s390/unwind: add machine check handler stack

Fixes: b61b1595 ("s390: add stack for machine check handler")
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>

arch/s390/include/asm/stacktrace.h

@@ -12,6 +12,7 @@ enum stack_type {
 	STACK_TYPE_IRQ,
 	STACK_TYPE_NODAT,
 	STACK_TYPE_RESTART,
+	STACK_TYPE_MCCK,
 };
 
 struct stack_info {

arch/s390/kernel/dumpstack.c

@@ -79,6 +79,15 @@ static bool in_nodat_stack(unsigned long sp, struct stack_info *info)
 	return in_stack(sp, info, STACK_TYPE_NODAT, top - THREAD_SIZE, top);
 }
 
+static bool in_mcck_stack(unsigned long sp, struct stack_info *info)
+{
+	unsigned long frame_size, top;
+
+	frame_size = STACK_FRAME_OVERHEAD + sizeof(struct pt_regs);
+	top = S390_lowcore.mcck_stack + frame_size;
+	return in_stack(sp, info, STACK_TYPE_MCCK, top - THREAD_SIZE, top);
+}
+
 static bool in_restart_stack(unsigned long sp, struct stack_info *info)
 {
 	unsigned long frame_size, top;
@@ -108,7 +117,8 @@ int get_stack_info(unsigned long sp, struct task_struct *task,
 	/* Check per-cpu stacks */
 	if (!in_irq_stack(sp, info) &&
 	    !in_nodat_stack(sp, info) &&
-	    !in_restart_stack(sp, info))
+	    !in_restart_stack(sp, info) &&
+	    !in_mcck_stack(sp, info))
 		goto unknown;
 
 recursion_check: