From: Alex Hung <[email protected]> [WHAT] Add a KUnit test for amdgpu_dm_plane_add_modifier() covering the allocation failure that happens while growing the modifier list.
[HOW] Seed a capacity whose doubling overflows the kmalloc_array() size product, so the allocation fails without fault injection, and assert the list is released and cleared for the caller. Assisted-by: Copilot:Claude-Opus-5 Reviewed-by: Bhawanpreet Lakha <[email protected]> Signed-off-by: Alex Hung <[email protected]> Signed-off-by: Chenyu Chen <[email protected]> --- .../amdgpu_dm/tests/amdgpu_dm_plane_test.c | 23 +++++++++++++++++++ 1 file changed, 23 insertions(+) diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/tests/amdgpu_dm_plane_test.c b/drivers/gpu/drm/amd/display/amdgpu_dm/tests/amdgpu_dm_plane_test.c index 939f79422d7e..13e07c4fc0c7 100644 --- a/drivers/gpu/drm/amd/display/amdgpu_dm/tests/amdgpu_dm_plane_test.c +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/tests/amdgpu_dm_plane_test.c @@ -3686,6 +3686,28 @@ static void dm_test_atomic_async_update_copies_state(struct kunit *test) KUNIT_EXPECT_EQ(test, cur_state->crtc_h, 64U); } +/** + * dm_test_add_modifier_alloc_failure() - Verify the growth allocation failure. + * @test: KUnit test context. + * + * Verify if a failed capacity growth releases and clears the modifier list so + * the caller can detect the allocation failure. + */ +static void dm_test_add_modifier_alloc_failure(struct kunit *test) +{ + /* Doubling this capacity overflows the kmalloc_array() size product. */ + u64 cap = 1ULL << 62; + u64 size = cap; + u64 *mods = kmalloc_array(1, sizeof(*mods), GFP_KERNEL); + + KUNIT_ASSERT_NOT_NULL(test, mods); + + amdgpu_dm_plane_add_modifier(&mods, &size, &cap, 0x1234ULL); + + KUNIT_EXPECT_PTR_EQ(test, mods, NULL); + KUNIT_EXPECT_EQ(test, size, 1ULL << 62); +} + static struct kunit_case amdgpu_dm_plane_test_cases[] = { /* amdgpu_dm_plane_is_video_format() */ KUNIT_CASE(dm_test_plane_is_video_format_known_video), @@ -3782,6 +3804,7 @@ static struct kunit_case amdgpu_dm_plane_test_cases[] = { KUNIT_CASE(dm_test_add_modifier_appends_value), KUNIT_CASE(dm_test_add_modifier_grows_capacity), KUNIT_CASE(dm_test_add_modifier_noop_when_mods_null), + KUNIT_CASE(dm_test_add_modifier_alloc_failure), /* amdgpu_dm_plane_add_modifier_dedup() */ KUNIT_CASE(dm_test_add_modifier_dedup_skips_duplicate), KUNIT_CASE(dm_test_add_modifier_dedup_noop_when_mods_null), -- 2.43.0
