/* * This file should be used only for "library" routines that may have * alternative implementations on specific architectures (generally * found in <asm-xx/string.h>), or get overloaded by FORTIFY_SOURCE. * (Specifically, this file is built with __NO_FORTIFY.) * * Other helper functions should live in string_helpers.c.
*/
#ifndef __HAVE_ARCH_STRNCASECMP /** * strncasecmp - Case insensitive, length-limited string comparison * @s1: One string * @s2: The other string * @len: the maximum number of characters to compare
*/ int strncasecmp(constchar *s1, constchar *s2, size_t len)
{ /* Yes, Virginia, it had better be unsigned */ unsignedchar c1, c2;
if (!len) return 0;
do {
c1 = *s1++;
c2 = *s2++; if (!c1 || !c2) break; if (c1 == c2) continue;
c1 = tolower(c1);
c2 = tolower(c2); if (c1 != c2) break;
} while (--len); return (int)c1 - (int)c2;
}
EXPORT_SYMBOL(strncasecmp); #endif
#ifndef __HAVE_ARCH_STRCASECMP int strcasecmp(constchar *s1, constchar *s2)
{ int c1, c2;
ssize_t sized_strscpy(char *dest, constchar *src, size_t count)
{ conststruct word_at_a_time constants = WORD_AT_A_TIME_CONSTANTS;
size_t max = count; long res = 0;
if (count == 0 || WARN_ON_ONCE(count > INT_MAX)) return -E2BIG;
#ifndef CONFIG_DCACHE_WORD_ACCESS #ifdef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS /* * If src is unaligned, don't cross a page boundary, * since we don't know if the next page is mapped.
*/ if ((long)src & (sizeof(long) - 1)) {
size_t limit = PAGE_SIZE - ((long)src & (PAGE_SIZE - 1)); if (limit < max)
max = limit;
} #else /* If src or dest is unaligned, don't do word-at-a-time. */ if (((long) dest | (long) src) & (sizeof(long) - 1))
max = 0; #endif #endif
/* * load_unaligned_zeropad() or read_word_at_a_time() below may read * uninitialized bytes after the trailing zero and use them in * comparisons. Disable this optimization under KMSAN to prevent * false positive reports.
*/ if (IS_ENABLED(CONFIG_KMSAN))
max = 0;
while (max >= sizeof(unsignedlong)) { unsignedlong c, data;
#ifdef CONFIG_DCACHE_WORD_ACCESS
c = load_unaligned_zeropad(src+res); #else
c = read_word_at_a_time(src+res); #endif if (has_zero(c, &data, &constants)) {
data = prep_zero_mask(c, data, &constants);
data = create_zero_mask(data);
*(unsignedlong *)(dest+res) = c & zero_bytemask(data); return res + find_zero(data);
}
count -= sizeof(unsignedlong); if (unlikely(!count)) {
c &= ALLBUTLAST_BYTE_MASK;
*(unsignedlong *)(dest+res) = c; return -E2BIG;
}
*(unsignedlong *)(dest+res) = c;
res += sizeof(unsignedlong);
max -= sizeof(unsignedlong);
}
while (count > 1) { char c;
c = src[res];
dest[res] = c; if (!c) return res;
res++;
count--;
}
/* Force NUL-termination. */
dest[res] = '\0';
/* Return E2BIG if the source didn't stop */ return src[res] ? -E2BIG : res;
}
EXPORT_SYMBOL(sized_strscpy);
/** * stpcpy - copy a string from src to dest returning a pointer to the new end * of dest, including src's %NUL-terminator. May overrun dest. * @dest: pointer to end of string being copied into. Must be large enough * to receive copy. * @src: pointer to the beginning of string being copied from. Must not overlap * dest. * * stpcpy differs from strcpy in a key way: the return value is a pointer * to the new %NUL-terminating character in @dest. (For strcpy, the return * value is a pointer to the start of @dest). This interface is considered * unsafe as it doesn't perform bounds checking of the inputs. As such it's * not recommended for usage. Instead, its definition is provided in case * the compiler lowers other libcalls to stpcpy.
