diff options
Diffstat (limited to 'net/core/drop_monitor.c')
| -rw-r--r-- | net/core/drop_monitor.c | 11 |
1 files changed, 9 insertions, 2 deletions
diff --git a/net/core/drop_monitor.c b/net/core/drop_monitor.c index 7b288a121a41..d5dc6be2522c 100644 --- a/net/core/drop_monitor.c +++ b/net/core/drop_monitor.c @@ -283,13 +283,17 @@ static void trace_napi_poll_hit(void *ignore, struct napi_struct *napi, rcu_read_lock(); list_for_each_entry_rcu(new_stat, &hw_stats_list, list) { + struct net_device *dev; + /* * only add a note to our monitor buffer if: * 1) this is the dev we received on * 2) its after the last_rx delta * 3) our rx_dropped count has gone up */ - if ((new_stat->dev == napi->dev) && + /* Paired with WRITE_ONCE() in dropmon_net_event() */ + dev = READ_ONCE(new_stat->dev); + if ((dev == napi->dev) && (time_after(jiffies, new_stat->last_rx + dm_hw_check_delta)) && (napi->dev->stats.rx_dropped != new_stat->last_drop_val)) { trace_drop_common(NULL, NULL); @@ -1576,7 +1580,10 @@ static int dropmon_net_event(struct notifier_block *ev_block, mutex_lock(&net_dm_mutex); list_for_each_entry_safe(new_stat, tmp, &hw_stats_list, list) { if (new_stat->dev == dev) { - new_stat->dev = NULL; + + /* Paired with READ_ONCE() in trace_napi_poll_hit() */ + WRITE_ONCE(new_stat->dev, NULL); + if (trace_state == TRACE_OFF) { list_del_rcu(&new_stat->list); kfree_rcu(new_stat, rcu); |