6.10-stable review patch. If anyone has any objections, please let me know.
------------------
From: Sean Anderson <sean.anderson@xxxxxxxxx>
[ Upstream commit 858430db28a5f5a11f8faa3a6fa805438e6f0851 ]
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@xxxxxxxxx>
Fixes: 8a3b7a252dca ("drivers/net/ethernet/xilinx: added Xilinx AXI Ethernet driver")
Link: https://patch.msgid.link/20240903175141.4132898-1-sean.anderson@xxxxxxxxx
Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/net/ethernet/xilinx/xilinx_axienet.h | 3 +++
drivers/net/ethernet/xilinx/xilinx_axienet_main.c | 8 ++++++++
2 files changed, 11 insertions(+)
diff --git a/drivers/net/ethernet/xilinx/xilinx_axienet.h b/drivers/net/ethernet/xilinx/xilinx_axienet.h
index 09c9f9787180..1223fcc1a8da 100644
--- a/drivers/net/ethernet/xilinx/xilinx_axienet.h
+++ b/drivers/net/ethernet/xilinx/xilinx_axienet.h
@@ -436,6 +436,8 @@ struct skbuf_dma_descriptor {
* @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
@@ -507,6 +509,7 @@ struct axienet_local {
struct u64_stats_sync tx_stat_sync;
struct work_struct dma_err_task;
+ bool stopping;
int tx_irq;
int rx_irq;
diff --git a/drivers/net/ethernet/xilinx/xilinx_axienet_main.c b/drivers/net/ethernet/xilinx/xilinx_axienet_main.c
index 559c0d60d948..88d7bc2ea713 100644
--- a/drivers/net/ethernet/xilinx/xilinx_axienet_main.c
+++ b/drivers/net/ethernet/xilinx/xilinx_axienet_main.c
@@ -1460,6 +1460,7 @@ static int axienet_init_legacy_dma(struct net_device *ndev)
struct axienet_local *lp = netdev_priv(ndev);
/* 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);
@@ -1580,6 +1581,9 @@ static int axienet_stop(struct net_device *ndev)
dev_dbg(&ndev->dev, "axienet_close()\n");
if (!lp->use_dmaengine) {
+ WRITE_ONCE(lp->stopping, true);
+ flush_work(&lp->dma_err_task);
+
napi_disable(&lp->napi_tx);
napi_disable(&lp->napi_rx);
}
@@ -2154,6 +2158,10 @@ static void axienet_dma_err_handler(struct work_struct *work)
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);
--
2.43.0
