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1#include <linux/unistd.h>
2#include <linux/kernel.h>
3#include <linux/fs.h>
4#include <linux/minix_fs.h>
5#include <linux/ext2_fs.h>
6#include <linux/romfs_fs.h>
7#include <linux/initrd.h>
8#include <linux/sched.h>
9#include <linux/freezer.h>
10
11#include "do_mounts.h"
12
13unsigned long initrd_start, initrd_end;
14int initrd_below_start_ok;
15unsigned int real_root_dev; /* do_proc_dointvec cannot handle kdev_t */
16static int __initdata old_fd, root_fd;
17static int __initdata mount_initrd = 1;
18
19static int __init no_initrd(char *str)
20{
21 mount_initrd = 0;
22 return 1;
23}
24
25__setup("noinitrd", no_initrd);
26
27static int __init do_linuxrc(void *_shell)
28{
29 static const char *argv[] = { "linuxrc", NULL, };
30 extern const char *envp_init[];
31 const char *shell = _shell;
32
33 sys_close(old_fd);sys_close(root_fd);
34 sys_setsid();
35 return kernel_execve(shell, argv, envp_init);
36}
37
38static void __init handle_initrd(void)
39{
40 int error;
41 int pid;
42
43 real_root_dev = new_encode_dev(ROOT_DEV);
44 create_dev("/dev/root.old", Root_RAM0);
45 /* mount initrd on rootfs' /root */
46 mount_block_root("/dev/root.old", root_mountflags & ~MS_RDONLY);
47 sys_mkdir("/old", 0700);
48 root_fd = sys_open("/", 0, 0);
49 old_fd = sys_open("/old", 0, 0);
50 /* move initrd over / and chdir/chroot in initrd root */
51 sys_chdir("/root");
52 sys_mount(".", "/", NULL, MS_MOVE, NULL);
53 sys_chroot(".");
54
55 /*
56 * In case that a resume from disk is carried out by linuxrc or one of
57 * its children, we need to tell the freezer not to wait for us.
58 */
59 current->flags |= PF_FREEZER_SKIP;
60
61 pid = kernel_thread(do_linuxrc, "/linuxrc", SIGCHLD);
62 if (pid > 0)
63 while (pid != sys_wait4(-1, NULL, 0, NULL))
64 yield();
65
66 current->flags &= ~PF_FREEZER_SKIP;
67
68 /* move initrd to rootfs' /old */
69 sys_fchdir(old_fd);
70 sys_mount("/", ".", NULL, MS_MOVE, NULL);
71 /* switch root and cwd back to / of rootfs */
72 sys_fchdir(root_fd);
73 sys_chroot(".");
74 sys_close(old_fd);
75 sys_close(root_fd);
76
77 if (new_decode_dev(real_root_dev) == Root_RAM0) {
78 sys_chdir("/old");
79 return;
80 }
81
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
108int __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}
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
15unsigned long initrd_start, initrd_end;
16int initrd_below_start_ok;
17static unsigned int real_root_dev; /* do_proc_dointvec cannot handle kdev_t */
18static int __initdata mount_initrd = 1;
19
20phys_addr_t phys_initrd_start __initdata;
21unsigned long phys_initrd_size __initdata;
22
23#ifdef CONFIG_SYSCTL
24static 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
35static __init int kernel_do_mounts_initrd_sysctls_init(void)
36{
37 register_sysctl_init("kernel", kern_do_mounts_initrd_table);
38 return 0;
39}
40late_initcall(kernel_do_mounts_initrd_sysctls_init);
41#endif /* CONFIG_SYSCTL */
42
43static int __init no_initrd(char *str)
44{
45 mount_initrd = 0;
46 return 1;
47}
48
49__setup("noinitrd", no_initrd);
50
51static int __init early_initrdmem(char *p)
52{
53 phys_addr_t start;
54 unsigned long size;
55 char *endp;
56
57 start = memparse(p, &endp);
58 if (*endp == ',') {
59 size = memparse(endp + 1, NULL);
60
61 phys_initrd_start = start;
62 phys_initrd_size = size;
63 }
64 return 0;
65}
66early_param("initrdmem", early_initrdmem);
67
68static int __init early_initrd(char *p)
69{
70 return early_initrdmem(p);
71}
72early_param("initrd", early_initrd);
73
74static int __init init_linuxrc(struct subprocess_info *info, struct cred *new)
75{
76 ksys_unshare(CLONE_FS | CLONE_FILES);
77 console_on_rootfs();
78 /* move initrd over / and chdir/chroot in initrd root */
79 init_chdir("/root");
80 init_mount(".", "/", NULL, MS_MOVE, NULL);
81 init_chroot(".");
82 ksys_setsid();
83 return 0;
84}
85
86static void __init handle_initrd(char *root_device_name)
87{
88 struct subprocess_info *info;
89 static char *argv[] = { "linuxrc", NULL, };
90 extern char *envp_init[];
91 int error;
92
93 pr_warn("using deprecated initrd support, will be removed in 2021.\n");
94
95 real_root_dev = new_encode_dev(ROOT_DEV);
96 create_dev("/dev/root.old", Root_RAM0);
97 /* mount initrd on rootfs' /root */
98 mount_root_generic("/dev/root.old", root_device_name,
99 root_mountflags & ~MS_RDONLY);
100 init_mkdir("/old", 0700);
101 init_chdir("/old");
102
103 info = call_usermodehelper_setup("/linuxrc", argv, envp_init,
104 GFP_KERNEL, init_linuxrc, NULL, NULL);
105 if (!info)
106 return;
107 call_usermodehelper_exec(info, UMH_WAIT_PROC|UMH_FREEZABLE);
108
109 /* move initrd to rootfs' /old */
110 init_mount("..", ".", NULL, MS_MOVE, NULL);
111 /* switch root and cwd back to / of rootfs */
112 init_chroot("..");
113
114 if (new_decode_dev(real_root_dev) == Root_RAM0) {
115 init_chdir("/old");
116 return;
117 }
118
119 init_chdir("/");
120 ROOT_DEV = new_decode_dev(real_root_dev);
121 mount_root(root_device_name);
122
123 printk(KERN_NOTICE "Trying to move old root to /initrd ... ");
124 error = init_mount("/old", "/root/initrd", NULL, MS_MOVE, NULL);
125 if (!error)
126 printk("okay\n");
127 else {
128 if (error == -ENOENT)
129 printk("/initrd does not exist. Ignored.\n");
130 else
131 printk("failed\n");
132 printk(KERN_NOTICE "Unmounting old root\n");
133 init_umount("/old", MNT_DETACH);
134 }
135}
136
137bool __init initrd_load(char *root_device_name)
138{
139 if (mount_initrd) {
140 create_dev("/dev/ram", Root_RAM0);
141 /*
142 * Load the initrd data into /dev/ram0. Execute it as initrd
143 * unless /dev/ram0 is supposed to be our actual root device,
144 * in that case the ram disk is just set up here, and gets
145 * mounted in the normal path.
146 */
147 if (rd_load_image("/initrd.image") && ROOT_DEV != Root_RAM0) {
148 init_unlink("/initrd.image");
149 handle_initrd(root_device_name);
150 return true;
151 }
152 }
153 init_unlink("/initrd.image");
154 return false;
155}