Crash in acpi_ns_validate_handle triggered by soundwire on Linux 5.10

[Marcin Ślusarz]

śr., 27 sty 2021 o 23:02 Pierre-Louis Bossart
<pierre-louis.bossart at linux.intel.com> napisał(a):
> On 1/27/21 1:18 PM, Marcin Ślusarz wrote:
> > śr., 27 sty 2021 o 18:28 Pierre-Louis Bossart
> > <pierre-louis.bossart at linux.intel.com> napisał(a):
> >>> Weird, I can't reproduce this problem with my self-compiled kernel :/
> >>> I don't even see soundwire modules loaded in. Manually loading them of course
> >>> doesn't do much.
> >>>
> >>> Previously I could boot into the "faulty" kernel by using "recovery mode", but
> >>> I can't do that anymore - it crashes too.
> >>>
> >>> Maybe there's some kind of race and this bug depends on some specific
> >>> ordering of events?
> >>
> >> missing Kconfig?
> >> You need CONFIG_SOUNDWIRE and CONFIG_SND_SOC_SOF_INTEL_SOUNDWIRE
> >> selected to enter this sdw_intel_acpi_scan() routine.
> >
> > It was a PEBKAC, but a slightly different one. I won't bore you with
> > (embarrassing) details ;).
> >
> > I reproduced the problem, tested both your and Rafael's patches
> > and the kernel still crashes, with the same stack trace.
> > (Yes, I'm sure I booted the right kernel :)
> >
> > Why "recovery mode" stopped working (or worked previously) is still a mystery.
> >
>
> Thanks Marcin for the information. If you have a consistent failure
> that's better to some extent.
>
> Maybe a bit of explanation of what this routine tries to do:
> when SoundWire is enabled in a system, we need to have the following
> pattern in the DSDT:
>
>      Scope (_SB.PCI0)
>      {
>          Device (HDAS)
>          {
>              Name (_ADR, 0x001F0003)  // _ADR: Address
>          }
>
>
>          Scope (HDAS)
>          {
>              Device (SNDW)
>              {
>                  Name (_ADR, 0x40000000)  // _ADR: Address
>
> The only thing the code does is to walk through the children and check
> if the valid _ADR 0x40000000 is found.
>
> You don't have SoundWire in your device so there should not be any
> children found. I don't see anything in the DSDT that looks like
> _SB.PCI0.HDAS.<something>, so in theory we should not even enter the
> callback.
>
> The error happens in acpi_bus_get_device(), after we read the adr but
> before we check it, so wondering if we shouldn't revert the checks. Can
> you try the diff below? I am not sure why there is a crash and we should
> root-cause this issue, just trying to triangulate what is happening.
>
> diff --git a/drivers/soundwire/intel_init.c b/drivers/soundwire/intel_init.c
> index cabdadb09a1b..6bc87a682fb3 100644
> --- a/drivers/soundwire/intel_init.c
> +++ b/drivers/soundwire/intel_init.c
> @@ -369,13 +369,6 @@ static acpi_status sdw_intel_acpi_cb(acpi_handle
> handle, u32 level,
>          if (ACPI_FAILURE(status))
>                  return AE_OK; /* keep going */
>
> -       if (acpi_bus_get_device(handle, &adev)) {
> -               pr_err("%s: Couldn't find ACPI handle\n", __func__);
> -               return AE_NOT_FOUND;
> -       }
> -
> -       info->handle = handle;
> -
>          /*
>           * On some Intel platforms, multiple children of the HDAS
>           * device can be found, but only one of them is the SoundWire
> @@ -386,6 +379,13 @@ static acpi_status sdw_intel_acpi_cb(acpi_handle
> handle, u32 level,
>          if (FIELD_GET(GENMASK(31, 28), adr) != SDW_LINK_TYPE)
>                  return AE_OK; /* keep going */
>
> +       if (acpi_bus_get_device(handle, &adev)) {
> +               pr_err("%s: Couldn't find ACPI handle\n", __func__);
> +               return AE_NOT_FOUND;
> +       }
> +
> +       info->handle = handle;
> +
>          /* device found, stop namespace walk */
>          return AE_CTRL_TERMINATE;
>   }

still the same crash