Re: [PATCH RFC 4/4] tpm: add the infrastructure for TPM space for TPM 2.0

From: Jarkko Sakkinen
Date: Mon Jan 02 2017 - 23:09:49 EST


On Mon, Jan 02, 2017 at 02:09:53PM -0700, Jason Gunthorpe wrote:
> On Mon, Jan 02, 2017 at 03:22:10PM +0200, Jarkko Sakkinen wrote:
> > Added a ioctl for creating a TPM space. The space is isolated from the
> > other users of the TPM. Only a process holding the file with the handle
> > can access the objects and only objects that are created through that
> > file handle can be accessed.
>
> I don't understand this comment. /dev/tpmX is forced to be
> single-process-open, so how can there ever be more than 1 FD for it?
>
> Since the space is tied to that single fd these patches just create a
> way for the single user-space process to auto-cleanup if it crashes?
>
> Is that the entire intent of this design? I guess it is OK as a
> stepping point..

is_open is cleared in tpm_ioc_new_space.

/Jarkko