lkml.org 
[lkml]   [2018]   [Jun]   [20]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 1/6] tpm: Introduce a kref for the tpm_chip
Date
Introduce a kref for the tpm_chip that we initialize when the tpm_chip has
been allocated and release before the tpm_chip is to be freed.

Signed-off-by: Stefan Berger <stefanb@linux.vnet.ibm.com>
---
drivers/char/tpm/tpm-chip.c | 24 +++++++++++++++++++-----
drivers/char/tpm/tpm.h | 1 +
2 files changed, 20 insertions(+), 5 deletions(-)

diff --git a/drivers/char/tpm/tpm-chip.c b/drivers/char/tpm/tpm-chip.c
index 0a62c19937b6..a933676194a4 100644
--- a/drivers/char/tpm/tpm-chip.c
+++ b/drivers/char/tpm/tpm-chip.c
@@ -119,8 +119,24 @@ struct tpm_chip *tpm_chip_find_get(struct tpm_chip *chip)
return res;
}

+static void tpm_chip_free(struct kref *kref)
+{
+ struct tpm_chip *chip = container_of(kref, struct tpm_chip, kref);
+
+ kfree(chip->log.bios_event_log);
+ kfree(chip->work_space.context_buf);
+ kfree(chip->work_space.session_buf);
+ kfree(chip);
+}
+
+static void tpm_chip_put(struct tpm_chip *chip)
+{
+ if (chip)
+ kref_put(&chip->kref, tpm_chip_free);
+}
+
/**
- * tpm_dev_release() - free chip memory and the device number
+ * tpm_dev_release() - free the device number and release reference to chip
* @dev: the character device for the TPM chip
*
* This is used as the release function for the character device.
@@ -133,10 +149,7 @@ static void tpm_dev_release(struct device *dev)
idr_remove(&dev_nums_idr, chip->dev_num);
mutex_unlock(&idr_lock);

- kfree(chip->log.bios_event_log);
- kfree(chip->work_space.context_buf);
- kfree(chip->work_space.session_buf);
- kfree(chip);
+ tpm_chip_put(chip);
}

static void tpm_devs_release(struct device *dev)
@@ -195,6 +208,7 @@ struct tpm_chip *tpm_chip_alloc(struct device *pdev,

mutex_init(&chip->tpm_mutex);
init_rwsem(&chip->ops_sem);
+ kref_init(&chip->kref);

chip->ops = ops;

diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h
index 7f2d0f489e9c..098d7dcc04a4 100644
--- a/drivers/char/tpm/tpm.h
+++ b/drivers/char/tpm/tpm.h
@@ -211,6 +211,7 @@ struct tpm_chip {
struct cdev cdev;
struct cdev cdevs;

+ struct kref kref;
/* 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.
--
2.13.6
\
 
 \ /
  Last update: 2018-06-20 18:23    [W:0.048 / U:0.692 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site