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 #include <linux/kmod.h> 20 21 #include "do_mounts.h" 22 23 unsigned long initrd_start, initrd_end; 24 int initrd_below_start_ok; 25 unsigned int real_root_dev; /* do_proc_dointvec cannot handle kdev_t */ 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_linuxrc(struct subprocess_info *info, struct cred *new) 37 { 38 sys_unshare(CLONE_FS | CLONE_FILES); 39 /* move initrd over / and chdir/chroot in initrd root */ 40 sys_chdir("/root"); 41 sys_mount(".", "/", NULL, MS_MOVE, NULL); 42 sys_chroot("."); 43 sys_setsid(); 44 return 0; 45 } 46 47 static void __init handle_initrd(void) 48 { 49 static char *argv[] = { "linuxrc", NULL, }; 50 extern char *envp_init[]; 51 int error; 52 53 real_root_dev = new_encode_dev(ROOT_DEV); 54 create_dev("/dev/root.old", Root_RAM0); 55 /* mount initrd on rootfs' /root */ 56 mount_block_root("/dev/root.old", root_mountflags & ~MS_RDONLY); 57 sys_mkdir("/old", 0700); 58 sys_chdir("/old"); 59 60 /* 61 * In case that a resume from disk is carried out by linuxrc or one of 62 * its children, we need to tell the freezer not to wait for us. 63 */ 64 current->flags |= PF_FREEZER_SKIP; 65 66 call_usermodehelper_fns("/linuxrc", argv, envp_init, UMH_WAIT_PROC, 67 init_linuxrc, NULL, NULL); 68 69 current->flags &= ~PF_FREEZER_SKIP; 70 71 /* move initrd to rootfs' /old */ 72 sys_mount("..", ".", NULL, MS_MOVE, NULL); 73 /* switch root and cwd back to / of rootfs */ 74 sys_chroot(".."); 75 76 if (new_decode_dev(real_root_dev) == Root_RAM0) { 77 sys_chdir("/old"); 78 return; 79 } 80 81 sys_chdir("/"); 82 ROOT_DEV = new_decode_dev(real_root_dev); 83 mount_root(); 84 85 printk(KERN_NOTICE "Trying to move old root to /initrd ... "); 86 error = sys_mount("/old", "/root/initrd", NULL, MS_MOVE, NULL); 87 if (!error) 88 printk("okay\n"); 89 else { 90 int fd = sys_open("/dev/root.old", O_RDWR, 0); 91 if (error == -ENOENT) 92 printk("/initrd does not exist. Ignored.\n"); 93 else 94 printk("failed\n"); 95 printk(KERN_NOTICE "Unmounting old root\n"); 96 sys_umount("/old", MNT_DETACH); 97 printk(KERN_NOTICE "Trying to free ramdisk memory ... "); 98 if (fd < 0) { 99 error = fd; 100 } else { 101 error = sys_ioctl(fd, BLKFLSBUF, 0); 102 sys_close(fd); 103 } 104 printk(!error ? "okay\n" : "failed\n"); 105 } 106 } 107 108 int __init initrd_load(void) 109 { 110 if (mount_initrd) { 111 create_dev("/dev/ram", Root_RAM0); 112 /* 113 * Load the initrd data into /dev/ram0. Execute it as initrd 114 * unless /dev/ram0 is supposed to be our actual root device, 115 * in that case the ram disk is just set up here, and gets 116 * mounted in the normal path. 117 */ 118 if (rd_load_image("/initrd.image") && ROOT_DEV != Root_RAM0) { 119 sys_unlink("/initrd.image"); 120 handle_initrd(); 121 return 1; 122 } 123 } 124 sys_unlink("/initrd.image"); 125 return 0; 126 } 127