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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 | */ | |
0c28130b | 88 | #undef strcpy |
51a0f0f6 | 89 | char *strcpy(char *dest, const char *src) |
1da177e4 LT |
90 | { |
91 | char *tmp = dest; | |
92 | ||
93 | while ((*dest++ = *src++) != '\0') | |
94 | /* nothing */; | |
95 | return tmp; | |
96 | } | |
97 | EXPORT_SYMBOL(strcpy); | |
98 | #endif | |
99 | ||
100 | #ifndef __HAVE_ARCH_STRNCPY | |
101 | /** | |
0046dd9f | 102 | * strncpy - Copy a length-limited, C-string |
1da177e4 LT |
103 | * @dest: Where to copy the string to |
104 | * @src: Where to copy the string from | |
105 | * @count: The maximum number of bytes to copy | |
106 | * | |
107 | * The result is not %NUL-terminated if the source exceeds | |
108 | * @count bytes. | |
25279526 | 109 | * |
110 | * In the case where the length of @src is less than that of | |
111 | * count, the remainder of @dest will be padded with %NUL. | |
112 | * | |
1da177e4 | 113 | */ |
51a0f0f6 | 114 | char *strncpy(char *dest, const char *src, size_t count) |
1da177e4 LT |
115 | { |
116 | char *tmp = dest; | |
117 | ||
118 | while (count) { | |
51a0f0f6 JJ |
119 | if ((*tmp = *src) != 0) |
120 | src++; | |
1da177e4 LT |
121 | tmp++; |
122 | count--; | |
123 | } | |
124 | return dest; | |
125 | } | |
126 | EXPORT_SYMBOL(strncpy); | |
127 | #endif | |
128 | ||
129 | #ifndef __HAVE_ARCH_STRLCPY | |
130 | /** | |
0046dd9f | 131 | * strlcpy - Copy a C-string into a sized buffer |
1da177e4 LT |
132 | * @dest: Where to copy the string to |
133 | * @src: Where to copy the string from | |
134 | * @size: size of destination buffer | |
135 | * | |
0e056eb5 | 136 | * Compatible with ``*BSD``: the result is always a valid |
1da177e4 LT |
137 | * NUL-terminated string that fits in the buffer (unless, |
138 | * of course, the buffer size is zero). It does not pad | |
139 | * out the result like strncpy() does. | |
140 | */ | |
141 | size_t strlcpy(char *dest, const char *src, size_t size) | |
142 | { | |
143 | size_t ret = strlen(src); | |
144 | ||
145 | if (size) { | |
51a0f0f6 | 146 | size_t len = (ret >= size) ? size - 1 : ret; |
1da177e4 LT |
147 | memcpy(dest, src, len); |
148 | dest[len] = '\0'; | |
149 | } | |
150 | return ret; | |
151 | } | |
152 | EXPORT_SYMBOL(strlcpy); | |
153 | #endif | |
154 | ||
30035e45 CM |
155 | #ifndef __HAVE_ARCH_STRSCPY |
156 | /** | |
157 | * strscpy - Copy a C-string into a sized buffer | |
158 | * @dest: Where to copy the string to | |
159 | * @src: Where to copy the string from | |
160 | * @count: Size of destination buffer | |
161 | * | |
458a3bf8 TH |
162 | * Copy the string, or as much of it as fits, into the dest buffer. The |
163 | * behavior is undefined if the string buffers overlap. The destination | |
164 | * buffer is always NUL terminated, unless it's zero-sized. | |
30035e45 CM |
165 | * |
166 | * Preferred to strlcpy() since the API doesn't require reading memory | |
167 | * from the src string beyond the specified "count" bytes, and since | |
168 | * the return value is easier to error-check than strlcpy()'s. | |
169 | * In addition, the implementation is robust to the string changing out | |
170 | * from underneath it, unlike the current strlcpy() implementation. | |
171 | * | |
172 | * Preferred to strncpy() since it always returns a valid string, and | |
173 | * doesn't unnecessarily force the tail of the destination buffer to be | |
458a3bf8 TH |
174 | * zeroed. If zeroing is desired please use strscpy_pad(). |
175 | * | |
176 | * Return: The number of characters copied (not including the trailing | |
177 | * %NUL) or -E2BIG if the destination buffer wasn't big enough. | |
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 | ||
185 | if (count == 0) | |
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 | * | |
256 | * Return: The number of characters copied (not including the trailing | |
