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 <linux/fs.h> 16 #include "trace_btf.h" 17 18 #include "trace_probe.h" 19 20 #undef C 21 #define C(a, b) b 22 23 static const char *trace_probe_err_text[] = { ERRORS }; 24 25 static const char *reserved_field_names[] = { 26 "common_type", 27 "common_flags", 28 "common_preempt_count", 29 "common_pid", 30 "common_tgid", 31 FIELD_STRING_IP, 32 FIELD_STRING_RETIP, 33 FIELD_STRING_FUNC, 34 }; 35 36 /* Printing in basic type function template */ 37 #define DEFINE_BASIC_PRINT_TYPE_FUNC(tname, type, fmt) \ 38 int PRINT_TYPE_FUNC_NAME(tname)(struct trace_seq *s, void *data, void *ent)\ 39 { \ 40 trace_seq_printf(s, fmt, *(type *)data); \ 41 return !trace_seq_has_overflowed(s); \ 42 } \ 43 const char PRINT_TYPE_FMT_NAME(tname)[] = fmt; 44 45 DEFINE_BASIC_PRINT_TYPE_FUNC(u8, u8, "%u") 46 DEFINE_BASIC_PRINT_TYPE_FUNC(u16, u16, "%u") 47 DEFINE_BASIC_PRINT_TYPE_FUNC(u32, u32, "%u") 48 DEFINE_BASIC_PRINT_TYPE_FUNC(u64, u64, "%Lu") 49 DEFINE_BASIC_PRINT_TYPE_FUNC(s8, s8, "%d") 50 DEFINE_BASIC_PRINT_TYPE_FUNC(s16, s16, "%d") 51 DEFINE_BASIC_PRINT_TYPE_FUNC(s32, s32, "%d") 52 DEFINE_BASIC_PRINT_TYPE_FUNC(s64, s64, "%Ld") 53 DEFINE_BASIC_PRINT_TYPE_FUNC(x8, u8, "0x%x") 54 DEFINE_BASIC_PRINT_TYPE_FUNC(x16, u16, "0x%x") 55 DEFINE_BASIC_PRINT_TYPE_FUNC(x32, u32, "0x%x") 56 DEFINE_BASIC_PRINT_TYPE_FUNC(x64, u64, "0x%Lx") 57 DEFINE_BASIC_PRINT_TYPE_FUNC(char, u8, "'%c'") 58 59 int PRINT_TYPE_FUNC_NAME(symbol)(struct trace_seq *s, void *data, void *ent) 60 { 61 trace_seq_printf(s, "%pS", (void *)*(unsigned long *)data); 62 return !trace_seq_has_overflowed(s); 63 } 64 const char PRINT_TYPE_FMT_NAME(symbol)[] = "%pS"; 65 66 /* Print type function for string type */ 67 int PRINT_TYPE_FUNC_NAME(string)(struct trace_seq *s, void *data, void *ent) 68 { 69 int len = *(u32 *)data >> 16; 70 71 if (!len) 72 trace_seq_puts(s, FAULT_STRING); 73 else 74 trace_seq_printf(s, "\"%s\"", 75 (const char *)get_loc_data(data, ent)); 76 return !trace_seq_has_overflowed(s); 77 } 78 79 const char PRINT_TYPE_FMT_NAME(string)[] = "\\\"%s\\\""; 80 81 /* Fetch type information table */ 82 static const struct fetch_type probe_fetch_types[] = { 83 /* Special types */ 84 __ASSIGN_FETCH_TYPE("string", string, string, sizeof(u32), 1, 1, 85 "__data_loc char[]"), 86 __ASSIGN_FETCH_TYPE("ustring", string, string, sizeof(u32), 1, 1, 87 "__data_loc char[]"), 88 __ASSIGN_FETCH_TYPE("symstr", string, string, sizeof(u32), 1, 1, 89 "__data_loc char[]"), 90 /* Basic types */ 91 ASSIGN_FETCH_TYPE(u8, u8, 0), 92 ASSIGN_FETCH_TYPE(u16, u16, 0), 93 ASSIGN_FETCH_TYPE(u32, u32, 0), 94 ASSIGN_FETCH_TYPE(u64, u64, 0), 95 ASSIGN_FETCH_TYPE(s8, u8, 1), 96 ASSIGN_FETCH_TYPE(s16, u16, 1), 97 ASSIGN_FETCH_TYPE(s32, u32, 1), 98 ASSIGN_FETCH_TYPE(s64, u64, 1), 99 ASSIGN_FETCH_TYPE_ALIAS(x8, u8, u8, 0), 100 ASSIGN_FETCH_TYPE_ALIAS(x16, u16, u16, 0), 101 ASSIGN_FETCH_TYPE_ALIAS(x32, u32, u32, 0), 102 ASSIGN_FETCH_TYPE_ALIAS(x64, u64, u64, 0), 103 ASSIGN_FETCH_TYPE_ALIAS(char, u8, u8, 0), 104 ASSIGN_FETCH_TYPE_ALIAS(symbol, ADDR_FETCH_TYPE, ADDR_FETCH_TYPE, 0), 105 106 ASSIGN_FETCH_TYPE_END 107 }; 108 109 static const struct fetch_type *find_fetch_type(const char *type, unsigned long flags) 110 { 111 int i; 112 113 /* Reject the symbol/symstr for uprobes */ 114 if (type && (flags & TPARG_FL_USER) && 115 (!strcmp(type, "symbol") || !strcmp(type, "symstr"))) 116 return NULL; 117 118 if (!type) 119 type = DEFAULT_FETCH_TYPE_STR; 120 121 /* Special case: bitfield */ 122 if (*type == 'b') { 123 unsigned long bs; 124 125 type = strchr(type, '/'); 126 if (!type) 127 goto fail; 128 129 type++; 130 if (kstrtoul(type, 0, &bs)) 131 goto fail; 132 133 switch (bs) { 134 case 8: 135 return find_fetch_type("u8", flags); 136 case 16: 137 return find_fetch_type("u16", flags); 138 case 32: 139 return find_fetch_type("u32", flags); 140 case 64: 141 return find_fetch_type("u64", flags); 142 default: 143 goto fail; 144 } 145 } 146 147 for (i = 0; probe_fetch_types[i].name; i++) { 148 if (strcmp(type, probe_fetch_types[i].name) == 0) 149 return &probe_fetch_types[i]; 150 } 151 152 fail: 153 return NULL; 154 } 155 156 static struct trace_probe_log trace_probe_log; 157 158 void trace_probe_log_init(const char *subsystem, int argc, const char **argv) 159 { 160 trace_probe_log.subsystem = subsystem; 161 trace_probe_log.argc = argc; 162 trace_probe_log.argv = argv; 163 trace_probe_log.index = 0; 164 } 165 166 void trace_probe_log_clear(void) 167 { 168 memset(&trace_probe_log, 0, sizeof(trace_probe_log)); 169 } 170 171 void trace_probe_log_set_index(int index) 172 { 173 trace_probe_log.index = index; 174 } 175 176 void __trace_probe_log_err(int offset, int err_type) 177 { 178 char *command, *p; 179 int i, len = 0, pos = 0; 180 181 if (!trace_probe_log.argv) 182 return; 183 184 /* Recalculate the length and allocate buffer */ 185 for (i = 0; i < trace_probe_log.argc; i++) { 186 if (i == trace_probe_log.index) 187 pos = len; 188 len += strlen(trace_probe_log.argv[i]) + 1; 189 } 190 command = kzalloc(len, GFP_KERNEL); 191 if (!command) 192 return; 193 194 if (trace_probe_log.index >= trace_probe_log.argc) { 195 /** 196 * Set the error position is next to the last arg + space. 197 * Note that len includes the terminal null and the cursor 198 * appears at pos + 1. 199 */ 200 pos = len; 201 offset = 0; 202 } 203 204 /* And make a command string from argv array */ 205 p = command; 206 for (i = 0; i < trace_probe_log.argc; i++) { 207 len = strlen(trace_probe_log.argv[i]); 208 strcpy(p, trace_probe_log.argv[i]); 209 p[len] = ' '; 210 p += len + 1; 211 } 212 *(p - 1) = '\0'; 213 214 tracing_log_err(NULL, trace_probe_log.subsystem, command, 215 trace_probe_err_text, err_type, pos + offset); 216 217 kfree(command); 218 } 219 220 /* Split symbol and offset. */ 221 int traceprobe_split_symbol_offset(char *symbol, long *offset) 222 { 223 char *tmp; 224 int ret; 225 226 if (!offset) 227 return -EINVAL; 228 229 tmp = strpbrk(symbol, "+-"); 230 if (tmp) { 231 ret = kstrtol(tmp, 0, offset); 232 if (ret) 233 return ret; 234 *tmp = '\0'; 235 } else 236 *offset = 0; 237 238 return 0; 239 } 240 241 /* @buf must has MAX_EVENT_NAME_LEN size */ 242 int traceprobe_parse_event_name(const char **pevent, const char **pgroup, 243 char *buf, int offset) 244 { 245 const char *slash, *event = *pevent; 246 int len; 247 248 slash = strchr(event, '/'); 249 if (!slash) 250 slash = strchr(event, '.'); 251 252 if (slash) { 253 if (slash == event) { 254 trace_probe_log_err(offset, NO_GROUP_NAME); 255 return -EINVAL; 256 } 257 if (slash - event + 1 > MAX_EVENT_NAME_LEN) { 258 trace_probe_log_err(offset, GROUP_TOO_LONG); 259 return -EINVAL; 260 } 261 strscpy(buf, event, slash - event + 1); 262 if (!is_good_system_name(buf)) { 263 trace_probe_log_err(offset, BAD_GROUP_NAME); 264 return -EINVAL; 265 } 266 *pgroup = buf; 267 *pevent = slash + 1; 268 offset += slash - event + 1; 269 event = *pevent; 270 } 271 len = strlen(event); 272 if (len == 0) { 273 if (slash) { 274 *pevent = NULL; 275 return 0; 276 } 277 trace_probe_log_err(offset, NO_EVENT_NAME); 278 return -EINVAL; 279 } else if (len > MAX_EVENT_NAME_LEN) { 280 trace_probe_log_err(offset, EVENT_TOO_LONG); 281 