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Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * linux/lib/string.c | |
3 | * | |
4 | * Copyright (C) 1991, 1992 Linus Torvalds | |
5 | */ | |
6 | ||
7 | /* | |
8 | * stupid library routines.. The optimized versions should generally be found | |
9 | * as inline code in <asm-xx/string.h> | |
10 | * | |
11 | * These are buggy as well.. | |
12 | * | |
13 | * * Fri Jun 25 1999, Ingo Oeser <ioe@informatik.tu-chemnitz.de> | |
14 | * - Added strsep() which will replace strtok() soon (because strsep() is | |
15 | * reentrant and should be faster). Use only strsep() in new code, please. | |
16 | * | |
17 | * * Sat Feb 09 2002, Jason Thomas <jason@topic.com.au>, | |
18 | * Matthew Hawkins <matt@mh.dropbear.id.au> | |
19 | * - Kissed strtok() goodbye | |
20 | */ | |
21 | ||
22 | #include <linux/types.h> | |
23 | #include <linux/string.h> | |
24 | #include <linux/ctype.h> | |
8bc3bcc9 PG |
25 | #include <linux/kernel.h> |
26 | #include <linux/export.h> | |
50af5ead | 27 | #include <linux/bug.h> |
8bc3bcc9 | 28 | #include <linux/errno.h> |
1da177e4 | 29 | |
30035e45 CM |
30 | #include <asm/byteorder.h> |
31 | #include <asm/word-at-a-time.h> | |
32 | #include <asm/page.h> | |
33 | ||
cd514e72 | 34 | #ifndef __HAVE_ARCH_STRNCASECMP |
1da177e4 | 35 | /** |
cd514e72 | 36 | * strncasecmp - Case insensitive, length-limited string comparison |
1da177e4 LT |
37 | * @s1: One string |
38 | * @s2: The other string | |
39 | * @len: the maximum number of characters to compare | |
40 | */ | |
cd514e72 | 41 | int strncasecmp(const char *s1, const char *s2, size_t len) |
1da177e4 LT |
42 | { |
43 | /* Yes, Virginia, it had better be unsigned */ | |
44 | unsigned char c1, c2; | |
45 | ||
a11d2b64 AGR |
46 | if (!len) |
47 | return 0; | |
48 | ||
49 | do { | |
50 | c1 = *s1++; | |
51 | c2 = *s2++; | |
52 | if (!c1 || !c2) | |
53 | break; | |
54 | if (c1 == c2) | |
55 | continue; | |
56 | c1 = tolower(c1); | |
57 | c2 = tolower(c2); | |
58 | if (c1 != c2) | |
59 | break; | |
60 | } while (--len); | |
1da177e4 LT |
61 | return (int)c1 - (int)c2; |
62 | } | |
cd514e72 RV |
63 | EXPORT_SYMBOL(strncasecmp); |
64 | #endif | |
1da177e4 | 65 | |
ded220bd DM |
66 | #ifndef __HAVE_ARCH_STRCASECMP |
67 | int strcasecmp(const char *s1, const char *s2) | |
68 | { | |
69 | int c1, c2; | |
70 | ||
71 | do { | |
72 | c1 = tolower(*s1++); | |
73 | c2 = tolower(*s2++); | |
74 | } while (c1 == c2 && c1 != 0); | |
75 | return c1 - c2; | |
76 | } | |
77 | EXPORT_SYMBOL(strcasecmp); | |
78 | #endif | |
79 | ||
1da177e4 LT |
80 | #ifndef __HAVE_ARCH_STRCPY |
81 | /** | |
82 | * strcpy - Copy a %NUL terminated string | |
83 | * @dest: Where to copy the string to | |
84 | * @src: Where to copy the string from | |
85 | */ | |
0c28130b | 86 | #undef strcpy |
51a0f0f6 | 87 | char *strcpy(char *dest, const char *src) |
1da177e4 LT |
88 | { |
89 | char *tmp = dest; | |
90 | ||
91 | while ((*dest++ = *src++) != '\0') | |
92 | /* nothing */; | |
93 | return tmp; | |
94 | } | |
95 | EXPORT_SYMBOL(strcpy); | |
96 | #endif | |
97 | ||
98 | #ifndef __HAVE_ARCH_STRNCPY | |
99 | /** | |
0046dd9f | 100 | * strncpy - Copy a length-limited, C-string |
1da177e4 LT |
101 | * @dest: Where to copy the string to |
102 | * @src: Where to copy the string from | |
103 | * @count: The maximum number of bytes to copy | |
104 | * | |
105 | * The result is not %NUL-terminated if the source exceeds | |
106 | * @count bytes. | |
25279526 | 107 | * |
108 | * In the case where the length of @src is less than that of | |
109 | * count, the remainder of @dest will be padded with %NUL. | |
110 | * | |
1da177e4 | 111 | */ |
51a0f0f6 | 112 | char *strncpy(char *dest, const char *src, size_t count) |
1da177e4 LT |
113 | { |
114 | char *tmp = dest; | |
115 | ||
116 | while (count) { | |
