1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Common code for probe-based Dynamic events. 4 * 5 * This code was copied from kernel/trace/trace_kprobe.c written by 6 * Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> 7 * 8 * Updates to make this generic: 9 * Copyright (C) IBM Corporation, 2010-2011 10 * Author: Srikar Dronamraju 11 */ 12 #define pr_fmt(fmt) "trace_probe: " fmt 13 14 #include <linux/bpf.h> 15 #include "trace_btf.h" 16 17 #include "trace_probe.h" 18 19 #undef C 20 #define C(a, b) b 21 22 static const char *trace_probe_err_text[] = { ERRORS }; 23 24 static const char *reserved_field_names[] = { 25 "common_type", 26 "common_flags", 27 "common_preempt_count", 28 "common_pid", 29 "common_tgid", 30 FIELD_STRING_IP, 31 FIELD_STRING_RETIP, 32 FIELD_STRING_FUNC, 33 }; 34 35 /* Printing in basic type function template */ 36 #define DEFINE_BASIC_PRINT_TYPE_FUNC(tname, type, fmt) \ 37 int PRINT_TYPE_FUNC_NAME(tname)(struct trace_seq *s, void *data, void *ent)\ 38 { \ 39 trace_seq_printf(s, fmt, *(type *)data); \ 40 return !trace_seq_has_overflowed(s); \ 41 } \ 42 const char PRINT_TYPE_FMT_NAME(tname)[] = fmt; 43 44 DEFINE_BASIC_PRINT_TYPE_FUNC(u8, u8, "%u") 45 DEFINE_BASIC_PRINT_TYPE_FUNC(u16, u16, "%u") 46 DEFINE_BASIC_PRINT_TYPE_FUNC(u32, u32, "%u") 47 DEFINE_BASIC_PRINT_TYPE_FUNC(u64, u64, "%Lu") 48 DEFINE_BASIC_PRINT_TYPE_FUNC(s8, s8, "%d") 49 DEFINE_BASIC_PRINT_TYPE_FUNC(s16, s16, "%d") 50 DEFINE_BASIC_PRINT_TYPE_FUNC(s32, s32, "%d") 51 DEFINE_BASIC_PRINT_TYPE_FUNC(s64, s64, "%Ld") 52 DEFINE_BASIC_PRINT_TYPE_FUNC(x8, u8, "0x%x") 53 DEFINE_BASIC_PRINT_TYPE_FUNC(x16, u16, "0x%x") 54 DEFINE_BASIC_PRINT_TYPE_FUNC(x32, u32, "0x%x") 55 DEFINE_BASIC_PRINT_TYPE_FUNC(x64, u64, "0x%Lx") 56 DEFINE_BASIC_PRINT_TYPE_FUNC(char, u8, "'%c'") 57 58 int PRINT_TYPE_FUNC_NAME(symbol)(struct trace_seq *s, void *data, void *ent) 59 { 60 trace_seq_printf(s, "%pS", (void *)*(unsigned long *)data); 61 return !trace_seq_has_overflowed(s); 62 } 63 const char PRINT_TYPE_FMT_NAME(symbol)[] = "%pS"; 64 65 /* Print type function for string type */ 66 int PRINT_TYPE_FUNC_NAME(string)(struct trace_seq *s, void *data, void *ent) 67 { 68 int len = *(u32 *)data >> 16; 69 70 if (!len) 71 trace_seq_puts(s, FAULT_STRING); 72 else 73 trace_seq_printf(s, "\"%s\"", 74 (const char *)get_loc_data(data, ent)); 75 return !trace_seq_has_overflowed(s); 76 } 77 78 const char PRINT_TYPE_FMT_NAME(string)[] = "\\\"%s\\\""; 79 80 /* Fetch type information table */ 81 static const struct fetch_type probe_fetch_types[] = { 82 /* Special types */ 83 __ASSIGN_FETCH_TYPE("string", string, string, sizeof(u32), 1, 1, 84 "__data_loc char[]"), 85 __ASSIGN_FETCH_TYPE("ustring", string, string, sizeof(u32), 1, 1, 86 "__data_loc char[]"), 87 __ASSIGN_FETCH_TYPE("symstr", string, string, sizeof(u32), 1, 1, 88 "__data_loc char[]"), 89 /* Basic types */ 90 ASSIGN_FETCH_TYPE(u8, u8, 0), 91 ASSIGN_FETCH_TYPE(u16, u16, 0), 92 ASSIGN_FETCH_TYPE(u32, u32, 0), 93 ASSIGN_FETCH_TYPE(u64, u64, 0), 94 ASSIGN_FETCH_TYPE(s8, u8, 1), 95 ASSIGN_FETCH_TYPE(s16, u16, 1), 96 ASSIGN_FETCH_TYPE(s32, u32, 1), 97 ASSIGN_FETCH_TYPE(s64, u64, 1), 98 ASSIGN_FETCH_TYPE_ALIAS(x8, u8, u8, 0), 99 ASSIGN_FETCH_TYPE_ALIAS(x16, u16, u16, 0), 100 ASSIGN_FETCH_TYPE_ALIAS(x32, u32, u32, 0), 101 ASSIGN_FETCH_TYPE_ALIAS(x64, u64, u64, 0), 102 ASSIGN_FETCH_TYPE_ALIAS(char, u8, u8, 0), 103 ASSIGN_FETCH_TYPE_ALIAS(symbol, ADDR_FETCH_TYPE, ADDR_FETCH_TYPE, 0), 104 105 ASSIGN_FETCH_TYPE_END 106 }; 107 108 static const struct fetch_type *find_fetch_type(const char *type, unsigned long flags) 109 { 110 int i; 111 112 /* Reject the symbol/symstr for uprobes */ 113 if (type && (flags & TPARG_FL_USER) && 114 (!strcmp(type, "symbol") || !strcmp(type, "symstr"))) 115 return NULL; 116 117 if (!type) 118 type = DEFAULT_FETCH_TYPE_STR; 119 120 /* Special case: bitfield */ 121 if (*type == 'b') { 122 unsigned long bs; 123 124 type = strchr(type, '/'); 125 if (!type) 126 goto fail; 127 128 type++; 129 if (kstrtoul(type, 0, &bs)) 130 goto fail; 131 132 switch (bs) { 133 case 8: 134 return find_fetch_type("u8", flags); 135 case 16: 136 return find_fetch_type("u16", flags); 137 case 32: 138 return find_fetch_type("u32", flags); 139 case 64: 140 return find_fetch_type("u64", flags); 141 default: 142 goto fail; 143 } 144 } 145 146 for (i = 0; probe_fetch_types[i].name; i++) { 147 if (strcmp(type, probe_fetch_types[i].name) == 0) 148 return &probe_fetch_types[i]; 149 } 150 151 fail: 152 return NULL; 153 } 154 155 static struct trace_probe_log trace_probe_log; 156 157 void trace_probe_log_init(const char *subsystem, int argc, const char **argv) 158 { 159 trace_probe_log.subsystem = subsystem; 160 trace_probe_log.argc = argc; 161 trace_probe_log.argv = argv; 162 trace_probe_log.index = 0; 163 } 164 165 void trace_probe_log_clear(void) 166 { 167 memset(&trace_probe_log, 0, sizeof(trace_probe_log)); 168 } 169 170 void trace_probe_log_set_index(int index) 171 { 172 trace_probe_log.index = index; 173 } 174 175 void __trace_probe_log_err(int offset, int err_type) 176 { 177 char *command, *p; 178 int i, len = 0, pos = 0; 179 180 if (!trace_probe_log.argv) 181 return; 182 183 /* Recalculate the length and allocate buffer */ 184 for (i = 0; i < trace_probe_log.argc; i++) { 185 if (i == trace_probe_log.index) 186 pos = len; 187 len += strlen(trace_probe_log.argv[i]) + 1; 188 } 189 command = kzalloc(len, GFP_KERNEL); 190 if (!command) 191 return; 192 193 if (trace_probe_log.index >= trace_probe_log.argc) { 194 /** 195 * Set the error position is next to the last arg + space. 196 * Note that len includes the terminal null and the cursor 197 * appears at pos + 1. 198 */ 199 pos = len; 200 offset = 0; 201 } 202 203 /* And make a command string from argv array */ 204 p = command; 205 for (i = 0; i < trace_probe_log.argc; i++) { 206 len = strlen(trace_probe_log.argv[i]); 207 strcpy(p, trace_probe_log.argv[i]); 208 p[len] = ' '; 209 p += len + 1; 210 } 211 *(p - 1) = '\0'; 212 213 tracing_log_err(NULL, trace_probe_log.subsystem, command, 214 trace_probe_err_text, err_type, pos + offset); 215 216 kfree(command); 217 } 218 219 /* Split symbol and offset. */ 220 int traceprobe_split_symbol_offset(char *symbol, long *offset) 221 { 222 char *tmp; 223 int ret; 224 225 if (!offset) 226 return -EINVAL; 227 228 tmp = strpbrk(symbol, "+-"); 229 if (tmp) { 230 ret = kstrtol(tmp, 0, offset); 231 if (ret) 232 return ret; 233 *tmp = '\0'; 234 } else 235 *offset = 0; 236 237 return 0; 238 } 239 240 /* @buf must has MAX_EVENT_NAME_LEN size */ 241 int traceprobe_parse_event_name(const char **pevent, const char **pgroup, 242 char *buf, int offset) 243 { 244 const char *slash, *event = *pevent; 245 int len; 246 247 slash = strchr(event, '/'); 248 if (!slash) 249 slash = strchr(event, '.'); 250 251 if (slash) { 252 if (slash == event) { 253 trace_probe_log_err(offset, NO_GROUP_NAME); 254 return -EINVAL; 255 } 256 if (slash - event + 1 > MAX_EVENT_NAME_LEN) { 257 trace_probe_log_err(offset, GROUP_TOO_LONG); 258 return -EINVAL; 259 } 260 strscpy(buf, event, slash - event + 1); 261 if (!is_good_system_name(buf)) { 262 trace_probe_log_err(offset, BAD_GROUP_NAME); 263 return -EINVAL; 264 } 265 *pgroup = buf; 266 *pevent = slash + 1; 267 offset += slash - event + 1; 268 event = *pevent; 269 } 270 len = strlen(event); 271 if (len == 0) { 272 if (slash) { 273 *pevent = NULL; 274 return 0; 275 } 276 trace_probe_log_err(offset, NO_EVENT_NAME); 277 return -EINVAL; 278 } else if (len >= MAX_EVENT_NAME_LEN) { 279 trace_probe_log_err(offset, EVENT_TOO_LONG); 280 return -EINVAL; 281 } 282 if (!is_good_name(event)) { 283 trace_probe_log_err(offset, BAD_EVENT_NAME); 284 return -EINVAL; 285 } 286 return 0; 287 } 288 289 static int parse_trace_event_arg(char *arg, struct fetch_insn *code, 290 struct traceprobe_parse_context *ctx) 291 { 292 struct ftrace_event_field *field; 293 struct list_head *head; 294 295 head = trace_get_fields(ctx->event); 296 list_for_each_entry(field, head, link) { 297 if (!strcmp(arg, field->name)) { 298 code->op = FETCH_OP_TP_ARG; 299 code->data = field; 300 return 0; 301 } 302 } 303 return -ENOENT; 304 } 305 306 #ifdef CONFIG_PROBE_EVENTS_BTF_ARGS 307 308 static u32 btf_type_int(const struct btf_type *t) 309 { 310 return *(u32 *)(t + 1); 311 } 312 313 static bool btf_type_is_char_ptr(struct btf *btf, const struct btf_type *type) 314 { 315 const struct btf_type *real_type; 316 u32 intdata; 317 s32 tid; 318 319 real_type = btf_type_skip_modifiers(btf, type->type, &tid); 320 if (!real_type) 321 return false; 322 323 if (BTF_INFO_KIND(real_type->info) != BTF_KIND_INT) 324 return false; 325 326 intdata = btf_type_int(real_type); 327 return !(BTF_INT_ENCODING(intdata) & BTF_INT_SIGNED) 328 && BTF_INT_BITS(intdata) == 8; 329 } 330 331 static bool btf_type_is_char_array(struct btf *btf, const struct btf_type *type) 332 { 333 const struct btf_type *real_type; 334 const struct btf_array *array; 335 u32 intdata; 336 s32 tid; 337 338 if (BTF_INFO_KIND(type->info) != BTF_KIND_ARRAY) 339 return false; 340 341 array = (const struct btf_array *)(type + 1); 342 343 real_type = btf_type_skip_modifiers(btf, array->type, &tid); 344 345 intdata = btf_type_int(real_type); 346 return !(BTF_INT_ENCODING(intdata) & BTF_INT_SIGNED) 347 && BTF_INT_BITS(intdata) == 8; 348 } 349 350 static int check_prepare_btf_string_fetch(char *typename, 351 struct fetch_insn **pcode, 352 struct traceprobe_parse_context *ctx) 353 { 354 struct btf *btf = ctx->btf; 355 356 if (!btf || !ctx->last_type) 357 return 0; 358 359 /* char [] does not need any change. */ 360 if (btf_type_is_char_array(btf, ctx->last_type)) 361 return 0; 362 363 /* char * requires dereference the pointer. */ 364 if (btf_type_is_char_ptr(btf, ctx->last_type)) { 365 struct fetch_insn *code = *pcode + 1; 366 367 if (code->op == FETCH_OP_END) { 368 trace_probe_log_err(ctx->offset, TOO_MANY_OPS); 369 return -E2BIG; 370 } 371 if (typename[0] == 'u') 372 code->op = FETCH_OP_UDEREF; 373 else 374 code->op = FETCH_OP_DEREF; 375 code->offset = 0; 376 *pcode = code; 377 return 0; 378 } 379 /* Other types are not available for string */ 380 trace_probe_log_err(ctx->offset, BAD_TYPE4STR); 381 return -EINVAL; 382 } 383 384 static const char *fetch_type_from_btf_type(struct btf *btf, 385 const struct btf_type *type, 386 struct traceprobe_parse_context *ctx) 387 { 388 u32 intdata; 389 390 /* TODO: const char * could be converted as a string */ 391 switch (BTF_INFO_KIND(type->info)) { 392 case BTF_KIND_ENUM: 393 /* enum is "int", so convert to "s32" */ 394 return "s32"; 395 case BTF_KIND_ENUM64: 396 return "s64"; 397 case BTF_KIND_PTR: 398 /* pointer will be converted to "x??" */ 399 if (IS_ENABLED(CONFIG_64BIT)) 400 return "x64"; 401 else 402 return "x32"; 403 case BTF_KIND_INT: 404 intdata = btf_type_int(type); 405 if (BTF_INT_ENCODING(intdata) & BTF_INT_SIGNED) { 406 switch (BTF_INT_BITS(intdata)) { 407 case 8: 408 return "s8"; 409 case 16: 410 return "s16"; 411 case 32: 412 return "s32"; 413 case 64: 414 return "s64"; 415 } 416 } else { /* unsigned */ 417 switch (BTF_INT_BITS(intdata)) { 418 case 8: 419 return "u8"; 420 case 16: 421 return "u16"; 422 case 32: 423 return "u32"; 424 case 64: 425 return "u64"; 426 } 427 /* bitfield, size is encoded in the type */ 428 ctx->last_bitsize = BTF_INT_BITS(intdata); 429 ctx->last_bitoffs += BTF_INT_OFFSET(intdata); 430 return "u64"; 431 } 432 } 433 /* TODO: support other types */ 434 435 return NULL; 436 } 437 438 static int query_btf_context(struct traceprobe_parse_context *ctx) 439 { 440 const struct btf_param *param; 441 const struct btf_type *type; 442 struct btf *btf; 443 s32 nr; 444 445 if (ctx->btf) 446 return 0; 447 448 if (!ctx->funcname) 449 return -EINVAL; 450 451 type = btf_find_func_proto(ctx->funcname, &btf); 452 if (!type) 453 return -ENOENT; 454 455 ctx->btf = btf; 456 ctx->proto = type; 457 458 /* ctx->params is optional, since func(void) will not have params. */ 459 nr = 0; 460 param = btf_get_func_param(type, &nr); 461 if (!IS_ERR_OR_NULL(param)) { 462 /* Hide the first 'data' argument of tracepoint */ 463 if (ctx->flags & TPARG_FL_TPOINT) { 464 nr--; 465 param++; 466 } 467 } 468 469 if (nr > 0) { 470 ctx->nr_params = nr; 471 ctx->params = param; 472 } else { 473 ctx->nr_params = 0; 474 ctx->params = NULL; 475 } 476 477 return 0; 478 } 479 480 static void clear_btf_context(struct traceprobe_parse_context *ctx) 481 { 482 if (ctx->btf) { 483 btf_put(ctx->btf); 484 ctx->btf = NULL; 485 ctx->proto = NULL; 486 ctx->params = NULL; 487 ctx->nr_params = 0; 488 } 489 } 490 491 /* Return 1 if the field separater is arrow operator ('->') */ 492 static int split_next_field(char *varname, char **next_field, 493 struct traceprobe_parse_context *ctx) 494 { 495 char *field; 496 int ret = 0; 497 498 field = strpbrk(varname, ".