return -EINVAL; 282 } 283 if (!is_good_name(event)) { 284 trace_probe_log_err(offset, BAD_EVENT_NAME); 285 return -EINVAL; 286 } 287 return 0; 288 } 289 290 static int parse_trace_event_arg(char *arg, struct fetch_insn *code, 291 struct traceprobe_parse_context *ctx) 292 { 293 struct ftrace_event_field *field; 294 struct list_head *head; 295 296 head = trace_get_fields(ctx->event); 297 list_for_each_entry(field, head, link) { 298 if (!strcmp(arg, field->name)) { 299 code->op = FETCH_OP_TP_ARG; 300 code->data = field; 301 return 0; 302 } 303 } 304 return -ENOENT; 305 } 306 307 #ifdef CONFIG_PROBE_EVENTS_BTF_ARGS 308 309 static u32 btf_type_int(const struct btf_type *t) 310 { 311 return *(u32 *)(t + 1); 312 } 313 314 static bool btf_type_is_char_ptr(struct btf *btf, const struct btf_type *type) 315 { 316 const struct btf_type *real_type; 317 u32 intdata; 318 s32 tid; 319 320 real_type = btf_type_skip_modifiers(btf, type->type, &tid); 321 if (!real_type) 322 return false; 323 324 if (BTF_INFO_KIND(real_type->info) != BTF_KIND_INT) 325 return false; 326 327 intdata = btf_type_int(real_type); 328 return !(BTF_INT_ENCODING(intdata) & BTF_INT_SIGNED) 329 && BTF_INT_BITS(intdata) == 8; 330 } 331 332 static bool btf_type_is_char_array(struct btf *btf, const struct btf_type *type) 333 { 334 const struct btf_type *real_type; 335 const struct btf_array *array; 336 u32 intdata; 337 s32 tid; 338 339 if (BTF_INFO_KIND(type->info) != BTF_KIND_ARRAY) 340 return false; 341 342 array = (const struct btf_array *)(type + 1); 343 344 real_type = btf_type_skip_modifiers(btf, array->type, &tid); 345 346 intdata = btf_type_int(real_type); 347 return !(BTF_INT_ENCODING(intdata) & BTF_INT_SIGNED) 348 && BTF_INT_BITS(intdata) == 8; 349 } 350 351 static int check_prepare_btf_string_fetch(char *typename, 352 struct fetch_insn **pcode, 353 struct traceprobe_parse_context *ctx) 354 { 355 struct btf *btf = ctx->btf; 356 357 if (!btf || !ctx->last_type) 358 return 0; 359 360 /* char [] does not need any change. */ 361 if (btf_type_is_char_array(btf, ctx->last_type)) 362 return 0; 363 364 /* char * requires dereference the pointer. */ 365 if (btf_type_is_char_ptr(btf, ctx->last_type)) { 366 struct fetch_insn *code = *pcode + 1; 367 368 if (code->op == FETCH_OP_END) { 369 trace_probe_log_err(ctx->offset, TOO_MANY_OPS); 370 return -E2BIG; 371 } 372 if (typename[0] == 'u') 373 code->op = FETCH_OP_UDEREF; 374 else 375 code->op = FETCH_OP_DEREF; 376 code->offset = 0; 377 *pcode = code; 378 return 0; 379 } 380 /* Other types are not available for string */ 381 trace_probe_log_err(ctx->offset, BAD_TYPE4STR); 382 return -EINVAL; 383 } 384 385 static const char *fetch_type_from_btf_type(struct btf *btf, 386 const struct btf_type *type, 387 struct traceprobe_parse_context *ctx) 388 { 389 u32 intdata; 390 391 /* TODO: const char * could be converted as a string */ 392 switch (BTF_INFO_KIND(type->info)) { 393 case BTF_KIND_ENUM: 394 /* enum is "int", so convert to "s32" */ 395 return "s32"; 396 case BTF_KIND_ENUM64: 397 return "s64"; 398 case BTF_KIND_PTR: 399 /* pointer will be converted to "x??" */ 400 if (IS_ENABLED(CONFIG_64BIT)) 401 return "x64"; 402 else 403 return "x32"; 404 case BTF_KIND_INT: 405 intdata = btf_type_int(type); 406 if (BTF_INT_ENCODING(intdata) & BTF_INT_SIGNED) { 407 switch (BTF_INT_BITS(intdata)) { 408 case 8: 409 return "s8"; 410 case 16: 411 return "s16"; 412 case 32: 413 return "s32"; 414 case 64: 415 return "s64"; 416 } 417 } else { /* unsigned */ 418 switch (BTF_INT_BITS(intdata)) { 419 case 8: 420 return "u8"; 421 case 16: 422 return "u16"; 423 case 32: 424 return "u32"; 425 case 64: 426 return "u64"; 427 } 428 /* bitfield, size is encoded in the type */ 429 ctx->last_bitsize = BTF_INT_BITS(intdata); 430 ctx->last_bitoffs += BTF_INT_OFFSET(intdata); 431 return "u64"; 432 } 433 } 434 /* TODO: support other types */ 435 436 return NULL; 437 } 438 439 static int query_btf_context(struct traceprobe_parse_context *ctx) 440 { 441 const struct btf_param *param; 442 const struct btf_type *type; 443 struct btf *btf; 444 s32 nr; 445 446 if (ctx->btf) 447 return 0; 448 449 if (!ctx->funcname) 450 return -EINVAL; 451 452 type = btf_find_func_proto(ctx->funcname, &btf); 453 if (!type) 454 return -ENOENT; 455 456 ctx->btf = btf; 457 ctx->proto = type; 458 459 /* ctx->params is optional, since func(void) will not have params. */ 460 nr = 0; 461 param = btf_get_func_param(type, &nr); 462 if (!IS_ERR_OR_NULL(param)) { 463 /* Hide the first 'data' argument of tracepoint */ 464 if (ctx->flags & TPARG_FL_TPOINT) { 465 nr--; 466 param++; 467 } 468 } 469 470 if (nr > 0) { 471 ctx->nr_params = nr; 472 ctx->params = param; 473 } else { 474 ctx->nr_params = 0; 475 ctx->params = NULL; 476 } 477 478 return 0; 479 } 480 481 static void clear_btf_context(struct traceprobe_parse_context *ctx) 482 { 483 if (ctx->btf) { 484 btf_put(ctx->btf); 485 ctx->btf = NULL; 486 ctx->proto = NULL; 487 ctx->params = NULL; 488 ctx->nr_params = 0; 489 } 490 } 491 492 /* Return 1 if the field separater is arrow operator ('->') */ 493 static int split_next_field(char *varname, char **next_field, 494 struct traceprobe_parse_context *ctx) 495 { 496 char *field; 497 int ret = 0; 498 499 field = strpbrk(varname, ".-"); 500 if (field) { 501 if (field[0] == '-' && field[1] == '>') { 502 field[0] = '\0'; 503 field += 2; 504 ret = 1; 505 } else if (field[0] == '.') { 506 field[0] = '\0'; 507 field += 1; 508 } else { 509 trace_probe_log_err(ctx->offset + field - varname, BAD_HYPHEN); 510 return -EINVAL; 511 } 512 *next_field = field; 513 } 514 515 return ret; 516 } 517 518 /* 519 * Parse the field of data structure. The @type must be a pointer type 520 * pointing the target data structure type. 521 */ 522 static int parse_btf_field(char *fieldname, const struct btf_type *type, 523 struct fetch_insn **pcode, struct fetch_insn *end, 524 struct traceprobe_parse_context *ctx) 525 { 526 struct fetch_insn *code = *pcode; 527 const struct btf_member *field; 528 u32 bitoffs, anon_offs; 529 char *next; 530 int is_ptr; 531 s32 tid; 532 533 do { 534 /* Outer loop for solving arrow operator ('->') */ 535 if (BTF_INFO_KIND(type->info) != BTF_KIND_PTR) { 536 trace_probe_log_err(ctx->offset, NO_PTR_STRCT); 537 return -EINVAL; 538 } 539 /* Convert a struct pointer type to a struct type */ 540 type = btf_type_skip_modifiers(ctx->btf, type->type, &tid); 541 if (!type) { 542 trace_probe_log_err(ctx->offset, BAD_BTF_TID); 543 return -EINVAL; 544 } 545 546 bitoffs = 0; 547 do { 548 /* Inner loop for solving dot operator ('.') */ 549 next = NULL; 550 is_ptr = split_next_field(fieldname, &next, ctx); 551 if (is_ptr < 0) 552 return is_ptr; 553 554 anon_offs = 0; 555 field = btf_find_struct_member(ctx->btf, type, fieldname, 556 &anon_offs); 557 if (!field) { 558 trace_probe_log_err(ctx->offset, NO_BTF_FIELD); 559 return -ENOENT; 560 } 561 /* Add anonymous structure/union offset */ 562 bitoffs += anon_offs; 563 564 /* Accumulate the bit-offsets of the dot-connected fields */ 565 if (btf_type_kflag(type)) { 566 bitoffs += BTF_MEMBER_BIT_OFFSET(field->offset); 567 ctx->last_bitsize = BTF_MEMBER_BITFIELD_SIZE(field->offset); 568 } else { 569 bitoffs += field->offset; 