USB: unify some error pathways in usbfs

This patch (as1496) unifies the error-return pathways of several
functions in the usbfs driver.  This is not a very important change by
itself; it merely prepares the way for the next patch in this series.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/usb/core/devio.c

@@ -806,8 +806,8 @@ static int proc_control(struct dev_state *ps, void __user *arg)
 	if (ctrl.bRequestType & 0x80) {
 		if (ctrl.wLength && !access_ok(VERIFY_WRITE, ctrl.data,
 					       ctrl.wLength)) {
-			free_page((unsigned long)tbuf);
-			return -EINVAL;
+			ret = -EINVAL;
+			goto done;
 		}
 		pipe = usb_rcvctrlpipe(dev, 0);
 		snoop_urb(dev, NULL, pipe, ctrl.wLength, tmo, SUBMIT, NULL, 0);
@@ -821,15 +821,15 @@ static int proc_control(struct dev_state *ps, void __user *arg)
 			  tbuf, max(i, 0));
 		if ((i > 0) && ctrl.wLength) {
 			if (copy_to_user(ctrl.data, tbuf, i)) {
-				free_page((unsigned long)tbuf);
-				return -EFAULT;
+				ret = -EFAULT;
+				goto done;
 			}
 		}
 	} else {
 		if (ctrl.wLength) {
 			if (copy_from_user(tbuf, ctrl.data, ctrl.wLength)) {
-				free_page((unsigned long)tbuf);
-				return -EFAULT;
+				ret = -EFAULT;
+				goto done;
 			}
 		}
 		pipe = usb_sndctrlpipe(dev, 0);
@@ -843,14 +843,16 @@ static int proc_control(struct dev_state *ps, void __user *arg)
 		usb_lock_device(dev);
 		snoop_urb(dev, NULL, pipe, max(i, 0), min(i, 0), COMPLETE, NULL, 0);
 	}
-	free_page((unsigned long)tbuf);
 	if (i < 0 && i != -EPIPE) {
 		dev_printk(KERN_DEBUG, &dev->dev, "usbfs: USBDEVFS_CONTROL "
 			   "failed cmd %s rqt %u rq %u len %u ret %d\n",
 			   current->comm, ctrl.bRequestType, ctrl.bRequest,
 			   ctrl.wLength, i);
 	}
-	return i;
+	ret = i;
+ done:
+	free_page((unsigned long) tbuf);
+	return ret;
 }
 
 static int proc_bulk(struct dev_state *ps, void __user *arg)
@@ -884,8 +886,8 @@ static int proc_bulk(struct dev_state *ps, void __user *arg)
 	tmo = bulk.timeout;
 	if (bulk.ep & 0x80) {
 		if (len1 && !access_ok(VERIFY_WRITE, bulk.data, len1)) {
-			kfree(tbuf);
-			return -EINVAL;
+			ret = -EINVAL;
+			goto done;
 		}
 		snoop_urb(dev, NULL, pipe, len1, tmo, SUBMIT, NULL, 0);
 
@@ -896,15 +898,15 @@ static int proc_bulk(struct dev_state *ps, void __user *arg)
 
 		if (!i && len2) {
 			if (copy_to_user(bulk.data, tbuf, len2)) {
-				kfree(tbuf);
-				return -EFAULT;
+				ret = -EFAULT;
+				goto done;
 			}
 		}
 	} else {
 		if (len1) {
 			if (copy_from_user(tbuf, bulk.data, len1)) {
-				kfree(tbuf);
-				return -EFAULT;
+				ret = -EFAULT;
+				goto done;
 			}
 		}
 		snoop_urb(dev, NULL, pipe, len1, tmo, SUBMIT, tbuf, len1);
@@ -914,10 +916,10 @@ static int proc_bulk(struct dev_state *ps, void __user *arg)
 		usb_lock_device(dev);
 		snoop_urb(dev, NULL, pipe, len2, i, COMPLETE, NULL, 0);
 	}
+	ret = (i < 0 ? i : len2);
+ done:
 	kfree(tbuf);
-	if (i < 0)
-		return i;
-	return len2;
+	return ret;
 }
 
