Commit | Line | Data |
---|---|---|
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); | |
30035e45 CM |
206 | if (has_zero(c, &data, &constants)) { |
207 | data = prep_zero_mask(c, data, &constants); | |
208 | data = create_zero_mask(data); | |
990486c8 | 209 | *(unsigned long *)(dest+res) = c & zero_bytemask(data); |
30035e45 CM |
210 | return res + find_zero(data); |
211 | } | |
990486c8 | 212 | *(unsigned long *)(dest+res) = c; |
30035e45 CM |
213 | res += sizeof(unsigned long); |
214 | count -= sizeof(unsigned long); | |
215 | max -= sizeof(unsigned long); | |
216 | } | |
217 | ||
218 | while (count) { | |
219 | char c; | |
220 | ||
221 | c = src[res]; | |
222 | dest[res] = c; | |
223 | if (!c) | |
224 | return res; | |
225 | res++; | |
226 | count--; | |
227 | } | |
228 | ||
229 | /* Hit buffer length without finding a NUL; force NUL-termination. */ | |
230 | if (res) | |
231 | dest[res-1] = '\0'; | |
232 | ||
233 | return -E2BIG; | |
234 | } | |
235 | EXPORT_SYMBOL(strscpy); | |
236 | #endif | |
237 | ||
1da177e4 LT |
238 | #ifndef __HAVE_ARCH_STRCAT |
239 | /** | |
240 | * strcat - Append one %NUL-terminated string to another | |
241 | * @dest: The string to be appended to | |
242 | * @src: The string to append to it | |
243 | */ | |
0c28130b | 244 | #undef strcat |
51a0f0f6 | 245 | char *strcat(char *dest, const char *src) |
1da177e4 LT |
246 | { |
247 | char *tmp = dest; | |
248 | ||
249 | while (*dest) | |
250 | dest++; | |
251 | while ((*dest++ = *src++) != '\0') | |
252 | ; | |
1da177e4 LT |
253 | return tmp; |
254 | } | |
255 | EXPORT_SYMBOL(strcat); | |
256 | #endif | |
257 | ||
258 | #ifndef __HAVE_ARCH_STRNCAT | |
259 | /** | |
0046dd9f | 260 | * strncat - Append a length-limited, C-string to another |
1da177e4 LT |
261 | * @dest: The string to be appended to |
262 | * @src: The string to append to it | |
263 | * @count: The maximum numbers of bytes to copy | |
264 | * | |
72fd4a35 | 265 | * Note that in contrast to strncpy(), strncat() ensures the result is |
1da177e4 LT |
266 | * terminated. |
267 | */ | |
51a0f0f6 | 268 | char *strncat(char *dest, const char *src, size_t count) |
1da177e4 LT |
269 | { |
270 | char *tmp = dest; | |
271 | ||
272 | if (count) { | |
273 | while (*dest) | |
274 | dest++; | |
275 | while ((*dest++ = *src++) != 0) { | |
276 | if (--count == 0) { | |
277 | *dest = '\0'; | |
278 | break; | |
279 | } | |
280 | } | |
281 | } | |
1da177e4 LT |
282 | return tmp; |
283 | } | |
284 | EXPORT_SYMBOL(strncat); | |
285 | #endif | |
286 | ||
287 | #ifndef __HAVE_ARCH_STRLCAT | |
288 | /** | |
0046dd9f | 289 | * strlcat - Append a length-limited, C-string to another |
1da177e4 LT |
290 | * @dest: The string to be appended to |
291 | * @src: The string to append to it | |
292 | * @count: The size of the destination buffer. | |
293 | */ | |
294 | size_t strlcat(char *dest, const char *src, size_t count) | |
295 | { | |
296 | size_t dsize = strlen(dest); | |
297 | size_t len = strlen(src); | |
