Linux-libre 4.8.2-gnupck-4.8.2-gnu

1 files changed, 213 insertions, 86 deletions

diff --git a/drivers/char/tpm/tpm-chip.c b/drivers/char/tpm/tpm-chip.c
index 274dd0123..e5950131b 100644
--- a/drivers/char/tpm/tpm-chip.c
+++ b/drivers/char/tpm/tpm-chip.c
@@ -29,33 +29,88 @@
 #include "tpm.h"
 #include "tpm_eventlog.h"
 
-static DECLARE_BITMAP(dev_mask, TPM_NUM_DEVICES);
-static LIST_HEAD(tpm_chip_list);
-static DEFINE_SPINLOCK(driver_lock);
+DEFINE_IDR(dev_nums_idr);
+static DEFINE_MUTEX(idr_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.
  */
-struct tpm_chip *tpm_chip_find_get(int chip_num)
+int tpm_try_get_ops(struct tpm_chip *chip)
 {
-	struct tpm_chip *pos, *chip = NULL;
+	int rc = -EIO;
 
-	rcu_read_lock();
-	list_for_each_entry_rcu(pos, &tpm_chip_list, list) {
-		if (chip_num != TPM_ANY_NUM && chip_num != pos->dev_num)
-			continue;
+	get_device(&chip->dev);
 
-		if (try_module_get(pos->pdev->driver->owner)) {
-			chip = pos;
-			break;
-		}
+	down_read(&chip->ops_sem);
+	if (!chip->ops)
+		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)
+{
+	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 *chip, *res = NULL;
+	int chip_prev;
+
+	mutex_lock(&idr_lock);
+
+	if (chip_num == TPM_ANY_NUM) {
+		chip_num = 0;
+		do {
+			chip_prev = chip_num;
+			chip = idr_get_next(&dev_nums_idr, &chip_num);
+			if (chip && !tpm_try_get_ops(chip)) {
+				res = chip;
+				break;
+			}
+		} while (chip_prev != chip_num);
+	} else {
+		chip = idr_find_slowpath(&dev_nums_idr, chip_num);
+		if (chip && !tpm_try_get_ops(chip))
+			res = chip;
 	}
-	rcu_read_unlock();
-	return chip;
+
+	mutex_unlock(&idr_lock);
+
+	return res;
 }
 
 /**
@@ -68,24 +123,25 @@ static void tpm_dev_release(struct device *dev)
 {
 	struct tpm_chip *chip = container_of(dev, struct tpm_chip, dev);
 
-	spin_lock(&driver_lock);
-	clear_bit(chip->dev_num, dev_mask);
-	spin_unlock(&driver_lock);
+	mutex_lock(&idr_lock);
+	idr_remove(&dev_nums_idr, chip->dev_num);
+	mutex_unlock(&idr_lock);
+
 	kfree(chip);
 }
 
 /**
- * tpmm_chip_alloc() - allocate a new struct tpm_chip instance
- * @dev: device to which the chip is associated
+ * tpm_chip_alloc() - allocate a new struct tpm_chip instance
+ * @pdev: device to which the chip is associated
+ *        At this point pdev mst be initialized, but does not have to
+ *        be registered
  * @ops: struct tpm_class_ops instance
  *
  * Allocates a new struct tpm_chip instance and assigns a free
- * device number for it. Caller does not have to worry about
- * freeing the allocated resources. When the devices is removed
- * devres calls tpmm_chip_remove() to do the job.
+ * device number for it. Must be paired with put_device(&chip->dev).
  */
-struct tpm_chip *tpmm_chip_alloc(struct device *dev,
-				 const struct tpm_class_ops *ops)
+struct tpm_chip *tpm_chip_alloc(struct device *dev,
+				const struct tpm_class_ops *ops)
 {
 	struct tpm_chip *chip;
 	int rc;
@@ -95,53 +151,75 @@ struct tpm_chip *tpmm_chip_alloc(struct device *dev,
 		return ERR_PTR(-ENOMEM);
 
 	mutex_init(&chip->tpm_mutex);
-	INIT_LIST_HEAD(&chip->list);
+	init_rwsem(&chip->ops_sem);
 
 	chip->ops = ops;
 
-	spin_lock(&driver_lock);
-	chip->dev_num = find_first_zero_bit(dev_mask, TPM_NUM_DEVICES);
-	spin_unlock(&driver_lock);
-
-	if (chip->dev_num >= TPM_NUM_DEVICES) {
+	mutex_lock(&idr_lock);
+	rc = idr_alloc(&dev_nums_idr, NULL, 0, TPM_NUM_DEVICES, GFP_KERNEL);
+	mutex_unlock(&idr_lock);
+	if (rc < 0) {
 		dev_err(dev, "No available tpm device numbers\n");
 		kfree(chip);
-		return ERR_PTR(-ENOMEM);
+		return ERR_PTR(rc);
 	}
+	chip->dev_num = rc;
 
