[v4,3/3] mac80211: add KCOV remote annotations to incoming frame processing

Message ID 20201028182018.1780842-4-aleksandrnogikh@gmail.com
State New
Headers show
Series
  • net, mac80211, kernel: enable KCOV remote coverage collection for 802.11 frame handling
Related show

Commit Message

Aleksandr Nogikh Oct. 28, 2020, 6:20 p.m.
From: Aleksandr Nogikh <nogikh@google.com>

Add KCOV remote annotations to ieee80211_iface_work and
ieee80211_rx. This will enable coverage-guided fuzzing of
mac80211 code that processes incoming 802.11 frames.

Signed-off-by: Aleksandr Nogikh <nogikh@google.com>
---
v1 -> v2:
* The commit now affects ieee80211_rx instead of
  ieee80211_tasklet_handler.
---
 include/net/mac80211.h | 2 ++
 net/mac80211/iface.c   | 2 ++
 2 files changed, 4 insertions(+)

Comments

Aleksandr Nogikh Oct. 29, 2020, 5:42 p.m. | #1
On Wed, Oct 28, 2020 at 10:25 PM Johannes Berg
<johannes@sipsolutions.net> wrote:
[...]
> Wouldn't it make more sense to push that a layer down

> into ieee80211_rx_napi(), or actually now perhaps even

> better ieee80211_rx_list(), so we get it even if the driver called that

> API in the first place?

>

> You might only care about hwsim at this point, but perhaps hwsim would

> get optimised ..


Yes, ieee80211_rx_list() seems to be a reasonable place to move these
annotations to. Thanks for the suggestion.

I've incorporated this change into v5:
https://lkml.kernel.org/r/20201029173620.2121359-1-aleksandrnogikh@gmail.com

Patch

diff --git a/include/net/mac80211.h b/include/net/mac80211.h
index e8e295dae744..f4c37a1b381e 100644
--- a/include/net/mac80211.h
+++ b/include/net/mac80211.h
@@ -4499,7 +4499,9 @@  void ieee80211_rx_napi(struct ieee80211_hw *hw, struct ieee80211_sta *sta,
  */
 static inline void ieee80211_rx(struct ieee80211_hw *hw, struct sk_buff *skb)
 {
+	kcov_remote_start_common(skb_get_kcov_handle(skb));
 	ieee80211_rx_napi(hw, NULL, skb, NULL);
+	kcov_remote_stop();
 }
 
 /**
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 */