From: Ido Schimmel <idosch@mellanox.com>
Date: Sat, 17 Aug 2019 16:28:13 +0300
Subject: drop_monitor: Consider all monitoring states before performing
 configuration
Patch-mainline: v5.4-rc1
Git-commit: 80cebed85c88e71fb435b9eb5948548f10f15cba
References: bsc#1154353

The drop monitor configuration (e.g., alert mode) is global, but user
will be able to enable monitoring of only software or hardware drops.

Therefore, ensure that monitoring of both software and hardware drops are
disabled before allowing drop monitor configuration to take place.

Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
 net/core/drop_monitor.c |    9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

--- a/net/core/drop_monitor.c
+++ b/net/core/drop_monitor.c
@@ -633,6 +633,11 @@ static int set_all_monitor_traces(int st
 	return rc;
 }
 
+static bool net_dm_is_monitoring(void)
+{
+	return trace_state == TRACE_ON || monitor_hw;
+}
+
 static int net_dm_alert_mode_get_from_info(struct genl_info *info,
 					   enum net_dm_alert_mode *p_alert_mode)
 {
@@ -694,8 +699,8 @@ static int net_dm_cmd_config(struct sk_b
 	struct netlink_ext_ack *extack = info->extack;
 	int rc;
 
-	if (trace_state == TRACE_ON) {
-		NL_SET_ERR_MSG_MOD(extack, "Cannot configure drop monitor while tracing is on");
+	if (net_dm_is_monitoring()) {
+		NL_SET_ERR_MSG_MOD(extack, "Cannot configure drop monitor during monitoring");
 		return -EBUSY;
 	}