1#include <linux/unistd.h>
  2#include <linux/kernel.h>
  3#include <linux/fs.h>
  4#include <linux/minix_fs.h>
  5#include <linux/ext2_fs.h>
  6#include <linux/romfs_fs.h>
  7#include <linux/initrd.h>
  8#include <linux/sched.h>
  9#include <linux/freezer.h>
 
 
 10
 11#include "do_mounts.h"
 12
 13unsigned long initrd_start, initrd_end;
 14int initrd_below_start_ok;
 15unsigned int real_root_dev;	/* do_proc_dointvec cannot handle kdev_t */
 16static int __initdata old_fd, root_fd;
 17static int __initdata mount_initrd = 1;
 18
 
 
 
 19static int __init no_initrd(char *str)
 20{
 21	mount_initrd = 0;
 22	return 1;
 23}
 24
 25__setup("noinitrd", no_initrd);
 26
 27static int __init do_linuxrc(void *_shell)
 28{
 29	static const char *argv[] = { "linuxrc", NULL, };
 30	extern const char *envp_init[];
 31	const char *shell = _shell;
 32
 33	sys_close(old_fd);sys_close(root_fd);
 34	sys_setsid();
 35	return kernel_execve(shell, argv, envp_init);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 36}
 37
 38static void __init handle_initrd(void)
 39{
 
 
 
 40	int error;
 41	int pid;
 
 42
 43	real_root_dev = new_encode_dev(ROOT_DEV);
 44	create_dev("/dev/root.old", Root_RAM0);
 45	/* mount initrd on rootfs' /root */
 46	mount_block_root("/dev/root.old", root_mountflags & ~MS_RDONLY);
 47	sys_mkdir("/old", 0700);
 48	root_fd = sys_open("/", 0, 0);
 49	old_fd = sys_open("/old", 0, 0);
 50	/* move initrd over / and chdir/chroot in initrd root */
 51	sys_chdir("/root");
 52	sys_mount(".", "/", NULL, MS_MOVE, NULL);
 53	sys_chroot(".");
 54
 55	/*
 56	 * In case that a resume from disk is carried out by linuxrc or one of
 57	 * its children, we need to tell the freezer not to wait for us.
 58	 */
 59	current->flags |= PF_FREEZER_SKIP;
 60
 61	pid = kernel_thread(do_linuxrc, "/linuxrc", SIGCHLD);
 62	if (pid > 0)
 63		while (pid != sys_wait4(-1, NULL, 0, NULL))
 64			yield();
 
 65
 66	current->flags &= ~PF_FREEZER_SKIP;
 67
 68	/* move initrd to rootfs' /old */
 69	sys_fchdir(old_fd);
 70	sys_mount("/", ".", NULL, MS_MOVE, NULL);
 71	/* switch root and cwd back to / of rootfs */
 72	sys_fchdir(root_fd);
 73	sys_chroot(".");
 74	sys_close(old_fd);
 75	sys_close(root_fd);
 76
 77	if (new_decode_dev(real_root_dev) == Root_RAM0) {
 78		sys_chdir("/old");
 79		return;
 80	}
 81
 
 82	ROOT_DEV = new_decode_dev(real_root_dev);
 83	mount_root();
 84
 85	printk(KERN_NOTICE "Trying to move old root to /initrd ... ");
 86	error = sys_mount("/old", "/root/initrd", NULL, MS_MOVE, NULL);
 87	if (!error)
 88		printk("okay\n");
 89	else {
 90		int fd = sys_open("/dev/root.old", O_RDWR, 0);
 91		if (error == -ENOENT)
 92			printk("/initrd does not exist. Ignored.\n");
 93		else
 94			printk("failed\n");
 95		printk(KERN_NOTICE "Unmounting old root\n");
 96		sys_umount("/old", MNT_DETACH);
 97		printk(KERN_NOTICE "Trying to free ramdisk memory ... ");
 98		if (fd < 0) {
 99			error = fd;
100		} else {
101			error = sys_ioctl(fd, BLKFLSBUF, 0);
102			sys_close(fd);
103		}
104		printk(!error ? "okay\n" : "failed\n");
105	}
106}
107
108int __init initrd_load(void)
109{
110	if (mount_initrd) {
111		create_dev("/dev/ram", Root_RAM0);
112		/*
113		 * Load the initrd data into /dev/ram0. Execute it as initrd
114		 * unless /dev/ram0 is supposed to be our actual root device,
115		 * in that case the ram disk is just set up here, and gets
116		 * mounted in the normal path.
117		 */
118		if (rd_load_image("/initrd.image") && ROOT_DEV != Root_RAM0) {
119			sys_unlink("/initrd.image");
120			handle_initrd();
121			return 1;
122		}
123	}
124	sys_unlink("/initrd.image");
125	return 0;
126}

  1// SPDX-License-Identifier: GPL-2.0
  2#include <linux/unistd.h>
  3#include <linux/kernel.h>
  4#include <linux/fs.h>
  5#include <linux/minix_fs.h>
 
