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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 | /* | |
9 | * stupid library routines.. The optimized versions should generally be found | |
10 | * as inline code in <asm-xx/string.h> | |
11 | * | |
12 | * These are buggy as well.. | |
13 | * | |
14 | * * Fri Jun 25 1999, Ingo Oeser <ioe@informatik.tu-chemnitz.de> | |
15 | * - Added strsep() which will replace strtok() soon (because strsep() is | |
16 | * reentrant and should be faster). Use only strsep() in new code, please. | |
17 | * | |
18 | * * Sat Feb 09 2002, Jason Thomas <jason@topic.com.au>, | |
19 | * Matthew Hawkins <matt@mh.dropbear.id.au> | |
20 | * - Kissed strtok() goodbye | |
21 | */ | |
22 | ||
23 | #include <linux/types.h> | |
24 | #include <linux/string.h> | |
25 | #include <linux/ctype.h> | |
8bc3bcc9 PG |
26 | #include <linux/kernel.h> |
27 | #include <linux/export.h> | |
50af5ead | 28 | #include <linux/bug.h> |
8bc3bcc9 | 29 | #include <linux/errno.h> |
ce76d938 | 30 | #include <linux/slab.h> |
1da177e4 | 31 | |
30035e45 CM |
32 | #include <asm/byteorder.h> |
33 | #include <asm/word-at-a-time.h> | |
34 | #include <asm/page.h> | |
35 | ||
cd514e72 | 36 | #ifndef __HAVE_ARCH_STRNCASECMP |
1da177e4 | 37 | /** |
cd514e72 | 38 | * strncasecmp - Case insensitive, length-limited string comparison |
1da177e4 LT |
39 | * @s1: One string |
40 | * @s2: The other string | |
41 | * @len: the maximum number of characters to compare | |
42 | */ | |
cd514e72 | 43 | int strncasecmp(const char *s1, const char *s2, size_t len) |
1da177e4 LT |
44 | { |
45 | /* Yes, Virginia, it had better be unsigned */ | |
46 | unsigned char c1, c2; | |
47 | ||
a11d2b64 AGR |
48 | if (!len) |
49 | return 0; | |
50 | ||
51 | do { | |
52 | c1 = *s1++; | |
53 | c2 = *s2++; | |
54 | if (!c1 || !c2) | |
55 | break; | |
56 | if (c1 == c2) | |
57 | continue; | |
58 | c1 = tolower(c1); | |
59 | c2 = tolower(c2); | |
60 | if (c1 != c2) | |
61 | break; | |
62 | } while (--len); | |
1da177e4 LT |
63 | return (int)c1 - (int)c2; |
64 | } | |
cd514e72 RV |
65 | EXPORT_SYMBOL(strncasecmp); |
66 | #endif | |
1da177e4 | 67 | |
ded220bd DM |
68 | #ifndef __HAVE_ARCH_STRCASECMP |
69 | int strcasecmp(const char *s1, const char *s2) | |
70 | { | |
71 | int c1, c2; | |
72 | ||
73 | do { | |
74 | c1 = tolower(*s1++); | |
75 | c2 = tolower(*s2++); | |
76 | } while (c1 == c2 && c1 != 0); | |
77 | return c1 - c2; | |
78 | } | |
79 | EXPORT_SYMBOL(strcasecmp); | |
80 | #endif | |
81 | ||
1da177e4 LT |
82 | #ifndef __HAVE_ARCH_STRCPY |
83 | /** | |
84 | * strcpy - Copy a %NUL terminated string | |
85 | * @dest: Where to copy the string to | |
86 | * @src: Where to copy the string from | |
87 | */ | |
51a0f0f6 | 88 | char *strcpy(char *dest, const char *src) |
1da177e4 LT |
89 | { |
90 | char *tmp = dest; | |
91 | ||
92 | while ((*dest++ = *src++) != '\0') | |
93 | /* nothing */; | |
94 | return tmp; | |
95 | } | |
96 | EXPORT_SYMBOL(strcpy); | |
97 | #endif | |
98 | ||
99 | #ifndef __HAVE_ARCH_STRNCPY | |
100 | /** | |
0046dd9f | 101 | * strncpy - Copy a length-limited, C-string |
1da177e4 LT |
102 | * @dest: Where to copy the string to |
103 | * @src: Where to copy the string from | |
104 | * @count: The maximum number of bytes to copy | |
105 | * | |
106 | * The result is not %NUL-terminated if the source exceeds | |
107 | * @count bytes. | |
25279526 | 108 | * |
109 | * In the case where the length of @src is less than that of | |
110 | * count, the remainder of @dest will be padded with %NUL. | |
111 | * | |
1da177e4 | 112 | */ |
51a0f0f6 | 113 | char *strncpy(char *dest, const char *src, size_t count) |
1da177e4 LT |
114 | { |
115 | char *tmp = dest; | |
116 | ||
117 | while (count) { | |
51a0f0f6 JJ |
118 | if ((*tmp = *src) != 0) |
119 | src++; | |
1da177e4 LT |
120 | tmp++; |
121 | count--; | |
122 | } | |
123 | return dest; | |
124 | } | |
125 | EXPORT_SYMBOL(strncpy); | |
126 | #endif | |
127 | ||
128 | #ifndef __HAVE_ARCH_STRLCPY | |
129 | /** | |
0046dd9f | 130 | * strlcpy - Copy a C-string into a sized buffer |
1da177e4 LT |
131 | * @dest: Where to copy the string to |
132 | * @src: Where to copy the string from | |
133 | * @size: size of destination buffer | |
134 | * | |
0e056eb5 | 135 | * Compatible with ``*BSD``: the result is always a valid |
1da177e4 LT |
136 | * NUL-terminated string that fits in the buffer (unless, |
137 | * of course, the buffer size is zero). It does not pad | |
138 | * out the result like strncpy() does. | |
139 | */ | |
140 | size_t strlcpy(char *dest, const char *src, size_t size) | |
141 | { | |
142 | size_t ret = strlen(src); | |
143 | ||
144 | if (size) { | |
51a0f0f6 | 145 | size_t len = (ret >= size) ? size - 1 : ret; |
1da177e4 LT |
146 | memcpy(dest, src, len); |
147 | dest[len] = '\0'; | |
148 | } | |
149 | return ret; | |
150 | } | |
151 | EXPORT_SYMBOL(strlcpy); | |
