1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Helpers for formatting and printing strings 4 * 5 * Copyright 31 August 2008 James Bottomley 6 * Copyright (C) 2013, Intel Corporation 7 */ 8 #include <linux/bug.h> 9 #include <linux/kernel.h> 10 #include <linux/math64.h> 11 #include <linux/export.h> 12 #include <linux/ctype.h> 13 #include <linux/device.h> 14 #include <linux/errno.h> 15 #include <linux/fs.h> 16 #include <linux/limits.h> 17 #include <linux/mm.h> 18 #include <linux/slab.h> 19 #include <linux/string.h> 20 #include <linux/string_helpers.h> 21 #include <kunit/test.h> 22 #include <kunit/test-bug.h> 23 24 /** 25 * string_get_size - get the size in the specified units 26 * @size: The size to be converted in blocks 27 * @blk_size: Size of the block (use 1 for size in bytes) 28 * @units: Units to use (powers of 1000 or 1024), whether to include space separator 29 * @buf: buffer to format to 30 * @len: length of buffer 31 * 32 * This function returns a string formatted to 3 significant figures 33 * giving the size in the required units. @buf should have room for 34 * at least 9 bytes and will always be zero terminated. 35 * 36 * Return value: number of characters of output that would have been written 37 * (which may be greater than len, if output was truncated). 38 */ 39 int string_get_size(u64 size, u64 blk_size, const enum string_size_units units, 40 char *buf, int len) 41 { 42 enum string_size_units units_base = units & STRING_UNITS_MASK; 43 static const char *const units_10[] = { 44 "", "k", "M", "G", "T", "P", "E", "Z", "Y", 45 }; 46 static const char *const units_2[] = { 47 "", "Ki", "Mi", "Gi", "Ti", "Pi", "Ei", "Zi", "Yi", 48 }; 49 static const char *const *const units_str[] = { 50 [STRING_UNITS_10] = units_10, 51 [STRING_UNITS_2] = units_2, 52 }; 53 static const unsigned int divisor[] = { 54 [STRING_UNITS_10] = 1000, 55 [STRING_UNITS_2] = 1024, 56 }; 57 static const unsigned int rounding[] = { 500, 50, 5 }; 58 int i = 0, j; 59 u32 remainder = 0, sf_cap; 60 char tmp[8]; 61 const char *unit; 62 63 tmp[0] = '\0'; 64 65 if (blk_size == 0) 66 size = 0; 67 if (size == 0) 68 goto out; 69 70 /* This is Napier's algorithm. Reduce the original block size to 71 * 72 * coefficient * divisor[units_base]^i 73 * 74 * we do the reduction so both coefficients are just under 32 bits so 75 * that multiplying them together won't overflow 64 bits and we keep 76 * as much precision as possible in the numbers. 77 * 78 * Note: it's safe to throw away the remainders here because all the 79 * precision is in the coefficients. 80 */ 81 while (blk_size >> 32) { 82 do_div(blk_size, divisor[units_base]); 83 i++; 84 } 85 86 while (size >> 32) { 87 do_div(size, divisor[units_base]); 88 i++; 89 } 90 91 /* now perform the actual multiplication keeping i as the sum of the 92 * two logarithms */ 93 size *= blk_size; 94 95 /* and logarithmically reduce it until it's just under the divisor */ 96 while (size >= divisor[units_base]) { 97 remainder = do_div(size, divisor[units_base]); 98 i++; 99 } 100 101 /* work out in j how many digits of precision we need from the 102 * remainder */ 103 sf_cap = size; 104 for (j = 0; sf_cap*10 < 1000; j++) 105 sf_cap *= 10; 106 107 if (units_base == STRING_UNITS_2) { 108 /* express the remainder as a decimal. It's currently the 109 * numerator of a fraction whose denominator is 110 * divisor[units_base], which is 1 << 10 for STRING_UNITS_2 */ 111 remainder *= 1000; 112 remainder >>= 10; 113 } 114 115 /* add a 5 to the digit below what will be printed to ensure 116 * an arithmetical round up and carry it through to size */ 117 remainder += rounding[j]; 118 if (remainder >= 1000) { 119 remainder -= 1000; 120 size += 1; 121 } 122 123 if (j) { 124 snprintf(tmp, sizeof(tmp), ".