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 (IS_ERR(field)) { 558 trace_probe_log_err(ctx->offset, BAD_BTF_TID); 559 return PTR_ERR(field); 560 } 561 if (!field) { 562 trace_probe_log_err(ctx->offset, NO_BTF_FIELD); 563 return -ENOENT; 564 } 565 /* Add anonymous structure/union offset */ 566 bitoffs += anon_offs; 567 568 /* Accumulate the bit-offsets of the dot-connected fields */ 569 if (btf_type_kflag(type)) { 570 bitoffs += BTF_MEMBER_BIT_OFFSET(field->offset); 571 ctx->last_bitsize = BTF_MEMBER_BITFIELD_SIZE(field->offset); 572 } else { 573 bitoffs += field->offset; 574 ctx->last_bitsize = 0; 575 } 576 577 type = btf_type_skip_modifiers(ctx->btf, field->type, &tid); 578 if (!type) { 579 trace_probe_log_err(ctx->offset, BAD_BTF_TID); 580 return -EINVAL; 581 } 582 583 ctx->offset += next - fieldname; 584 fieldname = next; 585 } while (!is_ptr && fieldname); 586 587 if (++code == end) { 588 trace_probe_log_err(ctx->offset, TOO_MANY_OPS); 589 return -EINVAL; 590 } 591 code->op = FETCH_OP_DEREF; /* TODO: user deref support */ 592 code->offset = bitoffs / 8; 593 *pcode = code; 594 595 ctx->last_bitoffs = bitoffs % 8; 596 ctx->last_type = type; 597 } while (fieldname); 598 599 return 0; 600 } 601 602 static int __store_entry_arg(struct trace_probe *tp, int argnum); 603 604 static int parse_btf_arg(char *varname, 605 struct fetch_insn **pcode, struct fetch_insn *end, 606 struct traceprobe_parse_context *ctx) 607 { 608 struct fetch_insn *code = *pcode; 609 const struct btf_param *params; 610 const struct btf_type *type; 611 char *field = NULL; 612 int i, is_ptr, ret; 613 u32 tid; 614 615 if (WARN_ON_ONCE(!ctx->funcname)) 616 return -EINVAL; 617 618 is_ptr = split_next_field(varname, &field, ctx); 619 if (is_ptr < 0) 620 return is_ptr; 621 if (!is_ptr && field) { 622 /* dot-connected field on an argument is not supported. */ 623 trace_probe_log_err(ctx->offset + field - varname, 624 NOSUP_DAT_ARG); 625 return -EOPNOTSUPP; 626 } 627 628 if (ctx->flags & TPARG_FL_RETURN && !strcmp(varname, "$retval")) { 629 code->op = FETCH_OP_RETVAL; 630 /* Check whether the function return type is not void */ 631 if (query_btf_context(ctx) == 0) { 632 if (ctx->proto->type == 0) { 633 trace_probe_log_err(ctx->offset, NO_RETVAL); 634 return -ENOENT; 635 } 636 tid = ctx->proto->type; 637 goto found; 638 } 639 if (field) { 640 trace_probe_log_err(ctx->offset + field - varname, 641 NO_BTF_ENTRY); 642 return -ENOENT; 643 } 644 return 0; 645 } 646 647 if (!ctx->btf) { 648 ret = query_btf_context(ctx); 649 if (ret < 0 || ctx->nr_params == 0) { 650 trace_probe_log_err(ctx->offset, NO_BTF_ENTRY); 651 return PTR_ERR(params); 652 } 653 } 654 params = ctx->params; 655 656 for (i = 0; i < ctx->nr_params; i++) { 657 const char *name = btf_name_by_offset(ctx->btf, params[i].name_off); 658 659 if (name && !strcmp(name, varname)) { 660 if (tparg_is_function_entry(ctx->flags)) { 661 code->op = FETCH_OP_ARG; 662 if (ctx->flags & TPARG_FL_TPOINT) 663 code->param = i + 1; 664 else 665 code->param = i; 666 } else if (tparg_is_function_return(ctx->flags)) { 667 code->op = FETCH_OP_EDATA; 668 ret = __store_entry_arg(ctx->tp, i); 669 if (ret < 0) { 670 /* internal error */ 671 return ret; 672 } 673 code->offset = ret; 674 } 675 tid = params[i].type; 676 goto found; 677 } 678 } 679 trace_probe_log_err(ctx->offset, NO_BTFARG); 680 return -ENOENT; 681 682 found: 683 type = btf_type_skip_modifiers(ctx->btf, tid, &tid); 684 if (!type) { 685 trace_probe_log_err(ctx->offset, BAD_BTF_TID); 686 return -EINVAL; 687 } 688 /* Initialize the last type information */ 689 ctx->last_type = type; 690 ctx->last_bitoffs = 0; 691 ctx->last_bitsize = 0; 692 if (field) { 693 ctx->offset += field - varname; 694 return parse_btf_field(field, type, pcode, end, ctx); 695 } 696 return 0; 697 } 698 699 static const struct fetch_type *find_fetch_type_from_btf_type( 700 struct traceprobe_parse_context *ctx) 701 { 702 struct btf *btf = ctx->btf; 703 const char *typestr = NULL; 704 705 if (btf && ctx->last_type) 706 typestr = fetch_type_from_btf_type(btf, ctx->last_type, ctx); 707 708 return find_fetch_type(typestr, ctx->flags); 709 } 710 711 static int parse_btf_bitfield(struct fetch_insn **pcode, 712 struct traceprobe_parse_context *ctx) 713 { 714 struct fetch_insn *code = *pcode; 715 716 if ((ctx->last_bitsize % 8 == 0) && ctx->last_bitoffs == 0) 717 return 0; 718 719 code++; 720 if (code->op != FETCH_OP_NOP) { 721 trace_probe_log_err(ctx->offset, TOO_MANY_OPS); 722 return -EINVAL; 723 } 724 *pcode = code; 725 726 code->op = FETCH_OP_MOD_BF; 727 code->lshift = 64 - (ctx->last_bitsize + ctx->last_bitoffs); 728 code->rshift = 64 - ctx->last_bitsize; 729 code->basesize = 64 / 8; 730 return 0; 731 } 732 733 #else 734 static void clear_btf_context(struct traceprobe_parse_context *ctx) 735 { 736 ctx->btf = NULL; 737 } 738 739 static int query_btf_context(struct traceprobe_parse_context *ctx) 740 { 741 return -EOPNOTSUPP; 742 } 743 744 static int parse_btf_arg(char *varname, 745 struct fetch_insn **pcode, struct fetch_insn *end, 746 struct traceprobe_parse_context *ctx) 747 { 748 trace_probe_log_err(ctx->offset, NOSUP_BTFARG); 749 return -EOPNOTSUPP; 750 } 751 752 static int parse_btf_bitfield(struct fetch_insn **pcode, 753 struct traceprobe_parse_context *ctx) 754 { 755 trace_probe_log_err(ctx->offset, NOSUP_BTFARG); 756 return -EOPNOTSUPP; 757 } 758 759 #define find_fetch_type_from_btf_type(ctx) \ 760 find_fetch_type(NULL, ctx->flags) 761 