From: Vasily Gorbik <gor@linux.ibm.com>
Date: Fri, 22 Nov 2019 17:15:35 +0100
Subject: s390/head64: correct init_task stack setup
Git-commit: cb7948e8c3f18f7ff0ab7d0fa1e6b108d938cdd6
Patch-mainline: v5.5-rc1
References: jsc#SLE-11178

Add missing allocation of pt_regs at the bottom of the stack. This
makes it consistent with other stack setup cases and also what stack
unwinder expects.

Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Acked-by: Miroslav Benes <mbenes@suse.cz>
---
 arch/s390/kernel/head64.S |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/arch/s390/kernel/head64.S
+++ b/arch/s390/kernel/head64.S
@@ -35,7 +35,7 @@ ENTRY(startup_continue)
 #
 	larl	%r14,init_task
 	stg	%r14,__LC_CURRENT
-	larl	%r15,init_thread_union+THREAD_SIZE-STACK_FRAME_OVERHEAD
+	larl	%r15,init_thread_union+THREAD_SIZE-STACK_FRAME_OVERHEAD-__PT_SIZE
 #
 # Save ipl parameters, clear bss memory, initialize storage key for kernel pages,
 # and create a kernel NSS if the SAVESYS= parm is defined