152 | #endif | |
153 | ||
30035e45 CM |
154 | #ifndef __HAVE_ARCH_STRSCPY |
155 | /** | |
156 | * strscpy - Copy a C-string into a sized buffer | |
157 | * @dest: Where to copy the string to | |
158 | * @src: Where to copy the string from | |
159 | * @count: Size of destination buffer | |
160 | * | |
458a3bf8 TH |
161 | * Copy the string, or as much of it as fits, into the dest buffer. The |
162 | * behavior is undefined if the string buffers overlap. The destination | |
163 | * buffer is always NUL terminated, unless it's zero-sized. | |
30035e45 CM |
164 | * |
165 | * Preferred to strlcpy() since the API doesn't require reading memory | |
166 | * from the src string beyond the specified "count" bytes, and since | |
167 | * the return value is easier to error-check than strlcpy()'s. | |
168 | * In addition, the implementation is robust to the string changing out | |
169 | * from underneath it, unlike the current strlcpy() implementation. | |
170 | * | |
171 | * Preferred to strncpy() since it always returns a valid string, and | |
172 | * doesn't unnecessarily force the tail of the destination buffer to be | |
458a3bf8 TH |
173 | * zeroed. If zeroing is desired please use strscpy_pad(). |
174 | * | |
917cda27 JP |
175 | * Returns: |
176 | * * The number of characters copied (not including the trailing %NUL) | |
177 | * * -E2BIG if count is 0 or @src was truncated. | |
30035e45 CM |
178 | */ |
179 | ssize_t strscpy(char *dest, const char *src, size_t count) | |
180 | { | |
181 | const struct word_at_a_time constants = WORD_AT_A_TIME_CONSTANTS; | |
182 | size_t max = count; | |
183 | long res = 0; | |
184 | ||
9a156466 | 185 | if (count == 0 || WARN_ON_ONCE(count > INT_MAX)) |
30035e45 CM |
186 | return -E2BIG; |
187 | ||
188 | #ifdef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS | |
189 | /* | |
190 | * If src is unaligned, don't cross a page boundary, | |
191 | * since we don't know if the next page is mapped. | |
192 | */ | |
193 | if ((long)src & (sizeof(long) - 1)) { | |
194 | size_t limit = PAGE_SIZE - ((long)src & (PAGE_SIZE - 1)); | |
195 | if (limit < max) | |
196 | max = limit; | |
197 | } | |
198 | #else | |
199 | /* If src or dest is unaligned, don't do word-at-a-time. */ | |
200 | if (((long) dest | (long) src) & (sizeof(long) - 1)) | |
201 | max = 0; | |
202 | #endif | |
203 | ||
204 | while (max >= sizeof(unsigned long)) { | |
205 | unsigned long c, data; | |
206 | ||
1a3241ff | 207 | c = read_word_at_a_time(src+res); |
30035e45 CM |
208 | if (has_zero(c, &data, &constants)) { |
209 | data = prep_zero_mask(c, data, &constants); | |
210 | data = create_zero_mask(data); | |
990486c8 | 211 | *(unsigned long *)(dest+res) = c & zero_bytemask(data); |
30035e45 CM |
212 | return res + find_zero(data); |
213 | } | |
990486c8 | 214 | *(unsigned long *)(dest+res) = c; |
30035e45 CM |
215 | res += sizeof(unsigned long); |
216 | count -= sizeof(unsigned long); | |
217 | max -= sizeof(unsigned long); | |
218 | } | |
219 | ||
220 | while (count) { | |
221 | char c; | |
222 | ||
223 | c = src[res]; | |
224 | dest[res] = c; | |
225 | if (!c) | |
226 | return res; | |
227 | res++; | |
228 | count--; | |
229 | } | |
230 | ||
231 | /* Hit buffer length without finding a NUL; force NUL-termination. */ | |
232 | if (res) | |
233 | dest[res-1] = '\0'; | |
234 | ||
235 | return -E2BIG; | |
236 | } | |
237 | EXPORT_SYMBOL(strscpy); | |
238 | #endif | |
239 | ||
458a3bf8 TH |
240 | /** |
241 | * strscpy_pad() - Copy a C-string into a sized buffer | |
242 | * @dest: Where to copy the string to | |
243 | * @src: Where to copy the string from | |
244 | * @count: Size of destination buffer | |
245 | * | |
246 | * Copy the string, or as much of it as fits, into the dest buffer. The | |
247 | * behavior is undefined if the string buffers overlap. The destination | |
248 | * buffer is always %NUL terminated, unless it's zero-sized. | |
249 | * | |
250 | * If the source string is shorter than the destination buffer, zeros | |
251 | * the tail of the destination buffer. | |
252 | * | |
253 | * For full explanation of why you may want to consider using the | |
254 | * 'strscpy' functions please see the function docstring for strscpy(). | |
255 | * | |
917cda27 JP |
256 | * Returns: |
257 | * * The number of characters copied (not including the trailing %NUL) | |
258 | * * -E2BIG if count is 0 or @src was truncated. | |
458a3bf8 TH |
259 | */ |
260 | ssize_t strscpy_pad(char *dest, const char *src, size_t count) | |
261 | { | |
262 | ssize_t written; | |
263 | ||
264 | written = strscpy(dest, src, count); | |
265 | if (written < 0 || written == count - 1) | |
266 | return written; | |
267 | ||
268 | memset(dest + written + 1, 0, count - written - 1); | |
269 | ||
270 | return written; | |
271 | } | |
272 | EXPORT_SYMBOL(strscpy_pad); | |
273 | ||
1e1b6d63 ND |
274 | /** |
