--- zzzz-none-000/linux-3.10.107/arch/um/kernel/process.c	2017-06-27 09:49:32.000000000 +0000
+++ scorpion-7490-727/linux-3.10.107/arch/um/kernel/process.c	2021-02-04 17:41:59.000000000 +0000
@@ -1,4 +1,6 @@
 /*
+ * Copyright (C) 2015 Anton Ivanov (aivanov@{brocade.com,kot-begemot.co.uk})
+ * Copyright (C) 2015 Thomas Meyer (thomas@m3y3r.de)
  * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
  * Copyright 2003 PathScale, Inc.
  * Licensed under the GPL
@@ -27,6 +29,7 @@
 #include <kern_util.h>
 #include <os.h>
 #include <skas.h>
+#include <timer-internal.h>
 
 /*
  * This is a per-cpu array.  A processor only modifies its entry and it only
@@ -82,31 +85,22 @@
 	to->thread.prev_sched = from;
 	set_current(to);
 
-	do {
-		current->thread.saved_task = NULL;
-
-		switch_threads(&from->thread.switch_buf,
-			       &to->thread.switch_buf);
-
-		arch_switch_to(current);
-
-		if (current->thread.saved_task)
-			show_regs(&(current->thread.regs));
-		to = current->thread.saved_task;
-		from = current;
-	} while (current->thread.saved_task);
+	switch_threads(&from->thread.switch_buf, &to->thread.switch_buf);
+	arch_switch_to(current);
 
 	return current->thread.prev_sched;
 }
 
 void interrupt_end(void)
 {
+	struct pt_regs *regs = &current->thread.regs;
+
 	if (need_resched())
 		schedule();
 	if (test_thread_flag(TIF_SIGPENDING))
-		do_signal();
+		do_signal(regs);
 	if (test_and_clear_thread_flag(TIF_NOTIFY_RESUME))
-		tracehook_notify_resume(&current->thread.regs);
+		tracehook_notify_resume(regs);
 }
 
 void exit_thread(void)
@@ -212,11 +206,8 @@
 
 void arch_cpu_idle(void)
 {
-	unsigned long long nsecs;
-
 	cpu_tasks[current_thread_info()->cpu].pid = os_getpid();
-	nsecs = disable_timer();
-	idle_sleep(nsecs);
+	os_idle_sleep(UM_NSEC_PER_SEC);
 	local_irq_enable();
 }
 
@@ -270,17 +261,6 @@
 	return strlen_user(str);
 }
 
-int smp_sigio_handler(void)
-{
-#ifdef CONFIG_SMP
-	int cpu = current_thread_info()->cpu;
-	IPI_handler(cpu);
-	if (cpu != 0)
-		return 1;
-#endif
-	return 0;
-}
-
 int cpu(void)
 {
 	return current_thread_info()->cpu;
@@ -370,7 +350,7 @@
 /*
  * Only x86 and x86_64 have an arch_align_stack().
  * All other arches have "#define arch_align_stack(x) (x)"
- * in their asm/system.h
+ * in their asm/exec.h
  * As this is included in UML from asm-um/system-generic.h,
  * we can use it to behave as the subarch does.
  */