diff options
| author | Eric Dumazet <edumazet@google.com> | 2015-03-16 07:14:34 -0700 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2015-03-16 16:32:23 -0400 |
| commit | 9f1ab18672bee992b6169bbfa2b5ae86b42e88a8 (patch) | |
| tree | eb41d9d508745c09bde7dd2b56dc83f6c9d0b0d6 /net/ipv4/tcp_metrics.c | |
| parent | bd76a116707bd2381da36cf7c3183df11293f1d6 (diff) | |
| download | linux-9f1ab18672bee992b6169bbfa2b5ae86b42e88a8.tar.bz2 | |
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.c | 20 |
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)) { |