RE: [PATCH v5 12/21] tpm: move pcr extend code to tpm2-cmd.c

From: Winkler, Tomas
Date: Thu Oct 04 2018 - 07:45:49 EST




> -----Original Message-----
> From: Jarkko Sakkinen [mailto:jarkko.sakkinen@xxxxxxxxxxxxxxx]
> Sent: Thursday, October 04, 2018 14:35
> To: Winkler, Tomas <tomas.winkler@xxxxxxxxx>
> Cc: Jason Gunthorpe <jgg@xxxxxxxx>; Nayna Jain
> <nayna@xxxxxxxxxxxxxxxxxx>; Usyskin, Alexander
> <alexander.usyskin@xxxxxxxxx>; Struk, Tadeusz <tadeusz.struk@xxxxxxxxx>;
> linux-integrity@xxxxxxxxxxxxxxx; linux-security-module@xxxxxxxxxxxxxxx;
> linux-kernel@xxxxxxxxxxxxxxx; roberto.sassu@xxxxxxxxxx
> Subject: Re: [PATCH v5 12/21] tpm: move pcr extend code to tpm2-cmd.c
>
> On Wed, Oct 03, 2018 at 10:24:09PM +0000, Winkler, Tomas wrote:
> >
> >
> > > -----Original Message-----
> > > From: Jarkko Sakkinen [mailto:jarkko.sakkinen@xxxxxxxxxxxxxxx]
> > > Sent: Wednesday, October 03, 2018 15:02
> > > To: Winkler, Tomas <tomas.winkler@xxxxxxxxx>
> > > Cc: Jason Gunthorpe <jgg@xxxxxxxx>; Nayna Jain
> > > <nayna@xxxxxxxxxxxxxxxxxx>; Usyskin, Alexander
> > > <alexander.usyskin@xxxxxxxxx>; Struk, Tadeusz
> > > <tadeusz.struk@xxxxxxxxx>; linux-integrity@xxxxxxxxxxxxxxx;
> > > linux-security-module@xxxxxxxxxxxxxxx;
> > > linux-kernel@xxxxxxxxxxxxxxx; roberto.sassu@xxxxxxxxxx
> > > Subject: Re: [PATCH v5 12/21] tpm: move pcr extend code to
> > > tpm2-cmd.c
> > >
> > > On Tue, Oct 02, 2018 at 04:58:25AM +0000, Winkler, Tomas wrote:
> > > >
> > > >
> > > > >
> > > > > On Sat, Sep 29, 2018 at 01:30:26AM +0300, Tomas Winkler wrote:
> > > > > > Add tpm2_pcr_extend() function to tpm2-cmd.c with signature
> > > > > > required by tpm-interface.c. It wraps the original open code
> > > implementation.
> > > > > > The original original tpm2_pcr_extend() function is renamed to
> > > > > > __tpm2_pcr_extend() and made static, it is called only from
> > > > > > new tpm2_pcr_extend().
> > > > > >
> > > > > > Fix warnings in __tpm2_pcr_extend()
> > > > > > tpm2-cmd.c:251:16: warning: comparison between signed and
> > > > > > unsigned integer expressions [-Wsign-compare]
> > > > > > tpm2-cmd.c:252:17: warning: comparison between signed and
> > > > > > unsigned integer expressions [-Wsign-compare]
> > > > > >
> > > > > > Signed-off-by: Tomas Winkler <tomas.winkler@xxxxxxxxx>
> > > > >
> > > > > We do not want the signature change, especially because as we
> > > > > are working on getting Roberto's changes in and also because it
> > > > > has absolutely a zero gain. Who cares if those functions take
> > > > > different
> > > parameters? I don't.
> > > >
> > > > Yes, we do care this series tries to have a clean cut between 1.x
> > > > and 2.x
> > > specs. Please, let's finish one transformation and then move to another.
> > > > I understand that Roberto will have to rebase anyhow, if this
> > > > series goes in
> > > first, if this is hard I can do it myself, it's trivial.
> > > >
> > > > Tomas
> > >
> > > I'm happy to tune this minor stuff.
> > What minor stuff? This patch is just okay, let's change the API in next
> round.
>
> The patch is not okay because it does a completely unnecessary API change.

There is no API change, in that sense.
The exported API is in tpm-interface.c int tpm_pcr_extend(struct tpm_chip *chip, int pcr_idx, const u8 *hash)
that is used is outside of the tpm reminds the same, only the open coded implementation of tpm2_pcr_extned has moved to
tpm2-cmd.c, This code is not called out of tpm module.
Please review the code again.

Thanks
Tomas