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 17 #include "trace_btf.h" 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 extern struct mutex dyn_event_ops_mutex; 158 159 const char *trace_probe_log_init(const char *subsystem, int argc, const char **argv) 160 { 161 lockdep_assert_held(&dyn_event_ops_mutex); 162 163 trace_probe_log.subsystem = subsystem; 164 trace_probe_log.argc = argc; 165 trace_probe_log.argv = argv; 166 trace_probe_log.index = 0; 167 return subsystem; 168 } 169 170 void trace_probe_log_clear(void) 171 { 172 lockdep_assert_held(&dyn_event_ops_mutex); 173 174 memset(&trace_probe_log, 0, sizeof(trace_probe_log)); 175 } 176 177 void trace_probe_log_set_index(int index) 178 { 179 lockdep_assert_held(&dyn_event_ops_mutex); 180 181 trace_probe_log.index = index; 182 } 183 184 void __trace_probe_log_err(int offset, int err_type) 185 { 186 char *command, *p; 187 int i, len = 0, pos = 0; 188 189 lockdep_assert_held(&dyn_event_ops_mutex); 190 191 if (!trace_probe_log.argv) 192 return; 193 194 /* Recalculate the length and allocate buffer */ 195 for (i = 0; i < trace_probe_log.argc; i++) { 196 if (i == trace_probe_log.index) 197 pos = len; 198 len += strlen(trace_probe_log.argv[i]) + 1; 199 } 200 command = kzalloc(len, GFP_KERNEL); 201 if (!command) 202 return; 203 204 if (trace_probe_log.index >= trace_probe_log.argc) { 205 /** 206 * Set the error position is next to the last arg + space. 207 * Note that len includes the terminal null and the cursor 208 * appears at pos + 1. 209 */ 210 pos = len; 211 offset = 0; 212 } 213 214 /* And make a command string from argv array */ 215 p = command; 216 for (i = 0; i < trace_probe_log.argc; i++) { 217 len = strlen(trace_probe_log.argv[i]); 218 memcpy(p, trace_probe_log.argv[i], len); 219 p[len] = ' '; 220 p += len + 1; 221 } 222 *(p - 1) = '\0'; 223 224 tracing_log_err(NULL, trace_probe_log.subsystem, command, 225 trace_probe_err_text, err_type, pos + offset); 226 227 kfree(command); 228 } 229 230 /* Split symbol and offset. */ 231 int traceprobe_split_symbol_offset(char *symbol, long *offset) 232 { 233 char *tmp; 234 int ret; 235 236 if (!offset) 237 return -EINVAL; 238 239 tmp = strpbrk(symbol, "+-"); 240 if (tmp) { 241 ret = kstrtol(tmp, 0, offset); 242 if (ret) 243 return ret; 244 *tmp = '\0'; 245 } else 246 *offset = 0; 247 248 return 0; 249 } 250 251 /** 252 * traceprobe_parse_event_name() - Parse a string into group and event names 253 * @pevent: A pointer to the string to be parsed. 254 * @pgroup: A pointer to the group name. 255 * @buf: A buffer to store the parsed group name. 256 * @offset: The offset of the string in the original user command, for logging. 257 * 258 * This parses a string with the format `[GROUP/][EVENT]` or `[GROUP.][EVENT]` 259 * (either GROUP or EVENT or both must be specified). 260 * Since the parsed group name is stored in @buf, the caller must ensure @buf 261 * is at least MAX_EVENT_NAME_LEN bytes. 262 * 263 * Return: 0 on success, or -EINVAL on failure. 264 * 265 * If success, *@pevent is updated to point to the event name part of the 266 * original string, or NULL if there is no event name. 267 * Also, *@pgroup is updated to point to the parsed group which is stored 268 * in @buf, or NULL if there is no group name. 269 */ 270 int traceprobe_parse_event_name(const char **pevent, const char **pgroup, 271 char *buf, int offset) 272 { 273 const char *slash, *event = *pevent; 274 int len; 275 276 slash = strchr(event, '/'); 277 if (!slash) 278 slash = strchr(event, '.'); 279 280 if (slash) { 281 if (slash == event) { 282 trace_probe_log_err(offset, NO_GROUP_NAME); 283 return -EINVAL; 284 } 285 if (slash - event + 1 > MAX_EVENT_NAME_LEN) { 286 trace_probe_log_err(offset, GROUP_TOO_LONG); 287 return -EINVAL; 288 } 289 strscpy(buf, event, slash - event + 1); 290 if (!is_good_system_name(buf)) { 291 trace_probe_log_err(offset, BAD_GROUP_NAME); 292 return -EINVAL; 293 } 294 *pgroup = buf; 295 *pevent = slash + 1; 296 offset += slash - event + 1; 297 event = *pevent; 298 } 299 len = strlen(event); 300 if (len == 0) { 301 if (slash) { 302 *pevent = NULL; 303 return 0; 304 } 305 trace_probe_log_err(offset, NO_EVENT_NAME); 306 return -EINVAL; 307 } else if (len >= MAX_EVENT_NAME_LEN) { 308 trace_probe_log_err(offset, EVENT_TOO_LONG); 309 return -EINVAL; 310 } 311 if (!is_good_name(event)) { 312 trace_probe_log_err(offset, BAD_EVENT_NAME); 313 return -EINVAL; 314 } 315 return 0; 316 } 317 318 static int parse_trace_event_arg(char *arg, struct fetch_insn *code, 319 struct traceprobe_parse_context *ctx) 320 { 321 struct ftrace_event_field *field; 322 struct list_head *head; 323 324 head = trace_get_fields(ctx->event); 325 list_for_each_entry(field, head, link) { 326 if (!strcmp(arg, field->name)) { 327 code->op = FETCH_OP_TP_ARG; 328 code->data = field; 329 return 0; 330 } 331 } 332 return -ENOENT; 333 } 334 335 static int parse_trace_event(char *arg, struct fetch_insn *code, 336 struct traceprobe_parse_context *ctx) 337 { 338 int ret; 339 340 if (code->data) 341 return -EFAULT; 342 ret = parse_trace_event_arg(arg, code, ctx); 343 if (!ret) 344 return 0; 345 if (strcmp(arg, "comm") == 0 || strcmp(arg, "COMM") == 0) { 346 code->op = FETCH_OP_COMM; 347 return 0; 348 } 349 return -EINVAL; 350 } 351 352 #ifdef CONFIG_PROBE_EVENTS_BTF_ARGS 353 354 static u32 btf_type_int(const struct btf_type *t) 355 { 356 return *(u32 *)(t + 1); 357 } 358 359 static bool btf_type_is_char_ptr(struct btf *btf, const struct btf_type *type) 360 { 361 const struct btf_type *real_type; 362 u32 intdata; 363 s32 tid; 364 365 real_type = btf_type_skip_modifiers(btf, type->type, &tid); 366 if (!real_type) 367 return false; 368 369 if (BTF_INFO_KIND(real_type->info) != BTF_KIND_INT) 370 return false; 371 372 intdata = btf_type_int(real_type); 373 return !(BTF_INT_ENCODING(intdata) & BTF_INT_SIGNED) 374 && BTF_INT_BITS(intdata) == 8; 375 } 376 377 static bool btf_type_is_char_array(struct btf *btf, const struct btf_type *type) 378 { 379 const struct btf_type *real_type; 380 const struct btf_array *array; 381 u32 intdata; 382 s32 tid; 383 384 if (BTF_INFO_KIND(type->info) != BTF_KIND_ARRAY) 385 return false; 386 387 array = (const struct btf_array *)(type + 1); 388 389 real_type = btf_type_skip_modifiers(btf, array->type, &tid); 390 391 intdata = btf_type_int(real_type); 392 return !