drm: Set vm_ops to GEM object's values during mmap

The GEM mmap code relies on the GEM object's mmap callback to set the
VMA's vm_ops field. This is easily forgotten and already led to a memory
leak in the CMA helpers. Instead set the vm_ops field in the DRM core
code to the GEM object's value. Drivers with different needs can override
this in their mmap callback.

v2:
	* support (vm_ops == NULL) if mmap is given; required by VRAM
	  helpers

Signed-off-by: Thomas Zimmermann <[email protected]>
Fixes: f5ca8eb6f9bd ("drm/cma-helper: Implement mmap as GEM CMA object functions")
Reviewed-by: Daniel Vetter <[email protected]>
Reported-by: Kieran Bingham <[email protected]>
Tested-by: Kieran Bingham <[email protected]>
Cc: Maxime Ripard <[email protected]>
Cc: Maarten Lankhorst <[email protected]>
Cc: David Airlie <[email protected]>
Cc: Daniel Vetter <[email protected]>
Cc: Eric Anholt <[email protected]>
Cc: [email protected]
Link: https://patchwork.freedesktop.org/patch/msgid/[email protected]

1 files changed, 2 insertions, 0 deletions

diff --git a/drivers/gpu/drm/drm_prime.c b/drivers/gpu/drm/drm_prime.c
index 683aa29ecd3b..2a54f86856af 100644
--- a/drivers/gpu/drm/drm_prime.c
+++ b/drivers/gpu/drm/drm_prime.c
@@ -717,6 +717,8 @@ int drm_gem_prime_mmap(struct drm_gem_object *obj, struct vm_area_struct *vma)
 	vma->vm_pgoff += drm_vma_node_start(&obj->vma_node);
 
 	if (obj->funcs && obj->funcs->mmap) {
+		vma->vm_ops = obj->funcs->vm_ops;
+
 		ret = obj->funcs->mmap(obj, vma);
 		if (ret)
 			return ret;