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 <[email protected]> 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 "trace_probe.h" 15 16 const char *reserved_field_names[] = { 17 "common_type", 18 "common_flags", 19 "common_preempt_count", 20 "common_pid", 21 "common_tgid", 22 FIELD_STRING_IP, 23 FIELD_STRING_RETIP, 24 FIELD_STRING_FUNC, 25 }; 26 27 /* Printing in basic type function template */ 28 #define DEFINE_BASIC_PRINT_TYPE_FUNC(tname, type, fmt) \ 29 int PRINT_TYPE_FUNC_NAME(tname)(struct trace_seq *s, void *data, void *ent)\ 30 { \ 31 trace_seq_printf(s, fmt, *(type *)data); \ 32 return !trace_seq_has_overflowed(s); \ 33 } \ 34 const char PRINT_TYPE_FMT_NAME(tname)[] = fmt; 35 36 DEFINE_BASIC_PRINT_TYPE_FUNC(u8, u8, "%u") 37 DEFINE_BASIC_PRINT_TYPE_FUNC(u16, u16, "%u") 38 DEFINE_BASIC_PRINT_TYPE_FUNC(u32, u32, "%u") 39 DEFINE_BASIC_PRINT_TYPE_FUNC(u64, u64, "%Lu") 40 DEFINE_BASIC_PRINT_TYPE_FUNC(s8, s8, "%d") 41 DEFINE_BASIC_PRINT_TYPE_FUNC(s16, s16, "%d") 42 DEFINE_BASIC_PRINT_TYPE_FUNC(s32, s32, "%d") 43 DEFINE_BASIC_PRINT_TYPE_FUNC(s64, s64, "%Ld") 44 DEFINE_BASIC_PRINT_TYPE_FUNC(x8, u8, "0x%x") 45 DEFINE_BASIC_PRINT_TYPE_FUNC(x16, u16, "0x%x") 46 DEFINE_BASIC_PRINT_TYPE_FUNC(x32, u32, "0x%x") 47 DEFINE_BASIC_PRINT_TYPE_FUNC(x64, u64, "0x%Lx") 48 49 int PRINT_TYPE_FUNC_NAME(symbol)(struct trace_seq *s, void *data, void *ent) 50 { 51 trace_seq_printf(s, "%pS", (void *)*(unsigned long *)data); 52 return !trace_seq_has_overflowed(s); 53 } 54 const char PRINT_TYPE_FMT_NAME(symbol)[] = "%pS"; 55 56 /* Print type function for string type */ 57 int PRINT_TYPE_FUNC_NAME(string)(struct trace_seq *s, void *data, void *ent) 58 { 59 int len = *(u32 *)data >> 16; 60 61 if (!len) 62 trace_seq_puts(s, "(fault)"); 63 else 64 trace_seq_printf(s, "\"%s\"", 65 (const char *)get_loc_data(data, ent)); 66 return !trace_seq_has_overflowed(s); 67 } 68 69 const char PRINT_TYPE_FMT_NAME(string)[] = "\\\"%s\\\""; 70 71 /* Fetch type information table */ 72 static const struct fetch_type probe_fetch_types[] = { 73 /* Special types */ 74 __ASSIGN_FETCH_TYPE("string", string, string, sizeof(u32), 1, 75 "__data_loc char[]"), 76 /* Basic types */ 77 ASSIGN_FETCH_TYPE(u8, u8, 0), 78 ASSIGN_FETCH_TYPE(u16, u16, 0), 79 ASSIGN_FETCH_TYPE(u32, u32, 0), 80 ASSIGN_FETCH_TYPE(u64, u64, 0), 81 ASSIGN_FETCH_TYPE(s8, u8, 1), 82 ASSIGN_FETCH_TYPE(s16, u16, 1), 83 ASSIGN_FETCH_TYPE(s32, u32, 1), 84 ASSIGN_FETCH_TYPE(s64, u64, 1), 85 ASSIGN_FETCH_TYPE_ALIAS(x8, u8, u8, 0), 86 ASSIGN_FETCH_TYPE_ALIAS(x16, u16, u16, 0), 87 ASSIGN_FETCH_TYPE_ALIAS(x32, u32, u32, 0), 88 ASSIGN_FETCH_TYPE_ALIAS(x64, u64, u64, 0), 89 ASSIGN_FETCH_TYPE_ALIAS(symbol, ADDR_FETCH_TYPE, ADDR_FETCH_TYPE, 0), 90 91 ASSIGN_FETCH_TYPE_END 92 }; 93 94 static const struct fetch_type *find_fetch_type(const char *type) 95 { 96 int i; 97 98 if (!type) 99 type = DEFAULT_FETCH_TYPE_STR; 100 101 /* Special case: bitfield */ 102 if (*type == 'b') { 103 unsigned long bs; 104 105 type = strchr(type, '/'); 106 if (!type) 107 goto fail; 108 109 type++; 110 if (kstrtoul(type, 0, &bs)) 111 goto fail; 112 