Re: [PATCH 7/8] PCI: mediatek: fix a leaked reference by adding missing of_node_put

Honghui Zhang
2019-03-01T01:59:14Z

On Wed, 2019-02-27 at 12:40 +0800, Wen Yang wrote:
> The call to of_get_next_child returns a node pointer with refcount
> incremented thus it must be explicitly decremented after the last
> usage.
> irq_domain_add_linear also calls of_node_get to increase refcount,
> so irq_domain will not be affected when it is released.
>
> Detected by coccinelle with the following warnings:
> ./drivers/pci/controller/pcie-mediatek.c:577:2-8: ERROR: missing of_node_put; acquired a node pointer with refcount incremented on line 567, but without a corresponding object release within this function.
> ./drivers/pci/controller/pcie-mediatek.c:583:3-9: ERROR: missing of_node_put; acquired a node pointer with refcount incremented on line 567, but without a corresponding object release within this function.
> ./drivers/pci/controller/pcie-mediatek.c:586:1-7: ERROR: missing of_node_put; acquired a node pointer with refcount incremented on line 567, but without a corresponding object release within this function.
>
> Signed-off-by: Wen Yang <wen.yang99@zte.com.cn>
> Cc: Ryder Lee <ryder.lee@mediatek.com>
> Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
> Cc: Bjorn Helgaas <bhelgaas@google.com>
> Cc: Matthias Brugger <matthias.bgg@gmail.com>
> Cc: linux-pci@vger.kernel.org
> Cc: linux-mediatek@lists.infradead.org
> Cc: linux-kernel@vger.kernel.org
> Cc: linux-arm-kernel@lists.infradead.org
> ---
> drivers/pci/controller/pcie-mediatek.c | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/drivers/pci/controller/pcie-mediatek.c b/drivers/pci/controller/pcie-mediatek.c
> index 55e471c..e91716a 100644
> --- a/drivers/pci/controller/pcie-mediatek.c
> +++ b/drivers/pci/controller/pcie-mediatek.c
> @@ -572,6 +572,7 @@ static int mtk_pcie_init_irq_domain(struct mtk_pcie_port *port,
>
> port->irq_domain = irq_domain_add_linear(pcie_intc_node, PCI_NUM_INTX,
> &intx_domain_ops, port);
> + of_node_put(pcie_intc_node);
> if (!port->irq_domain) {
> dev_err(dev, "failed to get INTx IRQ domain\n");
> return -ENODEV;

Thanks for fix this.

Acked-by: Honghui Zhang <honghui.zhang@mediatek.com>