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 <linux/bpf.h> 15 #include "trace_btf.h" 16 17 #include "trace_probe.h" 18 19 #undef C 20 #define C(a, b) b 21 22 static const char *trace_probe_err_text[] = { ERRORS }; 23 24 static const char *reserved_field_names[] = { 25 "common_type", 26 "common_flags", 27 "common_preempt_count", 28 "common_pid", 29 "common_tgid", 30 FIELD_STRING_IP, 31 FIELD_STRING_RETIP, 32 FIELD_STRING_FUNC, 33 }; 34 35 /* Printing in basic type function template */ 36 #define DEFINE_BASIC_PRINT_TYPE_FUNC(tname, type, fmt) \ 37 int PRINT_TYPE_FUNC_NAME(tname)(struct trace_seq *s, void *data, void *ent)\ 38 { \ 39 trace_seq_printf(s, fmt, *(type *)data); \ 40 return !trace_seq_has_overflowed(s); \ 41 } \ 42 const char PRINT_TYPE_FMT_NAME(tname)[] = fmt; 43 44 DEFINE_BASIC_PRINT_TYPE_FUNC(u8, u8, "%u") 45 DEFINE_BASIC_PRINT_TYPE_FUNC(u16, u16, "%u") 46 DEFINE_BASIC_PRINT_TYPE_FUNC(u32, u32, "%u") 47 DEFINE_BASIC_PRINT_TYPE_FUNC(u64, u64, "%Lu") 48 DEFINE_BASIC_PRINT_TYPE_FUNC(s8, s8, "%d") 49 DEFINE_BASIC_PRINT_TYPE_FUNC(s16, s16, "%d") 50 DEFINE_BASIC_PRINT_TYPE_FUNC(s32, s32, "%d") 51 DEFINE_BASIC_PRINT_TYPE_FUNC(s64, s64, "%Ld") 52 DEFINE_BASIC_PRINT_TYPE_FUNC(x8, u8, "0x%x") 53 DEFINE_BASIC_PRINT_TYPE_FUNC(x16, u16, "0x%x") 54 DEFINE_BASIC_PRINT_TYPE_FUNC(x32, u32, "0x%x") 55 DEFINE_BASIC_PRINT_TYPE_FUNC(x64, u64, "0x%Lx") 56 DEFINE_BASIC_PRINT_TYPE_FUNC(char, u8, "'%c'") 57 58 int PRINT_TYPE_FUNC_NAME(symbol)(struct trace_seq *s, void *data, void *ent) 59 { 60 trace_seq_printf(s, "%pS", (void *)*(unsigned long *)data); 61 return !trace_seq_has_overflowed(s); 62 } 63 const char PRINT_TYPE_FMT_NAME(symbol)[] = "%pS"; 64 65 /* Print type function for string type */ 66 int PRINT_TYPE_FUNC_NAME(string)(struct trace_seq *s, void *data, void *ent) 67 { 68 int len = *(u32 *)data >> 16; 69 70 if (!len) 71 trace_seq_puts(s, FAULT_STRING); 72 else 73 trace_seq_printf(s, "\"%s\"", 74 (const char *)get_loc_data(data, ent)); 75 return !trace_seq_has_overflowed(s); 76 } 77 78 const char PRINT_TYPE_FMT_NAME(string)[] = "\\\"%s\\\""; 79 80 /* Fetch type information table */ 81 static const struct fetch_type probe_fetch_types[] = { 82 /* Special types */ 83 __ASSIGN_FETCH_TYPE("string", string, string, sizeof(u32), 1, 1, 84 "__data_loc char[]"), 85 __ASSIGN_FETCH_TYPE("ustring", string, string, sizeof(u32), 1, 1, 86 "__data_loc char[]"), 87 __ASSIGN_FETCH_TYPE("symstr", string, string, sizeof(u32), 1, 1, 88 "__data_loc char[]"), 89 /* Basic types */ 90 ASSIGN_FETCH_TYPE(u8, u8, 0), 91 ASSIGN_FETCH_TYPE(u16, u16, 0), 92 ASSIGN_FETCH_TYPE(u32, u32, 0), 93 ASSIGN_FETCH_TYPE(u64, u64, 0), 94 ASSIGN_FETCH_TYPE(s8, u8, 1), 95 ASSIGN_FETCH_TYPE(s16, u16, 1), 96 ASSIGN_FETCH_TYPE(s32, u32, 1), 97 ASSIGN_FETCH_TYPE(s64, u64, 1), 98 ASSIGN_FETCH_TYPE_ALIAS(x8, u8, u8, 0), 99 ASSIGN_FETCH_TYPE_ALIAS(x16, u16, u16, 0), 100 ASSIGN_FETCH_TYPE_ALIAS(x32, u32, u32, 0), 101 ASSIGN_FETCH_TYPE_ALIAS(x64, u64, u64, 0), 102 ASSIGN_FETCH_TYPE_ALIAS(char, u8, u8, 0), 103 ASSIGN_FETCH_TYPE_ALIAS(symbol, ADDR_FETCH_TYPE, ADDR_FETCH_TYPE, 0), 104 105 ASSIGN_FETCH_TYPE_END 106 }; 107 108 static const struct fetch_type *find_fetch_type(const char *type, unsigned long flags) 109 { 110 int i; 111 112 /* Reject the symbol/symstr for uprobes */ 113 if (type && (flags & TPARG_FL_USER) && 114 (!strcmp(type, "symbol") || !strcmp(type, "symstr"))) 115 return NULL; 116 117 if (!type) 118 type = DEFAULT_FETCH_TYPE_STR; 119 120 /* Special case: bitfield */ 121 if (*type == 'b') { 122 unsigned long bs; 123 124 type = strchr(type, '/'); 125 if (!type) 126 goto fail; 127 128 type++; 129 if (kstrtoul(type, 0, &bs)) 130 goto fail; 131 132 switch (bs) { 133 case 8: 134 return find_fetch_type("u8", flags); 135 case 16: 136 return find_fetch_type("u16", flags); 137 case 32: 138 return find_fetch_type("u32", flags); 139 case 64: 140 return find_fetch_type("u64", flags); 141 default: 142 goto fail; 143 } 144 } 145 146 for (i = 0; probe_fetch_types[i].name; i++) { 147 if (strcmp(type, probe_fetch_types[i].name) == 0) 148 return &probe_fetch_types[i]; 149 } 150 151 fail: 152 return NULL; 153 } 154 155 static struct trace_probe_log trace_probe_log; 156 157 void trace_probe_log_init(const char *subsystem, int argc, const char **argv) 158 { 159 trace_probe_log.subsystem = subsystem; 160 trace_probe_log.argc = argc; 161 trace_probe_log.argv = argv; 162 trace_probe_log.index = 0; 163 } 164 165 void trace_probe_log_clear(void) 166 { 167 memset(&trace_probe_log, 0, sizeof(trace_probe_log)); 168 } 169 170 void trace_probe_log_set_index(int index) 171 { 172 trace_probe_log.index = index; 173 } 174 175 void __trace_probe_log_err(int offset, int err_type) 176 { 177 char *command, *p; 178 int i, len = 0, pos = 0; 179 180 if (!trace_probe_log.argv) 181 return; 182 183 /* Recalculate the length and allocate buffer */ 184 for (i = 0; i < trace_probe_log.argc; i++) { 185 if (i == trace_probe_log.index) 186 pos = len; 187 len += strlen(trace_probe_log.argv[i]) + 1; 188 } 189 command = kzalloc(len, GFP_KERNEL); 190 if (!command) 191 return; 192 193 if (trace_probe_log.index >= trace_probe_log.argc) { 194 /** 195 * Set the error position is next to the last arg + space. 196 * Note that len includes the terminal null and the cursor 197 * appears at pos + 1. 198 */ 199 pos = len; 200 offset = 0; 201 } 202 203 /* And make a command string from argv array */ 204 p = command; 205 for (i = 0; i < trace_probe_log.argc; i++) { 206 len = strlen(trace_probe_log.argv[i]); 207 strcpy(p, trace_probe_log.argv[i]); 208 p[len] = ' '; 209 p += len + 1; 210 } 211 *(p - 1) = '\0'; 212 213 tracing_log_err(NULL, trace_probe_log.subsystem, command, 214 trace_probe_err_text, err_type, pos + offset); 215 216 kfree(command); 217 } 218 219 /* Split symbol and offset. */ 220 int traceprobe_split_symbol_offset(char *symbol, long *offset) 221 { 222 char *tmp; 223 int ret; 224 225 if (!offset) 226 return -EINVAL; 227 228 tmp = strpbrk(symbol, "+-"); 229 if (tmp) { 230 ret = kstrtol(tmp, 0, offset); 231 if (ret) 232 return ret; 233 *tmp = '\0'; 234 } else 235 *offset = 0; 236 237 return 0; 238 } 239 240 /* @buf must has MAX_EVENT_NAME_LEN size */ 241 int traceprobe_parse_event_name(const char **pevent, const char **pgroup, 242 char *buf, int offset) 243 { 244 const char *slash, *event = *pevent; 245 int len; 246 247 slash = strchr(event, '/'); 248 if (!slash) 249 slash = strchr(event, '.'); 250 