%03u", remainder); 125 tmp[j+1] = '\0'; 126 } 127 128 out: 129 if (i >= ARRAY_SIZE(units_2)) 130 unit = "UNK"; 131 else 132 unit = units_str[units_base][i]; 133 134 return snprintf(buf, len, "%u%s%s%s%s", (u32)size, tmp, 135 (units & STRING_UNITS_NO_SPACE) ? "" : " ", 136 unit, 137 (units & STRING_UNITS_NO_BYTES) ? "" : "B"); 138 } 139 EXPORT_SYMBOL(string_get_size); 140 141 /** 142 * parse_int_array_user - Split string into a sequence of integers 143 * @from: The user space buffer to read from 144 * @count: The maximum number of bytes to read 145 * @array: Returned pointer to sequence of integers 146 * 147 * On success @array is allocated and initialized with a sequence of 148 * integers extracted from the @from plus an additional element that 149 * begins the sequence and specifies the integers count. 150 * 151 * Caller takes responsibility for freeing @array when it is no longer 152 * needed. 153 */ 154 int parse_int_array_user(const char __user *from, size_t count, int **array) 155 { 156 int *ints, nints; 157 char *buf; 158 int ret = 0; 159 160 buf = memdup_user_nul(from, count); 161 if (IS_ERR(buf)) 162 return PTR_ERR(buf); 163 164 get_options(buf, 0, &nints); 165 if (!nints) { 166 ret = -ENOENT; 167 goto free_buf; 168 } 169 170 ints = kcalloc(nints + 1, sizeof(*ints), GFP_KERNEL); 171 if (!ints) { 172 ret = -ENOMEM; 173 goto free_buf; 174 } 175 176 get_options(buf, nints + 1, ints); 177 *array = ints; 178 179 free_buf: 180 kfree(buf); 181 return ret; 182 } 183 EXPORT_SYMBOL(parse_int_array_user); 184 185 static bool unescape_space(char **src, char **dst) 186 { 187 char *p = *dst, *q = *src; 188 189 switch (*q) { 190 case 'n': 191 *p = '\n'; 192 break; 193 case 'r': 194 *p = '\r'; 195 break; 196 case 't': 197 *p = '\t'; 198 break; 199 case 'v': 200 *p = '\v'; 201 break; 202 case 'f': 203 *p = '\f'; 204 break; 205 default: 206 return false; 207 } 208 *dst += 1; 209 *src += 1; 210 return true; 211 } 212 213 static bool unescape_octal(char **src, char **dst) 214 { 215 char *p = *dst, *q = *src; 216 u8 num; 217 218 if (isodigit(*q) == 0) 219 return false; 220 221 num = (*q++) & 7; 222 while (num < 32 && isodigit(*q) && (q - *src < 3)) { 223 num <<= 3; 224 num += (*q++) & 7; 225 } 226 *p = num; 227 *dst += 1; 228 *src = q; 229 return true; 230 } 231 232 static bool unescape_hex(char **src, char **dst) 233 { 234 char *p = *dst, *q = *src; 235 int digit; 236 u8 num; 237 238 if (*q++ != 'x') 239 return false; 240 241 num = digit = hex_to_bin(*q++); 242 if (digit < 0) 243 return false; 244 245 digit = hex_to_bin(*q); 246 if (digit >= 0) { 247 q++; 248 num = (num << 4) | digit; 249 } 250 *p = num; 251 *dst += 1; 252 *src = q; 253 return true; 254 } 255 256 static bool unescape_special(char **src, char **dst) 257 { 258 char *p = *dst, *q = *src; 259 260 switch (*q) { 261 case '\"': 262 *p = '\"'; 263 break; 264 case '\\': 265 *p = '\\'; 266 break; 267 case 'a': 268 *p = '\a'; 269 break; 270 case 'e': 271 *p = '\e'; 272 break; 273 default: 274 return false; 275 } 276 *dst += 1; 277 *src += 1; 278 return true; 279 } 280 281 /** 282 * string_unescape - unquote characters in the given string 283 * @src: source buffer (escaped) 284 * @dst: destination buffer (unescaped) 285 * @size: size of the destination buffer (0 to unlimit) 286 * @flags: combination of the flags. 