linux-kernel - [PATCH AUTOSEL 4.18 26/58] net: stmmac: Fixup the tail addr setting in xmit path

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Mon,  8 Oct 2018 11:24:51 -0400
From:   Sasha Levin <sashal@...nel.org>
To:     stable@...r.kernel.org, linux-kernel@...r.kernel.org
Cc:     Jose Abreu <Jose.Abreu@...opsys.com>,
        Jose Abreu <joabreu@...opsys.com>,
        "David S . Miller" <davem@...emloft.net>,
        Joao Pinto <jpinto@...opsys.com>,
        Giuseppe Cavallaro <peppe.cavallaro@...com>,
        Alexandre Torgue <alexandre.torgue@...com>,
        Sasha Levin <alexander.levin@...rosoft.com>
Subject: [PATCH AUTOSEL 4.18 26/58] net: stmmac: Fixup the tail addr setting in xmit path

From: Jose Abreu <Jose.Abreu@...opsys.com>

[ Upstream commit 0431100b3d82c509729ece1ab22ada2484e209c1 ]

Currently we are always setting the tail address of descriptor list to
the end of the pre-allocated list.

According to databook this is not correct. Tail address should point to
the last available descriptor + 1, which means we have to update the
tail address everytime we call the xmit function.

This should make no impact in older versions of MAC but in newer
versions there are some DMA features which allows the IP to fetch
descriptors in advance and in a non sequential order so its critical
that we set the tail address correctly.

Signed-off-by: Jose Abreu <joabreu@...opsys.com>
Fixes: f748be531d70 ("stmmac: support new GMAC4")
Cc: David S. Miller <davem@...emloft.net>
Cc: Joao Pinto <jpinto@...opsys.com>
Cc: Giuseppe Cavallaro <peppe.cavallaro@...com>
Cc: Alexandre Torgue <alexandre.torgue@...com>
Signed-off-by: David S. Miller <davem@...emloft.net>
Signed-off-by: Sasha Levin <alexander.levin@...rosoft.com>
---
 drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index 04de46601c87..1c6ba74e294b 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -2186,8 +2186,7 @@ static int stmmac_init_dma_engine(struct stmmac_priv *priv)
 		stmmac_init_tx_chan(priv, priv->ioaddr, priv->plat->dma_cfg,
 				    tx_q->dma_tx_phy, chan);
 
-		tx_q->tx_tail_addr = tx_q->dma_tx_phy +
-			    (DMA_TX_SIZE * sizeof(struct dma_desc));
+		tx_q->tx_tail_addr = tx_q->dma_tx_phy;
 		stmmac_set_tx_tail_ptr(priv, priv->ioaddr,
 				       tx_q->tx_tail_addr, chan);
 	}
@@ -2982,6 +2981,7 @@ static netdev_tx_t stmmac_tso_xmit(struct sk_buff *skb, struct net_device *dev)
 
 	netdev_tx_sent_queue(netdev_get_tx_queue(dev, queue), skb->len);
 
+	tx_q->tx_tail_addr = tx_q->dma_tx_phy + (tx_q->cur_tx * sizeof(*desc));
 	stmmac_set_tx_tail_ptr(priv, priv->ioaddr, tx_q->tx_tail_addr, queue);
 
 	return NETDEV_TX_OK;
@@ -3189,6 +3189,7 @@ static netdev_tx_t stmmac_xmit(struct sk_buff *skb, struct net_device *dev)
 
 	stmmac_enable_dma_transmission(priv, priv->ioaddr);
 
+	tx_q->tx_tail_addr = tx_q->dma_tx_phy + (tx_q->cur_tx * sizeof(*desc));
 	stmmac_set_tx_tail_ptr(priv, priv->ioaddr, tx_q->tx_tail_addr, queue);
 
 	return NETDEV_TX_OK;
-- 
2.17.1