blob: 3e0878e8a80d65548ffac907a3285f9deea8d5a3 [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{
Lucas De Marchi907ed132013-04-30 15:28:07 -070053 struct subprocess_info *info;
Al Viroba4df282012-10-02 15:29:10 -040054 static char *argv[] = { "linuxrc", NULL, };
55 extern char *envp_init[];
Linus Torvalds1da177e2005-04-16 15:20:36 -070056 int error;
Linus Torvalds1da177e2005-04-16 15:20:36 -070057
58 real_root_dev = new_encode_dev(ROOT_DEV);
Greg Kroah-Hartmanbdaf8522005-06-20 21:15:16 -070059 create_dev("/dev/root.old", Root_RAM0);
Linus Torvalds1da177e2005-04-16 15:20:36 -070060 /* mount initrd on rootfs' /root */
61 mount_block_root("/dev/root.old", root_mountflags & ~MS_RDONLY);
62 sys_mkdir("/old", 0700);
Al Viroba4df282012-10-02 15:29:10 -040063 sys_chdir("/old");
Linus Torvalds1da177e2005-04-16 15:20:36 -070064
Tejun Heobb813f42013-01-18 14:05:56 -080065 /* try loading default modules from initrd */
66 load_default_modules();
67
Rafael J. Wysocki8baabde2007-11-21 02:50:17 +010068 /*
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
Lucas De Marchi907ed132013-04-30 15:28:07 -070074 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);
Rafael J. Wysocki8baabde2007-11-21 02:50:17 +010079
80 current->flags &= ~PF_FREEZER_SKIP;
Linus Torvalds1da177e2005-04-16 15:20:36 -070081
82 /* move initrd to rootfs' /old */
Al Viroba4df282012-10-02 15:29:10 -040083 sys_mount("..", ".", NULL, MS_MOVE, NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -070084 /* switch root and cwd back to / of rootfs */
Al Viroba4df282012-10-02 15:29:10 -040085 sys_chroot("..");
Linus Torvalds1da177e2005-04-16 15:20:36 -070086
87 if (new_decode_dev(real_root_dev) == Root_RAM0) {
88 sys_chdir("/old");
89 return;
90 }
91
Al Viroba4df282012-10-02 15:29:10 -040092 sys_chdir("/");
Linus Torvalds1da177e2005-04-16 15:20:36 -070093 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);
Jay Lanf220ab22005-06-30 02:59:03 -0700102 if (error == -ENOENT)
103 printk("/initrd does not exist. Ignored.\n");
104 else
105 printk("failed\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700106 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) {
Greg Kroah-Hartmanbdaf8522005-06-20 21:15:16 -0700122 create_dev("/dev/ram", Root_RAM0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700123 /*
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}