(BTF_INT_ENCODING(intdata) & BTF_INT_SIGNED) 393 && BTF_INT_BITS(intdata) == 8; 394 } 395 396 static struct btf *ctx_btf(struct traceprobe_parse_context *ctx) 397 { 398 return ctx->struct_btf ? : ctx->btf; 399 } 400 401 static int check_prepare_btf_string_fetch(char *typename, 402 struct fetch_insn **pcode, 403 struct traceprobe_parse_context *ctx) 404 { 405 struct btf *btf = ctx_btf(ctx); 406 407 if (!btf || !ctx->last_type) 408 return 0; 409 410 /* char [] does not need any change. */ 411 if (btf_type_is_char_array(btf, ctx->last_type)) 412 return 0; 413 414 /* char * requires dereference the pointer. */ 415 if (btf_type_is_char_ptr(btf, ctx->last_type)) { 416 struct fetch_insn *code = *pcode + 1; 417 418 if (code->op == FETCH_OP_END) { 419 trace_probe_log_err(ctx->offset, TOO_MANY_OPS); 420 return -E2BIG; 421 } 422 if (typename[0] == 'u') 423 code->op = FETCH_OP_UDEREF; 424 else 425 code->op = FETCH_OP_DEREF; 426 code->offset = 0; 427 *pcode = code; 428 return 0; 429 } 430 /* Other types are not available for string */ 431 trace_probe_log_err(ctx->offset, BAD_TYPE4STR); 432 return -EINVAL; 433 } 434 435 static const char *fetch_type_from_btf_type(struct btf *btf, 436 const struct btf_type *type, 437 struct traceprobe_parse_context *ctx) 438 { 439 u32 intdata; 440 441 /* TODO: const char * could be converted as a string */ 442 switch (BTF_INFO_KIND(type->info)) { 443 case BTF_KIND_ENUM: 444 /* enum is "int", so convert to "s32" */ 445 return "s32"; 446 case BTF_KIND_ENUM64: 447 return "s64"; 448 case BTF_KIND_PTR: 449 /* pointer will be converted to "x??" */ 450 if (IS_ENABLED(CONFIG_64BIT)) 451 return "x64"; 452 else 453 return "x32"; 454 case BTF_KIND_INT: 455 intdata = btf_type_int(type); 456 if (BTF_INT_ENCODING(intdata) & BTF_INT_SIGNED) { 457 switch (BTF_INT_BITS(intdata)) { 458 case 8: 459 return "s8"; 460 case 16: 461 return "s16"; 462 case 32: 463 return "s32"; 464 case 64: 465 return "s64"; 466 } 467 } else { /* unsigned */ 468 switch (BTF_INT_BITS(intdata)) { 469 case 8: 470 return "u8"; 471 case 16: 472 return "u16"; 473 case 32: 474 return "u32"; 475 case 64: 476 return "u64"; 477 } 478 /* bitfield, size is encoded in the type */ 479 ctx->last_bitsize = BTF_INT_BITS(intdata); 480 ctx->last_bitoffs += BTF_INT_OFFSET(intdata); 481 return "u64"; 482 } 483 } 484 /* TODO: support other types */ 485 486 return NULL; 487 } 488 489 static int query_btf_context(struct traceprobe_parse_context *ctx) 490 { 491 const struct btf_param *param; 492 const struct btf_type *type; 493 struct btf *btf; 494 s32 nr; 495 496 if (ctx->btf) 497 return 0; 498 499 if (!ctx->funcname) 500 return -EINVAL; 501 502 type = btf_find_func_proto(ctx->funcname, &btf); 503 if (!type) 504 return -ENOENT; 505 506 ctx->btf = btf; 507 ctx->proto = type; 508 509 /* ctx->params is optional, since func(void) will not have params. */ 510 nr = 0; 511 param = btf_get_func_param(type, &nr); 512 if (!IS_ERR_OR_NULL(param)) { 513 /* Hide the first 'data' argument of tracepoint */ 514 if (ctx->flags & TPARG_FL_TPOINT) { 515 nr--; 516 param++; 517 } 518 } 519 520 if (nr > 0) { 521 ctx->nr_params = nr; 522 ctx->params = param; 523 } else { 524 ctx->nr_params = 0; 525 ctx->params = NULL; 526 } 527 528 return 0; 529 } 530 531 static void clear_struct_btf(struct traceprobe_parse_context *ctx) 532 { 533 if (ctx->struct_btf) { 534 btf_put(ctx->struct_btf); 535 ctx->struct_btf = NULL; 536 ctx->last_struct = NULL; 537 } 538 } 539 540 static void clear_btf_context(struct traceprobe_parse_context *ctx) 541 { 542 if (ctx->btf) { 543 btf_put(ctx->btf); 544 ctx->btf = NULL; 545 ctx->proto = NULL; 546 ctx->params = NULL; 547 ctx->nr_params = 0; 548 } 549 } 550 551 /* Return 1 if the field separator is arrow operator ('->') */ 552 static int split_next_field(char *varname, char **next_field, 553 struct traceprobe_parse_context *ctx) 554 { 555 char *field; 556 int ret = 0; 557 558 field = strpbrk(varname, ".-"); 559 if (field) { 560 if (field[0] == '-' && field[1] == '>') { 561 field[0] = '\0'; 562 field += 2; 563 ret = 1; 564 } else if (field[0] == '.') { 565 field[0] = '\0'; 566 field += 1; 567 } else { 568 trace_probe_log_err(ctx->offset + field - varname, BAD_HYPHEN); 569 return -EINVAL; 570 } 571 *next_field = field; 572 } 573 574 return ret; 575 } 576 577 /* 578 * Parse the field of data structure. The @type must be a pointer type 579 * pointing the target data structure type. 580 */ 581 static int parse_btf_field(char *fieldname, const struct btf_type *type, 582 struct fetch_insn **pcode, struct fetch_insn *end, 583 struct traceprobe_parse_context *ctx) 584 { 585 struct fetch_insn *code = *pcode; 586 const struct btf_member *field; 587 u32 bitoffs, anon_offs; 588 bool is_struct = ctx->struct_btf != NULL; 589 struct btf *btf = ctx_btf(ctx); 590 char *next; 591 int is_ptr; 592 s32 tid; 593 594 do { 595 if (!is_struct) { 596 /* Outer loop for solving arrow operator ('->') */ 597 if (BTF_INFO_KIND(type->info) != BTF_KIND_PTR) { 598 trace_probe_log_err(ctx->offset, NO_PTR_STRCT); 599 return -EINVAL; 600 } 601 602 /* Convert a struct pointer type to a struct type */ 603 type = btf_type_skip_modifiers(btf, type->type, &tid); 604 if (!type) { 605 trace_probe_log_err(ctx->offset, BAD_BTF_TID); 606 return -EINVAL; 607 } 608 } 609 /* Only the first type can skip being a pointer */ 610 is_struct = false; 611 612 bitoffs = 0; 613 do { 614 /* Inner loop for solving dot operator ('.') */ 615 next = NULL; 616 is_ptr = split_next_field(fieldname, &next, ctx); 617 if (is_ptr < 0) 618 return is_ptr; 619 620 anon_offs = 0; 621 field = btf_find_struct_member(btf, type, fieldname, 622 &anon_offs); 623 if (IS_ERR(field)) { 624 trace_probe_log_err(ctx->offset, BAD_BTF_TID); 625 return PTR_ERR(field); 626 } 627 if (!field) { 628 trace_probe_log_err(ctx->offset, NO_BTF_FIELD); 629 return -ENOENT; 630 } 631 /* Add anonymous structure/union offset */ 632 bitoffs += anon_offs; 633 634 /* Accumulate the bit-offsets of the dot-connected fields */ 635 if (btf_type_kflag(type)) { 636 bitoffs += BTF_MEMBER_BIT_OFFSET(field->offset); 637 ctx->last_bitsize = BTF_MEMBER_BITFIELD_SIZE(field->offset); 638 } else { 639 bitoffs += field->offset; 640 ctx->last_bitsize = 0; 641 } 642 643 type = btf_type_skip_modifiers(btf, field->type, &tid); 644 if (!type) { 645 trace_probe_log_err(ctx->offset, BAD_BTF_TID); 646 return -EINVAL; 647 } 648 649 ctx->offset += next - fieldname; 650 fieldname = next; 651 } while (!is_ptr && fieldname); 652 653 if (++code == end) { 654 trace_probe_log_err(ctx->offset, TOO_MANY_OPS); 655 return -EINVAL; 656 } 657 code->op = FETCH_OP_DEREF; /* TODO: user deref support */ 658 code->offset = bitoffs / 8; 659 *pcode = code; 660 661 ctx->last_bitoffs = bitoffs % 8; 662 ctx->last_type = type; 663 } while (fieldname); 664 665 return 0; 666 } 667 668 static int __store_entry_arg(struct trace_probe *tp, int argnum); 669 670 static int parse_btf_arg(char *varname, 671 struct fetch_insn **pcode, struct fetch_insn *end, 672 struct traceprobe_parse_context *ctx) 673 { 674 struct fetch_insn *code = *pcode; 675 const struct btf_param *params; 676 const struct btf_type *type; 677 char *field = NULL; 678 int i, is_ptr, ret; 679 u32 tid; 680 681 if (WARN_ON_ONCE(!ctx->funcname && !(ctx->flags & TPARG_FL_TEVENT))) 682 return -EINVAL; 683 684 is_ptr = split_next_field(varname, &field, ctx); 685 if (is_ptr < 0) 686 return is_ptr; 687 if (!is_ptr && field) { 688 /* dot-connected field on an argument is not supported. */ 689 trace_probe_log_err(ctx->offset + field - varname, 690 NOSUP_DAT_ARG); 691 return -EOPNOTSUPP; 692 } 693 694 if (ctx->flags & TPARG_FL_TEVENT) { 695 ret = parse_trace_event(varname, code, ctx); 696 if (ret < 0) { 697 trace_probe_log_err(ctx->offset, BAD_ATTACH_ARG); 698 return ret; 699 } 700 /* TEVENT is only here via a typecast */ 701 if (WARN_ON_ONCE(ctx->struct_btf == NULL)) 702 return -EINVAL; 703 type = ctx->last_struct; 704 goto found_type; 705 } 706 707 if (ctx->flags & TPARG_FL_RETURN && !strcmp(varname, "$retval")) { 708 code->op = FETCH_OP_RETVAL; 709 /* Check whether the function return type is not void */ 710 if (query_btf_context(ctx) == 0) { 711 if (ctx->proto->type == 0) { 712 trace_probe_log_err(ctx->offset, NO_RETVAL); 713 return -ENOENT; 714 } 715 tid = ctx->proto->type; 716 goto found; 717 } 718 if (field) { 719 trace_probe_log_err(ctx->offset + field - varname, 720 NO_BTF_ENTRY); 721 return -ENOENT; 722 } 723 return 0; 724 } 725 726 if (!ctx->btf) { 727 ret = query_btf_context(ctx); 728 if (ret < 0 || ctx->nr_params == 0) { 729 trace_probe_log_err(ctx->offset, NO_BTF_ENTRY); 730 return -ENOENT; 731 } 732 } 733 params = ctx->params; 734 735 for (i = 0; i < ctx->nr_params; i++) { 736 const char *name = btf_name_by_offset(ctx->btf, params[i].name_off); 737 738 if (name && !strcmp(name, varname)) { 739 if (tparg_is_function_entry(ctx->flags)) { 740 code->op = FETCH_OP_ARG; 741 if (ctx->flags & TPARG_FL_TPOINT) 742 code->param = i + 1; 743 else 744 code->param = i; 745 } else if (tparg_is_function_return(ctx->flags)) { 746 code->op = FETCH_OP_EDATA; 747 ret = __store_entry_arg(ctx->tp, i); 748 if (ret < 0) { 749 /* internal error */ 750 return ret; 751 } 752 code->offset = ret; 753 } 754 tid = params[i].type; 755 goto found; 756 } 757 } 758 trace_probe_log_err(ctx->offset, NO_BTFARG); 759 return -ENOENT; 760 761 found: 762 type = btf_type_skip_modifiers(ctx->btf, tid, &tid); 763 found_type: 764 if (!type) { 765 trace_probe_log_err(ctx->offset, BAD_BTF_TID); 766 return -EINVAL; 767 } 768 /* Initialize the last type information */ 769 ctx->last_type = type; 770 ctx->last_bitoffs = 0; 771 ctx->last_bitsize = 0; 772 if (field) { 773 ctx->offset += field - varname; 774 return parse_btf_field(field, type, pcode, end, ctx); 775 } 776 return 0; 777 } 778 779 static const struct fetch_type *find_fetch_type_from_btf_type( 780 struct traceprobe_parse_context *ctx) 781 { 782 struct btf *btf = ctx_btf(ctx); 783 const char *typestr = NULL; 784 785 if (btf && ctx->last_type) 786 typestr = fetch_type_from_btf_type(btf, ctx->last_type, ctx); 787 788 return find_fetch_type(typestr, ctx->flags); 789 } 790 791 static int parse_btf_bitfield(struct fetch_insn **pcode, 792 struct traceprobe_parse_context *ctx) 793 { 794 struct fetch_insn *code = *pcode; 795 796 if ((ctx->last_bitsize % 8 == 0) && ctx->last_bitoffs == 0) 797 return 0; 798 799 code++; 800 if (code->op != FETCH_OP_NOP) { 801 trace_probe_log_err(ctx->offset, TOO_MANY_OPS); 802 return -EINVAL; 803 } 804 *pcode = code; 805 806 code->op = FETCH_OP_MOD_BF; 807 code->lshift = 64 - (ctx->last_bitsize + ctx->last_bitoffs); 808 code->rshift = 64 - ctx->last_bitsize; 809 code->basesize = 64 / 8; 810 return 0; 811 } 812 813 static int query_btf_struct(const char *sname, struct traceprobe_parse_context *ctx) 814 { 815 struct btf *btf = NULL; 816 int id; 817 818 /* A struct_btf should only be used by a single argument */ 819 if (WARN_ON_ONCE(ctx->struct_btf)) { 820 btf_put(ctx->struct_btf); 821 ctx->struct_btf = NULL; 822 } 823 824 id = bpf_find_btf_id(sname, BTF_KIND_STRUCT, &btf); 825 if (id < 0) 826 return id; 827 ctx->struct_btf = btf; 828 ctx->last_struct = btf_type_by_id(ctx->struct_btf, id); 829 return 0; 830 } 831 832 static int handle_typecast(char *arg, struct fetch_insn **pcode, 833 struct fetch_insn *end, 834 struct traceprobe_parse_context *ctx) 835 { 836 char *tmp; 837 int ret; 838 839 /* Currently this only works for eprobes */ 840 if (!(ctx->flags & TPARG_FL_TEVENT)) { 841 trace_probe_log_err(ctx->offset, TYPECAST_NOT_EVENT); 842 return -EINVAL; 843 } 844 845 tmp = strchr(arg, ')'); 846 if (!tmp) { 847 trace_probe_log_err(ctx->offset + strlen(arg), 848 DEREF_OPEN_BRACE); 849 return -EINVAL; 850 } 851 *tmp = '\0'; 852 ret = query_btf_struct(arg + 1, ctx); 853 *tmp = ')'; 854 855 if (ret < 0) { 856 trace_probe_log_err(ctx->offset + 1, NO_PTR_STRCT); 857 return -EINVAL; 858 } 859 860 tmp++; 861 862 ctx->offset += tmp - arg; 863 ret = parse_btf_arg(tmp, pcode, end, ctx); 864 return ret; 865 } 866 867 #else /* !CONFIG_PROBE_EVENTS_BTF_ARGS */ 868 869 static void clear_struct_btf(struct traceprobe_parse_context *ctx) 870 { 871 ctx->struct_btf = NULL; 872 } 873 874 static void clear_btf_context(struct traceprobe_parse_context *ctx) 875 { 876 ctx->btf = NULL; 877 } 878 879 static int query_btf_context(struct traceprobe_parse_context *ctx) 880 { 881 return -EOPNOTSUPP; 882 } 883 884 static int parse_btf_arg(char *varname, 885 struct fetch_insn **pcode, struct fetch_insn *end, 886 struct traceprobe_parse_context *ctx) 887 { 888 trace_probe_log_err(ctx->offset, NOSUP_BTFARG); 889 return -EOPNOTSUPP; 890 } 891 892 static int parse_btf_bitfield(struct fetch_insn **pcode, 893 struct traceprobe_parse_context *ctx) 894 { 895 trace_probe_log_err(ctx->offset, NOSUP_BTFARG); 896 return -EOPNOTSUPP; 897 } 898 899 #define find_fetch_type_from_btf_type(ctx) \ 900 find_fetch_type(NULL, ctx->flags) 901 902 static int check_prepare_btf_string_fetch(char *typename, 903 struct fetch_insn **pcode, 904 struct traceprobe_parse_context *ctx) 905 { 906 return 0; 907 } 908 909 static int handle_typecast(char *arg, struct fetch_insn **pcode, 910 struct fetch_insn *end, 911 struct traceprobe_parse_context *ctx) 912 { 913 trace_probe_log_err(ctx->offset, NOSUP_BTFARG); 914 return -EOPNOTSUPP; 915 } 916 917 #endif /* CONFIG_PROBE_EVENTS_BTF_ARGS */ 918 919 #ifdef CONFIG_HAVE_FUNCTION_ARG_ACCESS_API 920 921 static void store_entry_arg_at(struct fetch_insn *code, int argnum, int offset) 922 { 923 code[0].op = FETCH_OP_ARG; 924 code[0].param = argnum; 925 code[1].op = FETCH_OP_ST_EDATA; 926 code[1].offset = offset; 927 } 928 929 static int get_entry_arg_max_offset(struct probe_entry_arg *earg) 930 { 931 int i, max_offset = 0; 932 933 /* 934 * earg->code[] array has an operation sequence which is run in 935 * the entry handler. 936 * The sequence stopped by FETCH_OP_END and each data stored in 937 * the entry data buffer by FETCH_OP_ST_EDATA. The FETCH_OP_ST_EDATA 938 * stores the data at the data buffer + its offset, and all data are 939 * "unsigned long" size. The offset must be increased when a data is 940 * stored. Thus we need to find the last FETCH_OP_ST_EDATA in the 941 * code array. 942 */ 943 for (i = 0; i < earg->size - 1 && earg->code[i].op != FETCH_OP_END; i++) { 944 if (earg->code[i].op == FETCH_OP_ST_EDATA) 945 if (earg->code[i].offset > max_offset) 946 max_offset = earg->code[i].offset; 947 } 948 return max_offset; 949 } 950 951 /* 952 * Add the entry code to store the 'argnum'th parameter and return the offset 953 * in the entry data buffer where the data will be stored. 954 */ 955 static int __store_entry_arg(struct trace_probe *tp, int argnum) 956 { 957 struct probe_entry_arg *earg = tp->entry_arg; 958 int i, offset, last_offset = 0; 959 960 if (!earg) { 961 earg = kzalloc_flex(*earg, code, 2 * tp->nr_args + 1); 962 if (!earg) 963 return -ENOMEM; 964 earg->size = 2 * tp->nr_args + 1; 965 /* Fill the code buffer with 'end' to simplify it */ 966 for (i = 0; i < earg->size; i++) 967 earg->code[i].op = FETCH_OP_END; 968 tp->entry_arg = earg; 969 store_entry_arg_at(earg->code, argnum, 0); 970 return 0; 971 } 972 973 /* 974 * NOTE: if anyone change the following rule, please rewrite this. 975 * The entry code array is filled with the pair of 976 * 977 * [FETCH_OP_ARG(argnum)] 978 * [FETCH_OP_ST_EDATA(offset of entry data buffer)] 979 * 980 * and the rest of entries are filled with [FETCH_OP_END]. 981 * The offset should be incremented, thus the last pair should 982 * have the largest offset. 