[PATCH net] ibmveth: Disable tx queue while changing mtu
From: Thomas Falcon <hidden>
Date: 2016-08-09 17:47:42
Subsystem:
ibm power virtual ethernet device driver, linux for powerpc (32-bit and 64-bit), networking drivers, the rest · Maintainers:
Nick Child, Madhavan Srinivasan, Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
If the device is running while the MTU is changed, ibmveth is closed and the bounce buffer is freed. If a transmission is sent before ibmveth can be reopened, ibmveth_start_xmit tries to copy to the null bounce buffer, leading to a kernel oops. The proposed solution disables the tx queue until ibmveth is restarted. Reported-by: Jan Stancek <jstancek@redhat.com> Tested-by: Jan Stancek <jstancek@redhat.com> Signed-off-by: Thomas Falcon <redacted> --- drivers/net/ethernet/ibm/ibmveth.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-)
diff --git a/drivers/net/ethernet/ibm/ibmveth.c b/drivers/net/ethernet/ibm/ibmveth.c
index ebe6071..9a74e4c 100644
--- a/drivers/net/ethernet/ibm/ibmveth.c
+++ b/drivers/net/ethernet/ibm/ibmveth.c@@ -1362,6 +1362,7 @@ static int ibmveth_change_mtu(struct net_device *dev, int new_mtu) /* Deactivate all the buffer pools so that the next loop can activate only the buffer pools necessary to hold the new MTU */ if (netif_running(adapter->netdev)) { + netif_tx_disable(dev); need_restart = 1; adapter->pool_config = 1; ibmveth_close(adapter->netdev);
@@ -1378,14 +1379,18 @@ static int ibmveth_change_mtu(struct net_device *dev, int new_mtu) ibmveth_get_desired_dma (viodev)); if (need_restart) { - return ibmveth_open(adapter->netdev); + rc = ibmveth_open(adapter->netdev); + netif_wake_queue(dev); + return rc; } return 0; } } - if (need_restart && (rc = ibmveth_open(adapter->netdev))) + if (need_restart && (rc = ibmveth_open(adapter->netdev))) { + netif_wake_queue(dev); return rc; + } return -EINVAL; }
--
2.4.11