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b2441318 | 1 | // SPDX-License-Identifier: GPL-2.0 |
1da177e4 LT |
2 | /* |
3 | * linux/lib/string.c | |
4 | * | |
5 | * Copyright (C) 1991, 1992 Linus Torvalds | |
6 | */ | |
7 | ||
8 | /* | |
cfecea6e KC |
9 | * This file should be used only for "library" routines that may have |
10 | * alternative implementations on specific architectures (generally | |
11 | * found in <asm-xx/string.h>), or get overloaded by FORTIFY_SOURCE. | |
12 | * (Specifically, this file is built with __NO_FORTIFY.) | |
1da177e4 | 13 | * |
cfecea6e | 14 | * Other helper functions should live in string_helpers.c. |
1da177e4 LT |
15 | */ |
16 | ||
cfecea6e | 17 | #define __NO_FORTIFY |
1da177e4 LT |
18 | #include <linux/types.h> |
19 | #include <linux/string.h> | |
20 | #include <linux/ctype.h> | |
8bc3bcc9 PG |
21 | #include <linux/kernel.h> |
22 | #include <linux/export.h> | |
50af5ead | 23 | #include <linux/bug.h> |
8bc3bcc9 | 24 | #include <linux/errno.h> |
ce76d938 | 25 | #include <linux/slab.h> |
1da177e4 | 26 | |
291d47cc | 27 | #include <asm/unaligned.h> |
30035e45 CM |
28 | #include <asm/byteorder.h> |
29 | #include <asm/word-at-a-time.h> | |
30 | #include <asm/page.h> | |
31 | ||
cd514e72 | 32 | #ifndef __HAVE_ARCH_STRNCASECMP |
1da177e4 | 33 | /** |
cd514e72 | 34 | * strncasecmp - Case insensitive, length-limited string comparison |
1da177e4 LT |
35 | * @s1: One string |
36 | * @s2: The other string | |
37 | * @len: the maximum number of characters to compare | |
38 | */ | |
cd514e72 | 39 | int strncasecmp(const char *s1, const char *s2, size_t len) |
1da177e4 LT |
40 | { |
41 | /* Yes, Virginia, it had better be unsigned */ | |
42 | unsigned char c1, c2; | |
43 | ||
a11d2b64 AGR |
44 | if (!len) |
45 | return 0; | |
46 | ||
47 | do { | |
48 | c1 = *s1++; | |
49 | c2 = *s2++; | |
50 | if (!c1 || !c2) | |
51 | break; | |
52 | if (c1 == c2) | |
53 | continue; | |
54 | c1 = tolower(c1); | |
55 | c2 = tolower(c2); | |
56 | if (c1 != c2) | |
57 | break; | |
58 | } while (--len); | |
1da177e4 LT |
59 | return (int)c1 - (int)c2; |
60 | } | |
cd514e72 RV |
61 | EXPORT_SYMBOL(strncasecmp); |
62 | #endif | |
1da177e4 | 63 | |
ded220bd DM |
64 | #ifndef __HAVE_ARCH_STRCASECMP |
65 | int strcasecmp(const char *s1, const char *s2) | |
66 | { | |
67 | int c1, c2; | |
68 | ||
69 | do { | |
70 | c1 = tolower(*s1++); | |
71 | c2 = tolower(*s2++); | |
72 | } while (c1 == c2 && c1 != 0); | |
73 | return c1 - c2; | |
74 | } | |
75 | EXPORT_SYMBOL(strcasecmp); | |
76 | #endif | |
77 | ||
1da177e4 LT |
78 | #ifndef __HAVE_ARCH_STRCPY |
79 | /** | |
80 | * strcpy - Copy a %NUL terminated string | |
81 | * @dest: Where to copy the string to | |
82 | * @src: Where to copy the string from | |
83 | */ | |
51a0f0f6 | 84 | char *strcpy(char *dest, const char *src) |
1da177e4 LT |
85 | { |
86 | char *tmp = dest; | |
87 | ||
88 | while ((*dest++ = *src++) != '\0') | |
89 | /* nothing */; | |
90 | return tmp; | |
91 | } | |
92 | EXPORT_SYMBOL(strcpy); | |
93 | #endif | |
94 | ||
95 | #ifndef __HAVE_ARCH_STRNCPY | |
96 | /** | |
0046dd9f | 97 | * strncpy - Copy a length-limited, C-string |
1da177e4 LT |
98 | * @dest: Where to copy the string to |
99 | * @src: Where to copy the string from | |
100 | * @count: The maximum number of bytes to copy | |
101 | * | |
102 | * The result is not %NUL-terminated if the source exceeds | |
103 | * @count bytes. | |
25279526 | 104 | * |
105 | * In the case where the length of @src is less than that of | |
106 | * count, the remainder of @dest will be padded with %NUL. | |
107 | * | |
1da177e4 | 108 | */ |
51a0f0f6 | 109 | char *strncpy(char *dest, const char *src, size_t count) |
1da177e4 LT |
110 | { |
111 | char *tmp = dest; | |
112 | ||
113 | while (count) { | |
51a0f0f6 JJ |
114 | if ((*tmp = *src) != 0) |
115 | src++; | |
1da177e4 LT |
116 | tmp++; |
117 | count--; | |
118 | } | |
119 | return dest; | |
120 | } | |
121 | EXPORT_SYMBOL(strncpy); | |
122 | #endif | |
123 | ||
124 | #ifndef __HAVE_ARCH_STRLCPY | |
