Re: [PATCH] iommu:Check that iommu_device_create has completed successfully in alloc_iommu

[Joerg Roedel <joro-zLv9SwRftAIdnm+yROfE0A@public.gmane.org>]

On Tue, Dec 29, 2015 at 12:10:11AM -0500, Nicholas Krause wrote:
> This adds the proper check to alloc_iommu to make sure that the call
> to iommu_device_create has completed successfully and if not return
> to the caller the error code returned after freeing up resources
> allocated previously by alloc_iommu.
> 
> Signed-off-by: Nicholas Krause <xerofoify-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
> ---
>  drivers/iommu/dmar.c | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/iommu/dmar.c b/drivers/iommu/dmar.c
> index 80e3c17..27333b6 100644
> --- a/drivers/iommu/dmar.c
> +++ b/drivers/iommu/dmar.c
> @@ -1069,9 +1069,12 @@ static int alloc_iommu(struct dmar_drhd_unit *drhd)
>  		iommu->iommu_dev = iommu_device_create(NULL, iommu,
>  						       intel_iommu_groups,
>  						       "%s", iommu->name);
> +	if (IS_ERR(iommu->iommu_dev)) {
> +		err = PTR_ERR(iommu->iommu_dev);
> +		goto err_unmap;
> +	}

This leaves a dangling pointer to the iommu in drhd->iommu.

>  
>  	return 0;
> -

That blank line improves readability of the code, please leave it in.

>  err_unmap:
>  	unmap_iommu(iommu);
>  error_free_seq_id: