diff mbox series

[v7,3/6] iommu/mediatek: Add error path for loop of mm_dts_parse

Message ID 20221018024258.19073-4-yong.wu@mediatek.com (mailing list archive)
State New, archived
Headers show
Series iommu/mediatek: Improve safety from invalid dts input | expand

Commit Message

Yong Wu (吴勇) Oct. 18, 2022, 2:42 a.m. UTC
The mtk_iommu_mm_dts_parse will parse the smi larbs nodes. if the i+1
larb is parsed fail, we should put_device for the i..0 larbs.

There are two places need to comment:
1) The larbid may be not linear mapping, we should loop whole
   the array in the error path.
2) I move this line position: "data->larb_imu[id].dev = &plarbdev->dev;"
   before "if (!plarbdev->dev.driver)", That means set
   data->larb_imu[id].dev before the error path. then we don't need
   "platform_device_put(plarbdev)" again in probe_defer case. All depend
   on "put_device" of the error path in error cases.

Fixes: d2e9a1102cfc ("iommu/mediatek: Contain MM IOMMU flow with the MM TYPE")
Signed-off-by: Yong Wu <yong.wu@mediatek.com>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
---
 drivers/iommu/mtk_iommu.c | 27 ++++++++++++++++++++-------
 1 file changed, 20 insertions(+), 7 deletions(-)

Comments

Matthias Brugger Nov. 22, 2022, 4:32 p.m. UTC | #1
On 18/10/2022 04:42, Yong Wu wrote:
> The mtk_iommu_mm_dts_parse will parse the smi larbs nodes. if the i+1
> larb is parsed fail, we should put_device for the i..0 larbs.
> 
> There are two places need to comment:
> 1) The larbid may be not linear mapping, we should loop whole
>     the array in the error path.
> 2) I move this line position: "data->larb_imu[id].dev = &plarbdev->dev;"
>     before "if (!plarbdev->dev.driver)", That means set
>     data->larb_imu[id].dev before the error path. then we don't need
>     "platform_device_put(plarbdev)" again in probe_defer case. All depend
>     on "put_device" of the error path in error cases.
> 
> Fixes: d2e9a1102cfc ("iommu/mediatek: Contain MM IOMMU flow with the MM TYPE")
> Signed-off-by: Yong Wu <yong.wu@mediatek.com>
> Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>

Reviewed-by: Matthias Brugger <matthias.bgg@gmail.com>


> ---
>   drivers/iommu/mtk_iommu.c | 27 ++++++++++++++++++++-------
>   1 file changed, 20 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/iommu/mtk_iommu.c b/drivers/iommu/mtk_iommu.c
> index 38112ad87d70..912322494bc0 100644
> --- a/drivers/iommu/mtk_iommu.c
> +++ b/drivers/iommu/mtk_iommu.c
> @@ -1055,8 +1055,10 @@ static int mtk_iommu_mm_dts_parse(struct device *dev, struct component_match **m
>   		u32 id;
>   
>   		larbnode = of_parse_phandle(dev->of_node, "mediatek,larbs", i);
> -		if (!larbnode)
> -			return -EINVAL;
> +		if (!larbnode) {
> +			ret = -EINVAL;
> +			goto err_larbdev_put;
> +		}
>   
>   		if (!of_device_is_available(larbnode)) {
>   			of_node_put(larbnode);
> @@ -1069,14 +1071,16 @@ static int mtk_iommu_mm_dts_parse(struct device *dev, struct component_match **m
>   
>   		plarbdev = of_find_device_by_node(larbnode);
>   		of_node_put(larbnode);
> -		if (!plarbdev)
> -			return -ENODEV;
> +		if (!plarbdev) {
> +			ret = -ENODEV;
> +			goto err_larbdev_put;
> +		}
> +		data->larb_imu[id].dev = &plarbdev->dev;
>   
>   		if (!plarbdev->dev.driver) {
> -			platform_device_put(plarbdev);
> -			return -EPROBE_DEFER;
> +			ret = -EPROBE_DEFER;
> +			goto err_larbdev_put;
>   		}
> -		data->larb_imu[id].dev = &plarbdev->dev;
>   
>   		component_match_add(dev, match, component_compare_dev, &plarbdev->dev);
>   		platform_device_put(plarbdev);
> @@ -1111,6 +1115,15 @@ static int mtk_iommu_mm_dts_parse(struct device *dev, struct component_match **m
>   		return -EINVAL;
>   	}
>   	return 0;
> +
> +err_larbdev_put:
> +	/* id may be not linear mapping, loop whole the array */
> +	for (i = MTK_LARB_NR_MAX - 1; i >= 0; i++) {
> +		if (!data->larb_imu[i].dev)
> +			continue;
> +		put_device(data->larb_imu[i].dev);
> +	}
> +	return ret;
>   }
>   
>   static int mtk_iommu_probe(struct platform_device *pdev)
diff mbox series

Patch

diff --git a/drivers/iommu/mtk_iommu.c b/drivers/iommu/mtk_iommu.c
index 38112ad87d70..912322494bc0 100644
--- a/drivers/iommu/mtk_iommu.c
+++ b/drivers/iommu/mtk_iommu.c
@@ -1055,8 +1055,10 @@  static int mtk_iommu_mm_dts_parse(struct device *dev, struct component_match **m
 		u32 id;
 
 		larbnode = of_parse_phandle(dev->of_node, "mediatek,larbs", i);
-		if (!larbnode)
-			return -EINVAL;
+		if (!larbnode) {
+			ret = -EINVAL;
+			goto err_larbdev_put;
+		}
 
 		if (!of_device_is_available(larbnode)) {
 			of_node_put(larbnode);
@@ -1069,14 +1071,16 @@  static int mtk_iommu_mm_dts_parse(struct device *dev, struct component_match **m
 
 		plarbdev = of_find_device_by_node(larbnode);
 		of_node_put(larbnode);
-		if (!plarbdev)
-			return -ENODEV;
+		if (!plarbdev) {
+			ret = -ENODEV;
+			goto err_larbdev_put;
+		}
+		data->larb_imu[id].dev = &plarbdev->dev;
 
 		if (!plarbdev->dev.driver) {
-			platform_device_put(plarbdev);
-			return -EPROBE_DEFER;
+			ret = -EPROBE_DEFER;
+			goto err_larbdev_put;
 		}
-		data->larb_imu[id].dev = &plarbdev->dev;
 
 		component_match_add(dev, match, component_compare_dev, &plarbdev->dev);
 		platform_device_put(plarbdev);
@@ -1111,6 +1115,15 @@  static int mtk_iommu_mm_dts_parse(struct device *dev, struct component_match **m
 		return -EINVAL;
 	}
 	return 0;
+
+err_larbdev_put:
+	/* id may be not linear mapping, loop whole the array */
+	for (i = MTK_LARB_NR_MAX - 1; i >= 0; i++) {
+		if (!data->larb_imu[i].dev)
+			continue;
+		put_device(data->larb_imu[i].dev);
+	}
+	return ret;
 }
 
 static int mtk_iommu_probe(struct platform_device *pdev)