iommu: fix parameter check in tegra_smmu_debugfs_init()

[PATCH v1] iommu: fix parameter check in tegra_smmu_debugfs_init()

Posted by Minjie Du 2 years, 6 months ago

Make IS_ERR() judge the debugfs_create_dir() function return
in tegra_smmu_debugfs_init()

Signed-off-by: Minjie Du <duminjie@vivo.com>
---
 drivers/iommu/tegra-smmu.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/iommu/tegra-smmu.c b/drivers/iommu/tegra-smmu.c
index 1cbf063cc..841e14cce 100644
--- a/drivers/iommu/tegra-smmu.c
+++ b/drivers/iommu/tegra-smmu.c
@@ -1056,7 +1056,7 @@ DEFINE_SHOW_ATTRIBUTE(tegra_smmu_clients);
 static void tegra_smmu_debugfs_init(struct tegra_smmu *smmu)
 {
 	smmu->debugfs = debugfs_create_dir("smmu", NULL);
-	if (!smmu->debugfs)
+	if (IS_ERR(smmu->debugfs))
 		return;
 
 	debugfs_create_file("swgroups", S_IRUGO, smmu->debugfs, smmu,
-- 
2.39.0

Re: [PATCH v1] iommu: fix parameter check in tegra_smmu_debugfs_init()

Posted by Thierry Reding 2 years, 6 months ago

On Wed, Jul 12, 2023 at 07:31:45PM +0800, Minjie Du wrote:
> Make IS_ERR() judge the debugfs_create_dir() function return
> in tegra_smmu_debugfs_init()
> 
> Signed-off-by: Minjie Du <duminjie@vivo.com>
> ---
>  drivers/iommu/tegra-smmu.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/iommu/tegra-smmu.c b/drivers/iommu/tegra-smmu.c
> index 1cbf063cc..841e14cce 100644
> --- a/drivers/iommu/tegra-smmu.c
> +++ b/drivers/iommu/tegra-smmu.c
> @@ -1056,7 +1056,7 @@ DEFINE_SHOW_ATTRIBUTE(tegra_smmu_clients);
>  static void tegra_smmu_debugfs_init(struct tegra_smmu *smmu)
>  {
>  	smmu->debugfs = debugfs_create_dir("smmu", NULL);
> -	if (!smmu->debugfs)
> +	if (IS_ERR(smmu->debugfs))
>  		return;

I think we can just drop the error check altogether since
debugfs_create_file() will simply return early if smmu->debugfs is an
error pointer.

Thierry