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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 | * | |
162 | * Copy the string, or as much of it as fits, into the dest buffer. | |
163 | * The routine returns the number of characters copied (not including | |
164 | * the trailing NUL) or -E2BIG if the destination buffer wasn't big enough. | |
165 | * The behavior is undefined if the string buffers overlap. | |
166 | * The destination buffer is always NUL terminated, unless it's zero-sized. | |
167 | * | |
168 | * Preferred to strlcpy() since the API doesn't require reading memory | |
169 | * from the src string beyond the specified "count" bytes, and since | |
170 | * the return value is easier to error-check than strlcpy()'s. | |
171 | * In addition, the implementation is robust to the string changing out | |
172 | * from underneath it, unlike the current strlcpy() implementation. | |
173 | * | |
174 | * Preferred to strncpy() since it always returns a valid string, and | |
175 | * doesn't unnecessarily force the tail of the destination buffer to be | |
176 | * zeroed. If the zeroing is desired, it's likely cleaner to use strscpy() | |
177 | * with an overflow test, then just memset() the tail of the dest buffer. | |
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 | ||
1da177e4 LT |
240 | #ifndef __HAVE_ARCH_STRCAT |
241 | /** | |
242 | * strcat - Append one %NUL-terminated string to another | |
243 | * @dest: The string to be appended to | |
244 | * @src: The string to append to it | |
245 | */ | |
0c28130b | 246 | #undef strcat |
51a0f0f6 | 247 | char *strcat(char *dest, const char *src) |
1da177e4 LT |
248 | { |
249 | char *tmp = dest; | |
250 | ||
251 | while (*dest) | |
252 | dest++; | |
253 | while ((*dest++ = *src++) != '\0') | |
254 | ; | |
1da177e4 LT |
255 | return tmp; |
256 | } | |
257 | EXPORT_SYMBOL(strcat); | |
258 | #endif | |
259 | ||
260 | #ifndef __HAVE_ARCH_STRNCAT | |
261 | /** | |
0046dd9f | 262 | * strncat - Append a length-limited, C-string to another |
1da177e4 LT |
263 | * @dest: The string to be appended to |
264 | * @src: The string to append to it | |
265 | * @count: The maximum numbers of bytes to copy | |
266 | * | |
72fd4a35 | 267 | * Note that in contrast to strncpy(), strncat() ensures the result is |
1da177e4 LT |
268 | * terminated. |
269 | */ | |
51a0f0f6 | 270 | char *strncat(char *dest, const char *src, size_t count) |
1da177e4 LT |
271 | { |
272 | char *tmp = dest; | |
273 | ||
274 | if (count) { | |
275 | while (*dest) | |
276 | dest++; | |
277 | while ((*dest++ = *src++) != 0) { | |
278 | if (--count == 0) { | |
279 | *dest = '\0'; | |
280 | break; | |
281 | } | |
282 | } | |
283 | } | |
1da177e4 LT |
284 | return tmp; |
285 | } | |
286 | EXPORT_SYMBOL(strncat); | |
287 | #endif | |
288 | ||
289 | #ifndef __HAVE_ARCH_STRLCAT | |
290 | /** | |
0046dd9f | 291 | * strlcat - Append a length-limited, C-string to another |
1da177e4 LT |
292 | * @dest: The string to be appended to |
293 | * @src: The string to append to it | |
294 | * @count: The size of the destination buffer. | |
295 | */ | |
296 | size_t strlcat(char *dest, const char *src, size_t count) | |
297 | { | |
298 | size_t dsize = strlen(dest); | |
299 | size_t len = strlen(src); | |
300 | size_t res = dsize + len; | |
301 | ||
302 | /* This would be a bug */ | |
303 | BUG_ON(dsize >= count); | |
304 | ||
305 | dest += dsize; | |
306 | count -= dsize; | |
307 | if (len >= count) | |
308 | len = count-1; | |
309 | memcpy(dest, src, len); | |
310 | dest[len] = 0; | |
