On Thu, Jun 03, 2021 at 09:42:00PM +0300, Andi Shyti wrote:
> Hi Daniel,
>
> > +/*
> > + * This just sets wc mode for shmem helpers. vgem doesn't have any begin/end cpu
> > + * access ioctls, there must use coherent memory or dma-buf sharing just wont
> > + * work.
> > + */
> > +static struct drm_gem_object *vgem_gem_create_object(struct drm_device *dev, size_t size)
> > {
> > - struct drm_vgem_gem_object *obj;
> > - int npages;
> > + struct drm_gem_shmem_object *obj;
> >
> > - obj = __vgem_gem_create(dev, attach->dmabuf->size);
> > - if (IS_ERR(obj))
> > - return ERR_CAST(obj);
> > -
> > - npages = PAGE_ALIGN(attach->dmabuf->size) / PAGE_SIZE;
> > + obj = kzalloc(sizeof(*obj), GFP_KERNEL);
> > + if (!obj)
> > + return NULL;
> >
> > - obj->table = sg;
> > - obj->pages = kvmalloc_array(npages, sizeof(struct page *), GFP_KERNEL);
> > - if (!obj->pages) {
> > - __vgem_gem_destroy(obj);
> > - return ERR_PTR(-ENOMEM);
> > - }
> > + obj->base.funcs = &drm_gem_shmem_funcs;
> > + obj->map_wc = true;
> >
> > - obj->pages_pin_count++; /* perma-pinned */
> > - drm_prime_sg_to_page_array(obj->table, obj->pages, npages);
> > return &obj->base;
>
> here you are allocating a bigger object than what you are
> returning, in size. How does it get freed?
We're using the drm_gem_shmem_helper.c helpers, which set up all the shmem
functions for us, including an appropriate free callback.
-Daniel
--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch
