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 return -EINVAL; 346 } 347 348 #ifdef CONFIG_PROBE_EVENTS_BTF_ARGS 349 350 static u32 btf_type_int(const struct btf_type *t) 351 { 352 return *(u32 *)(t + 1); 353 } 354 355 static bool btf_type_is_char_ptr(struct btf *btf, const struct btf_type *type) 356 { 357 const struct btf_type *real_type; 358 u32 intdata; 359 s32 tid; 360 361 real_type = btf_type_skip_modifiers(btf, type->type, &tid); 362 if (!real_type) 363 return false; 364 365 if (BTF_INFO_KIND(real_type->info) != BTF_KIND_INT) 366 return false; 367 368 intdata = btf_type_int(real_type); 369 return !(BTF_INT_ENCODING(intdata) & BTF_INT_SIGNED) 370 && BTF_INT_BITS(intdata) == 8; 371 } 372 373 static bool btf_type_is_char_array(struct btf *btf, const struct btf_type *type) 374 { 375 const struct btf_type *real_type; 376 const struct btf_array *array; 377 u32 intdata; 378 s32 tid; 379 380 if (BTF_INFO_KIND(type->info) != BTF_KIND_ARRAY) 381 return false; 382 383 array = (const struct btf_array *)(type + 1); 384 385 real_type = btf_type_skip_modifiers(btf, array->type, &tid); 386 387 intdata = btf_type_int(real_type); 388 return !(BTF_INT_ENCODING(intdata) & BTF_INT_SIGNED) 389 && BTF_INT_BITS(intdata) == 8; 390 } 391 392 static struct btf *ctx_btf(struct traceprobe_parse_context *ctx) 393 { 394 return ctx->struct_btf ? : ctx->btf; 395 } 396 397 static int check_prepare_btf_string_fetch(char *typename, 398 struct fetch_insn **pcode, 399 struct traceprobe_parse_context *ctx) 400 { 401 struct btf *btf = ctx_btf(ctx); 402 403 if (!btf || !ctx->last_type) 404 return 0; 405 406 /* char [] does not need any change. */ 407 if (btf_type_is_char_array(btf, ctx->last_type)) 408 return 0; 409 410 /* char * requires dereference the pointer. */ 411 if (btf_type_is_char_ptr(btf, ctx->last_type)) { 412 struct fetch_insn *code = *pcode + 1; 413 414 if (code->op == FETCH_OP_END) { 415 trace_probe_log_err(ctx->offset, TOO_MANY_OPS); 416 return -E2BIG; 417 } 418 if (typename[0] == 'u') 419 code->op = FETCH_OP_UDEREF; 420 else 421 code->op = FETCH_OP_DEREF; 422 code->offset = 0; 423 *pcode = code; 424 return 0; 425 } 426 /* Other types are not available for string */ 427 trace_probe_log_err(ctx->offset, BAD_TYPE4STR); 428 return -EINVAL; 429 } 430 431 static const char *fetch_type_from_btf_type(struct btf *btf, 432 const struct btf_type *type, 433 struct traceprobe_parse_context *ctx) 434 { 435 u32 intdata; 436 437 /* TODO: const char * could be converted as a string */ 438 switch (BTF_INFO_KIND(type->info)) { 439 case BTF_KIND_ENUM: 440 /* enum is "int", so convert to "s32" */ 441 return "s32"; 442 case BTF_KIND_ENUM64: 443 return "s64"; 444 case BTF_KIND_PTR: 445 /* pointer will be converted to "x??" */ 446 if (IS_ENABLED(CONFIG_64BIT)) 447 return "x64"; 448 else 449 return "x32"; 450 case BTF_KIND_INT: 451 intdata = btf_type_int(type); 452 if (BTF_INT_ENCODING(intdata) & BTF_INT_SIGNED) { 453 switch (BTF_INT_BITS(intdata)) { 454 case 8: 455 return "s8"; 456 case 16: 457 return "s16"; 458 case 32: 459 return "s32"; 460 case 64: 461 return "s64"; 462 } 463 } else { /* unsigned */ 464 switch (BTF_INT_BITS(intdata)) { 465 case 8: 466 return "u8"; 467 case 16: 468 return "u16"; 469 case 32: 470 return "u32"; 471 case 64: 472 return "u64"; 473 } 474 /* bitfield, size is encoded in the type */ 475 ctx->last_bitsize = BTF_INT_BITS(intdata); 476 ctx->last_bitoffs += BTF_INT_OFFSET(intdata); 477 return "u64"; 478 } 479 } 480 /* TODO: support other types */ 481 482 return NULL; 483 } 484 485 static int query_btf_context(struct traceprobe_parse_context *ctx) 486 { 487 const struct btf_param *param; 488 const struct btf_type *type; 489 struct btf *btf; 490 s32 nr; 491 492 if (ctx->btf) 493 return 0; 494 495 if (!ctx->funcname) 496 return -EINVAL; 497 498 type = btf_find_func_proto(ctx->funcname, &btf); 499 if (!type) 500 return -ENOENT; 501 502 ctx->btf = btf; 503 ctx->proto = type; 504 505 /* ctx->params is optional, since func(void) will not have params. */ 506 nr = 0; 507 param = btf_get_func_param(type, &nr); 508 if (!IS_ERR_OR_NULL(param)) { 509 /* Hide the first 'data' argument of tracepoint */ 510 if (ctx->flags & TPARG_FL_TPOINT) { 511 nr--; 512 param++; 513 } 514 } 515 516 if (nr > 0) { 517 ctx->nr_params = nr; 518 ctx->params = param; 519 } else { 520 ctx->nr_params = 0; 521 ctx->params = NULL; 522 } 523 524 return 0; 525 } 526 527 static void clear_struct_btf(struct traceprobe_parse_context *ctx) 528 { 529 if (ctx->struct_btf) { 530 btf_put(ctx->struct_btf); 531 ctx->struct_btf = NULL; 532 ctx->last_struct = NULL; 533 } 534 } 535 536 static void clear_btf_context(struct traceprobe_parse_context *ctx) 537 { 538 if (ctx->btf) { 539 btf_put(ctx->btf); 540 ctx->btf = NULL; 541 ctx->proto = NULL; 542 ctx->params = NULL; 543 ctx->nr_params = 0; 544 } 545 } 546 547 /* Return 1 if the field separator is arrow operator ('->') */ 548 static int split_next_field(char *varname, char **next_field, 549 struct traceprobe_parse_context *ctx) 550 { 551 char *field; 552 int ret = 0; 553 554 field = strpbrk(varname, ".-"); 555 if (field) { 556 if (field[0] == '-' && field[1] == '>') { 557 field[0] = '\0'; 558 field += 2; 559 ret = 1; 560 } else if (field[0] == '.') { 561 field[0] = '\0'; 562 field += 1; 563 } else { 564 trace_probe_log_err(ctx->offset + field - varname, BAD_HYPHEN); 565 return -EINVAL; 566 } 567 *next_field = field; 568 } 569 570 return ret; 571 } 572 573 /* 574 * Parse the field of data structure. The @type must be a pointer type 575 * pointing the target data structure type. 576 */ 577 static int parse_btf_field(char *fieldname, const struct btf_type *type, 578 struct fetch_insn **pcode, struct fetch_insn *end, 579 struct traceprobe_parse_context *ctx) 580 { 581 struct fetch_insn *code = *pcode; 582 const struct btf_member *field; 583 u32 bitoffs, anon_offs; 584 bool is_struct = ctx->struct_btf != NULL; 585 struct btf *btf = ctx_btf(ctx); 586 char *next; 587 int is_ptr; 588 s32 tid; 589 590 do { 591 if (!is_struct) { 592 /* Outer loop for solving arrow operator ('->') */ 593 if (BTF_INFO_KIND(type->info) != BTF_KIND_PTR) { 594 trace_probe_log_err(ctx->offset, NO_PTR_STRCT); 595 return -EINVAL; 596 } 597 598 /* Convert a struct pointer type to a struct type */ 599 type = btf_type_skip_modifiers(btf, type->type, &tid); 600 if (!type) { 601 trace_probe_log_err(ctx->offset, BAD_BTF_TID); 602 return -EINVAL; 603 } 604 } 605 /* Only the first type can skip being a pointer */ 606 is_struct = false; 607 608 bitoffs = 0; 609 do { 610 /* Inner loop for solving dot operator ('.') */ 611 next = NULL; 612 is_ptr = split_next_field(fieldname, &next, ctx); 613 if (is_ptr < 0) 614 return is_ptr; 615 616 anon_offs = 0; 617 field = btf_find_struct_member(btf, type, fieldname, 618 &anon_offs); 619 if (IS_ERR(field)) { 