125 | /** | |
0046dd9f | 126 | * strlcpy - Copy a C-string into a sized buffer |
1da177e4 LT |
127 | * @dest: Where to copy the string to |
128 | * @src: Where to copy the string from | |
129 | * @size: size of destination buffer | |
130 | * | |
0e056eb5 | 131 | * Compatible with ``*BSD``: the result is always a valid |
1da177e4 LT |
132 | * NUL-terminated string that fits in the buffer (unless, |
133 | * of course, the buffer size is zero). It does not pad | |
134 | * out the result like strncpy() does. | |
135 | */ | |
136 | size_t strlcpy(char *dest, const char *src, size_t size) | |
137 | { | |
138 | size_t ret = strlen(src); | |
139 | ||
140 | if (size) { | |
51a0f0f6 | 141 | size_t len = (ret >= size) ? size - 1 : ret; |
1da177e4 LT |
142 | memcpy(dest, src, len); |
143 | dest[len] = '\0'; | |
144 | } | |
145 | return ret; | |
146 | } | |
147 | EXPORT_SYMBOL(strlcpy); | |
148 | #endif | |
149 | ||
30035e45 CM |
150 | #ifndef __HAVE_ARCH_STRSCPY |
151 | /** | |
152 | * strscpy - Copy a C-string into a sized buffer | |
153 | * @dest: Where to copy the string to | |
154 | * @src: Where to copy the string from | |
155 | * @count: Size of destination buffer | |
156 | * | |
458a3bf8 TH |
157 | * Copy the string, or as much of it as fits, into the dest buffer. The |
158 | * behavior is undefined if the string buffers overlap. The destination | |
159 | * buffer is always NUL terminated, unless it's zero-sized. | |
30035e45 CM |
160 | * |
161 | * Preferred to strlcpy() since the API doesn't require reading memory | |
162 | * from the src string beyond the specified "count" bytes, and since | |
163 | * the return value is easier to error-check than strlcpy()'s. | |
164 | * In addition, the implementation is robust to the string changing out | |
165 | * from underneath it, unlike the current strlcpy() implementation. | |
166 | * | |
167 | * Preferred to strncpy() since it always returns a valid string, and | |
168 | * doesn't unnecessarily force the tail of the destination buffer to be | |
458a3bf8 TH |
169 | * zeroed. If zeroing is desired please use strscpy_pad(). |
170 | * | |
917cda27 JP |
171 | * Returns: |
172 | * * The number of characters copied (not including the trailing %NUL) | |
173 | * * -E2BIG if count is 0 or @src was truncated. | |
30035e45 CM |
174 | */ |
175 | ssize_t strscpy(char *dest, const char *src, size_t count) | |
176 | { | |
177 | const struct word_at_a_time constants = WORD_AT_A_TIME_CONSTANTS; | |
178 | size_t max = count; | |
179 | long res = 0; | |
180 | ||
9a156466 | 181 | if (count == 0 || WARN_ON_ONCE(count > INT_MAX)) |
30035e45 CM |
182 | return -E2BIG; |
183 | ||
184 | #ifdef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS | |
185 | /* | |
186 | * If src is unaligned, don't cross a page boundary, | |
187 | * since we don't know if the next page is mapped. | |
188 | */ | |
189 | if ((long)src & (sizeof(long) - 1)) { | |
190 | size_t limit = PAGE_SIZE - ((long)src & (PAGE_SIZE - 1)); | |
191 | if (limit < max) | |
192 | max = limit; | |
193 | } | |
194 | #else | |
195 | /* If src or dest is unaligned, don't do word-at-a-time. */ | |
196 | if (((long) dest | (long) src) & (sizeof(long) - 1)) | |
197 | max = 0; | |
198 | #endif | |
199 | ||
200 | while (max >= sizeof(unsigned long)) { | |
201 | unsigned long c, data; | |
202 | ||
1a3241ff | 203 | c = read_word_at_a_time(src+res); |
30035e45 CM |
204 | if (has_zero(c, &data, &constants)) { |
205 | data = prep_zero_mask(c, data, &constants); | |
206 | data = create_zero_mask(data); | |
990486c8 | 207 | *(unsigned long *)(dest+res) = c & zero_bytemask(data); |
30035e45 CM |
208 | return res + find_zero(data); |
209 | } | |
990486c8 | 210 | *(unsigned long *)(dest+res) = c; |
30035e45 CM |
211 | res += sizeof(unsigned long); |
212 | count -= sizeof(unsigned long); | |
213 | max -= sizeof(unsigned long); | |
214 | } | |
215 | ||
216 | while (count) { | |
217 | char c; | |
218 | ||
219 | c = src[res]; | |
220 | dest[res] = c; | |
221 | if (!c) | |
