Root/
Source at commit b13e7eb172b6f08e5fc22da162bdde5fcde201b5 created 11 years 11 months ago. By Maarten ter Huurne, fbcon: Add 6x10 font | |
---|---|
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> |
25 | #include <linux/module.h> |
26 | |
27 | #ifndef __HAVE_ARCH_STRNICMP |
28 | /** |
29 | * strnicmp - Case insensitive, length-limited string comparison |
30 | * @s1: One string |
31 | * @s2: The other string |
32 | * @len: the maximum number of characters to compare |
33 | */ |
34 | int strnicmp(const char *s1, const char *s2, size_t len) |
35 | { |
36 | /* Yes, Virginia, it had better be unsigned */ |
37 | unsigned char c1, c2; |
38 | |
39 | if (!len) |
40 | return 0; |
41 | |
42 | do { |
43 | c1 = *s1++; |
44 | c2 = *s2++; |
45 | if (!c1 || !c2) |
46 | break; |
47 | if (c1 == c2) |
48 | continue; |
49 | c1 = tolower(c1); |
50 | c2 = tolower(c2); |
51 | if (c1 != c2) |
52 | break; |
53 | } while (--len); |
54 | return (int)c1 - (int)c2; |
55 | } |
56 | EXPORT_SYMBOL(strnicmp); |
57 | #endif |
58 | |
59 | #ifndef __HAVE_ARCH_STRCASECMP |
60 | int strcasecmp(const char *s1, const char *s2) |
61 | { |
62 | int c1, c2; |
63 | |
64 | do { |
65 | c1 = tolower(*s1++); |
66 | c2 = tolower(*s2++); |
67 | } while (c1 == c2 && c1 != 0); |
68 | return c1 - c2; |
69 | } |
70 | EXPORT_SYMBOL(strcasecmp); |
71 | #endif |
72 | |
73 | #ifndef __HAVE_ARCH_STRNCASECMP |
74 | int strncasecmp(const char *s1, const char *s2, size_t n) |
75 | { |
76 | int c1, c2; |
77 | |
78 | do { |
79 | c1 = tolower(*s1++); |
80 | c2 = tolower(*s2++); |
81 | } while ((--n > 0) && c1 == c2 && c1 != 0); |
82 | return c1 - c2; |
83 | } |
84 | EXPORT_SYMBOL(strncasecmp); |
85 | #endif |
86 | |
87 | #ifndef __HAVE_ARCH_STRCPY |
88 | /** |
89 | * strcpy - Copy a %NUL terminated string |
90 | * @dest: Where to copy the string to |
91 | * @src: Where to copy the string from |
92 | */ |
93 | #undef strcpy |
94 | char *strcpy(char *dest, const char *src) |
95 | { |
96 | char *tmp = dest; |
97 | |
98 | while ((*dest++ = *src++) != '\0') |
99 | /* nothing */; |
100 | return tmp; |
101 | } |
102 | EXPORT_SYMBOL(strcpy); |
103 | #endif |
104 | |
105 | #ifndef __HAVE_ARCH_STRNCPY |
106 | /** |
107 | * strncpy - Copy a length-limited, %NUL-terminated string |
108 | * @dest: Where to copy the string to |
109 | * @src: Where to copy the string from |
110 | * @count: The maximum number of bytes to copy |
111 | * |
112 | * The result is not %NUL-terminated if the source exceeds |
113 | * @count bytes. |
114 | * |
115 | * In the case where the length of @src is less than that of |
116 | * count, the remainder of @dest will be padded with %NUL. |
117 | * |
118 | */ |
119 | char *strncpy(char *dest, const char *src, size_t count) |
120 | { |
121 | char *tmp = dest; |
122 | |
123 | while (count) { |
124 | if ((*tmp = *src) != 0) |
125 | src++; |
126 | tmp++; |
127 | count--; |
128 | } |
129 | return dest; |
130 | } |
131 | EXPORT_SYMBOL(strncpy); |
132 | #endif |
133 | |
134 | #ifndef __HAVE_ARCH_STRLCPY |
135 | /** |
136 | * strlcpy - Copy a %NUL terminated string into a sized buffer |
