On Wed, Mar 22, 2017 at 04:09:21PM -0400, Ken Goldman wrote: > On 2/22/2017 12:39 PM, James Bottomley wrote: > > > > Right at the moment the kernel use of tpm2 looks like > > > > acquire chip->tpm_mutex > > load key > > process key > > unload key > > release chip->tpm_mutex > > > > While it does this, there's no need for it to have a RM interface > > because what it does between the acquisition and drop of the mutex > > can't be seen by or have any effect on userspace (whether it uses the > > RM or not). So currently, the question doesn't arise, which is the > > situation you see. > > 1 - This appears to depend on the RM not releasing the mutex until all > objects are swapped out. Correct? Same for sessions?
Yes. > 2 - A startauthsession can cause a regap error. Does the above depend on > the RM doing early regapping so the RM won't see that error? We are not trying to resolve that for 4.12. It can happen. > 3 - There's also the problem where the TPM saved session slots (typically > 64) are full. My intuition is that the best solution is for the RM to > reserve 3 slots for the kernel. Maybe but at the moment kernel does not use sessions. /Jarkko
