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 /* stdin/stdout/stderr for /linuxrc */ 40 sys_open("/dev/console", O_RDWR, 0); 41 sys_dup(0); 42 sys_dup(0); 43 /* move initrd over / and chdir/chroot in initrd root */ 44 sys_chdir("/root"); 45 sys_mount(".", "/", NULL, MS_MOVE, NULL); 46 sys_chroot("."); 47 sys_setsid(); 48 return 0; 49 } 50 51 static void __init handle_initrd(void) 52 { 53 static char *argv[] = { "linuxrc", NULL, }; 54 extern char *envp_init[]; 55 int error; 56 57 real_root_dev = new_encode_dev(ROOT_DEV); 58 create_dev("/dev/root.old", Root_RAM0); 59 /* mount initrd on rootfs' /root */ 60 mount_block_root("/dev/root.old", root_mountflags & ~MS_RDONLY); 61 sys_mkdir("/old", 0700); 62 sys_chdir("/old"); 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 call_usermodehelper_fns("/linuxrc", argv, envp_init, UMH_WAIT_PROC, 71 init_linuxrc, NULL, NULL); 72 73 current->flags &= ~PF_FREEZER_SKIP; 74 75 /* move initrd to rootfs' /old */ 76 sys_mount("..", ".", NULL, MS_MOVE, NULL); 77 /* switch root and cwd back to / of rootfs */ 78 sys_chroot(".."); 79 80 if (new_decode_dev(real_root_dev) == Root_RAM0) { 81 sys_chdir("/old"); 82 return; 83 } 84 85 sys_chdir("/"); 86 ROOT_DEV = new_decode_dev(real_root_dev); 87 mount_root(); 88 89 printk(KERN_NOTICE "Trying to move old root to /initrd ... "); 90 error = sys_mount("/old", "/root/initrd", NULL, MS_MOVE, NULL); 91 if (!error) 92 printk("okay\n"); 93 else { 94 int fd = sys_open("/dev/root.old", O_RDWR, 0); 95 if (error == -ENOENT) 96 printk("/initrd does not exist. Ignored.\n"); 97 else 98 printk("failed\n"); 99 printk(KERN_NOTICE "Unmounting old root\n"); 100 sys_umount("/old", MNT_DETACH); 101 printk(KERN_NOTICE "Trying to free ramdisk memory ... "); 102 if (fd < 0) { 103 error = fd; 104 } else { 105 error = sys_ioctl(fd, BLKFLSBUF, 0); 106 sys_close(fd); 107 } 108 printk(!error ? "okay\n" : "failed\n"); 109 } 110 } 111 112 int __init initrd_load(void) 113 { 114 if (mount_initrd) { 115 create_dev("/dev/ram", Root_RAM0); 116 /* 117 * Load the initrd data into /dev/ram0. Execute it as initrd 118 * unless /dev/ram0 is supposed to be our actual root device, 119 * in that case the ram disk is just set up here, and gets 120 * mounted in the normal path. 121 */ 122 if (rd_load_image("/initrd.image") && ROOT_DEV != Root_RAM0) { 123 sys_unlink("/initrd.image"); 124 handle_initrd(); 125 return 1; 126 } 127 } 128 sys_unlink("/initrd.image"); 129 return 0; 130 } 131