287 * 288 * Description: 289 * The function unquotes characters in the given string. 290 * 291 * Because the size of the output will be the same as or less than the size of 292 * the input, the transformation may be performed in place. 293 * 294 * Caller must provide valid source and destination pointers. Be aware that 295 * destination buffer will always be NULL-terminated. Source string must be 296 * NULL-terminated as well. The supported flags are:: 297 * 298 * UNESCAPE_SPACE: 299 * '\f' - form feed 300 * '\n' - new line 301 * '\r' - carriage return 302 * '\t' - horizontal tab 303 * '\v' - vertical tab 304 * UNESCAPE_OCTAL: 305 * '\NNN' - byte with octal value NNN (1 to 3 digits) 306 * UNESCAPE_HEX: 307 * '\xHH' - byte with hexadecimal value HH (1 to 2 digits) 308 * UNESCAPE_SPECIAL: 309 * '\"' - double quote 310 * '\\' - backslash 311 * '\a' - alert (BEL) 312 * '\e' - escape 313 * UNESCAPE_ANY: 314 * all previous together 315 * 316 * Return: 317 * The amount of the characters processed to the destination buffer excluding 318 * trailing '\0' is returned. 319 */ 320 int string_unescape(char *src, char *dst, size_t size, unsigned int flags) 321 { 322 char *out = dst; 323 324 if (!size) 325 size = SIZE_MAX; 326 327 while (*src && --size) { 328 if (src[0] == '\\' && src[1] != '\0' && size > 1) { 329 src++; 330 size--; 331 332 if (flags & UNESCAPE_SPACE && 333 unescape_space(&src, &out)) 334 continue; 335 336 if (flags & UNESCAPE_OCTAL && 337 unescape_octal(&src, &out)) 338 continue; 339 340 if (flags & UNESCAPE_HEX && 341 unescape_hex(&src, &out)) 342 continue; 343 344 if (flags & UNESCAPE_SPECIAL && 345 unescape_special(&src, &out)) 346 continue; 347 348 *out++ = '\\'; 349 } 350 *out++ = *src++; 351 } 352 *out = '\0'; 353 354 return out - dst; 355 } 356 EXPORT_SYMBOL(string_unescape); 357 358 static bool escape_passthrough(unsigned char c, char **dst, char *end) 359 { 360 char *out = *dst; 361 362 if (out < end) 363 *out = c; 364 *dst = out + 1; 365 return true; 366 } 367 368 static bool escape_space(unsigned char c, char **dst, char *end) 369 { 370 char *out = *dst; 371 unsigned char to; 372 373 switch (c) { 374 case '\n': 375 to = 'n'; 376 break; 377 case '\r': 378 to = 'r'; 379 break; 380 case '\t': 381 to = 't'; 382 break; 383 case '\v': 384 to = 'v'; 385 break; 386 case '\f': 387 to = 'f'; 388 break; 389 default: 390 return false; 391 } 392 393 if (out < end) 394 *out = '\\'; 395 ++out; 396 if (out < end) 397 *out = to; 398 ++out; 399 400 *dst = out; 401 return true; 402 } 403 404 static bool escape_special(unsigned char c, char **dst, char *end) 405 { 406 char *out = *dst; 407 unsigned char to; 408 409 switch (c) { 410 case '\\': 411 to = '\\'; 412 break; 413 case '\a': 414 to = 'a'; 415 break; 416 case '\e': 417 to = 'e'; 418 break; 419 case '"': 420 to = '"'; 421 break; 422 default: 423 return false; 424 } 425 426 if (out < end) 427 *out = '\\'; 428 ++out; 429 if (out < end) 430 *out = to; 431 ++out; 432 433 *dst = out; 434 return true; 435 } 436 437 static bool escape_null(unsigned char c, char **dst, char *end) 438 { 439 char *out = *dst; 440 441 if (c) 442 return false; 443 444 if (out < end) 445 *out = '\\'; 446 ++out; 447 if (out < end) 448 *out = '0'; 449 ++out; 450 451 *dst = out; 452 return true; 453 } 454 455 static bool escape_octal(unsigned char c, char **dst, char *end) 456 { 457 char *out = *dst; 