311 | return res; | |
312 | } | |
313 | EXPORT_SYMBOL(strlcat); | |
314 | #endif | |
315 | ||
316 | #ifndef __HAVE_ARCH_STRCMP | |
317 | /** | |
318 | * strcmp - Compare two strings | |
319 | * @cs: One string | |
320 | * @ct: Another string | |
321 | */ | |
0c28130b | 322 | #undef strcmp |
51a0f0f6 | 323 | int strcmp(const char *cs, const char *ct) |
1da177e4 | 324 | { |
a414f01a | 325 | unsigned char c1, c2; |
1da177e4 LT |
326 | |
327 | while (1) { | |
a414f01a LT |
328 | c1 = *cs++; |
329 | c2 = *ct++; | |
330 | if (c1 != c2) | |
331 | return c1 < c2 ? -1 : 1; | |
332 | if (!c1) | |
1da177e4 LT |
333 | break; |
334 | } | |
a414f01a | 335 | return 0; |
1da177e4 LT |
336 | } |
337 | EXPORT_SYMBOL(strcmp); | |
338 | #endif | |
339 | ||
340 | #ifndef __HAVE_ARCH_STRNCMP | |
341 | /** | |
342 | * strncmp - Compare two length-limited strings | |
343 | * @cs: One string | |
344 | * @ct: Another string | |
345 | * @count: The maximum number of bytes to compare | |
346 | */ | |
51a0f0f6 | 347 | int strncmp(const char *cs, const char *ct, size_t count) |
1da177e4 | 348 | { |
a414f01a | 349 | unsigned char c1, c2; |
1da177e4 LT |
350 | |
351 | while (count) { | |
a414f01a LT |
352 | c1 = *cs++; |
353 | c2 = *ct++; | |
354 | if (c1 != c2) | |
355 | return c1 < c2 ? -1 : 1; | |
356 | if (!c1) | |
1da177e4 LT |
357 | break; |
358 | count--; | |
359 | } | |
a414f01a | 360 | return 0; |
1da177e4 LT |
361 | } |
362 | EXPORT_SYMBOL(strncmp); | |
363 | #endif | |
364 | ||
365 | #ifndef __HAVE_ARCH_STRCHR | |
366 | /** | |
367 | * strchr - Find the first occurrence of a character in a string | |
368 | * @s: The string to be searched | |
369 | * @c: The character to search for | |
370 | */ | |
51a0f0f6 | 371 | char *strchr(const char *s, int c) |
1da177e4 | 372 | { |
51a0f0f6 | 373 | for (; *s != (char)c; ++s) |
1da177e4 LT |
374 | if (*s == '\0') |
375 | return NULL; | |
51a0f0f6 | 376 | return (char *)s; |
1da177e4 LT |
377 | } |
378 | EXPORT_SYMBOL(strchr); | |
379 | #endif | |
380 | ||
11d200e9 GL |
381 | #ifndef __HAVE_ARCH_STRCHRNUL |
382 | /** | |
383 | * strchrnul - Find and return a character in a string, or end of string | |
384 | * @s: The string to be searched | |
385 | * @c: The character to search for | |
386 | * | |
387 | * Returns pointer to first occurrence of 'c' in s. If c is not found, then | |
388 | * return a pointer to the null byte at the end of s. | |
389 | */ | |
390 | char *strchrnul(const char *s, int c) | |
391 | { | |
392 | while (*s && *s != (char)c) | |
393 | s++; | |
394 | return (char *)s; | |
395 | } | |
396 | EXPORT_SYMBOL(strchrnul); | |
397 | #endif | |
398 | ||
1da177e4 LT |
399 | #ifndef __HAVE_ARCH_STRRCHR |
400 | /** | |
401 | * strrchr - Find the last occurrence of a character in a string | |
402 | * @s: The string to be searched | |
403 | * @c: The character to search for | |
404 | */ | |
51a0f0f6 | 405 | char *strrchr(const char *s, int c) |
1da177e4 | 406 | { |
8da53d45 RV |
407 | const char *last = NULL; |
408 | do { | |
409 | if (*s == (char)c) | |
410 | last = s; | |
411 | } while (*s++); | |
412 | return (char *)last; | |
1da177e4 LT |
413 | } |
414 | EXPORT_SYMBOL(strrchr); | |
415 | #endif | |
416 | ||
417 | #ifndef __HAVE_ARCH_STRNCHR | |
418 | /** | |
419 | * strnchr - Find a character in a length limited string | |
420 | * @s: The string to be searched | |
421 | * @count: The number of characters to be searched | |
422 | * @c: The character to search for | |
423 | */ | |
424 | char *strnchr(const char *s, size_t count, int c) | |
