Re: [PATCH v4 14/14] tpm: Allow locality 2 to be set when initializing the TPM for Secure Launch

From: Jason Gunthorpe
Date: Fri Aug 27 2021 - 09:30:15 EST


On Fri, Aug 27, 2021 at 09:28:37AM -0400, Ross Philipson wrote:
> The Secure Launch MLE environment uses PCRs that are only accessible from
> the DRTM locality 2. By default the TPM drivers always initialize the
> locality to 0. When a Secure Launch is in progress, initialize the
> locality to 2.
>
> Signed-off-by: Ross Philipson <ross.philipson@xxxxxxxxxx>
> ---
> drivers/char/tpm/tpm-chip.c | 9 ++++++++-
> 1 file changed, 8 insertions(+), 1 deletion(-)

Global state like this seems quite dangerous, shouldn't the locality
be selected based on the PCR being accessed, or passed down from
higher up in the call chain?

Jason