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 <linux/bpf.h> 15 #include "trace_btf.h" 16 17 #include "trace_probe.h" 18 19 #undef C 20 #define C(a, b) b 21 22 static const char *trace_probe_err_text[] = { ERRORS }; 23 24 static const char *reserved_field_names[] = { 25 "common_type", 26 "common_flags", 27 "common_preempt_count", 28 "common_pid", 29 "common_tgid", 30 FIELD_STRING_IP, 31 FIELD_STRING_RETIP, 32 FIELD_STRING_FUNC, 33 }; 34 35 /* Printing in basic type function template */ 36 #define DEFINE_BASIC_PRINT_TYPE_FUNC(tname, type, fmt) \ 37 int PRINT_TYPE_FUNC_NAME(tname)(struct trace_seq *s, void *data, void *ent)\ 38 { \ 39 trace_seq_printf(s, fmt, *(type *)data); \ 40 return !trace_seq_has_overflowed(s); \ 41 } \ 42 const char PRINT_TYPE_FMT_NAME(tname)[] = fmt; 43 44 DEFINE_BASIC_PRINT_TYPE_FUNC(u8, u8, "%u") 45 DEFINE_BASIC_PRINT_TYPE_FUNC(u16, u16, "%u") 46 DEFINE_BASIC_PRINT_TYPE_FUNC(u32, u32, "%u") 47 DEFINE_BASIC_PRINT_TYPE_FUNC(u64, u64, "%Lu") 48 DEFINE_BASIC_PRINT_TYPE_FUNC(s8, s8, "%d") 49 DEFINE_BASIC_PRINT_TYPE_FUNC(s16, s16, "%d") 50 DEFINE_BASIC_PRINT_TYPE_FUNC(s32, s32, "%d") 51 DEFINE_BASIC_PRINT_TYPE_FUNC(s64, s64, "%Ld") 52 DEFINE_BASIC_PRINT_TYPE_FUNC(x8, u8, "0x%x") 53 DEFINE_BASIC_PRINT_TYPE_FUNC(x16, u16, "0x%x") 54 DEFINE_BASIC_PRINT_TYPE_FUNC(x32, u32, "0x%x") 55 DEFINE_BASIC_PRINT_TYPE_FUNC(x64, u64, "0x%Lx") 56 DEFINE_BASIC_PRINT_TYPE_FUNC(char, u8, "'%c'") 57 58 int PRINT_TYPE_FUNC_NAME(symbol)(struct trace_seq *s, void *data, void *ent) 59 { 60 trace_seq_printf(s, "%pS", (void *)*(unsigned long *)data); 61 return !trace_seq_has_overflowed(s); 62 } 63 const char PRINT_TYPE_FMT_NAME(symbol)[] = "%pS"; 64 65 /* Print type function for string type */ 66 int PRINT_TYPE_FUNC_NAME(string)(struct trace_seq *s, void *data, void *ent) 67 { 68 int len = *(u32 *)data >> 16; 69 70 if (!len) 71 trace_seq_puts(s, FAULT_STRING); 72 else 73 trace_seq_printf(s, "\"%s\"", 74 (const char *)get_loc_data(data, ent)); 75 return !trace_seq_has_overflowed(s); 76 } 77 78 const char PRINT_TYPE_FMT_NAME(string)[] = "\\\"%s\\\""; 79 80 /* Fetch type information table */ 81 static const struct fetch_type probe_fetch_types[] = { 82 /* Special types */ 83 __ASSIGN_FETCH_TYPE("string", string, string, sizeof(u32), 1, 1, 84 "__data_loc char[]"), 85 __ASSIGN_FETCH_TYPE("ustring", string, string, sizeof(u32), 1, 1, 86 "__data_loc char[]"), 87 __ASSIGN_FETCH_TYPE("symstr", string, string, sizeof(u32), 1, 1, 88 "__data_loc char[]"), 89 /* Basic types */ 90 ASSIGN_FETCH_TYPE(u8, u8, 0), 91 ASSIGN_FETCH_TYPE(u16, u16, 0), 92 ASSIGN_FETCH_TYPE(u32, u32, 0), 93 ASSIGN_FETCH_TYPE(u64, u64, 0), 94 ASSIGN_FETCH_TYPE(s8, u8, 1), 95 ASSIGN_FETCH_TYPE(s16, u16, 1), 96 ASSIGN_FETCH_TYPE(s32, u32, 1), 97 ASSIGN_FETCH_TYPE(s64, u64, 1), 98 ASSIGN_FETCH_TYPE_ALIAS(x8, u8, u8, 0), 99 ASSIGN_FETCH_TYPE_ALIAS(x16, u16, u16, 0), 100 ASSIGN_FETCH_TYPE_ALIAS(x32, u32, u32, 0), 101 ASSIGN_FETCH_TYPE_ALIAS(x64, u64, u64, 0), 102 ASSIGN_FETCH_TYPE_ALIAS(char, u8, u8, 0), 103 ASSIGN_FETCH_TYPE_ALIAS(symbol, ADDR_FETCH_TYPE, ADDR_FETCH_TYPE, 0), 104 105 ASSIGN_FETCH_TYPE_END 106 }; 107 108 static const struct fetch_type *find_fetch_type(const char *type, unsigned long flags) 109 { 110 int i; 111 112 /* Reject the symbol/symstr for uprobes */ 113 if (type && (flags & TPARG_FL_USER) && 114 (!strcmp(type, "symbol") || !strcmp(type, "symstr"))) 115 return NULL; 116 117 if (!type) 118 type = DEFAULT_FETCH_TYPE_STR; 119 120 /* Special case: bitfield */ 121 if (*type == 'b') { 122 unsigned long bs; 123 124 type = strchr(type, '/'); 125 if (!type) 126 goto fail; 127 128 type++; 129 if (kstrtoul(type, 0, &bs)) 130 goto fail; 131 132 switch (bs) { 133 case 8: 134 return find_fetch_type("u8", flags); 135 case 16: 136 return find_fetch_type("u16", flags); 137 case 32: 138 return find_fetch_type("u32", flags); 139 case 64: 140 return find_fetch_type("u64", flags); 141 default: 142 goto fail; 143 } 144 } 145 146 for (i = 0; probe_fetch_types[i].name; i++) { 147 if (strcmp(type, probe_fetch_types[i].name) == 0) 148 return &probe_fetch_types[i]; 149 } 150 151 fail: 152 return NULL; 153 } 154 155 static struct trace_probe_log trace_probe_log; 156 157 void trace_probe_log_init(const char *subsystem, int argc, const char **argv) 158 { 159 trace_probe_log.subsystem = subsystem; 160 trace_probe_log.argc = argc; 161 trace_probe_log.argv = argv; 162 trace_probe_log.index = 0; 163 } 164 165 void trace_probe_log_clear(void) 166 { 167 memset(&trace_probe_log, 0, sizeof(trace_probe_log)); 168 } 169 170 void trace_probe_log_set_index(int index) 171 { 172 trace_probe_log.index = index; 173 } 174 175 void __trace_probe_log_err(int offset, int err_type) 176 { 177 char *command, *p; 178 int i, len = 0, pos = 0; 179 180 if (!trace_probe_log.argv) 181 return; 182 183 /* Recalculate the length and allocate buffer */ 184 for (i = 0; i < trace_probe_log.argc; i++) { 185 if (i == trace_probe_log.index) 186 pos = len; 187 len += strlen(trace_probe_log.argv[i]) + 1; 188 } 189 command = kzalloc(len, GFP_KERNEL); 190 if (!command) 191 return; 192 193 if (trace_probe_log.index >= trace_probe_log.argc) { 194 /** 195 * Set the error position is next to the last arg + space. 196 * Note that len includes the terminal null and the cursor 197 * appears at pos + 1. 