On Mon, Sep 30, 2019 at 08:13:46AM +0200, Pavel Machek wrote:
From: Vadim Sukhomlinov <sukhomlinov@xxxxxxxxxx> 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.
I agree. I've dropped it from 4.19 and 4.14. Jarkko, can you take a look at this again please? -- Thanks, Sasha
