linux/fs/compat.c
Al Viro 0460b2a28b readdir: move compat syscalls from compat.c
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-04-17 12:52:24 -04:00

580 lines
15 KiB
C

/*
* 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)
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/stddef.h>
#include <linux/kernel.h>
#include <linux/linkage.h>
#include <linux/compat.h>
#include <linux/errno.h>
#include <linux/time.h>
#include <linux/cred.h>
#include <linux/fs.h>
#include <linux/fcntl.h>
#include <linux/namei.h>
#include <linux/file.h>
#include <linux/fdtable.h>
#include <linux/vfs.h>
#include <linux/ioctl.h>
#include <linux/init.h>
#include <linux/ncp_mount.h>
#include <linux/nfs4_mount.h>
#include <linux/syscalls.h>
#include <linux/ctype.h>
#include <linux/dirent.h>
#include <linux/fsnotify.h>
#include <linux/highuid.h>
#include <linux/personality.h>
#include <linux/rwsem.h>
#include <linux/tsacct_kern.h>
#include <linux/security.h>
#include <linux/highmem.h>
#include <linux/signal.h>
#include <linux/mm.h>
#include <linux/fs_struct.h>
#include <linux/slab.h>
#include <linux/pagemap.h>
#include <linux/aio.h>
#include <linux/uaccess.h>
#include <asm/mmu_context.h>
#include <asm/ioctls.h>
#include "internal.h"
static int cp_compat_stat(struct kstat *stat, struct compat_stat __user *ubuf)
{
struct compat_stat tmp;
if (!old_valid_dev(stat->dev) || !old_valid_dev(stat->rdev))
return -EOVERFLOW;
memset(&tmp, 0, sizeof(tmp));
tmp.st_dev = old_encode_dev(stat->dev);
tmp.st_ino = stat->ino;
if (sizeof(tmp.st_ino) < sizeof(stat->ino) && tmp.st_ino != stat->ino)
return -EOVERFLOW;
tmp.st_mode = stat->mode;
tmp.st_nlink = stat->nlink;
if (tmp.st_nlink != stat->nlink)
return -EOVERFLOW;
SET_UID(tmp.st_uid, from_kuid_munged(current_user_ns(), stat->uid));
SET_GID(tmp.st_gid, from_kgid_munged(current_user_ns(), stat->gid));
tmp.st_rdev = old_encode_dev(stat->rdev);
if ((u64) stat->size > MAX_NON_LFS)
return -EOVERFLOW;
tmp.st_size = stat->size;
tmp.st_atime = stat->atime.tv_sec;
tmp.st_atime_nsec = stat->atime.tv_nsec;
tmp.st_mtime = stat->mtime.tv_sec;
tmp.st_mtime_nsec = stat->mtime.tv_nsec;
tmp.st_ctime = stat->ctime.tv_sec;
tmp.st_ctime_nsec = stat->ctime.tv_nsec;
tmp.st_blocks = stat->blocks;
tmp.st_blksize = stat->blksize;
return copy_to_user(ubuf, &tmp, sizeof(tmp)) ? -EFAULT : 0;
}
COMPAT_SYSCALL_DEFINE2(newstat, const char __user *, filename,
struct compat_stat __user *, statbuf)
{
struct kstat stat;
int error;
error = vfs_stat(filename, &stat);
if (error)
return error;
return cp_compat_stat(&stat, statbuf);
}
COMPAT_SYSCALL_DEFINE2(newlstat, const char __user *, filename,
struct compat_stat __user *, statbuf)
{
struct kstat stat;
int error;
error = vfs_lstat(filename, &stat);
if (error)
return error;
return cp_compat_stat(&stat, statbuf);
}