198 */ 199 pos = len; 200 offset = 0; 201 } 202 203 /* And make a command string from argv array */ 204 p = command; 205 for (i = 0; i < trace_probe_log.argc; i++) { 206 len = strlen(trace_probe_log.argv[i]); 207 strcpy(p, trace_probe_log.argv[i]); 208 p[len] = ' '; 209 p += len + 1; 210 } 211 *(p - 1) = '\0'; 212 213 tracing_log_err(NULL, trace_probe_log.subsystem, command, 214 trace_probe_err_text, err_type, pos + offset); 215 216 kfree(command); 217 } 218 219 /* Split symbol and offset. */ 220 int traceprobe_split_symbol_offset(char *symbol, long *offset) 221 { 222 char *tmp; 223 int ret; 224 225 if (!offset) 226 return -EINVAL; 227 228 tmp = strpbrk(symbol, "+-"); 229 if (tmp) { 230 ret = kstrtol(tmp, 0, offset); 231 if (ret) 232 return ret; 233 *tmp = '\0'; 234 } else 235 *offset = 0; 236 237 return 0; 238 } 239 240 /* @buf must has MAX_EVENT_NAME_LEN size */ 241 int traceprobe_parse_event_name(const char **pevent, const char **pgroup, 242 char *buf, int offset) 243 { 244 const char *slash, *event = *pevent; 245 int len; 246 247 slash = strchr(event, '/'); 248 if (!slash) 249 slash = strchr(event, '.'); 250 251 if (slash) { 252 if (slash == event) { 253 trace_probe_log_err(offset, NO_GROUP_NAME); 254 return -EINVAL; 255 } 256 if (slash - event + 1 > MAX_EVENT_NAME_LEN) { 257 trace_probe_log_err(offset, GROUP_TOO_LONG); 258 return -EINVAL; 259 } 260 strscpy(buf, event, slash - event + 1); 261 if (!is_good_system_name(buf)) { 262 trace_probe_log_err(offset, BAD_GROUP_NAME); 263 return -EINVAL; 264 } 265 *pgroup = buf; 266 *pevent = slash + 1; 267 offset += slash - event + 1; 268 event = *pevent; 269 } 270 len = strlen(event); 271 if (len == 0) { 272 if (slash) { 273 *pevent = NULL; 274 return 0; 275 } 276 trace_probe_log_err(offset, NO_EVENT_NAME); 277 return -EINVAL; 278 } else if (len > MAX_EVENT_NAME_LEN) { 279 trace_probe_log_err(offset, EVENT_TOO_LONG); 280 return -EINVAL; 281 } 282 if (!is_good_name(event)) { 283 trace_probe_log_err(offset, BAD_EVENT_NAME); 284 return -EINVAL; 285 } 286 return 0; 287 } 288 289 static int parse_trace_event_arg(char *arg, struct fetch_insn *code, 290 struct traceprobe_parse_context *ctx) 291 { 292 struct ftrace_event_field *field; 293 struct list_head *head; 294 295 head = trace_get_fields(ctx->event); 296 list_for_each_entry(field, head, link) { 297 if (!strcmp(arg, field->name)) { 298 code->op = FETCH_OP_TP_ARG; 299 code->data = field; 300 return 0; 301 } 302 } 303 return -ENOENT; 304 } 305 306 #ifdef CONFIG_PROBE_EVENTS_BTF_ARGS 307 308 static u32 btf_type_int(const struct btf_type *t) 309 { 310 return *(u32 *)(t + 1); 311 } 312 313 static const char *type_from_btf_id(struct btf *btf, s32 id) 314 { 315 const struct btf_type *t; 316 u32 intdata; 317 s32 tid; 318 319 /* TODO: const char * could be converted as a string */ 320 t = btf_type_skip_modifiers(btf, id, &tid); 321 322 switch (BTF_INFO_KIND(t->info)) { 323 case BTF_KIND_ENUM: 324 /* enum is "int", so convert to "s32" */ 325 return "s32"; 326 case BTF_KIND_ENUM64: 327 return "s64"; 328 case BTF_KIND_PTR: 329 /* pointer will be converted to "x??" */ 330 if (IS_ENABLED(CONFIG_64BIT)) 331 return "x64"; 332 else 333 return "x32"; 334 case BTF_KIND_INT: 335 intdata = btf_type_int(t); 336 if (BTF_INT_ENCODING(intdata) & BTF_INT_SIGNED) { 337 switch (BTF_INT_BITS(intdata)) { 338 case 8: 339 return "s8"; 340 case 16: 341 return "s16"; 342 case 32: 343 return "s32"; 344 case 64: 345 return "s64"; 346 } 347 } else { /* unsigned */ 348 switch (BTF_INT_BITS(intdata)) { 349 case 8: 350 return "u8"; 351 case 16: 352 return "u16"; 353 case 32: 354 return "u32"; 355 case 64: 356 return "u64"; 357 } 358 } 359 } 360 /* TODO: support other types */ 361 362 return NULL; 363 } 364 365 static const struct btf_param *find_btf_func_param(const char *funcname, s32 *nr, 366 struct btf **btf_p, bool tracepoint) 367 { 368 const struct btf_param *param; 369 const struct btf_type *t; 370 struct btf *btf; 371 372 if (!funcname || !nr) 373 return ERR_PTR(-EINVAL); 374 375 t = btf_find_func_proto(funcname, &btf); 376 if (!t) 377 return (const struct btf_param *)t; 378 379 param = btf_get_func_param(t, nr); 380 if (IS_ERR_OR_NULL(param)) 381 goto err; 382 383 /* Hide the first 'data' argument of tracepoint */ 384 if (tracepoint) { 385 (*nr)--; 386 param++; 387 } 388 389 if (*nr > 0) { 390 *btf_p = btf; 391 return param; 392 } 393 394 err: 395 btf_put(btf); 396 return NULL; 397 } 398 399 static void clear_btf_context(struct traceprobe_parse_context *ctx) 400 { 401 if (ctx->btf) { 402 btf_put(ctx->btf); 403 ctx->btf = NULL; 404 ctx->params = NULL; 405 ctx->nr_params = 0; 406 } 407 } 408 409 static int parse_btf_arg(const char *varname, struct fetch_insn *code, 410 struct traceprobe_parse_context *ctx) 411 { 412 const struct btf_param *params; 413 int i; 414 415 if (WARN_ON_ONCE(!ctx->funcname)) 416 return -EINVAL; 417 418 if (!ctx->params) { 419 params = find_btf_func_param(ctx->funcname, 420 &ctx->nr_params, &ctx->btf, 421 ctx->flags & TPARG_FL_TPOINT); 422 if (IS_ERR_OR_NULL(params)) { 423 trace_probe_log_err(ctx->offset, NO_BTF_ENTRY); 424 return PTR_ERR(params); 425 } 426 ctx->params = params; 427 } else 428 params = ctx->params; 429 430 for (i = 0; i < ctx->nr_params; i++) { 431 const char *name = btf_name_by_offset(ctx->btf, params[i].name_off); 432 433 if (name && !strcmp(name, varname)) { 434 code->op = FETCH_OP_ARG; 435 if (ctx->flags & TPARG_FL_TPOINT) 436 code->param = i + 1; 437 else 438 code->param = i; 439 return 0; 440 } 441 } 442 trace_probe_log_err(ctx->offset, NO_BTFARG); 443 return -ENOENT; 444 } 445 446 static const struct fetch_type *parse_btf_arg_type(int arg_idx, 447 struct traceprobe_parse_context *ctx) 448 { 449 struct btf *btf = ctx->btf; 450 const char *typestr = NULL; 451 452 if (btf && ctx->params) { 453 if (ctx->flags & TPARG_FL_TPOINT) 454 arg_idx--; 455 typestr = type_from_btf_id(btf, ctx->params[arg_idx].type); 456 } 457 458 return find_fetch_type(typestr, ctx->flags); 459 } 460 461 static const struct fetch_type *parse_btf_retval_type( 462 struct traceprobe_parse_context *ctx) 463 { 464 const char *typestr = NULL; 465 const struct btf_type *t; 466 struct btf *btf; 467 468 if (ctx->funcname) { 469 /* Do not use ctx->btf, because it must be used with ctx->param */ 470 t = btf_find_func_proto(ctx->funcname, &btf); 471 if (t) { 472 typestr = type_from_btf_id(btf, t->type); 473 btf_put(btf); 474 } 475 } 476 477 return find_fetch_type(typestr, ctx->flags); 478 } 479 480 static bool is_btf_retval_void(const char *funcname) 481 { 482 const struct btf_type *t; 483 struct btf *btf; 484 bool ret; 485 486 t = btf_find_func_proto(funcname, &btf); 487 if (!t) 488 return false; 489 490 ret = (t->type == 0); 491 btf_put(btf); 492 return ret; 493 } 494 #else 495 static void clear_btf_context(struct traceprobe_parse_context *ctx) 496 { 497 ctx->btf = NULL; 498 } 499 500 static const struct btf_param *find_btf_func_param(const char *funcname, s32 *nr, 501 struct btf **btf_p, bool tracepoint) 502 { 503 return ERR_PTR(-EOPNOTSUPP); 504 } 505 506 static int parse_btf_arg(const char *varname, struct fetch_insn *code, 507 struct traceprobe_parse_context *ctx) 508 { 509 trace_probe_log_err(ctx->offset, NOSUP_BTFARG); 510 return -EOPNOTSUPP; 511 } 512 513 #define parse_btf_arg_type(idx, ctx) \ 514 find_fetch_type(NULL, ctx->flags) 515 516 #define parse_btf_retval_type(ctx) \ 517 find_fetch_type(NULL, ctx->flags) 518 519 #define is_btf_retval_void(funcname) (false) 520 521 #endif 522 523 #define PARAM_MAX_STACK (THREAD_SIZE / sizeof(unsigned long)) 524 525 static int parse_probe_vars(char *arg, const struct fetch_type *t, 526 struct fetch_insn *code, 527 struct traceprobe_parse_context *ctx) 528 { 529 unsigned long param; 530 int err = TP_ERR_BAD_VAR; 531 int ret = 0; 532 int len; 533 534 if (ctx->flags & TPARG_FL_TEVENT) { 535 if (code->data) 536 return -EFAULT; 537 ret = parse_trace_event_arg(arg, code, ctx); 538 if (!ret) 539 return 0; 540 if (strcmp(arg, "comm") == 0 || strcmp(arg, "COMM") == 0) { 541 code->op = FETCH_OP_COMM; 542 return 0; 543 } 544 /* backward compatibility */ 545 ctx->offset = 0; 546 goto inval; 547 } 548 549 if (strcmp(arg, "retval") == 0) { 550 if (ctx->flags & TPARG_FL_RETURN) { 551 if ((ctx->flags & TPARG_FL_KERNEL) && 552 is_btf_retval_void(ctx->funcname)) { 553 err = TP_ERR_NO_RETVAL; 554 goto inval; 555 } 556 code->op = FETCH_OP_RETVAL; 557 return 0; 558 } 559 err = TP_ERR_RETVAL_ON_PROBE; 560 goto inval; 561 } 562 563 len = str_has_prefix(arg, "stack"); 564 if (len) { 565 566 if (arg[len] == '\0') { 567 code->op = FETCH_OP_STACKP; 568 return 0; 569 } 570 571 if (isdigit(arg[len])) { 572 ret = kstrtoul(arg + len, 10, ¶m); 573 if (ret) 574 goto inval; 575 576 if ((ctx->flags & TPARG_FL_KERNEL) && 577 param > PARAM_MAX_STACK) { 578 err = TP_ERR_BAD_STACK_NUM; 579 goto inval; 580 } 581 code->op = FETCH_OP_STACK; 582 code->param = (unsigned int)param; 583 return 0; 584 } 585 goto inval; 586 } 587 588 if (strcmp(arg, "comm") == 0 || strcmp(arg, "COMM") == 0) { 589 code->op = FETCH_OP_COMM; 590 return 0; 591 } 592 593 #ifdef CONFIG_HAVE_FUNCTION_ARG_ACCESS_API 594 len = str_has_prefix(arg, "arg"); 595 if (len && tparg_is_function_entry(ctx->flags)) { 596 ret = kstrtoul(arg + len, 10, ¶m); 597 if (ret) 598 goto inval; 599 600 if (!param || param > PARAM_MAX_STACK) { 601 err = TP_ERR_BAD_ARG_NUM; 602 goto inval; 603 } 604 605 code->op = FETCH_OP_ARG; 606 code->param = (unsigned int)param - 1; 607 /* 608 * The tracepoint probe will probe a stub function, and the 609 * first parameter of the stub is a dummy and should be ignored. 610 */ 611 if (ctx->flags & TPARG_FL_TPOINT) 612 code->param++; 613 return 0; 614 } 615 #endif 616 617 inval: 618 __trace_probe_log_err(ctx->offset, err); 619 return -EINVAL; 620 } 621 622 static int str_to_immediate(char *str, unsigned long *imm) 623 { 624 if (isdigit(str[0])) 625 return kstrtoul(str, 0, imm); 626 else if (str[0] == '-') 627 return kstrtol(str, 0, (long *)imm); 628 else if (str[0] == '+') 629 return kstrtol(str + 1, 0, (long *)imm); 630 return -EINVAL; 631 } 632 633 static int __parse_imm_string(char *str, char **pbuf, int offs) 634 { 635 size_t len = strlen(str); 636 637 if (str[len - 1] != '"') { 638 trace_probe_log_err(offs + len, IMMSTR_NO_CLOSE); 639 return -EINVAL; 640 } 641 *pbuf = kstrndup(str, len - 1, GFP_KERNEL); 642 if (!*pbuf) 643 return -ENOMEM; 644 return 0; 645 } 646 647 /* Recursive argument parser */ 648 static int 649 parse_probe_arg(char *arg, const struct fetch_type *type, 650 struct fetch_insn **pcode, struct fetch_insn *end, 651 struct traceprobe_parse_context *ctx) 652 { 653 struct fetch_insn *code = *pcode; 654 unsigned long param; 655 int deref = FETCH_OP_DEREF; 656 long offset = 0; 657 char *tmp; 658 int ret = 0; 659 660 switch (arg[0]) { 661 case '$': 662 ret = parse_probe_vars(arg + 1, type, code, ctx); 663 break; 664 665 case '%': /* named register */ 666 if (ctx->flags & (TPARG_FL_TEVENT | TPARG_FL_FPROBE)) { 667 /* eprobe and fprobe do not handle registers */ 668 trace_probe_log_err(ctx->offset, BAD_VAR); 669 break; 670 } 671 ret = regs_query_register_offset(arg + 1); 672 if (ret >= 0) { 673 code->op = FETCH_OP_REG; 674 code->param = (unsigned int)ret; 675 ret = 0; 676 } else 677 trace_probe_log_err(ctx->offset, BAD_REG_NAME); 678 break; 679 680 case '@': /* memory, file-offset or symbol */ 681 if (isdigit(arg[1])) { 682 ret = kstrtoul(arg + 1, 0, ¶m); 683 if (ret) { 684 trace_probe_log_err(ctx->offset, BAD_MEM_ADDR); 685 break; 686 } 687 /* load address */ 688 code->op = FETCH_OP_IMM; 689 code->immediate = param; 690 } else if (arg[1] == '+') { 691 /* kprobes don't support file offsets */ 692 if (ctx->flags & TPARG_FL_KERNEL) { 693 trace_probe_log_err(ctx->offset, FILE_ON_KPROBE); 694 return -EINVAL; 695 } 696 ret = kstrtol(arg + 2, 0, &offset); 697 if (ret) { 698 trace_probe_log_err(ctx->offset, BAD_FILE_OFFS); 699 break; 700 } 701 702 code->op = FETCH_OP_FOFFS; 703 code->immediate = (unsigned long)offset; // imm64? 