458 459 if (out < end) 460 *out = '\\'; 461 ++out; 462 if (out < end) 463 *out = ((c >> 6) & 0x07) + '0'; 464 ++out; 465 if (out < end) 466 *out = ((c >> 3) & 0x07) + '0'; 467 ++out; 468 if (out < end) 469 *out = ((c >> 0) & 0x07) + '0'; 470 ++out; 471 472 *dst = out; 473 return true; 474 } 475 476 static bool escape_hex(unsigned char c, char **dst, char *end) 477 { 478 char *out = *dst; 479 480 if (out < end) 481 *out = '\\'; 482 ++out; 483 if (out < end) 484 *out = 'x'; 485 ++out; 486 if (out < end) 487 *out = hex_asc_hi(c); 488 ++out; 489 if (out < end) 490 *out = hex_asc_lo(c); 491 ++out; 492 493 *dst = out; 494 return true; 495 } 496 497 /** 498 * string_escape_mem - quote characters in the given memory buffer 499 * @src: source buffer (unescaped) 500 * @isz: source buffer size 501 * @dst: destination buffer (escaped) 502 * @osz: destination buffer size 503 * @flags: combination of the flags 504 * @only: NULL-terminated string containing characters used to limit 505 * the selected escape class. If characters are included in @only 506 * that would not normally be escaped by the classes selected 507 * in @flags, they will be copied to @dst unescaped. 508 * 509 * Description: 510 * The process of escaping byte buffer includes several parts. They are applied 511 * in the following sequence. 512 * 513 * 1. The character is not matched to the one from @only string and thus 514 * must go as-is to the output. 515 * 2. The character is matched to the printable and ASCII classes, if asked, 516 * and in case of match it passes through to the output. 517 * 3. The character is matched to the printable or ASCII class, if asked, 518 * and in case of match it passes through to the output. 519 * 4. The character is checked if it falls into the class given by @flags. 520 * %ESCAPE_OCTAL and %ESCAPE_HEX are going last since they cover any 521 * character. Note that they actually can't go together, otherwise 522 * %ESCAPE_HEX will be ignored. 523 * 524 * Caller must provide valid source and destination pointers. Be aware that 525 * destination buffer will not be NULL-terminated, thus caller have to append 526 * it if needs. The supported flags are:: 527 * 528 * %ESCAPE_SPACE: (special white space, not space itself) 529 * '\f' - form feed 530 * '\n' - new line 531 * '\r' - carriage return 532 * '\t' - horizontal tab 533 * '\v' - vertical tab 534 * %ESCAPE_SPECIAL: 535 * '\"' - double quote 536 * '\\' - backslash 537 * '\a' - alert (BEL) 538 * '\e' - escape 539 * %ESCAPE_NULL: 540 * '\0' - null 541 * %ESCAPE_OCTAL: 542 * '\NNN' - byte with octal value NNN (3 digits) 543 * %ESCAPE_ANY: 544 * all previous together 545 * %ESCAPE_NP: 546 * escape only non-printable characters, checked by isprint() 547 * %ESCAPE_ANY_NP: 548 * all previous together 549 * %ESCAPE_HEX: 550 * '\xHH' - byte with hexadecimal value HH (2 digits) 551 * %ESCAPE_NA: 552 * escape only non-ascii characters, checked by isascii() 553 * %ESCAPE_NAP: 554 * escape only non-printable or non-ascii characters 555 * %ESCAPE_APPEND: 556 * append characters from @only to be escaped by the given classes 557 * 558 * %ESCAPE_APPEND would help to pass additional characters to the escaped, when 559 * one of %ESCAPE_NP, %ESCAPE_NA, or %ESCAPE_NAP is provided. 560 * 561 * One notable caveat, the %ESCAPE_NAP, %ESCAPE_NP and %ESCAPE_NA have the 562 * higher priority than the rest of the flags (%ESCAPE_NAP is the highest). 