On Tue, Jun 07, 2022 at 12:49:11PM +0300, Jarkko Sakkinen wrote:
> On Fri, Jun 03, 2022 at 10:41:58AM +0200, Stefan Mahnke-Hartmann wrote:
> > In case a TPM in failure mode is detected, the TPM should be accessible
> > through a transparent communication channel for analysing purposes (e.g.
> > TPM_GetTestResult) or a field upgrade. Since a TPM in failure mode has
> > similar reduced functionality as in field upgrade mode, the flag
> > TPM_CHIP_FLAG_FIRMWARE_UPGRADE is also valid.
> >
> > As described in TCG TPM Main Part1 Design Principles, Revision 116,
> > chapter 9.2.1. the TPM also allows an update function in case a TPM is
> > in failure mode.
> >
> > If the TPM in failure mode is detected, the function tpm1_auto_startup()
> > sets TPM_CHIP_FLAG_FIRMWARE_UPGRADE flag, which is used later during
> > driver initialization/deinitialization to disable functionality which
> > makes no sense or will fail in the current TPM state. The following
> > functionality is affected:
> > * Do not register TPM as a hwrng
> > * Do not get pcr allocation
> > * Do not register sysfs entries which provide information impossible to
> > obtain in limited mode
> >
> > Signed-off-by: Stefan Mahnke-Hartmann <stefan.mahnke-hartmann@xxxxxxxxxxxx>
> > ---
> > Changelog:
> > * v3:
> > * Change kernel messages
> >
> > drivers/char/tpm/tpm.h | 1 +
> > drivers/char/tpm/tpm1-cmd.c | 7 ++++++-
> > 2 files changed, 7 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h
> > index 2163c6ee0d36..24ee4e1cc452 100644
> > --- a/drivers/char/tpm/tpm.h
> > +++ b/drivers/char/tpm/tpm.h
> > @@ -55,6 +55,7 @@ enum tpm_addr {
> > #define TPM_WARN_DOING_SELFTEST 0x802
> > #define TPM_ERR_DEACTIVATED 0x6
> > #define TPM_ERR_DISABLED 0x7
> > +#define TPM_ERR_FAILEDSELFTEST 0x1C
> > #define TPM_ERR_INVALID_POSTINIT 38
> >
> > #define TPM_TAG_RQU_COMMAND 193
> > diff --git a/drivers/char/tpm/tpm1-cmd.c b/drivers/char/tpm/tpm1-cmd.c
> > index f7dc986fa4a0..cf64c7385105 100644
> > --- a/drivers/char/tpm/tpm1-cmd.c
> > +++ b/drivers/char/tpm/tpm1-cmd.c
> > @@ -709,7 +709,12 @@ int tpm1_auto_startup(struct tpm_chip *chip)
> > if (rc)
> > goto out;
> > rc = tpm1_do_selftest(chip);
> > - if (rc) {
> > + if (rc == TPM_ERR_FAILEDSELFTEST) {
> > + dev_warn(&chip->dev, "TPM self test failed, switching to the firmware upgrade mode\n");
> > + /* A TPM in this state possibly allows or needs a firmware upgrade */
> > + chip->flags |= TPM_CHIP_FLAG_FIRMWARE_UPGRADE;
> > + return 0;
> > + } else if (rc) {
> > dev_err(&chip->dev, "TPM self test failed\n");
> > goto out;
> > }
> > --
> > 2.25.1
> >
>
> I think this looks good now, thanks for patience:
>
> Reviewed-by: Jarkko Sakkinen <jarkko@xxxxxxxxxx>
applied
BR, Jarkko