137 | * @dest: Where to copy the string to |
138 | * @src: Where to copy the string from |
139 | * @size: size of destination buffer |
140 | * |
141 | * Compatible with *BSD: the result is always a valid |
142 | * NUL-terminated string that fits in the buffer (unless, |
143 | * of course, the buffer size is zero). It does not pad |
144 | * out the result like strncpy() does. |
145 | */ |
146 | size_t strlcpy(char *dest, const char *src, size_t size) |
147 | { |
148 | size_t ret = strlen(src); |
149 | |
150 | if (size) { |
151 | size_t len = (ret >= size) ? size - 1 : ret; |
152 | memcpy(dest, src, len); |
153 | dest[len] = '\0'; |
154 | } |
155 | return ret; |
156 | } |
157 | EXPORT_SYMBOL(strlcpy); |
158 | #endif |
159 | |
160 | #ifndef __HAVE_ARCH_STRCAT |
161 | /** |
162 | * strcat - Append one %NUL-terminated string to another |
163 | * @dest: The string to be appended to |
164 | * @src: The string to append to it |
165 | */ |
166 | #undef strcat |
167 | char *strcat(char *dest, const char *src) |
168 | { |
169 | char *tmp = dest; |
170 | |
171 | while (*dest) |
172 | dest++; |
173 | while ((*dest++ = *src++) != '\0') |
174 | ; |
175 | return tmp; |
176 | } |
177 | EXPORT_SYMBOL(strcat); |
178 | #endif |
179 | |
180 | #ifndef __HAVE_ARCH_STRNCAT |
181 | /** |
182 | * strncat - Append a length-limited, %NUL-terminated string to another |
183 | * @dest: The string to be appended to |
184 | * @src: The string to append to it |
185 | * @count: The maximum numbers of bytes to copy |
186 | * |
187 | * Note that in contrast to strncpy(), strncat() ensures the result is |
188 | * terminated. |
189 | */ |
190 | char *strncat(char *dest, const char *src, size_t count) |
191 | { |
192 | char *tmp = dest; |
193 | |
194 | if (count) { |
195 | while (*dest) |
196 | dest++; |
197 | while ((*dest++ = *src++) != 0) { |
198 | if (--count == 0) { |
199 | *dest = '\0'; |
200 | break; |
201 | } |
202 | } |
203 | } |
204 | return tmp; |
205 | } |
206 | EXPORT_SYMBOL(strncat); |
207 | #endif |
208 | |
209 | #ifndef __HAVE_ARCH_STRLCAT |
210 | /** |
211 | * strlcat - Append a length-limited, %NUL-terminated string to another |
212 | * @dest: The string to be appended to |
213 | * @src: The string to append to it |
214 | * @count: The size of the destination buffer. |
215 | */ |
216 | size_t strlcat(char *dest, const char *src, size_t count) |
217 | { |
218 | size_t dsize = strlen(dest); |
219 | size_t len = strlen(src); |
220 | size_t res = dsize + len; |
221 | |
222 | /* This would be a bug */ |
223 | BUG_ON(dsize >= count); |
224 | |
225 | dest += dsize; |
226 | count -= dsize; |
227 | if (len >= count) |
228 | len = count-1; |
229 | memcpy(dest, src, len); |
230 | dest[len] = 0; |
231 | return res; |
232 | } |
233 | EXPORT_SYMBOL(strlcat); |
234 | #endif |
235 | |
236 | #ifndef __HAVE_ARCH_STRCMP |
237 | /** |
238 | * strcmp - Compare two strings |
239 | * @cs: One string |
240 | * @ct: Another string |
241 | */ |
242 | #undef strcmp |
243 | int strcmp(const char *cs, const char *ct) |
244 | { |
245 | unsigned char c1, c2; |
246 | |
247 | while (1) { |
248 | c1 = *cs++; |