257 | * %NUL) or -E2BIG if the destination buffer wasn't big enough. | |
258 | */ | |
259 | ssize_t strscpy_pad(char *dest, const char *src, size_t count) | |
260 | { | |
261 | ssize_t written; | |
262 | ||
263 | written = strscpy(dest, src, count); | |
264 | if (written < 0 || written == count - 1) | |
265 | return written; | |
266 | ||
267 | memset(dest + written + 1, 0, count - written - 1); | |
268 | ||
269 | return written; | |
270 | } | |
271 | EXPORT_SYMBOL(strscpy_pad); | |
272 | ||
1da177e4 LT |
273 | #ifndef __HAVE_ARCH_STRCAT |
274 | /** | |
275 | * strcat - Append one %NUL-terminated string to another | |
276 | * @dest: The string to be appended to | |
277 | * @src: The string to append to it | |
278 | */ | |
0c28130b | 279 | #undef strcat |
51a0f0f6 | 280 | char *strcat(char *dest, const char *src) |
1da177e4 LT |
281 | { |
282 | char *tmp = dest; | |
283 | ||
284 | while (*dest) | |
285 | dest++; | |
286 | while ((*dest++ = *src++) != '\0') | |
287 | ; | |
1da177e4 LT |
288 | return tmp; |
289 | } | |
290 | EXPORT_SYMBOL(strcat); | |
291 | #endif | |
292 | ||
293 | #ifndef __HAVE_ARCH_STRNCAT | |
294 | /** | |
0046dd9f | 295 | * strncat - Append a length-limited, C-string to another |
1da177e4 LT |
296 | * @dest: The string to be appended to |
297 | * @src: The string to append to it | |
298 | * @count: The maximum numbers of bytes to copy | |
299 | * | |
72fd4a35 | 300 | * Note that in contrast to strncpy(), strncat() ensures the result is |
1da177e4 LT |
301 | * terminated. |
302 | */ | |
51a0f0f6 | 303 | char *strncat(char *dest, const char *src, size_t count) |
1da177e4 LT |
304 | { |
305 | char *tmp = dest; | |
306 | ||
307 | if (count) { | |
308 | while (*dest) | |
309 | dest++; | |
310 | while ((*dest++ = *src++) != 0) { | |
311 | if (--count == 0) { | |
312 | *dest = '\0'; | |
313 | break; | |
314 | } | |
315 | } | |
316 | } | |
1da177e4 LT |
317 | return tmp; |
318 | } | |
319 | EXPORT_SYMBOL(strncat); | |
320 | #endif | |
321 | ||
322 | #ifndef __HAVE_ARCH_STRLCAT | |
323 | /** | |
0046dd9f | 324 | * strlcat - Append a length-limited, C-string to another |
1da177e4 LT |
325 | * @dest: The string to be appended to |
326 | * @src: The string to append to it | |
327 | * @count: The size of the destination buffer. | |
328 | */ | |
329 | size_t strlcat(char *dest, const char *src, size_t count) | |
330 | { | |
331 | size_t dsize = strlen(dest); | |
332 | size_t len = strlen(src); | |
333 | size_t res = dsize + len; | |
334 | ||
335 | /* This would be a bug */ | |
336 | BUG_ON(dsize >= count); | |
337 | ||
338 | dest += dsize; | |
339 | count -= dsize; | |
340 | if (len >= count) | |
341 | len = count-1; | |
342 | memcpy(dest, src, len); | |
343 | dest[len] = 0; | |
344 | return res; | |
345 | } | |
346 | EXPORT_SYMBOL(strlcat); | |
347 | #endif | |
348 | ||
349 | #ifndef __HAVE_ARCH_STRCMP | |
350 | /** | |
351 | * strcmp - Compare two strings | |
352 | * @cs: One string | |
353 | * @ct: Another string | |
354 | */ | |
0c28130b | 355 | #undef strcmp |
51a0f0f6 | 356 | int strcmp(const char *cs, const char *ct) |
1da177e4 | 357 | { |
a414f01a | 358 | unsigned char c1, c2; |
1da177e4 LT |
359 | |
360 | while (1) { | |
a414f01a LT |
361 | c1 = *cs++; |
362 | c2 = *ct++; | |
363 | if (c1 != c2) | |
364 | return c1 < c2 ? -1 : 1; | |
365 | if (!c1) | |
1da177e4 LT |
366 | break; |
367 | } | |
a414f01a | 368 | return 0; |
1da177e4 LT |
369 | } |
370 | EXPORT_SYMBOL(strcmp); | |
371 | #endif | |
372 | ||
373 | #ifndef __HAVE_ARCH_STRNCMP | |
374 | /** | |
375 | * strncmp - Compare two length-limited strings | |
376 | * @cs: One string | |
377 | * @ct: Another string | |
378 | * @count: The maximum number of bytes to compare | |
379 | */ | |
51a0f0f6 | 380 | int strncmp(const char *cs, const char *ct, size_t count) |
1da177e4 | 381 | { |
a414f01a | 382 | unsigned char c1, c2; |
1da177e4 LT |
383 | |
384 | while (count) { | |
