[PATCH -next] iommu/arm-smmu: fix potential NULL pointer dereference in arm_smmu_map()

[will.deacon@arm.com (Will Deacon)]

On Fri, Nov 15, 2013 at 09:45:03AM +0000, Wei Yongjun wrote:
> From: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
> 
> The dereference should be moved below the NULL test.
> 
> Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
> ---
>  drivers/iommu/arm-smmu.c | 3 +--
>  1 file changed, 1 insertion(+), 2 deletions(-)
> 
> diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c
> index 2349d62..a0cc0a5 100644
> --- a/drivers/iommu/arm-smmu.c
> +++ b/drivers/iommu/arm-smmu.c
> @@ -1420,9 +1420,8 @@ static int arm_smmu_map(struct iommu_domain *domain, unsigned long iova,
>  			phys_addr_t paddr, size_t size, int flags)
>  {
>  	struct arm_smmu_domain *smmu_domain = domain->priv;
> -	struct arm_smmu_device *smmu = smmu_domain->leaf_smmu;
>  
> -	if (!smmu_domain || !smmu)
> +	if (!smmu_domain || !smmu_domain->leaf_smmu)
>  		return -ENODEV;
>  
>  	/* Check for silent address truncation up the SMMU chain. */

I already have a patch for this, but actually, we can remove that check
altogether. I'll fix it in my tree.

Will