275 | * stpcpy - copy a string from src to dest returning a pointer to the new end | |
276 | * of dest, including src's %NUL-terminator. May overrun dest. | |
277 | * @dest: pointer to end of string being copied into. Must be large enough | |
278 | * to receive copy. | |
279 | * @src: pointer to the beginning of string being copied from. Must not overlap | |
280 | * dest. | |
281 | * | |
282 | * stpcpy differs from strcpy in a key way: the return value is a pointer | |
283 | * to the new %NUL-terminating character in @dest. (For strcpy, the return | |
284 | * value is a pointer to the start of @dest). This interface is considered | |
285 | * unsafe as it doesn't perform bounds checking of the inputs. As such it's | |
286 | * not recommended for usage. Instead, its definition is provided in case | |
287 | * the compiler lowers other libcalls to stpcpy. | |
288 | */ | |
289 | char *stpcpy(char *__restrict__ dest, const char *__restrict__ src); | |
290 | char *stpcpy(char *__restrict__ dest, const char *__restrict__ src) | |
291 | { | |
292 | while ((*dest++ = *src++) != '\0') | |
293 | /* nothing */; | |
294 | return --dest; | |
295 | } | |
296 | EXPORT_SYMBOL(stpcpy); | |
297 | ||
1da177e4 LT |
298 | #ifndef __HAVE_ARCH_STRCAT |
299 | /** | |
300 | * strcat - Append one %NUL-terminated string to another | |
301 | * @dest: The string to be appended to | |
302 | * @src: The string to append to it | |
303 | */ | |
51a0f0f6 | 304 | char *strcat(char *dest, const char *src) |
1da177e4 LT |
305 | { |
306 | char *tmp = dest; | |
307 | ||
308 | while (*dest) | |
309 | dest++; | |
310 | while ((*dest++ = *src++) != '\0') | |
311 | ; | |
1da177e4 LT |
312 | return tmp; |
313 | } | |
314 | EXPORT_SYMBOL(strcat); | |
315 | #endif | |
316 | ||
317 | #ifndef __HAVE_ARCH_STRNCAT | |
318 | /** | |
0046dd9f | 319 | * strncat - Append a length-limited, C-string to another |
1da177e4 LT |
320 | * @dest: The string to be appended to |
321 | * @src: The string to append to it | |
322 | * @count: The maximum numbers of bytes to copy | |
323 | * | |
72fd4a35 | 324 | * Note that in contrast to strncpy(), strncat() ensures the result is |
1da177e4 LT |
325 | * terminated. |
326 | */ | |
51a0f0f6 | 327 | char *strncat(char *dest, const char *src, size_t count) |
1da177e4 LT |
328 | { |
329 | char *tmp = dest; | |
330 | ||
331 | if (count) { | |
332 | while (*dest) | |
333 | dest++; | |
334 | while ((*dest++ = *src++) != 0) { | |
335 | if (--count == 0) { | |
336 | *dest = '\0'; | |
337 | break; | |
338 | } | |
339 | } | |
340 | } | |
1da177e4 LT |
341 | return tmp; |
342 | } | |
343 | EXPORT_SYMBOL(strncat); | |
344 | #endif | |
345 | ||
346 | #ifndef __HAVE_ARCH_STRLCAT | |
347 | /** | |
0046dd9f | 348 | * strlcat - Append a length-limited, C-string to another |
1da177e4 LT |
349 | * @dest: The string to be appended to |
350 | * @src: The string to append to it | |
351 | * @count: The size of the destination buffer. | |
352 | */ | |
353 | size_t strlcat(char *dest, const char *src, size_t count) | |
354 | { | |
355 | size_t dsize = strlen(dest); | |
356 | size_t len = strlen(src); | |
357 | size_t res = dsize + len; | |
358 | ||
359 | /* This would be a bug */ | |
360 | BUG_ON(dsize >= count); | |
361 | ||
362 | dest += dsize; | |
363 | count -= dsize; | |
364 | if (len >= count) | |
365 | len = count-1; | |
366 | memcpy(dest, src, len); | |
367 | dest[len] = 0; | |
368 | return res; | |
369 | } | |
370 | EXPORT_SYMBOL(strlcat); | |
371 | #endif | |
372 | ||
373 | #ifndef __HAVE_ARCH_STRCMP | |
374 | /** | |
375 | * strcmp - Compare two strings | |
376 | * @cs: One string | |
377 | * @ct: Another string | |
378 | */ | |
51a0f0f6 | 379 | int strcmp(const char *cs, const char *ct) |
1da177e4 | 380 | { |
a414f01a | 381 | unsigned char c1, c2; |
1da177e4 LT |
382 | |
383 | while (1) { | |
a414f01a LT |
384 | c1 = *cs++; |
385 | c2 = *ct++; | |
386 | if (c1 != c2) | |
387 | return c1 < c2 ? -1 : 1; | |
388 | if (!c1) | |
1da177e4 LT |
389 | break; |
390 | } | |
a414f01a | 391 | return 0; |
1da177e4 LT |
392 | } |
393 | EXPORT_SYMBOL(strcmp); | |
394 | #endif | |
395 | ||
396 | #ifndef __HAVE_ARCH_STRNCMP | |
397 | /** | |
398 | * strncmp - Compare two length-limited strings | |
399 | * @cs: One string | |
400 | * @ct: Another string | |
401 | * @count: The maximum number of bytes to compare | |
402 | */ | |
51a0f0f6 | 403 | int strncmp(const char *cs, const char *ct, size_t count) |
1da177e4 | 404 | { |
a414f01a | 405 | unsigned char c1, c2; |
1da177e4 LT |
406 | |
407 | while (count) { | |
a414f01a LT |
408 | c1 = *cs++; |
409 | c2 = *ct++; | |
410 | if (c1 != c2) | |
411 | return c1 < c2 ? -1 : 1; | |
412 | if (!c1) | |
1da177e4 LT |
413 | break; |
414 | count--; | |
415 | } | |
a414f01a | 416 | return 0; |
1da177e4 LT |
417 | } |
418 | EXPORT_SYMBOL(strncmp); | |
419 | #endif | |
420 | ||
421 | #ifndef __HAVE_ARCH_STRCHR | |
422 | /** | |