a414f01a LT |
385 | c1 = *cs++; |
386 | c2 = *ct++; | |
387 | if (c1 != c2) | |
388 | return c1 < c2 ? -1 : 1; | |
389 | if (!c1) | |
1da177e4 LT |
390 | break; |
391 | count--; | |
392 | } | |
a414f01a | 393 | return 0; |
1da177e4 LT |
394 | } |
395 | EXPORT_SYMBOL(strncmp); | |
396 | #endif | |
397 | ||
398 | #ifndef __HAVE_ARCH_STRCHR | |
399 | /** | |
400 | * strchr - Find the first occurrence of a character in a string | |
401 | * @s: The string to be searched | |
402 | * @c: The character to search for | |
403 | */ | |
51a0f0f6 | 404 | char *strchr(const char *s, int c) |
1da177e4 | 405 | { |
51a0f0f6 | 406 | for (; *s != (char)c; ++s) |
1da177e4 LT |
407 | if (*s == '\0') |
408 | return NULL; | |
51a0f0f6 | 409 | return (char *)s; |
1da177e4 LT |
410 | } |
411 | EXPORT_SYMBOL(strchr); | |
412 | #endif | |
413 | ||
11d200e9 GL |
414 | #ifndef __HAVE_ARCH_STRCHRNUL |
415 | /** | |
416 | * strchrnul - Find and return a character in a string, or end of string | |
417 | * @s: The string to be searched | |
418 | * @c: The character to search for | |
419 | * | |
420 | * Returns pointer to first occurrence of 'c' in s. If c is not found, then | |
421 | * return a pointer to the null byte at the end of s. | |
422 | */ | |
423 | char *strchrnul(const char *s, int c) | |
424 | { | |
425 | while (*s && *s != (char)c) | |
426 | s++; | |
427 | return (char *)s; | |
428 | } | |
429 | EXPORT_SYMBOL(strchrnul); | |
430 | #endif | |
431 | ||
1da177e4 LT |
432 | #ifndef __HAVE_ARCH_STRRCHR |
433 | /** | |
434 | * strrchr - Find the last occurrence of a character in a string | |
435 | * @s: The string to be searched | |
436 | * @c: The character to search for | |
437 | */ | |
51a0f0f6 | 438 | char *strrchr(const char *s, int c) |
1da177e4 | 439 | { |
8da53d45 RV |
440 | const char *last = NULL; |
441 | do { | |
442 | if (*s == (char)c) | |
443 | last = s; | |
444 | } while (*s++); | |
445 | return (char *)last; | |
1da177e4 LT |
446 | } |
447 | EXPORT_SYMBOL(strrchr); | |
448 | #endif | |
449 | ||
450 | #ifndef __HAVE_ARCH_STRNCHR | |
451 | /** | |
452 | * strnchr - Find a character in a length limited string | |
453 | * @s: The string to be searched | |
454 | * @count: The number of characters to be searched | |
455 | * @c: The character to search for | |
456 | */ | |
457 | char *strnchr(const char *s, size_t count, int c) | |
458 | { | |
459 | for (; count-- && *s != '\0'; ++s) | |
51a0f0f6 JJ |
460 | if (*s == (char)c) |
461 | return (char *)s; | |
1da177e4 LT |
462 | return NULL; |
463 | } | |
464 | EXPORT_SYMBOL(strnchr); | |
465 | #endif | |
466 | ||
f653398c | 467 | /** |
a6cd13f3 RD |
468 | * skip_spaces - Removes leading whitespace from @str. |
469 | * @str: The string to be stripped. | |
f653398c | 470 | * |
a6cd13f3 | 471 | * Returns a pointer to the first non-whitespace character in @str. |
f653398c AGR |
472 | */ |
473 | char *skip_spaces(const char *str) | |
474 | { | |
475 | while (isspace(*str)) | |
476 | ++str; | |
477 | return (char *)str; | |
478 | } | |
479 | EXPORT_SYMBOL(skip_spaces); | |
480 | ||
481fad48 | 481 | /** |
ca54cb8c | 482 | * strim - Removes leading and trailing whitespace from @s. |
481fad48 PE |
483 | * @s: The string to be stripped. |
484 | * | |
485 | * Note that the first trailing whitespace is replaced with a %NUL-terminator | |
486 | * in the given string @s. Returns a pointer to the first non-whitespace | |
487 | * character in @s. | |
488 | */ | |
ca54cb8c | 489 | char *strim(char *s) |
481fad48 PE |
490 | { |
491 | size_t size; | |
492 | char *end; | |
493 | ||
494 | size = strlen(s); | |
481fad48 PE |
495 | if (!size) |
496 | return s; | |
497 | ||
498 | end = s + size - 1; | |
6e6d9fa6 | 499 | while (end >= s && isspace(*end)) |
481fad48 PE |
500 | end--; |
501 | *(end + 1) = '\0'; | |
502 | ||
66f6958e | 503 | return skip_spaces(s); |
481fad48 | 504 | } |
ca54cb8c | 505 | EXPORT_SYMBOL(strim); |
481fad48 | 506 | |
