[PATCH v1 0/2] Run TPM2_Shutdown on system shutdown

[PATCH v1 0/2] Run TPM2_Shutdown on system shutdown

[Josh Zimmerman]

This is a backport to the 4.4 stable kernel.

I had to manually apply a couple of cherry picks and resolve some merge
conflicts, so some of this may be worth a closer look and test on Jarkko's or
some other TPM maintainer's part

This patchset causes all devices in the tpm class to issue TPM2_Shutdown
when the system is shutting down.

As a prerequisite, it adds a "shutdown" method to "struct class".

Backporting to 4.4 since this bug can lock users out of their TPMs.

 drivers/base/core.c                 |   6 +++++-
 drivers/char/tpm/tpm-chip.c         | 121 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++--------------
 drivers/char/tpm/tpm-dev.c          |  15 +++++++++++----
 drivers/char/tpm/tpm-interface.c    |  49 ++++++++++++++++++++++++++-----------------------
 drivers/char/tpm/tpm-sysfs.c        |  18 +++++++++++++++---
 drivers/char/tpm/tpm.h              |  15 +++++++++------
 drivers/char/tpm/tpm2-cmd.c         |   8 ++++----
 drivers/char/tpm/tpm_atmel.c        |  14 +++++++-------
 drivers/char/tpm/tpm_i2c_atmel.c    |  16 ++++++++--------
 drivers/char/tpm/tpm_i2c_infineon.c |   6 +++---
 drivers/char/tpm/tpm_i2c_nuvoton.c  |  22 +++++++++++-----------
 drivers/char/tpm/tpm_infineon.c     |  22 +++++++++++-----------
 drivers/char/tpm/tpm_nsc.c          |  20 ++++++++++----------
 drivers/char/tpm/tpm_tis.c          |  16 ++++++++--------
 include/linux/device.h              |   2 ++
 15 files changed, 237 insertions(+), 113 deletions(-)

[PATCH v1 1/4] tpm: Get rid of chip->pdev

[Josh Zimmerman]

From: Jason Gunthorpe <jgunthorpe@obsidianresearch.com>

This is a hold over from before the struct device conversion.

- All prints should be using &chip->dev, which is the Linux
  standard. This changes prints to use tpm0 as the device name,
  not the PnP/etc ID.
- The few places involving sysfs/modules that really do need the
  parent just use chip->dev.parent instead
- We no longer need to get_device(pdev) in any places since it is no
  longer used by any of the code. The kref on the parent is held
  by the device core during device_add and dropped in device_del

Signed-off-by: Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
Signed-off-by: Stefan Berger <stefanb@linux.vnet.ibm.com>
Tested-by: Stefan Berger <stefanb@linux.vnet.ibm.com>
Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Tested-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
(cherry picked from commit 8cfffc9d4d3786d3b496a021d7224e06328bac7d)
---
 drivers/char/tpm/tpm-chip.c         | 15 ++++++---------
 drivers/char/tpm/tpm-dev.c          |  4 +---
 drivers/char/tpm/tpm-interface.c    | 30 ++++++++++++++++--------------
 drivers/char/tpm/tpm-sysfs.c        |  6 +++---
 drivers/char/tpm/tpm.h              |  3 +--
 drivers/char/tpm/tpm2-cmd.c         |  8 ++++----
 drivers/char/tpm/tpm_atmel.c        | 14 +++++++-------
 drivers/char/tpm/tpm_i2c_atmel.c    | 16 ++++++++--------
 drivers/char/tpm/tpm_i2c_infineon.c |  6 +++---
 drivers/char/tpm/tpm_i2c_nuvoton.c  | 22 +++++++++++-----------
 drivers/char/tpm/tpm_infineon.c     | 22 +++++++++++-----------
 drivers/char/tpm/tpm_nsc.c          | 20 ++++++++++----------
 drivers/char/tpm/tpm_tis.c          | 16 ++++++++--------
 13 files changed, 89 insertions(+), 93 deletions(-)

diff --git a/drivers/char/tpm/tpm-chip.c b/drivers/char/tpm/tpm-chip.c
index 252142524ff2..f55b4921c723 100644
--- a/drivers/char/tpm/tpm-chip.c
+++ b/drivers/char/tpm/tpm-chip.c
@@ -49,7 +49,7 @@ struct tpm_chip *tpm_chip_find_get(int chip_num)
 		if (chip_num != TPM_ANY_NUM && chip_num != pos->dev_num)
 			continue;
 
-		if (try_module_get(pos->pdev->driver->owner)) {
+		if (try_module_get(pos->dev.parent->driver->owner)) {
 			chip = pos;
 			break;
 		}
@@ -112,13 +112,11 @@ struct tpm_chip *tpmm_chip_alloc(struct device *dev,
 
 	scnprintf(chip->devname, sizeof(chip->devname), "tpm%d", chip->dev_num);
 
-	chip->pdev = dev;
-
 	dev_set_drvdata(dev, chip);
 
 	chip->dev.class = tpm_class;
 	chip->dev.release = tpm_dev_release;
-	chip->dev.parent = chip->pdev;
+	chip->dev.parent = dev;
 #ifdef CONFIG_ACPI
 	chip->dev.groups = chip->groups;
 #endif
@@ -133,7 +131,7 @@ struct tpm_chip *tpmm_chip_alloc(struct device *dev,
 	device_initialize(&chip->dev);
 
 	cdev_init(&chip->cdev, &tpm_fops);
-	chip->cdev.owner = chip->pdev->driver->owner;
+	chip->cdev.owner = dev->driver->owner;
 	chip->cdev.kobj.parent = &chip->dev.kobj;
 
 	devm_add_action(dev, (void (*)(void *)) put_device, &chip->dev);
@@ -236,9 +234,8 @@ int tpm_chip_register(struct tpm_chip *chip)
 	chip->flags |= TPM_CHIP_FLAG_REGISTERED;
 
 	if (!(chip->flags & TPM_CHIP_FLAG_TPM2)) {
-		rc = __compat_only_sysfs_link_entry_to_kobj(&chip->pdev->kobj,
-							    &chip->dev.kobj,
-							    "ppi");
+		rc = __compat_only_sysfs_link_entry_to_kobj(
+		    &chip->dev.parent->kobj, &chip->dev.kobj, "ppi");
 		if (rc && rc != -ENOENT) {
 			tpm_chip_unregister(chip);
 			return rc;
@@ -273,7 +270,7 @@ void tpm_chip_unregister(struct tpm_chip *chip)
 	synchronize_rcu();
 
 	if (!(chip->flags & TPM_CHIP_FLAG_TPM2))
-		sysfs_remove_link(&chip->pdev->kobj, "ppi");
+		sysfs_remove_link(&chip->dev.parent->kobj, "ppi");
 
 	tpm1_chip_unregister(chip);
 	tpm_del_char_device(chip);
diff --git a/drivers/char/tpm/tpm-dev.c b/drivers/char/tpm/tpm-dev.c
index 4f3137d9a35e..6ed0651cbe58 100644
--- a/drivers/char/tpm/tpm-dev.c
+++ b/drivers/char/tpm/tpm-dev.c
@@ -61,7 +61,7 @@ static int tpm_open(struct inode *inode, struct file *file)
 	 * by the check of is_open variable, which is protected
 	 * by driver_lock. */
 	if (test_and_set_bit(0, &chip->is_open)) {
-		dev_dbg(chip->pdev, "Another process owns this TPM\n");
+		dev_dbg(&chip->dev, "Another process owns this TPM\n");
 		return -EBUSY;
 	}
 
