[PATCH 2/2] amdgpu: don't dereference a NULL resource in sysfs code

[Pierre-Eric Pelloux-Prayer]

dma_resv_trylock being successful doesn't guarantee that bo->tbo.base.resv
is not NULL, so check its validity before using it.

Signed-off-by: Pierre-Eric Pelloux-Prayer <pierre-eric.pelloux-pra...@amd.com>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_object.c | 63 +++++++++++-----------
 1 file changed, 33 insertions(+), 30 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c 
b/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c
index 1eadcad1856d..6faeb9e4a572 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c
@@ -1594,36 +1594,39 @@ u64 amdgpu_bo_print_info(int id, struct amdgpu_bo *bo, 
struct seq_file *m)
        u64 size;
 
        if (dma_resv_trylock(bo->tbo.base.resv)) {
-
-               switch (bo->tbo.resource->mem_type) {
-               case TTM_PL_VRAM:
-                       if (amdgpu_res_cpu_visible(adev, bo->tbo.resource))
-                               placement = "VRAM VISIBLE";
-                       else
-                               placement = "VRAM";
-                       break;
-               case TTM_PL_TT:
-                       placement = "GTT";
-                       break;
-               case AMDGPU_PL_GDS:
-                       placement = "GDS";
-                       break;
-               case AMDGPU_PL_GWS:
-                       placement = "GWS";
-                       break;
-               case AMDGPU_PL_OA:
-                       placement = "OA";
-                       break;
-               case AMDGPU_PL_PREEMPT:
-                       placement = "PREEMPTIBLE";
-                       break;
-               case AMDGPU_PL_DOORBELL:
-                       placement = "DOORBELL";
-                       break;
-               case TTM_PL_SYSTEM:
-               default:
-                       placement = "CPU";
-                       break;
+               if (!bo->tbo.resource) {
+                       placement = "NONE";
+               } else {
+                       switch (bo->tbo.resource->mem_type) {
+                       case TTM_PL_VRAM:
+                               if (amdgpu_res_cpu_visible(adev, 
bo->tbo.resource))
+                                       placement = "VRAM VISIBLE";
+                               else
+                                       placement = "VRAM";
+                               break;
+                       case TTM_PL_TT:
+                               placement = "GTT";
+                               break;
+                       case AMDGPU_PL_GDS:
+                               placement = "GDS";
+                               break;
+                       case AMDGPU_PL_GWS:
+                               placement = "GWS";
+                               break;
+                       case AMDGPU_PL_OA:
+                               placement = "OA";
+                               break;
+                       case AMDGPU_PL_PREEMPT:
+                               placement = "PREEMPTIBLE";
+                               break;
+                       case AMDGPU_PL_DOORBELL:
+                               placement = "DOORBELL";
+                               break;
+                       case TTM_PL_SYSTEM:
+                       default:
+                               placement = "CPU";
+                               break;
+                       }
                }
                dma_resv_unlock(bo->tbo.base.resv);
        } else {
-- 
2.40.1