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// SPDX-License-Identifier: GPL-2.0
/*
* Routines that mimic syscalls, but don't use the user address space or file
* descriptors. Only for init/ and related early init code.
*/
#include <linux/init.h>
#include <linux/mount.h>
#include <linux/namei.h>
#include <linux/fs.h>
#include <linux/fs_struct.h>
#include <linux/init_syscalls.h>
#include <linux/security.h>
#include "internal.h"
int __init init_mount(const char *dev_name, const char *dir_name,
const char *type_page, unsigned long flags, void *data_page)
{
struct path path;
int ret;
ret = kern_path(dir_name, LOOKUP_FOLLOW, &path);
if (ret)
return ret;
ret = path_mount(dev_name, &path, type_page, flags, data_page);
path_put(&path);
return ret;
}
int __init init_umount(const char *name, int flags)
{
int lookup_flags = LOOKUP_MOUNTPOINT;
struct path path;
int ret;
if (!(flags & UMOUNT_NOFOLLOW))
lookup_flags |= LOOKUP_FOLLOW;
ret = kern_path(name, lookup_flags, &path);
if (ret)
return ret;
return path_umount(&path, flags);
}
int __init init_chdir(const char *filename)
{
struct path path;
int error;
error = kern_path(filename, LOOKUP_FOLLOW | LOOKUP_DIRECTORY, &path);
if (error)
return error;
error = inode_permission(path.dentry->d_inode, MAY_EXEC | MAY_CHDIR);
if (!error)
set_fs_pwd(current->fs, &path);
path_put(&path);
return error;
}
int __init init_chroot(const char *filename)
{
struct path path;
int error;
error = kern_path(filename, LOOKUP_FOLLOW | LOOKUP_DIRECTORY, &path);
if (error)
return error;
error = inode_permission(path.dentry->d_inode, MAY_EXEC | MAY_CHDIR);
if (error)
goto dput_and_out;
error = -EPERM;
if (!ns_capable(current_user_ns(), CAP_SYS_CHROOT))
goto dput_and_out;
error = security_path_chroot(&path);
if (error)
goto dput_and_out;
set_fs_root(current->fs, &path);
dput_and_out:
path_put(&path);
return error;
}
int __init init_chown(const char *filename, uid_t user, gid_t group, int flags)
{
int lookup_flags = (flags & AT_SYMLINK_NOFOLLOW) ? 0 : LOOKUP_FOLLOW;
struct path path;
int error;
error = kern_path(filename, lookup_flags, &path);
if (error)
return error;
error = mnt_want_write(path.mnt);
if (!error) {
error = chown_common(&path, user, group);
mnt_drop_write(path.mnt);
}
path_put(&path);
return error;
}
int __init init_chmod(const char *filename, umode_t mode)
{
struct path path;
int error;
error = kern_path(filename, LOOKUP_FOLLOW, &path);
if (error)
return error;
error = chmod_common(&path, mode);
path_put(&path);
return error;
}
int __init init_unlink(const char *pathname)
{
return do_unlinkat(AT_FDCWD, getname_kernel(pathname));
}
int __init init_rmdir(const char *pathname)
{
return do_rmdir(AT_FDCWD, getname_kernel(pathname));
}
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