620 trace_probe_log_err(ctx->offset, BAD_BTF_TID); 621 return PTR_ERR(field); 622 } 623 if (!field) { 624 trace_probe_log_err(ctx->offset, NO_BTF_FIELD); 625 return -ENOENT; 626 } 627 /* Add anonymous structure/union offset */ 628 bitoffs += anon_offs; 629 630 /* Accumulate the bit-offsets of the dot-connected fields */ 631 if (btf_type_kflag(type)) { 632 bitoffs += BTF_MEMBER_BIT_OFFSET(field->offset); 633 ctx->last_bitsize = BTF_MEMBER_BITFIELD_SIZE(field->offset); 634 } else { 635 bitoffs += field->offset; 636 ctx->last_bitsize = 0; 637 } 638 639 type = btf_type_skip_modifiers(btf, field->type, &tid); 640 if (!type) { 641 trace_probe_log_err(ctx->offset, BAD_BTF_TID); 642 return -EINVAL; 643 } 644 645 ctx->offset += next - fieldname; 646 fieldname = next; 647 } while (!is_ptr && fieldname); 648 649 if (++code == end) { 650 trace_probe_log_err(ctx->offset, TOO_MANY_OPS); 651 return -EINVAL; 652 } 653 code->op = FETCH_OP_DEREF; /* TODO: user deref support */ 654 code->offset = bitoffs / 8; 655 *pcode = code; 656 657 ctx->last_bitoffs = bitoffs % 8; 658 ctx->last_type = type; 659 } while (fieldname); 660 661 return 0; 662 } 663 664 static int __store_entry_arg(struct trace_probe *tp, int argnum); 665 666 static int parse_btf_arg(char *varname, 667 struct fetch_insn **pcode, struct fetch_insn *end, 668 struct traceprobe_parse_context *ctx) 669 { 670 struct fetch_insn *code = *pcode; 671 const struct btf_param *params; 672 const struct btf_type *type; 673 char *field = NULL; 674 int i, is_ptr, ret; 675 u32 tid; 676 677 if (!ctx->funcname && !(ctx->flags & TPARG_FL_TEVENT)) 678 return -EINVAL; 679 680 is_ptr = split_next_field(varname, &field, ctx); 681 if (is_ptr < 0) 682 return is_ptr; 683 if (!is_ptr && field) { 684 /* dot-connected field on an argument is not supported. */ 685 trace_probe_log_err(ctx->offset + field - varname, 686 NOSUP_DAT_ARG); 687 return -EOPNOTSUPP; 688 } 689 690 if (ctx->flags & TPARG_FL_TEVENT) { 691 ret = parse_trace_event(varname, code, ctx); 692 if (ret < 0) { 693 trace_probe_log_err(ctx->offset, BAD_ATTACH_ARG); 694 return ret; 695 } 696 /* TEVENT is only here via a typecast */ 697 if (WARN_ON_ONCE(ctx->struct_btf == NULL)) 698 return -EINVAL; 699 type = ctx->last_struct; 700 goto found_type; 701 } 702 703 if (ctx->flags & TPARG_FL_RETURN && !strcmp(varname, "$retval")) { 704 code->op = FETCH_OP_RETVAL; 705 /* Check whether the function return type is not void */ 706 if (query_btf_context(ctx) == 0) { 707 if (ctx->proto->type == 0) { 708 trace_probe_log_err(ctx->offset, NO_RETVAL); 709 return -ENOENT; 710 } 711 tid = ctx->proto->type; 712 goto found; 713 } 714 if (field) { 715 trace_probe_log_err(ctx->offset + field - varname, 716 NO_BTF_ENTRY); 717 return -ENOENT; 718 } 719 return 0; 720 } 721 722 if (!ctx->btf) { 723 ret = query_btf_context(ctx); 724 if (ret < 0 || ctx->nr_params == 0) { 725 trace_probe_log_err(ctx->offset, NO_BTF_ENTRY); 726 return -ENOENT; 727 } 728 } 729 params = ctx->params; 730 731 for (i = 0; i < ctx->nr_params; i++) { 732 const char *name = btf_name_by_offset(ctx->btf, params[i].name_off); 733 734 if (name && !strcmp(name, varname)) { 735 if (tparg_is_function_entry(ctx->flags)) { 736 code->op = FETCH_OP_ARG; 737 if (ctx->flags & TPARG_FL_TPOINT) 738 code->param = i + 1; 739 else 740 code->param = i; 741 } else if (tparg_is_function_return(ctx->flags)) { 742 code->op = FETCH_OP_EDATA; 743 ret = __store_entry_arg(ctx->tp, i); 744 if (ret < 0) { 745 /* internal error */ 746 return ret; 747 } 748 code->offset = ret; 749 } 750 tid = params[i].type; 751 goto found; 752 } 753 } 754 trace_probe_log_err(ctx->offset, NO_BTFARG); 755 return -ENOENT; 756 757 found: 758 type = btf_type_skip_modifiers(ctx->btf, tid, &tid); 759 found_type: 760 if (!type) { 761 trace_probe_log_err(ctx->offset, BAD_BTF_TID); 762 return -EINVAL; 763 } 764 /* Initialize the last type information */ 765 ctx->last_type = type; 766 ctx->last_bitoffs = 0; 767 ctx->last_bitsize = 0; 768 if (field) { 769 ctx->offset += field - varname; 770 return parse_btf_field(field, type, pcode, end, ctx); 771 } 772 return 0; 773 } 774 775 static const struct fetch_type *find_fetch_type_from_btf_type( 776 struct traceprobe_parse_context *ctx) 777 { 778 struct btf *btf = ctx_btf(ctx); 779 const char *typestr = NULL; 780 781 if (btf && ctx->last_type) 782 typestr = fetch_type_from_btf_type(btf, ctx->last_type, ctx); 783 784 return find_fetch_type(typestr, ctx->flags); 785 } 786 787 static int parse_btf_bitfield(struct fetch_insn **pcode, 788 struct traceprobe_parse_context *ctx) 789 { 790 struct fetch_insn *code = *pcode; 791 792 if ((ctx->last_bitsize % 8 == 0) && ctx->last_bitoffs == 0) 793 return 0; 794 795 code++; 796 if (code->op != FETCH_OP_NOP) { 797 trace_probe_log_err(ctx->offset, TOO_MANY_OPS); 798 return -EINVAL; 799 } 800 *pcode = code; 801 802 code->op = FETCH_OP_MOD_BF; 803 code->lshift = 64 - (ctx->last_bitsize + ctx->last_bitoffs); 804 code->rshift = 64 - ctx->last_bitsize; 805 code->basesize = 64 / 8; 806 return 0; 807 } 808 809 static int query_btf_struct(const char *sname, struct traceprobe_parse_context *ctx) 810 { 811 struct btf *btf = NULL; 812 int id; 813 814 /* A struct_btf should only be used by a single argument */ 815 if (WARN_ON_ONCE(ctx->struct_btf)) { 816 btf_put(ctx->struct_btf); 817 ctx->struct_btf = NULL; 818 } 819 820 id = bpf_find_btf_id(sname, BTF_KIND_STRUCT, &btf); 821 if (id < 0) 822 return id; 823 ctx->struct_btf = btf; 824 ctx->last_struct = btf_type_by_id(ctx->struct_btf, id); 825 return 0; 826 } 827 828 static int handle_typecast(char *arg, struct fetch_insn **pcode, 829 struct fetch_insn *end, 830 struct traceprobe_parse_context *ctx) 831 { 832 char *tmp; 833 int ret; 834 835 /* Currently this only works for eprobes */ 836 if (!(ctx->flags & TPARG_FL_TEVENT)) { 837 trace_probe_log_err(ctx->offset, TYPECAST_NOT_EVENT); 838 return -EINVAL; 839 } 840 841 tmp = strchr(arg, ')'); 842 if (!tmp) { 843 trace_probe_log_err(ctx->offset + strlen(arg), 844 DEREF_OPEN_BRACE); 845 return -EINVAL; 846 } 847 *tmp = '\0'; 848 ret = query_btf_struct(arg + 1, ctx); 849 *tmp = ')'; 850 851 if (ret < 0) { 852 trace_probe_log_err(ctx->offset + 1, NO_PTR_STRCT); 853 return -EINVAL; 854 } 855 856 tmp++; 857 858 ctx->offset += tmp - arg; 859 ret = parse_btf_arg(tmp, pcode, end, ctx); 860 return ret; 861 } 862 863 #else /* !CONFIG_PROBE_EVENTS_BTF_ARGS */ 864 865 static void clear_struct_btf(struct traceprobe_parse_context *ctx) 866 { 867 ctx->struct_btf = NULL; 868 } 869 870 static void clear_btf_context(struct traceprobe_parse_context *ctx) 871 { 872 ctx->btf = NULL; 873 } 874 875 static int query_btf_context(struct traceprobe_parse_context *ctx) 876 { 877 return -EOPNOTSUPP; 878 } 879 880 static int parse_btf_arg(char *varname, 881 struct fetch_insn **pcode, struct fetch_insn *end, 882 struct traceprobe_parse_context *ctx) 883 { 884 trace_probe_log_err(ctx->offset, NOSUP_BTFARG); 885 return -EOPNOTSUPP; 886 } 887 888 static int parse_btf_bitfield(struct fetch_insn **pcode, 889 struct traceprobe_parse_context *ctx) 890 { 891 trace_probe_log_err(ctx->offset, NOSUP_BTFARG); 892 return -EOPNOTSUPP; 893 } 894 895 #define find_fetch_type_from_btf_type(ctx) \ 896 find_fetch_type(NULL, ctx->flags) 897 898 static int check_prepare_btf_string_fetch(char *typename, 899 struct fetch_insn **pcode, 900 struct traceprobe_parse_context *ctx) 901 { 902 return 0; 903 } 904 905 static int handle_typecast(char *arg, struct fetch_insn **pcode, 906 struct fetch_insn *end, 907 struct traceprobe_parse_context *ctx) 908 { 909 trace_probe_log_err(ctx->offset, NOSUP_BTFARG); 910 return -EOPNOTSUPP; 911 } 912 913 #endif /* CONFIG_PROBE_EVENTS_BTF_ARGS */ 914 915 #ifdef CONFIG_HAVE_FUNCTION_ARG_ACCESS_API 916 917 static void store_entry_arg_at(struct fetch_insn *code, int argnum, int offset) 918 { 919 code[0].op = FETCH_OP_ARG; 920 code[0].param = argnum; 921 code[1].op = FETCH_OP_ST_EDATA; 922 code[1].offset = offset; 923 } 924 925 static int get_entry_arg_max_offset(struct probe_entry_arg *earg) 926 { 927 int i, max_offset = 0; 928 929 /* 930 * earg->code[] array has an operation sequence which is run in 931 * the entry handler. 932 * The sequence stopped by FETCH_OP_END and each data stored in 933 * the entry data buffer by FETCH_OP_ST_EDATA. The FETCH_OP_ST_EDATA 934 * stores the data at the data buffer + its offset, and all data are 935 * "unsigned long" size. The offset must be increased when a data is 936 * stored. Thus we need to find the last FETCH_OP_ST_EDATA in the 937 * code array. 938 */ 939 for (i = 0; i < earg->size - 1 && earg->code[i].op != FETCH_OP_END; i++) { 940 if (earg->code[i].op == FETCH_OP_ST_EDATA) 941 if (earg->code[i].offset > max_offset) 942 max_offset = earg->code[i].offset; 943 } 944 return max_offset; 945 } 946 947 /* 948 * Add the entry code to store the 'argnum'th parameter and return the offset 949 * in the entry data buffer where the data will be stored. 950 */ 951 static int __store_entry_arg(struct trace_probe *tp, int argnum) 952 { 953 struct probe_entry_arg *earg = tp->entry_arg; 954 int i, offset, last_offset = 0; 955 956 if (!earg) { 957 earg = kzalloc_flex(*earg, code, 2 * tp->nr_args + 1); 958 if (!earg) 959 return -ENOMEM; 960 earg->size = 2 * tp->nr_args + 1; 961 /* Fill the code buffer with 'end' to simplify it */ 962 for (i = 0; i < earg->size; i++) 963 earg->code[i].op = FETCH_OP_END; 964 tp->entry_arg = earg; 965 store_entry_arg_at(earg->code, argnum, 0); 966 return 0; 967 } 968 969 /* 970 * NOTE: if anyone change the following rule, please rewrite this. 971 * The entry code array is filled with the pair of 972 * 973 * [FETCH_OP_ARG(argnum)] 974 * [FETCH_OP_ST_EDATA(offset of entry data buffer)] 975 * 976 * and the rest of entries are filled with [FETCH_OP_END]. 977 * The offset should be incremented, thus the last pair should 978 * have the largest offset. 979 */ 980 981 /* Search the offset for the sprcified argnum. */ 982 for (i = 0; i < earg->size - 1 && earg->code[i].op != FETCH_OP_END; i += 2) { 983 if (WARN_ON_ONCE(earg->code[i].op != FETCH_OP_ARG)) 984 return -EINVAL; 985 986 if (earg->code[i].param != argnum) 987 continue; 988 989 if (WARN_ON_ONCE(earg->code[i + 1].op != FETCH_OP_ST_EDATA)) 990 return -EINVAL; 991 992 return earg->code[i + 1].offset; 993 } 994 /* Not found, append new entry if possible. */ 995 if (i >= earg->size - 1) 996 return -ENOSPC; 997 998 /* The last entry must have the largest offset. */ 999 if (i != 0) { 1000 if (WARN_ON_ONCE(earg->code[i - 1].op != FETCH_OP_ST_EDATA)) 1001 return -EINVAL; 1002 last_offset = earg->code[i - 1].offset; 1003 } 1004 1005 offset = last_offset + sizeof(unsigned long); 1006 store_entry_arg_at(&earg->code[i], argnum, offset); 1007 return offset; 1008 } 1009 1010 int traceprobe_get_entry_data_size(struct trace_probe *tp) 1011 { 1012 struct probe_entry_arg *earg = tp->entry_arg; 1013 1014 if (!earg) 1015 return 0; 1016 1017 return get_entry_arg_max_offset(earg) + sizeof(unsigned long); 1018 } 1019 1020 void store_trace_entry_data(void *edata, struct trace_probe *tp, struct pt_regs *regs) 1021 { 1022 struct probe_entry_arg *earg = tp->entry_arg; 1023 unsigned long val = 0; 1024 int i; 1025 1026 if (!earg) 1027 return; 1028 1029 for (i = 0; i < earg->size; i++) { 1030 struct fetch_insn *code = &earg->code[i]; 1031 1032 switch (code->op) { 1033 case FETCH_OP_ARG: 1034 val = regs_get_kernel_argument(regs, code->param); 1035 break; 1036 case FETCH_OP_ST_EDATA: 1037 *(unsigned long *)((unsigned long)edata + code->offset) = val; 1038 break; 1039 case FETCH_OP_END: 1040 goto end; 1041 default: 1042 break; 1043 } 1044 } 1045 end: 1046 return; 1047 } 1048 NOKPROBE_SYMBOL(store_trace_entry_data) 1049 #endif 1050 1051 #define PARAM_MAX_STACK (THREAD_SIZE / sizeof(unsigned long)) 1052 1053 /* Parse $vars. @orig_arg points '$', which syncs to @ctx->offset */ 1054 static int parse_probe_vars(char *orig_arg, const struct fetch_type *t, 1055 struct fetch_insn **pcode, 1056 struct fetch_insn *end, 1057 struct traceprobe_parse_context *ctx) 1058 { 1059 struct fetch_insn *code = *pcode; 1060 int err = TP_ERR_BAD_VAR; 1061 char *arg = orig_arg + 1; 1062 unsigned long param; 1063 int ret = 0; 1064 int len; 1065 1066 if (ctx->flags & TPARG_FL_TEVENT) { 1067 if (parse_trace_event(arg, code, ctx) < 0) { 1068 /* 'comm' should be checked after field parsing. */ 1069 if (strcmp(arg, "comm") == 0 || strcmp(arg, "COMM") == 0) { 1070 code->op = FETCH_OP_COMM; 1071 return 0; 1072 } 1073 goto inval; 1074 } 1075 return 0; 1076 } 1077 1078 if (str_has_prefix(arg, "retval")) { 1079 if (!(ctx->flags & TPARG_FL_RETURN)) { 1080 err = TP_ERR_RETVAL_ON_PROBE; 1081 goto inval; 1082 } 1083 if (!(ctx->flags & TPARG_FL_KERNEL) || 1084 !IS_ENABLED(CONFIG_PROBE_EVENTS_BTF_ARGS)) { 1085 code->op = FETCH_OP_RETVAL; 1086 return 0; 1087 } 1088 return parse_btf_arg(orig_arg, pcode, end, ctx); 1089 } 1090 1091 len = str_has_prefix(arg, "stack"); 1092 if (len) { 1093 1094 if (arg[len] == '\0') { 1095 code->op = FETCH_OP_STACKP; 1096 return 0; 1097 } 1098 1099 if (isdigit(arg[len])) { 1100 ret = kstrtoul(arg + len, 10, ¶m); 1101 if (ret) 1102 goto inval; 1103 1104 if ((ctx->flags & TPARG_FL_KERNEL) && 1105 param > PARAM_MAX_STACK) { 1106 err = TP_ERR_BAD_STACK_NUM; 1107 goto inval; 1108 } 1109 code->op = FETCH_OP_STACK; 1110 code->param = (unsigned int)param; 1111 return 0; 1112 } 1113 goto inval; 1114 } 1115 1116 if (strcmp(arg, "comm") == 0 || strcmp(arg, "COMM") == 0) { 1117 code->op = FETCH_OP_COMM; 1118 return 0; 1119 } 1120 1121 #ifdef CONFIG_HAVE_FUNCTION_ARG_ACCESS_API 1122 len = str_has_prefix(arg, "arg"); 1123 if (len) { 1124 ret = kstrtoul(arg + len, 10, ¶m); 1125 if (ret) 1126 goto inval; 1127 1128 if (!param || param > PARAM_MAX_STACK) { 1129 err = TP_ERR_BAD_ARG_NUM; 1130 goto inval; 1131 } 1132 param--; /* argN starts from 1, but internal arg[N] starts from 0 */ 1133 1134 if (tparg_is_function_entry(ctx->flags)) { 1135 code->op = FETCH_OP_ARG; 1136 code->param = (unsigned int)param; 1137 /* 1138 * The tracepoint probe will probe a stub function, and the 1139 * first parameter of the stub is a dummy and should be ignored. 