Coverity: get_md_pagetable(): Control flow issues

Coverity: get_md_pagetable(): Control flow issues

[coverity-bot]

Hello!

This is an experimental semi-automated report about issues detected by
Coverity from a scan of next-20221102 as part of the linux-next scan project:
https://scan.coverity.com/projects/linux-next-weekly-scan

You're getting this email because you were associated with the identified
lines of code (noted below) that were touched by commits:

  Mon Oct 31 20:18:38 2022 -0300
    147393321d65 ("iommufd: Add a selftest")

Coverity reported the following:

*** CID 1527089:  Control flow issues  (UNREACHABLE)
/drivers/iommu/iommufd/selftest.c: 248 in get_md_pagetable()
242     				 IOMMUFD_OBJ_HW_PAGETABLE);
243     	if (IS_ERR(obj))
244     		return ERR_CAST(obj);
245     	hwpt = container_of(obj, struct iommufd_hw_pagetable, obj);
246     	if (hwpt->domain->ops != mock_ops.default_domain_ops) {
247     		return ERR_PTR(-EINVAL);
vvv     CID 1527089:  Control flow issues  (UNREACHABLE)
vvv     This code cannot be reached: "iommufd_put_object(&hwpt->o...".
248     		iommufd_put_object(&hwpt->obj);
249     	}
250     	*mock = container_of(hwpt->domain, struct mock_iommu_domain, domain);
251     	return hwpt;
252     }
253

If this is a false positive, please let us know so we can mark it as
such, or teach the Coverity rules to be smarter. If not, please make
sure fixes get into linux-next. :) For patches fixing this, please
include these lines (but double-check the "Fixes" first):

Reported-by: coverity-bot <keescook+coverity-bot@chromium.org>
Addresses-Coverity-ID: 1527089 ("Control flow issues")
Fixes: 147393321d65 ("iommufd: Add a selftest")

Thanks for your attention!

-- 
Coverity-bot

Re: Coverity: get_md_pagetable(): Control flow issues

[Jason Gunthorpe]

On Wed, Nov 02, 2022 at 12:57:33PM -0700, coverity-bot wrote:

> /drivers/iommu/iommufd/selftest.c: 248 in get_md_pagetable()
> 242     				 IOMMUFD_OBJ_HW_PAGETABLE);
> 243     	if (IS_ERR(obj))
> 244     		return ERR_CAST(obj);
> 245     	hwpt = container_of(obj, struct iommufd_hw_pagetable, obj);
> 246     	if (hwpt->domain->ops != mock_ops.default_domain_ops) {
> 247     		return ERR_PTR(-EINVAL);
> vvv     CID 1527089:  Control flow issues  (UNREACHABLE)
> vvv     This code cannot be reached: "iommufd_put_object(&hwpt->o...".
> 248     		iommufd_put_object(&hwpt->obj);
> 249     	}
> 250     	*mock = container_of(hwpt->domain, struct mock_iommu_domain, domain);
> 251     	return hwpt;
> 252     }
> 253
> 
> If this is a false positive, please let us know so we can mark it as
> such, or teach the Coverity rules to be smarter. If not, please make
> sure fixes get into linux-next. :) For patches fixing this, please
> include these lines (but double-check the "Fixes" first):

Yes, we already fixed this, thanks

Jason