298 | size_t res = dsize + len; | |
299 | ||
300 | /* This would be a bug */ | |
301 | BUG_ON(dsize >= count); | |
302 | ||
303 | dest += dsize; | |
304 | count -= dsize; | |
305 | if (len >= count) | |
306 | len = count-1; | |
307 | memcpy(dest, src, len); | |
308 | dest[len] = 0; | |
309 | return res; | |
310 | } | |
311 | EXPORT_SYMBOL(strlcat); | |
312 | #endif | |
313 | ||
314 | #ifndef __HAVE_ARCH_STRCMP | |
315 | /** | |
316 | * strcmp - Compare two strings | |
317 | * @cs: One string | |
318 | * @ct: Another string | |
319 | */ | |
0c28130b | 320 | #undef strcmp |
51a0f0f6 | 321 | int strcmp(const char *cs, const char *ct) |
1da177e4 | 322 | { |
a414f01a | 323 | unsigned char c1, c2; |
1da177e4 LT |
324 | |
325 | while (1) { | |
a414f01a LT |
326 | c1 = *cs++; |
327 | c2 = *ct++; | |
328 | if (c1 != c2) | |
329 | return c1 < c2 ? -1 : 1; | |
330 | if (!c1) | |
1da177e4 LT |
331 | break; |
332 | } | |
a414f01a | 333 | return 0; |
1da177e4 LT |
334 | } |
335 | EXPORT_SYMBOL(strcmp); | |
336 | #endif | |
337 | ||
338 | #ifndef __HAVE_ARCH_STRNCMP | |
339 | /** | |
340 | * strncmp - Compare two length-limited strings | |
341 | * @cs: One string | |
342 | * @ct: Another string | |
343 | * @count: The maximum number of bytes to compare | |
344 | */ | |
51a0f0f6 | 345 | int strncmp(const char *cs, const char *ct, size_t count) |
1da177e4 | 346 | { |
a414f01a | 347 | unsigned char c1, c2; |
1da177e4 LT |
348 | |
349 | while (count) { | |
a414f01a LT |
350 | c1 = *cs++; |
351 | c2 = *ct++; | |
352 | if (c1 != c2) | |
353 | return c1 < c2 ? -1 : 1; | |
354 | if (!c1) | |
1da177e4 LT |
355 | break; |
356 | count--; | |
357 | } | |
a414f01a | 358 | return 0; |
1da177e4 LT |
359 | } |
360 | EXPORT_SYMBOL(strncmp); | |
361 | #endif | |
362 | ||
363 | #ifndef __HAVE_ARCH_STRCHR | |
364 | /** | |
365 | * strchr - Find the first occurrence of a character in a string | |
366 | * @s: The string to be searched | |
367 | * @c: The character to search for | |
368 | */ | |
51a0f0f6 | 369 | char *strchr(const char *s, int c) |
1da177e4 | 370 | { |
51a0f0f6 | 371 | for (; *s != (char)c; ++s) |
1da177e4 LT |
372 | if (*s == '\0') |
373 | return NULL; | |
51a0f0f6 | 374 | return (char *)s; |
1da177e4 LT |
375 | } |
376 | EXPORT_SYMBOL(strchr); | |
377 | #endif | |
378 | ||
11d200e9 GL |
379 | #ifndef __HAVE_ARCH_STRCHRNUL |
380 | /** | |
381 | * strchrnul - Find and return a character in a string, or end of string | |
382 | * @s: The string to be searched | |
383 | * @c: The character to search for | |
384 | * | |
385 | * Returns pointer to first occurrence of 'c' in s. If c is not found, then | |
386 | * return a pointer to the null byte at the end of s. | |
387 | */ | |
388 | char *strchrnul(const char *s, int c) | |
389 | { | |
390 | while (*s && *s != (char)c) | |
391 | s++; | |
392 | return (char *)s; | |
393 | } | |
394 | EXPORT_SYMBOL(strchrnul); | |
395 | #endif | |
396 | ||
1da177e4 LT |
397 | #ifndef __HAVE_ARCH_STRRCHR |
