drm_atomic_set_mode_prop_for_crtc() has a few issues:
- it doesn't clear the state->mode, so old data may be left there when a
new mode is set.
- if an error happens, state->mode is left in a partially updated state.
This patch improves the situation by:
- bail out early if blob is of wrong length.
- construct drm_display_mode first in an initialized local variable, and
copy it to state->mode only when we know the call has succeeded.
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@xxxxxx>
---
drivers/gpu/drm/drm_atomic.c | 16 ++++++++++++----
1 file changed, 12 insertions(+), 4 deletions(-)
diff --git a/drivers/gpu/drm/drm_atomic.c b/drivers/gpu/drm/drm_atomic.c
index 3ff1ed7b33db..5bfecb2bbedf 100644
--- a/drivers/gpu/drm/drm_atomic.c
+++ b/drivers/gpu/drm/drm_atomic.c
@@ -348,16 +348,24 @@ int drm_atomic_set_mode_prop_for_crtc(struct drm_crtc_state *state,
if (blob == state->mode_blob)
return 0;
+ if (blob && blob->length != sizeof(struct drm_mode_modeinfo))
+ return -EINVAL;
+
drm_property_unreference_blob(state->mode_blob);
state->mode_blob = NULL;
if (blob) {
- if (blob->length != sizeof(struct drm_mode_modeinfo) ||
- drm_mode_convert_umode(&state->mode,
- (const struct drm_mode_modeinfo *)
- blob->data))
+ const struct drm_mode_modeinfo *umode =
+ (const struct drm_mode_modeinfo *)blob->data;
+ struct drm_display_mode mode;
+
+ memset(&mode, 0, sizeof(mode));
+
+ if (drm_mode_convert_umode(&mode, umode))
return -EINVAL;
+ state->mode = mode;
+
state->mode_blob = drm_property_reference_blob(blob);
state->enable = true;
DRM_DEBUG_ATOMIC("Set [MODE:%s] for CRTC state %p\n",
--
2.5.0
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