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23#include <linux/types.h>
24#include <linux/string.h>
25#include <linux/ctype.h>
26#include <linux/kernel.h>
27#include <linux/export.h>
28#include <linux/bug.h>
29#include <linux/errno.h>
30#include <linux/slab.h>
31
32#include <asm/unaligned.h>
33#include <asm/byteorder.h>
34#include <asm/word-at-a-time.h>
35#include <asm/page.h>
36
37#ifndef __HAVE_ARCH_STRNCASECMP
38
39
40
41
42
43
44int strncasecmp(const char *s1, const char *s2, size_t len)
45{
46
47 unsigned char c1, c2;
48
49 if (!len)
50 return 0;
51
52 do {
53 c1 = *s1++;
54 c2 = *s2++;
55 if (!c1 || !c2)
56 break;
57 if (c1 == c2)
58 continue;
59 c1 = tolower(c1);
60 c2 = tolower(c2);
61 if (c1 != c2)
62 break;
63 } while (--len);
64 return (int)c1 - (int)c2;
65}
66EXPORT_SYMBOL(strncasecmp);
67#endif
68
69#ifndef __HAVE_ARCH_STRCASECMP
70int strcasecmp(const char *s1, const char *s2)
71{
72 int c1, c2;
73
74 do {
75 c1 = tolower(*s1++);
76 c2 = tolower(*s2++);
77 } while (c1 == c2 && c1 != 0);
78 return c1 - c2;
79}
80EXPORT_SYMBOL(strcasecmp);
81#endif
82
83#ifndef __HAVE_ARCH_STRCPY
84
85
86
87
88
89char *strcpy(char *dest, const char *src)
90{
91 char *tmp = dest;
92
93 while ((*dest++ = *src++) != '\0')
94 ;
95 return tmp;
96}
97EXPORT_SYMBOL(strcpy);
98#endif
99
100#ifndef __HAVE_ARCH_STRNCPY
101
102
103
104
105
106
107
108
109
110
111
112
113
114char *strncpy(char *dest, const char *src, size_t count)
115{
116 char *tmp = dest;
117
118 while (count) {
119 if ((*tmp = *src) != 0)
120 src++;
121 tmp++;
122 count--;
123 }
124 return dest;
125}
126EXPORT_SYMBOL(strncpy);
127#endif
128
129#ifndef __HAVE_ARCH_STRLCPY
130
131
132
133
134
135
136
137
138
139
140
141size_t strlcpy(char *dest, const char *src, size_t size)
142{
143 size_t ret = strlen(src);
144
145 if (size) {
146 size_t len = (ret >= size) ? size - 1 : ret;
147 memcpy(dest, src, len);
148 dest[len] = '\0';
149 }
150 return ret;
151}
152EXPORT_SYMBOL(strlcpy);
153#endif
154
155#ifndef __HAVE_ARCH_STRSCPY
156
157
158
159
160
161
162
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164
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178
179
180ssize_t strscpy(char *dest, const char *src, size_t count)
181{
182 const struct word_at_a_time constants = WORD_AT_A_TIME_CONSTANTS;
183 size_t max = count;
184 long res = 0;
185
186 if (count == 0 || WARN_ON_ONCE(count > INT_MAX))
187 return -E2BIG;
188
189#ifdef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
190
191
192
193
194 if ((long)src & (sizeof(long) - 1)) {
195 size_t limit = PAGE_SIZE - ((long)src & (PAGE_SIZE - 1));
196 if (limit < max)
197 max = limit;
198 }
199#else
200
201 if (((long) dest | (long) src) & (sizeof(long) - 1))
202 max = 0;
203#endif
204
205 while (max >= sizeof(unsigned long)) {
206 unsigned long c, data;
207
208 c = read_word_at_a_time(src+res);
209 if (has_zero(c, &data, &constants)) {
210 data = prep_zero_mask(c, data, &constants);
211 data = create_zero_mask(data);
212 *(unsigned long *)(dest+res) = c & zero_bytemask(data);
213 return res + find_zero(data);
214 }
215 *(unsigned long *)(dest+res) = c;
216 res += sizeof(unsigned long);
217 count -= sizeof(unsigned long);
218 max -= sizeof(unsigned long);
219 }
220
221 while (count) {
222 char c;
223
224 c = src[res];
225 dest[res] = c;
226 if (!c)
227 return res;
228 res++;
229 count--;