1140 */ 1141 if (ctx->flags & TPARG_FL_TPOINT) 1142 code->param++; 1143 } else if (tparg_is_function_return(ctx->flags)) { 1144 /* function entry argument access from return probe */ 1145 ret = __store_entry_arg(ctx->tp, param); 1146 if (ret < 0) /* This error should be an internal error */ 1147 return ret; 1148 1149 code->op = FETCH_OP_EDATA; 1150 code->offset = ret; 1151 } else { 1152 err = TP_ERR_NOFENTRY_ARGS; 1153 goto inval; 1154 } 1155 return 0; 1156 } 1157 #endif 1158 1159 inval: 1160 __trace_probe_log_err(ctx->offset, err); 1161 return -EINVAL; 1162 } 1163 1164 static int str_to_immediate(char *str, unsigned long *imm) 1165 { 1166 if (isdigit(str[0])) 1167 return kstrtoul(str, 0, imm); 1168 else if (str[0] == '-') 1169 return kstrtol(str, 0, (long *)imm); 1170 else if (str[0] == '+') 1171 return kstrtol(str + 1, 0, (long *)imm); 1172 return -EINVAL; 1173 } 1174 1175 static int __parse_imm_string(char *str, char **pbuf, int offs) 1176 { 1177 size_t len = strlen(str); 1178 1179 if (!len || str[len - 1] != '"') { 1180 trace_probe_log_err(offs + len, IMMSTR_NO_CLOSE); 1181 return -EINVAL; 1182 } 1183 *pbuf = kstrndup(str, len - 1, GFP_KERNEL); 1184 if (!*pbuf) 1185 return -ENOMEM; 1186 return 0; 1187 } 1188 1189 /* Recursive argument parser */ 1190 static int 1191 parse_probe_arg(char *arg, const struct fetch_type *type, 1192 struct fetch_insn **pcode, struct fetch_insn *end, 1193 struct traceprobe_parse_context *ctx) 1194 { 1195 struct fetch_insn *code = *pcode; 1196 unsigned long param; 1197 int deref = FETCH_OP_DEREF; 1198 long offset = 0; 1199 char *tmp; 1200 int ret = 0; 1201 1202 switch (arg[0]) { 1203 case '$': 1204 ret = parse_probe_vars(arg, type, pcode, end, ctx); 1205 break; 1206 1207 case '%': /* named register */ 1208 if (ctx->flags & (TPARG_FL_TEVENT | TPARG_FL_FPROBE)) { 1209 /* eprobe and fprobe do not handle registers */ 1210 trace_probe_log_err(ctx->offset, BAD_VAR); 1211 break; 1212 } 1213 ret = regs_query_register_offset(arg + 1); 1214 if (ret >= 0) { 1215 code->op = FETCH_OP_REG; 1216 code->param = (unsigned int)ret; 1217 ret = 0; 1218 } else 1219 trace_probe_log_err(ctx->offset, BAD_REG_NAME); 1220 break; 1221 1222 case '@': /* memory, file-offset or symbol */ 1223 if (isdigit(arg[1])) { 1224 ret = kstrtoul(arg + 1, 0, ¶m); 1225 if (ret) { 1226 trace_probe_log_err(ctx->offset, BAD_MEM_ADDR); 1227 break; 1228 } 1229 /* load address */ 1230 code->op = FETCH_OP_IMM; 1231 code->immediate = param; 1232 } else if (arg[1] == '+') { 1233 /* kprobes don't support file offsets */ 1234 if (ctx->flags & TPARG_FL_KERNEL) { 1235 trace_probe_log_err(ctx->offset, FILE_ON_KPROBE); 1236 return -EINVAL; 1237 } 1238 ret = kstrtol(arg + 2, 0, &offset); 1239 if (ret) { 1240 trace_probe_log_err(ctx->offset, BAD_FILE_OFFS); 1241 break; 1242 } 1243 1244 code->op = FETCH_OP_FOFFS; 1245 code->immediate = (unsigned long)offset; // imm64? 1246 offset = 0; 1247 } else { 1248 /* uprobes don't support symbols */ 1249 if (!(ctx->flags & TPARG_FL_KERNEL)) { 1250 trace_probe_log_err(ctx->offset, SYM_ON_UPROBE); 1251 return -EINVAL; 1252 } 1253 /* Preserve symbol for updating */ 1254 code->op = FETCH_NOP_SYMBOL; 1255 code->data = kstrdup(arg + 1, GFP_KERNEL); 1256 if (!code->data) 1257 return -ENOMEM; 1258 if (++code == end) { 1259 trace_probe_log_err(ctx->offset, TOO_MANY_OPS); 1260 return -EINVAL; 1261 } 1262 code->op = FETCH_OP_IMM; 1263 code->immediate = 0; 1264 } 1265 /* These are fetching from memory */ 1266 if (++code == end) { 1267 trace_probe_log_err(ctx->offset, TOO_MANY_OPS); 1268 return -EINVAL; 1269 } 1270 *pcode = code; 1271 code->op = FETCH_OP_DEREF; 1272 code->offset = offset; 1273 break; 1274 1275 case '+': /* deref memory */ 1276 case '-': 1277 if (arg[1] == 'u') { 1278 deref = FETCH_OP_UDEREF; 1279 arg[1] = arg[0]; 1280 arg++; 1281 } 1282 if (arg[0] == '+') 1283 arg++; /* Skip '+', because kstrtol() rejects it. */ 1284 tmp = strchr(arg, '('); 1285 if (!tmp) { 1286 trace_probe_log_err(ctx->offset, DEREF_NEED_BRACE); 1287 return -EINVAL; 1288 } 1289 *tmp = '\0'; 1290 ret = kstrtol(arg, 0, &offset); 1291 if (ret) { 1292 trace_probe_log_err(ctx->offset, BAD_DEREF_OFFS); 1293 break; 1294 } 1295 ctx->offset += (tmp + 1 - arg) + (arg[0] != '-' ? 1 : 0); 1296 arg = tmp + 1; 1297 tmp = strrchr(arg, ')'); 1298 if (!tmp) { 1299 trace_probe_log_err(ctx->offset + strlen(arg), 1300 DEREF_OPEN_BRACE); 1301 return -EINVAL; 1302 } else { 1303 const struct fetch_type *t2 = find_fetch_type(NULL, ctx->flags); 1304 int cur_offs = ctx->offset; 1305 1306 *tmp = '\0'; 1307 ret = parse_probe_arg(arg, t2, &code, end, ctx); 1308 if (ret) 1309 break; 1310 ctx->offset = cur_offs; 1311 if (code->op == FETCH_OP_COMM || 1312 code->op == FETCH_OP_DATA) { 1313 trace_probe_log_err(ctx->offset, COMM_CANT_DEREF); 1314 return -EINVAL; 1315 } 1316 if (++code == end) { 1317 trace_probe_log_err(ctx->offset, TOO_MANY_OPS); 1318 return -EINVAL; 1319 } 1320 *pcode = code; 1321 1322 code->op = deref; 1323 code->offset = offset; 1324 /* Reset the last type if used */ 1325 ctx->last_type = NULL; 1326 } 1327 break; 1328 case '\\': /* Immediate value */ 1329 if (arg[1] == '"') { /* Immediate string */ 1330 ret = __parse_imm_string(arg + 2, &tmp, ctx->offset + 2); 1331 if (ret) 1332 break; 1333 code->op = FETCH_OP_DATA; 1334 code->data = tmp; 1335 } else { 1336 ret = str_to_immediate(arg + 1, &code->immediate); 1337 if (ret) 1338 trace_probe_log_err(ctx->offset + 1, BAD_IMM); 1339 else 1340 code->op = FETCH_OP_IMM; 1341 } 1342 break; 1343 case '(': 1344 ret = handle_typecast(arg, pcode, end, ctx); 1345 break; 1346 default: 1347 if (isalpha(arg[0]) || arg[0] == '_') { /* BTF variable */ 1348 if (!tparg_is_function_entry(ctx->flags) && 1349 !tparg_is_function_return(ctx->flags)) { 1350 trace_probe_log_err(ctx->offset, NOSUP_BTFARG); 1351 return -EINVAL; 1352 } 1353 ret = parse_btf_arg(arg, pcode, end, ctx); 1354 break; 1355 } 1356 } 1357 if (!ret && code->op == FETCH_OP_NOP) { 1358 /* Parsed, but do not find fetch method */ 1359 trace_probe_log_err(ctx->offset, BAD_FETCH_ARG); 1360 ret = -EINVAL; 1361 } 1362 return ret; 1363 } 1364 1365 /* Bitfield type needs to be parsed into a fetch function */ 1366 static int __parse_bitfield_probe_arg(const char *bf, 1367 const struct fetch_type *t, 