drm/i915: fix uninitialized pointer reads on pointers to and from

Currently pointers to and from are not initialized and may contain
garbage values. This will cause uninitialized pointer reads in the
call to intel_frontbuffer_track and later checks to see if to and from
are null.  Fix this by ensuring to and from are initialized to NULL.

Addresses-Coverity: ("Uninitialised pointer read)"
Fixes: 1d901903c885 ("drm/i915: Hold reference to intel_frontbuffer as we track activity")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20191219190916.24693-1-colin.king@canonical.com

diff --git a/drivers/gpu/drm/i915/display/intel_overlay.c b/drivers/gpu/drm/i915/display/intel_overlay.c
index 6097594468a9d805884cf8edfa5f7659d5df8c11..e869a3d86522bff6eb63243d4f3ac20258d6e8c6 100644 (file)
--- a/drivers/gpu/drm/i915/display/intel_overlay.c
+++ b/drivers/gpu/drm/i915/display/intel_overlay.c
@@ -279,7 +279,7 @@ static void intel_overlay_flip_prepare(struct intel_overlay *overlay,
                                       struct i915_vma *vma)
 {
        enum pipe pipe = overlay->crtc->pipe;
-       struct intel_frontbuffer *from, *to;
+       struct intel_frontbuffer *from = NULL, *to = NULL;
 
        WARN_ON(overlay->old_vma);