From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754872AbcFGXCp (ORCPT ); Tue, 7 Jun 2016 19:02:45 -0400 Received: from mga11.intel.com ([192.55.52.93]:62246 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754489AbcFGXCm (ORCPT ); Tue, 7 Jun 2016 19:02:42 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.26,436,1459839600"; d="scan'208";a="997311882" From: Jarkko Sakkinen To: Peter Huewe Cc: linux-security-module@vger.kernel.org, Jarkko Sakkinen , stable@vger.kernel.org, Marcel Selhorst , Jason Gunthorpe , tpmdd-devel@lists.sourceforge.net (moderated list:TPM DEVICE DRIVER), linux-kernel@vger.kernel.org (open list) Subject: [PATCH 1/3] tpm_crb: fix crb_req_canceled behavior Date: Wed, 8 Jun 2016 02:02:00 +0300 Message-Id: <1465340522-1112-2-git-send-email-jarkko.sakkinen@linux.intel.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1465340522-1112-1-git-send-email-jarkko.sakkinen@linux.intel.com> References: <1465340522-1112-1-git-send-email-jarkko.sakkinen@linux.intel.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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@vger.kernel.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 1547636..b4d46ae 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