249 | c2 = *ct++; |
250 | if (c1 != c2) |
251 | return c1 < c2 ? -1 : 1; |
252 | if (!c1) |
253 | break; |
254 | } |
255 | return 0; |
256 | } |
257 | EXPORT_SYMBOL(strcmp); |
258 | #endif |
259 | |
260 | #ifndef __HAVE_ARCH_STRNCMP |
261 | /** |
262 | * strncmp - Compare two length-limited strings |
263 | * @cs: One string |
264 | * @ct: Another string |
265 | * @count: The maximum number of bytes to compare |
266 | */ |
267 | int strncmp(const char *cs, const char *ct, size_t count) |
268 | { |
269 | unsigned char c1, c2; |
270 | |
271 | while (count) { |
272 | c1 = *cs++; |
273 | c2 = *ct++; |
274 | if (c1 != c2) |
275 | return c1 < c2 ? -1 : 1; |
276 | if (!c1) |
277 | break; |
278 | count--; |
279 | } |
280 | return 0; |
281 | } |
282 | EXPORT_SYMBOL(strncmp); |
283 | #endif |
284 | |
285 | #ifndef __HAVE_ARCH_STRCHR |
286 | /** |
287 | * strchr - Find the first occurrence of a character in a string |
288 | * @s: The string to be searched |
289 | * @c: The character to search for |
290 | */ |
291 | char *strchr(const char *s, int c) |
292 | { |
293 | for (; *s != (char)c; ++s) |
294 | if (*s == '\0') |
295 | return NULL; |
296 | return (char *)s; |
297 | } |
298 | EXPORT_SYMBOL(strchr); |
299 | #endif |
300 | |
301 | #ifndef __HAVE_ARCH_STRRCHR |
302 | /** |
303 | * strrchr - Find the last occurrence of a character in a string |
304 | * @s: The string to be searched |
305 | * @c: The character to search for |
306 | */ |
307 | char *strrchr(const char *s, int c) |
308 | { |
309 | const char *p = s + strlen(s); |
310 | do { |
311 | if (*p == (char)c) |
312 | return (char *)p; |
313 | } while (--p >= s); |
314 | return NULL; |
315 | } |
316 | EXPORT_SYMBOL(strrchr); |
317 | #endif |
318 | |
319 | #ifndef __HAVE_ARCH_STRNCHR |
320 | /** |
321 | * strnchr - Find a character in a length limited string |
322 | * @s: The string to be searched |
323 | * @count: The number of characters to be searched |
324 | * @c: The character to search for |
325 | */ |
326 | char *strnchr(const char *s, size_t count, int c) |
327 | { |
328 | for (; count-- && *s != '\0'; ++s) |
329 | if (*s == (char)c) |
330 | return (char *)s; |
331 | return NULL; |
332 | } |
333 | EXPORT_SYMBOL(strnchr); |
334 | #endif |
335 | |
336 | /** |
337 | * skip_spaces - Removes leading whitespace from @str. |
338 | * @str: The string to be stripped. |
339 | * |
340 | * Returns a pointer to the first non-whitespace character in @str. |
341 | */ |
342 | char *skip_spaces(const char *str) |
343 | { |
344 | while (isspace(*str)) |
345 | ++str; |
346 | return (char *)str; |
347 | } |
348 | EXPORT_SYMBOL(skip_spaces); |
349 | |
350 | /** |
351 | * strim - Removes leading and trailing whitespace from @s. |
352 | * @s: The string to be stripped. |
353 | * |
354 | * Note that the first trailing whitespace is replaced with a %NUL-terminator |
355 | * in the given string @s. Returns a pointer to the first non-whitespace |
356 | * character in @s. |
357 | */ |
358 | char *strim(char *s) |
359 | { |
360 | size_t size; |
361 | char *end; |
362 | |
363 | size = strlen(s); |
364 | if (!size) |