51a0f0f6 JJ |
117 | if ((*tmp = *src) != 0) |
118 | src++; | |
1da177e4 LT |
119 | tmp++; |
120 | count--; | |
121 | } | |
122 | return dest; | |
123 | } | |
124 | EXPORT_SYMBOL(strncpy); | |
125 | #endif | |
126 | ||
127 | #ifndef __HAVE_ARCH_STRLCPY | |
128 | /** | |
0046dd9f | 129 | * strlcpy - Copy a C-string into a sized buffer |
1da177e4 LT |
130 | * @dest: Where to copy the string to |
131 | * @src: Where to copy the string from | |
132 | * @size: size of destination buffer | |
133 | * | |
134 | * Compatible with *BSD: the result is always a valid | |
135 | * NUL-terminated string that fits in the buffer (unless, | |
136 | * of course, the buffer size is zero). It does not pad | |
137 | * out the result like strncpy() does. | |
138 | */ | |
139 | size_t strlcpy(char *dest, const char *src, size_t size) | |
140 | { | |
141 | size_t ret = strlen(src); | |
142 | ||
143 | if (size) { | |
51a0f0f6 | 144 | size_t len = (ret >= size) ? size - 1 : ret; |
1da177e4 LT |
145 | memcpy(dest, src, len); |
146 | dest[len] = '\0'; | |
147 | } | |
148 | return ret; | |
149 | } | |
150 | EXPORT_SYMBOL(strlcpy); | |
151 | #endif | |
152 | ||
30035e45 CM |
153 | #ifndef __HAVE_ARCH_STRSCPY |
154 | /** | |
155 | * strscpy - Copy a C-string into a sized buffer | |
156 | * @dest: Where to copy the string to | |
157 | * @src: Where to copy the string from | |
158 | * @count: Size of destination buffer | |
159 | * | |
160 | * Copy the string, or as much of it as fits, into the dest buffer. | |
161 | * The routine returns the number of characters copied (not including | |
162 | * the trailing NUL) or -E2BIG if the destination buffer wasn't big enough. | |
163 | * The behavior is undefined if the string buffers overlap. | |
164 | * The destination buffer is always NUL terminated, unless it's zero-sized. | |
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 | |
174 | * zeroed. If the zeroing is desired, it's likely cleaner to use strscpy() | |
175 | * with an overflow test, then just memset() the tail of the dest buffer. | |
176 | */ | |
177 | ssize_t strscpy(char *dest, const char *src, size_t count) | |
178 | { | |
179 | const struct word_at_a_time constants = WORD_AT_A_TIME_CONSTANTS; | |
180 | size_t max = count; | |
181 | long res = 0; | |
182 | ||
183 | if (count == 0) | |
184 | return -E2BIG; | |
185 | ||
186 | #ifdef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS | |
187 | /* | |
188 | * If src is unaligned, don't cross a page boundary, | |
189 | * since we don't know if the next page is mapped. | |
190 | */ | |
191 | if ((long)src & (sizeof(long) - 1)) { | |
192 | size_t limit = PAGE_SIZE - ((long)src & (PAGE_SIZE - 1)); | |
193 | if (limit < max) | |
194 | max = limit; | |
195 | } | |
196 | #else | |
197 | /* If src or dest is unaligned, don't do word-at-a-time. */ | |
198 | if (((long) dest | (long) src) & (sizeof(long) - 1)) | |
199 | max = 0; | |
200 | #endif | |
201 | ||
202 | while (max >= sizeof(unsigned long)) { | |
203 | unsigned long c, data; | |
204 | ||
205 | c = *(unsigned long *)(src+res); | |
206 | *(unsigned long *)(dest+res) = c; | |
207 | if (has_zero(c, &data, &constants)) { | |
208 | data = prep_zero_mask(c, data, &constants); | |
209 | data = create_zero_mask(data); | |
210 | return res + find_zero(data); | |
211 | } | |
212 | res += sizeof(unsigned long); | |
213 | count -= sizeof(unsigned long); | |
214 | max -= sizeof(unsigned long); | |
215 | } | |
216 | ||
217 | while (count) { | |
218 | char c; | |
219 | ||
220 | c = src[res]; | |
221 | dest[res] = c; | |
222 | if (!c) | |
223 | return res; | |
224 | res++; | |
225 | count--; | |
226 | } | |
227 | ||
228 | /* Hit buffer length without finding a NUL; force NUL-termination. */ | |
229 | if (res) | |
230 | dest[res-1] = '\0'; | |
231 | ||
232 | return -E2BIG; | |
