tools/testing/selftests/iommu/iommufd_utils.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
Fix to avoid the usage of the `res` variable uninitialized in the
following macro expansions.
It solves the following warning:
In function ‘iommufd_viommu_vdevice_alloc’,
inlined from ‘wrapper_iommufd_viommu_vdevice_alloc’ at
iommufd.c:2889:1:
../kselftest_harness.h:760:12: warning: ‘ret’ may be used uninitialized
[-Wmaybe-uninitialized]
760 | if (!(__exp _t __seen)) { \
| ^
../kselftest_harness.h:513:9: note: in expansion of macro ‘__EXPECT’
513 | __EXPECT(expected, #expected, seen, #seen, ==, 1)
| ^~~~~~~~
iommufd_utils.h:1057:9: note: in expansion of macro ‘ASSERT_EQ’
1057 | ASSERT_EQ(0, _test_cmd_trigger_vevents(self->fd, dev_id,
nvevents))
| ^~~~~~~~~
iommufd.c:2924:17: note: in expansion of macro
‘test_cmd_trigger_vevents’
2924 | test_cmd_trigger_vevents(dev_id, 3);
| ^~~~~~~~~~~~~~~~~~~~~~~~
The issue can be reproduced, building the tests, with the command:
make -C tools/testing/selftests TARGETS=iommu
Signed-off-by: Alessandro Zanni <alessandro.zanni87@gmail.com>
---
tools/testing/selftests/iommu/iommufd_utils.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/tools/testing/selftests/iommu/iommufd_utils.h b/tools/testing/selftests/iommu/iommufd_utils.h
index 3c3e08b8c90e..4ae0fcc4f871 100644
--- a/tools/testing/selftests/iommu/iommufd_utils.h
+++ b/tools/testing/selftests/iommu/iommufd_utils.h
@@ -1042,7 +1042,7 @@ static int _test_cmd_trigger_vevents(int fd, __u32 dev_id, __u32 nvevents)
.dev_id = dev_id,
},
};
- int ret;
+ int ret = 0;
while (nvevents--) {
ret = ioctl(fd, _IOMMU_TEST_CMD(IOMMU_TEST_OP_TRIGGER_VEVENT),
--
2.43.0
On Tue, Sep 23, 2025 at 05:01:06PM +0200, Alessandro Zanni wrote:
> Fix to avoid the usage of the `res` variable uninitialized in the
> following macro expansions.
>
> It solves the following warning:
> In function ‘iommufd_viommu_vdevice_alloc’,
> inlined from ‘wrapper_iommufd_viommu_vdevice_alloc’ at
> iommufd.c:2889:1:
> ../kselftest_harness.h:760:12: warning: ‘ret’ may be used uninitialized
> [-Wmaybe-uninitialized]
> 760 | if (!(__exp _t __seen)) { \
> | ^
> ../kselftest_harness.h:513:9: note: in expansion of macro ‘__EXPECT’
> 513 | __EXPECT(expected, #expected, seen, #seen, ==, 1)
> | ^~~~~~~~
> iommufd_utils.h:1057:9: note: in expansion of macro ‘ASSERT_EQ’
> 1057 | ASSERT_EQ(0, _test_cmd_trigger_vevents(self->fd, dev_id,
> nvevents))
> | ^~~~~~~~~
> iommufd.c:2924:17: note: in expansion of macro
> ‘test_cmd_trigger_vevents’
> 2924 | test_cmd_trigger_vevents(dev_id, 3);
> | ^~~~~~~~~~~~~~~~~~~~~~~~
>
> The issue can be reproduced, building the tests, with the command:
> make -C tools/testing/selftests TARGETS=iommu
>
> Signed-off-by: Alessandro Zanni <alessandro.zanni87@gmail.com>
> ---
> tools/testing/selftests/iommu/iommufd_utils.h | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
I think it should be like this?
@@ -1042,15 +1042,12 @@ static int _test_cmd_trigger_vevents(int fd, __u32 dev_id, __u32 nvevents)
.dev_id = dev_id,
},
};
- int ret;
- while (nvevents--) {
- ret = ioctl(fd, _IOMMU_TEST_CMD(IOMMU_TEST_OP_TRIGGER_VEVENT),
- &trigger_vevent_cmd);
- if (ret < 0)
+ while (nvevents--)
+ if (ioctl(fd, _IOMMU_TEST_CMD(IOMMU_TEST_OP_TRIGGER_VEVENT),
+ &trigger_vevent_cmd))
return -1;
- }
- return ret;
+ return 0;
}
And add a fixes line?
Jason
On Tue, Sep 23, 2025 at 02:28:22PM -0300, Jason Gunthorpe wrote:
> On Tue, Sep 23, 2025 at 05:01:06PM +0200, Alessandro Zanni wrote:
> > Fix to avoid the usage of the `res` variable uninitialized in the
> > following macro expansions.
