Re: [PATCH v2 3/3] drivers: base: test: Add ...find_device_by...(... NULL) tests

Brian Norris
2024-12-13T20:13:58Z

Hi Maxime,

On Fri, Dec 13, 2024 at 12:59:57PM +0100, Maxime Ripard wrote:
> On Wed, Dec 11, 2024 at 04:31:41PM -0800, Brian Norris wrote:
> > --- a/drivers/base/test/platform-device-test.c
> > +++ b/drivers/base/test/platform-device-test.c

> > @@ -217,7 +219,45 @@ static struct kunit_suite platform_device_devm_test_suite = {
> > .test_cases = platform_device_devm_tests,
> > };
> >
> > -kunit_test_suite(platform_device_devm_test_suite);
> > +static void platform_device_find_by_null_test(struct kunit *test)
> > +{
> > + struct platform_device *pdev;
> > + int ret;
> > +
> > + pdev = platform_device_alloc(DEVICE_NAME, PLATFORM_DEVID_NONE);
> > + KUNIT_ASSERT_NOT_ERR_OR_NULL(test, pdev);
> > +
> > + ret = platform_device_add(pdev);
> > + KUNIT_ASSERT_EQ(test, ret, 0);
>
> I *think* you have a bug there: if platform_device_add fails,
> KUNIT_ASSERT will stop the test execution and thus you will leak the
> platform_device you just allocated.
>
> You need to call platform_device_put in such a case, but if
> platform_device_add succeeds then you need to call
> platform_device_unregister instead.

Hehe, well I'm imitating the existing leaks in the other tests in this
file, then ;) But admittedly, those are a little more complex, because
the unregistration is actually part of the test flow.

> It would be better to use kunit_platform_device_alloc and
> kunit_platform_device_add that already deal with this.

Cool, thanks, I'll use those in v3 for my new test.

> The rest looks good to me, once fixed:
> Reviewed-by: Maxime Ripard <mripard@kernel.org>

Thanks for the tips and review.

Brian