Re: [tip:x86/urgent] x86/acpi: Prevent LAPIC id 0xff from being accounted

Re: [tip:x86/urgent] x86/acpi: Prevent LAPIC id 0xff from being accounted

[Yinghai Lu]

On Fri, Oct 7, 2016 at 6:28 AM, tip-bot for Thomas Gleixner
<tipbot@zytor.com> wrote:
> Commit-ID:  8237bded3959c6d038798b905485d3ba94b8ea10
> Gitweb:     http://git.kernel.org/tip/8237bded3959c6d038798b905485d3ba94b8ea10
> Author:     Thomas Gleixner <tglx@linutronix.de>
> AuthorDate: Fri, 7 Oct 2016 14:02:12 +0200
> Committer:  Thomas Gleixner <tglx@linutronix.de>
> CommitDate: Fri, 7 Oct 2016 15:22:15 +0200
>
> x86/acpi: Prevent LAPIC id 0xff from being accounted
>
> Yinghai reported that the recent changes to make the cpuid - nodeid
> relationship permanent causes a cpuid ordering regression on a system which
> has 2apic enabled..
>
> The reason is that the ACPI local APIC parser has no sanity check for
> apicid 0xff, which is an invalid id. So a CPU id for this invalid local
> APIC id is allocated and therefor breaks the cpuid ordering.
>
> Add a sanity check to acpi_parse_lapic() which ignores the invalid id.
>
> Fixes: 8f54969dc8d6 ("x86/acpi: Introduce persistent storage for cpuid <-> apicid mapping")
> Reported-by: Yinghai Lu <yinghai@kernel.org>
> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
> Cc: Gu Zheng <guz.fnst@cn.fujitsu.com>,
> Cc: Tang Chen <tangchen@cn.fujitsu.com>
> Cc: douly.fnst@cn.fujitsu.com,
> Cc: zhugh.fnst@cn.fujitsu.com
> Cc: Tony Luck <tony.luck@intel.com>
> Cc: Rafael J. Wysocki <rjw@rjwysocki.net>
> Cc: Len Brown <lenb@kernel.org>
> Cc: Lv Zheng <lv.zheng@intel.com>,
> Cc: robert.moore@intel.com
> Cc: linux-acpi@vger.kernel.org
> Link: https://lkml.kernel.org/r/CAE9FiQVQx6FRXT-RdR7Crz4dg5LeUWHcUSy1KacjR+JgU_vGJg@mail.gmail.com
> ---
>  arch/x86/kernel/acpi/boot.c | 3 +++
>  1 file changed, 3 insertions(+)
>
> diff --git a/arch/x86/kernel/acpi/boot.c b/arch/x86/kernel/acpi/boot.c
> index 32a7d70..6d35baf 100644
> --- a/arch/x86/kernel/acpi/boot.c
> +++ b/arch/x86/kernel/acpi/boot.c
> @@ -233,6 +233,9 @@ acpi_parse_lapic(struct acpi_subtable_header * header, const unsigned long end)
>
>         acpi_table_print_madt_entry(header);
>
> +       if (processor->id >= 0xff)
> +               return -EINVAL;
> +
>         /*
>          * We need to register disabled CPU as well to permit
>          * counting disabled CPUs. This allows us to size


some thing is wrong:

[   71.787437] ACPI: LAPIC (acpi_id[0xff] lapic_id[0xff] disabled)
[   71.799681] ACPI: Error parsing LAPIC/X2APIC entries
[   71.809934] ACPI: Invalid BIOS MADT, disabling ACPI

looks like should change
   return -EINVAL ;
==>
   return 0;

Re: [tip:x86/urgent] x86/acpi: Prevent LAPIC id 0xff from being accounted

[Yinghai Lu]

On Fri, Oct 7, 2016 at 10:26 PM, Yinghai Lu <yinghai@kernel.org> wrote:
> On Fri, Oct 7, 2016 at 6:28 AM, tip-bot for Thomas Gleixner
>> diff --git a/arch/x86/kernel/acpi/boot.c b/arch/x86/kernel/acpi/boot.c
>> index 32a7d70..6d35baf 100644
>> --- a/arch/x86/kernel/acpi/boot.c
>> +++ b/arch/x86/kernel/acpi/boot.c
>> @@ -233,6 +233,9 @@ acpi_parse_lapic(struct acpi_subtable_header * header, const unsigned long end)
>>
>>         acpi_table_print_madt_entry(header);
>>
>> +       if (processor->id >= 0xff)
>> +               return -EINVAL;
>> +
>>         /*
>>          * We need to register disabled CPU as well to permit
>>          * counting disabled CPUs. This allows us to size
>
>
> some thing is wrong:
>
> [   71.787437] ACPI: LAPIC (acpi_id[0xff] lapic_id[0xff] disabled)
> [   71.799681] ACPI: Error parsing LAPIC/X2APIC entries
> [   71.809934] ACPI: Invalid BIOS MADT, disabling ACPI
>
> looks like should change
>    return -EINVAL ;
> ==>
>    return 0;

also processor->id is u8,

so the patch should be:

