queue-5.1/drm-vmwgfx-fix-user-space-handle-equal-to-zero.patch

   1 From 8407f8a1d940fe28c4243ad4f0cb6a44dcee88f6 Mon Sep 17 00:00:00 2001
   2 From: Thomas Hellstrom <thellstrom@vmware.com>
   3 Date: Tue, 7 May 2019 11:10:10 +0200
   4 Subject: drm/vmwgfx: Fix user space handle equal to zero
   5
   6 From: Thomas Hellstrom <thellstrom@vmware.com>
   7
   8 commit 8407f8a1d940fe28c4243ad4f0cb6a44dcee88f6 upstream.
   9
  10 User-space handles equal to zero are interpreted as uninitialized or
  11 illegal by some drm systems (most notably kms). This means that a
  12 dumb buffer or surface with a zero user-space handle can never be
  13 used as a kms frame-buffer.
  14
  15 Cc: <stable@vger.kernel.org>
  16 Fixes: c7eae62666ad ("drm/vmwgfx: Make the object handles idr-generated")
  17 Signed-off-by: Thomas Hellstrom <thellstrom@vmware.com>
  18 Reviewed-by: Deepak Rawat <drawat@vmware.com>
  19 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  20
  21 ---
  22  drivers/gpu/drm/vmwgfx/ttm_object.c |    2 +-
  23  1 file changed, 1 insertion(+), 1 deletion(-)
  24
  25 --- a/drivers/gpu/drm/vmwgfx/ttm_object.c
  26 +++ b/drivers/gpu/drm/vmwgfx/ttm_object.c
  27 @@ -174,7 +174,7 @@ int ttm_base_object_init(struct ttm_obje
  28         kref_init(&base->refcount);
  29         idr_preload(GFP_KERNEL);
  30         spin_lock(&tdev->object_lock);
  31 -       ret = idr_alloc(&tdev->idr, base, 0, 0, GFP_NOWAIT);
  32 +       ret = idr_alloc(&tdev->idr, base, 1, 0, GFP_NOWAIT);
  33         spin_unlock(&tdev->object_lock);
  34         idr_preload_end();
  35         if (ret < 0)