GCC gets a bit confused and reports:
In function '_test_cmd_get_hw_info',
inlined from 'iommufd_ioas_get_hw_info' at iommufd.c:779:3,
inlined from 'wrapper_iommufd_ioas_get_hw_info' at iommufd.c:752:1:
>> iommufd_utils.h:804:37: warning: array subscript 'struct
>> iommu_test_hw_info[0]' is partly outside array bounds of 'struct
>> iommu_test_hw_info_buffer_smaller[1]' [-Warray-bounds=]
804 | assert(!info->flags);
| ~~~~^~~~~~~
iommufd.c: In function 'wrapper_iommufd_ioas_get_hw_info':
iommufd.c:761:11: note: object 'buffer_smaller' of size 4
761 | } buffer_smaller;
| ^~~~~~~~~~~~~~
While it is true that "struct iommu_test_hw_info[0]" is partly out of
bounds of the input pointer, it is not true that info->flags is out of
bounds. Unclear why it warns on this.
Reuse an existing properly sized stack buffer and pass a truncated length
instead to test the same thing.
Fixes: af4fde93c319 ("iommufd/selftest: Add coverage for IOMMU_GET_HW_INFO
ioctl")
Reported-by: kernel test robot <[email protected]>
Closes:
https://lore.kernel.org/oe-kbuild-all/[email protected]/
Signed-off-by: Jason Gunthorpe <[email protected]>
---
tools/testing/selftests/iommu/iommufd.c | 8 +++-----
1 file changed, 3 insertions(+), 5 deletions(-)
diff --git a/tools/testing/selftests/iommu/iommufd.c
b/tools/testing/selftests/iommu/iommufd.c
index 10e051b6f592df..dadad277f4eb2e 100644
--- a/tools/testing/selftests/iommu/iommufd.c
+++ b/tools/testing/selftests/iommu/iommufd.c
@@ -755,9 +755,6 @@ TEST_F(iommufd_ioas, get_hw_info)
struct iommu_test_hw_info info;
uint64_t trailing_bytes;
} buffer_larger;
- struct iommu_test_hw_info_buffer_smaller {
- __u32 flags;
- } buffer_smaller;
if (self->device_id) {
uint8_t max_pasid = 0;
@@ -789,8 +786,9 @@ TEST_F(iommufd_ioas, get_hw_info)
* the fields within the size range still gets updated.
*/
test_cmd_get_hw_info(self->device_id,
- IOMMU_HW_INFO_TYPE_DEFAULT,
- &buffer_smaller, sizeof(buffer_smaller));
+ IOMMU_HW_INFO_TYPE_DEFAULT, &buffer_exact,
+ offsetofend(struct iommu_test_hw_info,
+ flags));
test_cmd_get_hw_info_pasid(self->device_id, &max_pasid);
ASSERT_EQ(0, max_pasid);
if (variant->pasid_capable) {
base-commit: 93013488dd77dd2ea8bd23355a5587d9e6dac185
--
2.43.0
