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
no_initrd(char * str)23 static int __init no_initrd(char *str)
24 {
25 mount_initrd = 0;
26 return 1;
27 }
28
29 __setup("noinitrd", no_initrd);
30
early_initrdmem(char * p)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
early_initrd(char * p)48 static int __init early_initrd(char *p)
49 {
50 return early_initrdmem(p);
51 }
52 early_param("initrd", early_initrd);
53
init_linuxrc(struct subprocess_info * info,struct cred * new)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
handle_initrd(void)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
initrd_load(void)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
