Messages in this thread Patch in this message | | | Date | Fri, 20 Jan 2017 09:00:02 -0600 | From | "Dr. Greg Wettstein" <> | Subject | [PATCH] tpm: Restore functionality to xen vtpm driver. |
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Functionality of the xen-tpmfront driver was lost secondary to the introduction of xenbus multi-page support in the following commit:
ccc9d90a9a8b5c4ad7e9708ec41f75ff9e98d61d
xenbus_client: Extend interface to support multi-page ring
In this commit a pointer to the shared page address 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.
Cc: <stable@vger.kernel.org> # 4.1- Suggested-by: Daniel De Graaf <dgdegra@tycho.nsa.gov> Signed-off-by: Dr. Greg Wettstein <greg@enjellic.com> --- drivers/char/tpm/xen-tpmfront.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/char/tpm/xen-tpmfront.c b/drivers/char/tpm/xen-tpmfront.c index 3111f2778079..d1478f7b3f97 100644 --- a/drivers/char/tpm/xen-tpmfront.c +++ b/drivers/char/tpm/xen-tpmfront.c @@ -201,7 +201,7 @@ static int setup_ring(struct xenbus_device *dev, struct tpm_private *priv) 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; -- 2.11.0 As always, Dr. G.W. Wettstein, Ph.D. Enjellic Systems Development, LLC. 4206 N. 19th Ave. Specializing in information infra-structure Fargo, ND 58102 development. PH: 701-281-1686 FAX: 701-281-3949 EMAIL: greg@enjellic.com ------------------------------------------------------------------------------ "I will not eat aged beef." -- Johannes Christian Grosen Resurrection. --
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