704 } else { 705 /* uprobes don't support symbols */ 706 if (!(ctx->flags & TPARG_FL_KERNEL)) { 707 trace_probe_log_err(ctx->offset, SYM_ON_UPROBE); 708 return -EINVAL; 709 } 710 /* Preserve symbol for updating */ 711 code->op = FETCH_NOP_SYMBOL; 712 code->data = kstrdup(arg + 1, GFP_KERNEL); 713 if (!code->data) 714 return -ENOMEM; 715 if (++code == end) { 716 trace_probe_log_err(ctx->offset, TOO_MANY_OPS); 717 return -EINVAL; 718 } 719 code->op = FETCH_OP_IMM; 720 code->immediate = 0; 721 } 722 /* These are fetching from memory */ 723 if (++code == end) { 724 trace_probe_log_err(ctx->offset, TOO_MANY_OPS); 725 return -EINVAL; 726 } 727 *pcode = code; 728 code->op = FETCH_OP_DEREF; 729 code->offset = offset; 730 break; 731 732 case '+': /* deref memory */ 733 case '-': 734 if (arg[1] == 'u') { 735 deref = FETCH_OP_UDEREF; 736 arg[1] = arg[0]; 737 arg++; 738 } 739 if (arg[0] == '+') 740 arg++; /* Skip '+', because kstrtol() rejects it. */ 741 tmp = strchr(arg, '('); 742 if (!tmp) { 743 trace_probe_log_err(ctx->offset, DEREF_NEED_BRACE); 744 return -EINVAL; 745 } 746 *tmp = '\0'; 747 ret = kstrtol(arg, 0, &offset); 748 if (ret) { 749 trace_probe_log_err(ctx->offset, BAD_DEREF_OFFS); 750 break; 751 } 752 ctx->offset += (tmp + 1 - arg) + (arg[0] != '-' ? 1 : 0); 753 arg = tmp + 1; 754 tmp = strrchr(arg, ')'); 755 if (!tmp) { 756 trace_probe_log_err(ctx->offset + strlen(arg), 757 DEREF_OPEN_BRACE); 758 return -EINVAL; 759 } else { 760 const struct fetch_type *t2 = find_fetch_type(NULL, ctx->flags); 761 int cur_offs = ctx->offset; 762 763 *tmp = '\0'; 764 ret = parse_probe_arg(arg, t2, &code, end, ctx); 765 if (ret) 766 break; 767 ctx->offset = cur_offs; 768 if (code->op == FETCH_OP_COMM || 769 code->op == FETCH_OP_DATA) { 770 trace_probe_log_err(ctx->offset, COMM_CANT_DEREF); 771 return -EINVAL; 772 } 773 if (++code == end) { 774 trace_probe_log_err(ctx->offset, TOO_MANY_OPS); 775 return -EINVAL; 776 } 777 *pcode = code; 778 779 code->op = deref; 780 code->offset = offset; 781 } 782 break; 783 case '\\': /* Immediate value */ 784 if (arg[1] == '"') { /* Immediate string */ 785 ret = __parse_imm_string(arg + 2, &tmp, ctx->offset + 2); 786 if (ret) 787 break; 788 code->op = FETCH_OP_DATA; 789 code->data = tmp; 790 } else { 791 ret = str_to_immediate(arg + 1, &code->immediate); 792 if (ret) 793 trace_probe_log_err(ctx->offset + 1, BAD_IMM); 794 else 795 code->op = FETCH_OP_IMM; 796 } 797 break; 798 default: 799 if (isalpha(arg[0]) || arg[0] == '_') { /* BTF variable */ 800 if (!tparg_is_function_entry(ctx->flags)) { 801 trace_probe_log_err(ctx->offset, NOSUP_BTFARG); 802 return -EINVAL; 803 } 804 ret = parse_btf_arg(arg, code, ctx); 805 break; 806 } 807 } 808 if (!ret && code->op == FETCH_OP_NOP) { 809 /* Parsed, but do not find fetch method */ 810 trace_probe_log_err(ctx->offset, BAD_FETCH_ARG); 811 ret = -EINVAL; 812 } 813 return ret; 814 } 815 816 #define BYTES_TO_BITS(nb) ((BITS_PER_LONG * (nb)) / sizeof(long)) 817 818 /* Bitfield type needs to be parsed into a fetch function */ 819 static int __parse_bitfield_probe_arg(const char *bf, 820 const struct fetch_type *t, 821 struct fetch_insn **pcode) 822 { 823 struct fetch_insn *code = *pcode; 824 unsigned long bw, bo; 825 char *tail; 826 827 if (*bf != 'b') 828 return 0; 829 830 bw = simple_strtoul(bf + 1, &tail, 0); /* Use simple one */ 831 832 if (bw == 0 || *tail != '@') 833 return -EINVAL; 834 835 bf = tail + 1; 836 bo = simple_strtoul(bf, &tail, 0); 837 838 if (tail == bf || *tail != '/') 839 return -EINVAL; 840 code++; 841 if (code->op != FETCH_OP_NOP) 842 return -EINVAL; 843 *pcode = code; 844 845 code->op = FETCH_OP_MOD_BF; 846 code->lshift = BYTES_TO_BITS(t->size) - (bw + bo); 847 code->rshift = BYTES_TO_BITS(t->size) - bw; 848 code->basesize = t->size; 849 850 return (BYTES_TO_BITS(t->size) < (bw + bo)) ? -EINVAL : 0; 851 } 852 853 /* String length checking wrapper */ 854 static int traceprobe_parse_probe_arg_body(const char *argv, ssize_t *size, 855 struct probe_arg *parg, 856 struct traceprobe_parse_context *ctx) 857 { 858 struct fetch_insn *code, *scode, *tmp = NULL; 859 char *t, *t2, *t3; 860 int ret, len; 861 char *arg; 862 863 arg = kstrdup(argv, GFP_KERNEL); 864 if (!arg) 865 return -ENOMEM; 866 867 ret = -EINVAL; 868 len = strlen(arg); 869 if (len > MAX_ARGSTR_LEN) { 870 trace_probe_log_err(ctx->offset, ARG_TOO_LONG); 871 goto out; 872 } else if (len == 0) { 873 trace_probe_log_err(ctx->offset, NO_ARG_BODY); 874 goto out; 875 } 876 877 ret = -ENOMEM; 878 parg->comm = kstrdup(arg, GFP_KERNEL); 879 if (!parg->comm) 880 goto out; 881 882 ret = -EINVAL; 883 t = strchr(arg, ':'); 884 if (t) { 885 *t = '\0'; 886 t2 = strchr(++t, '['); 887 if (t2) { 888 *t2++ = '\0'; 889 t3 = strchr(t2, ']'); 890 if (!t3) { 891 int offs = t2 + strlen(t2) - arg; 892 893 trace_probe_log_err(ctx->offset + offs, 894 ARRAY_NO_CLOSE); 895 goto out; 896 } else if (t3[1] != '\0') { 897 trace_probe_log_err(ctx->offset + t3 + 1 - arg, 898 BAD_ARRAY_SUFFIX); 899 goto out; 900 } 901 *t3 = '\0'; 902 if (kstrtouint(t2, 0, &parg->count) || !parg->count) { 903 trace_probe_log_err(ctx->offset + t2 - arg, 904 BAD_ARRAY_NUM); 905 goto out; 906 } 907 if (parg->count > MAX_ARRAY_LEN) { 908 trace_probe_log_err(ctx->offset + t2 - arg, 909 ARRAY_TOO_BIG); 910 goto out; 911 } 912 } 913 } 914 915 /* 916 * Since $comm and immediate string can not be dereferenced, 917 * we can find those by strcmp. But ignore for eprobes. 