linux/drivers/bluetooth/btrtl.h
Gustavo A. R. Silva a7e454542b Bluetooth: Replace zero-length array with flexible-array member
The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:

struct foo {
        int stuff;
        struct boo array[];
};

By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.

Also, notice that, dynamic memory allocations won't be affected by
this change:

"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]

This issue was found with the help of Coccinelle.

[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 7649773293 ("cxgb3/l2t: Fix undefined behaviour")

Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
2020-02-28 08:30:02 +01:00

102 lines
2.3 KiB
C

/* SPDX-License-Identifier: GPL-2.0-or-later */
/*
* Bluetooth support for Realtek devices
*
* Copyright (C) 2015 Endless Mobile, Inc.
*/
#define RTL_FRAG_LEN 252
#define rtl_dev_err(dev, fmt, ...) bt_dev_err(dev, "RTL: " fmt, ##__VA_ARGS__)
#define rtl_dev_warn(dev, fmt, ...) bt_dev_warn(dev, "RTL: " fmt, ##__VA_ARGS__)
#define rtl_dev_info(dev, fmt, ...) bt_dev_info(dev, "RTL: " fmt, ##__VA_ARGS__)
#define rtl_dev_dbg(dev, fmt, ...) bt_dev_dbg(dev, "RTL: " fmt, ##__VA_ARGS__)
struct btrtl_device_info;
struct rtl_download_cmd {
__u8 index;
__u8 data[RTL_FRAG_LEN];
} __packed;
struct rtl_download_response {
__u8 status;
__u8 index;
} __packed;
struct rtl_rom_version_evt {
__u8 status;
__u8 version;
} __packed;
struct rtl_epatch_header {
__u8 signature[8];
__le32 fw_version;
__le16 num_patches;
} __packed;
struct rtl_vendor_config_entry {
__le16 offset;
__u8 len;
__u8 data[];
} __packed;
struct rtl_vendor_config {
__le32 signature;
__le16 total_len;
struct rtl_vendor_config_entry entry[];
} __packed;
#if IS_ENABLED(CONFIG_BT_RTL)
struct btrtl_device_info *btrtl_initialize(struct hci_dev *hdev,
const char *postfix);
void btrtl_free(struct btrtl_device_info *btrtl_dev);
int btrtl_download_firmware(struct hci_dev *hdev,
struct btrtl_device_info *btrtl_dev);
int btrtl_setup_realtek(struct hci_dev *hdev);
int btrtl_shutdown_realtek(struct hci_dev *hdev);
int btrtl_get_uart_settings(struct hci_dev *hdev,
struct btrtl_device_info *btrtl_dev,
unsigned int *controller_baudrate,
u32 *device_baudrate, bool *flow_control);
#else
static inline struct btrtl_device_info *btrtl_initialize(struct hci_dev *hdev,
const char *postfix)
{
return ERR_PTR(-EOPNOTSUPP);
}
static inline void btrtl_free(struct btrtl_device_info *btrtl_dev)
{
}
static inline int btrtl_download_firmware(struct hci_dev *hdev,
struct btrtl_device_info *btrtl_dev)
{
return -EOPNOTSUPP;
}
static inline int btrtl_setup_realtek(struct hci_dev *hdev)
{
return -EOPNOTSUPP;
}
static inline int btrtl_shutdown_realtek(struct hci_dev *hdev)
{
return -EOPNOTSUPP;
}
static inline int btrtl_get_uart_settings(struct hci_dev *hdev,
struct btrtl_device_info *btrtl_dev,
unsigned int *controller_baudrate,
u32 *device_baudrate,
bool *flow_control)
{
return -ENOENT;
}
#endif