Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/arch/powerpc/include/asm/setjmp.h b/arch/powerpc/include/asm/setjmp.h
index 279d03a..e9f81bb 100644
--- a/arch/powerpc/include/asm/setjmp.h
+++ b/arch/powerpc/include/asm/setjmp.h
@@ -1,18 +1,13 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
 /*
  * Copyright © 2008 Michael Neuling IBM Corporation
- *
- *      This program is free software; you can redistribute it and/or
- *      modify it under the terms of the GNU General Public License
- *      as published by the Free Software Foundation; either version
- *      2 of the License, or (at your option) any later version.
- *
  */
 #ifndef _ASM_POWERPC_SETJMP_H
 #define _ASM_POWERPC_SETJMP_H
 
 #define JMP_BUF_LEN    23
 
-extern long setjmp(long *);
-extern void longjmp(long *, long);
+extern long setjmp(long *) __attribute__((returns_twice));
+extern void longjmp(long *, long) __attribute__((noreturn));
 
 #endif /* _ASM_POWERPC_SETJMP_H */