983 */ 984 985 /* Search the offset for the sprcified argnum. */ 986 for (i = 0; i < earg->size - 1 && earg->code[i].op != FETCH_OP_END; i += 2) { 987 if (WARN_ON_ONCE(earg->code[i].op != FETCH_OP_ARG)) 988 return -EINVAL; 989 990 if (earg->code[i].param != argnum) 991 continue; 992 993 if (WARN_ON_ONCE(earg->code[i + 1].op != FETCH_OP_ST_EDATA)) 994 return -EINVAL; 995 996 return earg->code[i + 1].offset; 997 } 998 /* Not found, append new entry if possible. */ 999 if (i >= earg->size - 1) 1000 return -ENOSPC; 1001 1002 /* The last entry must have the largest offset. */ 1003 if (i != 0) { 1004 if (WARN_ON_ONCE(earg->code[i - 1].op != FETCH_OP_ST_EDATA)) 1005 return -EINVAL; 1006 last_offset = earg->code[i - 1].offset; 1007 } 1008 1009 offset = last_offset + sizeof(unsigned long); 1010 store_entry_arg_at(&earg->code[i], argnum, offset); 1011 return offset; 1012 } 1013 1014 int traceprobe_get_entry_data_size(struct trace_probe *tp) 1015 { 1016 struct probe_entry_arg *earg = tp->entry_arg; 1017 1018 if (!earg) 1019 return 0; 1020 1021 return get_entry_arg_max_offset(earg) + sizeof(unsigned long); 1022 } 1023 1024 void store_trace_entry_data(void *edata, struct trace_probe *tp, struct pt_regs *regs) 1025 { 1026 struct probe_entry_arg *earg = tp->entry_arg; 1027 unsigned long val = 0; 1028 int i; 1029 1030 if (!earg) 1031 return; 1032 1033 for (i = 0; i < earg->size; i++) { 1034 struct fetch_insn *code = &earg->code[i]; 1035 1036 switch (code->op) { 1037 case FETCH_OP_ARG: 1038 val = regs_get_kernel_argument(regs, code->param); 1039 break; 1040 case FETCH_OP_ST_EDATA: 1041 *(unsigned long *)((unsigned long)edata + code->offset) = val; 1042 break; 1043 case FETCH_OP_END: 1044 goto end; 1045 default: 1046 break; 1047 } 1048 } 1049 end: 1050 return; 1051 } 1052 NOKPROBE_SYMBOL(store_trace_entry_data) 1053 #endif 1054 1055 #define PARAM_MAX_STACK (THREAD_SIZE / sizeof(unsigned long)) 1056 1057 /* Parse $vars. @orig_arg points '$', which syncs to @ctx->offset */ 1058 static int parse_probe_vars(char *orig_arg, const struct fetch_type *t, 1059 struct fetch_insn **pcode, 1060 struct fetch_insn *end, 1061 struct traceprobe_parse_context *ctx) 1062 { 1063 struct fetch_insn *code = *pcode; 1064 int err = TP_ERR_BAD_VAR; 1065 char *arg = orig_arg + 1; 1066 unsigned long param; 1067 int ret = 0; 1068 int len; 1069 1070 if (ctx->flags & TPARG_FL_TEVENT) { 1071 if (parse_trace_event(arg, code, ctx) < 0) 1072 goto inval; 1073 return 0; 1074 } 1075 1076 if (str_has_prefix(arg, "retval")) { 1077 if (!(ctx->flags & TPARG_FL_RETURN)) { 1078 err = TP_ERR_RETVAL_ON_PROBE; 1079 goto inval; 1080 } 1081 if (!(ctx->flags & TPARG_FL_KERNEL) || 1082 !IS_ENABLED(CONFIG_PROBE_EVENTS_BTF_ARGS)) { 1083 code->op = FETCH_OP_RETVAL; 1084 return 0; 1085 } 1086 return parse_btf_arg(orig_arg, pcode, end, ctx); 1087 } 1088 1089 len = str_has_prefix(arg, "stack"); 1090 if (len) { 1091 1092 if (arg[len] == '\0') { 1093 code->op = FETCH_OP_STACKP; 1094 return 0; 1095 } 1096 1097 if (isdigit(arg[len])) { 1098 ret = kstrtoul(arg + len, 10, ¶m); 1099 if (ret) 1100 goto inval; 1101 1102 if ((ctx->flags & TPARG_FL_KERNEL) && 1103 param > PARAM_MAX_STACK) { 1104 err = TP_ERR_BAD_STACK_NUM; 1105 goto inval; 1106 } 1107 code->op = FETCH_OP_STACK; 1108 code->param = (unsigned int)param; 1109 return 0; 1110 } 1111 goto inval; 1112 } 1113 1114 if (strcmp(arg, "comm") == 0 || strcmp(arg, "COMM") == 0) { 1115 code->op = FETCH_OP_COMM; 1116 return 0; 1117 } 1118 1119 #ifdef CONFIG_HAVE_FUNCTION_ARG_ACCESS_API 1120 len = str_has_prefix(arg, "arg"); 1121 if (len) { 1122 ret = kstrtoul(arg + len, 10, ¶m); 1123 if (ret) 1124 goto inval; 1125 1126 if (!param || param > PARAM_MAX_STACK) { 1127 err = TP_ERR_BAD_ARG_NUM; 1128 goto inval; 1129 } 1130 param--; /* argN starts from 1, but internal arg[N] starts from 0 */ 1131 1132 if (tparg_is_function_entry(ctx->flags)) { 1133 code->op = FETCH_OP_ARG; 1134 code->param = (unsigned int)param; 1135 /* 1136 * The tracepoint probe will probe a stub function, and the 1137 * first parameter of the stub is a dummy and should be ignored. 1138 */ 1139 if (ctx->flags & TPARG_FL_TPOINT) 1140 code->param++; 1141 } else if (tparg_is_function_return(ctx->flags)) { 1142 /* function entry argument access from return probe */ 1143 ret = __store_entry_arg(ctx->tp, param); 1144 if (ret < 0) /* This error should be an internal error */ 1145 return ret; 1146 1147 code->op = FETCH_OP_EDATA; 1148 code->offset = ret; 1149 } else { 1150 err = TP_ERR_NOFENTRY_ARGS; 1151 goto inval; 1152 } 1153 return 0; 1154 } 1155 #endif 1156 1157 inval: 1158 __trace_probe_log_err(ctx->offset, err); 1159 return -EINVAL; 1160 } 1161 1162 static int str_to_immediate(char *str, unsigned long *imm) 1163 { 1164 if (isdigit(str[0])) 1165 return kstrtoul(str, 0, imm); 1166 else if (str[0] == '-') 1167 return kstrtol(str, 0, (long *)imm); 1168 else if (str[0] == '+') 1169 return kstrtol(str + 1, 0, (long *)imm); 1170 return -EINVAL; 1171 } 1172 1173 static int __parse_imm_string(char *str, char **pbuf, int offs) 1174 { 1175 size_t len = strlen(str); 1176 1177 if (!len || str[len - 1] != '"') { 1178 trace_probe_log_err(offs + len, IMMSTR_NO_CLOSE); 1179 return -EINVAL; 1180 } 1181 *pbuf = kstrndup(str, len - 1, GFP_KERNEL); 1182 if (!*pbuf) 1183 return -ENOMEM; 1184 return 0; 1185 } 1186 1187 /* Recursive argument parser */ 1188 static int 1189 parse_probe_arg(char *arg, const struct fetch_type *type, 1190 struct fetch_insn **pcode, struct fetch_insn *end, 1191 struct traceprobe_parse_context *ctx) 1192 { 1193 struct fetch_insn *code = *pcode; 1194 unsigned long param; 1195 int deref = FETCH_OP_DEREF; 1196 long offset = 0; 1197 char *tmp; 1198 int ret = 0; 1199 1200 switch (arg[0]) { 1201 case '$': 1202 ret = parse_probe_vars(arg, type, pcode, end, ctx); 1203 break; 1204 1205 case '%': /* named register */ 1206 if (ctx->flags & (TPARG_FL_TEVENT | TPARG_FL_FPROBE)) { 1207 /* eprobe and fprobe do not handle registers */ 1208 trace_probe_log_err(ctx->offset, BAD_VAR); 1209 break; 1210 } 1211 ret = regs_query_register_offset(arg + 1); 1212 if (ret >= 0) { 1213 code->op = FETCH_OP_REG; 1214 code->param = (unsigned int)ret; 1215 ret = 0; 1216 } else 1217 trace_probe_log_err(ctx->offset, BAD_REG_NAME); 1218 break; 1219 1220 case '@': /* memory, file-offset or symbol */ 1221 if (isdigit(arg[1])) { 1222 ret = kstrtoul(arg + 1, 0, ¶m); 1223 if (ret) { 1224 trace_probe_log_err(ctx->offset, BAD_MEM_ADDR); 1225 break; 1226 } 1227 /* load address */ 1228 code->op = FETCH_OP_IMM; 1229 code->immediate = param; 1230 } else if (arg[1] == '+') { 1231 /* kprobes don't support file offsets */ 1232 if (ctx->flags & TPARG_FL_KERNEL) { 1233 trace_probe_log_err(ctx->offset, FILE_ON_KPROBE); 1234 return -EINVAL; 1235 } 1236 ret = kstrtol(arg + 2, 0, &offset); 1237 if (ret) { 1238 trace_probe_log_err(ctx->offset, BAD_FILE_OFFS); 1239 break; 1240 } 1241 1242 code->op = FETCH_OP_FOFFS; 1243 code->immediate = (unsigned long)offset; // imm64? 1244 } else { 1245 /* uprobes don't support symbols */ 1246 if (!(ctx->flags & TPARG_FL_KERNEL)) { 1247 trace_probe_log_err(ctx->offset, SYM_ON_UPROBE); 1248 return -EINVAL; 1249 } 1250 /* Preserve symbol for updating */ 1251 code->op = FETCH_NOP_SYMBOL; 1252 code->data = kstrdup(arg + 1, GFP_KERNEL); 1253 if (!code->data) 1254 return -ENOMEM; 1255 if (++code == end) { 1256 trace_probe_log_err(ctx->offset, TOO_MANY_OPS); 1257 return -EINVAL; 1258 } 1259 code->op = FETCH_OP_IMM; 1260 code->immediate = 0; 1261 } 1262 /* These are fetching from memory */ 1263 if (++code == end) { 1264 trace_probe_log_err(ctx->offset, TOO_MANY_OPS); 1265 return -EINVAL; 1266 } 1267 *pcode = code; 1268 code->op = FETCH_OP_DEREF; 1269 code->offset = offset; 1270 break; 1271 1272 case '+': /* deref memory */ 1273 case '-': 1274 if (arg[1] == 'u') { 1275 deref = FETCH_OP_UDEREF; 1276 arg[1] = arg[0]; 1277 arg++; 1278 } 1279 if (arg[0] == '+') 1280 arg++; /* Skip '+', because kstrtol() rejects it. */ 1281 tmp = strchr(arg, '('); 1282 if (!tmp) { 1283 trace_probe_log_err(ctx->offset, DEREF_NEED_BRACE); 1284 return -EINVAL; 1285 } 1286 *tmp = '\0'; 1287 ret = kstrtol(arg, 0, &offset); 1288 if (ret) { 1289 trace_probe_log_err(ctx->offset, BAD_DEREF_OFFS); 1290 break; 1291 } 1292 ctx->offset += (tmp + 1 - arg) + (arg[0] != '-' ? 