// SPDX-License-Identifier: GPL-2.0-only/* *  linux/fs/compat.c * *  Kernel compatibililty routines for e.g. 32 bit syscall support *  on 64 bit kernels. * *  Copyright (C) 2002       Stephen Rothwell, IBM Corporation *  Copyright (C) 1997-2000  Jakub Jelinek  (jakub@redhat.com) *  Copyright (C) 1998       Eddie C. Dost  (ecd@skynet.be) *  Copyright (C) 2001,2002  Andi Kleen, SuSE Labs  *  Copyright (C) 2003       Pavel Machek (pavel@ucw.cz) */ #include <linux/compat.h>#include <linux/nfs4_mount.h>#include <linux/syscalls.h>#include <linux/slab.h>#include <linux/uaccess.h>#include "internal.h" struct compat_nfs_string {	compat_uint_t len;	compat_uptr_t data;}; static inline void compat_nfs_string(struct nfs_string *dst,				     struct compat_nfs_string *src){	dst->data = compat_ptr(src->data);	dst->len = src->len;} struct compat_nfs4_mount_data_v1 {	compat_int_t version;	compat_int_t flags;	compat_int_t rsize;	compat_int_t wsize;	compat_int_t timeo;	compat_int_t retrans;	compat_int_t acregmin;	compat_int_t acregmax;	compat_int_t acdirmin;	compat_int_t acdirmax;	struct compat_nfs_string client_addr;	struct compat_nfs_string mnt_path;	struct compat_nfs_string hostname;	compat_uint_t host_addrlen;	compat_uptr_t host_addr;	compat_int_t proto;	compat_int_t auth_flavourlen;	compat_uptr_t auth_flavours;}; static int do_nfs4_super_data_conv(void *raw_data){	int version = *(compat_uint_t *) raw_data; 	if (version == 1) {		struct compat_nfs4_mount_data_v1 *raw = raw_data;		struct nfs4_mount_data *real = raw_data; 		/* copy the fields backwards */		real->auth_flavours = compat_ptr(raw->auth_flavours);		real->auth_flavourlen = raw->auth_flavourlen;		real->proto = raw->proto;		real->host_addr = compat_ptr(raw->host_addr);		real->host_addrlen = raw->host_addrlen;		compat_nfs_string(&real->hostname, &raw->hostname);		compat_nfs_string(&real->mnt_path, &raw->mnt_path);		compat_nfs_string(&real->client_addr, &raw->client_addr);		real->acdirmax = raw->acdirmax;		real->acdirmin = raw->acdirmin;		real->acregmax = raw->acregmax;		real->acregmin = raw->acregmin;		real->retrans = raw->retrans;		real->timeo = raw->timeo;		real->wsize = raw->wsize;		real->rsize = raw->rsize;		real->flags = raw->flags;		real->version = raw->version;	} 	return 0;} #define NFS4_NAME	"nfs4" COMPAT_SYSCALL_DEFINE5(mount, const char __user *, dev_name,		       const char __user *, dir_name,		       const char __user *, type, compat_ulong_t, flags,		       const void __user *, data){	char *kernel_type;	void *options;	char *kernel_dev;	int retval; 	kernel_type = copy_mount_string(type);	retval = PTR_ERR(kernel_type);	if (IS_ERR(kernel_type))		goto out; 	kernel_dev = copy_mount_string(dev_name);	retval = PTR_ERR(kernel_dev);	if (IS_ERR(kernel_dev))		goto out1; 	options = copy_mount_options(data);	retval = PTR_ERR(options);	if (IS_ERR(options))		goto out2; 	if (kernel_type && options) {		if (!strcmp(kernel_type, NFS4_NAME)) {			retval = -EINVAL;			if (do_nfs4_super_data_conv(options))				goto out3;		}	} 	retval = do_mount(kernel_dev, dir_name, kernel_type, flags, options);  out3:	kfree(options); out2:	kfree(kernel_dev); out1:	kfree(kernel_type); out:	return retval;}