398 | /** | |
399 | * strrchr - Find the last occurrence of a character in a string | |
400 | * @s: The string to be searched | |
401 | * @c: The character to search for | |
402 | */ | |
51a0f0f6 | 403 | char *strrchr(const char *s, int c) |
1da177e4 | 404 | { |
8da53d45 RV |
405 | const char *last = NULL; |
406 | do { | |
407 | if (*s == (char)c) | |
408 | last = s; | |
409 | } while (*s++); | |
410 | return (char *)last; | |
1da177e4 LT |
411 | } |
412 | EXPORT_SYMBOL(strrchr); | |
413 | #endif | |
414 | ||
415 | #ifndef __HAVE_ARCH_STRNCHR | |
416 | /** | |
417 | * strnchr - Find a character in a length limited string | |
418 | * @s: The string to be searched | |
419 | * @count: The number of characters to be searched | |
420 | * @c: The character to search for | |
421 | */ | |
422 | char *strnchr(const char *s, size_t count, int c) | |
423 | { | |
424 | for (; count-- && *s != '\0'; ++s) | |
51a0f0f6 JJ |
425 | if (*s == (char)c) |
426 | return (char *)s; | |
1da177e4 LT |
427 | return NULL; |
428 | } | |
429 | EXPORT_SYMBOL(strnchr); | |
430 | #endif | |
431 | ||
f653398c | 432 | /** |
a6cd13f3 RD |
433 | * skip_spaces - Removes leading whitespace from @str. |
434 | * @str: The string to be stripped. | |
f653398c | 435 | * |
a6cd13f3 | 436 | * Returns a pointer to the first non-whitespace character in @str. |
f653398c AGR |
437 | */ |
438 | char *skip_spaces(const char *str) | |
439 | { | |
440 | while (isspace(*str)) | |
441 | ++str; | |
442 | return (char *)str; | |
443 | } | |
444 | EXPORT_SYMBOL(skip_spaces); | |
445 | ||
481fad48 | 446 | /** |
ca54cb8c | 447 | * strim - Removes leading and trailing whitespace from @s. |
481fad48 PE |
448 | * @s: The string to be stripped. |
449 | * | |
450 | * Note that the first trailing whitespace is replaced with a %NUL-terminator | |
451 | * in the given string @s. Returns a pointer to the first non-whitespace | |
452 | * character in @s. | |
453 | */ | |
ca54cb8c | 454 | char *strim(char *s) |
481fad48 PE |
455 | { |
456 | size_t size; | |
457 | char *end; | |
458 | ||
459 | size = strlen(s); | |
481fad48 PE |
460 | if (!size) |
461 | return s; | |
462 | ||
463 | end = s + size - 1; | |
6e6d9fa6 | 464 | while (end >= s && isspace(*end)) |
481fad48 PE |
465 | end--; |
466 | *(end + 1) = '\0'; | |
467 | ||
66f6958e | 468 | return skip_spaces(s); |
481fad48 | 469 | } |
ca54cb8c | 470 | EXPORT_SYMBOL(strim); |
481fad48 | 471 | |
1da177e4 LT |
472 | #ifndef __HAVE_ARCH_STRLEN |
473 | /** | |
474 | * strlen - Find the length of a string | |
475 | * @s: The string to be sized | |
476 | */ | |
51a0f0f6 | 477 | size_t strlen(const char *s) |
1da177e4 LT |
478 | { |
479 | const char *sc; | |
480 | ||
481 | for (sc = s; *sc != '\0'; ++sc) | |
482 | /* nothing */; | |
483 | return sc - s; | |
484 | } | |
485 | EXPORT_SYMBOL(strlen); | |
486 | #endif | |
487 | ||
488 | #ifndef __HAVE_ARCH_STRNLEN | |
489 | /** | |
490 | * strnlen - Find the length of a length-limited string | |
