[PATCH AUTOSEL for 4.9 193/293] datapath: Avoid using stack larger than 1024.

[Sasha Levin]

From: Tonghao Zhang 

[ Upstream commit 9cc9a5cb176ccb4f2cda5ac34da5a659926f125f ]

When compiling OvS-master on 4.4.0-81 kernel,
there is a warning:

CC [M]  /root/ovs/datapath/linux/datapath.o
/root/ovs/datapath/linux/datapath.c: In function
'ovs_flow_cmd_set':
/root/ovs/datapath/linux/datapath.c:1221:1: warning:
the frame size of 1040 bytes is larger than 1024 bytes
[-Wframe-larger-than=]

This patch factors out match-init and action-copy to avoid
"Wframe-larger-than=1024" warning. Because mask is only
used to get actions, we new a function to save some
stack space.

Signed-off-by: Tonghao Zhang 
Acked-by: Pravin B Shelar 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin 
---
 net/openvswitch/datapath.c | 81 +-
 1 file changed, 58 insertions(+), 23 deletions(-)

diff --git a/net/openvswitch/datapath.c b/net/openvswitch/datapath.c
index 453f806afe6e..0f594140c5ff 100644
--- a/net/openvswitch/datapath.c
+++ b/net/openvswitch/datapath.c
@@ -1105,6 +1105,58 @@ static struct sw_flow_actions *get_flow_actions(struct 
net *net,
return acts;
 }
 
+/* Factor out match-init and action-copy to avoid
+ * "Wframe-larger-than=1024" warning. Because mask is only
+ * used to get actions, we new a function to save some
+ * stack space.
+ *
+ * If there are not key and action attrs, we return 0
+ * directly. In the case, the caller will also not use the
+ * match as before. If there is action attr, we try to get
+ * actions and save them to *acts. Before returning from
+ * the function, we reset the match->mask pointer. Because
+ * we should not to return match object with dangling reference
+ * to mask.
+ * */
+static int ovs_nla_init_match_and_action(struct net *net,
+struct sw_flow_match *match,
+struct sw_flow_key *key,
+struct nlattr **a,
+struct sw_flow_actions **acts,
+bool log)
+{
+   struct sw_flow_mask mask;
+   int error = 0;
+
+   if (a[OVS_FLOW_ATTR_KEY]) {
+   ovs_match_init(match, key, true, );
+   error = ovs_nla_get_match(net, match, a[OVS_FLOW_ATTR_KEY],
+ a[OVS_FLOW_ATTR_MASK], log);
+   if (error)
+   goto error;
+   }
+
+   if (a[OVS_FLOW_ATTR_ACTIONS]) {
+   if (!a[OVS_FLOW_ATTR_KEY]) {
+   OVS_NLERR(log,
+ "Flow key attribute not present in set 
flow.");
+   return -EINVAL;
+   }
+
+   *acts = get_flow_actions(net, a[OVS_FLOW_ATTR_ACTIONS], key,
+, log);
+   if (IS_ERR(*acts)) {
+   error = PTR_ERR(*acts);
+   goto error;
+   }
+   }
+
+   /* On success, error is 0. */
+error:
+   match->mask = NULL;
+   return error;
+}
+
 static int ovs_flow_cmd_set(struct sk_buff *skb, struct genl_info *info)
 {
struct net *net = sock_net(skb->sk);
@@ -1112,7 +1164,6 @@ static int ovs_flow_cmd_set(struct sk_buff *skb, struct 
genl_info *info)
struct ovs_header *ovs_header = info->userhdr;
struct sw_flow_key key;
struct sw_flow *flow;
-   struct sw_flow_mask mask;
struct sk_buff *reply = NULL;
struct datapath *dp;
struct sw_flow_actions *old_acts = NULL, *acts = NULL;
@@ -1124,34 +1175,18 @@ static int ovs_flow_cmd_set(struct sk_buff *skb, struct 
genl_info *info)
bool ufid_present;
 
ufid_present = ovs_nla_get_ufid(, a[OVS_FLOW_ATTR_UFID], log);
-   if (a[OVS_FLOW_ATTR_KEY]) {
-   ovs_match_init(, , true, );
-   error = ovs_nla_get_match(net, , a[OVS_FLOW_ATTR_KEY],
- a[OVS_FLOW_ATTR_MASK], log);
-   } else if (!ufid_present) {
+   if (!a[OVS_FLOW_ATTR_KEY] && !ufid_present) {
OVS_NLERR(log,
  "Flow set message rejected, Key attribute missing.");
-   error = -EINVAL;
+   return -EINVAL;
}
+
+   error = ovs_nla_init_match_and_action(net, , , a,
+ , log);
if (error)
goto error;
 
-   /* Validate actions. */
-   if (a[OVS_FLOW_ATTR_ACTIONS]) {
-   if (!a[OVS_FLOW_ATTR_KEY]) {
-   OVS_NLERR(log,
- "Flow key attribute not present in set 
flow.");
-   error = -EINVAL;
-   goto error;
-   }
-
-   acts = get_flow_actions(net, a[OVS_FLOW_ATTR_ACTIONS], ,
- 

[PATCH AUTOSEL for 4.9 193/293] datapath: Avoid using stack larger than 1024.