563 * It doesn't make much sense to use either of them without %ESCAPE_OCTAL 564 * or %ESCAPE_HEX, because they cover most of the other character classes. 565 * %ESCAPE_NAP can utilize %ESCAPE_SPACE or %ESCAPE_SPECIAL in addition to 566 * the above. 567 * 568 * Return: 569 * The total size of the escaped output that would be generated for 570 * the given input and flags. To check whether the output was 571 * truncated, compare the return value to osz. There is room left in 572 * dst for a '\0' terminator if and only if ret < osz. 573 */ 574 int string_escape_mem(const char *src, size_t isz, char *dst, size_t osz, 575 unsigned int flags, const char *only) 576 { 577 char *p = dst; 578 char *end = p + osz; 579 bool is_dict = only && *only; 580 bool is_append = flags & ESCAPE_APPEND; 581 582 while (isz--) { 583 unsigned char c = *src++; 584 bool in_dict = is_dict && strchr(only, c); 585 586 /* 587 * Apply rules in the following sequence: 588 * - the @only string is supplied and does not contain a 589 * character under question 590 * - the character is printable and ASCII, when @flags has 591 * %ESCAPE_NAP bit set 592 * - the character is printable, when @flags has 593 * %ESCAPE_NP bit set 594 * - the character is ASCII, when @flags has 595 * %ESCAPE_NA bit set 596 * - the character doesn't fall into a class of symbols 597 * defined by given @flags 598 * In these cases we just pass through a character to the 599 * output buffer. 600 * 601 * When %ESCAPE_APPEND is passed, the characters from @only 602 * have been excluded from the %ESCAPE_NAP, %ESCAPE_NP, and 603 * %ESCAPE_NA cases. 604 */ 605 if (!(is_append || in_dict) && is_dict && 606 escape_passthrough(c, &p, end)) 607 continue; 608 609 if (!(is_append && in_dict) && isascii(c) && isprint(c) && 610 flags & ESCAPE_NAP && escape_passthrough(c, &p, end)) 611 continue; 612 613 if (!(is_append && in_dict) && isprint(c) && 614 flags & ESCAPE_NP && escape_passthrough(c, &p, end)) 615 continue; 616 617 if (!(is_append && in_dict) && isascii(c) && 618 flags & ESCAPE_NA && escape_passthrough(c, &p, end)) 619 continue; 620 621 if (flags & ESCAPE_SPACE && escape_space(c, &p, end)) 622 continue; 623 624 if (flags & ESCAPE_SPECIAL && escape_special(c, &p, end)) 625 continue; 626 627 if (flags & ESCAPE_NULL && escape_null(c, &p, end)) 628 continue; 629 630 /* ESCAPE_OCTAL and ESCAPE_HEX always go last */ 631 if (flags & ESCAPE_OCTAL && escape_octal(c, &p, end)) 632 continue; 633 634 if (flags & ESCAPE_HEX && escape_hex(c, &p, end)) 635 continue; 636 637 escape_passthrough(c, &p, end); 638 } 639 640 return p - dst; 641 } 642 EXPORT_SYMBOL(string_escape_mem); 643 644 /* 645 * Return an allocated string that has been escaped of special characters 646 * and double quotes, making it safe to log in quotes. 647 */ 648 char *kstrdup_quotable(const char *src, gfp_t gfp) 649 { 650 size_t slen, dlen; 651 char *dst; 652 const int flags = ESCAPE_HEX; 653 const char esc[] = "\f\n\r\t\v\a\e\\\""; 654 655 if (!src) 656 return NULL; 657 slen = strlen(src); 658 659 dlen = string_escape_mem(src, slen, NULL, 0, flags, esc); 660 dst = kmalloc(dlen + 1, gfp); 661 if (!dst) 662 return NULL; 663 664 WARN_ON(string_escape_mem(src, slen, dst, dlen, flags, esc) != dlen); 665 dst[dlen] = '\0'; 666 667 return dst; 668 } 669 EXPORT_SYMBOL_GPL(kstrdup_quotable); 670 671 /* 672 * Returns allocated NULL-terminated string containing process 673 * command line, with inter-argument NULLs replaced with spaces, 674 * and other special characters escaped. 