[PATCH 5.8 48/56] hinic: fix rewaking txq after netif_tx_disable

From: Greg Kroah-Hartman
Date: Fri Sep 25 2020 - 08:50:31 EST


From: Luo bin <luobin9@xxxxxxxxxx>

[ Upstream commit a1b80e0143a1b878f8e21d82fd55f3f46f0014be ]

When calling hinic_close in hinic_set_channels, all queues are
stopped after netif_tx_disable, but some queue may be rewaken in
free_tx_poll by mistake while drv is handling tx irq. If one queue
is rewaken core may call hinic_xmit_frame to send pkt after
netif_tx_disable within a short time which may results in accessing
memory that has been already freed in hinic_close. So we call
napi_disable before netif_tx_disable in hinic_close to fix this bug.

Fixes: 2eed5a8b614b ("hinic: add set_channels ethtool_ops support")
Signed-off-by: Luo bin <luobin9@xxxxxxxxxx>
Reviewed-by: Jakub Kicinski <kuba@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/net/ethernet/huawei/hinic/hinic_main.c | 24 ++++++++++++++++++++++++
drivers/net/ethernet/huawei/hinic/hinic_tx.c | 18 +++---------------
2 files changed, 27 insertions(+), 15 deletions(-)

--- a/drivers/net/ethernet/huawei/hinic/hinic_main.c
+++ b/drivers/net/ethernet/huawei/hinic/hinic_main.c
@@ -168,6 +168,24 @@ err_init_txq:
return err;
}

+static void enable_txqs_napi(struct hinic_dev *nic_dev)
+{
+ int num_txqs = hinic_hwdev_num_qps(nic_dev->hwdev);
+ int i;
+
+ for (i = 0; i < num_txqs; i++)
+ napi_enable(&nic_dev->txqs[i].napi);
+}
+
+static void disable_txqs_napi(struct hinic_dev *nic_dev)
+{
+ int num_txqs = hinic_hwdev_num_qps(nic_dev->hwdev);
+ int i;
+
+ for (i = 0; i < num_txqs; i++)
+ napi_disable(&nic_dev->txqs[i].napi);
+}
+
/**
* free_txqs - Free the Logical Tx Queues of specific NIC device
* @nic_dev: the specific NIC device
@@ -394,6 +412,8 @@ int hinic_open(struct net_device *netdev
goto err_create_txqs;
}

+ enable_txqs_napi(nic_dev);
+
err = create_rxqs(nic_dev);
if (err) {
netif_err(nic_dev, drv, netdev,
@@ -475,6 +495,7 @@ err_port_state:
}

err_create_rxqs:
+ disable_txqs_napi(nic_dev);
free_txqs(nic_dev);

err_create_txqs:
@@ -488,6 +509,9 @@ int hinic_close(struct net_device *netde
struct hinic_dev *nic_dev = netdev_priv(netdev);
unsigned int flags;

+ /* Disable txq napi firstly to aviod rewaking txq in free_tx_poll */
+ disable_txqs_napi(nic_dev);
+
down(&nic_dev->mgmt_lock);

flags = nic_dev->flags;
--- a/drivers/net/ethernet/huawei/hinic/hinic_tx.c
+++ b/drivers/net/ethernet/huawei/hinic/hinic_tx.c
@@ -684,18 +684,6 @@ static int free_tx_poll(struct napi_stru
return budget;
}

-static void tx_napi_add(struct hinic_txq *txq, int weight)
-{
- netif_napi_add(txq->netdev, &txq->napi, free_tx_poll, weight);
- napi_enable(&txq->napi);
-}
-
-static void tx_napi_del(struct hinic_txq *txq)
-{
- napi_disable(&txq->napi);
- netif_napi_del(&txq->napi);
-}
-
static irqreturn_t tx_irq(int irq, void *data)
{
struct hinic_txq *txq = data;
@@ -724,7 +712,7 @@ static int tx_request_irq(struct hinic_t
struct hinic_sq *sq = txq->sq;
int err;

- tx_napi_add(txq, nic_dev->tx_weight);
+ netif_napi_add(txq->netdev, &txq->napi, free_tx_poll, nic_dev->tx_weight);

hinic_hwdev_msix_set(nic_dev->hwdev, sq->msix_entry,
TX_IRQ_NO_PENDING, TX_IRQ_NO_COALESC,
@@ -734,7 +722,7 @@ static int tx_request_irq(struct hinic_t
err = request_irq(sq->irq, tx_irq, 0, txq->irq_name, txq);
if (err) {
dev_err(&pdev->dev, "Failed to request Tx irq\n");
- tx_napi_del(txq);
+ netif_napi_del(&txq->napi);
return err;
}

@@ -746,7 +734,7 @@ static void tx_free_irq(struct hinic_txq
struct hinic_sq *sq = txq->sq;

free_irq(sq->irq, txq);
- tx_napi_del(txq);
+ netif_napi_del(&txq->napi);
}

/**