918 */ 919 if (!(ctx->flags & TPARG_FL_TEVENT) && 920 (strcmp(arg, "$comm") == 0 || strcmp(arg, "$COMM") == 0 || 921 strncmp(arg, "\\\"", 2) == 0)) { 922 /* The type of $comm must be "string", and not an array. */ 923 if (parg->count || (t && strcmp(t, "string"))) 924 goto out; 925 parg->type = find_fetch_type("string", ctx->flags); 926 } else 927 parg->type = find_fetch_type(t, ctx->flags); 928 if (!parg->type) { 929 trace_probe_log_err(ctx->offset + (t ? (t - arg) : 0), BAD_TYPE); 930 goto out; 931 } 932 parg->offset = *size; 933 *size += parg->type->size * (parg->count ?: 1); 934 935 ret = -ENOMEM; 936 if (parg->count) { 937 len = strlen(parg->type->fmttype) + 6; 938 parg->fmt = kmalloc(len, GFP_KERNEL); 939 if (!parg->fmt) 940 goto out; 941 snprintf(parg->fmt, len, "%s[%d]", parg->type->fmttype, 942 parg->count); 943 } 944 945 code = tmp = kcalloc(FETCH_INSN_MAX, sizeof(*code), GFP_KERNEL); 946 if (!code) 947 goto out; 948 code[FETCH_INSN_MAX - 1].op = FETCH_OP_END; 949 950 ret = parse_probe_arg(arg, parg->type, &code, &code[FETCH_INSN_MAX - 1], 951 ctx); 952 if (ret) 953 goto fail; 954 955 /* Update storing type if BTF is available */ 956 if (IS_ENABLED(CONFIG_PROBE_EVENTS_BTF_ARGS) && !t) { 957 if (code->op == FETCH_OP_ARG) 958 parg->type = parse_btf_arg_type(code->param, ctx); 959 else if (code->op == FETCH_OP_RETVAL) 960 parg->type = parse_btf_retval_type(ctx); 961 } 962 963 ret = -EINVAL; 964 /* Store operation */ 965 if (parg->type->is_string) { 966 if (!strcmp(parg->type->name, "symstr")) { 967 if (code->op != FETCH_OP_REG && code->op != FETCH_OP_STACK && 968 code->op != FETCH_OP_RETVAL && code->op != FETCH_OP_ARG && 969 code->op != FETCH_OP_DEREF && code->op != FETCH_OP_TP_ARG) { 970 trace_probe_log_err(ctx->offset + (t ? (t - arg) : 0), 971 BAD_SYMSTRING); 972 goto fail; 973 } 974 } else { 975 if (code->op != FETCH_OP_DEREF && code->op != FETCH_OP_UDEREF && 976 code->op != FETCH_OP_IMM && code->op != FETCH_OP_COMM && 977 code->op != FETCH_OP_DATA && code->op != FETCH_OP_TP_ARG) { 978 trace_probe_log_err(ctx->offset + (t ? (t - arg) : 0), 979 BAD_STRING); 980 goto fail; 981 } 982 } 983 if (!strcmp(parg->type->name, "symstr") || 984 (code->op == FETCH_OP_IMM || code->op == FETCH_OP_COMM || 985 code->op == FETCH_OP_DATA) || code->op == FETCH_OP_TP_ARG || 986 parg->count) { 987 /* 988 * IMM, DATA and COMM is pointing actual address, those 989 * must be kept, and if parg->count != 0, this is an 990 * array of string pointers instead of string address 991 * itself. 992 * For the symstr, it doesn't need to dereference, thus 993 * it just get the value. 994 */ 995 code++; 996 if (code->op != FETCH_OP_NOP) { 997 trace_probe_log_err(ctx->offset, TOO_MANY_OPS); 998 goto fail; 999 } 1000 } 1001 /* If op == DEREF, replace it with STRING */ 1002 if (!strcmp(parg->type->name, "ustring") || 1003 code->op == FETCH_OP_UDEREF) 1004 code->op = FETCH_OP_ST_USTRING; 1005 else if (!strcmp(parg->type->name, "symstr")) 1006 code->op = FETCH_OP_ST_SYMSTR; 1007 else 1008 code->op = FETCH_OP_ST_STRING; 1009 code->size = parg->type->size; 1010 parg->dynamic = true; 1011 } else if (code->op == FETCH_OP_DEREF) { 1012 code->op = FETCH_OP_ST_MEM; 1013 code->size = parg->type->size; 1014 } else if (code->op == FETCH_OP_UDEREF) { 1015 code->op = FETCH_OP_ST_UMEM; 1016 code->size = parg->type->size; 1017 } else { 1018 code++; 1019 if (code->op != FETCH_OP_NOP) { 1020 trace_probe_log_err(ctx->offset, TOO_MANY_OPS); 1021 goto fail; 1022 } 1023 code->op = FETCH_OP_ST_RAW; 1024 code->size = parg->type->size; 1025 } 1026 scode = code; 1027 /* Modify operation */ 1028 if (t != NULL) { 1029 ret = __parse_bitfield_probe_arg(t, parg->type, &code); 1030 if (ret) { 1031 trace_probe_log_err(ctx->offset + t - arg, BAD_BITFIELD); 1032 goto fail; 1033 } 1034 } 1035 ret = -EINVAL; 1036 /* Loop(Array) operation */ 1037 if (parg->count) { 1038 if (scode->op != FETCH_OP_ST_MEM && 1039 scode->op != FETCH_OP_ST_STRING && 1040 scode->op != FETCH_OP_ST_USTRING) { 1041 trace_probe_log_err(ctx->offset + (t ? (t - arg) : 0), 1042 BAD_STRING); 1043 goto fail; 1044 } 1045 code++; 1046 if (code->op != FETCH_OP_NOP) { 1047 trace_probe_log_err(ctx->offset, TOO_MANY_OPS); 1048 goto fail; 1049 } 1050 code->op = FETCH_OP_LP_ARRAY; 1051 code->param = parg->count; 1052 } 1053 code++; 1054 code->op = FETCH_OP_END; 1055 1056 ret = 0; 1057 /* Shrink down the code buffer */ 1058 parg->code = kcalloc(code - tmp + 1, sizeof(*code), GFP_KERNEL); 1059 if (!parg->code) 1060 ret = -ENOMEM; 1061 else 1062 memcpy(parg->code, tmp, sizeof(*code) * (code - tmp + 1)); 1063 1064 fail: 1065 if (ret) { 1066 for (code = tmp; code < tmp + FETCH_INSN_MAX; code++) 1067 if (code->op == FETCH_NOP_SYMBOL || 1068 code->op == FETCH_OP_DATA) 1069 kfree(code->data); 1070 } 1071 kfree(tmp); 1072 out: 1073 kfree(arg); 1074 1075 return ret; 1076 } 1077 1078 /* Return 1 if name is reserved or already used by another argument */ 1079 static int traceprobe_conflict_field_name(const char *name, 1080 struct probe_arg *args, int narg) 1081 { 1082 int i; 1083 1084 for (i = 0; i < ARRAY_SIZE(reserved_field_names); i++) 1085 if (strcmp(reserved_field_names[i], name) == 0) 1086 return 1; 1087 1088 for (i = 0; i < narg; i++) 1089 if (strcmp(args[i].name, name) == 0) 1090 return 1; 1091 1092 return 0; 1093 } 1094 1095 static char *generate_probe_arg_name(const char *arg, int idx) 1096 { 1097 char *name = NULL; 1098 const char *end; 1099 1100 /* 1101 * If argument name is omitted, try arg as a name (BTF variable) 1102 * or "argN". 