6.1-stable review patch. If anyone has any objections, please let me know.
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From: Sean Anderson sean.anderson@linux.dev
commit 858430db28a5f5a11f8faa3a6fa805438e6f0851 upstream.
axienet_dma_err_handler can race with axienet_stop in the following manner:
CPU 1 CPU 2 ====================== ================== axienet_stop() napi_disable() axienet_dma_stop() axienet_dma_err_handler() napi_disable() axienet_dma_stop() axienet_dma_start() napi_enable() cancel_work_sync() free_irq()
Fix this by setting a flag in axienet_stop telling axienet_dma_err_handler not to bother doing anything. I chose not to use disable_work_sync to allow for easier backporting.
Signed-off-by: Sean Anderson sean.anderson@linux.dev Fixes: 8a3b7a252dca ("drivers/net/ethernet/xilinx: added Xilinx AXI Ethernet driver") Link: https://patch.msgid.link/20240903175141.4132898-1-sean.anderson@linux.dev Signed-off-by: Jakub Kicinski kuba@kernel.org [ Adjusted to apply before dmaengine support ] Signed-off-by: Sean Anderson sean.anderson@linux.dev Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/net/ethernet/xilinx/xilinx_axienet.h | 3 +++ drivers/net/ethernet/xilinx/xilinx_axienet_main.c | 8 ++++++++ 2 files changed, 11 insertions(+)
--- a/drivers/net/ethernet/xilinx/xilinx_axienet.h +++ b/drivers/net/ethernet/xilinx/xilinx_axienet.h @@ -419,6 +419,8 @@ struct axidma_bd { * @tx_bytes: TX byte count for statistics * @tx_stat_sync: Synchronization object for TX stats * @dma_err_task: Work structure to process Axi DMA errors + * @stopping: Set when @dma_err_task shouldn't do anything because we are + * about to stop the device. * @tx_irq: Axidma TX IRQ number * @rx_irq: Axidma RX IRQ number * @eth_irq: Ethernet core IRQ number @@ -481,6 +483,7 @@ struct axienet_local { struct u64_stats_sync tx_stat_sync;
struct work_struct dma_err_task; + bool stopping;
int tx_irq; int rx_irq; --- a/drivers/net/ethernet/xilinx/xilinx_axienet_main.c +++ b/drivers/net/ethernet/xilinx/xilinx_axienet_main.c @@ -1161,6 +1161,7 @@ static int axienet_open(struct net_devic phylink_start(lp->phylink);
/* Enable worker thread for Axi DMA error handling */ + lp->stopping = false; INIT_WORK(&lp->dma_err_task, axienet_dma_err_handler);
napi_enable(&lp->napi_rx); @@ -1216,6 +1217,9 @@ static int axienet_stop(struct net_devic
dev_dbg(&ndev->dev, "axienet_close()\n");
+ WRITE_ONCE(lp->stopping, true); + flush_work(&lp->dma_err_task); + napi_disable(&lp->napi_tx); napi_disable(&lp->napi_rx);
@@ -1760,6 +1764,10 @@ static void axienet_dma_err_handler(stru dma_err_task); struct net_device *ndev = lp->ndev;
+ /* Don't bother if we are going to stop anyway */ + if (READ_ONCE(lp->stopping)) + return; + napi_disable(&lp->napi_tx); napi_disable(&lp->napi_rx);