Commit 30188df0c387 ("drm/tests: Drop drm_kunit_helper_acquire_ctx_alloc()") removed a kunit-managed function to get a drm_modeset_acquire_ctx.
It converted the vc4_pv_muxing_test_init() function, used by drm_vc4_test_pv_muxing() and drm_vc4_test_pv_muxing_invalid(). However, during that conversion, it went from being kzalloc'd to being allocated on the stack. vc4_pv_muxing_test_init() then uses that context to allocate a drm_atomic_state using drm_kunit_helper_atomic_state_alloc(), which stores a pointer to the locking context in the allocated state. However, since vc4_pv_muxing_test_init() is a test init function, the context is then cleared when we leave the function, and before executing the test. We're then running the test with a dangling pointer, which then leads to various crashes. Rework the context initialization and state allocation to move them to drm_vc4_test_pv_muxing() and drm_vc4_test_pv_muxing_invalid(). Fixes: 30188df0c387 ("drm/tests: Drop drm_kunit_helper_acquire_ctx_alloc()") Reported-by: Catalin Marinas <catalin.mari...@arm.com> Closes: https://lore.kernel.org/r/z_95jwm2ymtgy...@arm.com/ Signed-off-by: Maxime Ripard <mrip...@kernel.org> --- drivers/gpu/drm/vc4/tests/vc4_test_pv_muxing.c | 38 ++++++++++++++++---------- 1 file changed, 24 insertions(+), 14 deletions(-) diff --git a/drivers/gpu/drm/vc4/tests/vc4_test_pv_muxing.c b/drivers/gpu/drm/vc4/tests/vc4_test_pv_muxing.c index 992e8f5c5c6ea8d92338a8fe739fa1115ff85338..a79b152f8b97add449cffc9674abec0df95239e3 100644 --- a/drivers/gpu/drm/vc4/tests/vc4_test_pv_muxing.c +++ b/drivers/gpu/drm/vc4/tests/vc4_test_pv_muxing.c @@ -18,11 +18,10 @@ #include "vc4_mock.h" struct pv_muxing_priv { struct vc4_dev *vc4; - struct drm_atomic_state *state; }; static bool check_fifo_conflict(struct kunit *test, const struct drm_atomic_state *state) { @@ -675,14 +674,22 @@ KUNIT_ARRAY_PARAM(vc5_test_pv_muxing_invalid, static void drm_vc4_test_pv_muxing(struct kunit *test) { const struct pv_muxing_param *params = test->param_value; const struct pv_muxing_priv *priv = test->priv; - struct drm_atomic_state *state = priv->state; + struct drm_modeset_acquire_ctx ctx; + struct drm_atomic_state *state; + struct drm_device *drm; unsigned int i; int ret; + drm_modeset_acquire_init(&ctx, 0); + + drm = &priv->vc4->base; + state = drm_kunit_helper_atomic_state_alloc(test, drm, &ctx); + KUNIT_ASSERT_NOT_ERR_OR_NULL(test, state); + for (i = 0; i < params->nencoders; i++) { enum vc4_encoder_type enc_type = params->encoders[i]; ret = vc4_mock_atomic_add_output(test, state, enc_type); KUNIT_ASSERT_EQ(test, ret, 0); @@ -698,56 +705,59 @@ static void drm_vc4_test_pv_muxing(struct kunit *test) enum vc4_encoder_type enc_type = params->encoders[i]; KUNIT_EXPECT_TRUE(test, check_channel_for_encoder(test, state, enc_type, params->check_fn)); } + + drm_modeset_drop_locks(&ctx); + drm_modeset_acquire_fini(&ctx); } static void drm_vc4_test_pv_muxing_invalid(struct kunit *test) { const struct pv_muxing_param *params = test->param_value; const struct pv_muxing_priv *priv = test->priv; - struct drm_atomic_state *state = priv->state; + struct drm_modeset_acquire_ctx ctx; + struct drm_atomic_state *state; + struct drm_device *drm; unsigned int i; int ret; + drm_modeset_acquire_init(&ctx, 0); + + drm = &priv->vc4->base; + state = drm_kunit_helper_atomic_state_alloc(test, drm, &ctx); + KUNIT_ASSERT_NOT_ERR_OR_NULL(test, state); + for (i = 0; i < params->nencoders; i++) { enum vc4_encoder_type enc_type = params->encoders[i]; ret = vc4_mock_atomic_add_output(test, state, enc_type); KUNIT_ASSERT_EQ(test, ret, 0); } ret = drm_atomic_check_only(state); KUNIT_EXPECT_LT(test, ret, 0); + + drm_modeset_drop_locks(&ctx); + drm_modeset_acquire_fini(&ctx); } static int vc4_pv_muxing_test_init(struct kunit *test) { const struct pv_muxing_param *params = test->param_value; - struct drm_modeset_acquire_ctx ctx; struct pv_muxing_priv *priv; - struct drm_device *drm; struct vc4_dev *vc4; priv = kunit_kzalloc(test, sizeof(*priv), GFP_KERNEL); KUNIT_ASSERT_NOT_NULL(test, priv); test->priv = priv; vc4 = params->mock_fn(test); KUNIT_ASSERT_NOT_ERR_OR_NULL(test, vc4); priv->vc4 = vc4; - drm_modeset_acquire_init(&ctx, 0); - - drm = &vc4->base; - priv->state = drm_kunit_helper_atomic_state_alloc(test, drm, &ctx); - KUNIT_ASSERT_NOT_ERR_OR_NULL(test, priv->state); - - drm_modeset_drop_locks(&ctx); - drm_modeset_acquire_fini(&ctx); - return 0; } static struct kunit_case vc4_pv_muxing_tests[] = { KUNIT_CASE_PARAM(drm_vc4_test_pv_muxing, --- base-commit: a5806cd506af5a7c19bcd596e4708b5c464bfd21 change-id: 20250520-drm-vc4-kunit-fixes-a681715c4409 Best regards, -- Maxime Ripard <mrip...@kernel.org>