This reverts commit e91eb3ae415472b28211d7fed07fa283845b311e.
The dma_buf field in struct drm_gem_object is not stable over the
object instance's lifetime. The field becomes NULL when user space
releases the final GEM handle on the buffer object. This resulted
in a NULL-pointer deref.
Workarounds in commit 5307dce878d4 ("drm/gem: Acquire references on
GEM handles for framebuffers") and commit f6bfc9afc751 ("drm/framebuffer:
Acquire internal references on GEM handles") only solved the problem
partially. They especially don't work for buffer objects without a DRM
framebuffer associated.
Hence, this revert to going back to using .import_attach->dmabuf.
Signed-off-by: Thomas Zimmermann <tzimmerm...@suse.de>
Reviewed-by: Simona Vetter <simona.vet...@ffwll.ch>
---
drivers/gpu/drm/etnaviv/etnaviv_gem_prime.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/etnaviv/etnaviv_gem_prime.c
b/drivers/gpu/drm/etnaviv/etnaviv_gem_prime.c
index 917ad527c961..40a50c60dfff 100644
--- a/drivers/gpu/drm/etnaviv/etnaviv_gem_prime.c
+++ b/drivers/gpu/drm/etnaviv/etnaviv_gem_prime.c
@@ -65,7 +65,7 @@ static void etnaviv_gem_prime_release(struct
etnaviv_gem_object *etnaviv_obj)
struct iosys_map map = IOSYS_MAP_INIT_VADDR(etnaviv_obj->vaddr);
if (etnaviv_obj->vaddr)
- dma_buf_vunmap_unlocked(etnaviv_obj->base.dma_buf, &map);
+
dma_buf_vunmap_unlocked(etnaviv_obj->base.import_attach->dmabuf, &map);
/* Don't drop the pages for imported dmabuf, as they are not
* ours, just free the array we allocated:
@@ -82,7 +82,7 @@ static void *etnaviv_gem_prime_vmap_impl(struct
etnaviv_gem_object *etnaviv_obj)
lockdep_assert_held(&etnaviv_obj->lock);
- ret = dma_buf_vmap(etnaviv_obj->base.dma_buf, &map);
+ ret = dma_buf_vmap(etnaviv_obj->base.import_attach->dmabuf, &map);
if (ret)
return NULL;
return map.vaddr;
--
2.50.0
