alistair23-linux/include/linux/hidraw.h
Yonghua Zheng 277fe44dd8 HID: hidraw: Add spinlock in struct hidraw to protect list
It is unsafe to call list_for_each_entry in hidraw_report_event to
traverse each hidraw_list node without a lock protection, the list
could be modified if someone calls hidraw_release and list_del to
remove itself from the list, this can cause hidraw_report_event
to touch a deleted list struct and panic.

To prevent this, introduce a spinlock in struct hidraw to protect
list from concurrent access.

Signed-off-by: Yonghua Zheng <younghua.zheng@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2013-08-26 21:40:24 +02:00

60 lines
1.5 KiB
C

/*
* Copyright (c) 2007 Jiri Kosina
*/
/*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
* version 2, as published by the Free Software Foundation.
*
* 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.,
* 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
*/
#ifndef _HIDRAW_H
#define _HIDRAW_H
#include <uapi/linux/hidraw.h>
struct hidraw {
unsigned int minor;
int exist;
int open;
wait_queue_head_t wait;
struct hid_device *hid;
struct device *dev;
spinlock_t list_lock;
struct list_head list;
};
struct hidraw_report {
__u8 *value;
int len;
};
struct hidraw_list {
struct hidraw_report buffer[HIDRAW_BUFFER_SIZE];
int head;
int tail;
struct fasync_struct *fasync;
struct hidraw *hidraw;
struct list_head node;
struct mutex read_mutex;
};
#ifdef CONFIG_HIDRAW
int hidraw_init(void);
void hidraw_exit(void);
int hidraw_report_event(struct hid_device *, u8 *, int);
int hidraw_connect(struct hid_device *);
void hidraw_disconnect(struct hid_device *);
#else
static inline int hidraw_init(void) { return 0; }
static inline void hidraw_exit(void) { }
static inline int hidraw_report_event(struct hid_device *hid, u8 *data, int len) { return 0; }
static inline int hidraw_connect(struct hid_device *hid) { return -1; }
static inline void hidraw_disconnect(struct hid_device *hid) { }
#endif
#endif