From: Michael Buesch Date: Sun, 24 Jan 2010 12:13:32 +0000 (+0100) Subject: b43: Workaround circular locking in hw-tkip key update callback X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=96869a39399269a776a94812e9fff3d38b47d838;p=linux-beck.git b43: Workaround circular locking in hw-tkip key update callback The TKIP key update callback is called from the RX path, where the driver mutex is already locked. This results in a circular locking bug. Avoid this by removing the lock. Johannes noted that there is a separate bug: The callback still breaks on SDIO hardware, because SDIO hardware access needs to sleep, but we are not allowed to sleep in the callback due to mac80211's RCU locking. Signed-off-by: Michael Buesch Tested-by: Larry Finger Reported-by: kecsa@kutfo.hit.bme.hu Cc: Johannes Berg Cc: stable Signed-off-by: John W. Linville --- diff --git a/drivers/net/wireless/b43/main.c b/drivers/net/wireless/b43/main.c index 6d7cf3c2f7bf..66220cde9c49 100644 --- a/drivers/net/wireless/b43/main.c +++ b/drivers/net/wireless/b43/main.c @@ -856,22 +856,19 @@ static void b43_op_update_tkip_key(struct ieee80211_hw *hw, if (B43_WARN_ON(!modparam_hwtkip)) return; - mutex_lock(&wl->mutex); - + /* This is only called from the RX path through mac80211, where + * our mutex is already locked. */ + B43_WARN_ON(!mutex_is_locked(&wl->mutex)); dev = wl->current_dev; - if (!dev || b43_status(dev) < B43_STAT_INITIALIZED) - goto out_unlock; + B43_WARN_ON(!dev || b43_status(dev) < B43_STAT_INITIALIZED); keymac_write(dev, index, NULL); /* First zero out mac to avoid race */ rx_tkip_phase1_write(dev, index, iv32, phase1key); /* only pairwise TKIP keys are supported right now */ if (WARN_ON(!sta)) - goto out_unlock; + return; keymac_write(dev, index, sta->addr); - -out_unlock: - mutex_unlock(&wl->mutex); } static void do_key_write(struct b43_wldev *dev,