233 | } | |
234 | EXPORT_SYMBOL(strscpy); | |
235 | #endif | |
236 | ||
1da177e4 LT |
237 | #ifndef __HAVE_ARCH_STRCAT |
238 | /** | |
239 | * strcat - Append one %NUL-terminated string to another | |
240 | * @dest: The string to be appended to | |
241 | * @src: The string to append to it | |
242 | */ | |
0c28130b | 243 | #undef strcat |
51a0f0f6 | 244 | char *strcat(char *dest, const char *src) |
1da177e4 LT |
245 | { |
246 | char *tmp = dest; | |
247 | ||
248 | while (*dest) | |
249 | dest++; | |
250 | while ((*dest++ = *src++) != '\0') | |
251 | ; | |
1da177e4 LT |
252 | return tmp; |
253 | } | |
254 | EXPORT_SYMBOL(strcat); | |
255 | #endif | |
256 | ||
257 | #ifndef __HAVE_ARCH_STRNCAT | |
258 | /** | |
0046dd9f | 259 | * strncat - Append a length-limited, C-string to another |
1da177e4 LT |
260 | * @dest: The string to be appended to |
261 | * @src: The string to append to it | |
262 | * @count: The maximum numbers of bytes to copy | |
263 | * | |
72fd4a35 | 264 | * Note that in contrast to strncpy(), strncat() ensures the result is |
1da177e4 LT |
265 | * terminated. |
266 | */ | |
51a0f0f6 | 267 | char *strncat(char *dest, const char *src, size_t count) |
1da177e4 LT |
268 | { |
269 | char *tmp = dest; | |
270 | ||
271 | if (count) { | |
272 | while (*dest) | |
273 | dest++; | |
274 | while ((*dest++ = *src++) != 0) { | |
275 | if (--count == 0) { | |
276 | *dest = '\0'; | |
277 | break; | |
278 | } | |
279 | } | |
280 | } | |
1da177e4 LT |
281 | return tmp; |
282 | } | |
283 | EXPORT_SYMBOL(strncat); | |
284 | #endif | |
285 | ||
286 | #ifndef __HAVE_ARCH_STRLCAT | |
287 | /** | |
0046dd9f | 288 | * strlcat - Append a length-limited, C-string to another |
1da177e4 LT |
289 | * @dest: The string to be appended to |
290 | * @src: The string to append to it | |
291 | * @count: The size of the destination buffer. | |
292 | */ | |
293 | size_t strlcat(char *dest, const char *src, size_t count) | |
294 | { | |
295 | size_t dsize = strlen(dest); | |
296 | size_t len = strlen(src); | |
297 | size_t res = dsize + len; | |
298 | ||
299 | /* This would be a bug */ | |
300 | BUG_ON(dsize >= count); | |
301 | ||
302 | dest += dsize; | |
303 | count -= dsize; | |
304 | if (len >= count) | |
305 | len = count-1; | |
306 | memcpy(dest, src, len); | |
307 | dest[len] = 0; | |
308 | return res; | |
309 | } | |
310 | EXPORT_SYMBOL(strlcat); | |
311 | #endif | |
312 | ||
313 | #ifndef __HAVE_ARCH_STRCMP | |
314 | /** | |
315 | * strcmp - Compare two strings | |
316 | * @cs: One string | |
317 | * @ct: Another string | |
318 | */ | |
0c28130b | 319 | #undef strcmp |
51a0f0f6 | 320 | int strcmp(const char *cs, const char *ct) |
1da177e4 | 321 | { |
a414f01a | 322 | unsigned char c1, c2; |
1da177e4 LT |
323 | |
324 | while (1) { | |
a414f01a LT |
325 | c1 = *cs++; |
326 | c2 = *ct++; | |
327 | if (c1 != c2) | |
328 | return c1 < c2 ? -1 : 1; | |
329 | if (!c1) | |
1da177e4 LT |
330 | break; |
331 | } | |
a414f01a | 332 | return 0; |
1da177e4 LT |
333 | } |
334 | EXPORT_SYMBOL(strcmp); | |
335 | #endif | |
336 | ||
337 | #ifndef __HAVE_ARCH_STRNCMP | |
338 | /** | |
339 | * strncmp - Compare two length-limited strings | |
340 | * @cs: One string | |
341 | * @ct: Another string | |
342 | * @count: The maximum number of bytes to compare | |
343 | */ | |
51a0f0f6 | 344 | int strncmp(const char *cs, const char *ct, size_t count) |
1da177e4 | 345 | { |
a414f01a | 346 | unsigned char c1, c2; |
1da177e4 LT |
347 | |
348 | while (count) { | |
a414f01a LT |
349 | c1 = *cs++; |
350 | c2 = *ct++; | |
351 | if (c1 != c2) | |
352 | return c1 < c2 ? -1 : 1; | |
353 | if (!c1) | |
1da177e4 LT |
354 | break; |
355 | count--; | |
356 | } | |
a414f01a | 357 | return 0; |
1da177e4 LT |
358 | } |
359 | EXPORT_SYMBOL(strncmp); | |
360 | #endif | |
361 | ||