  6#include <linux/romfs_fs.h>
  7#include <linux/initrd.h>
  8#include <linux/sched.h>
  9#include <linux/freezer.h>
 10#include <linux/kmod.h>
 11#include <uapi/linux/mount.h>
 12
 13#include "do_mounts.h"
 14
 15unsigned long initrd_start, initrd_end;
 16int initrd_below_start_ok;
 17unsigned int real_root_dev;	/* do_proc_dointvec cannot handle kdev_t */
 
 18static int __initdata mount_initrd = 1;
 19
 20phys_addr_t phys_initrd_start __initdata;
 21unsigned long phys_initrd_size __initdata;
 22
 23static int __init no_initrd(char *str)
 24{
 25	mount_initrd = 0;
 26	return 1;
 27}
 28
 29__setup("noinitrd", no_initrd);
 30
 31static int __init early_initrdmem(char *p)
 32{
 33	phys_addr_t start;
 34	unsigned long size;
 35	char *endp;
 36
 37	start = memparse(p, &endp);
 38	if (*endp == ',') {
 39		size = memparse(endp + 1, NULL);
 40
 41		phys_initrd_start = start;
 42		phys_initrd_size = size;
 43	}
 44	return 0;
 45}
 46early_param("initrdmem", early_initrdmem);
 47
 48static int __init early_initrd(char *p)
 49{
 50	return early_initrdmem(p);
 51}
 52early_param("initrd", early_initrd);
 53
 54static int __init init_linuxrc(struct subprocess_info *info, struct cred *new)
 55{
 56	ksys_unshare(CLONE_FS | CLONE_FILES);
 57	console_on_rootfs();
 58	/* move initrd over / and chdir/chroot in initrd root */
 59	init_chdir("/root");
 60	init_mount(".", "/", NULL, MS_MOVE, NULL);
 61	init_chroot(".");
 62	ksys_setsid();
 63	return 0;
 64}
 65
 66static void __init handle_initrd(void)
 67{
 68	struct subprocess_info *info;
 69	static char *argv[] = { "linuxrc", NULL, };
 70	extern char *envp_init[];
 71	int error;
 72
 73	pr_warn("using deprecated initrd support, will be removed in 2021.\n");
 74
 75	real_root_dev = new_encode_dev(ROOT_DEV);
 76	create_dev("/dev/root.old", Root_RAM0);
 77	/* mount initrd on rootfs' /root */
 78	mount_block_root("/dev/root.old", root_mountflags & ~MS_RDONLY);
 79	init_mkdir("/old", 0700);
 80	init_chdir("/old");
 
 
 
 
 
 81
 82	/*
 83	 * In case that a resume from disk is carried out by linuxrc or one of
 84	 * its children, we need to tell the freezer not to wait for us.
 85	 */
 86	current->flags |= PF_FREEZER_SKIP;
 87
 88	info = call_usermodehelper_setup("/linuxrc", argv, envp_init,
 89					 GFP_KERNEL, init_linuxrc, NULL, NULL);
 90	if (!info)
 91		return;
 92	call_usermodehelper_exec(info, UMH_WAIT_PROC);
 93
 94	current->flags &= ~PF_FREEZER_SKIP;
 95
 96	/* move initrd to rootfs' /old */
 97	init_mount("..", ".", NULL, MS_MOVE, NULL);
 
 98	/* switch root and cwd back to / of rootfs */
 99	init_chroot("..");
 
 
 
100
101	if (new_decode_dev(real_root_dev) == Root_RAM0) {
102		init_chdir("/old");
103		return;
104	}
105
106	init_chdir("/");
107	ROOT_DEV = new_decode_dev(real_root_dev);
108	mount_root();
109
110	printk(KERN_NOTICE "Trying to move old root to /initrd ... ");
111	error = init_mount("/old", "/root/initrd", NULL, MS_MOVE, NULL);
112	if (!error)
113		printk("okay\n");
114	else {
 
115		if (error == -ENOENT)
116			printk("/initrd does not exist. Ignored.\n");
117		else
118			printk("failed\n");
119		printk(KERN_NOTICE "Unmounting old root\n");
120		init_umount("/old", MNT_DETACH);
 
 
 
 
 
 
 
 
121	}
122}
123
124bool __init initrd_load(void)
125{
126	if (mount_initrd) {
127		create_dev("/dev/ram", Root_RAM0);
128		/*
129		 * Load the initrd data into /dev/ram0. Execute it as initrd
130		 * unless /dev/ram0 is supposed to be our actual root device,
131		 * in that case the ram disk is just set up here, and gets
132		 * mounted in the normal path.
133		 */
134		if (rd_load_image("/initrd.image") && ROOT_DEV != Root_RAM0) {
135			init_unlink("/initrd.image");
136			handle_initrd();
137			return true;
138		}
139	}
140	init_unlink("/initrd.image");
141	return false;
142}