425 | { | |
426 | for (; count-- && *s != '\0'; ++s) | |
51a0f0f6 JJ |
427 | if (*s == (char)c) |
428 | return (char *)s; | |
1da177e4 LT |
429 | return NULL; |
430 | } | |
431 | EXPORT_SYMBOL(strnchr); | |
432 | #endif | |
433 | ||
f653398c | 434 | /** |
a6cd13f3 RD |
435 | * skip_spaces - Removes leading whitespace from @str. |
436 | * @str: The string to be stripped. | |
f653398c | 437 | * |
a6cd13f3 | 438 | * Returns a pointer to the first non-whitespace character in @str. |
f653398c AGR |
439 | */ |
440 | char *skip_spaces(const char *str) | |
441 | { | |
442 | while (isspace(*str)) | |
443 | ++str; | |
444 | return (char *)str; | |
445 | } | |
446 | EXPORT_SYMBOL(skip_spaces); | |
447 | ||
481fad48 | 448 | /** |
ca54cb8c | 449 | * strim - Removes leading and trailing whitespace from @s. |
481fad48 PE |
450 | * @s: The string to be stripped. |
451 | * | |
452 | * Note that the first trailing whitespace is replaced with a %NUL-terminator | |
453 | * in the given string @s. Returns a pointer to the first non-whitespace | |
454 | * character in @s. | |
455 | */ | |
ca54cb8c | 456 | char *strim(char *s) |
481fad48 PE |
457 | { |
458 | size_t size; | |
459 | char *end; | |
460 | ||
461 | size = strlen(s); | |
481fad48 PE |
462 | if (!size) |
463 | return s; | |
464 | ||
465 | end = s + size - 1; | |
6e6d9fa6 | 466 | while (end >= s && isspace(*end)) |
481fad48 PE |
467 | end--; |
468 | *(end + 1) = '\0'; | |
469 | ||
66f6958e | 470 | return skip_spaces(s); |
481fad48 | 471 | } |
ca54cb8c | 472 | EXPORT_SYMBOL(strim); |
481fad48 | 473 | |
1da177e4 LT |
474 | #ifndef __HAVE_ARCH_STRLEN |
475 | /** | |
476 | * strlen - Find the length of a string | |
477 | * @s: The string to be sized | |
478 | */ | |
51a0f0f6 | 479 | size_t strlen(const char *s) |
1da177e4 LT |
480 | { |
481 | const char *sc; | |
482 | ||
483 | for (sc = s; *sc != '\0'; ++sc) | |
484 | /* nothing */; | |
485 | return sc - s; | |
486 | } | |
487 | EXPORT_SYMBOL(strlen); | |
488 | #endif | |
489 | ||
490 | #ifndef __HAVE_ARCH_STRNLEN | |
491 | /** | |
492 | * strnlen - Find the length of a length-limited string | |
493 | * @s: The string to be sized | |
494 | * @count: The maximum number of bytes to search | |
495 | */ | |
51a0f0f6 | 496 | size_t strnlen(const char *s, size_t count) |
1da177e4 LT |
497 | { |
498 | const char *sc; | |
499 | ||
500 | for (sc = s; count-- && *sc != '\0'; ++sc) | |
501 | /* nothing */; | |
502 | return sc - s; | |
503 | } | |
504 | EXPORT_SYMBOL(strnlen); | |
505 | #endif | |
506 | ||
507 | #ifndef __HAVE_ARCH_STRSPN | |
508 | /** | |
72fd4a35 | 509 | * strspn - Calculate the length of the initial substring of @s which only contain letters in @accept |
1da177e4 LT |
510 | * @s: The string to be searched |
511 | * @accept: The string to search for | |
512 | */ | |
513 | size_t strspn(const char *s, const char *accept) | |
514 | { | |
515 | const char *p; | |
516 | const char *a; | |
517 | size_t count = 0; | |
518 | ||
519 | for (p = s; *p != '\0'; ++p) { | |
520 | for (a = accept; *a != '\0'; ++a) { | |
521 | if (*p == *a) | |
522 | break; | |
523 | } | |
524 | if (*a == '\0') | |
525 | return count; | |
526 | ++count; | |
527 | } | |
1da177e4 LT |
528 | return count; |
529 | } | |
530 | ||
531 | EXPORT_SYMBOL(strspn); | |
532 | #endif | |
533 | ||
8833d328 | 534 | #ifndef __HAVE_ARCH_STRCSPN |
1da177e4 | 535 | /** |
72fd4a35 | 536 | * strcspn - Calculate the length of the initial substring of @s which does not contain letters in @reject |
1da177e4 LT |
537 | * @s: The string to be searched |
