drm/amdkfd: Check for NULL return values

This patch fixes issues when the code moves forward with a potential
NULL pointer, without checking.
Removed one redundant NULL check for a function parameter. This check
is already done in the only caller.

Signed-off-by: Andrew Martin <andrew.martin@amd.com>
Reviewed-by: Felix Kuehling <felix.kuehling@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

Author: andmar-amd

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

@@ -107,7 +107,7 @@ static const char *amdkfd_fence_get_timeline_name(struct dma_fence *f)
 {
 	struct amdgpu_amdkfd_fence *fence = to_amdgpu_amdkfd_fence(f);
 
-	return fence->timeline_name;
+	return fence ? fence->timeline_name : NULL;
 }
 
 /**

drivers/gpu/drm/amd/amdkfd/kfd_crat.c

@@ -2359,7 +2359,7 @@ static int kfd_create_vcrat_image_gpu(void *pcrat_image,
 	if (kdev->kfd->hive_id) {
 		for (nid = 0; nid < proximity_domain; ++nid) {
 			peer_dev = kfd_topology_device_by_proximity_domain_no_lock(nid);
-			if (!peer_dev->gpu)
+			if (!peer_dev || !peer_dev->gpu)
 				continue;
 			if (peer_dev->gpu->kfd->hive_id != kdev->kfd->hive_id)
 				continue;

drivers/gpu/drm/amd/amdkfd/kfd_debug.c

@@ -523,10 +523,15 @@ int kfd_dbg_trap_set_flags(struct kfd_process *target, uint32_t *flags)
 	int i, r = 0, rewind_count = 0;
 
 	for (i = 0; i < target->n_pdds; i++) {
+		uint32_t caps;
+		uint32_t caps2;
 		struct kfd_topology_device *topo_dev =
-				kfd_topology_device_by_id(target->pdds[i]->dev->id);
-		uint32_t caps = topo_dev->node_props.capability;
-		uint32_t caps2 = topo_dev->node_props.capability2;
+			kfd_topology_device_by_id(target->pdds[i]->dev->id);
+		if (!topo_dev)
+			return -EINVAL;
+
+		caps = topo_dev->node_props.capability;
+		caps2 = topo_dev->node_props.capability2;
 
 		if (!(caps & HSA_CAP_TRAP_DEBUG_PRECISE_MEMORY_OPERATIONS_SUPPORTED) &&
 			(*flags & KFD_DBG_TRAP_FLAG_SINGLE_MEM_OP)) {
@@ -1086,6 +1091,10 @@ int kfd_dbg_trap_device_snapshot(struct kfd_process *target,
 	for (i = 0; i < tmp_num_devices; i++) {
 		struct kfd_process_device *pdd = target->pdds[i];
 		struct kfd_topology_device *topo_dev = kfd_topology_device_by_id(pdd->dev->id);
+		if (!topo_dev) {
+			r = -EINVAL;
+			break;
+		}
 
 		device_info.gpu_id = pdd->dev->id;
 		device_info.exception_status = pdd->exception_status;

drivers/gpu/drm/amd/amdkfd/kfd_process.c

@@ -1773,9 +1773,6 @@ int kfd_process_device_init_vm(struct kfd_process_device *pdd,
 	struct kfd_node *dev;
 	int ret;
 
-	if (!drm_file)
-		return -EINVAL;
-
 	if (pdd->drm_priv)
 		return -EBUSY;