On 06/20/2018 02:38 PM, Jason Gunthorpe wrote:
On Wed, Jun 20, 2018 at 12:19:43PM -0400, Stefan Berger wrote:
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@xxxxxxxxxxxxxxxxxx>
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
+++ 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
+++ b/drivers/char/tpm/tpm.h
@@ -211,6 +211,7 @@ struct tpm_chip {
struct cdev cdev;
struct cdev cdevs;
+ struct kref kref;
NAK, there is already a kref in struct device, that one must be used.
Right. Should make it simpler...
Jason
