[bug report] drm/amdkfd: Validate queue cwsr area and eop buffer size

[Dan Carpenter]

Hello Philip Yang,

Commit 629568d25fea ("drm/amdkfd: Validate queue cwsr area and eop
buffer size") from Jun 26, 2024 (linux-next), leads to the following
Smatch static checker warning:

	drivers/gpu/drm/amd/amdgpu/../amdkfd/kfd_queue.c:265 kfd_queue_acquire_buffers()
	warn: missing error code 'err'

drivers/gpu/drm/amd/amdgpu/../amdkfd/kfd_queue.c
    226 int kfd_queue_acquire_buffers(struct kfd_process_device *pdd, struct queue_properties *properties)
    227 {
    228         struct kfd_topology_device *topo_dev;
    229         struct amdgpu_vm *vm;
    230         u32 total_cwsr_size;
    231         int err;
    232 
    233         topo_dev = kfd_topology_device_by_id(pdd->dev->id);
    234         if (!topo_dev)
    235                 return -EINVAL;
    236 
    237         vm = drm_priv_to_vm(pdd->drm_priv);
    238         err = amdgpu_bo_reserve(vm->root.bo, false);
    239         if (err)
    240                 return err;
    241 
    242         err = kfd_queue_buffer_get(vm, properties->write_ptr, &properties->wptr_bo, PAGE_SIZE);
    243         if (err)
    244                 goto out_err_unreserve;
    245 
    246         err = kfd_queue_buffer_get(vm, properties->read_ptr, &properties->rptr_bo, PAGE_SIZE);
    247         if (err)
    248                 goto out_err_unreserve;
    249 
    250         err = kfd_queue_buffer_get(vm, (void *)properties->queue_address,
    251                                    &properties->ring_bo, properties->queue_size);
    252         if (err)
    253                 goto out_err_unreserve;
    254 
    255         /* only compute queue requires EOP buffer and CWSR area */
    256         if (properties->type != KFD_QUEUE_TYPE_COMPUTE)
    257                 goto out_unreserve;

This is clearly a success path.

    258 
    259         /* EOP buffer is not required for all ASICs */
    260         if (properties->eop_ring_buffer_address) {
    261                 if (properties->eop_ring_buffer_size != topo_dev->node_props.eop_buffer_size) {
    262                         pr_debug("queue eop bo size 0x%lx not equal to node eop buf size 0x%x\n",
    263                                 properties->eop_buf_bo->tbo.base.size,
    264                                 topo_dev->node_props.eop_buffer_size);
--> 265                         goto out_err_unreserve;

This has err in the label name.  err = -EINVAL?

    266                 }
    267                 err = kfd_queue_buffer_get(vm, (void *)properties->eop_ring_buffer_address,
    268                                            &properties->eop_buf_bo,
    269                                            properties->eop_ring_buffer_size);
    270                 if (err)
    271                         goto out_err_unreserve;
    272         }
    273 
    274         if (properties->ctl_stack_size != topo_dev->node_props.ctl_stack_size) {
    275                 pr_debug("queue ctl stack size 0x%x not equal to node ctl stack size 0x%x\n",
    276                         properties->ctl_stack_size,
    277                         topo_dev->node_props.ctl_stack_size);
    278                 goto out_err_unreserve;

err?

    279         }
    280 
    281         if (properties->ctx_save_restore_area_size != topo_dev->node_props.cwsr_size) {
    282                 pr_debug("queue cwsr size 0x%x not equal to node cwsr size 0x%x\n",
    283                         properties->ctx_save_restore_area_size,
    284                         topo_dev->node_props.cwsr_size);
    285                 goto out_err_unreserve;

err?  Not sure.

    286         }
    287 
    288         total_cwsr_size = (topo_dev->node_props.cwsr_size + topo_dev->node_props.debug_memory_size)
    289                           * NUM_XCC(pdd->dev->xcc_mask);
    290         total_cwsr_size = ALIGN(total_cwsr_size, PAGE_SIZE);
    291 
    292         err = kfd_queue_buffer_get(vm, (void *)properties->ctx_save_restore_area_address,
    293                                    &properties->cwsr_bo, total_cwsr_size);
    294         if (!err)
    295                 goto out_unreserve;
    296 
    297         amdgpu_bo_unreserve(vm->root.bo);
    298 
    299         err = kfd_queue_buffer_svm_get(pdd, properties->ctx_save_restore_area_address,
    300                                        total_cwsr_size);
    301         if (err)
    302                 goto out_err_release;
    303 
    304         return 0;
    305 
    306 out_unreserve:
    307         amdgpu_bo_unreserve(vm->root.bo);
    308         return 0;
    309 
    310 out_err_unreserve:
    311         amdgpu_bo_unreserve(vm->root.bo);
    312 out_err_release:
    313         kfd_queue_release_buffers(pdd, properties);
    314         return err;
    315 }

regards,
dan carpenter