On Thu 2019-05-02 17:21:08, Greg Kroah-Hartman wrote:
> [ Upstream commit fa3a419d2f674b431d38748cb58fb7da17ee8949 ]
>
> The call to of_parse_phandle returns a node pointer with refcount
> incremented thus it must be explicitly decremented after the last
> usage.
>
> Detected by coccinelle with the following warnings:
> ./drivers/net/ethernet/xilinx/xilinx_axienet_main.c:1624:1-7: ERROR: missing of_node_put; acquired a node pointer with refcount incremented on line 1569, but without a corresponding object release within this function.
>
> Signed-off-by: Wen Yang <wen.yang99@xxxxxxxxxx>
> Cc: Anirudha Sarangi <anirudh@xxxxxxxxxx>
> Cc: John Linn <John.Linn@xxxxxxxxxx>
> Cc: "David S. Miller" <davem@xxxxxxxxxxxxx>
> Cc: Michal Simek <michal.simek@xxxxxxxxxx>
> Cc: netdev@xxxxxxxxxxxxxxx
> Cc: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
> Cc: linux-kernel@xxxxxxxxxxxxxxx
> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
> Signed-off-by: Sasha Levin (Microsoft) <sashal@xxxxxxxxxx>
Bug is real, but fix is horrible. This already uses gotos for error
handling, so use them....
This fixes it up.
Plus... I do not think these "of_node_put" fixes belong in
stable. They are theoretical bugs; so we hold reference to device tree
structure. a) it is small, b) it stays in memory, anyway. This does
not fix any real problem.
Pavel
diff --git a/drivers/net/ethernet/xilinx/xilinx_axienet_main.c b/drivers/net/ethernet/xilinx/xilinx_axienet_main.c
index 4041c75..490d440 100644
--- a/drivers/net/ethernet/xilinx/xilinx_axienet_main.c
+++ b/drivers/net/ethernet/xilinx/xilinx_axienet_main.c
@@ -1575,15 +1575,13 @@ static int axienet_probe(struct platform_device *pdev)
ret = of_address_to_resource(np, 0, &dmares);
if (ret) {
dev_err(&pdev->dev, "unable to get DMA resource\n");
- of_node_put(np);
- goto free_netdev;
+ goto free_netdev_put;
}
lp->dma_regs = devm_ioremap_resource(&pdev->dev, &dmares);
if (IS_ERR(lp->dma_regs)) {
dev_err(&pdev->dev, "could not map DMA regs\n");
ret = PTR_ERR(lp->dma_regs);
- of_node_put(np);
- goto free_netdev;
+ goto free_netdev_put;
}
lp->rx_irq = irq_of_parse_and_map(np, 1);
lp->tx_irq = irq_of_parse_and_map(np, 0);
@@ -1620,6 +1618,8 @@ static int axienet_probe(struct platform_device *pdev)
return 0;
+free_netdev_put:
+ of_node_put(np);
free_netdev:
free_netdev(ndev);
> ---
> drivers/net/ethernet/xilinx/xilinx_axienet_main.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/drivers/net/ethernet/xilinx/xilinx_axienet_main.c b/drivers/net/ethernet/xilinx/xilinx_axienet_main.c
> index f24f48f33802..7cfd7ff38e86 100644
> --- a/drivers/net/ethernet/xilinx/xilinx_axienet_main.c
> +++ b/drivers/net/ethernet/xilinx/xilinx_axienet_main.c
> @@ -1574,12 +1574,14 @@ static int axienet_probe(struct platform_device *pdev)
> ret = of_address_to_resource(np, 0, &dmares);
> if (ret) {
> dev_err(&pdev->dev, "unable to get DMA resource\n");
> + of_node_put(np);
> goto free_netdev;
> }
> lp->dma_regs = devm_ioremap_resource(&pdev->dev, &dmares);
> if (IS_ERR(lp->dma_regs)) {
> dev_err(&pdev->dev, "could not map DMA regs\n");
> ret = PTR_ERR(lp->dma_regs);
> + of_node_put(np);
> goto free_netdev;
> }
> lp->rx_irq = irq_of_parse_and_map(np, 1);
--
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
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