222 | return res; | |
223 | res++; | |
224 | count--; | |
225 | } | |
226 | ||
227 | /* Hit buffer length without finding a NUL; force NUL-termination. */ | |
228 | if (res) | |
229 | dest[res-1] = '\0'; | |
230 | ||
231 | return -E2BIG; | |
232 | } | |
233 | EXPORT_SYMBOL(strscpy); | |
234 | #endif | |
235 | ||
1e1b6d63 ND |
236 | /** |
237 | * stpcpy - copy a string from src to dest returning a pointer to the new end | |
238 | * of dest, including src's %NUL-terminator. May overrun dest. | |
239 | * @dest: pointer to end of string being copied into. Must be large enough | |
240 | * to receive copy. | |
241 | * @src: pointer to the beginning of string being copied from. Must not overlap | |
242 | * dest. | |
243 | * | |
244 | * stpcpy differs from strcpy in a key way: the return value is a pointer | |
245 | * to the new %NUL-terminating character in @dest. (For strcpy, the return | |
246 | * value is a pointer to the start of @dest). This interface is considered | |
247 | * unsafe as it doesn't perform bounds checking of the inputs. As such it's | |
248 | * not recommended for usage. Instead, its definition is provided in case | |
249 | * the compiler lowers other libcalls to stpcpy. | |
250 | */ | |
251 | char *stpcpy(char *__restrict__ dest, const char *__restrict__ src); | |
252 | char *stpcpy(char *__restrict__ dest, const char *__restrict__ src) | |
253 | { | |
254 | while ((*dest++ = *src++) != '\0') | |
255 | /* nothing */; | |
256 | return --dest; | |
257 | } | |
258 | EXPORT_SYMBOL(stpcpy); | |
259 | ||
1da177e4 LT |
260 | #ifndef __HAVE_ARCH_STRCAT |
261 | /** | |
262 | * strcat - Append one %NUL-terminated string to another | |
263 | * @dest: The string to be appended to | |
264 | * @src: The string to append to it | |
265 | */ | |
51a0f0f6 | 266 | char *strcat(char *dest, const char *src) |
1da177e4 LT |
267 | { |
268 | char *tmp = dest; | |
269 | ||
270 | while (*dest) | |
271 | dest++; | |
272 | while ((*dest++ = *src++) != '\0') | |
273 | ; | |
1da177e4 LT |
274 | return tmp; |
275 | } | |
276 | EXPORT_SYMBOL(strcat); | |
277 | #endif | |
278 | ||
279 | #ifndef __HAVE_ARCH_STRNCAT | |
280 | /** | |
0046dd9f | 281 | * strncat - Append a length-limited, C-string to another |
1da177e4 LT |
282 | * @dest: The string to be appended to |
283 | * @src: The string to append to it | |
284 | * @count: The maximum numbers of bytes to copy | |
285 | * | |
72fd4a35 | 286 | * Note that in contrast to strncpy(), strncat() ensures the result is |
1da177e4 LT |
287 | * terminated. |
288 | */ | |
51a0f0f6 | 289 | char *strncat(char *dest, const char *src, size_t count) |
1da177e4 LT |
290 | { |
291 | char *tmp = dest; | |
292 | ||
293 | if (count) { | |
294 | while (*dest) | |
295 | dest++; | |
296 | while ((*dest++ = *src++) != 0) { | |
297 | if (--count == 0) { | |
298 | *dest = '\0'; | |
299 | break; | |
300 | } | |
301 | } | |
302 | } | |
1da177e4 LT |
303 | return tmp; |
304 | } | |
305 | EXPORT_SYMBOL(strncat); | |
306 | #endif | |
307 | ||
308 | #ifndef __HAVE_ARCH_STRLCAT | |
309 | /** | |
0046dd9f | 310 | * strlcat - Append a length-limited, C-string to another |
1da177e4 LT |
311 | * @dest: The string to be appended to |
312 | * @src: The string to append to it | |
313 | * @count: The size of the destination buffer. | |
314 | */ | |
315 | size_t strlcat(char *dest, const char *src, size_t count) | |
316 | { | |
317 | size_t dsize = strlen(dest); | |
318 | size_t len = strlen(src); | |
319 | size_t res = dsize + len; | |
320 | ||
321 | /* This would be a bug */ | |
322 | BUG_ON(dsize >= count); | |
323 | ||
324 | dest += dsize; | |
325 | count -= dsize; | |
326 | if (len >= count) | |
327 | len = count-1; | |
328 | memcpy(dest, src, len); | |
329 | dest[len] = 0; | |
330 | return res; | |
331 | } | |
332 | EXPORT_SYMBOL(strlcat); | |
333 | #endif | |
334 | ||
335 | #ifndef __HAVE_ARCH_STRCMP | |
336 | /** | |
337 | * strcmp - Compare two strings | |
338 | * @cs: One string | |
339 | * @ct: Another string | |
340 | */ | |
