[PATCH v5 3/3] mac80211: add KCOV remote annotations to incoming frame processing

[Aleksandr Nogikh]

From: Aleksandr Nogikh <nog...@google.com>

Add KCOV remote annotations to ieee80211_iface_work() and
ieee80211_rx_list(). This will enable coverage-guided fuzzing of
mac80211 code that processes incoming 802.11 frames.

Signed-off-by: Aleksandr Nogikh <nog...@google.com>
---
v4 -> v5:
* Using ieee80211_rx_list() instead of ieee80211_rx().
v1 -> v2:
* The commit now affects ieee80211_rx() instead of
  ieee80211_tasklet_handler().
---
 net/mac80211/iface.c |  2 ++
 net/mac80211/rx.c    | 16 +++++++++-------
 2 files changed, 11 insertions(+), 7 deletions(-)

diff --git a/net/mac80211/iface.c b/net/mac80211/iface.c
index 1be775979132..56a1bcea2c1c 100644
--- a/net/mac80211/iface.c
+++ b/net/mac80211/iface.c
@@ -1356,6 +1356,7 @@ static void ieee80211_iface_work(struct work_struct *work)
        while ((skb = skb_dequeue(&sdata->skb_queue))) {
                struct ieee80211_mgmt *mgmt = (void *)skb->data;
 
+               kcov_remote_start_common(skb_get_kcov_handle(skb));
                if (ieee80211_is_action(mgmt->frame_control) &&
                    mgmt->u.action.category == WLAN_CATEGORY_BACK) {
                        int len = skb->len;
@@ -1465,6 +1466,7 @@ static void ieee80211_iface_work(struct work_struct *work)
                }
 
                kfree_skb(skb);
+               kcov_remote_stop();
        }
 
        /* then other type-dependent work */
diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c
index 1e2e5a406d58..09d1c9fb8872 100644
--- a/net/mac80211/rx.c
+++ b/net/mac80211/rx.c
@@ -4742,6 +4742,8 @@ void ieee80211_rx_list(struct ieee80211_hw *hw, struct 
ieee80211_sta *pubsta,
 
        status->rx_flags = 0;
 
+       kcov_remote_start_common(skb_get_kcov_handle(skb));
+
        /*
         * Frames with failed FCS/PLCP checksum are not returned,
         * all other frames are returned without radiotap header
@@ -4749,15 +4751,15 @@ void ieee80211_rx_list(struct ieee80211_hw *hw, struct 
ieee80211_sta *pubsta,
         * Also, frames with less than 16 bytes are dropped.
         */
        skb = ieee80211_rx_monitor(local, skb, rate);
-       if (!skb)
-               return;
-
-       ieee80211_tpt_led_trig_rx(local,
-                       ((struct ieee80211_hdr *)skb->data)->frame_control,
-                       skb->len);
+       if (skb) {
+               ieee80211_tpt_led_trig_rx(local,
+                                         ((struct ieee80211_hdr 
*)skb->data)->frame_control,
+                                         skb->len);
 
-       __ieee80211_rx_handle_packet(hw, pubsta, skb, list);
+               __ieee80211_rx_handle_packet(hw, pubsta, skb, list);
+       }
 
+       kcov_remote_stop();
        return;
  drop:
        kfree_skb(skb);
-- 
2.29.1.341.ge80a0c044ae-goog