diff --git a/arch/s390/include/asm/nmi.h b/arch/s390/include/asm/nmi.h
index af1cd3a6f406..227466ce9e41 100644
--- a/arch/s390/include/asm/nmi.h
+++ b/arch/s390/include/asm/nmi.h
@@ -101,9 +101,8 @@ void nmi_alloc_mcesa_early(u64 *mcesad);
 int nmi_alloc_mcesa(u64 *mcesad);
 void nmi_free_mcesa(u64 *mcesad);
 
-void s390_handle_mcck(struct pt_regs *regs);
-void __s390_handle_mcck(void);
-int s390_do_machine_check(struct pt_regs *regs);
+void s390_handle_mcck(void);
+void s390_do_machine_check(struct pt_regs *regs);
 
 #endif /* __ASSEMBLY__ */
 #endif /* _ASM_S390_NMI_H */
diff --git a/arch/s390/kernel/entry.S b/arch/s390/kernel/entry.S
index c8d8c9960936..76a06f3d3671 100644
--- a/arch/s390/kernel/entry.S
+++ b/arch/s390/kernel/entry.S
@@ -562,16 +562,6 @@ ENTRY(mcck_int_handler)
 	xc	__SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15)
 	lgr	%r2,%r11		# pass pointer to pt_regs
 	brasl	%r14,s390_do_machine_check
-	cghi	%r2,0
-	je	.Lmcck_return
-	lg	%r1,__LC_KERNEL_STACK	# switch to kernel stack
-	mvc	STACK_FRAME_OVERHEAD(__PT_SIZE,%r1),0(%r11)
-	xc	__SF_BACKCHAIN(8,%r1),__SF_BACKCHAIN(%r1)
-	la	%r11,STACK_FRAME_OVERHEAD(%r1)
-	lgr	%r2,%r11
-	lgr	%r15,%r1
-	brasl	%r14,s390_handle_mcck
-.Lmcck_return:
 	lctlg	%c1,%c1,__PT_CR1(%r11)
 	lmg	%r0,%r10,__PT_R0(%r11)
 	mvc	__LC_RETURN_MCCK_PSW(16),__PT_PSW(%r11) # move return PSW
diff --git a/arch/s390/kernel/nmi.c b/arch/s390/kernel/nmi.c
index 56d9c559afa1..38ec0487521c 100644
--- a/arch/s390/kernel/nmi.c
+++ b/arch/s390/kernel/nmi.c
@@ -156,7 +156,7 @@ NOKPROBE_SYMBOL(s390_handle_damage);
  * Main machine check handler function. Will be called with interrupts disabled
  * and machine checks enabled.
  */
-void __s390_handle_mcck(void)
+void s390_handle_mcck(void)
 {
 	struct mcck_struct mcck;
 
@@ -192,23 +192,16 @@ void __s390_handle_mcck(void)
 	if (mcck.stp_queue)
 		stp_queue_work();
 	if (mcck.kill_task) {
-		local_irq_enable();
 		printk(KERN_EMERG "mcck: Terminating task because of machine "
 		       "malfunction (code 0x%016lx).\n", mcck.mcck_code);
 		printk(KERN_EMERG "mcck: task: %s, pid: %d.\n",
 		       current->comm, current->pid);
-		make_task_dead(SIGSEGV);
+		if (is_global_init(current))
+			panic("mcck: Attempting to kill init!\n");
+		do_send_sig_info(SIGKILL, SEND_SIG_PRIV, current, PIDTYPE_PID);
 	}
 }
 
-void noinstr s390_handle_mcck(struct pt_regs *regs)
-{
-	trace_hardirqs_off();
-	pai_kernel_enter(regs);
-	__s390_handle_mcck();
-	pai_kernel_exit(regs);
-	trace_hardirqs_on();
-}
 /*
  * returns 0 if register contents could be validated
  * returns 1 otherwise
@@ -373,7 +366,7 @@ NOKPROBE_SYMBOL(s390_backup_mcck_info);
 /*
  * machine check handler.
  */
-int notrace s390_do_machine_check(struct pt_regs *regs)
+void notrace s390_do_machine_check(struct pt_regs *regs)
 {
 	static int ipd_count;
 	static DEFINE_SPINLOCK(ipd_lock);
@@ -503,16 +496,10 @@ int notrace s390_do_machine_check(struct pt_regs *regs)
 	}
 	clear_cpu_flag(CIF_MCCK_GUEST);
 
-	if (user_mode(regs) && mcck_pending) {
-		irqentry_nmi_exit(regs, irq_state);
-		return 1;
-	}
-
 	if (mcck_pending)
 		schedule_mcck_handler();
 
 	irqentry_nmi_exit(regs, irq_state);
-	return 0;
 }
 NOKPROBE_SYMBOL(s390_do_machine_check);
 
diff --git a/arch/s390/kernel/smp.c b/arch/s390/kernel/smp.c
index 23c427284773..97961522b317 100644
--- a/arch/s390/kernel/smp.c
+++ b/arch/s390/kernel/smp.c
@@ -522,7 +522,7 @@ static void smp_handle_ext_call(void)
 	if (test_bit(ec_call_function_single, &bits))
 		generic_smp_call_function_single_interrupt();
 	if (test_bit(ec_mcck_pending, &bits))
-		__s390_handle_mcck();
+		s390_handle_mcck();
 	if (test_bit(ec_irq_work, &bits))
 		irq_work_run();
 }