TEST_LENGTH passing ".size = sizeof(struct _struct) - 1" expects -EINVAL from "if (ucmd.user_size < op->min_size)" check in iommufd_fops_ioctl(). This has been working when min_size is exactly the size of the structure.

However, if the size of the structure becomes larger than min_size, i.e. the passing size above is larger than min_size, that min_size sanity no longer works.

Since the first test in TEST_LENGTH() was to test that min_size sanity routine, rework it to support a min_size calculation, rather than using the full size of the structure.

Signed-off-by: Nicolin Chen nicolinc@nvidia.com --- Hi Jason/Kevin,

This was a part of the nesting series. Its link in v4: https://lore.kernel.org/linux-iommu/20230921075138.124099-13-yi.l.liu@intel....

I just realized that this should go in prior to the nesting series. One of the nesting patches changes the IOMMU_HWPT_ALLOC structure, which would break the cmd_length test without this patch.

Thanks! Nicolin

tools/testing/selftests/iommu/iommufd.c | 29 ++++++++++++++----------- 1 file changed, 16 insertions(+), 13 deletions(-)

diff --git a/tools/testing/selftests/iommu/iommufd.c b/tools/testing/selftests/iommu/iommufd.c index c5eca2fee42c..6323153d277b 100644 --- a/tools/testing/selftests/iommu/iommufd.c +++ b/tools/testing/selftests/iommu/iommufd.c @@ -86,12 +86,13 @@ TEST_F(iommufd, cmd_fail)

TEST_F(iommufd, cmd_length) { -#define TEST_LENGTH(_struct, _ioctl) \ +#define TEST_LENGTH(_struct, _ioctl, _last) \ { \ + size_t min_size = offsetofend(struct _struct, _last); \ struct { \ struct _struct cmd; \ uint8_t extra; \ - } cmd = { .cmd = { .size = sizeof(struct _struct) - 1 }, \ + } cmd = { .cmd = { .size = min_size - 1 }, \ .extra = UINT8_MAX }; \ int old_errno; \ int rc; \ @@ -112,17 +113,19 @@ TEST_F(iommufd, cmd_length) } \ }

- TEST_LENGTH(iommu_destroy, IOMMU_DESTROY); - TEST_LENGTH(iommu_hw_info, IOMMU_GET_HW_INFO); - TEST_LENGTH(iommu_hwpt_alloc, IOMMU_HWPT_ALLOC); - TEST_LENGTH(iommu_ioas_alloc, IOMMU_IOAS_ALLOC); - TEST_LENGTH(iommu_ioas_iova_ranges, IOMMU_IOAS_IOVA_RANGES); - TEST_LENGTH(iommu_ioas_allow_iovas, IOMMU_IOAS_ALLOW_IOVAS); - TEST_LENGTH(iommu_ioas_map, IOMMU_IOAS_MAP); - TEST_LENGTH(iommu_ioas_copy, IOMMU_IOAS_COPY); - TEST_LENGTH(iommu_ioas_unmap, IOMMU_IOAS_UNMAP); - TEST_LENGTH(iommu_option, IOMMU_OPTION); - TEST_LENGTH(iommu_vfio_ioas, IOMMU_VFIO_IOAS); + TEST_LENGTH(iommu_destroy, IOMMU_DESTROY, id); + TEST_LENGTH(iommu_hw_info, IOMMU_GET_HW_INFO, __reserved); + TEST_LENGTH(iommu_hwpt_alloc, IOMMU_HWPT_ALLOC, __reserved); + TEST_LENGTH(iommu_ioas_alloc, IOMMU_IOAS_ALLOC, out_ioas_id); + TEST_LENGTH(iommu_ioas_iova_ranges, IOMMU_IOAS_IOVA_RANGES, + out_iova_alignment); + TEST_LENGTH(iommu_ioas_allow_iovas, IOMMU_IOAS_ALLOW_IOVAS, + allowed_iovas); + TEST_LENGTH(iommu_ioas_map, IOMMU_IOAS_MAP, iova); + TEST_LENGTH(iommu_ioas_copy, IOMMU_IOAS_COPY, src_iova); + TEST_LENGTH(iommu_ioas_unmap, IOMMU_IOAS_UNMAP, length); + TEST_LENGTH(iommu_option, IOMMU_OPTION, val64); + TEST_LENGTH(iommu_vfio_ioas, IOMMU_VFIO_IOAS, __reserved); #undef TEST_LENGTH }