Return-path: Received: from lunge.queued.net ([173.255.254.236]:58952 "EHLO lunge.queued.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932885Ab1JZR2O (ORCPT ); Wed, 26 Oct 2011 13:28:14 -0400 Date: Wed, 26 Oct 2011 10:19:26 -0700 From: Andres Salomon To: Dan Williams Cc: linville@tuxdriver.com, libertas-dev@lists.infradead.org, linux-wireless@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, dsd@laptop.org Subject: [PATCH] libertas: ensure we clean up a scan request properly Message-ID: <20111026101926.48109373@queued.net> (sfid-20111026_192823_535837_B9F87AAD) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Sender: linux-wireless-owner@vger.kernel.org List-ID: Commit 2e30168b ("libertas: terminate scan when stopping interface") adds cleanup code to lbs_eth_stop to call cfg80211_scan_done if there's an outstanding cfg80211_scan_request. However, it assumes that the scan request was allocated via the cfg80211 stack. Libertas has its own internal allocation method, kept track of with priv->internal_scan. This doesn't set scan_req->wiphy, amongst other things, which results in hitting a BUG() when we call cfg80211_scan_done on the request. This provides a function to take care of the low-level scan_req cleanup details. We simply call that to deal with finishing up scan requests. The bug we were hitting was: [ 964.321495] kernel BUG at net/wireless/core.h:87! [ 964.329970] Unable to handle kernel NULL pointer dereference at virtual address 00000000 [ 964.341963] pgd = dcf80000 ... [ 964.849998] 9fe0: 00000000 beb417b8 4018e280 401e822c 60000010 00000004 00000000 00000000 [ 964.865007] [] (__bug+0x1c/0x28) from [] (cfg80211_scan_done+0x54/0x6c) [ 964.895324] [] (cfg80211_scan_done+0x54/0x6c) from [] (lbs_eth_stop+0x10c/0x188 [libertas]) [ 964.895324] [] (lbs_eth_stop+0x10c/0x188 [libertas]) from [] (__dev_close_many+0x94/0xc4) [ 964.918995] [] (__dev_close_many+0x94/0xc4) from [] (dev_close_many+0x78/0xe0) Signed-off-by: Andres Salomon --- drivers/net/wireless/libertas/cfg.c | 25 +++++++++++++++++-------- drivers/net/wireless/libertas/cfg.h | 1 + drivers/net/wireless/libertas/main.c | 6 ++---- 3 files changed, 20 insertions(+), 12 deletions(-) diff --git a/drivers/net/wireless/libertas/cfg.c b/drivers/net/wireless/libertas/cfg.c index ff63782..4fcd653 100644 --- a/drivers/net/wireless/libertas/cfg.c +++ b/drivers/net/wireless/libertas/cfg.c @@ -728,15 +728,9 @@ static void lbs_scan_worker(struct work_struct *work) le16_to_cpu(scan_cmd->hdr.size), lbs_ret_scan, 0); - if (priv->scan_channel >= priv->scan_req->n_channels) { + if (priv->scan_channel >= priv->scan_req->n_channels) /* Mark scan done */ - if (priv->internal_scan) - kfree(priv->scan_req); - else - cfg80211_scan_done(priv->scan_req, false); - - priv->scan_req = NULL; - } + lbs_scan_done(priv); /* Restart network */ if (carrier) @@ -774,6 +768,21 @@ static void _internal_start_scan(struct lbs_private *priv, bool internal, lbs_deb_leave(LBS_DEB_CFG80211); } +/* + * Clean up priv->scan_req. Should be used to handle the allocation details. + */ +void lbs_scan_done(struct lbs_private *priv) +{ + WARN_ON(!priv->scan_req); + + if (priv->internal_scan) + kfree(priv->scan_req); + else + cfg80211_scan_done(priv->scan_req, false); + + priv->scan_req = NULL; +} + static int lbs_cfg_scan(struct wiphy *wiphy, struct net_device *dev, struct cfg80211_scan_request *request) diff --git a/drivers/net/wireless/libertas/cfg.h b/drivers/net/wireless/libertas/cfg.h index a02ee15..558168c 100644 --- a/drivers/net/wireless/libertas/cfg.h +++ b/drivers/net/wireless/libertas/cfg.h @@ -16,6 +16,7 @@ int lbs_reg_notifier(struct wiphy *wiphy, void lbs_send_disconnect_notification(struct lbs_private *priv); void lbs_send_mic_failureevent(struct lbs_private *priv, u32 event); +void lbs_scan_done(struct lbs_private *priv); void lbs_scan_deinit(struct lbs_private *priv); int lbs_disconnect(struct lbs_private *priv, u16 reason); diff --git a/drivers/net/wireless/libertas/main.c b/drivers/net/wireless/libertas/main.c index b03779b..39a6a7a 100644 --- a/drivers/net/wireless/libertas/main.c +++ b/drivers/net/wireless/libertas/main.c @@ -255,10 +255,8 @@ static int lbs_eth_stop(struct net_device *dev) lbs_update_mcast(priv); cancel_delayed_work_sync(&priv->scan_work); - if (priv->scan_req) { - cfg80211_scan_done(priv->scan_req, false); - priv->scan_req = NULL; - } + if (priv->scan_req) + lbs_scan_done(priv); netif_carrier_off(priv->dev); -- 1.7.2.5