diff options
Diffstat (limited to 'lib/string.c')
| -rw-r--r-- | lib/string.c | 48 |
1 files changed, 29 insertions, 19 deletions
diff --git a/lib/string.c b/lib/string.c index 6891d15ce991..eb4486ed40d2 100644 --- a/lib/string.c +++ b/lib/string.c @@ -15,19 +15,20 @@ */ #define __NO_FORTIFY -#include <linux/types.h> -#include <linux/string.h> -#include <linux/ctype.h> -#include <linux/kernel.h> -#include <linux/export.h> +#include <linux/bits.h> #include <linux/bug.h> +#include <linux/ctype.h> #include <linux/errno.h> -#include <linux/slab.h> +#include <linux/limits.h> +#include <linux/linkage.h> +#include <linux/stddef.h> +#include <linux/string.h> +#include <linux/types.h> -#include <asm/unaligned.h> -#include <asm/byteorder.h> -#include <asm/word-at-a-time.h> #include <asm/page.h> +#include <asm/rwonce.h> +#include <linux/unaligned.h> +#include <asm/word-at-a-time.h> #ifndef __HAVE_ARCH_STRNCASECMP /** @@ -103,8 +104,13 @@ char *strncpy(char *dest, const char *src, size_t count) EXPORT_SYMBOL(strncpy); #endif -#ifndef __HAVE_ARCH_STRSCPY -ssize_t strscpy(char *dest, const char *src, size_t count) +#ifdef __BIG_ENDIAN +# define ALLBUTLAST_BYTE_MASK (~255ul) +#else +# define ALLBUTLAST_BYTE_MASK (~0ul >> 8) +#endif + +ssize_t sized_strscpy(char *dest, const char *src, size_t count) { const struct word_at_a_time constants = WORD_AT_A_TIME_CONSTANTS; size_t max = count; @@ -147,13 +153,18 @@ ssize_t strscpy(char *dest, const char *src, size_t count) *(unsigned long *)(dest+res) = c & zero_bytemask(data); return res + find_zero(data); } + count -= sizeof(unsigned long); + if (unlikely(!count)) { + c &= ALLBUTLAST_BYTE_MASK; + *(unsigned long *)(dest+res) = c; + return -E2BIG; + } *(unsigned long *)(dest+res) = c; res += sizeof(unsigned long); - count -= sizeof(unsigned long); max -= sizeof(unsigned long); } - while (count) { + while (count > 1) { char c; c = src[res]; @@ -164,14 +175,13 @@ ssize_t strscpy(char *dest, const char *src, size_t count) count--; } - /* Hit buffer length without finding a NUL; force NUL-termination. */ - if (res) - dest[res-1] = '\0'; + /* Force NUL-termination. */ + dest[res] = '\0'; - return -E2BIG; + /* Return E2BIG if the source didn't stop */ + return src[res] ? -E2BIG : res; } -EXPORT_SYMBOL(strscpy); -#endif +EXPORT_SYMBOL(sized_strscpy); /** * stpcpy - copy a string from src to dest returning a pointer to the new end |