Re: [PATCH v2] iommu/qcom: Fix local_base status check

[Markus Elfring]

> The function qcom_iommu_device_probe() does not perform sufficient
> error checking after executing devm_ioremap_resource(), which can
> result in crashes if a critical error path is encountered.

Your update suggestion will be rechecked once more.

* Can it be that the patch would need a higher version number
  according to previous review comments?

* Would you like to adjust the patch subject?


â
> +++ b/drivers/iommu/qcom_iommu.c
> @@ -813,8 +813,11 @@ static int qcom_iommu_device_probe(struct platform_device *pdev)
>  	qcom_iommu->dev = dev;
>
>  	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> -	if (res)

I find the deletion of this check appropriate.


> +	if (res) {
>  		qcom_iommu->local_base = devm_ioremap_resource(dev, res);

But I do not see a need to preserve such a check because this function
performs input parameter validation.
https://elixir.bootlin.com/linux/v5.7-rc1/source/lib/devres.c#L116
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/lib/devres.c?id=50cc09c18985eacbbd666acfd7be2391394733f5#n116

Please take another look at a corresponding usage example.

Regards,
Markus