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
23 unsigned long initrd_start, initrd_end;
24 int initrd_below_start_ok;
25 unsigned int real_root_dev; /* do_proc_dointvec cannot handle kdev_t */
26 static int __initdata mount_initrd = 1;
27
no_initrd(char * str)28 static int __init no_initrd(char *str)
29 {
30 mount_initrd = 0;
31 return 1;
32 }
33
34 __setup("noinitrd", no_initrd);
35
init_linuxrc(struct subprocess_info * info,struct cred * new)36 static 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
handle_initrd(void)51 static 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
initrd_load(void)119 bool __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 }
138