4.4-stable review patch. If anyone has any objections, please let me know.
------------------ From: Dr. Greg Wettstein <g...@wind.enjellic.com> commit e487a0f52301293152a6f8c4e217f2a11dd808e3 upstream. Functionality of the xen-tpmfront driver was lost secondary to the introduction of xenbus multi-page support in commit ccc9d90a9a8b ("xenbus_client: Extend interface to support multi-page ring"). In this commit pointer to location of where the shared page address is stored was being passed to the xenbus_grant_ring() function rather then the address of the shared page itself. This resulted in a situation where the driver would attach to the vtpm-stubdom but any attempt to send a command to the stub domain would timeout. A diagnostic finding for this regression is the following error message being generated when the xen-tpmfront driver probes for a device: <3>vtpm vtpm-0: tpm_transmit: tpm_send: error -62 <3>vtpm vtpm-0: A TPM error (-62) occurred attempting to determine the timeouts This fix is relevant to all kernels from 4.1 forward which is the release in which multi-page xenbus support was introduced. Daniel De Graaf formulated the fix by code inspection after the regression point was located. Fixes: ccc9d90a9a8b ("xenbus_client: Extend interface to support multi-page ring") Signed-off-by: Dr. Greg Wettstein <g...@enjellic.com> Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org> [boris: Updated commit message, added Fixes tag] Signed-off-by: Boris Ostrovsky <boris.ostrov...@oracle.com> Cc: sta...@vger.kernel.org # v4.1+ Reviewed-by: Jarkko Sakkinen <jarkko.sakki...@linux.intel.com> Signed-off-by: Jarkko Sakkinen <jarkko.sakki...@linux.intel.com> --- drivers/char/tpm/xen-tpmfront.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/drivers/char/tpm/xen-tpmfront.c +++ b/drivers/char/tpm/xen-tpmfront.c @@ -201,7 +201,7 @@ static int setup_ring(struct xenbus_devi return -ENOMEM; } - rv = xenbus_grant_ring(dev, &priv->shr, 1, &gref); + rv = xenbus_grant_ring(dev, priv->shr, 1, &gref); if (rv < 0) return rv;