Repository navigation
Expand file tree
/
Copy pathdo_mounts_initrd.c
More file actions
155 lines (134 loc) · 3.76 KB
/
Copy pathdo_mounts_initrd.c
File metadata and controls
155 lines (134 loc) · 3.76 KB
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
// SPDX-License-Identifier: GPL-2.0
#include <linux/unistd.h>
#include <linux/kernel.h>
#include <linux/fs.h>
#include <linux/minix_fs.h>
#include <linux/romfs_fs.h>
#include <linux/initrd.h>
#include <linux/sched.h>
#include <linux/freezer.h>
#include <linux/kmod.h>
#include <uapi/linux/mount.h>
#include "do_mounts.h"
unsigned long initrd_start, initrd_end;
int initrd_below_start_ok;
static unsigned int real_root_dev; /* do_proc_dointvec cannot handle kdev_t */
static int __initdata mount_initrd = 1;
phys_addr_t phys_initrd_start __initdata;
unsigned long phys_initrd_size __initdata;
#ifdef CONFIG_SYSCTL
static struct ctl_table kern_do_mounts_initrd_table[] = {
{
.procname = "real-root-dev",
.data = &real_root_dev,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec,
},
{ }
};
static __init int kernel_do_mounts_initrd_sysctls_init(void)
{
register_sysctl_init("kernel", kern_do_mounts_initrd_table);
return 0;
}
late_initcall(kernel_do_mounts_initrd_sysctls_init);
#endif /* CONFIG_SYSCTL */
static int __init no_initrd(char *str)
{
mount_initrd = 0;
return 1;
}
__setup("noinitrd", no_initrd);
static int __init early_initrdmem(char *p)
{
phys_addr_t start;
unsigned long size;
char *endp;
start = memparse(p, &endp);
if (*endp == ',') {
size = memparse(endp + 1, NULL);
phys_initrd_start = start;
phys_initrd_size = size;
}
return 0;
}
early_param("initrdmem", early_initrdmem);
static int __init early_initrd(char *p)
{
return early_initrdmem(p);
}
early_param("initrd", early_initrd);
static int __init init_linuxrc(struct subproc
7DBD
ess_info *info, struct cred *new)
{
ksys_unshare(CLONE_FS | CLONE_FILES);
console_on_rootfs();
/* move initrd over / and chdir/chroot in initrd root */
init_chdir("/root");
init_mount(".", "/", NULL, MS_MOVE, NULL);
init_chroot(".");
ksys_setsid();
return 0;
}
static void __init handle_initrd(char *root_device_name)
{
struct subprocess_info *info;
static char *argv[] = { "linuxrc", NULL, };
extern char *envp_init[];
int error;
pr_warn("using deprecated initrd support, will be removed in 2021.\n");
real_root_dev = new_encode_dev(ROOT_DEV);
create_dev("/dev/root.old", Root_RAM0);
/* mount initrd on rootfs' /root */
mount_root_generic("/dev/root.old", root_device_name,
root_mountflags & ~MS_RDONLY);
init_mkdir("/old", 0700);
init_chdir("/old");
info = call_usermodehelper_setup("/linuxrc", argv, envp_init,
GFP_KERNEL, init_linuxrc, NULL, NULL);
if (!info)
return;
call_usermodehelper_exec(info, UMH_WAIT_PROC|UMH_FREEZABLE);
/* move initrd to rootfs' /old */
init_mount("..", ".", NULL, MS_MOVE, NULL);
/* switch root and cwd back to / of rootfs */
init_chroot("..");
if (new_decode_dev(real_root_dev) == Root_RAM0) {
init_chdir("/old");
return;
}
init_chdir("/");
ROOT_DEV = new_decode_dev(real_root_dev);
mount_root(root_device_name);
printk(KERN_NOTICE "Trying to move old root to /initrd ... ");
error = init_mount("/old", "/root/initrd", NULL, MS_MOVE, NULL);
if (!error)
printk("okay\n");
else {
if (error == -ENOENT)
printk("/initrd does not exist. Ignored.\n");
else
printk("failed\n");
printk(KERN_NOTICE "Unmounting old root\n");
init_umount("/old", MNT_DETACH);
}
}
bool __init initrd_load(char *root_device_name)
{
if (mount_initrd) {
create_dev("/dev/ram", Root_RAM0);
/*
* Load the initrd data into /dev/ram0. Execute it as initrd
* unless /dev/ram0 is supposed to be our actual root device,
* in that case the ram disk is just set up here, and gets
* mounted in the normal path.
*/
if (rd_load_image("/initrd.image") && ROOT_DEV != Root_RAM0) {
init_unlink("/initrd.image");
handle_initrd(root_device_name);
return true;
}
}
init_unlink("/initrd.image");
return false;
}