Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753581AbcC3NZq (ORCPT ); Wed, 30 Mar 2016 09:25:46 -0400 Received: from mga11.intel.com ([192.55.52.93]:17301 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753135AbcC3NZp (ORCPT ); Wed, 30 Mar 2016 09:25:45 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.24,416,1455004800"; d="scan'208";a="774671059" Date: Wed, 30 Mar 2016 16:25:41 +0300 From: Jarkko Sakkinen To: Peter Huewe Cc: Marcel Selhorst , Jason Gunthorpe , "moderated list:TPM DEVICE DRIVER" , open list Subject: Re: [PATCH] tpm: remove redundant code from self-test functions Message-ID: <20160330132541.GA22512@intel.com> References: <1459344045-21602-1-git-send-email-jarkko.sakkinen@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1459344045-21602-1-git-send-email-jarkko.sakkinen@linux.intel.com> Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 6288 Lines: 163 On Wed, Mar 30, 2016 at 04:20:45PM +0300, Jarkko Sakkinen wrote: > Self-test functions construct PCR read calls by ad hoc, which is only a > waste space. Use instead tpm_pcr_read_dev (renamed as tpm1_pcr_read() by > this commit) in tpm_do_selftest and tpm2_pcr_read() in > tpm2_do_selftest() functions in order to remove the duplicate code. > > Patch can be tested easily tested by running the a kernel with this > patch compiled in since self-test is done when the a device driver > initializes. This is now fixed version (I forgot to squash one fixup to the previous version). This could use peer test preferably with a FIFO device. It is easy as one only needs to load the driver and see that there are no errors in dmesg from self-additions. As an additional measure on a TPM 1.x device outputting 'pcrs' file could be a good idea. /Jarkko > Signed-off-by: Jarkko Sakkinen > --- > drivers/char/tpm/tpm-interface.c | 14 +++++--------- > drivers/char/tpm/tpm-sysfs.c | 2 +- > drivers/char/tpm/tpm.h | 2 +- > drivers/char/tpm/tpm2-cmd.c | 14 ++------------ > 4 files changed, 9 insertions(+), 23 deletions(-) > > diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c > index 5397b64..0c8140f 100644 > --- a/drivers/char/tpm/tpm-interface.c > +++ b/drivers/char/tpm/tpm-interface.c > @@ -1,6 +1,6 @@ > /* > * Copyright (C) 2004 IBM Corporation > - * Copyright (C) 2014 Intel Corporation > + * Copyright (C) 2014, 2016 Intel Corporation > * > * Authors: > * Leendert van Doorn > @@ -666,7 +666,7 @@ static struct tpm_input_header pcrread_header = { > .ordinal = TPM_ORDINAL_PCRREAD > }; > > -int tpm_pcr_read_dev(struct tpm_chip *chip, int pcr_idx, u8 *res_buf) > +int tpm1_pcr_read(struct tpm_chip *chip, int pcr_idx, u8 *res_buf) > { > int rc; > struct tpm_cmd_t cmd; > @@ -676,7 +676,7 @@ int tpm_pcr_read_dev(struct tpm_chip *chip, int pcr_idx, u8 *res_buf) > rc = tpm_transmit_cmd(chip, &cmd, READ_PCR_RESULT_SIZE, > "attempting to read a pcr value"); > > - if (rc == 0) > + if (rc == 0 && res_buf) > memcpy(res_buf, cmd.params.pcrread_out.pcr_result, > TPM_DIGEST_SIZE); > return rc; > @@ -728,7 +728,7 @@ int tpm_pcr_read(u32 chip_num, int pcr_idx, u8 *res_buf) > if (chip->flags & TPM_CHIP_FLAG_TPM2) > rc = tpm2_pcr_read(chip, pcr_idx, res_buf); > else > - rc = tpm_pcr_read_dev(chip, pcr_idx, res_buf); > + rc = tpm1_pcr_read(chip, pcr_idx, res_buf); > tpm_put_ops(chip); > return rc; > } > @@ -793,7 +793,6 @@ int tpm_do_selftest(struct tpm_chip *chip) > unsigned int loops; > unsigned int delay_msec = 100; > unsigned