[PATCH v6 03/29] iommu/arm-smmu-v3: Do not allow a SVA domain to be set on the wrong PASID

[Mostafa Saleh]

Hi Jason,

On Wed, Mar 27, 2024 at 03:07:49PM -0300, Jason Gunthorpe wrote:
> The SVA code is wired to assume that the SVA is programmed onto the
> mm->pasid. The current core code always does this, so it is fine.
> 
> Add a check for clarity.
> 
> Fixes: 386fa64fd52b ("arm-smmu-v3/sva: Add SVA domain support")
> Tested-by: Nicolin Chen <nicolinc at nvidia.com>
> Tested-by: Shameer Kolothum <shameerali.kolothum.thodi at huawei.com>
> Reviewed-by: Mostafa Saleh <smostafa at google.com>

I think there might have been a mix up, this was patch 01 in v5,
I didn’t add a tag on it. I don’t have a problem with the patch.
I just think (based on my limited understanding and rules in[1])
that it is not a fix as (mentioned in the last thread) the only
caller in the tree calls it properly.
But that’s up to the driver/stable maintainers.

[1] https://www.kernel.org/doc/html/next/process/stable-kernel-rules.html
> Signed-off-by: Jason Gunthorpe <jgg at nvidia.com>
> ---
>  drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c
> index 2cd433a9c8a0fa..41b44baef15e80 100644
> --- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c
> +++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c
> @@ -569,6 +569,9 @@ static int arm_smmu_sva_set_dev_pasid(struct iommu_domain *domain,
>  	int ret = 0;
>  	struct mm_struct *mm = domain->mm;
>  
> +	if (mm_get_enqcmd_pasid(mm) != id)
> +		return -EINVAL;
> +
>  	mutex_lock(&sva_lock);
>  	ret = __arm_smmu_sva_bind(dev, id, mm);
>  	mutex_unlock(&sva_lock);
> -- 
> 2.43.2
>

Thanks,
Mostafa