1 /* 2 * Common code for probe-based Dynamic events. 3 * 4 * This program is free software; you can redistribute it and/or modify 5 * it under the terms of the GNU General Public License version 2 as 6 * published by the Free Software Foundation. 7 * 8 * This program is distributed in the hope that it will be useful, 9 * but WITHOUT ANY WARRANTY; without even the implied warranty of 10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 11 * GNU General Public License for more details. 12 * 13 * You should have received a copy of the GNU General Public License 14 * along with this program; if not, write to the Free Software 15 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 16 * 17 * This code was copied from kernel/trace/trace_kprobe.c written by 18 * Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> 19 * 20 * Updates to make this generic: 21 * Copyright (C) IBM Corporation, 2010-2011 22 * Author: Srikar Dronamraju 23 */ 24 25 #include "trace_probe.h" 26 27 const char *reserved_field_names[] = { 28 "common_type", 29 "common_flags", 30 "common_preempt_count", 31 "common_pid", 32 "common_tgid", 33 FIELD_STRING_IP, 34 FIELD_STRING_RETIP, 35 FIELD_STRING_FUNC, 36 }; 37 38 /* Printing function type */ 39 #define PRINT_TYPE_FUNC_NAME(type) print_type_##type 40 #define PRINT_TYPE_FMT_NAME(type) print_type_format_##type 41 42 /* Printing in basic type function template */ 43 #define DEFINE_BASIC_PRINT_TYPE_FUNC(type, fmt, cast) \ 44 static __kprobes int PRINT_TYPE_FUNC_NAME(type)(struct trace_seq *s, \ 45 const char *name, \ 46 void *data, void *ent)\ 47 { \ 48 return trace_seq_printf(s, " %s=" fmt, name, (cast)*(type *)data);\ 49 } \ 50 static const char PRINT_TYPE_FMT_NAME(type)[] = fmt; 51 52 DEFINE_BASIC_PRINT_TYPE_FUNC(u8, "%x", unsigned int) 53 DEFINE_BASIC_PRINT_TYPE_FUNC(u16, "%x", unsigned int) 54 DEFINE_BASIC_PRINT_TYPE_FUNC(u32, "%lx", unsigned long) 55 DEFINE_BASIC_PRINT_TYPE_FUNC(u64, "%llx", unsigned long long) 56 DEFINE_BASIC_PRINT_TYPE_FUNC(s8, "%d", int) 57 DEFINE_BASIC_PRINT_TYPE_FUNC(s16, "%d", int) 58 DEFINE_BASIC_PRINT_TYPE_FUNC(s32, "%ld", long) 59 DEFINE_BASIC_PRINT_TYPE_FUNC(s64, "%lld", long long) 60 61 static inline void *get_rloc_data(u32 *dl) 62 { 63 return (u8 *)dl + get_rloc_offs(*dl); 64 } 65 66 /* For data_loc conversion */ 67 static inline void *get_loc_data(u32 *dl, void *ent) 68 { 69 return (u8 *)ent + get_rloc_offs(*dl); 70 } 71 72 /* For defining macros, define string/string_size types */ 73 typedef u32 string; 74 typedef u32 string_size; 75 76 /* Print type function for string type */ 77 static __kprobes int PRINT_TYPE_FUNC_NAME(string)(struct trace_seq *s, 78 const char *name, 79 void *data, void *ent) 80 { 81 int len = *(u32 *)data >> 16; 82 83 if (!len) 84 return trace_seq_printf(s, " %s=(fault)", name); 85 else 86 return