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}

  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
 20#include "do_mounts.h"
 21
 22unsigned long initrd_start, initrd_end;
 23int initrd_below_start_ok;
 24unsigned int real_root_dev;	/* do_proc_dointvec cannot handle kdev_t */
 25static int __initdata old_fd, root_fd;
 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 do_linuxrc(void *_shell)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 37{
 38	static const char *argv[] = { "linuxrc", NULL, };
 39	extern const char *envp_init[];
 40	const char *shell = _shell;
 41
 42	sys_close(old_fd);sys_close(root_fd);
 43	sys_setsid();
 44	return kernel_execve(shell, argv, envp_init);
 
 45}
 46
 47static void __init handle_initrd(void)
 48{
 
 
 
 49	int error;
 50	int pid;
 
 51
 52	real_root_dev = new_encode_dev(ROOT_DEV);
 53	create_dev("/dev/root.old", Root_RAM0);
 54	/* mount initrd on rootfs' /root */
 55	mount_block_root("/dev/root.old", root_mountflags & ~MS_RDONLY);
 56	sys_mkdir("/old", 0700);
 57	root_fd = sys_open("/", 0, 0);
 58	old_fd = sys_open("/old", 0, 0);
 59	/* move initrd over / and chdir/chroot in initrd root */
 60	sys_chdir("/root");
 61	sys_mount(".", "/", NULL, MS_MOVE, NULL);
 62	sys_chroot(".");
 63
 64	/*
 65	 * In case that a resume from disk is carried out by linuxrc or one of
 66	 * its children, we need to tell the freezer not to wait for us.
 67	 */
 68	current->flags |= PF_FREEZER_SKIP;
 69
 70	pid = kernel_thread(do_linuxrc, "/linuxrc", SIGCHLD);
 71	if (pid > 0)
 72		while (pid != sys_wait4(-1, NULL, 0, NULL))
 73			yield();
 
 74
 75	current->flags &= ~PF_FREEZER_SKIP;
 76
 77	/* move initrd to rootfs' /old */
 78	sys_fchdir(old_fd);
 79	sys_mount("/", ".", NULL, MS_MOVE, NULL);
 80	/* switch root and cwd back to / of rootfs */
 81	sys_fchdir(root_fd);
 82	sys_chroot(".");
 83	sys_close(old_fd);
 84	sys_close(root_fd);
 85
 86	if (new_decode_dev(real_root_dev) == Root_RAM0) {
 87		sys_chdir("/old");
 88		return;
 89	}
 90
 
 91	ROOT_DEV = new_decode_dev(real_root_dev);
 92	mount_root();
 93
 94	printk(KERN_NOTICE "Trying to move old root to /initrd ... ");
 95	error = sys_mount("/old", "/root/initrd", NULL, MS_MOVE, NULL);
 96	if (!error)
 97		printk("okay\n");
 98	else {
 99		int fd = sys_open("/dev/root.old", O_RDWR, 0);
100		if (error == -ENOENT)
101			printk("/initrd does not exist. Ignored.\n");
102		else
103			printk("failed\n");
104		printk(KERN_NOTICE "Unmounting old root\n");
105		sys_umount("/old", MNT_DETACH);
106		printk(KERN_NOTICE "Trying to free ramdisk memory ... ");
107		if (fd < 0) {
108			error = fd;
109		} else {
110			error = sys_ioctl(fd, BLKFLSBUF, 0);
111			sys_close(fd);
112		}
113		printk(!error ? "okay\n" : "failed\n");
114	}
115}
116
117int __init initrd_load(void)
118{
119	if (mount_initrd) {
120		create_dev("/dev/ram", Root_RAM0);
121		/*
122		 * Load the initrd data into /dev/ram0. Execute it as initrd
123		 * unless /dev/ram0 is supposed to be our actual root device,
124		 * in that case the ram disk is just set up here, and gets
125		 * mounted in the normal path.
126		 */
127		if (rd_load_image("/initrd.image") && ROOT_DEV != Root_RAM0) {
128			sys_unlink("/initrd.image");
129			handle_initrd();
130			return 1;
131		}
132	}
133	sys_unlink("/initrd.image");
134	return 0;
135}