usb: gadget: return the right length in ffs_epfile_io()
When the request length is aligned to maxpacketsize, sometimes
the return length ret > the user space requested len.
At that time, we will use min_t(size_t, ret, len) to limit the
size in case of user data buffer overflow.
But we need return the min_t(size_t, ret, len) to tell the user
space rightly also.
[ balbi@ti.com: also fix comment's indentation ]
Acked-by: Michal Nazarewicz <mina86@mina86.com>
Reviewed-by: David Cohen <david.a.cohen@linux.intel.com>
Signed-off-by: Chuansheng Liu <chuansheng.liu@intel.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
diff --git a/drivers/usb/gadget/f_fs.c b/drivers/usb/gadget/f_fs.c
index 42f7a0e..b2e922d 100644
--- a/drivers/usb/gadget/f_fs.c
+++ b/drivers/usb/gadget/f_fs.c
@@ -838,19 +838,21 @@
ret = -EINTR;
usb_ep_dequeue(ep->ep, req);
} else {
- /*
- * XXX We may end up silently droping data here.
- * Since data_len (i.e. req->length) may be bigger
- * than len (after being rounded up to maxpacketsize),
- * we may end up with more data then user space has
- * space for.
- */
- ret = ep->status;
- if (io_data->read && ret > 0 &&
- unlikely(copy_to_user(io_data->buf, data,
- min_t(size_t, ret,
- io_data->len))))
- ret = -EFAULT;
+ /*
+ * XXX We may end up silently droping data
+ * here. Since data_len (i.e. req->length) may
+ * be bigger than len (after being rounded up
+ * to maxpacketsize), we may end up with more
+ * data then user space has space for.
+ */
+ ret = ep->status;
+ if (io_data->read && ret > 0) {
+ ret = min_t(size_t, ret, io_data->len);
+
+ if (unlikely(copy_to_user(io_data->buf,
+ data, ret)))
+ ret = -EFAULT;
+ }
}
kfree(data);
}