570 ctx->last_bitsize = 0; 571 } 572 573 type = btf_type_skip_modifiers(ctx->btf, field->type, &tid); 574 if (!type) { 575 trace_probe_log_err(ctx->offset, BAD_BTF_TID); 576 return -EINVAL; 577 } 578 579 ctx->offset += next - fieldname; 580 fieldname = next; 581 } while (!is_ptr && fieldname); 582 583 if (++code == end) { 584 trace_probe_log_err(ctx->offset, TOO_MANY_OPS); 585 return -EINVAL; 586 } 587 code->op = FETCH_OP_DEREF; /* TODO: user deref support */ 588 code->offset = bitoffs / 8; 589 *pcode = code; 590 591 ctx->last_bitoffs = bitoffs % 8; 592 ctx->last_type = type; 593 } while (fieldname); 594 595 return 0; 596 } 597 598 static int __store_entry_arg(struct trace_probe *tp, int argnum); 599 600 static int parse_btf_arg(char *varname, 601 struct fetch_insn **pcode, struct fetch_insn *end, 602 struct traceprobe_parse_context *ctx) 603 { 604 struct fetch_insn *code = *pcode; 605 const struct btf_param *params; 606 const struct btf_type *type; 607 char *field = NULL; 608 int i, is_ptr, ret; 609 u32 tid; 610 611 if (WARN_ON_ONCE(!ctx->funcname)) 612 return -EINVAL; 613 614 is_ptr = split_next_field(varname, &field, ctx); 615 if (is_ptr < 0) 616 return is_ptr; 617 if (!is_ptr && field) { 618 /* dot-connected field on an argument is not supported. */ 619 trace_probe_log_err(ctx->offset + field - varname, 620 NOSUP_DAT_ARG); 621 return -EOPNOTSUPP; 622 } 623 624 if (ctx->flags & TPARG_FL_RETURN && !strcmp(varname, "$retval")) { 625 code->op = FETCH_OP_RETVAL; 626 /* Check whether the function return type is not void */ 627 if (query_btf_context(ctx) == 0) { 628 if (ctx->proto->type == 0) { 629 trace_probe_log_err(ctx->offset, NO_RETVAL); 630 return -ENOENT; 631 } 632 tid = ctx->proto->type; 633 goto found; 634 } 635 if (field) { 636 trace_probe_log_err(ctx->offset + field - varname, 637 NO_BTF_ENTRY); 638 return -ENOENT; 639 } 640 return 0; 641 } 642 643 if (!ctx->btf) { 644 ret = query_btf_context(ctx); 645 if (ret < 0 || ctx->nr_params == 0) { 646 trace_probe_log_err(ctx->offset, NO_BTF_ENTRY); 647 return PTR_ERR(params); 648 } 649 } 650 params = ctx->params; 651 652 for (i = 0; i < ctx->nr_params; i++) { 653 const char *name = btf_name_by_offset(ctx->btf, params[i].name_off); 654 655 if (name && !strcmp(name, varname)) { 656 if (tparg_is_function_entry(ctx->flags)) { 657 code->op = FETCH_OP_ARG; 658 if (ctx->flags & TPARG_FL_TPOINT) 659 code->param = i + 1; 660 else 661 code->param = i; 662 } else if (tparg_is_function_return(ctx->flags)) { 663 code->op = FETCH_OP_EDATA; 664 ret = __store_entry_arg(ctx->tp, i); 665 if (ret < 0) { 666 /* internal error */ 667 return ret; 668 } 669 code->offset = ret; 670 } 671 tid = params[i].type; 672 goto found; 673 } 674 } 675 trace_probe_log_err(ctx->offset, NO_BTFARG); 676 return -ENOENT; 677 678 found: 679 type = btf_type_skip_modifiers(ctx->btf, tid, &tid); 680 if (!type) { 681 trace_probe_log_err(ctx->offset, BAD_BTF_TID); 682 return -EINVAL; 683 } 684 /* Initialize the last type information */ 685 ctx->last_type = type; 686 ctx->last_bitoffs = 0; 687 ctx->last_bitsize = 0; 688 if (field) { 689 ctx->offset += field - varname; 690 return parse_btf_field(field, type, pcode, end, ctx); 691 } 692 return 0; 693 } 694 695 static const struct fetch_type *find_fetch_type_from_btf_type( 696 struct traceprobe_parse_context *ctx) 697 { 698 struct btf *btf = ctx->btf; 699 const char *typestr = NULL; 700 701 if (btf && ctx->last_type) 702 typestr = fetch_type_from_btf_type(btf, ctx->last_type, ctx); 703 704 return find_fetch_type(typestr, ctx->flags); 705 } 706 707 static int parse_btf_bitfield(struct fetch_insn **pcode, 708 struct traceprobe_parse_context *ctx) 709 { 710 struct fetch_insn *code = *pcode; 711 712 if ((ctx->last_bitsize % 8 == 0) && ctx->last_bitoffs == 0) 713 return 0; 714 715 code++; 716 if (code->op != FETCH_OP_NOP) { 717 trace_probe_log_err(ctx->offset, TOO_MANY_OPS); 718 return -EINVAL; 719 } 720 *pcode = code; 721 722 code->op = FETCH_OP_MOD_BF; 723 code->lshift = 64 - (ctx->last_bitsize + ctx->last_bitoffs); 724 code->rshift = 64 - ctx->last_bitsize; 725 code->basesize = 64 / 8; 726 return 0; 727 } 728 729 #else 730 static void clear_btf_context(struct traceprobe_parse_context *ctx) 731 { 732 ctx->btf = NULL; 733 } 734 735 static int query_btf_context(struct traceprobe_parse_context *ctx) 736 { 737 return -EOPNOTSUPP; 738 } 739 740 static int parse_btf_arg(char *varname, 741 struct fetch_insn **pcode, struct fetch_insn *end, 742 struct traceprobe_parse_context *ctx) 743 { 744 trace_probe_log_err(ctx->offset, NOSUP_BTFARG); 745 return -EOPNOTSUPP; 746 } 747 748 static int parse_btf_bitfield(struct fetch_insn **pcode, 749 struct traceprobe_parse_context *ctx) 750 { 751 trace_probe_log_err(ctx->offset, NOSUP_BTFARG); 752 return -EOPNOTSUPP; 753 } 754 755 #define find_fetch_type_from_btf_type(ctx) \ 756 find_fetch_type(NULL, ctx->flags) 757 758 static int check_prepare_btf_string_fetch(char *typename, 759 struct fetch_insn **pcode, 760 struct traceprobe_parse_context *ctx) 761 { 762 return 0; 763 } 764 765 #endif 766 767 #ifdef CONFIG_HAVE_FUNCTION_ARG_ACCESS_API 768 769 static int __store_entry_arg(struct trace_probe *tp, int argnum) 770 { 771 struct probe_entry_arg *earg = tp->entry_arg; 772 bool match = false; 773 int i, offset; 774 775 if (!earg) { 776 earg = kzalloc(sizeof(*tp->entry_arg), GFP_KERNEL); 777 if (!earg) 778 return -ENOMEM; 779 earg->size = 2 * tp->nr_args + 1; 780 earg->code = kcalloc(earg->size, sizeof(struct fetch_insn), 781 GFP_KERNEL); 782 if (!earg->code) { 783 kfree(earg); 784 return -ENOMEM; 785 } 786 /* Fill the code buffer with 'end' to simplify it */ 787 for (i = 0; i < earg->size; i++) 788 earg->code[i].op = FETCH_OP_END; 789 tp->entry_arg = earg; 790 } 791 792 offset = 0; 793 for (i = 0; i < earg->size - 1; i++) { 794 switch (earg->code[i].op) { 795 case FETCH_OP_END: 796 earg->code[i].op = FETCH_OP_ARG; 797 earg->code[i].param = argnum; 798 earg->code[i + 1].op = FETCH_OP_ST_EDATA; 799 earg->code[i + 1].offset = offset; 800 return offset; 801 case FETCH_OP_ARG: 802 match = (earg->code[i].param == argnum); 803 break; 804 case FETCH_OP_ST_EDATA: 805 offset = earg->code[i].offset; 806 if (match) 807 return offset; 808 offset += sizeof(unsigned long); 809 break; 810 default: 811 break; 812 } 813 } 814 return -ENOSPC; 815 } 816 817 int traceprobe_get_entry_data_size(struct trace_probe *tp) 818 { 819 struct probe_entry_arg *earg = tp->entry_arg; 820 int i, size = 0; 821 822 if (!earg) 823 return 0; 824 825 for (i = 0; i < earg->size; i++) { 826 switch (earg->code[i].op) { 827 case FETCH_OP_END: 828 goto out; 829 case FETCH_OP_ST_EDATA: 830 size = earg->code[i].offset + sizeof(unsigned long); 831 break; 832 default: 833 break; 834 } 835 } 836 out: 837 return size; 838 } 839 840 void store_trace_entry_data(void *edata, struct trace_probe *tp, struct pt_regs *regs) 841 { 842 struct probe_entry_arg *earg = tp->entry_arg; 843 unsigned long val = 0; 844 int i; 845 846 if (!earg) 847 return; 848 849 for (i = 0; i < earg->size; i++) { 850 struct fetch_insn *code = &earg->code[i]; 851 852 switch (code->op) { 853 case FETCH_OP_ARG: 854 val = regs_get_kernel_argument(regs, code->param); 855 