@@ -79,7 +79,6 @@ static int tpm_open(struct inode *inode, struct file *file)
 	INIT_WORK(&priv->work, timeout_work);
 
 	file->private_data = priv;
-	get_device(chip->pdev);
 	return 0;
 }
 
@@ -166,7 +165,6 @@ static int tpm_release(struct inode *inode, struct file *file)
 	file->private_data = NULL;
 	atomic_set(&priv->data_pending, 0);
 	clear_bit(0, &priv->chip->is_open);
-	put_device(priv->chip->pdev);
 	kfree(priv);
 	return 0;
 }
diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c
index 17abe52e6365..4391953a7711 100644
--- a/drivers/char/tpm/tpm-interface.c
+++ b/drivers/char/tpm/tpm-interface.c
@@ -343,7 +343,7 @@ ssize_t tpm_transmit(struct tpm_chip *chip, const u8 *buf, size_t bufsiz,
 	if (count == 0)
 		return -ENODATA;
 	if (count > bufsiz) {
-		dev_err(chip->pdev,
+		dev_err(&chip->dev,
 			"invalid count value %x %zx\n", count, bufsiz);
 		return -E2BIG;
 	}
@@ -353,7 +353,7 @@ ssize_t tpm_transmit(struct tpm_chip *chip, const u8 *buf, size_t bufsiz,
 
 	rc = chip->ops->send(chip, (u8 *) buf, count);
 	if (rc < 0) {
-		dev_err(chip->pdev,
+		dev_err(&chip->dev,
 			"tpm_transmit: tpm_send: error %zd\n", rc);
 		goto out;
 	}
@@ -372,7 +372,7 @@ ssize_t tpm_transmit(struct tpm_chip *chip, const u8 *buf, size_t bufsiz,
 			goto out_recv;
 
 		if (chip->ops->req_canceled(chip, status)) {
-			dev_err(chip->pdev, "Operation Canceled\n");
+			dev_err(&chip->dev, "Operation Canceled\n");
 			rc = -ECANCELED;
 			goto out;
 		}
@@ -382,14 +382,14 @@ ssize_t tpm_transmit(struct tpm_chip *chip, const u8 *buf, size_t bufsiz,
 	} while (time_before(jiffies, stop));
 
 	chip->ops->cancel(chip);
-	dev_err(chip->pdev, "Operation Timed out\n");
+	dev_err(&chip->dev, "Operation Timed out\n");
 	rc = -ETIME;
 	goto out;
 
 out_recv:
 	rc = chip->ops->recv(chip, (u8 *) buf, bufsiz);
 	if (rc < 0)
-		dev_err(chip->pdev,
+		dev_err(&chip->dev,
 			"tpm_transmit: tpm_recv: error %zd\n", rc);
 out:
 	if (!(flags & TPM_TRANSMIT_UNLOCKED))
@@ -416,7 +416,7 @@ ssize_t tpm_transmit_cmd(struct tpm_chip *chip, const void *cmd,
 
 	err = be32_to_cpu(header->return_code);
 	if (err != 0 && desc)
-		dev_err(chip->pdev, "A TPM error (%d) occurred %s\n", err,
+		dev_err(&chip->dev, "A TPM error (%d) occurred %s\n", err,
 			desc);
 
 	return err;
@@ -514,7 +514,7 @@ int tpm_get_timeouts(struct tpm_chip *chip)
 	if (rc == TPM_ERR_INVALID_POSTINIT) {
 		/* The TPM is not started, we are the first to talk to it.
 		   Execute a startup command. */
-		dev_info(chip->pdev, "Issuing TPM_STARTUP");
+		dev_info(&chip->dev, "Issuing TPM_STARTUP");
 		if (tpm_startup(chip, TPM_ST_CLEAR))
 			return rc;
 
@@ -526,7 +526,7 @@ int tpm_get_timeouts(struct tpm_chip *chip)
 				      0, NULL);
 	}
 	if (rc) {
-		dev_err(chip->pdev,
+		dev_err(&chip->dev,
 			"A TPM error (%zd) occurred attempting to determine the timeouts\n",
 			rc);
 		goto duration;
@@ -565,7 +565,7 @@ int tpm_get_timeouts(struct tpm_chip *chip)
 
 	/* Report adjusted timeouts */
 	if (chip->vendor.timeout_adjusted) {
-		dev_info(chip->pdev,
+		dev_info(&chip->dev,
 			 HW_ERR "Adjusting reported timeouts: A %lu->%luus B %lu->%luus C %lu->%luus D %lu->%luus\n",
 			 old_timeout[0], new_timeout[0],
 			 old_timeout[1], new_timeout[1],
@@ -612,7 +612,7 @@ duration:
 		chip->vendor.duration[TPM_MEDIUM] *= 1000;
 		chip->vendor.duration[TPM_LONG] *= 1000;
 		chip->vendor.duration_adjusted = true;
-		dev_info(chip->pdev, "Adjusting TPM timeout parameters.");
+		dev_info(&chip->dev, "Adjusting TPM timeout parameters.");
 	}
 	return 0;
 }
@@ -802,7 +802,9 @@ int tpm_do_selftest(struct tpm_chip *chip)
 		 * around 300ms while the self test is ongoing, keep trying
 		 * until the self test duration expires. */
 		if (rc == -ETIME) {
-			dev_info(chip->pdev, HW_ERR "TPM command timed out during continue self test");
+			dev_info(
+			    &chip->dev, HW_ERR
+			    "TPM command timed out during continue self test");
 			msleep(delay_msec);
 			continue;
 		}
@@ -812,7 +814,7 @@ int tpm_do_selftest(struct tpm_chip *chip)
 
 		rc = be32_to_cpu(cmd.header.out.return_code);
 		if (rc == TPM_ERR_DISABLED || rc == TPM_ERR_DEACTIVATED) {
-			dev_info(chip->pdev,
+			dev_info(&chip->dev,
 				 "TPM is disabled/deactivated (0x%X)\n", rc);
 			/* TPM is disabled and/or deactivated; driver can
 			 * proceed and TPM does handle commands for
@@ -966,10 +968,10 @@ int tpm_pm_suspend(struct device *dev)
 	}
 
 	if (rc)
-		dev_err(chip->pdev,
+		dev_err(&chip->dev,
 			"Error (%d) sending savestate before suspend\n", rc);
 	else if (try > 0)
-		dev_warn(chip->pdev, "TPM savestate took %dms\n",
+		dev_warn(&chip->dev, "TPM savestate took %dms\n",
 			 try * TPM_TIMEOUT_RETRY);
 
 	return rc;
diff --git a/drivers/char/tpm/tpm-sysfs.c b/drivers/char/tpm/tpm-sysfs.c
index f880856aa75e..10370c22e98b 100644
--- a/drivers/char/tpm/tpm-sysfs.c
+++ b/drivers/char/tpm/tpm-sysfs.c
@@ -284,16 +284,16 @@ static const struct attribute_group tpm_dev_group = {
 int tpm_sysfs_add_device(struct tpm_chip *chip)
 {
 	int err;
-	err = sysfs_create_group(&chip->pdev->kobj,
+	err = sysfs_create_group(&chip->dev.parent->kobj,
 				 &tpm_dev_group);
 
 	if (err)
-		dev_err(chip->pdev,
+		dev_err(&chip->dev,
 			"failed to create sysfs attributes, %d\n", err);
 	return err;
 }
 
 void tpm_sysfs_del_device(struct tpm_chip *chip)
 {
-	sysfs_remove_group(&chip->pdev->kobj, &tpm_dev_group);
+	sysfs_remove_group(&chip->dev.parent->kobj, &tpm_dev_group);
 }
diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h
index 2216861f89f1..57c4c26c38ea 100644
--- a/drivers/char/tpm/tpm.h
+++ b/drivers/char/tpm/tpm.h
@@ -171,7 +171,6 @@ enum tpm_chip_flags {
 };
 
 struct tpm_chip {
-	struct device *pdev;	/* Device stuff */
 	struct device dev;
 	struct cdev cdev;
 
@@ -203,7 +202,7 @@ struct tpm_chip {
 
 static inline void tpm_chip_put(struct tpm_chip *chip)
 {
-	module_put(chip->pdev->driver->owner);
+	module_put(chip->dev.parent->driver->owner);
 }
 
 static inline int tpm_read_index(int base, int index)
diff --git a/drivers/char/tpm/tpm2-cmd.c b/drivers/char/tpm/tpm2-cmd.c
index cb7e4f6b70ba..286bd090a488 100644
--- a/drivers/char/tpm/tpm2-cmd.c
+++ b/drivers/char/tpm/tpm2-cmd.c
@@ -570,7 +570,7 @@ static void tpm2_flush_context_cmd(struct tpm_chip *chip, u32 handle,
 
 	rc = tpm_buf_init(&buf, TPM2_ST_NO_SESSIONS, TPM2_CC_FLUSH_CONTEXT);
 	if (rc) {
-		dev_warn(chip->pdev, "0x%08x was not flushed, out of memory\n",
+		dev_warn(&chip->dev, "0x%08x was not flushed, out of memory\n",
 			 handle);
 		return;
 	}
@@ -580,7 +580,7 @@ static void tpm2_flush_context_cmd(struct tpm_chip *chip, u32 handle,
 	rc = tpm_transmit_cmd(chip, buf.data, PAGE_SIZE, flags,
 			      "flushing context");
 	if (rc)
-		dev_warn(chip->pdev, "0x%08x was not flushed, rc=%d\n", handle,
+		dev_warn(&chip->dev, "0x%08x was not flushed, rc=%d\n", handle,
 			 rc);
 
 	tpm_buf_destroy(&buf);
@@ -753,7 +753,7 @@ void tpm2_shutdown(struct tpm_chip *chip, u16 shutdown_type)
 	 * except print the error code on a system failure.
 	 */
 	if (rc < 0)
-		dev_warn(chip->pdev, "transmit returned %d while stopping the TPM",
+		dev_warn(&chip->dev, "transmit returned %d while stopping the TPM",
 			 rc);
 }
 EXPORT_SYMBOL_GPL(tpm2_shutdown);
@@ -820,7 +820,7 @@ static int tpm2_start_selftest(struct tpm_chip *chip, bool full)
 	 * immediately. This is a workaround for that.
 	 */
 	if (rc == TPM2_RC_TESTING) {
-		dev_warn(chip->pdev, "Got RC_TESTING, ignoring\n");
+		dev_warn(&chip->dev, "Got RC_TESTING, ignoring\n");
 		rc = 0;
 	}
 