-"); 499 if (field) { 500 if (field[0] == '-' && field[1] == '>') { 501 field[0] = '\0'; 502 field += 2; 503 ret = 1; 504 } else if (field[0] == '.') { 505 field[0] = '\0'; 506 field += 1; 507 } else { 508 trace_probe_log_err(ctx->offset + field - varname, BAD_HYPHEN); 509 return -EINVAL; 510 } 511 *next_field = field; 512 } 513 514 return ret; 515 } 516 517 /* 518 * Parse the field of data structure. The @type must be a pointer type 519 * pointing the target data structure type. 520 */ 521 static int parse_btf_field(char *fieldname, const struct btf_type *type, 522 struct fetch_insn **pcode, struct fetch_insn *end, 523 struct traceprobe_parse_context *ctx) 524 { 525 struct fetch_insn *code = *pcode; 526 const struct btf_member *field; 527 u32 bitoffs, anon_offs; 528 char *next; 529 int is_ptr; 530 s32 tid; 531 532 do { 533 /* Outer loop for solving arrow operator ('->') */ 534 if (BTF_INFO_KIND(type->info) != BTF_KIND_PTR) { 535 trace_probe_log_err(ctx->offset, NO_PTR_STRCT); 536 return -EINVAL; 537 } 538 /* Convert a struct pointer type to a struct type */ 539 type = btf_type_skip_modifiers(ctx->btf, type->type, &tid); 540 if (!type) { 541 trace_probe_log_err(ctx->offset, BAD_BTF_TID); 542 return -EINVAL; 543 } 544 545 bitoffs = 0; 546 do { 547 /* Inner loop for solving dot operator ('.') */ 548 next = NULL; 549 is_ptr = split_next_field(fieldname, &next, ctx); 550 if (is_ptr < 0) 551 return is_ptr; 552 553 anon_offs = 0; 554 field = btf_find_struct_member(ctx->btf, type, fieldname, 555 &anon_offs); 556 if (IS_ERR(field)) { 557 trace_probe_log_err(ctx->offset, BAD_BTF_TID); 558 return PTR_ERR(field); 559 } 560 if (!field) { 561 trace_probe_log_err(ctx->offset, NO_BTF_FIELD); 562 return -ENOENT; 563 } 564 /* Add anonymous structure/union offset */ 565 bitoffs += anon_offs; 566 567 /* Accumulate the bit-offsets of the dot-connected fields */ 568 if (btf_type_kflag(type)) { 569 bitoffs += BTF_MEMBER_BIT_OFFSET(field->offset); 570 ctx->last_bitsize = BTF_MEMBER_BITFIELD_SIZE(field->offset); 571 } else { 572 bitoffs += field->offset; 573 ctx->last_bitsize = 0; 574 } 575 576 type = btf_type_skip_modifiers(ctx->btf, field->type, &tid); 577 if (!type) { 578 trace_probe_log_err(ctx->offset, BAD_BTF_TID); 579 return -EINVAL; 580 } 581 582 ctx->offset += next - fieldname; 583 fieldname = next; 584 } while (!is_ptr && fieldname); 585 586 if (++code == end) { 587 trace_probe_log_err(ctx->offset, TOO_MANY_OPS); 588 return -EINVAL; 589 } 590 code->op = FETCH_OP_DEREF; /* TODO: user deref support */ 591 code->offset = bitoffs / 8; 592 *pcode = code; 593 594 ctx->last_bitoffs = bitoffs % 8; 595 ctx->last_type = type; 596 } while (fieldname); 597 598 return 0; 599 } 600 601 static int __store_entry_arg(struct trace_probe *tp, int argnum); 602 603 static int parse_btf_arg(char *varname, 604 struct fetch_insn **pcode, struct fetch_insn *end, 605 struct traceprobe_parse_context *ctx) 606 { 607 struct fetch_insn *code = *pcode; 608 const struct btf_param *params; 609 const struct btf_type *type; 610 char *field = NULL; 611 int i, is_ptr, ret; 612 u32 tid; 613 614 if (WARN_ON_ONCE(!ctx->funcname)) 615 return -EINVAL; 616 617 is_ptr = split_next_field(varname, &field, ctx); 618 if (is_ptr < 0) 619 return is_ptr; 620 if (!is_ptr && field) { 621 /* dot-connected field on an argument is not supported. */ 622 trace_probe_log_err(ctx->offset + field - varname, 623 NOSUP_DAT_ARG); 624 return -EOPNOTSUPP; 625 } 626 627 if (ctx->flags & TPARG_FL_RETURN && !strcmp(varname, "$retval")) { 628 code->op = FETCH_OP_RETVAL; 629 /* Check whether the function return type is not void */ 630 if (query_btf_context(ctx) == 0) { 631 if (ctx->proto->type == 0) { 632 trace_probe_log_err(ctx->offset, NO_RETVAL); 633 return -ENOENT; 634 } 635 tid = ctx->proto->type; 636 goto found; 637 } 638 if (field) { 639 trace_probe_log_err(ctx->offset + field - varname, 640 NO_BTF_ENTRY); 641 return -ENOENT; 642 } 643 return 0; 644 } 645 646 if (!ctx->btf) { 647 ret = query_btf_context(ctx); 648 if (ret < 0 || ctx->nr_params == 0) { 649 trace_probe_log_err(ctx->offset, NO_BTF_ENTRY); 650 return PTR_ERR(params); 651 } 652 } 653 params = ctx->params; 654 655 for (i = 0; i < ctx->nr_params; i++) { 656 const char *name = btf_name_by_offset(ctx->btf, params[i].name_off); 657 658 if (name && !strcmp(name, varname)) { 659 if (tparg_is_function_entry(ctx->flags)) { 660 code->op = FETCH_OP_ARG; 661 if (ctx->flags & TPARG_FL_TPOINT) 662 code->param = i + 1; 663 else 664 code->param = i; 665 } else if (tparg_is_function_return(ctx->flags)) { 666 code->op = FETCH_OP_EDATA; 667 ret = __store_entry_arg(ctx->tp, i); 668 if (ret < 0) { 669 /* internal error */ 670 return ret; 671 } 672 code->offset = ret; 673 } 674 tid = params[i].type; 675 goto found; 676 } 677 } 678 trace_probe_log_err(ctx->offset, NO_BTFARG); 679 return -ENOENT; 680 681 found: 682 type = btf_type_skip_modifiers(ctx->btf, tid, &tid); 683 if (!type) { 684 trace_probe_log_err(ctx->offset, BAD_BTF_TID); 685 return -EINVAL; 686 } 687 /* Initialize the last type information */ 688 ctx->last_type = type; 689 ctx->last_bitoffs = 0; 690 ctx->last_bitsize = 0; 691 if (field) { 692 ctx->offset += field - varname; 693 return parse_btf_field(field, type, pcode, end, ctx); 694 } 695 return 0; 696 } 697 698 static const struct fetch_type *find_fetch_type_from_btf_type( 699 struct traceprobe_parse_context *ctx) 700 { 701 struct btf *btf = ctx->btf; 702 const char *typestr = NULL; 703 704 if (btf && ctx->last_type) 705 typestr = fetch_type_from_btf_type(btf, ctx->last_type, ctx); 706 707 return find_fetch_type(typestr, ctx->flags); 708 } 709 710 static int parse_btf_bitfield(struct fetch_insn **pcode, 711 struct traceprobe_parse_context *ctx) 712 { 713 struct fetch_insn *code = *pcode; 714 715 if ((ctx->last_bitsize % 8 == 0) && ctx->last_bitoffs == 0) 716 return 0; 717 718 code++; 719 if (code->op != FETCH_OP_NOP) { 720 trace_probe_log_err(ctx->offset, TOO_MANY_OPS); 721 return -EINVAL; 722 } 723 *pcode = code; 724 725 code->op = FETCH_OP_MOD_BF; 726 code->lshift = 64 - (ctx->last_bitsize + ctx->last_bitoffs); 727 code->rshift = 64 - ctx->last_bitsize; 728 code->basesize = 64 / 8; 729 return 0; 730 } 731 732 #else 733 static void clear_btf_context(struct traceprobe_parse_context *ctx) 734 { 735 ctx->btf = NULL; 736 } 737 738 static int query_btf_context(struct traceprobe_parse_context *ctx) 739 { 740 return -EOPNOTSUPP; 741 } 742 743 static int parse_btf_arg(char *varname, 744 struct fetch_insn **pcode, struct fetch_insn *end, 745 struct traceprobe_parse_context *ctx) 746 { 747 trace_probe_log_err(ctx->offset, NOSUP_BTFARG); 748 return -EOPNOTSUPP; 749 } 750 751 static int parse_btf_bitfield(struct fetch_insn **pcode, 752 struct traceprobe_parse_context *ctx) 753 { 754 trace_probe_log_err(ctx->offset, NOSUP_BTFARG); 755 return -EOPNOTSUPP; 756 } 757 758 #define find_fetch_type_from_btf_type(ctx) \ 759 find_fetch_type(NULL, ctx->flags) 760 761 static int check_prepare_btf_string_fetch(char *typename, 762 struct fetch_insn **pcode, 763 struct traceprobe_parse_context *ctx) 764 { 765 return 0; 766 } 767 768 #endif 769 770 #ifdef CONFIG_HAVE_FUNCTION_ARG_ACCESS_API 771 772 static int __store_entry_arg(struct trace_probe *tp, int argnum) 773 { 774 struct probe_entry_arg *earg = tp->entry_arg; 775 bool match = false; 776 int i, offset; 777 778 if (!earg) { 779 earg = kzalloc(sizeof(*tp->entry_arg), GFP_KERNEL); 780 if (!earg) 781 return -ENOMEM; 782 earg->size = 2 * tp->nr_args + 1; 783 earg->code = kcalloc(earg->size, sizeof(struct fetch_insn), 784 GFP_KERNEL); 785 if (!earg->code) { 786 kfree(earg); 787 return -ENOMEM; 788 } 789 /* Fill the code buffer with 'end' to simplify it */ 790 for (i = 0; i < earg->size; i++) 791 earg->code[i].op = FETCH_OP_END; 792 tp->entry_arg = earg; 793 } 794 795 offset = 0; 796 for (i = 0; i < earg->size - 1; i++) { 797 switch (earg->code[i].op) { 798 case FETCH_OP_END: 799 earg->code[i].op = FETCH_OP_ARG; 800 earg->code[i].param = argnum; 801 earg->code[i + 1].op = FETCH_OP_ST_EDATA; 802 earg->code[i + 1].offset = offset; 803 return offset; 804 case FETCH_OP_ARG: 805 match = (earg->code[i].param == argnum); 806 break; 807 case FETCH_OP_ST_EDATA: 808 offset = earg->code[i].offset; 809 if (match) 810 return offset; 811 offset += sizeof(unsigned long); 812 break; 813 default: 814 break; 815 } 816 } 817 return -ENOSPC; 818 } 819 820 int traceprobe_get_entry_data_size(struct trace_probe *tp) 821 { 822 struct probe_entry_arg *earg = tp->entry_arg; 823 int i, size = 0; 824 825 if (!earg) 826 return 0; 827 828 for (i = 0; i < earg->size; i++) { 829 switch (earg->code[i].op) { 830 case FETCH_OP_END: 831 goto out; 832 case FETCH_OP_ST_EDATA: 833 size = earg->code[i].offset + sizeof(unsigned long); 834 break; 835 default: 836 break; 837 } 838 } 839 out: 840 return size; 841 } 842 843 void store_trace_entry_data(void *edata, struct trace_probe *tp, struct pt_regs *regs) 844 { 845 struct probe_entry_arg *earg = tp->entry_arg; 846 unsigned long val; 847 int i; 848 849 if (!earg) 850 return; 851 852 for (i = 0; i < earg->size; i++) { 853 struct fetch_insn *code = &earg->code[i]; 854 855 switch (code->op) { 856 case FETCH_OP_ARG: 857 val = regs_get_kernel_argument(regs, code->param); 858 break; 859 case FETCH_OP_ST_EDATA: 860 *(unsigned long *)((unsigned long)edata + code->offset) = val; 861 break; 862 case FETCH_OP_END: 863 goto end; 864 default: 865 break; 866 } 867 } 868 end: 869 return; 870 } 871 NOKPROBE_SYMBOL(store_trace_entry_data) 872 #endif 873 874 #define PARAM_MAX_STACK (THREAD_SIZE / sizeof(unsigned long)) 875 876 /* Parse $vars. @orig_arg points '$', which syncs to @ctx->offset */ 877 static int parse_probe_vars(char *orig_arg, const struct fetch_type *t, 878 struct fetch_insn **pcode, 879 struct fetch_insn *end, 880 struct traceprobe_parse_context *ctx) 881 { 882 struct fetch_insn *code = *pcode; 883 int err = TP_ERR_BAD_VAR; 884 char *arg = orig_arg + 1; 885 unsigned long param; 886 int ret = 0; 887 int len; 888 889 if (ctx->flags & TPARG_FL_TEVENT) { 890 if (code->data) 891 return -EFAULT; 892 ret = parse_trace_event_arg(arg, code, ctx); 893 if (!ret) 894 return 0; 895 if (strcmp(arg, "comm") == 0 || strcmp(arg, "COMM") == 0) { 896 code->op = FETCH_OP_COMM; 897 return 0; 898 } 899 /* backward compatibility */ 900 ctx->offset = 0; 901 goto inval; 902 } 903 904 if (str_has_prefix(arg, "retval")) { 905 if (!(ctx->flags & TPARG_FL_RETURN)) { 906 err = TP_ERR_RETVAL_ON_PROBE; 907 goto inval; 908 } 909 if (!(ctx->flags & TPARG_FL_KERNEL) || 910 !IS_ENABLED(CONFIG_PROBE_EVENTS_BTF_ARGS)) { 911 code->op = FETCH_OP_RETVAL; 912 return 0; 913 } 914 return parse_btf_arg(orig_arg, pcode, end, ctx); 915 } 916 917 len = str_has_prefix(arg, "stack"); 918 if (len) { 919 920 if (arg[len] == '\0') { 921 code->op = FETCH_OP_STACKP; 922 return 0; 923 } 924 925 if (isdigit(arg[len])) { 926 ret = kstrtoul(arg + len, 10, ¶m); 927 if (ret) 928 goto inval; 929 930 if ((ctx->flags & TPARG_FL_KERNEL) && 931 param > PARAM_MAX_STACK) { 932 err = TP_ERR_BAD_STACK_NUM; 933 goto inval; 934 } 935 code->op = FETCH_OP_STACK; 936 code->param = (unsigned int)param; 937 return 0; 938 } 939 goto inval; 940 } 941 942 if (strcmp(arg, "comm") == 0 || strcmp(arg, "COMM") == 0) { 943 code->op = FETCH_OP_COMM; 944 return 0; 945 } 946 947 #ifdef CONFIG_HAVE_FUNCTION_ARG_ACCESS_API 948 len = str_has_prefix(arg, "arg"); 949 if (len) { 950 ret = kstrtoul(arg + len, 10, ¶m); 951 if (ret) 952 goto inval; 953 954 if (!param || param > PARAM_MAX_STACK) { 955 err = TP_ERR_BAD_ARG_NUM; 956 goto inval; 957 } 958 param--; /* argN starts from 1, but internal arg[N] starts from 0 */ 959 960 if (tparg_is_function_entry(ctx->flags)) { 961 code->op = FETCH_OP_ARG; 962 code->param = (unsigned int)param; 963 /* 964 * The tracepoint probe will probe a stub function, and the 965 * first parameter of the stub is a dummy and should be ignored. 966 */ 967 if (ctx->flags & TPARG_FL_TPOINT) 968 code->param++; 969 } else if (tparg_is_function_return(ctx->flags)) { 970 /* function entry argument access from return probe */ 971 ret = __store_entry_arg(ctx->tp, param); 972 if (ret < 0) /* This error should be an internal error */ 973 return ret; 974 975 code->op = FETCH_OP_EDATA; 976 code->offset = ret; 977 } else { 978 err = TP_ERR_NOFENTRY_ARGS; 979 goto inval; 980 } 981 return 0; 982 } 983 #endif 984 985 inval: 986 __trace_probe_log_err(ctx->offset, err); 987 return -EINVAL; 988 } 989 990 static int str_to_immediate(char *str, unsigned long *imm) 991 { 992 if (isdigit(str[0])) 993 return kstrtoul(str, 0, imm); 994 else if (str[0] == '-') 995 return kstrtol(str, 0, (long *)imm); 996 else if (str[0] == '+') 997 return kstrtol(str + 1, 0, (long *)imm); 998 return -EINVAL; 999 } 1000 1001 static int __parse_imm_string(char *str, char **pbuf, int offs) 1002 { 1003 size_t len = strlen(str); 1004 1005 if (str[len - 1] != '"') { 1006 trace_probe_log_err(offs + len, IMMSTR_NO_CLOSE); 1007 return -EINVAL; 1008 } 1009 *pbuf = kstrndup(str, len - 1, GFP_KERNEL); 1010 if (!*pbuf) 1011 return -ENOMEM; 1012 return 0; 1013 } 1014 1015 /* Recursive argument parser */ 1016 static int 1017 parse_probe_arg(char *arg, const struct fetch_type *type, 1018 struct fetch_insn **pcode, struct fetch_insn *end, 1019 struct traceprobe_parse_context *ctx) 1020 { 1021 struct fetch_insn *code = *pcode; 1022 unsigned long param; 1023 int deref = FETCH_OP_DEREF; 1024 long offset = 0; 1025 char *tmp; 1026 int ret = 0; 1027 1028 switch (arg[0]) { 1029 case '$': 1030 ret = parse_probe_vars(arg, type, pcode, end, ctx); 1031 break; 1032 1033 case '%': /* named register */ 1034 if (ctx->flags & (TPARG_FL_TEVENT | TPARG_FL_FPROBE)) { 1035 /* eprobe and fprobe do not handle registers */ 1036 trace_probe_log_err(ctx->offset, BAD_VAR); 1037 break; 1038 } 1039 ret = regs_query_register_offset(arg + 1); 1040 if (ret >= 0) { 1041 code->op = FETCH_OP_REG; 1042 code->param = (unsigned int)ret; 1043 ret = 0; 1044 } else 1045 trace_probe_log_err(ctx->offset, BAD_REG_NAME); 1046 break; 1047 1048 case '@': /* memory, file-offset or symbol */ 1049 if (isdigit(arg[1])) { 1050 ret = kstrtoul(arg + 1, 0, ¶m); 1051 if (ret) { 1052 trace_probe_log_err(ctx->offset, BAD_MEM_ADDR); 1053 break; 1054 } 1055 /* load address */ 1056 code->op = FETCH_OP_IMM; 1057 code->immediate = param; 1058 } else if (arg[1] == '+') { 1059 /* kprobes don't support file offsets */ 1060 if (ctx->flags & TPARG_FL_KERNEL) { 1061 trace_probe_log_err(ctx->offset, FILE_ON_KPROBE); 1062 return -EINVAL; 1063 } 1064 ret = kstrtol(arg + 2, 0, &offset); 1065 if (ret) { 1066 trace_probe_log_err(ctx->offset, BAD_FILE_OFFS); 1067 break; 1068 } 1069 1070 code->op = FETCH_OP_FOFFS; 1071 code->immediate = (unsigned long)offset; // imm64? 1072 } else { 1073 /* uprobes don't support symbols */ 1074 if (!