| Message ID | 20210809192159.2176580-2-stefanb@linux.vnet.ibm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | ibmvtpm: Avoid error message when process gets signal while waiting | expand |
On 10/08/21 12:51 am, Stefan Berger wrote: > From: Stefan Berger <stefanb@linux.ibm.com> > > 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> Tested with /dev/hwrng and /dev/tpm0 and not seen any tpm errors from the kernel. > --- > drivers/char/tpm/tpm_ibmvtpm.c | 20 ++++++++++++-------- > drivers/char/tpm/tpm_ibmvtpm.h | 2 +- > 2 files changed, 13 insertions(+), 9 deletions(-) > > diff --git a/drivers/char/tpm/tpm_ibmvtpm.c b/drivers/char/tpm/tpm_ibmvtpm.c > index 903604769de9..7a9eca5768f8 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) { > @@ -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 = true, > .req_complete_val = 0, > .req_canceled = tpm_ibmvtpm_req_canceled, > }; > @@ -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 >
diff --git a/drivers/char/tpm/tpm_ibmvtpm.c b/drivers/char/tpm/tpm_ibmvtpm.c index 903604769de9..7a9eca5768f8 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) { @@ -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 = true, .req_complete_val = 0, .req_canceled = tpm_ibmvtpm_req_canceled, }; @@ -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