1da177e4 LT |
507 | #ifndef __HAVE_ARCH_STRLEN |
508 | /** | |
509 | * strlen - Find the length of a string | |
510 | * @s: The string to be sized | |
511 | */ | |
51a0f0f6 | 512 | size_t strlen(const char *s) |
1da177e4 LT |
513 | { |
514 | const char *sc; | |
515 | ||
516 | for (sc = s; *sc != '\0'; ++sc) | |
517 | /* nothing */; | |
518 | return sc - s; | |
519 | } | |
520 | EXPORT_SYMBOL(strlen); | |
521 | #endif | |
522 | ||
523 | #ifndef __HAVE_ARCH_STRNLEN | |
524 | /** | |
525 | * strnlen - Find the length of a length-limited string | |
526 | * @s: The string to be sized | |
527 | * @count: The maximum number of bytes to search | |
528 | */ | |
51a0f0f6 | 529 | size_t strnlen(const char *s, size_t count) |
1da177e4 LT |
530 | { |
531 | const char *sc; | |
532 | ||
533 | for (sc = s; count-- && *sc != '\0'; ++sc) | |
534 | /* nothing */; | |
535 | return sc - s; | |
536 | } | |
537 | EXPORT_SYMBOL(strnlen); | |
538 | #endif | |
539 | ||
540 | #ifndef __HAVE_ARCH_STRSPN | |
541 | /** | |
72fd4a35 | 542 | * strspn - Calculate the length of the initial substring of @s which only contain letters in @accept |
1da177e4 LT |
543 | * @s: The string to be searched |
544 | * @accept: The string to search for | |
545 | */ | |
546 | size_t strspn(const char *s, const char *accept) | |
547 | { | |
548 | const char *p; | |
549 | const char *a; | |
550 | size_t count = 0; | |
551 | ||
552 | for (p = s; *p != '\0'; ++p) { | |
553 | for (a = accept; *a != '\0'; ++a) { | |
554 | if (*p == *a) | |
555 | break; | |
556 | } | |
557 | if (*a == '\0') | |
558 | return count; | |
559 | ++count; | |
560 | } | |
1da177e4 LT |
561 | return count; |
562 | } | |
563 | ||
564 | EXPORT_SYMBOL(strspn); | |
565 | #endif | |
566 | ||
8833d328 | 567 | #ifndef __HAVE_ARCH_STRCSPN |
1da177e4 | 568 | /** |
72fd4a35 | 569 | * strcspn - Calculate the length of the initial substring of @s which does not contain letters in @reject |
1da177e4 LT |
570 | * @s: The string to be searched |
571 | * @reject: The string to avoid | |
572 | */ | |
573 | size_t strcspn(const char *s, const char *reject) | |
574 | { | |
575 | const char *p; | |
576 | const char *r; | |
577 | size_t count = 0; | |
578 | ||
579 | for (p = s; *p != '\0'; ++p) { | |
580 | for (r = reject; *r != '\0'; ++r) { | |
581 | if (*p == *r) | |
582 | return count; | |
583 | } | |
584 | ++count; | |
585 | } | |
1da177e4 | 586 | return count; |
51a0f0f6 | 587 | } |
1da177e4 | 588 | EXPORT_SYMBOL(strcspn); |
8833d328 | 589 | #endif |
1da177e4 LT |
590 | |
591 | #ifndef __HAVE_ARCH_STRPBRK | |
592 | /** | |
593 | * strpbrk - Find the first occurrence of a set of characters | |
594 | * @cs: The string to be searched | |
595 | * @ct: The characters to search for | |
596 | */ | |
51a0f0f6 | 597 | char *strpbrk(const char *cs, const char *ct) |
1da177e4 | 598 | { |
51a0f0f6 | 599 | const char *sc1, *sc2; |
1da177e4 | 600 | |
51a0f0f6 JJ |
601 | for (sc1 = cs; *sc1 != '\0'; ++sc1) { |
602 | for (sc2 = ct; *sc2 != '\0'; ++sc2) { | |
1da177e4 | 603 | if (*sc1 == *sc2) |
51a0f0f6 | 604 | return (char *)sc1; |
1da177e4 LT |
605 | } |
606 | } | |
607 | return NULL; | |
608 | } | |
894b5779 | 609 | EXPORT_SYMBOL(strpbrk); |
1da177e4 LT |
610 | #endif |
611 | ||
612 | #ifndef __HAVE_ARCH_STRSEP | |
613 | /** | |
614 | * strsep - Split a string into tokens | |
615 | * @s: The string to be searched | |
616 | * @ct: The characters to search for | |
617 | * | |
618 | * strsep() updates @s to point after the token, ready for the next call. | |
619 | * | |
620 | * It returns empty tokens, too, behaving exactly like the libc function | |
621 | * of that name. In fact, it was stolen from glibc2 and de-fancy-fied. | |
622 | * Same semantics, slimmer shape. ;) | |
623 | */ | |
51a0f0f6 | 624 | char *strsep(char **s, const char *ct) |
1da177e4 | 625 | { |
51a0f0f6 JJ |
626 | char *sbegin = *s; |
627 | char *end; | |
1da177e4 LT |
628 | |