(ctx->flags & TPARG_FL_KERNEL)) { 1075 trace_probe_log_err(ctx->offset, SYM_ON_UPROBE); 1076 return -EINVAL; 1077 } 1078 /* Preserve symbol for updating */ 1079 code->op = FETCH_NOP_SYMBOL; 1080 code->data = kstrdup(arg + 1, GFP_KERNEL); 1081 if (!code->data) 1082 return -ENOMEM; 1083 if (++code == end) { 1084 trace_probe_log_err(ctx->offset, TOO_MANY_OPS); 1085 return -EINVAL; 1086 } 1087 code->op = FETCH_OP_IMM; 1088 code->immediate = 0; 1089 } 1090 /* These are fetching from memory */ 1091 if (++code == end) { 1092 trace_probe_log_err(ctx->offset, TOO_MANY_OPS); 1093 return -EINVAL; 1094 } 1095 *pcode = code; 1096 code->op = FETCH_OP_DEREF; 1097 code->offset = offset; 1098 break; 1099 1100 case '+': /* deref memory */ 1101 case '-': 1102 if (arg[1] == 'u') { 1103 deref = FETCH_OP_UDEREF; 1104 arg[1] = arg[0]; 1105 arg++; 1106 } 1107 if (arg[0] == '+') 1108 arg++; /* Skip '+', because kstrtol() rejects it. */ 1109 tmp = strchr(arg, '('); 1110 if (!tmp) { 1111 trace_probe_log_err(ctx->offset, DEREF_NEED_BRACE); 1112 return -EINVAL; 1113 } 1114 *tmp = '\0'; 1115 ret = kstrtol(arg, 0, &offset); 1116 if (ret) { 1117 trace_probe_log_err(ctx->offset, BAD_DEREF_OFFS); 1118 break; 1119 } 1120 ctx->offset += (tmp + 1 - arg) + (arg[0] != '-' ? 1 : 0); 1121 arg = tmp + 1; 1122 tmp = strrchr(arg, ')'); 1123 if (!tmp) { 1124 trace_probe_log_err(ctx->offset + strlen(arg), 1125 DEREF_OPEN_BRACE); 1126 return -EINVAL; 1127 } else { 1128 const struct fetch_type *t2 = find_fetch_type(NULL, ctx->flags); 1129 int cur_offs = ctx->offset; 1130 1131 *tmp = '\0'; 1132 ret = parse_probe_arg(arg, t2, &code, end, ctx); 1133 if (ret) 1134 break; 1135 ctx->offset = cur_offs; 1136 if (code->op == FETCH_OP_COMM || 1137 code->op == FETCH_OP_DATA) { 1138 trace_probe_log_err(ctx->offset, COMM_CANT_DEREF); 1139 return -EINVAL; 1140 } 1141 if (++code == end) { 1142 trace_probe_log_err(ctx->offset, TOO_MANY_OPS); 1143 return -EINVAL; 1144 } 1145 *pcode = code; 1146 1147 code->op = deref; 1148 code->offset = offset; 1149 /* Reset the last type if used */ 1150 ctx->last_type = NULL; 1151 } 1152 break; 1153 case '\\': /* Immediate value */ 1154 if (arg[1] == '"') { /* Immediate string */ 1155 ret = __parse_imm_string(arg + 2, &tmp, ctx->offset + 2); 1156 if (ret) 1157 break; 1158 code->op = FETCH_OP_DATA; 1159 code->data = tmp; 1160 } else { 1161 ret = str_to_immediate(arg + 1, &code->immediate); 1162 if (ret) 1163 trace_probe_log_err(ctx->offset + 1, BAD_IMM); 1164 else 1165 code->op = FETCH_OP_IMM; 1166 } 1167 break; 1168 default: 1169 if (isalpha(arg[0]) || arg[0] == '_') { /* BTF variable */ 1170 if (!tparg_is_function_entry(ctx->flags) && 1171 !tparg_is_function_return(ctx->flags)) { 1172 trace_probe_log_err(ctx->offset, NOSUP_BTFARG); 1173 return -EINVAL; 1174 } 1175 ret = parse_btf_arg(arg, pcode, end, ctx); 1176 break; 1177 } 1178 } 1179 if (!ret && code->op == FETCH_OP_NOP) { 1180 /* Parsed, but do not find fetch method */ 1181 trace_probe_log_err(ctx->offset, BAD_FETCH_ARG); 1182 ret = -EINVAL; 1183 } 1184 return ret; 1185 } 1186 1187 #define BYTES_TO_BITS(nb) ((BITS_PER_LONG * (nb)) / sizeof(long)) 1188 1189 /* Bitfield type needs to be parsed into a fetch function */ 1190 static int __parse_bitfield_probe_arg(const char *bf, 1191 const struct fetch_type *t, 1192 struct fetch_insn **pcode) 1193 { 1194 struct fetch_insn *code = *pcode; 1195 unsigned long bw, bo; 1196 char *tail; 1197 1198 if (*bf != 'b') 1199 return 0; 1200 1201 bw = simple_strtoul(bf + 1, &tail, 0); /* Use simple one */ 1202 1203 if (bw == 0 || *tail != '@') 1204 return -EINVAL; 1205 1206 bf = tail + 1; 1207 bo = simple_strtoul(bf, &tail, 0); 1208 1209 if (tail == bf || *tail != '/') 1210 return -EINVAL; 1211 code++; 1212 if (code->op != FETCH_OP_NOP) 1213 return -EINVAL; 1214 *pcode = code; 1215 1216 code->op = FETCH_OP_MOD_BF; 1217 code->lshift = BYTES_TO_BITS(t->size) - (bw + bo); 1218 code->rshift = BYTES_TO_BITS(t->size) - bw; 1219 code->basesize = t->size; 1220 1221 return (BYTES_TO_BITS(t->size) < (bw + bo)) ? -EINVAL : 0; 1222 } 1223 1224 /* String length checking wrapper */ 1225 static int traceprobe_parse_probe_arg_body(const char *argv, ssize_t *size, 1226 struct probe_arg *parg, 1227 struct traceprobe_parse_context *ctx) 1228 { 1229 struct fetch_insn *code, *scode, *tmp = NULL; 1230 char *t, *t2, *t3; 1231 int ret, len; 1232 char *arg; 1233 1234 arg = kstrdup(argv, GFP_KERNEL); 1235 if (!arg) 1236 return -ENOMEM; 1237 1238 ret = -EINVAL; 1239 len = strlen(arg); 1240 if (len > MAX_ARGSTR_LEN) { 1241 trace_probe_log_err(ctx->offset, ARG_TOO_LONG); 1242 goto out; 1243 } else if (len == 0) { 1244 trace_probe_log_err(ctx->offset, NO_ARG_BODY); 1245 goto out; 1246 } 1247 1248 ret = -ENOMEM; 1249 parg->comm = kstrdup(arg, GFP_KERNEL); 1250 if (!parg->comm) 1251 goto out; 1252 1253 ret = -EINVAL; 1254 t = strchr(arg, ':'); 1255 if (t) { 1256 *t = '\0'; 1257 t2 = strchr(++t, '['); 1258 if (t2) { 1259 *t2++ = '\0'; 1260 t3 = strchr(t2, ']'); 1261 if (!t3) { 1262 int offs = t2 + strlen(t2) - arg; 1263 1264 trace_probe_log_err(ctx->offset + offs, 1265 ARRAY_NO_CLOSE); 1266 goto out; 1267 } else if (t3[1] != '\0') { 1268 trace_probe_log_err(ctx->offset + t3 + 1 - arg, 1269 BAD_ARRAY_SUFFIX); 1270 goto out; 1271 } 1272 *t3 = '\0'; 1273 if (kstrtouint(t2, 0, &parg->count) || !parg->count) { 1274 trace_probe_log_err(ctx->offset + t2 - arg, 1275 BAD_ARRAY_NUM); 1276 goto out; 1277 } 1278 if (parg->count > MAX_ARRAY_LEN) { 1279 trace_probe_log_err(ctx->offset + t2 - arg, 1280 ARRAY_TOO_BIG); 1281 goto out; 1282 } 1283 } 1284 } 1285 1286 /* 1287 * Since $comm and immediate string can not be dereferenced, 1288 * we can find those by strcmp. But ignore for eprobes. 1289 */ 1290 if (!(ctx->flags & TPARG_FL_TEVENT) && 1291 (strcmp(arg, "$comm") == 0 || strcmp(arg, "$COMM") == 0 || 1292 strncmp(arg, "\\\"", 2) == 0)) { 1293 /* The type of $comm must be "string", and not an array type. */ 1294 if (parg->count || (t && strcmp(t, "string"))) { 1295 trace_probe_log_err(ctx->offset + (t ? (t - arg) : 0), 1296 NEED_STRING_TYPE); 1297 goto out; 1298 } 1299 parg->type = find_fetch_type("string", ctx->flags); 1300 } else 1301 parg->type = find_fetch_type(t, ctx->flags); 1302 if (!parg->type) { 1303 trace_probe_log_err(ctx->offset + (t ? (t - arg) : 0), BAD_TYPE); 1304 goto out; 1305 } 1306 1307 code = tmp = kcalloc(FETCH_INSN_MAX, sizeof(*code), GFP_KERNEL); 1308 if (!code) 1309 goto out; 1310 code[FETCH_INSN_MAX - 1].op = FETCH_OP_END; 1311 1312 ctx->last_type = NULL; 1313 ret = parse_probe_arg(arg, parg->type, &code, &code[FETCH_INSN_MAX - 1], 1314 ctx); 1315 if (ret) 1316 goto fail; 1317 1318 /* Update storing type if BTF is available */ 1319 if (IS_ENABLED(CONFIG_PROBE_EVENTS_BTF_ARGS) && 1320 ctx->last_type) { 1321 if (!t) { 1322 parg->type = find_fetch_type_from_btf_type(ctx); 1323 } else if (strstr(t, "string")) { 1324 ret = check_prepare_btf_string_fetch(t, &code, ctx); 1325 if (ret) 1326 goto