365 | return s; |
366 | |
367 | end = s + size - 1; |
368 | while (end >= s && isspace(*end)) |
369 | end--; |
370 | *(end + 1) = '\0'; |
371 | |
372 | return skip_spaces(s); |
373 | } |
374 | EXPORT_SYMBOL(strim); |
375 | |
376 | #ifndef __HAVE_ARCH_STRLEN |
377 | /** |
378 | * strlen - Find the length of a string |
379 | * @s: The string to be sized |
380 | */ |
381 | size_t strlen(const char *s) |
382 | { |
383 | const char *sc; |
384 | |
385 | for (sc = s; *sc != '\0'; ++sc) |
386 | /* nothing */; |
387 | return sc - s; |
388 | } |
389 | EXPORT_SYMBOL(strlen); |
390 | #endif |
391 | |
392 | #ifndef __HAVE_ARCH_STRNLEN |
393 | /** |
394 | * strnlen - Find the length of a length-limited string |
395 | * @s: The string to be sized |
396 | * @count: The maximum number of bytes to search |
397 | */ |
398 | size_t strnlen(const char *s, size_t count) |
399 | { |
400 | const char *sc; |
401 | |
402 | for (sc = s; count-- && *sc != '\0'; ++sc) |
403 | /* nothing */; |
404 | return sc - s; |
405 | } |
406 | EXPORT_SYMBOL(strnlen); |
407 | #endif |
408 | |
409 | #ifndef __HAVE_ARCH_STRSPN |
410 | /** |
411 | * strspn - Calculate the length of the initial substring of @s which only contain letters in @accept |
412 | * @s: The string to be searched |
413 | * @accept: The string to search for |
414 | */ |
415 | size_t strspn(const char *s, const char *accept) |
416 | { |
417 | const char *p; |
418 | const char *a; |
419 | size_t count = 0; |
420 | |
421 | for (p = s; *p != '\0'; ++p) { |
422 | for (a = accept; *a != '\0'; ++a) { |
423 | if (*p == *a) |
424 | break; |
425 | } |
426 | if (*a == '\0') |
427 | return count; |
428 | ++count; |
429 | } |
430 | return count; |
431 | } |
432 | |
433 | EXPORT_SYMBOL(strspn); |
434 | #endif |
435 | |
436 | #ifndef __HAVE_ARCH_STRCSPN |
437 | /** |
438 | * strcspn - Calculate the length of the initial substring of @s which does not contain letters in @reject |
439 | * @s: The string to be searched |
440 | * @reject: The string to avoid |
441 | */ |
442 | size_t strcspn(const char *s, const char *reject) |
443 | { |
444 | const char *p; |
445 | const char *r; |
446 | size_t count = 0; |
447 | |
448 | for (p = s; *p != '\0'; ++p) { |
449 | for (r = reject; *r != '\0'; ++r) { |
450 | if (*p == *r) |
451 | return count; |
452 | } |
453 | ++count; |
454 | } |
455 | return count; |
456 | } |
457 | EXPORT_SYMBOL(strcspn); |
458 | #endif |
459 | |
460 | #ifndef __HAVE_ARCH_STRPBRK |
461 | /** |
462 | * strpbrk - Find the first occurrence of a set of characters |
463 | * @cs: The string to be searched |
464 | * @ct: The characters to search for |
465 | */ |
466 | char *strpbrk(const char *cs, const char *ct) |
467 | { |
468 | const char *sc1, *sc2; |
469 | |
470 | for (sc1 = cs; *sc1 != '\0'; ++sc1) { |
471 | for (sc2 = ct; *sc2 != '\0'; ++sc2) { |
472 | if (*sc1 == *sc2) |
473 | return (char *)sc1; |
474 | } |
475 | } |
476 | return NULL; |
477 | } |
478 | EXPORT_SYMBOL(strpbrk); |
479 | #endif |
480 | |
481 | #ifndef __HAVE_ARCH_STRSEP |
482 | /** |
483 | * strsep - Split a string into tokens |
484 | * @s: The string to be searched |