break; 856 case FETCH_OP_ST_EDATA: 857 *(unsigned long *)((unsigned long)edata + code->offset) = val; 858 break; 859 case FETCH_OP_END: 860 goto end; 861 default: 862 break; 863 } 864 } 865 end: 866 return; 867 } 868 NOKPROBE_SYMBOL(store_trace_entry_data) 869 #endif 870 871 #define PARAM_MAX_STACK (THREAD_SIZE / sizeof(unsigned long)) 872 873 /* Parse $vars. @orig_arg points '$', which syncs to @ctx->offset */ 874 static int parse_probe_vars(char *orig_arg, const struct fetch_type *t, 875 struct fetch_insn **pcode, 876 struct fetch_insn *end, 877 struct traceprobe_parse_context *ctx) 878 { 879 struct fetch_insn *code = *pcode; 880 int err = TP_ERR_BAD_VAR; 881 char *arg = orig_arg + 1; 882 unsigned long param; 883 int ret = 0; 884 int len; 885 886 if (ctx->flags & TPARG_FL_TEVENT) { 887 if (code->data) 888 return -EFAULT; 889 ret = parse_trace_event_arg(arg, code, ctx); 890 if (!ret) 891 return 0; 892 if (strcmp(arg, "comm") == 0 || strcmp(arg, "COMM") == 0) { 893 code->op = FETCH_OP_COMM; 894 return 0; 895 } 896 /* backward compatibility */ 897 ctx->offset = 0; 898 goto inval; 899 } 900 901 if (str_has_prefix(arg, "retval")) { 902 if (!(ctx->flags & TPARG_FL_RETURN)) { 903 err = TP_ERR_RETVAL_ON_PROBE; 904 goto inval; 905 } 906 if (!(ctx->flags & TPARG_FL_KERNEL) || 907 !IS_ENABLED(CONFIG_PROBE_EVENTS_BTF_ARGS)) { 908 code->op = FETCH_OP_RETVAL; 909 return 0; 910 } 911 return parse_btf_arg(orig_arg, pcode, end, ctx); 912 } 913 914 len = str_has_prefix(arg, "stack"); 915 if (len) { 916 917 if (arg[len] == '\0') { 918 code->op = FETCH_OP_STACKP; 919 return 0; 920 } 921 922 if (isdigit(arg[len])) { 923 ret = kstrtoul(arg + len, 10, ¶m); 924 if (ret) 925 goto inval; 926 927 if ((ctx->flags & TPARG_FL_KERNEL) && 928 param > PARAM_MAX_STACK) { 929 err = TP_ERR_BAD_STACK_NUM; 930 goto inval; 931 } 932 code->op = FETCH_OP_STACK; 933 code->param = (unsigned int)param; 934 return 0; 935 } 936 goto inval; 937 } 938 939 if (strcmp(arg, "comm") == 0 || strcmp(arg, "COMM") == 0) { 940 code->op = FETCH_OP_COMM; 941 return 0; 942 } 943 944 #ifdef CONFIG_HAVE_FUNCTION_ARG_ACCESS_API 945 len = str_has_prefix(arg, "arg"); 946 if (len) { 947 ret = kstrtoul(arg + len, 10, ¶m); 948 if (ret) 949 goto inval; 950 951 if (!param || param > PARAM_MAX_STACK) { 952 err = TP_ERR_BAD_ARG_NUM; 953 goto inval; 954 } 955 param--; /* argN starts from 1, but internal arg[N] starts from 0 */ 956 957 if (tparg_is_function_entry(ctx->flags)) { 958 code->op = FETCH_OP_ARG; 959 code->param = (unsigned int)param; 960 /* 961 * The tracepoint probe will probe a stub function, and the 962 * first parameter of the stub is a dummy and should be ignored. 963 */ 964 if (ctx->flags & TPARG_FL_TPOINT) 965 code->param++; 966 } else if (tparg_is_function_return(ctx->flags)) { 967 /* function entry argument access from return probe */ 968 ret = __store_entry_arg(ctx->tp, param); 969 if (ret < 0) /* This error should be an internal error */ 970 return ret; 971 972 code->op = FETCH_OP_EDATA; 973 code->offset = ret; 974 } else { 975 err = TP_ERR_NOFENTRY_ARGS; 976 goto inval; 977 } 978 return 0; 979 } 980 #endif 981 982 inval: 983 __trace_probe_log_err(ctx->offset, err); 984 return -EINVAL; 985 } 986 987 static int str_to_immediate(char *str, unsigned long *imm) 988 { 989 if (isdigit(str[0])) 990 return kstrtoul(str, 0, imm); 991 else if (str[0] == '-') 992 return kstrtol(str, 0, (long *)imm); 993 else if (str[0] == '+') 994 return kstrtol(str + 1, 0, (long *)imm); 995 return -EINVAL; 996 } 997 998 static int __parse_imm_string(char *str, char **pbuf, int offs) 999 { 1000 size_t len = strlen(str); 1001 1002 if (str[len - 1] != '"') { 1003 trace_probe_log_err(offs + len, IMMSTR_NO_CLOSE); 1004 return -EINVAL; 1005 } 1006 *pbuf = kstrndup(str, len - 1, GFP_KERNEL); 1007 if (!*pbuf) 1008 return -ENOMEM; 1009 return 0; 1010 } 1011 1012 /* Recursive argument parser */ 1013 static int 1014 parse_probe_arg(char *arg, const struct fetch_type *type, 1015 struct fetch_insn **pcode, struct fetch_insn *end, 1016 struct traceprobe_parse_context *ctx) 1017 { 1018 struct fetch_insn *code = *pcode; 1019 unsigned long param; 1020 int deref = FETCH_OP_DEREF; 1021 long offset = 0; 1022 char *tmp; 1023 int ret = 0; 1024 1025 switch (arg[0]) { 1026 case '$': 1027 ret = parse_probe_vars(arg, type, pcode, end, ctx); 1028 break; 1029 1030 case '%': /* named register */ 1031 if (ctx->flags & (TPARG_FL_TEVENT | TPARG_FL_FPROBE)) { 1032 /* eprobe and fprobe do not handle registers */ 1033 trace_probe_log_err(ctx->offset, BAD_VAR); 1034 break; 1035 } 1036 ret = regs_query_register_offset(arg + 1); 1037 if (ret >= 0) { 1038 code->op = FETCH_OP_REG; 1039 code->param = (unsigned int)ret; 1040 ret = 0; 1041 } else 1042 trace_probe_log_err(ctx->offset, BAD_REG_NAME); 1043 break; 1044 1045 case '@': /* memory, file-offset or symbol */ 1046 if (isdigit(arg[1])) { 1047 ret = kstrtoul(arg + 1, 0, ¶m); 1048 if (ret) { 1049 trace_probe_log_err(ctx->offset, BAD_MEM_ADDR); 1050 break; 1051 } 1052 /* load address */ 1053 code->op = FETCH_OP_IMM; 1054 code->immediate = param; 1055 } else if (arg[1] == '+') { 1056 /* kprobes don't support file offsets */ 1057 if (ctx->flags & TPARG_FL_KERNEL) { 1058 trace_probe_log_err(ctx->offset, FILE_ON_KPROBE); 1059 return -EINVAL; 1060 } 1061 ret = kstrtol(arg + 2, 0, &offset); 1062 if (ret) { 1063 trace_probe_log_err(ctx->offset, BAD_FILE_OFFS); 1064 break; 1065 } 1066 1067 code->op = FETCH_OP_FOFFS; 1068 code->immediate = (unsigned long)offset; // imm64? 1069 } else { 1070 /* uprobes don't support symbols */ 1071 if (!(ctx->flags & TPARG_FL_KERNEL)) { 1072 trace_probe_log_err(ctx->offset, SYM_ON_UPROBE); 1073 return -EINVAL; 1074 } 1075 /* Preserve symbol for updating */ 1076 code->op = FETCH_NOP_SYMBOL; 1077 code->data = kstrdup(arg + 1, GFP_KERNEL); 1078 if (!code->data) 1079 return -ENOMEM; 1080 if (++code == end) { 1081 trace_probe_log_err(ctx->offset, TOO_MANY_OPS); 1082 return -EINVAL; 1083 } 1084 code->op = FETCH_OP_IMM; 1085 code->immediate = 0; 1086 } 1087 /* These are fetching from memory */ 1088 if (++code == end) { 1089 trace_probe_log_err(ctx->offset, TOO_MANY_OPS); 1090 return -EINVAL; 1091 } 1092 *pcode = code; 1093 code->op = FETCH_OP_DEREF; 1094 code->offset = offset; 1095 break; 1096 1097 case '+': /* deref memory */ 1098 case '-': 1099 if (arg[1] == 'u') { 1100 deref = FETCH_OP_UDEREF; 1101 arg[1] = arg[0]; 1102 arg++; 1103 } 1104 if (arg[0] == '+') 1105 arg++; /* Skip '+', because kstrtol() rejects it. */ 1106 tmp = strchr(arg, '('); 1107 if (!tmp) { 1108 trace_probe_log_err(ctx->offset, DEREF_NEED_BRACE); 1109 return -EINVAL; 1110 } 1111 *tmp = '\0'; 1112 ret = kstrtol(arg, 0, &offset); 1113 if (ret) { 1114 trace_probe_log_err(ctx->offset, BAD_DEREF_OFFS); 1115 break; 1116 } 1117 ctx->offset += (tmp + 1 - arg) + (arg[0] != '-' ? 