From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from userp1040.oracle.com ([156.151.31.81]:39547 "EHLO userp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932300AbcFONC0 (ORCPT ); Wed, 15 Jun 2016 09:02:26 -0400 Subject: Re: [PATCH] libertas: Add spinlock to avoid race condition To: Pavel Andrianov , Kalle Valo References: <1465990443-19738-1-git-send-email-andrianov@ispras.ru> Cc: libertas-dev@lists.infradead.org, linux-wireless@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, ldv-project@linuxtesting.org From: Vaishali Thakkar Message-ID: <576151B3.9040802@oracle.com> (sfid-20160615_150249_028578_D11FC530) Date: Wed, 15 Jun 2016 18:31:39 +0530 MIME-Version: 1.0 In-Reply-To: <1465990443-19738-1-git-send-email-andrianov@ispras.ru> Content-Type: text/plain; charset=windows-1252 Sender: linux-wireless-owner@vger.kernel.org List-ID: On Wednesday 15 June 2016 05:04 PM, Pavel Andrianov wrote: > lbs_mac_event_disconnected may free priv->currenttxskb > while lbs_hard_start_xmit accesses to it. > The patch adds a spinlock for mutual exclusion. > > Tested on OLPC XO-1 (usb8388) and XO-1.5 (sd8686) with v4.7-rc3. > > Confirmed that lbs_mac_event_disconnected is being called on the > station when hostapd on access point is given SIGHUP. > > Signed-off-by: Pavel > Tested-by: James Cameron Looks good to me. Acked-by: Vaishali Thakkar > --- > drivers/net/wireless/marvell/libertas/cmdresp.c | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/drivers/net/wireless/marvell/libertas/cmdresp.c b/drivers/net/wireless/marvell/libertas/cmdresp.c > index c95bf6d..c67ae07 100644 > --- a/drivers/net/wireless/marvell/libertas/cmdresp.c > +++ b/drivers/net/wireless/marvell/libertas/cmdresp.c > @@ -27,6 +27,8 @@ > void lbs_mac_event_disconnected(struct lbs_private *priv, > bool locally_generated) > { > + unsigned long flags; > + > if (priv->connect_status != LBS_CONNECTED) > return; > > @@ -46,9 +48,11 @@ void lbs_mac_event_disconnected(struct lbs_private *priv, > netif_carrier_off(priv->dev); > > /* Free Tx and Rx packets */ > + spin_lock_irqsave(&priv->driver_lock, flags); > kfree_skb(priv->currenttxskb); > priv->currenttxskb = NULL; > priv->tx_pending_len = 0; > + spin_unlock_irqrestore(&priv->driver_lock, flags); > > priv->connect_status = LBS_DISCONNECTED; > > -- Vaishali