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
119int __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 1;
133		}
134	}
135	sys_unlink("/initrd.image");
136	return 0;
137}
138