230 }
231
232
233 if (res)
234 dest[res-1] = '\0';
235
236 return -E2BIG;
237}
238EXPORT_SYMBOL(strscpy);
239#endif
240
241
242
243
244
245
246
247
248
249
250
251
252
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259
260
261ssize_t strscpy_pad(char *dest, const char *src, size_t count)
262{
263 ssize_t written;
264
265 written = strscpy(dest, src, count);
266 if (written < 0 || written == count - 1)
267 return written;
268
269 memset(dest + written + 1, 0, count - written - 1);
270
271 return written;
272}
273EXPORT_SYMBOL(strscpy_pad);
274
275
276
277
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279
280
281
282
283
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285
286
287
288
289
290char *stpcpy(char *__restrict__ dest, const char *__restrict__ src);
291char *stpcpy(char *__restrict__ dest, const char *__restrict__ src)
292{
293 while ((*dest++ = *src++) != '\0')
294 ;
295 return --dest;
296}
297EXPORT_SYMBOL(stpcpy);
298
299#ifndef __HAVE_ARCH_STRCAT
300
301
302
303
304
305char *strcat(char *dest, const char *src)
306{
307 char *tmp = dest;
308
309 while (*dest)
310 dest++;
311 while ((*dest++ = *src++) != '\0')
312 ;
313 return tmp;
314}
315EXPORT_SYMBOL(strcat);
316#endif
317
318#ifndef __HAVE_ARCH_STRNCAT
319
320
321
322
323
324
325
326
327
328char *strncat(char *dest, const char *src, size_t count)
329{
330 char *tmp = dest;
331
332 if (count) {
333 while (*dest)
334 dest++;
335 while ((*dest++ = *src++) != 0) {
336 if (--count == 0) {
337 *dest = '\0';
338 break;
339 }
340 }
341 }
342 return tmp;
343}
344EXPORT_SYMBOL(strncat);
345#endif
346
347#ifndef __HAVE_ARCH_STRLCAT
348
349
350
351
352
353
354size_t strlcat(char *dest, const char *src, size_t count)
355{
356 size_t dsize = strlen(dest);
357 size_t len = strlen(src);
358 size_t res = dsize + len;
359
360
361 BUG_ON(dsize >= count);
362
363 dest += dsize;
364 count -= dsize;
365 if (len >= count)
366 len = count-1;
367 memcpy(dest, src, len);
368 dest[len] = 0;
369 return res;
370}
371EXPORT_SYMBOL(strlcat);
372#endif
373
374#ifndef __HAVE_ARCH_STRCMP
375
376
377
378
379
380int strcmp(const char *cs, const char *ct)
381{
382 unsigned char c1, c2;
383
384 while (1) {
385 c1 = *cs++;
386 c2 = *ct++;
387 if (c1 != c2)
388 return c1 < c2 ? -1 : 1;
389 if (!c1)
390 break;
391 }
392 return 0;
393}
394EXPORT_SYMBOL(strcmp);
395#endif
396
397#ifndef __HAVE_ARCH_STRNCMP
398
399
400
401
402
403
404int strncmp(const char *cs, const char *ct, size_t count)
405{
406 unsigned char c1, c2;
407
408 while (count) {
409 c1 = *cs++;
410 c2 = *ct++;
411 if (c1 != c2)
412 return c1 < c2 ? -1 : 1;
413 if (!c1)
414 break;
415 count--;
416 }
417 return 0;
418}
419EXPORT_SYMBOL(strncmp);
420#endif
421
422#ifndef __HAVE_ARCH_STRCHR
423
424
425
426
427
428
429
430
431char *strchr(const char *s, int c)
432{
433 for (; *s != (char)c; ++s)
434 if (*s == '\0')
435 return NULL;
436 return (char *)s;
437}
438EXPORT_SYMBOL(strchr);
439#endif
440
441#ifndef __HAVE_ARCH_STRCHRNUL
442
443
444
445
446
447
448
449
450char *strchrnul(const char *s, int c)
451{
452 while (*s && *s != (char)c)
453 s++;
454 return (char *)s;
455}
456EXPORT_SYMBOL(strchrnul);
457#endif
458
459
460
461
462
463
464
465
466
467
468
469char *strnchrnul(const char *s, size_t count, int c)
470{
471 while (count-- && *s && *s != (char)c)
472 s++;
473 return (char *)s;
474}