1368 struct fetch_insn **pcode) 1369 { 1370 struct fetch_insn *code = *pcode; 1371 unsigned long bw, bo; 1372 char *tail; 1373 1374 if (*bf != 'b') 1375 return 0; 1376 1377 bw = simple_strtoul(bf + 1, &tail, 0); /* Use simple one */ 1378 1379 if (bw == 0 || *tail != '@') 1380 return -EINVAL; 1381 1382 bf = tail + 1; 1383 bo = simple_strtoul(bf, &tail, 0); 1384 1385 if (tail == bf || *tail != '/') 1386 return -EINVAL; 1387 code++; 1388 if (code->op != FETCH_OP_NOP) 1389 return -EINVAL; 1390 *pcode = code; 1391 1392 code->op = FETCH_OP_MOD_BF; 1393 code->lshift = BYTES_TO_BITS(t->size) - (bw + bo); 1394 code->rshift = BYTES_TO_BITS(t->size) - bw; 1395 code->basesize = t->size; 1396 1397 return (BYTES_TO_BITS(t->size) < (bw + bo)) ? -EINVAL : 0; 1398 } 1399 1400 /* Split type part from @arg and return it. */ 1401 static char *parse_probe_arg_type(char *arg, struct probe_arg *parg, 1402 struct traceprobe_parse_context *ctx) 1403 { 1404 char *t = NULL, *t2, *t3; 1405 int offs; 1406 1407 t = strchr(arg, ':'); 1408 if (t) { 1409 *t++ = '\0'; 1410 t2 = strchr(t, '['); 1411 if (t2) { 1412 *t2++ = '\0'; 1413 t3 = strchr(t2, ']'); 1414 if (!t3) { 1415 offs = t2 + strlen(t2) - arg; 1416 1417 trace_probe_log_err(ctx->offset + offs, 1418 ARRAY_NO_CLOSE); 1419 return ERR_PTR(-EINVAL); 1420 } else if (t3[1] != '\0') { 1421 trace_probe_log_err(ctx->offset + t3 + 1 - arg, 1422 BAD_ARRAY_SUFFIX); 1423 return ERR_PTR(-EINVAL); 1424 } 1425 *t3 = '\0'; 1426 if (kstrtouint(t2, 0, &parg->count) || !parg->count) { 1427 trace_probe_log_err(ctx->offset + t2 - arg, 1428 BAD_ARRAY_NUM); 1429 return ERR_PTR(-EINVAL); 1430 } 1431 if (parg->count > MAX_ARRAY_LEN) { 1432 trace_probe_log_err(ctx->offset + t2 - arg, 1433 ARRAY_TOO_BIG); 1434 return ERR_PTR(-EINVAL); 1435 } 1436 } 1437 } 1438 offs = t ? t - arg : 0; 1439 1440 /* 1441 * Since $comm and immediate string can not be dereferenced, 1442 * we can find those by strcmp. But ignore for eprobes. 1443 */ 1444 if (!(ctx->flags & TPARG_FL_TEVENT) && 1445 (strcmp(arg, "$comm") == 0 || strcmp(arg, "$COMM") == 0 || 1446 strncmp(arg, "\\\"", 2) == 0)) { 1447 /* The type of $comm must be "string", and not an array type. */ 1448 if (parg->count || (t && strcmp(t, "string"))) { 1449 trace_probe_log_err(ctx->offset + offs, NEED_STRING_TYPE); 1450 return ERR_PTR(-EINVAL); 1451 } 1452 parg->type = find_fetch_type("string", ctx->flags); 1453 } else 1454 parg->type = find_fetch_type(t, ctx->flags); 1455 1456 if (!parg->type) { 1457 trace_probe_log_err(ctx->offset + offs, BAD_TYPE); 1458 return ERR_PTR(-EINVAL); 1459 } 1460 1461 return t; 1462 } 1463 1464 /* After parsing, adjust the fetch_insn according to the probe_arg */ 1465 static int finalize_fetch_insn(struct fetch_insn *code, 1466 struct probe_arg *parg, 1467 char *type, 1468 int type_offset, 1469 struct traceprobe_parse_context *ctx) 1470 { 1471 struct fetch_insn *scode; 1472 int ret; 1473 1474 /* Store operation */ 1475 if (parg->type->is_string) { 1476 /* Check bad combination of the type and the last fetch_insn. */ 1477 if (!strcmp(parg->type->name, "symstr")) { 1478 if (code->op != FETCH_OP_REG && code->op != FETCH_OP_STACK && 1479 code->op != FETCH_OP_RETVAL && code->op != FETCH_OP_ARG && 1480 code->op != FETCH_OP_DEREF && code->op != FETCH_OP_TP_ARG) { 1481 trace_probe_log_err(ctx->offset + type_offset, 1482 BAD_SYMSTRING); 1483 return -EINVAL; 1484 } 1485 } else { 1486 if (code->op != FETCH_OP_DEREF && code->op != FETCH_OP_UDEREF && 1487 code->op != FETCH_OP_IMM && code->op != FETCH_OP_COMM && 1488 code->op != FETCH_OP_DATA && code->op != FETCH_OP_TP_ARG) { 1489 trace_probe_log_err(ctx->offset + type_offset, 1490 BAD_STRING); 1491 return -EINVAL; 1492 } 1493 } 1494 1495 if (!strcmp(parg->type->name, "symstr") || 1496 (code->op == FETCH_OP_IMM || code->op == FETCH_OP_COMM || 1497 code->op == FETCH_OP_DATA) || code->op == FETCH_OP_TP_ARG || 1498 parg->count) { 1499 /* 1500 * IMM, DATA and COMM is pointing actual address, those 1501 * must be kept, and if parg->count != 0, this is an 1502 * array of string pointers instead of string address 1503 * itself. 1504 * For the symstr, it doesn't need to dereference, thus 1505 * it just get the value. 1506 */ 1507 code++; 1508 if (code->op != FETCH_OP_NOP) { 1509 trace_probe_log_err(ctx->offset, TOO_MANY_OPS); 1510 return -EINVAL; 1511 } 1512 } 1513 1514 /* If op == DEREF, replace it with STRING */ 1515 if (!strcmp(parg->type->name, "ustring") || 1516 code->op == FETCH_OP_UDEREF) 1517 code->op = FETCH_OP_ST_USTRING; 1518 else if (!strcmp(parg->type->name, "symstr")) 1519 code->op = FETCH_OP_ST_SYMSTR; 1520 else 1521 code->op = FETCH_OP_ST_STRING; 1522 code->size = parg->type->size; 1523 parg->dynamic = true; 1524 } else if (code->op == FETCH_OP_DEREF) { 1525 code->op = FETCH_OP_ST_MEM; 1526 code->size = parg->type->size; 1527 } else if (code->op == FETCH_OP_UDEREF) { 1528 code->op = FETCH_OP_ST_UMEM; 1529 code->size = parg->type->size; 1530 } else { 1531 code++; 1532 if (code->op != FETCH_OP_NOP) { 1533 trace_probe_log_err(ctx->offset, TOO_MANY_OPS); 1534 return -E2BIG; 1535 } 1536 code->op = FETCH_OP_ST_RAW; 1537 code->size = parg->type->size; 1538 } 1539 1540 /* Save storing fetch_insn. */ 1541 scode = code; 1542 1543 /* Modify operation */ 1544 if (type != NULL) { 1545 /* Bitfield needs a special fetch_insn. */ 1546 ret = __parse_bitfield_probe_arg(type, parg->type, &code); 1547 if (ret) { 1548 trace_probe_log_err(ctx->offset + type_offset, BAD_BITFIELD); 1549 return ret; 1550 } 1551 } else if (IS_ENABLED(CONFIG_PROBE_EVENTS_BTF_ARGS) && 1552 ctx->last_type) { 1553 /* If user not specified the type, try parsing BTF bitfield. */ 1554 ret = parse_btf_bitfield(&code, ctx); 1555 if (ret) 1556 return ret; 1557 } 1558 1559 /* Loop(Array) operation */ 1560 if (parg->count) { 1561 if (scode->op != FETCH_OP_ST_MEM && 1562 scode->op != FETCH_OP_ST_STRING && 1563 scode->op != FETCH_OP_ST_USTRING) { 1564 trace_probe_log_err(ctx->offset + type_offset, BAD_STRING); 1565 return -EINVAL; 1566 } 1567 code++; 1568 if (code->op != FETCH_OP_NOP) { 1569 trace_probe_log_err(ctx->offset, TOO_MANY_OPS); 1570 return -E2BIG; 1571 } 1572 code->op = FETCH_OP_LP_ARRAY; 1573 code->param = parg->count; 1574 } 1575 1576 /* Finalize the fetch_insn array. */ 1577 code++; 1578 code->op = FETCH_OP_END; 1579 1580 return 0; 1581 } 1582 1583 /* String length checking wrapper */ 1584 static int traceprobe_parse_probe_arg_body(const char *argv, ssize_t *size, 1585 struct probe_arg *parg, 1586 struct traceprobe_parse_context *ctx) 1587 { 1588 struct fetch_insn *code, *tmp = NULL; 1589 char *type, *arg __free(kfree) = NULL; 1590 int ret, len; 1591 1592 len = strlen(argv); 1593 if (len > MAX_ARGSTR_LEN) { 1594 trace_probe_log_err(ctx->offset, ARG_TOO_LONG); 1595 return -E2BIG; 1596 } else if (len == 0) { 1597 