Merge branch 'next-tpm' of git://git.kernel.org/pub/scm/linux/kernel/…

…git/jmorris/linux-security

Pull TPM updates from James Morris:
 "From Jarkko: The only new feature is non-blocking operation for
  /dev/tpm0"

* 'next-tpm' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security:
  tpm: Restore functionality to xen vtpm driver.
  tpm: add support for nonblocking operation
  tpm: add ptr to the tpm_space struct to file_priv
  tpm: Make SECURITYFS a weak dependency
  tpm: suppress transmit cmd error logs when TPM 1.2 is disabled/deactivated
  tpm: fix response size validation in tpm_get_random()

drivers/char/tpm/Kconfig

@@ -5,7 +5,7 @@
 menuconfig TCG_TPM
 	tristate "TPM Hardware Support"
 	depends on HAS_IOMEM
-	select SECURITYFS
+	imply SECURITYFS
 	select CRYPTO
 	select CRYPTO_HASH_INFO
 	---help---

drivers/char/tpm/tpm-dev-common.c

@@ -17,39 +17,69 @@
  * License.
  *
  */
+#include <linux/poll.h>
 #include <linux/slab.h>
 #include <linux/uaccess.h>
+#include <linux/workqueue.h>
 #include "tpm.h"
 #include "tpm-dev.h"
 
+static struct workqueue_struct *tpm_dev_wq;
+static DEFINE_MUTEX(tpm_dev_wq_lock);
+
+static void tpm_async_work(struct work_struct *work)
+{
+	struct file_priv *priv =
+			container_of(work, struct file_priv, async_work);
+	ssize_t ret;
+
+	mutex_lock(&priv->buffer_mutex);
+	priv->command_enqueued = false;
+	ret = tpm_transmit(priv->chip, priv->space, priv->data_buffer,
+			   sizeof(priv->data_buffer), 0);
+
+	tpm_put_ops(priv->chip);
+	if (ret > 0) {
+		priv->data_pending = ret;
+		mod_timer(&priv->user_read_timer, jiffies + (120 * HZ));
+	}
+	mutex_unlock(&priv->buffer_mutex);
+	wake_up_interruptible(&priv->async_wait);
+}
+
 static void user_reader_timeout(struct timer_list *t)
 {
 	struct file_priv *priv = from_timer(priv, t, user_read_timer);
 
 	pr_warn("TPM user space timeout is deprecated (pid=%d)\n",
 		task_tgid_nr(current));
 
-	schedule_work(&priv->work);
+	schedule_work(&priv->timeout_work);
 }
 
-static void timeout_work(struct work_struct *work)
+static void tpm_timeout_work(struct work_struct *work)
 {
-	struct file_priv *priv = container_of(work, struct file_priv, work);
+	struct file_priv *priv = container_of(work, struct file_priv,
+					      timeout_work);
 
 	mutex_lock(&priv->buffer_mutex);
 	priv->data_pending = 0;
 	memset(priv->data_buffer, 0, sizeof(priv->data_buffer));
 	mutex_unlock(&priv->buffer_mutex);
+	wake_up_interruptible(&priv->async_wait);
 }
 
 void tpm_common_open(struct file *file, struct tpm_chip *chip,
-		     struct file_priv *priv)
+		     struct file_priv *priv, struct tpm_space *space)
 {
 	priv->chip = chip;
+	priv->space = space;
+
 	mutex_init(&priv->buffer_mutex);
 	timer_setup(&priv->user_read_timer, user_reader_timeout, 0);
-	INIT_WORK(&priv->work, timeout_work);
-
+	INIT_WORK(&priv->timeout_work, tpm_timeout_work);
+	INIT_WORK(&priv->async_work, tpm_async_work);
+	init_waitqueue_head(&priv->async_wait);
 	file->private_data = priv;
 }
 
@@ -61,15 +91,17 @@ ssize_t tpm_common_read(struct file *file, char __user *buf,
 	int rc;
 
 	del_singleshot_timer_sync(&priv->user_read_timer);
-	flush_work(&priv->work);
+	flush_work(&priv->timeout_work);
 	mutex_lock(&priv->buffer_mutex);
 
 	if (priv->data_pending) {
 		ret_size = min_t(ssize_t, size, priv->data_pending);
-		rc = copy_to_user(buf, priv->data_buffer, ret_size);
-		memset(priv->data_buffer, 0, priv->data_pending);
-		if (rc)
-			ret_size = -EFAULT;
+		if (ret_size > 0) {
+			rc = copy_to_user(buf, priv->data_buffer, ret_size);
+			memset(priv->data_buffer, 0, priv->data_pending);
+			if (rc)
+				ret_size = -EFAULT;
+		}
 
 		priv->data_pending = 0;
 	}
@@ -79,13 +111,12 @@ ssize_t tpm_common_read(struct file *file, char __user *buf,
 }
 
 ssize_t tpm_common_write(struct file *file, const char __user *buf,
-			 size_t size, loff_t *off, struct tpm_space *space)
+			 size_t size, loff_t *off)
 {
 	struct file_priv *priv = file->private_data;
-	size_t in_size = size;
-	ssize_t out_size;
+	int ret = 0;
 
