> From: Vadim Sukhomlinov <sukhomli...@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.
> diff --git a/drivers/char/tpm/tpm-chip.c b/drivers/char/tpm/tpm-chip.c
> index 46caadca916a0..dccc61af9ffab 100644
> --- a/drivers/char/tpm/tpm-chip.c
> +++ b/drivers/char/tpm/tpm-chip.c
> @@ -187,12 +187,15 @@ 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);
This is wrong, it takes &chip->ops_sem twice, that can't be
good. db4d8cb9c9f2af71c4d087817160d866ed572cc9 does not have that
problem.
Best regards,
Pavel
--
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures)
http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
