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 --- drivers/char/tpm/tpm-chip.c | 3 +++ 1 file changed, 3 insertions(+)

diff --git a/drivers/char/tpm/tpm-chip.c b/drivers/char/tpm/tpm-chip.c index 0eca20c5a80c..ede8c1deca97 100644 --- a/drivers/char/tpm/tpm-chip.c +++ b/drivers/char/tpm/tpm-chip.c @@ -158,12 +158,15 @@ static int tpm_class_shutdown(struct device *dev) { struct tpm_chip *chip = container_of(dev, struct tpm_chip, dev);

+ down_write(&chip->ops_sem); if (chip->flags & TPM_CHIP_FLAG_TPM2) { down_write(&chip->ops_sem); tpm2_shutdown(chip, TPM2_SU_CLEAR); chip->ops = NULL; up_write(&chip->ops_sem); } + chip->ops = NULL; + up_write(&chip->ops_sem);

return 0; }