x86: remove more uaccess_32.h complexity

I'm looking at trying to possibly merge the 32-bit and 64-bit versions
of the x86 uaccess.h implementation, but first this needs to be cleaned
up.

For example, the 32-bit version of "__copy_from_user_inatomic()" is
mostly the special cases for the constant size, and it's actually almost
never relevant.  Most users aren't actually using a constant size
anyway, and the few cases that do small constant copies are better off
just using __get_user() instead.

So get rid of the unnecessary complexity.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 0 insertions, 26 deletions

diff --git a/arch/x86/include/asm/uaccess_32.h b/arch/x86/include/asm/uaccess_32.h
index 537cc88..4b32da24 100644
--- a/arch/x86/include/asm/uaccess_32.h
+++ b/arch/x86/include/asm/uaccess_32.h
@@ -65,32 +65,6 @@ __copy_to_user(void __user *to, const void *from, unsigned long n)
 static __always_inline unsigned long
 __copy_from_user_inatomic(void *to, const void __user *from, unsigned long n)
 {
-	/* Avoid zeroing the tail if the copy fails..
-	 * If 'n' is constant and 1, 2, or 4, we do still zero on a failure,
-	 * but as the zeroing behaviour is only significant when n is not
-	 * constant, that shouldn't be a problem.
-	 */
-	if (__builtin_constant_p(n)) {
-		unsigned long ret;
-
-		switch (n) {
-		case 1:
-			__uaccess_begin();
-			__get_user_size(*(u8 *)to, from, 1, ret, 1);
-			__uaccess_end();
-			return ret;
-		case 2:
-			__uaccess_begin();
-			__get_user_size(*(u16 *)to, from, 2, ret, 2);
-			__uaccess_end();
-			return ret;
-		case 4:
-			__uaccess_begin();
-			__get_user_size(*(u32 *)to, from, 4, ret, 4);
-			__uaccess_end();
-			return ret;
-		}
-	}
 	return __copy_from_user_ll_nozero(to, from, n);
 }