-	if (in_size > TPM_BUFSIZE)
+	if (size > TPM_BUFSIZE)
 		return -E2BIG;
 
 	mutex_lock(&priv->buffer_mutex);
@@ -94,56 +125,96 @@ ssize_t tpm_common_write(struct file *file, const char __user *buf,
 	 * tpm_read or a user_read_timer timeout. This also prevents split
 	 * buffered writes from blocking here.
 	 */
-	if (priv->data_pending != 0) {
-		mutex_unlock(&priv->buffer_mutex);
-		return -EBUSY;
+	if (priv->data_pending != 0 || priv->command_enqueued) {
+		ret = -EBUSY;
+		goto out;
 	}
 
-	if (copy_from_user
-	    (priv->data_buffer, (void __user *) buf, in_size)) {
-		mutex_unlock(&priv->buffer_mutex);
-		return -EFAULT;
+	if (copy_from_user(priv->data_buffer, buf, size)) {
+		ret = -EFAULT;
+		goto out;
 	}
 
-	if (in_size < 6 ||
-	    in_size < be32_to_cpu(*((__be32 *) (priv->data_buffer + 2)))) {
-		mutex_unlock(&priv->buffer_mutex);
-		return -EINVAL;
+	if (size < 6 ||
+	    size < be32_to_cpu(*((__be32 *)(priv->data_buffer + 2)))) {
+		ret = -EINVAL;
+		goto out;
 	}
 
 	/* 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;
+		ret = -EPIPE;
+		goto out;
 	}
-	out_size = tpm_transmit(priv->chip, space, priv->data_buffer,
-				sizeof(priv->data_buffer), 0);
 
-	tpm_put_ops(priv->chip);
-	if (out_size < 0) {
+	/*
+	 * If in nonblocking mode schedule an async job to send
+	 * the command return the size.
+	 * In case of error the err code will be returned in
+	 * the subsequent read call.
+	 */
+	if (file->f_flags & O_NONBLOCK) {
+		priv->command_enqueued = true;
+		queue_work(tpm_dev_wq, &priv->async_work);
 		mutex_unlock(&priv->buffer_mutex);
-		return out_size;
+		return size;
 	}
 
-	priv->data_pending = out_size;
+	ret = tpm_transmit(priv->chip, priv->space, priv->data_buffer,
+			   sizeof(priv->data_buffer), 0);
+	tpm_put_ops(priv->chip);
+
+	if (ret > 0) {
+		priv->data_pending = ret;
+		mod_timer(&priv->user_read_timer, jiffies + (120 * HZ));
+		ret = size;
+	}
+out:
 	mutex_unlock(&priv->buffer_mutex);
+	return ret;
+}
+
+__poll_t tpm_common_poll(struct file *file, poll_table *wait)
+{
+	struct file_priv *priv = file->private_data;
+	__poll_t mask = 0;
+
+	poll_wait(file, &priv->async_wait, wait);
 
-	/* Set a timeout by which the reader must come claim the result */
-	mod_timer(&priv->user_read_timer, jiffies + (120 * HZ));
+	if (priv->data_pending)
+		mask = EPOLLIN | EPOLLRDNORM;
+	else
+		mask = EPOLLOUT | EPOLLWRNORM;
 
-	return in_size;
+	return mask;
 }
 
 /*
  * Called on file close
  */
 void tpm_common_release(struct file *file, struct file_priv *priv)
 {
+	flush_work(&priv->async_work);
 	del_singleshot_timer_sync(&priv->user_read_timer);
-	flush_work(&priv->work);
+	flush_work(&priv->timeout_work);
 	file->private_data = NULL;
 	priv->data_pending = 0;
 }
+
+int __init tpm_dev_common_init(void)
+{
+	tpm_dev_wq = alloc_workqueue("tpm_dev_wq", WQ_MEM_RECLAIM, 0);
+
+	return !tpm_dev_wq ? -ENOMEM : 0;
+}
+
+void __exit tpm_dev_common_exit(void)
+{
+	if (tpm_dev_wq) {
+		destroy_workqueue(tpm_dev_wq);
+		tpm_dev_wq = NULL;
+	}
+}

drivers/char/tpm/tpm-dev.c

@@ -39,7 +39,7 @@ static int tpm_open(struct inode *inode, struct file *file)
 	if (priv == NULL)
 		goto out;
 
-	tpm_common_open(file, chip, priv);
+	tpm_common_open(file, chip, priv, NULL);
 
 	return 0;
 
@@ -48,12 +48,6 @@ static int tpm_open(struct inode *inode, struct file *file)
 	return -ENOMEM;
 }
 
