2019-12-26 09:52:47

by Masahiro Yamada

Subject: [PATCH] iommu/arm-smmu-v3: fix resource_size check

This is an off-by-one mistake.

resource_size() returns res->end - res->start + 1.

Signed-off-by: Masahiro Yamada <[email protected]>
---

drivers/iommu/arm-smmu-v3.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c
index d9e0d9c19b4f..b463599559d2 100644
--- a/drivers/iommu/arm-smmu-v3.c
+++ b/drivers/iommu/arm-smmu-v3.c
@@ -3599,7 +3599,7 @@ static int arm_smmu_device_probe(struct platform_device *pdev)

/* Base address */
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
- if (resource_size(res) + 1 < arm_smmu_resource_size(smmu)) {
+ if (resource_size(res) < arm_smmu_resource_size(smmu)) {
dev_err(dev, "MMIO region too small (%pr)\n", res);
return -EINVAL;
}
--
2.17.1

2020-01-09 15:06:36

by Robin Murphy

Subject: Re: [PATCH] iommu/arm-smmu-v3: fix resource_size check

On 26/12/2019 9:50 am, Masahiro Yamada wrote:
> This is an off-by-one mistake.
>
> resource_size() returns res->end - res->start + 1.

Heh, despite the optimism of "Avoid one-off errors by introducing a
resource_size() function", life finds a way...

Reviewed-by: Robin Murphy <[email protected]>

> Signed-off-by: Masahiro Yamada <[email protected]>
> ---
>
> drivers/iommu/arm-smmu-v3.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c
> index d9e0d9c19b4f..b463599559d2 100644
> --- a/drivers/iommu/arm-smmu-v3.c
> +++ b/drivers/iommu/arm-smmu-v3.c
> @@ -3599,7 +3599,7 @@ static int arm_smmu_device_probe(struct platform_device *pdev)
>
> /* Base address */
> res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> - if (resource_size(res) + 1 < arm_smmu_resource_size(smmu)) {
> + if (resource_size(res) < arm_smmu_resource_size(smmu)) {
> dev_err(dev, "MMIO region too small (%pr)\n", res);
> return -EINVAL;
> }
>