[Sasha Levin]

From: Tonghao Zhang 

[ Upstream commit 9cc9a5cb176ccb4f2cda5ac34da5a659926f125f ]

When compiling OvS-master on 4.4.0-81 kernel,
there is a warning:

CC [M]  /root/ovs/datapath/linux/datapath.o
/root/ovs/datapath/linux/datapath.c: In function
'ovs_flow_cmd_set':
/root/ovs/datapath/linux/datapath.c:1221:1: warning:
the frame size of 1040 bytes is larger than 1024 bytes
[-Wframe-larger-than=]

This patch factors out match-init and action-copy to avoid
"Wframe-larger-than=1024" warning. Because mask is only
used to get actions, we new a function to save some
stack space.

Signed-off-by: Tonghao Zhang 
Acked-by: Pravin B Shelar 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin 
---
 net/openvswitch/datapath.c | 81 +-
 1 file changed, 58 insertions(+), 23 deletions(-)

diff --git a/net/openvswitch/datapath.c b/net/openvswitch/datapath.c
index 453f806afe6e..0f594140c5ff 100644
--- a/net/openvswitch/datapath.c
+++ b/net/openvswitch/datapath.c
@@ -1105,6 +1105,58 @@ static struct sw_flow_actions *get_flow_actions(struct 
net *net,
return acts;
 }
 
+/* Factor out match-init and action-copy to avoid
+ * "Wframe-larger-than=1024" warning. Because mask is only
+ * used to get actions, we new a function to save some
+ * stack space.
+ *
+ * If there are not key and action attrs, we return 0
+ * directly. In the case, the caller will also not use the
+ * match as before. If there is action attr, we try to get
+ * actions and save them to *acts. Before returning from
+ * the function, we reset the match->mask pointer. Because
+ * we should not to return match object with dangling reference
+ * to mask.
+ * */
+static int ovs_nla_init_match_and_action(struct net *net,
+struct sw_flow_match *match,
+struct sw_flow_key *key,
+struct nlattr **a,
+struct sw_flow_actions **acts,
+bool log)
+{
+   struct sw_flow_mask mask;
+   int error = 0;
+
+   if (a[OVS_FLOW_ATTR_KEY]) {
+   ovs_match_init(match, key, true, );
+   error = ovs_nla_get_match(net, match, a[OVS_FLOW_ATTR_KEY],
+ a[OVS_FLOW_ATTR_MASK], log);
+   if (error)
+   goto error;
+   }
+
+   if (a[OVS_FLOW_ATTR_ACTIONS]) {
+   if (!a[OVS_FLOW_ATTR_KEY]) {
+   OVS_NLERR(log,
+ "Flow key attribute not present in set 
flow.");
+   return -EINVAL;
+   }
+
+   *acts = get_flow_actions(net, a[OVS_FLOW_ATTR_ACTIONS], key,
+, log);
+   if (IS_ERR(*acts)) {
+   error = PTR_ERR(*acts);
+   goto error;
+   }
+   }
+
+   /* On success, error is 0. */
+error:
+   match->mask = NULL;
+   return error;
+}
+
 static int ovs_flow_cmd_set(struct sk_buff *skb, struct genl_info *info)
 {
struct net *net = sock_net(skb->sk);
@@ -1112,7 +1164,6 @@ static int ovs_flow_cmd_set(struct sk_buff *skb, struct 
genl_info *info)
struct ovs_header *ovs_header = info->userhdr;
struct sw_flow_key key;
struct sw_flow *flow;
-   struct sw_flow_mask mask;
struct sk_buff *reply = NULL;
struct datapath *dp;
struct sw_flow_actions *old_acts = NULL, *acts = NULL;
@@ -1124,34 +1175,18 @@ static int ovs_flow_cmd_set(struct sk_buff *skb, struct 
genl_info *info)
bool ufid_present;
 
ufid_present = ovs_nla_get_ufid(, a[OVS_FLOW_ATTR_UFID], log);
-   if (a[OVS_FLOW_ATTR_KEY]) {
-   ovs_match_init(, , true, );
-   error = ovs_nla_get_match(net, , a[OVS_FLOW_ATTR_KEY],
- a[OVS_FLOW_ATTR_MASK], log);
-   } else if (!ufid_present) {
+   if (!a[OVS_FLOW_ATTR_KEY] && !ufid_present) {
OVS_NLERR(log,
  "Flow set message rejected, Key attribute missing.");
-   error = -EINVAL;
+   return -EINVAL;
}
+
+   error = ovs_nla_init_match_and_action(net, , , a,
+ , log);
if (error)
goto error;
 
-   /* Validate actions. */
-   if (a[OVS_FLOW_ATTR_ACTIONS]) {
-   if (!a[OVS_FLOW_ATTR_KEY]) {
-   OVS_NLERR(log,
- "Flow key attribute not present in set 
flow.");
-   error = -EINVAL;
-   goto error;
-   }
-
-   acts = get_flow_actions(net, a[OVS_FLOW_ATTR_ACTIONS], ,
-   , log);
-   if (IS_ERR(acts)) {
-   error =