423 | * strchr - Find the first occurrence of a character in a string | |
424 | * @s: The string to be searched | |
425 | * @c: The character to search for | |
b0975710 PR |
426 | * |
427 | * Note that the %NUL-terminator is considered part of the string, and can | |
428 | * be searched for. | |
1da177e4 | 429 | */ |
51a0f0f6 | 430 | char *strchr(const char *s, int c) |
1da177e4 | 431 | { |
51a0f0f6 | 432 | for (; *s != (char)c; ++s) |
1da177e4 LT |
433 | if (*s == '\0') |
434 | return NULL; | |
51a0f0f6 | 435 | return (char *)s; |
1da177e4 LT |
436 | } |
437 | EXPORT_SYMBOL(strchr); | |
438 | #endif | |
439 | ||
11d200e9 GL |
440 | #ifndef __HAVE_ARCH_STRCHRNUL |
441 | /** | |
442 | * strchrnul - Find and return a character in a string, or end of string | |
443 | * @s: The string to be searched | |
444 | * @c: The character to search for | |
445 | * | |
446 | * Returns pointer to first occurrence of 'c' in s. If c is not found, then | |
447 | * return a pointer to the null byte at the end of s. | |
448 | */ | |
449 | char *strchrnul(const char *s, int c) | |
450 | { | |
451 | while (*s && *s != (char)c) | |
452 | s++; | |
453 | return (char *)s; | |
454 | } | |
455 | EXPORT_SYMBOL(strchrnul); | |
456 | #endif | |
457 | ||
0bee0cec YN |
458 | /** |
459 | * strnchrnul - Find and return a character in a length limited string, | |
460 | * or end of string | |
461 | * @s: The string to be searched | |
462 | * @count: The number of characters to be searched | |
463 | * @c: The character to search for | |
464 | * | |
465 | * Returns pointer to the first occurrence of 'c' in s. If c is not found, | |
466 | * then return a pointer to the last character of the string. | |
467 | */ | |
468 | char *strnchrnul(const char *s, size_t count, int c) | |
469 | { | |
470 | while (count-- && *s && *s != (char)c) | |
471 | s++; | |
472 | return (char *)s; | |
473 | } | |
474 | ||
1da177e4 LT |
475 | #ifndef __HAVE_ARCH_STRRCHR |
476 | /** | |
477 | * strrchr - Find the last occurrence of a character in a string | |
478 | * @s: The string to be searched | |
479 | * @c: The character to search for | |
480 | */ | |
51a0f0f6 | 481 | char *strrchr(const char *s, int c) |
1da177e4 | 482 | { |
8da53d45 RV |
483 | const char *last = NULL; |
484 | do { | |
485 | if (*s == (char)c) | |
486 | last = s; | |
487 | } while (*s++); | |
488 | return (char *)last; | |
1da177e4 LT |
489 | } |
490 | EXPORT_SYMBOL(strrchr); | |
491 | #endif | |
492 | ||
493 | #ifndef __HAVE_ARCH_STRNCHR | |
494 | /** | |
495 | * strnchr - Find a character in a length limited string | |
496 | * @s: The string to be searched | |
497 | * @count: The number of characters to be searched | |
498 | * @c: The character to search for | |
b0975710 PR |
499 | * |
500 | * Note that the %NUL-terminator is considered part of the string, and can | |
501 | * be searched for. | |
1da177e4 LT |
502 | */ |
503 | char *strnchr(const char *s, size_t count, int c) | |
504 | { | |
b0975710 | 505 | while (count--) { |
51a0f0f6 JJ |
506 | if (*s == (char)c) |
507 | return (char *)s; | |
b0975710 PR |
508 | if (*s++ == '\0') |
509 | break; | |
510 | } | |
1da177e4 LT |
511 | return NULL; |
512 | } | |
513 | EXPORT_SYMBOL(strnchr); | |
514 | #endif | |
515 | ||
f653398c | 516 | /** |
a6cd13f3 RD |
517 | * skip_spaces - Removes leading whitespace from @str. |
518 | * @str: The string to be stripped. | |
f653398c | 519 | * |
a6cd13f3 | 520 | * Returns a pointer to the first non-whitespace character in @str. |
f653398c AGR |
521 | */ |
522 | char *skip_spaces(const char *str) | |
523 | { | |
524 | while (isspace(*str)) | |
525 | ++str; | |
526 | return (char *)str; | |
527 | } | |
528 | EXPORT_SYMBOL(skip_spaces); | |
529 | ||
481fad48 | 530 | /** |
ca54cb8c | 531 | * strim - Removes leading and trailing whitespace from @s. |
481fad48 PE |
532 | * @s: The string to be stripped. |
533 | * | |
534 | * Note that the first trailing whitespace is replaced with a %NUL-terminator | |
535 | * in the given string @s. Returns a pointer to the first non-whitespace | |
536 | * character in @s. | |
537 | */ | |
ca54cb8c | 538 | char *strim(char *s) |
481fad48 PE |
539 | { |
540 | size_t size; | |
541 | char *end; | |
542 | ||
543 | size = strlen(s); | |
481fad48 PE |
544 | if (!size) |
545 | return s; | |
546 | ||
547 | end = s + size - 1; | |
6e6d9fa6 | 548 | while (end >= s && isspace(*end)) |
481fad48 PE |
549 | end--; |
550 | *(end + 1) = '\0'; | |
551 | ||
66f6958e | 552 | return skip_spaces(s); |
481fad48 | 553 | } |
ca54cb8c | 554 | EXPORT_SYMBOL(strim); |
481fad48 | 555 | |
1da177e4 LT |
556 | #ifndef __HAVE_ARCH_STRLEN |
557 | /** | |
558 | * strlen - Find the length of a string | |
559 | * @s: The string to be sized | |
560 | */ | |
51a0f0f6 | 561 | size_t strlen(const char *s) |
1da177e4 LT |
562 | { |
563 | const char *sc; | |
564 | ||
565 | for (sc = s; *sc != '\0'; ++sc) | |