1 : 0); 1293 arg = tmp + 1; 1294 tmp = strrchr(arg, ')'); 1295 if (!tmp) { 1296 trace_probe_log_err(ctx->offset + strlen(arg), 1297 DEREF_OPEN_BRACE); 1298 return -EINVAL; 1299 } else { 1300 const struct fetch_type *t2 = find_fetch_type(NULL, ctx->flags); 1301 int cur_offs = ctx->offset; 1302 1303 *tmp = '\0'; 1304 ret = parse_probe_arg(arg, t2, &code, end, ctx); 1305 if (ret) 1306 break; 1307 ctx->offset = cur_offs; 1308 if (code->op == FETCH_OP_COMM || 1309 code->op == FETCH_OP_DATA) { 1310 trace_probe_log_err(ctx->offset, COMM_CANT_DEREF); 1311 return -EINVAL; 1312 } 1313 if (++code == end) { 1314 trace_probe_log_err(ctx->offset, TOO_MANY_OPS); 1315 return -EINVAL; 1316 } 1317 *pcode = code; 1318 1319 code->op = deref; 1320 code->offset = offset; 1321 /* Reset the last type if used */ 1322 ctx->last_type = NULL; 1323 } 1324 break; 1325 case '\\': /* Immediate value */ 1326 if (arg[1] == '"') { /* Immediate string */ 1327 ret = __parse_imm_string(arg + 2, &tmp, ctx->offset + 2); 1328 if (ret) 1329 break; 1330 code->op = FETCH_OP_DATA; 1331 code->data = tmp; 1332 } else { 1333 ret = str_to_immediate(arg + 1, &code->immediate); 1334 if (ret) 1335 trace_probe_log_err(ctx->offset + 1, BAD_IMM); 1336 else 1337 code->op = FETCH_OP_IMM; 1338 } 1339 break; 1340 case '(': 1341 ret = handle_typecast(arg, pcode, end, ctx); 1342 break; 1343 default: 1344 if (isalpha(arg[0]) || arg[0] == '_') { /* BTF variable */ 1345 if (!tparg_is_function_entry(ctx->flags) && 1346 !tparg_is_function_return(ctx->flags)) { 1347 trace_probe_log_err(ctx->offset, NOSUP_BTFARG); 1348 return -EINVAL; 1349 } 1350 ret = parse_btf_arg(arg, pcode, end, ctx); 1351 break; 1352 } 1353 } 1354 if (!ret && code->op == FETCH_OP_NOP) { 1355 /* Parsed, but do not find fetch method */ 1356 trace_probe_log_err(ctx->offset, BAD_FETCH_ARG); 1357 ret = -EINVAL; 1358 } 1359 return ret; 1360 } 1361 1362 /* Bitfield type needs to be parsed into a fetch function */ 1363 static int __parse_bitfield_probe_arg(const char *bf, 1364 const struct fetch_type *t, 1365 struct fetch_insn **pcode) 1366 { 1367 struct fetch_insn *code = *pcode; 1368 unsigned long bw, bo; 1369 char *tail; 1370 1371 if (*bf != 'b') 1372 return 0; 1373 1374 bw = simple_strtoul(bf + 1, &tail, 0); /* Use simple one */ 1375 1376 if (bw == 0 || *tail != '@') 1377 return -EINVAL; 1378 1379 bf = tail + 1; 1380 bo = simple_strtoul(bf, &tail, 0); 1381 1382 if (tail == bf || *tail != '/') 1383 return -EINVAL; 1384 code++; 1385 if (code->op != FETCH_OP_NOP) 1386 return -EINVAL; 1387 *pcode = code; 1388 1389 code->op = FETCH_OP_MOD_BF; 1390 code->lshift = BYTES_TO_BITS(t->size) - (bw + bo); 1391 code->rshift = BYTES_TO_BITS(t->size) - bw; 1392 code->basesize = t->size; 1393 1394 return (BYTES_TO_BITS(t->size) < (bw + bo)) ? -EINVAL : 0; 1395 } 1396 1397 /* Split type part from @arg and return it. */ 1398 static char *parse_probe_arg_type(char *arg, struct probe_arg *parg, 1399 struct traceprobe_parse_context *ctx) 1400 { 1401 char *t = NULL, *t2, *t3; 1402 int offs; 1403 1404 t = strchr(arg, ':'); 1405 if (t) { 1406 *t++ = '\0'; 1407 t2 = strchr(t, '['); 1408 if (t2) { 1409 *t2++ = '\0'; 1410 t3 = strchr(t2, ']'); 1411 if (!t3) { 1412 offs = t2 + strlen(t2) - arg; 1413 1414 trace_probe_log_err(ctx->offset + offs, 1415 ARRAY_NO_CLOSE); 1416 return ERR_PTR(-EINVAL); 1417 } else if (t3[1] != '\0') { 1418 trace_probe_log_err(ctx->offset + t3 + 1 - arg, 1419 BAD_ARRAY_SUFFIX); 1420 return ERR_PTR(-EINVAL); 1421 } 1422 *t3 = '\0'; 1423 if (kstrtouint(t2, 0, &parg->count) || !parg->count) { 1424 trace_probe_log_err(ctx->offset + t2 - arg, 1425 BAD_ARRAY_NUM); 1426 return ERR_PTR(-EINVAL); 1427 } 1428 if (parg->count > MAX_ARRAY_LEN) { 1429 trace_probe_log_err(ctx->offset + t2 - arg, 1430 ARRAY_TOO_BIG); 1431 return ERR_PTR(-EINVAL); 1432 } 1433 } 1434 } 1435 offs = t ? t - arg : 0; 1436 1437 /* 1438 * Since $comm and immediate string can not be dereferenced, 1439 * we can find those by strcmp. But ignore for eprobes. 1440 */ 1441 if (!(ctx->flags & TPARG_FL_TEVENT) && 1442 (strcmp(arg, "$comm") == 0 || strcmp(arg, "$COMM") == 0 || 1443 strncmp(arg, "\\\"", 2) == 0)) { 1444 /* The type of $comm must be "string", and not an array type. */ 1445 if (parg->count || (t && strcmp(t, "string"))) { 1446 trace_probe_log_err(ctx->offset + offs, NEED_STRING_TYPE); 1447 return ERR_PTR(-EINVAL); 1448 } 1449 parg->type = find_fetch_type("string", ctx->flags); 1450 } else 1451 parg->type = find_fetch_type(t, ctx->flags); 1452 1453 if (!parg->type) { 1454 trace_probe_log_err(ctx->offset + offs, BAD_TYPE); 1455 return ERR_PTR(-EINVAL); 1456 } 1457 1458 return t; 1459 } 1460 1461 /* After parsing, adjust the fetch_insn according to the probe_arg */ 1462 static int finalize_fetch_insn(struct fetch_insn *code, 1463 struct probe_arg *parg, 1464 char *type, 1465 int type_offset, 1466 struct traceprobe_parse_context *ctx) 1467 { 1468 struct fetch_insn *scode; 1469 int ret; 1470 1471 /* Store operation */ 1472 if (parg->type->is_string) { 1473 /* Check bad combination of the type and the last fetch_insn. */ 1474 if (!strcmp(parg->type->name, "symstr")) { 1475 if (code->op != FETCH_OP_REG && code->op != FETCH_OP_STACK && 1476 code->op != FETCH_OP_RETVAL && code->op != FETCH_OP_ARG && 1477 code->op != FETCH_OP_DEREF && code->op != FETCH_OP_TP_ARG) { 1478 trace_probe_log_err(ctx->offset + type_offset, 1479 BAD_SYMSTRING); 1480 return -EINVAL; 1481 } 1482 } else { 1483 if (code->op != FETCH_OP_DEREF && code->op != FETCH_OP_UDEREF && 1484 code->op != FETCH_OP_IMM && code->op != FETCH_OP_COMM && 1485 code->op != FETCH_OP_DATA && code->op != FETCH_OP_TP_ARG) { 1486 trace_probe_log_err(ctx->offset + type_offset, 1487 BAD_STRING); 1488 return -EINVAL; 1489 } 1490 } 1491 1492 if (!strcmp(parg->type->name, "symstr") || 1493 (code->op == FETCH_OP_IMM || code->op == FETCH_OP_COMM || 1494 code->op == FETCH_OP_DATA) || code->op == FETCH_OP_TP_ARG || 1495 parg->count) { 1496 /* 1497 * IMM, DATA and COMM is pointing actual address, those 1498 * must be kept, and if parg->count != 0, this is an 1499 * array of string pointers instead of string address 1500 * itself. 1501 * For the symstr, it doesn't need to dereference, thus 1502 * it just get the value. 