usb: gadget: fix check in sync read from ep in gadgetfs

When reading synchronously from a non-zero endpoint, gadgetfs will
return -EFAULT even if the read succeeds, due to a bad check of the
copy_to_iter() return value.

This fix compares the return value of copy_to_iter to the amount of
bytes that was passed, and only fails if they are not the same.

Signed-off-by: Binyamin Sharet <s.binyamin@gmail.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
This commit is contained in:
Binyamin Sharet 2016-07-07 22:22:04 +03:00 committed by Felipe Balbi
parent 528d28138f
commit 63196e9896

View File

@ -606,7 +606,7 @@ ep_read_iter(struct kiocb *iocb, struct iov_iter *to)
}
if (is_sync_kiocb(iocb)) {
value = ep_io(epdata, buf, len);
if (value >= 0 && copy_to_iter(buf, value, to))
if (value >= 0 && (copy_to_iter(buf, value, to) != value))
value = -EFAULT;
} else {
struct kiocb_priv *priv = kzalloc(sizeof *priv, GFP_KERNEL);