566 | /* nothing */; | |
567 | return sc - s; | |
568 | } | |
569 | EXPORT_SYMBOL(strlen); | |
570 | #endif | |
571 | ||
572 | #ifndef __HAVE_ARCH_STRNLEN | |
573 | /** | |
574 | * strnlen - Find the length of a length-limited string | |
575 | * @s: The string to be sized | |
576 | * @count: The maximum number of bytes to search | |
577 | */ | |
51a0f0f6 | 578 | size_t strnlen(const char *s, size_t count) |
1da177e4 LT |
579 | { |
580 | const char *sc; | |
581 | ||
582 | for (sc = s; count-- && *sc != '\0'; ++sc) | |
583 | /* nothing */; | |
584 | return sc - s; | |
585 | } | |
586 | EXPORT_SYMBOL(strnlen); | |
587 | #endif | |
588 | ||
589 | #ifndef __HAVE_ARCH_STRSPN | |
590 | /** | |
72fd4a35 | 591 | * strspn - Calculate the length of the initial substring of @s which only contain letters in @accept |
1da177e4 LT |
592 | * @s: The string to be searched |
593 | * @accept: The string to search for | |
594 | */ | |
595 | size_t strspn(const char *s, const char *accept) | |
596 | { | |
597 | const char *p; | |
598 | const char *a; | |
599 | size_t count = 0; | |
600 | ||
601 | for (p = s; *p != '\0'; ++p) { | |
602 | for (a = accept; *a != '\0'; ++a) { | |
603 | if (*p == *a) | |
604 | break; | |
605 | } | |
606 | if (*a == '\0') | |
607 | return count; | |
608 | ++count; | |
609 | } | |
1da177e4 LT |
610 | return count; |
611 | } | |
612 | ||
613 | EXPORT_SYMBOL(strspn); | |
614 | #endif | |
615 | ||
8833d328 | 616 | #ifndef __HAVE_ARCH_STRCSPN |
1da177e4 | 617 | /** |
72fd4a35 | 618 | * strcspn - Calculate the length of the initial substring of @s which does not contain letters in @reject |
1da177e4 LT |
619 | * @s: The string to be searched |
620 | * @reject: The string to avoid | |
621 | */ | |
622 | size_t strcspn(const char *s, const char *reject) | |
623 | { | |
624 | const char *p; | |
625 | const char *r; | |
626 | size_t count = 0; | |
627 | ||
628 | for (p = s; *p != '\0'; ++p) { | |
629 | for (r = reject; *r != '\0'; ++r) { | |
630 | if (*p == *r) | |
631 | return count; | |
632 | } | |
633 | ++count; | |
634 | } | |
1da177e4 | 635 | return count; |
51a0f0f6 | 636 | } |
1da177e4 | 637 | EXPORT_SYMBOL(strcspn); |
8833d328 | 638 | #endif |
1da177e4 LT |
639 | |
640 | #ifndef __HAVE_ARCH_STRPBRK | |
641 | /** | |
642 | * strpbrk - Find the first occurrence of a set of characters | |
643 | * @cs: The string to be searched | |
644 | * @ct: The characters to search for | |
645 | */ | |
51a0f0f6 | 646 | char *strpbrk(const char *cs, const char *ct) |
1da177e4 | 647 | { |
51a0f0f6 | 648 | const char *sc1, *sc2; |
1da177e4 | 649 | |
51a0f0f6 JJ |
650 | for (sc1 = cs; *sc1 != '\0'; ++sc1) { |
651 | for (sc2 = ct; *sc2 != '\0'; ++sc2) { | |
1da177e4 | 652 | if (*sc1 == *sc2) |
51a0f0f6 | 653 | return (char *)sc1; |
1da177e4 LT |
654 | } |
655 | } | |
656 | return NULL; | |
657 | } | |
894b5779 | 658 | EXPORT_SYMBOL(strpbrk); |
1da177e4 LT |
659 | #endif |
660 | ||
661 | #ifndef __HAVE_ARCH_STRSEP | |
662 | /** | |
663 | * strsep - Split a string into tokens | |
664 | * @s: The string to be searched | |
665 | * @ct: The characters to search for | |
666 | * | |
667 | * strsep() updates @s to point after the token, ready for the next call. | |
668 | * | |
669 | * It returns empty tokens, too, behaving exactly like the libc function | |
670 | * of that name. In fact, it was stolen from glibc2 and de-fancy-fied. | |
671 | * Same semantics, slimmer shape. ;) | |
672 | */ | |
51a0f0f6 | 673 | char *strsep(char **s, const char *ct) |
1da177e4 | 674 | { |
51a0f0f6 JJ |
675 | char *sbegin = *s; |
676 | char *end; | |
1da177e4 LT |
677 | |
678 | if (sbegin == NULL) | |
679 | return NULL; | |
680 | ||
681 | end = strpbrk(sbegin, ct); | |
682 | if (end) | |
683 | *end++ = '\0'; | |
684 | *s = end; | |
1da177e4 LT |
685 | return sbegin; |
686 | } | |
1da177e4 LT |
687 | EXPORT_SYMBOL(strsep); |
688 | #endif | |
689 | ||
34990cf7 DB |
690 | /** |
691 | * sysfs_streq - return true if strings are equal, modulo trailing newline | |
692 | * @s1: one string | |
693 | * @s2: another string | |
694 | * | |
695 | * This routine returns true iff two strings are equal, treating both | |
696 | * NUL and newline-then-NUL as equivalent string terminations. It's | |
697 | * geared for use with sysfs input strings, which generally terminate | |
698 | * with newlines but are compared against values without newlines. | |
699 | */ | |
700 | bool sysfs_streq(const char *s1, const char *s2) | |
701 | { | |
702 | while (*s1 && *s1 == *s2) { | |
703 | s1++; | |
704 | s2++; | |
705 | } | |
706 | ||
707 | if (*s1 == *s2) | |
708 | return true; | |
709 | if (!*s1 && *s2 == '\n' && !s2[1]) | |
710 | return true; | |
711 | if (*s1 == '\n' && !s1[1] && !*s2) | |
712 | return true; | |
713 | return false; | |
714 | } | |
715 | EXPORT_SYMBOL(sysfs_streq); | |
716 | ||
56b06081 AS |
717 | /** |
718 | * match_string - matches given string in an array | |