113 switch (bs) { 114 case 8: 115 return find_fetch_type("u8"); 116 case 16: 117 return find_fetch_type("u16"); 118 case 32: 119 return find_fetch_type("u32"); 120 case 64: 121 return find_fetch_type("u64"); 122 default: 123 goto fail; 124 } 125 } 126 127 for (i = 0; probe_fetch_types[i].name; i++) { 128 if (strcmp(type, probe_fetch_types[i].name) == 0) 129 return &probe_fetch_types[i]; 130 } 131 132 fail: 133 return NULL; 134 } 135 136 /* Split symbol and offset. */ 137 int traceprobe_split_symbol_offset(char *symbol, long *offset) 138 { 139 char *tmp; 140 int ret; 141 142 if (!offset) 143 return -EINVAL; 144 145 tmp = strpbrk(symbol, "+-"); 146 if (tmp) { 147 ret = kstrtol(tmp, 0, offset); 148 if (ret) 149 return ret; 150 *tmp = '\0'; 151 } else 152 *offset = 0; 153 154 return 0; 155 } 156 157 /* @buf must has MAX_EVENT_NAME_LEN size */ 158 int traceprobe_parse_event_name(const char **pevent, const char **pgroup, 159 char *buf) 160 { 161 const char *slash, *event = *pevent; 162 163 slash = strchr(event, '/'); 164 if (slash) { 165 if (slash == event) { 166 pr_info("Group name is not specified\n"); 167 return -EINVAL; 168 } 169 if (slash - event + 1 > MAX_EVENT_NAME_LEN) { 170 pr_info("Group name is too long\n"); 171 return -E2BIG; 172 } 173 strlcpy(buf, event, slash - event + 1); 174 *pgroup = buf; 175 *pevent = slash + 1; 176 } 177 if (strlen(event) == 0) { 178 pr_info("Event name is not specified\n"); 179 return -EINVAL; 180 } 181 return 0; 182 } 183 184 #define PARAM_MAX_STACK (THREAD_SIZE / sizeof(unsigned long)) 185 186 static int parse_probe_vars(char *arg, const struct fetch_type *t, 187 struct fetch_insn *code, unsigned int flags) 188 { 189 unsigned long param; 190 int ret = 0; 191 int len; 192 193 if (strcmp(arg, "retval") == 0) { 194 if (flags & TPARG_FL_RETURN) 195 code->op = FETCH_OP_RETVAL; 196 else 197 ret = -EINVAL; 198 } else if ((len = str_has_prefix(arg, "stack"))) { 199 if (arg[len] == '\0') { 200 code->op = FETCH_OP_STACKP; 201 } else if (isdigit(arg[len])) { 202 ret = kstrtoul(arg + len, 10, ¶m); 203 if (ret || ((flags & TPARG_FL_KERNEL) && 204 param > PARAM_MAX_STACK)) 205 ret = -EINVAL; 206 else { 207 code->op = FETCH_OP_STACK; 208 code->param = (unsigned int)param; 209 } 210 } else 211 ret = -EINVAL; 212 } else if (strcmp(arg, "comm") == 0) { 213 code->op = FETCH_OP_COMM; 214 #ifdef CONFIG_HAVE_FUNCTION_ARG_ACCESS_API 215 } else if (((flags & TPARG_FL_MASK) == 216 (TPARG_FL_KERNEL | TPARG_FL_FENTRY)) && 217 (len = str_has_prefix(arg, "arg"))) { 218 if (!isdigit(arg[len])) 219 return -EINVAL; 220 ret = kstrtoul(arg + len, 10, ¶m); 221 if (ret || !param || param > PARAM_MAX_STACK) 222 return -EINVAL; 223 code->op = FETCH_OP_ARG; 224 code->param = (unsigned int)param - 1; 225 #endif 226 } else 227 ret = -EINVAL; 228 229 return ret; 230 } 231 232 /* Recursive argument parser */ 233 static int 234 parse_probe_arg(char *arg, const struct fetch_type *type, 235 struct fetch_insn **pcode, struct fetch_insn *end, 236 unsigned int flags) 237 { 238 struct fetch_insn *code = *pcode; 239 unsigned long param; 240 long offset = 