Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933200Ab3FEVgZ (ORCPT ); Wed, 5 Jun 2013 17:36:25 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:38123 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933181Ab3FEVgX (ORCPT ); Wed, 5 Jun 2013 17:36:23 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Jan Beulich , Wei Liu , "David S. Miller" Subject: [ 123/127] xen-netback: avoid allocating variable size array on stack Date: Wed, 5 Jun 2013 14:34:50 -0700 Message-Id: <20130605213231.953827076@linuxfoundation.org> X-Mailer: git-send-email 1.8.3.rc0.20.gb99dd2e In-Reply-To: <20130605213217.966891866@linuxfoundation.org> References: <20130605213217.966891866@linuxfoundation.org> User-Agent: quilt/0.60-5.1.1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2303 Lines: 78 3.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Wei Liu commit 59ccb4ebbc35e36a3c143f2d1355deb75c2e628f upstream. Tune xen_netbk_count_requests to not touch working array beyond limit, so that we can make working array size constant. Suggested-by: Jan Beulich Signed-off-by: Wei Liu Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- drivers/net/xen-netback/netback.c | 16 ++++++++++++++-- 1 file changed, 14 insertions(+), 2 deletions(-) --- a/drivers/net/xen-netback/netback.c +++ b/drivers/net/xen-netback/netback.c @@ -934,11 +934,14 @@ static int netbk_count_requests(struct x RING_IDX cons = vif->tx.req_cons; int slots = 0; int drop_err = 0; + int more_data; if (!(first->flags & XEN_NETTXF_more_data)) return 0; do { + struct xen_netif_tx_request dropped_tx = { 0 }; + if (slots >= work_to_do) { netdev_err(vif->dev, "Asked for %d slots but exceeds this limit\n", @@ -972,6 +975,9 @@ static int netbk_count_requests(struct x drop_err = -E2BIG; } + if (drop_err) + txp = &dropped_tx; + memcpy(txp, RING_GET_REQUEST(&vif->tx, cons + slots), sizeof(*txp)); @@ -1001,7 +1007,13 @@ static int netbk_count_requests(struct x netbk_fatal_tx_err(vif); return -EINVAL; } - } while ((txp++)->flags & XEN_NETTXF_more_data); + + more_data = txp->flags & XEN_NETTXF_more_data; + + if (!drop_err) + txp++; + + } while (more_data); if (drop_err) { netbk_tx_err(vif, first, cons + slots); @@ -1413,7 +1425,7 @@ static unsigned xen_netbk_tx_build_gops( !list_empty(&netbk->net_schedule_list)) { struct xenvif *vif; struct xen_netif_tx_request txreq; - struct xen_netif_tx_request txfrags[max_skb_slots]; + struct xen_netif_tx_request txfrags[XEN_NETIF_NR_SLOTS_MIN]; struct page *page; struct xen_netif_extra_info extras[XEN_NETIF_EXTRA_TYPE_MAX-1]; u16 pending_idx; -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/