From: Nayna <nayna@linux.vnet.ibm.com>
To: Stefan Berger <stefanb@linux.vnet.ibm.com>,
jarkko.sakkinen@linux.intel.com, linux-integrity@vger.kernel.org
Cc: aik@ozlabs.ru, david@gibson.dropbear.id.au,
linux-kernel@vger.kernel.org, gcwilson@linux.ibm.com,
jgg@ziepe.ca, Stefan Berger <stefanb@linux.ibm.com>
Subject: Re: [PATCH v5 2/3] tpm: ibmvtpm: Wait for buffer to be set before proceeding
Date: Mon, 2 Mar 2020 12:57:30 -0500 [thread overview]
Message-ID: <fa5101bb-9ea3-3825-67b6-a227a696abc9@linux.vnet.ibm.com> (raw)
In-Reply-To: <20200228030330.18081-3-stefanb@linux.vnet.ibm.com>
On 2/27/20 10:03 PM, Stefan Berger wrote:
> From: Stefan Berger <stefanb@linux.ibm.com>
>
> Synchronize with the results from the CRQs before continuing with
> the initialization. This avoids trying to send TPM commands while
> the rtce buffer has not been allocated, yet.
>
> This patch fixes an existing race condition that may occurr if the
> hypervisor does not quickly respond to the VTPM_GET_RTCE_BUFFER_SIZE
> request sent during initialization and therefore the ibmvtpm->rtce_buf
> has not been allocated at the time the first TPM command is sent.
>
> Fixes: 132f76294744 ("Add new device driver to support IBM vTPM")
> Signed-off-by: Stefan Berger <stefanb@linux.ibm.com>
> ---
> drivers/char/tpm/tpm_ibmvtpm.c | 9 +++++++++
> drivers/char/tpm/tpm_ibmvtpm.h | 1 +
> 2 files changed, 10 insertions(+)
>
> diff --git a/drivers/char/tpm/tpm_ibmvtpm.c b/drivers/char/tpm/tpm_ibmvtpm.c
> index 78cc52690177..eee566eddb35 100644
> --- a/drivers/char/tpm/tpm_ibmvtpm.c
> +++ b/drivers/char/tpm/tpm_ibmvtpm.c
> @@ -571,6 +571,7 @@ static irqreturn_t ibmvtpm_interrupt(int irq, void *vtpm_instance)
> */
> while ((crq = ibmvtpm_crq_get_next(ibmvtpm)) != NULL) {
> ibmvtpm_crq_process(crq, ibmvtpm);
> + wake_up_interruptible(&ibmvtpm->crq_queue.wq);
> crq->valid = 0;
> smp_wmb();
> }
> @@ -618,6 +619,7 @@ static int tpm_ibmvtpm_probe(struct vio_dev *vio_dev,
> }
>
> crq_q->num_entry = CRQ_RES_BUF_SIZE / sizeof(*crq_q->crq_addr);
> + init_waitqueue_head(&crq_q->wq);
> ibmvtpm->crq_dma_handle = dma_map_single(dev, crq_q->crq_addr,
> CRQ_RES_BUF_SIZE,
> DMA_BIDIRECTIONAL);
> @@ -670,6 +672,13 @@ static int tpm_ibmvtpm_probe(struct vio_dev *vio_dev,
> if (rc)
> goto init_irq_cleanup;
>
> + if (!wait_event_timeout(ibmvtpm->crq_queue.wq,
> + ibmvtpm->rtce_buf != NULL,
> + HZ)) {
> + dev_err(dev, "Initialization failed\n");
> + goto init_irq_cleanup;
> + }
> +
> return tpm_chip_register(chip);
> init_irq_cleanup:
> do {
> diff --git a/drivers/char/tpm/tpm_ibmvtpm.h b/drivers/char/tpm/tpm_ibmvtpm.h
> index 7983f1a33267..b92aa7d3e93e 100644
> --- a/drivers/char/tpm/tpm_ibmvtpm.h
> +++ b/drivers/char/tpm/tpm_ibmvtpm.h
> @@ -26,6 +26,7 @@ struct ibmvtpm_crq_queue {
> struct ibmvtpm_crq *crq_addr;
> u32 index;
> u32 num_entry;
> + wait_queue_head_t wq;
> };
>
> struct ibmvtpm_dev {
Acked-by: Nayna Jain <nayna@linux.ibm.com>
Thanks & Regards,
- Nayna
next prev parent reply other threads:[~2020-03-02 17:57 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-02-28 3:03 [PATCH v5 0/3] Enable vTPM 2.0 for the IBM vTPM driver Stefan Berger
2020-02-28 3:03 ` [PATCH v5 1/3] tpm: of: Handle IBM,vtpm20 case when getting log parameters Stefan Berger
2020-02-28 3:03 ` [PATCH v5 2/3] tpm: ibmvtpm: Wait for buffer to be set before proceeding Stefan Berger
2020-03-02 11:11 ` Jarkko Sakkinen
2020-03-02 17:57 ` Nayna [this message]
2020-02-28 3:03 ` [PATCH v5 3/3] tpm: ibmvtpm: Add support for TPM 2 Stefan Berger
2020-03-02 11:15 ` Jarkko Sakkinen
2020-03-02 16:21 ` Stefan Berger
2020-03-03 20:11 ` Jarkko Sakkinen
2020-03-04 13:18 ` Stefan Berger
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=fa5101bb-9ea3-3825-67b6-a227a696abc9@linux.vnet.ibm.com \
--to=nayna@linux.vnet.ibm.com \
--cc=aik@ozlabs.ru \
--cc=david@gibson.dropbear.id.au \
--cc=gcwilson@linux.ibm.com \
--cc=jarkko.sakkinen@linux.intel.com \
--cc=jgg@ziepe.ca \
--cc=linux-integrity@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=stefanb@linux.ibm.com \
--cc=stefanb@linux.vnet.ibm.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;
as well as URLs for NNTP newsgroup(s).