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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/*
3 * Many of the syscalls used in this file expect some of the arguments
4 * to be __user pointers not __kernel pointers. To limit the sparse
5 * noise, turn off sparse checking for this file.
6 */
7#ifdef __CHECKER__
8#undef __CHECKER__
9#warning "Sparse checking disabled for this file"
10#endif
11
12#include <linux/unistd.h>
13#include <linux/kernel.h>
14#include <linux/fs.h>
15#include <linux/minix_fs.h>
16#include <linux/romfs_fs.h>
17#include <linux/initrd.h>
18#include <linux/sched.h>
19#include <linux/freezer.h>
20#include <linux/kmod.h>
21
22#include "do_mounts.h"
23
24unsigned long initrd_start, initrd_end;
25int initrd_below_start_ok;
26unsigned int real_root_dev; /* do_proc_dointvec cannot handle kdev_t */
27static int __initdata mount_initrd = 1;
28
29static int __init no_initrd(char *str)
30{
31 mount_initrd = 0;
32 return 1;
33}
34
35__setup("noinitrd", no_initrd);
36
37static int init_linuxrc(struct subprocess_info *info, struct cred *new)
38{
39 ksys_unshare(CLONE_FS | CLONE_FILES);
40 /* stdin/stdout/stderr for /linuxrc */
41 ksys_open("/dev/console", O_RDWR, 0);
42 ksys_dup(0);
43 ksys_dup(0);
44 /* move initrd over / and chdir/chroot in initrd root */
45 ksys_chdir("/root");
46 ksys_mount(".", "/", NULL, MS_MOVE, NULL);
47 ksys_chroot(".");
48 ksys_setsid();
49 return 0;
50}
51
52static void __init handle_initrd(void)
53{
54 struct subprocess_info *info;
55 static char *argv[] = { "linuxrc", NULL, };
56 extern char *envp_init[];
57 int error;
58
59 real_root_dev = new_encode_dev(ROOT_DEV);
60 create_dev("/dev/root.old", Root_RAM0);
61 /* mount initrd on rootfs' /root */
62 mount_block_root("/dev/root.old", root_mountflags & ~MS_RDONLY);
63 ksys_mkdir("/old", 0700);
64 ksys_chdir("/old");
65
66 /* try loading default modules from initrd */
67 load_default_modules();
68
69 /*
70 * In case that a resume from disk is carried out by linuxrc or one of
71 * its children, we need to tell the freezer not to wait for us.
72 */
73 current->flags |= PF_FREEZER_SKIP;
74
75 info = call_usermodehelper_setup("/linuxrc", argv, envp_init,
76 GFP_KERNEL, init_linuxrc, NULL, NULL);
77 if (!info)
78 return;
79 call_usermodehelper_exec(info, UMH_WAIT_PROC);
80
81 current->flags &= ~PF_FREEZER_SKIP;
82
83 /* move initrd to rootfs' /old */
84 ksys_mount("..", ".", NULL, MS_MOVE, NULL);
85 /* switch root and cwd back to / of rootfs */
86 ksys_chroot("..");
87
88 if (new_decode_dev(real_root_dev) == Root_RAM0) {
89 ksys_chdir("/old");
90 return;
91 }
92
93 ksys_chdir("/");
94 ROOT_DEV = new_decode_dev(real_root_dev);
95 mount_root();
96
97 printk(KERN_NOTICE "Trying to move old root to /initrd ... ");
98 error = ksys_mount("/old", "/root/initrd", NULL, MS_MOVE, NULL);
99 if (!error)
100 printk("okay\n");
101 else {
102 int fd = ksys_open("/dev/root.old", O_RDWR, 0);
103 if (error == -ENOENT)
104 printk("/initrd does not exist. Ignored.\n");
105 else
106 printk("failed\n");
107 printk(KERN_NOTICE "Unmounting old root\n");
108 ksys_umount("/old", MNT_DETACH);
109 printk(KERN_NOTICE "Trying to free ramdisk memory ... ");
110 if (fd < 0) {
111 error = fd;
112 } else {
113 error = ksys_ioctl(fd, BLKFLSBUF, 0);
114 ksys_close(fd);
115 }
116 printk(!error ? "okay\n" : "failed\n");
117 }
118}
119
120bool __init initrd_load(void)
121{
122 if (mount_initrd) {
123 create_dev("/dev/ram", Root_RAM0);
124 /*
125 * Load the initrd data into /dev/ram0. Execute it as initrd
126 * unless /dev/ram0 is supposed to be our actual root device,
127 * in that case the ram disk is just set up here, and gets
128 * mounted in the normal path.
129 */
130 if (rd_load_image("/initrd.image") && ROOT_DEV != Root_RAM0) {
131 ksys_unlink("/initrd.image");
132 handle_initrd();
133 return true;
134 }
135 }
136 ksys_unlink("/initrd.image");
137 return false;
138}