trace_probe_log_err(ctx->offset, NO_ARG_BODY); 1598 return -EINVAL; 1599 } 1600 1601 arg = kstrdup(argv, GFP_KERNEL); 1602 if (!arg) 1603 return -ENOMEM; 1604 1605 parg->comm = kstrdup(arg, GFP_KERNEL); 1606 if (!parg->comm) 1607 return -ENOMEM; 1608 1609 type = parse_probe_arg_type(arg, parg, ctx); 1610 if (IS_ERR(type)) 1611 return PTR_ERR(type); 1612 1613 code = tmp = kzalloc_objs(*code, FETCH_INSN_MAX); 1614 if (!code) 1615 return -ENOMEM; 1616 code[FETCH_INSN_MAX - 1].op = FETCH_OP_END; 1617 1618 ctx->last_type = NULL; 1619 ret = parse_probe_arg(arg, parg->type, &code, &code[FETCH_INSN_MAX - 1], 1620 ctx); 1621 if (ret < 0) 1622 goto fail; 1623 1624 /* Update storing type if BTF is available */ 1625 if (IS_ENABLED(CONFIG_PROBE_EVENTS_BTF_ARGS) && 1626 ctx->last_type) { 1627 if (!type) { 1628 parg->type = find_fetch_type_from_btf_type(ctx); 1629 } else if (strstr(type, "string")) { 1630 ret = check_prepare_btf_string_fetch(type, &code, ctx); 1631 if (ret) 1632 goto fail; 1633 } 1634 } 1635 parg->offset = *size; 1636 *size += parg->type->size * (parg->count ?: 1); 1637 1638 if (*size > MAX_PROBE_EVENT_SIZE) { 1639 ret = -E2BIG; 1640 trace_probe_log_err(ctx->offset, EVENT_TOO_BIG); 1641 goto fail; 1642 } 1643 1644 if (parg->count) { 1645 len = strlen(parg->type->fmttype) + 6; 1646 parg->fmt = kmalloc(len, GFP_KERNEL); 1647 if (!parg->fmt) { 1648 ret = -ENOMEM; 1649 goto fail; 1650 } 1651 snprintf(parg->fmt, len, "%s[%d]", parg->type->fmttype, 1652 parg->count); 1653 } 1654 1655 ret = finalize_fetch_insn(code, parg, type, type ? type - arg : 0, ctx); 1656 if (ret < 0) 1657 goto fail; 1658 1659 for (; code < tmp + FETCH_INSN_MAX; code++) 1660 if (code->op == FETCH_OP_END) 1661 break; 1662 /* Shrink down the code buffer */ 1663 parg->code = kzalloc_objs(*code, code - tmp + 1); 1664 if (!parg->code) 1665 ret = -ENOMEM; 1666 else 1667 memcpy(parg->code, tmp, sizeof(*code) * (code - tmp + 1)); 1668 1669 fail: 1670 if (ret < 0) { 1671 for (code = tmp; code < tmp + FETCH_INSN_MAX; code++) 1672 if (code->op == FETCH_NOP_SYMBOL || 1673 code->op == FETCH_OP_DATA) 1674 kfree(code->data); 1675 } 1676 kfree(tmp); 1677 1678 /* struct_btf should not be passed to other arguments */ 1679 clear_struct_btf(ctx); 1680 1681 return ret; 1682 } 1683 1684 /* Return 1 if name is reserved or already used by another argument */ 1685 static int traceprobe_conflict_field_name(const char *name, 1686 struct probe_arg *args, int narg) 1687 { 1688 int i; 1689 1690 for (i = 0; i < ARRAY_SIZE(reserved_field_names); i++) 1691 if (strcmp(reserved_field_names[i], name) == 0) 1692 return 1; 1693 1694 for (i = 0; i < narg; i++) 1695 if (strcmp(args[i].name, name) == 0) 1696 return 1; 1697 1698 return 0; 1699 } 1700 1701 static char *generate_probe_arg_name(const char *arg, int idx) 1702 { 1703 char *name = NULL; 1704 const char *end; 1705 1706 /* 1707 * If argument name is omitted, try arg as a name (BTF variable) 1708 * or "argN". 1709 */ 1710 if (IS_ENABLED(CONFIG_PROBE_EVENTS_BTF_ARGS)) { 1711 end = strchr(arg, ':'); 1712 if (!end) 1713 end = arg + strlen(arg); 1714 1715 name = kmemdup_nul(arg, end - arg, GFP_KERNEL); 1716 if (!name || !is_good_name(name)) { 1717 kfree(name); 1718 name = NULL; 1719 } 1720 } 1721 1722 if (!name) 1723 name = kasprintf(GFP_KERNEL, "arg%d", idx + 1); 1724 1725 return name; 1726 } 1727 1728 int traceprobe_parse_probe_arg(struct trace_probe *tp, int i, const char *arg, 1729 struct traceprobe_parse_context *ctx) 1730 { 1731 struct probe_arg *parg = &tp->args[i]; 1732 const char *body; 1733 1734 ctx->tp = tp; 1735 body = strchr(arg, '='); 1736 if (body) { 1737 if (body - arg > MAX_ARG_NAME_LEN) { 1738 trace_probe_log_err(0, ARG_NAME_TOO_LONG); 1739 return -EINVAL; 1740 } else if (body == arg) { 1741 trace_probe_log_err(0, NO_ARG_NAME); 1742 return -EINVAL; 1743 } 1744 parg->name = kmemdup_nul(arg, body - arg, GFP_KERNEL); 1745 body++; 1746 } else { 1747 parg->name = generate_probe_arg_name(arg, i); 1748 body = arg; 1749 } 1750 if (!parg->name) 1751 return -ENOMEM; 1752 1753 if (!is_good_name(parg->name)) { 1754 trace_probe_log_err(0, BAD_ARG_NAME); 1755 return -EINVAL; 1756 } 1757 if (traceprobe_conflict_field_name(parg->name, tp->args, i)) { 1758 trace_probe_log_err(0, USED_ARG_NAME); 1759 return -EINVAL; 1760 } 1761 ctx->offset = body - arg; 1762 /* Parse fetch argument */ 1763 return traceprobe_parse_probe_arg_body(body, &tp->size, parg, ctx); 1764 } 1765 1766 void traceprobe_free_probe_arg(struct probe_arg *arg) 1767 { 1768 struct fetch_insn *code = arg->code; 1769 1770 while (code && code->op != FETCH_OP_END) { 1771 if (code->op == FETCH_NOP_SYMBOL || 1772 code->op == FETCH_OP_DATA) 1773 kfree(code->data); 1774 code++; 1775 } 1776 kfree(arg->code); 1777 kfree(arg->name); 1778 kfree(arg->comm); 1779 kfree(arg->fmt); 1780 } 1781 1782 static int argv_has_var_arg(int argc, const char *argv[], int *args_idx, 1783 struct traceprobe_parse_context *ctx) 1784 { 1785 int i, found = 0; 1786 1787 for (i = 0; i < argc; i++) 1788 if (str_has_prefix(argv[i], "$arg")) { 1789 trace_probe_log_set_index(i + 2); 1790 1791 if (!tparg_is_function_entry(ctx->flags) && 1792 !tparg_is_function_return(ctx->flags)) { 1793 trace_probe_log_err(0, NOFENTRY_ARGS); 1794 return -EINVAL; 1795 } 1796 1797 if (isdigit(argv[i][4])) { 1798 found = 1; 1799 continue; 1800 } 1801 1802 if (argv[i][4] != '*') { 1803 trace_probe_log_err(0, BAD_VAR); 1804 return -EINVAL; 1805 } 1806 1807 if (*args_idx >= 0 && *args_idx < argc) { 1808 trace_probe_log_err(0, DOUBLE_ARGS); 1809 return -EINVAL; 1810 } 1811 found = 1; 1812 *args_idx = i; 1813 } 1814 1815 return found; 1816 } 1817 1818 static int sprint_nth_btf_arg(int idx, const char *type, 1819 char *buf, int bufsize, 1820 struct traceprobe_parse_context *ctx) 1821 { 1822 const char *name; 1823 int ret; 1824 1825 if (idx >= ctx->nr_params) { 1826 trace_probe_log_err(0, NO_BTFARG); 1827 return -ENOENT; 1828 } 1829 name = btf_name_by_offset(ctx->btf, ctx->params[idx].name_off); 1830 if (!name) { 1831 trace_probe_log_err(0, NO_BTF_ENTRY); 1832 return -ENOENT; 1833 } 1834 ret = snprintf(buf, bufsize, "%s%s", name, type); 1835 if (ret >= bufsize) { 1836 trace_probe_log_err(0, ARGS_2LONG); 1837 return -E2BIG; 1838 } 1839 return ret; 1840 } 1841 1842 /* Return new_argv which must be freed after use */ 1843 const char **traceprobe_expand_meta_args(int argc, const char *argv[], 1844 int *new_argc, char *buf, int bufsize, 1845 struct traceprobe_parse_context *ctx) 1846 { 1847 const struct btf_param *params = NULL; 1848 int i, j, n, used, ret, args_idx = -1; 1849 const char **new_argv __free(kfree) = NULL; 1850 1851 ret = argv_has_var_arg(argc, argv, &args_idx, ctx); 1852 if (ret < 0) 1853 return ERR_PTR(ret); 1854 1855 if (!ret) { 1856 *new_argc = argc; 1857 return NULL; 1858 } 1859 1860 ret = query_btf_context(ctx); 1861 if (ret < 0 || ctx->nr_params == 0) { 1862 if (args_idx != -1) { 1863 /* $arg* requires BTF info */ 1864 trace_probe_log_err(0, NOSUP_BTFARG); 1865 return (const char **)params; 1866 } 1867 *new_argc = argc; 1868 return NULL; 1869 } 1870 1871 if (args_idx >= 0) 1872 *new_argc = argc + ctx->nr_params - 1; 1873 else 1874 *new_argc = argc; 1875 1876 new_argv = kcalloc(*new_argc, sizeof(char *), GFP_KERNEL); 1877 if (!new_argv) 1878 return ERR_PTR(-ENOMEM); 1879 1880 used = 0; 1881 for (i = 0, j = 0; i < argc; i++) { 1882 trace_probe_log_set_index(i + 2); 1883 if (i == args_idx) { 1884 for (n = 0; n < ctx->nr_params; n++) { 1885 ret = sprint_nth_btf_arg(n, "", buf + used, 1886 bufsize - used, ctx); 1887 if (ret < 0) 1888 return ERR_PTR(ret); 1889 1890 new_argv[j++] = buf + used; 1891 used += ret + 1; 1892 } 1893 continue; 1894 } 1895 1896 if (str_has_prefix(argv[i], "$arg")) { 1897 char *type = NULL; 1898 1899 n = simple_strtoul(argv[i] + 4, &type, 10); 1900 if (type && !