1103 */ 1104 if (IS_ENABLED(CONFIG_PROBE_EVENTS_BTF_ARGS)) { 1105 end = strchr(arg, ':'); 1106 if (!end) 1107 end = arg + strlen(arg); 1108 1109 name = kmemdup_nul(arg, end - arg, GFP_KERNEL); 1110 if (!name || !is_good_name(name)) { 1111 kfree(name); 1112 name = NULL; 1113 } 1114 } 1115 1116 if (!name) 1117 name = kasprintf(GFP_KERNEL, "arg%d", idx + 1); 1118 1119 return name; 1120 } 1121 1122 int traceprobe_parse_probe_arg(struct trace_probe *tp, int i, const char *arg, 1123 struct traceprobe_parse_context *ctx) 1124 { 1125 struct probe_arg *parg = &tp->args[i]; 1126 const char *body; 1127 1128 /* Increment count for freeing args in error case */ 1129 tp->nr_args++; 1130 1131 body = strchr(arg, '='); 1132 if (body) { 1133 if (body - arg > MAX_ARG_NAME_LEN) { 1134 trace_probe_log_err(0, ARG_NAME_TOO_LONG); 1135 return -EINVAL; 1136 } else if (body == arg) { 1137 trace_probe_log_err(0, NO_ARG_NAME); 1138 return -EINVAL; 1139 } 1140 parg->name = kmemdup_nul(arg, body - arg, GFP_KERNEL); 1141 body++; 1142 } else { 1143 parg->name = generate_probe_arg_name(arg, i); 1144 body = arg; 1145 } 1146 if (!parg->name) 1147 return -ENOMEM; 1148 1149 if (!is_good_name(parg->name)) { 1150 trace_probe_log_err(0, BAD_ARG_NAME); 1151 return -EINVAL; 1152 } 1153 if (traceprobe_conflict_field_name(parg->name, tp->args, i)) { 1154 trace_probe_log_err(0, USED_ARG_NAME); 1155 return -EINVAL; 1156 } 1157 ctx->offset = body - arg; 1158 /* Parse fetch argument */ 1159 return traceprobe_parse_probe_arg_body(body, &tp->size, parg, ctx); 1160 } 1161 1162 void traceprobe_free_probe_arg(struct probe_arg *arg) 1163 { 1164 struct fetch_insn *code = arg->code; 1165 1166 while (code && code->op != FETCH_OP_END) { 1167 if (code->op == FETCH_NOP_SYMBOL || 1168 code->op == FETCH_OP_DATA) 1169 kfree(code->data); 1170 code++; 1171 } 1172 kfree(arg->code); 1173 kfree(arg->name); 1174 kfree(arg->comm); 1175 kfree(arg->fmt); 1176 } 1177 1178 static int argv_has_var_arg(int argc, const char *argv[], int *args_idx, 1179 struct traceprobe_parse_context *ctx) 1180 { 1181 int i, found = 0; 1182 1183 for (i = 0; i < argc; i++) 1184 if (str_has_prefix(argv[i], "$arg")) { 1185 trace_probe_log_set_index(i + 2); 1186 1187 if (!tparg_is_function_entry(ctx->flags)) { 1188 trace_probe_log_err(0, NOFENTRY_ARGS); 1189 return -EINVAL; 1190 } 1191 1192 if (isdigit(argv[i][4])) { 1193 found = 1; 1194 continue; 1195 } 1196 1197 if (argv[i][4] != '*') { 1198 trace_probe_log_err(0, BAD_VAR); 1199 return -EINVAL; 1200 } 1201 1202 if (*args_idx >= 0 && *args_idx < argc) { 1203 trace_probe_log_err(0, DOUBLE_ARGS); 1204 return -EINVAL; 1205 } 1206 found = 1; 1207 *args_idx = i; 1208 } 1209 1210 return found; 1211 } 1212 1213 static int sprint_nth_btf_arg(int idx, const char *type, 1214 char *buf, int bufsize, 1215 struct traceprobe_parse_context *ctx) 1216 { 1217 const char *name; 1218 int ret; 1219 1220 if (idx >= ctx->nr_params) { 1221 trace_probe_log_err(0, NO_BTFARG); 1222 return -ENOENT; 1223 } 1224 name = btf_name_by_offset(ctx->btf, ctx->params[idx].name_off); 1225 if (!name) { 1226 trace_probe_log_err(0, NO_BTF_ENTRY); 1227 return -ENOENT; 1228 } 1229 ret = snprintf(buf, bufsize, "%s%s", name, type); 1230 if (ret >= bufsize) { 1231 trace_probe_log_err(0, ARGS_2LONG); 1232 return -E2BIG; 1233 } 1234 return ret; 1235 } 1236 1237 /* Return new_argv which must be freed after use */ 1238 const char **traceprobe_expand_meta_args(int argc, const char *argv[], 1239 int *new_argc, char *buf, int bufsize, 1240 struct traceprobe_parse_context *ctx) 1241 { 1242 const struct btf_param *params = NULL; 1243 int i, j, n, used, ret, args_idx = -1; 1244 const char **new_argv = NULL; 1245 int nr_params; 1246 1247 ret = argv_has_var_arg(argc, argv, &args_idx, ctx); 1248 if (ret < 0) 1249 return ERR_PTR(ret); 1250 1251 if (!ret) { 1252 *new_argc = argc; 1253 return NULL; 1254 } 1255 1256 params = find_btf_func_param(ctx->funcname, &nr_params, &ctx->btf, 1257 ctx->flags & TPARG_FL_TPOINT); 1258 if (IS_ERR_OR_NULL(params)) { 1259 if (args_idx != -1) { 1260 /* $arg* requires BTF info */ 1261 trace_probe_log_err(0, NOSUP_BTFARG); 1262 return (const char **)params; 1263 } 1264 *new_argc = argc; 1265 return NULL; 1266 } 1267 ctx->params = params; 1268 ctx->nr_params = nr_params; 1269 1270 if (args_idx >= 0) 1271 *new_argc = argc + ctx->nr_params - 1; 1272 else 1273 *new_argc = argc; 1274 1275 new_argv = kcalloc(*new_argc, sizeof(char *), GFP_KERNEL); 1276 if (!new_argv) 1277 return ERR_PTR(-ENOMEM); 1278 1279 used = 0; 1280 for (i = 0, j = 0; i < argc; i++) { 1281 trace_probe_log_set_index(i + 2); 1282 if (i == args_idx) { 1283 for (n = 0; n < nr_params; n++) { 1284 ret = sprint_nth_btf_arg(n, "", buf + used, 1285 bufsize - used, ctx); 1286 if (ret < 0) 1287 goto error; 1288 1289 new_argv[j++] = buf + used; 1290 used += ret + 1; 1291 } 1292 continue; 1293 } 1294 1295 if (str_has_prefix(argv[i], "$arg")) { 1296 char *type = NULL; 1297 1298 n = simple_strtoul(argv[i] + 4, &type, 10); 1299 if (type && !