1503 */ 1504 code++; 1505 if (code->op != FETCH_OP_NOP) { 1506 trace_probe_log_err(ctx->offset, TOO_MANY_OPS); 1507 return -EINVAL; 1508 } 1509 } 1510 1511 /* If op == DEREF, replace it with STRING */ 1512 if (!strcmp(parg->type->name, "ustring") || 1513 code->op == FETCH_OP_UDEREF) 1514 code->op = FETCH_OP_ST_USTRING; 1515 else if (!strcmp(parg->type->name, "symstr")) 1516 code->op = FETCH_OP_ST_SYMSTR; 1517 else 1518 code->op = FETCH_OP_ST_STRING; 1519 code->size = parg->type->size; 1520 parg->dynamic = true; 1521 } else if (code->op == FETCH_OP_DEREF) { 1522 code->op = FETCH_OP_ST_MEM; 1523 code->size = parg->type->size; 1524 } else if (code->op == FETCH_OP_UDEREF) { 1525 code->op = FETCH_OP_ST_UMEM; 1526 code->size = parg->type->size; 1527 } else { 1528 code++; 1529 if (code->op != FETCH_OP_NOP) { 1530 trace_probe_log_err(ctx->offset, TOO_MANY_OPS); 1531 return -E2BIG; 1532 } 1533 code->op = FETCH_OP_ST_RAW; 1534 code->size = parg->type->size; 1535 } 1536 1537 /* Save storing fetch_insn. */ 1538 scode = code; 1539 1540 /* Modify operation */ 1541 if (type != NULL) { 1542 /* Bitfield needs a special fetch_insn. */ 1543 ret = __parse_bitfield_probe_arg(type, parg->type, &code); 1544 if (ret) { 1545 trace_probe_log_err(ctx->offset + type_offset, BAD_BITFIELD); 1546 return ret; 1547 } 1548 } else if (IS_ENABLED(CONFIG_PROBE_EVENTS_BTF_ARGS) && 1549 ctx->last_type) { 1550 /* If user not specified the type, try parsing BTF bitfield. */ 1551 ret = parse_btf_bitfield(&code, ctx); 1552 if (ret) 1553 return ret; 1554 } 1555 1556 /* Loop(Array) operation */ 1557 if (parg->count) { 1558 if (scode->op != FETCH_OP_ST_MEM && 1559 scode->op != FETCH_OP_ST_STRING && 1560 scode->op != FETCH_OP_ST_USTRING) { 1561 trace_probe_log_err(ctx->offset + type_offset, BAD_STRING); 1562 return -EINVAL; 1563 } 1564 code++; 1565 if (code->op != FETCH_OP_NOP) { 1566 trace_probe_log_err(ctx->offset, TOO_MANY_OPS); 1567 return -E2BIG; 1568 } 1569 code->op = FETCH_OP_LP_ARRAY; 1570 code->param = parg->count; 1571 } 1572 1573 /* Finalize the fetch_insn array. */ 1574 code++; 1575 code->op = FETCH_OP_END; 1576 1577 return 0; 1578 } 1579 1580 /* String length checking wrapper */ 1581 static int traceprobe_parse_probe_arg_body(const char *argv, ssize_t *size, 1582 struct probe_arg *parg, 1583 struct traceprobe_parse_context *ctx) 1584 { 1585 struct fetch_insn *code, *tmp = NULL; 1586 char *type, *arg __free(kfree) = NULL; 1587 int ret, len; 1588 1589 len = strlen(argv); 1590 if (len > MAX_ARGSTR_LEN) { 1591 trace_probe_log_err(ctx->offset, ARG_TOO_LONG); 1592 return -E2BIG; 1593 } else if (len == 0) { 1594 trace_probe_log_err(ctx->offset, NO_ARG_BODY); 1595 return -EINVAL; 1596 } 1597 1598 arg = kstrdup(argv, GFP_KERNEL); 1599 if (!arg) 1600 return -ENOMEM; 1601 1602 parg->comm = kstrdup(arg, GFP_KERNEL); 1603 if (!parg->comm) 1604 return -ENOMEM; 1605 1606 type = parse_probe_arg_type(arg, parg, ctx); 1607 if (IS_ERR(type)) 1608 return PTR_ERR(type); 1609 1610 code = tmp = kzalloc_objs(*code, FETCH_INSN_MAX); 1611 if (!code) 1612 return -ENOMEM; 1613 code[FETCH_INSN_MAX - 1].op = FETCH_OP_END; 1614 1615 ctx->last_type = NULL; 1616 ret = parse_probe_arg(arg, parg->type, &code, &code[FETCH_INSN_MAX - 1], 1617 ctx); 1618 if (ret < 0) 1619 goto fail; 1620 1621 /* Update storing type if BTF is available */ 1622 if (IS_ENABLED(CONFIG_PROBE_EVENTS_BTF_ARGS) && 1623 ctx->last_type) { 1624 if (!type) { 1625 parg->type = find_fetch_type_from_btf_type(ctx); 1626 } else if (strstr(type, "string")) { 1627 ret = check_prepare_btf_string_fetch(type, &code, ctx); 1628 if (ret) 1629 goto fail; 1630 } 1631 } 1632 parg->offset = *size; 1633 *size += parg->type->size * (parg->count ?: 1); 1634 1635 if (*size > MAX_PROBE_EVENT_SIZE) { 1636 ret = -E2BIG; 1637 trace_probe_log_err(ctx->offset, EVENT_TOO_BIG); 1638 goto fail; 1639 } 1640 1641 if (parg->count) { 1642 len = strlen(parg->type->fmttype) + 6; 1643 parg->fmt = kmalloc(len, GFP_KERNEL); 1644 if (!parg->fmt) { 1645 ret = -ENOMEM; 1646 goto fail; 1647 } 1648 snprintf(parg->fmt, len, "%s[%d]", parg->type->fmttype, 1649 parg->count); 1650 } 1651 1652 ret = finalize_fetch_insn(code, parg, type, type ? type - arg : 0, ctx); 1653 if (ret < 0) 1654 goto fail; 1655 1656 for (; code < tmp + FETCH_INSN_MAX; code++) 1657 if (code->op == FETCH_OP_END) 1658 break; 1659 /* Shrink down the code buffer */ 1660 parg->code = kzalloc_objs(*code, code - tmp + 1); 1661 if (!parg->code) 1662 ret = -ENOMEM; 1663 else 1664 memcpy(parg->code, tmp, sizeof(*code) * (code - tmp + 1)); 1665 1666 fail: 1667 if (ret < 0) { 1668 for (code = tmp; code < tmp + FETCH_INSN_MAX; code++) 1669 if (code->op == FETCH_NOP_SYMBOL || 1670 code->op == FETCH_OP_DATA) 1671 kfree(code->data); 1672 } 1673 kfree(tmp); 1674 1675 /* struct_btf should not be passed to other arguments */ 1676 clear_struct_btf(ctx); 1677 1678 return ret; 1679 } 1680 1681 /* Return 1 if name is reserved or already used by another argument */ 1682 static int traceprobe_conflict_field_name(const char *name, 1683 struct probe_arg *args, int narg) 1684 { 1685 int i; 1686 1687 for (i = 0; i < ARRAY_SIZE(reserved_field_names); i++) 1688 if (strcmp(reserved_field_names[i], name) == 0) 1689 return 1; 1690 1691 for (i = 0; i < narg; i++) 1692 if (strcmp(args[i].name, name) == 0) 1693 return 1; 1694 1695 return 0; 1696 } 1697 1698 static char *generate_probe_arg_name(const char *arg, int idx) 1699 { 1700 char *name = NULL; 1701 const char *end; 1702 1703 /* 1704 * If argument name is omitted, try arg as a name (BTF variable) 1705 * or "argN". 1706 */ 1707 if (IS_ENABLED(CONFIG_PROBE_EVENTS_BTF_ARGS)) { 1708 end = strchr(arg, ':'); 1709 if (!end) 1710 end = arg + strlen(arg); 1711 1712 name = kmemdup_nul(arg, end - arg, GFP_KERNEL); 1713 if (!name || !is_good_name(name)) { 1714 kfree(name); 1715 name = NULL; 1716 } 1717 } 1718 1719 if (!name) 1720 name = kasprintf(GFP_KERNEL, "arg%d", idx + 1); 1721 1722 return name; 1723 } 1724 1725 int traceprobe_parse_probe_arg(struct trace_probe *tp, int i, const char *arg, 1726 struct traceprobe_parse_context *ctx) 1727 { 1728 struct probe_arg *parg = &tp->args[i]; 1729 const char *body; 1730 1731 ctx->tp = tp; 1732 body = strchr(arg, '='); 1733 if (body) { 1734 if (body - arg > MAX_ARG_NAME_LEN) { 1735 trace_probe_log_err(0, ARG_NAME_TOO_LONG); 1736 return -EINVAL; 1737 } else if (body == arg) { 1738 trace_probe_log_err(0, NO_ARG_NAME); 1739 return -EINVAL; 1740 } 1741 parg->name = kmemdup_nul(arg, body - arg, GFP_KERNEL); 1742 body++; 1743 } else { 1744 parg->name = generate_probe_arg_name(arg, i); 1745 body = arg; 1746 } 1747 if (!parg->name) 1748 return -ENOMEM; 1749 1750 if (!is_good_name(parg->name)) { 1751 trace_probe_log_err(0, BAD_ARG_NAME); 1752 return -EINVAL; 1753 } 1754 if (traceprobe_conflict_field_name(parg->name, tp->args, i)) { 1755 trace_probe_log_err(0, USED_ARG_NAME); 1756 return -EINVAL; 1757 } 1758 ctx->offset = body - arg; 1759 /* Parse fetch argument */ 1760 return traceprobe_parse_probe_arg_body(body, &tp->size, parg, ctx); 1761 } 1762 1763 void traceprobe_free_probe_arg(struct probe_arg *arg) 1764 { 1765 struct fetch_insn *code = arg->code; 1766 1767 while (code && code->op != FETCH_OP_END) { 1768 if (code->op == FETCH_NOP_SYMBOL || 1769 code->op == FETCH_OP_DATA) 1770 kfree(code->data); 1771 code++; 1772 } 1773 kfree(arg->code); 1774 kfree(arg->name); 1775 kfree(arg->comm); 1776 kfree(arg->fmt); 1777 } 1778 1779 static int argv_has_var_arg(int argc, const char *argv[], int *args_idx, 1780 struct traceprobe_parse_context *ctx) 1781 { 1782 int i, found = 0; 1783 1784 for (i = 0; i < argc; i++) 1785 if (str_has_prefix(argv[i], "$arg")) { 1786 trace_probe_log_set_index(i + 2); 1787 1788 if (!tparg_is_function_entry(ctx->flags) && 1789 !tparg_is_function_return(ctx->flags)) { 1790 trace_probe_log_err(0, NOFENTRY_ARGS); 1791 return -EINVAL; 1792 } 1793 1794 if (isdigit(argv[i][4])) { 1795 found = 1; 1796 continue; 1797 } 1798 1799 if (argv[i][4] != '*') { 1800 trace_probe_log_err(0, BAD_VAR); 1801 return -EINVAL; 1802 } 1803 1804 if (*args_idx >= 0 && *args_idx < argc) { 1805 trace_probe_log_err(0, DOUBLE_ARGS); 1806 return -EINVAL; 1807 } 1808 