diff options
Diffstat (limited to 'lib/string.c')
| -rw-r--r-- | lib/string.c | 245 |
1 files changed, 58 insertions, 187 deletions
diff --git a/lib/string.c b/lib/string.c index 08ec58cc673b..485777c9da83 100644 --- a/lib/string.c +++ b/lib/string.c @@ -6,20 +6,15 @@ */ /* - * stupid library routines.. The optimized versions should generally be found - * as inline code in <asm-xx/string.h> + * 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.) * - * These are buggy as well.. - * - * * Fri Jun 25 1999, Ingo Oeser <ioe@informatik.tu-chemnitz.de> - * - Added strsep() which will replace strtok() soon (because strsep() is - * reentrant and should be faster). Use only strsep() in new code, please. - * - * * Sat Feb 09 2002, Jason Thomas <jason@topic.com.au>, - * Matthew Hawkins <matt@mh.dropbear.id.au> - * - Kissed strtok() goodbye + * Other helper functions should live in string_helpers.c. */ +#define __NO_FORTIFY #include <linux/types.h> #include <linux/string.h> #include <linux/ctype.h> @@ -29,6 +24,7 @@ #include <linux/errno.h> #include <linux/slab.h> +#include <asm/unaligned.h> #include <asm/byteorder.h> #include <asm/word-at-a-time.h> #include <asm/page.h> @@ -85,7 +81,6 @@ EXPORT_SYMBOL(strcasecmp); * @dest: Where to copy the string to * @src: Where to copy the string from */ -#undef strcpy char *strcpy(char *dest, const char *src) { char *tmp = dest; @@ -239,38 +234,28 @@ EXPORT_SYMBOL(strscpy); #endif /** - * strscpy_pad() - Copy a C-string into a sized buffer - * @dest: Where to copy the string to - * @src: Where to copy the string from - * @count: Size of destination buffer + * 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. * - * Copy the string, or as much of it as fits, into the dest buffer. The - * behavior is undefined if the string buffers overlap. The destination - * buffer is always %NUL terminated, unless it's zero-sized. - * - * If the source string is shorter than the destination buffer, zeros - * the tail of the destination buffer. - * - * For full explanation of why you may want to consider using the - * 'strscpy' functions please see the function docstring for strscpy(). - * - * Returns: - * * The number of characters copied (not including the trailing %NUL) - * * -E2BIG if count is 0 or @src was truncated. + * 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. */ -ssize_t strscpy_pad(char *dest, const char *src, size_t count) +char *stpcpy(char *__restrict__ dest, const char *__restrict__ src); +char *stpcpy(char *__restrict__ dest, const char *__restrict__ src) { - ssize_t written; - - written = strscpy(dest, src, count); - if (written < 0 || written == count - 1) - return written; - - memset(dest + written + 1, 0, count - written - 1); - - return written; + while ((*dest++ = *src++) != '\0') + /* nothing */; + return --dest; } -EXPORT_SYMBOL(strscpy_pad); +EXPORT_SYMBOL(stpcpy); #ifndef __HAVE_ARCH_STRCAT /** @@ -278,7 +263,6 @@ EXPORT_SYMBOL(strscpy_pad); * @dest: The string to be appended to * @src: The string to append to it */ -#undef strcat char *strcat(char *dest, const char *src) { char *tmp = dest; @@ -354,7 +338,6 @@ EXPORT_SYMBOL(strlcat); * @cs: One string * @ct: Another string */ -#undef strcmp int strcmp(const char *cs, const char *ct) { unsigned char c1, c2; @@ -434,6 +417,23 @@ char *strchrnul(const char *s, int c) 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(const char *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 @@ -475,46 +475,6 @@ char *strnchr(const char *s, size_t count, int c) EXPORT_SYMBOL(strnchr); #endif -/** - * skip_spaces - Removes leading whitespace from @str. - * @str: The string to be stripped. - * - * Returns a pointer to the first non-whitespace character in @str. - */ -char *skip_spaces(const char *str) -{ - while (isspace(*str)) - ++str; - return (char *)str; -} -EXPORT_SYMBOL(skip_spaces); - -/** - * strim - Removes leading and trailing whitespace from @s. - * @s: The string to be stripped. - * - * Note that the first trailing whitespace is replaced with a %NUL-terminator - * in the given string @s. Returns a pointer to the first non-whitespace - * character in @s. - */ -char *strim(char *s) -{ - size_t size; - char *end; - - size = strlen(s); - if (!size) - return s; - - end = s + size - 1; - while (end >= s && isspace(*end)) - end--; - *(end + 1) = '\0'; - - return skip_spaces(s); -} -EXPORT_SYMBOL(strim); - #ifndef __HAVE_ARCH_STRLEN /** * strlen - Find the length of a string @@ -649,85 +609,6 @@ char *strsep(char **s, const char *ct) EXPORT_SYMBOL(strsep); #endif -/** - * sysfs_streq - return true if strings are equal, modulo trailing newline - * @s1: one string - * @s2: another string - * - * This routine returns true iff two strings are equal, treating both - * NUL and newline-then-NUL as equivalent string terminations. It's - * geared for use with sysfs input strings, which generally terminate - * with newlines but are compared against values without newlines. - */ -bool sysfs_streq(const char *s1, const char *s2) -{ - while (*s1 && *s1 == *s2) { - s1++; - s2++; - } - - if (*s1 == *s2) - return true; - if (!*s1 && *s2 == '\n' && !s2[1]) - return true; - if (*s1 == '\n' && !s1[1] && !*s2) - return true; - return false; -} -EXPORT_SYMBOL(sysfs_streq); - -/** - * match_string - matches given string in an array - * @array: array of strings - * @n: number of strings in the array or -1 for NULL terminated arrays - * @string: string to match with - * - * Return: - * index of a @string in the @array if matches, or %-EINVAL otherwise. - */ -int match_string(const char * const *array, size_t n, const char *string) -{ - int index; - const char *item; - - for (index = 0; index < n; index++) { - item = array[index]; - if (!item) - break; - if (!strcmp(item, string)) - return index; - } - - return -EINVAL; -} -EXPORT_SYMBOL(match_string); - -/** - * __sysfs_match_string - matches given string in an array - * @array: array of strings - * @n: number of strings in the array or -1 for NULL terminated arrays - * @str: string to match with - * - * Returns index of @str in the @array or -EINVAL, just like match_string(). - * Uses sysfs_streq instead of strcmp for matching. - */ -int __sysfs_match_string(const char * const *array, size_t n, const char *str) -{ - const char *item; - int index; - - for (index = 0; index < n; index++) { - item = array[index]; - if (!item) - break; - if (sysfs_streq(item, str)) - return index; - } - - return -EINVAL; -} -EXPORT_SYMBOL(__sysfs_match_string); - #ifndef __HAVE_ARCH_MEMSET /** * memset - Fill a region of memory with the given value @@ -881,6 +762,21 @@ __visible int memcmp(const void *cs, const void *ct, size_t count) const unsigned char *su1, *su2; int res = 0; +#ifdef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS + if (count >= sizeof(unsigned long)) { + const unsigned long *u1 = cs; + const unsigned long *u2 = ct; + do { + if (get_unaligned(u1) != get_unaligned(u2)) + break; + u1++; + u2++; + count -= sizeof(unsigned long); + } while (count >= sizeof(unsigned long)); + cs = u1; + ct = u2; + } +#endif for (su1 = cs, su2 = ct; 0 < count; ++su1, ++su2, count--) if ((res = *su1 - *su2) != 0) break; @@ -901,7 +797,6 @@ EXPORT_SYMBOL(memcmp); * 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. */ -#undef bcmp int bcmp(const void *a, const void *b, size_t len) { return memcmp(a, b, len); @@ -924,7 +819,7 @@ void *memscan(void *addr, int c, size_t size) unsigned char *p = addr; while (size) { - if (*p == c) + if (*p == (unsigned char)c) return (void *)p; p++; size--; @@ -1072,27 +967,3 @@ void *memchr_inv(const void *start, int c, size_t bytes) return check_bytes8(start, value, bytes % 8); } EXPORT_SYMBOL(memchr_inv); - -/** - * strreplace - Replace all occurrences of character in string. - * @s: The string to operate on. - * @old: The character being replaced. - * @new: The character @old is replaced with. - * - * Returns pointer to the nul byte at the end of @s. - */ -char *strreplace(char *s, char old, char new) -{ - for (; *s; ++s) - if (*s == old) - *s = new; - return s; -} -EXPORT_SYMBOL(strreplace); - -void fortify_panic(const char *name) -{ - pr_emerg("detected buffer overflow in %s\n", name); - BUG(); -} -EXPORT_SYMBOL(fortify_panic); |