Hi
While sitting at the airport I started to think a bit about the context
gap issue.
I think first thing that would make sense would be to have a 64-bit
shadow count for every TPM space i.e.
atomic_long_t tpm2_ctx_cnt;
struct tpm2_space {
/* ... */
u64 ctx_cnt;
};
For every create and load of a session you will read the global count
and increase it. This way we have get a well defined order.
With this organization we could for example put tpm spaces to a
red-black tree and refresh the oldest tpm space (just first thought
that came to mind).
PS. While doing LPC and LSS slides I found error from the TPM 2.0
commands specification. TPM2_ContextSave can never emit
TPM2_RC_CONTEXT_GAP albeit the specification says so.
/Jarkko
