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Diffstat (limited to 'arch/x86/lib/usercopy.c')
-rw-r--r--arch/x86/lib/usercopy.c20
1 files changed, 8 insertions, 12 deletions
diff --git a/arch/x86/lib/usercopy.c b/arch/x86/lib/usercopy.c
index d6ae30bbd7bb..2e4e4b02c37a 100644
--- a/arch/x86/lib/usercopy.c
+++ b/arch/x86/lib/usercopy.c
@@ -44,13 +44,6 @@ copy_from_user_nmi(void *to, const void __user *from, unsigned long n)
}
EXPORT_SYMBOL_GPL(copy_from_user_nmi);
-static inline unsigned long count_bytes(unsigned long mask)
-{
- mask = (mask - 1) & ~mask;
- mask >>= 7;
- return count_masked_bytes(mask);
-}
-
/*
* Do a strncpy, return length of string without final '\0'.
* 'count' is the user-supplied count (return 'count' if we
@@ -69,16 +62,19 @@ static inline long do_strncpy_from_user(char *dst, const char __user *src, long
max = count;
while (max >= sizeof(unsigned long)) {
- unsigned long c;
+ 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;
- /* This can write a few bytes past the NUL character, but that's ok */
+ 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;
- c = has_zero(c);
- if (c)
- return res + count_bytes(c);
res += sizeof(unsigned long);
max -= sizeof(unsigned long);
}