Re: [PATCH] tpm: fixes uninitialized allocated banks for IBM vtpm driver

From: Jarkko Sakkinen
Date: Fri Jul 05 2019 - 13:50:39 EST

On Fri, 2019-07-05 at 11:32 -0400, Nayna wrote:
> I am not sure of the purpose of tpm_stop_chip(), so I have left it as it
> is. Jarkko, what do you think about the change ?

Stefan right. Your does not work, or will randomly work or not work
depending on the chip.

You need to turn the TPM on with tpm_chip_start() and turn it off with
tpm_chip_stop() once you are done. This is done in tpm_chip_register()
before calling tpm_auto_startup().

TPM power management was once in tpm_transmit() but not anymore after my
patch set that removed nested tpm_transmit() calls.

While you're on it please take into account my earlier feedback.

Also, short summary could be "tpm: tpm_ibm_vtpm: Fix unallocated banks"

Some oddballs in your patch that I have to ask.

if (chip->flags & TPM_CHIP_FLAG_TPM2) {
rc = tpm2_get_pcr_allocation(chip);
if (rc)
goto out;

chip->allocated_banks = kcalloc(1, sizeof(*chip->allocated_banks),
if (!chip->allocated_banks) {
rc = -ENOMEM;
goto out;

Why you don't return on site and instead jump somewhere? Also the
2nd line for kcalloc() is misaligned.

if (rc < 0)
rc = -ENODEV;

This will cause a new regression i.e. you let TPM error codes

To summarize this patch fixes one regression and introduces two
completely new ones...