762 static int check_prepare_btf_string_fetch(char *typename, 763 struct fetch_insn **pcode, 764 struct traceprobe_parse_context *ctx) 765 { 766 return 0; 767 } 768 769 #endif 770 771 #ifdef CONFIG_HAVE_FUNCTION_ARG_ACCESS_API 772 773 static int __store_entry_arg(struct trace_probe *tp, int argnum) 774 { 775 struct probe_entry_arg *earg = tp->entry_arg; 776 bool match = false; 777 int i, offset; 778 779 if (!earg) { 780 earg = kzalloc(sizeof(*tp->entry_arg), GFP_KERNEL); 781 if (!earg) 782 return -ENOMEM; 783 earg->size = 2 * tp->nr_args + 1; 784 earg->code = kcalloc(earg->size, sizeof(struct fetch_insn), 785 GFP_KERNEL); 786 if (!earg->code) { 787 kfree(earg); 788 return -ENOMEM; 789 } 790 /* Fill the code buffer with 'end' to simplify it */ 791 for (i = 0; i < earg->size; i++) 792 earg->code[i].op = FETCH_OP_END; 793 tp->entry_arg = earg; 794 } 795 796 offset = 0; 797 for (i = 0; i < earg->size - 1; i++) { 798 switch (earg->code[i].op) { 799 case FETCH_OP_END: 800 earg->code[i].op = FETCH_OP_ARG; 801 earg->code[i].param = argnum; 802 earg->code[i + 1].op = FETCH_OP_ST_EDATA; 803 earg->code[i + 1].offset = offset; 804 return offset; 805 case FETCH_OP_ARG: 806 match = (earg->code[i].param == argnum); 807 break; 808 case FETCH_OP_ST_EDATA: 809 offset = earg->code[i].offset; 810 if (match) 811 return offset; 812 offset += sizeof(unsigned long); 813 break; 814 default: 815 break; 816 } 817 } 818 return -ENOSPC; 819 } 820 821 int traceprobe_get_entry_data_size(struct trace_probe *tp) 822 { 823 struct probe_entry_arg *earg = tp->entry_arg; 824 int i, size = 0; 825 826 if (!earg) 827 return 0; 828 829 for (i = 0; i < earg->size; i++) { 830 switch (earg->code[i].op) { 831 case FETCH_OP_END: 832 goto out; 833 case FETCH_OP_ST_EDATA: 834 size = earg->code[i].offset + sizeof(unsigned long); 835 break; 836 default: 837 break; 838 } 839 } 840 out: 841 return size; 842 } 843 844 void store_trace_entry_data(void *edata, struct trace_probe *tp, struct pt_regs *regs) 845 { 846 struct probe_entry_arg *earg = tp->entry_arg; 847 unsigned long val = 0; 848 int i; 849 850 if (!earg) 851 return; 852 853 for (i = 0; i < earg->size; i++) { 854 struct fetch_insn *code = &earg->code[i]; 855 856 switch (code->op) { 857 case FETCH_OP_ARG: 858 val = regs_get_kernel_argument(regs, code->param); 859 break; 860 case FETCH_OP_ST_EDATA: 861 *(unsigned long *)((unsigned long)edata + code->offset) = val; 862 break; 863 case FETCH_OP_END: 864 goto end; 865 default: 866 break; 867 } 868 } 869 end: 870 return; 871 } 872 NOKPROBE_SYMBOL(store_trace_entry_data) 873 #endif 874 875 #define PARAM_MAX_STACK (THREAD_SIZE / sizeof(unsigned long)) 876 877 /* Parse $vars. @orig_arg points '$', which syncs to @ctx->offset */ 878 static int parse_probe_vars(char *orig_arg, const struct fetch_type *t, 879 struct fetch_insn **pcode, 880 struct fetch_insn *end, 881 struct traceprobe_parse_context *ctx) 882 { 883 struct fetch_insn *code = *pcode; 884 int err = TP_ERR_BAD_VAR; 885 char *arg = orig_arg + 1; 886 unsigned long param; 887 int ret = 0; 888 int len; 889 890 if (ctx->flags & TPARG_FL_TEVENT) { 891 if (code->data) 892 return -EFAULT; 893 ret = parse_trace_event_arg(arg, code, ctx); 894 if (!ret) 895 return 0; 896 if (strcmp(arg, "comm") == 0 || strcmp(arg, "COMM") == 0) { 897 code->op = FETCH_OP_COMM; 898 return 0; 899 } 900 /* backward compatibility */ 901 ctx->offset = 0; 902 goto inval; 903 } 904 905 if (str_has_prefix(arg, "retval")) { 906 if (!(ctx->flags & TPARG_FL_RETURN)) { 907 err = TP_ERR_RETVAL_ON_PROBE; 908 goto inval; 909 } 910 if (!(ctx->flags & TPARG_FL_KERNEL) || 911 !IS_ENABLED(CONFIG_PROBE_EVENTS_BTF_ARGS)) { 912 code->op = FETCH_OP_RETVAL; 913 return 0; 914 } 915 return parse_btf_arg(orig_arg, pcode, end, ctx); 916 } 917 918 len = str_has_prefix(arg, "stack"); 919 if (len) { 920 921 if (arg[len] == '\0') { 922 code->op = FETCH_OP_STACKP; 923 return 0; 924 } 925 926 if (isdigit(arg[len])) { 927 ret = kstrtoul(arg + len, 10, ¶m); 928 if (ret) 929 goto inval; 930 931 if ((ctx->flags & TPARG_FL_KERNEL) && 932 param > PARAM_MAX_STACK) { 933 err = TP_ERR_BAD_STACK_NUM; 934 goto inval; 935 } 936 code->op = FETCH_OP_STACK; 937 code->param = (unsigned int)param; 938 return 0; 939 } 940 goto inval; 941 } 942 943 if (strcmp(arg, "comm") == 0 || strcmp(arg, "COMM") == 0) { 944 code->op = FETCH_OP_COMM; 945 return 0; 946 } 947 948 #ifdef CONFIG_HAVE_FUNCTION_ARG_ACCESS_API 949 len = str_has_prefix(arg, "arg"); 950 if (len) { 951 ret = kstrtoul(arg + len, 10, ¶m); 952 if (ret) 953 goto inval; 954 955 if (!param || param > PARAM_MAX_STACK) { 956 err = TP_ERR_BAD_ARG_NUM; 957 goto inval; 958 } 959 param--; /* argN starts from 1, but internal arg[N] starts from 0 */ 960 961 if (tparg_is_function_entry(ctx->flags)) { 962 code->op = FETCH_OP_ARG; 963 code->param = (unsigned int)param; 964 /* 965 * The tracepoint probe will probe a stub function, and the 966 * first parameter of the stub is a dummy and should be ignored. 