trace_seq_printf(s, " %s=\"%s\"", name, 87 (const char *)get_loc_data(data, ent)); 88 } 89 90 static const char PRINT_TYPE_FMT_NAME(string)[] = "\\\"%s\\\""; 91 92 #define FETCH_FUNC_NAME(method, type) fetch_##method##_##type 93 /* 94 * Define macro for basic types - we don't need to define s* types, because 95 * we have to care only about bitwidth at recording time. 96 */ 97 #define DEFINE_BASIC_FETCH_FUNCS(method) \ 98 DEFINE_FETCH_##method(u8) \ 99 DEFINE_FETCH_##method(u16) \ 100 DEFINE_FETCH_##method(u32) \ 101 DEFINE_FETCH_##method(u64) 102 103 #define CHECK_FETCH_FUNCS(method, fn) \ 104 (((FETCH_FUNC_NAME(method, u8) == fn) || \ 105 (FETCH_FUNC_NAME(method, u16) == fn) || \ 106 (FETCH_FUNC_NAME(method, u32) == fn) || \ 107 (FETCH_FUNC_NAME(method, u64) == fn) || \ 108 (FETCH_FUNC_NAME(method, string) == fn) || \ 109 (FETCH_FUNC_NAME(method, string_size) == fn)) \ 110 && (fn != NULL)) 111 112 /* Data fetch function templates */ 113 #define DEFINE_FETCH_reg(type) \ 114 static __kprobes void FETCH_FUNC_NAME(reg, type)(struct pt_regs *regs, \ 115 void *offset, void *dest) \ 116 { \ 117 *(type *)dest = (type)regs_get_register(regs, \ 118 (unsigned int)((unsigned long)offset)); \ 119 } 120 DEFINE_BASIC_FETCH_FUNCS(reg) 121 /* No string on the register */ 122 #define fetch_reg_string NULL 123 #define fetch_reg_string_size NULL 124 125 #define DEFINE_FETCH_stack(type) \ 126 static __kprobes void FETCH_FUNC_NAME(stack, type)(struct pt_regs *regs,\ 127 void *offset, void *dest) \ 128 { \ 129 *(type *)dest = (type)regs_get_kernel_stack_nth(regs, \ 130 (unsigned int)((unsigned long)offset)); \ 131 } 132 DEFINE_BASIC_FETCH_FUNCS(stack) 133 /* No string on the stack entry */ 134 #define fetch_stack_string NULL 135 #define fetch_stack_string_size NULL 136 137 #define DEFINE_FETCH_retval(type) \ 138 static __kprobes void FETCH_FUNC_NAME(retval, type)(struct pt_regs *regs,\ 139 void *dummy, void *dest) \ 140 { \ 141 *(type *)dest = (type)regs_return_value(regs); \ 142 } 143 DEFINE_BASIC_FETCH_FUNCS(retval) 144 /* No string on the retval */ 145 #define fetch_retval_string NULL 146 #define fetch_retval_string_size NULL 147 148 #define DEFINE_FETCH_memory(type) \ 149 static __kprobes void FETCH_FUNC_NAME(memory, type)(struct pt_regs *regs,\ 150 void *addr, void *dest) \ 151 { \ 152 type retval; \ 153 if (probe_kernel_address(addr, retval)) \ 154 *(type *)dest = 0; \ 155 else \ 156 *(type *)dest = retval; \ 157 } 158 DEFINE_BASIC_FETCH_FUNCS(memory) 159 /* 160 * Fetch a null-terminated string. Caller MUST set *(u32 *)dest with max 161 * length and relative data location. 162 */ 163 static __kprobes void FETCH_FUNC_NAME(memory, string)(struct pt_regs *regs, 164 void *addr, void *dest) 165 { 166 long ret; 167 int maxlen = get_rloc_len(*(u32 *)dest); 168 u8 *dst = get_rloc_data(dest); 169 u8 *src = addr; 170 mm_segment_t old_fs = get_fs(); 171 172 if (!maxlen) 173 return; 174 175 /* 176 * Try to get string again, since the string can be changed while 177 * probing. 