diff --git a/drivers/char/tpm/tpm_atmel.c b/drivers/char/tpm/tpm_atmel.c
index dfadad0916a1..a48a878f791d 100644
--- a/drivers/char/tpm/tpm_atmel.c
+++ b/drivers/char/tpm/tpm_atmel.c
@@ -49,7 +49,7 @@ static int tpm_atml_recv(struct tpm_chip *chip, u8 *buf, size_t count)
 	for (i = 0; i < 6; i++) {
 		status = ioread8(chip->vendor.iobase + 1);
 		if ((status & ATML_STATUS_DATA_AVAIL) == 0) {
-			dev_err(chip->pdev, "error reading header\n");
+			dev_err(&chip->dev, "error reading header\n");
 			return -EIO;
 		}
 		*buf++ = ioread8(chip->vendor.iobase);
@@ -60,12 +60,12 @@ static int tpm_atml_recv(struct tpm_chip *chip, u8 *buf, size_t count)
 	size = be32_to_cpu(*native_size);
 
 	if (count < size) {
-		dev_err(chip->pdev,
+		dev_err(&chip->dev,
 			"Recv size(%d) less than available space\n", size);
 		for (; i < size; i++) {	/* clear the waiting data anyway */
 			status = ioread8(chip->vendor.iobase + 1);
 			if ((status & ATML_STATUS_DATA_AVAIL) == 0) {
-				dev_err(chip->pdev, "error reading data\n");
+				dev_err(&chip->dev, "error reading data\n");
 				return -EIO;
 			}
 		}
@@ -76,7 +76,7 @@ static int tpm_atml_recv(struct tpm_chip *chip, u8 *buf, size_t count)
 	for (; i < size; i++) {
 		status = ioread8(chip->vendor.iobase + 1);
 		if ((status & ATML_STATUS_DATA_AVAIL) == 0) {
-			dev_err(chip->pdev, "error reading data\n");
+			dev_err(&chip->dev, "error reading data\n");
 			return -EIO;
 		}
 		*buf++ = ioread8(chip->vendor.iobase);
@@ -86,7 +86,7 @@ static int tpm_atml_recv(struct tpm_chip *chip, u8 *buf, size_t count)
 	status = ioread8(chip->vendor.iobase + 1);
 
 	if (status & ATML_STATUS_DATA_AVAIL) {
-		dev_err(chip->pdev, "data available is stuck\n");
+		dev_err(&chip->dev, "data available is stuck\n");
 		return -EIO;
 	}
 
@@ -97,9 +97,9 @@ static int tpm_atml_send(struct tpm_chip *chip, u8 *buf, size_t count)
 {
 	int i;
 
-	dev_dbg(chip->pdev, "tpm_atml_send:\n");
+	dev_dbg(&chip->dev, "tpm_atml_send:\n");
 	for (i = 0; i < count; i++) {
-		dev_dbg(chip->pdev, "%d 0x%x(%d)\n",  i, buf[i], buf[i]);
+		dev_dbg(&chip->dev, "%d 0x%x(%d)\n",  i, buf[i], buf[i]);
  		iowrite8(buf[i], chip->vendor.iobase);
 	}
 
diff --git a/drivers/char/tpm/tpm_i2c_atmel.c b/drivers/char/tpm/tpm_i2c_atmel.c
index 8dfb88b9739c..dd8f0eb3170a 100644
--- a/drivers/char/tpm/tpm_i2c_atmel.c
+++ b/drivers/char/tpm/tpm_i2c_atmel.c
@@ -52,7 +52,7 @@ struct priv_data {
 static int i2c_atmel_send(struct tpm_chip *chip, u8 *buf, size_t len)
 {
 	struct priv_data *priv = chip->vendor.priv;
-	struct i2c_client *client = to_i2c_client(chip->pdev);
+	struct i2c_client *client = to_i2c_client(chip->dev.parent);
 	s32 status;
 
 	priv->len = 0;
@@ -62,7 +62,7 @@ static int i2c_atmel_send(struct tpm_chip *chip, u8 *buf, size_t len)
 
 	status = i2c_master_send(client, buf, len);
 
-	dev_dbg(chip->pdev,
+	dev_dbg(&chip->dev,
 		"%s(buf=%*ph len=%0zx) -> sts=%d\n", __func__,
 		(int)min_t(size_t, 64, len), buf, len, status);
 	return status;
@@ -71,7 +71,7 @@ static int i2c_atmel_send(struct tpm_chip *chip, u8 *buf, size_t len)
 static int i2c_atmel_recv(struct tpm_chip *chip, u8 *buf, size_t count)
 {
 	struct priv_data *priv = chip->vendor.priv;
-	struct i2c_client *client = to_i2c_client(chip->pdev);
+	struct i2c_client *client = to_i2c_client(chip->dev.parent);
 	struct tpm_output_header *hdr =
 		(struct tpm_output_header *)priv->buffer;
 	u32 expected_len;
@@ -88,7 +88,7 @@ static int i2c_atmel_recv(struct tpm_chip *chip, u8 *buf, size_t count)
 		return -ENOMEM;
 
 	if (priv->len >= expected_len) {
-		dev_dbg(chip->pdev,
+		dev_dbg(&chip->dev,
 			"%s early(buf=%*ph count=%0zx) -> ret=%d\n", __func__,
 			(int)min_t(size_t, 64, expected_len), buf, count,
 			expected_len);
@@ -97,7 +97,7 @@ static int i2c_atmel_recv(struct tpm_chip *chip, u8 *buf, size_t count)
 	}
 
 	rc = i2c_master_recv(client, buf, expected_len);
-	dev_dbg(chip->pdev,
+	dev_dbg(&chip->dev,
 		"%s reread(buf=%*ph count=%0zx) -> ret=%d\n", __func__,
 		(int)min_t(size_t, 64, expected_len), buf, count,
 		expected_len);
@@ -106,13 +106,13 @@ static int i2c_atmel_recv(struct tpm_chip *chip, u8 *buf, size_t count)
 
 static void i2c_atmel_cancel(struct tpm_chip *chip)
 {
-	dev_err(chip->pdev, "TPM operation cancellation was requested, but is not supported");
+	dev_err(&chip->dev, "TPM operation cancellation was requested, but is not supported");
 }
 
 static u8 i2c_atmel_read_status(struct tpm_chip *chip)
 {
 	struct priv_data *priv = chip->vendor.priv;
-	struct i2c_client *client = to_i2c_client(chip->pdev);
+	struct i2c_client *client = to_i2c_client(chip->dev.parent);
 	int rc;
 
 	/* The TPM fails the I2C read until it is ready, so we do the entire
@@ -125,7 +125,7 @@ static u8 i2c_atmel_read_status(struct tpm_chip *chip)
 	/* Once the TPM has completed the command the command remains readable
 	 * until another command is issued. */
 	rc = i2c_master_recv(client, priv->buffer, sizeof(priv->buffer));
-	dev_dbg(chip->pdev,
+	dev_dbg(&chip->dev,
 		"%s: sts=%d", __func__, rc);
 	if (rc <= 0)
 		return 0;
diff --git a/drivers/char/tpm/tpm_i2c_infineon.c b/drivers/char/tpm/tpm_i2c_infineon.c
index 63d5d22e9e60..f2aa99e34b4b 100644
--- a/drivers/char/tpm/tpm_i2c_infineon.c
+++ b/drivers/char/tpm/tpm_i2c_infineon.c
@@ -446,7 +446,7 @@ static int tpm_tis_i2c_recv(struct tpm_chip *chip, u8 *buf, size_t count)
 	/* read first 10 bytes, including tag, paramsize, and result */
 	size = recv_data(chip, buf, TPM_HEADER_SIZE);
 	if (size < TPM_HEADER_SIZE) {
-		dev_err(chip->pdev, "Unable to read header\n");
+		dev_err(&chip->dev, "Unable to read header\n");
 		goto out;
 	}
 
