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Commit 4fe9f8e2 authored by Ratan Nalumasu's avatar Ratan Nalumasu Committed by Jiri Kosina
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HID: hidraw: don't deallocate memory when it is in use 



When a device is unplugged, wait for all processes that have opened the device
to close before deallocating the device.

Signed-off-by: default avatarRatan Nalumasu <ratan@google.com>
Signed-off-by: default avatarJiri Kosina <jkosina@suse.cz>
parent cead24c1

drivers/hid/hidraw.c

+26 −43
Original line number Diff line number Diff line
@@ -42,6 +42,7 @@ static struct cdev hidraw_cdev; 
static struct class *hidraw_class;

static struct hidraw *hidraw_table[HIDRAW_MAX_DEVICES];

static DEFINE_MUTEX(minors_lock);

static void drop_ref(struct hidraw *hid, int exists_bit);



static ssize_t hidraw_read(struct file *file, char __user *buffer, size_t count, loff_t *ppos)

{
@@ -113,7 +114,7 @@ static ssize_t hidraw_send_report(struct file *file, const char __user *buffer, 
	__u8 *buf;

	int ret = 0;



	if (!hidraw_table[minor]) {

	if (!hidraw_table[minor] || !hidraw_table[minor]->exist) {

		ret = -ENODEV;

		goto out;

	}
@@ -261,7 +262,7 @@ static int hidraw_open(struct inode *inode, struct file *file) 
	}



	mutex_lock(&minors_lock);

	if (!hidraw_table[minor]) {

	if (!hidraw_table[minor] || !hidraw_table[minor]->exist) {

		err = -ENODEV;

		goto out_unlock;

	}
@@ -298,36 +299,12 @@ static int hidraw_open(struct inode *inode, struct file *file) 
static int hidraw_release(struct inode * inode, struct file * file)

{

	unsigned int minor = iminor(inode);

	struct hidraw *dev;

	struct hidraw_list *list = file->private_data;

	int ret;

	int i;



	mutex_lock(&minors_lock);

	if (!hidraw_table[minor]) {

		ret = -ENODEV;

		goto unlock;

	}



	drop_ref(hidraw_table[minor], 0);

	list_del(&list->node);

	dev = hidraw_table[minor];

	if (!--dev->open) {

		if (list->hidraw->exist) {

			hid_hw_power(dev->hid, PM_HINT_NORMAL);

			hid_hw_close(dev->hid);

		} else {

			kfree(list->hidraw);

		}

	}



	for (i = 0; i < HIDRAW_BUFFER_SIZE; ++i)

		kfree(list->buffer[i].value);

	kfree(list);

	ret = 0;

unlock:

	mutex_unlock(&minors_lock);



	return ret;

	return 0;

}



static long hidraw_ioctl(struct file *file, unsigned int cmd,
@@ -529,21 +506,7 @@ EXPORT_SYMBOL_GPL(hidraw_connect); 
void hidraw_disconnect(struct hid_device *hid)

{

	struct hidraw *hidraw = hid->hidraw;



	mutex_lock(&minors_lock);

	hidraw->exist = 0;



	device_destroy(hidraw_class, MKDEV(hidraw_major, hidraw->minor));



	hidraw_table[hidraw->minor] = NULL;



	if (hidraw->open) {

		hid_hw_close(hid);

		wake_up_interruptible(&hidraw->wait);

	} else {

		kfree(hidraw);

	}

	mutex_unlock(&minors_lock);

	drop_ref(hidraw, 1);

}

EXPORT_SYMBOL_GPL(hidraw_disconnect);
@@ -585,3 +548,23 @@ void hidraw_exit(void) 
	unregister_chrdev_region(dev_id, HIDRAW_MAX_DEVICES);



}



static void drop_ref(struct hidraw *hidraw, int exists_bit)

{

	mutex_lock(&minors_lock);

	if (exists_bit) {

		hid_hw_close(hidraw->hid);

		hidraw->exist = 0;

		if (hidraw->open)

			wake_up_interruptible(&hidraw->wait);

	} else {

		--hidraw->open;

	}



	if (!hidraw->open && !hidraw->exist) {

		device_destroy(hidraw_class, MKDEV(hidraw_major, hidraw->minor));

		hidraw_table[hidraw->minor] = NULL;

		kfree(hidraw);

	}

	mutex_unlock(&minors_lock);

}