From: Mohammed Shafi Shajakhan <mohammed@xxxxxxxxxxxxxxxx> read_lock(&tpt_trig->trig.leddev_list_lock) is accessed via the path ieee80211_open (->) ieee80211_do_open (->) ieee80211_mod_tpt_led_trig (->) ieee80211_start_tpt_led_trig (->) tpt_trig_timer before initializing it. the intilization of this read/write lock happens via the path ieee80211_led_init (->) led_trigger_register, but we are doing 'ieee80211_led_init' after 'ieeee80211_if_add' where we register netdev_ops. so we access leddev_list_lock before initializing it and causes the following bug in chrome laptops with AR928X cards with the following script while true do sudo modprobe -v ath9k sleep 3 sudo modprobe -r ath9k sleep 3 done BUG: rwlock bad magic on CPU#1, wpa_supplicant/358, f5b9eccc Pid: 358, comm: wpa_supplicant Not tainted 3.0.13 #1 Call Trace: [<8137b9df>] rwlock_bug+0x3d/0x47 [<81179830>] do_raw_read_lock+0x19/0x29 [<8137f063>] _raw_read_lock+0xd/0xf [<f9081957>] tpt_trig_timer+0xc3/0x145 [mac80211] [<f9081f3a>] ieee80211_mod_tpt_led_trig+0x152/0x174 [mac80211] [<f9076a3f>] ieee80211_do_open+0x11e/0x42e [mac80211] [<f9075390>] ? ieee80211_check_concurrent_iface+0x26/0x13c [mac80211] [<f9076d97>] ieee80211_open+0x48/0x4c [mac80211] [<812dbed8>] __dev_open+0x82/0xab [<812dc0c9>] __dev_change_flags+0x9c/0x113 [<812dc1ae>] dev_change_flags+0x18/0x44 [<8132144f>] devinet_ioctl+0x243/0x51a [<81321ba9>] inet_ioctl+0x93/0xac [<812cc951>] sock_ioctl+0x1c6/0x1ea [<812cc78b>] ? might_fault+0x20/0x20 [<810b1ebb>] do_vfs_ioctl+0x46e/0x4a2 [<810a6ebb>] ? fget_light+0x2f/0x70 [<812ce549>] ? sys_recvmsg+0x3e/0x48 [<810b1f35>] sys_ioctl+0x46/0x69 [<8137fa77>] sysenter_do_call+0x12/0x2 Cc: <stable@xxxxxxxxxxxxxxx> Cc: Gary Morain <gmorain@xxxxxxxxxx> Cc: Paul Stewart <pstew@xxxxxxxxxx> Cc: Abhijit Pradhan <abhijit@xxxxxxxxxxxxxxxx> Cc: Vasanthakumar Thiagarajan <vthiagar@xxxxxxxxxxxxxxxx> Cc: Rajkumar Manoharan <rmanohar@xxxxxxxxxxxxxxxx> Acked-by: Johannes Berg <johannes.berg@xxxxxxxxx> Tested-by: Mohammed Shafi Shajakhan <mohammed@xxxxxxxxxxxxxxxx> Signed-off-by: Mohammed Shafi Shajakhan <mohammed@xxxxxxxxxxxxxxxx> --- net/mac80211/main.c | 4 ++-- 1 files changed, 2 insertions(+), 2 deletions(-) diff --git a/net/mac80211/main.c b/net/mac80211/main.c index 831a5bd..2306d75 100644 --- a/net/mac80211/main.c +++ b/net/mac80211/main.c @@ -909,6 +909,8 @@ int ieee80211_register_hw(struct ieee80211_hw *hw) wiphy_debug(local->hw.wiphy, "Failed to initialize wep: %d\n", result); + ieee80211_led_init(local); + rtnl_lock(); result = ieee80211_init_rate_ctrl_alg(local, @@ -930,8 +932,6 @@ int ieee80211_register_hw(struct ieee80211_hw *hw) rtnl_unlock(); - ieee80211_led_init(local); - local->network_latency_notifier.notifier_call = ieee80211_max_network_latency; result = pm_qos_add_notifier(PM_QOS_NETWORK_LATENCY, -- 1.7.0.4 -- To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
