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