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authorEric Dumazet <edumazet@google.com>2015-03-16 15:14:34 +0100
committerDavid S. Miller <davem@davemloft.net>2015-03-16 21:32:23 +0100
commit9f1ab18672bee992b6169bbfa2b5ae86b42e88a8 (patch)
treeeb41d9d508745c09bde7dd2b56dc83f6c9d0b0d6 /net/ipv4/tcp_metrics.c
parentdsa: change "select" to "depends on" for NET_SWITCHDEV and for NET_DSA (diff)
downloadlinux-9f1ab18672bee992b6169bbfa2b5ae86b42e88a8.tar.xz
linux-9f1ab18672bee992b6169bbfa2b5ae86b42e88a8.zip
tcp_metrics: fix wrong lockdep annotations
Changes in tcp_metric hash table are protected by tcp_metrics_lock only, not by genl_mutex While we are at it use deref_locked() instead of rcu_dereference() in tcp_new() to avoid unnecessary barrier, as we hold tcp_metrics_lock as well. 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.") Reviewed-by: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4/tcp_metrics.c')
-rw-r--r--net/ipv4/tcp_metrics.c20
1 files changed, 8 insertions, 12 deletions
diff --git a/net/ipv4/tcp_metrics.c b/net/ipv4/tcp_metrics.c
index 366728cbee4a..5bef3513af77 100644
--- a/net/ipv4/tcp_metrics.c
+++ b/net/ipv4/tcp_metrics.c
@@ -152,6 +152,9 @@ static void tcpm_check_stamp(struct tcp_metrics_block *tm, struct dst_entry *dst
#define TCP_METRICS_RECLAIM_DEPTH 5
#define TCP_METRICS_RECLAIM_PTR (struct tcp_metrics_block *) 0x1UL
+#define deref_locked(p) \
+ rcu_dereference_protected(p, lockdep_is_held(&tcp_metrics_lock))
+
static struct tcp_metrics_block *tcpm_new(struct dst_entry *dst,
struct inetpeer_addr *saddr,
struct inetpeer_addr *daddr,
@@ -180,9 +183,9 @@ static struct tcp_metrics_block *tcpm_new(struct dst_entry *dst,
if (unlikely(reclaim)) {
struct tcp_metrics_block *oldest;
- oldest = rcu_dereference(tcp_metrics_hash[hash].chain);
- for (tm = rcu_dereference(oldest->tcpm_next); tm;
- tm = rcu_dereference(tm->tcpm_next)) {
+ oldest = deref_locked(tcp_metrics_hash[hash].chain);
+ for (tm = deref_locked(oldest->tcpm_next); tm;
+ tm = deref_locked(tm->tcpm_next)) {
if (time_before(tm->tcpm_stamp, oldest->tcpm_stamp))
oldest = tm;
}
@@ -1040,12 +1043,6 @@ 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())
-
static void tcp_metrics_flush_all(struct net *net)
{
unsigned int max_rows = 1U << tcp_metrics_hash_log;
@@ -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)) {