51a0f0f6 | 341 | int strcmp(const char *cs, const char *ct) |
1da177e4 | 342 | { |
a414f01a | 343 | unsigned char c1, c2; |
1da177e4 LT |
344 | |
345 | while (1) { | |
a414f01a LT |
346 | c1 = *cs++; |
347 | c2 = *ct++; | |
348 | if (c1 != c2) | |
349 | return c1 < c2 ? -1 : 1; | |
350 | if (!c1) | |
1da177e4 LT |
351 | break; |
352 | } | |
a414f01a | 353 | return 0; |
1da177e4 LT |
354 | } |
355 | EXPORT_SYMBOL(strcmp); | |
356 | #endif | |
357 | ||
358 | #ifndef __HAVE_ARCH_STRNCMP | |
359 | /** | |
360 | * strncmp - Compare two length-limited strings | |
361 | * @cs: One string | |
362 | * @ct: Another string | |
363 | * @count: The maximum number of bytes to compare | |
364 | */ | |
51a0f0f6 | 365 | int strncmp(const char *cs, const char *ct, size_t count) |
1da177e4 | 366 | { |
a414f01a | 367 | unsigned char c1, c2; |
1da177e4 LT |
368 | |
369 | while (count) { | |
a414f01a LT |
370 | c1 = *cs++; |
371 | c2 = *ct++; | |
372 | if (c1 != c2) | |
373 | return c1 < c2 ? -1 : 1; | |
374 | if (!c1) | |
1da177e4 LT |
375 | break; |
376 | count--; | |
377 | } | |
a414f01a | 378 | return 0; |
1da177e4 LT |
379 | } |
380 | EXPORT_SYMBOL(strncmp); | |
381 | #endif | |
382 | ||
383 | #ifndef __HAVE_ARCH_STRCHR | |
384 | /** | |
385 | * strchr - Find the first occurrence of a character in a string | |
386 | * @s: The string to be searched | |
387 | * @c: The character to search for | |
b0975710 PR |
388 | * |
389 | * Note that the %NUL-terminator is considered part of the string, and can | |
390 | * be searched for. | |
1da177e4 | 391 | */ |
51a0f0f6 | 392 | char *strchr(const char *s, int c) |
1da177e4 | 393 | { |
51a0f0f6 | 394 | for (; *s != (char)c; ++s) |
1da177e4 LT |
395 | if (*s == '\0') |
396 | return NULL; | |
51a0f0f6 | 397 | return (char *)s; |
1da177e4 LT |
398 | } |
399 | EXPORT_SYMBOL(strchr); | |
400 | #endif | |
401 | ||
11d200e9 GL |
402 | #ifndef __HAVE_ARCH_STRCHRNUL |
403 | /** | |
404 | * strchrnul - Find and return a character in a string, or end of string | |
405 | * @s: The string to be searched | |
406 | * @c: The character to search for | |
407 | * | |
408 | * Returns pointer to first occurrence of 'c' in s. If c is not found, then | |
409 | * return a pointer to the null byte at the end of s. | |
410 | */ | |
411 | char *strchrnul(const char *s, int c) | |
412 | { | |
413 | while (*s && *s != (char)c) | |
414 | s++; | |
415 | return (char *)s; | |
416 | } | |
417 | EXPORT_SYMBOL(strchrnul); | |
418 | #endif | |
419 | ||
0bee0cec YN |
420 | /** |
421 | * strnchrnul - Find and return a character in a length limited string, | |
422 | * or end of string | |
423 | * @s: The string to be searched | |
424 | * @count: The number of characters to be searched | |
425 | * @c: The character to search for | |
426 | * | |
427 | * Returns pointer to the first occurrence of 'c' in s. If c is not found, | |
428 | * then return a pointer to the last character of the string. | |
429 | */ | |
430 | char *strnchrnul(const char *s, size_t count, int c) | |
431 | { | |
432 | while (count-- && *s && *s != (char)c) | |
433 | s++; | |
434 | return (char *)s; | |
435 | } | |
436 | ||
1da177e4 LT |
437 | #ifndef __HAVE_ARCH_STRRCHR |
438 | /** | |
439 | * strrchr - Find the last occurrence of a character in a string | |
440 | * @s: The string to be searched | |
441 | * @c: The character to search for | |
442 | */ | |
51a0f0f6 | 443 | char *strrchr(const char *s, int c) |
1da177e4 | 444 | { |
8da53d45 RV |
445 | const char *last = NULL; |
446 | do { | |
447 | if (*s == (char)c) | |
448 | last = s; | |
449 | } while (*s++); | |
450 | return (char *)last; | |
1da177e4 LT |
451 | } |
452 | EXPORT_SYMBOL(strrchr); | |
453 | #endif | |
454 | ||
455 | #ifndef __HAVE_ARCH_STRNCHR | |
456 | /** | |
457 | * strnchr - Find a character in a length limited string | |
458 | * @s: The string to be searched | |
459 | * @count: The number of characters to be searched | |
460 | * @c: The character to search for | |
b0975710 PR |
461 | * |