0; 241 char *tmp; 242 int ret = 0; 243 244 switch (arg[0]) { 245 case '$': 246 ret = parse_probe_vars(arg + 1, type, code, flags); 247 break; 248 249 case '%': /* named register */ 250 ret = regs_query_register_offset(arg + 1); 251 if (ret >= 0) { 252 code->op = FETCH_OP_REG; 253 code->param = (unsigned int)ret; 254 ret = 0; 255 } 256 break; 257 258 case '@': /* memory, file-offset or symbol */ 259 if (isdigit(arg[1])) { 260 ret = kstrtoul(arg + 1, 0, ¶m); 261 if (ret) 262 break; 263 /* load address */ 264 code->op = FETCH_OP_IMM; 265 code->immediate = param; 266 } else if (arg[1] == '+') { 267 /* kprobes don't support file offsets */ 268 if (flags & TPARG_FL_KERNEL) 269 return -EINVAL; 270 271 ret = kstrtol(arg + 2, 0, &offset); 272 if (ret) 273 break; 274 275 code->op = FETCH_OP_FOFFS; 276 code->immediate = (unsigned long)offset; // imm64? 277 } else { 278 /* uprobes don't support symbols */ 279 if (!(flags & TPARG_FL_KERNEL)) 280 return -EINVAL; 281 282 /* Preserve symbol for updating */ 283 code->op = FETCH_NOP_SYMBOL; 284 code->data = kstrdup(arg + 1, GFP_KERNEL); 285 if (!code->data) 286 return -ENOMEM; 287 if (++code == end) 288 return -E2BIG; 289 290 code->op = FETCH_OP_IMM; 291 code->immediate = 0; 292 } 293 /* These are fetching from memory */ 294 if (++code == end) 295 return -E2BIG; 296 *pcode = code; 297 code->op = FETCH_OP_DEREF; 298 code->offset = offset; 299 break; 300 301 case '+': /* deref memory */ 302 arg++; /* Skip '+', because kstrtol() rejects it. */ 303 /* fall through */ 304 case '-': 305 tmp = strchr(arg, '('); 306 if (!tmp) 307 return -EINVAL; 308 309 *tmp = '\0'; 310 ret = kstrtol(arg, 0, &offset); 311 if (ret) 312 break; 313 314 arg = tmp + 1; 315 tmp = strrchr(arg, ')'); 316 317 if (tmp) { 318 const struct fetch_type *t2 = find_fetch_type(NULL); 319 320 *tmp = '\0'; 321 ret = parse_probe_arg(arg, t2, &code, end, flags); 322 if (ret) 323 break; 324 if (code->op == FETCH_OP_COMM) 325 return -EINVAL; 326 if (++code == end) 327 return -E2BIG; 328 *pcode = code; 329 330 code->op = FETCH_OP_DEREF; 331 code->offset = offset; 332 } 333 break; 334 } 335 if (!ret && code->op == FETCH_OP_NOP) { 336 /* Parsed, but do not find fetch method */ 337 ret = -EINVAL; 338 } 339 return ret; 340 } 341 342 #define BYTES_TO_BITS(nb) ((BITS_PER_LONG * (nb)) / sizeof(long)) 343 344 /* Bitfield type needs to be parsed into a fetch function */ 345 static int __parse_bitfield_probe_arg(const char *bf, 346 const struct fetch_type *t, 347 struct fetch_insn **pcode) 348 { 349 struct fetch_insn *code = *pcode; 350 unsigned long bw, bo; 351 char *tail; 352 353 if (*bf != 'b') 354 return 0; 355 356 bw = simple_strtoul(bf + 1, &tail, 0); /* Use simple one */ 357 358 if (bw == 0 || *tail != '@') 359 return -EINVAL; 360 361 bf = tail + 1; 362 bo = simple_strtoul(bf, &tail, 0); 363 364 if (tail == bf || *tail != '/') 365 return -EINVAL; 366 code++; 367 if (code->op != FETCH_OP_NOP) 368 return -E2BIG; 369 *pcode = code; 370 371 code->op = FETCH_OP_MOD_BF; 372 code->lshift = BYTES_TO_BITS(t->size) - (bw + bo); 373 code->rshift = BYTES_TO_BITS(t->size) - bw; 