Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/arch/arm64/lib/clear_user.S b/arch/arm64/lib/clear_user.S
index 21ba0b2..aeafc03 100644
--- a/arch/arm64/lib/clear_user.S
+++ b/arch/arm64/lib/clear_user.S
@@ -1,23 +1,13 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
 /*
  * Based on arch/arm/lib/clear_user.S
  *
  * Copyright (C) 2012 ARM Ltd.
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 #include <linux/linkage.h>
 
 #include <asm/asm-uaccess.h>
+#include <asm/assembler.h>
 
 	.text
 
@@ -30,7 +20,6 @@
  * Alignment fixed up by hardware.
  */
 ENTRY(__arch_clear_user)
-	uaccess_enable_not_uao x2, x3, x4
 	mov	x2, x1			// save the size for fixup return
 	subs	x1, x1, #8
 	b.mi	2f
@@ -50,9 +39,9 @@
 	b.mi	5f
 uao_user_alternative 9f, strb, sttrb, wzr, x0, 0
 5:	mov	x0, #0
-	uaccess_disable_not_uao x2, x3
 	ret
 ENDPROC(__arch_clear_user)
+EXPORT_SYMBOL(__arch_clear_user)
 
 	.section .fixup,"ax"
 	.align	2