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author | 2022-06-03 10:41:58 +0200 | |
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committer | 2022-08-03 23:56:19 +0300 | |
commit | 5e3a3f27cbded417e6d1ea2bb9739b572c09580e (patch) | |
tree | cecaa173565ccfad09d852989a2477d9d23fbbcf /drivers/char/tpm/tpm1-cmd.c | |
parent | Merge tag 'pull-work.dcache' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs (diff) | |
download | linux-dev-5e3a3f27cbded417e6d1ea2bb9739b572c09580e.tar.xz linux-dev-5e3a3f27cbded417e6d1ea2bb9739b572c09580e.zip |
tpm: Add upgrade/reduced mode support for TPM1.2 modules
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@infineon.com>
Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
Diffstat (limited to '')
-rw-r--r-- | drivers/char/tpm/tpm1-cmd.c | 7 |
1 files changed, 6 insertions, 1 deletions
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; } |