Re: [PATCH 4/7] iommu/arm-smmu: Pass arm_smmu_domain to arm_smmu_init_domain_context()

[Steven Price <steven.price@arm.com>]

On 05/10/2023 19:28, Jason Gunthorpe wrote:
> Instead of putting container_of() casts in the internals, use the proper
> type in this call chain. This makes it easier to check that the two global
> static domains are not leaking into call chains they should not.
> 
> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
> ---
>  drivers/iommu/arm/arm-smmu/arm-smmu.c | 28 +++++++++++++--------------
>  1 file changed, 13 insertions(+), 15 deletions(-)
> 
> diff --git a/drivers/iommu/arm/arm-smmu/arm-smmu.c b/drivers/iommu/arm/arm-smmu/arm-smmu.c
> index 0fc4f2e8bf3ed5..bf5f541be2399f 100644
> --- a/drivers/iommu/arm/arm-smmu/arm-smmu.c
> +++ b/drivers/iommu/arm/arm-smmu/arm-smmu.c
> @@ -393,7 +393,7 @@ static irqreturn_t arm_smmu_context_fault(int irq, void *dev)
>  	u32 fsr, fsynr, cbfrsynra;
>  	unsigned long iova;
>  	struct iommu_domain *domain = dev;
> -	struct arm_smmu_domain *smmu_domain = to_smmu_domain(domain);
> +	struct arm_smmu_domain *smmu_domain = dev;

Leaving aside Robin's objections - this change is clearly bogus. 'dev'
is now being case to both struct iommu_domain and struct
arm_smmu_domain. And AFAICT that won't even "happen to work" because the
struct iommu_domain isn't the first element of struct arm_smmu_domain.

Steve