From patchwork Sun Jan 22 23:44:33 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jarkko Sakkinen X-Patchwork-Id: 9531549 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 80166601D4 for ; Sun, 22 Jan 2017 23:45:34 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 752D827DA4 for ; Sun, 22 Jan 2017 23:45:34 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 69F1527F0B; Sun, 22 Jan 2017 23:45:34 +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 9BE1027DA4 for ; Sun, 22 Jan 2017 23:45:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750862AbdAVXpL (ORCPT ); Sun, 22 Jan 2017 18:45:11 -0500 Received: from mga14.intel.com ([192.55.52.115]:59313 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750853AbdAVXpK (ORCPT ); Sun, 22 Jan 2017 18:45:10 -0500 Received: from orsmga004.jf.intel.com ([10.7.209.38]) by fmsmga103.fm.intel.com with ESMTP; 22 Jan 2017 15:45:09 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.33,270,1477983600"; d="scan'208";a="51388129" Received: from ghffoulk-mobl.ger.corp.intel.com (HELO localhost) ([10.252.25.153]) by orsmga004.jf.intel.com with ESMTP; 22 Jan 2017 15:45:06 -0800 From: Jarkko Sakkinen To: tpmdd-devel@lists.sourceforge.net Cc: linux-security-module@vger.kernel.org, James Bottomley , Peter Huewe , Marcel Selhorst , Jarkko Sakkinen , Jason Gunthorpe , linux-kernel@vger.kernel.org (open list) Subject: [PATCH RFC v4 5/5] tpm2: expose spaces via a device link /dev/tpms Date: Mon, 23 Jan 2017 01:44:33 +0200 Message-Id: <20170122234438.12102-6-jarkko.sakkinen@linux.intel.com> X-Mailer: git-send-email 2.9.3 In-Reply-To: <20170122234438.12102-1-jarkko.sakkinen@linux.intel.com> References: <20170122234438.12102-1-jarkko.sakkinen@linux.intel.com> Sender: owner-linux-security-module@vger.kernel.org Precedence: bulk List-ID: X-Virus-Scanned: ClamAV using ClamSMTP From: James Bottomley Currently the tpm spaces are not exposed to userspace. Make this exposure via a separate device, which can now be opened multiple times because each read/write transaction goes separately via the space. Concurrency is protected by the chip->tpm_mutex for each read/write transaction separately. The TPM is cleared of all transient objects by the time the mutex is dropped, so there should be no interference between the kernel and userspace. Signed-off-by: James Bottomley --- drivers/char/tpm/Makefile | 2 +- drivers/char/tpm/tpm-chip.c | 71 ++++++++++++++++++++++++++++++++++++++-- drivers/char/tpm/tpm-interface.c | 13 ++++++-- drivers/char/tpm/tpm.h | 4 +++ drivers/char/tpm/tpms-dev.c | 65 ++++++++++++++++++++++++++++++++++++ 5 files changed, 149 insertions(+), 6 deletions(-) create mode 100644 drivers/char/tpm/tpms-dev.c diff --git a/drivers/char/tpm/Makefile b/drivers/char/tpm/Makefile index 13ff5da..e50d768 100644 --- a/drivers/char/tpm/Makefile +++ b/drivers/char/tpm/Makefile @@ -3,7 +3,7 @@ # obj-$(CONFIG_TCG_TPM) += tpm.o tpm-y := tpm-interface.o tpm-dev.o tpm-sysfs.o tpm-chip.o tpm2-cmd.o \ - tpm_eventlog.o tpm2-space.o tpm-dev-common.o + tpm_eventlog.o tpm2-space.o tpm-dev-common.o tpms-dev.o tpm-$(CONFIG_ACPI) += tpm_ppi.o tpm_acpi.o tpm-$(CONFIG_OF) += tpm_of.o obj-$(CONFIG_TCG_TIS_CORE) += tpm_tis_core.o diff --git a/drivers/char/tpm/tpm-chip.c b/drivers/char/tpm/tpm-chip.c index 993b9ae..ed4f887 100644 --- a/drivers/char/tpm/tpm-chip.c +++ b/drivers/char/tpm/tpm-chip.c @@ -33,6 +33,7 @@ DEFINE_IDR(dev_nums_idr); static DEFINE_MUTEX(idr_lock); struct class *tpm_class; +struct class *tpms_class; dev_t tpm_devt; /** @@ -132,6 +133,14 @@ static void tpm_dev_release(struct