Commit c8e7ff41 authored by Jann Horn's avatar Jann Horn Committed by Jiri Kosina
Browse files

HID: uhid: Use READ_ONCE()/WRITE_ONCE() for ->running 



The flag uhid->running can be set to false by uhid_device_add_worker()
without holding the uhid->devlock. Mark all reads/writes of the flag
that might race with READ_ONCE()/WRITE_ONCE() for clarity and
correctness.

Signed-off-by: default avatarJann Horn <jannh@google.com>
Signed-off-by: default avatarJiri Kosina <jkosina@suse.cz>
parent 4ea5763f

drivers/hid/uhid.c

+10 −10
Original line number Diff line number Diff line
@@ -84,7 +84,7 @@ static void uhid_device_add_worker(struct work_struct *work) 
		 * However, we do have to clear the ->running flag and do a

		 * wakeup to make sure userspace knows that the device is gone.

		 */

		uhid->running = false;

		WRITE_ONCE(uhid->running, false);

		wake_up_interruptible(&uhid->report_wait);

	}

}
@@ -194,9 +194,9 @@ static int __uhid_report_queue_and_wait(struct uhid_device *uhid, 
	spin_unlock_irqrestore(&uhid->qlock, flags);



	ret = wait_event_interruptible_timeout(uhid->report_wait,

				!uhid->report_running || !uhid->running,

				!uhid->report_running || !READ_ONCE(uhid->running),

				5 * HZ);

	if (!ret || !uhid->running || uhid->report_running)

	if (!ret || !READ_ONCE(uhid->running) || uhid->report_running)

		ret = -EIO;

	else if (ret < 0)

		ret = -ERESTARTSYS;
@@ -237,7 +237,7 @@ static int uhid_hid_get_report(struct hid_device *hid, unsigned char rnum, 
	struct uhid_event *ev;

	int ret;



	if (!uhid->running)

	if (!READ_ONCE(uhid->running))

		return -EIO;



	ev = kzalloc(sizeof(*ev), GFP_KERNEL);
@@ -279,7 +279,7 @@ static int uhid_hid_set_report(struct hid_device *hid, unsigned char rnum, 
	struct uhid_event *ev;

	int ret;



	if (!uhid->running || count > UHID_DATA_MAX)

	if (!READ_ONCE(uhid->running) || count > UHID_DATA_MAX)

		return -EIO;



	ev = kzalloc(sizeof(*ev), GFP_KERNEL);
@@ -579,7 +579,7 @@ static int uhid_dev_destroy(struct uhid_device *uhid) 
	if (!uhid->hid)

		return -EINVAL;



	uhid->running = false;

	WRITE_ONCE(uhid->running, false);

	wake_up_interruptible(&uhid->report_wait);



	cancel_work_sync(&uhid->worker);
@@ -593,7 +593,7 @@ static int uhid_dev_destroy(struct uhid_device *uhid) 


static int uhid_dev_input(struct uhid_device *uhid, struct uhid_event *ev)

{

	if (!uhid->running)

	if (!READ_ONCE(uhid->running))

		return -EINVAL;



	hid_input_report(uhid->hid, HID_INPUT_REPORT, ev->u.input.data,
@@ -604,7 +604,7 @@ static int uhid_dev_input(struct uhid_device *uhid, struct uhid_event *ev) 


static int uhid_dev_input2(struct uhid_device *uhid, struct uhid_event *ev)

{

	if (!uhid->running)

	if (!READ_ONCE(uhid->running))

		return -EINVAL;



	hid_input_report(uhid->hid, HID_INPUT_REPORT, ev->u.input2.data,
@@ -616,7 +616,7 @@ static int uhid_dev_input2(struct uhid_device *uhid, struct uhid_event *ev) 
static int uhid_dev_get_report_reply(struct uhid_device *uhid,

				     struct uhid_event *ev)

{

	if (!uhid->running)

	if (!READ_ONCE(uhid->running))

		return -EINVAL;



	uhid_report_wake_up(uhid, ev->u.get_report_reply.id, ev);
@@ -626,7 +626,7 @@ static int uhid_dev_get_report_reply(struct uhid_device *uhid, 
static int uhid_dev_set_report_reply(struct uhid_device *uhid,

				     struct uhid_event *ev)

{

	if (!uhid->running)

	if (!READ_ONCE(uhid->running))

		return -EINVAL;



	uhid_report_wake_up(uhid, ev->u.set_report_reply.id, ev);