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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 LT |
29 | |
30 | #ifndef __HAVE_ARCH_STRNICMP | |
31 | /** | |
32 | * strnicmp - Case insensitive, length-limited string comparison | |
33 | * @s1: One string | |
34 | * @s2: The other string | |
35 | * @len: the maximum number of characters to compare | |
36 | */ | |
37 | int strnicmp(const char *s1, const char *s2, size_t len) | |
38 | { | |
39 | /* Yes, Virginia, it had better be unsigned */ | |
40 | unsigned char c1, c2; | |
41 | ||
a11d2b64 AGR |
42 | if (!len) |
43 | return 0; | |
44 | ||
45 | do { | |
46 | c1 = *s1++; | |
47 | c2 = *s2++; | |
48 | if (!c1 || !c2) | |
49 | break; | |
50 | if (c1 == c2) | |
51 | continue; | |
52 | c1 = tolower(c1); | |
53 | c2 = tolower(c2); | |
54 | if (c1 != c2) | |
55 | break; | |
56 | } while (--len); | |
1da177e4 LT |
57 | return (int)c1 - (int)c2; |
58 | } | |
1da177e4 LT |
59 | EXPORT_SYMBOL(strnicmp); |
60 | #endif | |
61 | ||
ded220bd DM |
62 | #ifndef __HAVE_ARCH_STRCASECMP |
63 | int strcasecmp(const char *s1, const char *s2) | |
64 | { | |
65 | int c1, c2; | |
66 | ||
67 | do { | |
68 | c1 = tolower(*s1++); | |
69 | c2 = tolower(*s2++); | |
70 | } while (c1 == c2 && c1 != 0); | |
71 | return c1 - c2; | |
72 | } | |
73 | EXPORT_SYMBOL(strcasecmp); | |
74 | #endif | |
75 | ||
76 | #ifndef __HAVE_ARCH_STRNCASECMP | |
77 | int strncasecmp(const char *s1, const char *s2, size_t n) | |
78 | { | |
79 | int c1, c2; | |
80 | ||
81 | do { | |
82 | c1 = tolower(*s1++); | |
83 | c2 = tolower(*s2++); | |
84 | } while ((--n > 0) && c1 == c2 && c1 != 0); | |
85 | return c1 - c2; | |
86 | } | |
87 | EXPORT_SYMBOL(strncasecmp); | |
88 | #endif | |
89 | ||
1da177e4 LT |
90 | #ifndef __HAVE_ARCH_STRCPY |
91 | /** | |
92 | * strcpy - Copy a %NUL terminated string | |
93 | * @dest: Where to copy the string to | |
94 | * @src: Where to copy the string from | |
95 | */ | |
0c28130b | 96 | #undef strcpy |
51a0f0f6 | 97 | char *strcpy(char *dest, const char *src) |
1da177e4 LT |
98 | { |
99 | char *tmp = dest; | |
100 | ||
101 | while ((*dest++ = *src++) != '\0') | |
102 | /* nothing */; | |
103 | return tmp; | |
104 | } | |
105 | EXPORT_SYMBOL(strcpy); | |
106 | #endif | |
107 | ||
108 | #ifndef __HAVE_ARCH_STRNCPY | |
109 | /** | |
0046dd9f | 110 | * strncpy - Copy a length-limited, C-string |
1da177e4 LT |
111 | * @dest: Where to copy the string to |
112 | * @src: Where to copy the string from | |
113 | * @count: The maximum number of bytes to copy | |
114 | * | |
115 | * The result is not %NUL-terminated if the source exceeds | |
116 | * @count bytes. | |
25279526 | 117 | * |
118 | * In the case where the length of @src is less than that of | |
119 | * count, the remainder of @dest will be padded with %NUL. | |
120 | * | |
1da177e4 | 121 | */ |
51a0f0f6 | 122 | char *strncpy(char *dest, const char *src, size_t count) |
1da177e4 LT |
123 | { |
124 | char *tmp = dest; | |
125 | ||
126 | while (count) { | |
51a0f0f6 JJ |
127 | if ((*tmp = *src) != 0) |
128 | src++; | |
1da177e4 LT |
129 | tmp++; |
130 | count--; | |
131 | } | |
132 | return dest; | |
133 | } | |
134 | EXPORT_SYMBOL(strncpy); | |
