[RFC,v4,4/5] tpm: split out tpm-dev.c into tpm-dev.c and tpm-common-dev.c

Message ID	20170122234438.12102-5-jarkko.sakkinen@linux.intel.com (mailing list archive)
State	New, archived
Headers	show Return-Path: <linux-security-module-owner@kernel.org> From: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> To: tpmdd-devel@lists.sourceforge.net Cc: linux-security-module@vger.kernel.org, James Bottomley <James.Bottomley@HansenPartnership.com>, Peter Huewe <peterhuewe@gmx.de>, Marcel Selhorst <tpmdd@selhorst.net>, Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>, Jason Gunthorpe <jgunthorpe@obsidianresearch.com>, linux-kernel@vger.kernel.org (open list) Subject: [PATCH RFC v4 4/5] tpm: split out tpm-dev.c into tpm-dev.c and tpm-common-dev.c Date: Mon, 23 Jan 2017 01:44:32 +0200 Message-Id: <20170122234438.12102-5-jarkko.sakkinen@linux.intel.com> 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

diff --git a/drivers/char/tpm/Makefile b/drivers/char/tpm/Makefile index 251d0ed..13ff5da 100644 --- a/drivers/char/tpm/Makefile +++ b/drivers/char/tpm/Makefile @@ -3,7 +3,7 @@ # obj-$(CONFIG_TCG_TPM) += tpm.o tpm-y := tpm-interface.o tpm-dev.o tpm-sysfs.o tpm-chip.o tpm2-cmd.o \ - tpm_eventlog.o tpm2-space.o + tpm_eventlog.o tpm2-space.o tpm-dev-common.o tpm-$(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-dev-common.c b/drivers/char/tpm/tpm-dev-common.c new file mode 100644 index 0000000..0156562 --- /dev/null +++ b/drivers/char/tpm/tpm-dev-common.c @@ -0,0 +1,145 @@ +/* + * Copyright (C) 2004 IBM Corporation + * Authors: + * Leendert van Doorn <leendert@watson.ibm.com> + * Dave Safford <safford@watson.ibm.com> + * Reiner Sailer <sailer@watson.ibm.com> + * Kylene Hall <kjhall@us.ibm.com> + * + * Copyright (C) 2013 Obsidian Research Corp + * Jason Gunthorpe <jgunthorpe@obsidianresearch.com> + * + * Device file system interface to the TPM + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License as + * published by the Free Software Foundation, version 2 of the + * License. + * + */ +#include <linux/slab.h> +#include <linux/uaccess.h> +#include "tpm.h" +#include "tpm-dev.h" + +static void user_reader_timeout(unsigned long ptr) +{ + struct file_priv *priv = (struct file_priv *)ptr; + + schedule_work(&priv->work); +} + +static void timeout_work(struct work_struct *work) +{ + struct file_priv *priv = container_of(work, struct file_priv, work); + + mutex_lock(&priv->buffer_mutex); + atomic_set(&priv->data_pending, 0); + memset(priv->data_buffer, 0, sizeof(priv->data_buffer)); + mutex_unlock(&priv->buffer_mutex); +} + +void tpm_common_open(struct file *file, struct tpm_chip *chip, + struct file_priv *priv) +{ + priv->chip = chip; + atomic_set(&priv->data_pending, 0); + mutex_init(&priv->buffer_mutex); + setup_timer(&priv->user_read_timer, user_reader_timeout, + (unsigned long)priv); + INIT_WORK(&priv->work, timeout_work); + + file->private_data = priv; +} + +ssize_t tpm_common_read(struct file *file, char __user *buf, + size_t size, loff_t *off) +{ + struct file_priv *priv = file->private_data; + ssize_t ret_size; + ssize_t orig_ret_size; + int rc; + + del_singleshot_timer_sync(&priv->user_read_timer); + flush_work(&priv->work); + ret_size = atomic_read(&priv->data_pending); + if (ret_size > 0) { /* relay data */ + orig_ret_size = ret_size; + if (size < ret_size) + ret_size = size; + + mutex_lock(&priv->buffer_mutex); + rc = copy_to_user(buf, priv->data_buffer, ret_size); + memset(priv->data_buffer, 0, orig_ret_size); + if (rc) + ret_size = -EFAULT; + + mutex_unlock(&priv->buffer_mutex); + } + + atomic_set(&priv->data_pending, 0); + + return ret_size; +} + +ssize_t tpm_common_write(struct file *file, const char __user *buf, + size_t size, loff_t *off, struct tpm_space *space) +{ + struct file_priv *priv = file->private_data; + size_t in_size = size; + ssize_t out_size; + + /* Cannot perform a write until the read has cleared either via + * tpm_read or a user_read_timer timeout. This also prevents split + * buffered writes from blocking here. + */ + if (atomic_read(&priv->data_pending) != 0) + return -EBUSY; + + if (in_size > TPM_BUFSIZE) + return -E2BIG; + + mutex_lock(&priv->buffer_mutex); + + if (copy_from_user + (priv->data_buffer, (void __user *) buf, in_size)) { + mutex_unlock(&priv->buffer_mutex); + return -EFAULT; + } + + /* atomic tpm command send and result receive. We only hold the ops + * lock during this period so that the tpm can be unregistered even if + * the char dev is held open. + */ + if (tpm_try_get_ops(priv->chip)) { + mutex_unlock(&priv->buffer_mutex); + return -EPIPE; + } + out_size = tpm_transmit(priv->chip, space, priv->data_buffer, + sizeof(priv->data_buffer), 0); + + tpm_put_ops(priv->chip); + if (out_size < 0) { + mutex_unlock(&priv->buffer_mutex); + return out_size; + } + + atomic_set(&priv->data_pending, out_size); + mutex_unlock(&priv->buffer_mutex); + + /* Set a timeout by which the reader must come claim the result */ + mod_timer(&priv->user_read_timer, jiffies + (60 * HZ)); + + return in_size; +} + +/* + * Called on file close + */ +void tpm_common_release(struct file *file, struct file_priv *priv) +{ + del_singleshot_timer_sync(&priv->user_read_timer); + flush_work(&priv->work); + file->private_data = NULL; + atomic_set(&priv->data_pending, 0); +} diff --git a/drivers/char/tpm/tpm-dev.c b/drivers/char/tpm/tpm-dev.c index 249eeb0..ebd74ab 100644 --- a/drivers/char/tpm/tpm-dev.c +++ b/drivers/char/tpm/tpm-dev.c @@ -18,45 +18,15 @@ * */ #include <linux/slab.h> -#include <linux/uaccess.h> -#include "tpm.h" - -struct file_priv { - struct tpm_chip *chip; - - /* Data passed to and from the tpm via the read/write calls */ - atomic_t data_pending; - struct mutex buffer_mutex; - - struct timer_list user_read_timer; /* user needs to claim result */ - struct work_struct work; - - u8 data_buffer[TPM_BUFSIZE]; -}; - -static void user_reader_timeout(unsigned long ptr) -{ - struct file_priv *priv = (struct file_priv *)ptr; - - schedule_work(&priv->work); -} - -static void timeout_work(struct work_struct *work) -{ - struct file_priv *priv = container_of(work, struct file_priv, work); - - mutex_lock(&priv->buffer_mutex); - atomic_set(&priv->data_pending, 0); - memset(priv->data_buffer, 0, sizeof(priv->data_buffer)); - mutex_unlock(&priv->buffer_mutex); -} +#include "tpm-dev.h" static int tpm_open(struct inode *inode, struct file *file) { - struct tpm_chip *chip = - container_of(inode->i_cdev, struct tpm_chip, cdev); + struct tpm_chip *chip; struct file_priv *priv; + chip = container_of(inode->i_cdev, struct tpm_chip, cdev); + /* It's assured that the chip will be opened just once, * by the check of is_open variable, which is protected * by driver_lock. */ @@ -66,100 +36,22 @@ static int tpm_open(struct inode *inode, struct file *file) } priv = kzalloc(sizeof(*priv), GFP_KERNEL); - if (priv == NULL) { - clear_bit(0, &chip->is_open); - return -ENOMEM; - } + if (priv == NULL) + goto out; - priv->chip = chip; - atomic_set(&priv->data_pending, 0); - mutex_init(&priv->buffer_mutex); - setup_timer(&priv->user_read_timer, user_reader_timeout, - (unsigned long)priv); - INIT_WORK(&priv->work, timeout_work); + tpm_common_open(file, chip, priv); - file->private_data = priv; return 0; -} - -static ssize_t tpm_read(struct file *file, char __user *buf, - size_t size, loff_t *off) -{ - struct file_priv *priv = file->private_data; - ssize_t