*/ char *stpcpy(char *__restrict__ dest, constchar *__restrict__ src); char *stpcpy(char *__restrict__ dest, constchar *__restrict__ src)
{ while ((*dest++ = *src++) != '\0') /* nothing */; return --dest;
}
EXPORT_SYMBOL(stpcpy);
dest += dsize;
count -= dsize; if (len >= count)
len = count-1;
__builtin_memcpy(dest, src, len);
dest[len] = 0; return res;
}
EXPORT_SYMBOL(strlcat); #endif
#ifndef __HAVE_ARCH_STRCMP /** * strcmp - Compare two strings * @cs: One string * @ct: Another string
*/ int strcmp(constchar *cs, constchar *ct)
{ unsignedchar c1, c2;
while (1) {
c1 = *cs++;
c2 = *ct++; if (c1 != c2) return c1 < c2 ? -1 : 1; if (!c1) break;
} return 0;
}
EXPORT_SYMBOL(strcmp); #endif
#ifndef __HAVE_ARCH_STRNCMP /** * strncmp - Compare two length-limited strings * @cs: One string * @ct: Another string * @count: The maximum number of bytes to compare
*/ int strncmp(constchar *cs, constchar *ct, size_t count)
{ unsignedchar c1, c2;
#ifndef __HAVE_ARCH_STRCHR /** * strchr - Find the first occurrence of a character in a string * @s: The string to be searched * @c: The character to search for * * Note that the %NUL-terminator is considered part of the string, and can * be searched for.
*/ char *strchr(constchar *s, int c)
{ for (; *s != (char)c; ++s) if (*s == '\0') return NULL; return (char *)s;
}
EXPORT_SYMBOL(strchr); #endif
#ifndef __HAVE_ARCH_STRCHRNUL /** * strchrnul - Find and return a character in a string, or end of string * @s: The string to be searched * @c: The character to search for * * Returns pointer to first occurrence of 'c' in s. If c is not found, then * return a pointer to the null byte at the end of s.
*/ char *strchrnul(constchar *s, int c)
{ while (*s && *s != (char)c)
s++; return (char *)s;
}
EXPORT_SYMBOL(strchrnul); #endif
/** * strnchrnul - Find and return a character in a length limited string, * or end of string * @s: The string to be searched * @count: The number of characters to be searched * @c: The character to search for * * Returns pointer to the first occurrence of 'c' in s. If c is not found, * then return a pointer to the last character of the string.
*/ char *strnchrnul(constchar *s, size_t count, int c)
{ while (count-- && *s && *s != (char)c)
s++; return (char *)s;
}
#ifndef __HAVE_ARCH_STRRCHR /** * strrchr - Find the last occurrence of a character in a string * @s: The string to be searched * @c: The character to search for
*/ char *strrchr(constchar *s, int c)
{ constchar *last = NULL; do { if (*s == (char)c)
last = s;
} while (*s++); return (char *)last;
}
EXPORT_SYMBOL(strrchr); #endif
#ifndef __HAVE_ARCH_STRNCHR /** * strnchr - Find a character in a length limited string * @s: The string to be searched * @count: The number of characters to be searched * @c: The character to search for * * Note that the %NUL-terminator is considered part of the string, and can * be searched for.
