From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jarkko Sakkinen Subject: [PATCH 1/4] tpm_crb: fix crb_req_canceled behavior Date: Fri, 2 Sep 2016 22:34:17 +0300 Message-ID: <1472844861-24599-2-git-send-email-jarkko.sakkinen@linux.intel.com> References: <1472844861-24599-1-git-send-email-jarkko.sakkinen@linux.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1472844861-24599-1-git-send-email-jarkko.sakkinen-VuQAYsv1563Yd54FQh9/CA@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: tpmdd-devel-bounces-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org To: Peter Huewe Cc: open list , stable-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-security-module-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, "moderated list:TPM DEVICE DRIVER" List-Id: tpmdd-devel@lists.sourceforge.net The req_canceled() callback is used by tpm_transmit() periodically to check whether the request has been canceled while it is receiving a response from the TPM. The TPM_CRB_CTRL_CANCEL register was cleared already in the crb_cancel callback, which has two consequences: * Cancel might not happen. * req_canceled() always returns zero. A better place to clear the register is when starting to send a new command. The behavior of TPM_CRB_CTRL_CANCEL is described in the section 5.5.3.6 of the PTP specification. CC: stable-u79uwXL29TY76Z2rM5mHXA@public.gmane.org Fixes: 30fc8d138e91 ("tpm: TPM 2.0 CRB Interface") Signed-off-by: Jarkko Sakkinen --- drivers/char/tpm/tpm_crb.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/drivers/char/tpm/tpm_crb.c b/drivers/char/tpm/tpm_crb.c index 018c3825..1801f38 100644 --- a/drivers/char/tpm/tpm_crb.c +++ b/drivers/char/tpm/tpm_crb.c @@ -142,6 +142,11 @@ static int crb_send(struct tpm_chip *chip, u8 *buf, size_t len) struct crb_priv *priv = dev_get_drvdata(&chip->dev); int rc = 0; + /* Zero the cancel register so that the next command will not get + * canceled. + */ + iowrite32(0, &priv->cca->cancel); + if (len > ioread32(&priv->cca->cmd_size)) { dev_err(&chip->dev, "invalid command count value %x %zx\n", @@ -175,8 +180,6 @@ static void crb_cancel(struct tpm_chip *chip) if ((priv->flags & CRB_FL_ACPI_START) && crb_do_acpi_start(chip)) dev_err(&chip->dev, "ACPI Start failed\n"); - - iowrite32(0, &priv->cca->cancel); } static bool crb_req_canceled(struct tpm_chip *chip, u8 status) -- 2.7.4 ------------------------------------------------------------------------------