1 : 0); 1118 arg = tmp + 1; 1119 tmp = strrchr(arg, ')'); 1120 if (!tmp) { 1121 trace_probe_log_err(ctx->offset + strlen(arg), 1122 DEREF_OPEN_BRACE); 1123 return -EINVAL; 1124 } else { 1125 const struct fetch_type *t2 = find_fetch_type(NULL, ctx->flags); 1126 int cur_offs = ctx->offset; 1127 1128 *tmp = '\0'; 1129 ret = parse_probe_arg(arg, t2, &code, end, ctx); 1130 if (ret) 1131 break; 1132 ctx->offset = cur_offs; 1133 if (code->op == FETCH_OP_COMM || 1134 code->op == FETCH_OP_DATA) { 1135 trace_probe_log_err(ctx->offset, COMM_CANT_DEREF); 1136 return -EINVAL; 1137 } 1138 if (++code == end) { 1139 trace_probe_log_err(ctx->offset, TOO_MANY_OPS); 1140 return -EINVAL; 1141 } 1142 *pcode = code; 1143 1144 code->op = deref; 1145 code->offset = offset; 1146 /* Reset the last type if used */ 1147 ctx->last_type = NULL; 1148 } 1149 break; 1150 case '\\': /* Immediate value */ 1151 if (arg[1] == '"') { /* Immediate string */ 1152 ret = __parse_imm_string(arg + 2, &tmp, ctx->offset + 2); 1153 if (ret) 1154 break; 1155 code->op = FETCH_OP_DATA; 1156 code->data = tmp; 1157 } else { 1158 ret = str_to_immediate(arg + 1, &code->immediate); 1159 if (ret) 1160 trace_probe_log_err(ctx->offset + 1, BAD_IMM); 1161 else 1162 code->op = FETCH_OP_IMM; 1163 } 1164 break; 1165 default: 1166 if (isalpha(arg[0]) || arg[0] == '_') { /* BTF variable */ 1167 if (!tparg_is_function_entry(ctx->flags) && 1168 !tparg_is_function_return(ctx->flags)) { 1169 trace_probe_log_err(ctx->offset, NOSUP_BTFARG); 1170 return -EINVAL; 1171 } 1172 ret = parse_btf_arg(arg, pcode, end, ctx); 1173 break; 1174 } 1175 } 1176 if (!ret && code->op == FETCH_OP_NOP) { 1177 /* Parsed, but do not find fetch method */ 1178 trace_probe_log_err(ctx->offset, BAD_FETCH_ARG); 1179 ret = -EINVAL; 1180 } 1181 return ret; 1182 } 1183 1184 /* Bitfield type needs to be parsed into a fetch function */ 1185 static int __parse_bitfield_probe_arg(const char *bf, 1186 const struct fetch_type *t, 1187 struct fetch_insn **pcode) 1188 { 1189 struct fetch_insn *code = *pcode; 1190 unsigned long bw, bo; 1191 char *tail; 1192 1193 if (*bf != 'b') 1194 return 0; 1195 1196 bw = simple_strtoul(bf + 1, &tail, 0); /* Use simple one */ 1197 1198 if (bw == 0 || *tail != '@') 1199 return -EINVAL; 1200 1201 bf = tail + 1; 1202 bo = simple_strtoul(bf, &tail, 0); 1203 1204 if (tail == bf || *tail != '/') 1205 return -EINVAL; 1206 code++; 1207 if (code->op != FETCH_OP_NOP) 1208 return -EINVAL; 1209 *pcode = code; 1210 1211 code->op = FETCH_OP_MOD_BF; 1212 code->lshift = BYTES_TO_BITS(t->size) - (bw + bo); 1213 code->rshift = BYTES_TO_BITS(t->size) - bw; 1214 code->basesize = t->size; 1215 1216 return (BYTES_TO_BITS(t->size) < (bw + bo)) ? -EINVAL : 0; 1217 } 1218 1219 /* Split type part from @arg and return it. */ 1220 static char *parse_probe_arg_type(char *arg, struct probe_arg *parg, 1221 struct traceprobe_parse_context *ctx) 1222 { 1223 char *t = NULL, *t2, *t3; 1224 int offs; 1225 1226 t = strchr(arg, ':'); 1227 if (t) { 1228 *t++ = '\0'; 1229 t2 = strchr(t, '['); 1230 if (t2) { 1231 *t2++ = '\0'; 1232 t3 = strchr(t2, ']'); 1233 if (!t3) { 1234 offs = t2 + strlen(t2) - arg; 1235 1236 trace_probe_log_err(ctx->offset + offs, 1237 ARRAY_NO_CLOSE); 1238 return ERR_PTR(-EINVAL); 1239 } else if (t3[1] != '\0') { 1240 trace_probe_log_err(ctx->offset + t3 + 1 - arg, 1241 BAD_ARRAY_SUFFIX); 1242 return ERR_PTR(-EINVAL); 1243 } 1244 *t3 = '\0'; 1245 if (kstrtouint(t2, 0, &parg->count) || !parg->count) { 1246 trace_probe_log_err(ctx->offset + t2 - arg, 1247 BAD_ARRAY_NUM); 1248 return ERR_PTR(-EINVAL); 1249 } 1250 if (parg->count > MAX_ARRAY_LEN) { 1251 trace_probe_log_err(ctx->offset + t2 - arg, 1252 ARRAY_TOO_BIG); 1253 return ERR_PTR(-EINVAL); 1254 } 1255 } 1256 } 1257 offs = t ? t - arg : 0; 1258 1259 /* 1260 * Since $comm and immediate string can not be dereferenced, 1261 * we can find those by strcmp. But ignore for eprobes. 1262 */ 1263 if (!(ctx->flags & TPARG_FL_TEVENT) && 1264 (strcmp(arg, "$comm") == 0 || strcmp(arg, "$COMM") == 0 || 1265 strncmp(arg, "\\\"", 2) == 0)) { 1266 /* The type of $comm must be "string", and not an array type. */ 1267 if (parg->count || (t && strcmp(t, "string"))) { 1268 trace_probe_log_err(ctx->offset + offs, NEED_STRING_TYPE); 1269 return ERR_PTR(-EINVAL); 1270 } 1271 parg->type = find_fetch_type("string", ctx->flags); 1272 } else 1273 parg->type = find_fetch_type(t, ctx->flags); 1274 1275 if (!parg->type) { 1276 trace_probe_log_err(ctx->offset + offs, BAD_TYPE); 1277 return ERR_PTR(-EINVAL); 1278 } 1279 1280 return t; 1281 } 1282 1283 /* After parsing, adjust the fetch_insn according to the probe_arg */ 1284 static int finalize_fetch_insn(struct fetch_insn *code, 1285 struct probe_arg *parg, 1286 char *type, 1287 int type_offset, 1288 struct traceprobe_parse_context *ctx) 1289 { 1290 struct fetch_insn *scode; 1291 int ret; 1292 1293 /* Store operation */ 1294 if (parg->type->is_string) { 1295 /* Check bad combination of the type and the last fetch_insn. */ 1296 if (!strcmp(parg->type->name, "symstr")) { 1297 if (code->op != FETCH_OP_REG && code->op != FETCH_OP_STACK && 1298 code->op != FETCH_OP_RETVAL && code->op != FETCH_OP_ARG && 1299 code->op != FETCH_OP_DEREF && code->op != FETCH_OP_TP_ARG) { 1300 trace_probe_log_err(ctx->offset + type_offset, 1301 BAD_SYMSTRING); 1302 return -EINVAL; 1303 } 1304 } else { 1305 if (code->op != FETCH_OP_DEREF && code->op != FETCH_OP_UDEREF && 1306 code->op != FETCH_OP_IMM && code->op != FETCH_OP_COMM && 1307 code->op != FETCH_OP_DATA && code->op != FETCH_OP_TP_ARG) { 1308 trace_probe_log_err(ctx->offset + type_offset, 1309 BAD_STRING); 1310 return -EINVAL; 1311 } 1312 } 1313 1314 if (!strcmp(parg->type->name, "symstr") || 1315 (code->op == FETCH_OP_IMM || code->op == FETCH_OP_COMM || 1316 code->op == FETCH_OP_DATA) || code->op == FETCH_OP_TP_ARG || 1317 parg->count) { 1318 /* 1319 * IMM, DATA and COMM is pointing actual address, those 1320 * must be kept, and if parg->count != 0, this is an 1321 * array of string pointers instead of string address 1322 * itself. 1323 * For the symstr, it doesn't need to dereference, thus 1324 * it just get the value. 1325 */ 1326 code++; 1327 if (code->op != FETCH_OP_NOP) { 1328 trace_probe_log_err(ctx->offset, TOO_MANY_OPS); 1329 return -EINVAL; 1330 } 1331 } 1332 1333 /* If op == DEREF, replace it with STRING */ 1334 if (!strcmp(parg->type->name, "ustring") || 1335 code->op == FETCH_OP_UDEREF) 1336 code->op = FETCH_OP_ST_USTRING; 1337 else if (!strcmp(parg->type->name, "symstr")) 1338 code->op = FETCH_OP_ST_SYMSTR; 1339 else 1340 code->op = FETCH_OP_ST_STRING; 1341 code->size = parg->type->size; 1342 parg->dynamic = true; 1343 } else if (code->op == FETCH_OP_DEREF) { 1344 code->op = FETCH_OP_ST_MEM; 1345 code->size = parg->type->size; 1346 } else if (code->op == FETCH_OP_UDEREF) { 1347 code->op = FETCH_OP_ST_UMEM; 1348 code->size = parg->type->size; 1349 } else { 1350 code++; 1351 if (code->op != FETCH_OP_NOP) { 1352 trace_probe_log_err(ctx->offset, TOO_MANY_OPS); 1353 return -E2BIG; 1354 } 1355 code->op = FETCH_OP_ST_RAW; 1356 code->size = parg->type->size; 1357 } 1358 1359 /* Save storing fetch_insn. */ 1360 scode = code; 1361 1362 /* Modify operation */ 1363 if (type != NULL) { 1364 /* Bitfield needs a special fetch_insn. */ 1365 ret = __parse_bitfield_probe_arg(type, parg->type, &code); 1366 if (ret) { 1367 trace_probe_log_err(ctx->offset + type_offset, BAD_BITFIELD); 1368 return ret; 1369 } 1370 } else if (IS_ENABLED(CONFIG_PROBE_EVENTS_BTF_ARGS) && 1371 ctx->last_type) { 1372 /* If user not specified the