 static int proc_resetep(struct dev_state *ps, void __user *arg)
@@ -1062,7 +1064,7 @@ static int proc_do_submiturb(struct dev_state *ps, struct usbdevfs_urb *uurb,
 {
 	struct usbdevfs_iso_packet_desc *isopkt = NULL;
 	struct usb_host_endpoint *ep;
-	struct async *as;
+	struct async *as = NULL;
 	struct usb_ctrlrequest *dr = NULL;
 	unsigned int u, totlen, isofrmlen;
 	int ret, ifnum = -1;
@@ -1108,19 +1110,17 @@ static int proc_do_submiturb(struct dev_state *ps, struct usbdevfs_urb *uurb,
 		if (!dr)
 			return -ENOMEM;
 		if (copy_from_user(dr, uurb->buffer, 8)) {
-			kfree(dr);
-			return -EFAULT;
+			ret = -EFAULT;
+			goto error;
 		}
 		if (uurb->buffer_length < (le16_to_cpup(&dr->wLength) + 8)) {
-			kfree(dr);
-			return -EINVAL;
+			ret = -EINVAL;
+			goto error;
 		}
 		ret = check_ctrlrecip(ps, dr->bRequestType, dr->bRequest,
 				      le16_to_cpup(&dr->wIndex));
-		if (ret) {
-			kfree(dr);
-			return ret;
-		}
+		if (ret)
+			goto error;
 		uurb->number_of_packets = 0;
 		uurb->buffer_length = le16_to_cpup(&dr->wLength);
 		uurb->buffer += 8;
@@ -1176,22 +1176,22 @@ static int proc_do_submiturb(struct dev_state *ps, struct usbdevfs_urb *uurb,
 		if (!(isopkt = kmalloc(isofrmlen, GFP_KERNEL)))
 			return -ENOMEM;
 		if (copy_from_user(isopkt, iso_frame_desc, isofrmlen)) {
-			kfree(isopkt);
-			return -EFAULT;
+			ret = -EFAULT;
+			goto error;
 		}
 		for (totlen = u = 0; u < uurb->number_of_packets; u++) {
 			/* arbitrary limit,
 			 * sufficient for USB 2.0 high-bandwidth iso */
 			if (isopkt[u].length > 8192) {
-				kfree(isopkt);
-				return -EINVAL;
+				ret = -EINVAL;
+				goto error;
 			}
 			totlen += isopkt[u].length;
 		}
 		/* 3072 * 64 microframes */
 		if (totlen > 196608) {
-			kfree(isopkt);
-			return -EINVAL;
+			ret = -EINVAL;
+			goto error;
 		}
 		uurb->buffer_length = totlen;
 		break;
@@ -1202,24 +1202,20 @@ static int proc_do_submiturb(struct dev_state *ps, struct usbdevfs_urb *uurb,
 	if (uurb->buffer_length > 0 &&
 			!access_ok(is_in ? VERIFY_WRITE : VERIFY_READ,
 				uurb->buffer, uurb->buffer_length)) {
-		kfree(isopkt);
-		kfree(dr);
-		return -EFAULT;
+		ret = -EFAULT;
+		goto error;
 	}
 	as = alloc_async(uurb->number_of_packets);
 	if (!as) {
-		kfree(isopkt);
-		kfree(dr);
-		return -ENOMEM;
+		ret = -ENOMEM;
+		goto error;
 	}
 	if (uurb->buffer_length > 0) {
 		as->urb->transfer_buffer = kmalloc(uurb->buffer_length,
 				GFP_KERNEL);
 		if (!as->urb->transfer_buffer) {
-			kfree(isopkt);
-			kfree(dr);
-			free_async(as);
-			return -ENOMEM;
+			ret = -ENOMEM;
+			goto error;
 		}
 		/* Isochronous input data may end up being discontiguous
 		 * if some of the packets are short.  Clear the buffer so
@@ -1253,6 +1249,7 @@ static int proc_do_submiturb(struct dev_state *ps, struct usbdevfs_urb *uurb,
 
 	as->urb->transfer_buffer_length = uurb->buffer_length;
 	as->urb->setup_packet = (unsigned char *)dr;
+	dr = NULL;
 	as->urb->start_frame = uurb->start_frame;
 	as->urb->number_of_packets = uurb->number_of_packets;
 	if (uurb->type == USBDEVFS_URB_TYPE_ISO ||
@@ -1268,6 +1265,7 @@ static int proc_do_submiturb(struct dev_state *ps, struct usbdevfs_urb *uurb,
 		totlen += isopkt[u].length;
 	}
 	kfree(isopkt);
+	isopkt = NULL;
 	as->ps = ps;
 	as->userurb = arg;
 	if (is_in && uurb->buffer_length > 0)
@@ -1282,8 +1280,8 @@ static int proc_do_submiturb(struct dev_state *ps, struct usbdevfs_urb *uurb,
 	if (!is_in && uurb->buffer_length > 0) {
 		if (copy_from_user(as->urb->transfer_buffer, uurb->buffer,
 				uurb->buffer_length)) {
-			free_async(as);
-			return -EFAULT;
+			ret = -EFAULT;
+			goto error;
 		}
 	}
 	snoop_urb(ps->dev, as->userurb, as->urb->pipe,
@@ -1329,10 +1327,16 @@ static int proc_do_submiturb(struct dev_state *ps, struct usbdevfs_urb *uurb,
 		snoop_urb(ps->dev, as->userurb, as->urb->pipe,
 				0, ret, COMPLETE, NULL, 0);
 		async_removepending(as);
-		free_async(as);
-		return ret;
+		goto error;
 	}
 	return 0;
+
+ error:
+	kfree(isopkt);
+	kfree(dr);
+	if (as)
+		free_async(as);
+	return ret;
 }
 
 static int proc_submiturb(struct dev_state *ps, void __user *arg)