ret_size; - int rc; - - del_singleshot_timer_sync(&priv->user_read_timer); - flush_work(&priv->work); - ret_size = atomic_read(&priv->data_pending); - if (ret_size > 0) { /* relay data */ - ssize_t orig_ret_size = ret_size; - if (size < ret_size) - ret_size = size; - mutex_lock(&priv->buffer_mutex); - rc = copy_to_user(buf, priv->data_buffer, ret_size); - memset(priv->data_buffer, 0, orig_ret_size); - if (rc) - ret_size = -EFAULT; - - mutex_unlock(&priv->buffer_mutex); - } - - atomic_set(&priv->data_pending, 0); - - return ret_size; + out: + clear_bit(0, &chip->is_open); + return -ENOMEM; } static ssize_t tpm_write(struct file *file, const char __user *buf, size_t size, loff_t *off) { - struct file_priv *priv = file->private_data; - size_t in_size = size; - ssize_t out_size; - - /* cannot perform a write until the read has cleared - either via tpm_read or a user_read_timer timeout. - This also prevents splitted buffered writes from blocking here. - */ - if (atomic_read(&priv->data_pending) != 0) - return -EBUSY; - - if (in_size > TPM_BUFSIZE) - return -E2BIG; - - mutex_lock(&priv->buffer_mutex); - - if (copy_from_user - (priv->data_buffer, (void __user *) buf, in_size)) { - mutex_unlock(&priv->buffer_mutex); - return -EFAULT; - } - - /* atomic tpm command send and result receive. We only hold the ops - * lock during this period so that the tpm can be unregistered even if - * the char dev is held open. - */ - if (tpm_try_get_ops(priv->chip)) { - mutex_unlock(&priv->buffer_mutex); - return -EPIPE; - } - out_size = tpm_transmit(priv->chip, NULL, priv->data_buffer, - sizeof(priv->data_buffer), 0); - - tpm_put_ops(priv->chip); - if (out_size < 0) { - mutex_unlock(&priv->buffer_mutex); - return out_size; - } - - atomic_set(&priv->data_pending, out_size); - mutex_unlock(&priv->buffer_mutex); - - /* Set a timeout by which the reader must come claim the result */ - mod_timer(&priv->user_read_timer, jiffies + (60 * HZ)); - - return in_size; + return tpm_common_write(file, buf, size, off, NULL); } /* @@ -169,12 +61,10 @@ static int tpm_release(struct inode *inode, struct file *file) { struct file_priv *priv = file->private_data; - del_singleshot_timer_sync(&priv->user_read_timer); - flush_work(&priv->work); - file->private_data = NULL; - atomic_set(&priv->data_pending, 0); + tpm_common_release(file, priv); clear_bit(0, &priv->chip->is_open); kfree(priv); + return 0; } @@ -182,9 +72,7 @@ const struct file_operations tpm_fops = { .owner = THIS_MODULE, .llseek = no_llseek, .open = tpm_open, - .read = tpm_read, + .read = tpm_common_read, .write = tpm_write, .release = tpm_release, }; - - diff --git a/drivers/char/tpm/tpm-dev.h b/drivers/char/tpm/tpm-dev.h new file mode 100644 index 0000000..ff15cf7 --- /dev/null +++ b/drivers/char/tpm/tpm-dev.h @@ -0,0 +1,27 @@ +#ifndef _TPM_DEV_H +#define _TPM_DEV_H + +#include "tpm.h" + +struct file_priv { + struct tpm_chip *chip; + + /* Data passed to and from the tpm via the read/write calls */ + atomic_t data_pending; + struct mutex buffer_mutex; + + struct timer_list user_read_timer; /* user needs to claim result */ + struct work_struct work; + + u8 data_buffer[TPM_BUFSIZE]; +}; + +void tpm_common_open(struct file *file, struct tpm_chip *chip, + struct file_priv *priv); +ssize_t tpm_common_read(struct file *file, char __user *buf, + size_t size, loff_t *off); +ssize_t tpm_common_write(struct file *file, const char __user *buf, + size_t size, loff_t *off, struct tpm_space *space); +void tpm_common_release(struct file *file, struct file_priv *priv); + +#endif

[RFC,v4,4/5] tpm: split out tpm-dev.c into tpm-dev.c and tpm-common-dev.c

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