155 lines
3.8 KiB
C
155 lines
3.8 KiB
C
// SPDX-License-Identifier: GPL-2.0
|
|
#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 <uapi/linux/mount.h>
|
|
|
|
#include "do_mounts.h"
|
|
|
|
unsigned long initrd_start, initrd_end;
|
|
int initrd_below_start_ok;
|
|
static unsigned int real_root_dev; /* do_proc_dointvec cannot handle kdev_t */
|
|
static int __initdata mount_initrd = 1;
|
|
|
|
phys_addr_t phys_initrd_start __initdata;
|
|
unsigned long phys_initrd_size __initdata;
|
|
|
|
#ifdef CONFIG_SYSCTL
|
|
static struct ctl_table kern_do_mounts_initrd_table[] = {
|
|
{
|
|
.procname = "real-root-dev",
|
|
.data = &real_root_dev,
|
|
.maxlen = sizeof(int),
|
|
.mode = 0644,
|
|
.proc_handler = proc_dointvec,
|
|
},
|
|
};
|
|
|
|
static __init int kernel_do_mounts_initrd_sysctls_init(void)
|
|
{
|
|
register_sysctl_init("kernel", kern_do_mounts_initrd_table);
|
|
return 0;
|
|
}
|
|
late_initcall(kernel_do_mounts_initrd_sysctls_init);
|
|
#endif /* CONFIG_SYSCTL */
|
|
|
|
static int __init no_initrd(char *str)
|
|
{
|
|
mount_initrd = 0;
|
|
return 1;
|
|
}
|
|
|
|
__setup("noinitrd", no_initrd);
|
|
|
|
static int __init early_initrdmem(char *p)
|
|
{
|
|
phys_addr_t start;
|
|
unsigned long size;
|
|
char *endp;
|
|
|
|
start = memparse(p, &endp);
|
|
if (*endp == ',') {
|
|
size = memparse(endp + 1, NULL);
|
|
|
|
phys_initrd_start = start;
|
|
phys_initrd_size = size;
|
|
}
|
|
return 0;
|
|
}
|
|
early_param("initrdmem", early_initrdmem);
|
|
|
|
static int __init early_initrd(char *p)
|
|
{
|
|
return early_initrdmem(p);
|
|
}
|
|
early_param("initrd", early_initrd);
|
|
|
|
static int __init init_linuxrc(struct subprocess_info *info, struct cred *new)
|
|
{
|
|
ksys_unshare(CLONE_FS | CLONE_FILES);
|
|
console_on_rootfs();
|
|
/* move initrd over / and chdir/chroot in initrd root */
|
|
init_chdir("/root");
|
|
init_mount(".", "/", NULL, MS_MOVE, NULL);
|
|
init_chroot(".");
|
|
ksys_setsid();
|
|
return 0;
|
|
}
|
|
|
|
static void __init handle_initrd(char *root_device_name)
|
|
{
|
|
struct subprocess_info *info;
|
|
static char *argv[] = { "linuxrc", NULL, };
|
|
extern char *envp_init[];
|
|
int error;
|
|
|
|
pr_warn("using deprecated initrd support, will be removed in 2021.\n");
|
|
|
|
real_root_dev = new_encode_dev(ROOT_DEV);
|
|
create_dev("/dev/root.old", Root_RAM0);
|
|
/* mount initrd on rootfs' /root */
|
|
mount_root_generic("/dev/root.old", root_device_name,
|
|
root_mountflags & ~MS_RDONLY);
|
|
init_mkdir("/old", 0700);
|
|
init_chdir("/old");
|
|
|
|
info = call_usermodehelper_setup("/linuxrc", argv, envp_init,
|
|
GFP_KERNEL, init_linuxrc, NULL, NULL);
|
|
if (!info)
|
|
return;
|
|
call_usermodehelper_exec(info, UMH_WAIT_PROC|UMH_FREEZABLE);
|
|
|
|
/* move initrd to rootfs' /old */
|
|
init_mount("..", ".", NULL, MS_MOVE, NULL);
|
|
/* switch root and cwd back to / of rootfs */
|
|
init_chroot("..");
|
|
|
|
if (new_decode_dev(real_root_dev) == Root_RAM0) {
|
|
init_chdir("/old");
|
|
return;
|
|
}
|
|
|
|
init_chdir("/");
|
|
ROOT_DEV = new_decode_dev(real_root_dev);
|
|
mount_root(root_device_name);
|
|
|
|
printk(KERN_NOTICE "Trying to move old root to /initrd ... ");
|
|
error = init_mount("/old", "/root/initrd", NULL, MS_MOVE, NULL);
|
|
if (!error)
|
|
printk("okay\n");
|
|
else {
|
|
if (error == -ENOENT)
|
|
printk("/initrd does not exist. Ignored.\n");
|
|
else
|
|
printk("failed\n");
|
|
printk(KERN_NOTICE "Unmounting old root\n");
|
|
init_umount("/old", MNT_DETACH);
|
|
}
|
|
}
|
|
|
|
bool __init initrd_load(char *root_device_name)
|
|
{
|
|
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) {
|
|
init_unlink("/initrd.image");
|
|
handle_initrd(root_device_name);
|
|
return true;
|
|
}
|
|
}
|
|
init_unlink("/initrd.image");
|
|
return false;
|
|
}
|