drm: Use drm_mode_init() for on-stack modes

Initialize on-stack modes with drm_mode_init() to guarantee
no stack garbage in the list head, or that we aren't copying
over another mode's list head.

Based on the following cocci script, with manual fixups:
@decl@
identifier M;
expression E;
@@
- struct drm_display_mode M = E;
+ struct drm_display_mode M;

@@
identifier decl.M;
expression decl.E;
statement S, S1;
@@
struct drm_display_mode M;
... when != S
+ drm_mode_init(&M, &E);
+
S1

@@
expression decl.E;
@@
- &*E
+ E

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220218100403.7028-22-ville.syrjala@linux.intel.com
Reviewed-by: Andrzej Hajda <andrzej.hajda@intel.com>

1 files changed, 3 insertions, 1 deletions

diff --git a/drivers/gpu/drm/drm_modes.c b/drivers/gpu/drm/drm_modes.c
index 6e7e10f16ec0..e699950cc34d 100644
--- a/drivers/gpu/drm/drm_modes.c
+++ b/drivers/gpu/drm/drm_modes.c
@@ -837,7 +837,9 @@ EXPORT_SYMBOL(drm_mode_vrefresh);
 void drm_mode_get_hv_timing(const struct drm_display_mode *mode,
 			    int *hdisplay, int *vdisplay)
 {
-	struct drm_display_mode adjusted = *mode;
+	struct drm_display_mode adjusted;
+
+	drm_mode_init(&adjusted, mode);
 
 	drm_mode_set_crtcinfo(&adjusted, CRTC_STEREO_DOUBLE_ONLY);
 	*hdisplay = adjusted.crtc_hdisplay;