967 */ 968 if (ctx->flags & TPARG_FL_TPOINT) 969 code->param++; 970 } else if (tparg_is_function_return(ctx->flags)) { 971 /* function entry argument access from return probe */ 972 ret = __store_entry_arg(ctx->tp, param); 973 if (ret < 0) /* This error should be an internal error */ 974 return ret; 975 976 code->op = FETCH_OP_EDATA; 977 code->offset = ret; 978 } else { 979 err = TP_ERR_NOFENTRY_ARGS; 980 goto inval; 981 } 982 return 0; 983 } 984 #endif 985 986 inval: 987 __trace_probe_log_err(ctx->offset, err); 988 return -EINVAL; 989 } 990 991 static int str_to_immediate(char *str, unsigned long *imm) 992 { 993 if (isdigit(str[0])) 994 return kstrtoul(str, 0, imm); 995 else if (str[0] == '-') 996 return kstrtol(str, 0, (long *)imm); 997 else if (str[0] == '+') 998 return kstrtol(str + 1, 0, (long *)imm); 999 return -EINVAL; 1000 } 1001 1002 static int __parse_imm_string(char *str, char **pbuf, int offs) 1003 { 1004 size_t len = strlen(str); 1005 1006 if (str[len - 1] != '"') { 1007 trace_probe_log_err(offs + len, IMMSTR_NO_CLOSE); 1008 return -EINVAL; 1009 } 1010 *pbuf = kstrndup(str, len - 1, GFP_KERNEL); 1011 if (!*pbuf) 1012 return -ENOMEM; 1013 return 0; 1014 } 1015 1016 /* Recursive argument parser */ 1017 static int 1018 parse_probe_arg(char *arg, const struct fetch_type *type, 1019 struct fetch_insn **pcode, struct fetch_insn *end, 1020 struct traceprobe_parse_context *ctx) 1021 { 1022 struct fetch_insn *code = *pcode; 1023 unsigned long param; 1024 int deref = FETCH_OP_DEREF; 1025 long offset = 0; 1026 char *tmp; 1027 int ret = 0; 1028 1029 switch (arg[0]) { 1030 case '$': 1031 ret = parse_probe_vars(arg, type, pcode, end, ctx); 1032 break; 1033 1034 case '%': /* named register */ 1035 if (ctx->flags & (TPARG_FL_TEVENT | TPARG_FL_FPROBE)) { 1036 /* eprobe and fprobe do not handle registers */ 1037 trace_probe_log_err(ctx->offset, BAD_VAR); 1038 break; 1039 } 1040 ret = regs_query_register_offset(arg + 1); 1041 if (ret >= 0) { 1042 code->op = FETCH_OP_REG; 1043 code->param = (unsigned int)ret; 1044 ret = 0; 1045 } else 1046 trace_probe_log_err(ctx->offset, BAD_REG_NAME); 1047 break; 1048 1049 case '@': /* memory, file-offset or symbol */ 1050 if (isdigit(arg[1])) { 1051 ret = kstrtoul(arg + 1, 0, ¶m); 1052 if (ret) { 1053 trace_probe_log_err(ctx->offset, BAD_MEM_ADDR); 1054 break; 1055 } 1056 /* load address */ 1057 code->op = FETCH_OP_IMM; 1058 code->immediate = param; 1059 } else if (arg[1] == '+') { 1060 /* kprobes don't support file offsets */ 1061 if (ctx->flags & TPARG_FL_KERNEL) { 1062 trace_probe_log_err(ctx->offset, FILE_ON_KPROBE); 1063 return -EINVAL; 1064 } 1065 ret = kstrtol(arg + 2, 0, &offset); 1066 if (ret) { 1067 trace_probe_log_err(ctx->offset, BAD_FILE_OFFS); 1068 break; 1069 } 1070 1071 code->op = FETCH_OP_FOFFS; 1072 code->immediate = (unsigned long)offset; // imm64? 1073 } else { 1074 /* uprobes don't support symbols */ 1075 if (!(ctx->flags & TPARG_FL_KERNEL)) { 1076 trace_probe_log_err(ctx->offset, SYM_ON_UPROBE); 1077 return -EINVAL; 1078 } 1079 /* Preserve symbol for updating */ 1080 code->op = FETCH_NOP_SYMBOL; 1081 code->data = kstrdup(arg + 1, GFP_KERNEL); 1082 if (!code->data) 1083 return -ENOMEM; 1084 if (++code == end) { 1085 trace_probe_log_err(ctx->offset, TOO_MANY_OPS); 1086 return -EINVAL; 1087 } 1088 code->op = FETCH_OP_IMM; 1089 code->immediate = 0; 1090 } 1091 /* These are fetching from memory */ 1092 if (++code == end) { 1093 trace_probe_log_err(ctx->offset, TOO_MANY_OPS); 1094 return -EINVAL; 1095 } 1096 *pcode = code; 1097 code->op = FETCH_OP_DEREF; 1098 code->offset = offset; 1099 break; 1100 1101 case '+': /* deref memory */ 1102 case '-': 1103 if (arg[1] == 'u') { 1104 deref = FETCH_OP_UDEREF; 1105 arg[1] = arg[0]; 1106 arg++; 1107 } 1108 if (arg[0] == '+') 1109 arg++; /* Skip '+', because kstrtol() rejects it. */ 1110 tmp = strchr(arg, '('); 1111 if (!tmp) { 1112 trace_probe_log_err(ctx->offset, DEREF_NEED_BRACE); 1113 return -EINVAL; 1114 } 1115 *tmp = '\0'; 1116 ret = kstrtol(arg, 0, &offset); 1117 if (ret) { 1118 trace_probe_log_err(ctx->offset, BAD_DEREF_OFFS); 1119 break; 1120 } 1121 ctx->offset += (tmp + 1 - arg) + (arg[0] != '-' ? 1 : 0); 1122 arg = tmp + 1; 1123 tmp = strrchr(arg, ')'); 1124 if (!tmp) { 1125 trace_probe_log_err(ctx->offset + strlen(arg), 1126 DEREF_OPEN_BRACE); 1127 return -EINVAL; 1128 } else { 1129 const struct fetch_type *t2 = find_fetch_type(NULL, ctx->flags); 1130 int cur_offs = ctx->offset; 1131 1132 *tmp = '\0'; 1133 ret = parse_probe_arg(arg, t2, &code, end, ctx); 1134 if (ret) 1135 break; 1136 ctx->offset = cur_offs; 1137 if (code->op == FETCH_OP_COMM || 1138 code->op == FETCH_OP_DATA) { 1139 trace_probe_log_err(ctx->offset, COMM_CANT_DEREF); 1140 return -EINVAL; 1141 } 1142 if (++code == end) { 1143 trace_probe_log_err(ctx->offset, TOO_MANY_OPS); 1144 return -EINVAL; 1145 } 1146 *pcode = code; 1147 1148 code->op = deref; 1149 code->offset = offset; 1150 /* Reset the last type if used */ 1151 ctx->last_type = NULL; 1152 } 1153 break; 1154 case '\\': /* Immediate value */ 1155 if (arg[1] == '"') { /* Immediate string */ 1156 ret = __parse_imm_string(arg + 2, &tmp, ctx->offset + 2); 1157 if (ret) 1158 break; 1159 code->op = FETCH_OP_DATA; 1160 code->data = tmp; 1161 } else { 1162 ret = str_to_immediate(arg + 1, &code->immediate); 1163 if (ret) 1164 trace_probe_log_err(ctx->offset + 1, BAD_IMM); 1165 else 1166 code->op = FETCH_OP_IMM; 1167 } 1168 break; 1169 default: 1170 if (isalpha(arg[0]) || arg[0] == '_') { /* BTF variable */ 1171 if (!tparg_is_function_entry(ctx->flags) && 1172 !tparg_is_function_return(ctx->flags)) { 1173 trace_probe_log_err(ctx->offset, NOSUP_BTFARG); 1174 return -EINVAL; 1175 } 1176 ret = parse_btf_arg(arg, pcode, end, ctx); 1177 break; 1178 } 1179 } 1180 if (!ret && code->op == FETCH_OP_NOP) { 1181 /* Parsed, but do not find fetch method */ 1182 trace_probe_log_err(ctx->offset, BAD_FETCH_ARG); 1183 ret = -EINVAL; 1184 } 1185 return ret; 1186 } 1187 1188 /* Bitfield type needs to be parsed into a fetch function */ 1189 static int __parse_bitfield_probe_arg(const char *bf, 1190 const struct fetch_type *t, 1191 struct fetch_insn **pcode) 1192 { 1193 struct fetch_insn *code = *pcode; 1194 unsigned long bw, bo; 1195 char *tail; 1196 1197 if (*bf != 'b') 1198 return 0; 1199 1200 bw = simple_strtoul(bf + 1, &tail, 0); /* Use simple one */ 1201 1202 if (bw == 0 || *tail != '@') 1203 return -EINVAL; 1204 1205 bf = tail + 1; 1206 bo = simple_strtoul(bf, &tail, 0); 1207 1208 if (tail == bf || *tail != '/') 1209 return -EINVAL; 1210 code++; 1211 if (code->op != FETCH_OP_NOP) 1212 return -EINVAL; 1213 *pcode = code; 1214 1215 code->op = FETCH_OP_MOD_BF; 1216 code->lshift = BYTES_TO_BITS(t->size) - (bw + bo); 1217 code->rshift = BYTES_TO_BITS(t->size) - bw; 1218 code->basesize = t->size; 1219 1220 return (BYTES_TO_BITS(t->size) < (bw + bo)) ? -EINVAL : 0; 1221 } 1222 1223 /* Split type part from @arg and return it. */ 1224 static char *parse_probe_arg_type(char *arg, struct probe_arg *parg, 1225 struct traceprobe_parse_context *ctx) 1226 { 1227 char *t = NULL, *t2, *t3; 1228 int offs; 1229 1230 t = strchr(arg, ':'); 1231 if (t) { 1232 *t++ = '\0'; 1233 t2 = strchr(t, '['); 1234 if (t2) { 1235 *t2++ = '\0'; 1236 t3 = strchr(t2, ']'); 1237 if (!t3) { 1238 offs = t2 + strlen(t2) - arg; 1239 1240 trace_probe_log_err(ctx->offset + offs, 1241 ARRAY_NO_CLOSE); 1242 return ERR_PTR(-EINVAL); 1243 } else if (t3[1] != '\0') { 1244 trace_probe_log_err(ctx->offset + t3 + 1 - arg, 1245 BAD_ARRAY_SUFFIX); 1246 return ERR_PTR(-EINVAL); 1247 } 1248 *t3 = '\0'; 1249 if (kstrtouint(t2, 0, &parg->count) || !parg->count) { 1250 trace_probe_log_err(ctx->offset + t2 - arg, 1251 BAD_ARRAY_NUM); 1252 return ERR_PTR(-EINVAL); 1253 } 1254 if (parg->count > MAX_ARRAY_LEN) { 1255 trace_probe_log_err(ctx->offset + t2 - arg, 1256 ARRAY_TOO_BIG); 1257 return ERR_PTR(-EINVAL); 1258 } 1259 } 1260 } 1261 offs = t ? t - arg : 0; 1262 1263 /* 1264 * Since $comm and immediate string can not be dereferenced, 1265 * we can find those by strcmp. But ignore for eprobes. 1266 */ 1267 if (!(ctx->flags & TPARG_FL_TEVENT) && 1268 (strcmp(arg, "$comm") == 0 || strcmp(arg, "$COMM") == 0 || 1269 strncmp(arg, "\\\"", 2) == 0)) { 1270 /* The type of $comm must be "string", and not an array type. */ 1271 if (parg->count || (t && strcmp(t, "string"))) { 1272 trace_probe_log_err(ctx->offset + offs, NEED_STRING_TYPE); 1273 return ERR_PTR(-EINVAL); 1274 } 1275 parg->type = find_fetch_type("string", ctx->flags); 1276 } else 1277 parg->type = find_fetch_type(t, ctx->flags); 1278 1279 if (!parg->type) { 1280 trace_probe_log_err(ctx->offset + offs, BAD_TYPE); 1281 return ERR_PTR(-EINVAL); 1282 } 1283 1284 return t; 1285 } 1286 1287 /* After parsing, adjust the fetch_insn according to the probe_arg */ 1288 static int finalize_fetch_insn(struct fetch_insn *code, 1289 struct probe_arg *parg, 1290 char *type, 1291 int type_offset, 1292 struct traceprobe_parse_context *ctx) 1293 { 1294 struct fetch_insn *scode; 1295 int ret; 1296 1297 /* Store operation */ 1298 if (parg->type->is_string) { 1299 /* Check bad combination of the type and the last fetch_insn. */ 1300 if (!strcmp(parg->type->name, "symstr")) { 1301 if (code->op != FETCH_OP_REG && code->op != FETCH_OP_STACK && 1302 code->op != FETCH_OP_RETVAL && code->op != FETCH_OP_ARG && 1303 code->op != FETCH_OP_DEREF && code->op != FETCH_OP_TP_ARG) { 1304 trace_probe_log_err(ctx->offset + type_offset, 1305 BAD_SYMSTRING); 1306 return -EINVAL; 1307 } 1308 } else { 1309 if (code->op != FETCH_OP_DEREF && code->op != FETCH_OP_UDEREF && 1310 code->op != FETCH_OP_IMM && code->op != FETCH_OP_COMM && 1311 code->op != FETCH_OP_DATA && code->op != FETCH_OP_TP_ARG) { 1312 trace_probe_log_err(ctx->offset + type_offset, 1313 BAD_STRING); 1314 return -EINVAL; 1315 } 1316 } 1317 1318 if (!strcmp(parg->type->name, "symstr") || 1319 (code->op == FETCH_OP_IMM || code->op == FETCH_OP_COMM || 1320 code->op == FETCH_OP_DATA) || code->op == FETCH_OP_TP_ARG || 1321 parg->count) { 1322 /* 1323 * IMM, DATA and COMM is pointing actual address, those 1324 * must be kept, and if parg->count != 0, this is an 1325 * array of string pointers instead of string address 1326 * itself. 1327 * For the symstr, it doesn't need to dereference, thus 1328 * it just get the value. 1329 */ 1330 code++; 1331 if (code->op != FETCH_OP_NOP) { 1332 trace_probe_log_err(ctx->offset, TOO_MANY_OPS); 1333 return -EINVAL; 1334 } 1335 } 1336 1337 /* If op == DEREF, replace it with STRING */ 1338 if (!strcmp(parg->type->name, "ustring") || 1339 code->op == FETCH_OP_UDEREF) 1340 code->op = FETCH_OP_ST_USTRING; 1341 else if (!strcmp(parg->type->name, "symstr")) 1342 code->op = FETCH_OP_ST_SYMSTR; 1343 else 1344 code->op = FETCH_OP_ST_STRING; 1345 code->size = parg->type->size; 1346 parg->dynamic = true; 1347 } else if (code->op == FETCH_OP_DEREF) { 1348 code->op = FETCH_OP_ST_MEM; 1349 code->size = parg->type->size; 1350 } else if (code->op == FETCH_OP_UDEREF) { 1351 code->op = FETCH_OP_ST_UMEM; 1352 code->size = parg->type->size; 1353 } else { 1354 code++; 1355 if (code->op != FETCH_OP_NOP) { 1356 trace_probe_log_err(ctx->offset, TOO_MANY_OPS); 1357 return -E2BIG; 1358 } 1359 code->op = FETCH_OP_ST_RAW; 1360 code->size = parg->type->size; 1361 } 1362 1363 /* Save storing fetch_insn. */ 1364 scode = code; 1365 1366 /* Modify operation */ 1367 if (type != NULL) { 1368 /* Bitfield needs a special fetch_insn. */ 