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 <[email protected]> 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 #define BYTES_TO_BITS(nb) ((BITS_PER_LONG * (nb)) / sizeof(long)) 1185 1186 /* Bitfield type needs to be parsed into a fetch function */ 1187 static int __parse_bitfield_probe_arg(const char *bf, 1188 const struct fetch_type *t, 1189 struct fetch_insn **pcode) 1190 { 1191 struct fetch_insn *code = *pcode; 1192 unsigned long bw, bo; 1193 char *tail; 1194 1195 if (*bf != 'b') 1196 return 0; 1197 1198 bw = simple_strtoul(bf + 1, &tail, 0); /* Use simple one */ 1199 1200 if (bw == 0 || *tail != '@') 1201 return -EINVAL; 1202 1203 bf = tail + 1; 1204 bo = simple_strtoul(bf, &tail, 0); 1205 1206 if (tail == bf || *tail != '/') 1207 return -EINVAL; 1208 code++; 1209 if (code->op != FETCH_OP_NOP) 1210 return -EINVAL; 1211 *pcode = code; 1212 1213 code->op = FETCH_OP_MOD_BF; 1214 code->lshift = BYTES_TO_BITS(t->size) - (bw + bo); 1215 code->rshift = BYTES_TO_BITS(t->size) - bw; 1216 code->basesize = t->size; 1217 1218 return (BYTES_TO_BITS(t->size) < (bw + bo)) ? -EINVAL : 0; 1219 } 1220 1221 /* Split type part from @arg and return it. */ 1222 static char *parse_probe_arg_type(char *arg, struct probe_arg *parg, 1223 struct traceprobe_parse_context *ctx) 1224 { 1225 char *t = NULL, *t2, *t3; 1226 int offs; 1227 1228 t = strchr(arg, ':'); 1229 if (t) { 1230 *t++ = '\0'; 1231 t2 = strchr(t, '['); 1232 if (t2) { 1233 *t2++ = '\0'; 1234 t3 = strchr(t2, ']'); 1235 if (!t3) { 1236 offs = t2 + strlen(t2) - arg; 1237 1238 trace_probe_log_err(ctx->offset + offs, 1239 ARRAY_NO_CLOSE); 1240 return ERR_PTR(-EINVAL); 1241 } else if (t3[1] != '\0') { 1242 trace_probe_log_err(ctx->offset + t3 + 1 - arg, 1243 BAD_ARRAY_SUFFIX); 1244 return ERR_PTR(-EINVAL); 1245 } 1246 *t3 = '\0'; 1247 if (kstrtouint(t2, 0, &parg->count) || !parg->count) { 1248 trace_probe_log_err(ctx->offset + t2 - arg, 1249 BAD_ARRAY_NUM); 1250 return ERR_PTR(-EINVAL); 1251 } 1252 if (parg->count > MAX_ARRAY_LEN) { 1253 trace_probe_log_err(ctx->offset + t2 - arg, 1254 ARRAY_TOO_BIG); 1255 return ERR_PTR(-EINVAL); 1256 } 1257 } 1258 } 1259 offs = t ? t - arg : 0; 1260 1261 /* 1262 * Since $comm and immediate string can not be dereferenced, 1263 * we can find those by strcmp. But ignore for eprobes. 1264 */ 1265 if (!(ctx->flags & TPARG_FL_TEVENT) && 1266 (strcmp(arg, "$comm") == 0 || strcmp(arg, "$COMM") == 0 || 1267 strncmp(arg, "\\\"", 2) == 0)) { 1268 /* The type of $comm must be "string", and not an array type. */ 1269 if (parg->count || (t && strcmp(t, "string"))) { 1270 trace_probe_log_err(ctx->offset + offs, NEED_STRING_TYPE); 1271 return ERR_PTR(-EINVAL); 1272 } 1273 parg->type = find_fetch_type("string", ctx->flags); 1274 } else 1275 parg->type = find_fetch_type(t, ctx->flags); 1276 1277 if (!parg->type) { 1278 trace_probe_log_err(ctx->offset + offs, BAD_TYPE); 1279 return ERR_PTR(-EINVAL); 1280 } 1281 1282 return t; 1283 } 1284 1285 /* After parsing, adjust the fetch_insn according to the probe_arg */ 1286 static int finalize_fetch_insn(struct fetch_insn *code, 1287 struct probe_arg *parg, 1288 char *type, 1289 int type_offset, 1290 struct traceprobe_parse_context *ctx) 1291 { 1292 struct fetch_insn *scode; 1293 int ret; 1294 1295 /* Store operation */ 1296 if (parg->type->is_string) { 1297 /* Check bad combination of the type and the last fetch_insn. */ 1298 if (!strcmp(parg->type->name, "symstr")) { 1299 