Re: [Xen-devel] [Patch v6 04/11] IOMMU: propagate IOMMU Device-TLB flush error up to IOMMU mapping (top level ones)

["Jan Beulich" <JBeulich@xxxxxxxx>]

>>> On 07.06.16 at 10:40, <quan.xu@xxxxxxxxx> wrote:
> Along with discussion of  a local variable for _for()_ loop,  I need to 
> define this local variable into _while()_ loop:
> e.g., as above case:
>  
> +while ( i-- )
> +{
> +    int iommu_ret = iommu_unmap_page(p2m->domain, gfn + i);
> +
> +    break;
> +}
> 
> ,  right?

Something like this. As said, tricking Coverity into not reporting the
unused value as a possible problem would additionally be needed.
Andrew - do you know of any pre-existing pattern usable for this
purpose?

> But I really like this way:
> 
> + int iommu_ret;
> +
> +while ( i-- )
> +{
> +    iommu_ret = iommu_unmap_page(p2m->domain, gfn + i);
> +
> +    break;
> +}

Rather not - iommu_ret isn't used outside of the while() scope.
(Unless, of course, the Coverity related adjustment makes this
desirable / necessary, but I would guess the tool would then still
be able to figure that the assignment is pointless on all but the
last iteration.)

Jan


_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
http://lists.xen.org/xen-devel