538 | * @reject: The string to avoid | |
539 | */ | |
540 | size_t strcspn(const char *s, const char *reject) | |
541 | { | |
542 | const char *p; | |
543 | const char *r; | |
544 | size_t count = 0; | |
545 | ||
546 | for (p = s; *p != '\0'; ++p) { | |
547 | for (r = reject; *r != '\0'; ++r) { | |
548 | if (*p == *r) | |
549 | return count; | |
550 | } | |
551 | ++count; | |
552 | } | |
1da177e4 | 553 | return count; |
51a0f0f6 | 554 | } |
1da177e4 | 555 | EXPORT_SYMBOL(strcspn); |
8833d328 | 556 | #endif |
1da177e4 LT |
557 | |
558 | #ifndef __HAVE_ARCH_STRPBRK | |
559 | /** | |
560 | * strpbrk - Find the first occurrence of a set of characters | |
561 | * @cs: The string to be searched | |
562 | * @ct: The characters to search for | |
563 | */ | |
51a0f0f6 | 564 | char *strpbrk(const char *cs, const char *ct) |
1da177e4 | 565 | { |
51a0f0f6 | 566 | const char *sc1, *sc2; |
1da177e4 | 567 | |
51a0f0f6 JJ |
568 | for (sc1 = cs; *sc1 != '\0'; ++sc1) { |
569 | for (sc2 = ct; *sc2 != '\0'; ++sc2) { | |
1da177e4 | 570 | if (*sc1 == *sc2) |
51a0f0f6 | 571 | return (char *)sc1; |
1da177e4 LT |
572 | } |
573 | } | |
574 | return NULL; | |
575 | } | |
894b5779 | 576 | EXPORT_SYMBOL(strpbrk); |
1da177e4 LT |
577 | #endif |
578 | ||
579 | #ifndef __HAVE_ARCH_STRSEP | |
580 | /** | |
581 | * strsep - Split a string into tokens | |
582 | * @s: The string to be searched | |
583 | * @ct: The characters to search for | |
584 | * | |
585 | * strsep() updates @s to point after the token, ready for the next call. | |
586 | * | |
587 | * It returns empty tokens, too, behaving exactly like the libc function | |
588 | * of that name. In fact, it was stolen from glibc2 and de-fancy-fied. | |
589 | * Same semantics, slimmer shape. ;) | |
590 | */ | |
51a0f0f6 | 591 | char *strsep(char **s, const char *ct) |
1da177e4 | 592 | { |
51a0f0f6 JJ |
593 | char *sbegin = *s; |
594 | char *end; | |
1da177e4 LT |
595 | |
596 | if (sbegin == NULL) | |
597 | return NULL; | |
598 | ||
599 | end = strpbrk(sbegin, ct); | |
600 | if (end) | |
601 | *end++ = '\0'; | |
602 | *s = end; | |
1da177e4 LT |
603 | return sbegin; |
604 | } | |
1da177e4 LT |
605 | EXPORT_SYMBOL(strsep); |
606 | #endif | |
607 | ||
34990cf7 DB |
608 | /** |
609 | * sysfs_streq - return true if strings are equal, modulo trailing newline | |
610 | * @s1: one string | |
611 | * @s2: another string | |
612 | * | |
613 | * This routine returns true iff two strings are equal, treating both | |
614 | * NUL and newline-then-NUL as equivalent string terminations. It's | |
615 | * geared for use with sysfs input strings, which generally terminate | |
616 | * with newlines but are compared against values without newlines. | |
617 | */ | |
618 | bool sysfs_streq(const char *s1, const char *s2) | |
619 | { | |
620 | while (*s1 && *s1 == *s2) { | |
621 | s1++; | |
622 | s2++; | |
623 | } | |
624 | ||
625 | if (*s1 == *s2) | |
626 | return true; | |
627 | if (!*s1 && *s2 == '\n' && !s2[1]) | |
628 | return true; | |
629 | if (*s1 == '\n' && !s1[1] && !*s2) | |
630 | return true; | |
631 | return false; | |
632 | } | |
633 | EXPORT_SYMBOL(sysfs_streq); | |
634 | ||
56b06081 AS |
635 | /** |
636 | * match_string - matches given string in an array | |
637 | * @array: array of strings | |
638 | * @n: number of strings in the array or -1 for NULL terminated arrays | |
639 | * @string: string to match with | |
640 | * | |
641 | * Return: | |
642 | * index of a @string in the @array if matches, or %-EINVAL otherwise. | |
643 | */ | |