(*type == ':' || *type == '\0')) { 1901 trace_probe_log_err(0, BAD_VAR); 1902 return ERR_PTR(-ENOENT); 1903 } 1904 /* Note: $argN starts from $arg1 */ 1905 ret = sprint_nth_btf_arg(n - 1, type, buf + used, 1906 bufsize - used, ctx); 1907 if (ret < 0) 1908 return ERR_PTR(ret); 1909 new_argv[j++] = buf + used; 1910 used += ret + 1; 1911 } else 1912 new_argv[j++] = argv[i]; 1913 } 1914 1915 return_ptr(new_argv); 1916 } 1917 1918 /* @buf: *buf must be equal to NULL. Caller must to free *buf */ 1919 int traceprobe_expand_dentry_args(int argc, const char *argv[], char **buf) 1920 { 1921 int i, used, ret; 1922 const int bufsize = MAX_DENTRY_ARGS_LEN; 1923 char *tmpbuf __free(kfree) = NULL; 1924 1925 if (*buf) 1926 return -EINVAL; 1927 1928 used = 0; 1929 for (i = 0; i < argc; i++) { 1930 char *tmp __free(kfree) = NULL; 1931 char *equal; 1932 size_t arg_len; 1933 1934 if (!glob_match("*:%p[dD]", argv[i])) 1935 continue; 1936 1937 if (!tmpbuf) { 1938 tmpbuf = kmalloc(bufsize, GFP_KERNEL); 1939 if (!tmpbuf) 1940 return -ENOMEM; 1941 } 1942 1943 tmp = kstrdup(argv[i], GFP_KERNEL); 1944 if (!tmp) 1945 return -ENOMEM; 1946 1947 equal = strchr(tmp, '='); 1948 if (equal) 1949 *equal = '\0'; 1950 arg_len = strlen(argv[i]); 1951 tmp[arg_len - 4] = '\0'; 1952 if (argv[i][arg_len - 1] == 'd') 1953 ret = snprintf(tmpbuf + used, bufsize - used, 1954 "%s%s+0x0(+0x%zx(%s)):string", 1955 equal ? tmp : "", equal ? "=" : "", 1956 offsetof(struct dentry, d_name.name), 1957 equal ? equal + 1 : tmp); 1958 else 1959 ret = snprintf(tmpbuf + used, bufsize - used, 1960 "%s%s+0x0(+0x%zx(+0x%zx(%s))):string", 1961 equal ? tmp : "", equal ? "=" : "", 1962 offsetof(struct dentry, d_name.name), 1963 offsetof(struct file, f_path.dentry), 1964 equal ? equal + 1 : tmp); 1965 1966 if (ret >= bufsize - used) 1967 return -ENOMEM; 1968 argv[i] = tmpbuf + used; 1969 used += ret + 1; 1970 } 1971 1972 *buf = no_free_ptr(tmpbuf); 1973 return 0; 1974 } 1975 1976 void traceprobe_finish_parse(struct traceprobe_parse_context *ctx) 1977 { 1978 clear_btf_context(ctx); 1979 } 1980 1981 int traceprobe_update_arg(struct probe_arg *arg) 1982 { 1983 struct fetch_insn *code = arg->code; 1984 long offset; 1985 char *tmp; 1986 char c; 1987 int ret = 0; 1988 1989 while (code && code->op != FETCH_OP_END) { 1990 if (code->op == FETCH_NOP_SYMBOL) { 1991 if (code[1].op != FETCH_OP_IMM) 1992 return -EINVAL; 1993 1994 tmp = strpbrk(code->data, "+-"); 1995 if (tmp) 1996 c = *tmp; 1997 ret = traceprobe_split_symbol_offset(code->data, 1998 &offset); 1999 if (ret) 2000 return ret; 2001 2002 code[1].immediate = 2003 (unsigned long)kallsyms_lookup_name(code->data); 2004 if (tmp) 2005 *tmp = c; 2006 if (!code[1].immediate) 2007 return -ENOENT; 2008 code[1].immediate += offset; 2009 } 2010 code++; 2011 } 2012 return 0; 2013 } 2014 2015 /* When len=0, we just calculate the needed length */ 2016 #define LEN_OR_ZERO (len ? len - pos : 0) 2017 static int __set_print_fmt(struct trace_probe *tp, char *buf, int len, 2018 enum probe_print_type ptype) 2019 { 2020 struct probe_arg *parg; 2021 int i, j; 2022 int pos = 0; 2023 const char *fmt, *arg; 2024 2025 switch (ptype) { 2026 case PROBE_PRINT_NORMAL: 2027 fmt = "(%lx)"; 2028 arg = ", REC->" FIELD_STRING_IP; 2029 break; 2030 case PROBE_PRINT_RETURN: 2031 fmt = "(%lx <- %lx)"; 2032 arg = ", REC->" FIELD_STRING_FUNC ", REC->" FIELD_STRING_RETIP; 2033 break; 2034 case PROBE_PRINT_EVENT: 2035 fmt = ""; 2036 arg = ""; 2037 break; 2038 default: 2039 WARN_ON_ONCE(1); 2040 return 0; 2041 } 2042 2043 pos += snprintf(buf + pos, LEN_OR_ZERO, "\"%s", fmt); 2044 2045 for (i = 0; i < tp->nr_args; i++) { 2046 parg = tp->args + i; 2047 pos += snprintf(buf + pos, LEN_OR_ZERO, " %s=", parg->name); 2048 if (parg->count) { 2049 pos += snprintf(buf + pos, LEN_OR_ZERO, "{%s", 2050 parg->type->fmt); 2051 for (j = 1; j < parg->count; j++) 2052 pos += snprintf(buf + pos, LEN_OR_ZERO, ",%s", 2053 parg->type->fmt); 2054 pos += snprintf(buf + pos, LEN_OR_ZERO, "}"); 2055 } else 2056 pos += snprintf(buf + pos, LEN_OR_ZERO, "%s", 2057 parg->type->fmt); 2058 } 2059 2060 pos += snprintf(buf + pos, LEN_OR_ZERO, "\"%s", arg); 2061 2062 for (i = 0; i < tp->nr_args; i++) { 2063 parg = tp->args + i; 2064 if (parg->count) { 2065 if (parg->type->is_string) 2066 fmt = ", __get_str(%s[%d])"; 2067 else 2068 fmt = ", REC->%s[%d]"; 2069 for (j = 0; j < parg->count; j++) 2070 pos += snprintf(buf + pos, LEN_OR_ZERO, 2071 fmt, parg->name, j); 2072 } else { 2073 if (parg->type->is_string) 2074 fmt = ", __get_str(%s)"; 2075 else 2076 fmt = ", REC->%s"; 2077 pos += snprintf(buf + pos, LEN_OR_ZERO, 2078 fmt, parg->name); 2079 } 2080 } 2081 2082 /* return the length of print_fmt */ 2083 return pos; 2084 } 2085 #undef LEN_OR_ZERO 2086 2087 int traceprobe_set_print_fmt(struct trace_probe *tp, enum probe_print_type ptype) 2088 { 2089 struct trace_event_call *call = trace_probe_event_call(tp); 2090 int len; 2091 char *print_fmt; 2092 2093 /* First: called with 0 length to calculate the needed length */ 2094 len = __set_print_fmt(tp, NULL, 0, ptype); 2095 print_fmt = kmalloc(len + 1, GFP_KERNEL); 2096 if (!print_fmt) 2097 return -ENOMEM; 2098 2099 /* Second: actually write the @print_fmt */ 2100 __set_print_fmt(tp, print_fmt, len + 1, ptype); 2101 call->print_fmt = print_fmt; 2102 2103 return 0; 2104 } 2105 2106 int traceprobe_define_arg_fields(struct trace_event_call *event_call, 2107 size_t offset, struct trace_probe *tp) 2108 { 2109 int ret, i; 2110 2111 /* Set argument names as fields */ 2112 for (i = 0; i < tp->nr_args; i++) { 2113 struct probe_arg *parg = &tp->args[i]; 2114 const char *fmt = parg->type->fmttype; 2115 int size = parg->type->size; 2116 2117 if (parg->fmt) 2118 fmt = parg->fmt; 2119 if (parg->count) 2120 size *= parg->count; 2121 ret = trace_define_field(event_call, fmt, parg->name, 