>> +       if (processor->id == 0xff)
>> +               return -EINVAL;
>> +

Re: [tip:x86/urgent] x86/acpi: Prevent LAPIC id 0xff from being accounted

[Yinghai Lu]

On Fri, Oct 7, 2016 at 10:33 PM, Yinghai Lu <yinghai@kernel.org> wrote:
> On Fri, Oct 7, 2016 at 10:26 PM, Yinghai Lu <yinghai@kernel.org> wrote:
>> On Fri, Oct 7, 2016 at 6:28 AM, tip-bot for Thomas Gleixner
>>> diff --git a/arch/x86/kernel/acpi/boot.c b/arch/x86/kernel/acpi/boot.c
>>> index 32a7d70..6d35baf 100644
>>> --- a/arch/x86/kernel/acpi/boot.c
>>> +++ b/arch/x86/kernel/acpi/boot.c
>>> @@ -233,6 +233,9 @@ acpi_parse_lapic(struct acpi_subtable_header * header, const unsigned long end)
>>>
>>>         acpi_table_print_madt_entry(header);
>>>
>>> +       if (processor->id >= 0xff)
>>> +               return -EINVAL;
>>> +
>>>         /*
>>>          * We need to register disabled CPU as well to permit
>>>          * counting disabled CPUs. This allows us to size
>>
>>
>> some thing is wrong:
>>
>> [   71.787437] ACPI: LAPIC (acpi_id[0xff] lapic_id[0xff] disabled)
>> [   71.799681] ACPI: Error parsing LAPIC/X2APIC entries
>> [   71.809934] ACPI: Invalid BIOS MADT, disabling ACPI
>>
>> looks like should change
>>    return -EINVAL ;
>> ==>
>>    return 0;
>
> also processor->id is u8,
>
> so the patch should be:

+       if (processor->id == 0xff)
+               return 0;
+

Re: [tip:x86/urgent] x86/acpi: Prevent LAPIC id 0xff from being accounted

[Thomas Gleixner]

On Fri, 7 Oct 2016, Yinghai Lu wrote:
> On Fri, Oct 7, 2016 at 10:33 PM, Yinghai Lu <yinghai@kernel.org> wrote:
> > On Fri, Oct 7, 2016 at 10:26 PM, Yinghai Lu <yinghai@kernel.org> wrote:
> >> On Fri, Oct 7, 2016 at 6:28 AM, tip-bot for Thomas Gleixner
> >>> diff --git a/arch/x86/kernel/acpi/boot.c b/arch/x86/kernel/acpi/boot.c
> >>> index 32a7d70..6d35baf 100644
> >>> --- a/arch/x86/kernel/acpi/boot.c
> >>> +++ b/arch/x86/kernel/acpi/boot.c
> >>> @@ -233,6 +233,9 @@ acpi_parse_lapic(struct acpi_subtable_header * header, const unsigned long end)
> >>>
> >>>         acpi_table_print_madt_entry(header);
> >>>
> >>> +       if (processor->id >= 0xff)
> >>> +               return -EINVAL;
> >>> +
> >>>         /*
> >>>          * We need to register disabled CPU as well to permit
> >>>          * counting disabled CPUs. This allows us to size
> >>
> >>
> >> some thing is wrong:
> >>
> >> [   71.787437] ACPI: LAPIC (acpi_id[0xff] lapic_id[0xff] disabled)
> >> [   71.799681] ACPI: Error parsing LAPIC/X2APIC entries
> >> [   71.809934] ACPI: Invalid BIOS MADT, disabling ACPI
> >>
> >> looks like should change
> >>    return -EINVAL ;
> >> ==>
> >>    return 0;

Indeed.

> >
> > also processor->id is u8,
> >
> > so the patch should be:
> 
> +       if (processor->id == 0xff)
> +               return 0;
> +

Right. Amended the patch and pushed it out.

Thanks for pointing it out,

       tglx