644 | int match_string(const char * const *array, size_t n, const char *string) | |
645 | { | |
646 | int index; | |
647 | const char *item; | |
648 | ||
649 | for (index = 0; index < n; index++) { | |
650 | item = array[index]; | |
651 | if (!item) | |
652 | break; | |
653 | if (!strcmp(item, string)) | |
654 | return index; | |
655 | } | |
656 | ||
657 | return -EINVAL; | |
658 | } | |
659 | EXPORT_SYMBOL(match_string); | |
660 | ||
e1fe7b6a HK |
661 | /** |
662 | * __sysfs_match_string - matches given string in an array | |
663 | * @array: array of strings | |
664 | * @n: number of strings in the array or -1 for NULL terminated arrays | |
665 | * @str: string to match with | |
666 | * | |
667 | * Returns index of @str in the @array or -EINVAL, just like match_string(). | |
668 | * Uses sysfs_streq instead of strcmp for matching. | |
669 | */ | |
670 | int __sysfs_match_string(const char * const *array, size_t n, const char *str) | |
671 | { | |
672 | const char *item; | |
673 | int index; | |
674 | ||
675 | for (index = 0; index < n; index++) { | |
676 | item = array[index]; | |
677 | if (!item) | |
678 | break; | |
679 | if (sysfs_streq(item, str)) | |
680 | return index; | |
681 | } | |
682 | ||
683 | return -EINVAL; | |
684 | } | |
685 | EXPORT_SYMBOL(__sysfs_match_string); | |
686 | ||
1da177e4 LT |
687 | #ifndef __HAVE_ARCH_MEMSET |
688 | /** | |
689 | * memset - Fill a region of memory with the given value | |
690 | * @s: Pointer to the start of the area. | |
691 | * @c: The byte to fill the area with | |
692 | * @count: The size of the area. | |
693 | * | |
694 | * Do not use memset() to access IO space, use memset_io() instead. | |
695 | */ | |
51a0f0f6 | 696 | void *memset(void *s, int c, size_t count) |
1da177e4 | 697 | { |
850b9247 | 698 | char *xs = s; |
1da177e4 LT |
699 | |
700 | while (count--) | |
701 | *xs++ = c; | |
1da177e4 LT |
702 | return s; |
703 | } | |
704 | EXPORT_SYMBOL(memset); | |
705 | #endif | |
706 | ||
d4c5efdb DB |
707 | /** |
708 | * memzero_explicit - Fill a region of memory (e.g. sensitive | |
709 | * keying data) with 0s. | |
710 | * @s: Pointer to the start of the area. | |
711 | * @count: The size of the area. | |
712 | * | |
8155330a DB |
713 | * Note: usually using memset() is just fine (!), but in cases |
714 | * where clearing out _local_ data at the end of a scope is | |
715 | * necessary, memzero_explicit() should be used instead in | |
716 | * order to prevent the compiler from optimising away zeroing. | |
717 | * | |
d4c5efdb DB |
718 | * memzero_explicit() doesn't need an arch-specific version as |
719 | * it just invokes the one of memset() implicitly. | |
720 | */ | |
721 | void memzero_explicit(void *s, size_t count) | |
722 | { | |
723 | memset(s, 0, count); | |
7829fb09 | 724 | barrier_data(s); |
d4c5efdb DB |
725 | } |
726 | EXPORT_SYMBOL(memzero_explicit); | |
727 | ||
3b3c4bab MW |
728 | #ifndef __HAVE_ARCH_MEMSET16 |
729 | /** | |
730 | * memset16() - Fill a memory area with a uint16_t | |
731 | * @s: Pointer to the start of the area. | |
732 | * @v: The value to fill the area with | |
733 | * @count: The number of values to store | |
734 | * | |
735 | * Differs from memset() in that it fills with a uint16_t instead | |
736 | * of a byte. Remember that @count is the number of uint16_ts to | |
737 | * store, not the number of bytes. | |
738 | */ | |
739 | void *memset16(uint16_t *s, uint16_t v, size_t count) | |
740 | { | |
741 | uint16_t *xs = s; | |
742 | ||
743 | while (count--) | |
744 | *xs++ = v; | |
745 | return s; | |
746 | } | |
