# Re: \[PATCH v3\] acpi: Extend TPM2 ACPI table with missing log fields

- From: Stefan Berger \<stefanb@linux.ibm.com\>
- Date: 2020-06-23 11:28:01 
- List: linux-security-module
- Page: https://ratatoskr.run/linux-security-module/2020/06/6010754
- Thread: https://ratatoskr.run/linux-integrity/2020/03/5913764/t.md

```text
On 6/22/20 8:56 PM, Jarkko Sakkinen wrote:
> On Fri, Jun 19, 2020 at 11:14:20AM -0400, Stefan Berger wrote:
>> On 4/2/20 3:21 PM, Jarkko Sakkinen wrote:
>>> On Wed, Apr 01, 2020 at 11:05:36AM +0200, Rafael J. Wysocki wrote:
>>>> On Wed, Apr 1, 2020 at 10:37 AM Jarkko Sakkinen
>>>> [ref] wrote:
>>>>> On Tue, Mar 31, 2020 at 05:49:49PM -0400, Stefan Berger wrote:
>>>>>> From: Stefan Berger <stefanb@linux.ibm.com>
>>>>>>
>>>>>> Recent extensions of the TPM2 ACPI table added 3 more fields
>>>>>> including 12 bytes of start method specific parameters and Log Area
>>>>>> Minimum Length (u32) and Log Area Start Address (u64). So, we extend
>>>>>> the existing structure with these fields to allow non-UEFI systems
>>>>>> to access the TPM2's log.
>>>>>>
>>>>>> The specification that has the new fields is the following:
>>>>>>     TCG ACPI Specification
>>>>>>     Family "1.2" and "2.0"
>>>>>>     Version 1.2, Revision 8
>>>>>>
>>>>>> Adapt all existing table size calculations to use
>>>>>> offsetof(struct acpi_table_tpm2, start_method_specific)
>>>>>> [where start_method_specific is a newly added field]
>>>>>> rather than sizeof(struct acpi_table_tpm2) so that the addition
>>>>>> of the new fields does not affect current systems that may not
>>>>>> have them.
>>>>>>
>>>>>> Signed-off-by: Stefan Berger <stefanb@linux.ibm.com>
>>>>>> Cc: <redacted>
>>>>> I think I'm cool with this but needs an ack from ACPI maintainer.
>>>>>
>>>>> Rafael, given that this not an intrusive change in any possible means,
>>>>> can I pick this patch and put it to my next pull request?
>>>> Yes, please.
>>>>
>>>> Thanks!
>>> Great, thanks Rafael.
>>>
>>> Reviewed-by: Jarkko Sakkinen <redacted>
>>>
>>> Do you mind if I add your ack to the commit?
>>
>> Any chance to get v4 applied?
> You should split the actbl3.h change to a separate patch and add 'Cc:'
> tag to Rafael to the commit message.

I did this in one patch because it seems like a mistake to extend the structure and not modify the size checks.

  Stefan

>
> /Jarkko


```