From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Miller Subject: Re: [PATCH net-next V2] gro: introduce gro_mac_header_len Date: Mon, 06 Feb 2012 15:15:09 -0500 (EST) Message-ID: <20120206.151509.1959432192519622134.davem@davemloft.net> References: <20120206.145148.558736903670696169.davem@davemloft.net> <20120206.145652.1575591691467905094.davem@davemloft.net> Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Cc: eric.dumazet-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org, ogerlitz-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org, sean.hefty-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org, herbert-F6s6mLieUQo7FNHlEwC/lvQIK84fMopw@public.gmane.org, linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, shlomop-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org, netdev-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: roland-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org Return-path: In-Reply-To: Sender: linux-rdma-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: netdev.vger.kernel.org From: Roland Dreier Date: Mon, 6 Feb 2012 12:01:13 -0800 > On Mon, Feb 6, 2012 at 11:56 AM, David Miller wrote: >> But this needs a little bit of work since the qdisc_skb_cb ends with a >> variable length array, but we can put an upper bound on this just like >> we do for skb->cb[] itself to fix this issue. >> >> I'll toss something together. > > OK thanks. We need something like 20 bytes of space to stash an > ipoib LL addr. Which I guess leaves 28 bytes for sch use. I just pushed the following into net-next, you have 24 bytes available. -------------------- net: Make qdisc_skb_cb upper size bound explicit. Just like skb->cb[], so that qdisc_skb_cb can be encapsulated inside of other data structures. This is intended to be used by IPoIB so that it can remember addressing information stored at hard_header_ops->create() time that it can fetch when the packet gets to the transmit routine. Signed-off-by: David S. Miller --- include/net/sch_generic.h | 9 ++++++++- net/sched/sch_choke.c | 3 +-- net/sched/sch_netem.c | 3 +-- net/sched/sch_sfb.c | 3 +-- net/sched/sch_sfq.c | 5 ++--- 5 files changed, 13 insertions(+), 10 deletions(-) diff --git a/include/net/sch_generic.h b/include/net/sch_generic.h index f6bb08b..55ce96b 100644 --- a/include/net/sch_generic.h +++ b/include/net/sch_generic.h @@ -220,9 +220,16 @@ struct tcf_proto { struct qdisc_skb_cb { unsigned int pkt_len; - long data[]; + unsigned char data[24]; }; +static inline void qdisc_cb_private_validate(const struct sk_buff *skb, int sz) +{ + struct qdisc_skb_cb *qcb; + BUILD_BUG_ON(sizeof(skb->cb) < sizeof(unsigned int) + sz); + BUILD_BUG_ON(sizeof(qcb->data) < sz); +} + static inline int qdisc_qlen(const struct Qdisc *q) { return q->q.qlen; diff --git a/net/sched/sch_choke.c b/net/sched/sch_choke.c index e465064..7e267d7 100644 --- a/net/sched/sch_choke.c +++ b/net/sched/sch_choke.c @@ -148,8 +148,7 @@ struct choke_skb_cb { static inline struct choke_skb_cb *choke_skb_cb(const struct sk_buff *skb) { - BUILD_BUG_ON(sizeof(skb->cb) < - sizeof(struct qdisc_skb_cb) + sizeof(struct choke_skb_cb)); + qdisc_cb_private_validate(skb, sizeof(struct choke_skb_cb)); return (struct choke_skb_cb *)qdisc_skb_cb(skb)->data; } diff --git a/net/sched/sch_netem.c b/net/sched/sch_netem.c index 2776012..e83d61c 100644 --- a/net/sched/sch_netem.c +++ b/net/sched/sch_netem.c @@ -130,8 +130,7 @@ struct netem_skb_cb { static inline struct netem_skb_cb *netem_skb_cb(struct sk_buff *skb) { - BUILD_BUG_ON(sizeof(skb->cb) < - sizeof(struct qdisc_skb_cb) + sizeof(struct netem_skb_cb)); + qdisc_cb_private_validate(skb, sizeof(struct netem_skb_cb)); return (struct netem_skb_cb *)qdisc_skb_cb(skb)->data; } diff --git a/net/sched/sch_sfb.c b/net/sched/sch_sfb.c index 96e42ca..d7eea99 100644 --- a/net/sched/sch_sfb.c +++ b/net/sched/sch_sfb.c @@ -94,8 +94,7 @@ struct sfb_skb_cb { static inline struct sfb_skb_cb *sfb_skb_cb(const struct sk_buff *skb) { - BUILD_BUG_ON(sizeof(skb->cb) < - sizeof(struct qdisc_skb_cb) + sizeof(struct sfb_skb_cb)); + qdisc_cb_private_validate(skb, sizeof(struct sfb_skb_cb)); return (struct sfb_skb_cb *)qdisc_skb_cb(skb)->data; } diff --git a/net/sched/sch_sfq.c b/net/sched/sch_sfq.c index 67494ae..60d4718 100644 --- a/net/sched/sch_sfq.c +++ b/net/sched/sch_sfq.c @@ -166,9 +166,8 @@ struct sfq_skb_cb { static inline struct sfq_skb_cb *sfq_skb_cb(const struct sk_buff *skb) { - BUILD_BUG_ON(sizeof(skb->cb) < - sizeof(struct qdisc_skb_cb) + sizeof(struct sfq_skb_cb)); - return (struct sfq_skb_cb *)qdisc_skb_cb(skb)->data; + qdisc_cb_private_validate(skb, sizeof(struct sfq_skb_cb)); + return (struct sfq_skb_cb *)qdisc_skb_cb(skb)->data; } static unsigned int sfq_hash(const struct sfq_sched_data *q, -- 1.7.7.6 -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html