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v4.6
 
  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#include <linux/kmod.h>
 20
 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 */
 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_linuxrc(struct subprocess_info *info, struct cred *new)
 37{
 38	sys_unshare(CLONE_FS | CLONE_FILES);
 39	/* stdin/stdout/stderr for /linuxrc */
 40	sys_open("/dev/console", O_RDWR, 0);
 41	sys_dup(0);
 42	sys_dup(0);
 43	/* move initrd over / and chdir/chroot in initrd root */
 44	sys_chdir("/root");
 45	sys_mount(".", "/", NULL, MS_MOVE, NULL);
 46	sys_chroot(".");
 47	sys_setsid();
 48	return 0;
 49}
 50
 51static void __init handle_initrd(void)
 52{
 53	struct subprocess_info *info;
 54	static char *argv[] = { "linuxrc", NULL, };
 55	extern char *envp_init[];
 56	int error;
 57
 58	real_root_dev = new_encode_dev(ROOT_DEV);
 59	create_dev("/dev/root.old", Root_RAM0);
 60	/* mount initrd on rootfs' /root */
 61	mount_block_root("/dev/root.old", root_mountflags & ~MS_RDONLY);
 62	sys_mkdir("/old", 0700);
 63	sys_chdir("/old");
 64
 65	/* try loading default modules from initrd */
 66	load_default_modules();
 67
 68	/*
 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
 74	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);
 79
 80	current->flags &= ~PF_FREEZER_SKIP;
 81
 82	/* move initrd to rootfs' /old */
 83	sys_mount("..", ".", NULL, MS_MOVE, NULL);
 84	/* switch root and cwd back to / of rootfs */
 85	sys_chroot("..");
 86
 87	if (new_decode_dev(real_root_dev) == Root_RAM0) {
 88		sys_chdir("/old");
 89		return;
 90	}
 91
 92	sys_chdir("/");
 93	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);
102		if (error == -ENOENT)
103			printk("/initrd does not exist. Ignored.\n");
104		else
105			printk("failed\n");
106		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
119bool __init initrd_load(void)
120{
121	if (mount_initrd) {
122		create_dev("/dev/ram", Root_RAM0);
123		/*
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 true;
133		}
134	}
135	sys_unlink("/initrd.image");
136	return false;
137}
v4.17
  1// SPDX-License-Identifier: GPL-2.0
  2/*
  3 * Many of the syscalls used in this file expect some of the arguments
  4 * to be __user pointers not __kernel pointers.  To limit the sparse
  5 * noise, turn off sparse checking for this file.
  6 */
  7#ifdef __CHECKER__
  8#undef __CHECKER__
  9#warning "Sparse checking disabled for this file"
 10#endif
 11
 12#include <linux/unistd.h>
 13#include <linux/kernel.h>
 14#include <linux/fs.h>
 15#include <linux/minix_fs.h>
 16#include <linux/romfs_fs.h>
 17#include <linux/initrd.h>
 18#include <linux/sched.h>
 19#include <linux/freezer.h>
 20#include <linux/kmod.h>
 21
 22#include "do_mounts.h"
 23
 24unsigned long initrd_start, initrd_end;
 25int initrd_below_start_ok;
 26unsigned int real_root_dev;	/* do_proc_dointvec cannot handle kdev_t */
 27static int __initdata mount_initrd = 1;
 28
 29static int __init no_initrd(char *str)
 30{
 31	mount_initrd = 0;
 32	return 1;
 33}
 34
 35__setup("noinitrd", no_initrd);
 36
 37static int init_linuxrc(struct subprocess_info *info, struct cred *new)
 38{
 39	ksys_unshare(CLONE_FS | CLONE_FILES);
 40	/* stdin/stdout/stderr for /linuxrc */
 41	ksys_open("/dev/console", O_RDWR, 0);
 42	ksys_dup(0);
 43	ksys_dup(0);
 44	/* move initrd over / and chdir/chroot in initrd root */
 45	ksys_chdir("/root");
 46	ksys_mount(".", "/", NULL, MS_MOVE, NULL);
 47	ksys_chroot(".");
 48	ksys_setsid();
 49	return 0;
 50}
 51
 52static void __init handle_initrd(void)
 53{
 54	struct subprocess_info *info;
 55	static char *argv[] = { "linuxrc", NULL, };
 56	extern char *envp_init[];
 57	int error;
 58
 59	real_root_dev = new_encode_dev(ROOT_DEV);
 60	create_dev("/dev/root.old", Root_RAM0);
 61	/* mount initrd on rootfs' /root */
 62	mount_block_root("/dev/root.old", root_mountflags & ~MS_RDONLY);
 63	ksys_mkdir("/old", 0700);
 64	ksys_chdir("/old");
 65
 66	/* try loading default modules from initrd */
 67	load_default_modules();
 68
 69	/*
 70	 * In case that a resume from disk is carried out by linuxrc or one of
 71	 * its children, we need to tell the freezer not to wait for us.
 72	 */
 73	current->flags |= PF_FREEZER_SKIP;
 74
 75	info = call_usermodehelper_setup("/linuxrc", argv, envp_init,
 76					 GFP_KERNEL, init_linuxrc, NULL, NULL);
 77	if (!info)
 78		return;
 79	call_usermodehelper_exec(info, UMH_WAIT_PROC);
 80
 81	current->flags &= ~PF_FREEZER_SKIP;
 82
 83	/* move initrd to rootfs' /old */
 84	ksys_mount("..", ".", NULL, MS_MOVE, NULL);
 85	/* switch root and cwd back to / of rootfs */
 86	ksys_chroot("..");
 87
 88	if (new_decode_dev(real_root_dev) == Root_RAM0) {
 89		ksys_chdir("/old");
 90		return;
 91	}
 92
 93	ksys_chdir("/");
 94	ROOT_DEV = new_decode_dev(real_root_dev);
 95	mount_root();
 96
 97	printk(KERN_NOTICE "Trying to move old root to /initrd ... ");
 98	error = ksys_mount("/old", "/root/initrd", NULL, MS_MOVE, NULL);
 99	if (!error)
100		printk("okay\n");
101	else {
102		int fd = ksys_open("/dev/root.old", O_RDWR, 0);
103		if (error == -ENOENT)
104			printk("/initrd does not exist. Ignored.\n");
105		else
106			printk("failed\n");
107		printk(KERN_NOTICE "Unmounting old root\n");
108		ksys_umount("/old", MNT_DETACH);
109		printk(KERN_NOTICE "Trying to free ramdisk memory ... ");
110		if (fd < 0) {
111			error = fd;
112		} else {
113			error = ksys_ioctl(fd, BLKFLSBUF, 0);
114			ksys_close(fd);
115		}
116		printk(!error ? "okay\n" : "failed\n");
117	}
118}
119
120bool __init initrd_load(void)
121{
122	if (mount_initrd) {
123		create_dev("/dev/ram", Root_RAM0);
124		/*
125		 * Load the initrd data into /dev/ram0. Execute it as initrd
126		 * unless /dev/ram0 is supposed to be our actual root device,
127		 * in that case the ram disk is just set up here, and gets
128		 * mounted in the normal path.
129		 */
130		if (rd_load_image("/initrd.image") && ROOT_DEV != Root_RAM0) {
131			ksys_unlink("/initrd.image");
132			handle_initrd();
133			return true;
134		}
135	}
136	ksys_unlink("/initrd.image");
137	return false;
138}