719 | * @array: array of strings | |
720 | * @n: number of strings in the array or -1 for NULL terminated arrays | |
721 | * @string: string to match with | |
722 | * | |
c11d3fa0 AA |
723 | * This routine will look for a string in an array of strings up to the |
724 | * n-th element in the array or until the first NULL element. | |
725 | * | |
726 | * Historically the value of -1 for @n, was used to search in arrays that | |
727 | * are NULL terminated. However, the function does not make a distinction | |
728 | * when finishing the search: either @n elements have been compared OR | |
729 | * the first NULL element was found. | |
730 | * | |
56b06081 AS |
731 | * Return: |
732 | * index of a @string in the @array if matches, or %-EINVAL otherwise. | |
733 | */ | |
734 | int match_string(const char * const *array, size_t n, const char *string) | |
735 | { | |
736 | int index; | |
737 | const char *item; | |
738 | ||
739 | for (index = 0; index < n; index++) { | |
740 | item = array[index]; | |
741 | if (!item) | |
742 | break; | |
743 | if (!strcmp(item, string)) | |
744 | return index; | |
745 | } | |
746 | ||
747 | return -EINVAL; | |
748 | } | |
749 | EXPORT_SYMBOL(match_string); | |
750 | ||
e1fe7b6a HK |
751 | /** |
752 | * __sysfs_match_string - matches given string in an array | |
753 | * @array: array of strings | |
754 | * @n: number of strings in the array or -1 for NULL terminated arrays | |
755 | * @str: string to match with | |
756 | * | |
757 | * Returns index of @str in the @array or -EINVAL, just like match_string(). | |
758 | * Uses sysfs_streq instead of strcmp for matching. | |
c11d3fa0 AA |
759 | * |
760 | * This routine will look for a string in an array of strings up to the | |
761 | * n-th element in the array or until the first NULL element. | |
762 | * | |
763 | * Historically the value of -1 for @n, was used to search in arrays that | |
764 | * are NULL terminated. However, the function does not make a distinction | |
765 | * when finishing the search: either @n elements have been compared OR | |
766 | * the first NULL element was found. | |
e1fe7b6a HK |
767 | */ |
768 | int __sysfs_match_string(const char * const *array, size_t n, const char *str) | |
769 | { | |
770 | const char *item; | |
771 | int index; | |
772 | ||
773 | for (index = 0; index < n; index++) { | |
774 | item = array[index]; | |
775 | if (!item) | |
776 | break; | |
777 | if (sysfs_streq(item, str)) | |
778 | return index; | |
779 | } | |
780 | ||
781 | return -EINVAL; | |
782 | } | |
783 | EXPORT_SYMBOL(__sysfs_match_string); | |
784 | ||
1da177e4 LT |
785 | #ifndef __HAVE_ARCH_MEMSET |
786 | /** | |
787 | * memset - Fill a region of memory with the given value | |
788 | * @s: Pointer to the start of the area. | |
789 | * @c: The byte to fill the area with | |
790 | * @count: The size of the area. | |
791 | * | |
792 | * Do not use memset() to access IO space, use memset_io() instead. | |
793 | */ | |
51a0f0f6 | 794 | void *memset(void *s, int c, size_t count) |
1da177e4 | 795 | { |
850b9247 | 796 | char *xs = s; |
1da177e4 LT |
797 | |
798 | while (count--) | |
799 | *xs++ = c; | |
1da177e4 LT |
800 | return s; |
801 | } | |
802 | EXPORT_SYMBOL(memset); | |
803 | #endif | |
804 | ||
3b3c4bab MW |
805 | #ifndef __HAVE_ARCH_MEMSET16 |
806 | /** | |
807 | * memset16() - Fill a memory area with a uint16_t | |
808 | * @s: Pointer to the start of the area. | |
809 | * @v: The value to fill the area with | |
810 | * @count: The number of values to store | |
811 | * | |
812 | * Differs from memset() in that it fills with a uint16_t instead | |
813 | * of a byte. Remember that @count is the number of uint16_ts to | |
814 | * store, not the number of bytes. | |
815 | */ | |
816 | void *memset16(uint16_t *s, uint16_t v, size_t count) | |
817 | { | |
818 | uint16_t *xs = s; | |
819 | ||
820 | while (count--) | |
821 | *xs++ = v; | |
822 | return s; | |
823 | } | |
824 | EXPORT_SYMBOL(memset16); | |
825 | #endif | |
826 | ||
827 | #ifndef __HAVE_ARCH_MEMSET32 | |
828 | /** | |
829 | * memset32() - Fill a memory area with a uint32_t | |
830 | * @s: Pointer to the start of the area. | |
831 | * @v: The value to fill the area with | |
832 | * @count: The number of values to store | |
833 | * | |
834 | * Differs from memset() in that it fills with a uint32_t instead | |
835 | * of a byte. Remember that @count is the number of uint32_ts to | |
836 | * store, not the number of bytes. | |
837 | */ | |
838 | void *memset32(uint32_t *s, uint32_t v, size_t count) | |
839 | { | |
840 | uint32_t *xs = s; | |
841 | ||
842 | while (count--) | |
843 | *xs++ = v; | |
844 | return s; | |
845 | } | |
846 | EXPORT_SYMBOL(memset32); | |
847 | #endif | |
848 | ||
849 | #ifndef __HAVE_ARCH_MEMSET64 | |
850 | /** | |
851 | * memset64() - Fill a memory area with a uint64_t | |
852 | * @s: Pointer to the start of the area. | |
