Hi,
On 9/5/23 14:05, Maxime Ripard wrote:
Hi,
On Tue, Sep 05, 2023 at 10:58:31AM +0200, Thomas Hellström wrote:
Check that object freeing from within drm_exec_fini() works as expected
and doesn't generate any warnings.
Cc: Christian König <christian.koenig@xxxxxxx>
Cc: dri-devel@xxxxxxxxxxxxxxxxxxxxx
Signed-off-by: Thomas Hellström <thomas.hellstrom@xxxxxxxxxxxxxxx>
---
drivers/gpu/drm/tests/drm_exec_test.c | 47 +++++++++++++++++++++++++++
1 file changed, 47 insertions(+)
diff --git a/drivers/gpu/drm/tests/drm_exec_test.c b/drivers/gpu/drm/tests/drm_exec_test.c
index 563949d777dd..294c25f49cc7 100644
--- a/drivers/gpu/drm/tests/drm_exec_test.c
+++ b/drivers/gpu/drm/tests/drm_exec_test.c
@@ -170,6 +170,52 @@ static void test_prepare_array(struct kunit *test)
drm_gem_private_object_fini(&gobj2);
}
+static const struct drm_gem_object_funcs put_funcs = {
+ .free = (void *)kfree,
+};
+
+/*
+ * Check that freeing objects from within drm_exec_fini()
+ * behaves as expected.
+ */
+static void test_early_put(struct kunit *test)
+{
+ struct drm_exec_priv *priv = test->priv;
+ struct drm_gem_object *gobj1;
+ struct drm_gem_object *gobj2;
+ struct drm_gem_object *array[2];
+ struct drm_exec exec;
+ int ret;
+
+ gobj1 = kzalloc(sizeof(*gobj1), GFP_KERNEL);
+ KUNIT_EXPECT_NOT_ERR_OR_NULL(test, gobj1);
+ if (!gobj1)
+ return;
+
+ gobj2 = kzalloc(sizeof(*gobj2), GFP_KERNEL);
+ KUNIT_EXPECT_NOT_ERR_OR_NULL(test, gobj2);
+ if (!gobj2) {
+ kfree(gobj1);
+ return;
+ }
+
+ gobj1->funcs = &put_funcs;
+ gobj2->funcs = &put_funcs;
+ array[0] = gobj1;
+ array[1] = gobj2;
+ drm_gem_private_object_init(priv->drm, gobj1, PAGE_SIZE);
+ drm_gem_private_object_init(priv->drm, gobj2, PAGE_SIZE);
+
+ drm_exec_init(&exec, DRM_EXEC_INTERRUPTIBLE_WAIT);
+ drm_exec_until_all_locked(&exec)
+ ret = drm_exec_prepare_array(&exec, array, ARRAY_SIZE(array),
+ 1);
+ KUNIT_EXPECT_EQ(test, ret, 0);
+ drm_gem_object_put(gobj1);
+ drm_gem_object_put(gobj2);
+ drm_exec_fini(&exec);
It doesn't look like you actually check that "freeing objects from
within drm_exec_fini() behaves as expected." What is the expectation
here, and how is it checked?
Hm. Good question, I've been manually checking dmesg for lockdep splats.
Is there a way to automate that?
/Thomas
Maxime