362 | #ifndef __HAVE_ARCH_STRCHR | |
363 | /** | |
364 | * strchr - Find the first occurrence of a character in a string | |
365 | * @s: The string to be searched | |
366 | * @c: The character to search for | |
367 | */ | |
51a0f0f6 | 368 | char *strchr(const char *s, int c) |
1da177e4 | 369 | { |
51a0f0f6 | 370 | for (; *s != (char)c; ++s) |
1da177e4 LT |
371 | if (*s == '\0') |
372 | return NULL; | |
51a0f0f6 | 373 | return (char *)s; |
1da177e4 LT |
374 | } |
375 | EXPORT_SYMBOL(strchr); | |
376 | #endif | |
377 | ||
11d200e9 GL |
378 | #ifndef __HAVE_ARCH_STRCHRNUL |
379 | /** | |
380 | * strchrnul - Find and return a character in a string, or end of string | |
381 | * @s: The string to be searched | |
382 | * @c: The character to search for | |
383 | * | |
384 | * Returns pointer to first occurrence of 'c' in s. If c is not found, then | |
385 | * return a pointer to the null byte at the end of s. | |
386 | */ | |
387 | char *strchrnul(const char *s, int c) | |
388 | { | |
389 | while (*s && *s != (char)c) | |
390 | s++; | |
391 | return (char *)s; | |
392 | } | |
393 | EXPORT_SYMBOL(strchrnul); | |
394 | #endif | |
395 | ||
1da177e4 LT |
396 | #ifndef __HAVE_ARCH_STRRCHR |
397 | /** | |
398 | * strrchr - Find the last occurrence of a character in a string | |
399 | * @s: The string to be searched | |
400 | * @c: The character to search for | |
401 | */ | |
51a0f0f6 | 402 | char *strrchr(const char *s, int c) |
1da177e4 | 403 | { |
8da53d45 RV |
404 | const char *last = NULL; |
405 | do { | |
406 | if (*s == (char)c) | |
407 | last = s; | |
408 | } while (*s++); | |
409 | return (char *)last; | |
1da177e4 LT |
410 | } |
411 | EXPORT_SYMBOL(strrchr); | |
412 | #endif | |
413 | ||
414 | #ifndef __HAVE_ARCH_STRNCHR | |
415 | /** | |
416 | * strnchr - Find a character in a length limited string | |
417 | * @s: The string to be searched | |
418 | * @count: The number of characters to be searched | |
419 | * @c: The character to search for | |
420 | */ | |
421 | char *strnchr(const char *s, size_t count, int c) | |
422 | { | |
423 | for (; count-- && *s != '\0'; ++s) | |
51a0f0f6 JJ |
424 | if (*s == (char)c) |
425 | return (char *)s; | |
1da177e4 LT |
426 | return NULL; |
427 | } | |
428 | EXPORT_SYMBOL(strnchr); | |
429 | #endif | |
430 | ||
f653398c | 431 | /** |
a6cd13f3 RD |
432 | * skip_spaces - Removes leading whitespace from @str. |
433 | * @str: The string to be stripped. | |
f653398c | 434 | * |
a6cd13f3 | 435 | * Returns a pointer to the first non-whitespace character in @str. |
f653398c AGR |
436 | */ |
437 | char *skip_spaces(const char *str) | |
438 | { | |
439 | while (isspace(*str)) | |
440 | ++str; | |
441 | return (char *)str; | |
442 | } | |
443 | EXPORT_SYMBOL(skip_spaces); | |
444 | ||
481fad48 | 445 | /** |
ca54cb8c | 446 | * strim - Removes leading and trailing whitespace from @s. |
481fad48 PE |
447 | * @s: The string to be stripped. |
448 | * | |
449 | * Note that the first trailing whitespace is replaced with a %NUL-terminator | |
450 | * in the given string @s. Returns a pointer to the first non-whitespace | |
451 | * character in @s. | |
452 | */ | |
ca54cb8c | 453 | char *strim(char *s) |
481fad48 PE |
454 | { |
455 | size_t size; | |
456 | char *end; | |
457 | ||
458 | size = strlen(s); | |
481fad48 PE |
459 | if (!size) |
460 | return s; | |
461 | ||
462 | end = s + size - 1; | |
6e6d9fa6 | 463 | while (end >= s && isspace(*end)) |
481fad48 PE |
464 | end--; |
465 | *(end + 1) = '\0'; | |
466 | ||
66f6958e | 467 | return skip_spaces(s); |
481fad48 | 468 | } |
ca54cb8c | 469 | EXPORT_SYMBOL(strim); |
481fad48 | 470 | |
1da177e4 LT |
471 | #ifndef __HAVE_ARCH_STRLEN |
472 | /** | |
473 | * strlen - Find the length of a string | |
474 | * @s: The string to be sized | |
475 | */ | |
51a0f0f6 | 476 | size_t strlen(const char *s) |