853 | * @v: The value to fill the area with | |
854 | * @count: The number of values to store | |
855 | * | |
856 | * Differs from memset() in that it fills with a uint64_t instead | |
857 | * of a byte. Remember that @count is the number of uint64_ts to | |
858 | * store, not the number of bytes. | |
859 | */ | |
860 | void *memset64(uint64_t *s, uint64_t v, size_t count) | |
861 | { | |
862 | uint64_t *xs = s; | |
863 | ||
864 | while (count--) | |
865 | *xs++ = v; | |
866 | return s; | |
867 | } | |
868 | EXPORT_SYMBOL(memset64); | |
869 | #endif | |
870 | ||
1da177e4 LT |
871 | #ifndef __HAVE_ARCH_MEMCPY |
872 | /** | |
873 | * memcpy - Copy one area of memory to another | |
874 | * @dest: Where to copy to | |
875 | * @src: Where to copy from | |
876 | * @count: The size of the area. | |
877 | * | |
878 | * You should not use this function to access IO space, use memcpy_toio() | |
879 | * or memcpy_fromio() instead. | |
880 | */ | |
51a0f0f6 | 881 | void *memcpy(void *dest, const void *src, size_t count) |
1da177e4 | 882 | { |
850b9247 | 883 | char *tmp = dest; |
4c416ab7 | 884 | const char *s = src; |
1da177e4 LT |
885 | |
886 | while (count--) | |
887 | *tmp++ = *s++; | |
1da177e4 LT |
888 | return dest; |
889 | } | |
890 | EXPORT_SYMBOL(memcpy); | |
891 | #endif | |
892 | ||
893 | #ifndef __HAVE_ARCH_MEMMOVE | |
894 | /** | |
895 | * memmove - Copy one area of memory to another | |
896 | * @dest: Where to copy to | |
897 | * @src: Where to copy from | |
898 | * @count: The size of the area. | |
899 | * | |
900 | * Unlike memcpy(), memmove() copes with overlapping areas. | |
901 | */ | |
51a0f0f6 | 902 | void *memmove(void *dest, const void *src, size_t count) |
1da177e4 | 903 | { |
82da2c37 PJ |
904 | char *tmp; |
905 | const char *s; | |
1da177e4 LT |
906 | |
907 | if (dest <= src) { | |
850b9247 JJ |
908 | tmp = dest; |
909 | s = src; | |
1da177e4 LT |
910 | while (count--) |
911 | *tmp++ = *s++; | |
51a0f0f6 | 912 | } else { |
850b9247 JJ |
913 | tmp = dest; |
914 | tmp += count; | |
915 | s = src; | |
916 | s += count; | |
1da177e4 LT |
917 | while (count--) |
918 | *--tmp = *--s; | |
51a0f0f6 | 919 | } |
1da177e4 LT |
920 | return dest; |
921 | } | |
922 | EXPORT_SYMBOL(memmove); | |
923 | #endif | |
924 | ||
925 | #ifndef __HAVE_ARCH_MEMCMP | |
926 | /** | |
927 | * memcmp - Compare two areas of memory | |
928 | * @cs: One area of memory | |
929 | * @ct: Another area of memory | |
930 | * @count: The size of the area. | |
931 | */ | |
0c28130b | 932 | #undef memcmp |
a7330c99 | 933 | __visible int memcmp(const void *cs, const void *ct, size_t count) |
1da177e4 LT |
934 | { |
935 | const unsigned char *su1, *su2; | |
936 | int res = 0; | |
937 | ||
51a0f0f6 | 938 | for (su1 = cs, su2 = ct; 0 < count; ++su1, ++su2, count--) |
1da177e4 LT |
939 | if ((res = *su1 - *su2) != 0) |
940 | break; | |
941 | return res; | |
942 | } | |
943 | EXPORT_SYMBOL(memcmp); | |
944 | #endif | |
945 | ||
5f074f3e ND |
946 | #ifndef __HAVE_ARCH_BCMP |
947 | /** | |
948 | * bcmp - returns 0 if and only if the buffers have identical contents. | |
949 | * @a: pointer to first buffer. | |
950 | * @b: pointer to second buffer. | |
951 | * @len: size of buffers. | |
952 | * | |
953 | * The sign or magnitude of a non-zero return value has no particular | |
954 | * meaning, and architectures may implement their own more efficient bcmp(). So | |
955 | * while this particular implementation is a simple (tail) call to memcmp, do | |
956 | * not rely on anything but whether the return value is zero or non-zero. | |
957 | */ | |
5f074f3e ND |
958 | int bcmp(const void *a, const void *b, size_t len) |
959 | { | |
960 | return memcmp(a, b, len); | |
961 | } | |
962 | EXPORT_SYMBOL(bcmp); | |
963 | #endif | |
964 | ||
1da177e4 LT |
965 | #ifndef __HAVE_ARCH_MEMSCAN |
966 | /** | |
967 | * memscan - Find a character in an area of memory. | |
968 | * @addr: The memory area | |
969 | * @c: The byte to search for | |
970 | * @size: The size of the area. | |
971 | * | |
972 | * returns the address of the first occurrence of @c, or 1 byte past | |
973 | * the area if @c is not found | |
974 | */ | |
51a0f0f6 | 975 | void *memscan(void *addr, int c, size_t size) |
1da177e4 | 976 | { |
850b9247 | 977 | unsigned char *p = addr; |
1da177e4 LT |
978 | |
979 | while (size) { | |
980 | if (*p == c) | |
51a0f0f6 | 981 | return (void *)p; |
1da177e4 LT |
982 | p++; |
983 | size--; | |
984 | } | |
51a0f0f6 | 985 | return (void *)p; |
1da177e4 LT |
986 | } |
987 | EXPORT_SYMBOL(memscan); | |
988 | #endif | |
989 | ||
990 | #ifndef __HAVE_ARCH_STRSTR | |
991 | /** | |
992 | * strstr - Find the first substring in a %NUL terminated string | |
993 | * @s1: The string to be searched | |
994 | * @s2: The string to search for | |
995 | */ | |
51a0f0f6 | 996 | char *strstr(const char *s1, const char *s2) |