2122 offset + parg->offset, size, 2123 parg->type->is_signed, 2124 FILTER_OTHER); 2125 if (ret) 2126 return ret; 2127 } 2128 return 0; 2129 } 2130 2131 static void trace_probe_event_free(struct trace_probe_event *tpe) 2132 { 2133 kfree(tpe->class.system); 2134 kfree(tpe->call.name); 2135 kfree(tpe->call.print_fmt); 2136 kfree(tpe); 2137 } 2138 2139 int trace_probe_append(struct trace_probe *tp, struct trace_probe *to) 2140 { 2141 if (trace_probe_has_sibling(tp)) 2142 return -EBUSY; 2143 2144 list_del_init(&tp->list); 2145 trace_probe_event_free(tp->event); 2146 2147 tp->event = to->event; 2148 list_add_tail(&tp->list, trace_probe_probe_list(to)); 2149 2150 return 0; 2151 } 2152 2153 void trace_probe_unlink(struct trace_probe *tp) 2154 { 2155 list_del_init(&tp->list); 2156 if (list_empty(trace_probe_probe_list(tp))) 2157 trace_probe_event_free(tp->event); 2158 tp->event = NULL; 2159 } 2160 2161 void trace_probe_cleanup(struct trace_probe *tp) 2162 { 2163 int i; 2164 2165 for (i = 0; i < tp->nr_args; i++) 2166 traceprobe_free_probe_arg(&tp->args[i]); 2167 2168 if (tp->entry_arg) { 2169 kfree(tp->entry_arg); 2170 tp->entry_arg = NULL; 2171 } 2172 2173 if (tp->event) 2174 trace_probe_unlink(tp); 2175 } 2176 2177 int trace_probe_init(struct trace_probe *tp, const char *event, 2178 const char *group, bool alloc_filter, int nargs) 2179 { 2180 struct trace_event_call *call; 2181 size_t size = sizeof(struct trace_probe_event); 2182 int ret = 0; 2183 2184 if (!event || !group) 2185 return -EINVAL; 2186 2187 if (alloc_filter) 2188 size += sizeof(struct trace_uprobe_filter); 2189 2190 tp->event = kzalloc(size, GFP_KERNEL); 2191 if (!tp->event) 2192 return -ENOMEM; 2193 2194 INIT_LIST_HEAD(&tp->event->files); 2195 INIT_LIST_HEAD(&tp->event->class.fields); 2196 INIT_LIST_HEAD(&tp->event->probes); 2197 INIT_LIST_HEAD(&tp->list); 2198 list_add(&tp->list, &tp->event->probes); 2199 2200 call = trace_probe_event_call(tp); 2201 call->class = &tp->event->class; 2202 call->name = kstrdup(event, GFP_KERNEL); 2203 if (!call->name) { 2204 ret = -ENOMEM; 2205 goto error; 2206 } 2207 2208 tp->event->class.system = kstrdup(group, GFP_KERNEL); 2209 if (!tp->event->class.system) { 2210 ret = -ENOMEM; 2211 goto error; 2212 } 2213 2214 tp->nr_args = nargs; 2215 /* Make sure pointers in args[] are NULL */ 2216 if (nargs) 2217 memset(tp->args, 0, sizeof(tp->args[0]) * nargs); 2218 2219 return 0; 2220 2221 error: 2222 trace_probe_cleanup(tp); 2223 return ret; 2224 } 2225 2226 static struct trace_event_call * 2227 find_trace_event_call(const char *system, const char *event_name) 2228 { 2229 struct trace_event_call *tp_event; 2230 const char *name; 2231 2232 list_for_each_entry(tp_event, &ftrace_events, list) { 2233 if (!tp_event->class->system || 2234 strcmp(system, tp_event->class->system)) 2235 continue; 2236 name = trace_event_name(tp_event); 2237 if (!name || strcmp(event_name, name)) 2238 continue; 2239 return tp_event; 2240 } 2241 2242 return NULL; 2243 } 2244 2245 int trace_probe_register_event_call(struct trace_probe *tp) 2246 { 2247 struct trace_event_call *call = trace_probe_event_call(tp); 2248 int ret; 2249 2250 lockdep_assert_held(&event_mutex); 2251 2252 if (find_trace_event_call(trace_probe_group_name(tp), 2253 trace_probe_name(tp))) 2254 return -EEXIST; 2255 2256 ret = register_trace_event(&call->event); 2257 if (!ret) 2258 return -ENODEV; 2259 2260 ret = trace_add_event_call(call); 2261 if (ret) 2262 unregister_trace_event(&call->event); 2263 2264 return ret; 2265 } 2266 2267 int trace_probe_add_file(struct trace_probe *tp, struct trace_event_file *file) 2268 { 2269 struct event_file_link *link; 2270 2271 link = kmalloc_obj(*link); 2272 if (!link) 2273 return -ENOMEM; 2274 2275 link->file = file; 2276 INIT_LIST_HEAD(&link->list); 2277 list_add_tail_rcu(&link->list, &tp->event->files); 2278 trace_probe_set_flag(tp, TP_FLAG_TRACE); 2279 return 0; 2280 } 2281 2282 struct event_file_link *trace_probe_get_file_link(struct trace_probe *tp, 2283 struct trace_event_file *file) 2284 { 2285 struct event_file_link *link; 2286 2287 trace_probe_for_each_link(link, tp) { 2288 if (link->file == file) 2289 return link; 2290 } 2291 2292 return NULL; 2293 } 2294 2295 int trace_probe_remove_file(struct trace_probe *tp, 2296 struct trace_event_file *file) 2297 { 2298 struct event_file_link *link; 2299 2300 link = trace_probe_get_file_link(tp, file); 2301 if (!link) 2302 return -ENOENT; 2303 2304 list_del_rcu(&link->list); 2305 kvfree_rcu_mightsleep(link); 2306 2307 if (list_empty(&tp->event->files)) 2308 trace_probe_clear_flag(tp, TP_FLAG_TRACE); 2309 2310 return 0; 2311 } 2312 2313 /* 2314 * Return the smallest index of different type argument (start from 1). 2315 * If all argument types and name are same, return 0. 2316 */ 2317 int trace_probe_compare_arg_type(struct trace_probe *a, struct trace_probe *b) 2318 { 2319 int i; 2320 2321 /* In case of more arguments */ 2322 if (a->nr_args < b->nr_args) 2323 return a->nr_args + 1; 2324 if (a->nr_args > b->nr_args) 2325 return b->nr_args + 1; 2326 2327 for (i = 0; i < a->nr_args; i++) { 2328 if ((b->nr_args <= i) || 2329 ((a->args[i].type != b->args[i].type) || 2330 (a->args[i].count != b->args[i].count) || 2331 strcmp(a->args[i].name, b->args[i].name))) 2332 return i + 1; 2333 } 2334 2335 return 0; 2336 } 2337 2338 bool trace_probe_match_command_args(struct trace_probe *tp, 2339 int argc, const char **argv) 2340 { 2341 char buf[MAX_ARGSTR_LEN + 1]; 2342 int i; 2343 2344 if (tp->nr_args < argc) 2345 return false; 2346 2347 for (i = 0; i < argc; i++) { 2348 snprintf(buf, sizeof(buf), "%s=%s", 2349 tp->args[i].name, tp->args[i].comm); 2350 if (strcmp(buf, argv[i])) 2351 return false; 2352 } 2353 return true; 2354 } 2355 2356 int trace_probe_create(const char *raw_command, int (*createfn)(int, const char **)) 2357 { 2358 int argc = 0, ret = 0; 2359 char **argv; 2360 2361 argv = argv_split(GFP_KERNEL, raw_command, &argc); 2362 if (!argv) 2363 return -ENOMEM; 2364 2365 if (argc) 2366 ret = createfn(argc, (const char **)argv); 2367 2368 argv_free(argv); 2369 2370 return ret; 2371 } 2372 2373 int trace_probe_print_args(struct trace_seq *s, struct probe_arg *args, int nr_args, 2374 u8 *data, void *field) 2375 { 2376 void *p; 2377 int i, j; 2378 2379 for (i = 0; i < nr_args; i++) { 2380 struct probe_arg *a = args + i; 2381 2382 trace_seq_printf(s, " %s=", a->name); 2383 if (likely(!a->count)) { 2384 if (!a->type->print(s, data + a->offset, field)) 2385 return -ENOMEM; 2386 continue; 2387 } 2388 trace_seq_putc(s, '{'); 2389 p = data + a->offset; 2390 for (j = 0; j < a->count; j++) { 2391 if (!a->type->print(s, p, field)) 2392 return -ENOMEM; 2393 trace_seq_putc(s, j == a->count - 1 ? '}' : ','); 2394 p += a->type->size; 2395 } 2396 } 2397 return 0; 2398 } 2399