subject:"\[PATCH\] datapath\: Avoid using stack larger than 1024."

Re: [PATCH] datapath: Avoid using stack larger than 1024.

2017-06-27 Thread Pravin Shelar

On Tue, Jun 27, 2017 at 2:20 AM, Tonghao Zhang  wrote:
> 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 use kmalloc to malloc mem for sw_flow_mask and
> avoid using stack.
>
> Signed-off-by: Tonghao Zhang 
> ---
>  net/openvswitch/datapath.c | 11 ---
>  1 file changed, 8 insertions(+), 3 deletions(-)
>
> diff --git a/net/openvswitch/datapath.c b/net/openvswitch/datapath.c
> index c85029c..da8cd68 100644
> --- a/net/openvswitch/datapath.c
> +++ b/net/openvswitch/datapath.c
> @@ -1107,7 +1107,7 @@ 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 sw_flow_mask *mask;
> struct sk_buff *reply = NULL;
> struct datapath *dp;
> struct sw_flow_actions *old_acts = NULL, *acts = NULL;
> @@ -1120,7 +1120,11 @@ static int ovs_flow_cmd_set(struct sk_buff *skb, 
> struct genl_info *info)
>
> ufid_present = ovs_nla_get_ufid(, a[OVS_FLOW_ATTR_UFID], log);
> if (a[OVS_FLOW_ATTR_KEY]) {
> -   ovs_match_init(, , true, );
> +   mask = kmalloc(sizeof(struct sw_flow_mask), GFP_KERNEL);
> +   if (!mask)
> +   return -ENOMEM;
> +
> +   ovs_match_init(, , true, mask);

Rather than allocating mask object and freeing it at the end, can you
factor out code which needs mask into new function to save some stack
space in this function?

> error = ovs_nla_get_match(net, , a[OVS_FLOW_ATTR_KEY],
>   a[OVS_FLOW_ATTR_MASK], log);
> } else if (!ufid_present) {
> @@ -1141,7 +1145,7 @@ static int ovs_flow_cmd_set(struct sk_buff *skb, struct 
> genl_info *info)
> }
>
> acts = get_flow_actions(net, a[OVS_FLOW_ATTR_ACTIONS], ,
> -   , log);
> +   mask, log);
> if (IS_ERR(acts)) {
> error = PTR_ERR(acts);
> goto error;
> @@ -1216,6 +1220,7 @@ err_unlock_ovs:
>  err_kfree_acts:
> ovs_nla_free_flow_actions(acts);
>  error:
> +   kfree(mask);

mask free is missing in usual, no error case.

Re: [PATCH] datapath: Avoid using stack larger than 1024.

2017-06-27 Thread Greg Rose


On 06/27/2017 12:03 AM, Tonghao Zhang wrote:

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 use kmalloc to malloc mem for sw_flow_mask and
avoid using stack.

Signed-off-by: Tonghao Zhang 
---
  datapath/datapath.c | 11 ---
  1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/datapath/datapath.c b/datapath/datapath.c
index c85029c..da8cd68 100644
--- a/datapath/datapath.c
+++ b/datapath/datapath.c
@@ -1107,7 +1107,7 @@ 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 sw_flow_mask *mask;
  struct sk_buff *reply = NULL;
  struct datapath *dp;
  struct sw_flow_actions *old_acts = NULL, *acts = NULL;
@@ -1120,7 +1120,11 @@ static int ovs_flow_cmd_set(struct sk_buff *skb, struct 
genl_info *info)

  ufid_present = ovs_nla_get_ufid(, a[OVS_FLOW_ATTR_UFID], log);
  if (a[OVS_FLOW_ATTR_KEY]) {
-ovs_match_init(, , true, );
+mask = kmalloc(sizeof(struct sw_flow_mask), GFP_KERNEL);
+if (!mask)
+return -ENOMEM;
+
+ovs_match_init(, , true, mask);
  error = ovs_nla_get_match(net, , a[OVS_FLOW_ATTR_KEY],
a[OVS_FLOW_ATTR_MASK], log);
  } else if (!ufid_present) {
@@ -1141,7 +1145,7 @@ static int ovs_flow_cmd_set(struct sk_buff *skb, struct 
genl_info *info)
  }

  acts = get_flow_actions(net, a[OVS_FLOW_ATTR_ACTIONS], ,
-, log);
+mask, log);
  if (IS_ERR(acts)) {
  error = PTR_ERR(acts);
  goto error;
@@ -1216,6 +1220,7 @@ err_unlock_ovs:
  err_kfree_acts:
  ovs_nla_free_flow_actions(acts);
  error:
+kfree(mask);
  return error;
  }



It looks fine to me but let's copy the maintainer Pravin

- Greg

[PATCH] datapath: Avoid using stack larger than 1024.

