Messages in this thread | | | Subject | Re: [PATCH] tpm: Add Upgrade/Reduced mode support for TPM2 modules | From | Borys Movchan <> | Date | Wed, 28 Jul 2021 13:06:53 +0200 |
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On 7/27/21 4:58 AM, Jarkko Sakkinen wrote: > On Mon, Jul 19, 2021 at 03:37:17PM +0200, Borys Movchan wrote: > > On some systems, especially embedded, TPM might start in > > Upgrade/Reduced mode due to the previous failure of a firmware > > upgrade process. Allow the TPM driver to handle such situations > > properly. Enables a possibility for userspace application to > > finalize TPM upgrade or recovery if required. > > > Please add short explanation what you mean by upgrade/reduced mode. > > Maybe for clarity speak about upgrade mode.
I have send v2 patch with updated commit message and some notes.
Hope that would be more clear.
> > > > > Signed-off-by: Borys Movchan <borysmn@axis.com> > > --- > > drivers/char/tpm/tpm-chip.c | 23 +++++++++++++++-------- > > drivers/char/tpm/tpm2-cmd.c | 12 ++++++++++-- > > include/linux/tpm.h | 1 + > > 3 files changed, 26 insertions(+), 10 deletions(-) > > > > diff --git a/drivers/char/tpm/tpm-chip.c b/drivers/char/tpm/tpm-chip.c > > index ddaeceb7e109..ff2367c447fb 100644 > > --- a/drivers/char/tpm/tpm-chip.c > > +++ b/drivers/char/tpm/tpm-chip.c > > @@ -574,20 +574,25 @@ static int tpm_get_pcr_allocation(struct > tpm_chip *chip) > > int tpm_chip_register(struct tpm_chip *chip) > > { > > int rc; > > + bool limited_mode = false; > > > > rc = tpm_chip_start(chip); > > if (rc) > > return rc; > > rc = tpm_auto_startup(chip); > > - if (rc) { > > + if (rc == -EIO) { > > + limited_mode = true; > > + } else if (rc) { > > tpm_chip_stop(chip); > > return rc; > > } > > > > - rc = tpm_get_pcr_allocation(chip); > > - tpm_chip_stop(chip); > > - if (rc) > > - return rc; > > + if (!limited_mode) { > > + rc = tpm_get_pcr_allocation(chip); > > + tpm_chip_stop(chip); > > + if (rc) > > + return rc; > > + } > > > > tpm_sysfs_add_device(chip); > > > > @@ -595,9 +600,11 @@ int tpm_chip_register(struct tpm_chip *chip) > > > > tpm_add_ppi(chip); > > > > - rc = tpm_add_hwrng(chip); > > - if (rc) > > - goto out_ppi; > > + if (!limited_mode) { > > + rc = tpm_add_hwrng(chip); > > + if (rc) > > + goto out_ppi; > > + } > > > > rc = tpm_add_char_device(chip); > > if (rc) > > diff --git a/drivers/char/tpm/tpm2-cmd.c b/drivers/char/tpm/tpm2-cmd.c > > index a25815a6f625..7468353ed67d 100644 > > --- a/drivers/char/tpm/tpm2-cmd.c > > +++ b/drivers/char/tpm/tpm2-cmd.c > > @@ -718,7 +718,8 @@ static int tpm2_startup(struct tpm_chip *chip) > > * sequence > > * @chip: TPM chip to use > > * > > - * Returns 0 on success, < 0 in case of fatal error. > > + * Returns 0 on success, -ENODEV in case of fatal error, > > + * -EIO in case of Reduced/Upgrade mode > > */ > > int tpm2_auto_startup(struct tpm_chip *chip) > > { > > @@ -729,7 +730,10 @@ int tpm2_auto_startup(struct tpm_chip *chip) > > goto out; > > > > rc = tpm2_do_selftest(chip); > > - if (rc && rc != TPM2_RC_INITIALIZE) > > + if (rc == TPM2_RC_UPGRADE) { > > + rc = -EIO; > > + goto out; > > + } else if (rc && rc != TPM2_RC_INITIALIZE) > > goto out; > > > > if (rc == TPM2_RC_INITIALIZE) { > > @@ -743,6 +747,10 @@ int tpm2_auto_startup(struct tpm_chip *chip) > > } > > > > rc = tpm2_get_cc_attrs_tbl(chip); > > + if (rc) { /* Succeeded until here, but failed -> reduced mode */ > > + rc = -EIO; > > + goto out; > > + } > > > > out: > > if (rc > 0) > > diff --git a/include/linux/tpm.h b/include/linux/tpm.h > > index aa11fe323c56..e873c42907f0 100644 > > --- a/include/linux/tpm.h > > +++ b/include/linux/tpm.h > > @@ -207,6 +207,7 @@ enum tpm2_return_codes { > > TPM2_RC_INITIALIZE = 0x0100, /* RC_VER1 */ > > TPM2_RC_FAILURE = 0x0101, > > TPM2_RC_DISABLED = 0x0120, > > + TPM2_RC_UPGRADE = 0x012D, > > TPM2_RC_COMMAND_CODE = 0x0143, > > TPM2_RC_TESTING = 0x090A, /* RC_WARN */ > > TPM2_RC_REFERENCE_H0 = 0x0910, > > -- > > 2.20.1 > > > > > > /Jarkko
Kind regards,
Borys
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