This is a note to let you know that I've just added the patch titled
net: moxa: fix TX overrun memory leak
to the 4.9-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...
The filename of the patch is: net-moxa-fix-tx-overrun-memory-leak.patch and it can be found in the queue-4.9 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree, please let stable@vger.kernel.org know about it.
From foo@baz Thu Dec 21 09:02:40 CET 2017
From: Jonas Jensen jonas.jensen@gmail.com Date: Tue, 28 Mar 2017 12:12:38 +0200 Subject: net: moxa: fix TX overrun memory leak
From: Jonas Jensen jonas.jensen@gmail.com
[ Upstream commit c2b341a620018d4eaeb0e85c16274ac4e5f153d4 ]
moxart_mac_start_xmit() doesn't care where tx_tail is, tx_head can catch and pass tx_tail, which is bad because moxart_tx_finished() isn't guaranteed to catch up on freeing resources from tx_tail.
Add a check in moxart_mac_start_xmit() stopping the queue at the end of the circular buffer. Also add a check in moxart_tx_finished() waking the queue if the buffer has TX_WAKE_THRESHOLD or more free descriptors.
While we're at it, move spin_lock_irq() to happen before our descriptor pointer is assigned in moxart_mac_start_xmit().
Addresses https://bugzilla.kernel.org/show_bug.cgi?id=99451
Signed-off-by: Jonas Jensen jonas.jensen@gmail.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin alexander.levin@verizon.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/net/ethernet/moxa/moxart_ether.c | 20 ++++++++++++++++++-- drivers/net/ethernet/moxa/moxart_ether.h | 1 + 2 files changed, 19 insertions(+), 2 deletions(-)
--- a/drivers/net/ethernet/moxa/moxart_ether.c +++ b/drivers/net/ethernet/moxa/moxart_ether.c @@ -25,6 +25,7 @@ #include <linux/of_irq.h> #include <linux/crc32.h> #include <linux/crc32c.h> +#include <linux/circ_buf.h>
#include "moxart_ether.h"
@@ -278,6 +279,13 @@ rx_next: return rx; }
+static int moxart_tx_queue_space(struct net_device *ndev) +{ + struct moxart_mac_priv_t *priv = netdev_priv(ndev); + + return CIRC_SPACE(priv->tx_head, priv->tx_tail, TX_DESC_NUM); +} + static void moxart_tx_finished(struct net_device *ndev) { struct moxart_mac_priv_t *priv = netdev_priv(ndev); @@ -297,6 +305,9 @@ static void moxart_tx_finished(struct ne tx_tail = TX_NEXT(tx_tail); } priv->tx_tail = tx_tail; + if (netif_queue_stopped(ndev) && + moxart_tx_queue_space(ndev) >= TX_WAKE_THRESHOLD) + netif_wake_queue(ndev); }
static irqreturn_t moxart_mac_interrupt(int irq, void *dev_id) @@ -324,13 +335,18 @@ static int moxart_mac_start_xmit(struct struct moxart_mac_priv_t *priv = netdev_priv(ndev); void *desc; unsigned int len; - unsigned int tx_head = priv->tx_head; + unsigned int tx_head; u32 txdes1; int ret = NETDEV_TX_BUSY;
+ spin_lock_irq(&priv->txlock); + + tx_head = priv->tx_head; desc = priv->tx_desc_base + (TX_REG_DESC_SIZE * tx_head);
- spin_lock_irq(&priv->txlock); + if (moxart_tx_queue_space(ndev) == 1) + netif_stop_queue(ndev); + if (moxart_desc_read(desc + TX_REG_OFFSET_DESC0) & TX_DESC0_DMA_OWN) { net_dbg_ratelimited("no TX space for packet\n"); priv->stats.tx_dropped++; --- a/drivers/net/ethernet/moxa/moxart_ether.h +++ b/drivers/net/ethernet/moxa/moxart_ether.h @@ -59,6 +59,7 @@ #define TX_NEXT(N) (((N) + 1) & (TX_DESC_NUM_MASK)) #define TX_BUF_SIZE 1600 #define TX_BUF_SIZE_MAX (TX_DESC1_BUF_SIZE_MASK+1) +#define TX_WAKE_THRESHOLD 16
#define RX_DESC_NUM 64 #define RX_DESC_NUM_MASK (RX_DESC_NUM-1)
Patches currently in stable-queue which might be from jonas.jensen@gmail.com are
queue-4.9/net-moxa-fix-tx-overrun-memory-leak.patch