drm/amdgpu: add proper error handling to amdgpu_bo_list_get

Otherwise we silently don't use a BO list when the handle is invalid.
Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Chunming Zhou <david1.zhou@amd.com>
Reviewed-by: Huang Rui <ray.huang@amd.com>
Reviewed-by: Michel Dänzer <michel.daenzer@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/amdgpu/amdgpu.h

@@ -713,8 +713,8 @@ struct amdgpu_bo_list {
 	struct amdgpu_bo_list_entry *array;
 };
 
-struct amdgpu_bo_list *
-amdgpu_bo_list_get(struct amdgpu_fpriv *fpriv, int id);
+int amdgpu_bo_list_get(struct amdgpu_fpriv *fpriv, int id,
+		       struct amdgpu_bo_list **result);
 void amdgpu_bo_list_get_list(struct amdgpu_bo_list *list,
 			     struct list_head *validated);
 void amdgpu_bo_list_put(struct amdgpu_bo_list *list);

drivers/gpu/drm/amd/amdgpu/amdgpu_bo_list.c

@@ -180,27 +180,20 @@ static int amdgpu_bo_list_set(struct amdgpu_device *adev,
 	return r;
 }
 
-struct amdgpu_bo_list *
-amdgpu_bo_list_get(struct amdgpu_fpriv *fpriv, int id)
+int amdgpu_bo_list_get(struct amdgpu_fpriv *fpriv, int id,
+		       struct amdgpu_bo_list **result)
 {
-	struct amdgpu_bo_list *result;
-
 	rcu_read_lock();
-	result = idr_find(&fpriv->bo_list_handles, id);
+	*result = idr_find(&fpriv->bo_list_handles, id);
 
-	if (result) {
-		if (kref_get_unless_zero(&result->refcount)) {
-			rcu_read_unlock();
-			mutex_lock(&result->lock);
-		} else {
-			rcu_read_unlock();
-			result = NULL;
-		}
-	} else {
+	if (*result && kref_get_unless_zero(&(*result)->refcount)) {
 		rcu_read_unlock();
+		mutex_lock(&(*result)->lock);
+		return 0;
 	}
 
-	return result;
+	rcu_read_unlock();
+	return -ENOENT;
 }
 
 void amdgpu_bo_list_get_list(struct amdgpu_bo_list *list,
@@ -335,9 +328,8 @@ int amdgpu_bo_list_ioctl(struct drm_device *dev, void *data,
 		break;
 
 	case AMDGPU_BO_LIST_OP_UPDATE:
-		r = -ENOENT;
-		list = amdgpu_bo_list_get(fpriv, handle);
-		if (!list)
+		r = amdgpu_bo_list_get(fpriv, handle, &list);
+		if (r)
 			goto error_free;
 
 		r = amdgpu_bo_list_set(adev, filp, list, info,

drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c

@@ -572,11 +572,16 @@ static int amdgpu_cs_parser_bos(struct amdgpu_cs_parser *p,
 	INIT_LIST_HEAD(&p->validated);
 
 	/* p->bo_list could already be assigned if AMDGPU_CHUNK_ID_BO_HANDLES is present */
-	if (!p->bo_list)
-		p->bo_list = amdgpu_bo_list_get(fpriv, cs->in.bo_list_handle);
-	else
+	if (p->bo_list) {
 		mutex_lock(&p->bo_list->lock);
 
+	} else if (cs->in.bo_list_handle) {
+		r = amdgpu_bo_list_get(fpriv, cs->in.bo_list_handle,
+				       &p->bo_list);
+		if (r)
+			return r;
+	}
+
 	if (p->bo_list) {
 		amdgpu_bo_list_get_list(p->bo_list, &p->validated);
 		if (p->bo_list->first_userptr != p->bo_list->num_entries)