130 lines
		
	
	
	
		
			3.3 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			130 lines
		
	
	
	
		
			3.3 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
| /*
 | |
|  * Many of the syscalls used in this file expect some of the arguments
 | |
|  * to be __user pointers not __kernel pointers.  To limit the sparse
 | |
|  * noise, turn off sparse checking for this file.
 | |
|  */
 | |
| #ifdef __CHECKER__
 | |
| #undef __CHECKER__
 | |
| #warning "Sparse checking disabled for this file"
 | |
| #endif
 | |
| 
 | |
| #include <linux/unistd.h>
 | |
| #include <linux/kernel.h>
 | |
| #include <linux/fs.h>
 | |
| #include <linux/minix_fs.h>
 | |
| #include <linux/romfs_fs.h>
 | |
| #include <linux/initrd.h>
 | |
| #include <linux/sched.h>
 | |
| #include <linux/freezer.h>
 | |
| #include <linux/kmod.h>
 | |
| 
 | |
| #include "do_mounts.h"
 | |
| 
 | |
| unsigned long initrd_start, initrd_end;
 | |
| int initrd_below_start_ok;
 | |
| unsigned int real_root_dev;	/* do_proc_dointvec cannot handle kdev_t */
 | |
| static int __initdata mount_initrd = 1;
 | |
| 
 | |
| static int __init no_initrd(char *str)
 | |
| {
 | |
| 	mount_initrd = 0;
 | |
| 	return 1;
 | |
| }
 | |
| 
 | |
| __setup("noinitrd", no_initrd);
 | |
| 
 | |
| static int init_linuxrc(struct subprocess_info *info, struct cred *new)
 | |
| {
 | |
| 	sys_unshare(CLONE_FS | CLONE_FILES);
 | |
| 	/* stdin/stdout/stderr for /linuxrc */
 | |
| 	sys_open("/dev/console", O_RDWR, 0);
 | |
| 	sys_dup(0);
 | |
| 	sys_dup(0);
 | |
| 	/* move initrd over / and chdir/chroot in initrd root */
 | |
| 	sys_chdir("/root");
 | |
| 	sys_mount(".", "/", NULL, MS_MOVE, NULL);
 | |
| 	sys_chroot(".");
 | |
| 	sys_setsid();
 | |
| 	return 0;
 | |
| }
 | |
| 
 | |
| static void __init handle_initrd(void)
 | |
| {
 | |
| 	static char *argv[] = { "linuxrc", NULL, };
 | |
| 	extern char *envp_init[];
 | |
| 	int error;
 | |
| 
 | |
| 	real_root_dev = new_encode_dev(ROOT_DEV);
 | |
| 	create_dev("/dev/root.old", Root_RAM0);
 | |
| 	/* mount initrd on rootfs' /root */
 | |
| 	mount_block_root("/dev/root.old", root_mountflags & ~MS_RDONLY);
 | |
| 	sys_mkdir("/old", 0700);
 | |
| 	sys_chdir("/old");
 | |
| 
 | |
| 	/*
 | |
| 	 * In case that a resume from disk is carried out by linuxrc or one of
 | |
| 	 * its children, we need to tell the freezer not to wait for us.
 | |
| 	 */
 | |
| 	current->flags |= PF_FREEZER_SKIP;
 | |
| 
 | |
| 	call_usermodehelper_fns("/linuxrc", argv, envp_init, UMH_WAIT_PROC,
 | |
| 			init_linuxrc, NULL, NULL);
 | |
| 
 | |
| 	current->flags &= ~PF_FREEZER_SKIP;
 | |
| 
 | |
| 	/* move initrd to rootfs' /old */
 | |
| 	sys_mount("..", ".", NULL, MS_MOVE, NULL);
 | |
| 	/* switch root and cwd back to / of rootfs */
 | |
| 	sys_chroot("..");
 | |
| 
 | |
| 	if (new_decode_dev(real_root_dev) == Root_RAM0) {
 | |
| 		sys_chdir("/old");
 | |
| 		return;
 | |
| 	}
 | |
| 
 | |
| 	sys_chdir("/");
 | |
| 	ROOT_DEV = new_decode_dev(real_root_dev);
 | |
| 	mount_root();
 | |
| 
 | |
| 	printk(KERN_NOTICE "Trying to move old root to /initrd ... ");
 | |
| 	error = sys_mount("/old", "/root/initrd", NULL, MS_MOVE, NULL);
 | |
| 	if (!error)
 | |
| 		printk("okay\n");
 | |
| 	else {
 | |
| 		int fd = sys_open("/dev/root.old", O_RDWR, 0);
 | |
| 		if (error == -ENOENT)
 | |
| 			printk("/initrd does not exist. Ignored.\n");
 | |
| 		else
 | |
| 			printk("failed\n");
 | |
| 		printk(KERN_NOTICE "Unmounting old root\n");
 | |
| 		sys_umount("/old", MNT_DETACH);
 | |
| 		printk(KERN_NOTICE "Trying to free ramdisk memory ... ");
 | |
| 		if (fd < 0) {
 | |
| 			error = fd;
 | |
| 		} else {
 | |
| 			error = sys_ioctl(fd, BLKFLSBUF, 0);
 | |
| 			sys_close(fd);
 | |
| 		}
 | |
| 		printk(!error ? "okay\n" : "failed\n");
 | |
| 	}
 | |
| }
 | |
| 
 | |
| int __init initrd_load(void)
 | |
| {
 | |
| 	if (mount_initrd) {
 | |
| 		create_dev("/dev/ram", Root_RAM0);
 | |
| 		/*
 | |
| 		 * Load the initrd data into /dev/ram0. Execute it as initrd
 | |
| 		 * unless /dev/ram0 is supposed to be our actual root device,
 | |
| 		 * in that case the ram disk is just set up here, and gets
 | |
| 		 * mounted in the normal path.
 | |
| 		 */
 | |
| 		if (rd_load_image("/initrd.image") && ROOT_DEV != Root_RAM0) {
 | |
| 			sys_unlink("/initrd.image");
 | |
| 			handle_initrd();
 | |
| 			return 1;
 | |
| 		}
 | |
| 	}
 | |
| 	sys_unlink("/initrd.image");
 | |
| 	return 0;
 | |
| }
 | 