675 */ 676 char *kstrdup_quotable_cmdline(struct task_struct *task, gfp_t gfp) 677 { 678 char *buffer, *quoted; 679 int i, res; 680 681 buffer = kmalloc(PAGE_SIZE, GFP_KERNEL); 682 if (!buffer) 683 return NULL; 684 685 res = get_cmdline(task, buffer, PAGE_SIZE - 1); 686 buffer[res] = '\0'; 687 688 /* Collapse trailing NULLs, leave res pointing to last non-NULL. */ 689 while (--res >= 0 && buffer[res] == '\0') 690 ; 691 692 /* Replace inter-argument NULLs. */ 693 for (i = 0; i <= res; i++) 694 if (buffer[i] == '\0') 695 buffer[i] = ' '; 696 697 /* Make sure result is printable. */ 698 quoted = kstrdup_quotable(buffer, gfp); 699 kfree(buffer); 700 return quoted; 701 } 702 EXPORT_SYMBOL_GPL(kstrdup_quotable_cmdline); 703 704 /* 705 * Returns allocated NULL-terminated string containing pathname, 706 * with special characters escaped, able to be safely logged. If 707 * there is an error, the leading character will be "<". 708 */ 709 char *kstrdup_quotable_file(struct file *file, gfp_t gfp) 710 { 711 char *temp, *pathname; 712 713 if (!file) 714 return kstrdup("<unknown>", gfp); 715 716 /* We add 11 spaces for ' (deleted)' to be appended */ 717 temp = kmalloc(PATH_MAX + 11, GFP_KERNEL); 718 if (!temp) 719 return kstrdup("<no_memory>", gfp); 720 721 pathname = file_path(file, temp, PATH_MAX + 11); 722 if (IS_ERR(pathname)) 723 pathname = kstrdup("<too_long>", gfp); 724 else 725 pathname = kstrdup_quotable(pathname, gfp); 726 727 kfree(temp); 728 return pathname; 729 } 730 EXPORT_SYMBOL_GPL(kstrdup_quotable_file); 731 732 /* 733 * Returns duplicate string in which the @old characters are replaced by @new. 734 */ 735 char *kstrdup_and_replace(const char *src, char old, char new, gfp_t gfp) 736 { 737 char *dst; 738 739 dst = kstrdup(src, gfp); 740 if (!dst) 741 return NULL; 742 743 return strreplace(dst, old, new); 744 } 745 EXPORT_SYMBOL_GPL(kstrdup_and_replace); 746 747 /** 748 * kasprintf_strarray - allocate and fill array of sequential strings 749 * @gfp: flags for the slab allocator 750 * @prefix: prefix to be used 751 * @n: amount of lines to be allocated and filled 752 * 753 * Allocates and fills @n strings using pattern "%s-%zu", where prefix 754 * is provided by caller. The caller is responsible to free them with 755 * kfree_strarray() after use. 756 * 757 * Returns array of strings or NULL when memory can't be allocated. 758 */ 759 char **kasprintf_strarray(gfp_t gfp, const char *prefix, size_t n) 760 { 761 char **names; 762 size_t i; 763 764 names = kcalloc(n + 1, sizeof(char *), gfp); 765 if (!names) 766 return NULL; 767 768 for (i = 0; i < n; i++) { 769 names[i] = kasprintf(gfp, "%s-%zu", prefix, i); 770 if (!names[i]) { 771 kfree_strarray(names, i); 772 return NULL; 773 } 774 } 775 776 return names; 777 } 778 EXPORT_SYMBOL_GPL(kasprintf_strarray); 779 780 /** 781 * kfree_strarray - free a number of dynamically allocated strings contained 782 * in an array and the array itself 783 * 784 * @array: Dynamically allocated array of strings to free. 785 * @n: Number of strings (starting from the beginning of the array) to free. 786 * 787 * Passing a non-NULL @array and @n == 0 as well as NULL @array are valid 788 * use-cases. If @array is NULL, the function does nothing. 