On Wed, Nov 2, 2022 at 3:28 PM Jan Dąbroś <jsd@xxxxxxxxxxxx> wrote:
>
> > > - if (!tpm_chip_start(chip)) {
> > > + rc = tpm_try_get_ops(chip);
> > > + if (!rc) {
> > > if (chip->flags & TPM_CHIP_FLAG_TPM2)
> > > tpm2_shutdown(chip, TPM2_SU_STATE);
> > > else
> > > rc = tpm1_pm_suspend(chip, tpm_suspend_pcr);
> >
> > This if-else block is still interacting with the TPM even though
> > you're not guaranteed to have the lock, which could lead to
> > racy/inchorent results. Would it be better to just bail out entirely
> > since we can't safely attempt any recovery at this point. If it's
> > still worth attempting the shutdown command, it would at least be good
> > to add a comment admitting that we have no choice but to communicate
> > with the TPM without a lock.
>
> If tpm_try_get_ops() returns 0 it means that we have a lock. And if we
> don't have a lock, then we are not executing any TPM commands. Are you
> referring to tpm_mutex or something different?
Ah, yup, I was reading this backwards, thinking that something had
gone wrong when entering this block. Nevermind.
--
Tim Van Patten | ChromeOS | timvp@xxxxxxxxxx | (720) 432-0997
