Commit 47d35c1c authored by Thomas Zimmermann's avatar Thomas Zimmermann
Browse files

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: default avatarThomas Zimmermann <tzimmermann@suse.de>
Fixes: f5ca8eb6 ("drm/cma-helper: Implement mmap as GEM CMA object functions")
Reviewed-by: default avatarDaniel Vetter <daniel.vetter@ffwll.ch>
Reported-by: default avatarKieran Bingham <kieran.bingham+renesas@ideasonboard.com>
Tested-by: default avatarKieran Bingham <kieran.bingham+renesas@ideasonboard.com>
Cc: Maxime Ripard <mripard@kernel.org>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: David Airlie <airlied@linux.ie>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Eric Anholt <eric@anholt.net>
Cc: dri-devel@lists.freedesktop.org
Link: https://patchwork.freedesktop.org/patch/msgid/20210115093038.10345-1-tzimmermann@suse.de
parent 85dd1dd6

drivers/gpu/drm/drm_gem.c

+10 −9
Original line number Diff line number Diff line
@@ -1068,20 +1068,17 @@ int drm_gem_mmap_obj(struct drm_gem_object *obj, unsigned long obj_size, 
	drm_gem_object_get(obj);



	vma->vm_private_data = obj;

	vma->vm_ops = obj->funcs->vm_ops;



	if (obj->funcs->mmap) {

		ret = obj->funcs->mmap(obj, vma);

		if (ret) {

			drm_gem_object_put(obj);

			return ret;

		}

		if (ret)

			goto err_drm_gem_object_put;

		WARN_ON(!(vma->vm_flags & VM_DONTEXPAND));

	} else {

		if (obj->funcs->vm_ops)

			vma->vm_ops = obj->funcs->vm_ops;

		else {

			drm_gem_object_put(obj);

			return -EINVAL;

		if (!vma->vm_ops) {

			ret = -EINVAL;

			goto err_drm_gem_object_put;

		}



		vma->vm_flags |= VM_IO | VM_PFNMAP | VM_DONTEXPAND | VM_DONTDUMP;
@@ -1090,6 +1087,10 @@ int drm_gem_mmap_obj(struct drm_gem_object *obj, unsigned long obj_size, 
	}



	return 0;



err_drm_gem_object_put:

	drm_gem_object_put(obj);

	return ret;

}

EXPORT_SYMBOL(drm_gem_mmap_obj);

drivers/gpu/drm/drm_prime.c

+2 −0
Original line number Diff line number Diff line
@@ -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;