if (code->op != FETCH_OP_REG && code->op != FETCH_OP_STACK && 1300 code->op != FETCH_OP_RETVAL && code->op != FETCH_OP_ARG && 1301 code->op != FETCH_OP_DEREF && code->op != FETCH_OP_TP_ARG) { 1302 trace_probe_log_err(ctx->offset + type_offset, 1303 BAD_SYMSTRING); 1304 return -EINVAL; 1305 } 1306 } else { 1307 if (code->op != FETCH_OP_DEREF && code->op != FETCH_OP_UDEREF && 1308 code->op != FETCH_OP_IMM && code->op != FETCH_OP_COMM && 1309 code->op != FETCH_OP_DATA && code->op != FETCH_OP_TP_ARG) { 1310 trace_probe_log_err(ctx->offset + type_offset, 1311 BAD_STRING); 1312 return -EINVAL; 1313 } 1314 } 1315 1316 if (!strcmp(parg->type->name, "symstr") || 1317 (code->op == FETCH_OP_IMM || code->op == FETCH_OP_COMM || 1318 code->op == FETCH_OP_DATA) || code->op == FETCH_OP_TP_ARG || 1319 parg->count) { 1320 /* 1321 * IMM, DATA and COMM is pointing actual address, those 1322 * must be kept, and if parg->count != 0, this is an 1323 * array of string pointers instead of string address 1324 * itself. 1325 * For the symstr, it doesn't need to dereference, thus 1326 * it just get the value. 1327 */ 1328 code++; 1329 if (code->op != FETCH_OP_NOP) { 1330 trace_probe_log_err(ctx->offset, TOO_MANY_OPS); 1331 return -EINVAL; 1332 } 1333 } 1334 1335 /* If op == DEREF, replace it with STRING */ 1336 if (!strcmp(parg->type->name, "ustring") || 1337 code->op == FETCH_OP_UDEREF) 1338 code->op = FETCH_OP_ST_USTRING; 1339 else if (!strcmp(parg->type->name, "symstr")) 1340 code->op = FETCH_OP_ST_SYMSTR; 1341 else 1342 code->op = FETCH_OP_ST_STRING; 1343 code->size = parg->type->size; 1344 parg->dynamic = true; 1345 } else if (code->op == FETCH_OP_DEREF) { 1346 code->op = FETCH_OP_ST_MEM; 1347 code->size = parg->type->size; 1348 } else if (code->op == FETCH_OP_UDEREF) { 1349 code->op = FETCH_OP_ST_UMEM; 1350 code->size = parg->type->size; 1351 } else { 1352 code++; 1353 if (code->op != FETCH_OP_NOP) { 1354 trace_probe_log_err(ctx->offset, TOO_MANY_OPS); 1355 return -E2BIG; 1356 } 1357 code->op = FETCH_OP_ST_RAW; 1358 code->size = parg->type->size; 1359 } 1360 1361 /* Save storing fetch_insn. */ 1362 scode = code; 1363 1364 /* Modify operation */ 1365 if (type != NULL) { 1366 /* Bitfield needs a special fetch_insn. */ 1367 ret = __parse_bitfield_probe_arg(type, parg->type, &code); 1368 if (ret) { 1369 trace_probe_log_err(ctx->offset + type_offset, BAD_BITFIELD); 1370 return ret; 1371 } 1372 } else if (IS_ENABLED(CONFIG_PROBE_EVENTS_BTF_ARGS) && 1373 ctx->last_type) { 1374 /* If user not specified the type, try parsing BTF bitfield. */ 1375 ret = parse_btf_bitfield(&code, ctx); 1376 if (ret) 1377 return ret; 1378 } 1379 1380 /* Loop(Array) operation */ 1381 if (parg->count) { 1382 if (scode->op != FETCH_OP_ST_MEM && 1383 scode->op != FETCH_OP_ST_STRING && 1384 scode->op != FETCH_OP_ST_USTRING) { 1385 trace_probe_log_err(ctx->offset + type_offset, BAD_STRING); 1386 return -EINVAL; 1387 } 1388 code++; 1389 if (code->op != FETCH_OP_NOP) { 1390 trace_probe_log_err(ctx->offset, TOO_MANY_OPS); 1391 return -E2BIG; 1392 } 1393 code->op = FETCH_OP_LP_ARRAY; 1394 code->param = parg->count; 1395 } 1396 1397 /* Finalize the fetch_insn array. */ 1398 code++; 1399 code->op = FETCH_OP_END; 1400 1401 return 0; 1402 } 1403 1404 /* String length checking wrapper */ 1405 static int traceprobe_parse_probe_arg_body(const char *argv, ssize_t *size, 1406 struct probe_arg *parg, 1407 struct traceprobe_parse_context *ctx) 1408 { 