251 if (slash) { 252 if (slash == event) { 253 trace_probe_log_err(offset, NO_GROUP_NAME); 254 return -EINVAL; 255 } 256 if (slash - event + 1 > MAX_EVENT_NAME_LEN) { 257 trace_probe_log_err(offset, GROUP_TOO_LONG); 258 return -EINVAL; 259 } 260 strscpy(buf, event, slash - event + 1); 261 if (!is_good_system_name(buf)) { 262 trace_probe_log_err(offset, BAD_GROUP_NAME); 263 return -EINVAL; 264 } 265 *pgroup = buf; 266 *pevent = slash + 1; 267 offset += slash - event + 1; 268 event = *pevent; 269 } 270 len = strlen(event); 271 if (len == 0) { 272 if (slash) { 273 *pevent = NULL; 274 return 0; 275 } 276 trace_probe_log_err(offset, NO_EVENT_NAME); 277 return -EINVAL; 278 } else if (len > MAX_EVENT_NAME_LEN) { 279 trace_probe_log_err(offset, EVENT_TOO_LONG); 280 return -EINVAL; 281 } 282 if (!is_good_name(event)) { 283 trace_probe_log_err(offset, BAD_EVENT_NAME); 284 return -EINVAL; 285 } 286 return 0; 287 } 288 289 static int parse_trace_event_arg(char *arg, struct fetch_insn *code, 290 struct traceprobe_parse_context *ctx) 291 { 292 struct ftrace_event_field *field; 293 struct list_head *head; 294 295 head = trace_get_fields(ctx->event); 296 list_for_each_entry(field, head, link) { 297 if (!strcmp(arg, field->name)) { 298 code->op = FETCH_OP_TP_ARG; 299 code->data = field; 300 return 0; 301 } 302 } 303 return -ENOENT; 304 } 305 306 #ifdef CONFIG_PROBE_EVENTS_BTF_ARGS 307 308 static u32 btf_type_int(const struct btf_type *t) 309 { 310 return *(u32 *)(t + 1); 311 } 312 313 static bool btf_type_is_char_ptr(struct btf *btf, const struct btf_type *type) 314 { 315 const struct btf_type *real_type; 316 u32 intdata; 317 s32 tid; 318 319 real_type = btf_type_skip_modifiers(btf, type->type, &tid); 320 if (!real_type) 321 return false; 322 323 if (BTF_INFO_KIND(real_type->info) != BTF_KIND_INT) 324 return false; 325 326 intdata = btf_type_int(real_type); 327 return !(BTF_INT_ENCODING(intdata) & BTF_INT_SIGNED) 328 && BTF_INT_BITS(intdata) == 8; 329 } 330 331 static bool btf_type_is_char_array(struct btf *btf, const struct btf_type *type) 332 { 333 const struct btf_type *real_type; 334 const struct btf_array *array; 335 u32 intdata; 336 s32 tid; 337 338 if (BTF_INFO_KIND(type->info) != BTF_KIND_ARRAY) 339 return false; 340 341 array = (const struct btf_array *)(type + 1); 342 343 real_type = btf_type_skip_modifiers(btf, array->type, &tid); 344 345 intdata = btf_type_int(real_type); 346 return !(BTF_INT_ENCODING(intdata) & BTF_INT_SIGNED) 347 && BTF_INT_BITS(intdata) == 8; 348 } 349 350 static int check_prepare_btf_string_fetch(char *typename, 351 struct fetch_insn **pcode, 352 struct traceprobe_parse_context *ctx) 353 { 354 struct btf *btf = ctx->btf; 355 356 if (!btf || !ctx->last_type) 357 return 0; 358 359 /* char [] does not need any change. */ 360 if (btf_type_is_char_array(btf, ctx->last_type)) 361 return 0; 362 363 /* char * requires dereference the pointer. */ 364 if (btf_type_is_char_ptr(btf, ctx->last_type)) { 365 struct fetch_insn *code = *pcode + 1; 366 367 if (code->op == FETCH_OP_END) { 368 trace_probe_log_err(ctx->offset, TOO_MANY_OPS); 369 return -E2BIG; 370 } 371 if (typename[0] == 'u') 372 code->op = FETCH_OP_UDEREF; 373 else 374 code->op = FETCH_OP_DEREF; 375 code->offset = 0; 376 *pcode = code; 377 return 0; 378 } 379 /* Other types are not available for string */ 380 trace_probe_log_err(ctx->offset, BAD_TYPE4STR); 381 return -EINVAL; 382 } 383 384 static const char *fetch_type_from_btf_type(struct btf *btf, 385 const struct btf_type *type, 386 struct traceprobe_parse_context *ctx) 387 { 388 u32 intdata; 389 390 /* TODO: const char * could be converted as a string */ 391 switch (BTF_INFO_KIND(type->info)) { 392 case BTF_KIND_ENUM: 393 /* enum is "int", so convert to "s32" */ 394 return "s32"; 395 case BTF_KIND_ENUM64: 396 return "s64"; 397 case BTF_KIND_PTR: 398 /* pointer will be converted to "x??" */ 399 if (IS_ENABLED(CONFIG_64BIT)) 400 return "x64"; 401 else 402 return "x32"; 403 case BTF_KIND_INT: 404 intdata = btf_type_int(type); 405 if (BTF_INT_ENCODING(intdata) & BTF_INT_SIGNED) { 406 switch (BTF_INT_BITS(intdata)) { 407 case 8: 408 return "s8"; 409 case 16: 410 return "s16"; 411 case 32: 412 return "s32"; 413 case 64: 414 return "s64"; 415 } 416 } else { /* unsigned */ 417 switch (BTF_INT_BITS(intdata)) { 418 case 8: 419 return "u8"; 420 case 16: 421 return "u16"; 422 case 32: 423 return "u32"; 424 case 64: 425 return "u64"; 426 } 427 /* bitfield, size is encoded in the type */ 428 ctx->last_bitsize = BTF_INT_BITS(intdata); 429 ctx->last_bitoffs += BTF_INT_OFFSET(intdata); 430 return "u64"; 431 } 432 } 433 /* TODO: support other types */ 434 435 return NULL; 436 } 437 438 static int query_btf_context(struct traceprobe_parse_context *ctx) 439 { 440 const struct btf_param *param; 441 const struct btf_type *type; 442 struct btf *btf; 443 s32 nr; 444 445 if (ctx->btf) 446 return 0; 447 448 if (!ctx->funcname) 449 return -EINVAL; 450 451 type = btf_find_func_proto(ctx->funcname, &btf); 452 if (!type) 453 return -ENOENT; 454 455 ctx->btf = btf; 456 ctx->proto = type; 457 458 /* ctx->params is optional, since func(void) will not have params. */ 459 nr = 0; 460 param = btf_get_func_param(type, &nr); 461 if (!IS_ERR_OR_NULL(param)) { 462 /* Hide the first 'data' argument of tracepoint */ 463 if (ctx->flags & TPARG_FL_TPOINT) { 464 nr--; 465 param++; 466 } 467 } 468 469 if (nr > 0) { 470 ctx->nr_params = nr; 471 ctx->params = param; 472 } else { 473 ctx->nr_params = 0; 474 ctx->params = NULL; 475 } 476 477 return 0; 478 } 479 480 static void clear_btf_context(struct traceprobe_parse_context *ctx) 481 { 482 if (ctx->btf) { 483 btf_put(ctx->btf); 484 ctx->btf = NULL; 485 ctx->proto = NULL; 486 ctx->params = NULL; 487 ctx->nr_params = 0; 488 } 489 } 490 491 /* Return 1 if the field separater is arrow operator ('->') */ 492 static int split_next_field(char *varname, char **next_field, 493 struct traceprobe_parse_context *ctx) 494 { 495 char *field; 496 int ret = 0; 497 498 field = strpbrk(varname, ".