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 "kern.h" 10 #include "os.h" 11 #include "skas.h" 12 13 int new_mm(unsigned long stack) 14 { 15 int fd, err; 16 17 fd = os_open_file("/proc/mm", of_cloexec(of_write(OPENFLAGS())), 0); 18 if (fd < 0) 19 return fd; 20 21 if (skas_needs_stub) { 22 err = map_stub_pages(fd, STUB_CODE, STUB_DATA, stack); 23 if (err) { 24 os_close_file(fd); 25 return err; 26 } 27 } 28 29 return fd; 30 } 31 32 extern void start_kernel(void); 33 34 static int __init start_kernel_proc(void *unused) 35 { 36 int pid; 37 38 block_signals(); 39 pid = os_getpid(); 40 41 cpu_tasks[0].pid = pid; 42 cpu_tasks[0].task = current; 43 #ifdef CONFIG_SMP 44 cpu_online_map = cpumask_of_cpu(0); 45 #endif 46 start_kernel(); 47 return 0; 48 } 49 50 extern int userspace_pid[]; 51 52 extern char cpu0_irqstack[]; 53 54 int __init start_uml(void) 55 { 56 stack_protections((unsigned long) &cpu0_irqstack); 57 set_sigstack(cpu0_irqstack, THREAD_SIZE); 58 if (proc_mm) { 59 userspace_pid[0] = start_userspace(0); 60 if (userspace_pid[0] < 0) { 61 printf("start_uml - start_userspace returned %d\n", 62 userspace_pid[0]); 63 exit(1); 64 } 65 } 66 67 init_new_thread_signals(); 68 69 init_task.thread.request.u.thread.proc = start_kernel_proc; 70 init_task.thread.request.u.thread.arg = NULL; 71 return start_idle_thread(task_stack_page(&init_task), 72 &init_task.thread.switch_buf); 73 } 74 75 unsigned long current_stub_stack(void) 76 { 77 if (current->mm == NULL) 78 return 0; 79 80 return current->mm->context.id.stack; 81 } 82