1da177e4 LT |
477 | { |
478 | const char *sc; | |
479 | ||
480 | for (sc = s; *sc != '\0'; ++sc) | |
481 | /* nothing */; | |
482 | return sc - s; | |
483 | } | |
484 | EXPORT_SYMBOL(strlen); | |
485 | #endif | |
486 | ||
487 | #ifndef __HAVE_ARCH_STRNLEN | |
488 | /** | |
489 | * strnlen - Find the length of a length-limited string | |
490 | * @s: The string to be sized | |
491 | * @count: The maximum number of bytes to search | |
492 | */ | |
51a0f0f6 | 493 | size_t strnlen(const char *s, size_t count) |
1da177e4 LT |
494 | { |
495 | const char *sc; | |
496 | ||
497 | for (sc = s; count-- && *sc != '\0'; ++sc) | |
498 | /* nothing */; | |
499 | return sc - s; | |
500 | } | |
501 | EXPORT_SYMBOL(strnlen); | |
502 | #endif | |
503 | ||
504 | #ifndef __HAVE_ARCH_STRSPN | |
505 | /** | |
72fd4a35 | 506 | * strspn - Calculate the length of the initial substring of @s which only contain letters in @accept |
1da177e4 LT |
507 | * @s: The string to be searched |
508 | * @accept: The string to search for | |
509 | */ | |
510 | size_t strspn(const char *s, const char *accept) | |
511 | { | |
512 | const char *p; | |
513 | const char *a; | |
514 | size_t count = 0; | |
515 | ||
516 | for (p = s; *p != '\0'; ++p) { | |
517 | for (a = accept; *a != '\0'; ++a) { | |
518 | if (*p == *a) | |
519 | break; | |
520 | } | |
521 | if (*a == '\0') | |
522 | return count; | |
523 | ++count; | |
524 | } | |
1da177e4 LT |
525 | return count; |
526 | } | |
527 | ||
528 | EXPORT_SYMBOL(strspn); | |
529 | #endif | |
530 | ||
8833d328 | 531 | #ifndef __HAVE_ARCH_STRCSPN |
1da177e4 | 532 | /** |
72fd4a35 | 533 | * strcspn - Calculate the length of the initial substring of @s which does not contain letters in @reject |
1da177e4 LT |
534 | * @s: The string to be searched |
535 | * @reject: The string to avoid | |
536 | */ | |
537 | size_t strcspn(const char *s, const char *reject) | |
538 | { | |
539 | const char *p; | |
540 | const char *r; | |
541 | size_t count = 0; | |
542 | ||
543 | for (p = s; *p != '\0'; ++p) { | |
544 | for (r = reject; *r != '\0'; ++r) { | |
545 | if (*p == *r) | |
546 | return count; | |
547 | } | |
548 | ++count; | |
549 | } | |
1da177e4 | 550 | return count; |
51a0f0f6 | 551 | } |
1da177e4 | 552 | EXPORT_SYMBOL(strcspn); |
8833d328 | 553 | #endif |
1da177e4 LT |
554 | |
555 | #ifndef __HAVE_ARCH_STRPBRK | |
556 | /** | |
557 | * strpbrk - Find the first occurrence of a set of characters | |
558 | * @cs: The string to be searched | |
559 | * @ct: The characters to search for | |
560 | */ | |
51a0f0f6 | 561 | char *strpbrk(const char *cs, const char *ct) |
1da177e4 | 562 | { |
51a0f0f6 | 563 | const char *sc1, *sc2; |
1da177e4 | 564 | |
51a0f0f6 JJ |
565 | for (sc1 = cs; *sc1 != '\0'; ++sc1) { |
566 | for (sc2 = ct; *sc2 != '\0'; ++sc2) { | |
1da177e4 | 567 | if (*sc1 == *sc2) |
51a0f0f6 | 568 | return (char *)sc1; |
1da177e4 LT |
569 | } |
570 | } | |
571 | return NULL; | |
572 | } | |
894b5779 | 573 | EXPORT_SYMBOL(strpbrk); |
1da177e4 LT |
574 | #endif |
575 | ||
576 | #ifndef __HAVE_ARCH_STRSEP | |
577 | /** | |
578 | * strsep - Split a string into tokens | |
579 | * @s: The string to be searched | |
580 | * @ct: The characters to search for | |
581 | * | |
582 | * strsep() updates @s to point after the token, ready for the next call. | |
583 | * | |
584 | * It returns empty tokens, too, behaving exactly like the libc function | |
585 | * of that name. In fact, it was stolen from glibc2 and de-fancy-fied. | |
586 | * Same semantics, slimmer shape. ;) | |
587 | */ | |
51a0f0f6 | 588 | char *strsep(char **s, const char *ct) |
1da177e4 | 589 | { |
51a0f0f6 JJ |
590 | char *sbegin = *s; |
591 | char *end; | |
1da177e4 LT |
592 | |
593 | if (sbegin == NULL) | |
594 | return NULL; | |
595 | ||
596 | end = strpbrk(sbegin, ct); | |
597 | if (end) | |
