Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934364AbaKSW3H (ORCPT ); Wed, 19 Nov 2014 17:29:07 -0500 Received: from mail.linuxfoundation.org ([140.211.169.12]:56064 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932428AbaKSUyA (ORCPT ); Wed, 19 Nov 2014 15:54:00 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Slawomir Gajzner , Julien DAscenzio , Karl Beldan , Ian Campbell , Eric Dumazet , Ezequiel Garcia , Sebastian Hesselbarth , "David S. Miller" Subject: [PATCH 3.17 008/141] net: mv643xx_eth: reclaim TX skbs only when released by the HW Date: Wed, 19 Nov 2014 12:50:31 -0800 Message-Id: <20141119205150.954960197@linuxfoundation.org> X-Mailer: git-send-email 2.1.3 In-Reply-To: <20141119205150.700188369@linuxfoundation.org> References: <20141119205150.700188369@linuxfoundation.org> User-Agent: quilt/0.63-1 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.17-stable review patch. If anyone has any objections, please let me know. ------------------ From: Karl Beldan [ Upstream commit 2c2a9cbd64387d6b70ac5db013e9bfe9412c7354 ] ATM, txq_reclaim will dequeue and free an skb for each tx desc released by the hw that has TX_LAST_DESC set. However, in case of TSO, each hw desc embedding the last part of a segment has TX_LAST_DESC set, losing the one-to-one 'last skb frag'/'TX_LAST_DESC set' correspondance, which causes data corruption. Fix this by checking TX_ENABLE_INTERRUPT instead of TX_LAST_DESC, and warn when trying to dequeue from an empty txq (which can be symptomatic of releasing skbs prematurely). Fixes: 3ae8f4e0b98 ('net: mv643xx_eth: Implement software TSO') Reported-by: Slawomir Gajzner Reported-by: Julien D'Ascenzio Signed-off-by: Karl Beldan Cc: Ian Campbell Cc: Eric Dumazet Cc: Ezequiel Garcia Cc: Sebastian Hesselbarth Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- drivers/net/ethernet/marvell/mv643xx_eth.c | 18 ++++++++++-------- 1 file changed, 10 insertions(+), 8 deletions(-) --- a/drivers/net/ethernet/marvell/mv643xx_eth.c +++ b/drivers/net/ethernet/marvell/mv643xx_eth.c @@ -1047,7 +1047,6 @@ static int txq_reclaim(struct tx_queue * int tx_index; struct tx_desc *desc; u32 cmd_sts; - struct sk_buff *skb; tx_index = txq->tx_used_desc; desc = &txq->tx_desc_area[tx_index]; @@ -1066,19 +1065,22 @@ static int txq_reclaim(struct tx_queue * reclaimed++; txq->tx_desc_count--; - skb = NULL; - if (cmd_sts & TX_LAST_DESC) - skb = __skb_dequeue(&txq->tx_skb); + if (!IS_TSO_HEADER(txq, desc->buf_ptr)) + dma_unmap_single(mp->dev->dev.parent, desc->buf_ptr, + desc->byte_cnt, DMA_TO_DEVICE); + + if (cmd_sts & TX_ENABLE_INTERRUPT) { + struct sk_buff *skb = __skb_dequeue(&txq->tx_skb); + + if (!WARN_ON(!skb)) + dev_kfree_skb(skb); + } if (cmd_sts & ERROR_SUMMARY) { netdev_info(mp->dev, "tx error\n"); mp->dev->stats.tx_errors++; } - if (!IS_TSO_HEADER(txq, desc->buf_ptr)) - dma_unmap_single(mp->dev->dev.parent, desc->buf_ptr, - desc->byte_cnt, DMA_TO_DEVICE); - dev_kfree_skb(skb); } __netif_tx_unlock_bh(nq); -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/