type, try parsing BTF bitfield. */ 1373 ret = parse_btf_bitfield(&code, ctx); 1374 if (ret) 1375 return ret; 1376 } 1377 1378 /* Loop(Array) operation */ 1379 if (parg->count) { 1380 if (scode->op != FETCH_OP_ST_MEM && 1381 scode->op != FETCH_OP_ST_STRING && 1382 scode->op != FETCH_OP_ST_USTRING) { 1383 trace_probe_log_err(ctx->offset + type_offset, BAD_STRING); 1384 return -EINVAL; 1385 } 1386 code++; 1387 if (code->op != FETCH_OP_NOP) { 1388 trace_probe_log_err(ctx->offset, TOO_MANY_OPS); 1389 return -E2BIG; 1390 } 1391 code->op = FETCH_OP_LP_ARRAY; 1392 code->param = parg->count; 1393 } 1394 1395 /* Finalize the fetch_insn array. */ 1396 code++; 1397 code->op = FETCH_OP_END; 1398 1399 return 0; 1400 } 1401 1402 /* String length checking wrapper */ 1403 static int traceprobe_parse_probe_arg_body(const char *argv, ssize_t *size, 1404 struct probe_arg *parg, 1405 struct traceprobe_parse_context *ctx) 1406 { 1407 struct fetch_insn *code, *tmp = NULL; 1408 char *type, *arg; 1409 int ret, len; 1410 1411 len = strlen(argv); 1412 if (len > MAX_ARGSTR_LEN) { 1413 trace_probe_log_err(ctx->offset, ARG_TOO_LONG); 1414 return -E2BIG; 1415 } else if (len == 0) { 1416 trace_probe_log_err(ctx->offset, NO_ARG_BODY); 1417 return -EINVAL; 1418 } 1419 1420 arg = kstrdup(argv, GFP_KERNEL); 1421 if (!arg) 1422 return -ENOMEM; 1423 1424 parg->comm = kstrdup(arg, GFP_KERNEL); 1425 if (!parg->comm) { 1426 ret = -ENOMEM; 1427 goto out; 1428 } 1429 1430 type = parse_probe_arg_type(arg, parg, ctx); 1431 if (IS_ERR(type)) { 1432 ret = PTR_ERR(type); 1433 goto out; 1434 } 1435 1436 code = tmp = kcalloc(FETCH_INSN_MAX, sizeof(*code), GFP_KERNEL); 1437 if (!code) { 1438 ret = -ENOMEM; 1439 goto out; 1440 } 1441 code[FETCH_INSN_MAX - 1].op = FETCH_OP_END; 1442 1443 ctx->last_type = NULL; 1444 ret = parse_probe_arg(arg, parg->type, &code, &code[FETCH_INSN_MAX - 1], 1445 ctx); 1446 if (ret < 0) 1447 goto fail; 1448 1449 /* Update storing type if BTF is available */ 1450 if (IS_ENABLED(CONFIG_PROBE_EVENTS_BTF_ARGS) && 1451 ctx->last_type) { 1452 if (!type) { 1453 parg->type = find_fetch_type_from_btf_type(ctx); 1454 } else if (strstr(type, "string")) { 1455 ret = check_prepare_btf_string_fetch(type, &code, ctx); 1456 if (ret) 1457 goto fail; 1458 } 1459 } 1460 parg->offset = *size; 1461 *size += parg->type->size * (parg->count ?: 1); 1462 1463 if (parg->count) { 1464 len = strlen(parg->type->fmttype) + 6; 1465 parg->fmt = kmalloc(len, GFP_KERNEL); 1466 if (!parg->fmt) { 1467 ret = -ENOMEM; 1468 goto fail; 1469 } 1470 snprintf(parg->fmt, len, "%s[%d]", parg->type->fmttype, 1471 parg->count); 1472 } 1473 1474 ret = finalize_fetch_insn(code, parg, type, type ? type - arg : 0, ctx); 1475 if (ret < 0) 1476 goto fail; 1477 1478 for (; code < tmp + FETCH_INSN_MAX; code++) 1479 if (code->op == FETCH_OP_END) 1480 break; 1481 /* Shrink down the code buffer */ 1482 parg->code = kcalloc(code - tmp + 1, sizeof(*code), GFP_KERNEL); 1483 if (!parg->code) 1484 ret = -ENOMEM; 1485 else 1486 memcpy(parg->code, tmp, sizeof(*code) * (code - tmp + 1)); 1487 1488 fail: 1489 if (ret < 0) { 1490 for (code = tmp; code < tmp + FETCH_INSN_MAX; code++) 1491 if (code->op == FETCH_NOP_SYMBOL || 1492 code->op == FETCH_OP_DATA) 1493 kfree(code->data); 1494 } 1495 kfree(tmp); 1496 out: 1497 kfree(arg); 1498 1499 return ret; 1500 } 1501 1502 /* Return 1 if name is reserved or already used by another argument */ 1503 static int traceprobe_conflict_field_name(const char *name, 1504 struct probe_arg *args, int narg) 1505 { 1506 int i; 1507 1508 for (i = 0; i < ARRAY_SIZE(reserved_field_names); i++) 1509 if (strcmp(reserved_field_names[i], name) == 0) 1510 return 1; 1511 1512 for (i = 0; i < narg; i++) 1513 if (strcmp(args[i].name, name) == 0) 1514 return 1; 1515 1516 return 0; 1517 } 1518 1519 static char *generate_probe_arg_name(const char *arg, int idx) 1520 { 1521 char *name = NULL; 1522 const char *end; 1523 1524 /* 1525 * If argument name is omitted, try arg as a name (BTF variable) 1526 * or "argN". 1527 */ 1528 if (IS_ENABLED(CONFIG_PROBE_EVENTS_BTF_ARGS)) { 1529 end = strchr(arg, ':'); 1530 if (!end) 1531 end = arg + strlen(arg); 1532 1533 name = kmemdup_nul(arg, end - arg, GFP_KERNEL); 1534 if (!name || !is_good_name(name)) { 1535 kfree(name); 1536 name = NULL; 1537 } 1538 } 1539 1540 if (!name) 1541 name = kasprintf(GFP_KERNEL, "arg%d", idx + 1); 1542 1543 return name; 1544 } 1545 1546 int traceprobe_parse_probe_arg(struct trace_probe *tp, int i, const char *arg, 1547 struct traceprobe_parse_context *ctx) 1548 { 1549 struct probe_arg *parg = &tp->args[i]; 1550 const char *body; 1551 1552 ctx->tp = tp; 1553 body = strchr(arg, '='); 1554 if (body) { 1555 if (body - arg > MAX_ARG_NAME_LEN) { 1556 trace_probe_log_err(0, ARG_NAME_TOO_LONG); 1557 return -EINVAL; 1558 } else if (body == arg) { 1559 trace_probe_log_err(0, NO_ARG_NAME); 1560 return -EINVAL; 1561 } 1562 parg->name = kmemdup_nul(arg, body - arg, GFP_KERNEL); 1563 body++; 1564 } else { 1565 parg->name = generate_probe_arg_name(arg, i); 1566 body = arg; 1567 } 1568 if (!parg->name) 1569 return -ENOMEM; 1570 1571 if (!is_good_name(parg->name)) { 1572 trace_probe_log_err(0, BAD_ARG_NAME); 1573 return -EINVAL; 1574 } 1575 if (traceprobe_conflict_field_name(parg->name, tp->args, i)) { 1576 trace_probe_log_err(0, USED_ARG_NAME); 1577 return -EINVAL; 1578 } 1579 ctx->offset = body - arg; 1580 /* Parse fetch argument */ 1581 return traceprobe_parse_probe_arg_body(body, &tp->size, parg, ctx); 1582 } 1583 1584 void traceprobe_free_probe_arg(struct probe_arg *arg) 1585 { 1586 struct fetch_insn *code = arg->code; 1587 1588 while (code && code->op != FETCH_OP_END) { 1589 if (code->op == FETCH_NOP_SYMBOL || 1590 code->op == FETCH_OP_DATA) 1591 kfree(code->data); 1592 code++; 1593 } 1594 kfree(arg->code); 1595 kfree(arg->name); 1596 kfree(arg->comm); 1597 kfree(arg->fmt); 1598 } 1599 1600 static int argv_has_var_arg(int argc, const char *argv[], int *args_idx, 1601 struct traceprobe_parse_context *ctx) 1602 { 1603 int i, found = 0; 1604 1605 for (i = 0; i < argc; i++) 1606 if (str_has_prefix(argv[i], "$arg")) { 1607 trace_probe_log_set_index(i + 2); 1608 1609 if (!tparg_is_function_entry(ctx->flags) && 1610 !tparg_is_function_return(ctx->flags)) { 1611 trace_probe_log_err(0, NOFENTRY_ARGS); 1612 return -EINVAL; 1613 } 1614 1615 if (isdigit(argv[i][4])) { 1616 found = 1; 1617 continue; 1618 } 1619 1620 if (argv[i][4] != '*') { 1621 trace_probe_log_err(0, BAD_VAR); 1622 return -EINVAL; 1623 } 1624 1625 if (*args_idx >= 0 && *args_idx < argc) { 1626 trace_probe_log_err(0, DOUBLE_ARGS); 1627 return -EINVAL; 1628 } 1629 found = 1; 1630 *args_idx = i; 1631 } 1632 1633 return found; 1634 } 1635 1636 static int sprint_nth_btf_arg(int idx, const char *type, 1637 char *buf, int bufsize, 1638 struct traceprobe_parse_context *ctx) 1639 { 1640 const char *name; 1641 int ret; 1642 1643 if (idx >= ctx->nr_params) { 1644 trace_probe_log_err(0, NO_BTFARG); 1645 return -ENOENT; 1646 } 1647 name = btf_name_by_offset(ctx->btf, ctx->params[idx].name_off); 1648 if (!name) { 1649 trace_probe_log_err(0, NO_BTF_ENTRY); 1650 return -ENOENT; 1651 } 1652 ret = snprintf(buf, bufsize, "%s%s", name, type); 