lkml.org 
[lkml]   [2021]   [Jul]   [13]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [PATCH] tpm: ibmvtpm: Avoid error message when process gets signal while waiting
From
Date


On 12/07/21 9:55 pm, 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 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 <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>

> ---
> 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;
>

--
Thanks and Regards
R.Nageswara Sastry

\
 
 \ /
  Last update: 2021-07-13 07:04    [W:0.081 / U:0.456 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site