(*type == ':' || *type == '\0')) { 1300 trace_probe_log_err(0, BAD_VAR); 1301 ret = -ENOENT; 1302 goto error; 1303 } 1304 /* Note: $argN starts from $arg1 */ 1305 ret = sprint_nth_btf_arg(n - 1, type, buf + used, 1306 bufsize - used, ctx); 1307 if (ret < 0) 1308 goto error; 1309 new_argv[j++] = buf + used; 1310 used += ret + 1; 1311 } else 1312 new_argv[j++] = argv[i]; 1313 } 1314 1315 return new_argv; 1316 1317 error: 1318 kfree(new_argv); 1319 return ERR_PTR(ret); 1320 } 1321 1322 void traceprobe_finish_parse(struct traceprobe_parse_context *ctx) 1323 { 1324 clear_btf_context(ctx); 1325 } 1326 1327 int traceprobe_update_arg(struct probe_arg *arg) 1328 { 1329 struct fetch_insn *code = arg->code; 1330 long offset; 1331 char *tmp; 1332 char c; 1333 int ret = 0; 1334 1335 while (code && code->op != FETCH_OP_END) { 1336 if (code->op == FETCH_NOP_SYMBOL) { 1337 if (code[1].op != FETCH_OP_IMM) 1338 return -EINVAL; 1339 1340 tmp = strpbrk(code->data, "+-"); 1341 if (tmp) 1342 c = *tmp; 1343 ret = traceprobe_split_symbol_offset(code->data, 1344 &offset); 1345 if (ret) 1346 return ret; 1347 1348 code[1].immediate = 1349 (unsigned long)kallsyms_lookup_name(code->data); 1350 if (tmp) 1351 *tmp = c; 1352 if (!code[1].immediate) 1353 return -ENOENT; 1354 code[1].immediate += offset; 1355 } 1356 code++; 1357 } 1358 return 0; 1359 } 1360 1361 /* When len=0, we just calculate the needed length */ 1362 #define LEN_OR_ZERO (len ? len - pos : 0) 1363 static int __set_print_fmt(struct trace_probe *tp, char *buf, int len, 1364 enum probe_print_type ptype) 1365 { 1366 struct probe_arg *parg; 1367 int i, j; 1368 int pos = 0; 1369 const char *fmt, *arg; 1370 1371 switch (ptype) { 1372 case PROBE_PRINT_NORMAL: 1373 fmt = "(%lx)"; 1374 arg = ", REC->" FIELD_STRING_IP; 1375 break; 1376 case PROBE_PRINT_RETURN: 1377 fmt = "(%lx <- %lx)"; 1378 arg = ", REC->" FIELD_STRING_FUNC ", REC->" FIELD_STRING_RETIP; 1379 break; 1380 case PROBE_PRINT_EVENT: 1381 fmt = ""; 1382 arg = ""; 1383 break; 1384 default: 1385 WARN_ON_ONCE(1); 1386 return 0; 1387 } 1388 1389 pos += snprintf(buf + pos, LEN_OR_ZERO, "\"%s", fmt); 1390 1391 for (i = 0; i < tp->nr_args; i++) { 1392 parg = tp->args + i; 1393 pos += snprintf(buf + pos, LEN_OR_ZERO, " %s=", parg->name); 1394 if (parg->count) { 1395 pos += snprintf(buf + pos, LEN_OR_ZERO, "{%s", 1396 parg->type->fmt); 1397 for (j = 1; j < parg->count; j++) 1398 pos += snprintf(buf + pos, LEN_OR_ZERO, ",%s", 1399 parg->type->fmt); 1400 pos += snprintf(buf + pos, LEN_OR_ZERO, "}"); 1401 } else 1402 pos += snprintf(buf + pos, LEN_OR_ZERO, "%s", 1403 parg->type->fmt); 1404 } 1405 1406 pos += snprintf(buf + pos, LEN_OR_ZERO, "\"%s", arg); 1407 1408 for (i = 0; i < tp->nr_args; i++) { 1409 parg = tp->args + i; 1410 if (parg->count) { 1411 if (parg->type->is_string) 1412 fmt = ", __get_str(%s[%d])"; 1413 else 1414 fmt = ", REC->%s[%d]"; 1415 for (j = 0; j < parg->count; j++) 1416 pos += snprintf(buf + pos, LEN_OR_ZERO, 1417 fmt, parg->name, j); 1418 } else { 1419 if (parg->type->is_string) 1420 fmt = ", __get_str(%s)"; 1421 else 1422 fmt = ", REC->%s"; 1423 pos += snprintf(buf + pos, LEN_OR_ZERO, 1424 fmt, parg->name); 1425 } 1426 } 1427 1428 /* return the length of print_fmt */ 1429 return pos; 1430 } 1431 #undef LEN_OR_ZERO 1432 1433 int traceprobe_set_print_fmt(struct trace_probe *tp, enum probe_print_type ptype) 1434 { 1435 struct trace_event_call *call = trace_probe_event_call(tp); 1436 int len; 1437 char *print_fmt; 1438 1439 /* First: called with 0 length to calculate the needed length */ 1440 len = __set_print_fmt(tp, NULL, 0, ptype); 1441 print_fmt = kmalloc(len + 1, GFP_KERNEL); 1442 if (!print_fmt) 1443 return -ENOMEM; 1444 1445 /* Second: actually write the @print_fmt */ 1446 __set_print_fmt(tp, print_fmt, len + 1, ptype); 1447 call->print_fmt = print_fmt; 1448 1449 return 0; 1450 } 1451 1452 int traceprobe_define_arg_fields(struct trace_event_call *event_call, 1453 size_t offset, struct trace_probe *tp) 1454 { 1455 int ret, i; 1456 1457 /* Set argument names as fields */ 1458 for (i = 0; i < tp->nr_args; i++) { 1459 struct probe_arg *parg = &tp->args[i]; 1460 const char *fmt = parg->type->fmttype; 1461 int size = parg->type->size; 1462 1463 if (parg->fmt) 1464 fmt = parg->fmt; 1465 if (parg->count) 1466 size *= parg->count; 1467 ret = trace_define_field(event_call, fmt, parg->name, 1468 offset + parg->offset, size, 1469 parg->type->is_signed, 1470 FILTER_OTHER); 1471 if (ret) 1472 return ret; 1473 } 1474 return 0; 1475 } 1476 1477 static void trace_probe_event_free(struct trace_probe_event *tpe) 1478 { 1479 kfree(tpe->class.system); 1480 kfree(tpe->call.name); 1481 kfree(tpe->call.print_fmt); 1482 kfree(tpe); 1483 } 1484 1485 int trace_probe_append(struct trace_probe *tp, struct trace_probe *to) 1486 { 1487 if (trace_probe_has_sibling(tp)) 1488 return -EBUSY; 1489 1490 list_del_init(&tp->list); 1491 trace_probe_event_free(tp->event); 1492 1493 tp->event = to->event; 1494 list_add_tail(&tp->list, trace_probe_probe_list(to)); 1495 1496 return 0; 1497 } 1498 1499 void trace_probe_unlink(struct trace_probe *tp) 1500 { 1501 list_del_init(&tp->list); 1502 if (list_empty(trace_probe_probe_list(tp))) 1503 trace_probe_event_free(tp->event); 1504 tp->event = NULL; 1505 } 1506 1507 void trace_probe_cleanup(struct trace_probe *tp) 1508 { 1509 int i; 1510 1511 for (i = 0; i < tp->nr_args; i++) 1512 