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 "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 case '-': 304 tmp = strchr(arg, '('); 305 if (!tmp) 306 return -EINVAL; 307 308 *tmp = '\0'; 309 ret = kstrtol(arg, 0, &offset); 310 if (ret) 311 break; 312 313 arg = tmp + 1; 314 tmp = strrchr(arg, ')'); 315 316 if (tmp) { 317 const struct fetch_type *t2 = find_fetch_type(NULL); 318 319 *tmp = '\0'; 320 ret = parse_probe_arg(arg, t2, &code, end, flags); 321 if (ret) 322 break; 323 if (code->op == FETCH_OP_COMM) 324 return -EINVAL; 325 if (++code == end) 326 return -E2BIG; 327 *pcode = code; 328 329 code->op = FETCH_OP_DEREF; 330 code->offset = offset; 331 } 332 break; 333 } 334 if (!ret && code->op == FETCH_OP_NOP) { 335 /* Parsed, but do not find fetch method */ 336 ret = -EINVAL; 337 } 338 return ret; 339 } 340 341 #define BYTES_TO_BITS(nb) ((BITS_PER_LONG * (nb)) / sizeof(long)) 342 343 /* Bitfield type needs to be parsed into a fetch function */ 344 static int __parse_bitfield_probe_arg(const char *bf, 345 const struct fetch_type *t, 346 struct fetch_insn **pcode) 347 { 348 struct fetch_insn *code = *pcode; 349 unsigned long bw, bo; 350 char *tail; 351 352 if (*bf != 'b') 353 return 0; 354 355 bw = simple_strtoul(bf + 1, &tail, 0); /* Use simple one */ 356 357 if (bw == 0 || *tail != '@') 358 return -EINVAL; 359 360 bf = tail + 1; 361 bo = simple_strtoul(bf, &tail, 0); 362 363 if (tail == bf || *tail != '/') 364 return -EINVAL; 365 code++; 366 if (code->op != FETCH_OP_NOP) 367 return -E2BIG; 368 *pcode = code; 369 370 code->op = FETCH_OP_MOD_BF; 371 code->lshift = BYTES_TO_BITS(t->size) - (bw + bo); 372 code->rshift = BYTES_TO_BITS(t->size) - bw; 373 code->basesize = t->size; 374 375 return (BYTES_TO_BITS(t->size) < (bw + bo)) ? -EINVAL : 0; 376 } 377 378 /* String length checking wrapper */ 379 static int traceprobe_parse_probe_arg_body(char *arg, ssize_t *size, 380 struct probe_arg *parg, unsigned int flags) 381 { 382 struct fetch_insn *code, *scode, *tmp = NULL; 383 char *t, *t2; 384 int ret, len; 385 386 if (strlen(arg) > MAX_ARGSTR_LEN) { 387 pr_info("Argument is too long.: %s\n", arg); 388 return -ENOSPC; 389 } 390 parg->comm = kstrdup(arg, GFP_KERNEL); 391 if (!parg->comm) { 392 pr_info("Failed to allocate memory for command '%s'.\n", arg); 393 return -ENOMEM; 394 } 395 t = strchr(arg, ':'); 396 if (t) { 397 *t = '\0'; 398 t2 = strchr(++t, '['); 399 if (t2) { 400 *t2 = '\0'; 401 parg->count = simple_strtoul(t2 + 1, &t2, 0); 402 if (strcmp(t2, "]") || parg->count == 0) 403 return -EINVAL; 404 if (parg->count > MAX_ARRAY_LEN) 405 return -E2BIG; 406 } 407 } 408 /* 409 * The default type of $comm should be "string", and it can't be 410 * dereferenced. 411 */ 412 if (!t && strcmp(arg, "$comm") == 0) 413 parg->type = find_fetch_type("string"); 414 else 415 parg->type = find_fetch_type(t); 416 if (!parg->type) { 417 pr_info("Unsupported type: %s\n", t); 418 return -EINVAL; 419 } 420 parg->offset = *size; 421 *size += parg->type->size * (parg->count ?: 1); 422 423 if (parg->count) { 424 len = strlen(parg->type->fmttype) + 6; 425 parg->fmt = kmalloc(len, GFP_KERNEL); 426 if (!parg->fmt) 427 return -ENOMEM; 428 snprintf(parg->fmt, len, "%s[%d]", parg->type->fmttype, 429 parg->count); 430 } 431 432 code = tmp = kzalloc(sizeof(*code) * FETCH_INSN_MAX, GFP_KERNEL); 433 if (!code) 434 return -ENOMEM; 435 code[FETCH_INSN_MAX - 1].op = FETCH_OP_END; 436 437 ret = parse_probe_arg(arg, parg->type, &code, &code[FETCH_INSN_MAX - 1], 438 flags); 439 if (ret) 440 goto fail; 441 442 /* Store operation */ 443 if (!strcmp(parg->type->name, "string")) { 444 if (code->op != FETCH_OP_DEREF && code->op != FETCH_OP_IMM && 445 code->op != FETCH_OP_COMM) { 446 pr_info("string only accepts memory or address.