@@ -459,14 +459,14 @@ static int tpm_tis_i2c_recv(struct tpm_chip *chip, u8 *buf, size_t count)
 	size += recv_data(chip, &buf[TPM_HEADER_SIZE],
 			  expected - TPM_HEADER_SIZE);
 	if (size < expected) {
-		dev_err(chip->pdev, "Unable to read remainder of result\n");
+		dev_err(&chip->dev, "Unable to read remainder of result\n");
 		size = -ETIME;
 		goto out;
 	}
 
 	wait_for_stat(chip, TPM_STS_VALID, chip->vendor.timeout_c, &status);
 	if (status & TPM_STS_DATA_AVAIL) {	/* retry? */
-		dev_err(chip->pdev, "Error left over data\n");
+		dev_err(&chip->dev, "Error left over data\n");
 		size = -EIO;
 		goto out;
 	}
diff --git a/drivers/char/tpm/tpm_i2c_nuvoton.c b/drivers/char/tpm/tpm_i2c_nuvoton.c
index 847f1597fe9b..a1e1474dda30 100644
--- a/drivers/char/tpm/tpm_i2c_nuvoton.c
+++ b/drivers/char/tpm/tpm_i2c_nuvoton.c
@@ -96,13 +96,13 @@ static s32 i2c_nuvoton_write_buf(struct i2c_client *client, u8 offset, u8 size,
 /* read TPM_STS register */
 static u8 i2c_nuvoton_read_status(struct tpm_chip *chip)
 {
-	struct i2c_client *client = to_i2c_client(chip->pdev);
+	struct i2c_client *client = to_i2c_client(chip->dev.parent);
 	s32 status;
 	u8 data;
 
 	status = i2c_nuvoton_read_buf(client, TPM_STS, 1, &data);
 	if (status <= 0) {
-		dev_err(chip->pdev, "%s() error return %d\n", __func__,
+		dev_err(&chip->dev, "%s() error return %d\n", __func__,
 			status);
 		data = TPM_STS_ERR_VAL;
 	}
@@ -127,13 +127,13 @@ static s32 i2c_nuvoton_write_status(struct i2c_client *client, u8 data)
 /* write commandReady to TPM_STS register */
 static void i2c_nuvoton_ready(struct tpm_chip *chip)
 {
-	struct i2c_client *client = to_i2c_client(chip->pdev);
+	struct i2c_client *client = to_i2c_client(chip->dev.parent);
 	s32 status;
 
 	/* this causes the current command to be aborted */
 	status = i2c_nuvoton_write_status(client, TPM_STS_COMMAND_READY);
 	if (status < 0)
-		dev_err(chip->pdev,
+		dev_err(&chip->dev,
 			"%s() fail to write TPM_STS.commandReady\n", __func__);
 }
 
@@ -212,7 +212,7 @@ static int i2c_nuvoton_wait_for_stat(struct tpm_chip *chip, u8 mask, u8 value,
 				return 0;
 		} while (time_before(jiffies, stop));
 	}
-	dev_err(chip->pdev, "%s(%02x, %02x) -> timeout\n", __func__, mask,
+	dev_err(&chip->dev, "%s(%02x, %02x) -> timeout\n", __func__, mask,
 		value);
 	return -ETIMEDOUT;
 }
@@ -240,7 +240,7 @@ static int i2c_nuvoton_recv_data(struct i2c_client *client,
 					       &chip->vendor.read_queue) == 0) {
 		burst_count = i2c_nuvoton_get_burstcount(client, chip);
 		if (burst_count < 0) {
-			dev_err(chip->pdev,
+			dev_err(&chip->dev,
 				"%s() fail to read burstCount=%d\n", __func__,
 				burst_count);
 			return -EIO;
@@ -249,12 +249,12 @@ static int i2c_nuvoton_recv_data(struct i2c_client *client,
 		rc = i2c_nuvoton_read_buf(client, TPM_DATA_FIFO_R,
 					  bytes2read, &buf[size]);
 		if (rc < 0) {
-			dev_err(chip->pdev,
+			dev_err(&chip->dev,
 				"%s() fail on i2c_nuvoton_read_buf()=%d\n",
 				__func__, rc);
 			return -EIO;
 		}
-		dev_dbg(chip->pdev, "%s(%d):", __func__, bytes2read);
+		dev_dbg(&chip->dev, "%s(%d):", __func__, bytes2read);
 		size += bytes2read;
 	}
 
@@ -264,7 +264,7 @@ static int i2c_nuvoton_recv_data(struct i2c_client *client,
 /* Read TPM command results */
 static int i2c_nuvoton_recv(struct tpm_chip *chip, u8 *buf, size_t count)
 {
-	struct device *dev = chip->pdev;
+	struct device *dev = chip->dev.parent;
 	struct i2c_client *client = to_i2c_client(dev);
 	s32 rc;
 	int expected, status, burst_count, retries, size = 0;
@@ -334,7 +334,7 @@ static int i2c_nuvoton_recv(struct tpm_chip *chip, u8 *buf, size_t count)
 		break;
 	}
 	i2c_nuvoton_ready(chip);
-	dev_dbg(chip->pdev, "%s() -> %d\n", __func__, size);
+	dev_dbg(&chip->dev, "%s() -> %d\n", __func__, size);
 	return size;
 }
 
@@ -347,7 +347,7 @@ static int i2c_nuvoton_recv(struct tpm_chip *chip, u8 *buf, size_t count)
  */
 static int i2c_nuvoton_send(struct tpm_chip *chip, u8 *buf, size_t len)
 {
-	struct device *dev = chip->pdev;
+	struct device *dev = chip->dev.parent;
 	struct i2c_client *client = to_i2c_client(dev);
 	u32 ordinal;
 	size_t count = 0;
diff --git a/drivers/char/tpm/tpm_infineon.c b/drivers/char/tpm/tpm_infineon.c
index 6c488e635fdd..e3cf9f3545c5 100644
--- a/drivers/char/tpm/tpm_infineon.c
+++ b/drivers/char/tpm/tpm_infineon.c
@@ -195,9 +195,9 @@ static int wait(struct tpm_chip *chip, int wait_for_bit)
 	}
 	if (i == TPM_MAX_TRIES) {	/* timeout occurs */
 		if (wait_for_bit == STAT_XFE)
-			dev_err(chip->pdev, "Timeout in wait(STAT_XFE)\n");
+			dev_err(&chip->dev, "Timeout in wait(STAT_XFE)\n");
 		if (wait_for_bit == STAT_RDA)
-			dev_err(chip->pdev, "Timeout in wait(STAT_RDA)\n");
+			dev_err(&chip->dev, "Timeout in wait(STAT_RDA)\n");
 		return -EIO;
 	}
 	return 0;
@@ -220,7 +220,7 @@ static void wait_and_send(struct tpm_chip *chip, u8 sendbyte)
 static void tpm_wtx(struct tpm_chip *chip)
 {
 	number_of_wtx++;
-	dev_info(chip->pdev, "Granting WTX (%02d / %02d)\n",
+	dev_info(&chip->dev, "Granting WTX (%02d / %02d)\n",
 		 number_of_wtx, TPM_MAX_WTX_PACKAGES);
 	wait_and_send(chip, TPM_VL_VER);
 	wait_and_send(chip, TPM_CTRL_WTX);
@@ -231,7 +231,7 @@ static void tpm_wtx(struct tpm_chip *chip)
 
 static void tpm_wtx_abort(struct tpm_chip *chip)
 {
-	dev_info(chip->pdev, "Aborting WTX\n");
+	dev_info(&chip->dev, "Aborting WTX\n");
 	wait_and_send(chip, TPM_VL_VER);
 	wait_and_send(chip, TPM_CTRL_WTX_ABORT);
 	wait_and_send(chip, 0x00);
@@ -257,7 +257,7 @@ recv_begin:
 	}
 
 	if (buf[0] != TPM_VL_VER) {
-		dev_err(chip->pdev,
+		dev_err(&chip->dev,
 			"Wrong transport protocol implementation!\n");
 		return -EIO;
 	}
@@ -272,7 +272,7 @@ recv_begin:
 		}
 
 		if ((size == 0x6D00) && (buf[1] == 0x80)) {
-			dev_err(chip->pdev, "Error handling on vendor layer!\n");
+			dev_err(&chip->dev, "Error handling on vendor layer!\n");
 			return -EIO;
 		}
 
