diff mbox

[net-next] tcp_metrics: fix wrong lockdep annotations

Message ID 1426514329.11398.204.camel@edumazet-glaptop2.roam.corp.google.com
State Superseded, archived
Delegated to: David Miller
Headers show

Commit Message

Eric Dumazet March 16, 2015, 1:58 p.m. UTC 
From: Eric Dumazet <edumazet@google.com>

Changes in tcp_metric hash table are protected by tcp_metrics_lock
only, not by genl_mutex

Reported-by: Andrew Vagin <avagin@parallels.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Fixes: 098a697b497e ("tcp_metrics: Use a single hash table for all network namespaces.")
---
 net/ipv4/tcp_metrics.c |   12 ++++--------
 1 file changed, 4 insertions(+), 8 deletions(-)



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Comments

Eric Dumazet March 16, 2015, 2:10 p.m. UTC | #1 
On Mon, 2015-03-16 at 06:58 -0700, Eric Dumazet wrote:
> From: Eric Dumazet <edumazet@google.com>
> 
> Changes in tcp_metric hash table are protected by tcp_metrics_lock
> only, not by genl_mutex
> 
> Reported-by: Andrew Vagin <avagin@parallels.com>
> Signed-off-by: Eric Dumazet <edumazet@google.com>
> Fixes: 098a697b497e ("tcp_metrics: Use a single hash table for all network namespaces.")
> ---
>  net/ipv4/tcp_metrics.c |   12 ++++--------
>  1 file changed, 4 insertions(+), 8 deletions(-)

I'll send a v2 : We also can use deref_locked() in tcp_new() to avoid
unnecessary barrier (as they are implied in rcu_dereference())
 

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diff mbox

Patch

diff --git a/net/ipv4/tcp_metrics.c b/net/ipv4/tcp_metrics.c
index 366728cbee4a692394696f13e6aacf0331990eed..c7d34db9cfc99d85f6d21cf5bd7e718e80e404e7 100644
--- a/net/ipv4/tcp_metrics.c
+++ b/net/ipv4/tcp_metrics.c
@@ -1040,11 +1040,8 @@  out_free:
 	return ret;
 }
 
-#define deref_locked_genl(p)	\
-	rcu_dereference_protected(p, lockdep_genl_is_held() && \
-				     lockdep_is_held(&tcp_metrics_lock))
-
-#define deref_genl(p)	rcu_dereference_protected(p, lockdep_genl_is_held())
+#define deref_locked(p)	\
+	rcu_dereference_protected(p, lockdep_is_held(&tcp_metrics_lock))
 
 static void tcp_metrics_flush_all(struct net *net)
 {
@@ -1057,8 +1054,7 @@  static void tcp_metrics_flush_all(struct net *net)
 		struct tcp_metrics_block __rcu **pp;
 		spin_lock_bh(&tcp_metrics_lock);
 		pp = &hb->chain;
-		for (tm = deref_locked_genl(*pp); tm;
-		     tm = deref_locked_genl(*pp)) {
+		for (tm = deref_locked(*pp); tm; tm = deref_locked(*pp)) {
 			if (net_eq(tm_net(tm), net)) {
 				*pp = tm->tcpm_next;
 				kfree_rcu(tm, rcu_head);
@@ -1097,7 +1093,7 @@  static int tcp_metrics_nl_cmd_del(struct sk_buff *skb, struct genl_info *info)
 	hb = tcp_metrics_hash + hash;
 	pp = &hb->chain;
 	spin_lock_bh(&tcp_metrics_lock);
-	for (tm = deref_locked_genl(*pp); tm; tm = deref_locked_genl(*pp)) {
+	for (tm = deref_locked(*pp); tm; tm = deref_locked(*pp)) {
 		if (addr_same(&tm->tcpm_daddr, &daddr) &&
 		    (!src || addr_same(&tm->tcpm_saddr, &saddr)) &&
 		    net_eq(tm_net(tm), net)) {