1 files changed, 562 insertions, 37 deletions

diff --git a/net/core/drop_monitor.c b/net/core/drop_monitor.c
index 4deb86f990f1..39e094907391 100644
--- a/net/core/drop_monitor.c
+++ b/net/core/drop_monitor.c
@@ -51,11 +51,18 @@ static int trace_state = TRACE_OFF;
  */
 static DEFINE_MUTEX(net_dm_mutex);
 
+struct net_dm_stats {
+	u64 dropped;
+	struct u64_stats_sync syncp;
+};
+
 struct per_cpu_dm_data {
 	spinlock_t		lock;	/* Protects 'skb' and 'send_timer' */
 	struct sk_buff		*skb;
+	struct sk_buff_head	drop_queue;
 	struct work_struct	dm_alert_work;
 	struct timer_list	send_timer;
+	struct net_dm_stats	stats;
 };
 
 struct dm_hw_stat_delta {
@@ -75,6 +82,24 @@ static int dm_delay = 1;
 static unsigned long dm_hw_check_delta = 2*HZ;
 static LIST_HEAD(hw_stats_list);
 
+static enum net_dm_alert_mode net_dm_alert_mode = NET_DM_ALERT_MODE_SUMMARY;
+static u32 net_dm_trunc_len;
+static u32 net_dm_queue_len = 1000;
+
+struct net_dm_alert_ops {
+	void (*kfree_skb_probe)(void *ignore, struct sk_buff *skb,
+				void *location);
+	void (*napi_poll_probe)(void *ignore, struct napi_struct *napi,
+				int work, int budget);
+	void (*work_item_func)(struct work_struct *work);
+};
+
+struct net_dm_skb_cb {
+	void *pc;
+};
+
+#define NET_DM_SKB_CB(__skb) ((struct net_dm_skb_cb *)&((__skb)->cb[0]))
+
 static struct sk_buff *reset_per_cpu_data(struct per_cpu_dm_data *data)
 {
 	size_t al;
@@ -241,11 +266,318 @@ static void trace_napi_poll_hit(void *ignore, struct napi_struct *napi,
 	rcu_read_unlock();
 }
 
