From: Junwei Zhang <Jerry.Zhang@amd.com>
Date: Mon, 23 Apr 2018 17:21:21 +0800
Subject: drm/amdgpu: bo could be null when access in vm bo update
Git-commit: 8239f57ac3e9bf9ad0cf4d396ebfa721e91ac611
Patch-mainline: v4.18-rc1
References: FATE#326289 FATE#326079 FATE#326049 FATE#322398 FATE#326166

Signed-off-by: Junwei Zhang <Jerry.Zhang@amd.com>
Reviewed-by: David Zhou <david1.zhou@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Acked-by: Petr Tesarik <ptesarik@suse.com>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c |    5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
@@ -1509,7 +1509,6 @@ int amdgpu_vm_bo_update(struct amdgpu_de
 	struct drm_mm_node *nodes;
 	struct dma_fence *exclusive, **last_update;
 	uint64_t flags;
-	uint32_t mem_type;
 	int r;
 
 	if (clear || !bo_va->base.bo) {
@@ -1568,9 +1567,9 @@ int amdgpu_vm_bo_update(struct amdgpu_de
 	 * the evicted list so that it gets validated again on the
 	 * next command submission.
 	 */
-	mem_type = bo->tbo.mem.mem_type;
 	if (bo && bo->tbo.resv == vm->root.base.bo->tbo.resv &&
-	    !(bo->preferred_domains & amdgpu_mem_type_to_domain(mem_type)))
+	    !(bo->preferred_domains &
+	    amdgpu_mem_type_to_domain(bo->tbo.mem.mem_type)))
 		list_add_tail(&bo_va->base.vm_status, &vm->evicted);
 	spin_unlock(&vm->status_lock);