From e548510b30a5b74f9be9c501d955ca90c7d1a8d0 Mon Sep 17 00:00:00 2001 From: Michael Buesch Date: Fri, 19 Mar 2010 10:38:33 -0500 Subject: [PATCH] b43: Workaround circular locking in hw-tkip key update callback commit 96869a39399269a776a94812e9fff3d38b47d838 upstream 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 Signed-off-by: John W. Linville Signed-off-by: Greg Kroah-Hartman --- drivers/net/wireless/b43/main.c | 11 ++++------- 1 file changed, 4 insertions(+), 7 deletions(-) diff --git a/drivers/net/wireless/b43/main.c b/drivers/net/wireless/b43/main.c index 2bde1a9da34..a8a00d28a1a 100644 --- a/drivers/net/wireless/b43/main.c +++ b/drivers/net/wireless/b43/main.c @@ -852,19 +852,16 @@ 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); keymac_write(dev, index, addr); - -out_unlock: - mutex_unlock(&wl->mutex); } static void do_key_write(struct b43_wldev *dev, -- 2.11.4.GIT