Commit b129ff30 authored by Matthew Auld's avatar Matthew Auld Committed by Christian König
Browse files

drm/qxl: handle NULL bo->resource in move callback 



The ttm bo now initially has NULL bo->resource, and leaves the driver
the handle that. However it looks like we forgot to handle that for qxl.
It looks like this will just null-ptr-deref in qxl_bo_move(), if
bo->resource is NULL.

Fix this by calling move_null() if the new resource is TTM_PL_SYSTEM,
otherwise do the multi-hop sequence to ensure can safely call into
ttm_bo_move_memcpy(), since it might also need to clear the memory.
This should give the same behaviour as before.

Fixes: 18025378 ("drm/ttm: stop allocating dummy resources during BO creation")
Signed-off-by: default avatarMatthew Auld <matthew.auld@intel.com>
Cc: Christian König <christian.koenig@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230208145319.397235-2-matthew.auld@intel.com


Acked-by: default avatarChristian König <christian.koenig@amd.com>
Signed-off-by: default avatarChristian König <christian.koenig@amd.com>
parent c604d319

drivers/gpu/drm/qxl/qxl_ttm.c

+11 −0
Original line number Diff line number Diff line
@@ -143,6 +143,17 @@ static int qxl_bo_move(struct ttm_buffer_object *bo, bool evict, 
	struct ttm_resource *old_mem = bo->resource;

	int ret;



	if (!old_mem) {

		if (new_mem->mem_type != TTM_PL_SYSTEM) {

			hop->mem_type = TTM_PL_SYSTEM;

			hop->flags = TTM_PL_FLAG_TEMPORARY;

			return -EMULTIHOP;

		}



		ttm_bo_move_null(bo, new_mem);

		return 0;

	}



	qxl_bo_move_notify(bo, new_mem);



	ret = ttm_bo_wait_ctx(bo, ctx);