Re: [PATCH 1/1] tpm/tpm_crb: Fix error message in __crb_relinquish_locality()

From: Jarkko Sakkinen <jarkko@kernel.org>
To: "Michael Kelley (LINUX)" <mikelley@microsoft.com>
Cc: "peterhuewe@gmx.de" <peterhuewe@gmx.de>,
	"jgg@ziepe.ca" <jgg@ziepe.ca>,
	"tomas.winkler@intel.com" <tomas.winkler@intel.com>,
	"linux-integrity@vger.kernel.org"
	<linux-integrity@vger.kernel.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 1/1] tpm/tpm_crb: Fix error message in __crb_relinquish_locality()
Date: Sun, 4 Dec 2022 19:53:45 +0000	[thread overview]
Message-ID: <Y4z6yYHSidjsXABk@kernel.org> (raw)
In-Reply-To: <Y4z6OGSyvJtdVzIi@kernel.org>

On Sun, Dec 04, 2022 at 07:51:20PM +0000, Jarkko Sakkinen wrote:
> On Tue, Nov 29, 2022 at 04:34:09AM +0000, Michael Kelley (LINUX) wrote:
> > From: Jarkko Sakkinen <jarkko@kernel.org> Sent: Sunday, November 27, 2022 8:39 AM
> > > 
> > > On Fri, Nov 11, 2022 at 11:38:53AM -0800, Michael Kelley wrote:
> > > > The error message in __crb_relinquish_locality() mentions requestAccess
> > > > instead of Relinquish. Fix it.
> > > >
> > > > Fixes: 888d867df441 ("tpm: cmd_ready command can be issued only after granting locality")
> > > > Signed-off-by: Michael Kelley <mikelley@microsoft.com>
> > > > ---
> > > >  drivers/char/tpm/tpm_crb.c | 2 +-
> > > >  1 file changed, 1 insertion(+), 1 deletion(-)
> > > >
> > > > diff --git a/drivers/char/tpm/tpm_crb.c b/drivers/char/tpm/tpm_crb.c
> > > > index 1860665..65f8f17 100644
> > > > --- a/drivers/char/tpm/tpm_crb.c
> > > > +++ b/drivers/char/tpm/tpm_crb.c
> > > > @@ -252,7 +252,7 @@ static int __crb_relinquish_locality(struct device *dev,
> > > >  	iowrite32(CRB_LOC_CTRL_RELINQUISH, &priv->regs_h->loc_ctrl);
> > > >  	if (!crb_wait_for_reg_32(&priv->regs_h->loc_state, mask, value,
> > > >  				 TPM2_TIMEOUT_C)) {
> > > > -		dev_warn(dev, "TPM_LOC_STATE_x.requestAccess timed out\n");
> > > > +		dev_warn(dev, "TPM_LOC_STATE_x.Relinquish timed out\n");
> > > >  		return -ETIME;
> > > >  	}
> > > >
> > > > --
> > > > 1.8.3.1
> > > >
> > > 
> > > Please explain.
> > > 
> > 
> > There are two parallel functions:  __crb_request_locality() and
> > __crb_relinquish_locality().  In the current code, both return the
> > same text in the error message if a timeout occurs.  That
> > error message seems appropriate for __crb_request_locality()
> > since it is setting the "requestAccess" bit.
> > 
> > But the error message seems inappropriate for
> > __crb_relinquish_locality(), which is setting the "Relinquish" bit.
> > So the patch changes the error message to indicate that the
> > timeout occurred in setting the Relinquish bit.
> > 
> > I'm looking at Section 6.5.3.2.2.1 in the TCG PC Client Platform
> > TPM Profile Specification for TPM 2.0, Version 1.05 Revision 14.
> > This is where the "requestAccess" and "Relinquish" bits are defined.
> > 
> > Or maybe I am not understanding what you are getting at with
> > "Please explain."
> 
> I misread the callback name, when I first looked into this (in
> too much rush). You're absolutely correct.
> 
> Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>

Applied to git://git.kernel.org/pub/scm/linux/kernel/git/jarkko/linux-tpmdd.git

BR, Jarkko