From: Arnd Bergmann <a...@arndb.de>
clang-21 points out a variable that is conditionally initialized
but then dereferenced:
drivers/gpu/drm/msm/disp/dpu1/dpu_plane.c:1138:6: error: variable 'crtc_state'
is used uninitialized whenever 'if' condition is false
[-Werror,-Wsometimes-uninitialized]
1138 | if (plane_state->crtc)
| ^~~~~~~~~~~~~~~~~
drivers/gpu/drm/msm/disp/dpu1/dpu_plane.c:1142:58: note: uninitialized use
occurs here
1142 | ret = dpu_plane_atomic_check_nosspp(plane, plane_state,
crtc_state);
|
^~~~~~~~~~
drivers/gpu/drm/msm/disp/dpu1/dpu_plane.c:1138:2: note: remove the 'if' if its
condition is always true
1138 | if (plane_state->crtc)
| ^~~~~~~~~~~~~~~~~~~~~~
1139 | crtc_state = drm_atomic_get_new_crtc_state(state,
drivers/gpu/drm/msm/disp/dpu1/dpu_plane.c:1132:35: note: initialize the
variable 'crtc_state' to silence this warning
1132 | struct drm_crtc_state *crtc_state;
| ^
| = NULL
The bug is real, but the suggestion from clang to set it to NULL is
unfortunately just as harmful as dereferencing a NULL pointer is little
better than uninitialized data.
Change the function to return an error in this case.
Fixes: 774bcfb73176 ("drm/msm/dpu: add support for virtual planes")
Signed-off-by: Arnd Bergmann <a...@arndb.de>
---
drivers/gpu/drm/msm/disp/dpu1/dpu_plane.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_plane.c
b/drivers/gpu/drm/msm/disp/dpu1/dpu_plane.c
index 01171c535a27..4987f2f2fee0 100644
--- a/drivers/gpu/drm/msm/disp/dpu1/dpu_plane.c
+++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_plane.c
@@ -1135,10 +1135,10 @@ static int dpu_plane_virtual_atomic_check(struct
drm_plane *plane,
if (IS_ERR(plane_state))
return PTR_ERR(plane_state);
- if (plane_state->crtc)
- crtc_state = drm_atomic_get_new_crtc_state(state,
- plane_state->crtc);
+ if (!plane_state->crtc)
+ return -ENXIO;
+ crtc_state = drm_atomic_get_new_crtc_state(state, plane_state->crtc);
ret = dpu_plane_atomic_check_nosspp(plane, plane_state, crtc_state);
if (ret)
return ret;
--
2.39.5