*/ char *strnchr(constchar *s, size_t count, int c)
{ while (count--) { if (*s == (char)c) return (char *)s; if (*s++ == '\0') break;
} return NULL;
}
EXPORT_SYMBOL(strnchr); #endif
#ifndef __HAVE_ARCH_STRSPN /** * strspn - Calculate the length of the initial substring of @s which only contain letters in @accept * @s: The string to be searched * @accept: The string to search for
*/
size_t strspn(constchar *s, constchar *accept)
{ constchar *p;
for (p = s; *p != '\0'; ++p) { if (!strchr(accept, *p)) break;
} return p - s;
}
EXPORT_SYMBOL(strspn); #endif
#ifndef __HAVE_ARCH_STRCSPN /** * strcspn - Calculate the length of the initial substring of @s which does not contain letters in @reject * @s: The string to be searched * @reject: The string to avoid
*/
size_t strcspn(constchar *s, constchar *reject)
{ constchar *p;
for (p = s; *p != '\0'; ++p) { if (strchr(reject, *p)) break;
} return p - s;
}
EXPORT_SYMBOL(strcspn); #endif
#ifndef __HAVE_ARCH_STRPBRK /** * strpbrk - Find the first occurrence of a set of characters * @cs: The string to be searched * @ct: The characters to search for
*/ char *strpbrk(constchar *cs, constchar *ct)
{ constchar *sc;
#ifndef __HAVE_ARCH_STRSEP /** * strsep - Split a string into tokens * @s: The string to be searched * @ct: The characters to search for * * strsep() updates @s to point after the token, ready for the next call. * * It returns empty tokens, too, behaving exactly like the libc function * of that name. In fact, it was stolen from glibc2 and de-fancy-fied. * Same semantics, slimmer shape. ;)
*/ char *strsep(char **s, constchar *ct)
{ char *sbegin = *s; char *end;
if (sbegin == NULL) return NULL;
end = strpbrk(sbegin, ct); if (end)
*end++ = '\0';
*s = end; return sbegin;
}
EXPORT_SYMBOL(strsep); #endif
#ifndef __HAVE_ARCH_MEMSET /** * memset - Fill a region of memory with the given value * @s: Pointer to the start of the area. * @c: The byte to fill the area with * @count: The size of the area. * * Do not use memset() to access IO space, use memset_io() instead.
*/ void *memset(void *s, int c, size_t count)
{ char *xs = s;
while (count--)
*xs++ = c; return s;
}
EXPORT_SYMBOL(memset); #endif
#ifndef __HAVE_ARCH_MEMSET16 /** * memset16() - Fill a memory area with a uint16_t * @s: Pointer to the start of the area. * @v: The value to fill the area with * @count: The number of values to store * * Differs from memset() in that it fills with a uint16_t instead * of a byte. Remember that @count is the number of uint16_ts to * store, not the number of bytes.
*/ void *memset16(uint16_t *s, uint16_t v, size_t count)
{
uint16_t *xs = s;
while (count--)
*xs++ = v; return s;
}
EXPORT_SYMBOL(memset16); #endif
#ifndef __HAVE_ARCH_MEMSET32 /** * memset32() - Fill a memory area with a uint32_t * @s: Pointer to the start of the area. * @v: The value to fill the area with * @count: The number of values to store * * Differs from memset() in that it fills with a uint32_t instead * of a byte. Remember that @count is the number of uint32_ts to * store, not the number of bytes.
*/ void *memset32(uint32_t *s, uint32_t v, size_t count)
{
uint32_t *xs = s;
while (count--)
*xs++ = v; return s;
}
EXPORT_SYMBOL(memset32); #endif
#ifndef __HAVE_ARCH_MEMSET64 /** * memset64() - Fill a memory area with a uint64_t * @s: Pointer to the start of the area. * @v: The value to fill the area with * @count: The number of values to store * * Differs from memset() in that it fills with a uint64_t instead * of a byte. Remember that @count is the number of uint64_ts to * store, not the number of bytes.
*/ void *memset64(uint64_t *s, uint64_t v, size_t count)
{
uint64_t *xs = s;
while (count--)
*xs++ = v; return s;
}
EXPORT_SYMBOL(memset64); #endif
#ifndef __HAVE_ARCH_MEMCPY /** * memcpy - Copy one area of memory to another * @dest: Where to copy to * @src: Where to copy from * @count: The size of the area. * * You should not use this function to access IO space, use memcpy_toio() * or memcpy_fromio() instead.