\n"); 447 ret = -EINVAL; 448 goto fail; 449 } 450 if (code->op != FETCH_OP_DEREF || parg->count) { 451 /* 452 * IMM and COMM is pointing actual address, those must 453 * be kept, and if parg->count != 0, this is an array 454 * of string pointers instead of string address itself. 455 */ 456 code++; 457 if (code->op != FETCH_OP_NOP) { 458 ret = -E2BIG; 459 goto fail; 460 } 461 } 462 code->op = FETCH_OP_ST_STRING; /* In DEREF case, replace it */ 463 code->size = parg->type->size; 464 parg->dynamic = true; 465 } else if (code->op == FETCH_OP_DEREF) { 466 code->op = FETCH_OP_ST_MEM; 467 code->size = parg->type->size; 468 } else { 469 code++; 470 if (code->op != FETCH_OP_NOP) { 471 ret = -E2BIG; 472 goto fail; 473 } 474 code->op = FETCH_OP_ST_RAW; 475 code->size = parg->type->size; 476 } 477 scode = code; 478 /* Modify operation */ 479 if (t != NULL) { 480 ret = __parse_bitfield_probe_arg(t, parg->type, &code); 481 if (ret) 482 goto fail; 483 } 484 /* Loop(Array) operation */ 485 if (parg->count) { 486 if (scode->op != FETCH_OP_ST_MEM && 487 scode->op != FETCH_OP_ST_STRING) { 488 pr_info("array only accepts memory or address\n"); 489 ret = -EINVAL; 490 goto fail; 491 } 492 code++; 493 if (code->op != FETCH_OP_NOP) { 494 ret = -E2BIG; 495 goto fail; 496 } 497 code->op = FETCH_OP_LP_ARRAY; 498 code->param = parg->count; 499 } 500 code++; 501 code->op = FETCH_OP_END; 502 503 /* Shrink down the code buffer */ 504 parg->code = kzalloc(sizeof(*code) * (code - tmp + 1), GFP_KERNEL); 505 if (!parg->code) 506 ret = -ENOMEM; 507 else 508 memcpy(parg->code, tmp, sizeof(*code) * (code - tmp + 1)); 509 510 fail: 511 if (ret) { 512 for (code = tmp; code < tmp + FETCH_INSN_MAX; code++) 513 if (code->op == FETCH_NOP_SYMBOL) 514 kfree(code->data); 515 } 516 kfree(tmp); 517 518 return ret; 519 } 520 521 /* Return 1 if name is reserved or already used by another argument */ 522 static int traceprobe_conflict_field_name(const char *name, 523 struct probe_arg *args, int narg) 524 { 525 int i; 526 527 for (i = 0; i < ARRAY_SIZE(reserved_field_names); i++) 528 if (strcmp(reserved_field_names[i], name) == 0) 529 return 1; 530 531 for (i = 0; i < narg; i++) 532 if (strcmp(args[i].name, name) == 0) 533 return 1; 534 535 return 0; 536 } 537 538 int traceprobe_parse_probe_arg(struct trace_probe *tp, int i, char *arg, 539 unsigned int flags) 540 { 541 struct probe_arg *parg = &tp->args[i]; 542 char *body; 543 int ret; 544 545 /* Increment count for freeing args in error case */ 546 tp->nr_args++; 547 548 body = strchr(arg, '='); 549 if (body) { 550 parg->name = kmemdup_nul(arg, body - arg, GFP_KERNEL); 551 body++; 552 } else { 553 /* If argument name is omitted, set "argN" */ 554 parg->name = kasprintf(GFP_KERNEL, "arg%d", i + 1); 555 body = arg; 556 } 557 if (!parg->name) 558 return -ENOMEM; 559 560 if (!is_good_name(parg->name)) { 561 pr_info("Invalid argument[%d] name: %s\n", 562 i, parg->name); 563 return -EINVAL; 564 } 565 566 if (traceprobe_conflict_field_name(parg->name, tp->args, i)) { 567 pr_info("Argument[%d]: '%s' conflicts with another field.