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authorStefan Berger <stefanb@linux.ibm.com>2021-08-12 22:45:48 +0300
committerJarkko Sakkinen <jarkko@kernel.org>2021-08-23 19:55:42 +0300
commit047d4226b0bca1cda5267dc68bc8291cce5364ac (patch)
treec1464a083ec941aa301f422fd4545e389d9a2445
parenta4aed36ed5924a05ecfadc470584188bfba2b928 (diff)
downloadlinux-047d4226b0bca1cda5267dc68bc8291cce5364ac.tar.xz
tpm: ibmvtpm: Avoid error message when process gets signal while waiting
When rngd is run as root then lots of these types of message will appear in the kernel log if the TPM has been configured to provide random bytes: [ 7406.275163] tpm tpm0: tpm_transmit: tpm_recv: error -4 The issue is caused by the following call that is interrupted while waiting for the TPM's response. sig = wait_event_interruptible(ibmvtpm->wq, !ibmvtpm->tpm_processing_cmd); Rather than waiting for the response in the low level driver, have it use the polling loop in tpm_try_transmit() that uses a command's duration to poll until a result has been returned by the TPM, thus ending when the timeout has occurred but not responding to signals and ctrl-c anymore. To stay in this polling loop extend tpm_ibmvtpm_status() to return 'true' for as long as the vTPM is indicated as being busy in tpm_processing_cmd. Since the loop requires the TPM's timeouts, get them now using tpm_get_timeouts() after setting the TPM2 version flag on the chip. To recreat the resolved issue start rngd like this: sudo rngd -r /dev/hwrng -t sudo rngd -r /dev/tpm0 -t Link: https://bugzilla.redhat.com/show_bug.cgi?id=1981473 Fixes: 6674ff145eef ("tpm_ibmvtpm: properly handle interrupted packet receptions") Cc: Nayna Jain <nayna@linux.ibm.com> Cc: George Wilson <gcwilson@linux.ibm.com> Reported-by: Nageswara R Sastry <rnsastry@linux.ibm.com> Signed-off-by: Stefan Berger <stefanb@linux.ibm.com> Tested-by: Nageswara R Sastry <rnsastry@linux.ibm.com> Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org> Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
-rw-r--r--drivers/char/tpm/tpm_ibmvtpm.c26
-rw-r--r--drivers/char/tpm/tpm_ibmvtpm.h2
2 files changed, 16 insertions, 12 deletions
diff --git a/drivers/char/tpm/tpm_ibmvtpm.c b/drivers/char/tpm/tpm_ibmvtpm.c
index 903604769de9..3af4c07a9342 100644
--- a/drivers/char/tpm/tpm_ibmvtpm.c
+++ b/drivers/char/tpm/tpm_ibmvtpm.c
@@ -106,17 +106,12 @@ static int tpm_ibmvtpm_recv(struct tpm_chip *chip, u8 *buf, size_t count)
{
struct ibmvtpm_dev *ibmvtpm = dev_get_drvdata(&chip->dev);
u16 len;
- int sig;
if (!ibmvtpm->rtce_buf) {
dev_err(ibmvtpm->dev, "ibmvtpm device is not ready\n");
return 0;
}
- sig = wait_event_interruptible(ibmvtpm->wq, !ibmvtpm->tpm_processing_cmd);
- if (sig)
- return -EINTR;
-
len = ibmvtpm->res_len;
if (count < len) {
@@ -237,7 +232,7 @@ static int tpm_ibmvtpm_send(struct tpm_chip *chip, u8 *buf, size_t count)
* set the processing flag before the Hcall, since we may get the
* result (interrupt) before even being able to check rc.
*/
- ibmvtpm->tpm_processing_cmd = true;
+ ibmvtpm->tpm_processing_cmd = 1;
again:
rc = ibmvtpm_send_crq(ibmvtpm->vdev,
@@ -255,7 +250,7 @@ again:
goto again;
}
dev_err(ibmvtpm->dev, "tpm_ibmvtpm_send failed rc=%d\n", rc);
- ibmvtpm->tpm_processing_cmd = false;
+ ibmvtpm->tpm_processing_cmd = 0;
}
spin_unlock(&ibmvtpm->rtce_lock);
@@ -269,7 +264,9 @@ static void tpm_ibmvtpm_cancel(struct tpm_chip *chip)
static u8 tpm_ibmvtpm_status(struct tpm_chip *chip)
{
- return 0;
+ struct ibmvtpm_dev *ibmvtpm = dev_get_drvdata(&chip->dev);
+
+ return ibmvtpm->tpm_processing_cmd;
}
/**
@@ -457,7 +454,7 @@ static const struct tpm_class_ops tpm_ibmvtpm = {
.send = tpm_ibmvtpm_send,
.cancel = tpm_ibmvtpm_cancel,
.status = tpm_ibmvtpm_status,
- .req_complete_mask = 0,
+ .req_complete_mask = 1,
.req_complete_val = 0,
.req_canceled = tpm_ibmvtpm_req_canceled,
};
@@ -550,7 +547,7 @@ static void ibmvtpm_crq_process(struct ibmvtpm_crq *crq,
case VTPM_TPM_COMMAND_RES:
/* len of the data in rtce buffer */
ibmvtpm->res_len = be16_to_cpu(crq->len);
- ibmvtpm->tpm_processing_cmd = false;
+ ibmvtpm->tpm_processing_cmd = 0;
wake_up_interruptible(&ibmvtpm->wq);
return;
default:
@@ -688,8 +685,15 @@ static int tpm_ibmvtpm_probe(struct vio_dev *vio_dev,
goto init_irq_cleanup;
}
- if (!strcmp(id->compat, "IBM,vtpm20")) {
+
+ if (!strcmp(id->compat, "IBM,vtpm20"))
chip->flags |= TPM_CHIP_FLAG_TPM2;
+
+ rc = tpm_get_timeouts(chip);
+ if (rc)
+ goto init_irq_cleanup;
+
+ if (chip->flags & TPM_CHIP_FLAG_TPM2) {
rc = tpm2_get_cc_attrs_tbl(chip);
if (rc)
goto init_irq_cleanup;
diff --git a/drivers/char/tpm/tpm_ibmvtpm.h b/drivers/char/tpm/tpm_ibmvtpm.h
index b92aa7d3e93e..51198b137461 100644
--- a/drivers/char/tpm/tpm_ibmvtpm.h
+++ b/drivers/char/tpm/tpm_ibmvtpm.h
@@ -41,7 +41,7 @@ struct ibmvtpm_dev {
wait_queue_head_t wq;
u16 res_len;
u32 vtpm_version;
- bool tpm_processing_cmd;
+ u8 tpm_processing_cmd;
};
#define CRQ_RES_BUF_SIZE PAGE_SIZE