From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933393Ab3GCSoe (ORCPT ); Wed, 3 Jul 2013 14:44:34 -0400 Received: from hrndva-omtalb.mail.rr.com ([71.74.56.122]:4440 "EHLO hrndva-omtalb.mail.rr.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933303Ab3GCSlK (ORCPT ); Wed, 3 Jul 2013 14:41:10 -0400 X-Authority-Analysis: v=2.0 cv=Du3UCRD+ c=1 sm=0 a=Sro2XwOs0tJUSHxCKfOySw==:17 a=Drc5e87SC40A:10 a=Ciwy3NGCPMMA:10 a=vep89UUYZ68A:10 a=5SG0PmZfjMsA:10 a=bbbx4UPp9XUA:10 a=meVymXHHAAAA:8 a=KGjhK52YXX0A:10 a=1cJQfhlvqFIA:10 a=tHz9FfFoAAAA:8 a=iox4zFpeAAAA:8 a=J1Y8HTJGAAAA:8 a=pQFG53Joc4AfjvbZiugA:9 a=6O0IECtVFhoA:10 a=n9GBPR9yFnkA:10 a=4N9Db7Z2_RYA:10 a=jeBq3FmKZ4MA:10 a=Sro2XwOs0tJUSHxCKfOySw==:117 X-Cloudmark-Score: 0 X-Authenticated-User: X-Originating-IP: 67.255.60.225 Message-Id: <20130703184055.100034417@goodmis.org> User-Agent: quilt/0.60-1 Date: Wed, 03 Jul 2013 14:40:00 -0400 From: Steven Rostedt To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Jan Beulich , Wei Liu , "David S. Miller" Subject: [063/141] xen-netback: avoid allocating variable size array on stack References: <20130703183857.307196999@goodmis.org> Content-Disposition: inline; filename=0063-xen-netback-avoid-allocating-variable-size-array-on-.patch Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.6.11.6 stable review patch. If anyone has any objections, please let me know. ------------------ From: Wei Liu [ Upstream commit 59ccb4ebbc35e36a3c143f2d1355deb75c2e628f ] 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: Steven Rostedt --- 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 b78839e..4925188 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; -- 1.7.10.4