Hi,
On 2023/7/10 14:29, Dan Carpenter wrote:
tree: git://anongit.freedesktop.org/drm/drm-misc drm-misc-next
head: 8d1077cf2e43b15fefd76ebec2b71541eb27ef2c
commit: f39db26c54281da6a785259498ca74b5e470476f [2/3] drm: Add kms driver for
loongson display controller
config: i386-randconfig-m021-20230710
(https://download.01.org/0day-ci/archive/20230710/202307100423.rv7d05uq-...@intel.com/config)
compiler: gcc-12 (Debian 12.2.0-14) 12.2.0
reproduce:
(https://download.01.org/0day-ci/archive/20230710/202307100423.rv7d05uq-...@intel.com/reproduce)
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 <l...@intel.com>
| Reported-by: Dan Carpenter <dan.carpen...@linaro.org>
| Closes: https://lore.kernel.org/r/202307100423.rv7d05uq-...@intel.com/
smatch warnings:
drivers/gpu/drm/loongson/lsdc_plane.c:199
lsdc_cursor_plane_atomic_async_check() warn: variable dereferenced before check
'state' (see line 180)
vim +/state +199 drivers/gpu/drm/loongson/lsdc_plane.c
f39db26c54281d Sui Jingfeng 2023-06-15 174 static int
lsdc_cursor_plane_atomic_async_check(struct drm_plane *plane,
f39db26c54281d Sui Jingfeng 2023-06-15 175
struct drm_atomic_state *state)
f39db26c54281d Sui Jingfeng 2023-06-15 176 {
f39db26c54281d Sui Jingfeng 2023-06-15 177 struct drm_plane_state
*new_state;
f39db26c54281d Sui Jingfeng 2023-06-15 178 struct drm_crtc_state
*crtc_state;
f39db26c54281d Sui Jingfeng 2023-06-15 179
f39db26c54281d Sui Jingfeng 2023-06-15 @180 new_state =
drm_atomic_get_new_plane_state(state, plane);
^^^^^
state is dereferenced inside this function
f39db26c54281d Sui Jingfeng 2023-06-15 181
f39db26c54281d Sui Jingfeng 2023-06-15 182 if (!plane->state ||
!plane->state->fb) {
f39db26c54281d Sui Jingfeng 2023-06-15 183 drm_dbg(plane->dev, "%s: state
is NULL\n", plane->name);
f39db26c54281d Sui Jingfeng 2023-06-15 184 return -EINVAL;
f39db26c54281d Sui Jingfeng 2023-06-15 185 }
f39db26c54281d Sui Jingfeng 2023-06-15 186
f39db26c54281d Sui Jingfeng 2023-06-15 187 if (new_state->crtc_w !=
new_state->crtc_h) {
f39db26c54281d Sui Jingfeng 2023-06-15 188 drm_dbg(plane->dev,
"unsupported cursor size: %ux%u\n",
f39db26c54281d Sui Jingfeng 2023-06-15 189 new_state->crtc_w,
new_state->crtc_h);
f39db26c54281d Sui Jingfeng 2023-06-15 190 return -EINVAL;
f39db26c54281d Sui Jingfeng 2023-06-15 191 }
f39db26c54281d Sui Jingfeng 2023-06-15 192
f39db26c54281d Sui Jingfeng 2023-06-15 193 if (new_state->crtc_w != 64 &&
new_state->crtc_w != 32) {
f39db26c54281d Sui Jingfeng 2023-06-15 194 drm_dbg(plane->dev,
"unsupported cursor size: %ux%u\n",
f39db26c54281d Sui Jingfeng 2023-06-15 195 new_state->crtc_w,
new_state->crtc_h);
f39db26c54281d Sui Jingfeng 2023-06-15 196 return -EINVAL;
f39db26c54281d Sui Jingfeng 2023-06-15 197 }
f39db26c54281d Sui Jingfeng 2023-06-15 198
f39db26c54281d Sui Jingfeng 2023-06-15 @199 if (state) {
^^^^^
Checked too late
Yes, there no need to check here, simply writing the code as following
is OK.
```
crtc_state = drm_atomic_get_existing_crtc_state(state,
new_state->crtc);
```
f39db26c54281d Sui Jingfeng 2023-06-15 200 crtc_state =
drm_atomic_get_existing_crtc_state(state, new_state->crtc);
f39db26c54281d Sui Jingfeng 2023-06-15 201 } else {
f39db26c54281d Sui Jingfeng 2023-06-15 202 crtc_state =
plane->crtc->state;
f39db26c54281d Sui Jingfeng 2023-06-15 203 drm_dbg(plane->dev, "%s: atomic
state is NULL\n", plane->name);
f39db26c54281d Sui Jingfeng 2023-06-15 204 }
f39db26c54281d Sui Jingfeng 2023-06-15 205
f39db26c54281d Sui Jingfeng 2023-06-15 206 if (!crtc_state->active)
f39db26c54281d Sui Jingfeng 2023-06-15 207 return -EINVAL;
f39db26c54281d Sui Jingfeng 2023-06-15 208
f39db26c54281d Sui Jingfeng 2023-06-15 209 if (plane->state->crtc !=
new_state->crtc ||
f39db26c54281d Sui Jingfeng 2023-06-15 210 plane->state->src_w !=
new_state->src_w ||
f39db26c54281d Sui Jingfeng 2023-06-15 211 plane->state->src_h !=
new_state->src_h ||
f39db26c54281d Sui Jingfeng 2023-06-15 212 plane->state->crtc_w !=
new_state->crtc_w ||
f39db26c54281d Sui Jingfeng 2023-06-15 213 plane->state->crtc_h !=
new_state->crtc_h)
f39db26c54281d Sui Jingfeng 2023-06-15 214 return -EINVAL;
f39db26c54281d Sui Jingfeng 2023-06-15 215
f39db26c54281d Sui Jingfeng 2023-06-15 216 if (new_state->visible !=
plane->state->visible)
f39db26c54281d Sui Jingfeng 2023-06-15 217 return -EINVAL;
f39db26c54281d Sui Jingfeng 2023-06-15 218
f39db26c54281d Sui Jingfeng 2023-06-15 219 return
drm_atomic_helper_check_plane_state(plane->state,
f39db26c54281d Sui Jingfeng 2023-06-15 220
crtc_state,
f39db26c54281d Sui Jingfeng 2023-06-15 221
DRM_PLANE_NO_SCALING,
f39db26c54281d Sui Jingfeng 2023-06-15 222
DRM_PLANE_NO_SCALING,
f39db26c54281d Sui Jingfeng 2023-06-15 223
true, true);
f39db26c54281d Sui Jingfeng 2023-06-15 224 }
