xHCI: Add error handle for event completed handler.

BZ: 35199

This is klockwork tool build error. The ep_index variable possible equal
to -1, then cause the eps array overflow.

Change-Id: If7722a411d6cb415ba0481fc6a0e4784adc469f3
Signed-off-by: Yu Wang <yu.y.wang@intel.com>
Reviewed-on: http://android.intel.com:8080/47758
Reviewed-by: Tang, Richard <richard.tang@intel.com>
Tested-by: Gao, Yunpeng <yunpeng.gao@intel.com>
Reviewed-by: buildbot <buildbot@intel.com>
Tested-by: buildbot <buildbot@intel.com>

diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c
index d0871ea..3a98363 100644 (file)
--- a/drivers/usb/host/xhci-ring.c
+++ b/drivers/usb/host/xhci-ring.c
@@ -1952,6 +1952,10 @@ static int handle_tx_event(struct xhci_hcd *xhci,
 
        /* Endpoint ID is 1 based, our index is zero based */
        ep_index = TRB_TO_EP_ID(le32_to_cpu(event->flags)) - 1;
+       if (ep_index == -1) {
+               xhci_err(xhci, "ERROR event endpoint index should start from one\n ");
+               return -EINVAL;
+       }
        ep = &xdev->eps[ep_index];
        ep_ring = xhci_dma_to_transfer_ring(ep, le64_to_cpu(event->buffer));
        ep_ctx = xhci_get_ep_ctx(xhci, xdev->out_ctx, ep_index);