[PATCH 1/2] drm/udl: fix a NULL pointer reference in udl_gem_free_object().

[Haixia Shi]

Previously this function had a NULL pointer check for gem->map_list.map, but
that line was refactored after commit 0de23977cfeb5b357ec884ba15417ae118ff9e9bb
("drm/gem: convert to new unified vma manager").

After the refactor it is still necessasry to check that the vma manager is not
NULL because udl_gem_free_object() may come in after the vma manager is destroyed.

Signed-off-by: Haixia Shi <hshi at chromium.org>
Reviewed-by: Stéphane Marchesin <marcheu at chromium.org>
---
 drivers/gpu/drm/udl/udl_gem.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/udl/udl_gem.c b/drivers/gpu/drm/udl/udl_gem.c
index 818e707..72e1bd4 100644
--- a/drivers/gpu/drm/udl/udl_gem.c
+++ b/drivers/gpu/drm/udl/udl_gem.c
@@ -204,7 +204,8 @@ void udl_gem_free_object(struct drm_gem_object *gem_obj)
 	if (obj->pages)
 		udl_gem_put_pages(obj);
 
-	drm_gem_free_mmap_offset(gem_obj);
+	if (gem_obj->dev->vma_offset_manager)
+		drm_gem_free_mmap_offset(gem_obj);
 }
 
 /* the dumb interface doesn't work with the GEM straight MMAP
-- 
2.8.0.rc3.226.g39d4020