747 | EXPORT_SYMBOL(memset16); | |
748 | #endif | |
749 | ||
750 | #ifndef __HAVE_ARCH_MEMSET32 | |
751 | /** | |
752 | * memset32() - Fill a memory area with a uint32_t | |
753 | * @s: Pointer to the start of the area. | |
754 | * @v: The value to fill the area with | |
755 | * @count: The number of values to store | |
756 | * | |
757 | * Differs from memset() in that it fills with a uint32_t instead | |
758 | * of a byte. Remember that @count is the number of uint32_ts to | |
759 | * store, not the number of bytes. | |
760 | */ | |
761 | void *memset32(uint32_t *s, uint32_t v, size_t count) | |
762 | { | |
763 | uint32_t *xs = s; | |
764 | ||
765 | while (count--) | |
766 | *xs++ = v; | |
767 | return s; | |
768 | } | |
769 | EXPORT_SYMBOL(memset32); | |
770 | #endif | |
771 | ||
772 | #ifndef __HAVE_ARCH_MEMSET64 | |
773 | /** | |
774 | * memset64() - Fill a memory area with a uint64_t | |
775 | * @s: Pointer to the start of the area. | |
776 | * @v: The value to fill the area with | |
777 | * @count: The number of values to store | |
778 | * | |
779 | * Differs from memset() in that it fills with a uint64_t instead | |
780 | * of a byte. Remember that @count is the number of uint64_ts to | |
781 | * store, not the number of bytes. | |
782 | */ | |
783 | void *memset64(uint64_t *s, uint64_t v, size_t count) | |
784 | { | |
785 | uint64_t *xs = s; | |
786 | ||
787 | while (count--) | |
788 | *xs++ = v; | |
789 | return s; | |
790 | } | |
791 | EXPORT_SYMBOL(memset64); | |
792 | #endif | |
793 | ||
1da177e4 LT |
794 | #ifndef __HAVE_ARCH_MEMCPY |
795 | /** | |
796 | * memcpy - Copy one area of memory to another | |
797 | * @dest: Where to copy to | |
798 | * @src: Where to copy from | |
799 | * @count: The size of the area. | |
800 | * | |
801 | * You should not use this function to access IO space, use memcpy_toio() | |
802 | * or memcpy_fromio() instead. | |
803 | */ | |
51a0f0f6 | 804 | void *memcpy(void *dest, const void *src, size_t count) |
1da177e4 | 805 | { |
850b9247 | 806 | char *tmp = dest; |
4c416ab7 | 807 | const char *s = src; |
1da177e4 LT |
808 | |
809 | while (count--) | |
810 | *tmp++ = *s++; | |
1da177e4 LT |
811 | return dest; |
812 | } | |
813 | EXPORT_SYMBOL(memcpy); | |
814 | #endif | |
815 | ||
816 | #ifndef __HAVE_ARCH_MEMMOVE | |
817 | /** | |
818 | * memmove - Copy one area of memory to another | |
819 | * @dest: Where to copy to | |
820 | * @src: Where to copy from | |
821 | * @count: The size of the area. | |
822 | * | |
823 | * Unlike memcpy(), memmove() copes with overlapping areas. | |
824 | */ | |
51a0f0f6 | 825 | void *memmove(void *dest, const void *src, size_t count) |
1da177e4 | 826 | { |
82da2c37 PJ |
827 | char *tmp; |
828 | const char *s; | |
1da177e4 LT |
829 | |
830 | if (dest <= src) { | |
850b9247 JJ |
831 | tmp = dest; |
832 | s = src; | |
1da177e4 LT |
833 | while (count--) |
834 | *tmp++ = *s++; | |
51a0f0f6 | 835 | } else { |
850b9247 JJ |
836 | tmp = dest; |
837 | tmp += count; | |
838 | s = src; | |
839 | s += count; | |
1da177e4 LT |
840 | while (count--) |
841 | *--tmp = *--s; | |
51a0f0f6 | 842 | } |
1da177e4 LT |
843 | return dest; |
844 | } | |
845 | EXPORT_SYMBOL(memmove); | |
846 | #endif | |
847 | ||
848 | #ifndef __HAVE_ARCH_MEMCMP | |
849 | /** | |
850 | * memcmp - Compare two areas of memory | |
851 | * @cs: One area of memory | |
852 | * @ct: Another area of memory | |
853 | * @count: The size of the area. | |
854 | */ | |
0c28130b | 855 | #undef memcmp |
a7330c99 | 856 | __visible int memcmp(const void *cs, const void *ct, size_t count) |
