Commit 293cfb13 authored by Sean Anderson's avatar Sean Anderson Committed by Wen Zhiwei
Browse files

net: xilinx: axienet: Fix race in axienet_stop 

stable inclusion
from stable-v6.6.52
commit b1e1daf0125e08cf75b236e152d1872f6c7d8d65
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/IAYXOD

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=b1e1daf0125e08cf75b236e152d1872f6c7d8d65



--------------------------------

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: default avatarSean Anderson <sean.anderson@linux.dev>
Fixes: 8a3b7a25 ("drivers/net/ethernet/xilinx: added Xilinx AXI Ethernet driver")
Link: https://patch.msgid.link/20240903175141.4132898-1-sean.anderson@linux.dev


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
[ Adjusted to apply before dmaengine support ]
Signed-off-by: default avatarSean Anderson <sean.anderson@linux.dev>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: default avatarWen Zhiwei <wenzhiwei@kylinos.cn>
parent bd0615d5

drivers/net/ethernet/xilinx/xilinx_axienet.h

+3 −0
Original line number Diff line number Diff line
@@ -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;

drivers/net/ethernet/xilinx/xilinx_axienet_main.c

+8 −0
Original line number Diff line number Diff line
@@ -1162,6 +1162,7 @@ static int axienet_open(struct net_device *ndev) 
	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);
@@ -1217,6 +1218,9 @@ static int axienet_stop(struct net_device *ndev) 


	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);
@@ -1761,6 +1765,10 @@ 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);