found = 1; 1809 *args_idx = i; 1810 } 1811 1812 return found; 1813 } 1814 1815 static int sprint_nth_btf_arg(int idx, const char *type, 1816 char *buf, int bufsize, 1817 struct traceprobe_parse_context *ctx) 1818 { 1819 const char *name; 1820 int ret; 1821 1822 if (idx >= ctx->nr_params) { 1823 trace_probe_log_err(0, NO_BTFARG); 1824 return -ENOENT; 1825 } 1826 name = btf_name_by_offset(ctx->btf, ctx->params[idx].name_off); 1827 if (!name) { 1828 trace_probe_log_err(0, NO_BTF_ENTRY); 1829 return -ENOENT; 1830 } 1831 ret = snprintf(buf, bufsize, "%s%s", name, type); 1832 if (ret >= bufsize) { 1833 trace_probe_log_err(0, ARGS_2LONG); 1834 return -E2BIG; 1835 } 1836 return ret; 1837 } 1838 1839 /* Return new_argv which must be freed after use */ 1840 const char **traceprobe_expand_meta_args(int argc, const char *argv[], 1841 int *new_argc, char *buf, int bufsize, 1842 struct traceprobe_parse_context *ctx) 1843 { 1844 const struct btf_param *params = NULL; 1845 int i, j, n, used, ret, args_idx = -1; 1846 const char **new_argv __free(kfree) = NULL; 1847 1848 ret = argv_has_var_arg(argc, argv, &args_idx, ctx); 1849 if (ret < 0) 1850 return ERR_PTR(ret); 1851 1852 if (!ret) { 1853 *new_argc = argc; 1854 return NULL; 1855 } 1856 1857 ret = query_btf_context(ctx); 1858 if (ret < 0 || ctx->nr_params == 0) { 1859 if (args_idx != -1) { 1860 /* $arg* requires BTF info */ 1861 trace_probe_log_err(0, NOSUP_BTFARG); 1862 return (const char **)params; 1863 } 1864 *new_argc = argc; 1865 return NULL; 1866 } 1867 1868 if (args_idx >= 0) 1869 *new_argc = argc + ctx->nr_params - 1; 1870 else 1871 *new_argc = argc; 1872 1873 new_argv = kcalloc(*new_argc, sizeof(char *), GFP_KERNEL); 1874 if (!new_argv) 1875 return ERR_PTR(-ENOMEM); 1876 1877 used = 0; 1878 for (i = 0, j = 0; i < argc; i++) { 1879 trace_probe_log_set_index(i + 2); 1880 if (i == args_idx) { 1881 for (n = 0; n < ctx->nr_params; n++) { 1882 ret = sprint_nth_btf_arg(n, "", buf + used, 1883 bufsize - used, ctx); 1884 if (ret < 0) 1885 return ERR_PTR(ret); 1886 1887 new_argv[j++] = buf + used; 1888 used += ret + 1; 1889 } 1890 continue; 1891 } 1892 1893 if (str_has_prefix(argv[i], "$arg")) { 1894 char *type = NULL; 1895 1896 n = simple_strtoul(argv[i] + 4, &type, 10); 1897 if (type && !(*type == ':' || *type == '\0')) { 1898 trace_probe_log_err(0, BAD_VAR); 1899 return ERR_PTR(-ENOENT); 1900 } 1901 /* Note: $argN starts from $arg1 */ 1902 ret = sprint_nth_btf_arg(n - 1, type, buf + used, 1903 bufsize - used, ctx); 1904 if (ret < 0) 1905 return ERR_PTR(ret); 1906 new_argv[j++] = buf + used; 1907 used += ret + 1; 1908 } else 1909 new_argv[j++] = argv[i]; 1910 } 1911 1912 return_ptr(new_argv); 1913 } 1914 1915 /* @buf: *buf must be equal to NULL. Caller must to free *buf */ 1916 int traceprobe_expand_dentry_args(int argc, const char *argv[], char **buf) 1917 { 1918 int i, used, ret; 1919 const int bufsize = MAX_DENTRY_ARGS_LEN; 1920 char *tmpbuf __free(kfree) = NULL; 1921 1922 if (*buf) 1923 return -EINVAL; 1924 1925 used = 0; 1926 for (i = 0; i < argc; i++) { 1927 char *tmp __free(kfree) = NULL; 1928 char *equal; 1929 size_t arg_len; 1930 1931 if (!glob_match("*:%p[dD]", argv[i])) 1932 continue; 1933 1934 if (!tmpbuf) { 1935 tmpbuf = kmalloc(bufsize, GFP_KERNEL); 1936 if (!tmpbuf) 1937 return -ENOMEM; 1938 } 1939 1940 tmp = kstrdup(argv[i], GFP_KERNEL); 1941 if (!tmp) 1942 return -ENOMEM; 1943 1944 equal = strchr(tmp, '='); 1945 if (equal) 1946 *equal = '\0'; 1947 arg_len = strlen(argv[i]); 1948 tmp[arg_len - 4] = '\0'; 1949 if (argv[i][arg_len - 1] == 'd') 1950 ret = snprintf(tmpbuf + used, bufsize - used, 1951 "%s%s+0x0(+0x%zx(%s)):string", 1952 equal ? tmp : "", equal ? "=" : "", 1953 offsetof(struct dentry, d_name.name), 1954 equal ? equal + 1 : tmp); 1955 else 1956 ret = snprintf(tmpbuf + used, bufsize - used, 1957 "%s%s+0x0(+0x%zx(+0x%zx(%s))):string", 1958 equal ? tmp : "", equal ? "=" : "", 1959 offsetof(struct dentry, d_name.name), 1960 offsetof(struct file, f_path.dentry), 1961 equal ? equal + 1 : tmp); 1962 1963 if (ret >= bufsize - used) 1964 return -ENOMEM; 1965 argv[i] = tmpbuf + used; 1966 used += ret + 1; 1967 } 1968 1969 *buf = no_free_ptr(tmpbuf); 1970 return 0; 1971 } 1972 1973 void traceprobe_finish_parse(struct traceprobe_parse_context *ctx) 1974 { 1975 clear_btf_context(ctx); 1976 } 1977 1978 int traceprobe_update_arg(struct probe_arg *arg) 1979 { 1980 struct fetch_insn *code = arg->code; 1981 long offset; 1982 char *tmp; 1983 char c; 1984 int ret = 0; 1985 1986 while (code && code->op != FETCH_OP_END) { 1987 if (code->op == FETCH_NOP_SYMBOL) { 1988 if (code[1].op != FETCH_OP_IMM) 1989 return -EINVAL; 1990 1991 tmp = strpbrk(code->data, "+-"); 1992 if (tmp) 1993 c = *tmp; 1994 ret = traceprobe_split_symbol_offset(code->data, 1995 &offset); 1996 if (ret) 1997 return ret; 1998 1999 code[1].immediate = 2000 (unsigned long)kallsyms_lookup_name(code->data); 2001 if (tmp) 2002 *tmp = c; 2003 if (!code[1].immediate) 2004 return -ENOENT; 2005 code[1].immediate += offset; 2006 } 2007 code++; 2008 } 2009 return 0; 2010 } 2011 2012 /* When len=0, we just calculate the needed length */ 2013 #define LEN_OR_ZERO (len ? len - pos : 0) 2014 static int __set_print_fmt(struct trace_probe *tp, char *buf, int len, 2015 enum probe_print_type ptype) 2016 { 2017 struct probe_arg *parg; 2018 int i, j; 2019 int pos = 0; 2020 const char *fmt, *arg; 2021 2022 switch (ptype) { 2023 case PROBE_PRINT_NORMAL: 2024 fmt = "(%lx)"; 2025 arg = ", REC->" FIELD_STRING_IP; 2026 break; 2027 case PROBE_PRINT_RETURN: 2028 fmt = "(%lx <- %lx)"; 2029 arg = ", REC->" FIELD_STRING_FUNC ", REC->" FIELD_STRING_RETIP; 2030 break; 2031 case PROBE_PRINT_EVENT: 2032 fmt = ""; 2033 arg = ""; 2034 break; 2035 default: 2036 WARN_ON_ONCE(1); 2037 return 0; 2038 } 2039 2040 pos += snprintf(buf + pos, LEN_OR_ZERO, "\"%s", fmt); 2041 2042 for (i = 0; i < tp->nr_args; i++) { 2043 parg = tp->args + i; 2044 pos += snprintf(buf + pos, LEN_OR_ZERO, " %s=", parg->name); 2045 if (parg->count) { 2046 pos += snprintf(buf + pos, LEN_OR_ZERO, "{%s", 2047 parg->type->fmt); 2048 for (j = 1; j < parg->count; j++) 2049 pos += snprintf(buf + pos, LEN_OR_ZERO, ",%s", 2050 parg->type->fmt); 2051 pos += snprintf(buf + pos, LEN_OR_ZERO, "}"); 2052 } else 2053 pos += snprintf(buf + pos, LEN_OR_ZERO, "%s", 2054 parg->type->fmt); 2055 } 2056 2057 pos += snprintf(buf + pos, LEN_OR_ZERO, "\"%s", arg); 2058 2059 for (i = 0; i < tp->nr_args; i++) { 2060 parg = tp->args + i; 2061 if (parg->count) { 2062 if (parg->type->is_string) 2063 fmt = ", __get_str(%s[%d])"; 2064 else 2065 fmt = ", REC->%s[%d]"; 2066 for (j = 0; j < parg->count; j++) 2067 pos += snprintf(buf + pos, LEN_OR_ZERO, 2068 fmt, parg->name, j); 2069 } else { 2070 if (parg->type->is_string) 2071 fmt = ", __get_str(%s)"; 2072 else 2073 fmt = ", REC->%s"; 2074 pos += snprintf(buf + pos, LEN_OR_ZERO, 2075 fmt, parg->name); 2076 } 2077 } 2078 2079 /* return the length of print_fmt */ 2080 return pos; 2081 } 2082 #undef LEN_OR_ZERO 2083 2084 int traceprobe_set_print_fmt(struct trace_probe *tp, enum probe_print_type ptype) 2085 { 2086 struct trace_event_call *call = trace_probe_event_call(tp); 2087 int len; 2088 char *print_fmt; 2089 2090 /* First: called with 0 length to calculate the needed length */ 2091 len = __set_print_fmt(tp, NULL, 0, ptype); 2092 print_fmt = kmalloc(len + 1, GFP_KERNEL); 2093 if (!print_fmt) 2094 return -ENOMEM; 2095 2096 /* Second: actually