462 | * Note that the %NUL-terminator is considered part of the string, and can | |
463 | * be searched for. | |
1da177e4 LT |
464 | */ |
465 | char *strnchr(const char *s, size_t count, int c) | |
466 | { | |
b0975710 | 467 | while (count--) { |
51a0f0f6 JJ |
468 | if (*s == (char)c) |
469 | return (char *)s; | |
b0975710 PR |
470 | if (*s++ == '\0') |
471 | break; | |
472 | } | |
1da177e4 LT |
473 | return NULL; |
474 | } | |
475 | EXPORT_SYMBOL(strnchr); | |
476 | #endif | |
477 | ||
478 | #ifndef __HAVE_ARCH_STRLEN | |
479 | /** | |
480 | * strlen - Find the length of a string | |
481 | * @s: The string to be sized | |
482 | */ | |
51a0f0f6 | 483 | size_t strlen(const char *s) |
1da177e4 LT |
484 | { |
485 | const char *sc; | |
486 | ||
487 | for (sc = s; *sc != '\0'; ++sc) | |
488 | /* nothing */; | |
489 | return sc - s; | |
490 | } | |
491 | EXPORT_SYMBOL(strlen); | |
492 | #endif | |
493 | ||
494 | #ifndef __HAVE_ARCH_STRNLEN | |
495 | /** | |
496 | * strnlen - Find the length of a length-limited string | |
497 | * @s: The string to be sized | |
498 | * @count: The maximum number of bytes to search | |
499 | */ | |
51a0f0f6 | 500 | size_t strnlen(const char *s, size_t count) |
1da177e4 LT |
501 | { |
502 | const char *sc; | |
503 | ||
504 | for (sc = s; count-- && *sc != '\0'; ++sc) | |
505 | /* nothing */; | |
506 | return sc - s; | |
507 | } | |
508 | EXPORT_SYMBOL(strnlen); | |
509 | #endif | |
510 | ||
511 | #ifndef __HAVE_ARCH_STRSPN | |
512 | /** | |
72fd4a35 | 513 | * strspn - Calculate the length of the initial substring of @s which only contain letters in @accept |
1da177e4 LT |
514 | * @s: The string to be searched |
515 | * @accept: The string to search for | |
516 | */ | |
517 | size_t strspn(const char *s, const char *accept) | |
518 | { | |
519 | const char *p; | |
1da177e4 LT |
520 | |
521 | for (p = s; *p != '\0'; ++p) { | |
dffad91b RV |
522 | if (!strchr(accept, *p)) |
523 | break; | |
1da177e4 | 524 | } |
dffad91b | 525 | return p - s; |
1da177e4 | 526 | } |
1da177e4 LT |
527 | EXPORT_SYMBOL(strspn); |
528 | #endif | |
529 | ||
8833d328 | 530 | #ifndef __HAVE_ARCH_STRCSPN |
1da177e4 | 531 | /** |
72fd4a35 | 532 | * strcspn - Calculate the length of the initial substring of @s which does not contain letters in @reject |
1da177e4 LT |
533 | * @s: The string to be searched |
534 | * @reject: The string to avoid | |
535 | */ | |
536 | size_t strcspn(const char *s, const char *reject) | |
537 | { | |
538 | const char *p; | |
1da177e4 LT |
539 | |
540 | for (p = s; *p != '\0'; ++p) { | |
dffad91b RV |
541 | if (strchr(reject, *p)) |
542 | break; | |
1da177e4 | 543 | } |
dffad91b | 544 | return p - s; |
51a0f0f6 | 545 | } |
1da177e4 | 546 | EXPORT_SYMBOL(strcspn); |
8833d328 | 547 | #endif |
1da177e4 LT |
548 | |
549 | #ifndef __HAVE_ARCH_STRPBRK | |
550 | /** | |
551 | * strpbrk - Find the first occurrence of a set of characters | |
552 | * @cs: The string to be searched | |
553 | * @ct: The characters to search for | |
554 | */ | |
51a0f0f6 | 555 | char *strpbrk(const char *cs, const char *ct) |
1da177e4 | 556 | { |
51a0f0f6 | 557 | const char *sc1, *sc2; |
1da177e4 | 558 | |
51a0f0f6 JJ |
559 | for (sc1 = cs; *sc1 != '\0'; ++sc1) { |
560 | for (sc2 = ct; *sc2 != '\0'; ++sc2) { | |
1da177e4 | 561 | if (*sc1 == *sc2) |
51a0f0f6 | 562 | return (char *)sc1; |
1da177e4 LT |
563 | } |
564 | } | |
565 | return NULL; | |
566 | } | |
894b5779 | 567 | EXPORT_SYMBOL(strpbrk); |
1da177e4 LT |
568 | #endif |
569 | ||
570 | #ifndef __HAVE_ARCH_STRSEP | |
571 | /** | |
572 | * strsep - Split a string into tokens | |
573 | * @s: The string to be searched | |
574 | * @ct: The characters to search for | |
575 | * | |
576 | * strsep() updates @s to point after the token, ready for the next call. | |
577 | * | |
578 | * It returns empty tokens, too, behaving exactly like the libc function | |
579 | * of that name. In fact, it was stolen from glibc2 and de-fancy-fied. | |
580 | * Same semantics, slimmer shape. ;) | |
581 | */ | |
51a0f0f6 | 582 | char *strsep(char **s, const char *ct) |