long duration; > - struct tpm_cmd_t cmd; > > duration = tpm_calc_ordinal_duration(chip, TPM_ORD_CONTINUE_SELFTEST); > > @@ -808,9 +807,7 @@ int tpm_do_selftest(struct tpm_chip *chip) > > do { > /* Attempt to read a PCR value */ > - cmd.header.in = pcrread_header; > - cmd.params.pcrread_in.pcr_idx = cpu_to_be32(0); > - rc = tpm_transmit(chip, (u8 *) &cmd, READ_PCR_RESULT_SIZE); > + rc = tpm1_pcr_read(chip, 0, NULL); > /* Some buggy TPMs will not respond to tpm_tis_ready() for > * around 300ms while the self test is ongoing, keep trying > * until the self test duration expires. */ > @@ -825,7 +822,6 @@ int tpm_do_selftest(struct tpm_chip *chip) > if (rc < TPM_HEADER_SIZE) > return -EFAULT; > > - rc = be32_to_cpu(cmd.header.out.return_code); > if (rc == TPM_ERR_DISABLED || rc == TPM_ERR_DEACTIVATED) { > dev_info(&chip->dev, > "TPM is disabled/deactivated (0x%X)\n", rc); > diff --git a/drivers/char/tpm/tpm-sysfs.c b/drivers/char/tpm/tpm-sysfs.c > index 34e7fc7..48e30bd 100644 > --- a/drivers/char/tpm/tpm-sysfs.c > +++ b/drivers/char/tpm/tpm-sysfs.c > @@ -101,7 +101,7 @@ static ssize_t pcrs_show(struct device *dev, struct device_attribute *attr, > > num_pcrs = be32_to_cpu(cap.num_pcrs); > for (i = 0; i < num_pcrs; i++) { > - rc = tpm_pcr_read_dev(chip, i, digest); > + rc = tpm1_pcr_read(chip, i, digest); > if (rc) > break; > str += sprintf(str, "PCR-%02d: ", i); > diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h > index cd780c7..89740db 100644 > --- a/drivers/char/tpm/tpm.h > +++ b/drivers/char/tpm/tpm.h > @@ -511,7 +511,7 @@ extern void tpm_chip_unregister(struct tpm_chip *chip); > int tpm_sysfs_add_device(struct tpm_chip *chip); > void tpm_sysfs_del_device(struct tpm_chip *chip); > > -int tpm_pcr_read_dev(struct tpm_chip *chip, int pcr_idx, u8 *res_buf); > +int tpm1_pcr_read(struct tpm_chip *chip, int pcr_idx, u8 *res_buf); > > #ifdef CONFIG_ACPI > extern void tpm_add_ppi(struct tpm_chip *chip); > diff --git a/drivers/char/tpm/tpm2-cmd.c b/drivers/char/tpm/tpm2-cmd.c > index 5fc0e7c..afe8d47 100644 > --- a/drivers/char/tpm/tpm2-cmd.c > +++ b/drivers/char/tpm/tpm2-cmd.c > @@ -284,7 +284,7 @@ int tpm2_pcr_read(struct tpm_chip *chip, int pcr_idx, u8 *res_buf) > > rc = tpm_transmit_cmd(chip, &cmd, sizeof(cmd), > "attempting to read a pcr value"); > - if (rc == 0) { > + if (rc == 0 && res_buf) { > buf = cmd.params.pcrread_out.digest; > memcpy(res_buf, buf, TPM_DIGEST_SIZE); > } > @@ -861,7 +861,6 @@ int tpm2_do_selftest(struct tpm_chip *chip) > unsigned int loops; > unsigned int delay_msec = 100; > unsigned long duration; > - struct tpm2_cmd cmd; > int i; > > duration = tpm2_calc_ordinal_duration(chip, TPM2_CC_SELF_TEST); > @@ -874,19 +873,10 @@ int tpm2_do_selftest(struct tpm_chip *chip) > > for (i = 0; i < loops; i++) { > /* Attempt to read a PCR value */ > - cmd.header.in = tpm2_pcrread_header; > - cmd.params.pcrread_in.pcr_selects_cnt = cpu_to_be32(1); > - cmd.params.pcrread_in.hash_alg = cpu_to_be16(TPM2_ALG_SHA1); > - cmd.params.pcrread_in.pcr_select_size = TPM2_PCR_SELECT_MIN; > - cmd.params.pcrread_in.pcr_select[0] = 0x01; > - cmd.params.pcrread_in.pcr_select[1] = 0x00; > - cmd.params.pcrread_in.pcr_select[2] = 0x00; > - > - rc = tpm_transmit_cmd(chip, (u8 *) &cmd, sizeof(cmd), NULL); > + rc = tpm2_pcr_read(chip, 0, NULL); > if (rc < 0) > break; > > - rc = be32_to_cpu(cmd.header.out.return_code); > if (rc != TPM2_RC_TESTING) > break; > > -- > 1.9.1 >