475
476#ifndef __HAVE_ARCH_STRRCHR
477
478
479
480
481
482char *strrchr(const char *s, int c)
483{
484 const char *last = NULL;
485 do {
486 if (*s == (char)c)
487 last = s;
488 } while (*s++);
489 return (char *)last;
490}
491EXPORT_SYMBOL(strrchr);
492#endif
493
494#ifndef __HAVE_ARCH_STRNCHR
495
496
497
498
499
500
501
502
503
504char *strnchr(const char *s, size_t count, int c)
505{
506 while (count--) {
507 if (*s == (char)c)
508 return (char *)s;
509 if (*s++ == '\0')
510 break;
511 }
512 return NULL;
513}
514EXPORT_SYMBOL(strnchr);
515#endif
516
517
518
519
520
521
522
523char *skip_spaces(const char *str)
524{
525 while (isspace(*str))
526 ++str;
527 return (char *)str;
528}
529EXPORT_SYMBOL(skip_spaces);
530
531
532
533
534
535
536
537
538
539char *strim(char *s)
540{
541 size_t size;
542 char *end;
543
544 size = strlen(s);
545 if (!size)
546 return s;
547
548 end = s + size - 1;
549 while (end >= s && isspace(*end))
550 end--;
551 *(end + 1) = '\0';
552
553 return skip_spaces(s);
554}
555EXPORT_SYMBOL(strim);
556
557#ifndef __HAVE_ARCH_STRLEN
558
559
560
561
562size_t strlen(const char *s)
563{
564 const char *sc;
565
566 for (sc = s; *sc != '\0'; ++sc)
567 ;
568 return sc - s;
569}
570EXPORT_SYMBOL(strlen);
571#endif
572
573#ifndef __HAVE_ARCH_STRNLEN
574
575
576
577
578
579size_t strnlen(const char *s, size_t count)
580{
581 const char *sc;
582
583 for (sc = s; count-- && *sc != '\0'; ++sc)
584 ;
585 return sc - s;
586}
587EXPORT_SYMBOL(strnlen);
588#endif
589
590#ifndef __HAVE_ARCH_STRSPN
591
592
593
594
595
596size_t strspn(const char *s, const char *accept)
597{
598 const char *p;
599 const char *a;
600 size_t count = 0;
601
602 for (p = s; *p != '\0'; ++p) {
603 for (a = accept; *a != '\0'; ++a) {
604 if (*p == *a)
605 break;
606 }
607 if (*a == '\0')
608 return count;
609 ++count;
610 }
611 return count;
612}
613
614EXPORT_SYMBOL(strspn);
615#endif
616
617#ifndef __HAVE_ARCH_STRCSPN
618
619
620
621
622
623size_t strcspn(const char *s, const char *reject)
624{
625 const char *p;
626 const char *r;
627 size_t count = 0;
628
629 for (p = s; *p != '\0'; ++p) {
630 for (r = reject; *r != '\0'; ++r) {
631 if (*p == *r)
632 return count;
633 }
634 ++count;
635 }
636 return count;
637}
638EXPORT_SYMBOL(strcspn);
639#endif
640
641#ifndef __HAVE_ARCH_STRPBRK
642
643
644
645
646
647char *strpbrk(const char *cs, const char *ct)
648{
649 const char *sc1, *sc2;
650
651 for (sc1 = cs; *sc1 != '\0'; ++sc1) {
652 for (sc2 = ct; *sc2 != '\0'; ++sc2) {
653 if (*sc1 == *sc2)
654 return (char *)sc1;
655 }
656 }
657 return NULL;
658}
659EXPORT_SYMBOL(strpbrk);
660#endif
661
662#ifndef __HAVE_ARCH_STRSEP
663
664
665
666
667
668
669
670
671
672
673
674char *strsep(char **s, const char *ct)
675{
676 char *sbegin = *s;
677 char *end;
678
679 if (sbegin == NULL)
680 return NULL;
681
682 end = strpbrk(sbegin, ct);
683 if (end)
684 *end++ = '\0';
685 *s = end;
686 return sbegin;
687}
688EXPORT_SYMBOL(strsep);
689#endif
690
691
692
693
694
695
696
697
698
699
700
701bool sysfs_streq(const char *s1, const char *s2)
702{
703 while (*s1 && *s1 == *s2) {
704 s1++;
705 s2++;
706 }
707
708 if (*s1 == *s2)
709 return true;
710 if (!*s1 && *s2 == '\n' && !s2[1])
711 return true;
712 if (*s1 == '\n' && !s1[1] && !*s2)
713 return true;
714 return false;
715}
716EXPORT_SYMBOL(sysfs_streq);
717
718
719