traceprobe_free_probe_arg(&tp->args[i]); 1513 1514 if (tp->event) 1515 trace_probe_unlink(tp); 1516 } 1517 1518 int trace_probe_init(struct trace_probe *tp, const char *event, 1519 const char *group, bool alloc_filter) 1520 { 1521 struct trace_event_call *call; 1522 size_t size = sizeof(struct trace_probe_event); 1523 int ret = 0; 1524 1525 if (!event || !group) 1526 return -EINVAL; 1527 1528 if (alloc_filter) 1529 size += sizeof(struct trace_uprobe_filter); 1530 1531 tp->event = kzalloc(size, GFP_KERNEL); 1532 if (!tp->event) 1533 return -ENOMEM; 1534 1535 INIT_LIST_HEAD(&tp->event->files); 1536 INIT_LIST_HEAD(&tp->event->class.fields); 1537 INIT_LIST_HEAD(&tp->event->probes); 1538 INIT_LIST_HEAD(&tp->list); 1539 list_add(&tp->list, &tp->event->probes); 1540 1541 call = trace_probe_event_call(tp); 1542 call->class = &tp->event->class; 1543 call->name = kstrdup(event, GFP_KERNEL); 1544 if (!call->name) { 1545 ret = -ENOMEM; 1546 goto error; 1547 } 1548 1549 tp->event->class.system = kstrdup(group, GFP_KERNEL); 1550 if (!tp->event->class.system) { 1551 ret = -ENOMEM; 1552 goto error; 1553 } 1554 1555 return 0; 1556 1557 error: 1558 trace_probe_cleanup(tp); 1559 return ret; 1560 } 1561 1562 static struct trace_event_call * 1563 find_trace_event_call(const char *system, const char *event_name) 1564 { 1565 struct trace_event_call *tp_event; 1566 const char *name; 1567 1568 list_for_each_entry(tp_event, &ftrace_events, list) { 1569 if (!tp_event->class->system || 1570 strcmp(system, tp_event->class->system)) 1571 continue; 1572 name = trace_event_name(tp_event); 1573 if (!name || strcmp(event_name, name)) 1574 continue; 1575 return tp_event; 1576 } 1577 1578 return NULL; 1579 } 1580 1581 int trace_probe_register_event_call(struct trace_probe *tp) 1582 { 1583 struct trace_event_call *call = trace_probe_event_call(tp); 1584 int ret; 1585 1586 lockdep_assert_held(&event_mutex); 1587 1588 if (find_trace_event_call(trace_probe_group_name(tp), 1589 trace_probe_name(tp))) 1590 return -EEXIST; 1591 1592 ret = register_trace_event(&call->event); 1593 if (!ret) 1594 return -ENODEV; 1595 1596 ret = trace_add_event_call(call); 1597 if (ret) 1598 unregister_trace_event(&call->event); 1599 1600 return ret; 1601 } 1602 1603 int trace_probe_add_file(struct trace_probe *tp, struct trace_event_file *file) 1604 { 1605 struct event_file_link *link; 1606 1607 link = kmalloc(sizeof(*link), GFP_KERNEL); 1608 if (!link) 1609 return -ENOMEM; 1610 1611 link->file = file; 1612 INIT_LIST_HEAD(&link->list); 1613 list_add_tail_rcu(&link->list, &tp->event->files); 1614 trace_probe_set_flag(tp, TP_FLAG_TRACE); 1615 return 0; 1616 } 1617 1618 struct event_file_link *trace_probe_get_file_link(struct trace_probe *tp, 1619 struct trace_event_file *file) 1620 { 1621 struct event_file_link *link; 1622 1623 trace_probe_for_each_link(link, tp) { 1624 if (link->file == file) 1625 return link; 1626 } 1627 1628 return NULL; 1629 } 1630 1631 int trace_probe_remove_file(struct trace_probe *tp, 1632 struct trace_event_file *file) 1633 { 1634 struct event_file_link *link; 1635 1636 link = trace_probe_get_file_link(tp, file); 1637 if (!link) 1638 return -ENOENT; 1639 1640 list_del_rcu(&link->list); 1641 kvfree_rcu_mightsleep(link); 1642 1643 if (list_empty(&tp->event->files)) 1644 trace_probe_clear_flag(tp, TP_FLAG_TRACE); 1645 1646 return 0; 1647 } 1648 1649 /* 1650 * Return the smallest index of different type argument (start from 1). 1651 * If all argument types and name are same, return 0. 1652 */ 1653 int trace_probe_compare_arg_type(struct trace_probe *a, struct trace_probe *b) 1654 { 1655 int i; 1656 1657 /* In case of more arguments */ 1658 if (a->nr_args < b->nr_args) 1659 return a->nr_args + 1; 1660 if (a->nr_args > b->nr_args) 1661 return b->nr_args + 1; 1662 1663 for (i = 0; i < a->nr_args; i++) { 1664 if ((b->nr_args <= i) || 1665 ((a->args[i].type != b->args[i].type) || 1666 (a->args[i].count != b->args[i].count) || 1667 strcmp(a->args[i].name, b->args[i].name))) 1668 return i + 1; 1669 } 1670 1671 return 0; 1672 } 1673 1674 bool trace_probe_match_command_args(struct trace_probe *tp, 1675 int argc, const char **argv) 1676 { 1677 char buf[MAX_ARGSTR_LEN + 1]; 1678 int i; 1679 1680 if (tp->nr_args < argc) 1681 return false; 1682 1683 for (i = 0; i < argc; i++) { 1684 snprintf(buf, sizeof(buf), "%s=%s", 1685 tp->args[i].name, tp->args[i].comm); 1686 if (strcmp(buf, argv[i])) 1687 return false; 1688 } 1689 return true; 1690 } 1691 1692 int trace_probe_create(const char *raw_command, int (*createfn)(int, const char **)) 1693 { 1694 int argc = 0, ret = 0; 1695 char **argv; 1696 1697 argv = argv_split(GFP_KERNEL, raw_command, &argc); 1698 if (!argv) 1699 return -ENOMEM; 1700 1701 if (argc) 1702 ret = createfn(argc, (const char **)argv); 1703 1704 argv_free(argv); 1705 1706 return ret; 1707 } 1708 1709 int trace_probe_print_args(struct trace_seq *s, struct probe_arg *args, int nr_args, 1710 u8 *data, void *field) 1711 { 1712 void *p; 1713 int i, j; 1714 1715 for (i = 0; i < nr_args; i++) { 1716 struct probe_arg *a = args + i; 1717 1718 trace_seq_printf(s, " %s=", a->name); 1719 if (likely(!a->count)) { 1720 if (!a->type->print(s, data + a->offset, field)) 1721 return -ENOMEM; 1722 continue; 1723 } 1724 trace_seq_putc(s, '{'); 1725 p = data + a->offset; 1726 for (j = 0; j < a->count; j++) { 1727 if (!a->type->print(s, p, field)) 1728 return -ENOMEM; 1729 trace_seq_putc(s, j == a->count - 1 ? '}' : ','); 1730 p += a->type->size; 1731 } 1732 } 1733 return 0; 1734 } 1735