135 | #endif | |
136 | ||
137 | #ifndef __HAVE_ARCH_STRLCPY | |
138 | /** | |
0046dd9f | 139 | * strlcpy - Copy a C-string into a sized buffer |
1da177e4 LT |
140 | * @dest: Where to copy the string to |
141 | * @src: Where to copy the string from | |
142 | * @size: size of destination buffer | |
143 | * | |
144 | * Compatible with *BSD: the result is always a valid | |
145 | * NUL-terminated string that fits in the buffer (unless, | |
146 | * of course, the buffer size is zero). It does not pad | |
147 | * out the result like strncpy() does. | |
148 | */ | |
149 | size_t strlcpy(char *dest, const char *src, size_t size) | |
150 | { | |
151 | size_t ret = strlen(src); | |
152 | ||
153 | if (size) { | |
51a0f0f6 | 154 | size_t len = (ret >= size) ? size - 1 : ret; |
1da177e4 LT |
155 | memcpy(dest, src, len); |
156 | dest[len] = '\0'; | |
157 | } | |
158 | return ret; | |
159 | } | |
160 | EXPORT_SYMBOL(strlcpy); | |
161 | #endif | |
162 | ||
163 | #ifndef __HAVE_ARCH_STRCAT | |
164 | /** | |
165 | * strcat - Append one %NUL-terminated string to another | |
166 | * @dest: The string to be appended to | |
167 | * @src: The string to append to it | |
168 | */ | |
0c28130b | 169 | #undef strcat |
51a0f0f6 | 170 | char *strcat(char *dest, const char *src) |
1da177e4 LT |
171 | { |
172 | char *tmp = dest; | |
173 | ||
174 | while (*dest) | |
175 | dest++; | |
176 | while ((*dest++ = *src++) != '\0') | |
177 | ; | |
1da177e4 LT |
178 | return tmp; |
179 | } | |
180 | EXPORT_SYMBOL(strcat); | |
181 | #endif | |
182 | ||
183 | #ifndef __HAVE_ARCH_STRNCAT | |
184 | /** | |
0046dd9f | 185 | * strncat - Append a length-limited, C-string to another |
1da177e4 LT |
186 | * @dest: The string to be appended to |
187 | * @src: The string to append to it | |
188 | * @count: The maximum numbers of bytes to copy | |
189 | * | |
72fd4a35 | 190 | * Note that in contrast to strncpy(), strncat() ensures the result is |
1da177e4 LT |
191 | * terminated. |
192 | */ | |
51a0f0f6 | 193 | char *strncat(char *dest, const char *src, size_t count) |
1da177e4 LT |
194 | { |
195 | char *tmp = dest; | |
196 | ||
197 | if (count) { | |
198 | while (*dest) | |
199 | dest++; | |
200 | while ((*dest++ = *src++) != 0) { | |
201 | if (--count == 0) { | |
202 | *dest = '\0'; | |
203 | break; | |
204 | } | |
205 | } | |
206 | } | |
1da177e4 LT |
207 | return tmp; |
208 | } | |
209 | EXPORT_SYMBOL(strncat); | |
210 | #endif | |
211 | ||
212 | #ifndef __HAVE_ARCH_STRLCAT | |
213 | /** | |
0046dd9f | 214 | * strlcat - Append a length-limited, C-string to another |
1da177e4 LT |
215 | * @dest: The string to be appended to |
216 | * @src: The string to append to it | |
217 | * @count: The size of the destination buffer. | |
218 | */ | |
219 | size_t strlcat(char *dest, const char *src, size_t count) | |
220 | { | |
221 | size_t dsize = strlen(dest); | |
222 | size_t len = strlen(src); | |
223 | size_t res = dsize + len; | |
224 | ||
225 | /* This would be a bug */ | |
226 | BUG_ON(dsize >= count); | |
227 | ||
228 | dest += dsize; | |
229 | count -= dsize; | |
230 | if (len >= count) | |
231 | len = count-1; | |
232 | memcpy(dest, src, len); | |
233 | dest[len] = 0; | |
234 | return res; | |
235 | } | |
236 | EXPORT_SYMBOL(strlcat); | |
237 | #endif | |
238 | ||
239 | #ifndef __HAVE_ARCH_STRCMP | |
240 | /** | |
241 | * strcmp - Compare two strings | |
242 | * @cs: One string | |
243 | * @ct: Another string | |
244 | */ | |
0c28130b | 245 | #undef strcmp |
51a0f0f6 | 246 | int strcmp(const char *cs, const char *ct) |
1da177e4 | 247 | { |
a414f01a | 248 | unsigned char c1, c2; |
1da177e4 LT |
249 | |
250 | while (1) { | |
a414f01a LT |
251 | c1 = *cs++; |
252 | c2 = *ct++; | |
253 | if (c1 != c2) | |
254 | return c1 < c2 ? -1 : 1; | |
255 | if (!c1) | |
1da177e4 LT |
256 | break; |
257 | } | |
a414f01a | 258 | return 0; |
1da177e4 LT |
259 | } |
260 | EXPORT_SYMBOL(strcmp); | |
261 | #endif | |
262 | ||
263 | #ifndef __HAVE_ARCH_STRNCMP | |
264 | /** | |
265 | * strncmp - Compare two length-limited strings | |
266 | * @cs: One string | |
267 | * @ct: Another string | |
268 | * @count: The maximum number of bytes to compare | |
269 | */ | |
51a0f0f6 | 270 | int strncmp(const char *cs, const char *ct, size_t count) |
1da177e4 | 271 | { |
a414f01a | 272 | unsigned char c1, c2; |
1da177e4 LT |
273 | |
274 | while (count) { | |
a414f01a LT |
275 | c1 = *cs++; |
276 | c2 = *ct++; | |
277 | if (c1 != c2) | |
278 | return c1 < c2 ? -1 : 1; | |
279 | if (!c1) | |
1da177e4 LT |
280 | break; |
281 | count--; | |
282 | } | |
a414f01a | 283 | return 0; |
1da177e4 LT |
284 | } |
285 | EXPORT_SYMBOL(strncmp); | |
286 | #endif | |
287 | ||
288 | #ifndef __HAVE_ARCH_STRCHR | |
289 | /** | |
290 | * strchr - Find the first occurrence of a character in a string | |
291 | * @s: The string to be searched | |
292 | * @c: The character to search for | |
293 | */ | |
51a0f0f6 | 294 | char *strchr(const char *s, int c) |
1da177e4 | 295 | { |
51a0f0f6 | 296 | for (; *s != (char)c; ++s) |
1da177e4 LT |
297 | if (*s == '\0') |
298 | return NULL; | |
51a0f0f6 | 299 | return (char *)s; |
1da177e4 LT |
300 | } |
301 | EXPORT_SYMBOL(strchr); | |
302 | #endif | |
303 | ||
11d200e9 GL |
304 | #ifndef __HAVE_ARCH_STRCHRNUL |
305 | /** | |
306 | * strchrnul - Find and return a character in a string, or end of string | |
307 | * @s: The string to be searched | |
308 | * @c: The character to search for | |
309 | * | |
310 | * Returns pointer to first occurrence of 'c' in s. If c is not found, then | |
311 | * return a pointer to the null byte at the end of s. | |
312 | */ | |
313 | char *strchrnul(const char *s, int c) | |
314 | { | |
315 | while (*s && *s != (char)c) | |
316 | s++; | |
317 | return (char *)s; | |
318 | } | |
319 | EXPORT_SYMBOL(strchrnul); | |
320 | #endif | |
321 | ||
1da177e4 LT |
322 | #ifndef __HAVE_ARCH_STRRCHR |
323 | /** | |
324 | * strrchr - Find the last occurrence of a character in a string | |
325 | * @s: The string to be searched | |
326 | * @c: The character to search for | |
327 | */ | |
51a0f0f6 | 328 | char *strrchr(const char *s, int c) |
1da177e4 LT |
329 | { |
330 | const char *p = s + strlen(s); | |
331 | do { | |
332 | if (*p == (char)c) | |
333 | return (char *)p; | |
334 | } while (--p >= s); | |
335 | return NULL; | |
336 | } | |
337 | EXPORT_SYMBOL(strrchr); | |
