1 // SPDX-License-Identifier: GPL-2.0
11  * found in <asm-xx/string.h>), or get overloaded by FORTIFY_SOURCE.
31 #include <asm/word-at-a-time.h>
35  * strncasecmp - Case insensitive, length-limited string comparison
59 	} while (--len);  in strncasecmp()
60 	return (int)c1 - (int)c2;  in strncasecmp()
74 	return c1 - c2;  in strcasecmp()
100 		count--;  in strncpy()
120 		return -E2BIG;  in sized_strscpy()
127 	if ((long)src & (sizeof(long) - 1)) {  in sized_strscpy()
128 		size_t limit = PAGE_SIZE - ((long)src & (PAGE_SIZE - 1));  in sized_strscpy()
133 	/* If src or dest is unaligned, don't do word-at-a-time. */  in sized_strscpy()
134 	if (((long) dest | (long) src) & (sizeof(long) - 1))  in sized_strscpy()
156 		count -= sizeof(unsigned long);  in sized_strscpy()
160 			return -E2BIG;  in sized_strscpy()
164 		max -= sizeof(unsigned long);  in sized_strscpy()
175 		count--;  in sized_strscpy()
178 	/* Force NUL-termination. */  in sized_strscpy()
182 	return src[res] ? -E2BIG : res;  in sized_strscpy()
187  * stpcpy - copy a string from src to dest returning a pointer to the new end
188  *          of dest, including src's %NUL-terminator. May overrun dest.
194  * stpcpy differs from strcpy in a key way: the return value is a pointer
195  * to the new %NUL-terminating character in @dest. (For strcpy, the return
196  * value is a pointer to the start of @dest). This interface is considered
206 	return --dest;  in stpcpy()
233 			if (--count == 0) {  in strncat()
255 	count -= dsize;  in strlcat()
257 		len = count-1;  in strlcat()
267  * strcmp - Compare two strings
279 			return c1 < c2 ? -1 : 1;  in strcmp()
290  * strncmp - Compare two length-limited strings
303 			return c1 < c2 ? -1 : 1;  in strncmp()
306 		count--;  in strncmp()
315  * strchr - Find the first occurrence of a character in a string
319  * Note that the %NUL-terminator is considered part of the string, and can
334  * strchrnul - Find and return a character in a string, or end of string
351  * strnchrnul - Find and return a character in a length limited string,
362 	while (count-- && *s && *s != (char)c)  in strnchrnul()
369  * strrchr - Find the last occurrence of a character in a string
387  * strnchr - Find a character in a length limited string
392  * Note that the %NUL-terminator is considered part of the string, and can
397 	while (count--) {  in strnchr()
415 	return sc - s;  in strlen()
425 	for (sc = s; count-- && *sc != '\0'; ++sc)  in strnlen()
427 	return sc - s;  in strnlen()
434 …* strspn - Calculate the length of the initial substring of @s which only contain letters in @acce…
446 	return p - s;  in strspn()
453 …* strcspn - Calculate the length of the initial substring of @s which does not contain letters in …
465 	return p - s;  in strcspn()
472  * strpbrk - Find the first occurrence of a set of characters
491  * strsep - Split a string into tokens
498  * of that name. In fact, it was stolen from glibc2 and de-fancy-fied.
520  * memset - Fill a region of memory with the given value
521  * @s: Pointer to the start of the area.
531 	while (count--)  in memset()
540  * memset16() - Fill a memory area with a uint16_t
541  * @s: Pointer to the start of the area.
542  * @v: The value to fill the area with
553 	while (count--)  in memset16()
562  * memset32() - Fill a memory area with a uint32_t
563  * @s: Pointer to the start of the area.
564  * @v: The value to fill the area with
575 	while (count--)  in memset32()
584  * memset64() - Fill a memory area with a uint64_t
585  * @s: Pointer to the start of the area.
586  * @v: The value to fill the area with
597 	while (count--)  in memset64()
606  * memcpy - Copy one area of memory to another
619 	while (count--)  in memcpy()
628  * memmove - Copy one area of memory to another
643 		while (count--)  in memmove()
650 		while (count--)  in memmove()
651 			*--tmp = *--s;  in memmove()
660  * memcmp - Compare two areas of memory
680 			count -= sizeof(unsigned long);  in memcmp()
686 	for (su1 = cs, su2 = ct; 0 < count; ++su1, ++su2, count--)  in memcmp()
687 		if ((res = *su1 - *su2) != 0)  in memcmp()
696  * bcmp - returns 0 if and only if the buffers have identical contents.
701  * The sign or magnitude of a non-zero return value has no particular
704  * not rely on anything but whether the return value is zero or non-zero.
715  * memscan - Find a character in an area of memory.
731 		size--;  in memscan()
740  * strstr - Find the first substring in a %NUL terminated string
753 		l1--;  in strstr()
765  * strnstr - Find the first substring in a length-limited string
778 		len--;  in strnstr()
790  * memchr - Find a character in an area of memory.
801 	while (n-- != 0) {  in memchr()
803 			return (void *)(p - 1);  in memchr()
811 static void *check_bytes8(const u8 *start, u8 value, unsigned int bytes)  in check_bytes8()  argument
814 		if (*start != value)  in check_bytes8()
815 			return (void *)start;  in check_bytes8()
816 		start++;  in check_bytes8()
817 		bytes--;  in check_bytes8()
823  * memchr_inv - Find an unmatching character in an area of memory.
824  * @start: The memory area
831 void *memchr_inv(const void *start, int c, size_t bytes)  in memchr_inv()  argument
833 	u8 value = c;  in memchr_inv()  local
838 		return check_bytes8(start, value, bytes);  in memchr_inv()
840 	value64 = value;  in memchr_inv()
852 	prefix = (unsigned long)start % 8;  in memchr_inv()
856 		prefix = 8 - prefix;  in memchr_inv()
857 		r = check_bytes8(start, value, prefix);  in memchr_inv()
860 		start += prefix;  in memchr_inv()
861 		bytes -= prefix;  in memchr_inv()
867 		if (*(u64 *)start != value64)  in memchr_inv()
868 			return check_bytes8(start, value, 8);  in memchr_inv()
869 		start += 8;  in memchr_inv()
870 		words--;  in memchr_inv()
873 	return check_bytes8(start, value, bytes % 8);  in memchr_inv()