fail; 1327 } 1328 } 1329 parg->offset = *size; 1330 *size += parg->type->size * (parg->count ?: 1); 1331 1332 if (parg->count) { 1333 len = strlen(parg->type->fmttype) + 6; 1334 parg->fmt = kmalloc(len, GFP_KERNEL); 1335 if (!parg->fmt) { 1336 ret = -ENOMEM; 1337 goto out; 1338 } 1339 snprintf(parg->fmt, len, "%s[%d]", parg->type->fmttype, 1340 parg->count); 1341 } 1342 1343 ret = -EINVAL; 1344 /* Store operation */ 1345 if (parg->type->is_string) { 1346 if (!strcmp(parg->type->name, "symstr")) { 1347 if (code->op != FETCH_OP_REG && code->op != FETCH_OP_STACK && 1348 code->op != FETCH_OP_RETVAL && code->op != FETCH_OP_ARG && 1349 code->op != FETCH_OP_DEREF && code->op != FETCH_OP_TP_ARG) { 1350 trace_probe_log_err(ctx->offset + (t ? (t - arg) : 0), 1351 BAD_SYMSTRING); 1352 goto fail; 1353 } 1354 } else { 1355 if (code->op != FETCH_OP_DEREF && code->op != FETCH_OP_UDEREF && 1356 code->op != FETCH_OP_IMM && code->op != FETCH_OP_COMM && 1357 code->op != FETCH_OP_DATA && code->op != FETCH_OP_TP_ARG) { 1358 trace_probe_log_err(ctx->offset + (t ? (t - arg) : 0), 1359 BAD_STRING); 1360 goto fail; 1361 } 1362 } 1363 if (!strcmp(parg->type->name, "symstr") || 1364 (code->op == FETCH_OP_IMM || code->op == FETCH_OP_COMM || 1365 code->op == FETCH_OP_DATA) || code->op == FETCH_OP_TP_ARG || 1366 parg->count) { 1367 /* 1368 * IMM, DATA and COMM is pointing actual address, those 1369 * must be kept, and if parg->count != 0, this is an 1370 * array of string pointers instead of string address 1371 * itself. 1372 * For the symstr, it doesn't need to dereference, thus 1373 * it just get the value. 1374 */ 1375 code++; 1376 if (code->op != FETCH_OP_NOP) { 1377 trace_probe_log_err(ctx->offset, TOO_MANY_OPS); 1378 goto fail; 1379 } 1380 } 1381 /* If op == DEREF, replace it with STRING */ 1382 if (!strcmp(parg->type->name, "ustring") || 1383 code->op == FETCH_OP_UDEREF) 1384 code->op = FETCH_OP_ST_USTRING; 1385 else if (!strcmp(parg->type->name, "symstr")) 1386 code->op = FETCH_OP_ST_SYMSTR; 1387 else 1388 code->op = FETCH_OP_ST_STRING; 1389 code->size = parg->type->size; 1390 parg->dynamic = true; 1391 } else if (code->op == FETCH_OP_DEREF) { 1392 code->op = FETCH_OP_ST_MEM; 1393 code->size = parg->type->size; 1394 } else if (code->op == FETCH_OP_UDEREF) { 1395 code->op = FETCH_OP_ST_UMEM; 1396 code->size = parg->type->size; 1397 } else { 1398 code++; 1399 if (code->op != FETCH_OP_NOP) { 1400 trace_probe_log_err(ctx->offset, TOO_MANY_OPS); 1401 goto fail; 1402 } 1403 code->op = FETCH_OP_ST_RAW; 1404 code->size = parg->type->size; 1405 } 1406 scode = code; 1407 /* Modify operation */ 1408 if (t != NULL) { 1409 ret = __parse_bitfield_probe_arg(t, parg->type, &code); 1410 if (ret) { 1411 trace_probe_log_err(ctx->offset + t - arg, BAD_BITFIELD); 1412 goto fail; 1413 } 1414 } else if (IS_ENABLED(CONFIG_PROBE_EVENTS_BTF_ARGS) && 1415 ctx->last_type) { 1416 ret = parse_btf_bitfield(&code, ctx); 1417 if (ret) 1418 goto fail; 1419 } 1420 ret = -EINVAL; 1421 /* Loop(Array) operation */ 1422 if (parg->count) { 1423 if (scode->op != FETCH_OP_ST_MEM && 1424 scode->op != FETCH_OP_ST_STRING && 1425 scode->op != FETCH_OP_ST_USTRING) { 1426 trace_probe_log_err(ctx->offset + (t ? (t - arg) : 0), 1427 BAD_STRING); 1428 goto fail; 1429 } 1430 code++; 1431 if (code->op != FETCH_OP_NOP) { 1432 trace_probe_log_err(ctx->offset, TOO_MANY_OPS); 1433 goto fail; 1434 } 1435 code->op = FETCH_OP_LP_ARRAY; 1436 code->param = parg->count; 1437 } 1438 code++; 1439 code->op = FETCH_OP_END; 1440 1441 ret = 0; 1442 /* Shrink down the code buffer */ 1443 parg->code = kcalloc(code - tmp + 1, sizeof(*code), GFP_KERNEL); 1444 if (!parg->code) 1445 ret = -ENOMEM; 1446 else 1447 memcpy(parg->code, tmp, sizeof(*code) * (code - tmp + 1)); 1448 1449 fail: 1450 if (ret) { 1451 for (code = tmp; code < tmp + FETCH_INSN_MAX; code++) 1452 if (code->op == FETCH_NOP_SYMBOL || 1453 code->op == FETCH_OP_DATA) 1454 kfree(code->data); 1455 } 1456 kfree(tmp); 1457 out: 1458 kfree(arg); 1459 1460 return ret; 1461 } 1462 1463 /* Return 1 if name is reserved or already used by another argument */ 1464 static int traceprobe_conflict_field_name(const char *name, 1465 struct probe_arg *args, int narg) 1466 { 1467 int i; 1468 1469 for (i = 0; i < ARRAY_SIZE(reserved_field_names); i++) 1470 if (strcmp(reserved_field_names[i], name) == 0) 1471 return 1; 1472 1473 for (i = 0; i < narg; i++) 1474 if (strcmp(args[i].name, name) == 0) 1475 return 1; 1476 1477 return 0; 1478 } 1479 1480 static char *generate_probe_arg_name(const char *arg, int idx) 1481 { 1482 char *name = NULL; 1483 const char *end; 1484 1485 /* 1486 * If argument name is omitted, try arg as a name (BTF variable) 1487 * or "argN". 1488 */ 1489 if (IS_ENABLED(CONFIG_PROBE_EVENTS_BTF_ARGS)) { 1490 end = strchr(arg, ':'); 1491 if (!end) 1492 end = arg + strlen(arg); 1493 1494 name = kmemdup_nul(arg, end - arg, GFP_KERNEL); 1495 if (!name || !is_good_name(name)) { 1496 kfree(name); 1497 name = NULL; 1498 } 1499 } 1500 1501 if (!name) 1502 name = kasprintf(GFP_KERNEL, "arg%d", idx + 1); 1503 1504 return name; 1505 } 1506 1507 int traceprobe_parse_probe_arg(struct trace_probe *tp, int i, const char *arg, 1508 struct traceprobe_parse_context *ctx) 1509 { 1510 struct probe_arg *parg = &tp->args[i]; 1511 const char *body; 1512 1513 ctx->tp = tp; 1514 body = strchr(arg, '='); 1515 if (body) { 1516 if (body - arg > MAX_ARG_NAME_LEN) { 1517 trace_probe_log_err(0, ARG_NAME_TOO_LONG); 1518 return -EINVAL; 1519 } else if (body == arg) { 1520 trace_probe_log_err(0, NO_ARG_NAME); 1521 return -EINVAL; 1522 } 1523 parg->name = kmemdup_nul(arg, body - arg, GFP_KERNEL); 1524 body++; 1525 } else { 1526 parg->name = generate_probe_arg_name(arg, i); 1527 body = arg; 1528 } 1529 if (!parg->name) 1530 return -ENOMEM; 1531 1532 if (!is_good_name(parg->name)) { 1533 trace_probe_log_err(0, BAD_ARG_NAME); 1534 return -EINVAL; 1535 } 1536 if (traceprobe_conflict_field_name(parg->name, tp->args, i)) { 1537 trace_probe_log_err(0, USED_ARG_NAME); 1538 return -EINVAL; 1539 } 1540 ctx->offset = body - arg; 1541 /* Parse fetch argument */ 1542 return traceprobe_parse_probe_arg_body(body, &tp->size, parg, ctx); 1543 } 1544 1545 void traceprobe_free_probe_arg(struct probe_arg *arg) 1546 { 1547 struct fetch_insn *code = arg->code; 1548 1549 while (code && code->op != FETCH_OP_END) { 1550 if (code->op == FETCH_NOP_SYMBOL || 1551 code->op == FETCH_OP_DATA) 1552 kfree(code->data); 1553 code++; 1554 } 1555 kfree(arg->code); 1556 kfree(arg->name); 1557 kfree(arg->comm); 1558 kfree(arg->fmt); 1559 } 1560 1561 static int argv_has_var_arg(int argc, const char *argv[], int *args_idx, 1562 struct traceprobe_parse_context *ctx) 1563 { 1564 int i, found = 0; 1565 1566 for (i = 0; i < argc; i++) 1567 if (str_has_prefix(argv[i], "$arg")) { 1568 trace_probe_log_set_index(i + 2); 1569 1570 if (!tparg_is_function_entry(ctx->flags) && 1571 !tparg_is_function_return(ctx->flags)) { 