[PATCH] tpm: ibmvtpm: Avoid error message when process gets signal while waiting
From: Stefan Berger <hidden>
Date: 2021-07-12 16:25:13
Also in:
linux-integrity, lkml
Subsystem:
linux for powerpc (32-bit and 64-bit), the rest, tpm device driver · Maintainers:
Madhavan Srinivasan, Michael Ellerman, Linus Torvalds, Peter Huewe, Jarkko Sakkinen
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 configure 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);
The solution is to use wait_event() instead.
To recreat the issue start rngd like this:
sudo rngd -r /dev/hwrng -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 <redacted>
Reported-by: Nageswara R Sastry <redacted>
Signed-off-by: Stefan Berger <stefanb@linux.ibm.com>
---
drivers/char/tpm/tpm_ibmvtpm.c | 13 ++++---------
1 file changed, 4 insertions(+), 9 deletions(-)
diff --git a/drivers/char/tpm/tpm_ibmvtpm.c b/drivers/char/tpm/tpm_ibmvtpm.c
index 903604769de9..99b0442a5fdf 100644
--- a/drivers/char/tpm/tpm_ibmvtpm.c
+++ b/drivers/char/tpm/tpm_ibmvtpm.c@@ -106,16 +106,13 @@ 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; + wait_event(ibmvtpm->wq, !ibmvtpm->tpm_processing_cmd); len = ibmvtpm->res_len;
@@ -206,7 +203,7 @@ static int tpm_ibmvtpm_send(struct tpm_chip *chip, u8 *buf, size_t count) { struct ibmvtpm_dev *ibmvtpm = dev_get_drvdata(&chip->dev); bool retry = true; - int rc, sig; + int rc; if (!ibmvtpm->rtce_buf) { dev_err(ibmvtpm->dev, "ibmvtpm device is not ready\n");
@@ -224,9 +221,7 @@ static int tpm_ibmvtpm_send(struct tpm_chip *chip, u8 *buf, size_t count) dev_info(ibmvtpm->dev, "Need to wait for TPM to finish\n"); /* wait for previous command to finish */ - sig = wait_event_interruptible(ibmvtpm->wq, !ibmvtpm->tpm_processing_cmd); - if (sig) - return -EINTR; + wait_event(ibmvtpm->wq, !ibmvtpm->tpm_processing_cmd); } spin_lock(&ibmvtpm->rtce_lock);
@@ -551,7 +546,7 @@ static void ibmvtpm_crq_process(struct ibmvtpm_crq *crq, /* len of the data in rtce buffer */ ibmvtpm->res_len = be16_to_cpu(crq->len); ibmvtpm->tpm_processing_cmd = false; - wake_up_interruptible(&ibmvtpm->wq); + wake_up(&ibmvtpm->wq); return; default: return;
--
2.31.1