From: Vadim Sukhomlinov sukhomlinov@google.com
commit db4d8cb9c9f2af71c4d087817160d866ed572cc9 upstream.
TPM 2.0 Shutdown involve sending TPM2_Shutdown to TPM chip and disabling future TPM operations. TPM 1.2 behavior was different, future TPM operations weren't disabled, causing rare issues. This patch ensures that future TPM operations are disabled.
Fixes: d1bd4a792d39 ("tpm: Issue a TPM2_Shutdown for TPM2 devices.") Cc: stable@vger.kernel.org Signed-off-by: Vadim Sukhomlinov sukhomlinov@google.com [dianders: resolved merge conflicts with mainline] Signed-off-by: Douglas Anderson dianders@chromium.org Reviewed-by: Jarkko Sakkinen jarkko.sakkinen@linux.intel.com Signed-off-by: Jarkko Sakkinen jarkko.sakkinen@linux.intel.com --- This is the backport of the patch referenced above to 4.19 as was done in Chrome OS. See https://crrev.com/c/1495114 for details. It presumably applies to some older kernels. NOTE that the problem itself has existed for a long time, but continuing to backport this exact solution to super old kernels is out of scope for me. For those truly interested feel free to reference the past discussion [1].
Reason for backport: mainline has commit a3fbfae82b4c ("tpm: take TPM chip power gating out of tpm_transmit()") and commit 719b7d81f204 ("tpm: introduce tpm_chip_start() and tpm_chip_stop()") and it didn't seem like a good idea to backport 17 patches to avoid the conflict.
[1] https://lkml.kernel.org/r/CAD=FV=UoSV9LKOTMuXKRfgFir+7_qPkuhSLN6XJEKPiRPuJJw...
drivers/char/tpm/tpm-chip.c | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-)
diff --git a/drivers/char/tpm/tpm-chip.c b/drivers/char/tpm/tpm-chip.c index 46caadca916a..f784b6fd93b4 100644 --- a/drivers/char/tpm/tpm-chip.c +++ b/drivers/char/tpm/tpm-chip.c @@ -187,12 +187,11 @@ static int tpm_class_shutdown(struct device *dev) { struct tpm_chip *chip = container_of(dev, struct tpm_chip, dev);
- if (chip->flags & TPM_CHIP_FLAG_TPM2) { - down_write(&chip->ops_sem); + down_write(&chip->ops_sem); + if (chip->flags & TPM_CHIP_FLAG_TPM2) tpm2_shutdown(chip, TPM2_SU_CLEAR); - chip->ops = NULL; - up_write(&chip->ops_sem); - } + chip->ops = NULL; + up_write(&chip->ops_sem);
return 0; }