2017-06-27 Thread Tonghao Zhang

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 use kmalloc to malloc mem for sw_flow_mask and
avoid using stack.

Signed-off-by: Tonghao Zhang 
---
 net/openvswitch/datapath.c | 11 ---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/net/openvswitch/datapath.c b/net/openvswitch/datapath.c
index c85029c..da8cd68 100644
--- a/net/openvswitch/datapath.c
+++ b/net/openvswitch/datapath.c
@@ -1107,7 +1107,7 @@ 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 sw_flow_mask *mask;
struct sk_buff *reply = NULL;
struct datapath *dp;
struct sw_flow_actions *old_acts = NULL, *acts = NULL;
@@ -1120,7 +1120,11 @@ static int ovs_flow_cmd_set(struct sk_buff *skb, struct 
genl_info *info)
 
ufid_present = ovs_nla_get_ufid(, a[OVS_FLOW_ATTR_UFID], log);
if (a[OVS_FLOW_ATTR_KEY]) {
-   ovs_match_init(, , true, );
+   mask = kmalloc(sizeof(struct sw_flow_mask), GFP_KERNEL);
+   if (!mask)
+   return -ENOMEM;
+
+   ovs_match_init(, , true, mask);
error = ovs_nla_get_match(net, , a[OVS_FLOW_ATTR_KEY],
  a[OVS_FLOW_ATTR_MASK], log);
} else if (!ufid_present) {
@@ -1141,7 +1145,7 @@ static int ovs_flow_cmd_set(struct sk_buff *skb, struct 
genl_info *info)
}
 
acts = get_flow_actions(net, a[OVS_FLOW_ATTR_ACTIONS], ,
-   , log);
+   mask, log);
if (IS_ERR(acts)) {
error = PTR_ERR(acts);
goto error;
@@ -1216,6 +1220,7 @@ err_unlock_ovs:
 err_kfree_acts:
ovs_nla_free_flow_actions(acts);
 error:
+   kfree(mask);
return error;
 }
 
-- 
1.8.3.1

[PATCH] datapath: Avoid using stack larger than 1024.

2017-06-27 Thread Tonghao Zhang

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 use kmalloc to malloc mem for sw_flow_mask and
avoid using stack.

Signed-off-by: Tonghao Zhang 
---
 datapath/datapath.c | 11 ---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/datapath/datapath.c b/datapath/datapath.c
index c85029c..da8cd68 100644
--- a/datapath/datapath.c
+++ b/datapath/datapath.c
@@ -1107,7 +1107,7 @@ 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 sw_flow_mask *mask;
struct sk_buff *reply = NULL;
struct datapath *dp;
struct sw_flow_actions *old_acts = NULL, *acts = NULL;
@@ -1120,7 +1120,11 @@ static int ovs_flow_cmd_set(struct sk_buff *skb, struct 
genl_info *info)
 
ufid_present = ovs_nla_get_ufid(, a[OVS_FLOW_ATTR_UFID], log);
if (a[OVS_FLOW_ATTR_KEY]) {
-   ovs_match_init(, , true, );
+   mask = kmalloc(sizeof(struct sw_flow_mask), GFP_KERNEL);
+   if (!mask)
+   return -ENOMEM;
+
+   ovs_match_init(, , true, mask);
error = ovs_nla_get_match(net, , a[OVS_FLOW_ATTR_KEY],
  a[OVS_FLOW_ATTR_MASK], log);
} else if (!ufid_present) {
@@ -1141,7 +1145,7 @@ static int ovs_flow_cmd_set(struct sk_buff *skb, struct 
genl_info *info)
}
 
acts = get_flow_actions(net, a[OVS_FLOW_ATTR_ACTIONS], ,
-   , log);
+   mask, log);
if (IS_ERR(acts)) {
error = PTR_ERR(acts);
goto error;
@@ -1216,6 +1220,7 @@ err_unlock_ovs:
 err_kfree_acts:
ovs_nla_free_flow_actions(acts);
 error:
+   kfree(mask);
return error;
 }
 
-- 
1.8.3.1

Re: [PATCH] datapath: Avoid using stack larger than 1024.

Re: [PATCH] datapath: Avoid using stack larger than 1024.

[PATCH] datapath: Avoid using stack larger than 1024.

[PATCH] datapath: Avoid using stack larger than 1024.

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