1369 ret = __parse_bitfield_probe_arg(type, parg->type, &code); 1370 if (ret) { 1371 trace_probe_log_err(ctx->offset + type_offset, BAD_BITFIELD); 1372 return ret; 1373 } 1374 } else if (IS_ENABLED(CONFIG_PROBE_EVENTS_BTF_ARGS) && 1375 ctx->last_type) { 1376 /* If user not specified the type, try parsing BTF bitfield. */ 1377 ret = parse_btf_bitfield(&code, ctx); 1378 if (ret) 1379 return ret; 1380 } 1381 1382 /* Loop(Array) operation */ 1383 if (parg->count) { 1384 if (scode->op != FETCH_OP_ST_MEM && 1385 scode->op != FETCH_OP_ST_STRING && 1386 scode->op != FETCH_OP_ST_USTRING) { 1387 trace_probe_log_err(ctx->offset + type_offset, BAD_STRING); 1388 return -EINVAL; 1389 } 1390 code++; 1391 if (code->op != FETCH_OP_NOP) { 1392 trace_probe_log_err(ctx->offset, TOO_MANY_OPS); 1393 return -E2BIG; 1394 } 1395 code->op = FETCH_OP_LP_ARRAY; 1396 code->param = parg->count; 1397 } 1398 1399 /* Finalize the fetch_insn array. */ 1400 code++; 1401 code->op = FETCH_OP_END; 1402 1403 return 0; 1404 } 1405 1406 /* String length checking wrapper */ 1407 static int traceprobe_parse_probe_arg_body(const char *argv, ssize_t *size, 1408 struct probe_arg *parg, 1409 struct traceprobe_parse_context *ctx) 1410 { 1411 struct fetch_insn *code, *tmp = NULL; 1412 char *type, *arg; 1413 int ret, len; 1414 1415 len = strlen(argv); 1416 if (len > MAX_ARGSTR_LEN) { 1417 trace_probe_log_err(ctx->offset, ARG_TOO_LONG); 1418 return -E2BIG; 1419 } else if (len == 0) { 1420 trace_probe_log_err(ctx->offset, NO_ARG_BODY); 1421 return -EINVAL; 1422 } 1423 1424 arg = kstrdup(argv, GFP_KERNEL); 1425 if (!arg) 1426 return -ENOMEM; 1427 1428 parg->comm = kstrdup(arg, GFP_KERNEL); 1429 if (!parg->comm) { 1430 ret = -ENOMEM; 1431 goto out; 1432 } 1433 1434 type = parse_probe_arg_type(arg, parg, ctx); 1435 if (IS_ERR(type)) { 1436 ret = PTR_ERR(type); 1437 goto out; 1438 } 1439 1440 code = tmp = kcalloc(FETCH_INSN_MAX, sizeof(*code), GFP_KERNEL); 1441 if (!code) { 1442 ret = -ENOMEM; 1443 goto out; 1444 } 1445 code[FETCH_INSN_MAX - 1].op = FETCH_OP_END; 1446 1447 ctx->last_type = NULL; 1448 ret = parse_probe_arg(arg, parg->type, &code, &code[FETCH_INSN_MAX - 1], 1449 ctx); 1450 if (ret < 0) 1451 goto fail; 1452 1453 /* Update storing type if BTF is available */ 1454 if (IS_ENABLED(CONFIG_PROBE_EVENTS_BTF_ARGS) && 1455 ctx->last_type) { 1456 if (!type) { 1457 parg->type = find_fetch_type_from_btf_type(ctx); 1458 } else if (strstr(type, "string")) { 1459 ret = check_prepare_btf_string_fetch(type, &code, ctx); 1460 if (ret) 1461 goto fail; 1462 } 1463 } 1464 parg->offset = *size; 1465 *size += parg->type->size * (parg->count ?: 1); 1466 1467 if (parg->count) { 1468 len = strlen(parg->type->fmttype) + 6; 1469 parg->fmt = kmalloc(len, GFP_KERNEL); 1470 if (!parg->fmt) { 1471 ret = -ENOMEM; 1472 goto fail; 1473 } 1474 snprintf(parg->fmt, len, "%s[%d]", parg->type->fmttype, 1475 parg->count); 1476 } 1477 1478 ret = finalize_fetch_insn(code, parg, type, type ? type - arg : 0, ctx); 1479 if (ret < 0) 1480 goto fail; 1481 1482 for (; code < tmp + FETCH_INSN_MAX; code++) 1483 if (code->op == FETCH_OP_END) 1484 break; 1485 /* Shrink down the code buffer */ 1486 parg->code = kcalloc(code - tmp + 1, sizeof(*code), GFP_KERNEL); 1487 if (!parg->code) 1488 ret = -ENOMEM; 1489 else 1490 memcpy(parg->code, tmp, sizeof(*code) * (code - tmp + 1)); 1491 1492 fail: 1493 if (ret < 0) { 1494 for (code = tmp; code < tmp + FETCH_INSN_MAX; code++) 1495 if (code->op == FETCH_NOP_SYMBOL || 1496 code->op == FETCH_OP_DATA) 1497 kfree(code->data); 1498 } 1499 kfree(tmp); 1500 out: 1501 kfree(arg); 1502 1503 return ret; 1504 } 1505 1506 /* Return 1 if name is reserved or already used by another argument */ 1507 static int traceprobe_conflict_field_name(const char *name, 1508 struct probe_arg *args, int narg) 1509 { 1510 int i; 1511 1512 for (i = 0; i < ARRAY_SIZE(reserved_field_names); i++) 1513 if (strcmp(reserved_field_names[i], name) == 0) 1514 return 1; 1515 1516 for (i = 0; i < narg; i++) 1517 if (strcmp(args[i].name, name) == 0) 1518 return 1; 1519 1520 return 0; 1521 } 1522 1523 static char *generate_probe_arg_name(const char *arg, int idx) 1524 { 1525 char *name = NULL; 1526 const char *end; 1527 1528 /* 1529 * If argument name is omitted, try arg as a name (BTF variable) 1530 * or "argN". 1531 */ 1532 if (IS_ENABLED(CONFIG_PROBE_EVENTS_BTF_ARGS)) { 1533 end = strchr(arg, ':'); 1534 if (!end) 1535 end = arg + strlen(arg); 1536 1537 name = kmemdup_nul(arg, end - arg, GFP_KERNEL); 1538 if (!name || !is_good_name(name)) { 1539 kfree(name); 1540 name = NULL; 1541 } 1542 } 1543 1544 if (!name) 1545 name = kasprintf(GFP_KERNEL, "arg%d", idx + 1); 1546 1547 return name; 1548 } 1549 1550 int traceprobe_parse_probe_arg(struct trace_probe *tp, int i, const char *arg, 1551 struct traceprobe_parse_context *ctx) 1552 { 1553 struct probe_arg *parg = &tp->args[i]; 1554 const char *body; 1555 1556 ctx->tp = tp; 1557 body = strchr(arg, '='); 1558 if (body) { 1559 if (body - arg > MAX_ARG_NAME_LEN) { 1560 trace_probe_log_err(0, ARG_NAME_TOO_LONG); 1561 return -EINVAL; 1562 } else if (body == arg) { 1563 trace_probe_log_err(0, NO_ARG_NAME); 1564 return -EINVAL; 1565 } 1566 parg->name = kmemdup_nul(arg, body - arg, GFP_KERNEL); 1567 body++; 1568 } else { 1569 parg->name = generate_probe_arg_name(arg, i); 1570 body = arg; 1571 } 1572 if (!parg->name) 1573 return -ENOMEM; 1574 1575 if (!is_good_name(parg->name)) { 1576 trace_probe_log_err(0, BAD_ARG_NAME); 