Hello Ramesh Errabolu,
The patch 0f28cca87e9a: "drm/amdkfd: Extend KFD device topology to
surface peer-to-peer links" from May 26, 2022, leads to the following
Smatch static checker warning:
drivers/gpu/drm/amd/amdgpu/../amdkfd/kfd_topology.c:1428 kfd_create_indirect_link_prop() warn: iterator used outside loop: 'cpu_link'
drivers/gpu/drm/amd/amdgpu/../amdkfd/kfd_topology.c:1462 kfd_create_indirect_link_prop() error: we previously assumed 'cpu_dev' could be null (see line 1420)
drivers/gpu/drm/amd/amdgpu/../amdkfd/kfd_topology.c:1516 kfd_add_peer_prop() warn: iterator used outside loop: 'iolink3'
drivers/gpu/drm/amd/amdgpu/../display/amdgpu_dm/amdgpu_dm.c:4997 add_modifier() warn: use safer allocation function (eg: kmalloc_array)
drivers/gpu/drm/amd/amdgpu/../display/dc/bios/bios_parser2.c:1601 bios_parser_is_device_id_supported() warn: inconsistent indenting
drivers/gpu/drm/amd/amdgpu/../display/dc/bios/bios_parser2.c:407 get_bios_object_from_path_v3() warn: inconsistent indenting
drivers/gpu/drm/amd/amdgpu/../display/dc/bios/bios_parser2.c:613 bios_parser_get_hpd_info() warn: inconsistent indenting
drivers/gpu/drm/amd/amdgpu/../display/dc/bios/bios_parser2.c:820 bios_parser_get_device_tag() warn: inconsistent indenting
drivers/gpu/drm/amd/amdgpu/../display/dc/core/dc.c:3151 commit_planes_for_stream() warn: inconsistent indenting
drivers/gpu/drm/amd/amdgpu/../display/dc/core/dc_stream.c:395 dc_stream_set_cursor_position() warn: variable dereferenced before check 'stream' (see line 392)
drivers/gpu/drm/amd/amdgpu/../pm/swsmu/amdgpu_smu.c:140 smu_set_gfx_power_up_by_imu() error: we previously assumed 'smu->ppt_funcs' could be null (see line 140)
drivers/gpu/drm/amd/amdgpu/../amdkfd/kfd_topology.c
1393 static int kfd_create_indirect_link_prop(struct kfd_topology_device *kdev, int gpu_node)
1394 {
1395 struct kfd_iolink_properties *props = NULL, *props2 = NULL;
1396 struct kfd_iolink_properties *gpu_link, *cpu_link;
1397 struct kfd_topology_device *cpu_dev;
1398 int ret = 0;
1399 int i, num_cpu;
1400
1401 num_cpu = 0;
1402 list_for_each_entry(cpu_dev, &topology_device_list, list) {
1403 if (cpu_dev->gpu)
1404 break;
1405 num_cpu++;
1406 }
1407
1408 gpu_link = list_first_entry(&kdev->io_link_props,
1409 struct kfd_iolink_properties, list);
1410 if (!gpu_link)
1411 return -ENOMEM;
1412
1413 for (i = 0; i < num_cpu; i++) {
1414 /* CPU <--> GPU */
1415 if (gpu_link->node_to == i)
1416 continue;
1417
1418 /* find CPU <--> CPU links */
1419 cpu_dev = kfd_topology_device_by_proximity_domain(i);
1420 if (cpu_dev) {
1421 list_for_each_entry(cpu_link,
1422 &cpu_dev->io_link_props, list) {
1423 if (cpu_link->node_to == gpu_link->node_to)
1424 break;
1425 }
If we exit the loop without hitting the break statement then "cpu_link"
is not a valid pointer.
1426 }
1427
--> 1428 if (cpu_link->node_to != gpu_link->node_to)
It's weird that this doesn't trigger an uninitialized variable warning.
1429 return -ENOMEM;
1430
1431 /* CPU <--> CPU <--> GPU, GPU node*/
1432 props = kfd_alloc_struct(props);
1433 if (!props)
1434 return -ENOMEM;
1435
1436 memcpy(props, gpu_link, sizeof(struct kfd_iolink_properties));
1437 props->weight = gpu_link->weight + cpu_link->weight;
1438 props->min_latency = gpu_link->min_latency + cpu_link->min_latency;
1439 props->max_latency = gpu_link->max_latency + cpu_link->max_latency;
1440 props->min_bandwidth = min(gpu_link->min_bandwidth, cpu_link->min_bandwidth);
1441 props->max_bandwidth = min(gpu_link->max_bandwidth, cpu_link->max_bandwidth);
1442
1443 props->node_from = gpu_node;
1444 props->node_to = i;
1445 kdev->node_props.p2p_links_count++;
1446 list_add_tail(&props->list, &kdev->p2p_link_props);
1447 ret = kfd_build_p2p_node_entry(kdev, props);
1448 if (ret < 0)
1449 return ret;
1450
1451 /* for small Bar, no CPU --> GPU in-direct links */
1452 if (kfd_dev_is_large_bar(kdev->gpu)) {
1453 /* CPU <--> CPU <--> GPU, CPU node*/
1454 props2 = kfd_alloc_struct(props2);
1455 if (!props2)
1456 return -ENOMEM;
1457
1458 memcpy(props2, props, sizeof(struct kfd_iolink_properties));
1459 props2->node_from = i;
1460 props2->node_to = gpu_node;
1461 props2->kobj = NULL;
1462 cpu_dev->node_props.p2p_links_count++;
If you fix the exit condition above then probably this warning will go
away too?
1463 list_add_tail(&props2->list, &cpu_dev->p2p_link_props);
1464 ret = kfd_build_p2p_node_entry(cpu_dev, props2);
1465 if (ret < 0)
1466 return ret;
1467 }
1468 }
1469 return ret;
1470 }
regards,
dan carpenter
