xref: /linux/arch/um/kernel/skas/process.c (revision 24168c5e6dfbdd5b414f048f47f75d64533296ca)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (C) 2002 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
4  */
5 
6 #include <linux/init.h>
7 #include <linux/sched/mm.h>
8 #include <linux/sched/task_stack.h>
9 #include <linux/sched/task.h>
10 
11 #include <as-layout.h>
12 #include <kern.h>
13 #include <os.h>
14 #include <skas.h>
15 #include <kern_util.h>
16 
17 extern void start_kernel(void);
18 
19 static int __init start_kernel_proc(void *unused)
20 {
21 	block_signals_trace();
22 
23 	cpu_tasks[0].task = current;
24 
25 	start_kernel();
26 	return 0;
27 }
28 
29 extern int userspace_pid[];
30 
31 extern char cpu0_irqstack[];
32 
33 int __init start_uml(void)
34 {
35 	stack_protections((unsigned long) &cpu0_irqstack);
36 	set_sigstack(cpu0_irqstack, THREAD_SIZE);
37 
38 	init_new_thread_signals();
39 
40 	init_task.thread.request.u.thread.proc = start_kernel_proc;
41 	init_task.thread.request.u.thread.arg = NULL;
42 	return start_idle_thread(task_stack_page(&init_task),
43 				 &init_task.thread.switch_buf);
44 }
45 
46 unsigned long current_stub_stack(void)
47 {
48 	if (current->mm == NULL)
49 		return 0;
50 
51 	return current->mm->context.id.stack;
52 }
53