drm/vmwgfx: Fix an invalid read

[ Upstream commit 10a26e0d5f ]

vmw_move assumed that buffers to be moved would always be
vmw_buffer_object's but after introduction of new placement for mob
pages that's no longer the case.
The resulting invalid read didn't have any practical consequences
because the memory isn't used unless the object actually is a
vmw_buffer_object.
Fix it by moving the cast to the spot where the results are used.

Signed-off-by: Zack Rusin <zackr@vmware.com>
Fixes: f6be23264b ("drm/vmwgfx: Introduce a new placement for MOB page tables")
Reported-by: Chuck Lever III <chuck.lever@oracle.com>
Reviewed-by: Martin Krastev <krastevm@vmware.com>
Tested-by: Chuck Lever <chuck.lever@oracle.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220318174332.440068-2-zack@kde.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Zack Rusin 2022-03-18 13:43:28 -04:00 committed by Greg Kroah-Hartman
parent 4bbc9146ca
commit 8d62e3d506

View file

@ -859,22 +859,21 @@ void vmw_query_move_notify(struct ttm_buffer_object *bo,
struct ttm_device *bdev = bo->bdev;
struct vmw_private *dev_priv;
dev_priv = container_of(bdev, struct vmw_private, bdev);
mutex_lock(&dev_priv->binding_mutex);
dx_query_mob = container_of(bo, struct vmw_buffer_object, base);
if (!dx_query_mob || !dx_query_mob->dx_query_ctx) {
mutex_unlock(&dev_priv->binding_mutex);
return;
}
/* If BO is being moved from MOB to system memory */
if (new_mem->mem_type == TTM_PL_SYSTEM &&
old_mem->mem_type == VMW_PL_MOB) {
struct vmw_fence_obj *fence;
dx_query_mob = container_of(bo, struct vmw_buffer_object, base);
if (!dx_query_mob || !dx_query_mob->dx_query_ctx) {
mutex_unlock(&dev_priv->binding_mutex);
return;
}
(void) vmw_query_readback_all(dx_query_mob);
mutex_unlock(&dev_priv->binding_mutex);
@ -888,7 +887,6 @@ void vmw_query_move_notify(struct ttm_buffer_object *bo,
(void) ttm_bo_wait(bo, false, false);
} else
mutex_unlock(&dev_priv->binding_mutex);
}
/**