diff options
Diffstat (limited to 'lib/string.c')
| -rw-r--r-- | lib/string.c | 131 |
1 files changed, 123 insertions, 8 deletions
diff --git a/lib/string.c b/lib/string.c index f71bead1be3..992bf30af75 100644 --- a/lib/string.c +++ b/lib/string.c @@ -22,7 +22,10 @@ #include <linux/types.h> #include <linux/string.h> #include <linux/ctype.h> -#include <linux/module.h> +#include <linux/kernel.h> +#include <linux/export.h> +#include <linux/bug.h> +#include <linux/errno.h> #ifndef __HAVE_ARCH_STRNICMP /** @@ -104,7 +107,7 @@ EXPORT_SYMBOL(strcpy); #ifndef __HAVE_ARCH_STRNCPY /** - * strncpy - Copy a length-limited, %NUL-terminated string + * strncpy - Copy a length-limited, C-string * @dest: Where to copy the string to * @src: Where to copy the string from * @count: The maximum number of bytes to copy @@ -133,7 +136,7 @@ EXPORT_SYMBOL(strncpy); #ifndef __HAVE_ARCH_STRLCPY /** - * strlcpy - Copy a %NUL terminated string into a sized buffer + * strlcpy - Copy a C-string into a sized buffer * @dest: Where to copy the string to * @src: Where to copy the string from * @size: size of destination buffer @@ -179,7 +182,7 @@ EXPORT_SYMBOL(strcat); #ifndef __HAVE_ARCH_STRNCAT /** - * strncat - Append a length-limited, %NUL-terminated string to another + * strncat - Append a length-limited, C-string to another * @dest: The string to be appended to * @src: The string to append to it * @count: The maximum numbers of bytes to copy @@ -208,7 +211,7 @@ EXPORT_SYMBOL(strncat); #ifndef __HAVE_ARCH_STRLCAT /** - * strlcat - Append a length-limited, %NUL-terminated string to another + * strlcat - Append a length-limited, C-string to another * @dest: The string to be appended to * @src: The string to append to it * @count: The size of the destination buffer. @@ -298,6 +301,24 @@ char *strchr(const char *s, int c) 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(const char *s, int c) +{ + while (*s && *s != (char)c) + s++; + return (char *)s; +} +EXPORT_SYMBOL(strchrnul); +#endif + #ifndef __HAVE_ARCH_STRRCHR /** * strrchr - Find the last occurrence of a character in a string @@ -360,7 +381,6 @@ char *strim(char *s) size_t size; char *end; - s = skip_spaces(s); size = strlen(s); if (!size) return s; @@ -370,7 +390,7 @@ char *strim(char *s) end--; *(end + 1) = '\0'; - return s; + return skip_spaces(s); } EXPORT_SYMBOL(strim); @@ -535,6 +555,35 @@ bool sysfs_streq(const char *s1, const char *s2) } EXPORT_SYMBOL(sysfs_streq); +/** + * strtobool - convert common user inputs into boolean values + * @s: input string + * @res: result + * + * This routine returns 0 iff the first character is one of 'Yy1Nn0'. + * Otherwise it will return -EINVAL. Value pointed to by res is + * updated upon finding a match. + */ +int strtobool(const char *s, bool *res) +{ + switch (s[0]) { + case 'y': + case 'Y': + case '1': + *res = true; + break; + case 'n': + case 'N': + case '0': + *res = false; + break; + default: + return -EINVAL; + } + return 0; +} +EXPORT_SYMBOL(strtobool); + #ifndef __HAVE_ARCH_MEMSET /** * memset - Fill a region of memory with the given value @@ -617,7 +666,7 @@ EXPORT_SYMBOL(memmove); * @count: The size of the area. */ #undef memcmp -int memcmp(const void *cs, const void *ct, size_t count) +__visible int memcmp(const void *cs, const void *ct, size_t count) { const unsigned char *su1, *su2; int res = 0; @@ -727,3 +776,69 @@ void *memchr(const void *s, int c, size_t n) } EXPORT_SYMBOL(memchr); #endif + +static void *check_bytes8(const u8 *start, u8 value, unsigned int bytes) +{ + while (bytes) { + if (*start != value) + return (void *)start; + start++; + bytes--; + } + return NULL; +} + +/** + * 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(const void *start, int c, size_t bytes) +{ + u8 value = c; + u64 value64; + unsigned int words, prefix; + + if (bytes <= 16) + return check_bytes8(start, value, bytes); + + value64 = value; +#if defined(ARCH_HAS_FAST_MULTIPLIER) && BITS_PER_LONG == 64 + value64 *= 0x0101010101010101; +#elif defined(ARCH_HAS_FAST_MULTIPLIER) + value64 *= 0x01010101; + value64 |= value64 << 32; +#else + value64 |= value64 << 8; + value64 |= value64 << 16; + value64 |= value64 << 32; +#endif + + prefix = (unsigned long)start % 8; + if (prefix) { + u8 *r; + + prefix = 8 - prefix; + r = check_bytes8(start, value, prefix); + if (r) + return r; + start += prefix; + bytes -= prefix; + } + + words = bytes / 8; + + while (words) { + if (*(u64 *)start != value64) + return check_bytes8(start, value, 8); + start += 8; + words--; + } + + return check_bytes8(start, value, bytes % 8); +} +EXPORT_SYMBOL(memchr_inv); |