-"); 499 if (field) { 500 if (field[0] == '-' && field[1] == '>') { 501 field[0] = '\0'; 502 field += 2; 503 ret = 1; 504 } else if (field[0] == '.') { 505 field[0] = '\0'; 506 field += 1; 507 } else { 508 trace_probe_log_err(ctx->offset + field - varname, BAD_HYPHEN); 509 return -EINVAL; 510 } 511 *next_field = field; 512 } 513 514 return ret; 515 } 516 517 /* 518 * Parse the field of data structure. The @type must be a pointer type 519 * pointing the target data structure type. 520 */ 521 static int parse_btf_field(char *fieldname, const struct btf_type *type, 522 struct fetch_insn **pcode, struct fetch_insn *end, 523 struct traceprobe_parse_context *ctx) 524 { 525 struct fetch_insn *code = *pcode; 526 const struct btf_member *field; 527 u32 bitoffs, anon_offs; 528 char *next; 529 int is_ptr; 530 s32 tid; 531 532 do { 533 /* Outer loop for solving arrow operator ('->') */ 534 if (BTF_INFO_KIND(type->info) != BTF_KIND_PTR) { 535 trace_probe_log_err(ctx->offset, NO_PTR_STRCT); 536 return -EINVAL; 537 } 538 /* Convert a struct pointer type to a struct type */ 539 type = btf_type_skip_modifiers(ctx->btf, type->type, &tid); 540 if (!type) { 541 trace_probe_log_err(ctx->offset, BAD_BTF_TID); 542 return -EINVAL; 543 } 544 545 bitoffs = 0; 546 do { 547 /* Inner loop for solving dot operator ('.') */ 548 next = NULL; 549 is_ptr = split_next_field(fieldname, &next, ctx); 550 if (is_ptr < 0) 551 return is_ptr; 552 553 anon_offs = 0; 554 field = btf_find_struct_member(ctx->btf, type, fieldname, 555 &anon_offs); 556 if (IS_ERR(field)) { 557 trace_probe_log_err(ctx->offset, BAD_BTF_TID); 558 return PTR_ERR(field); 559 } 560 if (!field) { 561 trace_probe_log_err(ctx->offset, NO_BTF_FIELD); 562 return -ENOENT; 563 } 564 /* Add anonymous structure/union offset */ 565 bitoffs += anon_offs; 566 567 /* Accumulate the bit-offsets of the dot-connected fields */ 568 if (btf_type_kflag(type)) { 569 bitoffs += BTF_MEMBER_BIT_OFFSET(field->offset); 570 ctx->last_bitsize = BTF_MEMBER_BITFIELD_SIZE(field->offset); 571 } else { 572 bitoffs += field->offset; 573 ctx->last_bitsize = 0; 574 } 575 576 type = btf_type_skip_modifiers(ctx->btf, field->type, &tid); 577 if (!type) { 578 trace_probe_log_err(ctx->offset, BAD_BTF_TID); 579 return -EINVAL; 580 } 581 582 ctx->offset += next - fieldname; 583 fieldname = next; 584 } while (!is_ptr && fieldname); 585 586 if (++code == end) { 587 trace_probe_log_err(ctx->offset, TOO_MANY_OPS); 588 return -EINVAL; 589 } 590 code->op = FETCH_OP_DEREF; /* TODO: user deref support */ 591 code->offset = bitoffs / 8; 592 *pcode = code; 593 594 ctx->last_bitoffs = bitoffs % 8; 595 ctx->last_type = type; 596 } while (fieldname); 597 598 return 0; 599 } 600 601 static int parse_btf_arg(char *varname, 602 struct fetch_insn **pcode, struct fetch_insn *end, 603 struct traceprobe_parse_context *ctx) 604 { 605 struct fetch_insn *code = *pcode; 606 const struct btf_param *params; 607 const struct btf_type *type; 608 char *field = NULL; 609 int i, is_ptr, ret; 610 u32 tid; 611 612 if (WARN_ON_ONCE(!ctx->funcname)) 613 return -EINVAL; 614 615 is_ptr = split_next_field(varname, &field, ctx); 616 if (is_ptr < 0) 617 return is_ptr; 618 if (!is_ptr && field) { 619 /* dot-connected field on an argument is not supported. */ 620 trace_probe_log_err(ctx->offset + field - varname, 621 NOSUP_DAT_ARG); 622 return -EOPNOTSUPP; 623 } 624 625 if (ctx->flags & TPARG_FL_RETURN) { 626 if (strcmp(varname, "$retval") != 0) { 627 trace_probe_log_err(ctx->offset, NO_BTFARG); 628 return -ENOENT; 629 } 630 code->op = FETCH_OP_RETVAL; 631 /* Check whether the function return type is not void */ 632 if (query_btf_context(ctx) == 0) { 633 if (ctx->proto->type == 0) { 634 trace_probe_log_err(ctx->offset, NO_RETVAL); 635 return -ENOENT; 636 } 637 tid = ctx->proto->type; 638 goto found; 639 } 640 if (field) { 641 trace_probe_log_err(ctx->offset + field - varname, 642 NO_BTF_ENTRY); 643 return -ENOENT; 644 } 645 return 0; 646 } 647 648 if (!ctx->btf) { 649 ret = query_btf_context(ctx); 650 if (ret < 0 || ctx->nr_params == 0) { 651 trace_probe_log_err(ctx->offset, NO_BTF_ENTRY); 652 return PTR_ERR(params); 653 } 654 } 655 params = ctx->params; 656 657 for (i = 0; i < ctx->nr_params; i++) { 658 const char *name = btf_name_by_offset(ctx->btf, params[i].name_off); 659 660 if (name && !strcmp(name, varname)) { 661 code->op = FETCH_OP_ARG; 662 if (ctx->flags & TPARG_FL_TPOINT) 663 code->param = i + 1; 664 else 665 code->param = i; 666 tid = params[i].type; 667 goto found; 668 } 669 } 670 trace_probe_log_err(ctx->offset, NO_BTFARG); 671 return -ENOENT; 672 673 found: 674 type = btf_type_skip_modifiers(ctx->btf, tid, &tid); 675 if (!type) { 676 trace_probe_log_err(ctx->offset, BAD_BTF_TID); 677 return -EINVAL; 678 } 679 /* Initialize the last type information */ 680 ctx->last_type = type; 681 ctx->last_bitoffs = 0; 682 ctx->last_bitsize = 0; 683 if (field) { 684 ctx->offset += field - varname; 685 return parse_btf_field(field, type, pcode, end, ctx); 686 } 687 return 0; 688 } 689 690 static const struct fetch_type *find_fetch_type_from_btf_type( 691 struct traceprobe_parse_context *ctx) 692 { 693 struct btf *btf = ctx->btf; 694 const char *typestr = NULL; 695 696 if (btf && ctx->last_type) 697 typestr = fetch_type_from_btf_type(btf, ctx->last_type, ctx); 698 699 return find_fetch_type(typestr, ctx->flags); 700 } 701 702 static int parse_btf_bitfield(struct fetch_insn **pcode, 703 struct traceprobe_parse_context *ctx) 704 { 705 struct fetch_insn *code = *pcode; 706 707 if ((ctx->last_bitsize % 8 == 0) && ctx->last_bitoffs == 0) 708 return 0; 709 710 code++; 711 if (code->op != FETCH_OP_NOP) { 712 trace_probe_log_err(ctx->offset, TOO_MANY_OPS); 713 return -EINVAL; 714 } 715 *pcode = code; 716 717 code->op = FETCH_OP_MOD_BF; 718 code->lshift = 64 - (ctx->last_bitsize + ctx->last_bitoffs); 719 code->rshift = 64 - ctx->last_bitsize; 720 code->basesize = 64 / 8; 721 return 0; 722 } 723 724 #else 725 static void clear_btf_context(struct traceprobe_parse_context *ctx) 726 { 727 ctx->btf = NULL; 728 } 729 730 static int query_btf_context(struct traceprobe_parse_context *ctx) 731 { 732 return -EOPNOTSUPP; 733 } 734 735 static int parse_btf_arg(char *varname, 736 struct fetch_insn **pcode, struct fetch_insn *end, 737 struct traceprobe_parse_context *ctx) 738 { 739 trace_probe_log_err(ctx->offset, NOSUP_BTFARG); 740 return -EOPNOTSUPP; 741 } 742 743 static int parse_btf_bitfield(struct fetch_insn **pcode, 744 struct traceprobe_parse_context *ctx) 745 { 746 trace_probe_log_err(ctx->offset, NOSUP_BTFARG); 747 return -EOPNOTSUPP; 748 } 749 750 #define find_fetch_type_from_btf_type(ctx) \ 751 find_fetch_type(NULL, ctx->flags) 752 753 static int check_prepare_btf_string_fetch(char *typename, 754 struct fetch_insn **pcode, 755 struct traceprobe_parse_context *ctx) 756 { 757 return 0; 758 } 759 760 #endif 761 762 #define PARAM_MAX_STACK (THREAD_SIZE / sizeof(unsigned long)) 763 764 /* Parse $vars. @orig_arg points '$', which syncs to @ctx->offset */ 765 static int parse_probe_vars(char *orig_arg, const struct fetch_type *t, 766 struct fetch_insn **pcode, 767 struct fetch_insn *end, 768 struct traceprobe_parse_context *ctx) 769 { 770 struct fetch_insn *code = *pcode; 771 int err = TP_ERR_BAD_VAR; 772 char *arg = orig_arg + 1; 773 unsigned long param; 774 int ret = 0; 775 int len; 776 777 if (ctx->flags & TPARG_FL_TEVENT) { 778 if (code->data) 779 return -EFAULT; 780 ret = parse_trace_event_arg(arg, code, ctx); 781 if (!ret) 782 return 0; 783 if (strcmp(arg, "comm") == 0 || strcmp(arg, "COMM") == 0) { 784 code->op = FETCH_OP_COMM; 785 return 0; 786 } 787 /* backward compatibility */ 788 ctx->offset = 0; 789 goto inval; 790 } 791 792 if (str_has_prefix(arg, "retval")) { 793 if (!