1 /* 2 * Many of the syscalls used in this file expect some of the arguments 3 * to be __user pointers not __kernel pointers. To limit the sparse 4 * noise, turn off sparse checking for this file. 5 */ 6 #ifdef __CHECKER__ 7 #undef __CHECKER__ 8 #warning "Sparse checking disabled for this file" 9 #endif 10 11 #include <linux/unistd.h> 12 #include <linux/kernel.h> 13 #include <linux/fs.h> 14 #include <linux/minix_fs.h> 15 #include <linux/romfs_fs.h> 16 #include <linux/initrd.h> 17 #include <linux/sched.h> 18 #include <linux/freezer.h> 19 20 #include "do_mounts.h" 21 22 unsigned long initrd_start, initrd_end; 23 int initrd_below_start_ok; 24 unsigned int real_root_dev; /* do_proc_dointvec cannot handle kdev_t */ 25 static int __initdata old_fd, root_fd; 26 static int __initdata mount_initrd = 1; 27 28 static int __init no_initrd(char *str) 29 { 30 mount_initrd = 0; 31 return 1; 32 } 33 34 __setup("noinitrd", no_initrd); 35 36 static int __init do_linuxrc(void *_shell) 37 { 38 static const char *argv[] = { "linuxrc", NULL, }; 39 extern const char *envp_init[]; 40 const char *shell = _shell; 41 42 sys_close(old_fd);sys_close(root_fd); 43 sys_setsid(); 44 return kernel_execve(shell, argv, envp_init); 45 } 46 47 static void __init handle_initrd(void) 48 { 49 int error; 50 int pid; 51 52 real_root_dev = new_encode_dev(ROOT_DEV); 53 create_dev("/dev/root.old", Root_RAM0); 54 /* mount initrd on rootfs' /root */ 55 mount_block_root("/dev/root.old", root_mountflags & ~MS_RDONLY); 56 sys_mkdir("/old", 0700); 57 root_fd = sys_open("/", 0, 0); 58 old_fd = sys_open("/old", 0, 0); 59 /* move initrd over / and chdir/chroot in initrd root */ 60 sys_chdir("/root"); 61 sys_mount(".", "/", NULL, MS_MOVE, NULL); 62 sys_chroot("."); 63 64 /* 65 * In case that a resume from disk is carried out by linuxrc or one of 66 * its children, we need to tell the freezer not to wait for us. 67 */ 68 current->flags |= PF_FREEZER_SKIP; 69 70 pid = kernel_thread(do_linuxrc, "/linuxrc", SIGCHLD); 71 if (pid > 0) 72 while (pid != sys_wait4(-1, NULL, 0, NULL)) 73 yield(); 74 75 current->flags &= ~PF_FREEZER_SKIP; 76 77 /* move initrd to rootfs' /old */ 78 sys_fchdir(old_fd); 79 sys_mount("/", ".", NULL, MS_MOVE, NULL); 80 /* switch root and cwd back to / of rootfs */ 81 sys_fchdir(root_fd); 82 sys_chroot("."); 83 sys_close(old_fd); 84 sys_close(root_fd); 85 86 if (new_decode_dev(real_root_dev) == Root_RAM0) { 87 sys_chdir("/old"); 88 return; 89 } 90 91 ROOT_DEV = new_decode_dev(real_root_dev); 92 mount_root(); 93 94 printk(KERN_NOTICE "Trying to move old root to /initrd ... "); 95 error = sys_mount("/old", "/root/initrd", NULL, MS_MOVE, NULL); 96 if (!error) 97 printk("okay\n"); 98 else { 99 int fd = sys_open("/dev/root.old", O_RDWR, 0); 100 if (error == -ENOENT) 101 printk("/initrd does not exist. Ignored.\n"); 102 else 103 printk("failed\n"); 104 printk(KERN_NOTICE "Unmounting old root\n"); 105 sys_umount("/old", MNT_DETACH); 106 printk(KERN_NOTICE "Trying to free ramdisk memory ... "); 107 if (fd < 0) { 108 error = fd; 109 } else { 110 error = sys_ioctl(fd, BLKFLSBUF, 0); 111 sys_close(fd); 112 } 113 printk(!error ? "okay\n" : "failed\n"); 114 } 115 } 116 117 int __init initrd_load(void) 118 { 119 if (mount_initrd) { 120 create_dev("/dev/ram", Root_RAM0); 121 /* 122 * Load the initrd data into /dev/ram0. Execute it as initrd 123 * unless /dev/ram0 is supposed to be our actual root device, 124 * in that case the ram disk is just set up here, and gets 125 * mounted in the normal path. 126 */ 127 if (rd_load_image("/initrd.image") && ROOT_DEV != Root_RAM0) { 128 sys_unlink("/initrd.image"); 129 handle_initrd(); 130 return 1; 131 } 132 } 133 sys_unlink("/initrd.image"); 134 return 0; 135 } 136