Commit df0cfd69 authored by Jiri Kosina's avatar Jiri Kosina
Browse files

HID: hidraw: put old deallocation mechanism in place 



This basically reverts commit 4fe9f8e2. It causes multiple problems,
namely:

- after rmmod/modprobe cycle of bus driver, the input is not claimed any
  more. This is likely because of misplaced hid_hw_close()
- it causes memory corruption on hidraw_list

As original patch author is not responding to requests to fix his patch,
and the original deallocation mechanism is not exposing any problems, I
am reverting back to it.

Signed-off-by: default avatarJiri Kosina <jkosina@suse.cz>
parent 8d80da90

drivers/hid/hidraw.c

+43 −26
Original line number Diff line number Diff line
@@ -42,7 +42,6 @@ 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)

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

	int ret = 0;



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

	if (!hidraw_table[minor]) {

		ret = -ENODEV;

		goto out;

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



	mutex_lock(&minors_lock);

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

	if (!hidraw_table[minor]) {

		err = -ENODEV;

		goto out_unlock;

	}
@@ -299,12 +298,36 @@ out: 
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);

	return 0;

	ret = 0;

unlock:

	mutex_unlock(&minors_lock);



	return ret;

}



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

{

	struct hidraw *hidraw = hid->hidraw;

	drop_ref(hidraw, 1);



	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);

}

EXPORT_SYMBOL_GPL(hidraw_disconnect);
@@ -555,23 +592,3 @@ 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);

}

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