1 files changed, 7 insertions, 40 deletions

diff --git a/lib/strncpy_from_user.c b/lib/strncpy_from_user.c
index c4c09b0e96ba..bb2b201d6ad0 100644
--- a/lib/strncpy_from_user.c
+++ b/lib/strncpy_from_user.c
@@ -4,37 +4,7 @@
 #include <linux/errno.h>
 
 #include <asm/byteorder.h>
-
-static inline long find_zero(unsigned long mask)
-{
-        long byte = 0;
-
-#ifdef __BIG_ENDIAN
-#ifdef CONFIG_64BIT
-        if (mask >> 32)
-                mask >>= 32;
-        else
-                byte = 4;
-#endif
-        if (mask >> 16)
-                mask >>= 16;
-        else
-                byte += 2;
-        return (mask >> 8) ? byte : byte + 1;
-#else
-#ifdef CONFIG_64BIT
-        if (!((unsigned int) mask)) {
-                mask >>= 32;
-                byte = 4;
-        }
-#endif
-        if (!(mask & 0xffff)) {
-                mask >>= 16;
-                byte += 2;
-        }
-        return (mask & 0xff) ? byte : byte + 1;
-#endif
-}
+#include <asm/word-at-a-time.h>
 
 #ifdef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
 #define IS_UNALIGNED(src, dst)  0
@@ -51,8 +21,7 @@ static inline long find_zero(unsigned long mask)
  */
 static inline long do_strncpy_from_user(char *dst, const char __user *src, long count, unsigned long max)
 {
-        const unsigned long high_bits = REPEAT_BYTE(0xfe) + 1;
-        const unsigned long low_bits = REPEAT_BYTE(0x7f);
+        const struct word_at_a_time constants = WORD_AT_A_TIME_CONSTANTS;
         long res = 0;
 
         /*
@@ -66,18 +35,16 @@ static inline long do_strncpy_from_user(char *dst, const char __user *src, long
                 goto byte_at_a_time;
 
         while (max >= sizeof(unsigned long)) {
-                unsigned long c, v, rhs;
+                unsigned long c, data;
 
                 /* Fall back to byte-at-a-time if we get a page fault */
                 if (unlikely(__get_user(c,(unsigned long __user *)(src+res))))
                         break;
-                rhs = c | low_bits;
-                v = (c + high_bits) & ~rhs;
                 *(unsigned long *)(dst+res) = c;
-                if (v) {
-                        v = (c & low_bits) + low_bits;
-                        v = ~(v | rhs);
-                        return res + find_zero(v);
+                if (has_zero(c, &data, &constants)) {
+                        data = prep_zero_mask(c, data, &constants);
+                        data = create_zero_mask(data);
+                        return res + find_zero(data);
                 }
                 res += sizeof(unsigned long);
                 max -= sizeof(unsigned long);