@@ -284,7 +284,7 @@ recv_begin:
 	}
 
 	if (buf[1] == TPM_CTRL_WTX) {
-		dev_info(chip->pdev, "WTX-package received\n");
+		dev_info(&chip->dev, "WTX-package received\n");
 		if (number_of_wtx < TPM_MAX_WTX_PACKAGES) {
 			tpm_wtx(chip);
 			goto recv_begin;
@@ -295,14 +295,14 @@ recv_begin:
 	}
 
 	if (buf[1] == TPM_CTRL_WTX_ABORT_ACK) {
-		dev_info(chip->pdev, "WTX-abort acknowledged\n");
+		dev_info(&chip->dev, "WTX-abort acknowledged\n");
 		return size;
 	}
 
 	if (buf[1] == TPM_CTRL_ERROR) {
-		dev_err(chip->pdev, "ERROR-package received:\n");
+		dev_err(&chip->dev, "ERROR-package received:\n");
 		if (buf[4] == TPM_INF_NAK)
-			dev_err(chip->pdev,
+			dev_err(&chip->dev,
 				"-> Negative acknowledgement"
 				" - retransmit command!\n");
 		return -EIO;
@@ -321,7 +321,7 @@ static int tpm_inf_send(struct tpm_chip *chip, u8 * buf, size_t count)
 
 	ret = empty_fifo(chip, 1);
 	if (ret) {
-		dev_err(chip->pdev, "Timeout while clearing FIFO\n");
+		dev_err(&chip->dev, "Timeout while clearing FIFO\n");
 		return -EIO;
 	}
 
diff --git a/drivers/char/tpm/tpm_nsc.c b/drivers/char/tpm/tpm_nsc.c
index 289389ecef84..766370bed60c 100644
--- a/drivers/char/tpm/tpm_nsc.c
+++ b/drivers/char/tpm/tpm_nsc.c
@@ -113,7 +113,7 @@ static int nsc_wait_for_ready(struct tpm_chip *chip)
 	}
 	while (time_before(jiffies, stop));
 
-	dev_info(chip->pdev, "wait for ready failed\n");
+	dev_info(&chip->dev, "wait for ready failed\n");
 	return -EBUSY;
 }
 
@@ -129,12 +129,12 @@ static int tpm_nsc_recv(struct tpm_chip *chip, u8 * buf, size_t count)
 		return -EIO;
 
 	if (wait_for_stat(chip, NSC_STATUS_F0, NSC_STATUS_F0, &data) < 0) {
-		dev_err(chip->pdev, "F0 timeout\n");
+		dev_err(&chip->dev, "F0 timeout\n");
 		return -EIO;
 	}
 	if ((data =
 	     inb(chip->vendor.base + NSC_DATA)) != NSC_COMMAND_NORMAL) {
-		dev_err(chip->pdev, "not in normal mode (0x%x)\n",
+		dev_err(&chip->dev, "not in normal mode (0x%x)\n",
 			data);
 		return -EIO;
 	}
@@ -143,7 +143,7 @@ static int tpm_nsc_recv(struct tpm_chip *chip, u8 * buf, size_t count)
 	for (p = buffer; p < &buffer[count]; p++) {
 		if (wait_for_stat
 		    (chip, NSC_STATUS_OBF, NSC_STATUS_OBF, &data) < 0) {
-			dev_err(chip->pdev,
+			dev_err(&chip->dev,
 				"OBF timeout (while reading data)\n");
 			return -EIO;
 		}
@@ -154,11 +154,11 @@ static int tpm_nsc_recv(struct tpm_chip *chip, u8 * buf, size_t count)
 
 	if ((data & NSC_STATUS_F0) == 0 &&
 	(wait_for_stat(chip, NSC_STATUS_F0, NSC_STATUS_F0, &data) < 0)) {
-		dev_err(chip->pdev, "F0 not set\n");
+		dev_err(&chip->dev, "F0 not set\n");
 		return -EIO;
 	}
 	if ((data = inb(chip->vendor.base + NSC_DATA)) != NSC_COMMAND_EOC) {
-		dev_err(chip->pdev,
+		dev_err(&chip->dev,
 			"expected end of command(0x%x)\n", data);
 		return -EIO;
 	}
@@ -189,19 +189,19 @@ static int tpm_nsc_send(struct tpm_chip *chip, u8 * buf, size_t count)
 		return -EIO;
 
 	if (wait_for_stat(chip, NSC_STATUS_IBF, 0, &data) < 0) {
-		dev_err(chip->pdev, "IBF timeout\n");
+		dev_err(&chip->dev, "IBF timeout\n");
 		return -EIO;
 	}
 
 	outb(NSC_COMMAND_NORMAL, chip->vendor.base + NSC_COMMAND);
 	if (wait_for_stat(chip, NSC_STATUS_IBR, NSC_STATUS_IBR, &data) < 0) {
-		dev_err(chip->pdev, "IBR timeout\n");
+		dev_err(&chip->dev, "IBR timeout\n");
 		return -EIO;
 	}
 
 	for (i = 0; i < count; i++) {
 		if (wait_for_stat(chip, NSC_STATUS_IBF, 0, &data) < 0) {
-			dev_err(chip->pdev,
+			dev_err(&chip->dev,
 				"IBF timeout (while writing data)\n");
 			return -EIO;
 		}
@@ -209,7 +209,7 @@ static int tpm_nsc_send(struct tpm_chip *chip, u8 * buf, size_t count)
 	}
 
 	if (wait_for_stat(chip, NSC_STATUS_IBF, 0, &data) < 0) {
-		dev_err(chip->pdev, "IBF timeout\n");
+		dev_err(&chip->dev, "IBF timeout\n");
 		return -EIO;
 	}
 	outb(NSC_COMMAND_EOC, chip->vendor.base + NSC_COMMAND);
diff --git a/drivers/char/tpm/tpm_tis.c b/drivers/char/tpm/tpm_tis.c
index f10a107614b4..7f13221aeb30 100644
--- a/drivers/char/tpm/tpm_tis.c
+++ b/drivers/char/tpm/tpm_tis.c
@@ -293,7 +293,7 @@ static int tpm_tis_recv(struct tpm_chip *chip, u8 *buf, size_t count)
 	/* read first 10 bytes, including tag, paramsize, and result */
 	if ((size =
 	     recv_data(chip, buf, TPM_HEADER_SIZE)) < TPM_HEADER_SIZE) {
-		dev_err(chip->pdev, "Unable to read header\n");
+		dev_err(&chip->dev, "Unable to read header\n");
 		goto out;
 	}
 
@@ -306,7 +306,7 @@ static int tpm_tis_recv(struct tpm_chip *chip, u8 *buf, size_t count)
 	if ((size +=
 	     recv_data(chip, &buf[TPM_HEADER_SIZE],
 		       expected - TPM_HEADER_SIZE)) < expected) {
-		dev_err(chip->pdev, "Unable to read remainder of result\n");
+		dev_err(&chip->dev, "Unable to read remainder of result\n");
 		size = -ETIME;
 		goto out;
 	}
@@ -315,7 +315,7 @@ static int tpm_tis_recv(struct tpm_chip *chip, u8 *buf, size_t count)
 			  &chip->vendor.int_queue, false);
 	status = tpm_tis_status(chip);
 	if (status & TPM_STS_DATA_AVAIL) {	/* retry? */
-		dev_err(chip->pdev, "Error left over data\n");
+		dev_err(&chip->dev, "Error left over data\n");
 		size = -EIO;
 		goto out;
 	}
@@ -401,7 +401,7 @@ static void disable_interrupts(struct tpm_chip *chip)
 	iowrite32(intmask,
 		  chip->vendor.iobase +
 		  TPM_INT_ENABLE(chip->vendor.locality));
-	devm_free_irq(chip->pdev, chip->vendor.irq, chip);
+	devm_free_irq(&chip->dev, chip->vendor.irq, chip);
 	chip->vendor.irq = 0;
 }
 
@@ -463,7 +463,7 @@ static int tpm_tis_send(struct tpm_chip *chip, u8 *buf, size_t len)
 		msleep(1);
 	if (!priv->irq_tested) {
 		disable_interrupts(chip);
-		dev_err(chip->pdev,
+		dev_err(&chip->dev,
 			FW_BUG "TPM interrupt not working, polling instead\n");
 	}
 	priv->irq_tested = true;
@@ -533,7 +533,7 @@ static int probe_itpm(struct tpm_chip *chip)
 
 	rc = tpm_tis_send_data(chip, cmd_getticks, len);
 	if (rc == 0) {
-		dev_info(chip->pdev, "Detected an iTPM.\n");
+		dev_info(&chip->dev, "Detected an iTPM.\n");
 		rc = 1;
 	} else
 		rc = -EFAULT;
@@ -766,7 +766,7 @@ static int tpm_tis_init(struct device *dev, struct tpm_info *tpm_info,
 			if (devm_request_irq
 			    (dev, i, tis_int_probe, IRQF_SHARED,
 			     chip->devname, chip) != 0) {
-				dev_info(chip->pdev,
+				dev_info(&chip->dev,
 					 "Unable to request irq: %d for probe\n",
 					 i);
 				continue;
@@ -818,7 +818,7 @@ static int tpm_tis_init(struct device *dev, struct tpm_info *tpm_info,
 		if (devm_request_irq
 		    (dev, chip->vendor.irq, tis_int_handler, IRQF_SHARED,
 		     chip->devname, chip) != 0) {
-			dev_info(chip->pdev,
+			dev_info(&chip->dev,
 				 "Unable to request irq: %d for use\n",
 				 chip->vendor.irq);
 			chip->vendor.irq = 0;
-- 
2.13.2.932.g7449e964c-goog

[PATCH v1 2/4] tpm: Provide strong locking for device removal

[Josh Zimmerman]

From: Jason Gunthorpe <jgunthorpe@obsidianresearch.com>

Add a read/write semaphore around the ops function pointers so
ops can be set to null when the driver un-registers.

