blob: a32ec1ce882b22dc96ed714a3f68e5838ed98af3 [file] [log] [blame]
H Hartley Sweetenc67e5382012-05-31 16:26:10 -07001/*
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
Linus Torvalds1da177e2005-04-16 15:20:36 -070011#include <linux/unistd.h>
12#include <linux/kernel.h>
13#include <linux/fs.h>
14#include <linux/minix_fs.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070015#include <linux/romfs_fs.h>
16#include <linux/initrd.h>
17#include <linux/sched.h>
Nigel Cunningham7dfb7102006-12-06 20:34:23 -080018#include <linux/freezer.h>
Al Viroba4df282012-10-02 15:29:10 -040019#include <linux/kmod.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070020
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 */
Linus Torvalds1da177e2005-04-16 15:20:36 -070026static 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
Al Viroba4df282012-10-02 15:29:10 -040036static int init_linuxrc(struct subprocess_info *info, struct cred *new)
Linus Torvalds1da177e2005-04-16 15:20:36 -070037{
Al Viroba4df282012-10-02 15:29:10 -040038 sys_unshare(CLONE_FS | CLONE_FILES);
Al Viro43b16822013-01-19 13:29:54 -050039 /* stdin/stdout/stderr for /linuxrc */
40 sys_open("/dev/console", O_RDWR, 0);
41 sys_dup(0);
42 sys_dup(0);
Al Viroba4df282012-10-02 15:29:10 -040043 /* move initrd over / and chdir/chroot in initrd root */
44 sys_chdir("/root");
45 sys_mount(".", "/", NULL, MS_MOVE, NULL);
46 sys_chroot(".");
Linus Torvalds1da177e2005-04-16 15:20:36 -070047 sys_setsid();
Al Viroba4df282012-10-02 15:29:10 -040048 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -070049}
50
51static void __init handle_initrd(void)
52{
Al Viroba4df282012-10-02 15:29:10 -040053 static char *argv[] = { "linuxrc", NULL, };
54 extern char *envp_init[];
Linus Torvalds1da177e2005-04-16 15:20:36 -070055 int error;
Linus Torvalds1da177e2005-04-16 15:20:36 -070056
57 real_root_dev = new_encode_dev(ROOT_DEV);
Greg Kroah-Hartmanbdaf8522005-06-20 21:15:16 -070058 create_dev("/dev/root.old", Root_RAM0);
Linus Torvalds1da177e2005-04-16 15:20:36 -070059 /* mount initrd on rootfs' /root */
60 mount_block_root("/dev/root.old", root_mountflags & ~MS_RDONLY);
61 sys_mkdir("/old", 0700);
Al Viroba4df282012-10-02 15:29:10 -040062 sys_chdir("/old");
Linus Torvalds1da177e2005-04-16 15:20:36 -070063
Tejun Heobb813f42013-01-18 14:05:56 -080064 /* try loading default modules from initrd */
65 load_default_modules();
66
Rafael J. Wysocki8baabde2007-11-21 02:50:17 +010067 /*
68 * In case that a resume from disk is carried out by linuxrc or one of
69 * its children, we need to tell the freezer not to wait for us.
70 */
71 current->flags |= PF_FREEZER_SKIP;
72
Al Viroba4df282012-10-02 15:29:10 -040073 call_usermodehelper_fns("/linuxrc", argv, envp_init, UMH_WAIT_PROC,
74 init_linuxrc, NULL, NULL);
Rafael J. Wysocki8baabde2007-11-21 02:50:17 +010075
76 current->flags &= ~PF_FREEZER_SKIP;
Linus Torvalds1da177e2005-04-16 15:20:36 -070077
78 /* move initrd to rootfs' /old */
Al Viroba4df282012-10-02 15:29:10 -040079 sys_mount("..", ".", NULL, MS_MOVE, NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -070080 /* switch root and cwd back to / of rootfs */
Al Viroba4df282012-10-02 15:29:10 -040081 sys_chroot("..");
Linus Torvalds1da177e2005-04-16 15:20:36 -070082
83 if (new_decode_dev(real_root_dev) == Root_RAM0) {
84 sys_chdir("/old");
85 return;
86 }
87
Al Viroba4df282012-10-02 15:29:10 -040088 sys_chdir("/");
Linus Torvalds1da177e2005-04-16 15:20:36 -070089 ROOT_DEV = new_decode_dev(real_root_dev);
90 mount_root();
91
92 printk(KERN_NOTICE "Trying to move old root to /initrd ... ");
93 error = sys_mount("/old", "/root/initrd", NULL, MS_MOVE, NULL);
94 if (!error)
95 printk("okay\n");
96 else {
97 int fd = sys_open("/dev/root.old", O_RDWR, 0);
Jay Lanf220ab22005-06-30 02:59:03 -070098 if (error == -ENOENT)
99 printk("/initrd does not exist. Ignored.\n");
100 else
101 printk("failed\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700102 printk(KERN_NOTICE "Unmounting old root\n");
103 sys_umount("/old", MNT_DETACH);
104 printk(KERN_NOTICE "Trying to free ramdisk memory ... ");
105 if (fd < 0) {
106 error = fd;
107 } else {
108 error = sys_ioctl(fd, BLKFLSBUF, 0);
109 sys_close(fd);
110 }
111 printk(!error ? "okay\n" : "failed\n");
112 }
113}
114
115int __init initrd_load(void)
116{
117 if (mount_initrd) {
Greg Kroah-Hartmanbdaf8522005-06-20 21:15:16 -0700118 create_dev("/dev/ram", Root_RAM0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700119 /*
120 * Load the initrd data into /dev/ram0. Execute it as initrd
121 * unless /dev/ram0 is supposed to be our actual root device,
122 * in that case the ram disk is just set up here, and gets
123 * mounted in the normal path.
124 */
125 if (rd_load_image("/initrd.image") && ROOT_DEV != Root_RAM0) {
126 sys_unlink("/initrd.image");
127 handle_initrd();
128 return 1;
129 }
130 }
131 sys_unlink("/initrd.image");
132 return 0;
133}