Allocate the dst route dynamically rather than on stack, reducing
ovs_fragment stack usage from 400 to 160 bytes, at a cost of a
GFP_ATOMIC allocation.
Signed-off-by: Nicholas Piggin <npig...@gmail.com>
---
net/openvswitch/actions.c | 33 ++++++++++++++++++++++++---------
net/openvswitch/drop.h | 1 +
2 files changed, 25 insertions(+), 9 deletions(-)
diff --git a/net/openvswitch/actions.c b/net/openvswitch/actions.c
index 12ad998b70e2..a6e10f59838f 100644
--- a/net/openvswitch/actions.c
+++ b/net/openvswitch/actions.c
@@ -868,38 +868,53 @@ void ovs_fragment(struct net *net, struct vport *vport,
struct sk_buff *skb,
}
if (key->eth.type == htons(ETH_P_IP)) {
- struct rtable ovs_rt = { 0 };
+ struct rtable *ovs_rt;
unsigned long orig_dst;
+ ovs_rt = kzalloc(sizeof(*ovs_rt), GFP_ATOMIC);
+ if (!ovs_rt) {
+ OVS_NLERR(1, "No memory to fragment");
+ reason = OVS_DROP_NOMEM;
+ goto err;
+ }
+
prepare_frag(vport, skb, orig_network_offset,
ovs_key_mac_proto(key));
- dst_init(&ovs_rt.dst, &ovs_dst_ops, NULL, 1,
+ dst_init(&ovs_rt->dst, &ovs_dst_ops, NULL, 1,
DST_OBSOLETE_NONE, DST_NOCOUNT);
- ovs_rt.dst.dev = vport->dev;
+ ovs_rt->dst.dev = vport->dev;
orig_dst = skb->_skb_refdst;
- skb_dst_set_noref(skb, &ovs_rt.dst);
+ skb_dst_set_noref(skb, &ovs_rt->dst);
IPCB(skb)->frag_max_size = mru;
ip_do_fragment(net, skb->sk, skb, ovs_vport_output);
refdst_drop(orig_dst);
+ kfree(ovs_rt);
} else if (key->eth.type == htons(ETH_P_IPV6)) {
unsigned long orig_dst;
- struct rt6_info ovs_rt;
+ struct rt6_info *ovs_rt;
+
+ ovs_rt = kzalloc(sizeof(*ovs_rt), GFP_ATOMIC);
+ if (!ovs_rt) {
+ OVS_NLERR(1, "No memory to fragment");
+ reason = OVS_DROP_NOMEM;
+ goto err;
+ }
prepare_frag(vport, skb, orig_network_offset,
ovs_key_mac_proto(key));
- memset(&ovs_rt, 0, sizeof(ovs_rt));
- dst_init(&ovs_rt.dst, &ovs_dst_ops, NULL, 1,
+ dst_init(&ovs_rt->dst, &ovs_dst_ops, NULL, 1,
DST_OBSOLETE_NONE, DST_NOCOUNT);
- ovs_rt.dst.dev = vport->dev;
+ ovs_rt->dst.dev = vport->dev;
orig_dst = skb->_skb_refdst;
- skb_dst_set_noref(skb, &ovs_rt.dst);
+ skb_dst_set_noref(skb, &ovs_rt->dst);
IP6CB(skb)->frag_max_size = mru;
ipv6_stub->ipv6_fragment(net, skb->sk, skb, ovs_vport_output);
refdst_drop(orig_dst);
+ kfree(ovs_rt);
} else {
WARN_ONCE(1, "Failed fragment ->%s: eth=%04x, MRU=%d, MTU=%d.",
ovs_vport_name(vport), ntohs(key->eth.type), mru,
diff --git a/net/openvswitch/drop.h b/net/openvswitch/drop.h
index cedf9b7b5796..0bf156867a69 100644
--- a/net/openvswitch/drop.h
+++ b/net/openvswitch/drop.h
@@ -20,6 +20,7 @@
R(OVS_DROP_FRAG_INVALID_PROTO) \
R(OVS_DROP_CONNTRACK) \
R(OVS_DROP_IP_TTL) \
+ R(OVS_DROP_NOMEM) \
/* deliberate comment for trailing \ */
enum ovs_drop_reason {
--
2.40.1
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