485 | * @ct: The characters to search for |
486 | * |
487 | * strsep() updates @s to point after the token, ready for the next call. |
488 | * |
489 | * It returns empty tokens, too, behaving exactly like the libc function |
490 | * of that name. In fact, it was stolen from glibc2 and de-fancy-fied. |
491 | * Same semantics, slimmer shape. ;) |
492 | */ |
493 | char *strsep(char **s, const char *ct) |
494 | { |
495 | char *sbegin = *s; |
496 | char *end; |
497 | |
498 | if (sbegin == NULL) |
499 | return NULL; |
500 | |
501 | end = strpbrk(sbegin, ct); |
502 | if (end) |
503 | *end++ = '\0'; |
504 | *s = end; |
505 | return sbegin; |
506 | } |
507 | EXPORT_SYMBOL(strsep); |
508 | #endif |
509 | |
510 | /** |
511 | * sysfs_streq - return true if strings are equal, modulo trailing newline |
512 | * @s1: one string |
513 | * @s2: another string |
514 | * |
515 | * This routine returns true iff two strings are equal, treating both |
516 | * NUL and newline-then-NUL as equivalent string terminations. It's |
517 | * geared for use with sysfs input strings, which generally terminate |
518 | * with newlines but are compared against values without newlines. |
519 | */ |
520 | bool sysfs_streq(const char *s1, const char *s2) |
521 | { |
522 | while (*s1 && *s1 == *s2) { |
523 | s1++; |
524 | s2++; |
525 | } |
526 | |
527 | if (*s1 == *s2) |
528 | return true; |
529 | if (!*s1 && *s2 == '\n' && !s2[1]) |
530 | return true; |
531 | if (*s1 == '\n' && !s1[1] && !*s2) |
532 | return true; |
533 | return false; |
534 | } |
535 | EXPORT_SYMBOL(sysfs_streq); |
536 | |
537 | /** |
538 | * strtobool - convert common user inputs into boolean values |
539 | * @s: input string |
540 | * @res: result |
541 | * |
542 | * This routine returns 0 iff the first character is one of 'Yy1Nn0'. |
543 | * Otherwise it will return -EINVAL. Value pointed to by res is |
544 | * updated upon finding a match. |
545 | */ |
546 | int strtobool(const char *s, bool *res) |
547 | { |
548 | switch (s[0]) { |
549 | case 'y': |
550 | case 'Y': |
551 | case '1': |
552 | *res = true; |
553 | break; |
554 | case 'n': |
555 | case 'N': |
556 | case '0': |
557 | *res = false; |
558 | break; |
559 | default: |
560 | return -EINVAL; |
561 | } |
562 | return 0; |
563 | } |
564 | EXPORT_SYMBOL(strtobool); |
565 | |
566 | #ifndef __HAVE_ARCH_MEMSET |
567 | /** |
568 | * memset - Fill a region of memory with the given value |
569 | * @s: Pointer to the start of the area. |
570 | * @c: The byte to fill the area with |
571 | * @count: The size of the area. |
572 | * |
573 | * Do not use memset() to access IO space, use memset_io() instead. |
574 | */ |
575 | void *memset(void *s, int c, size_t count) |
576 | { |
577 | char *xs = s; |
578 | |
579 | while (count--) |
580 | *xs++ = c; |
581 | return s; |
582 | } |
583 | EXPORT_SYMBOL(memset); |
584 | #endif |
585 | |
586 | #ifndef __HAVE_ARCH_MEMCPY |
587 | /** |
588 | * memcpy - Copy one area of memory to another |
589 | * @dest: Where to copy to |
590 | * @src: Where to copy from |
591 | * @count: The size of the area. |
592 | * |
