Skip to contentSkip to conversation

drivers/gpu/drm/gud/gud_pipe.c:616 gud_plane_atomic_update() error: we previously assumed 'crtc' could be null (see line 597)

PATCH kernel test robot 1 participant 1 message Jan 14

lore
Share & tools
lore

kernel test robot

author build bot
#0 lore raw

BCC: [email protected]
CC: [email protected]
TO: Shenghao Yang <[email protected]>
CC: Ruben Wauters <[email protected]>

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master
head:   b775e489bec70895b7ef6b66927886bbac79598f
commit: dc2d5ddb193e363187bae2ad358245642d2721fb [5767/6121] drm/gud: fix NULL fb and crtc dereferences on USB disconnect

:::::: branch date: 8 hours ago
:::::: commit date: 23 hours ago
config: x86_64-randconfig-161-20260114 (https://download.01.org/0day-ci/archive/20260114/[email protected]/config)
compiler: clang version 20.1.8 (https://github.com/llvm/llvm-project 87f0227cb60147a26a1eeb4fb06e3b505e9c7261)
rustc: rustc 1.88.0 (6b00bc388 2025-06-23)
smatch version: v0.5.0-8985-g2614ff1a

If you fix the issue in a separate patch/commit (i.e. not just a new version of the same patch/commit), kindly add following tags

| Reported-by: kernel test robot <[email protected]>
| Reported-by: Dan Carpenter <[email protected]>
| Closes: https://lore.kernel.org/r/[email protected]/

smatch warnings:
drivers/gpu/drm/gud/gud_pipe.c:616 gud_plane_atomic_update() error: we previously assumed 'crtc' could be null (see line 597)

vim +/crtc +616 drivers/gpu/drm/gud/gud_pipe.c

40e1a70b4aedf2 Noralf Trønnes 2021-03-13 582

73cfd166e04576 Ruben Wauters  2025-08-18  583  void gud_plane_atomic_update(struct drm_plane *plane,
73cfd166e04576 Ruben Wauters  2025-08-18  584  			     struct drm_atomic_state *atomic_state)
40e1a70b4aedf2 Noralf Trønnes 2021-03-13  585  {
73cfd166e04576 Ruben Wauters  2025-08-18  586  	struct drm_device *drm = plane->dev;
40e1a70b4aedf2 Noralf Trønnes 2021-03-13  587  	struct gud_device *gdrm = to_gud_device(drm);
73cfd166e04576 Ruben Wauters  2025-08-18  588  	struct drm_plane_state *old_state = drm_atomic_get_old_plane_state(atomic_state, plane);
73cfd166e04576 Ruben Wauters  2025-08-18  589  	struct drm_plane_state *new_state = drm_atomic_get_new_plane_state(atomic_state, plane);
73cfd166e04576 Ruben Wauters  2025-08-18  590  	struct drm_shadow_plane_state *shadow_plane_state = to_drm_shadow_plane_state(new_state);
73cfd166e04576 Ruben Wauters  2025-08-18  591  	struct drm_framebuffer *fb = new_state->fb;
73cfd166e04576 Ruben Wauters  2025-08-18  592  	struct drm_crtc *crtc = new_state->crtc;

40e1a70b4aedf2 Noralf Trønnes 2021-03-13 593 struct drm_rect damage;
73cfd166e04576 Ruben Wauters 2025-08-18 594 struct drm_atomic_helper_damage_iter iter;
c17d048609bf09 Noralf Trønnes 2022-11-30 595 int ret, idx;
40e1a70b4aedf2 Noralf Trønnes 2021-03-13 596
dc2d5ddb193e36 Shenghao Yang 2025-12-31 @597 if (!crtc || crtc->state->mode_changed || !crtc->state->enable) {

40e1a70b4aedf2 Noralf Trønnes 2021-03-13  598  		cancel_work_sync(&gdrm->work);
40e1a70b4aedf2 Noralf Trønnes 2021-03-13  599  		mutex_lock(&gdrm->damage_lock);
40e1a70b4aedf2 Noralf Trønnes 2021-03-13  600  		if (gdrm->fb) {
40e1a70b4aedf2 Noralf Trønnes 2021-03-13  601  			drm_framebuffer_put(gdrm->fb);
40e1a70b4aedf2 Noralf Trønnes 2021-03-13  602  			gdrm->fb = NULL;
40e1a70b4aedf2 Noralf Trønnes 2021-03-13  603  		}
40e1a70b4aedf2 Noralf Trønnes 2021-03-13  604  		gud_clear_damage(gdrm);
c17d048609bf09 Noralf Trønnes 2022-11-30  605  		vfree(gdrm->shadow_buf);
c17d048609bf09 Noralf Trønnes 2022-11-30  606  		gdrm->shadow_buf = NULL;
40e1a70b4aedf2 Noralf Trønnes 2021-03-13  607  		mutex_unlock(&gdrm->damage_lock);
40e1a70b4aedf2 Noralf Trønnes 2021-03-13  608  	}
40e1a70b4aedf2 Noralf Trønnes 2021-03-13  609  
40e1a70b4aedf2 Noralf Trønnes 2021-03-13  610  	if (!drm_dev_enter(drm, &idx))
40e1a70b4aedf2 Noralf Trønnes 2021-03-13  611  		return;
40e1a70b4aedf2 Noralf Trønnes 2021-03-13  612  
40e1a70b4aedf2 Noralf Trønnes 2021-03-13  613  	if (!old_state->fb)
40e1a70b4aedf2 Noralf Trønnes 2021-03-13  614  		gud_usb_set_u8(gdrm, GUD_REQ_SET_CONTROLLER_ENABLE, 1);
40e1a70b4aedf2 Noralf Trønnes 2021-03-13  615

40e1a70b4aedf2 Noralf Trønnes 2021-03-13 @616 if (fb && (crtc->state->mode_changed || crtc->state->connectors_changed))

:::::: The code at line 616 was first introduced by commit
:::::: 40e1a70b4aedf2859a1829991b48ef0ebe650bf2 drm: Add GUD USB Display driver

:::::: TO: Noralf Trønnes <[email protected]>
:::::: CC: Noralf Trønnes <[email protected]>

Signature · 2 lines
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki