From d4766692e72422f3b0f0e9ac6773d92baad07d51 Mon Sep 17 00:00:00 2001 From: Jarek Poplawski Date: Wed, 13 Aug 2008 15:20:24 -0700 Subject: [PATCH] pkt_sched: Protect gen estimators under est_lock. gen_kill_estimator() required rtnl_lock() protection, but since it is moved to an RCU callback __qdisc_destroy() let's use est_lock instead. Signed-off-by: Jarek Poplawski Signed-off-by: David S. Miller --- net/core/gen_estimator.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/net/core/gen_estimator.c b/net/core/gen_estimator.c index 57abe8266be1..a89f32fa94f6 100644 --- a/net/core/gen_estimator.c +++ b/net/core/gen_estimator.c @@ -99,7 +99,7 @@ struct gen_estimator_head static struct gen_estimator_head elist[EST_MAX_INTERVAL+1]; -/* Protects against NULL dereference */ +/* Protects against NULL dereference and RCU write-side */ static DEFINE_RWLOCK(est_lock); static void est_timer(unsigned long arg) @@ -185,6 +185,7 @@ int gen_new_estimator(struct gnet_stats_basic *bstats, est->last_packets = bstats->packets; est->avpps = rate_est->pps<<10; + write_lock_bh(&est_lock); if (!elist[idx].timer.function) { INIT_LIST_HEAD(&elist[idx].list); setup_timer(&elist[idx].timer, est_timer, idx); @@ -194,6 +195,7 @@ int gen_new_estimator(struct gnet_stats_basic *bstats, mod_timer(&elist[idx].timer, jiffies + ((HZ/4) << idx)); list_add_rcu(&est->list, &elist[idx].list); + write_unlock_bh(&est_lock); return 0; } @@ -212,7 +214,6 @@ static void __gen_kill_estimator(struct rcu_head *head) * Removes the rate estimator specified by &bstats and &rate_est * and deletes the timer. * - * NOTE: Called under rtnl_mutex */ void gen_kill_estimator(struct gnet_stats_basic *bstats, struct gnet_stats_rate_est *rate_est) @@ -226,17 +227,17 @@ void gen_kill_estimator(struct gnet_stats_basic *bstats, if (!elist[idx].timer.function) continue; + write_lock_bh(&est_lock); list_for_each_entry_safe(e, n, &elist[idx].list, list) { if (e->rate_est != rate_est || e->bstats != bstats) continue; - write_lock_bh(&est_lock); e->bstats = NULL; - write_unlock_bh(&est_lock); list_del_rcu(&e->list); call_rcu(&e->e_rcu, __gen_kill_estimator); } + write_unlock_bh(&est_lock); } } -- 2.20.1