drm/lease: Make sure implicit planes are leased

If userspace doesn't enable universal planes, then we automatically
add the primary and cursor planes. But for universal userspace there's
no such check (and maybe we only want to give the lessee one plane,
maybe not even the primary one), hence we need to check for the
implied plane.

v2: don't forget setcrtc ioctl.

v3: Still allow disabling of the crtc in SETCRTC.

Cc: stable@vger.kernel.org
Cc: Keith Packard <keithp@keithp.com>
Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190228144910.26488-6-daniel.vetter@ffwll.ch

drivers/gpu/drm/drm_crtc.c

@@ -559,6 +559,10 @@ int drm_mode_setcrtc(struct drm_device *dev, void *data,
 
 	plane = crtc->primary;
 
+	/* allow disabling with the primary plane leased */
+	if (crtc_req->mode_valid && !drm_lease_held(file_priv, plane->base.id))
+		return -EACCES;
+
 	mutex_lock(&crtc->dev->mode_config.mutex);
 	DRM_MODESET_LOCK_ALL_BEGIN(dev, ctx,
 				   DRM_MODESET_ACQUIRE_INTERRUPTIBLE, ret);

drivers/gpu/drm/drm_plane.c

@@ -960,6 +960,11 @@ static int drm_mode_cursor_common(struct drm_device *dev,
 		if (ret)
 			goto out;
 
+		if (!drm_lease_held(file_priv, crtc->cursor->base.id)) {
+			ret = -EACCES;
+			goto out;
+		}
+
 		ret = drm_mode_cursor_universal(crtc, req, file_priv, &ctx);
 		goto out;
 	}
@@ -1062,6 +1067,9 @@ int drm_mode_page_flip_ioctl(struct drm_device *dev,
 
 	plane = crtc->primary;
 
+	if (!drm_lease_held(file_priv, plane->base.id))
+		return -EACCES;
+
 	if (crtc->funcs->page_flip_target) {
 		u32 current_vblank;
 		int r;