diff mbox

[net] net: revert "net_sched: move tp->root allocation into fw_init()"

Message ID 1442966471-22656-1-git-send-email-xiyou.wangcong@gmail.com
State Accepted, archived
Delegated to: David Miller
Headers show

Commit Message

Cong Wang Sept. 23, 2015, 12:01 a.m. UTC
fw filter uses tp->root==NULL to check if it is the old method,
so it doesn't need allocation at all in this case. This patch
reverts the offending commit and adds some comments for old
method to make it obvious.

Fixes: 33f8b9ecdb15 ("net_sched: move tp->root allocation into fw_init()")
Reported-by: Akshat Kakkar <akshat.1984@gmail.com>
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
---
 net/sched/cls_fw.c | 30 +++++++++++++++---------------
 1 file changed, 15 insertions(+), 15 deletions(-)

Comments

Jamal Hadi Salim Sept. 23, 2015, 6:43 p.m. UTC | #1
On 09/22/15 20:01, Cong Wang wrote:
> fw filter uses tp->root==NULL to check if it is the old method,
> so it doesn't need allocation at all in this case. This patch
> reverts the offending commit and adds some comments for old
> method to make it obvious.
>
> Fixes: 33f8b9ecdb15 ("net_sched: move tp->root allocation into fw_init()")
> Reported-by: Akshat Kakkar <akshat.1984@gmail.com>
> Cc: Jamal Hadi Salim <jhs@mojatatu.com>
> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>

Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>

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David Miller Sept. 24, 2015, 9:34 p.m. UTC | #2
From: Cong Wang <xiyou.wangcong@gmail.com>
Date: Tue, 22 Sep 2015 17:01:11 -0700

> fw filter uses tp->root==NULL to check if it is the old method,
> so it doesn't need allocation at all in this case. This patch
> reverts the offending commit and adds some comments for old
> method to make it obvious.
> 
> Fixes: 33f8b9ecdb15 ("net_sched: move tp->root allocation into fw_init()")
> Reported-by: Akshat Kakkar <akshat.1984@gmail.com>
> Cc: Jamal Hadi Salim <jhs@mojatatu.com>
> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>

Applied and queued up for -stable, thanks.
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diff mbox

Patch

diff --git a/net/sched/cls_fw.c b/net/sched/cls_fw.c
index 715e01e..f23a3b6 100644
--- a/net/sched/cls_fw.c
+++ b/net/sched/cls_fw.c
@@ -33,7 +33,6 @@ 
 
 struct fw_head {
 	u32			mask;
-	bool			mask_set;
 	struct fw_filter __rcu	*ht[HTSIZE];
 	struct rcu_head		rcu;
 };
@@ -84,7 +83,7 @@  static int fw_classify(struct sk_buff *skb, const struct tcf_proto *tp,
 			}
 		}
 	} else {
-		/* old method */
+		/* Old method: classify the packet using its skb mark. */
 		if (id && (TC_H_MAJ(id) == 0 ||
 			   !(TC_H_MAJ(id ^ tp->q->handle)))) {
 			res->classid = id;
@@ -114,14 +113,9 @@  static unsigned long fw_get(struct tcf_proto *tp, u32 handle)
 
 static int fw_init(struct tcf_proto *tp)
 {
-	struct fw_head *head;
-
-	head = kzalloc(sizeof(struct fw_head), GFP_KERNEL);
-	if (head == NULL)
-		return -ENOBUFS;
-
-	head->mask_set = false;
-	rcu_assign_pointer(tp->root, head);
+	/* We don't allocate fw_head here, because in the old method
+	 * we don't need it at all.
+	 */
 	return 0;
 }
 
@@ -252,7 +246,7 @@  static int fw_change(struct net *net, struct sk_buff *in_skb,
 	int err;
 
 	if (!opt)
-		return handle ? -EINVAL : 0;
+		return handle ? -EINVAL : 0; /* Succeed if it is old method. */
 
 	err = nla_parse_nested(tb, TCA_FW_MAX, opt, fw_policy);
 	if (err < 0)
@@ -302,11 +296,17 @@  static int fw_change(struct net *net, struct sk_buff *in_skb,
 	if (!handle)
 		return -EINVAL;
 
-	if (!head->mask_set) {
-		head->mask = 0xFFFFFFFF;
+	if (!head) {
+		u32 mask = 0xFFFFFFFF;
 		if (tb[TCA_FW_MASK])
-			head->mask = nla_get_u32(tb[TCA_FW_MASK]);
-		head->mask_set = true;
+			mask = nla_get_u32(tb[TCA_FW_MASK]);
+
+		head = kzalloc(sizeof(*head), GFP_KERNEL);
+		if (!head)
+			return -ENOBUFS;
+		head->mask = mask;
+
+		rcu_assign_pointer(tp->root, head);
 	}
 
 	f = kzalloc(sizeof(struct fw_filter), GFP_KERNEL);