-static ssize_t tpm_write(struct file *file, const char __user *buf,
-			 size_t size, loff_t *off)
-{
-	return tpm_common_write(file, buf, size, off, NULL);
-}
-
 /*
  * Called on file close
  */
@@ -73,6 +67,7 @@ const struct file_operations tpm_fops = {
 	.llseek = no_llseek,
 	.open = tpm_open,
 	.read = tpm_common_read,
-	.write = tpm_write,
+	.write = tpm_common_write,
+	.poll = tpm_common_poll,
 	.release = tpm_release,
 };

drivers/char/tpm/tpm-dev.h

@@ -2,27 +2,33 @@
 #ifndef _TPM_DEV_H
 #define _TPM_DEV_H
 
+#include <linux/poll.h>
 #include "tpm.h"
 
 struct file_priv {
 	struct tpm_chip *chip;
+	struct tpm_space *space;
 
-	/* Data passed to and from the tpm via the read/write calls */
-	size_t data_pending;
+	/* Holds the amount of data passed or an error code from async op */
+	ssize_t data_pending;
 	struct mutex buffer_mutex;
 
 	struct timer_list user_read_timer;      /* user needs to claim result */
-	struct work_struct work;
+	struct work_struct timeout_work;
+	struct work_struct async_work;
+	wait_queue_head_t async_wait;
+	bool command_enqueued;
 
 	u8 data_buffer[TPM_BUFSIZE];
 };
 
 void tpm_common_open(struct file *file, struct tpm_chip *chip,
-		     struct file_priv *priv);
+		     struct file_priv *priv, struct tpm_space *space);
 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);
+			 size_t size, loff_t *off);
+__poll_t tpm_common_poll(struct file *file, poll_table *wait);
 
+void tpm_common_release(struct file *file, struct file_priv *priv);
 #endif

drivers/char/tpm/tpm-interface.c

@@ -663,7 +663,8 @@ ssize_t tpm_transmit_cmd(struct tpm_chip *chip, struct tpm_space *space,
 		return len;
 
 	err = be32_to_cpu(header->return_code);
-	if (err != 0 && desc)
+	if (err != 0 && err != TPM_ERR_DISABLED && err != TPM_ERR_DEACTIVATED
+	    && desc)
 		dev_err(&chip->dev, "A TPM error (%d) occurred %s\n", err,
 			desc);
 	if (err)
@@ -1321,7 +1322,8 @@ int tpm_get_random(struct tpm_chip *chip, u8 *out, size_t max)
 		}
 
 		rlength = be32_to_cpu(tpm_cmd.header.out.length);
-		if (rlength < offsetof(struct tpm_getrandom_out, rng_data) +
+		if (rlength < TPM_HEADER_SIZE +
+			      offsetof(struct tpm_getrandom_out, rng_data) +
 			      recd) {
 			total = -EFAULT;
 			break;
@@ -1407,19 +1409,32 @@ static int __init tpm_init(void)
 	tpmrm_class = class_create(THIS_MODULE, "tpmrm");
 	if (IS_ERR(tpmrm_class)) {
 		pr_err("couldn't create tpmrm class\n");
-		class_destroy(tpm_class);
-		return PTR_ERR(tpmrm_class);
+		rc = PTR_ERR(tpmrm_class);
+		goto out_destroy_tpm_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(tpmrm_class);
-		class_destroy(tpm_class);
-		return rc;
+		goto out_destroy_tpmrm_class;
+	}
+
+	rc = tpm_dev_common_init();
+	if (rc) {
+		pr_err("tpm: failed to allocate char dev region\n");
+		goto out_unreg_chrdev;
 	}
 
 	return 0;
+
+out_unreg_chrdev:
+	unregister_chrdev_region(tpm_devt, 2 * TPM_NUM_DEVICES);
+out_destroy_tpmrm_class:
+	class_destroy(tpmrm_class);
+out_destroy_tpm_class:
+	class_destroy(tpm_class);
+
+	return rc;
 }
 
 static void __exit tpm_exit(void)
@@ -1428,6 +1443,7 @@ static void __exit tpm_exit(void)
 	class_destroy(tpm_class);
 	class_destroy(tpmrm_class);
 	unregister_chrdev_region(tpm_devt, 2*TPM_NUM_DEVICES);
+	tpm_dev_common_exit();
 }
 
 subsys_initcall(tpm_init);

drivers/char/tpm/tpm.h

@@ -604,4 +604,6 @@ int tpm2_commit_space(struct tpm_chip *chip, struct tpm_space *space,
 
 int tpm_bios_log_setup(struct tpm_chip *chip);
 void tpm_bios_log_teardown(struct tpm_chip *chip);
+int tpm_dev_common_init(void);
+void tpm_dev_common_exit(void);
 #endif

drivers/char/tpm/tpm2-cmd.c

@@ -329,7 +329,9 @@ int tpm2_get_random(struct tpm_chip *chip, u8 *dest, size_t max)
 			&buf.data[TPM_HEADER_SIZE];
 		recd = min_t(u32, be16_to_cpu(out->size), num_bytes);
 		if (tpm_buf_length(&buf) <
-		    offsetof(struct tpm2_get_random_out, buffer) + recd) {
+		    TPM_HEADER_SIZE +
+		    offsetof(struct tpm2_get_random_out, buffer) +
+		    recd) {
 			err = -EFAULT;
 			goto out;
 		}