# Re: \[PATCH v5 1/1\] tpm: add sysfs exports for all banks of PCR registers

- From: Jarkko Sakkinen \<jarkko@kernel.org\>
- Date: 2021-01-14 02:12:20 
- List: linux-api
- Page: https://ratatoskr.run/linux-api/2021/01/13329985
- Thread: https://ratatoskr.run/linux-integrity/2021/01/13329974/t.md

```text
On Wed, Jan 13, 2021 at 09:31:44AM -0800, James Bottomley wrote:
> On Wed, 2021-01-13 at 08:48 +0100, Greg KH wrote:
> > On Tue, Jan 12, 2021 at 05:59:58PM -0800, James Bottomley wrote:
> > > Create sysfs per hash groups with 24 PCR files in them one group,
> > > named pcr-<hash>, for each agile hash of the TPM.  The files are
> > > plugged in to a PCR read function which is TPM version agnostic, so
> > > this works also for TPM 1.2 but the hash is only sha1 in that case.
> > > 
> > > Note: the macros used to create the hashes emit spurious checkpatch
> > > warnings.  Do not try to "fix" them as checkpatch recommends,
> > > otherwise
> > > they'll break.
> > > 
> > > Signed-off-by: James Bottomley <
> > > James.Bottomley@HansenPartnership.com>
> > > Reviewed-by: Jerry Snitselaar <redacted>
> > > Tested-by: Thiago Jung Bauermann <redacted>
> > > 
> > > ---
> > > 
> > > v2: fix TPM 1.2 legacy links failure
> > > v3: fix warn on and add note to tpm_algorithms
> > > v4: reword commit and add tested-by
> > > v5: algorithm spelling fix WARN->dev_err
> > > ---
> > >  drivers/char/tpm/tpm-sysfs.c | 179
> > > +++++++++++++++++++++++++++++++++++
> > >  include/linux/tpm.h          |   9 +-
> > >  2 files changed, 187 insertions(+), 1 deletion(-)
> > 
> > You add new sysfs files, but do not add Documentation/ABI/ entries
> > showing how they are used and what they contain :(
> > 
> > Please do that for the next version of this patch.
> 
> It's a bit of a chicken and egg problem since I've no idea when this
> will go upstream and the entries require that information making the
> ABI more of a post accept type thing.  I can make a guess about the
> values if Jarkko is going to but this in for the next merge window.
> 
> James

I agree with the ABI side, so you can safely include this to the patch set. 
And yes, this looks like something I can include to the 5.12 PR.

Did you address Greg's remarks about warns?

Other than that, please send a version with ABI entries  so that
we can move forward with this.

/Jarkko
```