178 */ 179 set_fs(KERNEL_DS); 180 pagefault_disable(); 181 182 do 183 ret = __copy_from_user_inatomic(dst++, src++, 1); 184 while (dst[-1] && ret == 0 && src - (u8 *)addr < maxlen); 185 186 dst[-1] = '\0'; 187 pagefault_enable(); 188 set_fs(old_fs); 189 190 if (ret < 0) { /* Failed to fetch string */ 191 ((u8 *)get_rloc_data(dest))[0] = '\0'; 192 *(u32 *)dest = make_data_rloc(0, get_rloc_offs(*(u32 *)dest)); 193 } else { 194 *(u32 *)dest = make_data_rloc(src - (u8 *)addr, 195 get_rloc_offs(*(u32 *)dest)); 196 } 197 } 198 199 /* Return the length of string -- including null terminal byte */ 200 static __kprobes void FETCH_FUNC_NAME(memory, string_size)(struct pt_regs *regs, 201 void *addr, void *dest) 202 { 203 mm_segment_t old_fs; 204 int ret, len = 0; 205 u8 c; 206 207 old_fs = get_fs(); 208 set_fs(KERNEL_DS); 209 pagefault_disable(); 210 211 do { 212 ret = __copy_from_user_inatomic(&c, (u8 *)addr + len, 1); 213 len++; 214 } while (c && ret == 0 && len < MAX_STRING_SIZE); 215 216 pagefault_enable(); 217 set_fs(old_fs); 218 219 if (ret < 0) /* Failed to check the length */ 220 *(u32 *)dest = 0; 221 else 222 *(u32 *)dest = len; 223 } 224 225 /* Memory fetching by symbol */ 226 struct symbol_cache { 227 char *symbol; 228 long offset; 229 unsigned long addr; 230 }; 231 232 static unsigned long update_symbol_cache(struct symbol_cache *sc) 233 { 234 sc->addr = (unsigned long)kallsyms_lookup_name(sc->symbol); 235 236 if (sc->addr) 237 sc->addr += sc->offset; 238 239 return sc->addr; 240 } 241 242 static void free_symbol_cache(struct symbol_cache *sc) 243 { 244 kfree(sc->symbol); 245 kfree(sc); 246 } 247 248 static struct symbol_cache *alloc_symbol_cache(const char *sym, long offset) 249 { 250 struct symbol_cache *sc; 251 252 if (!sym || strlen(sym) == 0) 253 return NULL; 254 255 sc = kzalloc(sizeof(struct symbol_cache), GFP_KERNEL); 256 if (!sc) 257 return NULL; 258 259 sc->symbol = kstrdup(sym, GFP_KERNEL); 260 if (!sc->symbol) { 261 kfree(sc); 262 return NULL; 263 } 264 sc->offset = offset; 265 update_symbol_cache(sc); 266 267 return sc; 268 } 269 270 #define DEFINE_FETCH_symbol(type) \ 271 static __kprobes void FETCH_FUNC_NAME(symbol, type)(struct pt_regs *regs,\ 272 void *data, void *dest) \ 273 { \ 274 struct symbol_cache *sc = data; \ 275 if (sc->addr) \ 276 fetch_memory_##type(regs, (void *)sc->addr, dest); \ 277 else \ 278 *(type *)dest = 0; \ 279 } 280 DEFINE_BASIC_FETCH_FUNCS(symbol) 281 DEFINE_FETCH_symbol(string) 282 DEFINE_FETCH_symbol(string_size) 283 284 /* Dereference memory access function */ 285 struct deref_fetch_param { 286 struct fetch_param orig; 287 long offset; 288 }; 289 290 #define