[bug report] ASoC: SOF: ipc4-loader: Support for loading external libraries

[Dan Carpenter]

Hello Peter Ujfalusi,

The patch 73c091a2fe96: "ASoC: SOF: ipc4-loader: Support for loading
external libraries" from Oct 20, 2022, leads to the following Smatch
static checker warning:

	sound/soc/sof/ipc4-loader.c:207 sof_ipc4_load_library_by_uuid()
	warn: 'payload_offset' unsigned <= 0

sound/soc/sof/ipc4-loader.c
    167 static int sof_ipc4_load_library_by_uuid(struct snd_sof_dev *sdev,
    168                                          unsigned long lib_id, const guid_t *uuid)
    169 {
    170         struct sof_ipc4_fw_data *ipc4_data = sdev->private;
    171         struct sof_ipc4_fw_library *fw_lib;
    172         const char *fw_filename;
    173         size_t payload_offset;
                ^^^^^^^^^^^^^^^^^^^^^

    174         int ret, i, err;
    175 
    176         if (!sdev->pdata->fw_lib_prefix) {
    177                 dev_err(sdev->dev,
    178                         "Library loading is not supported due to not set library path\n");
    179                 return -EINVAL;
    180         }
    181 
    182         if (!ipc4_data->load_library) {
    183                 dev_err(sdev->dev, "Library loading is not supported on this platform\n");
    184                 return -EOPNOTSUPP;
    185         }
    186 
    187         fw_lib = devm_kzalloc(sdev->dev, sizeof(*fw_lib), GFP_KERNEL);
    188         if (!fw_lib)
    189                 return -ENOMEM;
    190 
    191         fw_filename = kasprintf(GFP_KERNEL, "%s/%pUL.bin",
    192                                 sdev->pdata->fw_lib_prefix, uuid);
    193         if (!fw_filename) {
    194                 ret = -ENOMEM;
    195                 goto free_fw_lib;
    196         }
    197 
    198         ret = request_firmware(&fw_lib->sof_fw.fw, fw_filename, sdev->dev);
    199         if (ret < 0) {
    200                 dev_err(sdev->dev, "Library file '%s' is missing\n", fw_filename);
    201                 goto free_filename;
    202         } else {
    203                 dev_dbg(sdev->dev, "Library file '%s' loaded\n", fw_filename);
    204         }
    205 
    206         payload_offset = sof_ipc4_fw_parse_ext_man(sdev, fw_lib);
--> 207         if (payload_offset <= 0) {
                    ^^^^^^^^^^^^^^^^^^^
sof_ipc4_fw_parse_ext_man() returns negative error codes but as size_t.
It should just return int.  If it returns > INT_MAX that can't work on
32bit systems.

    208                 if (!payload_offset)
    209                         ret = -EINVAL;
    210                 else
    211                         ret = payload_offset;
    212 
    213                 goto release;
    214         }
    215 
    216         fw_lib->sof_fw.payload_offset = payload_offset;
    217         fw_lib->id = lib_id;
    218 
    219         /* Fix up the module ID numbers within the library */
    220         for (i = 0; i < fw_lib->num_modules; i++)
    221                 fw_lib->modules[i].man4_module_entry.id |= (lib_id << SOF_IPC4_MOD_LIB_ID_SHIFT);
    222 
    223         /*
    224          * Make sure that the DSP is booted and stays up while attempting the
    225          * loading the library for the first time
    226          */
    227         ret = pm_runtime_resume_and_get(sdev->dev);
    228         if (ret < 0 && ret != -EACCES) {
    229                 dev_err_ratelimited(sdev->dev, "%s: pm_runtime resume failed: %d\n",
    230                                     __func__, ret);
    231                 goto release;
    232         }
    233 
    234         ret = ipc4_data->load_library(sdev, fw_lib, false);
    235 
    236         pm_runtime_mark_last_busy(sdev->dev);
    237         err = pm_runtime_put_autosuspend(sdev->dev);
    238         if (err < 0)
    239                 dev_err_ratelimited(sdev->dev, "%s: pm_runtime idle failed: %d\n",
    240                                     __func__, err);
    241 
    242         if (ret)
    243                 goto release;
    244 
    245         ret = xa_insert(&ipc4_data->fw_lib_xa, lib_id, fw_lib, GFP_KERNEL);
    246         if (unlikely(ret))
    247                 goto release;
    248 
    249         kfree(fw_filename);
    250 
    251         return 0;
    252 
    253 release:
    254         release_firmware(fw_lib->sof_fw.fw);
    255         /* Allocated within sof_ipc4_fw_parse_ext_man() */
    256         devm_kfree(sdev->dev, fw_lib->modules);
    257 free_filename:
    258         kfree(fw_filename);
    259 free_fw_lib:
    260         devm_kfree(sdev->dev, fw_lib);
    261 
    262         return ret;
    263 }

regards,
dan carpenter