https://github.com/torvalds/linux
Tip revision: a1b8638ba1320e6684aa98233c15255eb803fac7 authored by Linus Torvalds on 27 September 2020, 21:38:10 UTC
Linux 5.9-rc7
Linux 5.9-rc7
Tip revision: a1b8638
compat.c
// 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;
}