Re: [PATCH] tpm_tis: verify locality released before returning from release_locality

[Jerry Snitselaar]

On Mon May 28 18, Laurent Bigonville wrote:
> Hello,
>
> Top posting, sorry.
>
> I don't know if I did it well to include the "Tested-by" tag because I 
> don't see that the patch has landed in linus branch already.
>
> And as far as I understand, this will not be in the upcoming 4.17 
> release as we are already late in the cycle?
>
> Kind regards,
>
> Laurent Bigonville

It should go into his branch during the merge window for 4.18.

> Le 11/05/18 à 21:02, Laurent Bigonville a écrit :
> > Le 05/05/18 à 22:03, Jerry Snitselaar a écrit :
> > > On Sat May 05 18, Jerry Snitselaar wrote:
> > > > For certain tpm chips releasing locality can take long enough that a
> > > > subsequent call to request_locality will see the locality as being
> > > > active when the access register is read in check_locality. So check
> > > > that the locality has been released before returning from
> > > > release_locality.
> > > >
> > > > Cc: Jarkko Sakkinen <jarkko.sakkinen@xxxxxxxxxxxxxxx>
> > > > Cc: Peter Huewe <peterhuewe@xxxxxx>
> > > > Cc: Jason Gunthorpe <jgg@xxxxxxxx>
> > > > Reported-by: Laurent Bigonville <bigon@xxxxxxxxxx>
> > > > Signed-off-by: Jerry Snitselaar <jsnitsel@xxxxxxxxxx>
> > Tested-by: Laurent Bigonville <bigon@xxxxxxxxxx>
> > > > ---
> > > > drivers/char/tpm/tpm_tis_core.c | 47 
> > > > ++++++++++++++++++++++++++++++++++++++++-
> > > > 1 file changed, 46 insertions(+), 1 deletion(-)
> > > >
> > > > diff --git a/drivers/char/tpm/tpm_tis_core.c 
> > > > b/drivers/char/tpm/tpm_tis_core.c
> > > > index 5a1f47b43947..d547cd309dbd 100644
> > > > --- a/drivers/char/tpm/tpm_tis_core.c
> > > > +++ b/drivers/char/tpm/tpm_tis_core.c
> > > > @@ -143,13 +143,58 @@ static bool check_locality(struct tpm_chip 
> > > > *chip, int l)
> > > >     return false;
> > > > }
> > > >
> > > > +static bool locality_inactive(struct tpm_chip *chip, int l)
> > > > +{
> > > > +    struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
> > > > +    int rc;
> > > > +    u8 access;
> > > > +
> > > > +    rc = tpm_tis_read8(priv, TPM_ACCESS(l), &access);
> > > > +    if (rc < 0)
> > > > +        return false;
> > > > +
> > > > +    if ((access & (TPM_ACCESS_VALID | TPM_ACCESS_ACTIVE_LOCALITY))
> > > > +        == TPM_ACCESS_VALID)
> > > > +        return true;
> > > > +
> > > > +    return false;
> > > > +}
> > > > +
> > > > static int release_locality(struct tpm_chip *chip, int l)
> > > > {
> > > >     struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
> > > > +    unsigned long stop, timeout;
> > > > +    long rc;
> > > >
> > > >     tpm_tis_write8(priv, TPM_ACCESS(l), TPM_ACCESS_ACTIVE_LOCALITY);
> > > >
> > > > -    return 0;
> > > > +    stop = jiffies + chip->timeout_a;
> > > > +
> > > > +    if (chip->flags & TPM_CHIP_FLAG_IRQ) {
> > > > +again:
> > > > +        timeout = stop - jiffies;
> > > > +        if ((long)timeout <= 0)
> > > > +            return -1;
> > > > +
> > > > +        rc = wait_event_interruptible_timeout(priv->int_queue,
> > > > +                              (locality_inactive(chip, l)),
> > > > +                              timeout);
> > > > +
> > > > +        if (rc > 0)
> > > > +            return 0;
> > > > +
> > > > +        if (rc == -ERESTARTSYS && freezing(current)) {
> > > > +            clear_thread_flag(TIF_SIGPENDING);
> > > > +            goto again;
> > > > +        }
> > > > +    } else {
> > > > +        do {
> > > > +            if (locality_inactive(chip, l))
> > > > +                return 0;
> > > > +            tpm_msleep(TPM_TIMEOUT);
> > > > +        } while (time_before(jiffies, stop));
> > > > +    }
> > > > +    return -1;
> > > > }
> > > >
> > > > static int request_locality(struct tpm_chip *chip, int l)
> > > > --
> > > > 2.15.0
> > >
> > > Laurent,
> > >
> > > Can you try this patch with your system since it is the one
> > > that has exhibited the problem so far. I've tested on a
> > > tpm2.0 and tpm1.2 system here.
> > >
> > > Regards,
> > > Jerry