1653 if (ret >= bufsize) { 1654 trace_probe_log_err(0, ARGS_2LONG); 1655 return -E2BIG; 1656 } 1657 return ret; 1658 } 1659 1660 /* Return new_argv which must be freed after use */ 1661 const char **traceprobe_expand_meta_args(int argc, const char *argv[], 1662 int *new_argc, char *buf, int bufsize, 1663 struct traceprobe_parse_context *ctx) 1664 { 1665 const struct btf_param *params = NULL; 1666 int i, j, n, used, ret, args_idx = -1; 1667 const char **new_argv = NULL; 1668 1669 ret = argv_has_var_arg(argc, argv, &args_idx, ctx); 1670 if (ret < 0) 1671 return ERR_PTR(ret); 1672 1673 if (!ret) { 1674 *new_argc = argc; 1675 return NULL; 1676 } 1677 1678 ret = query_btf_context(ctx); 1679 if (ret < 0 || ctx->nr_params == 0) { 1680 if (args_idx != -1) { 1681 /* $arg* requires BTF info */ 1682 trace_probe_log_err(0, NOSUP_BTFARG); 1683 return (const char **)params; 1684 } 1685 *new_argc = argc; 1686 return NULL; 1687 } 1688 1689 if (args_idx >= 0) 1690 *new_argc = argc + ctx->nr_params - 1; 1691 else 1692 *new_argc = argc; 1693 1694 new_argv = kcalloc(*new_argc, sizeof(char *), GFP_KERNEL); 1695 if (!new_argv) 1696 return ERR_PTR(-ENOMEM); 1697 1698 used = 0; 1699 for (i = 0, j = 0; i < argc; i++) { 1700 trace_probe_log_set_index(i + 2); 1701 if (i == args_idx) { 1702 for (n = 0; n < ctx->nr_params; n++) { 1703 ret = sprint_nth_btf_arg(n, "", buf + used, 1704 bufsize - used, ctx); 1705 if (ret < 0) 1706 goto error; 1707 1708 new_argv[j++] = buf + used; 1709 used += ret + 1; 1710 } 1711 continue; 1712 } 1713 1714 if (str_has_prefix(argv[i], "$arg")) { 1715 char *type = NULL; 1716 1717 n = simple_strtoul(argv[i] + 4, &type, 10); 1718 if (type && !(*type == ':' || *type == '\0')) { 1719 trace_probe_log_err(0, BAD_VAR); 1720 ret = -ENOENT; 1721 goto error; 1722 } 1723 /* Note: $argN starts from $arg1 */ 1724 ret = sprint_nth_btf_arg(n - 1, type, buf + used, 1725 bufsize - used, ctx); 1726 if (ret < 0) 1727 goto error; 1728 new_argv[j++] = buf + used; 1729 used += ret + 1; 1730 } else 1731 new_argv[j++] = argv[i]; 1732 } 1733 1734 return new_argv; 1735 1736 error: 1737 kfree(new_argv); 1738 return ERR_PTR(ret); 1739 } 1740 1741 /* @buf: *buf must be equal to NULL. Caller must to free *buf */ 1742 int traceprobe_expand_dentry_args(int argc, const char *argv[], char **buf) 1743 { 1744 int i, used, ret; 1745 const int bufsize = MAX_DENTRY_ARGS_LEN; 1746 char *tmpbuf = NULL; 1747 1748 if (*buf) 1749 return -EINVAL; 1750 1751 used = 0; 1752 for (i = 0; i < argc; i++) { 1753 char *tmp; 1754 char *equal; 1755 size_t arg_len; 1756 1757 if (!glob_match("*:%p[dD]", argv[i])) 1758 continue; 1759 1760 if (!tmpbuf) { 1761 tmpbuf = kmalloc(bufsize, GFP_KERNEL); 1762 if (!tmpbuf) 1763 return -ENOMEM; 1764 } 1765 1766 tmp = kstrdup(argv[i], GFP_KERNEL); 1767 if (!tmp) 1768 goto nomem; 1769 1770 equal = strchr(tmp, '='); 1771 if (equal) 1772 *equal = '\0'; 1773 arg_len = strlen(argv[i]); 1774 tmp[arg_len - 4] = '\0'; 1775 if (argv[i][arg_len - 1] == 'd') 1776 ret = snprintf(tmpbuf + used, bufsize - used, 1777 "%s%s+0x0(+0x%zx(%s)):string", 1778 equal ? tmp : "", equal ? "=" : "", 1779 offsetof(struct dentry, d_name.name), 1780 equal ? equal + 1 : tmp); 1781 else 1782 ret = snprintf(tmpbuf + used, bufsize - used, 1783 "%s%s+0x0(+0x%zx(+0x%zx(%s))):string", 1784 equal ? tmp : "", equal ? "=" : "", 1785 offsetof(struct dentry, d_name.name), 1786 offsetof(struct file, f_path.dentry), 1787 equal ? equal + 1 : tmp); 1788 1789 kfree(tmp); 1790 if (ret >= bufsize - used) 1791 goto nomem; 1792 argv[i] = tmpbuf + used; 1793 used += ret + 1; 1794 } 1795 1796 *buf = tmpbuf; 1797 return 0; 1798 nomem: 1799 kfree(tmpbuf); 1800 return -ENOMEM; 1801 } 1802 1803 void traceprobe_finish_parse(struct traceprobe_parse_context *ctx) 1804 { 1805 clear_btf_context(ctx); 1806 } 1807 1808 int traceprobe_update_arg(struct probe_arg *arg) 1809 { 1810 struct fetch_insn *code = arg->code; 1811 long offset; 1812 char *tmp; 1813 char c; 1814 int ret = 0; 1815 1816 while (code && code->op != FETCH_OP_END) { 1817 if (code->op == FETCH_NOP_SYMBOL) { 1818 if (code[1].op != FETCH_OP_IMM) 1819 return -EINVAL; 1820 1821 tmp = strpbrk(code->data, "+-"); 1822 if (tmp) 1823 c = *tmp; 1824 ret = traceprobe_split_symbol_offset(code->data, 1825 &offset); 1826 if (ret) 1827 return ret; 1828 1829 code[1].immediate = 1830 (unsigned long)kallsyms_lookup_name(code->data); 1831 if (tmp) 1832 *tmp = c; 1833 if (!code[1].immediate) 1834 return -ENOENT; 1835 code[1].immediate += offset; 1836 } 1837 code++; 1838 } 1839 return 0; 1840 } 1841 1842 /* When len=0, we just calculate the needed length */ 1843 #define LEN_OR_ZERO (len ? len - pos : 0) 1844 static int __set_print_fmt(struct trace_probe *tp, char *buf, int len, 1845 enum probe_print_type ptype) 1846 { 1847 struct probe_arg *parg; 1848 int i, j; 1849 int pos = 0; 1850 const char *fmt, *arg; 1851 1852 switch (ptype) { 1853 case PROBE_PRINT_NORMAL: 1854 fmt = "(%lx)"; 1855 arg = ", REC->" FIELD_STRING_IP; 1856 break; 1857 case PROBE_PRINT_RETURN: 1858 fmt = "(%lx <- %lx)"; 1859 arg = ", REC->" FIELD_STRING_FUNC ", REC->" FIELD_STRING_RETIP; 1860 break; 1861 case PROBE_PRINT_EVENT: 1862 fmt = ""; 1863 arg = ""; 1864 break; 1865 default: 1866 WARN_ON_ONCE(1); 1867 return 0; 1868 } 1869 1870 pos += snprintf(buf + pos, LEN_OR_ZERO, "\"%s", fmt); 1871 1872 for (i = 0; i < tp->nr_args; i++) { 1873 parg = tp->args + i; 1874 pos += snprintf(buf + pos, LEN_OR_ZERO, " %s=", parg->name); 1875 if (parg->count) { 1876 pos += snprintf(buf + pos, LEN_OR_ZERO, "{%s", 1877 parg->type->fmt); 1878 for (j = 1; j < parg->count; j++) 1879 pos += snprintf(buf + pos, LEN_OR_ZERO, ",%s", 1880 parg->type->fmt); 1881 pos += snprintf(buf + pos, LEN_OR_ZERO, "}"); 1882 } else 1883 pos += snprintf(buf + pos, LEN_OR_ZERO, "%s", 1884 parg->type->fmt); 1885 } 1886 1887 pos += snprintf(buf + pos, LEN_OR_ZERO, "\"%s", arg); 1888 1889 for (i = 0; i < tp->nr_args; i++) { 1890 parg = tp->args + i; 1891 if (parg->count) { 1892 if (parg->type->is_string) 1893 fmt = ", __get_str(%s[%d])"; 1894 else 1895 fmt = ", REC->%s[%d]"; 1896 for (j = 0; j < parg->count; j++) 1897 pos += snprintf(buf + pos, LEN_OR_ZERO, 1898 fmt, parg->name, j); 1899 } else { 1900 if (parg->type->is_string) 1901 fmt = ", __get_str(%s)"; 1902 else 1903 fmt = ", REC->%s"; 1904 pos += snprintf(buf + pos, LEN_OR_ZERO, 1905 fmt, parg->name); 1906 } 1907 } 1908 1909 /* return the length of print_fmt */ 1910 return pos; 1911 } 1912 #undef LEN_OR_ZERO 1913 1914 int traceprobe_set_print_fmt(struct trace_probe *tp, enum probe_print_type ptype) 1915 { 1916 struct trace_event_call *call = trace_probe_event_call(tp); 1917 int len; 1918 char *print_fmt; 1919 1920 /* First: called with 0 length to calculate the needed length */ 1921 len = __set_print_fmt(tp, NULL, 0, ptype); 1922 print_fmt = kmalloc(len + 1, GFP_KERNEL); 1923 if (!print_fmt) 1924 return -ENOMEM; 1925 1926 /* Second: actually write the @print_fmt */ 1927 __set_print_fmt(tp, print_fmt, len + 1, ptype); 1928 call->print_fmt = print_fmt; 1929 1930 return 0; 1931 } 1932 1933 int traceprobe_define_arg_fields(struct trace_event_call *event_call, 1934 size_t offset, struct trace_probe *tp) 1935 { 1936 int ret, i; 