DEFINE_FETCH_deref(type) \ 291 static __kprobes void FETCH_FUNC_NAME(deref, type)(struct pt_regs *regs,\ 292 void *data, void *dest) \ 293 { \ 294 struct deref_fetch_param *dprm = data; \ 295 unsigned long addr; \ 296 call_fetch(&dprm->orig, regs, &addr); \ 297 if (addr) { \ 298 addr += dprm->offset; \ 299 fetch_memory_##type(regs, (void *)addr, dest); \ 300 } else \ 301 *(type *)dest = 0; \ 302 } 303 DEFINE_BASIC_FETCH_FUNCS(deref) 304 DEFINE_FETCH_deref(string) 305 DEFINE_FETCH_deref(string_size) 306 307 static __kprobes void update_deref_fetch_param(struct deref_fetch_param *data) 308 { 309 if (CHECK_FETCH_FUNCS(deref, data->orig.fn)) 310 update_deref_fetch_param(data->orig.data); 311 else if (CHECK_FETCH_FUNCS(symbol, data->orig.fn)) 312 update_symbol_cache(data->orig.data); 313 } 314 315 static __kprobes void free_deref_fetch_param(struct deref_fetch_param *data) 316 { 317 if (CHECK_FETCH_FUNCS(deref, data->orig.fn)) 318 free_deref_fetch_param(data->orig.data); 319 else if (CHECK_FETCH_FUNCS(symbol, data->orig.fn)) 320 free_symbol_cache(data->orig.data); 321 kfree(data); 322 } 323 324 /* Bitfield fetch function */ 325 struct bitfield_fetch_param { 326 struct fetch_param orig; 327 unsigned char hi_shift; 328 unsigned char low_shift; 329 }; 330 331 #define DEFINE_FETCH_bitfield(type) \ 332 static __kprobes void FETCH_FUNC_NAME(bitfield, type)(struct pt_regs *regs,\ 333 void *data, void *dest) \ 334 { \ 335 struct bitfield_fetch_param *bprm = data; \ 336 type buf = 0; \ 337 call_fetch(&bprm->orig, regs, &buf); \ 338 if (buf) { \ 339 buf <<= bprm->hi_shift; \ 340 buf >>= bprm->low_shift; \ 341 } \ 342 *(type *)dest = buf; \ 343 } 344 345 DEFINE_BASIC_FETCH_FUNCS(bitfield) 346 #define fetch_bitfield_string NULL 347 #define fetch_bitfield_string_size NULL 348 349 static __kprobes void 350 update_bitfield_fetch_param(struct bitfield_fetch_param *data) 351 { 352 /* 353 * Don't check the bitfield itself, because this must be the 354 * last fetch function. 355 */ 356 if (CHECK_FETCH_FUNCS(deref, data->orig.fn)) 357 update_deref_fetch_param(data->orig.data); 358 else if (CHECK_FETCH_FUNCS(symbol, data->orig.fn)) 359 update_symbol_cache(data->orig.data); 360 } 361 362 static __kprobes void 363 free_bitfield_fetch_param(struct bitfield_fetch_param *data) 364 { 365 /* 366 * Don't check the bitfield itself, because this must be the 367 * last fetch function. 368 */ 369 if (CHECK_FETCH_FUNCS(deref, data->orig.fn)) 370 free_deref_fetch_param(data->orig.data); 371 else if (CHECK_FETCH_FUNCS(symbol, data->orig.fn)) 372 free_symbol_cache(data->orig.data); 373 374 kfree(data); 375 } 376 377 /* Default (unsigned long) fetch type */ 378 #define __DEFAULT_FETCH_TYPE(t) u##t 379 #define _DEFAULT_FETCH_TYPE(t) __DEFAULT_FETCH_TYPE(t) 380 #define DEFAULT_FETCH_TYPE _DEFAULT_FETCH_TYPE(BITS_PER_LONG) 381 #define DEFAULT_FETCH_TYPE_STR __stringify(DEFAULT_FETCH_TYPE) 382 383 #define ASSIGN_FETCH_FUNC(method, type) \ 384 [FETCH_MTD_##method] = FETCH_FUNC_NAME(method, type) 385 386 #define __ASSIGN_FETCH_TYPE(_name, ptype, ftype, _size, sign, _fmttype) \ 387 {.name = _name, \ 388 .size = _size, \ 389 .is_signed = sign, \ 390 .print = PRINT_TYPE_FUNC_NAME(ptype), \ 391 .fmt = PRINT_TYPE_FMT_NAME(ptype), \ 392 .fmttype = _fmttype, \ 393 .fetch = { \ 394 ASSIGN_FETCH_FUNC(reg, ftype), \ 395 ASSIGN_FETCH_FUNC(stack, ftype), \ 396 ASSIGN_FETCH_FUNC(retval, ftype), \ 397 ASSIGN_FETCH_FUNC(memory, ftype), \ 398 ASSIGN_FETCH_FUNC(symbol, ftype), \ 399 ASSIGN_FETCH_FUNC(deref, ftype), \ 400 ASSIGN_FETCH_FUNC(bitfield, ftype), \ 401 } \ 402 } 403 404 #define ASSIGN_FETCH_TYPE(ptype, ftype, sign) \ 405 __ASSIGN_FETCH_TYPE(#ptype, ptype, ftype, sizeof(ftype), sign, #ptype) 406 407 #define FETCH_TYPE_STRING 0 408 #define FETCH_TYPE_STRSIZE 1 409 410 /* Fetch type information table */ 411 static const struct fetch_type fetch_type_table[] = { 412 /* Special types */ 413 [FETCH_TYPE_STRING] = __ASSIGN_FETCH_TYPE("string", string, string, 414 sizeof(u32), 1, "__data_loc char[]"), 415 [FETCH_TYPE_STRSIZE] = __ASSIGN_FETCH_TYPE("string_size", u32, 416 string_size, sizeof(u32), 0, "u32"), 417 /* Basic types */ 418 ASSIGN_FETCH_TYPE(u8, u8, 0), 419 ASSIGN_FETCH_TYPE(u16, u16, 0), 420 ASSIGN_FETCH_TYPE(u32, u32, 0), 421 ASSIGN_FETCH_TYPE(u64, u64, 0), 422 ASSIGN_FETCH_TYPE(s8, u8, 1), 423 ASSIGN_FETCH_TYPE(s16, u16, 1), 424 ASSIGN_FETCH_TYPE(s32, u32, 1), 425 ASSIGN_FETCH_TYPE(s64, u64, 1), 426 }; 427 428 static const struct fetch_type *find_fetch_type(const char *type) 429 { 430 int i; 431 432 if (!type) 433 type = DEFAULT_FETCH_TYPE_STR; 434 435 /* Special case: bitfield */ 436 if (*type == 'b') { 437 unsigned long bs; 438 439 type = strchr(type, '/'); 440 if (!type) 441 goto fail; 442 443 type++; 444 if (strict_strtoul(type, 0, &bs)) 445 goto fail; 446 447 switch (bs) { 448 case 8: 449 return find_fetch_type("u8"); 450 case 16: 451 return find_fetch_type("u16"); 452 case 32: 453 return find_fetch_type("u32"); 454 case 64: 455 return find_fetch_type("u64"); 456 default: 457 goto fail; 458 } 459 } 460 461 for (i = 0; i < ARRAY_SIZE(fetch_type_table); i++) 462 if (strcmp(type, fetch_type_table[i].name) == 0) 463 return &fetch_type_table[i]; 464 465 fail: 466 return NULL; 467 } 468 469 /* Special function : only accept unsigned long */ 470 static __kprobes void fetch_stack_address(struct pt_regs *regs, 471 void *dummy, void *dest) 472 { 473 *(unsigned long *)dest = kernel_stack_pointer(regs); 474 } 475 476 static fetch_func_t get_fetch_size_function(const struct fetch_type *type, 477 fetch_func_t orig_fn) 478 { 479 int i; 480 481 if (type != &fetch_type_table[FETCH_TYPE_STRING]) 482 return NULL; /* Only