On Mon, Jul 22, 2024 at 04:06:58PM +0200, Pierre-Louis Bossart wrote:
> Thanks Dan for the report.
>
>
> > Commit f87b4402163b ("ASoC: Intel: cht_bsw_rt5645: Set
> > card.components string") from Nov 26, 2023 (linux-next), leads to the
> > following Smatch static checker warning:
> >
> > sound/soc/intel/boards/cht_bsw_rt5645.c:587 snd_cht_mc_probe()
> > error: we previously assumed 'adev' could be null (see line 581)
> >
> > sound/soc/intel/boards/cht_bsw_rt5645.c
> > 570 /* set correct codec name */
> > 571 for (i = 0; i < ARRAY_SIZE(cht_dailink); i++)
> > 572 if (cht_dailink[i].codecs->name &&
> > 573 !strcmp(cht_dailink[i].codecs->name,
> > 574 "i2c-10EC5645:00")) {
> > 575 dai_index = i;
> > 576 break;
> > 577 }
> > 578
> > 579 /* fixup codec name based on HID */
> > 580 adev = acpi_dev_get_first_match_dev(mach->id, NULL, -1);
> > 581 if (adev) {
> > ^^^^
> > The old code assumes adev can be NULL
> >
> > 582 snprintf(cht_rt5645_codec_name, sizeof(cht_rt5645_codec_name),
> > 583 "i2c-%s", acpi_dev_name(adev));
> > 584 cht_dailink[dai_index].codecs->name = cht_rt5645_codec_name;
> > 585 }
> > 586 /* acpi_get_first_physical_node() returns a borrowed ref, no need to deref */
> > --> 587 codec_dev = acpi_get_first_physical_node(adev);
> > ^^^^
> > Unchecked dereference
>
> This looks like a problem in multiple machine drivers sharing similar
> code, if we want to consistently check the output we probably need
> something like https://github.com/thesofproject/linux/pull/5117 ?
>
These are actually Smatch warnings, not Sparse warnings btw. (Smatch
uses Sparse as a parser. Everyone gets them mixed up).
regards,
dan carpenter
