Re: TPM 2.0 RM flushcontext returning bad address

[Jason Gunthorpe <jgunthorpe-ePGOBjL8dl3ta4EC/59zMFaTQe2KTcn/@public.gmane.org>]

On Wed, Jan 11, 2017 at 02:43:50PM -0500, Ken Goldman wrote:

> I'll try again with additional reasons:

There is *always* going to be the possibility of errnos from TPM
command excution, it has to be handled. You can quibble if certain
specific cases should be errno or TPM errors, but we can't release the
mid layer from coping with this.

> - There's no guarantee that EBADF means "invalid handle".  I counted 17 
> EFAULT uses, most low level driver errors.  The TSS could mislead the user.

Yes, we'd have to audit the kernel if we go this way. As I said, the
possible errnos from ioctl would have to be well defined and properly
implemented in the kernel.

> Solution:
> 
> I suspect that the RM could just code:
> 
> 	if (can't map the transient handle for this connection)
> 		map it to TPM_RH_NULL
> 
> and let the TPM do the rest.

Sounds reasonable to me.

Jason

------------------------------------------------------------------------------
Developer Access Program for Intel Xeon Phi Processors
Access to Intel Xeon Phi processor-based developer platforms.
With one year of Intel Parallel Studio XE.
Training and support from Colfax.
Order your platform today. http://sdm.link/xeonphi