linux/drivers/bluetooth/hci_uart.h
Dean Jenkins dec2c92880 Bluetooth: hci_ldisc: Use rwlocking to avoid closing proto races
When HCI_UART_PROTO_READY is in the set state, the Data Link protocol
layer (proto) is bound to the HCI UART driver. This state allows the
registered proto function pointers to be used by the HCI UART driver.

When unbinding (closing) the Data Link protocol layer, the proto
function pointers much be prevented from being used immediately before
running the proto close function pointer. Otherwise, there is a risk
that a proto non-close function pointer is used during or after the
proto close function pointer is used. The consequences are likely to
be a kernel crash because the proto close function pointer will free
resources used in the Data Link protocol layer.

Therefore, add a reader writer lock (rwlock) solution to prevent the
close proto function pointer from running by using write_lock_irqsave()
whilst the other proto function pointers are protected using
read_lock(). This means HCI_UART_PROTO_READY can safely be cleared
in the knowledge that no proto function pointers are running.

When flag HCI_UART_PROTO_READY is put into the clear state,
proto close function pointer can safely be run. Note
flag HCI_UART_PROTO_SET being in the set state prevents the proto
open function pointer from being run so there is no race condition
between proto open and close function pointers.

Signed-off-by: Dean Jenkins <Dean_Jenkins@mentor.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
2017-05-18 13:52:50 +02:00

206 lines
5.1 KiB
C

/*
*
* Bluetooth HCI UART driver
*
* Copyright (C) 2000-2001 Qualcomm Incorporated
* Copyright (C) 2002-2003 Maxim Krasnyansky <maxk@qualcomm.com>
* Copyright (C) 2004-2005 Marcel Holtmann <marcel@holtmann.org>
*
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* 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.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
*/
#ifndef N_HCI
#define N_HCI 15
#endif
/* Ioctls */
#define HCIUARTSETPROTO _IOW('U', 200, int)
#define HCIUARTGETPROTO _IOR('U', 201, int)
#define HCIUARTGETDEVICE _IOR('U', 202, int)
#define HCIUARTSETFLAGS _IOW('U', 203, int)
#define HCIUARTGETFLAGS _IOR('U', 204, int)
/* UART protocols */
#define HCI_UART_MAX_PROTO 12
#define HCI_UART_H4 0
#define HCI_UART_BCSP 1
#define HCI_UART_3WIRE 2
#define HCI_UART_H4DS 3
#define HCI_UART_LL 4
#define HCI_UART_ATH3K 5
#define HCI_UART_INTEL 6
#define HCI_UART_BCM 7
#define HCI_UART_QCA 8
#define HCI_UART_AG6XX 9
#define HCI_UART_NOKIA 10
#define HCI_UART_MRVL 11
#define HCI_UART_RAW_DEVICE 0
#define HCI_UART_RESET_ON_INIT 1
#define HCI_UART_CREATE_AMP 2
#define HCI_UART_INIT_PENDING 3
#define HCI_UART_EXT_CONFIG 4
#define HCI_UART_VND_DETECT 5
struct hci_uart;
struct serdev_device;
struct hci_uart_proto {
unsigned int id;
const char *name;
unsigned int manufacturer;
unsigned int init_speed;
unsigned int oper_speed;
int (*open)(struct hci_uart *hu);
int (*close)(struct hci_uart *hu);
int (*flush)(struct hci_uart *hu);
int (*setup)(struct hci_uart *hu);
int (*set_baudrate)(struct hci_uart *hu, unsigned int speed);
int (*recv)(struct hci_uart *hu, const void *data, int len);
int (*enqueue)(struct hci_uart *hu, struct sk_buff *skb);
struct sk_buff *(*dequeue)(struct hci_uart *hu);
};
struct hci_uart {
struct tty_struct *tty;
struct serdev_device *serdev;
struct hci_dev *hdev;
unsigned long flags;
unsigned long hdev_flags;
struct work_struct init_ready;
struct work_struct write_work;
const struct hci_uart_proto *proto;
rwlock_t proto_lock; /* Stop work for proto close */
void *priv;
struct sk_buff *tx_skb;
unsigned long tx_state;
unsigned int init_speed;
unsigned int oper_speed;
u8 alignment;
u8 padding;
};
/* HCI_UART proto flag bits */
#define HCI_UART_PROTO_SET 0
#define HCI_UART_REGISTERED 1
#define HCI_UART_PROTO_READY 2
/* TX states */
#define HCI_UART_SENDING 1
#define HCI_UART_TX_WAKEUP 2
int hci_uart_register_proto(const struct hci_uart_proto *p);
int hci_uart_unregister_proto(const struct hci_uart_proto *p);
int hci_uart_register_device(struct hci_uart *hu, const struct hci_uart_proto *p);
int hci_uart_tx_wakeup(struct hci_uart *hu);
int hci_uart_init_ready(struct hci_uart *hu);
void hci_uart_set_baudrate(struct hci_uart *hu, unsigned int speed);
void hci_uart_set_flow_control(struct hci_uart *hu, bool enable);
void hci_uart_set_speeds(struct hci_uart *hu, unsigned int init_speed,
unsigned int oper_speed);
#ifdef CONFIG_BT_HCIUART_H4
int h4_init(void);
int h4_deinit(void);
struct h4_recv_pkt {
u8 type; /* Packet type */
u8 hlen; /* Header length */
u8 loff; /* Data length offset in header */
u8 lsize; /* Data length field size */
u16 maxlen; /* Max overall packet length */
int (*recv)(struct hci_dev *hdev, struct sk_buff *skb);
};
#define H4_RECV_ACL \
.type = HCI_ACLDATA_PKT, \
.hlen = HCI_ACL_HDR_SIZE, \
.loff = 2, \
.lsize = 2, \
.maxlen = HCI_MAX_FRAME_SIZE \
#define H4_RECV_SCO \
.type = HCI_SCODATA_PKT, \
.hlen = HCI_SCO_HDR_SIZE, \
.loff = 2, \
.lsize = 1, \
.maxlen = HCI_MAX_SCO_SIZE
#define H4_RECV_EVENT \
.type = HCI_EVENT_PKT, \
.hlen = HCI_EVENT_HDR_SIZE, \
.loff = 1, \
.lsize = 1, \
.maxlen = HCI_MAX_EVENT_SIZE
struct sk_buff *h4_recv_buf(struct hci_dev *hdev, struct sk_buff *skb,
const unsigned char *buffer, int count,
const struct h4_recv_pkt *pkts, int pkts_count);
#endif
#ifdef CONFIG_BT_HCIUART_BCSP
int bcsp_init(void);
int bcsp_deinit(void);
#endif
#ifdef CONFIG_BT_HCIUART_LL
int ll_init(void);
int ll_deinit(void);
#endif
#ifdef CONFIG_BT_HCIUART_ATH3K
int ath_init(void);
int ath_deinit(void);
#endif
#ifdef CONFIG_BT_HCIUART_3WIRE
int h5_init(void);
int h5_deinit(void);
#endif
#ifdef CONFIG_BT_HCIUART_INTEL
int intel_init(void);
int intel_deinit(void);
#endif
#ifdef CONFIG_BT_HCIUART_BCM
int bcm_init(void);
int bcm_deinit(void);
#endif
#ifdef CONFIG_BT_HCIUART_QCA
int qca_init(void);
int qca_deinit(void);
#endif
#ifdef CONFIG_BT_HCIUART_AG6XX
int ag6xx_init(void);
int ag6xx_deinit(void);
#endif
#ifdef CONFIG_BT_HCIUART_MRVL
int mrvl_init(void);
int mrvl_deinit(void);
#endif