Re: [PATCH v11 00/16] Remove nested TPM operations

[Alexander Steffen]

On 08.02.2019 03:14, Stefan Berger wrote:
> On 2/7/19 8:51 PM, Stefan Berger wrote:
> > On 2/7/19 7:33 PM, Jarkko Sakkinen wrote:
> > > On Thu, Feb 07, 2019 at 06:29:43PM -0500, Stefan Berger wrote:
> > > > On 2/7/19 4:29 PM, Jarkko Sakkinen wrote:
> >
> >
> > > > diff --git a/drivers/char/tpm/tpm2-cmd.c b/drivers/char/tpm/tpm2-cmd.c
> > > > index e74c5b7b64bf..52afe20cc8a1 100644
> > > > --- a/drivers/char/tpm/tpm2-cmd.c
> > > > +++ b/drivers/char/tpm/tpm2-cmd.c
> > > > @@ -799,7 +799,9 @@ int tpm2_probe(struct tpm_chip *chip)
> > > > ÂÂÂÂÂ tpm_buf_append_u32(&buf, TPM2_CAP_TPM_PROPERTIES);
> > > > ÂÂÂÂÂ tpm_buf_append_u32(&buf, TPM_PT_TOTAL_COMMANDS);
> > > > ÂÂÂÂÂ tpm_buf_append_u32(&buf, 1);
> > > > +ÂÂÂ tpm_chip_start(chip);
> > > > ÂÂÂÂÂ rc = tpm_transmit_cmd(chip, &buf, 0, NULL);
> > > > +ÂÂÂ tpm_chip_stop(chip);
> > > Thanks Stefan! I added call to tpm_tis_core as tpm2-cmd.c is to be kept
> > > out of chip management common case being that you call 
> > > tpm_try_get_ops(),
> > > do 1-N TPM commands and release with tpm_put_ops(). These functions take
> > > care starting and stopping the chip.
> > >
> > > I fixed the 2nd issue in the master.
> >
> > You also need to export the tpm_chip_start/stop symbols.
> >
> >
> > Master now seems to (still) have a problem when rmmod'ing:
> >
> > A TPM error (325) occurred stopping the TPM. This happens at the same 
> > patch where I had to add the tpm_chip_start/stop above.
>
> Here's my current overall patch against your master. I suppose the other 
> tpm2_shutdown() for power management doesn't need the chip start ?
>
> diff --git a/drivers/char/tpm/tpm-chip.c b/drivers/char/tpm/tpm-chip.c
> index 9865776ee2cd..f7147706a9c3 100644
> --- a/drivers/char/tpm/tpm-chip.c
> +++ b/drivers/char/tpm/tpm-chip.c
> @@ -115,6 +115,7 @@ int tpm_chip_start(struct tpm_chip *chip)
>
>  ÂÂÂÂ return 0;
>  Â}
> +EXPORT_SYMBOL_GPL(tpm_chip_start);
>
>  Â/**
>  Â * tpm_chip_stop() - power off the TPM
> @@ -131,7 +132,7 @@ void tpm_chip_stop(struct tpm_chip *chip)
>  ÂÂÂÂ if (chip->ops->clk_enable)
>  ÂÂÂÂ ÂÂÂ chip->ops->clk_enable(chip, false);
>  Â}
> -
> +EXPORT_SYMBOL_GPL(tpm_chip_stop);
>
>  Â/**
>  Â * tpm_try_get_ops() - Get a ref to the tpm_chip
> @@ -474,8 +475,11 @@ static void tpm_del_char_device(struct tpm_chip *chip)
>
>  ÂÂÂÂ /* Make the driver uncallable. */
>  ÂÂÂÂ down_write(&chip->ops_sem);
> -ÂÂÂ if (chip->flags & TPM_CHIP_FLAG_TPM2)
> +ÂÂÂ if (chip->flags & TPM_CHIP_FLAG_TPM2) {
> +ÂÂÂ ÂÂÂ tpm_chip_start(chip, 0);
>  ÂÂÂÂ ÂÂÂ tpm2_shutdown(chip, TPM2_SU_CLEAR);
> +ÂÂÂ ÂÂÂ tpm_chip_stop(chip, 0);
> +ÂÂÂ }
>  ÂÂÂÂ chip->ops = NULL;
>  ÂÂÂÂ up_write(&chip->ops_sem);
>  Â}
> diff --git a/drivers/char/tpm/tpm-interface.c 
> b/drivers/char/tpm/tpm-interface.c
> index 02e8cffd1163..fcd845ad8c3c 100644
> --- a/drivers/char/tpm/tpm-interface.c
> +++ b/drivers/char/tpm/tpm-interface.c
> @@ -124,6 +124,8 @@ static ssize_t tpm_try_transmit(struct tpm_chip 
> *chip, void *buf, size_t bufsiz)
>  ÂÂÂÂ ÂÂÂ dev_err(&chip->dev, "tpm_transmit: tpm_recv: error %d\n", rc);
>  ÂÂÂÂ } else if (len < TPM_HEADER_SIZE || len != 
> be32_to_cpu(header->length))
>  ÂÂÂÂ ÂÂÂ rc = -EFAULT;
> +ÂÂÂ else
> +ÂÂÂ ÂÂÂ rc = 0;
>
>  ÂÂÂÂ return rc ? rc : len;
>  Â}

Applying those changes fixes all the issues I saw, thanks. I'll retest 
Jarkko's tree without custom patches, once you've agreed on the rc question.

Alexander