\n", 568 i, parg->name); 569 return -EINVAL; 570 } 571 572 /* Parse fetch argument */ 573 ret = traceprobe_parse_probe_arg_body(body, &tp->size, parg, flags); 574 if (ret) 575 pr_info("Parse error at argument[%d]. (%d)\n", i, ret); 576 return ret; 577 } 578 579 void traceprobe_free_probe_arg(struct probe_arg *arg) 580 { 581 struct fetch_insn *code = arg->code; 582 583 while (code && code->op != FETCH_OP_END) { 584 if (code->op == FETCH_NOP_SYMBOL) 585 kfree(code->data); 586 code++; 587 } 588 kfree(arg->code); 589 kfree(arg->name); 590 kfree(arg->comm); 591 kfree(arg->fmt); 592 } 593 594 int traceprobe_update_arg(struct probe_arg *arg) 595 { 596 struct fetch_insn *code = arg->code; 597 long offset; 598 char *tmp; 599 char c; 600 int ret = 0; 601 602 while (code && code->op != FETCH_OP_END) { 603 if (code->op == FETCH_NOP_SYMBOL) { 604 if (code[1].op != FETCH_OP_IMM) 605 return -EINVAL; 606 607 tmp = strpbrk(code->data, "+-"); 608 if (tmp) 609 c = *tmp; 610 ret = traceprobe_split_symbol_offset(code->data, 611 &offset); 612 if (ret) 613 return ret; 614 615 code[1].immediate = 616 (unsigned long)kallsyms_lookup_name(code->data); 617 if (tmp) 618 *tmp = c; 619 if (!code[1].immediate) 620 return -ENOENT; 621 code[1].immediate += offset; 622 } 623 code++; 624 } 625 return 0; 626 } 627 628 /* When len=0, we just calculate the needed length */ 629 #define LEN_OR_ZERO (len ? len - pos : 0) 630 static int __set_print_fmt(struct trace_probe *tp, char *buf, int len, 631 bool is_return) 632 { 633 struct probe_arg *parg; 634 int i, j; 635 int pos = 0; 636 const char *fmt, *arg; 637 638 if (!is_return) { 639 fmt = "(%lx)"; 640 arg = "REC->" FIELD_STRING_IP; 641 } else { 642 fmt = "(%lx <- %lx)"; 643 arg = "REC->" FIELD_STRING_FUNC ", REC->" FIELD_STRING_RETIP; 644 } 645 646 pos += snprintf(buf + pos, LEN_OR_ZERO, "\"%s", fmt); 647 648 for (i = 0; i < tp->nr_args; i++) { 649 parg = tp->args + i; 650 pos += snprintf(buf + pos, LEN_OR_ZERO, " %s=", parg->name); 651 if (parg->count) { 652 pos += snprintf(buf + pos, LEN_OR_ZERO, "{%s", 653 parg->type->fmt); 654 for (j = 1; j < parg->count; j++) 655 pos += snprintf(buf + pos, LEN_OR_ZERO, ",%s", 656 parg->type->fmt); 657 pos += snprintf(buf + pos, LEN_OR_ZERO, "}"); 658 } else 659 pos += snprintf(buf + pos, LEN_OR_ZERO, "%s", 660 parg->type->fmt); 661 } 662 663 pos += snprintf(buf + pos, LEN_OR_ZERO, "\", %s", arg); 664 665 for (i = 0; i < tp->nr_args; i++) { 666 parg = tp->args + i; 667 if (parg->count) { 668 if (strcmp(parg->type->name, "string") == 0) 669 fmt = ", __get_str(%s[%d])"; 670 else 671 fmt = ", REC->%s[%d]"; 672 for (j = 0; j < parg->count; j++) 673 pos += snprintf(buf + pos, LEN_OR_ZERO, 674 fmt, parg->name, j); 675 } else { 676 if (strcmp(parg->type->name, "string") == 0) 677 fmt = ", __get_str(%s)"; 678 else 679 fmt = ", REC->%s"; 680 pos += snprintf(buf + pos, LEN_OR_ZERO, 681 fmt, parg->name); 682 } 683 } 684 685 /* return the length of print_fmt */ 686 return pos; 687 } 688 #undef LEN_OR_ZERO 689 690 int traceprobe_set_print_fmt(struct trace_probe *tp, bool is_return) 691 { 692 int len; 693 char *print_fmt; 694 695 /* First: called with 0 length to calculate the needed length */ 696 len = __set_print_fmt(tp, NULL, 0, is_return); 697 print_fmt = kmalloc(len + 1, GFP_KERNEL); 698 if (!print_fmt) 699 return -ENOMEM; 700 701 /* Second: actually write the @print_fmt */ 702 __set_print_fmt(tp, print_fmt, len + 1, is_return); 703 tp->call.print_fmt = print_fmt; 704 705 return 0; 706 } 707 708 int traceprobe_define_arg_fields(struct trace_event_call *event_call, 709 size_t offset, struct trace_probe *tp) 710 { 711 int ret, i; 712 713 /* Set argument names as fields */ 714 for (i = 0; i < tp->nr_args; i++) { 715 struct probe_arg *parg = &tp->args[i]; 716 const char *fmt = parg->type->fmttype; 717 int size = parg->type->size; 718 719 if (parg->fmt) 720 fmt = parg->fmt; 721 if (parg->count) 722 size *= parg->count; 723 ret = trace_define_field(event_call, fmt, parg->name, 724 offset + parg->offset, size, 725 parg->type->is_signed, 726 FILTER_OTHER); 727 if (ret) 728 return ret; 729 } 730 return 0; 731 } 732