From: Jarkko Sakkinen <jarkko@kernel.org>
To: Tianjia Zhang <tianjia.zhang@linux.alibaba.com>
Cc: Peter Huewe <peterhuewe@gmx.de>, Jason Gunthorpe <jgg@ziepe.ca>,
linux-integrity@vger.kernel.org, linux-kernel@vger.kernel.org,
Jia Zhang <zhang.jia@linux.alibaba.com>
Subject: Re: [PATCH] tpm/tpm_tis: Fix variable reset during IRQ probing
Date: Fri, 15 Jan 2021 11:23:46 +0200 [thread overview]
Message-ID: <YAFfIqaohjneVCO6@kernel.org> (raw)
In-Reply-To: <44c35c27-0cd4-e451-1b9c-d6fe48e58e51@linux.alibaba.com>
On Thu, Jan 14, 2021 at 12:12:16PM +0800, Tianjia Zhang wrote:
>
>
> On 1/14/21 10:51 AM, Jarkko Sakkinen wrote:
> > On Wed, Jan 13, 2021 at 08:00:21PM +0800, Tianjia Zhang wrote:
> > > In tpm_tis_core_init(), tpm2_probe() will be called first, this
> > > function will eventually call tpm_tis_send(), and then
> > > tpm_tis_probe_irq_single() will detect whether the interrupt is
> > > normal, mainly the installation interrupted, set `priv->irq_tested`
> > > to false. The logic will eventually be executed to tpm_tis_send()
> > > to trigger an interrupt.
> > >
> > > There is currently such a scenario, which will cause the IRQ probe
> > > code to never be executed, so that the TPM device is in polling
> > > mode: after setting irq_tested to false, an interrupt occurs
> > > between entering the ttpm_tis_send() function, and the interrupt
> > > will be first set irq_tested to true will cause the IRQ probe code
> > > to never be executed.
> >
> > Can you describe the scenario more detail?
> >
>
> The problematic scenario we encountered is like this. The following figure
> shows the execution flow of tpm_tis_core_init(). An interrupt occurred
> before the IRQ probe. This interrupt was caused by tpm2_probe(), but it was
> triggered before the IRQ probe was executed, and the interrupt handler would
> set irq_tested to true, so the IRQ probe code can never execute, that is,
> the code marked 2 in the figure will never happen.
TPM_INT_ENABLE is cleared on reset [*].
[*] Section 5.9.1
https://trustedcomputinggroup.org/resource/pc-client-work-group-pc-client-specific-tpm-interface-specification-tis/
/Jarkko
next prev parent reply other threads:[~2021-01-15 9:24 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-13 12:00 [PATCH] tpm/tpm_tis: Fix variable reset during IRQ probing Tianjia Zhang
2021-01-14 2:51 ` Jarkko Sakkinen
2021-01-14 4:12 ` Tianjia Zhang
2021-01-15 9:23 ` Jarkko Sakkinen [this message]
2021-01-20 4:03 ` Tianjia Zhang
2021-01-28 5:20 ` [tpm/tpm_tis] cad8219df0: BUG:unable_to_handle_page_fault_for_address kernel test robot
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=YAFfIqaohjneVCO6@kernel.org \
--to=jarkko@kernel.org \
--cc=jgg@ziepe.ca \
--cc=linux-integrity@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=peterhuewe@gmx.de \
--cc=tianjia.zhang@linux.alibaba.com \
--cc=zhang.jia@linux.alibaba.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox