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| author | Michael Buesch <mb@bu3sch.de> | 2010-03-19 10:38:33 -0500 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2010-04-01 15:58:55 -0700 |
| commit | e548510b30a5b74f9be9c501d955ca90c7d1a8d0 (patch) | |
| tree | ce31ad373e269c63ca5a1f1456de37de907c3386 /drivers | |
| parent | f15a9d8a07f97af708304414910e7daeb5e5936d (diff) | |
| download | lwn-e548510b30a5b74f9be9c501d955ca90c7d1a8d0.tar.gz lwn-e548510b30a5b74f9be9c501d955ca90c7d1a8d0.zip | |
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 <mb@bu3sch.de>
Tested-by: Larry Finger <Larry.Finger@lwfinger.net>
Reported-by: kecsa@kutfo.hit.bme.hu
Cc: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/net/wireless/b43/main.c | 11 |
1 files changed, 4 insertions, 7 deletions
diff --git a/drivers/net/wireless/b43/main.c b/drivers/net/wireless/b43/main.c index 2bde1a9da343..a8a00d28a1a8 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, |