usb: interface authorization: Use a flag for the default device authorization

With this patch a flag instead of a variable
is used for the default device authorization.

Signed-off-by: Stefan Koch <stefan.koch10@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/core/hcd.c

@@ -854,10 +854,10 @@ static ssize_t authorized_default_show(struct device *dev,
 {
 	struct usb_device *rh_usb_dev = to_usb_device(dev);
 	struct usb_bus *usb_bus = rh_usb_dev->bus;
-	struct usb_hcd *usb_hcd;
+	struct usb_hcd *hcd;
 
-	usb_hcd = bus_to_hcd(usb_bus);
-	return snprintf(buf, PAGE_SIZE, "%u\n", usb_hcd->authorized_default);
+	hcd = bus_to_hcd(usb_bus);
+	return snprintf(buf, PAGE_SIZE, "%u\n", !!HCD_DEV_AUTHORIZED(hcd));
 }
 
 static ssize_t authorized_default_store(struct device *dev,
@@ -868,12 +868,16 @@ static ssize_t authorized_default_store(struct device *dev,
 	unsigned val;
 	struct usb_device *rh_usb_dev = to_usb_device(dev);
 	struct usb_bus *usb_bus = rh_usb_dev->bus;
-	struct usb_hcd *usb_hcd;
+	struct usb_hcd *hcd;
 
-	usb_hcd = bus_to_hcd(usb_bus);
+	hcd = bus_to_hcd(usb_bus);
 	result = sscanf(buf, "%u\n", &val);
 	if (result == 1) {
-		usb_hcd->authorized_default = val ? 1 : 0;
+		if (val)
+			set_bit(HCD_FLAG_DEV_AUTHORIZED, &hcd->flags);
+		else
+			clear_bit(HCD_FLAG_DEV_AUTHORIZED, &hcd->flags);
+
 		result = size;
 	} else {
 		result = -EINVAL;
@@ -2720,10 +2724,17 @@ int usb_add_hcd(struct usb_hcd *hcd,
 	dev_info(hcd->self.controller, "%s\n", hcd->product_desc);
 
 	/* Keep old behaviour if authorized_default is not in [0, 1]. */
-	if (authorized_default < 0 || authorized_default > 1)
-		hcd->authorized_default = hcd->wireless ? 0 : 1;
+	if (authorized_default < 0 || authorized_default > 1) {
+		if (hcd->wireless)
+			clear_bit(HCD_FLAG_DEV_AUTHORIZED, &hcd->flags);
 		else
-		hcd->authorized_default = authorized_default;
+			set_bit(HCD_FLAG_DEV_AUTHORIZED, &hcd->flags);
+	} else {
+		if (authorized_default)
+			set_bit(HCD_FLAG_DEV_AUTHORIZED, &hcd->flags);
+		else
+			clear_bit(HCD_FLAG_DEV_AUTHORIZED, &hcd->flags);
+	}
 	set_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags);
 
 	/* per default all interfaces are authorized */

drivers/usb/core/usb.c

@@ -510,7 +510,7 @@ struct usb_device *usb_alloc_dev(struct usb_device *parent,
 	if (root_hub)	/* Root hub always ok [and always wired] */
 		dev->authorized = 1;
 	else {
-		dev->authorized = usb_hcd->authorized_default;
+		dev->authorized = !!HCD_DEV_AUTHORIZED(usb_hcd);
 		dev->wusb = usb_bus_is_wusb(bus) ? 1 : 0;
 	}
 	return dev;

include/linux/usb/hcd.h

@@ -58,12 +58,6 @@
  *
  * Since "struct usb_bus" is so thin, you can't share much code in it.
  * This framework is a layer over that, and should be more sharable.
- *
- * @authorized_default: Specifies if new devices are authorized to
- *                      connect by default or they require explicit
- *                      user space authorization; this bit is settable
- *                      through /sys/class/usb_host/X/authorized_default.
- *                      For the rest is RO, so we don't lock to r/w it.
  */
 
 /*-------------------------------------------------------------------------*/
@@ -121,6 +115,7 @@ struct usb_hcd {
 #define HCD_FLAG_RH_RUNNING		5	/* root hub is running? */
 #define HCD_FLAG_DEAD			6	/* controller has died? */
 #define HCD_FLAG_INTF_AUTHORIZED	7	/* authorize interfaces? */
+#define HCD_FLAG_DEV_AUTHORIZED		8	/* authorize devices? */
 
 	/* The flags can be tested using these macros; they are likely to
 	 * be slightly faster than test_bit().
@@ -140,6 +135,14 @@ struct usb_hcd {
 #define HCD_INTF_AUTHORIZED(hcd) \
 	((hcd)->flags & (1U << HCD_FLAG_INTF_AUTHORIZED))
 
+	/*
+	 * Specifies if devices are authorized by default
+	 * or they require explicit user space authorization; this bit is
+	 * settable through /sys/class/usb_host/X/authorized_default
+	 */
+#define HCD_DEV_AUTHORIZED(hcd) \
+	((hcd)->flags & (1U << HCD_FLAG_DEV_AUTHORIZED))
+
 	/* Flags that get set only during HCD registration or removal. */
 	unsigned		rh_registered:1;/* is root hub registered? */
 	unsigned		rh_pollable:1;	/* may we poll the root hub? */
@@ -150,7 +153,6 @@ struct usb_hcd {
 	 * support the new root-hub polling mechanism. */
 	unsigned		uses_new_polling:1;
 	unsigned		wireless:1;	/* Wireless USB HCD */
-	unsigned		authorized_default:1;
 	unsigned		has_tt:1;	/* Integrated TT in root hub */
 	unsigned		amd_resume_bug:1; /* AMD remote wakeup quirk */
 	unsigned		can_do_streams:1; /* HC supports streams */