789 */ 790 void kfree_strarray(char **array, size_t n) 791 { 792 unsigned int i; 793 794 if (!array) 795 return; 796 797 for (i = 0; i < n; i++) 798 kfree(array[i]); 799 kfree(array); 800 } 801 EXPORT_SYMBOL_GPL(kfree_strarray); 802 803 struct strarray { 804 char **array; 805 size_t n; 806 }; 807 808 static void devm_kfree_strarray(struct device *dev, void *res) 809 { 810 struct strarray *array = res; 811 812 kfree_strarray(array->array, array->n); 813 } 814 815 char **devm_kasprintf_strarray(struct device *dev, const char *prefix, size_t n) 816 { 817 struct strarray *ptr; 818 819 ptr = devres_alloc(devm_kfree_strarray, sizeof(*ptr), GFP_KERNEL); 820 if (!ptr) 821 return ERR_PTR(-ENOMEM); 822 823 ptr->array = kasprintf_strarray(GFP_KERNEL, prefix, n); 824 if (!ptr->array) { 825 devres_free(ptr); 826 return ERR_PTR(-ENOMEM); 827 } 828 829 ptr->n = n; 830 devres_add(dev, ptr); 831 832 return ptr->array; 833 } 834 EXPORT_SYMBOL_GPL(devm_kasprintf_strarray); 835 836 /** 837 * skip_spaces - Removes leading whitespace from @str. 838 * @str: The string to be stripped. 839 * 840 * Returns a pointer to the first non-whitespace character in @str. 841 */ 842 char *skip_spaces(const char *str) 843 { 844 while (isspace(*str)) 845 ++str; 846 return (char *)str; 847 } 848 EXPORT_SYMBOL(skip_spaces); 849 850 /** 851 * strim - Removes leading and trailing whitespace from @s. 852 * @s: The string to be stripped. 853 * 854 * Note that the first trailing whitespace is replaced with a %NUL-terminator 855 * in the given string @s. Returns a pointer to the first non-whitespace 856 * character in @s. 857 */ 858 char *strim(char *s) 859 { 860 size_t size; 861 char *end; 862 863 size = strlen(s); 864 if (!size) 865 return s; 866 867 end = s + size - 1; 868 while (end >= s && isspace(*end)) 869 end--; 870 *(end + 1) = '\0'; 871 872 return skip_spaces(s); 873 } 874 EXPORT_SYMBOL(strim); 875 876 /** 877 * sysfs_streq - return true if strings are equal, modulo trailing newline 878 * @s1: one string 879 * @s2: another string 880 * 881 * This routine returns true iff two strings are equal, treating both 882 * NUL and newline-then-NUL as equivalent string terminations. It's 883 * geared for use with sysfs input strings, which generally terminate 884 * with newlines but are compared against values without newlines. 885 */ 886 bool sysfs_streq(const char *s1, const char *s2) 887 { 888 while (*s1 && *s1 == *s2) { 889 s1++; 890 s2++; 891 } 892 893 if (*s1 == *s2) 894 return true; 895 if (!*s1 && *s2 == '\n' && !s2[1]) 896 return true; 897 if (*s1 == '\n' && !s1[1] && !*s2) 898 return true; 899 return false; 900 } 901 EXPORT_SYMBOL(sysfs_streq); 902 903 /** 904 * match_string - matches given string in an array 905 * @array: array of strings 906 * @n: number of strings in the array or -1 for NULL terminated arrays 907 * @string: string to match with 908 * 909 * This routine will look for a string in an array of strings up to the 910 * n-th element in the array or until the first NULL element. 911 * 912 * Historically the value of -1 for @n, was used to search in arrays that 913 * are NULL terminated. However, the function does not make a distinction 914 * when finishing the search: either @n elements have been compared OR 915 * the first NULL element was found. 916 * 917 * Return: 918 * index of a @string in the @array if matches, or %-EINVAL otherwise. 919 */ 920 int match_string(const char * const *array, size_t n, const char *string) 921 { 922 int index; 923 const char *item; 924 925 for (index = 0; index < n; index++) { 926 item = array[index]; 927 if (!item) 928 break; 929 if (!strcmp(item, string)) 930 return index; 931 } 932 933 return -EINVAL; 934 } 935 EXPORT_SYMBOL(match_string); 936 937 /** 938 * __sysfs_match_string - matches given string in an array 939 * @array: array of strings 940 * @n: number of strings in the array or -1 for NULL terminated arrays 941 * @str: string to match with 942 * 943 * Returns index of @str in the @array or -EINVAL, just like match_string(). 