Re: [bug report] Bluetooth: btrtl: split the device initialization into smaller parts

[Luis Chamberlain <mcgrof@kernel.org>]

On Fri, Mar 21, 2025 at 05:35:18PM +0300, Dan Carpenter wrote:
> On Mon, Aug 06, 2018 at 11:42:57PM +0300, Dan Carpenter wrote:
> > Hello Martin Blumenstingl,
> > 
> > The patch 26503ad25de8: "Bluetooth: btrtl: split the device
> > initialization into smaller parts" from Aug 2, 2018, leads to the
> > following static checker warning:
> > 
> > 	drivers/bluetooth/btrtl.c:592 btrtl_initialize()
> > 	warn: passing zero to 'ERR_PTR'
> > 
> > drivers/bluetooth/btrtl.c
> >    559          btrtl_dev->fw_len = rtl_load_file(hdev, btrtl_dev->ic_info->fw_name,
> >    560                                            &btrtl_dev->fw_data);
> >    561          if (btrtl_dev->fw_len < 0) {
> >    562                  rtl_dev_err(hdev, "firmware file %s not found\n",
> >    563                              btrtl_dev->ic_info->fw_name);
> >    564                  ret = btrtl_dev->fw_len;
> >    565                  goto err_free;
> >    566          }
> >    567  
> >    568          if (btrtl_dev->ic_info->cfg_name) {
> >    569                  if (postfix) {
> >    570                          snprintf(cfg_name, sizeof(cfg_name), "%s-%s.bin",
> >    571                                   btrtl_dev->ic_info->cfg_name, postfix);
> >    572                  } else {
> >    573                          snprintf(cfg_name, sizeof(cfg_name), "%s.bin",
> >    574                                   btrtl_dev->ic_info->cfg_name);
> >    575                  }
> >    576                  btrtl_dev->cfg_len = rtl_load_file(hdev, cfg_name,
> >    577                                                     &btrtl_dev->cfg_data);
> >    578                  if (btrtl_dev->ic_info->config_needed &&
> >    579                      btrtl_dev->cfg_len <= 0) {
> >                             ^^^^^^^^^^^^^^^^^^^^^^^
> > Assume btrtl_dev->cfg_len == 0
> > 
> 
> This is the length of the firmware file.  Does it make sense for
> request_firmware() to load empty files?  Probably there is a test for
> this in the firmware code which rejects zero length files?

We don't know the size of the file until we try to read it. Although
kernel_read_file_from_path_initns() perhaps should allow for empty
files, I do agree it seems odd to use the firmware API for 0 length
files.

We should extend tools/testing/selftests/firmware/ to check for this.
Care for a patch?

  Luis