629 | if (sbegin == NULL) | |
630 | return NULL; | |
631 | ||
632 | end = strpbrk(sbegin, ct); | |
633 | if (end) | |
634 | *end++ = '\0'; | |
635 | *s = end; | |
1da177e4 LT |
636 | return sbegin; |
637 | } | |
1da177e4 LT |
638 | EXPORT_SYMBOL(strsep); |
639 | #endif | |
640 | ||
34990cf7 DB |
641 | /** |
642 | * sysfs_streq - return true if strings are equal, modulo trailing newline | |
643 | * @s1: one string | |
644 | * @s2: another string | |
645 | * | |
646 | * This routine returns true iff two strings are equal, treating both | |
647 | * NUL and newline-then-NUL as equivalent string terminations. It's | |
648 | * geared for use with sysfs input strings, which generally terminate | |
649 | * with newlines but are compared against values without newlines. | |
650 | */ | |
651 | bool sysfs_streq(const char *s1, const char *s2) | |
652 | { | |
653 | while (*s1 && *s1 == *s2) { | |
654 | s1++; | |
655 | s2++; | |
656 | } | |
657 | ||
658 | if (*s1 == *s2) | |
659 | return true; | |
660 | if (!*s1 && *s2 == '\n' && !s2[1]) | |
661 | return true; | |
662 | if (*s1 == '\n' && !s1[1] && !*s2) | |
663 | return true; | |
664 | return false; | |
665 | } | |
666 | EXPORT_SYMBOL(sysfs_streq); | |
667 | ||
56b06081 AS |
668 | /** |
669 | * match_string - matches given string in an array | |
670 | * @array: array of strings | |
671 | * @n: number of strings in the array or -1 for NULL terminated arrays | |
672 | * @string: string to match with | |
673 | * | |
674 | * Return: | |
675 | * index of a @string in the @array if matches, or %-EINVAL otherwise. | |
676 | */ | |
677 | int match_string(const char * const *array, size_t n, const char *string) | |
678 | { | |
679 | int index; | |
680 | const char *item; | |
681 | ||
682 | for (index = 0; index < n; index++) { | |
683 | item = array[index]; | |
684 | if (!item) | |
685 | break; | |
686 | if (!strcmp(item, string)) | |
687 | return index; | |
688 | } | |
689 | ||
690 | return -EINVAL; | |
691 | } | |
692 | EXPORT_SYMBOL(match_string); | |
693 | ||
e1fe7b6a HK |
694 | /** |
695 | * __sysfs_match_string - matches given string in an array | |
696 | * @array: array of strings | |
697 | * @n: number of strings in the array or -1 for NULL terminated arrays | |
698 | * @str: string to match with | |
699 | * | |
700 | * Returns index of @str in the @array or -EINVAL, just like match_string(). | |
701 | * Uses sysfs_streq instead of strcmp for matching. | |
702 | */ | |
703 | int __sysfs_match_string(const char * const *array, size_t n, const char *str) | |
704 | { | |
705 | const char *item; | |
706 | int index; | |
707 | ||
708 | for (index = 0; index < n; index++) { | |
709 | item = array[index]; | |
710 | if (!item) | |
711 | break; | |
712 | if (sysfs_streq(item, str)) | |
713 | return index; | |
714 | } | |
715 | ||
716 | return -EINVAL; | |
717 | } | |
718 | EXPORT_SYMBOL(__sysfs_match_string); | |
719 | ||
1da177e4 LT |
720 | #ifndef __HAVE_ARCH_MEMSET |
721 | /** | |
722 | * memset - Fill a region of memory with the given value | |
723 | * @s: Pointer to the start of the area. | |
724 | * @c: The byte to fill the area with | |
725 | * @count: The size of the area. | |
726 | * | |
727 | * Do not use memset() to access IO space, use memset_io() instead. | |
728 | */ | |
51a0f0f6 | 729 | void *memset(void *s, int c, size_t count) |
1da177e4 | 730 | { |
850b9247 | 731 | char *xs = s; |
1da177e4 LT |
732 | |
733 | while (count--) | |
734 | *xs++ = c; | |
1da177e4 LT |
735 | return s; |
736 | } | |
737 | EXPORT_SYMBOL(memset); | |
738 | #endif | |
739 | ||
d4c5efdb DB |
740 | /** |
741 | * memzero_explicit - Fill a region of memory (e.g. sensitive | |
742 | * keying data) with 0s. | |
743 | * @s: Pointer to the start of the area. | |
744 | * @count: The size of the area. | |
745 | * | |
8155330a DB |
746 | * Note: usually using memset() is just fine (!), but in cases |
