mac80211: annotate MMIC head/tailroom warning

This message occasionally triggers for some people as in
https://bugzilla.redhat.com/show_bug.cgi?id=1111740 but
it's not clear which (headroom or tailroom) is at fault.
Annotate the message a bit to get more information.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>

diff --git a/net/mac80211/wpa.c b/net/mac80211/wpa.c
index f7d4ca4c46e0bf68c6232d339d4b54f7934798ba..983527a4c1aba22c4ae6dc43c113ed1df9f1eb9c 100644 (file)
--- a/net/mac80211/wpa.c
+++ b/net/mac80211/wpa.c
@@ -64,8 +64,11 @@ ieee80211_tx_h_michael_mic_add(struct ieee80211_tx_data *tx)
        if (!info->control.hw_key)
                tail += IEEE80211_TKIP_ICV_LEN;
 
-       if (WARN_ON(skb_tailroom(skb) < tail ||
-                   skb_headroom(skb) < IEEE80211_TKIP_IV_LEN))
+       if (WARN(skb_tailroom(skb) < tail ||
+                skb_headroom(skb) < IEEE80211_TKIP_IV_LEN,
+                "mmic: not enough head/tail (%d/%d,%d/%d)\n",
+                skb_headroom(skb), IEEE80211_TKIP_IV_LEN,
+                skb_tailroom(skb), tail))
                return TX_DROP;
 
        key = &tx->key->conf.key[NL80211_TKIP_DATA_OFFSET_TX_MIC_KEY];