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Message-ID: <1484335110.2527.25.camel@HansenPartnership.com>
Date: Fri, 13 Jan 2017 11:18:30 -0800
From: James Bottomley <James.Bottomley@...senPartnership.com>
To: Jarkko Sakkinen <jarkko.sakkinen@...ux.intel.com>,
tpmdd-devel@...ts.sourceforge.net
Cc: open list <linux-kernel@...r.kernel.org>,
linux-security-module@...r.kernel.org
Subject: Re: [tpmdd-devel] [PATCH RFC v2 4/5] tpm: split out tpm-dev.c into
tpm-dev.c and tpm-common-dev.c
This version has a bug in that it doesn't do a clear_bit(0, &chip
->is_open) on release. so fixed that
James
---
>From c006f181988dd2fd54e5a84f3e4a6dc0157c96f5 Mon Sep 17 00:00:00 2001
From: James Bottomley <James.Bottomley@...senPartnership.com>
Date: Tue, 10 Jan 2017 19:08:53 -0800
Subject: [PATCH 4/5] tpm: split out tpm-dev.c into tpm-dev.c and
tpm-common-dev.c
In preparation for adding a space management device, split out all of
the common routines that would be shareable between these device types
into a common file.
Signed-off-by: James Bottomley <James.Bottomley@...senPartnership.com>
---
drivers/char/tpm/Makefile | 2 +-
drivers/char/tpm/tpm-dev-common.c | 145 ++++++++++++++++++++++++++++++++++++++
drivers/char/tpm/tpm-dev.c | 142 +++++--------------------------------
drivers/char/tpm/tpm-dev.h | 27 +++++++
4 files changed, 189 insertions(+), 127 deletions(-)
create mode 100644 drivers/char/tpm/tpm-dev-common.c
create mode 100644 drivers/char/tpm/tpm-dev.h
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@...son.ibm.com>
+ * Dave Safford <safford@...son.ibm.com>
+ * Reiner Sailer <sailer@...son.ibm.com>
+ * Kylene Hall <kjhall@...ibm.com>
+ *
+ * Copyright (C) 2013 Obsidian Research Corp
+ * Jason Gunthorpe <jgunthorpe@...idianresearch.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..92fc2c6 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 +61,12 @@ 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 +74,7 @@ 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
--
2.6.6
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