On Tue, Aug 18, 2020 at 07:19:57PM +0300, Jarkko Sakkinen wrote: > On Tue, Aug 18, 2020 at 07:12:09PM +0300, Jarkko Sakkinen wrote: > > On Mon, Aug 17, 2020 at 02:35:06PM -0700, James Bottomley wrote: > > > Create sysfs per hash groups with 24 PCR files in them one group, > > > named pcr-<hash>, for each agile hash of the TPM. The files are > > > plugged in to a PCR read function which is TPM version agnostic, so > > > this works also for TPM 1.2 but the hash is only sha1 in that case. > > > > > > Note: the macros used to create the hashes emit spurious checkpatch > > > warnings. Do not try to "fix" them as checkpatch recommends, otherwise > > > they'll break. > > > > > > Signed-off-by: James Bottomley <James.Bottomley@xxxxxxxxxxxxxxxxxxxxx> > > > Reviewed-by: Jerry Snitselaar <jsnitsel@xxxxxxxxxx> > > > Tested-by: Thiago Jung Bauermann <bauerman@xxxxxxxxxxxxx> > > > > I have hard time understanding why this is required. > > > > You can grab the information through /dev/tpm0 just fine. > > I just think it is principally wrong to add sysfs files if they don't > have any measurable value other than perhaps some convenience. > > It is trival to write only a libc dependent program that outputs PCRs. > > I think this is essentially an user space problem that is getting sorted > out with kernel code. Jason, what do you make of this? I recall that it was you who I discussed with about this topic when TPM 2.0 support was first upstreamed. /Jarkko