374 code->basesize = t->size; 375 376 return (BYTES_TO_BITS(t->size) < (bw + bo)) ? -EINVAL : 0; 377 } 378 379 /* String length checking wrapper */ 380 static int traceprobe_parse_probe_arg_body(char *arg, ssize_t *size, 381 struct probe_arg *parg, unsigned int flags) 382 { 383 struct fetch_insn *code, *scode, *tmp = NULL; 384 char *t, *t2; 385 int ret, len; 386 387 if (strlen(arg) > MAX_ARGSTR_LEN) { 388 pr_info("Argument is too long.: %s\n", arg); 389 return -ENOSPC; 390 } 391 parg->comm = kstrdup(arg, GFP_KERNEL); 392 if (!parg->comm) { 393 pr_info("Failed to allocate memory for command '%s'.\n", arg); 394 return -ENOMEM; 395 } 396 t = strchr(arg, ':'); 397 if (t) { 398 *t = '\0'; 399 t2 = strchr(++t, '['); 400 if (t2) { 401 *t2 = '\0'; 402 parg->count = simple_strtoul(t2 + 1, &t2, 0); 403 if (strcmp(t2, "]") || parg->count == 0) 404 return -EINVAL; 405 if (parg->count > MAX_ARRAY_LEN) 406 return -E2BIG; 407 } 408 } 409 /* 410 * The default type of $comm should be "string", and it can't be 411 * dereferenced. 412 */ 413 if (!t && strcmp(arg, "$comm") == 0) 414 parg->type = find_fetch_type("string"); 415 else 416 parg->type = find_fetch_type(t); 417 if (!parg->type) { 418 pr_info("Unsupported type: %s\n", t); 419 return -EINVAL; 420 } 421 parg->offset = *size; 422 *size += parg->type->size * (parg->count ?: 1); 423 424 if (parg->count) { 425 len = strlen(parg->type->fmttype) + 6; 426 parg->fmt = kmalloc(len, GFP_KERNEL); 427 if (!parg->fmt) 428 return -ENOMEM; 429 snprintf(parg->fmt, len, "%s[%d]", parg->type->fmttype, 430 parg->count); 431 } 432 433 code = tmp = kzalloc(sizeof(*code) * FETCH_INSN_MAX, GFP_KERNEL); 434 if (!code) 435 return -ENOMEM; 436 code[FETCH_INSN_MAX - 1].op = FETCH_OP_END; 437 438 ret = parse_probe_arg(arg, parg->type, &code, &code[FETCH_INSN_MAX - 1], 439 flags); 440 if (ret) 441 goto fail; 442 443 /* Store operation */ 444 if (!strcmp(parg->type->name, "string")) { 445 if (code->op != FETCH_OP_DEREF && code->op != FETCH_OP_IMM && 446 code->op != FETCH_OP_COMM) { 447 pr_info("string only accepts memory or address.\n"); 448 ret = -EINVAL; 449 goto fail; 450 } 451 if (code->op != FETCH_OP_DEREF || parg->count) { 452 /* 453 * IMM and COMM is pointing actual address, those must 454 * be kept, and if parg->count != 0, this is an array 455 * of string pointers instead of string address itself. 456 */ 457 code++; 458 if (code->op != FETCH_OP_NOP) { 459 ret = -E2BIG; 460 goto fail; 461 } 462 } 463 code->op = FETCH_OP_ST_STRING; /* In DEREF case, replace it */ 464 code->size = parg->type->size; 465 parg->dynamic = true; 466 } else if (code->op == FETCH_OP_DEREF) { 467 code->op = FETCH_OP_ST_MEM; 468 code->size = parg->type->size; 469 } else { 470 code++; 471 if (code->op != FETCH_OP_NOP) { 472 ret = -E2BIG; 473 goto fail; 474 } 475 code->op = FETCH_OP_ST_RAW; 476 code->size = parg->type->size; 477 } 478 scode = code; 479 /* Modify operation */ 480 if (t != NULL) { 481 ret = __parse_bitfield_probe_arg(t, parg->type, &code); 482 if (ret) 483 goto fail; 484 } 485 /* Loop(Array) operation */ 486 if (parg->count) { 