From: Stefan Berger <stefanb@xxxxxxxxxxxxx> [ Upstream commit 047d4226b0bca1cda5267dc68bc8291cce5364ac ] 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@xxxxxxxxxxxxx> Cc: George Wilson <gcwilson@xxxxxxxxxxxxx> Reported-by: Nageswara R Sastry <rnsastry@xxxxxxxxxxxxx> Signed-off-by: Stefan Berger <stefanb@xxxxxxxxxxxxx> Tested-by: Nageswara R Sastry <rnsastry@xxxxxxxxxxxxx> Reviewed-by: Jarkko Sakkinen <jarkko@xxxxxxxxxx> Signed-off-by: Jarkko Sakkinen <jarkko@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- drivers/char/tpm/tpm_ibmvtpm.c | 26 +++++++++++++++----------- drivers/char/tpm/tpm_ibmvtpm.h | 2 +- 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 -- 2.30.2