1409 struct fetch_insn *code, *tmp = NULL; 1410 char *type, *arg; 1411 int ret, len; 1412 1413 len = strlen(argv); 1414 if (len > MAX_ARGSTR_LEN) { 1415 trace_probe_log_err(ctx->offset, ARG_TOO_LONG); 1416 return -E2BIG; 1417 } else if (len == 0) { 1418 trace_probe_log_err(ctx->offset, NO_ARG_BODY); 1419 return -EINVAL; 1420 } 1421 1422 arg = kstrdup(argv, GFP_KERNEL); 1423 if (!arg) 1424 return -ENOMEM; 1425 1426 parg->comm = kstrdup(arg, GFP_KERNEL); 1427 if (!parg->comm) { 1428 ret = -ENOMEM; 1429 goto out; 1430 } 1431 1432 type = parse_probe_arg_type(arg, parg, ctx); 1433 if (IS_ERR(type)) { 1434 ret = PTR_ERR(type); 1435 goto out; 1436 } 1437 1438 code = tmp = kcalloc(FETCH_INSN_MAX, sizeof(*code), GFP_KERNEL); 1439 if (!code) { 1440 ret = -ENOMEM; 1441 goto out; 1442 } 1443 code[FETCH_INSN_MAX - 1].op = FETCH_OP_END; 1444 1445 ctx->last_type = NULL; 1446 ret = parse_probe_arg(arg, parg->type, &code, &code[FETCH_INSN_MAX - 1], 1447 ctx); 1448 if (ret < 0) 1449 goto fail; 1450 1451 /* Update storing type if BTF is available */ 1452 if (IS_ENABLED(CONFIG_PROBE_EVENTS_BTF_ARGS) && 1453 ctx->last_type) { 1454 if (!type) { 1455 parg->type = find_fetch_type_from_btf_type(ctx); 1456 } else if (strstr(type, "string")) { 1457 ret = check_prepare_btf_string_fetch(type, &code, ctx); 1458 if (ret) 1459 goto fail; 1460 } 1461 } 1462 parg->offset = *size; 1463 *size += parg->type->size * (parg->count ?: 1); 1464 1465 if (parg->count) { 1466 len = strlen(parg->type->fmttype) + 6; 1467 parg->fmt = kmalloc(len, GFP_KERNEL); 1468 if (!parg->fmt) { 1469 ret = -ENOMEM; 1470 goto out; 1471 } 1472 snprintf(parg->fmt, len, "%s[%d]", parg->type->fmttype, 1473 parg->count); 1474 } 1475 1476 ret = finalize_fetch_insn(code, parg, type, type ? type - arg : 0, ctx); 1477 if (ret < 0) 1478 goto fail; 1479 1480 for (; code < tmp + FETCH_INSN_MAX; code++) 1481 if (code->op == FETCH_OP_END) 1482 break; 1483 /* Shrink down the code buffer */ 1484 parg->code = kcalloc(code - tmp + 1, sizeof(*code), GFP_KERNEL); 1485 if (!parg->code) 1486 ret = -ENOMEM; 1487 else 1488 memcpy(parg->code, tmp, sizeof(*code) * (code - tmp + 1)); 1489 1490 fail: 1491 if (ret < 0) { 1492 for (code = tmp; code < tmp + FETCH_INSN_MAX; code++) 1493 if (code->op == FETCH_NOP_SYMBOL || 1494 code->op == FETCH_OP_DATA) 1495 kfree(code->data); 1496 } 1497 kfree(tmp); 1498 out: 1499 kfree(arg); 1500 1501 return ret; 1502 } 1503 1504 /* Return 1 if name is reserved or already used by another argument */ 1505 static int traceprobe_conflict_field_name(const char *name, 1506 struct probe_arg *args, int narg) 1507 { 1508 int i; 1509 1510 for (i = 0; i < ARRAY_SIZE(reserved_field_names); i++) 1511 if (strcmp(reserved_field_names[i], name) == 0) 1512 return 1; 1513 1514 for (i = 0; i < narg; i++) 1515 if (strcmp(args[i].name, name) == 0) 1516 return 1; 1517 1518 return 0; 1519 } 1520 1521 static char *generate_probe_arg_name(const char *arg, int idx) 1522 { 1523 char *name = NULL; 1524 const char *end; 1525 1526 /* 1527 * If argument name is omitted, try arg as a name (BTF variable) 1528 * or "argN". 