string type needs size function */ 483 484 for (i = 0; i < FETCH_MTD_END; i++) 485 if (type->fetch[i] == orig_fn) 486 return fetch_type_table[FETCH_TYPE_STRSIZE].fetch[i]; 487 488 WARN_ON(1); /* This should not happen */ 489 490 return NULL; 491 } 492 493 /* Split symbol and offset. */ 494 int traceprobe_split_symbol_offset(char *symbol, unsigned long *offset) 495 { 496 char *tmp; 497 int ret; 498 499 if (!offset) 500 return -EINVAL; 501 502 tmp = strchr(symbol, '+'); 503 if (tmp) { 504 /* skip sign because strict_strtol doesn't accept '+' */ 505 ret = strict_strtoul(tmp + 1, 0, offset); 506 if (ret) 507 return ret; 508 509 *tmp = '\0'; 510 } else 511 *offset = 0; 512 513 return 0; 514 } 515 516 #define PARAM_MAX_STACK (THREAD_SIZE / sizeof(unsigned long)) 517 518 static int parse_probe_vars(char *arg, const struct fetch_type *t, 519 struct fetch_param *f, bool is_return) 520 { 521 int ret = 0; 522 unsigned long param; 523 524 if (strcmp(arg, "retval") == 0) { 525 if (is_return) 526 f->fn = t->fetch[FETCH_MTD_retval]; 527 else 528 ret = -EINVAL; 529 } else if (strncmp(arg, "stack", 5) == 0) { 530 if (arg[5] == '\0') { 531 if (strcmp(t->name, DEFAULT_FETCH_TYPE_STR) == 0) 532 f->fn = fetch_stack_address; 533 else 534 ret = -EINVAL; 535 } else if (isdigit(arg[5])) { 536 ret = strict_strtoul(arg + 5, 10, ¶m); 537 if (ret || param > PARAM_MAX_STACK) 538 ret = -EINVAL; 539 else { 540 f->fn = t->fetch[FETCH_MTD_stack]; 541 f->data = (void *)param; 542 } 543 } else 544 ret = -EINVAL; 545 } else 546 ret = -EINVAL; 547 548 return ret; 549 } 550 551 /* Recursive argument parser */ 552 static int parse_probe_arg(char *arg, const struct fetch_type *t, 553 struct fetch_param *f, bool is_return, bool is_kprobe) 554 { 555 unsigned long param; 556 long offset; 557 char *tmp; 558 int ret; 559 560 ret = 0; 561 562 /* Until uprobe_events supports only reg arguments */ 563 if (!is_kprobe && arg[0] != '%') 564 return -EINVAL; 565 566 switch (arg[0]) { 567 case '$': 568 ret = parse_probe_vars(arg + 1, t, f, is_return); 569 break; 570 571 case '%': /* named register */ 572 ret = regs_query_register_offset(arg + 1); 573 if (ret >= 0) { 574 f->fn = t->fetch[FETCH_MTD_reg]; 575 f->data = (void *)(unsigned long)ret; 576 ret = 0; 577 } 578 break; 579 580 case '@': /* memory or symbol */ 581 if (isdigit(arg[1])) { 582 ret = strict_strtoul(arg + 1, 0, ¶m); 583 if (ret) 584 break; 585 586 f->fn = t->fetch[FETCH_MTD_memory]; 587 f->data = (void *)param; 588 } else { 589 ret = traceprobe_split_symbol_offset(arg + 1, &offset); 590 if (ret) 591 break; 592 593 f->data = alloc_symbol_cache(arg + 1, offset); 594 if (f->data) 595 f->fn = t->fetch[FETCH_MTD_symbol]; 596 } 597 break; 598 599 case '+': /* deref memory */ 600 arg++; /* Skip '+', because strict_strtol() rejects it. */ 601 case '-': 602 tmp = strchr(arg, '('); 603 if (!tmp) 604 break; 605 606 *tmp = '\0'; 607 ret = strict_strtol(arg, 0, &offset); 608 609 if (ret) 610 break; 611 612 arg = tmp + 1; 613 tmp = strrchr(arg, ')'); 614 615 if (tmp) { 616 struct deref_fetch_param *dprm; 617 const struct fetch_type *t2; 618 619 t2 = find_fetch_type(NULL); 620 *tmp = '\0'; 621 dprm = kzalloc(sizeof(struct deref_fetch_param), GFP_KERNEL); 622 623 if (!dprm) 624 return -ENOMEM; 625 626 dprm->offset = offset; 627 ret = parse_probe_arg(arg, t2, &dprm->orig, is_return, 628 is_kprobe); 629 if (ret) 630 kfree(dprm); 631 else { 632 f->fn = t->fetch[FETCH_MTD_deref]; 633 f->data = (void *)dprm; 634 } 635 } 636 break; 637 } 638 if (!ret && !f->fn) { /* Parsed, but do not find fetch method */ 639 pr_info("%s type has no corresponding fetch method.\n", t->name); 640 ret = -EINVAL; 641 } 642 643 return ret; 644 } 645 646 #define BYTES_TO_BITS(nb) ((BITS_PER_LONG * (nb)) / sizeof(long)) 647 648 /* Bitfield type needs to be parsed into a fetch function */ 649 static int __parse_bitfield_probe_arg(const char *bf, 650 const struct fetch_type *t, 651 struct fetch_param *f) 652 { 653 struct bitfield_fetch_param *bprm; 654 unsigned long bw, bo; 655 char *tail; 656 657 if (*bf != 'b') 658 return 0; 659 660 bprm = kzalloc(sizeof(*bprm), GFP_KERNEL); 661 if (!bprm) 662 return -ENOMEM; 663 664 bprm->orig = *f; 665 f->fn = t->fetch[FETCH_MTD_bitfield]; 666 f->data = (void *)bprm; 667 bw = simple_strtoul(bf + 1, &tail, 0); /* Use simple one */ 668 669 if (bw == 0 || *tail != '@') 670 return -EINVAL; 671 672 bf = tail + 1; 673 bo = simple_strtoul(bf, &tail, 0); 674 675 if (tail == bf || *tail != '/') 676 return -EINVAL; 677 678 bprm->hi_shift = BYTES_TO_BITS(t->size) - (bw + bo); 679 bprm->low_shift = bprm->hi_shift + bo; 680 681 return (BYTES_TO_BITS(t->size) < (bw + bo)) ? -EINVAL : 0; 682 } 683 684 /* String length checking wrapper */ 685 int traceprobe_parse_probe_arg(char *arg, ssize_t *size, 686 struct probe_arg *parg, bool is_return, bool is_kprobe) 687 { 688 const char *t; 689 int ret; 690 691 if (strlen(arg) > MAX_ARGSTR_LEN) { 692 pr_info("Argument is too long.: %s\n", arg); 693 return -ENOSPC; 694 } 695 parg->comm = kstrdup(arg, GFP_KERNEL); 696 if (!parg->comm) { 697 pr_info("Failed to allocate memory for command '%s'.\n", arg); 698 return -ENOMEM; 699 } 700 t = strchr(parg->comm, ':'); 701 if (t) { 702 arg[t - parg->comm] = '\0'; 703 t++; 704 } 705 parg->type = find_fetch_type(t); 706 if (!parg->type) { 707 pr_info("Unsupported type: %s\n", t); 708 return -EINVAL; 709 } 710 parg->offset = *size; 711 *size += parg->type->size; 712 ret = parse_probe_arg(arg, parg->type, &parg->fetch, is_return, is_kprobe); 713 714 if (ret >= 0 && t != NULL) 715 ret = __parse_bitfield_probe_arg(t, parg->type, &parg->fetch); 716 717 if (ret >= 0) { 718 