Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754911AbcJNLn5 (ORCPT ); Fri, 14 Oct 2016 07:43:57 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:39737 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754735AbcJNLm1 (ORCPT ); Fri, 14 Oct 2016 07:42:27 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Jarkko Sakkinen Subject: [PATCH 4.4 21/21] tpm_crb: fix crb_req_canceled behavior Date: Fri, 14 Oct 2016 13:40:59 +0200 Message-Id: <20161014114025.631521627@linuxfoundation.org> X-Mailer: git-send-email 2.10.0 In-Reply-To: <20161014114024.667943585@linuxfoundation.org> References: <20161014114024.667943585@linuxfoundation.org> User-Agent: quilt/0.64 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1732 Lines: 54 4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Jarkko Sakkinen commit 72fd50e14e46dc0edf360631bdece87c2f066a97 upstream. 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. Fixes: 30fc8d138e91 ("tpm: TPM 2.0 CRB Interface") Signed-off-by: Jarkko Sakkinen Signed-off-by: Greg Kroah-Hartman --- drivers/char/tpm/tpm_crb.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) --- a/drivers/char/tpm/tpm_crb.c +++ b/drivers/char/tpm/tpm_crb.c @@ -149,6 +149,11 @@ static int crb_send(struct tpm_chip *chi struct crb_priv *priv = chip->vendor.priv; int rc = 0; + /* Zero the cancel register so that the next command will not get + * canceled. + */ + iowrite32(0, &priv->cca->cancel); + if (len > le32_to_cpu(ioread32(&priv->cca->cmd_size))) { dev_err(&chip->dev, "invalid command count value %x %zx\n", @@ -182,8 +187,6 @@ static void crb_cancel(struct tpm_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)