#ifndef __ARCH_WANT_STAT64
COMPAT_SYSCALL_DEFINE4(newfstatat, unsigned int, dfd,
const char __user *, filename,
struct compat_stat __user *, statbuf, int, flag)
{
struct kstat stat;
int error;
error = vfs_fstatat(dfd, filename, &stat, flag);
if (error)
return error;
return cp_compat_stat(&stat, statbuf);
}
#endif
COMPAT_SYSCALL_DEFINE2(newfstat, unsigned int, fd,
struct compat_stat __user *, statbuf)
{
struct kstat stat;
int error = vfs_fstat(fd, &stat);
if (!error)
error = cp_compat_stat(&stat, statbuf);
return error;
}
static int get_compat_flock(struct flock *kfl, struct compat_flock __user *ufl)
{
if (!access_ok(VERIFY_READ, ufl, sizeof(*ufl)) ||
__get_user(kfl->l_type, &ufl->l_type) ||
__get_user(kfl->l_whence, &ufl->l_whence) ||
__get_user(kfl->l_start, &ufl->l_start) ||
__get_user(kfl->l_len, &ufl->l_len) ||
__get_user(kfl->l_pid, &ufl->l_pid))
return -EFAULT;
return 0;
}
static int put_compat_flock(struct flock *kfl, struct compat_flock __user *ufl)
{
if (!access_ok(VERIFY_WRITE, ufl, sizeof(*ufl)) ||
__put_user(kfl->l_type, &ufl->l_type) ||
__put_user(kfl->l_whence, &ufl->l_whence) ||
__put_user(kfl->l_start, &ufl->l_start) ||
__put_user(kfl->l_len, &ufl->l_len) ||
__put_user(kfl->l_pid, &ufl->l_pid))
return -EFAULT;
return 0;
}
#ifndef HAVE_ARCH_GET_COMPAT_FLOCK64
static int get_compat_flock64(struct flock *kfl, struct compat_flock64 __user *ufl)
{
if (!access_ok(VERIFY_READ, ufl, sizeof(*ufl)) ||
__get_user(kfl->l_type, &ufl->l_type) ||
__get_user(kfl->l_whence, &ufl->l_whence) ||
__get_user(kfl->l_start, &ufl->l_start) ||
__get_user(kfl->l_len, &ufl->l_len) ||
__get_user(kfl->l_pid, &ufl->l_pid))
return -EFAULT;
return 0;
}
#endif
#ifndef HAVE_ARCH_PUT_COMPAT_FLOCK64
static int put_compat_flock64(struct flock *kfl, struct compat_flock64 __user *ufl)
{
if (!access_ok(VERIFY_WRITE, ufl, sizeof(*ufl)) ||
__put_user(kfl->l_type, &ufl->l_type) ||
__put_user(kfl->l_whence, &ufl->l_whence) ||
__put_user(kfl->l_start, &ufl->l_start) ||
__put_user(kfl->l_len, &ufl->l_len) ||
__put_user(kfl->l_pid, &ufl->l_pid))
return -EFAULT;
return 0;
}
#endif
static unsigned int
convert_fcntl_cmd(unsigned int cmd)
{
switch (cmd) {
case F_GETLK64:
return F_GETLK;
case F_SETLK64:
return F_SETLK;
case F_SETLKW64:
return F_SETLKW;
}
return cmd;
}
COMPAT_SYSCALL_DEFINE3(fcntl64, unsigned int, fd, unsigned int, cmd,
compat_ulong_t, arg)
{
mm_segment_t old_fs;
struct flock f;
long ret;
unsigned int conv_cmd;
switch (cmd) {
case F_GETLK:
case F_SETLK:
case F_SETLKW:
ret = get_compat_flock(&f, compat_ptr(arg));
if (ret != 0)
break;
old_fs = get_fs();
set_fs(KERNEL_DS);
ret = sys_fcntl(fd, cmd, (unsigned long)&f);
set_fs(old_fs);
if (cmd == F_GETLK && ret == 0) {
/* GETLK was successful and we need to return the data...
* but it needs to fit in the compat structure.