1572 trace_probe_log_err(0, NOFENTRY_ARGS); 1573 return -EINVAL; 1574 } 1575 1576 if (isdigit(argv[i][4])) { 1577 found = 1; 1578 continue; 1579 } 1580 1581 if (argv[i][4] != '*') { 1582 trace_probe_log_err(0, BAD_VAR); 1583 return -EINVAL; 1584 } 1585 1586 if (*args_idx >= 0 && *args_idx < argc) { 1587 trace_probe_log_err(0, DOUBLE_ARGS); 1588 return -EINVAL; 1589 } 1590 found = 1; 1591 *args_idx = i; 1592 } 1593 1594 return found; 1595 } 1596 1597 static int sprint_nth_btf_arg(int idx, const char *type, 1598 char *buf, int bufsize, 1599 struct traceprobe_parse_context *ctx) 1600 { 1601 const char *name; 1602 int ret; 1603 1604 if (idx >= ctx->nr_params) { 1605 trace_probe_log_err(0, NO_BTFARG); 1606 return -ENOENT; 1607 } 1608 name = btf_name_by_offset(ctx->btf, ctx->params[idx].name_off); 1609 if (!name) { 1610 trace_probe_log_err(0, NO_BTF_ENTRY); 1611 return -ENOENT; 1612 } 1613 ret = snprintf(buf, bufsize, "%s%s", name, type); 1614 if (ret >= bufsize) { 1615 trace_probe_log_err(0, ARGS_2LONG); 1616 return -E2BIG; 1617 } 1618 return ret; 1619 } 1620 1621 /* Return new_argv which must be freed after use */ 1622 const char **traceprobe_expand_meta_args(int argc, const char *argv[], 1623 int *new_argc, char *buf, int bufsize, 1624 struct traceprobe_parse_context *ctx) 1625 { 1626 const struct btf_param *params = NULL; 1627 int i, j, n, used, ret, args_idx = -1; 1628 const char **new_argv = NULL; 1629 1630 ret = argv_has_var_arg(argc, argv, &args_idx, ctx); 1631 if (ret < 0) 1632 return ERR_PTR(ret); 1633 1634 if (!ret) { 1635 *new_argc = argc; 1636 return NULL; 1637 } 1638 1639 ret = query_btf_context(ctx); 1640 if (ret < 0 || ctx->nr_params == 0) { 1641 if (args_idx != -1) { 1642 /* $arg* requires BTF info */ 1643 trace_probe_log_err(0, NOSUP_BTFARG); 1644 return (const char **)params; 1645 } 1646 *new_argc = argc; 1647 return NULL; 1648 } 1649 1650 if (args_idx >= 0) 1651 *new_argc = argc + ctx->nr_params - 1; 1652 else 1653 *new_argc = argc; 1654 1655 new_argv = kcalloc(*new_argc, sizeof(char *), GFP_KERNEL); 1656 if (!new_argv) 1657 return ERR_PTR(-ENOMEM); 1658 1659 used = 0; 1660 for (i = 0, j = 0; i < argc; i++) { 1661 trace_probe_log_set_index(i + 2); 1662 if (i == args_idx) { 1663 for (n = 0; n < ctx->nr_params; n++) { 1664 ret = sprint_nth_btf_arg(n, "", buf + used, 1665 bufsize - used, ctx); 1666 if (ret < 0) 1667 goto error; 1668 1669 new_argv[j++] = buf + used; 1670 used += ret + 1; 1671 } 1672 continue; 1673 } 1674 1675 if (str_has_prefix(argv[i], "$arg")) { 1676 char *type = NULL; 1677 1678 n = simple_strtoul(argv[i] + 4, &type, 10); 1679 if (type && !(*type == ':' || *type == '\0')) { 1680 trace_probe_log_err(0, BAD_VAR); 1681 ret = -ENOENT; 1682 goto error; 1683 } 1684 /* Note: $argN starts from $arg1 */ 1685 ret = sprint_nth_btf_arg(n - 1, type, buf + used, 1686 bufsize - used, ctx); 1687 if (ret < 0) 1688 goto error; 1689 new_argv[j++] = buf + used; 1690 used += ret + 1; 1691 } else 1692 new_argv[j++] = argv[i]; 1693 } 1694 1695 return new_argv; 1696 1697 error: 1698 kfree(new_argv); 1699 return ERR_PTR(ret); 1700 } 1701 1702 void traceprobe_finish_parse(struct traceprobe_parse_context *ctx) 1703 { 1704 clear_btf_context(ctx); 1705 } 1706 1707 int traceprobe_update_arg(struct probe_arg *arg) 1708 { 1709 struct fetch_insn *code = arg->code; 1710 long offset; 1711 char *tmp; 1712 char c; 1713 int ret = 0; 1714 1715 while (code && code->op != FETCH_OP_END) { 1716 if (code->op == FETCH_NOP_SYMBOL) { 1717 if (code[1].op != FETCH_OP_IMM) 1718 return -EINVAL; 1719 1720 tmp = strpbrk(code->data, "+-"); 1721 if (tmp) 1722 c = *tmp; 1723 ret = traceprobe_split_symbol_offset(code->data, 1724 &offset); 1725 if (ret) 1726 return ret; 1727 1728 code[1].immediate = 1729 (unsigned long)kallsyms_lookup_name(code->data); 1730 if (tmp) 1731 *tmp = c; 1732 if (!code[1].immediate) 1733 return -ENOENT; 1734 code[1].immediate += offset; 1735 } 1736 code++; 1737 } 1738 return 0; 1739 } 1740 1741 /* When len=0, we just calculate the needed length */ 1742 #define LEN_OR_ZERO (len ? len - pos : 0) 1743 static int __set_print_fmt(struct trace_probe *tp, char *buf, int len, 1744 enum probe_print_type ptype) 1745 { 1746 struct probe_arg *parg; 1747 int i, j; 1748 int pos = 0; 1749 const char *fmt, *arg; 1750 1751 switch (ptype) { 1752 case PROBE_PRINT_NORMAL: 1753 fmt = "(%lx)"; 1754 arg = ", REC->" FIELD_STRING_IP; 1755 break; 1756 case PROBE_PRINT_RETURN: 1757 fmt = "(%lx <- %lx)"; 1758 arg = ", REC->" FIELD_STRING_FUNC ", REC->" FIELD_STRING_RETIP; 1759 break; 1760 case PROBE_PRINT_EVENT: 1761 fmt = ""; 1762 arg = ""; 1763 break; 1764 default: 1765 WARN_ON_ONCE(1); 1766 return 0; 1767 } 1768 1769 pos += snprintf(buf + pos, LEN_OR_ZERO, "\"%s", fmt); 1770 1771 for (i = 0; i < tp->nr_args; i++) { 1772 parg = tp->args + i; 1773 pos += snprintf(buf + pos, LEN_OR_ZERO, " %s=", parg->name); 1774 if (parg->count) { 1775 pos += snprintf(buf + pos, LEN_OR_ZERO, "{%s", 1776 parg->type->fmt); 1777 for (j = 1; j < parg->count; j++) 1778 pos += snprintf(buf + pos, LEN_OR_ZERO, ",%s", 1779 parg->type->fmt); 1780 pos += snprintf(buf + pos, LEN_OR_ZERO, "}"); 1781 } else 1782 pos += snprintf(buf + pos, LEN_OR_ZERO, "%s", 1783 parg->type->fmt); 1784 } 1785 1786 pos += snprintf(buf + pos, LEN_OR_ZERO, "\"%s", arg); 1787 1788 for (i = 0; i < tp->nr_args; i++) { 1789 parg = tp->args + i; 1790 if (parg->count) { 1791 if (parg->type->is_string) 1792 fmt = ", __get_str(%s[%d])"; 1793 else 1794 fmt = ", REC->%s[%d]"; 1795 for (j = 0; j < parg->count; j++) 1796 pos += snprintf(buf + pos, LEN_OR_ZERO, 1797 fmt, parg->name, j); 1798 } else { 1799 if (parg->type->is_string) 1800 fmt = ", __get_str(%s)"; 1801 else 1802 fmt = ", REC->%s"; 1803 pos += snprintf(buf + pos, LEN_OR_ZERO, 1804 fmt, parg->name); 1805 } 1806 } 1807 1808 /* return the length of print_fmt */ 1809 return pos; 1810 } 1811 #undef LEN_OR_ZERO 1812 1813 int traceprobe_set_print_fmt(struct trace_probe *tp, enum probe_print_type ptype) 1814 { 1815 struct trace_event_call *call = trace_probe_event_call(tp); 1816 int len; 1817 char *print_fmt; 1818 1819 /* First: called with 0 length to calculate the needed length */ 1820 len = __set_print_fmt(tp, NULL, 0, ptype); 1821 print_fmt = kmalloc(len + 1, GFP_KERNEL); 1822 if (!print_fmt) 1823 return -ENOMEM; 1824 1825 /* Second: actually write the @print_fmt */ 1826 __set_print_fmt(tp, print_fmt, len + 1, ptype); 1827 call->print_fmt = print_fmt; 1828 1829 return 0; 1830 } 1831 1832 int traceprobe_define_arg_fields(struct trace_event_call *event_call, 1833 size_t offset, struct trace_probe *tp) 1834 { 1835 int ret, i; 1836 1837 /* Set argument names as fields */ 1838 for (i = 0; i < tp->nr_args; i++) { 1839 struct probe_arg *parg = &tp->args[i]; 1840 const char *fmt = parg->type->fmttype; 1841 int size = parg->type->size; 1842 1843 if (parg->fmt) 1844 fmt = parg->fmt; 1845 if (parg->count) 1846 