[Linux-kernel-mentees] [PATCH 1/4] net: usbnet: use usb_control_msg_recv() and usb_control_msg_send()

[Himadri Pandya <himadrispandya@gmail.com>]

Potential incorrect use of usb_control_msg() has resulted in new wrapper
functions to enforce its correct usage with proper error check. Hence
use these new wrapper functions instead of calling usb_control_msg()
directly.

Signed-off-by: Himadri Pandya <himadrispandya@gmail.com>
---
 drivers/net/usb/usbnet.c | 46 ++++------------------------------------
 1 file changed, 4 insertions(+), 42 deletions(-)

diff --git a/drivers/net/usb/usbnet.c b/drivers/net/usb/usbnet.c
index 2b2a841cd938..a38a85bef46a 100644
--- a/drivers/net/usb/usbnet.c
+++ b/drivers/net/usb/usbnet.c
@@ -1982,64 +1982,26 @@ EXPORT_SYMBOL(usbnet_link_change);
 static int __usbnet_read_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
 			     u16 value, u16 index, void *data, u16 size)
 {
-	void *buf = NULL;
-	int err = -ENOMEM;
-
 	netdev_dbg(dev->net, "usbnet_read_cmd cmd=0x%02x reqtype=%02x"
 		   " value=0x%04x index=0x%04x size=%d\n",
 		   cmd, reqtype, value, index, size);
 
-	if (size) {
-		buf = kmalloc(size, GFP_KERNEL);
-		if (!buf)
-			goto out;
-	}
-
-	err = usb_control_msg(dev->udev, usb_rcvctrlpipe(dev->udev, 0),
-			      cmd, reqtype, value, index, buf, size,
+	return usb_control_msg_recv(dev->udev, 0,
+			      cmd, reqtype, value, index, data, size,
 			      USB_CTRL_GET_TIMEOUT);
-	if (err > 0 && err <= size) {
-        if (data)
-            memcpy(data, buf, err);
-        else
-            netdev_dbg(dev->net,
-                "Huh? Data requested but thrown away.\n");
-    }
-	kfree(buf);
-out:
-	return err;
 }
 
 static int __usbnet_write_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
 			      u16 value, u16 index, const void *data,
 			      u16 size)
 {
-	void *buf = NULL;
-	int err = -ENOMEM;
-
 	netdev_dbg(dev->net, "usbnet_write_cmd cmd=0x%02x reqtype=%02x"
 		   " value=0x%04x index=0x%04x size=%d\n",
 		   cmd, reqtype, value, index, size);
 
-	if (data) {
-		buf = kmemdup(data, size, GFP_KERNEL);
-		if (!buf)
-			goto out;
-	} else {
-        if (size) {
-            WARN_ON_ONCE(1);
-            err = -EINVAL;
-            goto out;
-        }
-    }
-
-	err = usb_control_msg(dev->udev, usb_sndctrlpipe(dev->udev, 0),
-			      cmd, reqtype, value, index, buf, size,
+	return usb_control_msg_send(dev->udev, 0,
+			      cmd, reqtype, value, index, data, size,
 			      USB_CTRL_SET_TIMEOUT);
-	kfree(buf);
-
-out:
-	return err;
 }
 
 /*
-- 
2.17.1

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