1 // SPDX-License-Identifier: GPL-2.0 2 #include <linux/unistd.h> 3 #include <linux/kernel.h> 4 #include <linux/fs.h> 5 #include <linux/minix_fs.h> 6 #include <linux/romfs_fs.h> 7 #include <linux/initrd.h> 8 #include <linux/sched.h> 9 #include <linux/freezer.h> 10 #include <linux/kmod.h> 11 #include <uapi/linux/mount.h> 12 13 #include "do_mounts.h" 14 15 unsigned long initrd_start, initrd_end; 16 int initrd_below_start_ok; 17 unsigned int real_root_dev; /* do_proc_dointvec cannot handle kdev_t */ 18 static int __initdata mount_initrd = 1; 19 20 phys_addr_t phys_initrd_start __initdata; 21 unsigned long phys_initrd_size __initdata; 22 23 static int __init no_initrd(char *str) 24 { 25 mount_initrd = 0; 26 return 1; 27 } 28 29 __setup("noinitrd", no_initrd); 30 31 static int __init early_initrdmem(char *p) 32 { 33 phys_addr_t start; 34 unsigned long size; 35 char *endp; 36 37 start = memparse(p, &endp); 38 if (*endp == ',') { 39 size = memparse(endp + 1, NULL); 40 41 phys_initrd_start = start; 42 phys_initrd_size = size; 43 } 44 return 0; 45 } 46 early_param("initrdmem", early_initrdmem); 47 48 static int __init early_initrd(char *p) 49 { 50 return early_initrdmem(p); 51 } 52 early_param("initrd", early_initrd); 53 54 static int __init init_linuxrc(struct subprocess_info *info, struct cred *new) 55 { 56 ksys_unshare(CLONE_FS | CLONE_FILES); 57 console_on_rootfs(); 58 /* move initrd over / and chdir/chroot in initrd root */ 59 init_chdir("/root"); 60 init_mount(".", "/", NULL, MS_MOVE, NULL); 61 init_chroot("."); 62 ksys_setsid(); 63 return 0; 64 } 65 66 static void __init handle_initrd(void) 67 { 68 struct subprocess_info *info; 69 static char *argv[] = { "linuxrc", NULL, }; 70 extern char *envp_init[]; 71 int error; 72 73 pr_warn("using deprecated initrd support, will be removed in 2021.\n"); 74 75 real_root_dev = new_encode_dev(ROOT_DEV); 76 create_dev("/dev/root.old", Root_RAM0); 77 /* mount initrd on rootfs' /root */ 78 mount_block_root("/dev/root.old", root_mountflags & ~MS_RDONLY); 79 init_mkdir("/old", 0700); 80 init_chdir("/old"); 81 82 /* 83 * In case that a resume from disk is carried out by linuxrc or one of 84 * its children, we need to tell the freezer not to wait for us. 85 */ 86 current->flags |= PF_FREEZER_SKIP; 87 88 info = call_usermodehelper_setup("/linuxrc", argv, envp_init, 89 GFP_KERNEL, init_linuxrc, NULL, NULL); 90 if (!info) 91 return; 92 call_usermodehelper_exec(info, UMH_WAIT_PROC); 93 94 current->flags &= ~PF_FREEZER_SKIP; 95 96 /* move initrd to rootfs' /old */ 97 init_mount("..", ".", NULL, MS_MOVE, NULL); 98 /* switch root and cwd back to / of rootfs */ 99 init_chroot(".."); 100 101 if (new_decode_dev(real_root_dev) == Root_RAM0) { 102 init_chdir("/old"); 103 return; 104 } 105 106 init_chdir("/"); 107 ROOT_DEV = new_decode_dev(real_root_dev); 108 mount_root(); 109 110 printk(KERN_NOTICE "Trying to move old root to /initrd ... "); 111 error = init_mount("/old", "/root/initrd", NULL, MS_MOVE, NULL); 112 if (!error) 113 printk("okay\n"); 114 else { 115 if (error == -ENOENT) 116 printk("/initrd does not exist. Ignored.\n"); 117 else 118 printk("failed\n"); 119 printk(KERN_NOTICE "Unmounting old root\n"); 120 init_umount("/old", MNT_DETACH); 121 } 122 } 123 124 bool __init initrd_load(void) 125 { 126 if (mount_initrd) { 127 create_dev("/dev/ram", Root_RAM0); 128 /* 129 * Load the initrd data into /dev/ram0. Execute it as initrd 130 * unless /dev/ram0 is supposed to be our actual root device, 131 * in that case the ram disk is just set up here, and gets 132 * mounted in the normal path. 133 */ 134 if (rd_load_image("/initrd.image") && ROOT_DEV != Root_RAM0) { 135 init_unlink("/initrd.image"); 136 handle_initrd(); 137 return true; 138 } 139 } 140 init_unlink("/initrd.image"); 141 return false; 142 } 143