size *= parg->count; 1847 ret = trace_define_field(event_call, fmt, parg->name, 1848 offset + parg->offset, size, 1849 parg->type->is_signed, 1850 FILTER_OTHER); 1851 if (ret) 1852 return ret; 1853 } 1854 return 0; 1855 } 1856 1857 static void trace_probe_event_free(struct trace_probe_event *tpe) 1858 { 1859 kfree(tpe->class.system); 1860 kfree(tpe->call.name); 1861 kfree(tpe->call.print_fmt); 1862 kfree(tpe); 1863 } 1864 1865 int trace_probe_append(struct trace_probe *tp, struct trace_probe *to) 1866 { 1867 if (trace_probe_has_sibling(tp)) 1868 return -EBUSY; 1869 1870 list_del_init(&tp->list); 1871 trace_probe_event_free(tp->event); 1872 1873 tp->event = to->event; 1874 list_add_tail(&tp->list, trace_probe_probe_list(to)); 1875 1876 return 0; 1877 } 1878 1879 void trace_probe_unlink(struct trace_probe *tp) 1880 { 1881 list_del_init(&tp->list); 1882 if (list_empty(trace_probe_probe_list(tp))) 1883 trace_probe_event_free(tp->event); 1884 tp->event = NULL; 1885 } 1886 1887 void trace_probe_cleanup(struct trace_probe *tp) 1888 { 1889 int i; 1890 1891 for (i = 0; i < tp->nr_args; i++) 1892 traceprobe_free_probe_arg(&tp->args[i]); 1893 1894 if (tp->entry_arg) { 1895 kfree(tp->entry_arg->code); 1896 kfree(tp->entry_arg); 1897 tp->entry_arg = NULL; 1898 } 1899 1900 if (tp->event) 1901 trace_probe_unlink(tp); 1902 } 1903 1904 int trace_probe_init(struct trace_probe *tp, const char *event, 1905 const char *group, bool alloc_filter, int nargs) 1906 { 1907 struct trace_event_call *call; 1908 size_t size = sizeof(struct trace_probe_event); 1909 int ret = 0; 1910 1911 if (!event || !group) 1912 return -EINVAL; 1913 1914 if (alloc_filter) 1915 size += sizeof(struct trace_uprobe_filter); 1916 1917 tp->event = kzalloc(size, GFP_KERNEL); 1918 if (!tp->event) 1919 return -ENOMEM; 1920 1921 INIT_LIST_HEAD(&tp->event->files); 1922 INIT_LIST_HEAD(&tp->event->class.fields); 1923 INIT_LIST_HEAD(&tp->event->probes); 1924 INIT_LIST_HEAD(&tp->list); 1925 list_add(&tp->list, &tp->event->probes); 1926 1927 call = trace_probe_event_call(tp); 1928 call->class = &tp->event->class; 1929 call->name = kstrdup(event, GFP_KERNEL); 1930 if (!call->name) { 1931 ret = -ENOMEM; 1932 goto error; 1933 } 1934 1935 tp->event->class.system = kstrdup(group, GFP_KERNEL); 1936 if (!tp->event->class.system) { 1937 ret = -ENOMEM; 1938 goto error; 1939 } 1940 1941 tp->nr_args = nargs; 1942 /* Make sure pointers in args[] are NULL */ 1943 if (nargs) 1944 memset(tp->args, 0, sizeof(tp->args[0]) * nargs); 1945 1946 return 0; 1947 1948 error: 1949 trace_probe_cleanup(tp); 1950 return ret; 1951 } 1952 1953 static struct trace_event_call * 1954 find_trace_event_call(const char *system, const char *event_name) 1955 { 1956 struct trace_event_call *tp_event; 1957 const char *name; 1958 1959 list_for_each_entry(tp_event, &ftrace_events, list) { 1960 if (!tp_event->class->system || 1961 strcmp(system, tp_event->class->system)) 1962 continue; 1963 name = trace_event_name(tp_event); 1964 if (!name || strcmp(event_name, name)) 1965 continue; 1966 return tp_event; 1967 } 1968 1969 return NULL; 1970 } 1971 1972 int trace_probe_register_event_call(struct trace_probe *tp) 1973 { 1974 struct trace_event_call *call = trace_probe_event_call(tp); 1975 int ret; 1976 1977 lockdep_assert_held(&event_mutex); 1978 1979 if (find_trace_event_call(trace_probe_group_name(tp), 1980 trace_probe_name(tp))) 1981 return -EEXIST; 1982 1983 ret = register_trace_event(&call->event); 1984 if (!ret) 1985 return -ENODEV; 1986 1987 ret = trace_add_event_call(call); 1988 if (ret) 1989 unregister_trace_event(&call->event); 1990 1991 return ret; 1992 } 1993 1994 int trace_probe_add_file(struct trace_probe *tp, struct trace_event_file *file) 1995 { 1996 struct event_file_link *link; 1997 1998 link = kmalloc(sizeof(*link), GFP_KERNEL); 1999 if (!link) 2000 return -ENOMEM; 2001 2002 link->file = file; 2003 INIT_LIST_HEAD(&link->list); 2004 list_add_tail_rcu(&link->list, &tp->event->files); 2005 trace_probe_set_flag(tp, TP_FLAG_TRACE); 2006 return 0; 2007 } 2008 2009 struct event_file_link *trace_probe_get_file_link(struct trace_probe *tp, 2010 struct trace_event_file *file) 2011 { 2012 struct event_file_link *link; 2013 2014 trace_probe_for_each_link(link, tp) { 2015 if (link->file == file) 2016 return link; 2017 } 2018 2019 return NULL; 2020 } 2021 2022 int trace_probe_remove_file(struct trace_probe *tp, 2023 struct trace_event_file *file) 2024 { 2025 struct event_file_link *link; 2026 2027 link = trace_probe_get_file_link(tp, file); 2028 if (!link) 2029 return -ENOENT; 2030 2031 list_del_rcu(&link->list); 2032 kvfree_rcu_mightsleep(link); 2033 2034 if (list_empty(&tp->event->files)) 2035 trace_probe_clear_flag(tp, TP_FLAG_TRACE); 2036 2037 return 0; 2038 } 2039 2040 /* 2041 * Return the smallest index of different type argument (start from 1). 2042 * If all argument types and name are same, return 0. 2043 */ 2044 int trace_probe_compare_arg_type(struct trace_probe *a, struct trace_probe *b) 2045 { 2046 int i; 2047 2048 /* In case of more arguments */ 2049 if (a->nr_args < b->nr_args) 2050 return a->nr_args + 1; 2051 if (a->nr_args > b->nr_args) 2052 return b->nr_args + 1; 2053 2054 for (i = 0; i < a->nr_args; i++) { 2055 if ((b->nr_args <= i) || 2056 ((a->args[i].type != b->args[i].type) || 2057 (a->args[i].count != b->args[i].count) || 2058 strcmp(a->args[i].name, b->args[i].name))) 2059 return i + 1; 2060 } 2061 2062 return 0; 2063 } 2064 2065 bool trace_probe_match_command_args(struct trace_probe *tp, 2066 int argc, const char **argv) 2067 { 2068 char buf[MAX_ARGSTR_LEN + 1]; 2069 int i; 2070 2071 if (tp->nr_args < argc) 2072 return false; 2073 2074 for (i = 0; i < argc; i++) { 2075 snprintf(buf, sizeof(buf), "%s=%s", 2076 tp->args[i].name, tp->args[i].comm); 2077 if (strcmp(buf, argv[i])) 2078 return false; 2079 } 2080 return true; 2081 } 2082 2083 int trace_probe_create(const char *raw_command, int (*createfn)(int, const char **)) 2084 { 2085 int argc = 0, ret = 0; 2086 char **argv; 2087 2088 argv = argv_split(GFP_KERNEL, raw_command, &argc); 2089 if (!argv) 2090 return -ENOMEM; 2091 2092 if (argc) 2093 ret = createfn(argc, (const char **)argv); 2094 2095 argv_free(argv); 2096 2097 return ret; 2098 } 2099 2100 int trace_probe_print_args(struct trace_seq *s, struct probe_arg *args, int nr_args, 2101 u8 *data, void *field) 2102 { 2103 void *p; 2104 int i, j; 2105 2106 for (i = 0; i < nr_args; i++) { 2107 struct probe_arg *a = args + i; 2108 2109 trace_seq_printf(s, " %s=", a->name); 2110 if (likely(!a->count)) { 2111 if (!a->type->print(s, data + a->offset, field)) 2112 return -ENOMEM; 2113 continue; 2114 } 2115 trace_seq_putc(s, '{'); 2116 p = data + a->offset; 2117 for (j = 0; j < a->count; j++) { 2118 if (!a->type->print(s, p, field)) 2119 return -ENOMEM; 2120 trace_seq_putc(s, j == a->count - 1 ? '}' : ','); 2121 p += a->type->size; 2122 } 2123 } 2124 return 0; 2125 } 2126