* l_start shouldn't be too big, unless the original
* start + end is greater than COMPAT_OFF_T_MAX, in which
* case the app was asking for trouble, so we return
* -EOVERFLOW in that case.
* l_len could be too big, in which case we just truncate it,
* and only allow the app to see that part of the conflicting
* lock that might make sense to it anyway
*/
if (f.l_start > COMPAT_OFF_T_MAX)
ret = -EOVERFLOW;
if (f.l_len > COMPAT_OFF_T_MAX)
f.l_len = COMPAT_OFF_T_MAX;
if (ret == 0)
ret = put_compat_flock(&f, compat_ptr(arg));
}
break;
case F_GETLK64:
case F_SETLK64:
case F_SETLKW64:
case F_OFD_GETLK:
case F_OFD_SETLK:
case F_OFD_SETLKW:
ret = get_compat_flock64(&f, compat_ptr(arg));
if (ret != 0)
break;
old_fs = get_fs();
set_fs(KERNEL_DS);
conv_cmd = convert_fcntl_cmd(cmd);
ret = sys_fcntl(fd, conv_cmd, (unsigned long)&f);
set_fs(old_fs);
if ((conv_cmd == F_GETLK || conv_cmd == F_OFD_GETLK) && ret == 0) {
/* need to return lock information - see above for commentary */
if (f.l_start > COMPAT_LOFF_T_MAX)
ret = -EOVERFLOW;
if (f.l_len > COMPAT_LOFF_T_MAX)
f.l_len = COMPAT_LOFF_T_MAX;
if (ret == 0)
ret = put_compat_flock64(&f, compat_ptr(arg));
}
break;
default:
ret = sys_fcntl(fd, cmd, arg);
break;
}
return ret;
}
COMPAT_SYSCALL_DEFINE3(fcntl, unsigned int, fd, unsigned int, cmd,
compat_ulong_t, arg)
{
switch (cmd) {
case F_GETLK64:
case F_SETLK64:
case F_SETLKW64:
case F_OFD_GETLK:
case F_OFD_SETLK:
case F_OFD_SETLKW:
return -EINVAL;
}
return compat_sys_fcntl64(fd, cmd, arg);
}
/* A write operation does a read from user space and vice versa */
#define vrfy_dir(type) ((type) == READ ? VERIFY_WRITE : VERIFY_READ)
ssize_t compat_rw_copy_check_uvector(int type,
const struct compat_iovec __user *uvector, unsigned long nr_segs,
unsigned long fast_segs, struct iovec *fast_pointer,
struct iovec **ret_pointer)
{
compat_ssize_t tot_len;
struct iovec *iov = *ret_pointer = fast_pointer;
ssize_t ret = 0;
int seg;
/*
* SuS says "The readv() function *may* fail if the iovcnt argument
* was less than or equal to 0, or greater than {IOV_MAX}. Linux has
* traditionally returned zero for zero segments, so...
*/
if (nr_segs == 0)
goto out;
ret = -EINVAL;
if (nr_segs > UIO_MAXIOV)
goto out;
if (nr_segs > fast_segs) {
ret = -ENOMEM;
iov = kmalloc(nr_segs*sizeof(struct iovec), GFP_KERNEL);
if (iov == NULL)
goto out;
}
*ret_pointer = iov;
ret = -EFAULT;
if (!access_ok(VERIFY_READ, uvector, nr_segs*sizeof(*uvector)))
goto out;
/*
* Single unix specification:
* We should -EINVAL if an element length is not >= 0 and fitting an
* ssize_t.
*
* In Linux, the total length is limited to MAX_RW_COUNT, there is
* no overflow possibility.
