alpha: get rid of tail-zeroing in __copy_user()

... and adjust copy_from_user() accordingly

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

1 files changed, 5 insertions, 4 deletions

diff --git a/arch/alpha/include/asm/uaccess.h b/arch/alpha/include/asm/uaccess.h
index 466e42e96bfa..94f587535dee 100644
--- a/arch/alpha/include/asm/uaccess.h
+++ b/arch/alpha/include/asm/uaccess.h
@@ -396,11 +396,12 @@ copy_to_user(void __user *to, const void *from, long n)
 extern inline long
 copy_from_user(void *to, const void __user *from, long n)
 {
+	long res = n;
 	if (likely(__access_ok((unsigned long)from, n, get_fs())))
-		n = __copy_tofrom_user_nocheck(to, (__force void *)from, n);
-	else
-		memset(to, 0, n);
-	return n;
+		res = __copy_from_user_inatomic(to, from, n);
+	if (unlikely(res))
+		memset(to + (n - res), 0, res);
+	return res;
 }
 
 extern void __do_clear_user(void);