xen-netfront: cast grant table reference first to type int

commit 269ebce4531b8edc4224259a02143181a1c1d77c upstream.

IS_ERR_VALUE() in commit 87557efc27f6a50140fb20df06a917f368ce3c66
("xen-netfront: do not cast grant table reference to signed short") would
not return true for error code unless we cast ref first to type int.

Signed-off-by: Dongli Zhang <dongli.zhang@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Cc: Blake Cooper <blake.cooper@braintreepayments.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/net/xen-netfront.c b/drivers/net/xen-netfront.c
index 986a025..888e9cf 100644 (file)
--- a/drivers/net/xen-netfront.c
+++ b/drivers/net/xen-netfront.c
@@ -304,7 +304,7 @@ static void xennet_alloc_rx_buffers(struct netfront_queue *queue)
                queue->rx_skbs[id] = skb;
 
                ref = gnttab_claim_grant_reference(&queue->gref_rx_head);
-               WARN_ON_ONCE(IS_ERR_VALUE((unsigned long)ref));
+               WARN_ON_ONCE(IS_ERR_VALUE((unsigned long)(int)ref));
                queue->grant_rx_ref[id] = ref;
 
                page = skb_frag_page(&skb_shinfo(skb)->frags[0]);
@@ -437,7 +437,7 @@ static void xennet_tx_setup_grant(unsigned long gfn, unsigned int offset,
        id = get_id_from_freelist(&queue->tx_skb_freelist, queue->tx_skbs);
        tx = RING_GET_REQUEST(&queue->tx, queue->tx.req_prod_pvt++);
        ref = gnttab_claim_grant_reference(&queue->gref_tx_head);
-       WARN_ON_ONCE(IS_ERR_VALUE((unsigned long)ref));
+       WARN_ON_ONCE(IS_ERR_VALUE((unsigned long)(int)ref));
 
        gnttab_grant_foreign_access_ref(ref, queue->info->xbdev->otherend_id,
                                        gfn, GNTMAP_readonly);