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