1da177e4 | 583 | { |
51a0f0f6 JJ |
584 | char *sbegin = *s; |
585 | char *end; | |
1da177e4 LT |
586 | |
587 | if (sbegin == NULL) | |
588 | return NULL; | |
589 | ||
590 | end = strpbrk(sbegin, ct); | |
591 | if (end) | |
592 | *end++ = '\0'; | |
593 | *s = end; | |
1da177e4 LT |
594 | return sbegin; |
595 | } | |
1da177e4 LT |
596 | EXPORT_SYMBOL(strsep); |
597 | #endif | |
598 | ||
599 | #ifndef __HAVE_ARCH_MEMSET | |
600 | /** | |
601 | * memset - Fill a region of memory with the given value | |
602 | * @s: Pointer to the start of the area. | |
603 | * @c: The byte to fill the area with | |
604 | * @count: The size of the area. | |
605 | * | |
606 | * Do not use memset() to access IO space, use memset_io() instead. | |
607 | */ | |
51a0f0f6 | 608 | void *memset(void *s, int c, size_t count) |
1da177e4 | 609 | { |
850b9247 | 610 | char *xs = s; |
1da177e4 LT |
611 | |
612 | while (count--) | |
613 | *xs++ = c; | |
1da177e4 LT |
614 | return s; |
615 | } | |
616 | EXPORT_SYMBOL(memset); | |
617 | #endif | |
618 | ||
3b3c4bab MW |
619 | #ifndef __HAVE_ARCH_MEMSET16 |
620 | /** | |
621 | * memset16() - Fill a memory area with a uint16_t | |
622 | * @s: Pointer to the start of the area. | |
623 | * @v: The value to fill the area with | |
624 | * @count: The number of values to store | |
625 | * | |
626 | * Differs from memset() in that it fills with a uint16_t instead | |
627 | * of a byte. Remember that @count is the number of uint16_ts to | |
628 | * store, not the number of bytes. | |
629 | */ | |
630 | void *memset16(uint16_t *s, uint16_t v, size_t count) | |
631 | { | |
632 | uint16_t *xs = s; | |
633 | ||
634 | while (count--) | |
635 | *xs++ = v; | |
636 | return s; | |
637 | } | |
638 | EXPORT_SYMBOL(memset16); | |
639 | #endif | |
640 | ||
641 | #ifndef __HAVE_ARCH_MEMSET32 | |
642 | /** | |
643 | * memset32() - Fill a memory area with a uint32_t | |
644 | * @s: Pointer to the start of the area. | |
645 | * @v: The value to fill the area with | |
646 | * @count: The number of values to store | |
647 | * | |
648 | * Differs from memset() in that it fills with a uint32_t instead | |
649 | * of a byte. Remember that @count is the number of uint32_ts to | |
650 | * store, not the number of bytes. | |
651 | */ | |
652 | void *memset32(uint32_t *s, uint32_t v, size_t count) | |
653 | { | |
654 | uint32_t *xs = s; | |
655 | ||
656 | while (count--) | |
657 | *xs++ = v; | |
658 | return s; | |
659 | } | |
660 | EXPORT_SYMBOL(memset32); | |
661 | #endif | |
662 | ||
663 | #ifndef __HAVE_ARCH_MEMSET64 | |
664 | /** | |
665 | * memset64() - Fill a memory area with a uint64_t | |
666 | * @s: Pointer to the start of the area. | |
667 | * @v: The value to fill the area with | |
668 | * @count: The number of values to store | |
669 | * | |
670 | * Differs from memset() in that it fills with a uint64_t instead | |
671 | * of a byte. Remember that @count is the number of uint64_ts to | |
672 | * store, not the number of bytes. | |
673 | */ | |
674 | void *memset64(uint64_t *s, uint64_t v, size_t count) | |
675 | { | |
676 | uint64_t *xs = s; | |
677 | ||
678 | while (count--) | |
679 | *xs++ = v; | |
680 | return s; | |
681 | } | |
682 | EXPORT_SYMBOL(memset64); | |
683 | #endif | |
684 | ||
1da177e4 LT |
685 | #ifndef __HAVE_ARCH_MEMCPY |
686 | /** | |
687 | * memcpy - Copy one area of memory to another | |
688 | * @dest: Where to copy to | |
689 | * @src: Where to copy from | |
690 | * @count: The size of the area. | |
691 | * | |
692 | * You should not use this function to access IO space, use memcpy_toio() | |
693 | * or memcpy_fromio() instead. | |
694 | */ | |
51a0f0f6 | 695 | void *memcpy(void *dest, const void *src, size_t count) |
1da177e4 | 696 | { |
850b9247 | 697 | char *tmp = dest; |
4c416ab7 | 698 | const char *s = src; |
1da177e4 LT |
699 | |
700 | while (count--) | |
701 | *tmp++ = *s++; | |
1da177e4 LT |
702 | return dest; |
703 | } | |
704 | EXPORT_SYMBOL(memcpy); | |
705 | #endif | |
706 | ||
