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@vger.kernel.org Fixes: c7eae62666ad ("drm/vmwgfx: Make the object handles idr-generated") Signed-off-by: Thomas Hellstrom thellstrom@vmware.com Reviewed-by: Deepak Rawat drawat@vmware.com --- drivers/gpu/drm/vmwgfx/ttm_object.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/vmwgfx/ttm_object.c b/drivers/gpu/drm/vmwgfx/ttm_object.c index 36990b80e790..16077785ad47 100644 --- 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_object_file *tfile, 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)