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![David Herrmann](/assets/img/avatar_default.png)
The comment in ./fs/open.c clearly states that nonseekable_open() will never fail. Therefore, we can safely ignore the return code. This is the recommended way to deal with nonseekable_open(). Our current code looks like nonseekable_open() is checked for the return code. However, if we check the return code, we must also kfree() our private data if the open fails. To avoid this overhead and to avoid confusion, we simply drop the return code and return 0. Signed-off-by: David Herrmann <dh.herrmann@googlemail.com> Acked-by: Marcel Holtmann <marcel@holtmann.org> Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
311 lines
6.2 KiB
C
311 lines
6.2 KiB
C
/*
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*
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* Bluetooth virtual HCI driver
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*
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* Copyright (C) 2000-2001 Qualcomm Incorporated
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* Copyright (C) 2002-2003 Maxim Krasnyansky <maxk@qualcomm.com>
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* Copyright (C) 2004-2006 Marcel Holtmann <marcel@holtmann.org>
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*
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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*
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*/
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#include <linux/module.h>
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#include <linux/kernel.h>
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#include <linux/init.h>
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#include <linux/slab.h>
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#include <linux/types.h>
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#include <linux/errno.h>
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#include <linux/sched.h>
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#include <linux/poll.h>
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#include <linux/skbuff.h>
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#include <linux/miscdevice.h>
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#include <net/bluetooth/bluetooth.h>
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#include <net/bluetooth/hci_core.h>
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#define VERSION "1.3"
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static bool amp;
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struct vhci_data {
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struct hci_dev *hdev;
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unsigned long flags;
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wait_queue_head_t read_wait;
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struct sk_buff_head readq;
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};
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static int vhci_open_dev(struct hci_dev *hdev)
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{
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set_bit(HCI_RUNNING, &hdev->flags);
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return 0;
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}
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static int vhci_close_dev(struct hci_dev *hdev)
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{
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struct vhci_data *data = hci_get_drvdata(hdev);
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if (!test_and_clear_bit(HCI_RUNNING, &hdev->flags))
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return 0;
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skb_queue_purge(&data->readq);
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return 0;
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}
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static int vhci_flush(struct hci_dev *hdev)
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{
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struct vhci_data *data = hci_get_drvdata(hdev);
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skb_queue_purge(&data->readq);
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return 0;
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}
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static int vhci_send_frame(struct sk_buff *skb)
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{
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struct hci_dev* hdev = (struct hci_dev *) skb->dev;
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struct vhci_data *data;
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if (!hdev) {
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BT_ERR("Frame for unknown HCI device (hdev=NULL)");
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return -ENODEV;
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}
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if (!test_bit(HCI_RUNNING, &hdev->flags))
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return -EBUSY;
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data = hci_get_drvdata(hdev);
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memcpy(skb_push(skb, 1), &bt_cb(skb)->pkt_type, 1);
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skb_queue_tail(&data->readq, skb);
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wake_up_interruptible(&data->read_wait);
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return 0;
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}
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static inline ssize_t vhci_get_user(struct vhci_data *data,
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const char __user *buf, size_t count)
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{
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struct sk_buff *skb;
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if (count > HCI_MAX_FRAME_SIZE)
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return -EINVAL;
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skb = bt_skb_alloc(count, GFP_KERNEL);
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if (!skb)
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return -ENOMEM;
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if (copy_from_user(skb_put(skb, count), buf, count)) {
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kfree_skb(skb);
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return -EFAULT;
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}
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skb->dev = (void *) data->hdev;
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bt_cb(skb)->pkt_type = *((__u8 *) skb->data);
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skb_pull(skb, 1);
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hci_recv_frame(skb);
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return count;
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}
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static inline ssize_t vhci_put_user(struct vhci_data *data,
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struct sk_buff *skb, char __user *buf, int count)
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{
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char __user *ptr = buf;
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int len, total = 0;
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len = min_t(unsigned int, skb->len, count);
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if (copy_to_user(ptr, skb->data, len))
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return -EFAULT;
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total += len;
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data->hdev->stat.byte_tx += len;
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switch (bt_cb(skb)->pkt_type) {
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case HCI_COMMAND_PKT:
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data->hdev->stat.cmd_tx++;
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break;
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case HCI_ACLDATA_PKT:
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data->hdev->stat.acl_tx++;
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break;
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case HCI_SCODATA_PKT:
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data->hdev->stat.sco_tx++;
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break;
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};
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return total;
