Re: [PATCH] tpm: ibmvtpm: Avoid error message when process gets signal while waiting

From: Jarkko Sakkinen
Date: Wed Jul 28 2021 - 17:50:38 EST


On Mon, Jul 26, 2021 at 11:00:51PM -0400, Stefan Berger wrote:
>
> On 7/26/21 10:42 PM, Jarkko Sakkinen wrote:
> > On Mon, Jul 12, 2021 at 12:25:05PM -0400, Stefan Berger wrote:
> > > From: Stefan Berger <stefanb@xxxxxxxxxxxxx>
> > >
> > > 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.
> > Why?
>
> So it becomes uninterruptible and these error messages go away.

We do not want to make a process uninterruptible. That would prevent
killing it.

/Jarkko