Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758935AbcJaFkH (ORCPT ); Mon, 31 Oct 2016 01:40:07 -0400 Received: from aserp1040.oracle.com ([141.146.126.69]:34678 "EHLO aserp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758852AbcJaFkF (ORCPT ); Mon, 31 Oct 2016 01:40:05 -0400 From: Dongli Zhang To: linux-kernel@vger.kernel.org, xen-devel@lists.xenproject.org, netdev@vger.kernel.org Cc: boris.ostrovsky@oracle.com, david.vrabel@citrix.com, jgross@suse.com Subject: [PATCH 1/1] xen-netfront: do not cast grant table reference to signed short Date: Mon, 31 Oct 2016 13:38:29 +0800 Message-Id: <1477892309-7150-1-git-send-email-dongli.zhang@oracle.com> X-Mailer: git-send-email 2.7.4 X-Source-IP: aserv0021.oracle.com [141.146.126.233] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1373 Lines: 35 While grant reference is of type uint32_t, xen-netfront erroneously casts it to signed short in BUG_ON(). This would lead to the xen domU panic during boot-up or migration when it is attached with lots of paravirtual devices. Signed-off-by: Dongli Zhang --- drivers/net/xen-netfront.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/net/xen-netfront.c b/drivers/net/xen-netfront.c index e17879d..189a28d 100644 --- 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); - BUG_ON((signed short)ref < 0); + WARN_ON_ONCE(IS_ERR_VALUE((unsigned long)ref)); queue->grant_rx_ref[id] = ref; page = skb_frag_page(&skb_shinfo(skb)->frags[0]); @@ -428,7 +428,7 @@ 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); - BUG_ON((signed short)ref < 0); + WARN_ON_ONCE(IS_ERR_VALUE((unsigned long)ref)); gnttab_grant_foreign_access_ref(ref, queue->info->xbdev->otherend_id, gfn, GNTMAP_readonly); -- 2.7.4