338 | #endif | |
339 | ||
340 | #ifndef __HAVE_ARCH_STRNCHR | |
341 | /** | |
342 | * strnchr - Find a character in a length limited string | |
343 | * @s: The string to be searched | |
344 | * @count: The number of characters to be searched | |
345 | * @c: The character to search for | |
346 | */ | |
347 | char *strnchr(const char *s, size_t count, int c) | |
348 | { | |
349 | for (; count-- && *s != '\0'; ++s) | |
51a0f0f6 JJ |
350 | if (*s == (char)c) |
351 | return (char *)s; | |
1da177e4 LT |
352 | return NULL; |
353 | } | |
354 | EXPORT_SYMBOL(strnchr); | |
355 | #endif | |
356 | ||
f653398c | 357 | /** |
a6cd13f3 RD |
358 | * skip_spaces - Removes leading whitespace from @str. |
359 | * @str: The string to be stripped. | |
f653398c | 360 | * |
a6cd13f3 | 361 | * Returns a pointer to the first non-whitespace character in @str. |
f653398c AGR |
362 | */ |
363 | char *skip_spaces(const char *str) | |
364 | { | |
365 | while (isspace(*str)) | |
366 | ++str; | |
367 | return (char *)str; | |
368 | } | |
369 | EXPORT_SYMBOL(skip_spaces); | |
370 | ||
481fad48 | 371 | /** |
ca54cb8c | 372 | * strim - Removes leading and trailing whitespace from @s. |
481fad48 PE |
373 | * @s: The string to be stripped. |
374 | * | |
375 | * Note that the first trailing whitespace is replaced with a %NUL-terminator | |
376 | * in the given string @s. Returns a pointer to the first non-whitespace | |
377 | * character in @s. | |
378 | */ | |
ca54cb8c | 379 | char *strim(char *s) |
481fad48 PE |
380 | { |
381 | size_t size; | |
382 | char *end; | |
383 | ||
384 | size = strlen(s); | |
481fad48 PE |
385 | if (!size) |
386 | return s; | |
387 | ||
388 | end = s + size - 1; | |
6e6d9fa6 | 389 | while (end >= s && isspace(*end)) |
481fad48 PE |
390 | end--; |
391 | *(end + 1) = '\0'; | |
392 | ||
66f6958e | 393 | return skip_spaces(s); |
481fad48 | 394 | } |
ca54cb8c | 395 | EXPORT_SYMBOL(strim); |
481fad48 | 396 | |
1da177e4 LT |
397 | #ifndef __HAVE_ARCH_STRLEN |
398 | /** | |
399 | * strlen - Find the length of a string | |
400 | * @s: The string to be sized | |
401 | */ | |
51a0f0f6 | 402 | size_t strlen(const char *s) |
1da177e4 LT |
403 | { |
404 | const char *sc; | |
405 | ||
406 | for (sc = s; *sc != '\0'; ++sc) | |
407 | /* nothing */; | |
408 | return sc - s; | |
409 | } | |
410 | EXPORT_SYMBOL(strlen); | |
411 | #endif | |
412 | ||
413 | #ifndef __HAVE_ARCH_STRNLEN | |
414 | /** | |
415 | * strnlen - Find the length of a length-limited string | |
416 | * @s: The string to be sized | |
417 | * @count: The maximum number of bytes to search | |
418 | */ | |
51a0f0f6 | 419 | size_t strnlen(const char *s, size_t count) |
1da177e4 LT |
420 | { |
421 | const char *sc; | |
422 | ||
423 | for (sc = s; count-- && *sc != '\0'; ++sc) | |
424 | /* nothing */; | |
425 | return sc - s; | |
426 | } | |
427 | EXPORT_SYMBOL(strnlen); | |
428 | #endif | |
429 | ||
430 | #ifndef __HAVE_ARCH_STRSPN | |
431 | /** | |
72fd4a35 | 432 | * strspn - Calculate the length of the initial substring of @s which only contain letters in @accept |
1da177e4 LT |
433 | * @s: The string to be searched |
434 | * @accept: The string to search for | |
435 | */ | |
