releases/4.19.49/drm-lease-make-sure-implicit-planes-are-leased.patch

From 204f640da6914844b3270b41b29c84f6e3b74083 Mon Sep 17 00:00:00 2001
From: Daniel Vetter <daniel.vetter@ffwll.ch>
Date: Thu, 28 Feb 2019 15:49:08 +0100
Subject: drm/lease: Make sure implicit planes are leased

From: Daniel Vetter <daniel.vetter@ffwll.ch>

commit 204f640da6914844b3270b41b29c84f6e3b74083 upstream.

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
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/gpu/drm/drm_crtc.c  |    4 ++++
 drivers/gpu/drm/drm_plane.c |    8 ++++++++
 2 files changed, 12 insertions(+)

--- a/drivers/gpu/drm/drm_crtc.c
+++ b/drivers/gpu/drm/drm_crtc.c
@@ -595,6 +595,10 @@ int drm_mode_setcrtc(struct drm_device *
 
 	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_acquire_init(&ctx, DRM_MODESET_ACQUIRE_INTERRUPTIBLE);
 retry:
--- a/drivers/gpu/drm/drm_plane.c
+++ b/drivers/gpu/drm/drm_plane.c
@@ -940,6 +940,11 @@ retry:
 		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;
 	}
@@ -1042,6 +1047,9 @@ int drm_mode_page_flip_ioctl(struct drm_
 
 	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;