Previously the tpm core expected module locking to be enough to
ensure that tpm_unregister could not be called during certain times,
however that hasn't been sufficient for a long time.

Introduce a read/write semaphore around 'ops' so the core can set
it to null when unregistering. This provides a strong fence around
the driver callbacks, guaranteeing to the driver that no callbacks
are running or will run again.

For now the ops_lock is placed very high in the call stack, it could
be pushed down and made more granular in future if necessary.

Signed-off-by: Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
Reviewed-by: Stefan Berger <stefanb@linux.vnet.ibm.com>
Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
(cherry picked from commit 4e26195f240d73150e8308ae42874702e3df8d2c)
---
 drivers/char/tpm/tpm-chip.c      | 72 ++++++++++++++++++++++++++++++++++++----
 drivers/char/tpm/tpm-dev.c       | 11 +++++-
 drivers/char/tpm/tpm-interface.c | 19 ++++++-----
 drivers/char/tpm/tpm-sysfs.c     |  5 +++
 drivers/char/tpm/tpm.h           | 14 +++++---
 5 files changed, 100 insertions(+), 21 deletions(-)

diff --git a/drivers/char/tpm/tpm-chip.c b/drivers/char/tpm/tpm-chip.c
index f55b4921c723..f3a887e4f692 100644
--- a/drivers/char/tpm/tpm-chip.c
+++ b/drivers/char/tpm/tpm-chip.c
@@ -36,10 +36,60 @@ static DEFINE_SPINLOCK(driver_lock);
 struct class *tpm_class;
 dev_t tpm_devt;
 
-/*
- * tpm_chip_find_get - return tpm_chip for a given chip number
- * @chip_num the device number for the chip
+/**
+ * tpm_try_get_ops() - Get a ref to the tpm_chip
+ * @chip: Chip to ref
+ *
+ * The caller must already have some kind of locking to ensure that chip is
+ * valid. This function will lock the chip so that the ops member can be
+ * accessed safely. The locking prevents tpm_chip_unregister from
+ * completing, so it should not be held for long periods.
+ *
+ * Returns -ERRNO if the chip could not be got.
  */
+int tpm_try_get_ops(struct tpm_chip *chip)
+{
+	int rc = -EIO;
+
+	get_device(&chip->dev);
+
+	down_read(&chip->ops_sem);
+	if (!chip->ops)
+		goto out_lock;
+
+	if (!try_module_get(chip->dev.parent->driver->owner))
+		goto out_lock;
+
+	return 0;
+out_lock:
+	up_read(&chip->ops_sem);
+	put_device(&chip->dev);
+	return rc;
+}
+EXPORT_SYMBOL_GPL(tpm_try_get_ops);
+
+/**
+ * tpm_put_ops() - Release a ref to the tpm_chip
+ * @chip: Chip to put
+ *
+ * This is the opposite pair to tpm_try_get_ops(). After this returns chip may
+ * be kfree'd.
+ */
+void tpm_put_ops(struct tpm_chip *chip)
+{
+	module_put(chip->dev.parent->driver->owner);
+	up_read(&chip->ops_sem);
+	put_device(&chip->dev);
+}
+EXPORT_SYMBOL_GPL(tpm_put_ops);
+
+/**
+ * tpm_chip_find_get() - return tpm_chip for a given chip number
+ * @chip_num: id to find
+ *
+ * The return'd chip has been tpm_try_get_ops'd and must be released via
+ * tpm_put_ops
+  */
 struct tpm_chip *tpm_chip_find_get(int chip_num)
 {
 	struct tpm_chip *pos, *chip = NULL;
@@ -49,10 +99,10 @@ struct tpm_chip *tpm_chip_find_get(int chip_num)
 		if (chip_num != TPM_ANY_NUM && chip_num != pos->dev_num)
 			continue;
 
-		if (try_module_get(pos->dev.parent->driver->owner)) {
+		/* rcu prevents chip from being free'd */
+		if (!tpm_try_get_ops(pos))
 			chip = pos;
-			break;
-		}
+		break;
 	}
 	rcu_read_unlock();
 	return chip;
@@ -94,6 +144,7 @@ struct tpm_chip *tpmm_chip_alloc(struct device *dev,
 		return ERR_PTR(-ENOMEM);
 
 	mutex_init(&chip->tpm_mutex);
+	init_rwsem(&chip->ops_sem);
 	INIT_LIST_HEAD(&chip->list);
 
 	chip->ops = ops;
@@ -171,6 +222,12 @@ static int tpm_add_char_device(struct tpm_chip *chip)
 static void tpm_del_char_device(struct tpm_chip *chip)
 {
 	cdev_del(&chip->cdev);
+
+	/* Make the driver uncallable. */
+	down_write(&chip->ops_sem);
+	chip->ops = NULL;
+	up_write(&chip->ops_sem);
+
 	device_del(&chip->dev);
 }
 
@@ -256,6 +313,9 @@ EXPORT_SYMBOL_GPL(tpm_chip_register);
  * Takes the chip first away from the list of available TPM chips and then
  * cleans up all the resources reserved by tpm_chip_register().
  *
+ * Once this function returns the driver call backs in 'op's will not be
+ * running and will no longer start.
+ *
  * NOTE: This function should be only called before deinitializing chip
  * resources.
  */
diff --git a/drivers/char/tpm/tpm-dev.c b/drivers/char/tpm/tpm-dev.c
index 6ed0651cbe58..912ad30be585 100644
--- a/drivers/char/tpm/tpm-dev.c
+++ b/drivers/char/tpm/tpm-dev.c
@@ -136,9 +136,18 @@ static ssize_t tpm_write(struct file *file, const char __user *buf,
 		return -EFAULT;
 	}
 
-	/* atomic tpm command send and result receive */
+	/* 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, 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;
diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c
index 4391953a7711..8588f2e4b9af 100644
--- a/drivers/char/tpm/tpm-interface.c
+++ b/drivers/char/tpm/tpm-interface.c
@@ -687,7 +687,7 @@ int tpm_is_tpm2(u32 chip_num)
 
 	rc = (chip->flags & TPM_CHIP_FLAG_TPM2) != 0;
 
-	tpm_chip_put(chip);
+	tpm_put_ops(chip);
 
 	return rc;
 }
@@ -716,7 +716,7 @@ int tpm_pcr_read(u32 chip_num, int pcr_idx, u8 *res_buf)
 		rc = tpm2_pcr_read(chip, pcr_idx, res_buf);
 	else
 		rc = tpm_pcr_read_dev(chip, pcr_idx, res_buf);
-	tpm_chip_put(chip);
+	tpm_put_ops(chip);
 	return rc;
 }
 EXPORT_SYMBOL_GPL(tpm_pcr_read);
@@ -751,7 +751,7 @@ int tpm_pcr_extend(u32 chip_num, int pcr_idx, const u8 *hash)
 
 	if (chip->flags & TPM_CHIP_FLAG_TPM2) {
 		rc = tpm2_pcr_extend(chip, pcr_idx, hash);
-		tpm_chip_put(chip);
+		tpm_put_ops(chip);
 		return rc;
 	}
 
@@ -761,7 +761,7 @@ int tpm_pcr_extend(u32 chip_num, int pcr_idx, const u8 *hash)
 	rc = tpm_transmit_cmd(chip, &cmd, EXTEND_PCR_RESULT_SIZE, 0,
 			      "attempting extend a PCR value");
 
-	tpm_chip_put(chip);
+	tpm_put_ops(chip);
 	return rc;
 }
 EXPORT_SYMBOL_GPL(tpm_pcr_extend);
@@ -842,7 +842,7 @@ int tpm_send(u32 chip_num, void *cmd, size_t buflen)
 
 	rc = tpm_transmit_cmd(chip, cmd, buflen, 0, "attempting tpm_cmd");
 
-	tpm_chip_put(chip);
+	tpm_put_ops(chip);
 	return rc;
 }
 EXPORT_SYMBOL_GPL(tpm_send);
@@ -1025,7 +1025,7 @@ int tpm_get_random(u32 chip_num, u8 *out, size_t max)
 
 	if (chip->flags & TPM_CHIP_FLAG_TPM2) {
 		err = tpm2_get_random(chip, out, max);
-		tpm_chip_put(chip);
+		tpm_put_ops(chip);
 		return err;
 	}
 
@@ -1047,7 +1047,7 @@ int tpm_get_random(u32 chip_num, u8 *out, size_t max)
 		num_bytes -= recd;
 	} while (retries-- && total < max);
 