(ctx->flags & TPARG_FL_RETURN)) { 794 err = TP_ERR_RETVAL_ON_PROBE; 795 goto inval; 796 } 797 if (!(ctx->flags & TPARG_FL_KERNEL) || 798 !IS_ENABLED(CONFIG_PROBE_EVENTS_BTF_ARGS)) { 799 code->op = FETCH_OP_RETVAL; 800 return 0; 801 } 802 return parse_btf_arg(orig_arg, pcode, end, ctx); 803 } 804 805 len = str_has_prefix(arg, "stack"); 806 if (len) { 807 808 if (arg[len] == '\0') { 809 code->op = FETCH_OP_STACKP; 810 return 0; 811 } 812 813 if (isdigit(arg[len])) { 814 ret = kstrtoul(arg + len, 10, ¶m); 815 if (ret) 816 goto inval; 817 818 if ((ctx->flags & TPARG_FL_KERNEL) && 819 param > PARAM_MAX_STACK) { 820 err = TP_ERR_BAD_STACK_NUM; 821 goto inval; 822 } 823 code->op = FETCH_OP_STACK; 824 code->param = (unsigned int)param; 825 return 0; 826 } 827 goto inval; 828 } 829 830 if (strcmp(arg, "comm") == 0 || strcmp(arg, "COMM") == 0) { 831 code->op = FETCH_OP_COMM; 832 return 0; 833 } 834 835 #ifdef CONFIG_HAVE_FUNCTION_ARG_ACCESS_API 836 len = str_has_prefix(arg, "arg"); 837 if (len && tparg_is_function_entry(ctx->flags)) { 838 ret = kstrtoul(arg + len, 10, ¶m); 839 if (ret) 840 goto inval; 841 842 if (!param || param > PARAM_MAX_STACK) { 843 err = TP_ERR_BAD_ARG_NUM; 844 goto inval; 845 } 846 847 code->op = FETCH_OP_ARG; 848 code->param = (unsigned int)param - 1; 849 /* 850 * The tracepoint probe will probe a stub function, and the 851 * first parameter of the stub is a dummy and should be ignored. 852 */ 853 if (ctx->flags & TPARG_FL_TPOINT) 854 code->param++; 855 return 0; 856 } 857 #endif 858 859 inval: 860 __trace_probe_log_err(ctx->offset, err); 861 return -EINVAL; 862 } 863 864 static int str_to_immediate(char *str, unsigned long *imm) 865 { 866 if (isdigit(str[0])) 867 return kstrtoul(str, 0, imm); 868 else if (str[0] == '-') 869 return kstrtol(str, 0, (long *)imm); 870 else if (str[0] == '+') 871 return kstrtol(str + 1, 0, (long *)imm); 872 return -EINVAL; 873 } 874 875 static int __parse_imm_string(char *str, char **pbuf, int offs) 876 { 877 size_t len = strlen(str); 878 879 if (str[len - 1] != '"') { 880 trace_probe_log_err(offs + len, IMMSTR_NO_CLOSE); 881 return -EINVAL; 882 } 883 *pbuf = kstrndup(str, len - 1, GFP_KERNEL); 884 if (!*pbuf) 885 return -ENOMEM; 886 return 0; 887 } 888 889 /* Recursive argument parser */ 890 static int 891 parse_probe_arg(char *arg, const struct fetch_type *type, 892 struct fetch_insn **pcode, struct fetch_insn *end, 893 struct traceprobe_parse_context *ctx) 894 { 895 struct fetch_insn *code = *pcode; 896 unsigned long param; 897 int deref = FETCH_OP_DEREF; 898 long offset = 0; 899 char *tmp; 900 int ret = 0; 901 902 switch (arg[0]) { 903 case '$': 904 ret = parse_probe_vars(arg, type, pcode, end, ctx); 905 break; 906 907 case '%': /* named register */ 908 if (ctx->flags & (TPARG_FL_TEVENT | TPARG_FL_FPROBE)) { 909 /* eprobe and fprobe do not handle registers */ 910 trace_probe_log_err(ctx->offset, BAD_VAR); 911 break; 912 } 913 ret = regs_query_register_offset(arg + 1); 914 if (ret >= 0) { 915 code->op = FETCH_OP_REG; 916 code->param = (unsigned int)ret; 917 ret = 0; 918 } else 919 trace_probe_log_err(ctx->offset, BAD_REG_NAME); 920 break; 921 922 case '@': /* memory, file-offset or symbol */ 923 if (isdigit(arg[1])) { 924 ret = kstrtoul(arg + 1, 0, ¶m); 925 if (ret) { 926 trace_probe_log_err(ctx->offset, BAD_MEM_ADDR); 927 break; 928 } 929 /* load address */ 930 code->op = FETCH_OP_IMM; 931 code->immediate = param; 932 } else if (arg[1] == '+') { 933 /* kprobes don't support file offsets */ 934 if (ctx->flags & TPARG_FL_KERNEL) { 935 trace_probe_log_err(ctx->offset, FILE_ON_KPROBE); 936 return -EINVAL; 937 } 938 ret = kstrtol(arg + 2, 0, &offset); 939 if (ret) { 940 trace_probe_log_err(ctx->offset, BAD_FILE_OFFS); 941 break; 942 } 943 944 code->op = FETCH_OP_FOFFS; 945 code->immediate = (unsigned long)offset; // imm64? 946 } else { 947 /* uprobes don't support symbols */ 948 if (!(ctx->flags & TPARG_FL_KERNEL)) { 949 trace_probe_log_err(ctx->offset, SYM_ON_UPROBE); 950 return -EINVAL; 951 } 952 /* Preserve symbol for updating */ 953 code->op = FETCH_NOP_SYMBOL; 954 code->data = kstrdup(arg + 1, GFP_KERNEL); 955 if (!code->data) 956 return -ENOMEM; 957 if (++code == end) { 958 trace_probe_log_err(ctx->offset, TOO_MANY_OPS); 959 return -EINVAL; 960 } 961 code->op = FETCH_OP_IMM; 962 code->immediate = 0; 963 } 964 /* These are fetching from memory */ 965 if (++code == end) { 966 trace_probe_log_err(ctx->offset, TOO_MANY_OPS); 967 return -EINVAL; 968 } 969 *pcode = code; 970 code->op = FETCH_OP_DEREF; 971 code->offset = offset; 972 break; 973 974 case '+': /* deref memory */ 975 case '-': 976 if (arg[1] == 'u') { 977 deref = FETCH_OP_UDEREF; 978 arg[1] = arg[0]; 979 arg++; 980 } 981 if (arg[0] == '+') 982 arg++; /* Skip '+', because kstrtol() rejects it. */ 983 tmp = strchr(arg, '('); 984 if (!tmp) { 985 trace_probe_log_err(ctx->offset, DEREF_NEED_BRACE); 986 return -EINVAL; 987 } 988 *tmp = '\0'; 989 ret = kstrtol(arg, 0, &offset); 990 if (ret) { 991 trace_probe_log_err(ctx->offset, BAD_DEREF_OFFS); 992 break; 993 } 994 ctx->offset += (tmp + 1 - arg) + (arg[0] != '-' ? 