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| author | Wei Liu <wei.liu2@citrix.com> | 2013-05-02 00:43:58 +0000 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2013-05-02 16:50:08 -0400 |
| commit | 59ccb4ebbc35e36a3c143f2d1355deb75c2e628f (patch) | |
| tree | 7c93d18c8162dc66538064676d30f76a1fbc0714 /drivers/net/xen-netback | |
| parent | ac69c26e7accb04ae2cb9ab0872068983a42b3c8 (diff) | |
| download | linux-59ccb4ebbc35e36a3c143f2d1355deb75c2e628f.tar.gz linux-59ccb4ebbc35e36a3c143f2d1355deb75c2e628f.tar.bz2 linux-59ccb4ebbc35e36a3c143f2d1355deb75c2e628f.zip | |
xen-netback: avoid allocating variable size array on stack
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 <jbeulich@suse.com>
Signed-off-by: Wei Liu <wei.liu2@citrix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/net/xen-netback')
| -rw-r--r-- | drivers/net/xen-netback/netback.c | 16 |
1 files changed, 14 insertions, 2 deletions
diff --git a/drivers/net/xen-netback/netback.c b/drivers/net/xen-netback/netback.c index c44772d6bba0..ce8109f7d56f 100644 --- a/drivers/net/xen-netback/netback.c +++ b/drivers/net/xen-netback/netback.c @@ -934,11 +934,14 @@ 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", @@ -972,6 +975,9 @@ 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)); @@ -1001,7 +1007,13 @@ 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); @@ -1408,7 +1420,7 @@ 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; |