-	set_bit(chip->dev_num, dev_mask);
-
-	scnprintf(chip->devname, sizeof(chip->devname), "tpm%d", chip->dev_num);
-
-	chip->pdev = dev;
-
-	dev_set_drvdata(dev, chip);
+	device_initialize(&chip->dev);
 
 	chip->dev.class = tpm_class;
 	chip->dev.release = tpm_dev_release;
-	chip->dev.parent = chip->pdev;
-#ifdef CONFIG_ACPI
+	chip->dev.parent = dev;
 	chip->dev.groups = chip->groups;
-#endif
 
 	if (chip->dev_num == 0)
 		chip->dev.devt = MKDEV(MISC_MAJOR, TPM_MINOR);
 	else
 		chip->dev.devt = MKDEV(MAJOR(tpm_devt), chip->dev_num);
 
-	dev_set_name(&chip->dev, "%s", chip->devname);
+	rc = dev_set_name(&chip->dev, "tpm%d", chip->dev_num);
+	if (rc)
+		goto out;
 
-	device_initialize(&chip->dev);
+	if (!dev)
+		chip->flags |= TPM_CHIP_FLAG_VIRTUAL;
 
 	cdev_init(&chip->cdev, &tpm_fops);
-	chip->cdev.owner = chip->pdev->driver->owner;
+	chip->cdev.owner = THIS_MODULE;
 	chip->cdev.kobj.parent = &chip->dev.kobj;
 
-	rc = devm_add_action(dev, (void (*)(void *)) put_device, &chip->dev);
-	if (rc) {
-		put_device(&chip->dev);
+	return chip;
+
+out:
+	put_device(&chip->dev);
+	return ERR_PTR(rc);
+}
+EXPORT_SYMBOL_GPL(tpm_chip_alloc);
+
+/**
+ * tpmm_chip_alloc() - allocate a new struct tpm_chip instance
+ * @pdev: parent device to which the chip is associated
+ * @ops: struct tpm_class_ops instance
+ *
+ * Same as tpm_chip_alloc except devm is used to do the put_device
+ */
+struct tpm_chip *tpmm_chip_alloc(struct device *pdev,
+				 const struct tpm_class_ops *ops)
+{
+	struct tpm_chip *chip;
+	int rc;
+
+	chip = tpm_chip_alloc(pdev, ops);
+	if (IS_ERR(chip))
+		return chip;
+
+	rc = devm_add_action_or_reset(pdev,
+				      (void (*)(void *)) put_device,
+				      &chip->dev);
+	if (rc)
 		return ERR_PTR(rc);
-	}
+
+	dev_set_drvdata(pdev, chip);
 
 	return chip;
 }
@@ -155,7 +233,7 @@ static int tpm_add_char_device(struct tpm_chip *chip)
 	if (rc) {
 		dev_err(&chip->dev,
 			"unable to cdev_add() %s, major %d, minor %d, err=%d\n",
-			chip->devname, MAJOR(chip->dev.devt),
+			dev_name(&chip->dev), MAJOR(chip->dev.devt),
 			MINOR(chip->dev.devt), rc);
 
 		return rc;
@@ -165,13 +243,18 @@ static int tpm_add_char_device(struct tpm_chip *chip)
 	if (rc) {
 		dev_err(&chip->dev,
 			"unable to device_register() %s, major %d, minor %d, err=%d\n",
-			chip->devname, MAJOR(chip->dev.devt),
+			dev_name(&chip->dev), MAJOR(chip->dev.devt),
 			MINOR(chip->dev.devt), rc);
 
 		cdev_del(&chip->cdev);
 		return rc;
 	}
 
+	/* Make the chip available. */
+	mutex_lock(&idr_lock);
+	idr_replace(&dev_nums_idr, chip, chip->dev_num);
+	mutex_unlock(&idr_lock);
+
 	return rc;
 }
 
@@ -179,20 +262,28 @@ static void tpm_del_char_device(struct tpm_chip *chip)
 {
 	cdev_del(&chip->cdev);
 	device_del(&chip->dev);
+
+	/* Make the chip unavailable. */
+	mutex_lock(&idr_lock);
+	idr_replace(&dev_nums_idr, NULL, chip->dev_num);
+	mutex_unlock(&idr_lock);
+
+	/* Make the driver uncallable. */
+	down_write(&chip->ops_sem);
+	if (chip->flags & TPM_CHIP_FLAG_TPM2)
+		tpm2_shutdown(chip, TPM2_SU_CLEAR);
+	chip->ops = NULL;
+	up_write(&chip->ops_sem);
 }
 
 static int tpm1_chip_register(struct tpm_chip *chip)
 {
-	int rc;
-
 	if (chip->flags & TPM_CHIP_FLAG_TPM2)
 		return 0;
 
