xref: /linux/arch/um/kernel/skas/process.c (revision e2ad626f8f409899baf1bf192d0533a851128b19)
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 
16 extern void start_kernel(void);
17 
18 static int __init start_kernel_proc(void *unused)
19 {
20 	int pid;
21 
22 	block_signals_trace();
23 	pid = os_getpid();
24 
25 	cpu_tasks[0].pid = pid;
26 	cpu_tasks[0].task = current;
27 
28 	start_kernel();
29 	return 0;
30 }
31 
32 extern int userspace_pid[];
33 
34 extern char cpu0_irqstack[];
35 
36 int __init start_uml(void)
37 {
38 	stack_protections((unsigned long) &cpu0_irqstack);
39 	set_sigstack(cpu0_irqstack, THREAD_SIZE);
40 
41 	init_new_thread_signals();
42 
43 	init_task.thread.request.u.thread.proc = start_kernel_proc;
44 	init_task.thread.request.u.thread.arg = NULL;
45 	return start_idle_thread(task_stack_page(&init_task),
46 				 &init_task.thread.switch_buf);
47 }
48 
49 unsigned long current_stub_stack(void)
50 {
51 	if (current->mm == NULL)
52 		return 0;
53 
54 	return current->mm->context.id.stack;
55 }
56