1529 */ 1530 if (IS_ENABLED(CONFIG_PROBE_EVENTS_BTF_ARGS)) { 1531 end = strchr(arg, ':'); 1532 if (!end) 1533 end = arg + strlen(arg); 1534 1535 name = kmemdup_nul(arg, end - arg, GFP_KERNEL); 1536 if (!name || !is_good_name(name)) { 1537 kfree(name); 1538 name = NULL; 1539 } 1540 } 1541 1542 if (!name) 1543 name = kasprintf(GFP_KERNEL, "arg%d", idx + 1); 1544 1545 return name; 1546 } 1547 1548 int traceprobe_parse_probe_arg(struct trace_probe *tp, int i, const char *arg, 1549 struct traceprobe_parse_context *ctx) 1550 { 1551 struct probe_arg *parg = &tp->args[i]; 1552 const char *body; 1553 1554 ctx->tp = tp; 1555 body = strchr(arg, '='); 1556 if (body) { 1557 if (body - arg > MAX_ARG_NAME_LEN) { 1558 trace_probe_log_err(0, ARG_NAME_TOO_LONG); 1559 return -EINVAL; 1560 } else if (body == arg) { 1561 trace_probe_log_err(0, NO_ARG_NAME); 1562 return -EINVAL; 1563 } 1564 parg->name = kmemdup_nul(arg, body - arg, GFP_KERNEL); 1565 body++; 1566 } else { 1567 parg->name = generate_probe_arg_name(arg, i); 1568 body = arg; 1569 } 1570 if (!parg->name) 1571 return -ENOMEM; 1572 1573 if (!is_good_name(parg->name)) { 1574 trace_probe_log_err(0, BAD_ARG_NAME); 1575 return -EINVAL; 1576 } 1577 if (traceprobe_conflict_field_name(parg->name, tp->args, i)) { 1578 trace_probe_log_err(0, USED_ARG_NAME); 1579 return -EINVAL; 1580 } 1581 ctx->offset = body - arg; 1582 /* Parse fetch argument */ 1583 return traceprobe_parse_probe_arg_body(body, &tp->size, parg, ctx); 1584 } 1585 1586 void traceprobe_free_probe_arg(struct probe_arg *arg) 1587 { 1588 struct fetch_insn *code = arg->code; 1589 1590 while (code && code->op != FETCH_OP_END) { 1591 if (code->op == FETCH_NOP_SYMBOL || 1592 code->op == FETCH_OP_DATA) 1593 kfree(code->data); 1594 code++; 1595 } 1596 kfree(arg->code); 1597 kfree(arg->name); 1598 kfree(arg->comm); 1599 kfree(arg->fmt); 1600 } 1601 1602 static int argv_has_var_arg(int argc, const char *argv[], int *args_idx, 1603 struct traceprobe_parse_context *ctx) 1604 { 1605 int i, found = 0; 1606 1607 for (i = 0; i < argc; i++) 1608 if (str_has_prefix(argv[i], "$arg")) { 1609 trace_probe_log_set_index(i + 2); 1610 1611 if (!tparg_is_function_entry(ctx->flags) && 1612 !tparg_is_function_return(ctx->flags)) { 1613 trace_probe_log_err(0, NOFENTRY_ARGS); 1614 return -EINVAL; 1615 } 1616 1617 if (isdigit(argv[i][4])) { 1618 found = 1; 1619 continue; 1620 } 1621 1622 if (argv[i][4] != '*') { 1623 trace_probe_log_err(0, BAD_VAR); 1624 return -EINVAL; 1625 } 1626 1627 if (*args_idx >= 0 && *args_idx < argc) { 1628 trace_probe_log_err(0, DOUBLE_ARGS); 1629 return -EINVAL; 1630 } 1631 found = 1; 1632 *args_idx = i; 1633 } 1634 1635 return found; 1636 } 1637 1638 static int sprint_nth_btf_arg(int idx, const char *type, 1639 char *buf, int bufsize, 1640 struct traceprobe_parse_context *ctx) 1641 { 1642 const char *name; 1643 int ret; 1644 1645 if (idx >= ctx->nr_params) { 1646 trace_probe_log_err(0, NO_BTFARG); 1647 return -ENOENT; 1648 } 1649 name = btf_name_by_offset(ctx->btf, ctx->params[idx].name_off); 1650 if (!name) { 1651 trace_probe_log_err(0, NO_BTF_ENTRY); 1652 return -ENOENT; 1653 } 1654 ret = snprintf(buf, bufsize, "%s%s", name, type); 1655 if (ret >= bufsize) { 1656 trace_probe_log_err(0, ARGS_2LONG); 1657 return -E2BIG; 1658 } 1659 return ret; 1660 } 1661 1662 /* Return new_argv which must be freed after use */ 1663 const char **traceprobe_expand_meta_args(int argc, const char *argv[], 1664 int *new_argc, char *buf, int bufsize, 1665 struct traceprobe_parse_context *ctx) 1666 { 1667 const struct btf_param *params = NULL; 1668 int i, j, n, used, ret, args_idx = -1; 1669 const char **new_argv = NULL; 1670 1671 ret = argv_has_var_arg(argc, argv, &args_idx, ctx); 1672 if (ret < 0) 1673 return ERR_PTR(ret); 1674 1675 if (!ret) { 1676 *new_argc = argc; 1677 return NULL; 1678 } 1679 1680 ret = query_btf_context(ctx); 1681 if (ret < 0 || ctx->nr_params == 0) { 1682 if (args_idx != -1) { 1683 /* $arg* requires BTF info */ 1684 trace_probe_log_err(0, NOSUP_BTFARG); 1685 return (const char **)params; 1686 } 1687 *new_argc = argc; 1688 return NULL; 1689 } 1690 1691 if (args_idx >= 0) 1692 *new_argc = argc + ctx->nr_params - 1; 1693 else 1694 *new_argc = argc; 1695 1696 new_argv = kcalloc(*new_argc, sizeof(char *), GFP_KERNEL); 1697 if (!new_argv) 1698 return ERR_PTR(-ENOMEM); 1699 1700 used = 0; 1701 for (i = 0, j = 0; i < argc; i++) { 1702 trace_probe_log_set_index(i + 2); 1703 if (i == args_idx) { 1704 for (n = 0; n < ctx->nr_params; n++) { 1705 ret = sprint_nth_btf_arg(n, "", buf + used, 1706 bufsize - used, ctx); 1707 if (ret < 0) 1708 goto error; 1709 1710 new_argv[j++] = buf + used; 1711 used += ret + 1; 1712 } 1713 continue; 1714 } 1715 1716 if (str_has_prefix(argv[i], "$arg")) { 1717 char *type = NULL; 1718 1719 n = simple_strtoul(argv[i] + 4, &type, 10); 1720 if (type && !(*type == ':' || *type == '\0')) { 1721 trace_probe_log_err(0, BAD_VAR); 1722 ret = -ENOENT; 1723 goto error; 1724 } 1725 /* Note: $argN starts from $arg1 */ 1726 ret = sprint_nth_btf_arg(n - 1, type, buf + used, 1727 bufsize - used, ctx); 1728 if (ret < 0) 1729 goto error; 1730 new_argv[j++] = buf + used; 1731 used += ret + 1; 1732 } else 1733 new_argv[j++] = argv[i]; 1734 } 1735 1736 return new_argv; 1737 1738 error: 1739 kfree(new_argv); 1740 return ERR_PTR(ret); 1741 } 1742 1743 /* @buf: *buf must be equal to NULL. Caller must to free *buf */ 1744 int traceprobe_expand_dentry_args(int argc, const char *argv[], char **buf) 1745 { 1746 int i, used, ret; 1747 const int bufsize = MAX_DENTRY_ARGS_LEN; 1748 char *tmpbuf = NULL; 1749 1750 if (*buf) 1751 return -EINVAL; 1752 1753 used = 0; 1754 for (i = 0; i < argc; i++) { 1755 char *tmp; 1756 char *equal; 1757 size_t arg_len; 1758 1759 if (!glob_match("*:%p[dD]", argv[i])) 1760 continue; 1761 1762 if (!tmpbuf) { 1763 tmpbuf = kmalloc(bufsize, GFP_KERNEL); 1764 if (!tmpbuf) 1765 return -ENOMEM; 1766 } 1767 1768 tmp = kstrdup(argv[i], GFP_KERNEL); 1769 if (!tmp) 1770 goto nomem; 1771 1772 equal = strchr(tmp, '='); 1773 if (equal) 1774 *equal = '\0'; 1775 arg_len = strlen(argv[i]); 1776 tmp[arg_len - 4] = '\0'; 1777 if (argv[i][arg_len - 1] == 'd') 1778 ret = snprintf(tmpbuf + used, bufsize - used, 1779 "%s%s+0x0(+0x%zx(%s)):string", 1780 equal ? tmp : "", equal ? "=" : "", 1781 offsetof(struct dentry, d_name.name), 1782 equal ? equal + 1 : tmp); 1783 else 1784 ret = snprintf(tmpbuf + used, bufsize - used, 1785 "%s%s+0x0(+0x%zx(+0x%zx(%s))):string", 1786 equal ? tmp : "", equal ? "=" : "", 1787 offsetof(struct dentry, d_name.name), 1788 offsetof(struct file, f_path.dentry), 1789 equal ? equal + 1 : tmp); 1790 1791 kfree(tmp); 1792 if (ret >= bufsize - used) 1793 goto nomem; 1794 argv[i] = tmpbuf + used; 1795 used += ret + 1; 1796 } 1797 1798 *buf = tmpbuf; 1799 return 0; 1800 nomem: 1801 kfree(tmpbuf); 1802 return -ENOMEM; 1803 } 1804 1805 void traceprobe_finish_parse(struct traceprobe_parse_context *ctx) 1806 { 1807 clear_btf_context(ctx); 1808 } 1809 1810 int traceprobe_update_arg(struct probe_arg *arg) 1811 { 1812 struct fetch_insn *code = arg->code; 1813 long offset; 1814 char *tmp; 1815 char c; 1816 int ret = 0; 1817 1818 while (code && code->op != FETCH_OP_END) { 1819 if (code->op == FETCH_NOP_SYMBOL) { 