1577 return -EINVAL; 1578 } 1579 if (traceprobe_conflict_field_name(parg->name, tp->args, i)) { 1580 trace_probe_log_err(0, USED_ARG_NAME); 1581 return -EINVAL; 1582 } 1583 ctx->offset = body - arg; 1584 /* Parse fetch argument */ 1585 return traceprobe_parse_probe_arg_body(body, &tp->size, parg, ctx); 1586 } 1587 1588 void traceprobe_free_probe_arg(struct probe_arg *arg) 1589 { 1590 struct fetch_insn *code = arg->code; 1591 1592 while (code && code->op != FETCH_OP_END) { 1593 if (code->op == FETCH_NOP_SYMBOL || 1594 code->op == FETCH_OP_DATA) 1595 kfree(code->data); 1596 code++; 1597 } 1598 kfree(arg->code); 1599 kfree(arg->name); 1600 kfree(arg->comm); 1601 kfree(arg->fmt); 1602 } 1603 1604 static int argv_has_var_arg(int argc, const char *argv[], int *args_idx, 1605 struct traceprobe_parse_context *ctx) 1606 { 1607 int i, found = 0; 1608 1609 for (i = 0; i < argc; i++) 1610 if (str_has_prefix(argv[i], "$arg")) { 1611 trace_probe_log_set_index(i + 2); 1612 1613 if (!tparg_is_function_entry(ctx->flags) && 1614 !tparg_is_function_return(ctx->flags)) { 1615 trace_probe_log_err(0, NOFENTRY_ARGS); 1616 return -EINVAL; 1617 } 1618 1619 if (isdigit(argv[i][4])) { 1620 found = 1; 1621 continue; 1622 } 1623 1624 if (argv[i][4] != '*') { 1625 trace_probe_log_err(0, BAD_VAR); 1626 return -EINVAL; 1627 } 1628 1629 if (*args_idx >= 0 && *args_idx < argc) { 1630 trace_probe_log_err(0, DOUBLE_ARGS); 1631 return -EINVAL; 1632 } 1633 found = 1; 1634 *args_idx = i; 1635 } 1636 1637 return found; 1638 } 1639 1640 static int sprint_nth_btf_arg(int idx, const char *type, 1641 char *buf, int bufsize, 1642 struct traceprobe_parse_context *ctx) 1643 { 1644 const char *name; 1645 int ret; 1646 1647 if (idx >= ctx->nr_params) { 1648 trace_probe_log_err(0, NO_BTFARG); 1649 return -ENOENT; 1650 } 1651 name = btf_name_by_offset(ctx->btf, ctx->params[idx].name_off); 1652 if (!name) { 1653 trace_probe_log_err(0, NO_BTF_ENTRY); 1654 return -ENOENT; 1655 } 1656 ret = snprintf(buf, bufsize, "%s%s", name, type); 1657 if (ret >= bufsize) { 1658 trace_probe_log_err(0, ARGS_2LONG); 1659 return -E2BIG; 1660 } 1661 return ret; 1662 } 1663 1664 /* Return new_argv which must be freed after use */ 1665 const char **traceprobe_expand_meta_args(int argc, const char *argv[], 1666 int *new_argc, char *buf, int bufsize, 1667 struct traceprobe_parse_context *ctx) 1668 { 1669 const struct btf_param *params = NULL; 1670 int i, j, n, used, ret, args_idx = -1; 1671 const char **new_argv = NULL; 1672 1673 ret = argv_has_var_arg(argc, argv, &args_idx, ctx); 1674 if (ret < 0) 1675 return ERR_PTR(ret); 1676 1677 if (!ret) { 1678 *new_argc = argc; 1679 return NULL; 1680 } 1681 1682 ret = query_btf_context(ctx); 1683 if (ret < 0 || ctx->nr_params == 0) { 1684 if (args_idx != -1) { 1685 /* $arg* requires BTF info */ 1686 trace_probe_log_err(0, NOSUP_BTFARG); 1687 return (const char **)params; 1688 } 1689 *new_argc = argc; 1690 return NULL; 1691 } 1692 1693 if (args_idx >= 0) 1694 *new_argc = argc + ctx->nr_params - 1; 1695 else 1696 *new_argc = argc; 1697 1698 new_argv = kcalloc(*new_argc, sizeof(char *), GFP_KERNEL); 1699 if (!new_argv) 1700 return ERR_PTR(-ENOMEM); 1701 1702 used = 0; 1703 for (i = 0, j = 0; i < argc; i++) { 1704 trace_probe_log_set_index(i + 2); 1705 if (i == args_idx) { 1706 for (n = 0; n < ctx->nr_params; n++) { 1707 ret = sprint_nth_btf_arg(n, "", buf + used, 1708 bufsize - used, ctx); 1709 if (ret < 0) 1710 goto error; 1711 1712 new_argv[j++] = buf + used; 1713 used += ret + 1; 1714 } 1715 continue; 1716 } 1717 1718 if (str_has_prefix(argv[i], "$arg")) { 1719 char *type = NULL; 1720 1721 n = simple_strtoul(argv[i] + 4, &type, 10); 1722 if (type && !(*type == ':' || *type == '\0')) { 1723 trace_probe_log_err(0, BAD_VAR); 1724 ret = -ENOENT; 1725 goto error; 1726 } 1727 /* Note: $argN starts from $arg1 */ 1728 ret = sprint_nth_btf_arg(n - 1, type, buf + used, 1729 bufsize - used, ctx); 1730 if (ret < 0) 1731 goto error; 1732 new_argv[j++] = buf + used; 1733 used += ret + 1; 1734 } else 1735 new_argv[j++] = argv[i]; 1736 } 1737 1738 return new_argv; 1739 1740 error: 1741 kfree(new_argv); 1742 return ERR_PTR(ret); 1743 } 1744 1745 /* @buf: *buf must be equal to NULL. Caller must to free *buf */ 1746 int traceprobe_expand_dentry_args(int argc, const char *argv[], char **buf) 1747 { 1748 int i, used, ret; 1749 const int bufsize = MAX_DENTRY_ARGS_LEN; 1750 char *tmpbuf = NULL; 1751 1752 if (*buf) 1753 return -EINVAL; 1754 1755 used = 0; 1756 for (i = 0; i < argc; i++) { 1757 char *tmp; 1758 char *equal; 1759 size_t arg_len; 1760 1761 if (!glob_match("*:%p[dD]", argv[i])) 1762 continue; 1763 1764 if (!tmpbuf) { 1765 tmpbuf = kmalloc(bufsize, GFP_KERNEL); 1766 if (!tmpbuf) 1767 return -ENOMEM; 1768 } 1769 1770 tmp = kstrdup(argv[i], GFP_KERNEL); 1771 if (!tmp) 1772 goto nomem; 1773 1774 equal = strchr(tmp, '='); 1775 if (equal) 1776 *equal = '\0'; 1777 arg_len = strlen(argv[i]); 1778 tmp[arg_len - 4] = '\0'; 1779 if (argv[i][arg_len - 1] == 'd') 1780 ret = snprintf(tmpbuf + used, bufsize - used, 1781 "%s%s+0x0(+0x%zx(%s)):string", 1782 equal ? tmp : "", equal ? "=" : "", 1783 offsetof(struct dentry, d_name.name), 1784 equal ? equal + 1 : tmp); 1785 else 1786 ret = snprintf(tmpbuf + used, bufsize - used, 1787 "%s%s+0x0(+0x%zx(+0x%zx(%s))):string", 1788 equal ? tmp : "", equal ? "=" : "", 1789 offsetof(struct dentry, d_name.name), 1790 offsetof(struct file, f_path.dentry), 1791 equal ? equal + 1 : tmp); 1792 1793 