1 : 0); 995 arg = tmp + 1; 996 tmp = strrchr(arg, ')'); 997 if (!tmp) { 998 trace_probe_log_err(ctx->offset + strlen(arg), 999 DEREF_OPEN_BRACE); 1000 return -EINVAL; 1001 } else { 1002 const struct fetch_type *t2 = find_fetch_type(NULL, ctx->flags); 1003 int cur_offs = ctx->offset; 1004 1005 *tmp = '\0'; 1006 ret = parse_probe_arg(arg, t2, &code, end, ctx); 1007 if (ret) 1008 break; 1009 ctx->offset = cur_offs; 1010 if (code->op == FETCH_OP_COMM || 1011 code->op == FETCH_OP_DATA) { 1012 trace_probe_log_err(ctx->offset, COMM_CANT_DEREF); 1013 return -EINVAL; 1014 } 1015 if (++code == end) { 1016 trace_probe_log_err(ctx->offset, TOO_MANY_OPS); 1017 return -EINVAL; 1018 } 1019 *pcode = code; 1020 1021 code->op = deref; 1022 code->offset = offset; 1023 /* Reset the last type if used */ 1024 ctx->last_type = NULL; 1025 } 1026 break; 1027 case '\\': /* Immediate value */ 1028 if (arg[1] == '"') { /* Immediate string */ 1029 ret = __parse_imm_string(arg + 2, &tmp, ctx->offset + 2); 1030 if (ret) 1031 break; 1032 code->op = FETCH_OP_DATA; 1033 code->data = tmp; 1034 } else { 1035 ret = str_to_immediate(arg + 1, &code->immediate); 1036 if (ret) 1037 trace_probe_log_err(ctx->offset + 1, BAD_IMM); 1038 else 1039 code->op = FETCH_OP_IMM; 1040 } 1041 break; 1042 default: 1043 if (isalpha(arg[0]) || arg[0] == '_') { /* BTF variable */ 1044 if (!tparg_is_function_entry(ctx->flags)) { 1045 trace_probe_log_err(ctx->offset, NOSUP_BTFARG); 1046 return -EINVAL; 1047 } 1048 ret = parse_btf_arg(arg, pcode, end, ctx); 1049 break; 1050 } 1051 } 1052 if (!ret && code->op == FETCH_OP_NOP) { 1053 /* Parsed, but do not find fetch method */ 1054 trace_probe_log_err(ctx->offset, BAD_FETCH_ARG); 1055 ret = -EINVAL; 1056 } 1057 return ret; 1058 } 1059 1060 #define BYTES_TO_BITS(nb) ((BITS_PER_LONG * (nb)) / sizeof(long)) 1061 1062 /* Bitfield type needs to be parsed into a fetch function */ 1063 static int __parse_bitfield_probe_arg(const char *bf, 1064 const struct fetch_type *t, 1065 struct fetch_insn **pcode) 1066 { 1067 struct fetch_insn *code = *pcode; 1068 unsigned long bw, bo; 1069 char *tail; 1070 1071 if (*bf != 'b') 1072 return 0; 1073 1074 bw = simple_strtoul(bf + 1, &tail, 0); /* Use simple one */ 1075 1076 if (bw == 0 || *tail != '@') 1077 return -EINVAL; 1078 1079 bf = tail + 1; 1080 bo = simple_strtoul(bf, &tail, 0); 1081 1082 if (tail == bf || *tail != '/') 1083 return -EINVAL; 1084 code++; 1085 if (code->op != FETCH_OP_NOP) 1086 return -EINVAL; 1087 *pcode = code; 1088 1089 code->op = FETCH_OP_MOD_BF; 1090 code->lshift = BYTES_TO_BITS(t->size) - (bw + bo); 1091 code->rshift = BYTES_TO_BITS(t->size) - bw; 1092 code->basesize = t->size; 1093 1094 return (BYTES_TO_BITS(t->size) < (bw + bo)) ? -EINVAL : 0; 1095 } 1096 1097 /* String length checking wrapper */ 1098 static int traceprobe_parse_probe_arg_body(const char *argv, ssize_t *size, 1099 struct probe_arg *parg, 1100 struct traceprobe_parse_context *ctx) 1101 { 1102 struct fetch_insn *code, *scode, *tmp = NULL; 1103 char *t, *t2, *t3; 1104 int ret, len; 1105 char *arg; 1106 1107 arg = kstrdup(argv, GFP_KERNEL); 1108 if (!arg) 1109 return -ENOMEM; 1110 1111 ret = -EINVAL; 1112 len = strlen(arg); 1113 if (len > MAX_ARGSTR_LEN) { 1114 trace_probe_log_err(ctx->offset, ARG_TOO_LONG); 1115 goto out; 1116 } else if (len == 0) { 1117 trace_probe_log_err(ctx->offset, NO_ARG_BODY); 1118 goto out; 1119 } 1120 1121 ret = -ENOMEM; 1122 parg->comm = kstrdup(arg, GFP_KERNEL); 1123 if (!parg->comm) 1124 goto out; 1125 1126 ret = -EINVAL; 1127 t = strchr(arg, ':'); 1128 if (t) { 1129 *t = '\0'; 1130 t2 = strchr(++t, '['); 1131 if (t2) { 1132 *t2++ = '\0'; 1133 t3 = strchr(t2, ']'); 1134 if (!t3) { 1135 int offs = t2 + strlen(t2) - arg; 1136 1137 trace_probe_log_err(ctx->offset + offs, 1138 ARRAY_NO_CLOSE); 1139 goto out; 1140 } else if (t3[1] != '\0') { 1141 trace_probe_log_err(ctx->offset + t3 + 1 - arg, 1142 BAD_ARRAY_SUFFIX); 1143 goto out; 1144 } 1145 *t3 = '\0'; 1146 if (kstrtouint(t2, 0, &parg->count) || !parg->count) { 1147 trace_probe_log_err(ctx->offset + t2 - arg, 1148 BAD_ARRAY_NUM); 1149 goto out; 1150 } 1151 if (parg->count > MAX_ARRAY_LEN) { 1152 trace_probe_log_err(ctx->offset + t2 - arg, 1153 ARRAY_TOO_BIG); 1154 goto out; 1155 } 1156 } 1157 } 1158 1159 /* 1160 * Since $comm and immediate string can not be dereferenced, 1161 * we can find those by strcmp. But ignore for eprobes. 1162 */ 1163 if (!(ctx->flags & TPARG_FL_TEVENT) && 1164 (strcmp(arg, "$comm") == 0 || strcmp(arg, "$COMM") == 0 || 1165 strncmp(arg, "\\\"", 2) == 0)) { 1166 /* The type of $comm must be "string", and not an array type. */ 1167 if (parg->count || (t && strcmp(t, "string"))) { 1168 trace_probe_log_err(ctx->offset + (t ? (t - arg) : 0), 1169 NEED_STRING_TYPE); 1170 goto out; 1171 } 1172 parg->type = find_fetch_type("string", ctx->flags); 1173 } else 1174 parg->type = find_fetch_type(t, ctx->flags); 1175 if (!parg->type) { 1176 trace_probe_log_err(ctx->offset + (t ? (t - arg) : 0), BAD_TYPE); 1177 goto out; 1178 } 1179 1180 code = tmp = kcalloc(FETCH_INSN_MAX, sizeof(*code), GFP_KERNEL); 1181 if (!code) 1182 goto out; 1183 code[FETCH_INSN_MAX - 1].op = FETCH_OP_END; 1184 1185 ctx->last_type = NULL; 1186 ret = parse_probe_arg(arg, parg->type, &code, &code[FETCH_INSN_MAX - 1], 1187 ctx); 1188 if (ret) 1189 goto fail; 1190 1191 /* Update storing type if BTF is available */ 1192 if (IS_ENABLED(CONFIG_PROBE_EVENTS_BTF_ARGS) && 1193 ctx->last_type) { 1194 if (!t) { 1195 parg->type = find_fetch_type_from_btf_type(ctx); 1196 } else if (strstr(t, "string")) { 1197 ret = check_prepare_btf_string_fetch(t, &code, ctx); 1198 if (ret) 1199 goto fail; 1200 } 1201 } 1202 parg->offset = *size; 1203 *size += parg->type->size * (parg->count ?: 1); 1204 1205 if (parg->count) { 1206 len = strlen(parg->type->fmttype) + 6; 1207 parg->fmt = kmalloc(len, GFP_KERNEL); 1208 if (!parg->fmt) { 1209 ret = -ENOMEM; 1210 goto out; 1211 } 1212 snprintf(parg->fmt, len, "%s[%d]", parg->type->fmttype, 1213 parg->count); 1214 } 1215 1216 ret = -EINVAL; 1217 /* Store operation */ 1218 if (parg->type->is_string) { 1219 if (!strcmp(parg->type->name, "symstr")) { 1220 if (code->op != FETCH_OP_REG && code->op != FETCH_OP_STACK && 1221 code->op != FETCH_OP_RETVAL && code->op != FETCH_OP_ARG && 1222 code->op != FETCH_OP_DEREF && code->op != FETCH_OP_TP_ARG) { 1223 trace_probe_log_err(ctx->offset + (t ? (t - arg) : 0), 1224 BAD_SYMSTRING); 1225 goto fail; 1226 } 1227 } else { 1228 if (code->op != FETCH_OP_DEREF && code->op != FETCH_OP_UDEREF && 1229 code->op != FETCH_OP_IMM && code->op != FETCH_OP_COMM && 1230 code->op != FETCH_OP_DATA && code->op != FETCH_OP_TP_ARG) { 1231 trace_probe_log_err(ctx->offset + (t ? (t - arg) : 0), 1232 BAD_STRING); 1233 goto fail; 1234 } 1235 } 1236 if (!strcmp(parg->type->name, "symstr") || 1237 (code->op == FETCH_OP_IMM || code->op == FETCH_OP_COMM || 1238 code->op == FETCH_OP_DATA) || code->op == FETCH_OP_TP_ARG || 1239 parg->count) { 1240 /* 1241 * IMM, DATA and COMM is pointing actual address, those 1242 * must be kept, and if parg->count != 0, this is an 1243 * array of string pointers instead of string address 1244 * itself. 