747 | * where clearing out _local_ data at the end of a scope is | |
748 | * necessary, memzero_explicit() should be used instead in | |
749 | * order to prevent the compiler from optimising away zeroing. | |
750 | * | |
d4c5efdb DB |
751 | * memzero_explicit() doesn't need an arch-specific version as |
752 | * it just invokes the one of memset() implicitly. | |
753 | */ | |
754 | void memzero_explicit(void *s, size_t count) | |
755 | { | |
756 | memset(s, 0, count); | |
7829fb09 | 757 | barrier_data(s); |
d4c5efdb DB |
758 | } |
759 | EXPORT_SYMBOL(memzero_explicit); | |
760 | ||
3b3c4bab MW |
761 | #ifndef __HAVE_ARCH_MEMSET16 |
762 | /** | |
763 | * memset16() - Fill a memory area with a uint16_t | |
764 | * @s: Pointer to the start of the area. | |
765 | * @v: The value to fill the area with | |
766 | * @count: The number of values to store | |
767 | * | |
768 | * Differs from memset() in that it fills with a uint16_t instead | |
769 | * of a byte. Remember that @count is the number of uint16_ts to | |
770 | * store, not the number of bytes. | |
771 | */ | |
772 | void *memset16(uint16_t *s, uint16_t v, size_t count) | |
773 | { | |
774 | uint16_t *xs = s; | |
775 | ||
776 | while (count--) | |
777 | *xs++ = v; | |
778 | return s; | |
779 | } | |
780 | EXPORT_SYMBOL(memset16); | |
781 | #endif | |
782 | ||
783 | #ifndef __HAVE_ARCH_MEMSET32 | |
784 | /** | |
785 | * memset32() - Fill a memory area with a uint32_t | |
786 | * @s: Pointer to the start of the area. | |
787 | * @v: The value to fill the area with | |
788 | * @count: The number of values to store | |
789 | * | |
790 | * Differs from memset() in that it fills with a uint32_t instead | |
791 | * of a byte. Remember that @count is the number of uint32_ts to | |
792 | * store, not the number of bytes. | |
793 | */ | |
794 | void *memset32(uint32_t *s, uint32_t v, size_t count) | |
795 | { | |
796 | uint32_t *xs = s; | |
797 | ||
798 | while (count--) | |
799 | *xs++ = v; | |
800 | return s; | |
801 | } | |
802 | EXPORT_SYMBOL(memset32); | |
803 | #endif | |
804 | ||
805 | #ifndef __HAVE_ARCH_MEMSET64 | |
806 | /** | |
807 | * memset64() - Fill a memory area with a uint64_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 uint64_t instead | |
813 | * of a byte. Remember that @count is the number of uint64_ts to | |
814 | * store, not the number of bytes. | |
815 | */ | |
816 | void *memset64(uint64_t *s, uint64_t v, size_t count) | |
817 | { | |
818 | uint64_t *xs = s; | |
819 | ||
820 | while (count--) | |
821 | *xs++ = v; | |
822 | return s; | |
823 | } | |
824 | EXPORT_SYMBOL(memset64); | |
825 | #endif | |
826 | ||
1da177e4 LT |
827 | #ifndef __HAVE_ARCH_MEMCPY |
828 | /** | |
829 | * memcpy - Copy one area of memory to another | |
830 | * @dest: Where to copy to | |
831 | * @src: Where to copy from | |
832 | * @count: The size of the area. | |
833 | * | |
834 | * You should not use this function to access IO space, use memcpy_toio() | |
835 | * or memcpy_fromio() instead. | |
836 | */ | |
51a0f0f6 | 837 | void *memcpy(void *dest, const void *src, size_t count) |
1da177e4 | 838 | { |
850b9247 | 839 | char *tmp = dest; |
4c416ab7 | 840 | const char *s = src; |
1da177e4 LT |
841 | |
842 | while (count--) | |
843 | *tmp++ = *s++; | |
1da177e4 LT |
844 | return dest; |
845 | } | |
846 | EXPORT_SYMBOL(memcpy); | |
847 | #endif | |
848 | ||
849 | #ifndef __HAVE_ARCH_MEMMOVE | |
850 | /** | |
851 | * memmove - Copy one area of memory to another | |
852 | * @dest: Where to copy to | |
853 | * @src: Where to copy from | |
854 | * @count: The size of the area. | |
855 | * | |
856 | * Unlike memcpy(), memmove() copes with overlapping areas. | |
857 | */ | |
51a0f0f6 | 858 | void *memmove(void *dest, const void *src, size_t count) |
1da177e4 | 859 | { |
82da2c37 PJ |
860 | char *tmp; |
861 | const char *s; | |
1da177e4 LT |
862 | |
863 | if (dest <= src) { | |
850b9247 JJ |
864 | tmp = dest; |
865 | s = src; | |