1820 if (code[1].op != FETCH_OP_IMM) 1821 return -EINVAL; 1822 1823 tmp = strpbrk(code->data, "+-"); 1824 if (tmp) 1825 c = *tmp; 1826 ret = traceprobe_split_symbol_offset(code->data, 1827 &offset); 1828 if (ret) 1829 return ret; 1830 1831 code[1].immediate = 1832 (unsigned long)kallsyms_lookup_name(code->data); 1833 if (tmp) 1834 *tmp = c; 1835 if (!code[1].immediate) 1836 return -ENOENT; 1837 code[1].immediate += offset; 1838 } 1839 code++; 1840 } 1841 return 0; 1842 } 1843 1844 /* When len=0, we just calculate the needed length */ 1845 #define LEN_OR_ZERO (len ? len - pos : 0) 1846 static int __set_print_fmt(struct trace_probe *tp, char *buf, int len, 1847 enum probe_print_type ptype) 1848 { 1849 struct probe_arg *parg; 1850 int i, j; 1851 int pos = 0; 1852 const char *fmt, *arg; 1853 1854 switch (ptype) { 1855 case PROBE_PRINT_NORMAL: 1856 fmt = "(%lx)"; 1857 arg = ", REC->" FIELD_STRING_IP; 1858 break; 1859 case PROBE_PRINT_RETURN: 1860 fmt = "(%lx <- %lx)"; 1861 arg = ", REC->" FIELD_STRING_FUNC ", REC->" FIELD_STRING_RETIP; 1862 break; 1863 case PROBE_PRINT_EVENT: 1864 fmt = ""; 1865 arg = ""; 1866 break; 1867 default: 1868 WARN_ON_ONCE(1); 1869 return 0; 1870 } 1871 1872 pos += snprintf(buf + pos, LEN_OR_ZERO, "\"%s", fmt); 1873 1874 for (i = 0; i < tp->nr_args; i++) { 1875 parg = tp->args + i; 1876 pos += snprintf(buf + pos, LEN_OR_ZERO, " %s=", parg->name); 1877 if (parg->count) { 1878 pos += snprintf(buf + pos, LEN_OR_ZERO, "{%s", 1879 parg->type->fmt); 1880 for (j = 1; j < parg->count; j++) 1881 pos += snprintf(buf + pos, LEN_OR_ZERO, ",%s", 1882 parg->type->fmt); 1883 pos += snprintf(buf + pos, LEN_OR_ZERO, "}"); 1884 } else 1885 pos += snprintf(buf + pos, LEN_OR_ZERO, "%s", 1886 parg->type->fmt); 1887 } 1888 1889 pos += snprintf(buf + pos, LEN_OR_ZERO, "\"%s", arg); 1890 1891 for (i = 0; i < tp->nr_args; i++) { 1892 parg = tp->args + i; 1893 if (parg->count) { 1894 if (parg->type->is_string) 1895 fmt = ", __get_str(%s[%d])"; 1896 else 1897 fmt = ", REC->%s[%d]"; 1898 for (j = 0; j < parg->count; j++) 1899 pos += snprintf(buf + pos, LEN_OR_ZERO, 1900 fmt, parg->name, j); 1901 } else { 1902 if (parg->type->is_string) 1903 fmt = ", __get_str(%s)"; 1904 else 1905 fmt = ", REC->%s"; 1906 pos += snprintf(buf + pos, LEN_OR_ZERO, 1907 fmt, parg->name); 1908 } 1909 } 1910 1911 /* return the length of print_fmt */ 1912 return pos; 1913 } 1914 #undef LEN_OR_ZERO 1915 1916 int traceprobe_set_print_fmt(struct trace_probe *tp, enum probe_print_type ptype) 1917 { 1918 struct trace_event_call *call = trace_probe_event_call(tp); 1919 int len; 1920 char *print_fmt; 1921 1922 /* First: called with 0 length to calculate the needed length */ 1923 len = __set_print_fmt(tp, NULL, 0, ptype); 1924 print_fmt = kmalloc(len + 1, GFP_KERNEL); 1925 if (!print_fmt) 1926 return -ENOMEM; 1927 1928 /* Second: actually write the @print_fmt */ 1929 __set_print_fmt(tp, print_fmt, len + 1, ptype); 1930 call->print_fmt = print_fmt; 1931 1932 return 0; 1933 } 1934 1935 int traceprobe_define_arg_fields(struct trace_event_call *event_call, 1936 size_t offset, struct trace_probe *tp) 1937 { 1938 int ret, i; 1939 1940 /* Set argument names as fields */ 1941 for (i = 0; i < tp->nr_args; i++) { 1942 struct probe_arg *parg = &tp->args[i]; 1943 const char *fmt = parg->type->fmttype; 1944 int size = parg->type->size; 1945 1946 if (parg->fmt) 1947 fmt = parg->fmt; 1948 if (parg->count) 1949 size *= parg->count; 1950 