436 | size_t strspn(const char *s, const char *accept) | |
437 | { | |
438 | const char *p; | |
439 | const char *a; | |
440 | size_t count = 0; | |
441 | ||
442 | for (p = s; *p != '\0'; ++p) { | |
443 | for (a = accept; *a != '\0'; ++a) { | |
444 | if (*p == *a) | |
445 | break; | |
446 | } | |
447 | if (*a == '\0') | |
448 | return count; | |
449 | ++count; | |
450 | } | |
1da177e4 LT |
451 | return count; |
452 | } | |
453 | ||
454 | EXPORT_SYMBOL(strspn); | |
455 | #endif | |
456 | ||
8833d328 | 457 | #ifndef __HAVE_ARCH_STRCSPN |
1da177e4 | 458 | /** |
72fd4a35 | 459 | * strcspn - Calculate the length of the initial substring of @s which does not contain letters in @reject |
1da177e4 LT |
460 | * @s: The string to be searched |
461 | * @reject: The string to avoid | |
462 | */ | |
463 | size_t strcspn(const char *s, const char *reject) | |
464 | { | |
465 | const char *p; | |
466 | const char *r; | |
467 | size_t count = 0; | |
468 | ||
469 | for (p = s; *p != '\0'; ++p) { | |
470 | for (r = reject; *r != '\0'; ++r) { | |
471 | if (*p == *r) | |
472 | return count; | |
473 | } | |
474 | ++count; | |
475 | } | |
1da177e4 | 476 | return count; |
51a0f0f6 | 477 | } |
1da177e4 | 478 | EXPORT_SYMBOL(strcspn); |
8833d328 | 479 | #endif |
1da177e4 LT |
480 | |
481 | #ifndef __HAVE_ARCH_STRPBRK | |
482 | /** | |
483 | * strpbrk - Find the first occurrence of a set of characters | |
484 | * @cs: The string to be searched | |
485 | * @ct: The characters to search for | |
486 | */ | |
51a0f0f6 | 487 | char *strpbrk(const char *cs, const char *ct) |
1da177e4 | 488 | { |
51a0f0f6 | 489 | const char *sc1, *sc2; |
1da177e4 | 490 | |
51a0f0f6 JJ |
491 | for (sc1 = cs; *sc1 != '\0'; ++sc1) { |
492 | for (sc2 = ct; *sc2 != '\0'; ++sc2) { | |
1da177e4 | 493 | if (*sc1 == *sc2) |
51a0f0f6 | 494 | return (char *)sc1; |
1da177e4 LT |
495 | } |
496 | } | |
497 | return NULL; | |
498 | } | |
894b5779 | 499 | EXPORT_SYMBOL(strpbrk); |
1da177e4 LT |
500 | #endif |
501 | ||
502 | #ifndef __HAVE_ARCH_STRSEP | |
503 | /** | |
504 | * strsep - Split a string into tokens | |
505 | * @s: The string to be searched | |
506 | * @ct: The characters to search for | |
507 | * | |
508 | * strsep() updates @s to point after the token, ready for the next call. | |
509 | * | |
510 | * It returns empty tokens, too, behaving exactly like the libc function | |
511 | * of that name. In fact, it was stolen from glibc2 and de-fancy-fied. | |
512 | * Same semantics, slimmer shape. ;) | |
513 | */ | |
51a0f0f6 | 514 | char *strsep(char **s, const char *ct) |
1da177e4 | 515 | { |
51a0f0f6 JJ |
516 | char *sbegin = *s; |
517 | char *end; | |
1da177e4 LT |
518 | |
519 | if (sbegin == NULL) | |
520 | return NULL; | |
521 | ||
522 | end = strpbrk(sbegin, ct); | |
523 | if (end) | |
524 | *end++ = '\0'; | |
525 | *s = end; | |
1da177e4 LT |
526 | return sbegin; |
527 | } | |
1da177e4 LT |
528 | EXPORT_SYMBOL(strsep); |
529 | #endif | |
530 | ||
34990cf7 DB |
531 | /** |
532 | * sysfs_streq - return true if strings are equal, modulo trailing newline | |
533 | * @s1: one string | |
534 | * @s2: another string | |
535 | * | |
536 | * This routine returns true iff two strings are equal, treating both | |