-	rc = tpm_sysfs_add_device(chip);
-	if (rc)
-		return rc;
+	tpm_sysfs_add_device(chip);
 
-	chip->bios_dir = tpm_bios_log_setup(chip->devname);
+	chip->bios_dir = tpm_bios_log_setup(dev_name(&chip->dev));
 
 	return 0;
 }
@@ -204,10 +295,50 @@ static void tpm1_chip_unregister(struct tpm_chip *chip)
 
 	if (chip->bios_dir)
 		tpm_bios_log_teardown(chip->bios_dir);
+}
+
+static void tpm_del_legacy_sysfs(struct tpm_chip *chip)
+{
+	struct attribute **i;
+
+	if (chip->flags & (TPM_CHIP_FLAG_TPM2 | TPM_CHIP_FLAG_VIRTUAL))
+		return;
+
+	sysfs_remove_link(&chip->dev.parent->kobj, "ppi");
 
-	tpm_sysfs_del_device(chip);
+	for (i = chip->groups[0]->attrs; *i != NULL; ++i)
+		sysfs_remove_link(&chip->dev.parent->kobj, (*i)->name);
 }
 
+/* For compatibility with legacy sysfs paths we provide symlinks from the
+ * parent dev directory to selected names within the tpm chip directory. Old
+ * kernel versions created these files directly under the parent.
+ */
+static int tpm_add_legacy_sysfs(struct tpm_chip *chip)
+{
+	struct attribute **i;
+	int rc;
+
+	if (chip->flags & (TPM_CHIP_FLAG_TPM2 | TPM_CHIP_FLAG_VIRTUAL))
+		return 0;
+
+	rc = __compat_only_sysfs_link_entry_to_kobj(
+		    &chip->dev.parent->kobj, &chip->dev.kobj, "ppi");
+	if (rc && rc != -ENOENT)
+		return rc;
+
+	/* All the names from tpm-sysfs */
+	for (i = chip->groups[0]->attrs; *i != NULL; ++i) {
+		rc = __compat_only_sysfs_link_entry_to_kobj(
+		    &chip->dev.parent->kobj, &chip->dev.kobj, (*i)->name);
+		if (rc) {
+			tpm_del_legacy_sysfs(chip);
+			return rc;
+		}
+	}
+
+	return 0;
+}
 /*
  * tpm_chip_register() - create a character device for the TPM chip
  * @chip: TPM chip to use.
@@ -223,6 +354,15 @@ int tpm_chip_register(struct tpm_chip *chip)
 {
 	int rc;
 
+	if (chip->ops->flags & TPM_OPS_AUTO_STARTUP) {
+		if (chip->flags & TPM_CHIP_FLAG_TPM2)
+			rc = tpm2_auto_startup(chip);
+		else
+			rc = tpm1_auto_startup(chip);
+		if (rc)
+			return rc;
+	}
+
 	rc = tpm1_chip_register(chip);
 	if (rc)
 		return rc;
@@ -230,30 +370,20 @@ int tpm_chip_register(struct tpm_chip *chip)
 	tpm_add_ppi(chip);
 
 	rc = tpm_add_char_device(chip);
-	if (rc)
-		goto out_err;
-
-	/* Make the chip available. */
-	spin_lock(&driver_lock);
-	list_add_tail_rcu(&chip->list, &tpm_chip_list);
-	spin_unlock(&driver_lock);
+	if (rc) {
+		tpm1_chip_unregister(chip);
+		return rc;
+	}
 
 	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");
-		if (rc && rc != -ENOENT) {
-			tpm_chip_unregister(chip);
-			return rc;
-		}
+	rc = tpm_add_legacy_sysfs(chip);
+	if (rc) {
+		tpm_chip_unregister(chip);
+		return rc;
 	}
 
 	return 0;
-out_err:
-	tpm1_chip_unregister(chip);
-	return rc;
 }
 EXPORT_SYMBOL_GPL(tpm_chip_register);
 
@@ -264,6 +394,9 @@ 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.
  */
@@ -272,13 +405,7 @@ void tpm_chip_unregister(struct tpm_chip *chip)
 	if (!(chip->flags & TPM_CHIP_FLAG_REGISTERED))
 		return;
 
-	spin_lock(&driver_lock);
-	list_del_rcu(&chip->list);
-	spin_unlock(&driver_lock);
-	synchronize_rcu();
-
-	if (!(chip->flags & TPM_CHIP_FLAG_TPM2))
-		sysfs_remove_link(&chip->pdev->kobj, "ppi");
+	tpm_del_legacy_sysfs(chip);
 
 	tpm1_chip_unregister(chip);
 	tpm_del_char_device(chip);