s390: initialize backchain for ext_int_handler()
To allow correct stack backtraces the backchain for the external
interrupt handler is now initialized with zero like it is already
done for example by io_int_handler().
Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/arch/s390/kernel/entry64.S b/arch/s390/kernel/entry64.S
index 4e1c292..6b5ea90 100644
--- a/arch/s390/kernel/entry64.S
+++ b/arch/s390/kernel/entry64.S
@@ -622,6 +622,7 @@
mvc __PT_R8(64,%r11),__LC_SAVE_AREA_ASYNC
stmg %r8,%r9,__PT_PSW(%r11)
TRACE_IRQS_OFF
+ xc __SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15)
lghi %r1,4096
lgr %r2,%r11 # pass pointer to pt_regs
llgf %r3,__LC_EXT_CPU_ADDR # get cpu address + interruption code