593 | * You should not use this function to access IO space, use memcpy_toio() |
594 | * or memcpy_fromio() instead. |
595 | */ |
596 | void *memcpy(void *dest, const void *src, size_t count) |
597 | { |
598 | char *tmp = dest; |
599 | const char *s = src; |
600 | |
601 | while (count--) |
602 | *tmp++ = *s++; |
603 | return dest; |
604 | } |
605 | EXPORT_SYMBOL(memcpy); |
606 | #endif |
607 | |
608 | #ifndef __HAVE_ARCH_MEMMOVE |
609 | /** |
610 | * memmove - Copy one area of memory to another |
611 | * @dest: Where to copy to |
612 | * @src: Where to copy from |
613 | * @count: The size of the area. |
614 | * |
615 | * Unlike memcpy(), memmove() copes with overlapping areas. |
616 | */ |
617 | void *memmove(void *dest, const void *src, size_t count) |
618 | { |
619 | char *tmp; |
620 | const char *s; |
621 | |
622 | if (dest <= src) { |
623 | tmp = dest; |
624 | s = src; |
625 | while (count--) |
626 | *tmp++ = *s++; |
627 | } else { |
628 | tmp = dest; |
629 | tmp += count; |
630 | s = src; |
631 | s += count; |
632 | while (count--) |
633 | *--tmp = *--s; |
634 | } |
635 | return dest; |
636 | } |
637 | EXPORT_SYMBOL(memmove); |
638 | #endif |
639 | |
640 | #ifndef __HAVE_ARCH_MEMCMP |
641 | /** |
642 | * memcmp - Compare two areas of memory |
643 | * @cs: One area of memory |
644 | * @ct: Another area of memory |
645 | * @count: The size of the area. |
646 | */ |
647 | #undef memcmp |
648 | int memcmp(const void *cs, const void *ct, size_t count) |
649 | { |
650 | const unsigned char *su1, *su2; |
651 | int res = 0; |
652 | |
653 | for (su1 = cs, su2 = ct; 0 < count; ++su1, ++su2, count--) |
654 | if ((res = *su1 - *su2) != 0) |
655 | break; |
656 | return res; |
657 | } |
658 | EXPORT_SYMBOL(memcmp); |
659 | #endif |
660 | |
661 | #ifndef __HAVE_ARCH_MEMSCAN |
662 | /** |
663 | * memscan - Find a character in an area of memory. |
664 | * @addr: The memory area |
665 | * @c: The byte to search for |
666 | * @size: The size of the area. |
667 | * |
668 | * returns the address of the first occurrence of @c, or 1 byte past |
669 | * the area if @c is not found |
670 | */ |
671 | void *memscan(void *addr, int c, size_t size) |
672 | { |
673 | unsigned char *p = addr; |
674 | |
675 | while (size) { |
676 | if (*p == c) |
677 | return (void *)p; |
678 | p++; |
679 | size--; |
680 | } |
681 | return (void *)p; |
682 | } |
683 | EXPORT_SYMBOL(memscan); |
684 | #endif |
685 | |
686 | #ifndef __HAVE_ARCH_STRSTR |
687 | /** |
688 | * strstr - Find the first substring in a %NUL terminated string |
689 | * @s1: The string to be searched |
690 | * @s2: The string to search for |
691 | */ |
692 | char *strstr(const char *s1, const char *s2) |
693 | { |
694 | size_t l1, l2; |
695 | |
696 | l2 = strlen(s2); |
697 | if (!l2) |
698 | return (char *)s1; |
699 | l1 = strlen(s1); |
700 | while (l1 >= l2) { |
701 | l1--; |
702 | if (!memcmp(s1, s2, l2)) |
703 | return (char *)s1; |
704 | s1++; |
705 | } |
706 | return NULL; |
707 | } |
708 | EXPORT_SYMBOL(strstr); |
709 | #endif |
710 | |
711 | #ifndef __HAVE_ARCH_STRNSTR |
712 | /** |
713 | * strnstr - Find the first substring in a length-limited string |
