[PATCH] s390: fix kernel oops for CONFIG_MARCH_Z900=y builds

[Martin Schwidefsky]

The LAST_BREAK macro in entry.S uses a different instruction sequence
for CONFIG_MARCH_Z900 builds. The branch target offset to skip the
store of the last breaking event address needs to take the different
length of the code block into account.

Fixes: f8fc82b47149e344 ("s390: move sys_call_table and last_break from thread_info to thread_struct")
Reported-by: Guenter Roeck <linux@xxxxxxxxxxxx>
Signed-off-by: Martin Schwidefsky <schwidefsky@xxxxxxxxxx>
---
 arch/s390/kernel/entry.S | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/arch/s390/kernel/entry.S b/arch/s390/kernel/entry.S
index 1cc4578..e2e47f7 100644
--- a/arch/s390/kernel/entry.S
+++ b/arch/s390/kernel/entry.S
@@ -123,10 +123,11 @@ _PIF_WORK	= (_PIF_PER_TRAP)
 
 	.macro	LAST_BREAK scratch
 	srag	\scratch,%r10,23
-	jz	.+10
 #ifdef CONFIG_HAVE_MARCH_Z990_FEATURES
+	jz	.+10
 	stg	%r10,__TASK_thread+__THREAD_last_break(%r12)
 #else
+	jz	.+14
 	lghi	\scratch,__TASK_thread
 	stg	%r10,__THREAD_last_break(\scratch,%r12)
 #endif
-- 
2.8.4
-- 
blue skies,
   Martin.

"Reality continues to ruin my life." - Calvin.