From patchwork Tue Feb 20 22:53:47 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jarkko Sakkinen X-Patchwork-Id: 10230979 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 5AAE260594 for ; Tue, 20 Feb 2018 22:54:05 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 4B85D28928 for ; Tue, 20 Feb 2018 22:54:05 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 401BA28980; Tue, 20 Feb 2018 22:54:05 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id AE1A328982 for ; Tue, 20 Feb 2018 22:54:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751346AbeBTWyD (ORCPT ); Tue, 20 Feb 2018 17:54:03 -0500 Received: from mga03.intel.com ([134.134.136.65]:5788 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751053AbeBTWyA (ORCPT ); Tue, 20 Feb 2018 17:54:00 -0500 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga001.jf.intel.com ([10.7.209.18]) by orsmga103.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 20 Feb 2018 14:53:59 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.46,541,1511856000"; d="scan'208";a="32882854" Received: from nwochtma-mobl.ger.corp.intel.com (HELO localhost) ([10.249.254.17]) by orsmga001.jf.intel.com with ESMTP; 20 Feb 2018 14:53:55 -0800 From: Jarkko Sakkinen To: linux-integrity@vger.kernel.org Cc: linux-security-module@vger.kernel.org, Alexander Steffen , James Bottomley , Jarkko Sakkinen , Peter Huewe , Jarkko Sakkinen , Jason Gunthorpe , linux-kernel@vger.kernel.org (open list) Subject: [PATCH v4] tpm: Trigger only missing TPM 2.0 self tests Date: Wed, 21 Feb 2018 00:53:47 +0200 Message-Id: <20180220225347.25448-1-jarkko.sakkinen@linux.intel.com> X-Mailer: git-send-email 2.14.1 Sender: owner-linux-security-module@vger.kernel.org Precedence: bulk List-ID: X-Virus-Scanned: ClamAV using ClamSMTP From: Alexander Steffen My Nuvoton 6xx in a Dell XPS-13 has been intermittently failing to work (necessitating a reboot). The problem seems to be that the TPM gets into a state where the partial self-test doesn't return TPM_RC_SUCCESS (meaning all tests have run to completion), but instead returns TPM_RC_TESTING (meaning some tests are still running in the background). There are various theories that resending the self-test command actually causes the tests to restart and thus triggers more TPM_RC_TESTING returns until the timeout is exceeded. There are several issues here: firstly being we shouldn't slow down the boot sequence waiting for the self test to complete once the TPM backgrounds them. It will actually make available all functions that have passed and if it gets a failure return TPM_RC_FAILURE to every subsequent command. So the fix is to kick off self tests once and if they return TPM_RC_TESTING log that as a backgrounded self test and continue on. In order to prevent other tpm users from seeing any TPM_RC_TESTING returns (which it might if they send a command that needs a TPM subsystem which is still under test), we loop in tpm_transmit_cmd until either a timeout or we don't get a TPM_RC_TESTING return. Finally, there have been observations of strange returns from a partial test. One Nuvoton is occasionally returning TPM_RC_COMMAND_CODE, so treat any unexpected return from a partial self test as an indication we need to run a full self test. Signed-off-by: Alexander Steffen Signed-off-by: James Bottomley Signed-off-by: Jarkko Sakkinen Fixes: 2482b1bba5122b1d5516c909832bdd282015b8e9 --- v4: Some updatees from jarkko.sakkinen@linux.intel.com: - squashed tpm_buf migration - cleaned up a bunch of clutter from the original patch v3: - must pass through TPM2_RC_INTIALIZE v2: - review feedback: encapsulate transmission and rename NOWAIT constant - Rewrite selftest routine to run full test on any unexpected (meaning not TPM2_RC_TESTING, TPM2_RC_SUCCESS or TPM2_RC_FAILURE) from the partial selftest. drivers/char/tpm/tpm-interface.c | 20 ++++++++++++--- drivers/char/tpm/tpm.h | 1 + drivers/char/tpm/tpm2-cmd.c | 55 +++++++++++++--------------------------- 3 files changed, 34 insertions(+), 42 deletions(-) diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c index 9e80a953d693..1adb976a2e37 100644 --- a/drivers/char/tpm/tpm-interface.c +++ b/drivers/char/tpm/tpm-interface.c @@ -537,14 +537,26 @@ ssize_t tpm_transmit_cmd(struct tpm_chip *chip, struct tpm_space *space, const char *desc) { const struct tpm_output_header *header = buf; + unsigned int delay_msec = TPM2_DURATION_SHORT; int err; ssize_t len; - len = tpm_transmit(chip, space, (u8 *)buf, bufsiz, flags); - if (len < 0) - return len; + for (;;) { + len = tpm_transmit(chip, space, (u8 *)buf, bufsiz, flags); + if (len < 0) + return len; + err = be32_to_cpu(header->return_code); + if (err != TPM2_RC_TESTING) + break; + + delay_msec *= 2; + if (delay_msec > TPM2_DURATION_LONG) { + dev_err(&chip->dev, "the self test is still running\n"); + break; + } + tpm_msleep(delay_msec); + } - err = be32_to_cpu(header->return_code); if (err != 0 && desc) dev_err(&chip->dev, "A TPM error (%d) occurred %s\n", err, desc); diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h index f895fba4e20d..cccd5994a0e1 100644 --- a/drivers/char/tpm/tpm.h +++ b/drivers/char/tpm/tpm.h @@ -104,6 +104,7 @@ enum tpm2_return_codes { TPM2_RC_HASH = 0x0083, /* RC_FMT1 */ TPM2_RC_HANDLE = 0x008B, TPM2_RC_INITIALIZE = 0x0100, /* RC_VER1 */ + TPM2_RC_FAILURE = 0x0101, TPM2_RC_DISABLED = 0x0120, TPM2_RC_COMMAND_CODE = 0x0143, TPM2_RC_TESTING = 0x090A, /* RC_WARN */ diff --git a/drivers/char/tpm/tpm2-cmd.c b/drivers/char/tpm/tpm2-cmd.c index a700f8f9ead7..3b24311918d5 100644 --- a/drivers/char/tpm/tpm2-cmd.c +++ b/drivers/char/tpm/tpm2-cmd.c @@ -31,10 +31,6 @@ struct tpm2_startup_in { __be16 startup_type; } __packed; -struct tpm2_self_test_in { - u8 full_test; -} __packed; - struct tpm2_get_tpm_pt_in { __be32 cap_id; __be32 property_id; @@ -60,7 +56,6 @@ struct tpm2_get_random_out { union tpm2_cmd_params { struct tpm2_startup_in startup_in; - struct tpm2_self_test_in selftest_in; struct tpm2_get_tpm_pt_in get_tpm_pt_in; struct tpm2_get_tpm_pt_out get_tpm_pt_out; struct tpm2_get_random_in getrandom_in; @@ -827,16 +822,6 @@ unsigned long tpm2_calc_ordinal_duration(struct tpm_chip *chip, u32 ordinal) } EXPORT_SYMBOL_GPL(tpm2_calc_ordinal_duration); -#define TPM2_SELF_TEST_IN_SIZE \ - (sizeof(struct tpm_input_header) + \ - sizeof(struct tpm2_self_test_in)) - -static const struct tpm_input_header tpm2_selftest_header = { - .tag = cpu_to_be16(TPM2_ST_NO_SESSIONS), - .length = cpu_to_be32(TPM2_SELF_TEST_IN_SIZE), - .ordinal = cpu_to_be32(TPM2_CC_SELF_TEST) -}; - /** * tpm2_do_selftest() - ensure that all self tests have passed * @@ -853,28 +838,26 @@ static const struct tpm_input_header tpm2_selftest_header = { static int tpm2_do_selftest(struct tpm_chip *chip) { int rc; - unsigned int delay_msec = 10; - long duration; - struct tpm2_cmd cmd; - - duration = jiffies_to_msecs( - tpm2_calc_ordinal_duration(chip, TPM2_CC_SELF_TEST)); - - while (1) { - cmd.header.in = tpm2_selftest_header; - cmd.params.selftest_in.full_test = 0; + struct tpm_buf buf; + int full; - rc = tpm_transmit_cmd(chip, NULL, &cmd, TPM2_SELF_TEST_IN_SIZE, - 0, 0, "continue selftest"); + for (full = 0; full < 2; full++) { + rc = tpm_buf_init(&buf, TPM2_ST_NO_SESSIONS, TPM2_CC_SELF_TEST); + if (rc) + return rc; - if (rc != TPM2_RC_TESTING || delay_msec >= duration) - break; + tpm_buf_append_u8(&buf, full); + rc = tpm_transmit_cmd(chip, NULL, buf.data, PAGE_SIZE, 0, 0, + "attempting the self test\n"); + tpm_buf_destroy(&buf); - /* wait longer than before */ - delay_msec *= 2; - tpm_msleep(delay_msec); + if (rc == TPM2_RC_TESTING) + rc = TPM2_RC_SUCCESS; + if (rc == TPM2_RC_INITIALIZE || rc == TPM2_RC_SUCCESS) + return rc; } + dev_err(&chip->dev, "the self test failed, fullTest=%d\n", full); return rc; } @@ -1058,10 +1041,8 @@ int tpm2_auto_startup(struct tpm_chip *chip) goto out; rc = tpm2_do_selftest(chip); - if (rc != 0 && rc != TPM2_RC_INITIALIZE) { - dev_err(&chip->dev, "TPM self test failed\n"); + if (rc && rc != TPM2_RC_INITIALIZE) goto out; - } if (rc == TPM2_RC_INITIALIZE) { rc = tpm_startup(chip); @@ -1069,10 +1050,8 @@ int tpm2_auto_startup(struct tpm_chip *chip) goto out; rc = tpm2_do_selftest(chip); - if (rc) { - dev_err(&chip->dev, "TPM self test failed\n"); + if (rc) goto out; - } } rc = tpm2_get_pcr_allocation(chip);