1245 * For the symstr, it doesn't need to dereference, thus 1246 * it just get the value. 1247 */ 1248 code++; 1249 if (code->op != FETCH_OP_NOP) { 1250 trace_probe_log_err(ctx->offset, TOO_MANY_OPS); 1251 goto fail; 1252 } 1253 } 1254 /* If op == DEREF, replace it with STRING */ 1255 if (!strcmp(parg->type->name, "ustring") || 1256 code->op == FETCH_OP_UDEREF) 1257 code->op = FETCH_OP_ST_USTRING; 1258 else if (!strcmp(parg->type->name, "symstr")) 1259 code->op = FETCH_OP_ST_SYMSTR; 1260 else 1261 code->op = FETCH_OP_ST_STRING; 1262 code->size = parg->type->size; 1263 parg->dynamic = true; 1264 } else if (code->op == FETCH_OP_DEREF) { 1265 code->op = FETCH_OP_ST_MEM; 1266 code->size = parg->type->size; 1267 } else if (code->op == FETCH_OP_UDEREF) { 1268 code->op = FETCH_OP_ST_UMEM; 1269 code->size = parg->type->size; 1270 } else { 1271 code++; 1272 if (code->op != FETCH_OP_NOP) { 1273 trace_probe_log_err(ctx->offset, TOO_MANY_OPS); 1274 goto fail; 1275 } 1276 code->op = FETCH_OP_ST_RAW; 1277 code->size = parg->type->size; 1278 } 1279 scode = code; 1280 /* Modify operation */ 1281 if (t != NULL) { 1282 ret = __parse_bitfield_probe_arg(t, parg->type, &code); 1283 if (ret) { 1284 trace_probe_log_err(ctx->offset + t - arg, BAD_BITFIELD); 1285 goto fail; 1286 } 1287 } else if (IS_ENABLED(CONFIG_PROBE_EVENTS_BTF_ARGS) && 1288 ctx->last_type) { 1289 ret = parse_btf_bitfield(&code, ctx); 1290 if (ret) 1291 goto fail; 1292 } 1293 ret = -EINVAL; 1294 /* Loop(Array) operation */ 1295 if (parg->count) { 1296 if (scode->op != FETCH_OP_ST_MEM && 1297 scode->op != FETCH_OP_ST_STRING && 1298 scode->op != FETCH_OP_ST_USTRING) { 1299 trace_probe_log_err(ctx->offset + (t ? (t - arg) : 0), 1300 BAD_STRING); 1301 goto fail; 1302 } 1303 code++; 1304 if (code->op != FETCH_OP_NOP) { 1305 trace_probe_log_err(ctx->offset, TOO_MANY_OPS); 1306 goto fail; 1307 } 1308 code->op = FETCH_OP_LP_ARRAY; 1309 code->param = parg->count; 1310 } 1311 code++; 1312 code->op = FETCH_OP_END; 1313 1314 ret = 0; 1315 /* Shrink down the code buffer */ 1316 parg->code = kcalloc(code - tmp + 1, sizeof(*code), GFP_KERNEL); 1317 if (!parg->code) 1318 ret = -ENOMEM; 1319 else 1320 memcpy(parg->code, tmp, sizeof(*code) * (code - tmp + 1)); 1321 1322 fail: 1323 if (ret) { 1324 for (code = tmp; code < tmp + FETCH_INSN_MAX; code++) 1325 if (code->op == FETCH_NOP_SYMBOL || 1326 code->op == FETCH_OP_DATA) 1327 kfree(code->data); 1328 } 1329 kfree(tmp); 1330 out: 1331 kfree(arg); 1332 1333 return ret; 1334 } 1335 1336 /* Return 1 if name is reserved or already used by another argument */ 1337 static int traceprobe_conflict_field_name(const char *name, 1338 struct probe_arg *args, int narg) 1339 { 1340 int i; 1341 1342 for (i = 0; i < ARRAY_SIZE(reserved_field_names); i++) 1343 if (strcmp(reserved_field_names[i], name) == 0) 1344 return 1; 1345 1346 for (i = 0; i < narg; i++) 1347 if (strcmp(args[i].name, name) == 0) 1348 return 1; 1349 1350 return 0; 1351 } 1352 1353 static char *generate_probe_arg_name(const char *arg, int idx) 1354 { 1355 char *name = NULL; 1356 const char *end; 1357 1358 /* 1359 * If argument name is omitted, try arg as a name (BTF variable) 1360 * or "argN". 1361 */ 1362 if (IS_ENABLED(CONFIG_PROBE_EVENTS_BTF_ARGS)) { 1363 end = strchr(arg, ':'); 1364 if (!end) 1365 end = arg + strlen(arg); 1366 1367 name = kmemdup_nul(arg, end - arg, GFP_KERNEL); 1368 if (!name || !is_good_name(name)) { 1369 kfree(name); 1370 name = NULL; 1371 } 1372 } 1373 1374 if (!name) 1375 name = kasprintf(GFP_KERNEL, "arg%d", idx + 1); 1376 1377 return name; 1378 } 1379 1380 int traceprobe_parse_probe_arg(struct trace_probe *tp, int i, const char *arg, 1381 struct traceprobe_parse_context *ctx) 1382 { 1383 struct probe_arg *parg = &tp->args[i]; 1384 const char *body; 1385 1386 /* Increment count for freeing args in error case */ 1387 tp->nr_args++; 1388 1389 body = strchr(arg, '='); 1390 if (body) { 1391 if (body - arg > MAX_ARG_NAME_LEN) { 1392 trace_probe_log_err(0, ARG_NAME_TOO_LONG); 1393 return -EINVAL; 1394 } else if (body == arg) { 1395 trace_probe_log_err(0, NO_ARG_NAME); 1396 return -EINVAL; 1397 } 1398 parg->name = kmemdup_nul(arg, body - arg, GFP_KERNEL); 1399 body++; 1400 } else { 1401 parg->name = generate_probe_arg_name(arg, i); 1402 body = arg; 1403 } 1404 if (!parg->name) 1405 return -ENOMEM; 1406 1407 if (!is_good_name(parg->name)) { 1408 trace_probe_log_err(0, BAD_ARG_NAME); 1409 return -EINVAL; 1410 } 1411 if (traceprobe_conflict_field_name(parg->name, tp->args, i)) { 1412 trace_probe_log_err(0, USED_ARG_NAME); 1413 return -EINVAL; 1414 } 1415 ctx->offset = body - arg; 1416 /* Parse fetch argument */ 1417 return traceprobe_parse_probe_arg_body(body, &tp->size, parg, ctx); 1418 } 1419 1420 void traceprobe_free_probe_arg(struct probe_arg *arg) 1421 { 1422 struct fetch_insn *code = arg->code; 1423 1424 while (code && code->op != FETCH_OP_END) { 1425 if (code->op == FETCH_NOP_SYMBOL || 1426 code->op == FETCH_OP_DATA) 1427 kfree(code->data); 1428 code++; 1429 } 1430 kfree(arg->code); 1431 kfree(arg->name); 1432 kfree(arg->comm); 1433 kfree(arg->fmt); 1434 } 1435 1436 static int argv_has_var_arg(int argc, const char *argv[], int *args_idx, 1437 struct traceprobe_parse_context *ctx) 1438 { 1439 int i, found = 0; 1440 1441 for (i = 0; i < argc; i++) 1442 if (str_has_prefix(argv[i], "$arg")) { 1443 trace_probe_log_set_index(i + 2); 1444 1445 if (!tparg_is_function_entry(ctx->flags)) { 1446 trace_probe_log_err(0, NOFENTRY_ARGS); 1447 return -EINVAL; 1448 } 1449 1450 if (isdigit(argv[i][4])) { 1451 found = 1; 1452 continue; 1453 } 1454 1455 if (argv[i][4] != '*') { 1456 trace_probe_log_err(0, BAD_VAR); 1457 return -EINVAL; 1458 } 1459 1460 if (*args_idx >= 0 && *args_idx < argc) { 1461 trace_probe_log_err(0, DOUBLE_ARGS); 1462 return -EINVAL; 1463 } 1464 found = 1; 1465 *args_idx = i; 1466 } 1467 1468 return found; 1469 } 1470 1471 static int sprint_nth_btf_arg(int idx, const char *type, 1472 char *buf, int bufsize, 1473 struct traceprobe_parse_context *ctx) 1474 { 1475 const char *name; 1476 int ret; 1477 1478 if (idx >= ctx->nr_params) { 1479 