From: Simon Ser Date: Thu, 2 Mar 2023 14:35:09 +0000 (+0000) Subject: drm/prime: reject DMA-BUF attach when get_sg_table is missing X-Git-Tag: microblaze-v6.6~31^2~21^2~195 X-Git-Url: http://git.monstr.eu/?a=commitdiff_plain;h=207395da5a97035f06360638f0c2fcd92963ce95;p=linux-2.6-microblaze.git drm/prime: reject DMA-BUF attach when get_sg_table is missing drm_gem_map_dma_buf() requires drm_gem_object_funcs.get_sg_table to be implemented, or else WARNs. Allow drivers to leave this hook unimplemented to implement purely local DMA-BUFs (ie, DMA-BUFs which cannot be imported anywhere else but the device which allocated them). In that case, reject imports to other devices in drm_gem_map_attach(). v2: new patch v3: use ENOSYS Signed-off-by: Simon Ser Cc: Daniel Vetter Cc: Tian Tao Cc: Maxime Ripard Cc: Hans de Goede Acked-by: Thomas Zimmermann Reviewed-by: Christian König Link: https://patchwork.freedesktop.org/patch/msgid/20230302143502.500661-1-contact@emersion.fr --- diff --git a/drivers/gpu/drm/drm_prime.c b/drivers/gpu/drm/drm_prime.c index 149cd4ff6a3b..d29dafce9bb0 100644 --- a/drivers/gpu/drm/drm_prime.c +++ b/drivers/gpu/drm/drm_prime.c @@ -544,7 +544,8 @@ int drm_prime_handle_to_fd_ioctl(struct drm_device *dev, void *data, * Optional pinning of buffers is handled at dma-buf attach and detach time in * drm_gem_map_attach() and drm_gem_map_detach(). Backing storage itself is * handled by drm_gem_map_dma_buf() and drm_gem_unmap_dma_buf(), which relies on - * &drm_gem_object_funcs.get_sg_table. + * &drm_gem_object_funcs.get_sg_table. If &drm_gem_object_funcs.get_sg_table is + * unimplemented, exports into another device are rejected. * * For kernel-internal access there's drm_gem_dmabuf_vmap() and * drm_gem_dmabuf_vunmap(). Userspace mmap support is provided by @@ -583,6 +584,9 @@ int drm_gem_map_attach(struct dma_buf *dma_buf, { struct drm_gem_object *obj = dma_buf->priv; + if (!obj->funcs->get_sg_table) + return -ENOSYS; + return drm_gem_pin(obj); } EXPORT_SYMBOL(drm_gem_map_attach);