+static const struct net_dm_alert_ops net_dm_alert_summary_ops = {
+	.kfree_skb_probe	= trace_kfree_skb_hit,
+	.napi_poll_probe	= trace_napi_poll_hit,
+	.work_item_func		= send_dm_alert,
+};
+
+static void net_dm_packet_trace_kfree_skb_hit(void *ignore,
+					      struct sk_buff *skb,
+					      void *location)
+{
+	ktime_t tstamp = ktime_get_real();
+	struct per_cpu_dm_data *data;
+	struct sk_buff *nskb;
+	unsigned long flags;
+
+	nskb = skb_clone(skb, GFP_ATOMIC);
+	if (!nskb)
+		return;
+
+	NET_DM_SKB_CB(nskb)->pc = location;
+	/* Override the timestamp because we care about the time when the
+	 * packet was dropped.
+	 */
+	nskb->tstamp = tstamp;
+
+	data = this_cpu_ptr(&dm_cpu_data);
+
+	spin_lock_irqsave(&data->drop_queue.lock, flags);
+	if (skb_queue_len(&data->drop_queue) < net_dm_queue_len)
+		__skb_queue_tail(&data->drop_queue, nskb);
+	else
+		goto unlock_free;
+	spin_unlock_irqrestore(&data->drop_queue.lock, flags);
+
+	schedule_work(&data->dm_alert_work);
+
+	return;
+
+unlock_free:
+	spin_unlock_irqrestore(&data->drop_queue.lock, flags);
+	u64_stats_update_begin(&data->stats.syncp);
+	data->stats.dropped++;
+	u64_stats_update_end(&data->stats.syncp);
+	consume_skb(nskb);
+}
+
+static void net_dm_packet_trace_napi_poll_hit(void *ignore,
+					      struct napi_struct *napi,
+					      int work, int budget)
+{
+}
+
+static size_t net_dm_in_port_size(void)
+{
+	       /* NET_DM_ATTR_IN_PORT nest */
+	return nla_total_size(0) +
+	       /* NET_DM_ATTR_PORT_NETDEV_IFINDEX */
+	       nla_total_size(sizeof(u32));
+}
+
+#define NET_DM_MAX_SYMBOL_LEN 40
+
+static size_t net_dm_packet_report_size(size_t payload_len)
+{
+	size_t size;
+
+	size = nlmsg_msg_size(GENL_HDRLEN + net_drop_monitor_family.hdrsize);
+
+	return NLMSG_ALIGN(size) +
+	       /* NET_DM_ATTR_PC */
+	       nla_total_size(sizeof(u64)) +
+	       /* NET_DM_ATTR_SYMBOL */
+	       nla_total_size(NET_DM_MAX_SYMBOL_LEN + 1) +
+	       /* NET_DM_ATTR_IN_PORT */
+	       net_dm_in_port_size() +
+	       /* NET_DM_ATTR_TIMESTAMP */
+	       nla_total_size(sizeof(struct timespec)) +
+	       /* NET_DM_ATTR_ORIG_LEN */
+	       nla_total_size(sizeof(u32)) +
+	       /* NET_DM_ATTR_PROTO */
+	       nla_total_size(sizeof(u16)) +
+	       /* NET_DM_ATTR_PAYLOAD */
+	       nla_total_size(payload_len);
+}
+
+static int net_dm_packet_report_in_port_put(struct sk_buff *msg, int ifindex)
+{
+	struct nlattr *attr;
+
+	attr = nla_nest_start(msg, NET_DM_ATTR_IN_PORT);
+	if (!attr)
+		return -EMSGSIZE;
+
+	if (ifindex &&
+	    nla_put_u32(msg, NET_DM_ATTR_PORT_NETDEV_IFINDEX, ifindex))
+		goto nla_put_failure;
+
+	nla_nest_end(msg, attr);
+
+	return 0;
+
+nla_put_failure:
+	nla_nest_cancel(msg, attr);
+	return -EMSGSIZE;
+}
+
+static int net_dm_packet_report_fill(struct sk_buff *msg, struct sk_buff *skb,
+				     size_t payload_len)
+{
+	u64 pc = (u64)(uintptr_t) NET_DM_SKB_CB(skb)->pc;
+	char buf[NET_DM_MAX_SYMBOL_LEN];
+	struct nlattr *attr;
+	struct timespec ts;
+	void *hdr;
+	int rc;
+
+	hdr = genlmsg_put(msg, 0, 0, &net_drop_monitor_family, 0,
+			  NET_DM_CMD_PACKET_ALERT);
+	if (!hdr)
+		return -EMSGSIZE;
+
+	if (nla_put_u64_64bit(msg, NET_DM_ATTR_PC, pc, NET_DM_ATTR_PAD))
+		goto nla_put_failure;
+
+	snprintf(buf, sizeof(buf), "%pS", NET_DM_SKB_CB(skb)->pc);
+	if (nla_put_string(msg, NET_DM_ATTR_SYMBOL, buf))
+		goto nla_put_failure;
+
+	rc = net_dm_packet_report_in_port_put(msg, skb->skb_iif);
+	if (rc)
+		goto nla_put_failure;
+
+	if (ktime_to_timespec_cond(skb->tstamp, &ts) &&
+	    nla_put(msg, NET_DM_ATTR_TIMESTAMP, sizeof(ts), &ts))
+		goto nla_put_failure;
+
+	if (nla_put_u32(msg, NET_DM_ATTR_ORIG_LEN, skb->len))
+		goto nla_put_failure;
+
+	if (!payload_len)
+		goto out;
+
+	if (nla_put_u16(msg, NET_DM_ATTR_PROTO, be16_to_cpu(skb->protocol)))
+		goto nla_put_failure;
+
+	attr = skb_put(msg, nla_total_size(payload_len));
+	attr->nla_type = NET_DM_ATTR_PAYLOAD;
+	attr->nla_len = nla_attr_size(payload_len);
+	if (skb_copy_bits(skb, 0, nla_data(attr), payload_len))
+		goto nla_put_failure;
+
+out:
+	genlmsg_end(msg, hdr);
+
+	return 0;
+
+nla_put_failure:
+	genlmsg_cancel(msg, hdr);
+	return -EMSGSIZE;
+}
+
+#define NET_DM_MAX_PACKET_SIZE (0xffff - NLA_HDRLEN - NLA_ALIGNTO)