1da177e4 LT |
857 | { |
858 | const unsigned char *su1, *su2; | |
859 | int res = 0; | |
860 | ||
51a0f0f6 | 861 | for (su1 = cs, su2 = ct; 0 < count; ++su1, ++su2, count--) |
1da177e4 LT |
862 | if ((res = *su1 - *su2) != 0) |
863 | break; | |
864 | return res; | |
865 | } | |
866 | EXPORT_SYMBOL(memcmp); | |
867 | #endif | |
868 | ||
5f074f3e ND |
869 | #ifndef __HAVE_ARCH_BCMP |
870 | /** | |
871 | * bcmp - returns 0 if and only if the buffers have identical contents. | |
872 | * @a: pointer to first buffer. | |
873 | * @b: pointer to second buffer. | |
874 | * @len: size of buffers. | |
875 | * | |
876 | * The sign or magnitude of a non-zero return value has no particular | |
877 | * meaning, and architectures may implement their own more efficient bcmp(). So | |
878 | * while this particular implementation is a simple (tail) call to memcmp, do | |
879 | * not rely on anything but whether the return value is zero or non-zero. | |
880 | */ | |
881 | #undef bcmp | |
882 | int bcmp(const void *a, const void *b, size_t len) | |
883 | { | |
884 | return memcmp(a, b, len); | |
885 | } | |
886 | EXPORT_SYMBOL(bcmp); | |
887 | #endif | |
888 | ||
1da177e4 LT |
889 | #ifndef __HAVE_ARCH_MEMSCAN |
890 | /** | |
891 | * memscan - Find a character in an area of memory. | |
892 | * @addr: The memory area | |
893 | * @c: The byte to search for | |
894 | * @size: The size of the area. | |
895 | * | |
896 | * returns the address of the first occurrence of @c, or 1 byte past | |
897 | * the area if @c is not found | |
898 | */ | |
51a0f0f6 | 899 | void *memscan(void *addr, int c, size_t size) |
1da177e4 | 900 | { |
850b9247 | 901 | unsigned char *p = addr; |
1da177e4 LT |
902 | |
903 | while (size) { | |
904 | if (*p == c) | |
51a0f0f6 | 905 | return (void *)p; |
1da177e4 LT |
906 | p++; |
907 | size--; | |
908 | } | |
51a0f0f6 | 909 | return (void *)p; |
1da177e4 LT |
910 | } |
911 | EXPORT_SYMBOL(memscan); | |
912 | #endif | |
913 | ||
914 | #ifndef __HAVE_ARCH_STRSTR | |
915 | /** | |
916 | * strstr - Find the first substring in a %NUL terminated string | |
917 | * @s1: The string to be searched | |
918 | * @s2: The string to search for | |
919 | */ | |
51a0f0f6 | 920 | char *strstr(const char *s1, const char *s2) |
1da177e4 | 921 | { |
d5f1fb53 | 922 | size_t l1, l2; |
1da177e4 LT |
923 | |
924 | l2 = strlen(s2); | |
925 | if (!l2) | |
51a0f0f6 | 926 | return (char *)s1; |
1da177e4 LT |
927 | l1 = strlen(s1); |
928 | while (l1 >= l2) { | |
929 | l1--; | |
51a0f0f6 JJ |
930 | if (!memcmp(s1, s2, l2)) |
931 | return (char *)s1; | |
1da177e4 LT |
932 | s1++; |
933 | } | |
934 | return NULL; | |
935 | } | |
936 | EXPORT_SYMBOL(strstr); | |
937 | #endif | |
938 | ||
d5f1fb53 LZ |
939 | #ifndef __HAVE_ARCH_STRNSTR |
940 | /** | |
941 | * strnstr - Find the first substring in a length-limited string | |
942 | * @s1: The string to be searched | |
943 | * @s2: The string to search for | |
944 | * @len: the maximum number of characters to search | |
945 | */ | |
946 | char *strnstr(const char *s1, const char *s2, size_t len) | |
947 | { | |
d6a2eedf | 948 | size_t l2; |
d5f1fb53 LZ |
949 | |
950 | l2 = strlen(s2); | |
951 | if (!l2) | |
952 | return (char *)s1; | |
d6a2eedf AGR |
953 | while (len >= l2) { |
954 | len--; | |
d5f1fb53 LZ |
955 | if (!memcmp(s1, s2, l2)) |
956 | return (char *)s1; | |
957 | s1++; | |
958 | } | |
959 | return NULL; | |
960 | } | |
961 | EXPORT_SYMBOL(strnstr); | |
962 | #endif | |
963 | ||
1da177e4 LT |
964 | #ifndef __HAVE_ARCH_MEMCHR |