*/ void *memcpy(void *dest, constvoid *src, size_t count)
{ char *tmp = dest; constchar *s = src;
while (count--)
*tmp++ = *s++; return dest;
}
EXPORT_SYMBOL(memcpy); #endif
#ifndef __HAVE_ARCH_MEMMOVE /** * memmove - Copy one area of memory to another * @dest: Where to copy to * @src: Where to copy from * @count: The size of the area. * * Unlike memcpy(), memmove() copes with overlapping areas.
*/ void *memmove(void *dest, constvoid *src, size_t count)
{ char *tmp; constchar *s;
if (dest <= src) {
tmp = dest;
s = src; while (count--)
*tmp++ = *s++;
} else {
tmp = dest;
tmp += count;
s = src;
s += count; while (count--)
*--tmp = *--s;
} return dest;
}
EXPORT_SYMBOL(memmove); #endif
#ifndef __HAVE_ARCH_MEMCMP /** * memcmp - Compare two areas of memory * @cs: One area of memory * @ct: Another area of memory * @count: The size of the area.
*/ #undef memcmp
__visible int memcmp(constvoid *cs, constvoid *ct, size_t count)
{ constunsignedchar *su1, *su2; int res = 0;
#ifndef __HAVE_ARCH_BCMP /** * bcmp - returns 0 if and only if the buffers have identical contents. * @a: pointer to first buffer. * @b: pointer to second buffer. * @len: size of buffers. * * The sign or magnitude of a non-zero return value has no particular * meaning, and architectures may implement their own more efficient bcmp(). So * while this particular implementation is a simple (tail) call to memcmp, do * not rely on anything but whether the return value is zero or non-zero.
*/ int bcmp(constvoid *a, constvoid *b, size_t len)
{ return memcmp(a, b, len);
}
EXPORT_SYMBOL(bcmp); #endif
#ifndef __HAVE_ARCH_MEMSCAN /** * memscan - Find a character in an area of memory. * @addr: The memory area * @c: The byte to search for * @size: The size of the area. * * returns the address of the first occurrence of @c, or 1 byte past * the area if @c is not found
*/ void *memscan(void *addr, int c, size_t size)
{ unsignedchar *p = addr;
while (size) { if (*p == (unsignedchar)c) return (void *)p;
p++;
size--;
} return (void *)p;
}
EXPORT_SYMBOL(memscan); #endif
#ifndef __HAVE_ARCH_STRSTR /** * strstr - Find the first substring in a %NUL terminated string * @s1: The string to be searched * @s2: The string to search for
*/ char *strstr(constchar *s1, constchar *s2)
{
size_t l1, l2;
#ifndef __HAVE_ARCH_STRNSTR /** * strnstr - Find the first substring in a length-limited string * @s1: The string to be searched * @s2: The string to search for * @len: the maximum number of characters to search
*/ char *strnstr(constchar *s1, constchar *s2, size_t len)
{
size_t l2;
l2 = strlen(s2); if (!l2) return (char *)s1; while (len >= l2) {
len--; if (!memcmp(s1, s2, l2)) return (char *)s1;
s1++;
} return NULL;
}
EXPORT_SYMBOL(strnstr); #endif
#ifndef __HAVE_ARCH_MEMCHR /** * memchr - Find a character in an area of memory. * @s: The memory area * @c: The byte to search for * @n: The size of the area. * * returns the address of the first occurrence of @c, or %NULL * if @c is not found
*/ void *memchr(constvoid *s, int c, size_t n)
{ constunsignedchar *p = s; while (n-- != 0) { if ((unsignedchar)c == *p++) { return (void *)(p - 1);
}
} return NULL;
}
EXPORT_SYMBOL(memchr); #endif
/** * memchr_inv - Find an unmatching character in an area of memory. * @start: The memory area * @c: Find a character other than c * @bytes: The size of the area. * * returns the address of the first character other than @c, or %NULL * if the whole buffer contains just @c.
*/ void *memchr_inv(constvoid *start, int c, size_t bytes)
{
u8 value = c;
u64 value64; unsignedint words, prefix;
if (bytes <= 16) return check_bytes8(start, value, bytes);