537 | * NUL and newline-then-NUL as equivalent string terminations. It's | |
538 | * geared for use with sysfs input strings, which generally terminate | |
539 | * with newlines but are compared against values without newlines. | |
540 | */ | |
541 | bool sysfs_streq(const char *s1, const char *s2) | |
542 | { | |
543 | while (*s1 && *s1 == *s2) { | |
544 | s1++; | |
545 | s2++; | |
546 | } | |
547 | ||
548 | if (*s1 == *s2) | |
549 | return true; | |
550 | if (!*s1 && *s2 == '\n' && !s2[1]) | |
551 | return true; | |
552 | if (*s1 == '\n' && !s1[1] && !*s2) | |
553 | return true; | |
554 | return false; | |
555 | } | |
556 | EXPORT_SYMBOL(sysfs_streq); | |
557 | ||
d0f1fed2 JC |
558 | /** |
559 | * strtobool - convert common user inputs into boolean values | |
560 | * @s: input string | |
561 | * @res: result | |
562 | * | |
563 | * This routine returns 0 iff the first character is one of 'Yy1Nn0'. | |
564 | * Otherwise it will return -EINVAL. Value pointed to by res is | |
565 | * updated upon finding a match. | |
566 | */ | |
567 | int strtobool(const char *s, bool *res) | |
568 | { | |
569 | switch (s[0]) { | |
570 | case 'y': | |
571 | case 'Y': | |
572 | case '1': | |
573 | *res = true; | |
574 | break; | |
575 | case 'n': | |
576 | case 'N': | |
577 | case '0': | |
578 | *res = false; | |
579 | break; | |
580 | default: | |
581 | return -EINVAL; | |
582 | } | |
583 | return 0; | |
584 | } | |
585 | EXPORT_SYMBOL(strtobool); | |
586 | ||
1da177e4 LT |
587 | #ifndef __HAVE_ARCH_MEMSET |
588 | /** | |
589 | * memset - Fill a region of memory with the given value | |
590 | * @s: Pointer to the start of the area. | |
591 | * @c: The byte to fill the area with | |
592 | * @count: The size of the area. | |
593 | * | |
594 | * Do not use memset() to access IO space, use memset_io() instead. | |
595 | */ | |
51a0f0f6 | 596 | void *memset(void *s, int c, size_t count) |
1da177e4 | 597 | { |
850b9247 | 598 | char *xs = s; |
1da177e4 LT |
599 | |
600 | while (count--) | |
601 | *xs++ = c; | |
1da177e4 LT |
602 | return s; |
603 | } | |
604 | EXPORT_SYMBOL(memset); | |
605 | #endif | |
606 | ||
607 | #ifndef __HAVE_ARCH_MEMCPY | |
608 | /** | |
609 | * memcpy - Copy one area of memory to another | |
610 | * @dest: Where to copy to | |
611 | * @src: Where to copy from | |
612 | * @count: The size of the area. | |
613 | * | |
614 | * You should not use this function to access IO space, use memcpy_toio() | |
615 | * or memcpy_fromio() instead. | |
616 | */ | |
51a0f0f6 | 617 | void *memcpy(void *dest, const void *src, size_t count) |
1da177e4 | 618 | { |
850b9247 | 619 | char *tmp = dest; |
4c416ab7 | 620 | const char *s = src; |
1da177e4 LT |
621 | |
622 | while (count--) | |
623 | *tmp++ = *s++; | |
1da177e4 LT |
624 | return dest; |
625 | } | |
626 | EXPORT_SYMBOL(memcpy); | |
627 | #endif | |
628 | ||
629 | #ifndef __HAVE_ARCH_MEMMOVE | |
630 | /** | |
631 | * memmove - Copy one area of memory to another | |
632 | * @dest: Where to copy to | |
633 | * @src: Where to copy from | |
634 | * @count: The size of the area. | |
635 | * | |
636 | * Unlike memcpy(), memmove() copes with overlapping areas. | |
