Re: [RFC PATCH 1/6] mm/damon/tests/core-kunit: test damon_commit_filter()

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Medium] The kunit test uses the wrong enum type `DAMOS_FILTER_TYPE_MEMCG` instead of `DAMON_FILTER_TYPE_MEMCG` when checking `src->type`, causing the `memcg_id` assertion to be silently skipped.
--

--- Patch [1]: [RFC PATCH 1/6] mm/damon/tests/core-kunit: test damon_commit_filter() ---
commit e16ea26a19f85858bdb608d81842e976d30c3270
Author: SJ Park <sj@kernel.org>

mm/damon/tests/core-kunit: test damon_commit_filter()
    
Add kunit test to ensure damon_commit_filter() updates destination
filter as expected for valid inputs.

> diff --git a/mm/damon/tests/core-kunit.h b/mm/damon/tests/core-kunit.h
> index 4a536d41cdb2d..6cbe22accabfb 100644
> --- a/mm/damon/tests/core-kunit.h
> +++ b/mm/damon/tests/core-kunit.h
> @@ -1306,6 +1306,45 @@ static void damon_test_commit_target_regions(struct kunit *test)

[ ... ]

> +static void damon_test_commit_filter_for(struct kunit *test,
> +		struct damon_filter *dst, struct damon_filter *src)
> +{
> +	damon_commit_filter(dst, src);
> +	KUNIT_EXPECT_EQ(test, dst->type, src->type);
> +	KUNIT_EXPECT_EQ(test, dst->matching, src->matching);
> +	KUNIT_EXPECT_EQ(test, dst->allow, src->allow);
> +	switch (src->type) {
> +	case DAMOS_FILTER_TYPE_MEMCG:
> +		KUNIT_EXPECT_EQ(test, dst->memcg_id, src->memcg_id);
> +		break;

[Severity: Medium]
Will this case label ever be matched?

This code checks against DAMOS_FILTER_TYPE_MEMCG, but damon_test_commit_filter()
below initializes the source filter with type DAMON_FILTER_TYPE_MEMCG.

Because of this mismatch, the switch statement falls through to the default
case, and the test silently skips the assertion for memcg_id.

> +	default:
> +		break;
> +	}
> +}
> +
> +static void damon_test_commit_filter(struct kunit *test)
> +{

[ ... ]

> +	damon_test_commit_filter_for(test, &dst,
> +			&(struct damon_filter){
> +			.type = DAMON_FILTER_TYPE_MEMCG,
> +			.matching = false,
> +			.allow = false,
> +			.memcg_id = 123,
> +			});
> +}

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260729144738.90895-1-sj@kernel.org?part=1