| | 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 | static 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 | #ifdef CONFIG_SYSCTL |
| | 24 | static const struct ctl_table kern_do_mounts_initrd_table[] = { |
| | 25 | { |
| | 26 | .procname = "real-root-dev", |
| | 27 | .data = &real_root_dev, |
| | 28 | .maxlen = sizeof(int), |
| | 29 | .mode = 0644, |
| | 30 | .proc_handler = proc_dointvec, |
| | 31 | }, |
| | 32 | }; |
| | 33 | |
| | 34 | static __init int kernel_do_mounts_initrd_sysctls_init(void) |
| | 35 | { |
| | 36 | register_sysctl_init("kernel", kern_do_mounts_initrd_table); |
| | 37 | return 0; |
| | 38 | } |
| | 39 | late_initcall(kernel_do_mounts_initrd_sysctls_init); |
| | 40 | #endif /* CONFIG_SYSCTL */ |
| | 41 | |
| | 42 | static int __init no_initrd(char *str) |
| | 43 | { |
| | 44 | mount_initrd = 0; |
| | 45 | return 1; |
| | 46 | } |
| | 47 | |
| | 48 | __setup("noinitrd", no_initrd); |
| | 49 | |
| | 50 | static int __init early_initrdmem(char *p) |
| | 51 | { |
| | 52 | phys_addr_t start; |
| | 53 | unsigned long size; |
| | 54 | char *endp; |
| | 55 | |
| | 56 | start = memparse(p, &endp); |
| | 57 | if (*endp == ',') { |
| | 58 | size = memparse(endp + 1, NULL); |
| | 59 | |
| | 60 | phys_initrd_start = start; |
| | 61 | phys_initrd_size = size; |
| | 62 | } |
| | 63 | return 0; |
| | 64 | } |
| | 65 | early_param("initrdmem", early_initrdmem); |
| | 66 | |
| | 67 | static int __init early_initrd(char *p) |
| | 68 | { |
| | 69 | return early_initrdmem(p); |
| | 70 | } |
| | 71 | early_param("initrd", early_initrd); |
| | 72 | |
| | 73 | static int __init init_linuxrc(struct subprocess_info *info, struct cred *new) |
| | 74 | { |
| | 75 | ksys_unshare(CLONE_FS | CLONE_FILES); |
| | 76 | console_on_rootfs(); |
| | 77 | /* move initrd over / and chdir/chroot in initrd root */ |
| | 78 | init_chdir("/root"); |
| | 79 | init_mount(".", "/", NULL, MS_MOVE, NULL); |
| | 80 | init_chroot("."); |
| | 81 | ksys_setsid(); |
| | 82 | return 0; |
| | 83 | } |
| | 84 | |
| | 85 | static void __init handle_initrd(char *root_device_name) |
| | 86 | { |
| | 87 | struct subprocess_info *info; |
| | 88 | static char *argv[] = { "linuxrc", NULL, }; |
| | 89 | extern char *envp_init[]; |
| | 90 | int error; |
| | 91 | |
| | 92 | pr_warn("using deprecated initrd support, will be removed soon.\n"); |
| | 93 | |
| | 94 | real_root_dev = new_encode_dev(ROOT_DEV); |
| | 95 | create_dev("/dev/root.old", Root_RAM0); |
| | 96 | /* mount initrd on rootfs' /root */ |
| | 97 | mount_root_generic("/dev/root.old", root_device_name, |
| | 98 | root_mountflags & ~MS_RDONLY); |
| | 99 | init_mkdir("/old", 0700); |
| | 100 | init_chdir("/old"); |
| | 101 | |
| | 102 | info = call_usermodehelper_setup("/linuxrc", argv, envp_init, |
| | 103 | GFP_KERNEL, init_linuxrc, NULL, NULL); |
| | 104 | if (!info) |
| | 105 | return; |
| | 106 | call_usermodehelper_exec(info, UMH_WAIT_PROC|UMH_FREEZABLE); |
| | 107 | |
| | 108 | /* move initrd to rootfs' /old */ |
| | 109 | init_mount("..", ".", NULL, MS_MOVE, NULL); |
| | 110 | /* switch root and cwd back to / of rootfs */ |
| | 111 | init_chroot(".."); |
| | 112 | |
| | 113 | if (new_decode_dev(real_root_dev) == Root_RAM0) { |
| | 114 | init_chdir("/old"); |
| | 115 | return; |
| | 116 | } |
| | 117 | |
| | 118 | init_chdir("/"); |
| | 119 | ROOT_DEV = new_decode_dev(real_root_dev); |
| | 120 | mount_root(root_device_name); |
| | 121 | |
| | 122 | printk(KERN_NOTICE "Trying to move old root to /initrd ... "); |
| | 123 | error = init_mount("/old", "/root/initrd", NULL, MS_MOVE, NULL); |
| | 124 | if (!error) |
| | 125 | printk("okay\n"); |
| | 126 | else { |
| | 127 | if (error == -ENOENT) |
| | 128 | printk("/initrd does not exist. Ignored.\n"); |
| | 129 | else |
| | 130 | printk("failed\n"); |
| | 131 | printk(KERN_NOTICE "Unmounting old root\n"); |
| | 132 | init_umount("/old", MNT_DETACH); |
| | 133 | } |
| | 134 | } |
| | 135 | |
| | 136 | bool __init initrd_load(char *root_device_name) |
| | 137 | { |
| | 138 | if (mount_initrd) { |
| | 139 | create_dev("/dev/ram", Root_RAM0); |
| | 140 | /* |
| | 141 | * Load the initrd data into /dev/ram0. Execute it as initrd |
| | 142 | * unless /dev/ram0 is supposed to be our actual root device, |
| | 143 | * in that case the ram disk is just set up here, and gets |
| | 144 | * mounted in the normal path. |
| | 145 | */ |
| | 146 | if (rd_load_image("/initrd.image") && ROOT_DEV != Root_RAM0) { |
| | 147 | init_unlink("/initrd.image"); |
| | 148 | handle_initrd(root_device_name); |
| | 149 | return true; |
| | 150 | } |
| | 151 | } |
| | 152 | init_unlink("/initrd.image"); |
| | 153 | return false; |
| | 154 | } |
projects / linux-2.6-block.git / blame_incremental