device *dev) kfree(chip); } +static void tpm_devs_release(struct device *dev) +{ + struct tpm_chip *chip = container_of(dev, struct tpm_chip, devs); + + /* release the master device reference */ + put_device(&chip->dev); +} + /** * tpm_chip_alloc() - allocate a new struct tpm_chip instance * @pdev: device to which the chip is associated @@ -168,27 +177,46 @@ struct tpm_chip *tpm_chip_alloc(struct device *pdev, chip->dev_num = rc; device_initialize(&chip->dev); + device_initialize(&chip->devs); chip->dev.class = tpm_class; chip->dev.release = tpm_dev_release; chip->dev.parent = pdev; chip->dev.groups = chip->groups; + chip->devs.parent = pdev; + chip->devs.class = tpms_class; + chip->devs.release = tpm_devs_release; + /* get extra reference on main device to hold on + * behalf of devs. This holds the chip structure + * while cdevs is in use. The corresponding put + * is in the tpm_devs_release */ + get_device(&chip->dev); + if (chip->dev_num == 0) chip->dev.devt = MKDEV(MISC_MAJOR, TPM_MINOR); else chip->dev.devt = MKDEV(MAJOR(tpm_devt), chip->dev_num); + chip->devs.devt = + MKDEV(MAJOR(tpm_devt), chip->dev_num + TPM_NUM_DEVICES); + rc = dev_set_name(&chip->dev, "tpm%d", chip->dev_num); if (rc) goto out; + rc = dev_set_name(&chip->devs, "tpms%d", chip->dev_num); + if (rc) + goto out; if (!pdev) chip->flags |= TPM_CHIP_FLAG_VIRTUAL; cdev_init(&chip->cdev, &tpm_fops); + cdev_init(&chip->cdevs, &tpms_fops); chip->cdev.owner = THIS_MODULE; + chip->cdevs.owner = THIS_MODULE; chip->cdev.kobj.parent = &chip->dev.kobj; + chip->cdevs.kobj.parent = &chip->devs.kobj; chip->work_space.context_buf = kzalloc(PAGE_SIZE, GFP_KERNEL); if (!chip->work_space.context_buf) { @@ -199,6 +227,7 @@ struct tpm_chip *tpm_chip_alloc(struct device *pdev, return chip; out: + put_device(&chip->devs); put_device(&chip->dev); return ERR_PTR(rc); } @@ -244,7 +273,7 @@ static int tpm_add_char_device(struct tpm_chip *chip) dev_name(&chip->dev), MAJOR(chip->dev.devt), MINOR(chip->dev.devt), rc); - return rc; + goto err_1; } rc = device_add(&chip->dev); @@ -254,16 +283,44 @@ static int tpm_add_char_device(struct tpm_chip *chip) dev_name(&chip->dev), MAJOR(chip->dev.devt), MINOR(chip->dev.devt), rc); - cdev_del(&chip->cdev); - return rc; + goto err_2; + } + + if (chip->flags & TPM_CHIP_FLAG_TPM2) + rc = cdev_add(&chip->cdevs, chip->devs.devt, 1); + if (rc) { + dev_err(&chip->dev, + "unable to cdev_add() %s, major %d, minor %d, err=%d\n", + dev_name(&chip->devs), MAJOR(chip->devs.devt), + MINOR(chip->devs.devt), rc); + + goto err_3; } + if (chip->flags & TPM_CHIP_FLAG_TPM2) + rc = device_add(&chip->devs); + if (rc) { + dev_err(&chip->dev, + "unable to device_register() %s, major %d, minor %d, err=%d\n", + dev_name(&chip->devs), MAJOR(chip->devs.devt), + MINOR(chip->devs.devt), rc); + + goto err_4; + } /* Make the chip available. */ mutex_lock(&idr_lock); idr_replace(&dev_nums_idr, chip, chip->dev_num); mutex_unlock(&idr_lock); return rc; + err_4: + cdev_del(&chip->cdevs); + err_3: + device_del(&chip->dev); + err_2: + cdev_del(&chip->cdev); + err_1: + return rc; } static void tpm_del_char_device(struct tpm_chip *chip) @@ -271,6 +328,11 @@ static void tpm_del_char_device(struct tpm_chip *chip) cdev_del(&chip->cdev); device_del(&chip->dev); + if (chip->flags & TPM_CHIP_FLAG_TPM2) { + cdev_del(&chip->cdevs); + device_del(&chip->devs); + } + /* Make the chip unavailable. */ mutex_lock(&idr_lock); idr_replace(&dev_nums_idr, NULL, chip->dev_num); @@ -282,6 +344,9 @@ static void tpm_del_char_device(struct tpm_chip *chip) tpm2_shutdown(chip, TPM2_SU_CLEAR); chip->ops = NULL; up_write(&chip->ops_sem); + /* will release the devs reference to the chip->dev unless + * something has cdevs open */ + put_device(&chip->devs); } static void tpm_del_legacy_sysfs(struct tpm_chip *chip) diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c index ef72c28..70ee347 100644 --- a/drivers/char/tpm/tpm-interface.c +++ b/drivers/char/tpm/tpm-interface.c @@ -1241,9 +1241,17 @@ static int __init tpm_init(void) return PTR_ERR(tpm_class); } - rc = alloc_chrdev_region(&tpm_devt, 0, TPM_NUM_DEVICES, "tpm"); + tpms_class = class_create(THIS_MODULE, "tpms"); + if (IS_ERR(tpms_class)) { + pr_err("couldn't create tpms class\n"); + class_destroy(tpm_class); + return PTR_ERR(tpms_class); + } + + rc = alloc_chrdev_region(&tpm_devt, 0, 2*TPM_NUM_DEVICES, "tpm"); if (rc < 0) { pr_err("tpm: failed to allocate char dev region\n"); + class_destroy(tpms_class); class_destroy(tpm_class); return rc; } @@ -1255,7 +1263,8 @@ static void __exit tpm_exit(void) { idr_destroy(&dev_nums_idr); class_destroy(tpm_class); - unregister_chrdev_region(tpm_devt, TPM_NUM_DEVICES); + class_destroy(tpms_class); + unregister_chrdev_region(tpm_devt, 2*TPM_NUM_DEVICES); } subsys_initcall(tpm_init); diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h index 37c9760..fdc916c 100644 --- a/drivers/char/tpm/tpm.h +++ b/drivers/char/tpm/tpm.h @@ -174,7 +174,9 @@ struct tpm_chip_seqops { struct tpm_chip { struct device dev; + struct device devs; struct cdev cdev; + struct cdev cdevs; /* A driver callback under ops cannot be run unless ops_sem is held * (sometimes implicitly, eg for the sysfs code). ops becomes null @@ -511,8 +513,10 @@ static inline void tpm_buf_append_u32(struct tpm_buf *buf, const u32 value) } extern struct class *tpm_class; +extern struct class *tpms_class; extern dev_t tpm_devt; extern const struct file_operations tpm_fops; +extern const struct file_operations tpms_fops; extern struct idr dev_nums_idr; enum tpm_transmit_flags { diff --git a/drivers/char/tpm/tpms-dev.c b/drivers/char/tpm/tpms-dev.c new file mode 100644 index 0000000..2ac2537 --- /dev/null +++ b/drivers/char/tpm/tpms-dev.c @@ -0,0 +1,65 @@ +/* + * Copyright (C) 2017 James.Bottomley@HansenPartnership.com + * + * GPLv2 + */ +#include +#include "tpm-dev.h" + +struct tpms_priv { + struct file_priv priv; + struct tpm_space space; +}; + +static int tpms_open(struct inode *inode, struct file *file) +{ + struct tpm_chip *chip; + struct tpms_priv *priv; + int rc; + + chip = container_of(inode->i_cdev, struct tpm_chip, cdevs); + priv = kzalloc(sizeof(*priv), GFP_KERNEL); + if (priv == NULL) + return -ENOMEM; + + rc = tpm2_init_space(chip, &priv->space); + if (rc) { + kfree(priv); + return -ENOMEM; + } + + tpm_common_open(file, chip, &priv->priv); + + return 0; +} + +static int tpms_release(struct inode *inode, struct file *file) +{ + struct file_priv *fpriv = file->private_data; + struct tpms_priv *priv = container_of(fpriv, struct tpms_priv, priv); + + tpm_common_release(file, fpriv); + kfree(priv->space.context_buf); + kfree(priv); + + return 0; +} + +ssize_t tpms_write(struct file *file, const char __user *buf, + size_t size, loff_t *off) +{ + struct file_priv *fpriv = file->private_data; + struct tpms_priv *priv = container_of(fpriv, struct tpms_priv, priv); + + return tpm_common_write(file, buf, size, off, &priv->space); +} + +const struct file_operations tpms_fops = { + .owner = THIS_MODULE, + .llseek = no_llseek, + .open = tpms_open, + .read = tpm_common_read, + .write = tpms_write, + .release = tpms_release, +}; +