mac80211: stop Rx during HW reconfig

While HW reconfig is in progress, drop all incoming Rx. This prevents
incoming packets from changing the internal state of the driver or
calling callbacks of the low level driver while it is in inconsistent
state.

Signed-off-by: Arik Nemtsov <arik@wizery.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

4 files changed, 17 insertions, 0 deletions

diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index e6cbf5b68c89..ddf768f6350e 100644
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -881,6 +881,9 @@ struct ieee80211_local {
         /* device is started */
         bool started;
 
+        /* device is during a HW reconfig */
+        bool in_reconfig;
+
         /* wowlan is enabled -- don't reconfig on resume */
         bool wowlan;
 
diff --git a/net/mac80211/main.c b/net/mac80211/main.c
index d81c178c7712..976e41365c25 100644
--- a/net/mac80211/main.c
+++ b/net/mac80211/main.c
@@ -345,6 +345,13 @@ void ieee80211_restart_hw(struct ieee80211_hw *hw)
         ieee80211_stop_queues_by_reason(hw,
                 IEEE80211_QUEUE_STOP_REASON_SUSPEND);
 
+        /*
+         * Stop all Rx during the reconfig. We don't want state changes
+         * or driver callbacks while this is in progress.
+         */
+        local->in_reconfig = true;
+        barrier();
+
         schedule_work(&local->restart_work);
 }
 EXPORT_SYMBOL(ieee80211_restart_hw);
diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c
index 6fd2cb0838c4..072e8f3afa2b 100644
--- a/net/mac80211/rx.c
+++ b/net/mac80211/rx.c
@@ -3027,6 +3027,10 @@ void ieee80211_rx(struct ieee80211_hw *hw, struct sk_buff *skb)
         if (unlikely(local->quiescing || local->suspended))
                 goto drop;
 
+        /* We might be during a HW reconfig, prevent Rx for the same reason */
+        if (unlikely(local->in_reconfig))
+                goto drop;
+
         /*
          * The same happens when we're not even started,
          * but that's worth a warning.
diff --git a/net/mac80211/util.c b/net/mac80211/util.c
index 1df4019f294b..242ecde381f6 100644
--- a/net/mac80211/util.c
+++ b/net/mac80211/util.c
@@ -1411,6 +1411,9 @@ int ieee80211_reconfig(struct ieee80211_local *local)
                 if (ieee80211_sdata_running(sdata))
                         ieee80211_enable_keys(sdata);
 
+        local->in_reconfig = false;
+        barrier();
+
  wake_up:
         /*
          * Clear the WLAN_STA_BLOCK_BA flag so new aggregation