes); 1046 1047 call = trace_probe_event_call(tp); 1048 call->class = &tp->event->class; 1049 call->name = kstrdup(event, GFP_KERNEL); 1050 if (!call->name) { 1051 ret = -ENOMEM; 1052 goto error; 1053 } 1054 1055 tp->event->class.system = kstrdup(group, GFP_KERNEL); 1056 if (!tp->event->class.system) { 1057 ret = -ENOMEM; 1058 goto error; 1059 } 1060 1061 return 0; 1062 1063 error: 1064 trace_probe_cleanup(tp); 1065 return ret; 1066 } 1067 1068 static struct trace_event_call * 1069 find_trace_event_call(const char *system, const char *event_name) 1070 { 1071 struct trace_event_call *tp_event; 1072 const char *name; 1073 1074 list_for_each_entry(tp_event, &ftrace_events, list) { 1075 if (!tp_event->class->system || 1076 strcmp(system, tp_event->class->system)) 1077 continue; 1078 name = trace_event_name(tp_event); 1079 if (!name || strcmp(event_name, name)) 1080 continue; 1081 return tp_event; 1082 } 1083 1084 return NULL; 1085 } 1086 1087 int trace_probe_register_event_call(struct trace_probe *tp) 1088 { 1089 struct trace_event_call *call = trace_probe_event_call(tp); 1090 int ret; 1091 1092 lockdep_assert_held(&event_mutex); 1093 1094 if (find_trace_event_call(trace_probe_group_name(tp), 1095 trace_probe_name(tp))) 1096 return -EEXIST; 1097 1098 ret = register_trace_event(&call->event); 1099 if (!ret) 1100 return -ENODEV; 1101 1102 ret = trace_add_event_call(call); 1103 if (ret) 1104 unregister_trace_event(&call->event); 1105 1106 return ret; 1107 } 1108 1109 int trace_probe_add_file(struct trace_probe *tp, struct trace_event_file *file) 1110 { 1111 struct event_file_link *link; 1112 1113 link = kmalloc(sizeof(*link), GFP_KERNEL); 1114 if (!link) 1115 return -ENOMEM; 1116 1117 link->file = file; 1118 INIT_LIST_HEAD(&link->list); 1119 list_add_tail_rcu(&link->list, &tp->event->files); 1120 trace_probe_set_flag(tp, TP_FLAG_TRACE); 1121 return 0; 1122 } 1123 1124 struct event_file_link *trace_probe_get_file_link(struct trace_probe *tp, 1125 struct trace_event_file *file) 1126 { 1127 struct event_file_link *link; 1128 1129 trace_probe_for_each_link(link, tp) { 1130 if (link->file == file) 1131 return link; 1132 } 1133 1134 return NULL; 1135 } 1136 1137 int trace_probe_remove_file(struct trace_probe *tp, 1138 struct trace_event_file *file) 1139 { 1140 struct event_file_link *link; 1141 1142 link = trace_probe_get_file_link(tp, file); 1143 if (!link) 1144 return -ENOENT; 1145 1146 list_del_rcu(&link->list); 1147 kvfree_rcu(link); 1148 1149 if (list_empty(&tp->event->files)) 1150 trace_probe_clear_flag(tp, TP_FLAG_TRACE); 1151 1152 return 0; 1153 } 1154 1155 /* 1156 * Return the smallest index of different type argument (start from 1). 1157 * If all argument types and name are same, return 0. 1158 */ 1159 int trace_probe_compare_arg_type(struct trace_probe *a, struct trace_probe *b) 1160 { 1161 int i; 1162 1163 /* In case of more arguments */ 1164 if (a->nr_args < b->nr_args) 1165 return a->nr_args + 1; 1166 if (a->nr_args > b->nr_args) 1167 return b->nr_args + 1; 1168 1169 for (i = 0; i < a->nr_args; i++) { 1170 if ((b->nr_args <= i) || 1171 ((a->args[i].type != b->args[i].type) || 1172 (a->args[i].count != b->args[i].count) || 1173 strcmp(a->args[i].name, b->args[i].name))) 1174 return i + 1; 1175 } 1176 1177 return 0; 1178 } 1179 1180 bool trace_probe_match_command_args(struct trace_probe *tp, 1181 int argc, const char **argv) 1182 { 1183 char buf[MAX_ARGSTR_LEN + 1]; 1184 int i; 1185 1186 if (tp->nr_args < argc) 1187 return false; 1188 1189 for (i = 0; i < argc; i++) { 1190 snprintf(buf, sizeof(buf), "%s=%s", 1191 tp->args[i].name, tp->args[i].comm); 1192 if (strcmp(buf, argv[i])) 1193 return false; 1194 } 1195 return true; 1196 } 1197 1198 int trace_probe_create(const char *raw_command, int (*createfn)(int, const char **)) 1199 { 1200 int argc = 0, ret = 0; 1201 char **argv; 1202 1203 argv = argv_split(GFP_KERNEL, raw_command, &argc); 1204 if (!argv) 1205 return -ENOMEM; 1206 1207 if (argc) 1208 ret = createfn(argc, (const char **)argv); 1209 1210 argv_free(argv); 1211 1212 return ret; 1213 } 1214