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/*
*
* Copyright (C) 2011 Google, Inc.
*
* This software is licensed under the terms of the GNU General Public
* License version 2, as published by the Free Software Foundation, and
* may be copied, distributed, and modified under those terms.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
*/
#include <linux/kernel.h>
#include <linux/file.h>
#include <linux/fs.h>
#include <linux/uaccess.h>
#include "ion.h"
#include "ion_priv.h"
#include "compat_ion.h"
union ion_ioctl_arg {
struct ion_fd_data fd;
struct ion_allocation_data allocation;
struct ion_handle_data handle;
struct ion_custom_data custom;
struct ion_heap_query query;
};
/* Must hold the client lock */
static void user_ion_handle_get(struct ion_handle *handle)
{
if (handle->user_ref_count++ == 0)
kref_get(&handle->ref);
}
/* Must hold the client lock */
static struct ion_handle *user_ion_handle_get_check_overflow(
struct ion_handle *handle)
{
if (handle->user_ref_count + 1 == 0)
return ERR_PTR(-EOVERFLOW);
user_ion_handle_get(handle);
return handle;
}
/* passes a kref to the user ref count.
* We know we're holding a kref to the object before and
* after this call, so no need to reverify handle.
*/
static struct ion_handle *pass_to_user(struct ion_handle *handle)
{
struct ion_client *client = handle->client;
struct ion_handle *ret;
mutex_lock(&client->lock);
ret = user_ion_handle_get_check_overflow(handle);
ion_handle_put_nolock(handle);
mutex_unlock(&client->lock);
return ret;
}
/* Must hold the client lock */
static int user_ion_handle_put_nolock(struct ion_handle *handle)
{
int ret;
if (--handle->user_ref_count == 0)
ret = ion_handle_put_nolock(handle);
return ret;
}
static void user_ion_free_nolock(struct ion_client *client,
struct ion_handle *handle)
{
bool valid_handle;
WARN_ON(client != handle->client);
valid_handle = ion_handle_validate(client, handle);
if (!valid_handle) {
WARN(1, "%s: invalid handle passed to free.\n", __func__);
return;
}
if (handle->user_ref_count == 0) {
WARN(1, "%s: User does not have access!\n", __func__);
return;
}
user_ion_handle_put_nolock(handle);
}
static int validate_ioctl_arg(unsigned int cmd, union ion_ioctl_arg *arg)
{
int ret = 0;
switch (cmd) {
case ION_IOC_HEAP_QUERY:
ret = arg->query.reserved0 != 0;
ret |= arg->query.reserved1 != 0;
ret |= arg->query.reserved2 != 0;
break;
default:
break;
}
return ret ? -EINVAL : 0;
}
/* fix up the cases where the ioctl direction bits are incorrect */
static unsigned int ion_ioctl_dir(unsigned int cmd)
{
switch (cmd) {
case ION_IOC_SYNC:
case ION_IOC_FREE:
case ION_IOC_CUSTOM:
return _IOC_WRITE;
default:
return _IOC_DIR(cmd);
}
}
long ion_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
{
struct ion_client *client = filp->private_data;
struct ion_device *dev = client->dev;
struct ion_handle *cleanup_handle = NULL;
int ret = 0;
unsigned int dir;
union ion_ioctl_arg data;
dir = ion_ioctl_dir(cmd);
if (_IOC_SIZE(cmd) > sizeof(data))
return -EINVAL;
/*
* The copy_from_user is unconditional here for both read and write
* to do the validate. If there is no write for the ioctl, the
* buffer is cleared
*/
if (copy_from_user(&data, (void __user *)arg, _IOC_SIZE(cmd)))
return -EFAULT;
ret = validate_ioctl_arg(cmd, &data);
if (ret) {
pr_warn_once("%s: ioctl validate failed\n", __func__);
return ret;
}
if (!(dir & _IOC_WRITE))
memset(&data, 0, sizeof(data));
switch (cmd) {
case ION_IOC_ALLOC:
{
struct ion_handle *handle;
handle = __ion_alloc(client, data.allocation.len,
data.allocation.align,
data.allocation.heap_id_mask,
data.allocation.flags, true);
if (IS_ERR(handle))
return PTR_ERR(handle);
pass_to_user(handle);
data.allocation.handle = handle->id;
cleanup_handle = handle;
break;
}
case ION_IOC_FREE:
{
struct ion_handle *handle;
mutex_lock(&client->lock);
handle = ion_handle_get_by_id_nolock(client, data.handle.handle);
if (IS_ERR(handle)) {
mutex_unlock(&client->lock);
return PTR_ERR(handle);
}
user_ion_free_nolock(client, handle);
ion_handle_put_nolock(handle);
mutex_unlock(&client->lock);
break;
}
case ION_IOC_SHARE:
case ION_IOC_MAP:
{
struct ion_handle *handle;
mutex_lock(&client->lock);
handle = ion_handle_get_by_id_nolock(client, data.handle.handle);
if (IS_ERR(handle)) {
mutex_unlock(&client->lock);
return PTR_ERR(handle);
}
data.fd.fd = ion_share_dma_buf_fd_nolock(client, handle);
ion_handle_put_nolock(handle);
mutex_unlock(&client->lock);
if (data.fd.fd < 0)
ret = data.fd.fd;
break;
}
case ION_IOC_IMPORT:
{
struct ion_handle *handle;
handle = ion_import_dma_buf_fd(client, data.fd.fd);
if (IS_ERR(handle)) {
ret = PTR_ERR(handle);
} else {
handle = pass_to_user(handle);
if (IS_ERR(handle))
ret = PTR_ERR(handle);
else
data.handle.handle = handle->id;
}
break;
}
case ION_IOC_SYNC:
{
ret = ion_sync_for_device(client, data.fd.fd);
break;
}
case ION_IOC_CUSTOM:
{
if (!dev->custom_ioctl)
return -ENOTTY;
ret = dev->custom_ioctl(client, data.custom.cmd,
data.custom.arg);
break;
}
case ION_IOC_HEAP_QUERY:
ret = ion_query_heaps(client, &data.query);
break;
default:
return -ENOTTY;
}
if (dir & _IOC_READ) {
if (copy_to_user((void __user *)arg, &data, _IOC_SIZE(cmd))) {
if (cleanup_handle) {
mutex_lock(&client->lock);
user_ion_free_nolock(client, cleanup_handle);
ion_handle_put_nolock(cleanup_handle);
mutex_unlock(&client->lock);
}
return -EFAULT;
}
}
if (cleanup_handle)
ion_handle_put(cleanup_handle);
return ret;
}
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