Re: [PATCH 2/2] tpm: of: If available Use linux,sml-log to get the log and its size

From: Stefan Berger <stefanb@linux.ibm.com>
To: Jarkko Sakkinen <jarkko@kernel.org>,
	Michael Ellerman <mpe@ellerman.id.au>,
	linux-integrity@vger.kernel.org, linuxppc-dev@lists.ozlabs.org
Cc: linux-kernel@vger.kernel.org, rnsastry@linux.ibm.com,
	peterhuewe@gmx.de, viparash@in.ibm.com
Subject: Re: [PATCH 2/2] tpm: of: If available Use linux,sml-log to get the log and its size
Date: Tue, 12 Mar 2024 15:08:47 -0400	[thread overview]
Message-ID: <e1b818ae-c932-4d25-98a5-26b258b63365@linux.ibm.com> (raw)
In-Reply-To: <CZRW3GY5O5C0.R5HY5SOFCFJA@kernel.org>

On 3/12/24 11:50, Jarkko Sakkinen wrote:
> On Tue Mar 12, 2024 at 12:35 PM EET, Michael Ellerman wrote:
>> Stefan Berger <stefanb@linux.ibm.com> writes:
>>> On 3/7/24 15:00, Jarkko Sakkinen wrote:
>>>> On Thu Mar 7, 2024 at 9:57 PM EET, Jarkko Sakkinen wrote:
>>>>> in short summary: s/Use/use/
>>>>>
>>>>> On Wed Mar 6, 2024 at 5:55 PM EET, Stefan Berger wrote:
>>>>>> If linux,sml-log is available use it to get the TPM log rather than the
>>>>>> pointer found in linux,sml-base. This resolves an issue on PowerVM and KVM
>>>>>> on Power where after a kexec the memory pointed to by linux,sml-base may
>>>>>> have been corrupted. Also, linux,sml-log has replaced linux,sml-base and
>>>>>> linux,sml-size on these two platforms.
>>>>>>
>>>>>> Signed-off-by: Stefan Berger <stefanb@linux.ibm.com>
>>>>>
>>>>> So shouldn't this have a fixed tag, or not?
>>>>
>>>> In English: do we want this to be backported to stable kernel releases or not?
>>>
>>> Ideally, yes. v3 will have 3 patches and all 3 of them will have to be
>>> backported *together* and not applied otherwise if any one of them
>>> fails. Can this be 'guaranteed'?
>>
>> You can use Depends-on: <previous commit SHA> to indicate the relationship.
>>
>> cheers
> 
> Thanks, I've missed depends-on tag.
> 
> Stefan, please add also "Cc: stable@vger.kernel.org" just to make sure
> that I don't forget to add it.

Yeah, once we know whether this is the way forward or not... I posted v2 
as RFC to figure this out.

v2's 2/3 patch will only apply to 6.8. To avoid any inconsistencies 
between code and bindings we cannot even go further back with this 
series (IFF it's the way forward at all). So I am inclined to remove the 
Fixes tags. I also find little under Documentation about the Depends-on 
tag and what it's supposed to be formatted like -- a commit hash of 1/3 
appearing in 2/3 for example? The commit hash is not stable at this 
point so I couldn't created it.

> Right, and since these are so small scoped commits, and bug fixes in
> particular, it is also possible to do PR during the release cycle.
> 
> BR, Jarkko