ret = trace_define_field(event_call, fmt, parg->name, 1951 offset + parg->offset, size, 1952 parg->type->is_signed, 1953 FILTER_OTHER); 1954 if (ret) 1955 return ret; 1956 } 1957 return 0; 1958 } 1959 1960 static void trace_probe_event_free(struct trace_probe_event *tpe) 1961 { 1962 kfree(tpe->class.system); 1963 kfree(tpe->call.name); 1964 kfree(tpe->call.print_fmt); 1965 kfree(tpe); 1966 } 1967 1968 int trace_probe_append(struct trace_probe *tp, struct trace_probe *to) 1969 { 1970 if (trace_probe_has_sibling(tp)) 1971 return -EBUSY; 1972 1973 list_del_init(&tp->list); 1974 trace_probe_event_free(tp->event); 1975 1976 tp->event = to->event; 1977 list_add_tail(&tp->list, trace_probe_probe_list(to)); 1978 1979 return 0; 1980 } 1981 1982 void trace_probe_unlink(struct trace_probe *tp) 1983 { 1984 list_del_init(&tp->list); 1985 if (list_empty(trace_probe_probe_list(tp))) 1986 trace_probe_event_free(tp->event); 1987 tp->event = NULL; 1988 } 1989 1990 void trace_probe_cleanup(struct trace_probe *tp) 1991 { 1992 int i; 1993 1994 for (i = 0; i < tp->nr_args; i++) 1995 traceprobe_free_probe_arg(&tp->args[i]); 1996 1997 if (tp->entry_arg) { 1998 kfree(tp->entry_arg->code); 1999 kfree(tp->entry_arg); 2000 tp->entry_arg = NULL; 2001 } 2002 2003 if (tp->event) 2004 trace_probe_unlink(tp); 2005 } 2006 2007 int trace_probe_init(struct trace_probe *tp, const char *event, 2008 const char *group, bool alloc_filter, int nargs) 2009 { 2010 struct trace_event_call *call; 2011 size_t size = sizeof(struct trace_probe_event); 2012 int ret = 0; 2013 2014 if (!event || !group) 2015 return -EINVAL; 2016 2017 if (alloc_filter) 2018 size += sizeof(struct trace_uprobe_filter); 2019 2020 tp->event = kzalloc(size, GFP_KERNEL); 2021 if (!tp->event) 2022 return -ENOMEM; 2023 2024 INIT_LIST_HEAD(&tp->event->files); 2025 INIT_LIST_HEAD(&tp->event->class.fields); 2026 INIT_LIST_HEAD(&tp->event->probes); 2027 INIT_LIST_HEAD(&tp->list); 2028 list_add(&tp->list, &tp->event->probes); 2029 2030 call = trace_probe_event_call(tp); 2031 call->class = &tp->event->class; 2032 call->name = kstrdup(event, GFP_KERNEL); 2033 if (!call->name) { 2034 ret = -ENOMEM; 2035 goto error; 2036 } 2037 2038 tp->event->class.system = kstrdup(group, GFP_KERNEL); 2039 if (!tp->event->class.system) { 2040 ret = -ENOMEM; 2041 goto error; 2042 } 2043 2044 tp->nr_args = nargs; 2045 /* Make sure pointers in args[] are NULL */ 2046 if (nargs) 2047 memset(tp->args, 0, sizeof(tp->args[0]) * nargs); 2048 2049 return 0; 2050 2051 error: 2052 trace_probe_cleanup(tp); 2053 return ret; 2054 } 2055 2056 static struct trace_event_call * 2057 find_trace_event_call(const char *system, const char *event_name) 2058 { 2059 struct trace_event_call *tp_event; 2060 const char *name; 2061 2062 list_for_each_entry(tp_event, &ftrace_events, list) { 2063 if (!tp_event->class->system || 2064 strcmp(system, tp_event->class->system)) 2065 continue; 2066 name = trace_event_name(tp_event); 2067 if (!name || strcmp(event_name, name)) 2068 continue; 2069 return tp_event; 2070 } 2071 2072 return NULL; 2073 } 2074 2075 int trace_probe_register_event_call(struct trace_probe *tp) 2076 { 2077 struct trace_event_call *call = trace_probe_event_call(tp); 2078 int ret; 2079 2080 lockdep_assert_held(&event_mutex); 2081 2082 if (find_trace_event_call(trace_probe_group_name(tp), 2083 trace_probe_name(tp))) 2084 return -EEXIST; 2085 2086 ret = register_trace_event(&call->event); 2087 if (!ret) 2088 return -ENODEV; 2089 2090 ret = trace_add_event_call(call); 2091 if (ret) 2092 unregister_trace_event(&call->event); 2093 2094 return ret; 2095 } 2096 2097 int trace_probe_add_file(struct trace_probe *tp, struct trace_event_file *file) 2098 { 2099 struct event_file_link *link; 2100 2101 link = kmalloc(sizeof(*link), GFP_KERNEL); 2102 if (!link) 2103 return -ENOMEM; 2104 2105 link->file = file; 2106 INIT_LIST_HEAD(&link->list); 2107 list_add_tail_rcu(&link->list, &tp->event->files); 2108 trace_probe_set_flag(tp, TP_FLAG_TRACE); 2109 return 0; 2110 } 2111 2112 struct event_file_link *trace_probe_get_file_link(struct trace_probe *tp, 2113 struct trace_event_file *file) 2114 { 2115 struct event_file_link *link; 2116 2117 trace_probe_for_each_link(link, tp) { 2118 if (link->file == file) 2119 return link; 2120 } 2121 2122 return NULL; 2123 } 2124 2125 int trace_probe_remove_file(struct trace_probe *tp, 2126 struct trace_event_file *file) 2127 { 2128 struct event_file_link *link; 2129 2130 link = trace_probe_get_file_link(tp, file); 2131 if (!link) 2132 return -ENOENT; 2133 2134 list_del_rcu(&link->list); 2135 kvfree_rcu_mightsleep(link); 2136 2137 if (list_empty(&tp->event->files)) 2138 trace_probe_clear_flag(tp, TP_FLAG_TRACE); 2139 2140 return 0; 2141 } 2142 2143 /* 2144 * Return the smallest index of different type argument (start from 1). 2145 * If all argument types and name are same, return 0. 2146 */ 2147 int trace_probe_compare_arg_type(struct trace_probe *a, struct trace_probe *b) 2148 { 2149 int i; 2150 2151 /* In case of more arguments */ 2152 if (a->nr_args < b->nr_args) 2153 return a->nr_args + 1; 2154 if (a->nr_args > b->nr_args) 2155 return b->nr_args + 1; 2156 2157 for (i = 0; i < a->nr_args; i++) { 2158 if ((b->nr_args <= i) || 2159 ((a->args[i].type != b->args[i].type) || 2160 (a->args[i].count != b->args[i].count) || 2161 strcmp(a->args[i].name, b->args[i].name))) 2162 return i + 1; 2163 } 2164 2165 return 0; 2166 } 2167 2168 bool trace_probe_match_command_args(struct trace_probe *tp, 2169 int argc, const char **argv) 2170 { 2171 char buf[MAX_ARGSTR_LEN + 1]; 2172 int i; 2173 2174 if (tp->nr_args < argc) 2175 return false; 2176 2177 for (i = 0; i < argc; i++) { 2178 snprintf(buf, sizeof(buf), "%s=%s", 2179 tp->args[i].name, tp->args[i].comm); 2180 if (strcmp(buf, argv[i])) 2181 return false; 2182 } 2183 return true; 2184 } 2185 2186 int trace_probe_create(const char *raw_command, int (*createfn)(int, const char **)) 2187 { 2188 int argc = 0, ret = 0; 2189 char **argv; 2190 2191 argv = argv_split(GFP_KERNEL, raw_command, &argc); 2192 if (!argv) 2193 return -ENOMEM; 2194 2195 if (argc) 2196 ret = createfn(argc, (const char **)argv); 2197 2198 argv_free(argv); 2199 2200 return ret; 2201 } 2202 2203 int trace_probe_print_args(struct trace_seq *s, struct probe_arg *args, int nr_args, 2204 u8 *data, void *field) 2205 { 2206 void *p; 2207 int i, j; 2208 2209 for (i = 0; i < nr_args; i++) { 2210 struct probe_arg *a = args + i; 2211 2212 trace_seq_printf(s, " %s=", a->name); 2213 if (likely(!a->count)) { 2214 if (!a->type->print(s, data + a->offset, field)) 2215 return -ENOMEM; 2216 continue; 2217 } 2218 trace_seq_putc(s, '{'); 2219 p = data + a->offset; 2220 for (j = 0; j < a->count; j++) { 2221 if (!a->type->print(s, p, field)) 2222 return -ENOMEM; 2223 trace_seq_putc(s, j == a->count - 1 ? '}' : ','); 2224 p += a->type->size; 2225 } 2226 } 2227 return 0; 2228 } 2229