diff options
| -rw-r--r-- | drivers/input/misc/uinput.c | 28 |
1 files changed, 21 insertions, 7 deletions
diff --git a/drivers/input/misc/uinput.c b/drivers/input/misc/uinput.c index 13336a2fd49c..a973e82205b5 100644 --- a/drivers/input/misc/uinput.c +++ b/drivers/input/misc/uinput.c @@ -57,6 +57,7 @@ struct uinput_device { struct input_dev *dev; struct mutex mutex; enum uinput_state state; + spinlock_t state_lock; wait_queue_head_t waitq; unsigned char ready; unsigned char head; @@ -146,19 +147,15 @@ static void uinput_request_release_slot(struct uinput_device *udev, static int uinput_request_send(struct uinput_device *udev, struct uinput_request *request) { - int retval; + int retval = 0; - retval = mutex_lock_interruptible(&udev->mutex); - if (retval) - return retval; + spin_lock(&udev->state_lock); if (udev->state != UIST_CREATED) { retval = -ENODEV; goto out; } - init_completion(&request->done); - /* * Tell our userspace application about this new request * by queueing an input event. @@ -166,7 +163,7 @@ static int uinput_request_send(struct uinput_device *udev, uinput_dev_event(udev->dev, EV_UINPUT, request->code, request->id); out: - mutex_unlock(&udev->mutex); + spin_unlock(&udev->state_lock); return retval; } @@ -175,6 +172,13 @@ static int uinput_request_submit(struct uinput_device *udev, { int retval; + /* + * Initialize completion before allocating the request slot. + * Once the slot is allocated, uinput_flush_requests() may + * complete it at any time, so it must be initialized first. + */ + init_completion(&request->done); + retval = uinput_request_reserve_slot(udev, request); if (retval) return retval; @@ -289,7 +293,14 @@ static void uinput_destroy_device(struct uinput_device *udev) struct input_dev *dev = udev->dev; enum uinput_state old_state = udev->state; + /* + * Update state under state_lock so that concurrent + * uinput_request_send() sees the state change before we + * flush pending requests and tear down the device. + */ + spin_lock(&udev->state_lock); udev->state = UIST_NEW_DEVICE; + spin_unlock(&udev->state_lock); if (dev) { name = dev->name; @@ -366,7 +377,9 @@ static int uinput_create_device(struct uinput_device *udev) if (error) goto fail2; + spin_lock(&udev->state_lock); udev->state = UIST_CREATED; + spin_unlock(&udev->state_lock); return 0; @@ -384,6 +397,7 @@ static int uinput_open(struct inode *inode, struct file *file) return -ENOMEM; mutex_init(&newdev->mutex); + spin_lock_init(&newdev->state_lock); spin_lock_init(&newdev->requests_lock); init_waitqueue_head(&newdev->requests_waitq); init_waitqueue_head(&newdev->waitq); |