write the @print_fmt */ 2097 __set_print_fmt(tp, print_fmt, len + 1, ptype); 2098 call->print_fmt = print_fmt; 2099 2100 return 0; 2101 } 2102 2103 int traceprobe_define_arg_fields(struct trace_event_call *event_call, 2104 size_t offset, struct trace_probe *tp) 2105 { 2106 int ret, i; 2107 2108 /* Set argument names as fields */ 2109 for (i = 0; i < tp->nr_args; i++) { 2110 struct probe_arg *parg = &tp->args[i]; 2111 const char *fmt = parg->type->fmttype; 2112 int size = parg->type->size; 2113 2114 if (parg->fmt) 2115 fmt = parg->fmt; 2116 if (parg->count) 2117 size *= parg->count; 2118 ret = trace_define_field(event_call, fmt, parg->name, 2119 offset + parg->offset, size, 2120 parg->type->is_signed, 2121 FILTER_OTHER); 2122 if (ret) 2123 return ret; 2124 } 2125 return 0; 2126 } 2127 2128 static void trace_probe_event_free(struct trace_probe_event *tpe) 2129 { 2130 kfree(tpe->class.system); 2131 kfree(tpe->call.name); 2132 kfree(tpe->call.print_fmt); 2133 kfree(tpe); 2134 } 2135 2136 int trace_probe_append(struct trace_probe *tp, struct trace_probe *to) 2137 { 2138 if (trace_probe_has_sibling(tp)) 2139 return -EBUSY; 2140 2141 list_del_init(&tp->list); 2142 trace_probe_event_free(tp->event); 2143 2144 tp->event = to->event; 2145 list_add_tail(&tp->list, trace_probe_probe_list(to)); 2146 2147 return 0; 2148 } 2149 2150 void trace_probe_unlink(struct trace_probe *tp) 2151 { 2152 list_del_init(&tp->list); 2153 if (list_empty(trace_probe_probe_list(tp))) 2154 trace_probe_event_free(tp->event); 2155 tp->event = NULL; 2156 } 2157 2158 void trace_probe_cleanup(struct trace_probe *tp) 2159 { 2160 int i; 2161 2162 for (i = 0; i < tp->nr_args; i++) 2163 traceprobe_free_probe_arg(&tp->args[i]); 2164 2165 if (tp->entry_arg) { 2166 kfree(tp->entry_arg); 2167 tp->entry_arg = NULL; 2168 } 2169 2170 if (tp->event) 2171 trace_probe_unlink(tp); 2172 } 2173 2174 int trace_probe_init(struct trace_probe *tp, const char *event, 2175 const char *group, bool alloc_filter, int nargs) 2176 { 2177 struct trace_event_call *call; 2178 size_t size = sizeof(struct trace_probe_event); 2179 int ret = 0; 2180 2181 if (!event || !group) 2182 return -EINVAL; 2183 2184 if (alloc_filter) 2185 size += sizeof(struct trace_uprobe_filter); 2186 2187 tp->event = kzalloc(size, GFP_KERNEL); 2188 if (!tp->event) 2189 return -ENOMEM; 2190 2191 INIT_LIST_HEAD(&tp->event->files); 2192 INIT_LIST_HEAD(&tp->event->class.fields); 2193 INIT_LIST_HEAD(&tp->event->probes); 2194 INIT_LIST_HEAD(&tp->list); 2195 list_add(&tp->list, &tp->event->probes); 2196 2197 call = trace_probe_event_call(tp); 2198 call->class = &tp->event->class; 2199 call->name = kstrdup(event, GFP_KERNEL); 2200 if (!call->name) { 2201 ret = -ENOMEM; 2202 goto error; 2203 } 2204 2205 tp->event->class.system = kstrdup(group, GFP_KERNEL); 2206 if (!tp->event->class.system) { 2207 ret = -ENOMEM; 2208 goto error; 2209 } 2210 2211 tp->nr_args = nargs; 2212 /* Make sure pointers in args[] are NULL */ 2213 if (nargs) 2214 memset(tp->args, 0, sizeof(tp->args[0]) * nargs); 2215 2216 return 0; 2217 2218 error: 2219 trace_probe_cleanup(tp); 2220 return ret; 2221 } 2222 2223 static struct trace_event_call * 2224 find_trace_event_call(const char *system, const char *event_name) 2225 { 2226 struct trace_event_call *tp_event; 2227 const char *name; 2228 2229 list_for_each_entry(tp_event, &ftrace_events, list) { 2230 if (!tp_event->class->system || 2231 strcmp(system, tp_event->class->system)) 2232 continue; 2233 name = trace_event_name(tp_event); 2234 if (!name || strcmp(event_name, name)) 2235 continue; 2236 return tp_event; 2237 } 2238 2239 return NULL; 2240 } 2241 2242 int trace_probe_register_event_call(struct trace_probe *tp) 2243 { 2244 struct trace_event_call *call = trace_probe_event_call(tp); 2245 int ret; 2246 2247 lockdep_assert_held(&event_mutex); 2248 2249 if (find_trace_event_call(trace_probe_group_name(tp), 2250 trace_probe_name(tp))) 2251 return -EEXIST; 2252 2253 ret = register_trace_event(&call->event); 2254 if (!ret) 2255 return -ENODEV; 2256 2257 ret = trace_add_event_call(call); 2258 if (ret) 2259 unregister_trace_event(&call->event); 2260 2261 return ret; 2262 } 2263 2264 int trace_probe_add_file(struct trace_probe *tp, struct trace_event_file *file) 2265 { 2266 struct event_file_link *link; 2267 2268 link = kmalloc_obj(*link); 2269 if (!link) 2270 return -ENOMEM; 2271 2272 link->file = file; 2273 INIT_LIST_HEAD(&link->list); 2274 list_add_tail_rcu(&link->list, &tp->event->files); 2275 trace_probe_set_flag(tp, TP_FLAG_TRACE); 2276 return 0; 2277 } 2278 2279 struct event_file_link *trace_probe_get_file_link(struct trace_probe *tp, 2280 struct trace_event_file *file) 2281 { 2282 struct event_file_link *link; 2283 2284 trace_probe_for_each_link(link, tp) { 2285 if (link->file == file) 2286 return link; 2287 } 2288 2289 return NULL; 2290 } 2291 2292 int trace_probe_remove_file(struct trace_probe *tp, 2293 struct trace_event_file *file) 2294 { 2295 struct event_file_link *link; 2296 2297 link = trace_probe_get_file_link(tp, file); 2298 if (!link) 2299 return -ENOENT; 2300 2301 list_del_rcu(&link->list); 2302 kvfree_rcu_mightsleep(link); 2303 2304 if (list_empty(&tp->event->files)) 2305 trace_probe_clear_flag(tp, TP_FLAG_TRACE); 2306 2307 return 0; 2308 } 2309 2310 /* 2311 * Return the smallest index of different type argument (start from 1). 2312 * If all argument types and name are same, return 0. 2313 */ 2314 int trace_probe_compare_arg_type(struct trace_probe *a, struct trace_probe *b) 2315 { 2316 int i; 2317 2318 /* In case of more arguments */ 2319 if (a->nr_args < b->nr_args) 2320 return a->nr_args + 1; 2321 if (a->nr_args > b->nr_args) 2322 return b->nr_args + 1; 2323 2324 for (i = 0; i < a->nr_args; i++) { 2325 if ((b->nr_args <= i) || 2326 ((a->args[i].type != b->args[i].type) || 2327 (a->args[i].count != b->args[i].count) || 2328 strcmp(a->args[i].name, b->args[i].name))) 2329 return i + 1; 2330 } 2331 2332 return 0; 2333 } 2334 2335 bool trace_probe_match_command_args(struct trace_probe *tp, 2336 int argc, const char **argv) 2337 { 2338 char buf[MAX_ARGSTR_LEN + 1]; 2339 int i; 2340 2341 if (tp->nr_args < argc) 2342 return false; 2343 2344 for (i = 0; i < argc; i++) { 2345 snprintf(buf, sizeof(buf), "%s=%s", 2346 tp->args[i].name, tp->args[i].comm); 2347 if (strcmp(buf, argv[i])) 2348 return false; 2349 } 2350 return true; 2351 } 2352 2353 int trace_probe_create(const char *raw_command, int (*createfn)(int, const char **)) 2354 { 2355 int argc = 0, ret = 0; 2356 char **argv; 2357 2358 argv = argv_split(GFP_KERNEL, raw_command, &argc); 2359 if (!argv) 2360 return -ENOMEM; 2361 2362 if (argc) 2363 ret = createfn(argc, (const char **)argv); 2364 2365 argv_free(argv); 2366 2367 return ret; 2368 } 2369 2370 int trace_probe_print_args(struct trace_seq *s, struct probe_arg *args, int nr_args, 2371 u8 *data, void *field) 2372 { 2373 void *p; 2374 int i, j; 2375 2376 for (i = 0; i < nr_args; i++) { 2377 struct probe_arg *a = args + i; 2378 2379 trace_seq_printf(s, " %s=", a->name); 2380 if (likely(!a->count)) { 2381 if (!a->type->print(s, data + a->offset, field)) 2382 return -ENOMEM; 2383 continue; 2384 } 2385 trace_seq_putc(s, '{'); 2386 p = data + a->offset; 2387 for (j = 0; j < a->count; j++) { 2388 if (!a->type->print(s, p, field)) 2389 return -ENOMEM; 2390 trace_seq_putc(s, j == a->count - 1 ? '}' : ','); 2391 p += a->type->size; 2392 } 2393 } 2394 return 0; 2395 } 2396