2016-03-31 14:41:51

by Hon Ching(Vicky) Lo

Subject: [PATCH v2] vTPM: fix missing error handling for suspend operation

ibmvtpm_send_crq in tpm_ibmvtpm_suspend returns errors in a more
granular level than what the existing code does. This patch adds
the missing CRQ transport event code checks to ensure appropriate
action taken, in the case that ibmvtpm_send_crq returns H_CLOSED.

Signed-off-by: Hon Ching(Vicky) Lo <[email protected]>
---
drivers/char/tpm/tpm_ibmvtpm.c | 43 ++++++++++++++++++++++++++++++++++++---
drivers/char/tpm/tpm_ibmvtpm.h | 7 ++++++
2 files changed, 46 insertions(+), 4 deletions(-)

diff --git a/drivers/char/tpm/tpm_ibmvtpm.c b/drivers/char/tpm/tpm_ibmvtpm.c
index 3e6a226..ea2a970 100644
--- a/drivers/char/tpm/tpm_ibmvtpm.c
+++ b/drivers/char/tpm/tpm_ibmvtpm.c
@@ -335,17 +335,46 @@ static int tpm_ibmvtpm_suspend(struct device *dev)
struct ibmvtpm_crq crq;
u64 *buf = (u64 *) &crq;
int rc = 0;
+ int counter = 0;
+ int sig;

- crq.valid = (u8)IBMVTPM_VALID_CMD;
- crq.msg = (u8)VTPM_PREPARE_TO_SUSPEND;
+suspend:
+ crq_initialized = 0;
+ crq.valid = (u8) IBMVTPM_VALID_CMD;
+ crq.msg = (u8) VTPM_PREPARE_TO_SUSPEND;

rc = ibmvtpm_send_crq(ibmvtpm->vdev, cpu_to_be64(buf[0]),
cpu_to_be64(buf[1]));
+
+ if ((rc == H_CLOSED) && (crq.valid == (u8) VALID_TRANSPORT_EVENT)) {
+ if (crq.msg == (u8) PARTNER_PARTITION_FAILED) {
+ dev_err(ibmvtpm->dev,
+ "vtpm has terminated fatally; reboot to reinstate a trusted state.\n");
+ }
+
+ if ((crq.msg == (u8) PARTNER_PARTITION_DEREG_CRQ)
+ && (counter < 1)) {
+ counter++;
+
+ /* The vtpm is in the process of being reloaded by
+ * firmware and has de-registered CRQ. The client
+ * must wait for the CRQ INITIALIZATION message and
+ * respond and must resubmit suspend message.
+ */
+ sig =
+ wait_event_interruptible(ibmvtpm->wq,
+ crq_initialized == 1);
+ if (sig)
+ return -EINTR;
+ goto suspend;
+ }
+ }
+
if (rc != H_SUCCESS)
- dev_err(ibmvtpm->dev,
- "tpm_ibmvtpm_suspend failed rc=%d\n", rc);
+ dev_err(ibmvtpm->dev, "tpm_ibmvtpm_suspend failed rc=%d\n", rc);

return rc;
+
}

/**
@@ -477,6 +506,9 @@ static void ibmvtpm_crq_process(struct ibmvtpm_crq *crq,
case INIT_CRQ_COMP_RES:
dev_info(ibmvtpm->dev,
"CRQ initialization completed\n");
+ /* in case vtpm is being reloaded */
+ crq_initialized = 1;
+ wake_up_interruptible(&ibmvtpm->wq);
return;
default:
dev_err(ibmvtpm->dev, "Unknown crq message type: %d\n", crq->msg);
@@ -517,6 +549,9 @@ static void ibmvtpm_crq_process(struct ibmvtpm_crq *crq,
ibmvtpm->res_len = be16_to_cpu(crq->len);
wake_up_interruptible(&ibmvtpm->wq);
return;
+ case VTPM_PREPARE_TO_SUSPEND_RES:
+ dev_info(ibmvtpm->dev, "Prepare to Suspend Response\n");
+ return;
default:
return;
}
diff --git a/drivers/char/tpm/tpm_ibmvtpm.h b/drivers/char/tpm/tpm_ibmvtpm.h
index 6af9289..ed5fd5f 100644
--- a/drivers/char/tpm/tpm_ibmvtpm.h
+++ b/drivers/char/tpm/tpm_ibmvtpm.h
@@ -73,4 +73,11 @@ struct ibmvtpm_dev {
#define VTPM_PREPARE_TO_SUSPEND 0x04
#define VTPM_PREPARE_TO_SUSPEND_RES (0x04 | VTPM_MSG_RES)

+/* vTPM CRQ Transport Event codes */
+#define VALID_TRANSPORT_EVENT 0xFF
+#define PARTNER_PARTITION_FAILED 0x01
+#define PARTNER_PARTITION_DEREG_CRQ 0x02
+
+int crq_initialized;
+
#endif
--
1.7.1

2016-03-31 16:42:31

by Greg Kroah-Hartman

Subject: Re: [PATCH v2] vTPM: fix missing error handling for suspend operation

On Thu, Mar 31, 2016 at 10:41:23AM -0400, Hon Ching(Vicky) Lo wrote:
> ibmvtpm_send_crq in tpm_ibmvtpm_suspend returns errors in a more
> granular level than what the existing code does. This patch adds
> the missing CRQ transport event code checks to ensure appropriate
> action taken, in the case that ibmvtpm_send_crq returns H_CLOSED.
>
> Signed-off-by: Hon Ching(Vicky) Lo <[email protected]>
> ---
> drivers/char/tpm/tpm_ibmvtpm.c | 43 ++++++++++++++++++++++++++++++++++++---
> drivers/char/tpm/tpm_ibmvtpm.h | 7 ++++++
> 2 files changed, 46 insertions(+), 4 deletions(-)

<formletter>

This is not the correct way to submit patches for inclusion in the
stable kernel tree. Please read Documentation/stable_kernel_rules.txt
for how to do this properly.

</formletter>