-	tpm_chip_put(chip);
+	tpm_put_ops(chip);
 	return total ? total : -EIO;
 }
 EXPORT_SYMBOL_GPL(tpm_get_random);
@@ -1073,7 +1073,7 @@ int tpm_seal_trusted(u32 chip_num, struct trusted_key_payload *payload,
 
 	rc = tpm2_seal_trusted(chip, payload, options);
 
-	tpm_chip_put(chip);
+	tpm_put_ops(chip);
 	return rc;
 }
 EXPORT_SYMBOL_GPL(tpm_seal_trusted);
@@ -1099,7 +1099,8 @@ int tpm_unseal_trusted(u32 chip_num, struct trusted_key_payload *payload,
 
 	rc = tpm2_unseal_trusted(chip, payload, options);
 
-	tpm_chip_put(chip);
+	tpm_put_ops(chip);
+
 	return rc;
 }
 EXPORT_SYMBOL_GPL(tpm_unseal_trusted);
diff --git a/drivers/char/tpm/tpm-sysfs.c b/drivers/char/tpm/tpm-sysfs.c
index 10370c22e98b..8af4145d10c7 100644
--- a/drivers/char/tpm/tpm-sysfs.c
+++ b/drivers/char/tpm/tpm-sysfs.c
@@ -295,5 +295,10 @@ int tpm_sysfs_add_device(struct tpm_chip *chip)
 
 void tpm_sysfs_del_device(struct tpm_chip *chip)
 {
+	/* The sysfs routines rely on an implicit tpm_try_get_ops, this
+	 * function is called before ops is null'd and the sysfs core
+	 * synchronizes this removal so that no callbacks are running or can
+	 * run again
+	 */
 	sysfs_remove_group(&chip->dev.parent->kobj, &tpm_dev_group);
 }
diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h
index 57c4c26c38ea..e21e2c599e66 100644
--- a/drivers/char/tpm/tpm.h
+++ b/drivers/char/tpm/tpm.h
@@ -174,7 +174,13 @@ struct tpm_chip {
 	struct device dev;
 	struct cdev cdev;
 
+	/* A driver callback under ops cannot be run unless ops_sem is held
+	 * (sometimes implicitly, eg for the sysfs code). ops becomes null
+	 * when the driver is unregistered, see tpm_try_get_ops.
+	 */
+	struct rw_semaphore ops_sem;
 	const struct tpm_class_ops *ops;
+
 	unsigned int flags;
 
 	int dev_num;		/* /dev/tpm# */
@@ -200,11 +206,6 @@ struct tpm_chip {
 
 #define to_tpm_chip(d) container_of(d, struct tpm_chip, dev)
 
-static inline void tpm_chip_put(struct tpm_chip *chip)
-{
-	module_put(chip->dev.parent->driver->owner);
-}
-
 static inline int tpm_read_index(int base, int index)
 {
 	outb(index, base);
@@ -516,6 +517,9 @@ extern int wait_for_tpm_stat(struct tpm_chip *, u8, unsigned long,
 			     wait_queue_head_t *, bool);
 
 struct tpm_chip *tpm_chip_find_get(int chip_num);
+__must_check int tpm_try_get_ops(struct tpm_chip *chip);
+void tpm_put_ops(struct tpm_chip *chip);
+
 extern struct tpm_chip *tpmm_chip_alloc(struct device *dev,
 				       const struct tpm_class_ops *ops);
 extern int tpm_chip_register(struct tpm_chip *chip);
-- 
2.13.2.932.g7449e964c-goog

[PATCH v1 3/4] Add "shutdown" to "struct class".'

[Josh Zimmerman]

Backport of commit f77af15165847406b15d8f70c382c4cb15846b2a upstream.

The TPM class has some common shutdown code that must be executed for
all drivers. This adds some needed functionality for that.
---
 drivers/base/core.c    | 6 +++++-
 include/linux/device.h | 2 ++
 2 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/drivers/base/core.c b/drivers/base/core.c
index f18856f5954b..afe045792796 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -2094,7 +2094,11 @@ void device_shutdown(void)
 		pm_runtime_get_noresume(dev);
 		pm_runtime_barrier(dev);
 
-		if (dev->bus && dev->bus->shutdown) {
+		if (dev->class && dev->class->shutdown) {
+			if (initcall_debug)
+				dev_info(dev, "shutdown\n");
+			dev->class->shutdown(dev);
+		} else if (dev->bus && dev->bus->shutdown) {
 			if (initcall_debug)
 				dev_info(dev, "shutdown\n");
 			dev->bus->shutdown(dev);
diff --git a/include/linux/device.h b/include/linux/device.h
index b8f411b57dcb..3656df6cf638 100644
--- a/include/linux/device.h
+++ b/include/linux/device.h
@@ -368,6 +368,7 @@ int subsys_virtual_register(struct bus_type *subsys,
  * @suspend:	Used to put the device to sleep mode, usually to a low power
  *		state.
  * @resume:	Used to bring the device from the sleep mode.
+ * @shutdown:  Called at shut-down time to quiesce the device.
  * @ns_type:	Callbacks so sysfs can detemine namespaces.
  * @namespace:	Namespace of the device belongs to this class.
  * @pm:		The default device power management operations of this class.
@@ -396,6 +397,7 @@ struct class {
 
 	int (*suspend)(struct device *dev, pm_message_t state);
 	int (*resume)(struct device *dev);
+	int (*shutdown)(struct device *dev);
 
 	const struct kobj_ns_type_operations *ns_type;
 	const void *(*namespace)(struct device *dev);
-- 
2.13.2.932.g7449e964c-goog

[PATCH v1 4/4] tpm: Issue a TPM2_Shutdown for TPM2 devices.

[Josh Zimmerman]

Backport of d1bd4a792d3961a04e6154118816b00167aad91a upstream.

If a TPM2 loses power without a TPM2_Shutdown command being issued (a
"disorderly reboot"), it may lose some state that has yet to be
persisted to NVRam, and will increment the DA counter. After the DA
counter gets sufficiently large, the TPM will lock the user out.

NOTE: This only changes behavior on TPM2 devices. Since TPM1 uses sysfs,
and sysfs relies on implicit locking on chip->ops, it is not safe to
allow this code to run in TPM1, or to add sysfs support to TPM2, until
that locking is made explicit.
---
 drivers/char/tpm/tpm-chip.c  | 36 ++++++++++++++++++++++++++++++++++++
 drivers/char/tpm/tpm-sysfs.c |  7 +++++++
 2 files changed, 43 insertions(+)

diff --git a/drivers/char/tpm/tpm-chip.c b/drivers/char/tpm/tpm-chip.c
index f3a887e4f692..6d56877b2e0a 100644
--- a/drivers/char/tpm/tpm-chip.c
+++ b/drivers/char/tpm/tpm-chip.c
@@ -124,6 +124,41 @@ static void tpm_dev_release(struct device *dev)
 	kfree(chip);
 }
 
+
+/**
+ * tpm_class_shutdown() - prepare the TPM device for loss of power.
+ * @dev: device to which the chip is associated.
+ *
+ * Issues a TPM2_Shutdown command prior to loss of power, as required by the
+ * TPM 2.0 spec.
+ * Then, calls bus- and device- specific shutdown code.
+ *
+ * XXX: This codepath relies on the fact that sysfs is not enabled for
+ * TPM2: sysfs uses an implicit lock on chip->ops, so this could race if TPM2
+ * has sysfs support enabled before TPM sysfs's implicit locking is fixed.
+ */
+static int tpm_class_shutdown(struct device *dev)
+{
+	struct tpm_chip *chip = container_of(dev, struct tpm_chip, dev);
+
+	if (chip->flags & TPM_CHIP_FLAG_TPM2) {
+		down_write(&chip->ops_sem);
+		tpm2_shutdown(chip, TPM2_SU_CLEAR);
+		chip->ops = NULL;
+		up_write(&chip->ops_sem);
+	}
+	/* Allow bus- and device-specific code to run. Note: since chip->ops
+	 * is NULL, more-specific shutdown code will not be able to issue TPM
+	 * commands.
+	 */
+	if (dev->bus && dev->bus->shutdown)
+		dev->bus->shutdown(dev);
+	else if (dev->driver && dev->driver->shutdown)
+		dev->driver->shutdown(dev);
+	return 0;
+}
+
+
 /**
  * tpmm_chip_alloc() - allocate a new struct tpm_chip instance
  * @dev: device to which the chip is associated
@@ -166,6 +201,7 @@ struct tpm_chip *tpmm_chip_alloc(struct device *dev,
 	dev_set_drvdata(dev, chip);
 
 	chip->dev.class = tpm_class;
+	chip->dev.class->shutdown = tpm_class_shutdown;
 	chip->dev.release = tpm_dev_release;
 	chip->dev.parent = dev;
 #ifdef CONFIG_ACPI
diff --git a/drivers/char/tpm/tpm-sysfs.c b/drivers/char/tpm/tpm-sysfs.c
index 8af4145d10c7..6a4056a3f7ee 100644
--- a/drivers/char/tpm/tpm-sysfs.c
+++ b/drivers/char/tpm/tpm-sysfs.c
@@ -284,6 +284,13 @@ static const struct attribute_group tpm_dev_group = {
 int tpm_sysfs_add_device(struct tpm_chip *chip)
 {
 	int err;
+
+	/* XXX: If you wish to remove this restriction, you must first update
+	 * tpm_sysfs to explicitly lock chip->ops.
+	 */
+	if (chip->flags & TPM_CHIP_FLAG_TPM2)
+		return 0;
+
 	err = sysfs_create_group(&chip->dev.parent->kobj,
 				 &tpm_dev_group);
 
-- 
2.13.2.932.g7449e964c-goog

Re: [PATCH v1 3/4] Add "shutdown" to "struct class".'