491 | * @s: The string to be sized | |
492 | * @count: The maximum number of bytes to search | |
493 | */ | |
51a0f0f6 | 494 | size_t strnlen(const char *s, size_t count) |
1da177e4 LT |
495 | { |
496 | const char *sc; | |
497 | ||
498 | for (sc = s; count-- && *sc != '\0'; ++sc) | |
499 | /* nothing */; | |
500 | return sc - s; | |
501 | } | |
502 | EXPORT_SYMBOL(strnlen); | |
503 | #endif | |
504 | ||
505 | #ifndef __HAVE_ARCH_STRSPN | |
506 | /** | |
72fd4a35 | 507 | * strspn - Calculate the length of the initial substring of @s which only contain letters in @accept |
1da177e4 LT |
508 | * @s: The string to be searched |
509 | * @accept: The string to search for | |
510 | */ | |
511 | size_t strspn(const char *s, const char *accept) | |
512 | { | |
513 | const char *p; | |
514 | const char *a; | |
515 | size_t count = 0; | |
516 | ||
517 | for (p = s; *p != '\0'; ++p) { | |
518 | for (a = accept; *a != '\0'; ++a) { | |
519 | if (*p == *a) | |
520 | break; | |
521 | } | |
522 | if (*a == '\0') | |
523 | return count; | |
524 | ++count; | |
525 | } | |
1da177e4 LT |
526 | return count; |
527 | } | |
528 | ||
529 | EXPORT_SYMBOL(strspn); | |
530 | #endif | |
531 | ||
8833d328 | 532 | #ifndef __HAVE_ARCH_STRCSPN |
1da177e4 | 533 | /** |
72fd4a35 | 534 | * strcspn - Calculate the length of the initial substring of @s which does not contain letters in @reject |
1da177e4 LT |
535 | * @s: The string to be searched |
536 | * @reject: The string to avoid | |
537 | */ | |
538 | size_t strcspn(const char *s, const char *reject) | |
539 | { | |
540 | const char *p; | |
541 | const char *r; | |
542 | size_t count = 0; | |
543 | ||
544 | for (p = s; *p != '\0'; ++p) { | |
545 | for (r = reject; *r != '\0'; ++r) { | |
546 | if (*p == *r) | |
547 | return count; | |
548 | } | |
549 | ++count; | |
550 | } | |
1da177e4 | 551 | return count; |
51a0f0f6 | 552 | } |
1da177e4 | 553 | EXPORT_SYMBOL(strcspn); |
8833d328 | 554 | #endif |
1da177e4 LT |
555 | |
556 | #ifndef __HAVE_ARCH_STRPBRK | |
557 | /** | |
558 | * strpbrk - Find the first occurrence of a set of characters | |
559 | * @cs: The string to be searched | |
560 | * @ct: The characters to search for | |
561 | */ | |
51a0f0f6 | 562 | char *strpbrk(const char *cs, const char *ct) |
1da177e4 | 563 | { |
51a0f0f6 | 564 | const char *sc1, *sc2; |
1da177e4 | 565 | |
51a0f0f6 JJ |
566 | for (sc1 = cs; *sc1 != '\0'; ++sc1) { |
567 | for (sc2 = ct; *sc2 != '\0'; ++sc2) { | |
1da177e4 | 568 | if (*sc1 == *sc2) |
51a0f0f6 | 569 | return (char *)sc1; |
1da177e4 LT |
570 | } |
571 | } | |
572 | return NULL; | |
573 | } | |
894b5779 | 574 | EXPORT_SYMBOL(strpbrk); |
1da177e4 LT |
575 | #endif |
576 | ||
577 | #ifndef __HAVE_ARCH_STRSEP | |
578 | /** | |
579 | * strsep - Split a string into tokens | |
580 | * @s: The string to be searched | |
581 | * @ct: The characters to search for | |
582 | * | |
583 | * strsep() updates @s to point after the token, ready for the next call. | |
584 | * | |