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731
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733
734
735int match_string(const char * const *array, size_t n, const char *string)
736{
737 int index;
738 const char *item;
739
740 for (index = 0; index < n; index++) {
741 item = array[index];
742 if (!item)
743 break;
744 if (!strcmp(item, string))
745 return index;
746 }
747
748 return -EINVAL;
749}
750EXPORT_SYMBOL(match_string);
751
752
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764
765
766
767
768
769int __sysfs_match_string(const char * const *array, size_t n, const char *str)
770{
771 const char *item;
772 int index;
773
774 for (index = 0; index < n; index++) {
775 item = array[index];
776 if (!item)
777 break;
778 if (sysfs_streq(item, str))
779 return index;
780 }
781
782 return -EINVAL;
783}
784EXPORT_SYMBOL(__sysfs_match_string);
785
786#ifndef __HAVE_ARCH_MEMSET
787
788
789
790
791
792
793
794
795void *memset(void *s, int c, size_t count)
796{
797 char *xs = s;
798
799 while (count--)
800 *xs++ = c;
801 return s;
802}
803EXPORT_SYMBOL(memset);
804#endif
805
806#ifndef __HAVE_ARCH_MEMSET16
807
808
809
810
811
812
813
814
815
816
817void *memset16(uint16_t *s, uint16_t v, size_t count)
818{
819 uint16_t *xs = s;
820
821 while (count--)
822 *xs++ = v;
823 return s;
824}
825EXPORT_SYMBOL(memset16);
826#endif
827
828#ifndef __HAVE_ARCH_MEMSET32
829
830
831
832
833
834
835
836
837
838
839void *memset32(uint32_t *s, uint32_t v, size_t count)
840{
841 uint32_t *xs = s;
842
843 while (count--)
844 *xs++ = v;
845 return s;
846}
847EXPORT_SYMBOL(memset32);
848#endif
849
850#ifndef __HAVE_ARCH_MEMSET64
851
852
853
854
855
856
857
858
859
860
861void *memset64(uint64_t *s, uint64_t v, size_t count)
862{
863 uint64_t *xs = s;
864
865 while (count--)
866 *xs++ = v;
867 return s;
868}
869EXPORT_SYMBOL(memset64);
870#endif
871
872#ifndef __HAVE_ARCH_MEMCPY
873
874
875
876
877
878
879
880
881
882void *memcpy(void *dest, const void *src, size_t count)
883{
884 char *tmp = dest;
885 const char *s = src;
886
887 while (count--)
888 *tmp++ = *s++;
889 return dest;
890}
891EXPORT_SYMBOL(memcpy);
892#endif
893
894#ifndef __HAVE_ARCH_MEMMOVE
895
896
897
898
899
900
901
902
903void *memmove(void *dest, const void *src, size_t count)
904{
905 char *tmp;
906 const char *s;
907
908 if (dest <= src) {
909 tmp = dest;
910 s = src;
911 while (count--)
912 *tmp++ = *s++;
913 } else {
914 tmp = dest;
915 tmp += count;
916 s = src;
917 s += count;
918 while (count--)
919 *--tmp = *--s;
920 }
921 return dest;
922}
923EXPORT_SYMBOL(memmove);
924#endif
925
926#ifndef __HAVE_ARCH_MEMCMP
927
928
929
930
931
932
933#undef memcmp
934__visible int memcmp(const void *cs, const void *ct, size_t count)
935{
936 const unsigned char *su1, *su2;
937 int res = 0;
938
939#ifdef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
940 if (count >= sizeof(unsigned long)) {
941 const unsigned long *u1 = cs;
942 const unsigned long *u2 = ct;
943 do {
944 if (get_unaligned(u1) != get_unaligned(u2))
945 break;
946 u1++;
947 u2++;
948 count -= sizeof(unsigned long);
949 } while (count >= sizeof(unsigned long));
950 cs = u1;
951 ct = u2;
952 }
953#endif
954 for (su1 = cs, su2 = ct; 0 < count; ++su1, ++su2, count--)
955 if ((res = *su1 - *su2) != 0)
956 break;
957 return res;
958}
959EXPORT_SYMBOL(memcmp);
960#endif
961