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}
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static ssize_t vhci_read(struct file *file,
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char __user *buf, size_t count, loff_t *pos)
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{
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struct vhci_data *data = file->private_data;
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struct sk_buff *skb;
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ssize_t ret = 0;
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while (count) {
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skb = skb_dequeue(&data->readq);
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if (skb) {
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ret = vhci_put_user(data, skb, buf, count);
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if (ret < 0)
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skb_queue_head(&data->readq, skb);
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else
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kfree_skb(skb);
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break;
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}
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if (file->f_flags & O_NONBLOCK) {
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ret = -EAGAIN;
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break;
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}
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ret = wait_event_interruptible(data->read_wait,
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!skb_queue_empty(&data->readq));
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if (ret < 0)
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break;
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}
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return ret;
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}
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static ssize_t vhci_write(struct file *file,
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const char __user *buf, size_t count, loff_t *pos)
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{
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struct vhci_data *data = file->private_data;
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return vhci_get_user(data, buf, count);
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}
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static unsigned int vhci_poll(struct file *file, poll_table *wait)
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{
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struct vhci_data *data = file->private_data;
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poll_wait(file, &data->read_wait, wait);
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if (!skb_queue_empty(&data->readq))
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return POLLIN | POLLRDNORM;
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return POLLOUT | POLLWRNORM;
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}
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static int vhci_open(struct inode *inode, struct file *file)
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{
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struct vhci_data *data;
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struct hci_dev *hdev;
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data = kzalloc(sizeof(struct vhci_data), GFP_KERNEL);
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if (!data)
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return -ENOMEM;
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skb_queue_head_init(&data->readq);
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init_waitqueue_head(&data->read_wait);
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hdev = hci_alloc_dev();
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if (!hdev) {
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kfree(data);
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return -ENOMEM;
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}
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data->hdev = hdev;
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hdev->bus = HCI_VIRTUAL;
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hci_set_drvdata(hdev, data);
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if (amp)
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hdev->dev_type = HCI_AMP;
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hdev->open = vhci_open_dev;
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hdev->close = vhci_close_dev;
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hdev->flush = vhci_flush;
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hdev->send = vhci_send_frame;
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if (hci_register_dev(hdev) < 0) {
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BT_ERR("Can't register HCI device");
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kfree(data);
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hci_free_dev(hdev);
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return -EBUSY;
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}
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file->private_data = data;
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nonseekable_open(inode, file);
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return 0;
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}
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static int vhci_release(struct inode *inode, struct file *file)
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{
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struct vhci_data *data = file->private_data;
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struct hci_dev *hdev = data->hdev;
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hci_unregister_dev(hdev);
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hci_free_dev(hdev);
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file->private_data = NULL;
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kfree(data);
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return 0;
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}
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static const struct file_operations vhci_fops = {
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.owner = THIS_MODULE,
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.read = vhci_read,
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.write = vhci_write,
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.poll = vhci_poll,
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.open = vhci_open,
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.release = vhci_release,
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.llseek = no_llseek,
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};
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static struct miscdevice vhci_miscdev= {
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.name = "vhci",
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.fops = &vhci_fops,
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.minor = MISC_DYNAMIC_MINOR,
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};
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static int __init vhci_init(void)
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{
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BT_INFO("Virtual HCI driver ver %s", VERSION);
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return misc_register(&vhci_miscdev);
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}
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static void __exit vhci_exit(void)
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{
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misc_deregister(&vhci_miscdev);
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}
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module_init(vhci_init);
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module_exit(vhci_exit);
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module_param(amp, bool, 0644);
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MODULE_PARM_DESC(amp, "Create AMP controller device");
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MODULE_AUTHOR("Marcel Holtmann <marcel@holtmann.org>");
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MODULE_DESCRIPTION("Bluetooth virtual HCI driver ver " VERSION);
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MODULE_VERSION(VERSION);
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MODULE_LICENSE("GPL");
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