kfree(tmp); 1794 if (ret >= bufsize - used) 1795 goto nomem; 1796 argv[i] = tmpbuf + used; 1797 used += ret + 1; 1798 } 1799 1800 *buf = tmpbuf; 1801 return 0; 1802 nomem: 1803 kfree(tmpbuf); 1804 return -ENOMEM; 1805 } 1806 1807 void traceprobe_finish_parse(struct traceprobe_parse_context *ctx) 1808 { 1809 clear_btf_context(ctx); 1810 } 1811 1812 int traceprobe_update_arg(struct probe_arg *arg) 1813 { 1814 struct fetch_insn *code = arg->code; 1815 long offset; 1816 char *tmp; 1817 char c; 1818 int ret = 0; 1819 1820 while (code && code->op != FETCH_OP_END) { 1821 if (code->op == FETCH_NOP_SYMBOL) { 1822 if (code[1].op != FETCH_OP_IMM) 1823 return -EINVAL; 1824 1825 tmp = strpbrk(code->data, "+-"); 1826 if (tmp) 1827 c = *tmp; 1828 ret = traceprobe_split_symbol_offset(code->data, 1829 &offset); 1830 if (ret) 1831 return ret; 1832 1833 code[1].immediate = 1834 (unsigned long)kallsyms_lookup_name(code->data); 1835 if (tmp) 1836 *tmp = c; 1837 if (!code[1].immediate) 1838 return -ENOENT; 1839 code[1].immediate += offset; 1840 } 1841 code++; 1842 } 1843 return 0; 1844 } 1845 1846 /* When len=0, we just calculate the needed length */ 1847 #define LEN_OR_ZERO (len ? len - pos : 0) 1848 static int __set_print_fmt(struct trace_probe *tp, char *buf, int len, 1849 enum probe_print_type ptype) 1850 { 1851 struct probe_arg *parg; 1852 int i, j; 1853 int pos = 0; 1854 const char *fmt, *arg; 1855 1856 switch (ptype) { 1857 case PROBE_PRINT_NORMAL: 1858 fmt = "(%lx)"; 1859 arg = ", REC->" FIELD_STRING_IP; 1860 break; 1861 case PROBE_PRINT_RETURN: 1862 fmt = "(%lx <- %lx)"; 1863 arg = ", REC->" FIELD_STRING_FUNC ", REC->" FIELD_STRING_RETIP; 1864 break; 1865 case PROBE_PRINT_EVENT: 1866 fmt = ""; 1867 arg = ""; 1868 break; 1869 default: 1870 WARN_ON_ONCE(1); 1871 return 0; 1872 } 1873 1874 pos += snprintf(buf + pos, LEN_OR_ZERO, "\"%s", fmt); 1875 1876 for (i = 0; i < tp->nr_args; i++) { 1877 parg = tp->args + i; 1878 pos += snprintf(buf + pos, LEN_OR_ZERO, " %s=", parg->name); 1879 if (parg->count) { 1880 pos += snprintf(buf + pos, LEN_OR_ZERO, "{%s", 1881 parg->type->fmt); 1882 for (j = 1; j < parg->count; j++) 1883 pos += snprintf(buf + pos, LEN_OR_ZERO, ",%s", 1884 parg->type->fmt); 1885 pos += snprintf(buf + pos, LEN_OR_ZERO, "}"); 1886 } else 1887 pos += snprintf(buf + pos, LEN_OR_ZERO, "%s", 1888 parg->type->fmt); 1889 } 1890 1891 pos += snprintf(buf + pos, LEN_OR_ZERO, "\"%s", arg); 1892 1893 for (i = 0; i < tp->nr_args; i++) { 1894 parg = tp->args + i; 1895 if (parg->count) { 1896 if (parg->type->is_string) 1897 fmt = ", __get_str(%s[%d])"; 1898 else 1899 fmt = ", REC->%s[%d]"; 1900 for (j = 0; j < parg->count; j++) 1901 pos += snprintf(buf + pos, LEN_OR_ZERO, 1902 fmt, parg->name, j); 1903 } else { 1904 if (parg->type->is_string) 1905 fmt = ", __get_str(%s)"; 1906 else 1907 fmt = ", REC->%s"; 1908 pos += snprintf(buf + pos, LEN_OR_ZERO, 1909 fmt, parg->name); 1910 } 1911 } 1912 1913 /* return the length of print_fmt */ 1914 return pos; 1915 } 1916 #undef LEN_OR_ZERO 1917 1918 int traceprobe_set_print_fmt(struct trace_probe *tp, enum probe_print_type ptype) 1919 { 1920 struct trace_event_call *call = trace_probe_event_call(tp); 1921 int len; 1922 char *print_fmt; 1923 1924 /* First: called with 0 length to calculate the needed length */ 1925 len = __set_print_fmt(tp, NULL, 0, ptype); 1926 print_fmt = kmalloc(len + 1, GFP_KERNEL); 1927 if (!print_fmt) 1928 return -ENOMEM; 1929 1930 /* Second: actually write the @print_fmt */ 1931 __set_print_fmt(tp, print_fmt, len + 1, ptype); 1932 call->print_fmt = print_fmt; 1933 1934 return 0; 1935 } 1936 1937 int traceprobe_define_arg_fields(struct trace_event_call *event_call, 1938 size_t offset, struct trace_probe *tp) 1939 { 1940 int ret, i; 1941 1942 /* Set argument names as fields */ 1943 for (i = 0; i < tp->nr_args; i++) { 1944 struct probe_arg *parg = &tp->args[i]; 1945 const char *fmt = parg->type->fmttype; 1946 int size = parg->type->size; 1947 1948 if (parg->fmt) 1949 fmt = parg->fmt; 1950 if (parg->count) 1951 size *= parg->count; 1952 ret = trace_define_field(event_call, fmt, parg->name, 1953 offset + parg->offset, size, 1954 parg->type->is_signed, 1955 FILTER_OTHER); 1956 if (ret) 1957 return ret; 1958 } 1959 return 0; 1960 } 1961 1962 static void trace_probe_event_free(struct trace_probe_event *tpe) 1963 { 1964 kfree(tpe->class.system); 1965 kfree(tpe->call.name); 1966 kfree(tpe->call.print_fmt); 1967 kfree(tpe); 1968 } 1969 1970 int trace_probe_append(struct trace_probe *tp, struct trace_probe *to) 1971 { 1972 if (trace_probe_has_sibling(tp)) 1973 return -EBUSY; 1974 1975 list_del_init(&tp->list); 1976 trace_probe_event_free(tp->event); 1977 1978 tp->event = to->event; 1979 list_add_tail(&tp->list, trace_probe_probe_list(to)); 1980 1981 return 0; 1982 } 1983 1984 void trace_probe_unlink(struct trace_probe *tp) 1985 { 1986 list_del_init(&tp->list); 1987 if (list_empty(trace_probe_probe_list(tp))) 1988 trace_probe_event_free(tp->event); 1989 tp->event = NULL; 1990 } 1991 1992 void trace_probe_cleanup(struct trace_probe *tp) 1993 { 1994 int i; 1995 1996 for (i = 0; i < tp->nr_args; i++) 1997 traceprobe_free_probe_arg(&tp->args[i]); 1998 1999 if (tp->entry_arg) { 2000 kfree(tp->entry_arg->code); 2001 kfree(tp->entry_arg); 2002 tp->entry_arg = NULL; 2003 } 2004 2005 if (tp->event) 2006 trace_probe_unlink(tp); 2007 } 2008 2009 int trace_probe_init(struct trace_probe *tp, const char *event, 2010 const char *group, bool alloc_filter, int