*/
tot_len = 0;
ret = -EINVAL;
for (seg = 0; seg < nr_segs; seg++) {
compat_uptr_t buf;
compat_ssize_t len;
if (__get_user(len, &uvector->iov_len) ||
__get_user(buf, &uvector->iov_base)) {
ret = -EFAULT;
goto out;
}
if (len < 0) /* size_t not fitting in compat_ssize_t .. */
goto out;
if (type >= 0 &&
!access_ok(vrfy_dir(type), compat_ptr(buf), len)) {
ret = -EFAULT;
goto out;
}
if (len > MAX_RW_COUNT - tot_len)
len = MAX_RW_COUNT - tot_len;
tot_len += len;
iov->iov_base = compat_ptr(buf);
iov->iov_len = (compat_size_t) len;
uvector++;
iov++;
}
ret = tot_len;
out:
return ret;
}
struct compat_ncp_mount_data {
compat_int_t version;
compat_uint_t ncp_fd;
__compat_uid_t mounted_uid;
compat_pid_t wdog_pid;
unsigned char mounted_vol[NCP_VOLNAME_LEN + 1];
compat_uint_t time_out;
compat_uint_t retry_count;
compat_uint_t flags;
__compat_uid_t uid;
__compat_gid_t gid;
compat_mode_t file_mode;
compat_mode_t dir_mode;
};
struct compat_ncp_mount_data_v4 {
compat_int_t version;
compat_ulong_t flags;
compat_ulong_t mounted_uid;
compat_long_t wdog_pid;
compat_uint_t ncp_fd;
compat_uint_t time_out;
compat_uint_t retry_count;
compat_ulong_t uid;
compat_ulong_t gid;
compat_ulong_t file_mode;
compat_ulong_t dir_mode;
};
static void *do_ncp_super_data_conv(void *raw_data)
{
int version = *(unsigned int *)raw_data;
if (version == 3) {
struct compat_ncp_mount_data *c_n = raw_data;
struct ncp_mount_data *n = raw_data;
n->dir_mode = c_n->dir_mode;
n->file_mode = c_n->file_mode;
n->gid = c_n->gid;
n->uid = c_n->uid;
memmove (n->mounted_vol, c_n->mounted_vol, (sizeof (c_n->mounted_vol) + 3 * sizeof (unsigned int)));
n->wdog_pid = c_n->wdog_pid;
n->mounted_uid = c_n->mounted_uid;
} else if (version == 4) {
struct compat_ncp_mount_data_v4 *c_n = raw_data;
struct ncp_mount_data_v4 *n = raw_data;
n->dir_mode = c_n->dir_mode;
n->file_mode = c_n->file_mode;
n->gid = c_n->gid;
n->uid = c_n->uid;
n->retry_count = c_n->retry_count;
n->time_out = c_n->time_out;
n->ncp_fd = c_n->ncp_fd;
n->wdog_pid = c_n->wdog_pid;
n->mounted_uid = c_n->mounted_uid;
n->flags = c_n->flags;
} else if (version != 5) {
return NULL;
}
return raw_data;
}
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 NCPFS_NAME "ncpfs"
#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, NCPFS_NAME)) {
do_ncp_super_data_conv(options);
} else 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;
}
/*
* Exactly like fs/open.c:sys_open(), except that it doesn't set the
* O_LARGEFILE flag.
*/
COMPAT_SYSCALL_DEFINE3(open, const char __user *, filename, int, flags, umode_t, mode)
{
return do_sys_open(AT_FDCWD, filename, flags, mode);
}
/*
* Exactly like fs/open.c:sys_openat(), except that it doesn't set the
* O_LARGEFILE flag.
*/
COMPAT_SYSCALL_DEFINE4(openat, int, dfd, const char __user *, filename, int, flags, umode_t, mode)
{
return do_sys_open(dfd, filename, flags, mode);
}
#ifdef CONFIG_FHANDLE
/*
* Exactly like fs/open.c:sys_open_by_handle_at(), except that it
* doesn't set the O_LARGEFILE flag.
*/
COMPAT_SYSCALL_DEFINE3(open_by_handle_at, int, mountdirfd,
struct file_handle __user *, handle, int, flags)
{
return do_handle_open(mountdirfd, handle, flags);
}
#endif