From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756688Ab3FDOJy (ORCPT ); Tue, 4 Jun 2013 10:09:54 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:46968 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756540Ab3FDOIs (ORCPT ); Tue, 4 Jun 2013 10:08:48 -0400 From: Luis Henriques To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Wei Liu , "David S. Miller" , Luis Henriques Subject: [PATCH 66/70] xen-netback: avoid allocating variable size array on stack Date: Tue, 4 Jun 2013 15:07:22 +0100 Message-Id: <1370354846-14213-67-git-send-email-luis.henriques@canonical.com> X-Mailer: git-send-email 1.8.1.2 In-Reply-To: <1370354846-14213-1-git-send-email-luis.henriques@canonical.com> References: <1370354846-14213-1-git-send-email-luis.henriques@canonical.com> X-Extended-Stable: 3.5 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.5.7.14 -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: Luis Henriques --- drivers/net/xen-netback/netback.c | 16 ++++++++++++++-- 1 file changed, 14 insertions(+), 2 deletions(-) diff --git a/drivers/net/xen-netback/netback.c b/drivers/net/xen-netback/netback.c index bc812b7..aea1604 100644 --- a/drivers/net/xen-netback/netback.c +++ b/drivers/net/xen-netback/netback.c @@ -905,11 +905,14 @@ static int netbk_count_requests(struct xenvif *vif, 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", @@ -943,6 +946,9 @@ static int netbk_count_requests(struct xenvif *vif, drop_err = -E2BIG; } + if (drop_err) + txp = &dropped_tx; + memcpy(txp, RING_GET_REQUEST(&vif->tx, cons + slots), sizeof(*txp)); @@ -972,7 +978,13 @@ static int netbk_count_requests(struct xenvif *vif, 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); @@ -1384,7 +1396,7 @@ static unsigned xen_netbk_tx_build_gops(struct xen_netbk *netbk) !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; -- 1.8.1.2