From: Johannes Berg <johannes.berg@xxxxxxxxx> When an internal scan is started, nothing protects the is_internal_short_scan variable which can cause crashes, cf. https://bugzilla.kernel.org/show_bug.cgi?id=15667. Fix this by making the short scan request use the mutex for locking, which requires making the request go to a work struct so that it can sleep. Reported-by: Peter Zijlstra <peterz@xxxxxxxxxxxxx> Signed-off-by: Johannes Berg <johannes.berg@xxxxxxxxx> Signed-off-by: Reinette Chatre <reinette.chatre@xxxxxxxxx> --- drivers/net/wireless/iwlwifi/iwl-agn.c | 1 + drivers/net/wireless/iwlwifi/iwl-core.c | 1 - drivers/net/wireless/iwlwifi/iwl-core.h | 2 +- drivers/net/wireless/iwlwifi/iwl-dev.h | 1 + drivers/net/wireless/iwlwifi/iwl-scan.c | 31 ++++++++++++++++++++----------- 5 files changed, 23 insertions(+), 13 deletions(-) diff --git a/drivers/net/wireless/iwlwifi/iwl-agn.c b/drivers/net/wireless/iwlwifi/iwl-agn.c index e4c2e1e..ba0fdba 100644 --- a/drivers/net/wireless/iwlwifi/iwl-agn.c +++ b/drivers/net/wireless/iwlwifi/iwl-agn.c @@ -3330,6 +3330,7 @@ static void iwl_cancel_deferred_work(struct iwl_priv *priv) cancel_delayed_work_sync(&priv->init_alive_start); cancel_delayed_work(&priv->scan_check); + cancel_work_sync(&priv->start_internal_scan); cancel_delayed_work(&priv->alive_start); cancel_work_sync(&priv->beacon_update); del_timer_sync(&priv->statistics_periodic); diff --git a/drivers/net/wireless/iwlwifi/iwl-core.c b/drivers/net/wireless/iwlwifi/iwl-core.c index 894bcb8..1459cdb 100644 --- a/drivers/net/wireless/iwlwifi/iwl-core.c +++ b/drivers/net/wireless/iwlwifi/iwl-core.c @@ -3357,7 +3357,6 @@ static void iwl_force_rf_reset(struct iwl_priv *priv) */ IWL_DEBUG_INFO(priv, "perform radio reset.\n"); iwl_internal_short_hw_scan(priv); - return; } diff --git a/drivers/net/wireless/iwlwifi/iwl-core.h b/drivers/net/wireless/iwlwifi/iwl-core.h index 732590f..36940a9 100644 --- a/drivers/net/wireless/iwlwifi/iwl-core.h +++ b/drivers/net/wireless/iwlwifi/iwl-core.h @@ -506,7 +506,7 @@ void iwl_init_scan_params(struct iwl_priv *priv); int iwl_scan_cancel(struct iwl_priv *priv); int iwl_scan_cancel_timeout(struct iwl_priv *priv, unsigned long ms); int iwl_mac_hw_scan(struct ieee80211_hw *hw, struct cfg80211_scan_request *req); -int iwl_internal_short_hw_scan(struct iwl_priv *priv); +void iwl_internal_short_hw_scan(struct iwl_priv *priv); int iwl_force_reset(struct iwl_priv *priv, int mode); u16 iwl_fill_probe_req(struct iwl_priv *priv, struct ieee80211_mgmt *frame, const u8 *ie, int ie_len, int left); diff --git a/drivers/net/wireless/iwlwifi/iwl-dev.h b/drivers/net/wireless/iwlwifi/iwl-dev.h index 6054c5f..ef1720a 100644 --- a/drivers/net/wireless/iwlwifi/iwl-dev.h +++ b/drivers/net/wireless/iwlwifi/iwl-dev.h @@ -1296,6 +1296,7 @@ struct iwl_priv { struct work_struct tt_work; struct work_struct ct_enter; struct work_struct ct_exit; + struct work_struct start_internal_scan; struct tasklet_struct irq_tasklet; diff --git a/drivers/net/wireless/iwlwifi/iwl-scan.c b/drivers/net/wireless/iwlwifi/iwl-scan.c index bd2f7c4..5062f4e 100644 --- a/drivers/net/wireless/iwlwifi/iwl-scan.c +++ b/drivers/net/wireless/iwlwifi/iwl-scan.c @@ -469,6 +469,8 @@ EXPORT_SYMBOL(iwl_init_scan_params); static int iwl_scan_initiate(struct iwl_priv *priv) { + WARN_ON(!mutex_is_locked(&priv->mutex)); + IWL_DEBUG_INFO(priv, "Starting scan...\n"); set_bit(STATUS_SCANNING, &priv->status); priv->is_internal_short_scan = false; @@ -546,24 +548,31 @@ EXPORT_SYMBOL(iwl_mac_hw_scan); * internal short scan, this function should only been called while associated. * It will reset and tune the radio to prevent possible RF related problem */ -int iwl_internal_short_hw_scan(struct iwl_priv *priv) +void iwl_internal_short_hw_scan(struct iwl_priv *priv) { - int ret = 0; + queue_work(priv->workqueue, &priv->start_internal_scan); +} + +static void iwl_bg_start_internal_scan(struct work_struct *work) +{ + struct iwl_priv *priv = + container_of(work, struct iwl_priv, start_internal_scan); + + mutex_lock(&priv->mutex); if (!iwl_is_ready_rf(priv)) { - ret = -EIO; IWL_DEBUG_SCAN(priv, "not ready or exit pending\n"); - goto out; + goto unlock; } + if (test_bit(STATUS_SCANNING, &priv->status)) { IWL_DEBUG_SCAN(priv, "Scan already in progress.\n"); - ret = -EAGAIN; - goto out; + goto unlock; } + if (test_bit(STATUS_SCAN_ABORTING, &priv->status)) { IWL_DEBUG_SCAN(priv, "Scan request while abort pending\n"); - ret = -EAGAIN; - goto out; + goto unlock; } priv->scan_bands = 0; @@ -576,9 +585,8 @@ int iwl_internal_short_hw_scan(struct iwl_priv *priv) set_bit(STATUS_SCANNING, &priv->status); priv->is_internal_short_scan = true; queue_work(priv->workqueue, &priv->request_scan); - -out: - return ret; + unlock: + mutex_unlock(&priv->mutex); } EXPORT_SYMBOL(iwl_internal_short_hw_scan); @@ -964,6 +972,7 @@ void iwl_setup_scan_deferred_work(struct iwl_priv *priv) INIT_WORK(&priv->scan_completed, iwl_bg_scan_completed); INIT_WORK(&priv->request_scan, iwl_bg_request_scan); INIT_WORK(&priv->abort_scan, iwl_bg_abort_scan); + INIT_WORK(&priv->start_internal_scan, iwl_bg_start_internal_scan); INIT_DELAYED_WORK(&priv->scan_check, iwl_bg_scan_check); } EXPORT_SYMBOL(iwl_setup_scan_deferred_work); -- 1.6.3.3 -- 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
