[PATCH 5.1 72/85] drm/vmwgfx: Fix user space handle equal to zero

[Greg Kroah-Hartman]

From: Thomas Hellstrom <thellstrom@xxxxxxxxxx>

commit 8407f8a1d940fe28c4243ad4f0cb6a44dcee88f6 upstream.

User-space handles equal to zero are interpreted as uninitialized or
illegal by some drm systems (most notably kms). This means that a
dumb buffer or surface with a zero user-space handle can never be
used as a kms frame-buffer.

Cc: <stable@xxxxxxxxxxxxxxx>
Fixes: c7eae62666ad ("drm/vmwgfx: Make the object handles idr-generated")
Signed-off-by: Thomas Hellstrom <thellstrom@xxxxxxxxxx>
Reviewed-by: Deepak Rawat <drawat@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 drivers/gpu/drm/vmwgfx/ttm_object.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/gpu/drm/vmwgfx/ttm_object.c
+++ b/drivers/gpu/drm/vmwgfx/ttm_object.c
@@ -174,7 +174,7 @@ int ttm_base_object_init(struct ttm_obje
 	kref_init(&base->refcount);
 	idr_preload(GFP_KERNEL);
 	spin_lock(&tdev->object_lock);
-	ret = idr_alloc(&tdev->idr, base, 0, 0, GFP_NOWAIT);
+	ret = idr_alloc(&tdev->idr, base, 1, 0, GFP_NOWAIT);
 	spin_unlock(&tdev->object_lock);
 	idr_preload_end();
 	if (ret < 0)