1da177e4 LT |
866 | while (count--) |
867 | *tmp++ = *s++; | |
51a0f0f6 | 868 | } else { |
850b9247 JJ |
869 | tmp = dest; |
870 | tmp += count; | |
871 | s = src; | |
872 | s += count; | |
1da177e4 LT |
873 | while (count--) |
874 | *--tmp = *--s; | |
51a0f0f6 | 875 | } |
1da177e4 LT |
876 | return dest; |
877 | } | |
878 | EXPORT_SYMBOL(memmove); | |
879 | #endif | |
880 | ||
881 | #ifndef __HAVE_ARCH_MEMCMP | |
882 | /** | |
883 | * memcmp - Compare two areas of memory | |
884 | * @cs: One area of memory | |
885 | * @ct: Another area of memory | |
886 | * @count: The size of the area. | |
887 | */ | |
0c28130b | 888 | #undef memcmp |
a7330c99 | 889 | __visible int memcmp(const void *cs, const void *ct, size_t count) |
1da177e4 LT |
890 | { |
891 | const unsigned char *su1, *su2; | |
892 | int res = 0; | |
893 | ||
51a0f0f6 | 894 | for (su1 = cs, su2 = ct; 0 < count; ++su1, ++su2, count--) |
1da177e4 LT |
895 | if ((res = *su1 - *su2) != 0) |
896 | break; | |
897 | return res; | |
898 | } | |
899 | EXPORT_SYMBOL(memcmp); | |
900 | #endif | |
901 | ||
5f074f3e ND |
902 | #ifndef __HAVE_ARCH_BCMP |
903 | /** | |
904 | * bcmp - returns 0 if and only if the buffers have identical contents. | |
905 | * @a: pointer to first buffer. | |
906 | * @b: pointer to second buffer. | |
907 | * @len: size of buffers. | |
908 | * | |
909 | * The sign or magnitude of a non-zero return value has no particular | |
910 | * meaning, and architectures may implement their own more efficient bcmp(). So | |
911 | * while this particular implementation is a simple (tail) call to memcmp, do | |
912 | * not rely on anything but whether the return value is zero or non-zero. | |
913 | */ | |
914 | #undef bcmp | |
915 | int bcmp(const void *a, const void *b, size_t len) | |
916 | { | |
917 | return memcmp(a, b, len); | |
918 | } | |
919 | EXPORT_SYMBOL(bcmp); | |
920 | #endif | |
921 | ||
1da177e4 LT |
922 | #ifndef __HAVE_ARCH_MEMSCAN |
923 | /** | |
924 | * memscan - Find a character in an area of memory. | |
925 | * @addr: The memory area | |
926 | * @c: The byte to search for | |
927 | * @size: The size of the area. | |
928 | * | |
929 | * returns the address of the first occurrence of @c, or 1 byte past | |
930 | * the area if @c is not found | |
931 | */ | |
51a0f0f6 | 932 | void *memscan(void *addr, int c, size_t size) |
1da177e4 | 933 | { |
850b9247 | 934 | unsigned char *p = addr; |
1da177e4 LT |
935 | |
936 | while (size) { | |
937 | if (*p == c) | |
51a0f0f6 | 938 | return (void *)p; |
1da177e4 LT |
939 | p++; |
940 | size--; | |
941 | } | |
51a0f0f6 | 942 | return (void *)p; |
1da177e4 LT |
943 | } |
944 | EXPORT_SYMBOL(memscan); | |
945 | #endif | |
946 | ||
947 | #ifndef __HAVE_ARCH_STRSTR | |
948 | /** | |
949 | * strstr - Find the first substring in a %NUL terminated string | |
950 | * @s1: The string to be searched | |
951 | * @s2: The string to search for | |
952 | */ | |
51a0f0f6 | 953 | char *strstr(const char *s1, const char *s2) |
1da177e4 | 954 | { |
d5f1fb53 | 955 | size_t l1, l2; |
1da177e4 LT |
956 | |
957 | l2 = strlen(s2); | |
958 | if (!l2) | |
51a0f0f6 | 959 | return (char *)s1; |
1da177e4 LT |
960 | l1 = strlen(s1); |
961 | while (l1 >= l2) { | |
962 | l1--; | |
51a0f0f6 JJ |
963 | if (!memcmp(s1, s2, l2)) |
964 | return (char *)s1; | |
1da177e4 LT |
965 | s1++; |
966 | } | |
967 | return NULL; | |
968 | } | |
969 | EXPORT_SYMBOL(strstr); | |
970 | #endif | |
971 | ||
d5f1fb53 LZ |
972 | #ifndef __HAVE_ARCH_STRNSTR |
973 | /** | |
974 | * strnstr - Find the first substring in a length-limited string | |
975 | * @s1: The string to be searched | |
976 | * @s2: The string to search for | |
977 | * @len: the maximum number of characters to search | |
978 | */ | |
979 | char *strnstr(const char *s1, const char *s2, size_t len) | |
980 | { | |
d6a2eedf | 981 | size_t l2; |
d5f1fb53 LZ |
982 | |
983 | l2 = strlen(s2); | |
984 | if (!l2) | |