585 | * It returns empty tokens, too, behaving exactly like the libc function | |
586 | * of that name. In fact, it was stolen from glibc2 and de-fancy-fied. | |
587 | * Same semantics, slimmer shape. ;) | |
588 | */ | |
51a0f0f6 | 589 | char *strsep(char **s, const char *ct) |
1da177e4 | 590 | { |
51a0f0f6 JJ |
591 | char *sbegin = *s; |
592 | char *end; | |
1da177e4 LT |
593 | |
594 | if (sbegin == NULL) | |
595 | return NULL; | |
596 | ||
597 | end = strpbrk(sbegin, ct); | |
598 | if (end) | |
599 | *end++ = '\0'; | |
600 | *s = end; | |
1da177e4 LT |
601 | return sbegin; |
602 | } | |
1da177e4 LT |
603 | EXPORT_SYMBOL(strsep); |
604 | #endif | |
605 | ||
34990cf7 DB |
606 | /** |
607 | * sysfs_streq - return true if strings are equal, modulo trailing newline | |
608 | * @s1: one string | |
609 | * @s2: another string | |
610 | * | |
611 | * This routine returns true iff two strings are equal, treating both | |
612 | * NUL and newline-then-NUL as equivalent string terminations. It's | |
613 | * geared for use with sysfs input strings, which generally terminate | |
614 | * with newlines but are compared against values without newlines. | |
615 | */ | |
616 | bool sysfs_streq(const char *s1, const char *s2) | |
617 | { | |
618 | while (*s1 && *s1 == *s2) { | |
619 | s1++; | |
620 | s2++; | |
621 | } | |
622 | ||
623 | if (*s1 == *s2) | |
624 | return true; | |
625 | if (!*s1 && *s2 == '\n' && !s2[1]) | |
626 | return true; | |
627 | if (*s1 == '\n' && !s1[1] && !*s2) | |
628 | return true; | |
629 | return false; | |
630 | } | |
631 | EXPORT_SYMBOL(sysfs_streq); | |
632 | ||
d0f1fed2 JC |
633 | /** |
634 | * strtobool - convert common user inputs into boolean values | |
635 | * @s: input string | |
636 | * @res: result | |
637 | * | |
638 | * This routine returns 0 iff the first character is one of 'Yy1Nn0'. | |
639 | * Otherwise it will return -EINVAL. Value pointed to by res is | |
640 | * updated upon finding a match. | |
641 | */ | |
642 | int strtobool(const char *s, bool *res) | |
643 | { | |
644 | switch (s[0]) { | |
645 | case 'y': | |
646 | case 'Y': | |
647 | case '1': | |
648 | *res = true; | |
649 | break; | |
650 | case 'n': | |
651 | case 'N': | |
652 | case '0': | |
653 | *res = false; | |
654 | break; | |
655 | default: | |
656 | return -EINVAL; | |
657 | } | |
658 | return 0; | |
659 | } | |
660 | EXPORT_SYMBOL(strtobool); | |
661 | ||
1da177e4 LT |
662 | #ifndef __HAVE_ARCH_MEMSET |
663 | /** | |
664 | * memset - Fill a region of memory with the given value | |
665 | * @s: Pointer to the start of the area. | |
666 | * @c: The byte to fill the area with | |
667 | * @count: The size of the area. | |
668 | * | |
669 | * Do not use memset() to access IO space, use memset_io() instead. | |
670 | */ | |
51a0f0f6 | 671 | void *memset(void *s, int c, size_t count) |
1da177e4 | 672 | { |
850b9247 | 673 | char *xs = s; |
1da177e4 LT |
674 | |
675 | while (count--) | |
676 | *xs++ = c; | |
1da177e4 LT |
677 | return s; |
678 | } | |