487 if (scode->op != FETCH_OP_ST_MEM && 488 scode->op != FETCH_OP_ST_STRING) { 489 pr_info("array only accepts memory or address\n"); 490 ret = -EINVAL; 491 goto fail; 492 } 493 code++; 494 if (code->op != FETCH_OP_NOP) { 495 ret = -E2BIG; 496 goto fail; 497 } 498 code->op = FETCH_OP_LP_ARRAY; 499 code->param = parg->count; 500 } 501 code++; 502 code->op = FETCH_OP_END; 503 504 /* Shrink down the code buffer */ 505 parg->code = kzalloc(sizeof(*code) * (code - tmp + 1), GFP_KERNEL); 506 if (!parg->code) 507 ret = -ENOMEM; 508 else 509 memcpy(parg->code, tmp, sizeof(*code) * (code - tmp + 1)); 510 511 fail: 512 if (ret) { 513 for (code = tmp; code < tmp + FETCH_INSN_MAX; code++) 514 if (code->op == FETCH_NOP_SYMBOL) 515 kfree(code->data); 516 } 517 kfree(tmp); 518 519 return ret; 520 } 521 522 /* Return 1 if name is reserved or already used by another argument */ 523 static int traceprobe_conflict_field_name(const char *name, 524 struct probe_arg *args, int narg) 525 { 526 int i; 527 528 for (i = 0; i < ARRAY_SIZE(reserved_field_names); i++) 529 if (strcmp(reserved_field_names[i], name) == 0) 530 return 1; 531 532 for (i = 0; i < narg; i++) 533 if (strcmp(args[i].name, name) == 0) 534 return 1; 535 536 return 0; 537 } 538 539 int traceprobe_parse_probe_arg(struct trace_probe *tp, int i, char *arg, 540 unsigned int flags) 541 { 542 struct probe_arg *parg = &tp->args[i]; 543 char *body; 544 int ret; 545 546 /* Increment count for freeing args in error case */ 547 tp->nr_args++; 548 549 body = strchr(arg, '='); 550 if (body) { 551 parg->name = kmemdup_nul(arg, body - arg, GFP_KERNEL); 552 body++; 553 } else { 554 /* If argument name is omitted, set "argN" */ 555 parg->name = kasprintf(GFP_KERNEL, "arg%d", i + 1); 556 body = arg; 557 } 558 if (!parg->name) 559 return -ENOMEM; 560 561 if (!is_good_name(parg->name)) { 562 pr_info("Invalid argument[%d] name: %s\n", 563 i, parg->name); 564 return -EINVAL; 565 } 566 567 if (traceprobe_conflict_field_name(parg->name, tp->args, i)) { 568 pr_info("Argument[%d]: '%s' conflicts with another field.\n", 569 i, parg->name); 570 return -EINVAL; 571 } 572 573 /* Parse fetch argument */ 574 ret = traceprobe_parse_probe_arg_body(body, &tp->size, parg, flags); 575 if (ret) 576 pr_info("Parse error at argument[%d]. (%d)\n", i, ret); 577 return ret; 578 } 579 580 void traceprobe_free_probe_arg(struct probe_arg *arg) 581 { 582 struct fetch_insn *code = arg->code; 583 584 while (code && code->op != FETCH_OP_END) { 585 if (code->op == FETCH_NOP_SYMBOL) 586 kfree(code->data); 587 code++; 588 } 589 kfree(arg->code); 590 kfree(arg->name); 591 kfree(arg->comm); 592 kfree(arg->fmt); 593 } 594 595 int traceprobe_update_arg(struct probe_arg *arg) 596 { 597 struct fetch_insn *code = arg->code; 598 long offset; 599 char *tmp; 600 char c; 601 int ret = 0; 602 603 while (code && code->op != FETCH_OP_END) { 604 if (code->op == FETCH_NOP_SYMBOL) { 605 if (code[1].op != FETCH_OP_IMM) 606 return -EINVAL; 607 608 tmp = strpbrk(code->data, "+-"); 609 if (tmp) 610 c = *tmp; 611 ret = traceprobe_split_symbol_offset(code->data, 612 &offset); 613 if (ret) 614 return ret; 615 616 code[1].immediate = 617 (unsigned long)kallsyms_lookup_name(code->data); 618 if (tmp) 619 *tmp = c; 620 if (!code[1].immediate) 621 return -ENOENT; 622 code[1].immediate += offset; 623 } 624 code++; 625 } 626 return 0; 627 } 628 629 /* When len=0, we just calculate the needed length */ 630 #define LEN_OR_ZERO (len ? len - pos : 0) 631 static int __set_print_fmt(struct trace_probe *tp, char *buf, int len, 632 bool is_return) 633 { 634 struct probe_arg *parg; 635 int i, j; 636 int pos = 0; 637 const char *fmt, *arg; 638 639 if (!is_return) { 640 fmt = "(%lx)"; 641 arg = "REC->" FIELD_STRING_IP; 642 } else { 643 fmt = "(%lx <- %lx)"; 644 arg = "REC->" FIELD_STRING_FUNC ", REC->" FIELD_STRING_RETIP; 645 } 646 647 pos += snprintf(buf + pos, LEN_OR_ZERO, "\"%s", fmt); 648 649 for (i = 0; i < tp->nr_args; i++) { 650 parg = tp->args + i; 651 pos += snprintf(buf + pos, LEN_OR_ZERO, " %s=", parg->name); 652 if (parg->count) { 653 pos += snprintf(buf + pos, LEN_OR_ZERO, "{%s", 654 parg->type->fmt); 655 for (j = 1; j < parg->count; j++) 656 pos += snprintf(buf + pos, LEN_OR_ZERO, ",%s", 657 parg->type->fmt); 658 pos += snprintf(buf + pos, LEN_OR_ZERO, "}"); 659 } else 660 pos += snprintf(buf + pos, LEN_OR_ZERO, "%s", 661 parg->type->fmt); 662 } 663 664 pos += snprintf(buf + pos, LEN_OR_ZERO, "\", %s", arg); 665 666 for (i = 0; i < tp->nr_args; i++) { 667 parg = tp->args + i; 668 if (parg->count) { 669 if (strcmp(parg->type->name, "string") == 0) 670 fmt = ", __get_str(%s[%d])"; 671 else 672 fmt = ", REC->%s[%d]"; 673 for (j = 0; j < parg->count; j++) 674 pos += snprintf(buf + pos, LEN_OR_ZERO, 675 fmt, parg->name, j); 676 } else { 677 if (strcmp(parg->type->name, "string") == 0) 678 fmt = ", __get_str(%s)"; 679 else 680 fmt = ", REC->%s"; 681 pos += snprintf(buf + pos, LEN_OR_ZERO, 682 fmt, parg->name); 683 } 684 } 685 686 /* return the length of print_fmt */ 687 return pos; 688 } 689 #undef LEN_OR_ZERO 690 691 int traceprobe_set_print_fmt(struct trace_probe *tp, bool is_return) 692 { 693 int len; 694 char *print_fmt; 695 696 /* First: called with 0 length to calculate the needed length */ 697 len = __set_print_fmt(tp, NULL, 0, is_return); 698 print_fmt = kmalloc(len + 1, GFP_KERNEL); 699 if (!print_fmt) 700 return -ENOMEM; 701 702 /* Second: actually write the @print_fmt */ 703 __set_print_fmt(tp, print_fmt, len + 1, is_return); 704 tp->call.print_fmt = print_fmt; 705 706 return 0; 707 } 708 709 int traceprobe_define_arg_fields(struct trace_event_call *event_call, 710 size_t offset, struct trace_probe *tp) 711 { 712 int ret, i; 713 714 /* Set argument names as fields */ 715 for (i = 0; i < tp->nr_args; i++) { 716 struct probe_arg *parg = &tp->args[i]; 717 const char *fmt = parg->type->fmttype; 718 int size = parg->type->size; 719 720 if (parg->fmt) 721 fmt = parg->fmt; 722 if (parg->count) 723 size *= parg->count; 724 ret = trace_define_field(event_call, fmt, parg->name, 725 offset + parg->offset, size, 726 parg->type->is_signed, 727 FILTER_OTHER); 728 if (ret) 729 return ret; 730 } 731 return 0; 732 } 733