1937 1938 /* Set argument names as fields */ 1939 for (i = 0; i < tp->nr_args; i++) { 1940 struct probe_arg *parg = &tp->args[i]; 1941 const char *fmt = parg->type->fmttype; 1942 int size = parg->type->size; 1943 1944 if (parg->fmt) 1945 fmt = parg->fmt; 1946 if (parg->count) 1947 size *= parg->count; 1948 ret = trace_define_field(event_call, fmt, parg->name, 1949 offset + parg->offset, size, 1950 parg->type->is_signed, 1951 FILTER_OTHER); 1952 if (ret) 1953 return ret; 1954 } 1955 return 0; 1956 } 1957 1958 static void trace_probe_event_free(struct trace_probe_event *tpe) 1959 { 1960 kfree(tpe->class.system); 1961 kfree(tpe->call.name); 1962 kfree(tpe->call.print_fmt); 1963 kfree(tpe); 1964 } 1965 1966 int trace_probe_append(struct trace_probe *tp, struct trace_probe *to) 1967 { 1968 if (trace_probe_has_sibling(tp)) 1969 return -EBUSY; 1970 1971 list_del_init(&tp->list); 1972 trace_probe_event_free(tp->event); 1973 1974 tp->event = to->event; 1975 list_add_tail(&tp->list, trace_probe_probe_list(to)); 1976 1977 return 0; 1978 } 1979 1980 void trace_probe_unlink(struct trace_probe *tp) 1981 { 1982 list_del_init(&tp->list); 1983 if (list_empty(trace_probe_probe_list(tp))) 1984 trace_probe_event_free(tp->event); 1985 tp->event = NULL; 1986 } 1987 1988 void trace_probe_cleanup(struct trace_probe *tp) 1989 { 1990 int i; 1991 1992 for (i = 0; i < tp->nr_args; i++) 1993 traceprobe_free_probe_arg(&tp->args[i]); 1994 1995 if (tp->entry_arg) { 1996 kfree(tp->entry_arg->code); 1997 kfree(tp->entry_arg); 1998 tp->entry_arg = NULL; 1999 } 2000 2001 if (tp->event) 2002 trace_probe_unlink(tp); 2003 } 2004 2005 int trace_probe_init(struct trace_probe *tp, const char *event, 2006 const char *group, bool alloc_filter, int nargs) 2007 { 2008 struct trace_event_call *call; 2009 size_t size = sizeof(struct trace_probe_event); 2010 int ret = 0; 2011 2012 if (!event || !group) 2013 return -EINVAL; 2014 2015 if (alloc_filter) 2016 size += sizeof(struct trace_uprobe_filter); 2017 2018 tp->event = kzalloc(size, GFP_KERNEL); 2019 if (!tp->event) 2020 return -ENOMEM; 2021 2022 INIT_LIST_HEAD(&tp->event->files); 2023 INIT_LIST_HEAD(&tp->event->class.fields); 2024 INIT_LIST_HEAD(&tp->event->probes); 2025 INIT_LIST_HEAD(&tp->list); 2026 list_add(&tp->list, &tp->event->probes); 2027 2028 call = trace_probe_event_call(tp); 2029 call->class = &tp->event->class; 2030 call->name = kstrdup(event, GFP_KERNEL); 2031 if (!call->name) { 2032 ret = -ENOMEM; 2033 goto error; 2034 } 2035 2036 tp->event->class.system = kstrdup(group, GFP_KERNEL); 2037 if (!tp->event->class.system) { 2038 ret = -ENOMEM; 2039 goto error; 2040 } 2041 2042 tp->nr_args = nargs; 2043 /* Make sure pointers in args[] are NULL */ 2044 if (nargs) 2045 memset(tp->args, 0, sizeof(tp->args[0]) * nargs); 2046 2047 return 0; 2048 2049 error: 2050 trace_probe_cleanup(tp); 2051 return ret; 2052 } 2053 2054 static struct trace_event_call * 2055 find_trace_event_call(const char *system, const char *event_name) 2056 { 2057 struct trace_event_call *tp_event; 2058 const char *name; 2059 2060 list_for_each_entry(tp_event, &ftrace_events, list) { 2061 if (!tp_event->class->system || 2062 strcmp(system, tp_event->class->system)) 2063 continue; 2064 name = trace_event_name(tp_event); 2065 if (!name || strcmp(event_name, name)) 2066 continue; 2067 return tp_event; 2068 } 2069 2070 return NULL; 2071 } 2072 2073 int trace_probe_register_event_call(struct trace_probe *tp) 2074 { 2075 struct trace_event_call *call = trace_probe_event_call(tp); 2076 int ret; 2077 2078 lockdep_assert_held(&event_mutex); 2079 2080 if (find_trace_event_call(trace_probe_group_name(tp), 2081 trace_probe_name(tp))) 2082 return -EEXIST; 2083 2084 ret = register_trace_event(&call->event); 2085 if (!ret) 2086 return -ENODEV; 2087 2088 ret = trace_add_event_call(call); 2089 if (ret) 2090 unregister_trace_event(&call->event); 2091 2092 return ret; 2093 } 2094 2095 int trace_probe_add_file(struct trace_probe *tp, struct trace_event_file *file) 2096 { 2097 struct event_file_link *link; 2098 2099 link = kmalloc(sizeof(*link), GFP_KERNEL); 2100 if (!link) 2101 return -ENOMEM; 2102 2103 link->file = file; 2104 INIT_LIST_HEAD(&link->list); 2105 list_add_tail_rcu(&link->list, &tp->event->files); 2106 trace_probe_set_flag(tp, TP_FLAG_TRACE); 2107 return 0; 2108 } 2109 2110 struct event_file_link *trace_probe_get_file_link(struct trace_probe *tp, 2111 struct trace_event_file *file) 2112 { 2113 struct event_file_link *link; 2114 2115 trace_probe_for_each_link(link, tp) { 2116 if (link->file == file) 2117 return link; 2118 } 2119 2120 return NULL; 2121 } 2122 2123 int trace_probe_remove_file(struct trace_probe *tp, 2124 struct trace_event_file *file) 2125 { 2126 struct event_file_link *link; 2127 2128 link = trace_probe_get_file_link(tp, file); 2129 if (!link) 2130 return -ENOENT; 2131 2132 list_del_rcu(&link->list); 2133 kvfree_rcu_mightsleep(link); 2134 2135 if (list_empty(&tp->event->files)) 2136 trace_probe_clear_flag(tp, TP_FLAG_TRACE); 2137 2138 return 0; 2139 } 2140 2141 /* 2142 * Return the smallest index of different type argument (start from 1). 2143 * If all argument types and name are same, return 0. 2144 */ 2145 int trace_probe_compare_arg_type(struct trace_probe *a, struct trace_probe *b) 2146 { 2147 int i; 2148 2149 /* In case of more arguments */ 2150 if (a->nr_args < b->nr_args) 2151 return a->nr_args + 1; 2152 if (a->nr_args > b->nr_args) 2153 return b->nr_args + 1; 2154 2155 for (i = 0; i < a->nr_args; i++) { 2156 if ((b->nr_args <= i) || 2157 ((a->args[i].type != b->args[i].type) || 2158 (a->args[i].count != b->args[i].count) || 2159 strcmp(a->args[i].name, b->args[i].name))) 2160 return i + 1; 2161 } 2162 2163 return 0; 2164 } 2165 2166 bool trace_probe_match_command_args(struct trace_probe *tp, 2167 int argc, const char **argv) 2168 { 2169 char buf[MAX_ARGSTR_LEN + 1]; 2170 int i; 2171 2172 if (tp->nr_args < argc) 2173 return false; 2174 2175 for (i = 0; i < argc; i++) { 2176 snprintf(buf, sizeof(buf), "%s=%s", 2177 tp->args[i].name, tp->args[i].comm); 2178 if (strcmp(buf, argv[i])) 2179 return false; 2180 } 2181 return true; 2182 } 2183 2184 int trace_probe_create(const char *raw_command, int (*createfn)(int, const char **)) 2185 { 2186 int argc = 0, ret = 0; 2187 char **argv; 2188 2189 argv = argv_split(GFP_KERNEL, raw_command, &argc); 2190 if (!argv) 2191 return -ENOMEM; 2192 2193 if (argc) 2194 ret = createfn(argc, (const char **)argv); 2195 2196 argv_free(argv); 2197 2198 return ret; 2199 } 2200 2201 int trace_probe_print_args(struct trace_seq *s, struct probe_arg *args, int nr_args, 2202 u8 *data, void *field) 2203 { 2204 void *p; 2205 int i, j; 2206 2207 for (i = 0; i < nr_args; i++) { 2208 struct probe_arg *a = args + i; 2209 2210 trace_seq_printf(s, " %s=", a->name); 2211 if (likely(!a->count)) { 2212 if (!a->type->print(s, data + a->offset, field)) 2213 return -ENOMEM; 2214 continue; 2215 } 2216 trace_seq_putc(s, '{'); 2217 p = data + a->offset; 2218 for (j = 0; j < a->count; j++) { 2219 if (!a->type->print(s, p, field)) 2220 return -ENOMEM; 2221 trace_seq_putc(s, j == a->count - 1 ? '}' : ','); 2222 p += a->type->size; 2223 } 2224 } 2225 return 0; 2226 } 2227