679 | EXPORT_SYMBOL(memset); | |
680 | #endif | |
681 | ||
d4c5efdb DB |
682 | /** |
683 | * memzero_explicit - Fill a region of memory (e.g. sensitive | |
684 | * keying data) with 0s. | |
685 | * @s: Pointer to the start of the area. | |
686 | * @count: The size of the area. | |
687 | * | |
8155330a DB |
688 | * Note: usually using memset() is just fine (!), but in cases |
689 | * where clearing out _local_ data at the end of a scope is | |
690 | * necessary, memzero_explicit() should be used instead in | |
691 | * order to prevent the compiler from optimising away zeroing. | |
692 | * | |
d4c5efdb DB |
693 | * memzero_explicit() doesn't need an arch-specific version as |
694 | * it just invokes the one of memset() implicitly. | |
695 | */ | |
696 | void memzero_explicit(void *s, size_t count) | |
697 | { | |
698 | memset(s, 0, count); | |
7829fb09 | 699 | barrier_data(s); |
d4c5efdb DB |
700 | } |
701 | EXPORT_SYMBOL(memzero_explicit); | |
702 | ||
1da177e4 LT |
703 | #ifndef __HAVE_ARCH_MEMCPY |
704 | /** | |
705 | * memcpy - Copy one area of memory to another | |
706 | * @dest: Where to copy to | |
707 | * @src: Where to copy from | |
708 | * @count: The size of the area. | |
709 | * | |
710 | * You should not use this function to access IO space, use memcpy_toio() | |
711 | * or memcpy_fromio() instead. | |
712 | */ | |
51a0f0f6 | 713 | void *memcpy(void *dest, const void *src, size_t count) |
1da177e4 | 714 | { |
850b9247 | 715 | char *tmp = dest; |
4c416ab7 | 716 | const char *s = src; |
1da177e4 LT |
717 | |
718 | while (count--) | |
719 | *tmp++ = *s++; | |
1da177e4 LT |
720 | return dest; |
721 | } | |
722 | EXPORT_SYMBOL(memcpy); | |
723 | #endif | |
724 | ||
725 | #ifndef __HAVE_ARCH_MEMMOVE | |
726 | /** | |
727 | * memmove - Copy one area of memory to another | |
728 | * @dest: Where to copy to | |
729 | * @src: Where to copy from | |
730 | * @count: The size of the area. | |
731 | * | |
732 | * Unlike memcpy(), memmove() copes with overlapping areas. | |
733 | */ | |
51a0f0f6 | 734 | void *memmove(void *dest, const void *src, size_t count) |
1da177e4 | 735 | { |
82da2c37 PJ |
736 | char *tmp; |
737 | const char *s; | |
1da177e4 LT |
738 | |
739 | if (dest <= src) { | |
850b9247 JJ |
740 | tmp = dest; |
741 | s = src; | |
1da177e4 LT |
742 | while (count--) |
743 | *tmp++ = *s++; | |
51a0f0f6 | 744 | } else { |
850b9247 JJ |
745 | tmp = dest; |
746 | tmp += count; | |
747 | s = src; | |
748 | s += count; | |
1da177e4 LT |
749 | while (count--) |
750 | *--tmp = *--s; | |
51a0f0f6 | 751 | } |
1da177e4 LT |
752 | return dest; |
753 | } | |
754 | EXPORT_SYMBOL(memmove); | |
755 | #endif | |
756 | ||
757 | #ifndef __HAVE_ARCH_MEMCMP | |
758 | /** | |
759 | * memcmp - Compare two areas of memory | |
760 | * @cs: One area of memory | |
761 | * @ct: Another area of memory | |
762 | * @count: The size of the area. | |
763 | */ | |
0c28130b | 764 | #undef memcmp |
a7330c99 | 765 | __visible int memcmp(const void *cs, const void *ct, size_t count) |