962#ifndef __HAVE_ARCH_BCMP
963
964
965
966
967
968
969
970
971
972
973
974int bcmp(const void *a, const void *b, size_t len)
975{
976 return memcmp(a, b, len);
977}
978EXPORT_SYMBOL(bcmp);
979#endif
980
981#ifndef __HAVE_ARCH_MEMSCAN
982
983
984
985
986
987
988
989
990
991void *memscan(void *addr, int c, size_t size)
992{
993 unsigned char *p = addr;
994
995 while (size) {
996 if (*p == (unsigned char)c)
997 return (void *)p;
998 p++;
999 size--;
1000 }
1001 return (void *)p;
1002}
1003EXPORT_SYMBOL(memscan);
1004#endif
1005
1006#ifndef __HAVE_ARCH_STRSTR
1007
1008
1009
1010
1011
1012char *strstr(const char *s1, const char *s2)
1013{
1014 size_t l1, l2;
1015
1016 l2 = strlen(s2);
1017 if (!l2)
1018 return (char *)s1;
1019 l1 = strlen(s1);
1020 while (l1 >= l2) {
1021 l1--;
1022 if (!memcmp(s1, s2, l2))
1023 return (char *)s1;
1024 s1++;
1025 }
1026 return NULL;
1027}
1028EXPORT_SYMBOL(strstr);
1029#endif
1030
1031#ifndef __HAVE_ARCH_STRNSTR
1032
1033
1034
1035
1036
1037
1038char *strnstr(const char *s1, const char *s2, size_t len)
1039{
1040 size_t l2;
1041
1042 l2 = strlen(s2);
1043 if (!l2)
1044 return (char *)s1;
1045 while (len >= l2) {
1046 len--;
1047 if (!memcmp(s1, s2, l2))
1048 return (char *)s1;
1049 s1++;
1050 }
1051 return NULL;
1052}
1053EXPORT_SYMBOL(strnstr);
1054#endif
1055
1056#ifndef __HAVE_ARCH_MEMCHR
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066void *memchr(const void *s, int c, size_t n)
1067{
1068 const unsigned char *p = s;
1069 while (n-- != 0) {
1070 if ((unsigned char)c == *p++) {
1071 return (void *)(p - 1);
1072 }
1073 }
1074 return NULL;
1075}
1076EXPORT_SYMBOL(memchr);
1077#endif
1078
1079static void *check_bytes8(const u8 *start, u8 value, unsigned int bytes)
1080{
1081 while (bytes) {
1082 if (*start != value)
1083 return (void *)start;
1084 start++;
1085 bytes--;
1086 }
1087 return NULL;
1088}
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099void *memchr_inv(const void *start, int c, size_t bytes)
1100{
1101 u8 value = c;
1102 u64 value64;
1103 unsigned int words, prefix;
1104
1105 if (bytes <= 16)
1106 return check_bytes8(start, value, bytes);
1107
1108 value64 = value;
1109#if defined(CONFIG_ARCH_HAS_FAST_MULTIPLIER) && BITS_PER_LONG == 64
1110 value64 *= 0x0101010101010101ULL;
1111#elif defined(CONFIG_ARCH_HAS_FAST_MULTIPLIER)
1112 value64 *= 0x01010101;
1113 value64 |= value64 << 32;
1114#else
1115 value64 |= value64 << 8;
1116 value64 |= value64 << 16;
1117 value64 |= value64 << 32;
1118#endif
1119
1120 prefix = (unsigned long)start % 8;
1121 if (prefix) {
1122 u8 *r;
1123
1124 prefix = 8 - prefix;
1125 r = check_bytes8(start, value, prefix);
1126 if (r)
1127 return r;
1128 start += prefix;
1129 bytes -= prefix;
1130 }
1131
1132 words = bytes / 8;
1133
1134 while (words) {
1135 if (*(u64 *)start != value64)
1136 return check_bytes8(start, value, 8);
1137 start += 8;
1138 words--;
1139 }
1140
1141 return check_bytes8(start, value, bytes % 8);
1142}
1143EXPORT_SYMBOL(memchr_inv);
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153char *strreplace(char *s, char old, char new)
1154{
1155 for (; *s; ++s)
1156 if (*s == old)
1157 *s = new;
1158 return s;
1159}
1160EXPORT_SYMBOL(strreplace);
1161
1162void fortify_panic(const char *name)
1163{
1164 pr_emerg("detected buffer overflow in %s\n", name);
1165 BUG();
1166}
1167EXPORT_SYMBOL(fortify_panic);
1168