pkt_sched: gen_kill_estimator() rcu fixes

gen_kill_estimator() API is incomplete or not well documented, since
caller should make sure an RCU grace period is respected before
freeing stats_lock.

This was partially addressed in commit 5d944c640b4
(gen_estimator: deadlock fix), but same problem exist for all
gen_kill_estimator() users, if lock they use is not already RCU
protected.

A code review shows xt_RATEEST.c, act_api.c, act_police.c have this
problem. Other are ok because they use qdisc lock, already RCU
protected.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 3 insertions, 0 deletions

diff --git a/include/net/act_api.h b/include/net/act_api.h
index c05fd717c588..bab385f13ac3 100644
--- a/include/net/act_api.h
+++ b/include/net/act_api.h
@@ -20,6 +20,7 @@ struct tcf_common {
         struct gnet_stats_queue         tcfc_qstats;
         struct gnet_stats_rate_est      tcfc_rate_est;
         spinlock_t                      tcfc_lock;
+        struct rcu_head                 tcfc_rcu;
 };
 #define tcf_next        common.tcfc_next
 #define tcf_index       common.tcfc_index
@@ -32,6 +33,7 @@ struct tcf_common {
 #define tcf_qstats      common.tcfc_qstats
 #define tcf_rate_est    common.tcfc_rate_est
 #define tcf_lock        common.tcfc_lock
+#define tcf_rcu         common.tcfc_rcu
 
 struct tcf_police {
         struct tcf_common       common;
diff --git a/include/net/netfilter/xt_rateest.h b/include/net/netfilter/xt_rateest.h
index ddbf37e19616..5e1427795928 100644
--- a/include/net/netfilter/xt_rateest.h
+++ b/include/net/netfilter/xt_rateest.h
@@ -9,6 +9,7 @@ struct xt_rateest {
         struct gnet_estimator           params;
         struct gnet_stats_rate_est      rstats;
         struct gnet_stats_basic_packed  bstats;
+        struct rcu_head                 rcu;
 };
 
 extern struct xt_rateest *xt_rateest_lookup(const char *name);