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1/*
2 * Many of the syscalls used in this file expect some of the arguments
3 * to be __user pointers not __kernel pointers. To limit the sparse
4 * noise, turn off sparse checking for this file.
5 */
6#ifdef __CHECKER__
7#undef __CHECKER__
8#warning "Sparse checking disabled for this file"
9#endif
10
11#include <linux/unistd.h>
12#include <linux/kernel.h>
13#include <linux/fs.h>
14#include <linux/minix_fs.h>
15#include <linux/romfs_fs.h>
16#include <linux/initrd.h>
17#include <linux/sched.h>
18#include <linux/freezer.h>
19#include <linux/kmod.h>
20
21#include "do_mounts.h"
22
23unsigned long initrd_start, initrd_end;
24int initrd_below_start_ok;
25unsigned int real_root_dev; /* do_proc_dointvec cannot handle kdev_t */
26static int __initdata mount_initrd = 1;
27
28static int __init no_initrd(char *str)
29{
30 mount_initrd = 0;
31 return 1;
32}
33
34__setup("noinitrd", no_initrd);
35
36static int init_linuxrc(struct subprocess_info *info, struct cred *new)
37{
38 sys_unshare(CLONE_FS | CLONE_FILES);
39 /* stdin/stdout/stderr for /linuxrc */
40 sys_open("/dev/console", O_RDWR, 0);
41 sys_dup(0);
42 sys_dup(0);
43 /* move initrd over / and chdir/chroot in initrd root */
44 sys_chdir("/root");
45 sys_mount(".", "/", NULL, MS_MOVE, NULL);
46 sys_chroot(".");
47 sys_setsid();
48 return 0;
49}
50
51static void __init handle_initrd(void)
52{
53 struct subprocess_info *info;
54 static char *argv[] = { "linuxrc", NULL, };
55 extern char *envp_init[];
56 int error;
57
58 real_root_dev = new_encode_dev(ROOT_DEV);
59 create_dev("/dev/root.old", Root_RAM0);
60 /* mount initrd on rootfs' /root */
61 mount_block_root("/dev/root.old", root_mountflags & ~MS_RDONLY);
62 sys_mkdir("/old", 0700);
63 sys_chdir("/old");
64
65 /* try loading default modules from initrd */
66 load_default_modules();
67
68 /*
69 * In case that a resume from disk is carried out by linuxrc or one of
70 * its children, we need to tell the freezer not to wait for us.
71 */
72 current->flags |= PF_FREEZER_SKIP;
73
74 info = call_usermodehelper_setup("/linuxrc", argv, envp_init,
75 GFP_KERNEL, init_linuxrc, NULL, NULL);
76 if (!info)
77 return;
78 call_usermodehelper_exec(info, UMH_WAIT_PROC);
79
80 current->flags &= ~PF_FREEZER_SKIP;
81
82 /* move initrd to rootfs' /old */
83 sys_mount("..", ".", NULL, MS_MOVE, NULL);
84 /* switch root and cwd back to / of rootfs */
85 sys_chroot("..");
86
87 if (new_decode_dev(real_root_dev) == Root_RAM0) {
88 sys_chdir("/old");
89 return;
90 }
91
92 sys_chdir("/");
93 ROOT_DEV = new_decode_dev(real_root_dev);
94 mount_root();
95
96 printk(KERN_NOTICE "Trying to move old root to /initrd ... ");
97 error = sys_mount("/old", "/root/initrd", NULL, MS_MOVE, NULL);
98 if (!error)
99 printk("okay\n");
100 else {
101 int fd = sys_open("/dev/root.old", O_RDWR, 0);
102 if (error == -ENOENT)
103 printk("/initrd does not exist. Ignored.\n");
104 else
105 printk("failed\n");
106 printk(KERN_NOTICE "Unmounting old root\n");
107 sys_umount("/old", MNT_DETACH);
108 printk(KERN_NOTICE "Trying to free ramdisk memory ... ");
109 if (fd < 0) {
110 error = fd;
111 } else {
112 error = sys_ioctl(fd, BLKFLSBUF, 0);
113 sys_close(fd);
114 }
115 printk(!error ? "okay\n" : "failed\n");
116 }
117}
118
119bool __init initrd_load(void)
120{
121 if (mount_initrd) {
122 create_dev("/dev/ram", Root_RAM0);
123 /*
124 * Load the initrd data into /dev/ram0. Execute it as initrd
125 * unless /dev/ram0 is supposed to be our actual root device,
126 * in that case the ram disk is just set up here, and gets
127 * mounted in the normal path.
128 */
129 if (rd_load_image("/initrd.image") && ROOT_DEV != Root_RAM0) {
130 sys_unlink("/initrd.image");
131 handle_initrd();
132 return true;
133 }
134 }
135 sys_unlink("/initrd.image");
136 return false;
137}
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(void)
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_block_root("/dev/root.old", 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();
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
136bool __init initrd_load(void)
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();
149 return true;
150 }
151 }
152 init_unlink("/initrd.image");
153 return false;
154}