[PATCH v2] media: xilinx: fix leaked of_node references

From: Wen Yang
Date: Mon Jul 01 2019 - 04:32:24 EST


The call to of_get_child_by_name 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/media/platform/xilinx/xilinx-vipp.c:487:3-9: ERROR: missing of_node_put; acquired a node pointer with refcount incremented on line 477, but without a corresponding object release within this function.
drivers/media/platform/xilinx/xilinx-vipp.c:491:1-7: ERROR: missing of_node_put; acquired a node pointer with refcount incremented on line 477, but without a corresponding object release within this function.
drivers/media/platform/xilinx/xilinx-tpg.c:732:3-9: ERROR: missing of_node_put; acquired a node pointer with refcount incremented on line 717, but without a corresponding object release within this function.
drivers/media/platform/xilinx/xilinx-tpg.c:741:3-9: ERROR: missing of_node_put; acquired a node pointer with refcount incremented on line 717, but without a corresponding object release within this function.
drivers/media/platform/xilinx/xilinx-tpg.c:757:2-8: ERROR: missing of_node_put; acquired a node pointer with refcount incremented on line 717, but without a corresponding object release within this function.
drivers/media/platform/xilinx/xilinx-tpg.c:764:1-7: ERROR: missing of_node_put; acquired a node pointer with refcount incremented on line 717, but without a corresponding object release within this function.

Signed-off-by: Wen Yang <wen.yang99@xxxxxxxxxx>
Cc: Patrice Chotard <patrice.chotard@xxxxxx>
Cc: Hyun Kwon <hyun.kwon@xxxxxxxxxx>
Cc: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>
Cc: Mauro Carvalho Chehab <mchehab@xxxxxxxxxx>
Cc: Michal Simek <michal.simek@xxxxxxxxxx>
Cc: linux-media@xxxxxxxxxxxxxxx
Cc: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx
---
v2: fix Comparison to NULL

drivers/media/platform/xilinx/xilinx-tpg.c | 18 +++++++++++++-----
drivers/media/platform/xilinx/xilinx-vipp.c | 8 +++++---
2 files changed, 18 insertions(+), 8 deletions(-)

diff --git a/drivers/media/platform/xilinx/xilinx-tpg.c b/drivers/media/platform/xilinx/xilinx-tpg.c
index ed01bed..e71d022 100644
--- a/drivers/media/platform/xilinx/xilinx-tpg.c
+++ b/drivers/media/platform/xilinx/xilinx-tpg.c
@@ -713,10 +713,13 @@ static int xtpg_parse_of(struct xtpg_device *xtpg)
struct device_node *port;
unsigned int nports = 0;
bool has_endpoint = false;
+ int ret = 0;

ports = of_get_child_by_name(node, "ports");
- if (ports == NULL)
+ if (!ports) {
ports = node;
+ of_node_get(ports);
+ }

for_each_child_of_node(ports, port) {
const struct xvip_video_format *format;
@@ -729,7 +732,8 @@ static int xtpg_parse_of(struct xtpg_device *xtpg)
if (IS_ERR(format)) {
dev_err(dev, "invalid format in DT");
of_node_put(port);
- return PTR_ERR(format);
+ ret = PTR_ERR(format);
+ goto out_put_node;
}

/* Get and check the format description */
@@ -738,7 +742,8 @@ static int xtpg_parse_of(struct xtpg_device *xtpg)
} else if (xtpg->vip_format != format) {
dev_err(dev, "in/out format mismatch in DT");
of_node_put(port);
- return -EINVAL;
+ ret = -EINVAL;
+ goto out_put_node;
}

if (nports == 0) {
@@ -754,14 +759,17 @@ static int xtpg_parse_of(struct xtpg_device *xtpg)

if (nports != 1 && nports != 2) {
dev_err(dev, "invalid number of ports %u\n", nports);
- return -EINVAL;
+ ret = -EINVAL;
+ goto out_put_node;
}

xtpg->npads = nports;
if (nports == 2 && has_endpoint)
xtpg->has_input = true;

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

static int xtpg_probe(struct platform_device *pdev)
diff --git a/drivers/media/platform/xilinx/xilinx-vipp.c b/drivers/media/platform/xilinx/xilinx-vipp.c
index edce040..307717c 100644
--- a/drivers/media/platform/xilinx/xilinx-vipp.c
+++ b/drivers/media/platform/xilinx/xilinx-vipp.c
@@ -472,7 +472,7 @@ static int xvip_graph_dma_init(struct xvip_composite_device *xdev)
{
struct device_node *ports;
struct device_node *port;
- int ret;
+ int ret = 0;

ports = of_get_child_by_name(xdev->dev->of_node, "ports");
if (ports == NULL) {
@@ -484,11 +484,13 @@ static int xvip_graph_dma_init(struct xvip_composite_device *xdev)
ret = xvip_graph_dma_init_one(xdev, port);
if (ret < 0) {
of_node_put(port);
- return ret;
+ goto out_put_node;
}
}

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

static void xvip_graph_cleanup(struct xvip_composite_device *xdev)
--
2.9.5