// 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/file.h>#include <linux/init_syscalls.h>#include <linux/security.h>#include "internal.h" int __init init_pivot_root(const char *new_root, const char *put_old){	struct path new_path __free(path_put) = {};	struct path old_path __free(path_put) = {};	int ret; 	ret = kern_path(new_root, LOOKUP_FOLLOW | LOOKUP_DIRECTORY, &new_path);	if (ret)		return ret; 	ret = kern_path(put_old, LOOKUP_FOLLOW | LOOKUP_DIRECTORY, &old_path);	if (ret)		return ret; 	return path_pivot_root(&new_path, &old_path);} 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 = path_permission(&path, 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 = path_permission(&path, 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_eaccess(const char *filename){	struct path path;	int error; 	error = kern_path(filename, LOOKUP_FOLLOW, &path);	if (error)		return error;	error = path_permission(&path, MAY_ACCESS);	path_put(&path);	return error;} int __init init_stat(const char *filename, struct kstat *stat, 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 = vfs_getattr(&path, stat, STATX_BASIC_STATS,			    flags | AT_NO_AUTOMOUNT);	path_put(&path);	return error;} int __init init_mknod(const char *filename, umode_t mode, unsigned int dev){	CLASS(filename_kernel, name)(filename);	return filename_mknodat(AT_FDCWD, name, mode, dev);} int __init init_link(const char *oldname, const char *newname){	CLASS(filename_kernel, old)(oldname);	CLASS(filename_kernel, new)(newname);	return filename_linkat(AT_FDCWD, old, AT_FDCWD, new, 0);} int __init init_symlink(const char *oldname, const char *newname){	CLASS(filename_kernel, old)(oldname);	CLASS(filename_kernel, new)(newname);	return filename_symlinkat(old, AT_FDCWD, new);} int __init init_unlink(const char *pathname){	CLASS(filename_kernel, name)(pathname);	return filename_unlinkat(AT_FDCWD, name);} int __init init_mkdir(const char *pathname, umode_t mode){	CLASS(filename_kernel, name)(pathname);	return filename_mkdirat(AT_FDCWD, name, mode);} int __init init_rmdir(const char *pathname){	CLASS(filename_kernel, name)(pathname);	return filename_rmdir(AT_FDCWD, name);} int __init init_utimes(char *filename, struct timespec64 *ts){	struct path path;	int error; 	error = kern_path(filename, 0, &path);	if (error)		return error;	error = vfs_utimes(&path, ts);	path_put(&path);	return error;} int __init init_dup(struct file *file){	int fd; 	fd = get_unused_fd_flags(0);	if (fd < 0)		return fd;	fd_install(fd, get_file(file));	return 0;}