598 | *end++ = '\0'; | |
599 | *s = end; | |
1da177e4 LT |
600 | return sbegin; |
601 | } | |
1da177e4 LT |
602 | EXPORT_SYMBOL(strsep); |
603 | #endif | |
604 | ||
34990cf7 DB |
605 | /** |
606 | * sysfs_streq - return true if strings are equal, modulo trailing newline | |
607 | * @s1: one string | |
608 | * @s2: another string | |
609 | * | |
610 | * This routine returns true iff two strings are equal, treating both | |
611 | * NUL and newline-then-NUL as equivalent string terminations. It's | |
612 | * geared for use with sysfs input strings, which generally terminate | |
613 | * with newlines but are compared against values without newlines. | |
614 | */ | |
615 | bool sysfs_streq(const char *s1, const char *s2) | |
616 | { | |
617 | while (*s1 && *s1 == *s2) { | |
618 | s1++; | |
619 | s2++; | |
620 | } | |
621 | ||
622 | if (*s1 == *s2) | |
623 | return true; | |
624 | if (!*s1 && *s2 == '\n' && !s2[1]) | |
625 | return true; | |
626 | if (*s1 == '\n' && !s1[1] && !*s2) | |
627 | return true; | |
628 | return false; | |
629 | } | |
630 | EXPORT_SYMBOL(sysfs_streq); | |
631 | ||
d0f1fed2 JC |
632 | /** |
633 | * strtobool - convert common user inputs into boolean values | |
634 | * @s: input string | |
635 | * @res: result | |
636 | * | |
637 | * This routine returns 0 iff the first character is one of 'Yy1Nn0'. | |
638 | * Otherwise it will return -EINVAL. Value pointed to by res is | |
639 | * updated upon finding a match. | |
640 | */ | |
641 | int strtobool(const char *s, bool *res) | |
642 | { | |
643 | switch (s[0]) { | |
644 | case 'y': | |
645 | case 'Y': | |
646 | case '1': | |
647 | *res = true; | |
648 | break; | |
649 | case 'n': | |
650 | case 'N': | |
651 | case '0': | |
652 | *res = false; | |
653 | break; | |
654 | default: | |
655 | return -EINVAL; | |
656 | } | |
657 | return 0; | |
658 | } | |
659 | EXPORT_SYMBOL(strtobool); | |
660 | ||
1da177e4 LT |
661 | #ifndef __HAVE_ARCH_MEMSET |
662 | /** | |
663 | * memset - Fill a region of memory with the given value | |
664 | * @s: Pointer to the start of the area. | |
665 | * @c: The byte to fill the area with | |
666 | * @count: The size of the area. | |
667 | * | |
668 | * Do not use memset() to access IO space, use memset_io() instead. | |
669 | */ | |
51a0f0f6 | 670 | void *memset(void *s, int c, size_t count) |
1da177e4 | 671 | { |
850b9247 | 672 | char *xs = s; |
1da177e4 LT |
673 | |
674 | while (count--) | |
675 | *xs++ = c; | |
1da177e4 LT |
676 | return s; |
677 | } | |
678 | EXPORT_SYMBOL(memset); | |
679 | #endif | |
680 | ||
d4c5efdb DB |
681 | /** |
682 | * memzero_explicit - Fill a region of memory (e.g. sensitive | |
683 | * keying data) with 0s. | |
684 | * @s: Pointer to the start of the area. | |
685 | * @count: The size of the area. | |
686 | * | |
8155330a DB |
687 | * Note: usually using memset() is just fine (!), but in cases |
688 | * where clearing out _local_ data at the end of a scope is | |
689 | * necessary, memzero_explicit() should be used instead in | |
690 | * order to prevent the compiler from optimising away zeroing. | |
691 | * | |
d4c5efdb DB |
692 | * memzero_explicit() doesn't need an arch-specific version as |
693 | * it just invokes the one of memset() implicitly. | |
694 | */ | |
695 | void memzero_explicit(void *s, size_t count) | |
696 | { | |
697 | memset(s, 0, count); | |
7829fb09 | 698 | barrier_data(s); |
d4c5efdb DB |
699 | } |
700 | EXPORT_SYMBOL(memzero_explicit); | |
701 | ||
1da177e4 LT |
702 | #ifndef __HAVE_ARCH_MEMCPY |
703 | /** | |
704 | * memcpy - Copy one area of memory to another | |
705 | * @dest: Where to copy to | |
706 | * @src: Where to copy from | |
707 | * @count: The size of the area. | |
708 | * | |
709 | * You should not use this function to access IO space, use memcpy_toio() | |
710 | * or memcpy_fromio() instead. | |