trace_probe_log_err(0, NO_BTFARG); 1480 return -ENOENT; 1481 } 1482 name = btf_name_by_offset(ctx->btf, ctx->params[idx].name_off); 1483 if (!name) { 1484 trace_probe_log_err(0, NO_BTF_ENTRY); 1485 return -ENOENT; 1486 } 1487 ret = snprintf(buf, bufsize, "%s%s", name, type); 1488 if (ret >= bufsize) { 1489 trace_probe_log_err(0, ARGS_2LONG); 1490 return -E2BIG; 1491 } 1492 return ret; 1493 } 1494 1495 /* Return new_argv which must be freed after use */ 1496 const char **traceprobe_expand_meta_args(int argc, const char *argv[], 1497 int *new_argc, char *buf, int bufsize, 1498 struct traceprobe_parse_context *ctx) 1499 { 1500 const struct btf_param *params = NULL; 1501 int i, j, n, used, ret, args_idx = -1; 1502 const char **new_argv = NULL; 1503 1504 ret = argv_has_var_arg(argc, argv, &args_idx, ctx); 1505 if (ret < 0) 1506 return ERR_PTR(ret); 1507 1508 if (!ret) { 1509 *new_argc = argc; 1510 return NULL; 1511 } 1512 1513 ret = query_btf_context(ctx); 1514 if (ret < 0 || ctx->nr_params == 0) { 1515 if (args_idx != -1) { 1516 /* $arg* requires BTF info */ 1517 trace_probe_log_err(0, NOSUP_BTFARG); 1518 return (const char **)params; 1519 } 1520 *new_argc = argc; 1521 return NULL; 1522 } 1523 1524 if (args_idx >= 0) 1525 *new_argc = argc + ctx->nr_params - 1; 1526 else 1527 *new_argc = argc; 1528 1529 new_argv = kcalloc(*new_argc, sizeof(char *), GFP_KERNEL); 1530 if (!new_argv) 1531 return ERR_PTR(-ENOMEM); 1532 1533 used = 0; 1534 for (i = 0, j = 0; i < argc; i++) { 1535 trace_probe_log_set_index(i + 2); 1536 if (i == args_idx) { 1537 for (n = 0; n < ctx->nr_params; n++) { 1538 ret = sprint_nth_btf_arg(n, "", buf + used, 1539 bufsize - used, ctx); 1540 if (ret < 0) 1541 goto error; 1542 1543 new_argv[j++] = buf + used; 1544 used += ret + 1; 1545 } 1546 continue; 1547 } 1548 1549 if (str_has_prefix(argv[i], "$arg")) { 1550 char *type = NULL; 1551 1552 n = simple_strtoul(argv[i] + 4, &type, 10); 1553 if (type && !(*type == ':' || *type == '\0')) { 1554 trace_probe_log_err(0, BAD_VAR); 1555 ret = -ENOENT; 1556 goto error; 1557 } 1558 /* Note: $argN starts from $arg1 */ 1559 ret = sprint_nth_btf_arg(n - 1, type, buf + used, 1560 bufsize - used, ctx); 1561 if (ret < 0) 1562 goto error; 1563 new_argv[j++] = buf + used; 1564 used += ret + 1; 1565 } else 1566 new_argv[j++] = argv[i]; 1567 } 1568 1569 return new_argv; 1570 1571 error: 1572 kfree(new_argv); 1573 return ERR_PTR(ret); 1574 } 1575 1576 void traceprobe_finish_parse(struct traceprobe_parse_context *ctx) 1577 { 1578 clear_btf_context(ctx); 1579 } 1580 1581 int traceprobe_update_arg(struct probe_arg *arg) 1582 { 1583 struct fetch_insn *code = arg->code; 1584 long offset; 1585 char *tmp; 1586 char c; 1587 int ret = 0; 1588 1589 while (code && code->op != FETCH_OP_END) { 1590 if (code->op == FETCH_NOP_SYMBOL) { 1591 if (code[1].op != FETCH_OP_IMM) 1592 return -EINVAL; 1593 1594 tmp = strpbrk(code->data, "+-"); 1595 if (tmp) 1596 c = *tmp; 1597 ret = traceprobe_split_symbol_offset(code->data, 1598 &offset); 1599 if (ret) 1600 return ret; 1601 1602 code[1].immediate = 1603 (unsigned long)kallsyms_lookup_name(code->data); 1604 if (tmp) 1605 *tmp = c; 1606 if (!code[1].immediate) 1607 return -ENOENT; 1608 code[1].immediate += offset; 1609 } 1610 code++; 1611 } 1612 return 0; 1613 } 1614 1615 /* When len=0, we just calculate the needed length */ 1616 #define LEN_OR_ZERO (len ? len - pos : 0) 1617 static int __set_print_fmt(struct trace_probe *tp, char *buf, int len, 1618 enum probe_print_type ptype) 1619 { 1620 struct probe_arg *parg; 1621 int i, j; 1622 int pos = 0; 1623 const char *fmt, *arg; 1624 1625 switch (ptype) { 1626 case PROBE_PRINT_NORMAL: 1627 fmt = "(%lx)"; 1628 arg = ", REC->" FIELD_STRING_IP; 1629 break; 1630 case PROBE_PRINT_RETURN: 1631 fmt = "(%lx <- %lx)"; 1632 arg = ", REC->" FIELD_STRING_FUNC ", REC->" FIELD_STRING_RETIP; 1633 break; 1634 case PROBE_PRINT_EVENT: 1635 fmt = ""; 1636 arg = ""; 1637 break; 1638 default: 1639 WARN_ON_ONCE(1); 1640 return 0; 1641 } 1642 1643 pos += snprintf(buf + pos, LEN_OR_ZERO, "\"%s", fmt); 1644 1645 for (i = 0; i < tp->nr_args; i++) { 1646 parg = tp->args + i; 1647 pos += snprintf(buf + pos, LEN_OR_ZERO, " %s=", parg->name); 1648 if (parg->count) { 1649 pos += snprintf(buf + pos, LEN_OR_ZERO, "{%s", 1650 parg->type->fmt); 1651 for (j = 1; j < parg->count; j++) 1652 pos += snprintf(buf + pos, LEN_OR_ZERO, ",%s", 1653 parg->type->fmt); 1654 pos += snprintf(buf + pos, LEN_OR_ZERO, "}"); 1655 } else 1656 pos += snprintf(buf + pos, LEN_OR_ZERO, "%s", 1657 parg->type->fmt); 1658 } 1659 1660 pos += snprintf(buf + pos, LEN_OR_ZERO, "\"%s", arg); 1661 1662 for (i = 0; i < tp->nr_args; i++) { 1663 parg = tp->args + i; 1664 if (parg->count) { 1665 if (parg->type->is_string) 1666 fmt = ", __get_str(%s[%d])"; 1667 else 1668 fmt = ", REC->%s[%d]"; 1669 for (j = 0; j < parg->count; j++) 1670 pos += snprintf(buf + pos, LEN_OR_ZERO, 1671 fmt, parg->name, j); 1672 } else { 1673 if (parg->type->is_string) 1674 fmt = ", __get_str(%s)"; 1675 else 1676 fmt = ", REC->%s"; 1677 pos += snprintf(buf + pos, LEN_OR_ZERO, 1678 fmt, parg->name); 1679 } 1680 } 1681 1682 /* return the length of print_fmt */ 1683 return pos; 1684 } 1685 #undef LEN_OR_ZERO 1686 1687 int traceprobe_set_print_fmt(struct trace_probe *tp, enum probe_print_type ptype) 1688 { 1689 struct trace_event_call *call = trace_probe_event_call(tp); 1690 int len; 1691 char *print_fmt; 1692 1693 /* First: called with 0 length to calculate the needed length */ 1694 len = __set_print_fmt(tp, NULL, 0, ptype); 1695 print_fmt = kmalloc(len + 1, GFP_KERNEL); 1696 if (!print_fmt) 1697 return -ENOMEM; 1698 1699 /* Second: actually write the @print_fmt */ 1700 __set_print_fmt(tp, print_fmt, len + 1, ptype); 1701 call->print_fmt = print_fmt; 1702 1703 return 0; 1704 } 1705 1706 int traceprobe_define_arg_fields(struct trace_event_call *event_call, 1707 size_t offset, struct trace_probe *tp) 1708 { 1709 int ret, i; 1710 1711 /* Set argument names as fields */ 1712 for (i = 0; i < tp->nr_args; i++) { 1713 struct probe_arg *parg = &tp->args[i]; 1714 const char *fmt = parg->type->fmttype; 1715 int size = parg->type->size; 1716 1717 if (parg->fmt) 1718 fmt = parg->fmt; 1719 if (parg->count) 1720 size *= parg->count; 1721 ret = trace_define_field(event_call, fmt, parg->name, 1722 offset + parg->offset, size, 1723 parg->type->is_signed, 1724 FILTER_OTHER); 1725 if (ret) 1726 return ret; 1727 } 