diff options
Diffstat (limited to 'arch/x86/lib/usercopy.c')
| -rw-r--r-- | arch/x86/lib/usercopy.c | 97 | 
1 files changed, 0 insertions, 97 deletions
diff --git a/arch/x86/lib/usercopy.c b/arch/x86/lib/usercopy.c index 2e4e4b02c37..f61ee67ec00 100644 --- a/arch/x86/lib/usercopy.c +++ b/arch/x86/lib/usercopy.c @@ -43,100 +43,3 @@ copy_from_user_nmi(void *to, const void __user *from, unsigned long n)  	return len;  }  EXPORT_SYMBOL_GPL(copy_from_user_nmi); - -/* - * Do a strncpy, return length of string without final '\0'. - * 'count' is the user-supplied count (return 'count' if we - * hit it), 'max' is the address space maximum (and we return - * -EFAULT if we hit it). - */ -static inline long do_strncpy_from_user(char *dst, const char __user *src, long count, unsigned long max) -{ -	long res = 0; - -	/* -	 * Truncate 'max' to the user-specified limit, so that -	 * we only have one limit we need to check in the loop -	 */ -	if (max > count) -		max = count; - -	while (max >= sizeof(unsigned long)) { -		unsigned long c, mask; - -		/* Fall back to byte-at-a-time if we get a page fault */ -		if (unlikely(__get_user(c,(unsigned long __user *)(src+res)))) -			break; -		mask = has_zero(c); -		if (mask) { -			mask = (mask - 1) & ~mask; -			mask >>= 7; -			*(unsigned long *)(dst+res) = c & mask; -			return res + count_masked_bytes(mask); -		} -		*(unsigned long *)(dst+res) = c; -		res += sizeof(unsigned long); -		max -= sizeof(unsigned long); -	} - -	while (max) { -		char c; - -		if (unlikely(__get_user(c,src+res))) -			return -EFAULT; -		dst[res] = c; -		if (!c) -			return res; -		res++; -		max--; -	} - -	/* -	 * Uhhuh. We hit 'max'. But was that the user-specified maximum -	 * too? If so, that's ok - we got as much as the user asked for. -	 */ -	if (res >= count) -		return res; - -	/* -	 * Nope: we hit the address space limit, and we still had more -	 * characters the caller would have wanted. That's an EFAULT. -	 */ -	return -EFAULT; -} - -/** - * strncpy_from_user: - Copy a NUL terminated string from userspace. - * @dst:   Destination address, in kernel space.  This buffer must be at - *         least @count bytes long. - * @src:   Source address, in user space. - * @count: Maximum number of bytes to copy, including the trailing NUL. - * - * Copies a NUL-terminated string from userspace to kernel space. - * - * On success, returns the length of the string (not including the trailing - * NUL). - * - * If access to userspace fails, returns -EFAULT (some data may have been - * copied). - * - * If @count is smaller than the length of the string, copies @count bytes - * and returns @count. - */ -long -strncpy_from_user(char *dst, const char __user *src, long count) -{ -	unsigned long max_addr, src_addr; - -	if (unlikely(count <= 0)) -		return 0; - -	max_addr = current_thread_info()->addr_limit.seg; -	src_addr = (unsigned long)src; -	if (likely(src_addr < max_addr)) { -		unsigned long max = max_addr - src_addr; -		return do_strncpy_from_user(dst, src, count, max); -	} -	return -EFAULT; -} -EXPORT_SYMBOL(strncpy_from_user);  |