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
vmwgfx. It looks like this will just null-ptr-deref in vmw_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: 180253782038 ("drm/ttm: stop allocating dummy resources during BO creation")
Signed-off-by: Matthew Auld <matthew.auld@xxxxxxxxx>
Cc: Christian König <christian.koenig@xxxxxxx>
---
drivers/gpu/drm/vmwgfx/vmwgfx_ttm_buffer.c | 15 ++++++++++++++-
1 file changed, 14 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_ttm_buffer.c b/drivers/gpu/drm/vmwgfx/vmwgfx_ttm_buffer.c
index 856a352a72a6..c598c5a9fe2c 100644
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_ttm_buffer.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_ttm_buffer.c
@@ -596,10 +596,23 @@ static int vmw_move(struct ttm_buffer_object *bo,
struct ttm_resource *new_mem,
struct ttm_place *hop)
{
- struct ttm_resource_manager *old_man = ttm_manager_type(bo->bdev, bo->resource->mem_type);
+ struct ttm_resource_manager *old_man;
struct ttm_resource_manager *new_man = ttm_manager_type(bo->bdev, new_mem->mem_type);
int ret;
+ if (!bo->resource) {
+ 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;
+ }
+
+ old_man = ttm_manager_type(bo->bdev, bo->resource->mem_type);
+
if (new_man->use_tt && !vmw_memtype_is_system(new_mem->mem_type)) {
ret = vmw_ttm_bind(bo->bdev, bo->ttm, new_mem);
if (ret)
--
2.39.1
