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fix suspicious rcu_dereference_check in net/sched/sch_fq_codel.c

PATCH In review Valdis Kletnieks 4 participants 4 messages Dec 9, 2014 – Dec 10, 2014

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Networking Network drivers Traffic control (tc)
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Valdis Kletnieks

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#0 lore raw

PATCH 1/1 fix suspicious rcu_dereference_check in net/sched/sch_fq_codel.c

commit 46e5da40ae (net: qdisc: use rcu prefix and silence
sparse warnings) triggers a spurious warning:

net/sched/sch_fq_codel.c:97 suspicious rcu_dereference_check() usage!

The code should be using the _bh variant of rcu_dereference.

Signed-off-by Valdis Kletnieks <[email protected]>
---
 net/sched/sch_fq_codel.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
net/sched/sch_fq_codel.c +1 -1
index b9ca32ebc1de..1e52decb7b59 100644
@@ -94,7 +94,7 @@ static unsigned int fq_codel_classify(struct sk_buff *skb, struct Qdisc *sch,
 	    TC_H_MIN(skb->priority) <= q->flows_cnt)
 		return TC_H_MIN(skb->priority);
 
-	filter = rcu_dereference(q->filter_list);
+	filter = rcu_dereference_bh(q->filter_list);
 	if (!filter)
 		return fq_codel_hash(q, skb) + 1;
Signature · 1 line
2.2.0
Acked-by on v1 1/1
#1 lore raw
Quoted 11 lines · Valdis Kletnieks

commit 46e5da40ae (net: qdisc: use rcu prefix and silence
sparse warnings) triggers a spurious warning:

net/sched/sch_fq_codel.c:97 suspicious rcu_dereference_check() usage!

The code should be using the _bh variant of rcu_dereference.

Signed-off-by Valdis Kletnieks <[email protected]>
---
 net/sched/sch_fq_codel.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
Acked-by Eric Dumazet <[email protected]>

Thanks !

Acked-by
#2 lore raw
Quoted 8 lines · Eric Dumazet
Quoted 7 lines · Valdis Kletnieks

commit 46e5da40ae (net: qdisc: use rcu prefix and silence
sparse warnings) triggers a spurious warning:

net/sched/sch_fq_codel.c:97 suspicious rcu_dereference_check() usage!

The code should be using the _bh variant of rcu_dereference.

Quoted 10 lines
Quoted 4 lines
Signed-off-by Valdis Kletnieks <[email protected]>
---
 net/sched/sch_fq_codel.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
Acked-by Eric Dumazet <[email protected]>

Thanks !

Great thanks for finding/fixing!

Acked-by John Fastabend <[email protected]>
maintainer
#3 lore raw
In reply to Valdis Kletnieks

From: Valdis Kletnieks <[email protected]>
Date: Tue, 09 Dec 2014 16:15:50 -0500

Quoted 8 lines

commit 46e5da40ae (net: qdisc: use rcu prefix and silence
sparse warnings) triggers a spurious warning:

net/sched/sch_fq_codel.c:97 suspicious rcu_dereference_check() usage!

The code should be using the _bh variant of rcu_dereference.

Signed-off-by Valdis Kletnieks <[email protected]>

Applied and queued up for -stable, thanks.