+
+static void net_dm_packet_report(struct sk_buff *skb)
+{
+	struct sk_buff *msg;
+	size_t payload_len;
+	int rc;
+
+	/* Make sure we start copying the packet from the MAC header */
+	if (skb->data > skb_mac_header(skb))
+		skb_push(skb, skb->data - skb_mac_header(skb));
+	else
+		skb_pull(skb, skb_mac_header(skb) - skb->data);
+
+	/* Ensure packet fits inside a single netlink attribute */
+	payload_len = min_t(size_t, skb->len, NET_DM_MAX_PACKET_SIZE);
+	if (net_dm_trunc_len)
+		payload_len = min_t(size_t, net_dm_trunc_len, payload_len);
+
+	msg = nlmsg_new(net_dm_packet_report_size(payload_len), GFP_KERNEL);
+	if (!msg)
+		goto out;
+
+	rc = net_dm_packet_report_fill(msg, skb, payload_len);
+	if (rc) {
+		nlmsg_free(msg);
+		goto out;
+	}
+
+	genlmsg_multicast(&net_drop_monitor_family, msg, 0, 0, GFP_KERNEL);
+
+out:
+	consume_skb(skb);
+}
+
+static void net_dm_packet_work(struct work_struct *work)
+{
+	struct per_cpu_dm_data *data;
+	struct sk_buff_head list;
+	struct sk_buff *skb;
+	unsigned long flags;
+
+	data = container_of(work, struct per_cpu_dm_data, dm_alert_work);
+
+	__skb_queue_head_init(&list);
+
+	spin_lock_irqsave(&data->drop_queue.lock, flags);
+	skb_queue_splice_tail_init(&data->drop_queue, &list);
+	spin_unlock_irqrestore(&data->drop_queue.lock, flags);
+
+	while ((skb = __skb_dequeue(&list)))
+		net_dm_packet_report(skb);
+}
+
+static const struct net_dm_alert_ops net_dm_alert_packet_ops = {
+	.kfree_skb_probe	= net_dm_packet_trace_kfree_skb_hit,
+	.napi_poll_probe	= net_dm_packet_trace_napi_poll_hit,
+	.work_item_func		= net_dm_packet_work,
+};
+
+static const struct net_dm_alert_ops *net_dm_alert_ops_arr[] = {
+	[NET_DM_ALERT_MODE_SUMMARY]	= &net_dm_alert_summary_ops,
+	[NET_DM_ALERT_MODE_PACKET]	= &net_dm_alert_packet_ops,
+};
+
+static int net_dm_trace_on_set(struct netlink_ext_ack *extack)
+{
+	const struct net_dm_alert_ops *ops;
+	int cpu, rc;
+
+	ops = net_dm_alert_ops_arr[net_dm_alert_mode];
+
+	if (!try_module_get(THIS_MODULE)) {
+		NL_SET_ERR_MSG_MOD(extack, "Failed to take reference on module");
+		return -ENODEV;
+	}
+
+	for_each_possible_cpu(cpu) {
+		struct per_cpu_dm_data *data = &per_cpu(dm_cpu_data, cpu);
+		struct sk_buff *skb;
+
+		INIT_WORK(&data->dm_alert_work, ops->work_item_func);
+		timer_setup(&data->send_timer, sched_send_work, 0);
+		/* Allocate a new per-CPU skb for the summary alert message and
+		 * free the old one which might contain stale data from
+		 * previous tracing.
+		 */
+		skb = reset_per_cpu_data(data);
+		consume_skb(skb);
+	}
+
+	rc = register_trace_kfree_skb(ops->kfree_skb_probe, NULL);
+	if (rc) {
+		NL_SET_ERR_MSG_MOD(extack, "Failed to connect probe to kfree_skb() tracepoint");
+		goto err_module_put;
+	}
+
+	rc = register_trace_napi_poll(ops->napi_poll_probe, NULL);
+	if (rc) {
+		NL_SET_ERR_MSG_MOD(extack, "Failed to connect probe to napi_poll() tracepoint");
+		goto err_unregister_trace;
+	}
+
+	return 0;
+
+err_unregister_trace:
+	unregister_trace_kfree_skb(ops->kfree_skb_probe, NULL);
+err_module_put:
+	module_put(THIS_MODULE);
+	return rc;
+}
+
+static void net_dm_trace_off_set(void)
+{
+	struct dm_hw_stat_delta *new_stat, *temp;
+	const struct net_dm_alert_ops *ops;
+	int cpu;
+
+	ops = net_dm_alert_ops_arr[net_dm_alert_mode];
+
+	unregister_trace_napi_poll(ops->napi_poll_probe, NULL);
+	unregister_trace_kfree_skb(ops->kfree_skb_probe, NULL);
+
+	tracepoint_synchronize_unregister();
+
+	/* Make sure we do not send notifications to user space after request
+	 * to stop tracing returns.
+	 */
+	for_each_possible_cpu(cpu) {
+		struct per_cpu_dm_data *data = &per_cpu(dm_cpu_data, cpu);
+		struct sk_buff *skb;
+
+		del_timer_sync(&data->send_timer);
+		cancel_work_sync(&data->dm_alert_work);
+		while ((skb = __skb_dequeue(&data->drop_queue)))
+			consume_skb(skb);
+	}
+
+	list_for_each_entry_safe(new_stat, temp, &hw_stats_list, list) {
+		if (new_stat->dev == NULL) {
+			list_del_rcu(&new_stat->list);
+			kfree_rcu(new_stat, rcu);
+		}
+	}
+
+	module_put(THIS_MODULE);
+}
+
 static int set_all_monitor_traces(int state, struct netlink_ext_ack *extack)
 {
 	int rc = 0;
-	struct dm_hw_stat_delta *new_stat = NULL;
-	struct dm_hw_stat_delta *temp;
 