637 | */ | |
51a0f0f6 | 638 | void *memmove(void *dest, const void *src, size_t count) |
1da177e4 | 639 | { |
82da2c37 PJ |
640 | char *tmp; |
641 | const char *s; | |
1da177e4 LT |
642 | |
643 | if (dest <= src) { | |
850b9247 JJ |
644 | tmp = dest; |
645 | s = src; | |
1da177e4 LT |
646 | while (count--) |
647 | *tmp++ = *s++; | |
51a0f0f6 | 648 | } else { |
850b9247 JJ |
649 | tmp = dest; |
650 | tmp += count; | |
651 | s = src; | |
652 | s += count; | |
1da177e4 LT |
653 | while (count--) |
654 | *--tmp = *--s; | |
51a0f0f6 | 655 | } |
1da177e4 LT |
656 | return dest; |
657 | } | |
658 | EXPORT_SYMBOL(memmove); | |
659 | #endif | |
660 | ||
661 | #ifndef __HAVE_ARCH_MEMCMP | |
662 | /** | |
663 | * memcmp - Compare two areas of memory | |
664 | * @cs: One area of memory | |
665 | * @ct: Another area of memory | |
666 | * @count: The size of the area. | |
667 | */ | |
0c28130b | 668 | #undef memcmp |
a7330c99 | 669 | __visible int memcmp(const void *cs, const void *ct, size_t count) |
1da177e4 LT |
670 | { |
671 | const unsigned char *su1, *su2; | |
672 | int res = 0; | |
673 | ||
51a0f0f6 | 674 | for (su1 = cs, su2 = ct; 0 < count; ++su1, ++su2, count--) |
1da177e4 LT |
675 | if ((res = *su1 - *su2) != 0) |
676 | break; | |
677 | return res; | |
678 | } | |
679 | EXPORT_SYMBOL(memcmp); | |
680 | #endif | |
681 | ||
682 | #ifndef __HAVE_ARCH_MEMSCAN | |
683 | /** | |
684 | * memscan - Find a character in an area of memory. | |
685 | * @addr: The memory area | |
686 | * @c: The byte to search for | |
687 | * @size: The size of the area. | |
688 | * | |
689 | * returns the address of the first occurrence of @c, or 1 byte past | |
690 | * the area if @c is not found | |
691 | */ | |
51a0f0f6 | 692 | void *memscan(void *addr, int c, size_t size) |
1da177e4 | 693 | { |
850b9247 | 694 | unsigned char *p = addr; |
1da177e4 LT |
695 | |
696 | while (size) { | |
697 | if (*p == c) | |
51a0f0f6 | 698 | return (void *)p; |
1da177e4 LT |
699 | p++; |
700 | size--; | |
701 | } | |
51a0f0f6 | 702 | return (void *)p; |
1da177e4 LT |
703 | } |
704 | EXPORT_SYMBOL(memscan); | |
705 | #endif | |
706 | ||
707 | #ifndef __HAVE_ARCH_STRSTR | |
708 | /** | |
709 | * strstr - Find the first substring in a %NUL terminated string | |
710 | * @s1: The string to be searched | |
711 | * @s2: The string to search for | |
712 | */ | |
51a0f0f6 | 713 | char *strstr(const char *s1, const char *s2) |
1da177e4 | 714 | { |
d5f1fb53 | 715 | size_t l1, l2; |
1da177e4 LT |
716 | |
717 | l2 = strlen(s2); | |
718 | if (!l2) | |
51a0f0f6 | 719 | return (char *)s1; |
1da177e4 LT |
720 | l1 = strlen(s1); |
721 | while (l1 >= l2) { | |
722 | l1--; | |
51a0f0f6 JJ |
723 | if (!memcmp(s1, s2, l2)) |
724 | return (char *)s1; | |
1da177e4 LT |
725 | s1++; |
726 | } | |
727 | return NULL; | |
728 | } | |
729 | EXPORT_SYMBOL(strstr); | |
730 | #endif | |
731 | ||
d5f1fb53 LZ |
732 | #ifndef __HAVE_ARCH_STRNSTR |
733 | /** | |
734 | * strnstr - Find the first substring in a length-limited string | |
735 | * @s1: The string to be searched | |
736 | * @s2: The string to search for | |
737 | * @len: the maximum number of characters to search | |
738 | */ | |