707 | #ifndef __HAVE_ARCH_MEMMOVE | |
708 | /** | |
709 | * memmove - Copy one area of memory to another | |
710 | * @dest: Where to copy to | |
711 | * @src: Where to copy from | |
712 | * @count: The size of the area. | |
713 | * | |
714 | * Unlike memcpy(), memmove() copes with overlapping areas. | |
715 | */ | |
51a0f0f6 | 716 | void *memmove(void *dest, const void *src, size_t count) |
1da177e4 | 717 | { |
82da2c37 PJ |
718 | char *tmp; |
719 | const char *s; | |
1da177e4 LT |
720 | |
721 | if (dest <= src) { | |
850b9247 JJ |
722 | tmp = dest; |
723 | s = src; | |
1da177e4 LT |
724 | while (count--) |
725 | *tmp++ = *s++; | |
51a0f0f6 | 726 | } else { |
850b9247 JJ |
727 | tmp = dest; |
728 | tmp += count; | |
729 | s = src; | |
730 | s += count; | |
1da177e4 LT |
731 | while (count--) |
732 | *--tmp = *--s; | |
51a0f0f6 | 733 | } |
1da177e4 LT |
734 | return dest; |
735 | } | |
736 | EXPORT_SYMBOL(memmove); | |
737 | #endif | |
738 | ||
739 | #ifndef __HAVE_ARCH_MEMCMP | |
740 | /** | |
741 | * memcmp - Compare two areas of memory | |
742 | * @cs: One area of memory | |
743 | * @ct: Another area of memory | |
744 | * @count: The size of the area. | |
745 | */ | |
0c28130b | 746 | #undef memcmp |
a7330c99 | 747 | __visible int memcmp(const void *cs, const void *ct, size_t count) |
1da177e4 LT |
748 | { |
749 | const unsigned char *su1, *su2; | |
750 | int res = 0; | |
751 | ||
291d47cc LT |
752 | #ifdef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS |
753 | if (count >= sizeof(unsigned long)) { | |
754 | const unsigned long *u1 = cs; | |
755 | const unsigned long *u2 = ct; | |
756 | do { | |
757 | if (get_unaligned(u1) != get_unaligned(u2)) | |
758 | break; | |
759 | u1++; | |
760 | u2++; | |
761 | count -= sizeof(unsigned long); | |
762 | } while (count >= sizeof(unsigned long)); | |
763 | cs = u1; | |
764 | ct = u2; | |
765 | } | |
766 | #endif | |
51a0f0f6 | 767 | for (su1 = cs, su2 = ct; 0 < count; ++su1, ++su2, count--) |
1da177e4 LT |
768 | if ((res = *su1 - *su2) != 0) |
769 | break; | |
770 | return res; | |
771 | } | |
772 | EXPORT_SYMBOL(memcmp); | |
773 | #endif | |
774 | ||
5f074f3e ND |
775 | #ifndef __HAVE_ARCH_BCMP |
776 | /** | |
777 | * bcmp - returns 0 if and only if the buffers have identical contents. | |
778 | * @a: pointer to first buffer. | |
779 | * @b: pointer to second buffer. | |
780 | * @len: size of buffers. | |
781 | * | |
782 | * The sign or magnitude of a non-zero return value has no particular | |
783 | * meaning, and architectures may implement their own more efficient bcmp(). So | |
784 | * while this particular implementation is a simple (tail) call to memcmp, do | |
785 | * not rely on anything but whether the return value is zero or non-zero. | |
786 | */ | |
5f074f3e ND |
787 | int bcmp(const void *a, const void *b, size_t len) |
788 | { | |
789 | return memcmp(a, b, len); | |
790 | } | |
791 | EXPORT_SYMBOL(bcmp); | |
792 | #endif | |
793 | ||
1da177e4 LT |
794 | #ifndef __HAVE_ARCH_MEMSCAN |
795 | /** | |
796 | * memscan - Find a character in an area of memory. | |
797 | * @addr: The memory area | |
798 | * @c: The byte to search for | |
799 | * @size: The size of the area. | |
800 | * | |
801 | * returns the address of the first occurrence of @c, or 1 byte past | |
802 | * the area if @c is not found | |
803 | */ | |
51a0f0f6 | 804 | void *memscan(void *addr, int c, size_t size) |
1da177e4 | 805 | { |
850b9247 | 806 | unsigned char *p = addr; |
1da177e4 LT |
807 | |
808 | while (size) { | |
1a58be62 | 809 | if (*p == (unsigned char)c) |
51a0f0f6 | 810 | return (void *)p; |
1da177e4 LT |
811 | p++; |
812 | size--; | |
813 | } | |
51a0f0f6 | 814 | return (void *)p; |
1da177e4 LT |
815 | } |
816 | EXPORT_SYMBOL(memscan); | |
817 | #endif | |
818 | ||
819 | #ifndef __HAVE_ARCH_STRSTR | |
820 | /** | |
821 | * strstr - Find the first substring in a %NUL terminated string | |
822 | * @s1: The string to be searched | |
823 | * @s2: The string to search for | |
824 | */ | |
