svn commit: r321401 - head/sys/net80211

[Andriy Voskoboinyk]

Author: avos
Date: Sun Jul 23 22:38:00 2017
New Revision: 321401
URL: https://svnweb.freebsd.org/changeset/base/321401

Log:
  net80211: do not allow to unload rate control module if it is still in use.
  
  Keep 'nrefs' counter up-to-date, so 'kldunload wlan_amrr' with 1+ active
  wlan(4) interface will not lead to kernel panic.
  
  MFC after:	5 days

Modified:
  head/sys/net80211/ieee80211_amrr.c
  head/sys/net80211/ieee80211_rssadapt.c

Modified: head/sys/net80211/ieee80211_amrr.c
==============================================================================
--- head/sys/net80211/ieee80211_amrr.c	Sun Jul 23 21:28:00 2017	(r321400)
+++ head/sys/net80211/ieee80211_amrr.c	Sun Jul 23 22:38:00 2017	(r321401)
@@ -117,6 +117,7 @@ amrr_init(struct ieee80211vap *vap)
 
 	KASSERT(vap->iv_rs == NULL, ("%s called multiple times", __func__));
 
+	nrefs++;		/* XXX locking */
 	amrr = vap->iv_rs = IEEE80211_MALLOC(sizeof(struct ieee80211_amrr),
 	    M_80211_RATECTL, IEEE80211_M_NOWAIT | IEEE80211_M_ZERO);
 	if (amrr == NULL) {
@@ -133,6 +134,8 @@ static void
 amrr_deinit(struct ieee80211vap *vap)
 {
 	IEEE80211_FREE(vap->iv_rs, M_80211_RATECTL);
+	KASSERT(nrefs > 0, ("imbalanced attach/detach"));
+	nrefs--;		/* XXX locking */
 }
 
 /*

Modified: head/sys/net80211/ieee80211_rssadapt.c
==============================================================================
--- head/sys/net80211/ieee80211_rssadapt.c	Sun Jul 23 21:28:00 2017	(r321400)
+++ head/sys/net80211/ieee80211_rssadapt.c	Sun Jul 23 22:38:00 2017	(r321401)
@@ -130,7 +130,8 @@ rssadapt_init(struct ieee80211vap *vap)
 
 	KASSERT(vap->iv_rs == NULL, ("%s: iv_rs already initialized",
 	    __func__));
-	
+
+	nrefs++;		/* XXX locking */
 	vap->iv_rs = rs = IEEE80211_MALLOC(sizeof(struct ieee80211_rssadapt),
 	    M_80211_RATECTL, IEEE80211_M_NOWAIT | IEEE80211_M_ZERO);
 	if (rs == NULL) {
@@ -146,6 +147,8 @@ static void
 rssadapt_deinit(struct ieee80211vap *vap)
 {
 	IEEE80211_FREE(vap->iv_rs, M_80211_RATECTL);
+	KASSERT(nrefs > 0, ("imbalanced attach/detach"));
+	nrefs--;		/* XXX locking */
 }
 
 static void