 	if (state == trace_state) {
 		NL_SET_ERR_MSG_MOD(extack, "Trace state already set to requested state");
@@ -254,34 +586,10 @@ static int set_all_monitor_traces(int state, struct netlink_ext_ack *extack)
 
 	switch (state) {
 	case TRACE_ON:
-		if (!try_module_get(THIS_MODULE)) {
-			NL_SET_ERR_MSG_MOD(extack, "Failed to take reference on module");
-			rc = -ENODEV;
-			break;
-		}
-
-		rc |= register_trace_kfree_skb(trace_kfree_skb_hit, NULL);
-		rc |= register_trace_napi_poll(trace_napi_poll_hit, NULL);
+		rc = net_dm_trace_on_set(extack);
 		break;
-
 	case TRACE_OFF:
-		rc |= unregister_trace_kfree_skb(trace_kfree_skb_hit, NULL);
-		rc |= unregister_trace_napi_poll(trace_napi_poll_hit, NULL);
-
-		tracepoint_synchronize_unregister();
-
-		/*
-		 * Clean the device list
-		 */
-		list_for_each_entry_safe(new_stat, temp, &hw_stats_list, list) {
-			if (new_stat->dev == NULL) {
-				list_del_rcu(&new_stat->list);
-				kfree_rcu(new_stat, rcu);
-			}
-		}
-
-		module_put(THIS_MODULE);
-
+		net_dm_trace_off_set();
 		break;
 	default:
 		rc = 1;
@@ -296,12 +604,81 @@ static int set_all_monitor_traces(int state, struct netlink_ext_ack *extack)
 	return rc;
 }
 
+static int net_dm_alert_mode_get_from_info(struct genl_info *info,
+					   enum net_dm_alert_mode *p_alert_mode)
+{
+	u8 val;
+
+	val = nla_get_u8(info->attrs[NET_DM_ATTR_ALERT_MODE]);
+
+	switch (val) {
+	case NET_DM_ALERT_MODE_SUMMARY: /* fall-through */
+	case NET_DM_ALERT_MODE_PACKET:
+		*p_alert_mode = val;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int net_dm_alert_mode_set(struct genl_info *info)
+{
+	struct netlink_ext_ack *extack = info->extack;
+	enum net_dm_alert_mode alert_mode;
+	int rc;
+
+	if (!info->attrs[NET_DM_ATTR_ALERT_MODE])
+		return 0;
+
+	rc = net_dm_alert_mode_get_from_info(info, &alert_mode);
+	if (rc) {
+		NL_SET_ERR_MSG_MOD(extack, "Invalid alert mode");
+		return -EINVAL;
+	}
+
+	net_dm_alert_mode = alert_mode;
+
+	return 0;
+}
+
+static void net_dm_trunc_len_set(struct genl_info *info)
+{
+	if (!info->attrs[NET_DM_ATTR_TRUNC_LEN])
+		return;
+
+	net_dm_trunc_len = nla_get_u32(info->attrs[NET_DM_ATTR_TRUNC_LEN]);
+}
+
+static void net_dm_queue_len_set(struct genl_info *info)
+{
+	if (!info->attrs[NET_DM_ATTR_QUEUE_LEN])
+		return;
+
+	net_dm_queue_len = nla_get_u32(info->attrs[NET_DM_ATTR_QUEUE_LEN]);
+}
+
 static int net_dm_cmd_config(struct sk_buff *skb,
 			struct genl_info *info)
 {
-	NL_SET_ERR_MSG_MOD(info->extack, "Command not supported");
+	struct netlink_ext_ack *extack = info->extack;
+	int rc;
 