1da177e4 | 997 | { |
d5f1fb53 | 998 | size_t l1, l2; |
1da177e4 LT |
999 | |
1000 | l2 = strlen(s2); | |
1001 | if (!l2) | |
51a0f0f6 | 1002 | return (char *)s1; |
1da177e4 LT |
1003 | l1 = strlen(s1); |
1004 | while (l1 >= l2) { | |
1005 | l1--; | |
51a0f0f6 JJ |
1006 | if (!memcmp(s1, s2, l2)) |
1007 | return (char *)s1; | |
1da177e4 LT |
1008 | s1++; |
1009 | } | |
1010 | return NULL; | |
1011 | } | |
1012 | EXPORT_SYMBOL(strstr); | |
1013 | #endif | |
1014 | ||
d5f1fb53 LZ |
1015 | #ifndef __HAVE_ARCH_STRNSTR |
1016 | /** | |
1017 | * strnstr - Find the first substring in a length-limited string | |
1018 | * @s1: The string to be searched | |
1019 | * @s2: The string to search for | |
1020 | * @len: the maximum number of characters to search | |
1021 | */ | |
1022 | char *strnstr(const char *s1, const char *s2, size_t len) | |
1023 | { | |
d6a2eedf | 1024 | size_t l2; |
d5f1fb53 LZ |
1025 | |
1026 | l2 = strlen(s2); | |
1027 | if (!l2) | |
1028 | return (char *)s1; | |
d6a2eedf AGR |
1029 | while (len >= l2) { |
1030 | len--; | |
d5f1fb53 LZ |
1031 | if (!memcmp(s1, s2, l2)) |
1032 | return (char *)s1; | |
1033 | s1++; | |
1034 | } | |
1035 | return NULL; | |
1036 | } | |
1037 | EXPORT_SYMBOL(strnstr); | |
1038 | #endif | |
1039 | ||
1da177e4 LT |
1040 | #ifndef __HAVE_ARCH_MEMCHR |
1041 | /** | |
1042 | * memchr - Find a character in an area of memory. | |
1043 | * @s: The memory area | |
1044 | * @c: The byte to search for | |
1045 | * @n: The size of the area. | |
1046 | * | |
1047 | * returns the address of the first occurrence of @c, or %NULL | |
1048 | * if @c is not found | |
1049 | */ | |
1050 | void *memchr(const void *s, int c, size_t n) | |
1051 | { | |
1052 | const unsigned char *p = s; | |
1053 | while (n-- != 0) { | |
1054 | if ((unsigned char)c == *p++) { | |
51a0f0f6 | 1055 | return (void *)(p - 1); |
1da177e4 LT |
1056 | } |
1057 | } | |
1058 | return NULL; | |
1059 | } | |
1060 | EXPORT_SYMBOL(memchr); | |
1061 | #endif | |
79824820 AM |
1062 | |
1063 | static void *check_bytes8(const u8 *start, u8 value, unsigned int bytes) | |
1064 | { | |
1065 | while (bytes) { | |
1066 | if (*start != value) | |
1067 | return (void *)start; | |
1068 | start++; | |
1069 | bytes--; | |
1070 | } | |
1071 | return NULL; | |
1072 | } | |
1073 | ||
1074 | /** | |
1075 | * memchr_inv - Find an unmatching character in an area of memory. | |
1076 | * @start: The memory area | |
1077 | * @c: Find a character other than c | |
1078 | * @bytes: The size of the area. | |
1079 | * | |
1080 | * returns the address of the first character other than @c, or %NULL | |
1081 | * if the whole buffer contains just @c. | |
1082 | */ | |
1083 | void *memchr_inv(const void *start, int c, size_t bytes) | |
1084 | { | |
1085 | u8 value = c; | |
1086 | u64 value64; | |
1087 | unsigned int words, prefix; | |
1088 | ||
1089 | if (bytes <= 16) | |
1090 | return check_bytes8(start, value, bytes); | |
1091 | ||
f43804bf | 1092 | value64 = value; |
72d93104 | 1093 | #if defined(CONFIG_ARCH_HAS_FAST_MULTIPLIER) && BITS_PER_LONG == 64 |
3368e8fb | 1094 | value64 *= 0x0101010101010101ULL; |
72d93104 | 1095 | #elif defined(CONFIG_ARCH_HAS_FAST_MULTIPLIER) |
f43804bf AM |
1096 | value64 *= 0x01010101; |
1097 | value64 |= value64 << 32; | |
1098 | #else | |
1099 | value64 |= value64 << 8; | |
1100 | value64 |= value64 << 16; | |
1101 | value64 |= value64 << 32; | |
1102 | #endif | |
79824820 | 1103 | |
f43804bf | 1104 | prefix = (unsigned long)start % 8; |
79824820 | 1105 | if (prefix) { |
f43804bf AM |
1106 | u8 *r; |
1107 | ||
1108 | prefix = 8 - prefix; | |
1109 | r = check_bytes8(start, value, prefix); | |
79824820 AM |
1110 | if (r) |
1111 | return r; | |
1112 | start += prefix; | |
1113 | bytes -= prefix; | |
1114 | } | |
1115 | ||
1116 | words = bytes / 8; | |
1117 | ||
1118 | while (words) { | |
1119 | if (*(u64 *)start != value64) | |
1120 | return check_bytes8(start, value, 8); | |
1121 | start += 8; | |
1122 | words--; | |
1123 | } | |
1124 | ||
1125 | return check_bytes8(start, value, bytes % 8); | |
1126 | } | |
1127 | EXPORT_SYMBOL(memchr_inv); | |
94df2904 RV |
1128 | |
1129 | /** | |
1130 | * strreplace - Replace all occurrences of character in string. | |
1131 | * @s: The string to operate on. | |
1132 | * @old: The character being replaced. | |
1133 | * @new: The character @old is replaced with. | |
1134 | * | |
1135 | * Returns pointer to the nul byte at the end of @s. | |
1136 | */ | |
1137 | char *strreplace(char *s, char old, char new) | |
1138 | { | |
1139 | for (; *s; ++s) | |
1140 | if (*s == old) | |
1141 | *s = new; | |
1142 | return s; | |
1143 | } | |
1144 | EXPORT_SYMBOL(strreplace); | |
6974f0c4 DM |
1145 | |
1146 | void fortify_panic(const char *name) | |
1147 | { | |
1148 | pr_emerg("detected buffer overflow in %s\n", name); | |
1149 | BUG(); | |
1150 | } | |
1151 | EXPORT_SYMBOL(fortify_panic); |