51a0f0f6 | 825 | char *strstr(const char *s1, const char *s2) |
1da177e4 | 826 | { |
d5f1fb53 | 827 | size_t l1, l2; |
1da177e4 LT |
828 | |
829 | l2 = strlen(s2); | |
830 | if (!l2) | |
51a0f0f6 | 831 | return (char *)s1; |
1da177e4 LT |
832 | l1 = strlen(s1); |
833 | while (l1 >= l2) { | |
834 | l1--; | |
51a0f0f6 JJ |
835 | if (!memcmp(s1, s2, l2)) |
836 | return (char *)s1; | |
1da177e4 LT |
837 | s1++; |
838 | } | |
839 | return NULL; | |
840 | } | |
841 | EXPORT_SYMBOL(strstr); | |
842 | #endif | |
843 | ||
d5f1fb53 LZ |
844 | #ifndef __HAVE_ARCH_STRNSTR |
845 | /** | |
846 | * strnstr - Find the first substring in a length-limited string | |
847 | * @s1: The string to be searched | |
848 | * @s2: The string to search for | |
849 | * @len: the maximum number of characters to search | |
850 | */ | |
851 | char *strnstr(const char *s1, const char *s2, size_t len) | |
852 | { | |
d6a2eedf | 853 | size_t l2; |
d5f1fb53 LZ |
854 | |
855 | l2 = strlen(s2); | |
856 | if (!l2) | |
857 | return (char *)s1; | |
d6a2eedf AGR |
858 | while (len >= l2) { |
859 | len--; | |
d5f1fb53 LZ |
860 | if (!memcmp(s1, s2, l2)) |
861 | return (char *)s1; | |
862 | s1++; | |
863 | } | |
864 | return NULL; | |
865 | } | |
866 | EXPORT_SYMBOL(strnstr); | |
867 | #endif | |
868 | ||
1da177e4 LT |
869 | #ifndef __HAVE_ARCH_MEMCHR |
870 | /** | |
871 | * memchr - Find a character in an area of memory. | |
872 | * @s: The memory area | |
873 | * @c: The byte to search for | |
874 | * @n: The size of the area. | |
875 | * | |
876 | * returns the address of the first occurrence of @c, or %NULL | |
877 | * if @c is not found | |
878 | */ | |
879 | void *memchr(const void *s, int c, size_t n) | |
880 | { | |
881 | const unsigned char *p = s; | |
882 | while (n-- != 0) { | |
883 | if ((unsigned char)c == *p++) { | |
51a0f0f6 | 884 | return (void *)(p - 1); |
1da177e4 LT |
885 | } |
886 | } | |
887 | return NULL; | |
888 | } | |
889 | EXPORT_SYMBOL(memchr); | |
890 | #endif | |
79824820 AM |
891 | |
892 | static void *check_bytes8(const u8 *start, u8 value, unsigned int bytes) | |
893 | { | |
894 | while (bytes) { | |
895 | if (*start != value) | |
896 | return (void *)start; | |
897 | start++; | |
898 | bytes--; | |
899 | } | |
900 | return NULL; | |
901 | } | |
902 | ||
903 | /** | |
904 | * memchr_inv - Find an unmatching character in an area of memory. | |
905 | * @start: The memory area | |
906 | * @c: Find a character other than c | |
907 | * @bytes: The size of the area. | |
908 | * | |
909 | * returns the address of the first character other than @c, or %NULL | |
910 | * if the whole buffer contains just @c. | |
911 | */ | |
912 | void *memchr_inv(const void *start, int c, size_t bytes) | |
913 | { | |
914 | u8 value = c; | |
915 | u64 value64; | |
916 | unsigned int words, prefix; | |
917 | ||
918 | if (bytes <= 16) | |
919 | return check_bytes8(start, value, bytes); | |
920 | ||
f43804bf | 921 | value64 = value; |
72d93104 | 922 | #if defined(CONFIG_ARCH_HAS_FAST_MULTIPLIER) && BITS_PER_LONG == 64 |
3368e8fb | 923 | value64 *= 0x0101010101010101ULL; |
72d93104 | 924 | #elif defined(CONFIG_ARCH_HAS_FAST_MULTIPLIER) |
f43804bf AM |
925 | value64 *= 0x01010101; |
926 | value64 |= value64 << 32; | |
927 | #else | |
928 | value64 |= value64 << 8; | |
929 | value64 |= value64 << 16; | |
930 | value64 |= value64 << 32; | |
931 | #endif | |
79824820 | 932 | |
f43804bf | 933 | prefix = (unsigned long)start % 8; |
79824820 | 934 | if (prefix) { |
f43804bf AM |
935 | u8 *r; |
936 | ||
937 | prefix = 8 - prefix; | |
938 | r = check_bytes8(start, value, prefix); | |
79824820 AM |
939 | if (r) |
940 | return r; | |
941 | start += prefix; | |
942 | bytes -= prefix; | |
943 | } | |
944 | ||
945 | words = bytes / 8; | |
946 | ||
947 | while (words) { | |
948 | if (*(u64 *)start != value64) | |
949 | return check_bytes8(start, value, 8); | |
950 | start += 8; | |
951 | words--; | |
952 | } | |
953 | ||
954 | return check_bytes8(start, value, bytes % 8); | |
955 | } | |
956 | EXPORT_SYMBOL(memchr_inv); |