1728 return 0; 1729 } 1730 1731 static void trace_probe_event_free(struct trace_probe_event *tpe) 1732 { 1733 kfree(tpe->class.system); 1734 kfree(tpe->call.name); 1735 kfree(tpe->call.print_fmt); 1736 kfree(tpe); 1737 } 1738 1739 int trace_probe_append(struct trace_probe *tp, struct trace_probe *to) 1740 { 1741 if (trace_probe_has_sibling(tp)) 1742 return -EBUSY; 1743 1744 list_del_init(&tp->list); 1745 trace_probe_event_free(tp->event); 1746 1747 tp->event = to->event; 1748 list_add_tail(&tp->list, trace_probe_probe_list(to)); 1749 1750 return 0; 1751 } 1752 1753 void trace_probe_unlink(struct trace_probe *tp) 1754 { 1755 list_del_init(&tp->list); 1756 if (list_empty(trace_probe_probe_list(tp))) 1757 trace_probe_event_free(tp->event); 1758 tp->event = NULL; 1759 } 1760 1761 void trace_probe_cleanup(struct trace_probe *tp) 1762 { 1763 int i; 1764 1765 for (i = 0; i < tp->nr_args; i++) 1766 traceprobe_free_probe_arg(&tp->args[i]); 1767 1768 if (tp->event) 1769 trace_probe_unlink(tp); 1770 } 1771 1772 int trace_probe_init(struct trace_probe *tp, const char *event, 1773 const char *group, bool alloc_filter) 1774 { 1775 struct trace_event_call *call; 1776 size_t size = sizeof(struct trace_probe_event); 1777 int ret = 0; 1778 1779 if (!event || !group) 1780 return -EINVAL; 1781 1782 if (alloc_filter) 1783 size += sizeof(struct trace_uprobe_filter); 1784 1785 tp->event = kzalloc(size, GFP_KERNEL); 1786 if (!tp->event) 1787 return -ENOMEM; 1788 1789 INIT_LIST_HEAD(&tp->event->files); 1790 INIT_LIST_HEAD(&tp->event->class.fields); 1791 INIT_LIST_HEAD(&tp->event->probes); 1792 INIT_LIST_HEAD(&tp->list); 1793 list_add(&tp->list, &tp->event->probes); 1794 1795 call = trace_probe_event_call(tp); 1796 call->class = &tp->event->class; 1797 call->name = kstrdup(event, GFP_KERNEL); 1798 if (!call->name) { 1799 ret = -ENOMEM; 1800 goto error; 1801 } 1802 1803 tp->event->class.system = kstrdup(group, GFP_KERNEL); 1804 if (!tp->event->class.system) { 1805 ret = -ENOMEM; 1806 goto error; 1807 } 1808 1809 return 0; 1810 1811 error: 1812 trace_probe_cleanup(tp); 1813 return ret; 1814 } 1815 1816 static struct trace_event_call * 1817 find_trace_event_call(const char *system, const char *event_name) 1818 { 1819 struct trace_event_call *tp_event; 1820 const char *name; 1821 1822 list_for_each_entry(tp_event, &ftrace_events, list) { 1823 if (!tp_event->class->system || 1824 strcmp(system, tp_event->class->system)) 1825 continue; 1826 name = trace_event_name(tp_event); 1827 if (!name || strcmp(event_name, name)) 1828 continue; 1829 return tp_event; 1830 } 1831 1832 return NULL; 1833 } 1834 1835 int trace_probe_register_event_call(struct trace_probe *tp) 1836 { 1837 struct trace_event_call *call = trace_probe_event_call(tp); 1838 int ret; 1839 1840 lockdep_assert_held(&event_mutex); 1841 1842 if (find_trace_event_call(trace_probe_group_name(tp), 1843 trace_probe_name(tp))) 1844 return -EEXIST; 1845 1846 ret = register_trace_event(&call->event); 1847 if (!ret) 1848 return -ENODEV; 1849 1850 ret = trace_add_event_call(call); 1851 if (ret) 1852 unregister_trace_event(&call->event); 1853 1854 return ret; 1855 } 1856 1857 int trace_probe_add_file(struct trace_probe *tp, struct trace_event_file *file) 1858 { 1859 struct event_file_link *link; 1860 1861 link = kmalloc(sizeof(*link), GFP_KERNEL); 1862 if (!link) 1863 return -ENOMEM; 1864 1865 link->file = file; 1866 INIT_LIST_HEAD(&link->list); 1867 list_add_tail_rcu(&link->list, &tp->event->files); 1868 trace_probe_set_flag(tp, TP_FLAG_TRACE); 1869 return 0; 1870 } 1871 1872 struct event_file_link *trace_probe_get_file_link(struct trace_probe *tp, 1873 struct trace_event_file *file) 1874 { 1875 struct event_file_link *link; 1876 1877 trace_probe_for_each_link(link, tp) { 1878 if (link->file == file) 1879 return link; 1880 } 1881 1882 return NULL; 1883 } 1884 1885 int trace_probe_remove_file(struct trace_probe *tp, 1886 struct trace_event_file *file) 1887 { 1888 struct event_file_link *link; 1889 1890 link = trace_probe_get_file_link(tp, file); 1891 if (!link) 1892 return -ENOENT; 1893 1894 list_del_rcu(&link->list); 1895 kvfree_rcu_mightsleep(link); 1896 1897 if (list_empty(&tp->event->files)) 1898 trace_probe_clear_flag(tp, TP_FLAG_TRACE); 1899 1900 return 0; 1901 } 1902 1903 /* 1904 * Return the smallest index of different type argument (start from 1). 1905 * If all argument types and name are same, return 0. 1906 */ 1907 int trace_probe_compare_arg_type(struct trace_probe *a, struct trace_probe *b) 1908 { 1909 int i; 1910 1911 /* In case of more arguments */ 1912 if (a->nr_args < b->nr_args) 1913 return a->nr_args + 1; 1914 if (a->nr_args > b->nr_args) 1915 return b->nr_args + 1; 1916 1917 for (i = 0; i < a->nr_args; i++) { 1918 if ((b->nr_args <= i) || 1919 ((a->args[i].type != b->args[i].type) || 1920 (a->args[i].count != b->args[i].count) || 1921 strcmp(a->args[i].name, b->args[i].name))) 1922 return i + 1; 1923 } 1924 1925 return 0; 1926 } 1927 1928 bool trace_probe_match_command_args(struct trace_probe *tp, 1929 int argc, const char **argv) 1930 { 1931 char buf[MAX_ARGSTR_LEN + 1]; 1932 int i; 1933 1934 if (tp->nr_args < argc) 1935 return false; 1936 1937 for (i = 0; i < argc; i++) { 1938 snprintf(buf, sizeof(buf), "%s=%s", 1939 tp->args[i].name, tp->args[i].comm); 1940 if (strcmp(buf, argv[i])) 1941 return false; 1942 } 1943 return true; 1944 } 1945 1946 int trace_probe_create(const char *raw_command, int (*createfn)(int, const char **)) 1947 { 1948 int argc = 0, ret = 0; 1949 char **argv; 1950 1951 argv = argv_split(GFP_KERNEL, raw_command, &argc); 1952 if (!argv) 1953 return -ENOMEM; 1954 1955 if (argc) 1956 ret = createfn(argc, (const char **)argv); 1957 1958 argv_free(argv); 1959 1960 return ret; 1961 } 1962 1963 int trace_probe_print_args(struct trace_seq *s, struct probe_arg *args, int nr_args, 1964 u8 *data, void *field) 1965 { 1966 void *p; 1967 int i, j; 1968 1969 for (i = 0; i < nr_args; i++) { 1970 struct probe_arg *a = args + i; 1971 1972 trace_seq_printf(s, " %s=", a->name); 1973 if (likely(!a->count)) { 1974 if (!a->type->print(s, data + a->offset, field)) 1975 return -ENOMEM; 1976 continue; 1977 } 1978 trace_seq_putc(s, '{'); 1979 p = data + a->offset; 1980 for (j = 0; j < a->count; j++) { 1981 if (!a->type->print(s, p, field)) 1982 return -ENOMEM; 1983 trace_seq_putc(s, j == a->count - 1 ? '}' : ','); 1984 p += a->type->size; 1985 } 1986 } 1987 return 0; 1988 } 1989