parg->fetch_size.fn = get_fetch_size_function(parg->type, 719 parg->fetch.fn); 720 parg->fetch_size.data = parg->fetch.data; 721 } 722 723 return ret; 724 } 725 726 /* Return 1 if name is reserved or already used by another argument */ 727 int traceprobe_conflict_field_name(const char *name, 728 struct probe_arg *args, int narg) 729 { 730 int i; 731 732 for (i = 0; i < ARRAY_SIZE(reserved_field_names); i++) 733 if (strcmp(reserved_field_names[i], name) == 0) 734 return 1; 735 736 for (i = 0; i < narg; i++) 737 if (strcmp(args[i].name, name) == 0) 738 return 1; 739 740 return 0; 741 } 742 743 void traceprobe_update_arg(struct probe_arg *arg) 744 { 745 if (CHECK_FETCH_FUNCS(bitfield, arg->fetch.fn)) 746 update_bitfield_fetch_param(arg->fetch.data); 747 else if (CHECK_FETCH_FUNCS(deref, arg->fetch.fn)) 748 update_deref_fetch_param(arg->fetch.data); 749 else if (CHECK_FETCH_FUNCS(symbol, arg->fetch.fn)) 750 update_symbol_cache(arg->fetch.data); 751 } 752 753 void traceprobe_free_probe_arg(struct probe_arg *arg) 754 { 755 if (CHECK_FETCH_FUNCS(bitfield, arg->fetch.fn)) 756 free_bitfield_fetch_param(arg->fetch.data); 757 else if (CHECK_FETCH_FUNCS(deref, arg->fetch.fn)) 758 free_deref_fetch_param(arg->fetch.data); 759 else if (CHECK_FETCH_FUNCS(symbol, arg->fetch.fn)) 760 free_symbol_cache(arg->fetch.data); 761 762 kfree(arg->name); 763 kfree(arg->comm); 764 } 765 766 int traceprobe_command(const char *buf, int (*createfn)(int, char **)) 767 { 768 char **argv; 769 int argc, ret; 770 771 argc = 0; 772 ret = 0; 773 argv = argv_split(GFP_KERNEL, buf, &argc); 774 if (!argv) 775 return -ENOMEM; 776 777 if (argc) 778 ret = createfn(argc, argv); 779 780 argv_free(argv); 781 782 return ret; 783 } 784 785 #define WRITE_BUFSIZE 4096 786 787 ssize_t traceprobe_probes_write(struct file *file, const char __user *buffer, 788 size_t count, loff_t *ppos, 789 int (*createfn)(int, char **)) 790 { 791 char *kbuf, *tmp; 792 int ret = 0; 793 size_t done = 0; 794 size_t size; 795 796 kbuf = kmalloc(WRITE_BUFSIZE, GFP_KERNEL); 797 if (!kbuf) 798 return -ENOMEM; 799 800 while (done < count) { 801 size = count - done; 802 803 if (size >= WRITE_BUFSIZE) 804 size = WRITE_BUFSIZE - 1; 805 806 if (copy_from_user(kbuf, buffer + done, size)) { 807 ret = -EFAULT; 808 goto out; 809 } 810 kbuf[size] = '\0'; 811 tmp = strchr(kbuf, '\n'); 812 813 if (tmp) { 814 *tmp = '\0'; 815 size = tmp - kbuf + 1; 816 } else if (done + size < count) { 817 pr_warning("Line length is too long: " 818 "Should be less than %d.", WRITE_BUFSIZE); 819 ret = -EINVAL; 820 goto out; 821 } 822 done += size; 823 /* Remove comments */ 824 tmp = strchr(kbuf, '#'); 825 826 if (tmp) 827 *tmp = '\0'; 828 829 ret = traceprobe_command(kbuf, createfn); 830 if (ret) 831 goto out; 832 } 833 ret = done; 834 835 out: 836 kfree(kbuf); 837 838 return ret; 839 } 840