-	return -EOPNOTSUPP;
+	if (trace_state == TRACE_ON) {
+		NL_SET_ERR_MSG_MOD(extack, "Cannot configure drop monitor while tracing is on");
+		return -EBUSY;
+	}
+
+	rc = net_dm_alert_mode_set(info);
+	if (rc)
+		return rc;
+
+	net_dm_trunc_len_set(info);
+
+	net_dm_queue_len_set(info);
+
+	return 0;
 }
 
 static int net_dm_cmd_trace(struct sk_buff *skb,
@@ -317,6 +694,140 @@ static int net_dm_cmd_trace(struct sk_buff *skb,
 	return -EOPNOTSUPP;
 }
 
+static int net_dm_config_fill(struct sk_buff *msg, struct genl_info *info)
+{
+	void *hdr;
+
+	hdr = genlmsg_put(msg, info->snd_portid, info->snd_seq,
+			  &net_drop_monitor_family, 0, NET_DM_CMD_CONFIG_NEW);
+	if (!hdr)
+		return -EMSGSIZE;
+
+	if (nla_put_u8(msg, NET_DM_ATTR_ALERT_MODE, net_dm_alert_mode))
+		goto nla_put_failure;
+
+	if (nla_put_u32(msg, NET_DM_ATTR_TRUNC_LEN, net_dm_trunc_len))
+		goto nla_put_failure;
+
+	if (nla_put_u32(msg, NET_DM_ATTR_QUEUE_LEN, net_dm_queue_len))
+		goto nla_put_failure;
+
+	genlmsg_end(msg, hdr);
+
+	return 0;
+
+nla_put_failure:
+	genlmsg_cancel(msg, hdr);
+	return -EMSGSIZE;
+}
+
+static int net_dm_cmd_config_get(struct sk_buff *skb, struct genl_info *info)
+{
+	struct sk_buff *msg;
+	int rc;
+
+	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
+	if (!msg)
+		return -ENOMEM;
+
+	rc = net_dm_config_fill(msg, info);
+	if (rc)
+		goto free_msg;
+
+	return genlmsg_reply(msg, info);
+
+free_msg:
+	nlmsg_free(msg);
+	return rc;
+}
+
+static void net_dm_stats_read(struct net_dm_stats *stats)
+{
+	int cpu;
+
+	memset(stats, 0, sizeof(*stats));
+	for_each_possible_cpu(cpu) {
+		struct per_cpu_dm_data *data = &per_cpu(dm_cpu_data, cpu);
+		struct net_dm_stats *cpu_stats = &data->stats;
+		unsigned int start;
+		u64 dropped;
+
+		do {
+			start = u64_stats_fetch_begin_irq(&cpu_stats->syncp);
+			dropped = cpu_stats->dropped;
+		} while (u64_stats_fetch_retry_irq(&cpu_stats->syncp, start));
+
+		stats->dropped += dropped;
+	}
+}
+
+static int net_dm_stats_put(struct sk_buff *msg)
+{
+	struct net_dm_stats stats;
+	struct nlattr *attr;
+
+	net_dm_stats_read(&stats);
+
+	attr = nla_nest_start(msg, NET_DM_ATTR_STATS);
+	if (!attr)
+		return -EMSGSIZE;
+
+	if (nla_put_u64_64bit(msg, NET_DM_ATTR_STATS_DROPPED,
+			      stats.dropped, NET_DM_ATTR_PAD))
+		goto nla_put_failure;
+
+	nla_nest_end(msg, attr);
+
+	return 0;
+
+nla_put_failure:
+	nla_nest_cancel(msg, attr);
+	return -EMSGSIZE;
+}
+
+static int net_dm_stats_fill(struct sk_buff *msg, struct genl_info *info)
+{
+	void *hdr;
+	int rc;
+
+	hdr = genlmsg_put(msg, info->snd_portid, info->snd_seq,
+			  &net_drop_monitor_family, 0, NET_DM_CMD_STATS_NEW);
+	if (!hdr)
+		return -EMSGSIZE;
+
+	rc = net_dm_stats_put(msg);
+	if (rc)
+		goto nla_put_failure;
+
+	genlmsg_end(msg, hdr);
+
+	return 0;
+
+nla_put_failure:
+	genlmsg_cancel(msg, hdr);
+	return -EMSGSIZE;
+}
+
+static int net_dm_cmd_stats_get(struct sk_buff *skb, struct genl_info *info)
+{
+	struct sk_buff *msg;
+	int rc;
+
+	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
+	if (!msg)
+		return -ENOMEM;
+
+	rc = net_dm_stats_fill(msg, info);
+	if (rc)
+		goto free_msg;
+
+	return genlmsg_reply(msg, info);
+
+free_msg:
+	nlmsg_free(msg);
+	return rc;
+}
+
 static int dropmon_net_event(struct notifier_block *ev_block,
 			     unsigned long event, void *ptr)
 {
@@ -356,11 +867,19 @@ out:
 	return NOTIFY_DONE;
 }
 