711 | */ | |
51a0f0f6 | 712 | void *memcpy(void *dest, const void *src, size_t count) |
1da177e4 | 713 | { |
850b9247 | 714 | char *tmp = dest; |
4c416ab7 | 715 | const char *s = src; |
1da177e4 LT |
716 | |
717 | while (count--) | |
718 | *tmp++ = *s++; | |
1da177e4 LT |
719 | return dest; |
720 | } | |
721 | EXPORT_SYMBOL(memcpy); | |
722 | #endif | |
723 | ||
724 | #ifndef __HAVE_ARCH_MEMMOVE | |
725 | /** | |
726 | * memmove - Copy one area of memory to another | |
727 | * @dest: Where to copy to | |
728 | * @src: Where to copy from | |
729 | * @count: The size of the area. | |
730 | * | |
731 | * Unlike memcpy(), memmove() copes with overlapping areas. | |
732 | */ | |
51a0f0f6 | 733 | void *memmove(void *dest, const void *src, size_t count) |
1da177e4 | 734 | { |
82da2c37 PJ |
735 | char *tmp; |
736 | const char *s; | |
1da177e4 LT |
737 | |
738 | if (dest <= src) { | |
850b9247 JJ |
739 | tmp = dest; |
740 | s = src; | |
1da177e4 LT |
741 | while (count--) |
742 | *tmp++ = *s++; | |
51a0f0f6 | 743 | } else { |
850b9247 JJ |
744 | tmp = dest; |
745 | tmp += count; | |
746 | s = src; | |
747 | s += count; | |
1da177e4 LT |
748 | while (count--) |
749 | *--tmp = *--s; | |
51a0f0f6 | 750 | } |
1da177e4 LT |
751 | return dest; |
752 | } | |
753 | EXPORT_SYMBOL(memmove); | |
754 | #endif | |
755 | ||
756 | #ifndef __HAVE_ARCH_MEMCMP | |
757 | /** | |
758 | * memcmp - Compare two areas of memory | |
759 | * @cs: One area of memory | |
760 | * @ct: Another area of memory | |
761 | * @count: The size of the area. | |
762 | */ | |
0c28130b | 763 | #undef memcmp |
a7330c99 | 764 | __visible int memcmp(const void *cs, const void *ct, size_t count) |
1da177e4 LT |
765 | { |
766 | const unsigned char *su1, *su2; | |
767 | int res = 0; | |
768 | ||
51a0f0f6 | 769 | for (su1 = cs, su2 = ct; 0 < count; ++su1, ++su2, count--) |
1da177e4 LT |
770 | if ((res = *su1 - *su2) != 0) |
771 | break; | |
772 | return res; | |
773 | } | |
774 | EXPORT_SYMBOL(memcmp); | |
775 | #endif | |
776 | ||
777 | #ifndef __HAVE_ARCH_MEMSCAN | |
778 | /** | |
779 | * memscan - Find a character in an area of memory. | |
780 | * @addr: The memory area | |
781 | * @c: The byte to search for | |
782 | * @size: The size of the area. | |
783 | * | |
784 | * returns the address of the first occurrence of @c, or 1 byte past | |
785 | * the area if @c is not found | |
786 | */ | |
51a0f0f6 | 787 | void *memscan(void *addr, int c, size_t size) |
1da177e4 | 788 | { |
850b9247 | 789 | unsigned char *p = addr; |
1da177e4 LT |
790 | |
791 | while (size) { | |
792 | if (*p == c) | |
51a0f0f6 | 793 | return (void *)p; |
1da177e4 LT |
794 | p++; |
795 | size--; | |
796 | } | |
51a0f0f6 | 797 | return (void *)p; |
1da177e4 LT |
798 | } |
799 | EXPORT_SYMBOL(memscan); | |
800 | #endif | |
801 | ||
802 | #ifndef __HAVE_ARCH_STRSTR | |
803 | /** | |
804 | * strstr - Find the first substring in a %NUL terminated string | |
805 | * @s1: The string to be searched | |
806 | * @s2: The string to search for | |
807 | */ | |
51a0f0f6 | 808 | char *strstr(const char *s1, const char *s2) |
1da177e4 | 809 | { |
d5f1fb53 | 810 | size_t l1, l2; |
1da177e4 LT |
811 | |
812 | l2 = strlen(s2); | |
813 | if (!l2) | |
51a0f0f6 | 814 | return (char *)s1; |
1da177e4 LT |
815 | l1 = strlen(s1); |
816 | while (l1 >= l2) { | |
817 | l1--; | |
51a0f0f6 JJ |
818 | if (!memcmp(s1, s2, l2)) |
819 | return (char *)s1; | |
1da177e4 LT |
820 | s1++; |
821 | } | |
822 | return NULL; | |
823 | } | |
824 | EXPORT_SYMBOL(strstr); | |
825 | #endif | |
826 | ||
d5f1fb53 LZ |
827 | #ifndef __HAVE_ARCH_STRNSTR |
828 | /** | |
829 | * strnstr - Find the first substring in a length-limited string | |
830 | * @s1: The string to be searched | |
831 | * @s2: The string to search for | |
832 | * @len: the maximum number of characters to search | |