944 * Uses sysfs_streq instead of strcmp for matching. 945 * 946 * This routine will look for a string in an array of strings up to the 947 * n-th element in the array or until the first NULL element. 948 * 949 * Historically the value of -1 for @n, was used to search in arrays that 950 * are NULL terminated. However, the function does not make a distinction 951 * when finishing the search: either @n elements have been compared OR 952 * the first NULL element was found. 953 */ 954 int __sysfs_match_string(const char * const *array, size_t n, const char *str) 955 { 956 const char *item; 957 int index; 958 959 for (index = 0; index < n; index++) { 960 item = array[index]; 961 if (!item) 962 break; 963 if (sysfs_streq(item, str)) 964 return index; 965 } 966 967 return -EINVAL; 968 } 969 EXPORT_SYMBOL(__sysfs_match_string); 970 971 /** 972 * strreplace - Replace all occurrences of character in string. 973 * @str: The string to operate on. 974 * @old: The character being replaced. 975 * @new: The character @old is replaced with. 976 * 977 * Replaces the each @old character with a @new one in the given string @str. 978 * 979 * Return: pointer to the string @str itself. 980 */ 981 char *strreplace(char *str, char old, char new) 982 { 983 char *s = str; 984 985 for (; *s; ++s) 986 if (*s == old) 987 *s = new; 988 return str; 989 } 990 EXPORT_SYMBOL(strreplace); 991 992 /** 993 * memcpy_and_pad - Copy one buffer to another with padding 994 * @dest: Where to copy to 995 * @dest_len: The destination buffer size 996 * @src: Where to copy from 997 * @count: The number of bytes to copy 998 * @pad: Character to use for padding if space is left in destination. 999 */ 1000 void memcpy_and_pad(void *dest, size_t dest_len, const void *src, size_t count, 1001 int pad) 1002 { 1003 if (dest_len > count) { 1004 memcpy(dest, src, count); 1005 memset(dest + count, pad, dest_len - count); 1006 } else { 1007 memcpy(dest, src, dest_len); 1008 } 1009 } 1010 EXPORT_SYMBOL(memcpy_and_pad); 1011 1012 #ifdef CONFIG_FORTIFY_SOURCE 1013 /* These are placeholders for fortify compile-time warnings. */ 1014 void __read_overflow2_field(size_t avail, size_t wanted) { } 1015 EXPORT_SYMBOL(__read_overflow2_field); 1016 void __write_overflow_field(size_t avail, size_t wanted) { } 1017 EXPORT_SYMBOL(__write_overflow_field); 1018 1019 static const char * const fortify_func_name[] = { 1020 #define MAKE_FORTIFY_FUNC_NAME(func) [MAKE_FORTIFY_FUNC(func)] = #func 1021 EACH_FORTIFY_FUNC(MAKE_FORTIFY_FUNC_NAME) 1022 #undef MAKE_FORTIFY_FUNC_NAME 1023 }; 1024 1025 void __fortify_report(const u8 reason, const size_t avail, const size_t size) 1026 { 1027 const u8 func = FORTIFY_REASON_FUNC(reason); 1028 const bool write = FORTIFY_REASON_DIR(reason); 1029 const char *name; 1030 1031 name = fortify_func_name[umin(func, FORTIFY_FUNC_UNKNOWN)]; 1032 WARN(1, "%s: detected buffer overflow: %zu byte %s of buffer size %zu\n", 1033 name, size, str_read_write(!write), avail); 1034 } 1035 EXPORT_SYMBOL(__fortify_report); 1036 1037 void __fortify_panic(const u8 reason, const size_t avail, const size_t size) 1038 { 1039 __fortify_report(reason, avail, size); 1040 BUG(); 1041 } 1042 EXPORT_SYMBOL(__fortify_panic); 1043 #endif /* CONFIG_FORTIFY_SOURCE */ 1044