+static const struct nla_policy net_dm_nl_policy[NET_DM_ATTR_MAX + 1] = {
+	[NET_DM_ATTR_UNSPEC] = { .strict_start_type = NET_DM_ATTR_UNSPEC + 1 },
+	[NET_DM_ATTR_ALERT_MODE] = { .type = NLA_U8 },
+	[NET_DM_ATTR_TRUNC_LEN] = { .type = NLA_U32 },
+	[NET_DM_ATTR_QUEUE_LEN] = { .type = NLA_U32 },
+};
+
 static const struct genl_ops dropmon_ops[] = {
 	{
 		.cmd = NET_DM_CMD_CONFIG,
 		.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
 		.doit = net_dm_cmd_config,
+		.flags = GENL_ADMIN_PERM,
 	},
 	{
 		.cmd = NET_DM_CMD_START,
@@ -372,6 +891,14 @@ static const struct genl_ops dropmon_ops[] = {
 		.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
 		.doit = net_dm_cmd_trace,
 	},
+	{
+		.cmd = NET_DM_CMD_CONFIG_GET,
+		.doit = net_dm_cmd_config_get,
+	},
+	{
+		.cmd = NET_DM_CMD_STATS_GET,
+		.doit = net_dm_cmd_stats_get,
+	},
 };
 
 static int net_dm_nl_pre_doit(const struct genl_ops *ops,
@@ -392,6 +919,8 @@ static struct genl_family net_drop_monitor_family __ro_after_init = {
 	.hdrsize        = 0,
 	.name           = "NET_DM",
 	.version        = 2,
+	.maxattr	= NET_DM_ATTR_MAX,
+	.policy		= net_dm_nl_policy,
 	.pre_doit	= net_dm_nl_pre_doit,
 	.post_doit	= net_dm_nl_post_doit,
 	.module		= THIS_MODULE,
@@ -434,10 +963,9 @@ static int __init init_net_drop_monitor(void)
 
 	for_each_possible_cpu(cpu) {
 		data = &per_cpu(dm_cpu_data, cpu);
-		INIT_WORK(&data->dm_alert_work, send_dm_alert);
-		timer_setup(&data->send_timer, sched_send_work, 0);
 		spin_lock_init(&data->lock);
-		reset_per_cpu_data(data);
+		skb_queue_head_init(&data->drop_queue);
+		u64_stats_init(&data->stats.syncp);
 	}
 
 	goto out;
@@ -458,19 +986,16 @@ static void exit_net_drop_monitor(void)
 	/*
 	 * Because of the module_get/put we do in the trace state change path
 	 * we are guarnateed not to have any current users when we get here
-	 * all we need to do is make sure that we don't have any running timers
-	 * or pending schedule calls
 	 */
 
 	for_each_possible_cpu(cpu) {
 		data = &per_cpu(dm_cpu_data, cpu);
-		del_timer_sync(&data->send_timer);
-		cancel_work_sync(&data->dm_alert_work);
 		/*
 		 * At this point, we should have exclusive access
 		 * to this struct and can free the skb inside it
 		 */
 		kfree_skb(data->skb);
+		WARN_ON(!skb_queue_empty(&data->drop_queue));
 	}
 
 	BUG_ON(genl_unregister_family(&net_drop_monitor_family));