714 | * @s1: The string to be searched |
715 | * @s2: The string to search for |
716 | * @len: the maximum number of characters to search |
717 | */ |
718 | char *strnstr(const char *s1, const char *s2, size_t len) |
719 | { |
720 | size_t l2; |
721 | |
722 | l2 = strlen(s2); |
723 | if (!l2) |
724 | return (char *)s1; |
725 | while (len >= l2) { |
726 | len--; |
727 | if (!memcmp(s1, s2, l2)) |
728 | return (char *)s1; |
729 | s1++; |
730 | } |
731 | return NULL; |
732 | } |
733 | EXPORT_SYMBOL(strnstr); |
734 | #endif |
735 | |
736 | #ifndef __HAVE_ARCH_MEMCHR |
737 | /** |
738 | * memchr - Find a character in an area of memory. |
739 | * @s: The memory area |
740 | * @c: The byte to search for |
741 | * @n: The size of the area. |
742 | * |
743 | * returns the address of the first occurrence of @c, or %NULL |
744 | * if @c is not found |
745 | */ |
746 | void *memchr(const void *s, int c, size_t n) |
747 | { |
748 | const unsigned char *p = s; |
749 | while (n-- != 0) { |
750 | if ((unsigned char)c == *p++) { |
751 | return (void *)(p - 1); |
752 | } |
753 | } |
754 | return NULL; |
755 | } |
756 | EXPORT_SYMBOL(memchr); |
757 | #endif |
758 | |
759 | static void *check_bytes8(const u8 *start, u8 value, unsigned int bytes) |
760 | { |
761 | while (bytes) { |
762 | if (*start != value) |
763 | return (void *)start; |
764 | start++; |
765 | bytes--; |
766 | } |
767 | return NULL; |
768 | } |
769 | |
770 | /** |
771 | * memchr_inv - Find an unmatching character in an area of memory. |
772 | * @start: The memory area |
773 | * @c: Find a character other than c |
774 | * @bytes: The size of the area. |
775 | * |
776 | * returns the address of the first character other than @c, or %NULL |
777 | * if the whole buffer contains just @c. |
778 | */ |
779 | void *memchr_inv(const void *start, int c, size_t bytes) |
780 | { |
781 | u8 value = c; |
782 | u64 value64; |
783 | unsigned int words, prefix; |
784 | |
785 | if (bytes <= 16) |
786 | return check_bytes8(start, value, bytes); |
787 | |
788 | value64 = value | value << 8 | value << 16 | value << 24; |
789 | value64 = (value64 & 0xffffffff) | value64 << 32; |
790 | prefix = 8 - ((unsigned long)start) % 8; |
791 | |
792 | if (prefix) { |
793 | u8 *r = check_bytes8(start, value, prefix); |
794 | if (r) |
795 | return r; |
796 | start += prefix; |
797 | bytes -= prefix; |
798 | } |
799 | |
800 | words = bytes / 8; |
801 | |
802 | while (words) { |
803 | if (*(u64 *)start != value64) |
804 | return check_bytes8(start, value, 8); |
805 | start += 8; |
806 | words--; |
807 | } |
808 | |
809 | return check_bytes8(start, value, bytes % 8); |
810 | } |
811 | EXPORT_SYMBOL(memchr_inv); |
812 |
Branches:
ben-wpan
ben-wpan-stefan
javiroman/ks7010
jz-2.6.34
jz-2.6.34-rc5
jz-2.6.34-rc6
jz-2.6.34-rc7
jz-2.6.35
jz-2.6.36
jz-2.6.37
jz-2.6.38
jz-2.6.39
jz-3.0
jz-3.1
jz-3.11
jz-3.12
jz-3.13
jz-3.15
jz-3.16
jz-3.18-dt
jz-3.2
jz-3.3
jz-3.4
jz-3.5
jz-3.6
jz-3.6-rc2-pwm
jz-3.9
jz-3.9-clk
jz-3.9-rc8
jz47xx
jz47xx-2.6.38
master
Tags:
od-2011-09-04
od-2011-09-18
v2.6.34-rc5
v2.6.34-rc6
v2.6.34-rc7
v3.9