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

Wen Yang
2019-02-27T04:42:35Z

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;