Re: [PATCH v5 5/5] tpm: flush the auth session only when /dev/tpm0 is open

["Jarkko Sakkinen" <jarkko@kernel.org>]

On Wed Sep 25, 2024 at 10:46 AM EEST, Jarkko Sakkinen wrote:
> On Wed Sep 25, 2024 at 10:42 AM EEST, Jarkko Sakkinen wrote:
> > Fair enough. I can buy this.
> >
> > I'll phrase it that (since it was mentioned in the bugzilla comment)
> > in the bug in question the root is in PCR extend but since in my own
> > tests I got overhead from trusted keys I also mention that it overally
> > affects also that and tpm2_get_random().
>
> I do not want to take null key flushing away although I got the
> reasoning given the small amount of time is saved (maybe 25-50 ms
> in my QEMU setup if I recall correctly) but it would make sense to
> squash it auth session patch.
>
> I'll also check 1/2 and 2/2 if I'm doing too much in them. Not
> adding any tags to v6 and it really makes sense to develop 
> benchmarks and not rush with the new version now that I got
> also your feedback, since it is past rc1 timeline.
>
> Good target rcX would be around rc3.

I have to admit this: I had blind spot on that PCR extend comment
because I did not get hits on that when testing this so it definitely
needs to be documented. I spotted it only yesterday.

BR, Jarkko