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| author | Jonas Jensen <jonas.jensen@gmail.com> | 2017-03-28 12:12:38 +0200 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2017-03-28 18:02:05 -0700 |
| commit | c2b341a620018d4eaeb0e85c16274ac4e5f153d4 (patch) | |
| tree | 28b751d30475eecc67268570c3d0f114b460a49f /drivers/net | |
| parent | af109a2cf6a9a6271fa420ae2d64d72d86c92b7d (diff) | |
| download | linux-c2b341a620018d4eaeb0e85c16274ac4e5f153d4.tar.bz2 | |
net: moxa: fix TX overrun memory leak
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>
Diffstat (limited to 'drivers/net')
| -rw-r--r-- | drivers/net/ethernet/moxa/moxart_ether.c | 20 | ||||
| -rw-r--r-- | drivers/net/ethernet/moxa/moxart_ether.h | 1 |
2 files changed, 19 insertions, 2 deletions
diff --git a/drivers/net/ethernet/moxa/moxart_ether.c b/drivers/net/ethernet/moxa/moxart_ether.c index 06c9f4100cb9..6ad44be08b33 100644 --- 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 net_device *ndev) 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 sk_buff *skb, struct net_device *ndev) 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++; diff --git a/drivers/net/ethernet/moxa/moxart_ether.h b/drivers/net/ethernet/moxa/moxart_ether.h index 93a9563ac7c6..afc32ec998c0 100644 --- 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) |