nargs) 2011 { 2012 struct trace_event_call *call; 2013 size_t size = sizeof(struct trace_probe_event); 2014 int ret = 0; 2015 2016 if (!event || !group) 2017 return -EINVAL; 2018 2019 if (alloc_filter) 2020 size += sizeof(struct trace_uprobe_filter); 2021 2022 tp->event = kzalloc(size, GFP_KERNEL); 2023 if (!tp->event) 2024 return -ENOMEM; 2025 2026 INIT_LIST_HEAD(&tp->event->files); 2027 INIT_LIST_HEAD(&tp->event->class.fields); 2028 INIT_LIST_HEAD(&tp->event->probes); 2029 INIT_LIST_HEAD(&tp->list); 2030 list_add(&tp->list, &tp->event->probes); 2031 2032 call = trace_probe_event_call(tp); 2033 call->class = &tp->event->class; 2034 call->name = kstrdup(event, GFP_KERNEL); 2035 if (!call->name) { 2036 ret = -ENOMEM; 2037 goto error; 2038 } 2039 2040 tp->event->class.system = kstrdup(group, GFP_KERNEL); 2041 if (!tp->event->class.system) { 2042 ret = -ENOMEM; 2043 goto error; 2044 } 2045 2046 tp->nr_args = nargs; 2047 /* Make sure pointers in args[] are NULL */ 2048 if (nargs) 2049 memset(tp->args, 0, sizeof(tp->args[0]) * nargs); 2050 2051 return 0; 2052 2053 error: 2054 trace_probe_cleanup(tp); 2055 return ret; 2056 } 2057 2058 static struct trace_event_call * 2059 find_trace_event_call(const char *system, const char *event_name) 2060 { 2061 struct trace_event_call *tp_event; 2062 const char *name; 2063 2064 list_for_each_entry(tp_event, &ftrace_events, list) { 2065 if (!tp_event->class->system || 2066 strcmp(system, tp_event->class->system)) 2067 continue; 2068 name = trace_event_name(tp_event); 2069 if (!name || strcmp(event_name, name)) 2070 continue; 2071 return tp_event; 2072 } 2073 2074 return NULL; 2075 } 2076 2077 int trace_probe_register_event_call(struct trace_probe *tp) 2078 { 2079 struct trace_event_call *call = trace_probe_event_call(tp); 2080 int ret; 2081 2082 lockdep_assert_held(&event_mutex); 2083 2084 if (find_trace_event_call(trace_probe_group_name(tp), 2085 trace_probe_name(tp))) 2086 return -EEXIST; 2087 2088 ret = register_trace_event(&call->event); 2089 if (!ret) 2090 return -ENODEV; 2091 2092 ret = trace_add_event_call(call); 2093 if (ret) 2094 unregister_trace_event(&call->event); 2095 2096 return ret; 2097 } 2098 2099 int trace_probe_add_file(struct trace_probe *tp, struct trace_event_file *file) 2100 { 2101 struct event_file_link *link; 2102 2103 link = kmalloc(sizeof(*link), GFP_KERNEL); 2104 if (!link) 2105 return -ENOMEM; 2106 2107 link->file = file; 2108 INIT_LIST_HEAD(&link->list); 2109 list_add_tail_rcu(&link->list, &tp->event->files); 2110 trace_probe_set_flag(tp, TP_FLAG_TRACE); 2111 return 0; 2112 } 2113 2114 struct event_file_link *trace_probe_get_file_link(struct trace_probe *tp, 2115 struct trace_event_file *file) 2116 { 2117 struct event_file_link *link; 2118 2119 trace_probe_for_each_link(link, tp) { 2120 if (link->file == file) 2121 return link; 2122 } 2123 2124 return NULL; 2125 } 2126 2127 int trace_probe_remove_file(struct trace_probe *tp, 2128 struct trace_event_file *file) 2129 { 2130 struct event_file_link *link; 2131 2132 link = trace_probe_get_file_link(tp, file); 2133 if (!link) 2134 return -ENOENT; 2135 2136 list_del_rcu(&link->list); 2137 kvfree_rcu_mightsleep(link); 2138 2139 if (list_empty(&tp->event->files)) 2140 trace_probe_clear_flag(tp, TP_FLAG_TRACE); 2141 2142 return 0; 2143 } 2144 2145 /* 2146 * Return the smallest index of different type argument (start from 1). 2147 * If all argument types and name are same, return 0. 2148 */ 2149 int trace_probe_compare_arg_type(struct trace_probe *a, struct trace_probe *b) 2150 { 2151 int i; 2152 2153 /* In case of more arguments */ 2154 if (a->nr_args < b->nr_args) 2155 return a->nr_args + 1; 2156 if (a->nr_args > b->nr_args) 2157 return b->nr_args + 1; 2158 2159 for (i = 0; i < a->nr_args; i++) { 2160 if ((b->nr_args <= i) || 2161 ((a->args[i].type != b->args[i].type) || 2162 (a->args[i].count != b->args[i].count) || 2163 strcmp(a->args[i].name, b->args[i].name))) 2164 return i + 1; 2165 } 2166 2167 return 0; 2168 } 2169 2170 bool trace_probe_match_command_args(struct trace_probe *tp, 2171 int argc, const char **argv) 2172 { 2173 char buf[MAX_ARGSTR_LEN + 1]; 2174 int i; 2175 2176 if (tp->nr_args < argc) 2177 return false; 2178 2179 for (i = 0; i < argc; i++) { 2180 snprintf(buf, sizeof(buf), "%s=%s", 2181 tp->args[i].name, tp->args[i].comm); 2182 if (strcmp(buf, argv[i])) 2183 return false; 2184 } 2185 return true; 2186 } 2187 2188 int trace_probe_create(const char *raw_command, int (*createfn)(int, const char **)) 2189 { 2190 int argc = 0, ret = 0; 2191 char **argv; 2192 2193 argv = argv_split(GFP_KERNEL, raw_command, &argc); 2194 if (!argv) 2195 return -ENOMEM; 2196 2197 if (argc) 2198 ret = createfn(argc, (const char **)argv); 2199 2200 argv_free(argv); 2201 2202 return ret; 2203 } 2204 2205 int trace_probe_print_args(struct trace_seq *s, struct probe_arg *args, int nr_args, 2206 u8 *data, void *field) 2207 { 2208 void *p; 2209 int i, j; 2210 2211 for (i = 0; i < nr_args; i++) { 2212 struct probe_arg *a = args + i; 2213 2214 trace_seq_printf(s, " %s=", a->name); 2215 if (likely(!a->count)) { 2216 if (!a->type->print(s, data + a->offset, field)) 2217 return -ENOMEM; 2218 continue; 2219 } 2220 trace_seq_putc(s, '{'); 2221 p = data + a->offset; 2222 for (j = 0; j < a->count; j++) { 2223 if (!a->type->print(s, p, field)) 2224 return -ENOMEM; 2225 trace_seq_putc(s, j == a->count - 1 ? '}' : ','); 2226 p += a->type->size; 2227 } 2228 } 2229 return 0; 2230 } 2231