[Greg KH]

On Fri, Jul 14, 2017 at 12:58:02PM -0700, Josh Zimmerman wrote:
> Backport of commit f77af15165847406b15d8f70c382c4cb15846b2a upstream.
> 
> The TPM class has some common shutdown code that must be executed for
> all drivers. This adds some needed functionality for that.
> ---
>  drivers/base/core.c    | 6 +++++-
>  include/linux/device.h | 2 ++
>  2 files changed, 7 insertions(+), 1 deletion(-)

You forgot all of the signed-off-by and the like :(

I've taken the original patch instead, but please be more careful next
time.

thanks,

greg k-h

Re: [PATCH v1 4/4] tpm: Issue a TPM2_Shutdown for TPM2 devices.

[Greg KH]

On Fri, Jul 14, 2017 at 12:58:03PM -0700, Josh Zimmerman wrote:
> Backport of d1bd4a792d3961a04e6154118816b00167aad91a upstream.
> 
> If a TPM2 loses power without a TPM2_Shutdown command being issued (a
> "disorderly reboot"), it may lose some state that has yet to be
> persisted to NVRam, and will increment the DA counter. After the DA
> counter gets sufficiently large, the TPM will lock the user out.
> 
> NOTE: This only changes behavior on TPM2 devices. Since TPM1 uses sysfs,
> and sysfs relies on implicit locking on chip->ops, it is not safe to
> allow this code to run in TPM1, or to add sysfs support to TPM2, until
> that locking is made explicit.
> ---
>  drivers/char/tpm/tpm-chip.c  | 36 ++++++++++++++++++++++++++++++++++++
>  drivers/char/tpm/tpm-sysfs.c |  7 +++++++
>  2 files changed, 43 insertions(+)
> 

Again no signed-off-by :(

Re: [PATCH v1 0/2] Run TPM2_Shutdown on system shutdown

[Greg KH]

On Fri, Jul 14, 2017 at 12:57:59PM -0700, Josh Zimmerman wrote:
> This is a backport to the 4.4 stable kernel.
> 
> I had to manually apply a couple of cherry picks and resolve some merge
> conflicts, so some of this may be worth a closer look and test on Jarkko's or
> some other TPM maintainer's part
> 
> This patchset causes all devices in the tpm class to issue TPM2_Shutdown
> when the system is shutting down.
> 
> As a prerequisite, it adds a "shutdown" method to "struct class".
> 
> Backporting to 4.4 since this bug can lock users out of their TPMs.

All now queued up, thanks.

greg k-h

Re: [PATCH v1 4/4] tpm: Issue a TPM2_Shutdown for TPM2 devices.

[Josh Zimmerman]

On Tue, Jul 18, 2017 at 8:49 AM, Greg KH <gregkh@linuxfoundation.org> wrote:
> On Fri, Jul 14, 2017 at 12:58:03PM -0700, Josh Zimmerman wrote:
>> Backport of d1bd4a792d3961a04e6154118816b00167aad91a upstream.
>>
>> If a TPM2 loses power without a TPM2_Shutdown command being issued (a
>> "disorderly reboot"), it may lose some state that has yet to be
>> persisted to NVRam, and will increment the DA counter. After the DA
>> counter gets sufficiently large, the TPM will lock the user out.
>>
>> NOTE: This only changes behavior on TPM2 devices. Since TPM1 uses sysfs,
>> and sysfs relies on implicit locking on chip->ops, it is not safe to
>> allow this code to run in TPM1, or to add sysfs support to TPM2, until
>> that locking is made explicit.
>> ---
>>  drivers/char/tpm/tpm-chip.c  | 36 ++++++++++++++++++++++++++++++++++++
>>  drivers/char/tpm/tpm-sysfs.c |  7 +++++++
>>  2 files changed, 43 insertions(+)
>>
>
> Again no signed-off-by :(

Oops, sorry about that.

Did you pull in the two cherry-picks as well? They're needed for these
two to build and merge cleanly.

I can send a v2 if you need with a corrected signed-off-by and correct
number of patches in the cover letter.

Josh

Re: [PATCH v1 4/4] tpm: Issue a TPM2_Shutdown for TPM2 devices.

[Greg KH]

On Tue, Jul 18, 2017 at 09:11:49AM -0700, Josh Zimmerman wrote:
> On Tue, Jul 18, 2017 at 8:49 AM, Greg KH <gregkh@linuxfoundation.org> wrote:
> > On Fri, Jul 14, 2017 at 12:58:03PM -0700, Josh Zimmerman wrote:
> >> Backport of d1bd4a792d3961a04e6154118816b00167aad91a upstream.
> >>
> >> If a TPM2 loses power without a TPM2_Shutdown command being issued (a
> >> "disorderly reboot"), it may lose some state that has yet to be
> >> persisted to NVRam, and will increment the DA counter. After the DA
> >> counter gets sufficiently large, the TPM will lock the user out.
> >>
> >> NOTE: This only changes behavior on TPM2 devices. Since TPM1 uses sysfs,
> >> and sysfs relies on implicit locking on chip->ops, it is not safe to
> >> allow this code to run in TPM1, or to add sysfs support to TPM2, until
> >> that locking is made explicit.
> >> ---
> >>  drivers/char/tpm/tpm-chip.c  | 36 ++++++++++++++++++++++++++++++++++++
> >>  drivers/char/tpm/tpm-sysfs.c |  7 +++++++
> >>  2 files changed, 43 insertions(+)
> >>
> >
> > Again no signed-off-by :(
> 
> Oops, sorry about that.
> 
> Did you pull in the two cherry-picks as well? They're needed for these
> two to build and merge cleanly.
> 
> I can send a v2 if you need with a corrected signed-off-by and correct
> number of patches in the cover letter.

I should have them all now, and you should have gotten emails about
it...

thanks,

greg k-h

Re: [PATCH v1 4/4] tpm: Issue a TPM2_Shutdown for TPM2 devices.

[Josh Zimmerman]

Hm, strange. I see them in the archives for linux-stable@, but not in
my inbox. Perhaps I forgot to Cc myself on those patches.

Thanks!
Josh


On Tue, Jul 18, 2017 at 9:29 AM, Greg KH <gregkh@linuxfoundation.org> wrote:
> On Tue, Jul 18, 2017 at 09:11:49AM -0700, Josh Zimmerman wrote:
>> On Tue, Jul 18, 2017 at 8:49 AM, Greg KH <gregkh@linuxfoundation.org> wrote:
>> > On Fri, Jul 14, 2017 at 12:58:03PM -0700, Josh Zimmerman wrote:
>> >> Backport of d1bd4a792d3961a04e6154118816b00167aad91a upstream.
>> >>
>> >> If a TPM2 loses power without a TPM2_Shutdown command being issued (a
>> >> "disorderly reboot"), it may lose some state that has yet to be
>> >> persisted to NVRam, and will increment the DA counter. After the DA
>> >> counter gets sufficiently large, the TPM will lock the user out.
>> >>
>> >> NOTE: This only changes behavior on TPM2 devices. Since TPM1 uses sysfs,
>> >> and sysfs relies on implicit locking on chip->ops, it is not safe to
>> >> allow this code to run in TPM1, or to add sysfs support to TPM2, until
>> >> that locking is made explicit.
>> >> ---
>> >>  drivers/char/tpm/tpm-chip.c  | 36 ++++++++++++++++++++++++++++++++++++
>> >>  drivers/char/tpm/tpm-sysfs.c |  7 +++++++
>> >>  2 files changed, 43 insertions(+)
>> >>
>> >
>> > Again no signed-off-by :(
>>
>> Oops, sorry about that.
>>
>> Did you pull in the two cherry-picks as well? They're needed for these
>> two to build and merge cleanly.
>>
>> I can send a v2 if you need with a corrected signed-off-by and correct
>> number of patches in the cover letter.
>
> I should have them all now, and you should have gotten emails about
> it...
>
> thanks,
>
> greg k-h