833 | */ | |
834 | char *strnstr(const char *s1, const char *s2, size_t len) | |
835 | { | |
d6a2eedf | 836 | size_t l2; |
d5f1fb53 LZ |
837 | |
838 | l2 = strlen(s2); | |
839 | if (!l2) | |
840 | return (char *)s1; | |
d6a2eedf AGR |
841 | while (len >= l2) { |
842 | len--; | |
d5f1fb53 LZ |
843 | if (!memcmp(s1, s2, l2)) |
844 | return (char *)s1; | |
845 | s1++; | |
846 | } | |
847 | return NULL; | |
848 | } | |
849 | EXPORT_SYMBOL(strnstr); | |
850 | #endif | |
851 | ||
1da177e4 LT |
852 | #ifndef __HAVE_ARCH_MEMCHR |
853 | /** | |
854 | * memchr - Find a character in an area of memory. | |
855 | * @s: The memory area | |
856 | * @c: The byte to search for | |
857 | * @n: The size of the area. | |
858 | * | |
859 | * returns the address of the first occurrence of @c, or %NULL | |
860 | * if @c is not found | |
861 | */ | |
862 | void *memchr(const void *s, int c, size_t n) | |
863 | { | |
864 | const unsigned char *p = s; | |
865 | while (n-- != 0) { | |
866 | if ((unsigned char)c == *p++) { | |
51a0f0f6 | 867 | return (void *)(p - 1); |
1da177e4 LT |
868 | } |
869 | } | |
870 | return NULL; | |
871 | } | |
872 | EXPORT_SYMBOL(memchr); | |
873 | #endif | |
79824820 AM |
874 | |
875 | static void *check_bytes8(const u8 *start, u8 value, unsigned int bytes) | |
876 | { | |
877 | while (bytes) { | |
878 | if (*start != value) | |
879 | return (void *)start; | |
880 | start++; | |
881 | bytes--; | |
882 | } | |
883 | return NULL; | |
884 | } | |
885 | ||
886 | /** | |
887 | * memchr_inv - Find an unmatching character in an area of memory. | |
888 | * @start: The memory area | |
889 | * @c: Find a character other than c | |
890 | * @bytes: The size of the area. | |
891 | * | |
892 | * returns the address of the first character other than @c, or %NULL | |
893 | * if the whole buffer contains just @c. | |
894 | */ | |
895 | void *memchr_inv(const void *start, int c, size_t bytes) | |
896 | { | |
897 | u8 value = c; | |
898 | u64 value64; | |
899 | unsigned int words, prefix; | |
900 | ||
901 | if (bytes <= 16) | |
902 | return check_bytes8(start, value, bytes); | |
903 | ||
f43804bf | 904 | value64 = value; |
72d93104 | 905 | #if defined(CONFIG_ARCH_HAS_FAST_MULTIPLIER) && BITS_PER_LONG == 64 |
f43804bf | 906 | value64 *= 0x0101010101010101; |
72d93104 | 907 | #elif defined(CONFIG_ARCH_HAS_FAST_MULTIPLIER) |
f43804bf AM |
908 | value64 *= 0x01010101; |
909 | value64 |= value64 << 32; | |
910 | #else | |
911 | value64 |= value64 << 8; | |
912 | value64 |= value64 << 16; | |
913 | value64 |= value64 << 32; | |
914 | #endif | |
79824820 | 915 | |
f43804bf | 916 | prefix = (unsigned long)start % 8; |
79824820 | 917 | if (prefix) { |
f43804bf AM |
918 | u8 *r; |
919 | ||
920 | prefix = 8 - prefix; | |
921 | r = check_bytes8(start, value, prefix); | |
79824820 AM |
922 | if (r) |
923 | return r; | |
924 | start += prefix; | |
925 | bytes -= prefix; | |
926 | } | |
927 | ||
928 | words = bytes / 8; | |
929 | ||
930 | while (words) { | |
931 | if (*(u64 *)start != value64) | |
932 | return check_bytes8(start, value, 8); | |
933 | start += 8; | |
934 | words--; | |
935 | } | |
936 | ||
937 | return check_bytes8(start, value, bytes % 8); | |
938 | } | |
939 | EXPORT_SYMBOL(memchr_inv); | |
94df2904 RV |
940 | |
941 | /** | |
942 | * strreplace - Replace all occurrences of character in string. | |
943 | * @s: The string to operate on. | |
944 | * @old: The character being replaced. | |
945 | * @new: The character @old is replaced with. | |
946 | * | |
947 | * Returns pointer to the nul byte at the end of @s. | |
948 | */ | |
949 | char *strreplace(char *s, char old, char new) | |
950 | { | |
951 | for (; *s; ++s) | |
952 | if (*s == old) | |
953 | *s = new; | |
954 | return s; | |
955 | } | |
956 | EXPORT_SYMBOL(strreplace); |