965 | /** | |
966 | * memchr - Find a character in an area of memory. | |
967 | * @s: The memory area | |
968 | * @c: The byte to search for | |
969 | * @n: The size of the area. | |
970 | * | |
971 | * returns the address of the first occurrence of @c, or %NULL | |
972 | * if @c is not found | |
973 | */ | |
974 | void *memchr(const void *s, int c, size_t n) | |
975 | { | |
976 | const unsigned char *p = s; | |
977 | while (n-- != 0) { | |
978 | if ((unsigned char)c == *p++) { | |
51a0f0f6 | 979 | return (void *)(p - 1); |
1da177e4 LT |
980 | } |
981 | } | |
982 | return NULL; | |
983 | } | |
984 | EXPORT_SYMBOL(memchr); | |
985 | #endif | |
79824820 AM |
986 | |
987 | static void *check_bytes8(const u8 *start, u8 value, unsigned int bytes) | |
988 | { | |
989 | while (bytes) { | |
990 | if (*start != value) | |
991 | return (void *)start; | |
992 | start++; | |
993 | bytes--; | |
994 | } | |
995 | return NULL; | |
996 | } | |
997 | ||
998 | /** | |
999 | * memchr_inv - Find an unmatching character in an area of memory. | |
1000 | * @start: The memory area | |
1001 | * @c: Find a character other than c | |
1002 | * @bytes: The size of the area. | |
1003 | * | |
1004 | * returns the address of the first character other than @c, or %NULL | |
1005 | * if the whole buffer contains just @c. | |
1006 | */ | |
1007 | void *memchr_inv(const void *start, int c, size_t bytes) | |
1008 | { | |
1009 | u8 value = c; | |
1010 | u64 value64; | |
1011 | unsigned int words, prefix; | |
1012 | ||
1013 | if (bytes <= 16) | |
1014 | return check_bytes8(start, value, bytes); | |
1015 | ||
f43804bf | 1016 | value64 = value; |
72d93104 | 1017 | #if defined(CONFIG_ARCH_HAS_FAST_MULTIPLIER) && BITS_PER_LONG == 64 |
3368e8fb | 1018 | value64 *= 0x0101010101010101ULL; |
72d93104 | 1019 | #elif defined(CONFIG_ARCH_HAS_FAST_MULTIPLIER) |
f43804bf AM |
1020 | value64 *= 0x01010101; |
1021 | value64 |= value64 << 32; | |
1022 | #else | |
1023 | value64 |= value64 << 8; | |
1024 | value64 |= value64 << 16; | |
1025 | value64 |= value64 << 32; | |
1026 | #endif | |
79824820 | 1027 | |
f43804bf | 1028 | prefix = (unsigned long)start % 8; |
79824820 | 1029 | if (prefix) { |
f43804bf AM |
1030 | u8 *r; |
1031 | ||
1032 | prefix = 8 - prefix; | |
1033 | r = check_bytes8(start, value, prefix); | |
79824820 AM |
1034 | if (r) |
1035 | return r; | |
1036 | start += prefix; | |
1037 | bytes -= prefix; | |
1038 | } | |
1039 | ||
1040 | words = bytes / 8; | |
1041 | ||
1042 | while (words) { | |
1043 | if (*(u64 *)start != value64) | |
1044 | return check_bytes8(start, value, 8); | |
1045 | start += 8; | |
1046 | words--; | |
1047 | } | |
1048 | ||
1049 | return check_bytes8(start, value, bytes % 8); | |
1050 | } | |
1051 | EXPORT_SYMBOL(memchr_inv); | |
94df2904 RV |
1052 | |
1053 | /** | |
1054 | * strreplace - Replace all occurrences of character in string. | |
1055 | * @s: The string to operate on. | |
1056 | * @old: The character being replaced. | |
1057 | * @new: The character @old is replaced with. | |
1058 | * | |
1059 | * Returns pointer to the nul byte at the end of @s. | |
1060 | */ | |
1061 | char *strreplace(char *s, char old, char new) | |
1062 | { | |
1063 | for (; *s; ++s) | |
1064 | if (*s == old) | |
1065 | *s = new; | |
1066 | return s; | |
1067 | } | |
1068 | EXPORT_SYMBOL(strreplace); | |
6974f0c4 DM |
1069 | |
1070 | void fortify_panic(const char *name) | |
1071 | { | |
1072 | pr_emerg("detected buffer overflow in %s\n", name); | |
1073 | BUG(); | |
1074 | } | |
1075 | EXPORT_SYMBOL(fortify_panic); |