[PATCH] phy: qualcomm: phy-qcom-qmp: Add of_node_put() before return

[PATCH] phy: qualcomm: phy-qcom-qmp: Add of_node_put() before return

[Nishka Dasgupta]

Each iteration of for_each_available_child_of_node() puts the previous
node, but in the case of a return from the middle of the loop, there is
no put, thus causing a memory leak. Hence create a new label,
err_node_put, that puts the previous node (child) before returning the
required value. Also include the statement pm_runtime_disable() under
this label in order to avoid repetition among mid-loop return
conditions. Edit the mid-loop return statements to instead go to this
new label err_node_put.
Issue found with Coccinelle.

Signed-off-by: Nishka Dasgupta <nishkadg.linux@gmail.com>
---
 drivers/phy/qualcomm/phy-qcom-qmp.c | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/drivers/phy/qualcomm/phy-qcom-qmp.c b/drivers/phy/qualcomm/phy-qcom-qmp.c
index 34ff6434da8f..e7b8283acce8 100644
--- a/drivers/phy/qualcomm/phy-qcom-qmp.c
+++ b/drivers/phy/qualcomm/phy-qcom-qmp.c
@@ -2093,8 +2093,7 @@ static int qcom_qmp_phy_probe(struct platform_device *pdev)
 		if (ret) {
 			dev_err(dev, "failed to create lane%d phy, %d\n",
 				id, ret);
-			pm_runtime_disable(dev);
-			return ret;
+			goto err_node_put;
 		}
 
 		/*
@@ -2105,8 +2104,7 @@ static int qcom_qmp_phy_probe(struct platform_device *pdev)
 		if (ret) {
 			dev_err(qmp->dev,
 				"failed to register pipe clock source\n");
-			pm_runtime_disable(dev);
-			return ret;
+			goto err_node_put;
 		}
 		id++;
 	}
@@ -2118,6 +2116,11 @@ static int qcom_qmp_phy_probe(struct platform_device *pdev)
 		pm_runtime_disable(dev);
 
 	return PTR_ERR_OR_ZERO(phy_provider);
+
+err_node_put:
+	pm_runtime_disable(dev);
+	of_node_put(child);
+	return ret;
 }
 
 static struct platform_driver qcom_qmp_phy_driver = {
-- 
2.19.1

Re: [PATCH] phy: qualcomm: phy-qcom-qmp: Add of_node_put() before return

[Markus Elfring]

> +++ b/drivers/phy/qualcomm/phy-qcom-qmp.c
> @@ -2094,6 +2094,7 @@ static int qcom_qmp_phy_probe(struct platform_device *pdev)
>  			dev_err(dev, "failed to create lane%d phy, %d\n",
>  				id, ret);
>  			pm_runtime_disable(dev);
> +			of_node_put(child);
>  			return ret;
>  		}

I suggest to move a bit of common exception handling code to the end of
this function implementation.
Would you like to add a jump target?

Regards,
Markus

Re: [PATCH] phy: qualcomm: phy-qcom-qmp: Add of_node_put() before return

[Vivek Gautam]

On Sun, Aug 4, 2019 at 9:54 PM Nishka Dasgupta <nishkadg.linux@gmail.com> wrote:
>
> Each iteration of for_each_available_child_of_node puts the previous
> node, but in the case of a return from the middle of the loop, there is
> no put, thus causing a memory leak. Hence add an of_node_put before the
> return in two places.
> Issue found with Coccinelle.
>
> Signed-off-by: Nishka Dasgupta <nishkadg.linux@gmail.com>
> ---
>  drivers/phy/qualcomm/phy-qcom-qmp.c | 2 ++
>  1 file changed, 2 insertions(+)
>
> diff --git a/drivers/phy/qualcomm/phy-qcom-qmp.c b/drivers/phy/qualcomm/phy-qcom-qmp.c
> index 34ff6434da8f..2f0652efebf0 100644
> --- a/drivers/phy/qualcomm/phy-qcom-qmp.c
> +++ b/drivers/phy/qualcomm/phy-qcom-qmp.c
> @@ -2094,6 +2094,7 @@ static int qcom_qmp_phy_probe(struct platform_device *pdev)
>                         dev_err(dev, "failed to create lane%d phy, %d\n",
>                                 id, ret);
>                         pm_runtime_disable(dev);
> +                       of_node_put(child);
>                         return ret;
>                 }
>
> @@ -2106,6 +2107,7 @@ static int qcom_qmp_phy_probe(struct platform_device *pdev)
>                         dev_err(qmp->dev,
>                                 "failed to register pipe clock source\n");
>                         pm_runtime_disable(dev);
> +                       of_node_put(child);

Nice find. Thanks for the patch.

Reviewed-by: Vivek Gautam <vivek.gautam@codeaurora.org>

Best regards
Vivek

[snip]
-- 
QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member
of Code Aurora Forum, hosted by The Linux Foundation

[PATCH] phy: qualcomm: phy-qcom-qmp: Add of_node_put() before return

[Nishka Dasgupta]

Each iteration of for_each_available_child_of_node puts the previous
node, but in the case of a return from the middle of the loop, there is
no put, thus causing a memory leak. Hence add an of_node_put before the
return in two places.
Issue found with Coccinelle.

Signed-off-by: Nishka Dasgupta <nishkadg.linux@gmail.com>
---
 drivers/phy/qualcomm/phy-qcom-qmp.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/phy/qualcomm/phy-qcom-qmp.c b/drivers/phy/qualcomm/phy-qcom-qmp.c
index 34ff6434da8f..2f0652efebf0 100644
--- a/drivers/phy/qualcomm/phy-qcom-qmp.c
+++ b/drivers/phy/qualcomm/phy-qcom-qmp.c
@@ -2094,6 +2094,7 @@ static int qcom_qmp_phy_probe(struct platform_device *pdev)
 			dev_err(dev, "failed to create lane%d phy, %d\n",
 				id, ret);
 			pm_runtime_disable(dev);
+			of_node_put(child);
 			return ret;
 		}
 
@@ -2106,6 +2107,7 @@ static int qcom_qmp_phy_probe(struct platform_device *pdev)
 			dev_err(qmp->dev,
 				"failed to register pipe clock source\n");
 			pm_runtime_disable(dev);
+			of_node_put(child);
 			return ret;
 		}
 		id++;
-- 
2.19.1