[PATCH 5/9] mm/damon/core-test: fix damon_test_ops_registration() for DAMON_VADDR unset case

[SeongJae Park]

DAMON core kunit test can be executed without CONFIG_DAMON_VADDR.  In
the case, vaddr DAMON ops is not registered.  Meanwhile, ops
registration kunit test assumes the vaddr ops is registered.  Check and
handle the case by registrering fake vaddr ops inside the test code.

Fixes: 4f540f5ab4f2 ("mm/damon/core-test: add a kunit test case for ops registration")
Signed-off-by: SeongJae Park <sj@xxxxxxxxxx>
---
 mm/damon/core-test.h | 17 ++++++++++++++++-
 1 file changed, 16 insertions(+), 1 deletion(-)

diff --git a/mm/damon/core-test.h b/mm/damon/core-test.h
index ef36d586d6ee..ae03df71737e 100644
--- a/mm/damon/core-test.h
+++ b/mm/damon/core-test.h
@@ -247,8 +247,16 @@ static void damon_test_ops_registration(struct kunit *test)
 {
 	struct damon_ctx *c = damon_new_ctx();
 	struct damon_operations ops = {.id = DAMON_OPS_VADDR}, bak;
+	bool need_cleanup = false;
 
-	/* DAMON_OPS_VADDR is registered on subsys_initcall */
+	/* DAMON_OPS_VADDR is registered only if CONFIG_DAMON_VADDR is set */
+	if (!damon_is_registered_ops(DAMON_OPS_VADDR)) {
+		bak.id = DAMON_OPS_VADDR;
+		KUNIT_EXPECT_EQ(test, damon_register_ops(&bak), 0);
+		need_cleanup = true;
+	}
+
+	/* DAMON_OPS_VADDR is ensured to be registered */
 	KUNIT_EXPECT_EQ(test, damon_select_ops(c, DAMON_OPS_VADDR), 0);
 
 	/* Double-registration is prohibited */
@@ -274,6 +282,13 @@ static void damon_test_ops_registration(struct kunit *test)
 	KUNIT_EXPECT_EQ(test, damon_register_ops(&ops), -EINVAL);
 
 	damon_destroy_ctx(c);
+
+	if (need_cleanup) {
+		mutex_lock(&damon_ops_lock);
+		damon_registered_ops[DAMON_OPS_VADDR] =
+			(struct damon_operations){};
+		mutex_unlock(&damon_ops_lock);
+	}
 }
 
 static void damon_test_set_regions(struct kunit *test)
-- 
2.39.2