4.9-stable review patch. If anyone has any objections, please let me know.
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From: Dr. Greg Wettstein greg@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 greg@enjellic.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
[boris: Updated commit message, added Fixes tag] Signed-off-by: Boris Ostrovsky boris.ostrovsky@oracle.com Cc: stable@vger.kernel.org # v4.1+ Reviewed-by: Jarkko Sakkinen jarkko.sakkinen@linux.intel.com Signed-off-by: Jarkko Sakkinen jarkko.sakkinen@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 @@ -203,7 +203,7 @@ 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;