Am 15.04.25 um 11:20 schrieb Thomas Zimmermann: > Test struct drm_gem_object.import_attach to detect imported objects > during cleanup. At that point, the imported DMA buffer might have > already been released and the dma_buf field is NULL. The object's > free callback then does a cleanup as for native objects.
I don't think that this is a good idea. The DMA-buf is separately reference counted through the import attachment. > Happens for calls to drm_mode_destroy_dumb_ioctl() that eventually > clear the dma_buf field in drm_gem_object_exported_dma_buf_free(). That is for exported DMA-buf and should *NEVER* be used for imported ones. Regards, Christian. > > Signed-off-by: Thomas Zimmermann <[email protected]> > Fixes: b57aa47d39e9 ("drm/gem: Test for imported GEM buffers with helper") > Reported-by: Andy Yan <[email protected]> > Closes: > https://lore.kernel.org/dri-devel/[email protected]/ > Tested-by: Andy Yan <[email protected]> > Cc: Thomas Zimmermann <[email protected]> > Cc: Anusha Srivatsa <[email protected]> > Cc: Christian König <[email protected]> > Cc: Maarten Lankhorst <[email protected]> > Cc: Maxime Ripard <[email protected]> > Cc: David Airlie <[email protected]> > Cc: Simona Vetter <[email protected]> > Cc: Sumit Semwal <[email protected]> > Cc: "Christian König" <[email protected]> > Cc: [email protected] > Cc: [email protected] > Cc: [email protected] > --- > include/drm/drm_gem.h | 8 +++++++- > 1 file changed, 7 insertions(+), 1 deletion(-) > > diff --git a/include/drm/drm_gem.h b/include/drm/drm_gem.h > index 9b71f7a9f3f8..f09b8afcf86d 100644 > --- a/include/drm/drm_gem.h > +++ b/include/drm/drm_gem.h > @@ -589,7 +589,13 @@ static inline bool > drm_gem_object_is_shared_for_memory_stats(struct drm_gem_obje > static inline bool drm_gem_is_imported(const struct drm_gem_object *obj) > { > /* The dma-buf's priv field points to the original GEM object. */ > - return obj->dma_buf && (obj->dma_buf->priv != obj); > + return (obj->dma_buf && (obj->dma_buf->priv != obj)) || > + /* > + * TODO: During object release, the dma-buf might already > + * be gone. For now keep testing import_attach, but > + * this should be removed at some point. > + */ > + obj->import_attach; > } > > #ifdef CONFIG_LOCKDEP