1da177e4 LT |
766 | { |
767 | const unsigned char *su1, *su2; | |
768 | int res = 0; | |
769 | ||
51a0f0f6 | 770 | for (su1 = cs, su2 = ct; 0 < count; ++su1, ++su2, count--) |
1da177e4 LT |
771 | if ((res = *su1 - *su2) != 0) |
772 | break; | |
773 | return res; | |
774 | } | |
775 | EXPORT_SYMBOL(memcmp); | |
776 | #endif | |
777 | ||
778 | #ifndef __HAVE_ARCH_MEMSCAN | |
779 | /** | |
780 | * memscan - Find a character in an area of memory. | |
781 | * @addr: The memory area | |
782 | * @c: The byte to search for | |
783 | * @size: The size of the area. | |
784 | * | |
785 | * returns the address of the first occurrence of @c, or 1 byte past | |
786 | * the area if @c is not found | |
787 | */ | |
51a0f0f6 | 788 | void *memscan(void *addr, int c, size_t size) |
1da177e4 | 789 | { |
850b9247 | 790 | unsigned char *p = addr; |
1da177e4 LT |
791 | |
792 | while (size) { | |
793 | if (*p == c) | |
51a0f0f6 | 794 | return (void *)p; |
1da177e4 LT |
795 | p++; |
796 | size--; | |
797 | } | |
51a0f0f6 | 798 | return (void *)p; |
1da177e4 LT |
799 | } |
800 | EXPORT_SYMBOL(memscan); | |
801 | #endif | |
802 | ||
803 | #ifndef __HAVE_ARCH_STRSTR | |
804 | /** | |
805 | * strstr - Find the first substring in a %NUL terminated string | |
806 | * @s1: The string to be searched | |
807 | * @s2: The string to search for | |
808 | */ | |
51a0f0f6 | 809 | char *strstr(const char *s1, const char *s2) |
1da177e4 | 810 | { |
d5f1fb53 | 811 | size_t l1, l2; |
1da177e4 LT |
812 | |
813 | l2 = strlen(s2); | |
814 | if (!l2) | |
51a0f0f6 | 815 | return (char *)s1; |
1da177e4 LT |
816 | l1 = strlen(s1); |
817 | while (l1 >= l2) { | |
818 | l1--; | |
51a0f0f6 JJ |
819 | if (!memcmp(s1, s2, l2)) |
820 | return (char *)s1; | |
1da177e4 LT |
821 | s1++; |
822 | } | |
823 | return NULL; | |
824 | } | |
825 | EXPORT_SYMBOL(strstr); | |
826 | #endif | |
827 | ||
d5f1fb53 LZ |
828 | #ifndef __HAVE_ARCH_STRNSTR |
829 | /** | |
830 | * strnstr - Find the first substring in a length-limited string | |
831 | * @s1: The string to be searched | |
832 | * @s2: The string to search for | |
833 | * @len: the maximum number of characters to search | |
834 | */ | |
835 | char *strnstr(const char *s1, const char *s2, size_t len) | |
836 | { | |
d6a2eedf | 837 | size_t l2; |
d5f1fb53 LZ |
838 | |
839 | l2 = strlen(s2); | |
840 | if (!l2) | |
841 | return (char *)s1; | |
d6a2eedf AGR |
842 | while (len >= l2) { |
843 | len--; | |
d5f1fb53 LZ |
844 | if (!memcmp(s1, s2, l2)) |
845 | return (char *)s1; | |
846 | s1++; | |
847 | } | |
848 | return NULL; | |
849 | } | |
850 | EXPORT_SYMBOL(strnstr); | |
851 | #endif | |
852 | ||
1da177e4 LT |
853 | #ifndef __HAVE_ARCH_MEMCHR |
854 | /** | |
855 | * memchr - Find a character in an area of memory. | |
856 | * @s: The memory area | |
857 | * @c: The byte to search for | |
858 | * @n: The size of the area. | |
859 | * | |
860 | * returns the address of the first occurrence of @c, or %NULL | |
