[PATCH 5/8] PCI: aardvark: fix a leaked reference by adding missing of_node_put

Wen Yang
2019-02-27T04:42:05Z

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/pci-aardvark.c:826:1-7: ERROR: missing of_node_put; acquired a node pointer with refcount incremented on line 798, but without a corresponding object release within this function.

Signed-off-by: Wen Yang <wen.yang99@zte.com.cn>
Cc: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: linux-pci@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
---
drivers/pci/controller/pci-aardvark.c | 13 ++++++++-----
1 file changed, 8 insertions(+), 5 deletions(-)

diff --git a/drivers/pci/controller/pci-aardvark.c b/drivers/pci/controller/pci-aardvark.c
index 750081c..56ecb16 100644
--- a/drivers/pci/controller/pci-aardvark.c
+++ b/drivers/pci/controller/pci-aardvark.c
@@ -794,6 +794,7 @@ static int advk_pcie_init_irq_domain(struct advk_pcie *pcie)
struct device_node *node = dev->of_node;
struct device_node *pcie_intc_node;
struct irq_chip *irq_chip;
+ int ret = 0;

pcie_intc_node = of_get_next_child(node, NULL);
if (!pcie_intc_node) {
@@ -806,8 +807,8 @@ static int advk_pcie_init_irq_domain(struct advk_pcie *pcie)
irq_chip->name = devm_kasprintf(dev, GFP_KERNEL, "%s-irq",
dev_name(dev));
if (!irq_chip->name) {
- of_node_put(pcie_intc_node);
- return -ENOMEM;
+ ret = -ENOMEM;
+ goto out_put_node;
}

irq_chip->irq_mask = advk_pcie_irq_mask;
@@ -819,11 +820,13 @@ static int advk_pcie_init_irq_domain(struct advk_pcie *pcie)
&advk_pcie_irq_domain_ops, pcie);
if (!pcie->irq_domain) {
dev_err(dev, "Failed to get a INTx IRQ domain\n");
- of_node_put(pcie_intc_node);
- return -ENOMEM;
+ ret = -ENOMEM;
+ goto out_put_node;
}

- return 0;
+out_put_node:
+ of_node_put(pcie_intc_node);
+ return ret;
}

static void advk_pcie_remove_irq_domain(struct advk_pcie *pcie)