diff --git a/drivers/usb/misc/chaoskey.c b/drivers/usb/misc/chaoskey.c index 6fb5140e29b9dd..e8b63df5f97598 100644 --- a/drivers/usb/misc/chaoskey.c +++ b/drivers/usb/misc/chaoskey.c @@ -27,6 +27,8 @@ static struct usb_class_driver chaoskey_class; static int chaoskey_rng_read(struct hwrng *rng, void *data, size_t max, bool wait); +static DEFINE_MUTEX(chaoskey_list_lock); + #define usb_dbg(usb_if, format, arg...) \ dev_dbg(&(usb_if)->dev, format, ## arg) @@ -230,6 +232,7 @@ static void chaoskey_disconnect(struct usb_interface *interface) if (dev->hwrng_registered) hwrng_unregister(&dev->hwrng); + mutex_lock(&chaoskey_list_lock); usb_deregister_dev(interface, &chaoskey_class); usb_set_intfdata(interface, NULL); @@ -244,6 +247,7 @@ static void chaoskey_disconnect(struct usb_interface *interface) } else mutex_unlock(&dev->lock); + mutex_unlock(&chaoskey_list_lock); usb_dbg(interface, "disconnect done"); } @@ -251,6 +255,7 @@ static int chaoskey_open(struct inode *inode, struct file *file) { struct chaoskey *dev; struct usb_interface *interface; + int rv = 0; /* get the interface from minor number and driver information */ interface = usb_find_interface(&chaoskey_driver, iminor(inode)); @@ -266,18 +271,23 @@ static int chaoskey_open(struct inode *inode, struct file *file) } file->private_data = dev; + mutex_lock(&chaoskey_list_lock); mutex_lock(&dev->lock); - ++dev->open; + if (dev->present) + ++dev->open; + else + rv = -ENODEV; mutex_unlock(&dev->lock); + mutex_unlock(&chaoskey_list_lock); - usb_dbg(interface, "open success"); - return 0; + return rv; } static int chaoskey_release(struct inode *inode, struct file *file) { struct chaoskey *dev = file->private_data; struct usb_interface *interface; + int rv = 0; if (dev == NULL) return -ENODEV; @@ -286,14 +296,15 @@ static int chaoskey_release(struct inode *inode, struct file *file) usb_dbg(interface, "release"); + mutex_lock(&chaoskey_list_lock); mutex_lock(&dev->lock); usb_dbg(interface, "open count at release is %d", dev->open); if (dev->open <= 0) { usb_dbg(interface, "invalid open count (%d)", dev->open); - mutex_unlock(&dev->lock); - return -ENODEV; + rv = -ENODEV; + goto bail; } --dev->open; @@ -302,13 +313,15 @@ static int chaoskey_release(struct inode *inode, struct file *file) if (dev->open == 0) { mutex_unlock(&dev->lock); chaoskey_free(dev); - } else - mutex_unlock(&dev->lock); - } else - mutex_unlock(&dev->lock); - + goto destruction; + } + } +bail: + mutex_unlock(&dev->lock); +destruction: + mutex_lock(&chaoskey_list_lock); usb_dbg(interface, "release success"); - return 0; + return rv; } static void chaos_read_callback(struct urb *urb)