739 | char *strnstr(const char *s1, const char *s2, size_t len) | |
740 | { | |
d6a2eedf | 741 | size_t l2; |
d5f1fb53 LZ |
742 | |
743 | l2 = strlen(s2); | |
744 | if (!l2) | |
745 | return (char *)s1; | |
d6a2eedf AGR |
746 | while (len >= l2) { |
747 | len--; | |
d5f1fb53 LZ |
748 | if (!memcmp(s1, s2, l2)) |
749 | return (char *)s1; | |
750 | s1++; | |
751 | } | |
752 | return NULL; | |
753 | } | |
754 | EXPORT_SYMBOL(strnstr); | |
755 | #endif | |
756 | ||
1da177e4 LT |
757 | #ifndef __HAVE_ARCH_MEMCHR |
758 | /** | |
759 | * memchr - Find a character in an area of memory. | |
760 | * @s: The memory area | |
761 | * @c: The byte to search for | |
762 | * @n: The size of the area. | |
763 | * | |
764 | * returns the address of the first occurrence of @c, or %NULL | |
765 | * if @c is not found | |
766 | */ | |
767 | void *memchr(const void *s, int c, size_t n) | |
768 | { | |
769 | const unsigned char *p = s; | |
770 | while (n-- != 0) { | |
771 | if ((unsigned char)c == *p++) { | |
51a0f0f6 | 772 | return (void *)(p - 1); |
1da177e4 LT |
773 | } |
774 | } | |
775 | return NULL; | |
776 | } | |
777 | EXPORT_SYMBOL(memchr); | |
778 | #endif | |
79824820 AM |
779 | |
780 | static void *check_bytes8(const u8 *start, u8 value, unsigned int bytes) | |
781 | { | |
782 | while (bytes) { | |
783 | if (*start != value) | |
784 | return (void *)start; | |
785 | start++; | |
786 | bytes--; | |
787 | } | |
788 | return NULL; | |
789 | } | |
790 | ||
791 | /** | |
792 | * memchr_inv - Find an unmatching character in an area of memory. | |
793 | * @start: The memory area | |
794 | * @c: Find a character other than c | |
795 | * @bytes: The size of the area. | |
796 | * | |
797 | * returns the address of the first character other than @c, or %NULL | |
798 | * if the whole buffer contains just @c. | |
799 | */ | |
800 | void *memchr_inv(const void *start, int c, size_t bytes) | |
801 | { | |
802 | u8 value = c; | |
803 | u64 value64; | |
804 | unsigned int words, prefix; | |
805 | ||
806 | if (bytes <= 16) | |
807 | return check_bytes8(start, value, bytes); | |
808 | ||
f43804bf AM |
809 | value64 = value; |
810 | #if defined(ARCH_HAS_FAST_MULTIPLIER) && BITS_PER_LONG == 64 | |
811 | value64 *= 0x0101010101010101; | |
812 | #elif defined(ARCH_HAS_FAST_MULTIPLIER) | |
813 | value64 *= 0x01010101; | |
814 | value64 |= value64 << 32; | |
815 | #else | |
816 | value64 |= value64 << 8; | |
817 | value64 |= value64 << 16; | |
818 | value64 |= value64 << 32; | |
819 | #endif | |
79824820 | 820 | |
f43804bf | 821 | prefix = (unsigned long)start % 8; |
79824820 | 822 | if (prefix) { |
f43804bf AM |
823 | u8 *r; |
824 | ||
825 | prefix = 8 - prefix; | |
826 | r = check_bytes8(start, value, prefix); | |
79824820 AM |
827 | if (r) |
828 | return r; | |
829 | start += prefix; | |
830 | bytes -= prefix; | |
831 | } | |
832 | ||
833 | words = bytes / 8; | |
834 | ||
835 | while (words) { | |
836 | if (*(u64 *)start != value64) | |
837 | return check_bytes8(start, value, 8); | |
838 | start += 8; | |
839 | words--; | |
840 | } | |
841 | ||
842 | return check_bytes8(start, value, bytes % 8); | |
843 | } | |
844 | EXPORT_SYMBOL(memchr_inv); |