> >
> > It solves the following warning:
> > In function ‘iommufd_viommu_vdevice_alloc’,
> > inlined from ‘wrapper_iommufd_viommu_vdevice_alloc’ at
> > iommufd.c:2889:1:
> > ../kselftest_harness.h:760:12: warning: ‘ret’ may be used uninitialized
> > [-Wmaybe-uninitialized]
> > 760 | if (!(__exp _t __seen)) { \
> > | ^
> > ../kselftest_harness.h:513:9: note: in expansion of macro ‘__EXPECT’
> > 513 | __EXPECT(expected, #expected, seen, #seen, ==, 1)
> > | ^~~~~~~~
> > iommufd_utils.h:1057:9: note: in expansion of macro ‘ASSERT_EQ’
> > 1057 | ASSERT_EQ(0, _test_cmd_trigger_vevents(self->fd, dev_id,
> > nvevents))
> > | ^~~~~~~~~
> > iommufd.c:2924:17: note: in expansion of macro
> > ‘test_cmd_trigger_vevents’
> > 2924 | test_cmd_trigger_vevents(dev_id, 3);
> > | ^~~~~~~~~~~~~~~~~~~~~~~~
> >
> > The issue can be reproduced, building the tests, with the command:
> > make -C tools/testing/selftests TARGETS=iommu
> >
> > Signed-off-by: Alessandro Zanni <alessandro.zanni87@gmail.com>
> > ---
> > tools/testing/selftests/iommu/iommufd_utils.h | 2 +-
> > 1 file changed, 1 insertion(+), 1 deletion(-)
>
> I think it should be like this?
>
> @@ -1042,15 +1042,12 @@ static int _test_cmd_trigger_vevents(int fd, __u32 dev_id, __u32 nvevents)
> .dev_id = dev_id,
> },
> };
> - int ret;
>
> - while (nvevents--) {
> - ret = ioctl(fd, _IOMMU_TEST_CMD(IOMMU_TEST_OP_TRIGGER_VEVENT),
> - &trigger_vevent_cmd);
> - if (ret < 0)
> + while (nvevents--)
> + if (ioctl(fd, _IOMMU_TEST_CMD(IOMMU_TEST_OP_TRIGGER_VEVENT),
> + &trigger_vevent_cmd))
> return -1;
> - }
> - return ret;
> + return 0;
> }
>
> And add a fixes line?
>
> Jason
Thank you for the reply.
I'm not sure the right behavior the test should have:
- in the version you proposed, when ioctl() returns a positive
value the loop ends and the next tests are skipped.
- in the original version, if the function ioctl() returns a
positive value the loop continues with the following tests.
Which one is the desired behavior?
Thanks,
Alessandro
On Tue, Sep 23, 2025 at 11:38:13PM +0200, Alessandro Zanni wrote:
> On Tue, Sep 23, 2025 at 02:28:22PM -0300, Jason Gunthorpe wrote:
> > On Tue, Sep 23, 2025 at 05:01:06PM +0200, Alessandro Zanni wrote:
> > > Fix to avoid the usage of the `res` variable uninitialized in the
> > > following macro expansions.
> > >
> > > It solves the following warning:
> > > In function ‘iommufd_viommu_vdevice_alloc’,
> > > inlined from ‘wrapper_iommufd_viommu_vdevice_alloc’ at
> > > iommufd.c:2889:1:
> > > ../kselftest_harness.h:760:12: warning: ‘ret’ may be used uninitialized
> > > [-Wmaybe-uninitialized]
> > > 760 | if (!(__exp _t __seen)) { \
> > > | ^
> > > ../kselftest_harness.h:513:9: note: in expansion of macro ‘__EXPECT’
> > > 513 | __EXPECT(expected, #expected, seen, #seen, ==, 1)
> > > | ^~~~~~~~
> > > iommufd_utils.h:1057:9: note: in expansion of macro ‘ASSERT_EQ’
> > > 1057 | ASSERT_EQ(0, _test_cmd_trigger_vevents(self->fd, dev_id,
> > > nvevents))
> > > | ^~~~~~~~~
> > > iommufd.c:2924:17: note: in expansion of macro
> > > ‘test_cmd_trigger_vevents’
> > > 2924 | test_cmd_trigger_vevents(dev_id, 3);
> > > | ^~~~~~~~~~~~~~~~~~~~~~~~
> > >
> > > The issue can be reproduced, building the tests, with the command:
> > > make -C tools/testing/selftests TARGETS=iommu
> > >
> > > Signed-off-by: Alessandro Zanni <alessandro.zanni87@gmail.com>
> > > ---
> > > tools/testing/selftests/iommu/iommufd_utils.h | 2 +-
> > > 1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > I think it should be like this?
> >
> > @@ -1042,15 +1042,12 @@ static int _test_cmd_trigger_vevents(int fd, __u32 dev_id, __u32 nvevents)
> > .dev_id = dev_id,
> > },
> > };
> > - int ret;
> >
> > - while (nvevents--) {
> > - ret = ioctl(fd, _IOMMU_TEST_CMD(IOMMU_TEST_OP_TRIGGER_VEVENT),
> > - &trigger_vevent_cmd);
> > - if (ret < 0)
> > + while (nvevents--)
> > + if (ioctl(fd, _IOMMU_TEST_CMD(IOMMU_TEST_OP_TRIGGER_VEVENT),
> > + &trigger_vevent_cmd))
> > return -1;
> > - }
> > - return ret;
> > + return 0;
> > }
> >
> > And add a fixes line?
> >
> > Jason
>
> Thank you for the reply.
> I'm not sure the right behavior the test should have:
> - in the version you proposed, when ioctl() returns a positive
> value the loop ends and the next tests are skipped.
> - in the original version, if the function ioctl() returns a
> positive value the loop continues with the following tests.
>
> Which one is the desired behavior?
Sorry it should be !ioctl()
The ioctl will only return 0 or -errno
Jason
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