arch/um/kernel/skas/process.c

   1 /*
   2  * Copyright (C) 2002 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
   3  * Licensed under the GPL
   4  */
   5
   6 #include "linux/init.h"
   7 #include "linux/sched.h"
   8 #include "as-layout.h"
   9 #include "os.h"
  10 #include "skas.h"
  11
  12 int new_mm(unsigned long stack)
  13 {
  14         int fd;
  15
  16         fd = os_open_file("/proc/mm", of_cloexec(of_write(OPENFLAGS())), 0);
  17         if (fd < 0)
  18                 return fd;
  19
  20         if (skas_needs_stub)
  21                 map_stub_pages(fd, CONFIG_STUB_CODE, CONFIG_STUB_DATA, stack);
  22
  23         return fd;
  24 }
  25
  26 extern void start_kernel(void);
  27
  28 static int __init start_kernel_proc(void *unused)
  29 {
  30         int pid;
  31
  32         block_signals();
  33         pid = os_getpid();
  34
  35         cpu_tasks[0].pid = pid;
  36         cpu_tasks[0].task = current;
  37 #ifdef CONFIG_SMP
  38         cpu_online_map = cpumask_of_cpu(0);
  39 #endif
  40         start_kernel();
  41         return 0;
  42 }
  43
  44 extern int userspace_pid[];
  45
  46 extern char cpu0_irqstack[];
  47
  48 int __init start_uml(void)
  49 {
  50         stack_protections((unsigned long) &cpu0_irqstack);
  51         set_sigstack(cpu0_irqstack, THREAD_SIZE);
  52         if (proc_mm)
  53                 userspace_pid[0] = start_userspace(0);
  54
  55         init_new_thread_signals();
  56
  57         init_task.thread.request.u.thread.proc = start_kernel_proc;
  58         init_task.thread.request.u.thread.arg = NULL;
  59         return start_idle_thread(task_stack_page(&init_task),
  60                                  &init_task.thread.switch_buf);
  61 }
  62
  63 unsigned long current_stub_stack(void)
  64 {
  65         if (current->mm == NULL)
  66                 return 0;
  67
  68         return current->mm->context.id.stack;
  69 }