985 | return (char *)s1; | |
d6a2eedf AGR |
986 | while (len >= l2) { |
987 | len--; | |
d5f1fb53 LZ |
988 | if (!memcmp(s1, s2, l2)) |
989 | return (char *)s1; | |
990 | s1++; | |
991 | } | |
992 | return NULL; | |
993 | } | |
994 | EXPORT_SYMBOL(strnstr); | |
995 | #endif | |
996 | ||
1da177e4 LT |
997 | #ifndef __HAVE_ARCH_MEMCHR |
998 | /** | |
999 | * memchr - Find a character in an area of memory. | |
1000 | * @s: The memory area | |
1001 | * @c: The byte to search for | |
1002 | * @n: The size of the area. | |
1003 | * | |
1004 | * returns the address of the first occurrence of @c, or %NULL | |
1005 | * if @c is not found | |
1006 | */ | |
1007 | void *memchr(const void *s, int c, size_t n) | |
1008 | { | |
1009 | const unsigned char *p = s; | |
1010 | while (n-- != 0) { | |
1011 | if ((unsigned char)c == *p++) { | |
51a0f0f6 | 1012 | return (void *)(p - 1); |
1da177e4 LT |
1013 | } |
1014 | } | |
1015 | return NULL; | |
1016 | } | |
1017 | EXPORT_SYMBOL(memchr); | |
1018 | #endif | |
79824820 AM |
1019 | |
1020 | static void *check_bytes8(const u8 *start, u8 value, unsigned int bytes) | |
1021 | { | |
1022 | while (bytes) { | |
1023 | if (*start != value) | |
1024 | return (void *)start; | |
1025 | start++; | |
1026 | bytes--; | |
1027 | } | |
1028 | return NULL; | |
1029 | } | |
1030 | ||
1031 | /** | |
1032 | * memchr_inv - Find an unmatching character in an area of memory. | |
1033 | * @start: The memory area | |
1034 | * @c: Find a character other than c | |
1035 | * @bytes: The size of the area. | |
1036 | * | |
1037 | * returns the address of the first character other than @c, or %NULL | |
1038 | * if the whole buffer contains just @c. | |
1039 | */ | |
1040 | void *memchr_inv(const void *start, int c, size_t bytes) | |
1041 | { | |
1042 | u8 value = c; | |
1043 | u64 value64; | |
1044 | unsigned int words, prefix; | |
1045 | ||
1046 | if (bytes <= 16) | |
1047 | return check_bytes8(start, value, bytes); | |
1048 | ||
f43804bf | 1049 | value64 = value; |
72d93104 | 1050 | #if defined(CONFIG_ARCH_HAS_FAST_MULTIPLIER) && BITS_PER_LONG == 64 |
3368e8fb | 1051 | value64 *= 0x0101010101010101ULL; |
72d93104 | 1052 | #elif defined(CONFIG_ARCH_HAS_FAST_MULTIPLIER) |
f43804bf AM |
1053 | value64 *= 0x01010101; |
1054 | value64 |= value64 << 32; | |
1055 | #else | |
1056 | value64 |= value64 << 8; | |
1057 | value64 |= value64 << 16; | |
1058 | value64 |= value64 << 32; | |
1059 | #endif | |
79824820 | 1060 | |
f43804bf | 1061 | prefix = (unsigned long)start % 8; |
79824820 | 1062 | if (prefix) { |
f43804bf AM |
1063 | u8 *r; |
1064 | ||
1065 | prefix = 8 - prefix; | |
1066 | r = check_bytes8(start, value, prefix); | |
79824820 AM |
1067 | if (r) |
1068 | return r; | |
1069 | start += prefix; | |
1070 | bytes -= prefix; | |
1071 | } | |
1072 | ||
1073 | words = bytes / 8; | |
1074 | ||
1075 | while (words) { | |
1076 | if (*(u64 *)start != value64) | |
1077 | return check_bytes8(start, value, 8); | |
1078 | start += 8; | |
1079 | words--; | |
1080 | } | |
1081 | ||
1082 | return check_bytes8(start, value, bytes % 8); | |
1083 | } | |
1084 | EXPORT_SYMBOL(memchr_inv); | |
94df2904 RV |
1085 | |
1086 | /** | |
1087 | * strreplace - Replace all occurrences of character in string. | |
1088 | * @s: The string to operate on. | |
1089 | * @old: The character being replaced. | |
1090 | * @new: The character @old is replaced with. | |
1091 | * | |
1092 | * Returns pointer to the nul byte at the end of @s. | |
1093 | */ | |
1094 | char *strreplace(char *s, char old, char new) | |
1095 | { | |
1096 | for (; *s; ++s) | |
1097 | if (*s == old) | |
1098 | *s = new; | |
1099 | return s; | |
1100 | } | |
1101 | EXPORT_SYMBOL(strreplace); | |
6974f0c4 DM |
1102 | |
1103 | void fortify_panic(const char *name) | |
1104 | { | |
1105 | pr_emerg("detected buffer overflow in %s\n", name); | |
1106 | BUG(); | |
1107 | } | |
1108 | EXPORT_SYMBOL(fortify_panic); |