861 | * if @c is not found | |
862 | */ | |
863 | void *memchr(const void *s, int c, size_t n) | |
864 | { | |
865 | const unsigned char *p = s; | |
866 | while (n-- != 0) { | |
867 | if ((unsigned char)c == *p++) { | |
51a0f0f6 | 868 | return (void *)(p - 1); |
1da177e4 LT |
869 | } |
870 | } | |
871 | return NULL; | |
872 | } | |
873 | EXPORT_SYMBOL(memchr); | |
874 | #endif | |
79824820 AM |
875 | |
876 | static void *check_bytes8(const u8 *start, u8 value, unsigned int bytes) | |
877 | { | |
878 | while (bytes) { | |
879 | if (*start != value) | |
880 | return (void *)start; | |
881 | start++; | |
882 | bytes--; | |
883 | } | |
884 | return NULL; | |
885 | } | |
886 | ||
887 | /** | |
888 | * memchr_inv - Find an unmatching character in an area of memory. | |
889 | * @start: The memory area | |
890 | * @c: Find a character other than c | |
891 | * @bytes: The size of the area. | |
892 | * | |
893 | * returns the address of the first character other than @c, or %NULL | |
894 | * if the whole buffer contains just @c. | |
895 | */ | |
896 | void *memchr_inv(const void *start, int c, size_t bytes) | |
897 | { | |
898 | u8 value = c; | |
899 | u64 value64; | |
900 | unsigned int words, prefix; | |
901 | ||
902 | if (bytes <= 16) | |
903 | return check_bytes8(start, value, bytes); | |
904 | ||
f43804bf | 905 | value64 = value; |
72d93104 | 906 | #if defined(CONFIG_ARCH_HAS_FAST_MULTIPLIER) && BITS_PER_LONG == 64 |
f43804bf | 907 | value64 *= 0x0101010101010101; |
72d93104 | 908 | #elif defined(CONFIG_ARCH_HAS_FAST_MULTIPLIER) |
f43804bf AM |
909 | value64 *= 0x01010101; |
910 | value64 |= value64 << 32; | |
911 | #else | |
912 | value64 |= value64 << 8; | |
913 | value64 |= value64 << 16; | |
914 | value64 |= value64 << 32; | |
915 | #endif | |
79824820 | 916 | |
f43804bf | 917 | prefix = (unsigned long)start % 8; |
79824820 | 918 | if (prefix) { |
f43804bf AM |
919 | u8 *r; |
920 | ||
921 | prefix = 8 - prefix; | |
922 | r = check_bytes8(start, value, prefix); | |
79824820 AM |
923 | if (r) |
924 | return r; | |
925 | start += prefix; | |
926 | bytes -= prefix; | |
927 | } | |
928 | ||
929 | words = bytes / 8; | |
930 | ||
931 | while (words) { | |
932 | if (*(u64 *)start != value64) | |
933 | return check_bytes8(start, value, 8); | |
934 | start += 8; | |
935 | words--; | |
936 | } | |
937 | ||
938 | return check_bytes8(start, value, bytes % 8); | |
939 | } | |
940 | EXPORT_SYMBOL(memchr_inv); | |
94df2904 RV |
941 | |
942 | /** | |
943 | * strreplace - Replace all occurrences of character in string. | |
944 | * @s: The string to operate on. | |
945 | * @old: The character being replaced. | |
946 | * @new: The character @old is replaced with. | |
947 | * | |
948 | * Returns pointer to the nul byte at the end of @s. | |
949 | */ | |
950 | char *strreplace(char *s, char old, char new) | |
951 | { | |
952 | for (; *s; ++s) | |
953 | if (*s == old) | |
954 | *s = new; | |
955 | return s; | |
956 | } | |
957 | EXPORT_SYMBOL(strreplace); |