1 // SPDX-License-Identifier: GPL-2.0
11  * found in <asm-xx/string.h>), or get overloaded by FORTIFY_SOURCE.
29 #include <asm/word-at-a-time.h>
34  * strncasecmp - Case insensitive, length-limited string comparison
37  * @len: the maximum number of characters to compare
58 	} while (--len);  in strncasecmp()
59 	return (int)c1 - (int)c2;  in strncasecmp()
73 	return c1 - c2;  in strcasecmp()
80  * strcpy - Copy a %NUL terminated string
97  * strncpy - Copy a length-limited, C-string
100  * @count: The maximum number of bytes to copy
102  * The result is not %NUL-terminated if the source exceeds
117 		count--;  in strncpy()
126  * strlcpy - Copy a C-string into a sized buffer
132  * NUL-terminated string that fits in the buffer (unless,
141 		size_t len = (ret >= size) ? size - 1 : ret;  in strlcpy()
152  * strscpy - Copy a C-string into a sized buffer
159  * buffer is always NUL terminated, unless it's zero-sized.
163  * the return value is easier to error-check than strlcpy()'s.
172  * * The number of characters copied (not including the trailing %NUL)
173  * * -E2BIG if count is 0 or @src was truncated.
182 		return -E2BIG;  in strscpy()
189 	if ((long)src & (sizeof(long) - 1)) {  in strscpy()
190 		size_t limit = PAGE_SIZE - ((long)src & (PAGE_SIZE - 1));  in strscpy()
195 	/* If src or dest is unaligned, don't do word-at-a-time. */  in strscpy()
196 	if (((long) dest | (long) src) & (sizeof(long) - 1))  in strscpy()
220 		count -= sizeof(unsigned long);  in strscpy()
221 		max -= sizeof(unsigned long);  in strscpy()
232 		count--;  in strscpy()
235 	/* Hit buffer length without finding a NUL; force NUL-termination. */  in strscpy()
237 		dest[res-1] = '\0';  in strscpy()
239 	return -E2BIG;  in strscpy()
245  * stpcpy - copy a string from src to dest returning a pointer to the new end
246  *          of dest, including src's %NUL-terminator. May overrun dest.
253  * to the new %NUL-terminating character in @dest. (For strcpy, the return
264 	return --dest;  in stpcpy()
270  * strcat - Append one %NUL-terminated string to another
289  * strncat - Append a length-limited, C-string to another
305 			if (--count == 0) {  in strncat()
318  * strlcat - Append a length-limited, C-string to another
333 	count -= dsize;  in strlcat()
335 		len = count-1;  in strlcat()
345  * strcmp - Compare two strings
346  * @cs: One string
349 int strcmp(const char *cs, const char *ct)  in strcmp()  argument
354 		c1 = *cs++;  in strcmp()
357 			return c1 < c2 ? -1 : 1;  in strcmp()
368  * strncmp - Compare two length-limited strings
369  * @cs: One string
371  * @count: The maximum number of bytes to compare
373 int strncmp(const char *cs, const char *ct, size_t count)  in strncmp()  argument
378 		c1 = *cs++;  in strncmp()
381 			return c1 < c2 ? -1 : 1;  in strncmp()
384 		count--;  in strncmp()
393  * strchr - Find the first occurrence of a character in a string
397  * Note that the %NUL-terminator is considered part of the string, and can
412  * strchrnul - Find and return a character in a string, or end of string
429  * strnchrnul - Find and return a character in a length limited string,
432  * @count: The number of characters to be searched
440 	while (count-- && *s && *s != (char)c)  in strnchrnul()
447  * strrchr - Find the last occurrence of a character in a string
465  * strnchr - Find a character in a length limited string
467  * @count: The number of characters to be searched
470  * Note that the %NUL-terminator is considered part of the string, and can
475 	while (count--) {  in strnchr()
488  * strlen - Find the length of a string
497 	return sc - s;  in strlen()
504  * strnlen - Find the length of a length-limited string
506  * @count: The maximum number of bytes to search
512 	for (sc = s; count-- && *sc != '\0'; ++sc)  in strnlen()
514 	return sc - s;  in strnlen()
521 …* strspn - Calculate the length of the initial substring of @s which only contain letters in @acce…
533 	return p - s;  in strspn()
540 …* strcspn - Calculate the length of the initial substring of @s which does not contain letters in …
552 	return p - s;  in strcspn()
559  * strpbrk - Find the first occurrence of a set of characters
560  * @cs: The string to be searched
563 char *strpbrk(const char *cs, const char *ct)  in strpbrk()  argument
567 	for (sc1 = cs; *sc1 != '\0'; ++sc1) {  in strpbrk()
580  * strsep - Split a string into tokens
587  * of that name. In fact, it was stolen from glibc2 and de-fancy-fied.
609  * memset - Fill a region of memory with the given value
620 	while (count--)  in memset()
629  * memset16() - Fill a memory area with a uint16_t
632  * @count: The number of values to store
635  * of a byte.  Remember that @count is the number of uint16_ts to
636  * store, not the number of bytes.
642 	while (count--)  in memset16()
651  * memset32() - Fill a memory area with a uint32_t
654  * @count: The number of values to store
657  * of a byte.  Remember that @count is the number of uint32_ts to
658  * store, not the number of bytes.
664 	while (count--)  in memset32()
673  * memset64() - Fill a memory area with a uint64_t
676  * @count: The number of values to store
679  * of a byte.  Remember that @count is the number of uint64_ts to
680  * store, not the number of bytes.
686 	while (count--)  in memset64()
695  * memcpy - Copy one area of memory to another
708 	while (count--)  in memcpy()
717  * memmove - Copy one area of memory to another
732 		while (count--)  in memmove()
739 		while (count--)  in memmove()
740 			*--tmp = *--s;  in memmove()
749  * memcmp - Compare two areas of memory
750  * @cs: One area of memory
755 __visible int memcmp(const void *cs, const void *ct, size_t count)  in memcmp()  argument
762 		const unsigned long *u1 = cs;  in memcmp()
769 			count -= sizeof(unsigned long);  in memcmp()
771 		cs = u1;  in memcmp()
775 	for (su1 = cs, su2 = ct; 0 < count; ++su1, ++su2, count--)  in memcmp()
776 		if ((res = *su1 - *su2) != 0)  in memcmp()
785  * bcmp - returns 0 if and only if the buffers have identical contents.
790  * The sign or magnitude of a non-zero return value has no particular
793  * not rely on anything but whether the return value is zero or non-zero.
804  * memscan - Find a character in an area of memory.
820 		size--;  in memscan()
829  * strstr - Find the first substring in a %NUL terminated string
842 		l1--;  in strstr()
854  * strnstr - Find the first substring in a length-limited string
857  * @len: the maximum number of characters to search
867 		len--;  in strnstr()
879  * memchr - Find a character in an area of memory.
890 	while (n-- != 0) {  in memchr()
892 			return (void *)(p - 1);  in memchr()
906 		bytes--;  in check_bytes8()
912  * memchr_inv - Find an unmatching character in an area of memory.
945 		prefix = 8 - prefix;  in memchr_inv()
950 		bytes -= prefix;  in memchr_inv()
959 		words--;  in memchr_inv()